Minseok Oh

Indirect time-of-flight (iToF) cameras operate by illuminating a scene with modulated light and inferring depth at each pixel by combining the back-reflected light with different gating signals. This article focuses on amplitude-modulated continuous-wave (AMCW) time-of-flight (ToF), which, because of its robustness and stability properties, is the most common form of iToF. The figures of merit that drive iToF performance are explained and plotted, and system parameters that drive a camera’s final performance are summarized. Different iToF pixel and chip architectures are compared and the basic phasor methods for extracting depth from the pixel output values are explained. The evolution of pixel size is discussed, showing performance improvement over time. Depth pipelines, which play a key role in filtering and enhancing data, have also greatly improved over time with sophisticated denoising methods now available. Key remaining challenges, such as ambient light resilience and multipath invariance, are explained, and state-of-the-art mitigation techniques are referenced. Finally, applications, use cases, and benefits of iToF are listed.

In the climate change era, urban geometry serves to ensure sustainability for urban planners since it notably affects building energy consumption. However, previous studies have mainly conducted experimental investigations under hypothetical conditions. Without empirical evidence, it is difficult to implement these findings under real conditions. This paper examined empirical data to determine the urban geometry effect on building energy consumption in a large, complicated urban area. Urban geometric parameters, including the surface-to-volume ratio, obstruction angle, and building orientation, were measured across Seoul, and their correlations with building energy use were analyzed. The results show that the surface-to-volume ratio and obstruction angle are important, despite the empirical data complexity. Additional data analysis indicates that the heating energy type and building use consideration yields more reliable correlation coefficient trends. The potential impacts of natural ventilation and the urban heat island (UHI) effect on building energy consumption were examined. The UHI effect, rather than shadows on buildings, predominantly impacts the building electricity use in August and September. The correlation variation caused by the building permit date was investigated. The results in this paper could help urban planners and designers develop blueprints to control urban geometry and establish relevant design guidelines.

This paper aims to find the impact of geometric parameters on the energy performance of buildings, to using them to identify types regarding major geometric characteristics of a target area. Conventional approaches to control energy efficiency of buildings mainly focus on materials and capacity of insulation, but rarely consider urban and building geometries. By examining energy impacts on urban blocks by urban geometric forms, this paper seeks to identify urban geometric types and energy patterns on urban blocks. To achieve the aims of this study, this paper follows two steps: First, significant indicators for analyzing energy performance are identified in urban geometries; second, the types that capture urban geometry of a real city are categorized. As a result, as a reference for urban planning and design, the paper identifies 13 types that represent the characteristics of urban geometries regarding energy performance. The geometric indicators are carefully measured and their significance to energy performance of buildings is examined through regression analysis. According to these indicators, the 13 types are categorized using a hierarchical clustering algorithm, a machine learning method. Additionally, the 13 types are discussed for implementation as references in urban planning and design, particularly in block planning for a city.

Amyloid-β (Aβ) in the form of neurotoxic aggregates is regarded as the main pathological initiator and key therapeutic target of Alzheimer's disease. However, anti-Aβ drug development has been impeded by the lack of a target needed for structure-based drug design and low permeability of the blood-brain barrier (BBB). An attractive therapeutic strategy is the development of amyloid-based anti-Aβ peptidomimetics that exploit the self-assembling nature of Aβ and penetrate the BBB. Herein, we designed a dimeric peptide drug candidate based on the N-terminal fragment of Aβ, DAB, found to cross the BBB and solubilize Aβ oligomers and fibrils. Administration of DAB reduced amyloid burden in 5XFAD mice, and downregulated neuroinflammation and prevented memory impairment in the Y-maze test. Peptide mapping assays and molecular docking studies were utilized to elucidate DAB-Aβ interaction. To further understand the active regions of DAB, we assessed the dissociative activity of DAB with sequence modifications.

Bioelectronic devices that offer real-time measurements, biological signal processing, and continuous monitoring while maintaining stable performance are in high demand. The materials used in organic electrochemical transistors (OECTs) demonstrate high transconductance (GM) and excellent biocompatibility, making them suitable for bioelectronics in a biological environment. However, ion migration in OECTs induces a delayed response time and low cut-off frequency, and the adverse biological environment causes OECT durability problems. Herein, we present OECTs with a faster response time and improved durability, made possible by using a nanofiber mat channel of a conventional OECT structure. Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/polyacrylamide (PAAm) nanofiber mat channel OECTs are fabricated and subjected to various durability tests for the first time based on continuous measurements and mechanical stability assessments. The results indicate that the nanofiber mat channel OECTs have a faster response time and longer life spans compared to those of film channel OECTs. The improvements can be attributed to the increased surface area and fibrous structure of the nanofiber mat channel. Furthermore, the hydrogel helps to maintain the structure of the nanofiber, facilitates material exchange, and eliminates the need for a crosslinker.

Autonomous vehicles (AVs) and their potential impact on the transformation of the built environment of cities have become a topic of interest across disciplines. Despite policy and design implications, realistic projections of future urban landscape changes were primarily obtained based on street-scale design in earlier studies, leaving questions about the successful integration of repurposed urban elements. This study aimed to formulate design strategies in an incremental fashion applicable to large areas of cities to enhance the connectivity between AVs and existing transportation modes. A conceptual model was built referring to blocks of different forms and functions in Gangnam-gu, Seoul, to extend our designs from the street level to the district level. Urban elements—streets, public spaces and transit systems—were redesigned and merged into the patchwork concept, which links different street and zone types as an efficient system. The above urban design concept proposes the separation of AVs and regular vehicles and adopts unique linkage structures to effectively connect zones assigned to AV usage. The strategies and designs developed in this study contribute to the limited studies on city-scale future AV projections and provide spatial implications as a guideline to address preparations considering AVs in the urban space.

Heterocyclic amines (HCAs) and acrylamide are unintended hazardous substances generated by heating or processing of foods and are known as carcinogenic and mutagenic agents by the animal experiments. A simple method was established for a rapid and accurate determination of 12 types of HCAs (IQ, MeIQ, Glu-P-1, Glu-P-2, MeIQx, Trp-P-1, Trp-P-2, PhIP, AαC, MeAαC, Harman and Norharman) and acrylamide in three food matrices (non-fat liquid, non-fat solid and fat solid) by isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). In every sample, a mixture of internal standards including IQ-d3, MeIQx-d3, PhIP-d3, Trp-P-2-(13)C2-(15)N and MeAαC-d3 was spiked for quantification of HCAs and (13)C3-acrylamide was also spiked for the analysis of acrylamide. HCAs and acrylamide in sample were extracted with acetonitrile and water, respectively, and then two solid-phase extraction cartridges, ChemElut: HLB for HCAs and Accucat: HLB for acrylamide, were used for efficiently removing interferences such as pigment, lipid, polar, nonpolar and ionic compounds. Established method was validated in terms of recovery, accuracy, precision, limit of detection, limit of quantitation, and linearity. This method showed good precision (RSD < 20%), accuracy (71.8~119.1%) and recovery (66.0~118.9%). The detection limits were < 3.1 ng/g for all analytes. The correlation coefficients for all the HCAs and acrylamide were > 0.995, showing excellent linearity. These methods for the detection of HCAs and acrylamide by LC-MS/MS were applied to real samples and were successfully used for quantitative monitoring in the total diet study and this can be applied to risk assessment in various food matrices.

Abstract Background Antibody-based therapeutics (ABTs) including monoclonal/polyclonal antibodies and Fc-fusion proteins are increasingly used in disease treatment, driving the global market growth. Understanding the pharmacokinetic (PK) properties of ABTs is crucial for their clinical effectiveness. This study investigated the PK profile and tissue distribution of efineptakin alfa, a long-acting recombinant human interleukin-7 (rhIL-7-hyFc), using enzyme-linked immunosorbent assay (ELISA) and accelerator mass spectrometry (AMS). Methods Total 4 rats were injected intramuscularly with 1 mg/kg of rhIL-7-hyFc containing 14C-rhIL-7-hyFc, prepared via reductive methylation. Serum total radioactivity (TRA) and serum rhIL-7-hyFc concentrations were quantified using AMS and ELISA, respectively. TRA concentrations in organs were determined by AMS. Results Serum TRA peaked at 10 hours with a terminal half-life of 40 hours. rhIL-7-hyFc exhibited a mean peak concentration at around 17 hours and a rapid elimination with a half-life of 12.3 hours. Peak concentration and area under the curve of TRA were higher than those of rhIL-7-hyFc. Tissue distribution analysis showed elevated TRA concentrations in lymph nodes, kidneys, and spleen, indicating rhIL-7-hyFc’s affinity for these organs. The study also simulated the positions of 14C labeling in rhIL-7-hyFc, identifying specific residues in the fragment of rhIL-7 portion, and provided the explanation of distinct analytes targeted by each method. Conclusions Combining ELISA and AMS provided advantages by offering sensitivity and specificity for quantification, as well as enabling the identification of analyte forms. The integrated use of ELISA and AMS offer valuable insights for the development and optimization of ABT.

A critical requirement of spectroscopic large scale structure analyses is correcting for selection of which galaxies to observe from an isotropic target list. This selection is often limited by the hardware used to perform the survey which will impose angular constraints of simultaneously observable targets, requiring multiple passes to observe all of them. In SDSS this manifested solely as the collision of physical fibers and plugs placed in plates. In DESI, there is the additional constraint of the robotic positioner which controls each fiber being limited to a finite patrol radius. A number of approximate methods have previously been proposed to correct the galaxy clustering statistics for these effects, but these generally fail on small scales. To accurately correct the clustering we need to upweight pairs of galaxies based on the inverse probability that those pairs would be observed (Bianchi \& Percival 2017). This paper details an implementation of that method to correct the Dark Energy Spectroscopic Instrument (DESI) survey for incompleteness. To calculate the required probabilities, we need a set of alternate realizations of DESI where we vary the relative priority of otherwise identical targets. These realizations take the form of alternate Merged Target Ledgers (AMTL), the files that link DESI observations and targets. We present the method used to generate these alternate realizations and how they are tracked forward in time using the real observational record and hardware status, propagating the survey as though the alternate orderings had been adopted. We detail the first applications of this method to the DESI One-Percent Survey (SV3) and the DESI year 1 data. We include evaluations of the pipeline outputs, estimation of survey completeness from this and other methods, and validation of the method using mock galaxy catalogs.

Ga 2 O 3 (1 wt%)-doped ZnO (GZO) thin films were deposited on α-Al 2 O 3 (0001) by rf magnetron sputtering at 550°C and a polycrystalline structure was obtained. As-grown GZO thin films show poor electrical properties and photoluminescence (PL). For the improvement of these properties, GZO thin films were annealed at 800–900°C in N 2 atmosphere for 3 min. After rapid thermal annealing, deep-defect-level emission disappears and near-band emission is greatly enhanced. Annealed GZO thin films show very low resistivity of 2.6×10 -4 Ω·cm with 3.9×10 20 /cm 3 carrier concentration and exceptionally high mobility of 60 cm 2 /V·s. These improved physical properties are explained in terms of the translation of doped-Ga atoms from interstitial to substitutional sites.

LED (light-emitting diodes) lighting is steadily finding its way into the market of artificial illumination. An additional characteristic of LED lighting is the ability to accommodate switching times that are high enough to transmit data via the visible light it emit. This paper proposes a scheme for providing a data transmission with less flicker in VLC (visible light communication). The scheme utilizes a modulation using dual slope pulses. Due to its moderately increasing and decreasing pulse characteristic. This scheme can also be effectively used in an extremely low light condition. A recovery process in the receiver is proposed.

A quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was developed and combined with liquid chromatography–tandem mass spectrometry to analyze 12 acidic pesticides in cabbage and spinach. The extraction solvents, phase partition salts and sorbents effect was studied to optimize the method followed by dilution before sample injection. The extraction involved 5% formic acid in acetonitrile, and the liquid-liquid partition was salt-induced. Carbopack Z, a high surface area graphitized carbon black, was a new sorbent used in the clean-up. The results show that Carbopack Z effectively removes interferences with little loss of acidic pesticides. All tested pesticide recoveries were satisfactory when Carbopack Z was combined with C18 in the clean-up at optimized condition. After clean-up, the extract was subjected to 10-fold dilution to sufficiently reduce the matrix effect (<20%). The limit of quantification (LOQ) was 1–5 ng/g, and the mean recovery was between 95 and 110% with a relative standard deviation <20% (between 2% and 10%) for the spiking of three concentrations: 5, 50, and 500 ng/g. The extract was less pigmented in the modified QuEChERS method than its original version. Thus, the modified method is a useful alternative for investigating the acidic pesticide residues in cabbage and spinach.

The origin of the 1.356 eV emission band measured by photoluminescence (PL) is investigated by correlating the Hall measurement data for the same materials. The crystals grown by the horizontal-Bridgman technique were As or Ga rich by controlling As-zone temperatures. Type conversion from n to p type with the thermal activation energy ΔE=0.133 eV and ΔE=0.05 eV were achieved by heat treatment of the As-rich crystals. The Ev +0.133 eV level and the 1.356 eV band may not be attributed to the same defect because the Ev +0.133 eV level is electrically active with a nonradiative center and the 1.356 eV band is radiative with an electrically inactive (neutral) center. Therefore, both Ev +0.133 eV level and the 1.356 eV band were not attributed to copper impurity because copper is electrically and optically an active center in GaAs. The 1.356 eV band measured by PL may be due to a gallium-vacancy related complex, but differs from VGa -donor complex.

BACKGROUND:This study was carried out to investigate pesticide residues from fifty streams in Korea.Water samples were collected at two times.Thee first sampling was performed from april to may, which was the season for start of pesticide application and the second sampling event was from august to september, which was a period for spraying pesticides multiple times. METHODS AND RESULTS:The 136 pesticide residues were analyzed by LC-MS/MS and GC/ECD.As a result, eleven of the pesticide residues were detected at the first sampling.Twenty eight of the pesticide residues were detected at the second sampling.Seven pesticides were frequently detected from more than 10 water samples.Ecological risk assessment (ERA) was carried out by using residual and toxicological data.Four scenarios were applied for the ERA.Scenario 1 and 2 were performed using LC50 values and mean and maximum concentrations.Scenarios 3 and 4 were conducted by NOEC values and mean and maximum concentrations.CONCLUSION: Frequently detected pesticide residues tended to coincide with the period of preventing pathogen and pest at paddy rice.As a result of ERA, five pesticides (butachlor, carbendazim, carbofuran, chlorantranilprole, and oxadiazon) were assessed to be risks at scenario 4.However, only oxadiazon was assessed to be a risk at scenario 3 for the first sampling.Oxadiazon was not assessed to be a risk at the second sampling.It seems to be temporary phenomenon at the first sampling, because usage of herbicides such as oxadiazon increased from April to march for preventing weeds at paddy fields.However, this study suggested that five pesticides which were assessed to be risks need to be monitored continuously for the residues.

Al-doped zinc oxide (AZO) thin films have been grown on (0001) substrate by radio-frequency (rf) magnetron sputtering at 550°C. The AZO films have been annealed by a rapid thermal process in exposure with a temperature range of 600-1000°C. Effects of hydrogen on the AZO films have been investigated using photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The as-grown AZO film shows only broad deep defect-level PL. After annealing at 600°C, deep defect-level emission is quenched and near-band-edge (NBE) emission is observed at around 382 nm (3.2 eV), which can be explained by the passivation effect. At elevated temperature, two interesting peaks corresponding to violet (406 nm, 3.05 eV) and blue (436 nm, 2.84 eV) emissions have been observed for the first time in annealed AZO thin films. Incorporation of hydrogen and formation of oxygen deficient in annealed AZO films have been studied using XPS. Surface morphology and microstructure of AZO films have been carried out by SEM. © 2003 The Electrochemical Society. All rights reserved.

With the spread of an aging society, the mobility constrained seniors' need for public transportation is increasing. This paper investigates accessibility to welfare facilities for elderly people, that is, whether elderly people can easily access the welfare facilities that they frequently visit. We consider welfare facilities including residential welfare institutions, medical and welfare institutions, leisure and welfare institutions, and commuting-system welfare facilities. We verify spatial distribution of welfare facilities and relationship to the unequal development of urban or public transportation networks. Inequality of accessibility was found between the urban and suburban areas of the study area. This paper identified the spatial inequity of facilities for elderly people by measuring spatial accessibility considering public transportation accessibility and walking time to the facilities. This paper suggested that improving public transportation accessibility would increase the spatial equity of welfare services for elderly people.

AODV (ad hoc on-demand distance vector) routing protocol provides communication between mobile nodes with minimal control overhead and minimal route acquisition latency. It is well-known as a reactive routing protocol along with OLSR (optimized link state routing). Its goal is to reduce the need for system-wide broadcasts to the furthest extent possible. To control network-wide broadcasts of RREQs, the source node uses an expanding ring search technique, which allows a search of increasingly larger areas of the network if a route to the destination is not found. In this paper, we investigate the effectiveness of this ring search scheme by comparing the number of routing messages during routing discovery procedure.

Molecular weights (MW) of major proteins in milk of 3 Korean dairy goat breeds were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, after treatment of milk samples with the reduction buffer used in capillary electrophoresis. The MW of caprine milk proteins were compared with those of Holstein milk counterparts using commercial bovine milk protein standards. The MW of α-lactalbumin, β-lactoglobulin, and α- and β-casein standards were 14,197 ± 3.4, 18,326 ± 26.3, 23,591 ± 13.0, and 23,967 ± 12.8 m/z, respectively, whereas those of Holstein milk treated with the reduction buffer were 14,199 ± 8.3, 18,397 ± 25.9, 23,614 ± 64.8, and 23,984 ± 75.6 m/z, respectively. The respective MW of α-lactalbumin in Saanen, Toggenberg, and Alpine milk were 14,194 ± 27.2, 14,266 ± 105.9, and 14,241 ± 13.2 m/z, which were not different from those of the bovine milk. The respective MW of β- lactoglobulin in corresponding caprine milk were 18,840 ± 31.5, 18,856 ± 26.3, and 18,857 ± 21.3 m/z, which were higher than those in the bovine milk. The MW of β-casein in corresponding caprine milk were 23,860 ± 27.2, 23,886 ± 12.3, and 23,901 ± 8.4 m/z, which were lower than those in the bovine milk. The results indicated that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry could be used for rapid determination of MW of Korean caprine milk proteins without protein separation steps.

In the field of visible light communication (VLC), light-emitting diodes (LEDs) are used for transmitting data via visible light.In this study, we analyze pulse dual slope modulation (PDSM) as a means of delivering information in VLC.PDSM involves the modulation of symmetrical slope pulses to encode binary 0s and 1s, and owing to the moderately increasing and decreasing pulse shapes that are created, this method enables more spectral efficiency than the variable pulse position modulation (VPPM) technique currently adopted in IEEE 802.15.7.In particular, PDSM allows for the avoidance of intra-frame flicker by providing idle pulses in a spectrum-efficient way.A simple detection scheme is proposed for PDSM signals, and its bit error rate (BER) is analyzed mathematically at varying slopes to validate the process through simulation.The BER performance of PDSM detection using dual sampling is compared to the performances of PDSM and VPPM using correlation detection.It is found that, when the probability of idle pulse transmission is less than 0.08 and higher than 0, the BER of dual sampling PDSM is lower than that of PDSM using correlation detection over the entire light intensity range.

An effective analytical method was optimized for residues including chlorpyrifos–methyl, deltamethrin, fenoxanil, thiobencarb and fludioxonil in mealworms, the larval form of Tenebrio molitor. They are listed for pest control during wheat cultivation and can be found in wheat-bran feed for growing mealworms in South Korea. Analytes were extracted using acetonitrile and salt packet. Four clean-up methods ((1) MgSO4 + 25 mg PSA + 25 mg C18; (2) MgSO4 + 50 mg PSA + 50 mg C18; (3) EMR-lipidTM tube; and (4) 10 mL n-hexane) were investigated and the method (1) was selected due to its robustness. Low-temperature precipitation of fat and proteins improved the recoveries. Recoveries from the Method (1) were satisfying with 70–120% with &lt;20% relative SD at a spiking level of 0.01 mg/kg. With the simultaneous sample preparation, fenoxanil, thiobencarb and fludioxonil were analyzed by liquid chromatography tandem mass spectrometry (LC–MS/MS) and chlorpyrifos–methyl and deltamethrin by gas chromatography tandem mass spectrometry (GC–MS/MS). Quantification limits for LC–MS/MS and GC–MS/MS were 0.5 and 2.5 μg/L, respectively. No pesticides of interest were detected in 30 real samples collected across the nation. However, the data can be provided for establishing maximum residue limits for the pesticides in mealworms in response to the positive list system.

The Al-Ni system is known as a high energy density materials (HEDM) because of its highly exothermic nature during intermetallic compound (IMC) formation. In this study, elemental Al and Ni powder were milled to explore the effect of cryomilling atmosphere on the microstructure and exothermic behavior. Scanning electron microscope (SEM) observations show continuous structural refinement up to 8 h of cryomilling. No IMC phase was detected in the X-ray diffraction (XRD) spectrum. Differential thermal analyzer (DTA) results show two exothermic peaks for 8 h cryomilled powder as compared to that of powder milled for 1 h. The ignition temperature of prepared powder mixture also decreased due to gradual structural refinement. The activation energy was also calculated and correlated with the DTA and SEM results. The cryomilled Al-Ni powder is composed of fine Al-Ni metastable junctions which improve the reactivity at a lower exothermic reaction temperature.

This article demonstrates that interdiffusion, which is inherent in heteroepitaxy, can be well suppressed by inserting a thin buffer layer grown at sufficiently lower temperature with taking a ZnSe/GaAs heteroepitaxy as an example. Two types of samples are prepared by molecular beam epitaxy (MBE): a 1114 Å thick ZnSe epilayer grown on a 150 Å thick low-temperature ZnSe buffer layer on a GaAs (0 0 1) substrate, and a 1356 Å thick ZnSe layer grown directly on GaAs. The composition profile at the heterointerface measured by secondary ion mass spectrometry (SIMS) clearly shows that the Ga diffusion is greatly suppressed in the ZnSe/GaAs system prepared with the low-temperature buffer layers, while considerable Ga interdiffusion from the GaAs substrate into the ZnSe epilayer is observed in the sample without the low-temperature buffer layer. The suppression of interdiffusion is also evidenced by low-temperature photoluminescence (PL) spectroscopy which shows no trace of donor–acceptor pair (DAP) emission at around 2.7 eV normally observed in ZnSe epilayers. In addition to the suppression of interdiffusion, Se reaction with GaAs surfaces is suppressed, which leads to the reduction of built-in defect generation due to heterovalency. Consequently, the ZnSe layer grown on a thin low-temperature ZnSe buffer layer shows high crystallinity as indicated by strong and sharp exciton emission in low-temperature photoluminescence spectrum and narrow X-ray line width.

Wireless ad hoc networks can be very mobile, where mobile nodes (MNs) are moving frequently relative to one another. The faster the MNs are moving, the more the routing information is required to keep each MNs informed of the route information to other MNs. This paper proposes another hybrid routing algorithm, whose behavior is modified dynamically based on MN’s mobility in the network following a prior work [1]. This would allow using proactive algorithms when a network has low mobility, and allow using reactive algorithms when a network becomes very mobile. In this paper, Destination Sequenced Distance Vector (DSDV) is used as a proactive routing algorithm and Dynamic Source Routing (DSR) is used as a reactive algorithm.

Coordination polymer nanoparticles (NPs) with gamma-emitting nuclide (Au-198), 411keV, 675keV, 822keV and 1087keV were prepared by coordination polymerization of the radioisotope Au(3+) ions and 1,4-bis(imidazole-1-ylmethyl)benzene in an aqueous solution at room temperature for 3h. Here, the radioisotope Au(3+) ions were prepared by dissolution of Au-198 foil, which was prepared by neutron irradiation from the HANARO reactor, in KCN aqueous solution. The successful synthesis of the radioisotope coordination polymer NPs with 5±0.5nm was confirmed via UV-vis spectroscopy, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDXS), Thermogravimetric analysis (TGA), and Gamma spectroscopy analysis. The synthesized radioisotope coordination polymer NPs can be used as radiotracers in science, engineering, and industrial fields.

Conventional dual half-bridge converter has been previously shown to have advantages in low voltage and high current input applications. This characteristic is suited to photovoltaic application or battery application likes energy storage system (ESS) or uninterruptible power supply (UPS). However, conventional dual half-bridge converter cannot charge the battery because the power flow is one-way. Also, when switches are turned off, high voltage spikes occur by parasitic inductance. To solve this problem, a DC/DC converter which can operate in bi-direction and eliminated voltage spikes are proposed in this paper. Also proposed converter is operated under zero voltage switching (ZVS) condition. In this paper, operation principles and design method of proposed converter are described. These are verified by PSIM simulation and experimental results.

Ad hoc networks can be very mobile, where mobile nodes (MNs) are moving frequently relative to one another. The faster the MNs are moving, the more the routing information is required to keep each MNs informed of the route information to other MNs. This paper proposes a hybrid routing algorithm, whose behavior is modified dynamically based on MN's mobility in the network. This would allow using proactive algorithms when a network has low mobility, and allow using reactive algorithms when a network becomes very mobile. In this paper, destination sequenced distance vector (DSDV) is used as a proactive routing algorithm and ad hoc on-demand vector (AODV) is used as a reactive algorithm.

In this paper, we compare two mesh routing protocols, BATMAN-ADV and FLAME, which run on Layer 2 of the OSI reference model. Those are a few protocols available in software package incorporated into the OpenWrt OS for embedded systems. Our experiments involves the throughput and delay performance on a linear mesh network over varying number of hops between end nodes. We have used 5.8 ㎓ channel bands to avoid any interference with existing 802.11g radios. The results show that BATMAN-ADV performs better than FLAME slightly. The better performance is due to the elaborate routing mechanism and up-to-date release of BATMAN-ADV compared to FLAME.

We present and discuss parameters of a high dynamic range (HDR) image sensor with LED flicker mitigation (LFM) operating in automotive temperature range. The total SNR (SNR including dark fixed pattern noise), of the sensor is degraded by floating diffusion (FD) dark current (DC) and dark signal non-uniformity (DSNU). We present results of FD DC and DSNU reduction, to provide required SNR versus signal level at temperatures up to 120 °C. Additionally we discuss temperature dependencies of quantum efficiency (QE), sensitivity, color effects, and other pixel parameters for backside illuminated image sensors. Comparing +120 °C junction vs. room temperature, in visual range we measured a few relative percent increase, while in 940 nm band range we measured 1.46x increase in sensitivity. Measured change of sensitivity for visual bands—such as blue, green, and red colors—reflected some impact to captured image color accuracy that created slight image color tint at high temperature. The tint is, however, hard to detect visually and may be removed by auto white balancing and temperature adjusted color correction matrixes.

Since broflanilide is a newly developed pesticide, analytical methods are required to determine the corresponding pesticide residues in diverse crops and foods. In this study, a pesticide residue analysis method was optimized for the detection and quantification of broflanilide and its two metabolites, DM-8007 and S(PFH-OH)-8007, in brown rice, soybean, apple, green pepper, mandarin, and kimchi cabbage. Residue samples were extracted from the produce using QuEChERS acetate and citrate buffering methods and were purified by dispersive solid-phase extraction (d-SPE) using six different adsorbent compositions with varying amounts of primary secondary amine (PSA), C18, and graphitized carbon black. All the sample preparation methods gave low-to-medium matrix effects, as confirmed by liquid chromatography–tandem mass spectrometry using standard solutions and matrix-matched standards. In particular, the use of the citrate buffering method, in combination with purification by d-SPE using 25 mg of PSA and a mixture of other adsorbents, consistently gave low matrix effects that in the range from −18.3 to 18.8%. Pesticide recoveries within the valid recovery range 70–120% were obtained both with and without d-SPE purification using 25 mg of PSA and other adsorbents. Thus, the developed residue analysis method is viable for the determination of broflanilide and its metabolites in various crops.

Simulation systems have been used in many fields of society. Training effects, budget reductions, and situation prediction can be achieved by experiencing activities in the real world through simulation. Because of these advantages, simulation systems have been used in national defense fieldsin particular. National defense simulations can be divided into three parts, live simulations, virtual simulations, and constructive simulations, and each simulation has respective features and advantages. L-V-C integrated simulation in the national defense field is becoming increasingly important because itallows a variety of operations/training scenarios to be conducted by joint training. It also improves the accuracy of training and can reduce both time and budget. However, in the case where L-V-C have heterogeneous middleware, interoperation of each middleware is necessary for integration of L-V-C. In this research, we propose ontology based interoperation between DDS (a live middleware) and HLA (a virtual middleware). For this, we constructed an ontology that has relation information of APIs and parameters between HLA and DDS, and stored the ontology in a triple store. Furthermore, we developed an ontology processing module for management of the ontology. The proposed ontology-based system allows interoperation between HLA and DDS. Keywords: DDS, HLA, Interoperation, L-V-C Middleware, Ontology, Simulation

In order to understand the counter anionic effects in a non-aqueous vanadium redox flow battery (VRFB), we synthesized four types of electrolyte salts (1-ethyltriethamine tertafluoroborate, [E-TEDA]⁺[BF₄]^&#x2212;, 1-ethyltriethamine hexafluorophosphate, [E-TEDA]⁺[PF₆]^&#x2212;, 1-butyltriethylamine tertafluoroborate, [B-TEDA]⁺[BF₄]^&#x2212;, and 1-buthyltriethamine hexafluorophosphate [B-TEDA]⁺[PF₆]^&#x2212;) by counter anion exchange reaction after the SN₂ reaction. We confirmed the successful synthesis of the electrolyte salts [E-TEDA]⁺[Br]^&#x2212; and [B-TEDA]⁺[Br]^&#x2212; via ¹H-NMR spectroscopy and GC-mass analysis before the counter anion exchange reaction. The electric potential of the vanadium acetylacetonate, V(acac)₃, as an energy storage chemical was shown to be 2.2 V in the acetonitrile solvent with each of the [E-TEDA]⁺[BF₄]^&#x2212;, [E-TEDA]⁺[PF₆]^&#x2212;, [B-TEDA]⁺[BF₄]^&#x2212;, and [B-TEDA]⁺[PF₆]^&#x2212; electrolyte salts. In a non-aqueous VRFB with a commercial Neosepta AFN membrane, the maximum voltages reached 1.0 V and 1.5 V under a fixed current value of 0.1 mA in acetonitrile with the [E-TEDA]⁺[BF₄]^&#x2212; and [E-TEDA]⁺[PF₆]^&#x2212; electrolyte salts, respectively. The maximum voltage was 0.8 V and 1.1 V under a fixed current value of 0.1 mA in acetonitrile with the [B-TEDA]⁺[BF₄]^&#x2212; and [B-TEDA]⁺[PF₆]^&#x2212; electrolyte salts, respectively. From these results, we concluded that in the non-aqueous VRFB more of the [PF₆]^&#x2212; counter anion than the [BF₄]^&#x2212; counter anion was transported onto the commercial Neosepta AFN anion exchange membrane.

A 0.25-/spl mu/m modular high-energy implanted complementary BiCMOS (HEICBiC) technology has been developed for wireless-communication VLSIs. The technology demonstrates a high f/sub T/=52 GHz and a high f/sub T/BV/sub CEO/=160 GHz-V for single-poly emitter NPN transistors and a high f/sub T/=10.7 GHz for implanted-emitter PNP transistors. It is one of the best results for single-poly BiCMOS/bipolar technologies without an epitaxial buried collector. In comparison with 0.25-/spl mu/m NMOS, HEICBiC shows lower power consumption and higher RF performance.

In this letter, we propose a scheme for constructing a reliable alarm detection structure in the communication networks. We investigate how to allocate a minimal set of management agents and still cover all alarms in mesh networks under the assumption that alarms are delivered along provisioned paths. We also consider the probabilistic nature of alarm loss and propose an efficient scheme for allocating a minimal set of agents while keeping the overall alarm loss probability below a threshold.

As today's networks evolve towards an IP-based integrated network, the role of transmission control protocol (TCP) has been increasing as well. As a well-known issue, the performance of TCP is affected by its loss recovery mechanism that is comprised of two algorithms; fast retransmit and fast recovery. Although retransmission timeout (RTO) caused by multiple packet losses can be avoided by the modified fast recovery algorithm of TCP NewReno or selective acknowledgement (SACK) option, RTO cannot be avoided if a retransmitted packet is lost. To cope with the problem, lost retransmission detection (LRD) has been proposed for each TCP in B. Kim and J. Lee (2004). In this paper, we evaluate the LRD algorithm by tracing TCP sender's behaviors for several scenarios where a retransmitted packet is lost. In addition, we consider the 'conservation of packets' rule to advocate that LRD does not violate fairness with TCP connections that do not support the LRD algorithm.

In this paper, a puncturing method for block-type rate-compatible low-density parity-check (LDPC) codes with 'good' performance is proposed. Puncturing is a scheme to obtain a series of higher rate codes from a low rate mother code. It is widely used in channel coding but it causes performance loss compared with non-punctured error correcting codes at the same rate. There have been many researches about puncturing to reduce the performance loss. However, these researches are not optimized for specific types such as block-type LDPC (B-LDPC) codes adopted in IEEE 802.16e standards. B-LDPC codes are constructed as irregular quasi-cyclic LDPC (QC-LDPC) codes for reduced required memory size and efficient encoding. In this paper, we suggest a modified puncturing scheme which is optimized for B-LDPC codes and compare the performance with previous scheme.

가시광통신(VLC)은 실내 무선망과 옥외용 데이터 전송 분야에서 점차 관심을 얻고 있다. 가시광통신 시스템에서 사용되는 LED는 조명 및 무선 데이터 전송의 두 가지 역할을 수행한다. 본 논문에서는 PDSM(양변 경사 펄스 변조) 방식을 이용해서 가시광통신에서 보다 깜박임(flicker)이 적은 데이터 전송 방식을 제안한다. PDSM 펄스의 완만한 증가 및 감소 특성 때문에 펄스의 시작과 끝이 급격히 변하는 PWM이나 PPM에 비해 효과적으로 깜박임을 줄일 수 있다. 또한 PDSM 방식은 매우 낮은 조명 환경에서도 추가적으로 진폭을 조절함으로써 효율적으로 적용될 수 있다. 그리고 끝으로 제안된 PDSM 방식에서 전송부호를 검출하는 방법을 제안하고 및 매끄러운 밝기 조절을 위한 경사도 변화에 대한 밝기 민감도 분석을 수행한다. 분석 결과로부터 밝기의 변화를 주기 위한 경사의 변화 정도가 펄스에 수평 영역이 있느냐 없느냐에 따라 달라지는 것을 확인할 수 있었다.

In this paper, we propose a new hybrid automatic repeat request (H-ARQ) scheme in MIMO. The proposed scheme performs bit-level exchanges and modifications every retransmission and covers all combinations of number of antennas and number of retransmissions in M-QAM. In order to obtain a better bitwise mapping scheme, we define two independent bitwise suboperations, which are called bit swapping and inversion (BSI) and bit shifting between antennas (BSA), and derive sets for BSI and BSA. The performance of the proposed scheme is evaluated through link simulations with a 3GPP long-term evolution (LTE) specification and is compared to previous H-ARQ schemes in MIMO. The results show that the proposed bitwise mapping scheme provides approximately 2 dB gain over the conventional scheme even at a high mobile speed.

In this paper, we focus on a workflow distribution methodology for deploying the workflow enactment functionality over enterprise grid computing environments. The essential idea of the workflow distribution methodology is about how to fragment a workflow model and how to allocate the fragmented workflow models over the workflow enactment infrastructure based upon an enterprise grid computing environment. The workflow distribution methodology, as an impeccable solution to implement the essential idea, proposed in the paper is a workflow fragmentation framework, which is broken down into three fragmentating approaches vertical workflow fragmentation approach, horizontal workflow fragmentation approach and hybrid of both. Conceptually speaking, the typical vertical fragmentation approach implies semantic-driven fragmentation methods, while on the other the horizontal fragmentation approach is to represent syntactic-driven fragmentation methods. Based on the ICN-based structured workflow model, this paper formalizes the proposed approaches of the workflow fragmentation framework and their detailed algorithms, and applies one of the approaches to an ICN-based structured workflow model as an operational example.

The effects of pre-mixed complexes of PAE (polyamideamine-epichlorohydrin) and PVA(polyvinyl alcohol) on wet web strength and dry strength of NC (nitrocellulose fibers) -SwBKP (softwood bleached kraft pulp) sheets were investigated in terms of the mixing ratio and the dosage of the polymers. It was found that the addition of PAE or PAE-PVA complexes increased wet web tensile strength and dry strength of NC-SwBKP sheets. Especially, a small portion of addition of PVA, i.e ., about 5% to 10% of PVA with 90% to 95% of PAE, was effective for increasing wet web strength and dry strength such as tensile strength and compressive strength. Increased solids content of NC-SwBKP wet webs after wet pressing with increased temperature of the pressing plates improved wet web tensile strength. In addition, improved formation of dry sheets resulted in the increased wet web strength.

The effects of step-by-step addition of PAE (polyamideamine-epichlorohydrin) and micropolymer dual polymer system on wet web strength and dry strength of NC (nitrocellulose fibers)-SwBKP (softwood bleached kraft pulp) sheets were investigated in terms of the addition ratio of PAE and micropolymer and the dosage of the polymers. It was found that the addition of PAE alone or the step-by-step addition of PAE and micropolymer increased wet web tensile strength and dry strength of NC-SwBKP sheets. The dual polymer strengthening aids consisted of PAE and micropolymer in the ratio of 60:40 and 50:50 showed the highest increase in tensile strength and TEA. In case of bursting strength and compressive strength, it was obtained with the ratio of 70:30 (PAE: micropolymer). Tensile strength was able to be increased to a maximum of 84.1%, TEA was increased 126.4%, bursting strength was increased 73.5%, and compressive strength was increased to a maximum of 132.8%. In addition, the wet web tensile strength of NC-SwBKP sheets was able to be increased to a maximum of 68.7% with the step-by-step addition of PAE and micropolymer in the ratio of 95:5.

In order to improve runnability of the production process of combustible cartridge case(CCC), the effects of pre-mixed complexes of polyamideamine-epichlorohydrin (PAE) and polyvinyl alcohol (PVA) on wet-web strength and dry strength of nitrocellulose fibers (NC) - softwood bleached kraft pulp (SwBKP) sheets were investigated in terms of types of PVA. It was found that the addition of PAE or PAE-PVA complexes increased wet web tensile strength and dry strength of NC-SwBKP sheets. In order to improve the wet web tensile strength, the PVA with a higher degree of saponification and with a higher molecular weight had to be chosen for the PAE-PVA pre-mixed complexes. For the dry strength of NC-SwBKP sheets, the PVA with a higher degree of saponification resulted in a higher strength. Concerning the strength improvement of NC-SwBKP sheets, the degree of saponification of PVA was more important factor than the molecular weight of PVA. It is speculated that PAE-PVA pre-mixed complexes improved wet web tensile strength and dry strength of NC-SwBKP sheets by increasing interactions between fibers and by improving formation of sheets.

We report on an alternative atomic layer deposited (ALD) TaN barrier process for Cu interconnects for 14nm technology node and beyond. ALD films provide ultrathin, conformal barrier with reduced overhang and bottom thickness in contrast to physical vapor deposited (PVD) films. This enables via-contact resistance reduction and improved gap-fill while maximizing Cu volume in a trench/via structure. Blanket film studies show that ALD films are 10-15% less dense compared to Ta-rich PVD films, and more importantly only desired low-resistance a-Ta nucleates on ALD films vs. thin PVD films. To maximize density while protecting low-k dielectric during deposition and maintaining low-contact resistance, we explored different flavors and combinations of thermal (tALD) and plasma-enhanced ALD (PEALD). We achieved via contact resistance reduction of 25-35%, with equivalent or better performance for yield, defectivity and electromigration (EM), time-dependent dielectric breakdown (TDDB) and stress migration (SM) reliability.

Sheathed high‐ T c superconducting ceramic wire composites have been fabricated by wire drawing. Superconducting powders of YBa 2 Cu 3 O 7‐x (Y‐123) and Bi 4 (Sr, Ca) 6 Cu 4 O 16+x (Bi‐464) have both been prepared and successfully fabricated into continuous wire form. Under certain circumstances, a displacement reaction occurs at the interface between the ceramic superconductor and the containment tube; the nature of this displacement reaction and its prevention are discussed. Microcracking of the ceramic core is attributable predominantly to relative shrinkage effects during sintering. Failure of the metal wall during wire fabrication is attributed to drawing conditions and the mechanical properties of core and cladding.

The size of mesh networks depends upon the usage scenario so that the use of any single routing algorithm alone, either proactive or reactive, may not work efficiently. This letter proposes a hybrid routing algorithm, where a different algorithm is applied depending on the hop count between source and destination nodes. The algorithm allows using a proactive algorithm when a destination is nearby and a reactive algorithm when a destination is away from a source node. In this letter, we adopt the Destination Sequenced Distance Vector routing protocol (DSDV) for a nearby destination and the Ad hoc On-Demand Vector routing protocol (AODV) for a remote destination. A node maintains only a shared routing table for routing protocols, which helps reducing the size of the routing table at a node within a mesh network. Its routing performance is compared to those in DSDV and AODV in terms of normalized routing load, average packet transmission delay, and the average number of entries in the routing table.

This study aims to suggest some problems, which occur when environmental lighting zone is set by use-zone only, by comparing and analyzing the artificial illumination luminance. In addition, this study aims to review the control standards of light pollution and to suggest a practical environmental lighting zone-setting method. I checked out the standards of average surface luminance and luminance contrast as for light pollution management. In addition, I did some research on evaluation of light pollution on surroundings based on investigation of use-environment as for lighting environment setting method.

Abstract Amyloid‐β (Aβ) in the form of neurotoxic aggregates is regarded as the main pathological initiator and key therapeutic target of Alzheimer's disease. However, anti‐Aβ drug development has been impeded by the lack of a target needed for structure‐based drug design and low permeability of the blood–brain barrier (BBB). An attractive therapeutic strategy is the development of amyloid‐based anti‐Aβ peptidomimetics that exploit the self‐assembling nature of Aβ and penetrate the BBB. Herein, we designed a dimeric peptide drug candidate based on the N‐terminal fragment of Aβ, DAB, found to cross the BBB and solubilize Aβ oligomers and fibrils. Administration of DAB reduced amyloid burden in 5XFAD mice, and downregulated neuroinflammation and prevented memory impairment in the Y‐maze test. Peptide mapping assays and molecular docking studies were utilized to elucidate DAB‐Aβ interaction. To further understand the active regions of DAB, we assessed the dissociative activity of DAB with sequence modifications.

Abstract Phytophthora capsici , which causes diseases in solanaceous crops, secretes necrosis and ethylene-inducing peptide 1-like proteins (NLPs) that induce plant defense responses and leaf necrosis. In this study, we used RNA interference (RNAi) technique, a proven strategy for crop protection and gene regulation in plants, to suppress P . capsici infection through the inhibition of PcNLPs . In the RNAi mechanism, Dicer processes double-stranded RNA (dsRNA) into smaller entities known as small interfering RNAs (siRNAs). These siRNAs subsequently integrate into the RNA-induced silencing complex to form sequence-specific base pairing with complementary regions of the target mRNA. This interaction effectively initiates the degradation process of the target mRNA. We designed and synthesized dsRNAs targeting the “AIMY” and “GHRHDWE” conserved motifs of PcNLP gene family, which are predicted to be key elements for the expression of NLPs and pathogen infection. After infiltration of dsRNAs targeting the motifs and inoculation with P . capsici , we confirmed a significant suppression of P . capsici infection and downregulation of the PcNLP gene family. These findings imply that the dsRNA-mediated RNAi technique holds potential for mitigating a wide range of pathogens, while simultaneously suppressing the expression of a particular gene family using dsRNA targeting functional conserved motifs in the gene family.

In this paper, we introduce our experience with implementation of an ad hoc network. We have built a test bed for a wireless mesh network in Kyonggi University Suwon campus. The network covers a quarter of the whole campus area and for the time being the network will be configured linearly to measure and enhance the delay and throughput across a multihop connection. We hope this will be a experimental ground for a mesh network research.

For a reliable communication, all the alarms generated from a node should be delivered to a network management center. In general, before a management center receives alarms, they are collected through agents. It may be ideal for an agent to reside in every communication node, but it will use up the node's resource, such as processing power and communication bandwidth, as well as increase the cost of the node. When agents are deployed in a few selected nodes, however, there are chances that multiple fault may prohibit alarms from reaching the alarm collecting agents assuming the alarms travel along the provisioned path, as does usually in a WAN, such as in SDH/SONET. This paper investigates a way of finding the shortest path while a newly provisioned path does not cause multiple faults to block alarms basing on Bellman-Ford algorithm, and the proposed algorithm is proven mathematically.

[목적] 본 연구는 대중제 골프장의 서비스스케이프와 인적서비스, 이용객 만족, 몰입 및 방문 후 행동의 구조적 관계 규명을 통해 방문 후 행동 활성화를 위한 전략을 제시함에 그 목적이 있다. [방법] 본 연구를 위해 서울, 경기 및 충 청권 대중제 골프장에 내장 경험이 있는 20세 이상의 성인 남·녀 400명으로부터 설문지를 표집, 이중 불성실하거나 응답이 완료되지 못한 71부를 제외한 329부를 유효 표본으로 사용하고 SPSS 20.0과 AMOS 20.0을 사용하여 자료를 처리하였다. [결과] 대중제 골프장의 서비스스케이프는 이용자 만족에 유의미한 영향을 미치는 것으로 나타났으나, 인적서비스품질은 이용객 만족에 영향을 미치지 않는 것으로 확인되었으며, 이용객 만족은 이용자 몰입에, 이용자 몰입은 방문 후 행동에 영향을 미치는 것으로 나타났다, 이용객 만족은 이용객 몰입을 통하지 않고도 방문 후 행동 에 유의미한 영향을 미치지만, 이용객몰입을 통할 때 방문 후 행동을 더욱 활성화시키는 것으로 확인되었다. [결론] 따라서 대중제 골프장의 이용객 방문 후 행동 향상을 위해서는 서비스스케이프에 중점을 두어야하며 아울러 이용객 만족 및 몰입시키는 전략을 적극 모색하여야 할 것으로 판단된다.

In a ubiquitous environment, people can communicate with others and have access to various computing services any time, any place. The multipoint conference systems in a ubiquitous environment are expected to be one of the leading applications to connect people. In this paper the various multipoint conference systems are compared for their efficiency in a ubiquitous environment and shows why the endpoint mixing conference scheme performs effectively in an ad hoc environment. However, the endpoint mixing conference scheme has its own drawbacks as well and we propose solutions for them.

Four types of coated films (DFT: 300um), that is pure zinc, pure aluminum, and two Al - Zn alloy ( Al : Zn =85:15 and Al : Zn =95:5), were coated onto carbon steel (SS401) with arc spraying, and the corrosion behavior of their samples were evaluated by the electrochemical method in this study. The pure aluminum sample had the high corrosion resistance when exposed to seawater solution and pure zinc and alloy ( Al : Zn =95:5) samples followed the pure aluminum sample. The other alloy ( Al : Zn =85:15), the so-called galvalume that was coated onto the carbon steel, ranked 4th in corrosion resistance in this study. The results of the porosity ratio of those samples are well matched with the electrochemical data

Wi-Fi 단말의 밀도가 높은 곳에서 주변 기기의 영향을 덜 받으며, 사용자가 실제로 느끼는 전송속도를 향상시키고 유지하려는 노력이 지속되어 왔다. 그러한 노력의 일환으로 HEW(High Efficiency WLAN)이라 불리는 IEEE 802.11ax TG(Task Group)가 구성되어 현재 무선랜 기술 표준화가 진행 중이다. 주변 기기의 영향을 줄이는 방법 중의 하나로써 TG는 CCA(Clear Channel Assessment) 기준치를 가변적으로 변화시키는 기법을 고려중에 있다. 본 논문에서는 어떻게 이 기법이 은익단말문제와 노출단말문제를 동시에 해결함으로써 전송속도 향상을 가져올 수 있는지 설명하고, 시뮬레이션을 통해서 AP/STA가 많은 지역에서 동적 CCA 기준치 제어 기법의 성능 향상 결과를 보여준다.

Recently, damages resulting from light trespass that affects the human body (sleep) as one of light pollution control elements of outdoor Luminaires equipment are leading to continuous civil complaints and disputes and this is gradually expanding into a social problem. Accordingly, this study considers the need to develop a shielding plate in consideration of light distribution performance as an efficient measure to cope with damages from light trespass. Therefore, this study developed a shielding plate for LED Luminaires with a fine view that maximally inhibited light toward the backlight area compared to existing shielding plates and verified its performance.

There have been light pollution standards just for architectural lighting and sign in the “Light Pollution Abatement Law” so far. However, both of them regulate only one of the three main light pollution elements-“Glare”. Therefore, it is imperative to do research on the other two light pollution elements-“Upward” and “Light Trespass” and make proper restriction.<BR> Subsequently, this study focuses on the upward light from the street light and suggests its analysis method. Eventually, this study aims to make viable management which is suitable for the nation and, in addition, to suggest appropriate level of restriction to “Light Pollution Abatement Law” by doing site survey.

가상현실(VR)은 사용자가 전에는 느껴보지 못했던 수준까지 몰입할 수 있게 되면서 점점 인기를 더해가고 있다. 그러나 지금까지의 대부분의 VR 시스템은 헤드셋 방향으로 전력과 고해상도의 콘텐츠를 전송하기 위해 번거로운 유선을 사용해 왔다. 이를 해결하기 위해 PC 콘솔과 VR HMD(head mounted display) 사이를 무선으로 연결하기 위한 많은 노력이 제품 개발 및 무선 통신기술 표준화에서 현재 진행되고 있다. 본 논문에서는 무선 VR HMD의 기술적 요건과 무선 전송 기술 성능의 격차를 분석한다면 기술 개발자 또는 표준 개발자들로 하여금 그 격차를 줄이도록 하는데 도움이 될 수 있을 것이다. 본 논문에서는 무선 VR HMD의 원활한 동작을 위한 기술 요건을 열거하고 VR 장치의 무선 부분에 대한 후보 기술의 성능을 조사한다. 끝으로 보다 관심을 기울여야 할 영역에 대해 논의한다.

The shading device on the window of the building can be an passive solution to reduce the cooling load and lighting energy, as well as improving the indoor comfort. It is also an architectural element that must be considered for building energy-efficient buildings such as eco-buildings and zero-energy buildings. However, due to various building environments and various shading devices, the installation of excessive shade may lead to the risk of losing the effectiveness of windows. In this study, we propose a method for optimal automatic control of shading device and evaluate its effectiveness by energy analysis of several shading devices.

This study was carried out to evaluate the Life Cycle Cost(LCC) of three types of RTPV(Building Integrated Photovoltaic) systems-Glass plus Granite. Crystalline BIPV and See through Amorphous BIPV-which were vertically installed to generate the same power output(76 kW level). Initial investment costs. cost. savings and maintenance costs had been predicted during the period of analysing the LCC of three types of BIPV(Building Integrated Photovoltaic) systems installed for the purpose of evaluating the LCC. In case of cost savings, it had been analyzed by measuring the amount of electric power generated, reduction in lighting load and heat & cooling loads through simulation. From this analysis, it was predicted that the See-through amorphous BIPV offering cost saving advantages demonstrated the economical efficiency similar to the Class plus Granite when it is backed by more than 20 years of durability.

Cognitive Radio systems offer the opportunity to improve spectrum utilization by detecting unused spectrum bands with respect to timing, and adapting the transmission to those bands while avoiding the interference to primary users. In this paper, the energy detector for detecting unoccupied spectrum bands substitutes fixed thresholds with adaptive thresholds for better performance. This paper shows the adaptive threshold, controlled by the average of the present threshold and the received signal power, makes the detector highly robust against fading, shadowing, and interference by simulation results.

We present a soft-decision decoding method for Reed-Solomon codes (RS codes) using both cyclic and squaring permutations. These permutations are used to provide a convenient sequence which is predicted to have relatively low complex error pattern with respect to a modified Fano sequential algorithm[1]. In order to preserve bit-level soft-decision values, each sequence of those permutation groups must keep equal weight distribution in symbol and bit level. Trellis construction is based on Wolf’s method[2] and a binary systematic parity check matrix of RS codes is used for bit-level decoding[9]. In simulation results, it is shown that a hybrid of those two permutations can be used for low complexity decoding approaching maximum likelihood performance.

TThe Seoul Metropolitan Government announced a comprehensive plan for "Solar City, Seoul," which is aimed at 1GW of power for 1 million households by 2022.Subsidies for the installation of BIPV(Building Integrated Photovoltaic Systems) in private buildings were expanded in 2020.It is therefore necessary to consider the building-integrated photovoltaic performance to harmonize with urban landscapes using renewable energy sources to realize zero-energy buildings.A field experiment was conducted to investigate the conditions of the BIPV, and the performance impact factors were analyzed.The results showed that the general glass, BIPV intermediate space, and internal surface of the BIPV temperature increased when insulation was added to the BIPV back panel in the spandrel part.The temperature increase in the Spandrel part is mainly caused by solar radiation, and the intermediate space temperature of the general glass rises higher than that of the BIPV module installation.The performance of the BIPV system was evaluated through a simulation.The simulation results showed that the temperature of the solar cell during BIPV generation depended on the energy balance of the effective solar radiation and ambient temperature.In the future, a comprehensive review of the module and material performances, such as the power generation and efficiency, will be required based on experimental verification.

The authors present a new sequential decoding method for RS codes using a squaring permutation on a normal basis. The permutation provides m different sequences for bit-level soft-decision sequential decoding. It is shown that squaring the permutation produces an improvement in performance with low complexity.

본 논문은 ECC(error correcting code)의 오버헤드를 고려한 패리티의 저장 정책 및 그에 따른 낸드 플래시 메모리 컨트롤러의 구조를 제안한다. 일반적인 낸드 플래시 메모리의 용법은 데이터 영역과 스페어 영역을 분리하는 것이다. ECC 패리티는 낸드 플래시 메모리에 데이터가 입력될 때 생성된다. 일반적으로 ECC의 메시지 길이는 낸드 플래시 메모리의 한 페이지 보다 작기 때문에, 각 메시지의 패리티를 모두 모아 스페어 영역에 저장하게 된다. 읽기 동작 시에는 데이터 영역에 이어 스페어 영역의 ECC 패리티까지 모두 읽은 후에 ECC 처리를 통한 데이터 정정이 가능하다. 이 때 발생하는 오버헤드를 줄이기 위해 데이터/스페어 영역의 구분없이 ECC 처리된 데이터와 패리티를 연속으로 저장하는 분산형 정책을 사용하였다. 제안된 분산형 정책과 기존의 수집형 정책의 오버헤드를 설계적인 측면과 타이밍 측면으로 분석하고, 그에 맞는 낸드 플래시 메모리 컨트롤러의 구조를 제시한다. 페이지의 크기에 따른 액세스 시간을 시뮬레이션을 통해 분석한 결과, 읽기 동작 시, 분산형 정책의 액세스 시간이 수집형 정책에 비해 짧았고 페이지의 크기가 커질수록 감소율이 컸다. 실험에 사용된 16KB의 페이지 크기를 갖는 낸드 플래시 메모리의 경우 분산형 정책의 액세스 시간이 수집형 정책에 비해 13.6% 감소하였다. 이는 4GB 크기의 영상 파일을 읽을 때 약 1분가량의 시간이 단축되는 효과를 얻을 수 있다. 또한 읽기 동작이 많은 SSD(solid state drive)의 특성 상 전반적인 시스템의 성능 향상을 기대할 수 있다. This paper presents a new method of parity storing for ECC(error correcting code) in SSD (solid-state drive) and suitable structure of the controller. In general usage of NAND flash memory, we partition a page into data and spare area. ECC parity is stored in the spare area. The method has overhead on area and timing due to access of the page memory discontinuously. This paper proposes a new parity policy storing method that reduces overhead and R(read)/W(write) timing by using whole page area continuously without partitioning. We analyzed overhead and R/W timing. As a result, the proposed parity storing has 13.6% less read access time than the conventional parity policy with 16KB page size. For 4GB video file transfer, it has about a minute less than the conventional parity policy. It will enhance the system performance because the read operation is key function in SSD.

We report on an alternative, atomic layer deposited (ALD) TaN barrier scheme for Cu interconnects for 14nm technology node and beyond, i.e., 64nm pitch and/or smaller interconnects. With VLSI integration requiring denser packing of interconnects, conformal fill of progressively narrower trenches and vias with high aspect ratio, presents tough challenge for line-of-sight physical vapor deposition processes. ALD overcomes these gap-fill challenges but has disadvantages of low throughput, chemical residues and relatively lower density of ALD barriers for effective blocking of O 2 and Cu diffusion. From gap-fill perspective, ALD films enable ultrathin, conformal barrier with reduced problems of overhang and large bottom thickness, typical of physical vapor deposited (PVD) films. Reduced bottom-thickness enables via-contact resistance reduction and less overhang improves gap-fill, while maximizing Cu volume in a trench/via structure. Our blanket film studies show that ALD films are 10-15% less dense compared to Ta-rich PVD films, and more importantly only desired low-resistance alpha-Ta nucleates on ALD films vs. thin PVD films. The conformality of ALD TaN as well as the nucleation of alpha-Ta on it form the basis of via contact resistance reduction, leading to performance enhancement.A plasma-enhanced ALD (PEALD) process helps increase density and improves the hermeticity of the barrier. But PEALD can cause dielectric damage and lead to TDDB failures especially in smaller technology nodes. To maximize density while protecting low-k dielectric during deposition and maintaining low-contact resistance, we explored different flavors and combinations of thermal (tALD) and plasma-enhanced ALD (PEALD). In this work, we use a new, commercially available 40 MHz direct-plasma ALD tool and corresponding optimized processes to maximize throughput and minimize dielectric damage. Different ALD flavors, viz., tALD+post plasma(PP) treatment, tALD/PEALD bilayer films were evaluated for 14 nm technology groundrule interconnects in k=2.7 and k=2.55 dielectric levels. We were able to achieve via contact resistance reduction of 25-35%, with equivalent or better performance for yield, defectivity and electromigration (EM), time-dependent dielectric breakdown (TDDB) and stress migration (SM) reliability. In-line measured defect density for dual-damascene interconnects in k=2.55 dielectric was studied with a conservative ALD TaN thickness process window; the splits with 15-20A of tALDPP TaN barrier layers were found to have the lowest defectivity. Similar data for various ALD splits vs. PVD showed that the same tALDPP process with a certain thickness combination of the bilayer TaN/ Ta resulted in least defect density. This same optimized condition looked best for viachain yield for a macro with ~10 8 via links at 14nm groundrule. We also confirmed that the same condition resulted in the lowest via contact resistance for fully landed vias for 45 chiplets across 3 wafers; where via bottom size variation was &lt;10%. Another study with several bilayer ALD splits in k=2.55 dielectric, showed that the 5tALD/5PEALD condition with initial tALD layer protecting the low-k dielectric followed by denser PEALD to get a more effective barrier, yielded better than PVD TaN. The lowest via resistance data was also recorded for the same split. The EM stress results for both via and line-depletion at each of k=2.7 and k=2.55 levels were also studied. ALD splits were slightly worse than PVD condition with the exception of one stress direction, but still pass reliability targets scaled from the 22 nm technology node. The kinetics data for via depletion tests results in activation energy in excess of 1 eV. TDDB stress results were obtained for builds in both k=2.7 and k=2.55 dielectrics. The most significant impact of ALD on TDDB was the restoration of voltage acceleration parameter (gamma) for both levels. Gammas (slopes of lines) for ALD of all three devices were clearly higher. This confirmed that our optimized ALD condition does no damage to the dielectric. Lastly, impact of different liner processes on stress migration (SM) was investigated at 225 o C stress for 1000 hours. There were no stress fails on any of the liner splits from the traditional plate and nose type SM structures. In summary, ALD TaN is shown to be a robust alternative barrier for Cu interconnect technology for technologies nodes like 14nm and smaller. The process can be optimized to give ~30% reduction in via contact reduction while preserving healthy yield, defect density and EM, TDDB and SM reliability.

충돌 처리는 게임의 물리 법칙을 구현하기 위하여 매우 중요한 요소 중의 하나이며, 게임을 생동감 있게 하기 위한 과정이다. 충돌 처리는 매우 많은 연산이 필요하기 때문에 게임 성능에 중대한 영향을 미친다. 이를 해결하기 위해서 연산량을 줄이는 방식의 연구가 많이 진행되었고, 대표적으로 SAP 알고리즘이 많이 사용되고 있으나 반복되는 연산이 있어 효율성이 떨어진다. 본 논문에서는 충돌 처리의 연산량을 줄이고 SAP 알고리즘의 문제점을 해결하기 위하여, 거리기반 SAP 알고리즘을 새롭게 제안한다. 본 논문에서 제안한 알고리즘으로 만든 시뮬레이션 프로그램을 이용하여 FPS를 측정하는 실험을 진행한 결과, 제안한 알고리즘을 사용하는 경우가 사용하지 않는 경우에 비해서 FPS가 약 2~33배 높았기 때문에 충돌 처리의 효율이 향상되었다고 판단할 수 있었다.

Night-Scape Lighting with the use of LED lighting has become very popular recently by the merits of energy saving, environmental friendlyness, sensitivity and conversion trends. LED lighting designs are being used diversly as outer elements for screen media stage production as well as buildings with fusioning of information technology. However, methods for analyzing the cases effectively are far from completion. This research evaluates the recent trends of Night-Scape Lighting with LED and processes it through database and aims to propose LED Night-Scape Design process for the various architectural night-scape lighting designs.

In this paper, we compare and analyze the performances of two mesh routing protocols (BATMAN-ADV and FLAME) and a WDS implementation of the IEEE 802.11, all of which run on Layer 2 of the OSI reference model. Sometimes the mesh network may simply form a linear topology to provide a service coverage to a line-shaped area. A linear topology can be built without any routing protocol involved, using WDS. The first two routing protocols are a few protocols available in software package incorporated into the OpenWrt OS for embedded systems. Our experiments involves the throughput and delay performance measured on a linear mesh network over varying number of hops between two end nodes. We have used 5.8GHz channel bands to avoid any interference with existing 802.11g radios. The results show that WDS performs best in throughput and round trip time delay. The higher throughput and the lower delay of WDS is attributed to the structural efficiency of the WDS delivery mechanism.

A technique to measure the recombination parameter of a-Si/c-Si heterojunction solar cell is described in the work. In this methodology, the experimentally measured inverse lifetime by Sinton lifetime tester is fitted with A+BΔn+CΔn <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> to determine the recombination parameters. The coefficients B and C are radiative and auger recombination coefficient while coefficient A depends on bulk lifetime and surface recombination velocity. The radiative and auger recombination coefficients determined from the work agrees well with previously published results while the surface recombination velocity extracted from coefficient A is typical of well passivated c-Si surface in a-Si/c-Si heterojunction solar cell.

경로 탐색은 인공지능의 매우 중요한 요소 중의 하나이며, 여러 분야에서 두루 쓰이는 과정이다. 경로 탐색은 매우 많은 연산이 필요하기 때문에 성능에 매우 중대한 영향을 미친다. 이를 해결하기 위해서 연산량을 줄이는 방식의 연구가 많이 진행되었고, 대표적으로 A* 알고리즘이 있으나 불필요한 연산이 있어 효율성이 떨어진다. 본 논문에서는 A* 알고리즘 중 연산 비용이 높은 노드 탐색 수 등 연산량을 줄이기 위해서 가중치 기반의 선수행 A* 알고리즘을 새롭게 제안한다. 제안한 알고리즘의 효율성을 측정하기 위해 시뮬레이션을 구현하였으며, 실험 결과 가중치를 이용하는 방법이 일반적인 방법보다 약 1~2배 높은 효율을 보였다.

Many protection methods such as surface coating, electric protection, or other methods have been applied to the numerous steel structures widely used in continental and marine areas to control their corrosion, which is done from an economic point of view.Most of these steel structures are primarily protected by coating methods.However, some steel piles under seawater are protected by the electric protection method, that is, either using an impressed current or a sacrificial anode method.Furthermore, environmental contamination may cause a severely corrosive environment, which, in turn, causes the accelerated corrosion of steel structures.Subsequently, coated steel structures could deteriorate more rapidly than the designed lifetime because of the acid rain caused by air pollution, etc.Therefore, a coating of marine paint exposed to seawater, that is, underwater hardening painting, is increasingly required to be fast drying as well as highly corrosion resistant.In this study, five types of underwater hardening paints were prepared with different resin series and additives.Their corrosion and water resistances were investigated using electrochemical methods such as corrosion potential, polarization curves, impedance and cyclic voltammogram measurements, etc.Even though it is generally accepted that the corrosion resistance of bare steel tends to increase with a shift of the corrosion potential in the noble direction, the corrosion resistance of a sample with a coating exhibited a relatively better tendency when it had a lower corrosion potential in this study.The corrosion current density was also decreased with a decrease in the diffusion limiting current density, which may mean that there is some relationship between corrosion and water resistance.The S sample of the ceramic resin series showed the relatively best corrosion and water resistance among those of samples, while the worst corrosion and water resistance were observed for the R sample of the epoxy resin series.The corrosion and water resistance of those samples tended to deteriorate with an increase in the immersion days, and their corrosion and water resistances were considered to be apparently improved by the types of resin and additives.

A promising, low-cost alternative for providing last-mile wireless connectivity is the concept of Wireless Mesh Networks (WMN). The true potential of any network, however, cannot be exploited without considering and adequately addressing the security issues. The broadcast nature of transmission and the dependency on the intermediate nodes for routing the user traffic leads to security vulnerabilities making the WMN prone to various attacks. In this paper, we will discuss the security vulnerabilities in multi-hop wireless networks that are relevant to the WMN. We will consider the attacks in the MAC layer in the WMN in detail and the possible solution mechanisms in the MAC layer to prevent and detect these attacks.

In this paper, we compare and analyze the performances of two mesh routing protocols (BATMAN-ADV and FLAME) and a WDS implementation of the IEEE 802.11, all of which run on Layer 2 of the OSI reference model. Sometimes the mesh network may simply form a linear topology to provide a service coverage to a line-shaped area. A linear topology can be built without any routing protocol involved using WDS. The first two routing protocols are a few protocols available in software package incorporated into the OpenWrt OS for embedded systems. Our experiments involves the throughput and delay performance measured on a linear mesh network over varying number of hops between two end nodes. We have used 5.8㎓ channel bands to avoid any interference with existing 802.11g radios. The results show that BATMAN-ADV performs best in throughput and WDS best in delay. The higher throughput of BATMAN-ADV is due to the elaborateness of the routing mechanism and the up-to-date release of BATMAN-ADV over FLAME. The lower delay of WDS is attributed to the structural efficiency of the WDS delivery mechanism.

Although fault management has been a subject of research from the earliest days of networking, it is still considered a hard problem and there still exist communication networks that cannot be well managed for faults. Furthermore, while solutions have been found to many fault management problems, the networking community is still locked in debates over which solutions are preferred. In this paper we make it clear why fault identification and alarm correlation in communication systems are difficult, then carry out a systematic inquiry to discover the characteristics of alarms in communication networks and finally studies the currently available fault diagnosis methods. This article will provide an essential, comprehensive, and solid ground for those who research on the fault management in communication networks.

In this paper, we introduce our experiences with an ad hoc network and propose an enhancement to the ad hoc routing algorithm. The routing algorithm known as FLAME (Forwarding Layer for Meshing) uses in-band traffic to distribute the routing information instead of providing a separate routing protocol, which means that the routing information is delivered along with the user traffic. An ad hoc network having 4-node linear topology is formed to measure the throughput and the delay with respect to varying hops. The throughput reduces exponentially approximately by 60% for every hop increment. The delay increase approximately linearly for every hop increment. We have also compared the throughput and delay when the routing protocol is applied with those when it is not, to see how much the routing protocol deteriorates the performance for one hop link connection (since more than one hop connection always requires a routing protocol). The cause of the performance degradation for this specific routing protocol has been analyzed. We have enhanced the routing algorithm by changing the broadcast period based on the link usage and the delay has been reduced by 31% on average.

In this paper, We propose a multipath AODV with path accumulation (Ad hoc On-demand Distance Vector, MAODV-PA) routing protocol free from a loop. In a wireless ad hoc network, the mobility of nodes may be high which results in frequent link breakages. Setting up a new route will consume network resources, such as CPU power, bandwidth and battery power. In this paper we introduce a scheme for a fast recovery from a link breakage by providing multiple routes to a destination node which can be used alternatively. The proposed MAODV-PA is not only loop-free, but also efficient in obtaining route information along the control packet's movement.

This paper presents high speed image data transmission using MIPI(mobile industry processor interface) CSI-2(camera serial interface) interface for high resolution touch panels. On MIPI CSI-2, the receiver corrects 1bit error on the header of packets, but just checks errors on the data of packets without correction. If there are errors, the receiver notices these errors to upper layer including application layer. Error-handling is a duty of application layers that will bring touch response delay consequently. In this work, we added an error handling path to low level protocol layer. In addition, to compensate signal attenuation due to increasing transmission distance, the adaptive equalizer using FVC(frequency-voltage converter) was applied to the receiver. The proposed architecture was tuned with 800Mbps that transfers data of 800×600 high resolution panels less than 10ms with a single data lane.

Wi-Fi 단말기의 밀도가 높은 곳에서 주변 기기의 영향을 덜 받으며, 사용자가 실제로 체험하는 속도를 높이려는 노력이 IEEE 802.11에서 진행되고 있다. HEW(High Efficiency WLAN)이라 IEEE 802.11ax TG(Task Group)가 구성되어 현재 기술 표준화가 진행 중이다. 주변 WLAN 기기의 영향을 줄이는 방법 중의 하나로써 CCA Threshold를 동적으로 변화되도록 하는 방법인 Adaptive Sensitivity Threshold(AST)을 채택하였다. 또한 다른 기법으로 다른 BSS(Basic Service Set)로부터 오는 신호를 구분하기 위해 preamble에 BSS Color를 넣는 BSS Coloring이 있다. 본 논문에서는 시뮬레이션을 통해서 단말기 밀도가 높은 지역에서 AST 기법과 BSS Coloring기법의 성능 결과를 제시하고, 802.11ac에 대비하여 큰 이득을 얻는 것을 보여준다.