Inseok Yoon

Direct use of waste oil as fuel to meet the residential energy demands, is very attractive due to its potentials to decrease fossil fuel consumption, reduce pollution and increase sustainability. This paper uses a domestic stove with an internal heat re-circulation and self-atomization technology to burn yellow waste cooking oil (WCO-1), brown waste cooking oil (WCO-2) and waste lubricant oil (WLO). Emission factors (EFs), energy efficiency and modified combustion efficiency (MCE) of this combined fuel/stove system were determined under space-heating and cooking modes. The results showed that EFs of CO, PM2.5, total 16 PAHs and corresponding toxic equivalent quantity (TEQ) values ranged from 2.18 × 103 to 4.90 × 103 mg/MJnet, 16.36–69.40 mg/MJnet, 2.39–12.93 μg/MJnet and 0.16–0.92 μg of TEQ/MJnet. WCO-1 was verified to be the cleanest fuel with the highest energy efficiency (85.3 ± 3.3% and 90.4 ± 2.2%) and lowest emission levels, such as NO (53.75 ± 2.62 and 37.09 ± 5.41 mg/MJnet), NO2 (82.40 ± 3.96 and 56.87 ± 8.29 mg/MJnet) and PM2.5 (20.94 ± 6.55 and 16.35 ± 5.06 mg/MJnet) compared to WCO-2 and WLO. The estimated total cost of using waste oil for each household in winter was much cheaper than some current available clean energy means, including only USD$ 400 of stove price and USD$ 250/ton of fuel per year. It is a promising candidate choice for replacing low-quality solid fuels in rural China and 2.62 million rural households would achieve environmental and economic benefits if promoting direct combustion of waste oil for daily heating and cooking.

In this document the PHENIX collaboration proposes a major upgrade to the PHENIX detector at the Relativistic Heavy Ion Collider. This upgrade, sPHENIX, enables an extremely rich jet and beauty quarkonia physics program addressing fundamental questions about the nature of the strongly coupled quark-gluon plasma (QGP), discovered experimentally at RHIC to be a perfect fluid. The startling dynamics of the QGP on fluid-like length scales is an emergent property of quantum chromodynamics (QCD), seemingly implicit in the Lagrangian but stubbornly hidden from view. QCD is an asymptotically free theory, but how QCD manifests as a strongly coupled fluid with specific shear viscosity near $T_C$, as low as allowed by the uncertainty principle, is as fundamental an issue as that of how confinement itself arises.

The PHENIX collaboration presents a concept for a major upgrade to the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). This upgrade, referred to as sPHENIX, brings exciting new capability to the RHIC program by opening new and important channels for experimental investigation and utilizing fully the luminosity of the recently upgraded RHIC facility. sPHENIX enables a compelling jet physics program that will address fundamental questions about the nature of the strongly coupled quark-gluon plasma discovered experimentally at RHIC to be a perfect fluid. The upgrade concept addresses specific questions whose answers are necessary to advance our understanding of the quark-gluon plasma: (1) How to reconcile the observed strongly coupled quark-gluon plasma with the asymptotically free theory of quarks and gluons? (2) What are the dynamical changes to the quark-gluon plasma in terms of quasiparticles and excitations as a function of temperature? (3) How sharp is the transition of the quark-gluon plasma from the most strongly coupled regime near Tc to a weakly coupled system of partons known to emerge at asymptotically high temperatures? In three Appendices, we detail the additional physics capabilities gained through further upgrades: (A) two midrapidity detector additions, (B) a forward rapidity upgrade, and (C) an evolution to an ePHENIX detector suitable for a future Electron Ion Collider at RHIC.

Abstract This study presents techniques for the mass production of large-sized GEM foils for the CMS phase-2 upgrade by the Korean CMS group. The foil production facility is designed with a focus on mass production, including the adoption of the double-mask technique. A polyimide wet etching technology that uses mono ethanolamine is reported, providing a safer working environment due to its lower inhalation toxicity compared to ethylene diamine. The study also covers the denaturation of the etchant over time and the process of retuning. Finally, R&D results on soldering surface mount resistors with hot air for faster production are discussed.

After the Phase-2 high-luminosity upgrade to the Large Hadron Collider (LHC), the collision rate and therefore the background rate will significantly increase, particularly in the high $\eta$ region. To improve both the tracking and triggering of muons, the Compact Muon Solenoid (CMS) Collaboration plans to install triple-layer Gas Electron Multiplier (GEM) detectors in the CMS muon endcaps. Demonstrator GEM detectors were installed in CMS during 2017 to gain operational experience and perform a preliminary investigation of detector performance. We present the results of triple-GEM detector performance studies performed in situ during normal CMS and LHC operations in 2018. The distribution of cluster size and the efficiency to reconstruct high $p_T$ muons in proton--proton collisions are presented as well as the measurement of the environmental background rate to produce hits in the GEM detector.

The purpose of this study is to investigate the differences in readability as defined by Kim (2002) between textbooks used in grades 3~6 in American textbooks and 9~11 in Korean English textbooks. Based on Park (2015)’s observations on conjunction length and readability, has been hypothesized that the number of conjunctions used in complex sentences differentiates readability between language proficiency levels. Using 17 textbook samples from three widely used American textbook publishers ranging from grades 3~6 and 39 samples from twelve official Korean English textbooks ranging from grades 9~11—for a total of over 200,000 words—the study used the L2 Syntactic Complexity Analyzer (L2SCA), the Flesch-Kincaid Grade Level (FKGL), and the Flesch Reading Ease (FRE) scale, finding that the American textbooks had far more frequent instances of conjunctions used in between complex sentences, leading to decreased readability—as supported by Lee (2010), who found the readability of Korean English textbooks to be higher than corresponding American English textbooks. The study was limited in the scope of its sampled data and further studies should include datasets from more publishers and sources in order to corroborate the present findings.

Given the inevitability of domain shifts during inference in real-world applications, test-time adaptation (TTA) is essential for model adaptation after deployment. However, the real-world scenario of continuously changing target distributions presents challenges including catastrophic forgetting and error accumulation. Existing TTA methods for non-stationary domain shifts, while effective, incur excessive computational load, making them impractical for on-device settings. In this paper, we introduce a layer-wise auto-weighting algorithm for continual and gradual TTA that autonomously identifies layers for preservation or concentrated adaptation. By leveraging the Fisher Information Matrix (FIM), we first design the learning weight to selectively focus on layers associated with log-likelihood changes while preserving unrelated ones. Then, we further propose an exponential min-max scaler to make certain layers nearly frozen while mitigating outliers. This minimizes forgetting and error accumulation, leading to efficient adaptation to non-stationary target distribution. Experiments on CIFAR-10C, CIFAR-100C, and ImageNet-C show our method outperforms conventional continual and gradual TTA approaches while significantly reducing computational load, highlighting the importance of FIM-based learning weight in adapting to continuously or gradually shifting target domains.

Since a luminosity upgrade of the LHC is scheduled, an upgrade of the CMS experiment is also planned. As part, detectors based on the gas electron multiplier (GEM) technology will be installed in the CMS endcaps. The Korean CMS group is one the group responsible for the large GEM foil production. As the foils are produced by a new manufacturer, Mecaro, an extensive quality check was planned and implemented. Several CMS GE1/1 GEM detectors with GEM foils produced by Mecaro have been assembled and the properties of those detectors have been measured. According to the measurements, the Mecaro foils are as good as CERN foils in terms of the effective gas gain, the uniformity of the gain, the rate capability and the radiation hardness. The results of the validation are presented.

An estimate of environmental background hit rate on triple-GEM chambers is performed using Monte Carlo (MC) simulation and compared to data taken by test chambers installed in the CMS experiment (GE1/1) during Run-2 at the Large Hadron Collider (LHC). The hit rate is measured using data collected with proton-proton collisions at 13 TeV and a luminosity of 1.5$\times10^{34}$ cm$^{-2}$ s$^{-1}$. The simulation framework uses a combination of the FLUKA and Geant4 packages to obtain the hit rate. FLUKA provides the radiation environment around the GE1/1 chambers, which is comprised of the particle flux with momentum direction and energy spectra ranging from $10^{-11}$ to $10^{4}$ MeV for neutrons, $10^{-3}$ to $10^{4}$ MeV for $\gamma$'s, $10^{-2}$ to $10^{4}$ MeV for $e^{\pm}$, and $10^{-1}$ to $10^{4}$ MeV for charged hadrons. Geant4 provides an estimate of detector response (sensitivity) based on an accurate description of detector geometry, material composition and interaction of particles with the various detector layers. The MC simulated hit rate is estimated as a function of the perpendicular distance from the beam line and agrees with data within the assigned uncertainties of 10-14.5%. This simulation framework can be used to obtain a reliable estimate of background rates expected at the High Luminosity LHC.

It is one of the important purposes of relativistic heavy ion collider (RHIC) longitudinally polarized proton program to constrain the gluon helicity distribution ([Formula: see text]) to the proton by measuring the double helicity asymmetries ([Formula: see text]) via various probes such as [Formula: see text] ([Formula: see text]). The measurement at center of mass energy, [Formula: see text] GeV has been successfully finished and published. To explore lower x region, where dominant uncertainty remains, new measurements were carried out at an increased [Formula: see text] GeV. At this increased energy central [Formula: see text] measurements can reach a lower x range of [Formula: see text], while the previous can reach x range, [Formula: see text]. Also the statistical precision at the same transverse momentum ([Formula: see text]) is substantially improved due to accumulating about 10 times as much luminosity. Preliminary results of [Formula: see text] are presented. Larger asymmetry is observed at [Formula: see text] GeV than at [Formula: see text] GeV at the same [Formula: see text] which is expected due to evolution.

PHENIX measurements are presented for the cross-section and double-helicity asymmetry ($A_{LL}$) of inclusive $\pi^{0}$ production ($A_{LL}^{\pi^{0}}$) at midrapidity from $p+p$ collisions at $\sqrt{s}=510$ GeV from data taken in 2012 and 2013 at the Relativistic Heavy Ion Collider (RHIC). The next-to-leading order (NLO) perturbative QCD (pQCD) calculation agrees excellently with the presented cross-section result. The $A_{LL}^{\pi^{0}}$ follows an increasingly positive asymmetry as functions of $p_{T}$ and $\sqrt{s}$ at the fixed $x_{T}$. The latest global analysis results, which support the positive spin contribution of gluon ($\Delta{}G$), agrees excellently with the presented asymmetry result. The asymmetry result extends the experimental sensitivity to the previously unexplored $x$ region down to $x\sim0.01$ and provides additional constraints on $\Delta{}G$.

PHENIX measurements are presented for the cross-section and double-helicity asymmetry ($A_{LL}$) of inclusive $π^{0}$ production ($A_{LL}^{π^{0}}$) at midrapidity from $p+p$ collisions at $\sqrt{s}=510$ GeV from data taken in 2012 and 2013 at the Relativistic Heavy Ion Collider (RHIC). The next-to-leading order (NLO) perturbative QCD (pQCD) calculation agrees excellently with the presented cross-section result. The $A_{LL}^{π^{0}}$ follows an increasingly positive asymmetry as functions of $p_{T}$ and $\sqrt{s}$ at the fixed $x_{T}$. The latest global analysis results, which support the positive spin contribution of gluon ($ΔG$), agrees excellently with the presented asymmetry result. The asymmetry result extends the experimental sensitivity to the previously unexplored $x$ region down to $x\sim0.01$ and provides additional constraints on $ΔG$.

To improve the productivity and safety of cranes, deep reinforcement learning (DRL) has received widespread attention as a framework for developing automated control methods. However, the major challenge of DRL is sample efficiency, which is further exacerbated by the operational and kinematic characteristics of the crane. Our study proposes an approach to improve the sample efficiency in training control policies for two subtasks: horizontal transportation and sway suppression. To do this, we built a simulation environment and defined the state of the environment and the reward. Then, we performed experiments to find out whether three DRL techniques (reward shaping, curriculum learning, and generative adversarial imitation learning) can mitigate the sample efficiency degradation caused by operational and kinematic characteristics. The results show that the techniques used in our experiment are effective in the improvement of the sample efficiency and learning performance of the DRL model for crane operation.