Frank Jensen

Age is a powerful variable that can be of significant value when modelling the health of forest-dominated ecosystem. Traditional investigations have attempted to extract age information from remotely sensed data by regressing the spectral values with in situ derived age data. Traditional statistical approaches assume (a) normally distributed remote sensing and in situ data, (b) no collinearity among variables, and (c) linear data relationships. Artificial neural networks (ANNs) are not bound by such assumptions and may yield improved predictive modelling of forest stand biophysical parameters if properly utilized. This study investigated traditional statistical and ANN approaches to perform the predictive modelling of the age of loblolly pine (Pinus taeda) for large stands in southern Brazil using Thematic Mapper (TM) data. An extensive comparison of pattern associator and back-propagation ANNs versus both linear and nonlinear regression analysis was conducted. Various neural network architectures were investigated to determine the optimal configuration for this particular dataset. Certain back-propagation ANNs modelled stand age significantly better than traditional statistical approaches because of their ability to take into account nonlinear, non-normally distributed data. The results suggest that ANN analysis may be of significant value when using remote sensing data to model certain forest variables.

We search for single-photon decays of the Υ(1S) resonance, Υ → γ + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A⁰, or a pair of dark matter particles, χχ. Both A⁰ and χ are assumed to have zero spin. We tag Υ(1S) decays with a dipion transition Υ(2S) → π⁺π⁻Υ(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m(A⁰) ≤ 9.2 GeV and m(χ) ≤ 4.5 GeV in the sample of 98 × 10⁶ Υ(2S) decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.

The cost-effective MC-TST/CTSR protocol was tested against five families of C 3 -fluorinated OVOCs, yielding OH-initiated oxidation reaction rate constants within a factor of two from the recommended experimental values.

A new ATLAS pixel chip FE-I4 is being developed for use in upgraded LHC luminosity environments, including the near-term Insertable B-Layer (IBL) upgrade. FE-I4 is designed in a 130 nm CMOS technology, presenting advantages in terms of radiation tolerance and digital logic density compared to the 0.25μm CMOS technology used for the current ATLAS pixel IC, FE-I3. The FE-I4 architecture is based on an array of 80×336 pixels, each 50×250μm2, consisting of analog and digital sections. In the summer 2010, a first full scale prototype FE-I4A was submitted for an engineering run. This IC features the full scale pixel array as well as the complex periphery of the future full-size FE-I4. The FE-I4A contains also various extra test features which should prove very useful for the chip characterization, but deviate from the needs for standard operation of the final FE-I4 for IBL. In this paper, focus will be brought to the various features implemented in the FE-I4A submission, while also underlining the main differences between the FE-I4A IC and the final FE-I4 as envisioned for IBL.

The FE-I4 is a new pixel readout integrated circuit designed to meet the requirements of ATLAS experiment upgrades. The first samples of the FE-I4 engineering run (called FE-I4A) delivered promising results in terms of the requested performances. The FE-I4 team envisaged a number of modifications and fine-tuning before the actual exploitation, planned within the Insertable B-Layer (IBL) of ATLAS. As the IBL schedule was pushed significantly forward, a quick and efficient plan had to be devised for the FE-I4 redesign. This article will present the main objectives of the resubmission, together with the major changes that were a driving factor for this redesign. In addition, the top-level verification and test efforts of the FE-I4 will also be addressed.

The preparation of samples is discussed. The investigations were based on rat liver tissue, which has a high concentration of heavy metals and is very homogeneous.

We study the primary photolysis dynamics of aqueous carbonate, CO32-(aq), and hydrogen carbonate, HCO3-(aq), when they are excited at λ = 200 nm. The photolysis is recorded with sub-picosecond time resolution using UV pump-Vis probe and UV pump-IR probe transient absorption spectroscopy and interpreted with the aid of density functional theory calculations. When CO32- is excited via single photon absorption at λ = 200 nm, Φ(t = 20 ps) = 82 ± 5% of the excited di-anions either detach an electron or dissociate. The electron detachment takes place from the excited state in t < 1 ps and forms ground state CO3˙- and eaq-. Dissociation occurs from both the electronic ground and excited states of CO32-. Dissociation from the CO32- excited state is assisted by water molecules and forms CO2˙-, OH˙ and OH-. The dissociation occurs both directly from the Franck-Condon region in t < 1 ps and indirectly with a time constant of τ = 13.9 ± 0.5 ps as the excited state relaxes. Dissociation of vibrationally excited CO32- molecules in the electronic ground state is also assisted by water molecules and forms CO2 and two OH- anions. The dissociation and subsequent vibrational relaxation of CO2 occur with a time constant of τ = 10.2 ± 0.5 ps. The residual 1 - Φ(t = 20 ps) = 18 ± 5% of the excited CO32- di-anions return by internal conversion to the equilibrated CO32- ground state with a time constant of τ = 4.0 ± 0.4 ps. The extinction coefficient of aqueous hydrogen carbonate HCO3-(aq) at λ = 200 nm is an order of magnitude smaller than that of carbonate, so even though the hydrogen carbonate anions dominate the carbonate di-anions in the hydrogen carbonate solution, the primary photolysis of hydrogen carbonate is obscured by the photo-products of carbonate. Hence, we are unable to assess the primary photolysis of hydrogen carbonate. However, the weak one-photon absorption facilitates two-photon ionization of water, which forms hydronium, H3O+, cations. The sudden increase in the acidity induced by two-photon ionization protonates the ground state hydrogen carbonate molecules, thus offering a rare spectroscopic glimpse of aqueous carbonic acid.

Abstract Diamond sensors are studied as an alternative to silicon sensors to withstand the high radiation doses that are expected in future upgrades of the pixel detectors for the SLHC. Diamond pixel sensors are intrinsically radiation hard and are considered as a possible solution for the innermost tracker layers close to the interaction point where current silicon sensors cannot cope with the harsh radiation environment.An effort to study possible candidates for the upgrades is undergoing using the Fermilab test-beam facility (FTBF), where diamonds and 3D silicon sensors have been studied. Using a CMS pixel-based telescope built and installed at the FTBF, we are studying charge collection efficiencies for un-irradiated and irradiated devices bump-bonded to the CMS PSI46 pixel readout chip. A description of the test-beam effort and preliminary results on diamond sensors will be presented.

The FE-I4 chip for the B-layer upgrade is designed in a 130 nm CMOS process. For this design, configuration memories are based on the DICE latches where layout considerations are followed to improve the tolerance to SEU. Tests have shown that DICE latches for which layout approaches are adopted are 30 times more tolerant to SEU than the standard DICE latches. To prepare for the new pixel readout chip planned for the future upgrades, a prototype chip containing 512 pixels has been designed in a 65 nm CMOS process and a new approach is adopted for SEU tolerant latches. Results in terms of SEU and TID tolerance are presented.

In preparation for the tenfold luminosity upgrade of the Large Hadron Collider (the HL-LHC) around 2020, three-dimensional (3D) silicon pixel sensors are being developed as a radiation-hard candidate to replace the planar ones currently being used in the CMS pixel detector. This study examines an early batch of FBK sensors (named ATLAS08) of three 3D pixel geometries: 1E, 2E, and 4E, which respectively contain one, two, and four readout electrodes for each pixel, passing completely through the bulk. We present electrical characteristics and beam test performance results for each detector before and after irradiation. The maximum fluence applied is 3.5×1015 n eq/cm2.

Three-dimensional (3D) silicon detectors are emerging as one of the most promising technologies for the innermost layers of tracking devices for the foreseen upgrades of the LHC. 3D sensors compatible with the CMS readout, fabricated at FBK (Trento, Italy), were tested in the laboratory and with a 120 GeV/c proton beam at the FNAL test beam facility, before and after irradiation up to a fluence of 3.5×1015neq/cm2. Preliminary results of the data analysis are presented.

Abstract Silicon 3D detectors consist of an array of columnar electrodes of both doping types which penetrate entirely in the detector bulk, perpendicularly to the surface. They are emerging as one of the most promising technologies for innermost layers of tracking devices for the foreseen upgrades of the LHC. Until recently, properties of 3D sensors have been investigated mostly with ATLAS readout electronics. 3D pixel sensors compatible with the CMS readout were first fabricated at SINTEF (Oslo, Norway), and more recently at FBK (Trento, Italy) and CNM (Barcelona, Spain). Several sensors with different electrode configurations, bump-bonded with the CMS pixel PSI46 readout chip, were characterized in laboratory and tested at Fermilab with a proton beam of 120 GeV/ c . Preliminary results of the data analysis are presented.

The CMS silicon pixel detector is the tracking device closest to the LHC p–p collisions, which precisely reconstructs the charged particle trajectories. The planar technology used in the current innermost layer of the pixel detector will reach the design limit for radiation hardness at the end of Phase I upgrade and will need to be replaced before the Phase II upgrade in 2020. Due to its unprecedented performance in harsh radiation environments, 3D silicon technology is under consideration as a possible replacement of planar technology for the High Luminosity-LHC or HL-LHC. 3D silicon detectors are fabricated by the Deep Reactive-Ion-Etching (DRIE) technique which allows p- and n-type electrodes to be processed through the silicon substrate as opposed to being implanted through the silicon surface. The 3D CMS pixel devices presented in this paper were processed at FBK. They were bump bonded to the current CMS pixel readout chip, tested in the laboratory, and testbeams carried out at FNAL with the proton beam of 120 GeV/c. In this paper we present the laboratory and beam test results for the irradiated 3D CMS pixel devices.

The paper deals with optimality issues in connection with updating beliefs in networks. We address two processes: triangulation and construction of junction trees. In the first part, we give a simple algorithm for constructing an optimal junction tree from a triangulated network. In the second part, we argue that any exact method based on local calculations must either be less efficient than the junction tree method, or it has an optimality problem equivalent to that of triangulation.

We present an approach to the solution of decision problems formulated as influence diagrams. This approach involves a special triangulation of the underlying graph, the construction of a junction tree with special properties, and a message passing algorithm operating on the junction tree for computation of expected utilities and optimal decision policies.

In this paper it is shown that the sensitivity of the Evans-Kirby version of the gravity model depends primarily on two factors: the size of the errors in the interzonal costs, and the smallest singular value of a certain matrix.

The present Neutral Beam Power Supplies consist of 16 units, each with a capacity of 80W/60A. Each of these units can be connected to a 80kV/60A Neutral Injector or alternatively two of these units can be connected in series giving 160kV/60A output capability. In this latter configuration two 160kV/30A Neutral injectors are connected in parallel at the output of the series connected units. In both cases the total DC output power of the Power Supplies is the same and equal to 76.8MW. In the future JET would like to increase the available neutral injection heating power for the plasma. This can be achieved by either increasing the output current of the existing power supplies or by increasing the output voltage. It is preferred to increase the voltage because this limits the increase in plasma density caused by the injected particles. The increase in voltage is obtained by connecting a new 60kV/60A power supply in series with the output of the existing unit. This paper explains the main requirements for this design and presents a reference design based on these requirements.

We present a comparative characterization of the performance of a single-crystal and a polycrystalline diamond pixel-detector employing the standard CMS pixel readout chips. Measurements were carried out at the Fermilab Test Beam Facility, FTBF, using protons of momentum 120 GeV/c tracked by a high-resolution pixel telescope. Particular attention was directed to the study of the charge-collection, the charge-sharing among adjacent pixels and the achievable position resolution. The performance of the single-crystal detector was excellent and comparable to the best available silicon pixel-detectors. The measured average detection-efficiency was near unity, ε = 0.99860±0.00006, and the position-resolution for shared hits was about 6 μm. On the other hand, the performance of the polycrystalline detector was hampered by its lower charge collection distance and the readout chip threshold. A new readout chip, capable of operating at much lower threshold (around 1 ke−), would be required to fully exploit the potential performance of the polycrystalline diamond pixel-detector.

Alkali dimers, $\mathrm{Ak}_2$, residing on the surface of He nanodroplets are doubly ionized due to multiphoton absorption from an intense, 50-fs laser pulse leading to fragmentation into a pair of alkali cations. Based on the measured kinetic energy distributions, $P(E_{\text{kin}})$, of the $\mathrm{Ak}^+$ fragment ions, we retrieve the distribution of internuclear distances, $P(R)$, via the $\mathrm{Ak}_2^{2+}$ potential curve. Results are obtained for $\mathrm{{Na}_2}$, $\mathrm{K}_2$, $\mathrm{Rb}_2$, and $\mathrm{Cs}_2$ in both the 1 $^1Σ_{g}^+$ ground state and in the lowest-lying triplet state 1 $^3Σ_{u}^+$, and for $\mathrm{Li}_2$ in the 1 $^3Σ_{u}^+$ state. For $\mathrm{Li}_2$, $\mathrm{K}_2$, and $\mathrm{Rb}_2$, the center of the measured $P(R)$'s is close to the center of the wave function, $Ψ(R)$, of the vibrational ground state in the 1 $^1Σ_{g}^+$ and 1 $^3Σ_{u}^+$ states, whereas for $\mathrm{{Na}_2}$ and $\mathrm{{Cs}_2}$ small shifts are observed. For all the $\mathrm{{Ak}_2}$, the width of the measured $P(R)$ is broader than $|Ψ(R)|^2$ by a factor of 2-4. We discuss that resonance effects in the multiphoton ionization and interaction of the $\mathrm{Ak}^+$ ion with the He droplet give rise to the observed deviations of $P(R)$ from $|Ψ(R)|^2$. Despite these deviations, we deem that timed Coulomb explosion will allow imaging of vibrational wave packets in alkali dimers on He droplets surfaces.

We extend the framework for polarizable force fields to include the case where the electrostatic multipoles are not determined by a variational minimization of the electrostatic energy. Such models formally require that the polarization response is calculated for all electrostatic parameters for all possible geometrical perturbationsin order to obtain the energy gradient required for performing molecular dynamics simulations. By making use of a Lagrange formalism, however, this computational demanding task can be replaced by solving a single equation similar to that for determining the polarization energy itself. Using the recently proposed bond capacity model that describes molecular polarization at the charge-only level, we show that the energy gradient for non-variational energy models with periodic boundary conditions can be calculated with a computational effort similar to that for variational polarization models. The possibility of separating the equation for calculating the electrostatic parameters from the energy expression depending on these parameters without a large computational penalty provides flexibility in the design of new force fields.

&lt;div&gt; &lt;div&gt; &lt;div&gt; &lt;p&gt;We extend the framework for polarizable force fields to include the case where the electrostatic multipoles are not determined by a variational minimization of the electrostatic energy. Such models formally require that the polarization response is calculated for all possible geometrical perturbations in order to obtain the energy gradient required for performing molecular dynamics simulations. &lt;/p&gt;&lt;div&gt; &lt;div&gt; &lt;div&gt; &lt;p&gt;By making use of a Lagrange formalism, however, this computational demanding task can be re- placed by solving a single equation similar to that for determining the electrostatic variables themselves. Using the recently proposed bond capacity model that describes molecular polarization at the charge-only level, we show that the energy gradient for non-variational energy models with periodic boundary conditions can be calculated with a computational effort similar to that for variational polarization models. The possibility of separating the equation for calculating the electrostatic variables from the energy expression depending on these variables without a large computational penalty provides flexibility in the design of new force fields. &lt;/p&gt;&lt;div&gt;&lt;div&gt;&lt;div&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;p&gt; &lt;/p&gt;&lt;div&gt; &lt;div&gt; &lt;div&gt; &lt;p&gt;variables themselves. Using the recently proposed bond capacity model that describes molecular polarization at the charge-only level, we show that the energy gradient for non-variational energy models with periodic boundary conditions can be calculated with a computational effort similar to that for variational polarization models. The possibility of separating the equation for calculating the electrostatic variables from the energy expression depending on these variables without a large computational penalty provides flexibility in the design of new force fields. &lt;/p&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt;

Åbning af mødet i anledning af Dansk Kriminalistforenings 100-års jubilæum

I dette papir gives en oversigt over dele af den omfattende litteratur om regulering af forurening under asymmetrisk information - bA¥de punkt og ikke-punkt forurening gennemgA¥s. PrimA¦r mA¥lgruppe for papiret er A¸konomer med kendskab til informationsA¸konomi, men med begrA¦nset kendskab til miljA¸A¸konomi. Desuden skitseres kort hvilke incitamentmekanismer, der vil blive forsA¸gt tilpasset en analyse af regulering af fornybare naturlige ressourcer under asymmetrisk information. Papiret har en tA¦t kobling til teori om asymmetrisk information.

International Journal of Quantum ChemistryVolume 72, Issue 5 p. 535-535 Book Review Book Review Frank Jensen, Frank JensenSearch for more papers by this author Frank Jensen, Frank JensenSearch for more papers by this author First published: 22 February 1999 https://doi.org/10.1002/(SICI)1097-461X(1999)72:5<535::AID-QUA7>3.0.CO;2-HAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume72, Issue51999Pages 535-535 RelatedInformation