gebhart/patrepeval huggingface dataset:
CT image reconstruction from fan‐parallel data (1999)

Third generation fan‐beam computerized tomography (CT) scanners acquire data one entire projection at a time. The associated filtered‐backprojection algorithm requires a computationally expensive pixel‐dependent weight factor in the backprojector. Methods of simplifying the reconstruction include rebinning the fan‐beam data to parallel projections. The rebinning can be separated into two steps: azimuthal interpolation, leading to the fan‐parallel geometry, where data are unevenly spaced on radial lines through the origin of Radon space, and a subsequent axial interpolation to parallel data. Under appropriate view and projection sampling conditions, the azimuthal interpolation can be replaced by either data resorting or projection channel‐dependent delays. This article investigates an arcsin algorithm to reconstruct an image directly from the fan‐parallel data. Although it is shown that the algorithm cannot be exact, a natural approximation is described. The pre‐ and postconvolution weights, and the reconstruction filter, are derived analytically. Imaging results demonstrate that arcsin image quality matches that of parallel reconstruction. The fan‐parallel reconstruction method eliminates the resolution‐compromising axial interpolation and the costly pixel‐dependent backprojection weight. Further, an arcsin detector design is proposed for direct parallel reconstruction from fan‐beam data.
ChemInform Abstract: Reduction of Azides to Amines with SmI2 or Cp2TiCl2‐Sm System. (1996)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Remotely controlling TrustZone applications? A study on securely and resiliently receiving remote commands (2021)

Mobile devices are becoming an indispensable part of work for corporations and governments to store and process sensitive information. Thus, it is important for remote administrators to maintain control of these devices via Mobile Device Management (MDM) solutions. ARM TrustZone has been widely regarded as the de facto solution for protecting the security-sensitive software, such as MDM agents, from attacks of a compromised rich OS. However, little attention has been given to protecting the MDM control channel, a fundamental component for a remote administrator to invoke the TrustZone-based MDM agents and perform specific management operations. In this work, we design an ARM TrustZone-based network mechanism, called TZNIC, towards enabling resilient and secure access to TrustZone-based software, even in the presence of a malicious rich OS. TZNIC deploys two NIC drivers, one secure-world driver and one normal-world driver, multiplexing one physical NIC. We utilize the ARM TrustZone-based high privilege to protect the secure-world driver and further resolve several challenges on sharing one set of hardware peripherals between two isolated software environments. TZNIC does not require any changes or collaboration of the rich OS. We implement a prototype of TZNIC, and the evaluation results show that TZNIC can provide a reliable network channel to invoke the security software in the secure world, with minimal system overhead on the rich OS.
Differentiated Surveillance for Static and Random Mobile Sensor Networks (2008)

The utility of a sensor network derives primarily from the sensing data it gathers. Therefore, a critical issue of sensor networks is to efficiently provide sensing coverage. This paper proposes a scheme, enhanced differentiated surveillance (EDS), to maintain the required coverage for sensor networks by establishing working schedules of sensors for the purpose of energy saving. EDS allows every sensor in a sensor network to establish its working schedule in a distributive manner, based on random reference times generated through integer hashing and a proposed coverage measurement rule. The required coverage is continuously guaranteed when every sensor senses following its own working schedule.While most existing coverage maintenance schemes are only applicable for static sensors with equal sensing range (homogeneous sensors), EDS is versatile in applications. It can be applied to sensors with different sensing ranges (heterogeneous sensors), and extended to random mobile sensor networks, where sensors randomly roam and cannot control their movements. Compared with existing work, the advantages of EDS lie in minimum communication overhead, fast convergence, load balancing, and high battery efficiency. The effectiveness and efficiency of EDS are investigated through numerical examples of static and random mobile sensor networks.
Klystrons, Traveling Wave Tubes, Magnetrons, Cross-Field Amplifiers, and Gyrotrons (2011)

Microwave tubes are vacuum electron devices used for the generation and amplification of radio frequencies in the microwave range. An established technology area, the use of tubes remains essential in the field today for high-power applications. The culmination of the author's 50 years of industry experience, this authoritative resource offers you a thorough understanding of the operations and major classes of microwave tubes. Minimizing the use of advanced mathematics, the book places emphasis on clear qualitative explanations of phenomena. This practical reference serves as an excellent introduction for newcomers to the field and offers established tube engineers a comprehensive refresher. Professionals find coverage of all major tube classifications, including klystrons, traveling wave tubes (TWTs), magnetrons, cross field amplifiers, and gyrotrons.
Traffic sign recognition in color image sequences (2003)

At the Daimler-Benz Research Center in Ulm a system for traffic sign recognition is under development. The task of the system is to detect and interpret traffic signs in colour image sequences; these images are acquired by a camera mounted in a car. The color segmentation of the incoming images is performed with a high order neural network. Based on this color segmented images and using a priori knowledge, hypotheses on image regions containing traffic signs are generated. The kind of traffic sign is also hypothesized. The preselected image regions are further analysed in order to verify or reject the hypothesis. The analysis finally interprets the contents of the traffic signs. The control of the analysis is supported by knowledge on traffic signs and outdoor scenes in general. The whole knowledge is stored in a framebased network.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Effects of Volute Curvature on Performance of a Low Specific-Speed Centrifugal Pump at Design and Off-Design Conditions (2014)

The effects of the volute geometry on the head, efficiency, and radial force of a low specific-speed centrifugal pump were investigated focusing on off-design conditions. This paper is divided into three parts. In the first part, the three-dimensional flow inside the pump with rectangular volute was simulated using three well-known turbulence models. Simulation results were compared with the available experimental data, and an acceptable agreement was obtained. In the second part, two volute design methods, namely, the constant velocity and the constant angular momentum were investigated. Obtained results showed that in general the constant velocity method gives more satisfactory performance. In the third part, three volutes with different cross section and diffuser shape were designed. In general, it was found that circular cross section volute with radial diffuser provides higher head and efficiency. Moreover, the minimum radial force occurs at higher flowrate in circular volute geometry comparing to rectangular cross section volute.
Autocorrelation Based Signal-to-Noise Ratio Estimator in AWGN Channels (2007)

Signal-to-noise ratio (SNR) estimation is an important technique in receiver design for wireless communications. In the receivers, many algorithms require SNR information to achieve optimal performance. In this paper, an autocorrelation based SNR estimator is proposed. This method utilizes the correlation properties of symbol sequence and noise sequence to distinguish the signal power from the noise power. According to the simulation results, mean and normalized mean-square-error performance of the proposed SNR estimator is better than that of the conventional SNR estimators.
Enzymes in organic synthesis. 14. Stereoselective horse liver alcohol dehydrogenase catalyzed oxidations of diols containing a prochiral centre and of related hemiacetals (1979)

The asymmetric synthetic potential of horse liver alcohol dehydrogenase catalyzed oxidations of variously 3-substituted pentane-1,5-diols has been further delineated. The oxidations proceed with enantiotopic selectivity to give the corresponding (3S)-3-substituted valerolactones of up to 78% ee. The reactions occur via initial oxidation of the pro-S hydroxyethyl group, with the initially-formed hydroxyaldehydes undergoing further in situ enzyme-catalyzed oxidation in their hemiacetal forms to give the (3S)-lactones directly. The hemiacetal oxidation step is also stereoselective, with oxidation of the (4S)-enantiomer being much preferred. The size of the substituent at C-3 in the diols (C-4 in the hemiacetals) affects both the enantiotopic and enantiomeric specificity of the enzyme. Both types of stereospecificity are highest when the substituents are smallest, such as methyl or ethyl, and diminish progressively for diol or hemiacetal substrates bearing large aliphatic or aromatic substituents. All reactions were carried out on a preparative (up to 2 g) scale.
T-ray imaging: new possibilities in the far infrared (2003)

Since the initial demonstrations of T-ray imaging in 1995, there has been considerable progress in the development of this field. Many possible applications have been explored, and a commercial terahertz time-domain spectrometer is now operating in a manufacturing environment. In addition, several new imaging techniques which exploit the unique properties of the THz system have been developed. We describe one technique, which permits time-of-flight imaging with depth resolution well below the Rayleigh limit. We demonstrate the capability to resolve two reflecting surfaces separated by only a few percent of the coherence length of the THz radiation.
Ultrafast Forwarding Architecture Using a Single Optical Processor for Multiple SAC-Label Recognition Based on FWM (2008)

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We propose and demonstrate a novel ultrafast label processor that can recognize multiple spectral amplitude coded (SAC) labels using four wave mixing (FWM) sideband allocation and selective optical filtering. Our proposed solution favors hardware simplicity over bandwidth efficiency in order to achieve ultrafast label recognition at reasonable cost. Our implementation, unlike all other optical label processing techniques, does not require time gating, envelope detectors, or serial-to-parallel converters. Labels are transmitted simultaneously with the payload, improving temporal efficiency at the expense of spectral efficiency. Note that bandwidth efficiency can be improved through a frequency management scheme that uses irregular spacing of wavelengths for payload and label, a complexity overhead in management similar to that in long-haul networks employing irregular spacing of carriers to avoid FWM products. We present two experiments of the single processor for ultrafast forwarding using first optoelectronic and then all-optical switches. In the first experiment, we use 10 SAC labels with minimum bin separation of 25 GHz, 10 Gb/s variable-length data packets, and forward packets over 200 km using electrooptical switches. In the second experiment, all-optical switching at 40 Gb/s is demonstrated using a SAC family for up to 36 labels. We present details on the families of spectral codes for label recognition, using unequally spaced frequency bins. A code family with weight 2 and length 9 uniquely identifies 36 labels. Hardware complexity is moderate compared with short-pulse code labels (mode-locked laser) techniques. Two stable tunable lasers are required for label generation of this code family; all other hardware is commercial, off-the-shelf components such as semiconductor optical amplifiers, array waveguide gratings, optoelectronic switches, and photodetectors. </para>
Formation of a putative relaxation intermediate during T‐DNA processing directed by the <i>Agrobacterium tumefaciens</i> VirD1, D2 endonuclease (1993)

During the initial stages of crown gall tumorigenesis, the T-DNA region of the Agrobacterium tumefaciens Ti-plasmid is processed, resulting in the production of T-DNA molecules that are subsequently transferred to the plant cell. Processing of the T-DNA in the bacterium involves the nicking of T-DNA border sequences by an endonuclease encoded by the virD locus, and the subsequent tight (possibly covalent) association of the VirD2 protein with the 5' end of the processed single-stranded or double-stranded T-DNA molecule. To investigate the interaction of the VirD1,D2 endonuclease with a right T-DNA border, a set of plasmids containing both the border and virD sequences on the same high-copy-number replicon has been constructed and introduced into Escherichia coli. In this model system a tight nucleoprotein complex is formed between the relaxed double-stranded substrate plasmid and the VirD2 protein. This putative T-DNA processing complex may be analogous to the covalent relaxation complex formed between the pilot protein and plasmid DNA during bacterial conjugation. VirD2 attachment to the relaxed substrate plasmid was resistant to denaturing agents but sensitive to S1 nuclease digestion, indicating a single-stranded region near the site of protein attachment. We speculate that this structure may be an intermediate formed prior to T-strand unwinding from the substrate plasmid in a host bacterium.
부모의 게임 중독이 유아의 신체활동에 미치는 영향 (2017)

The purpose of this study was to investigate how the parent’s game addiction has an effect on children’s physical activity, physical self-conception...
<i>e</i>/<i>a</i> Determination for the transition metal element TM in Al–Cu–TM–Si (TM = Fe and Ru) approximants and B2-compounds by means of the FLAPW-Fourier method (2009)

Abstract By using the FLAPW-Fourier method, we could determine the e / a value for Al–Cu–TM–Si (TM = Fe and Ru) 1/1 – 1/1 – 1/1 approximants and several B2 compounds including CuZn, NiZn, NiAl, MnZn, and AlMg. The NiAl, NiZn and MnZn B2-compounds involving the transition metal element as a partner element are found to be no longer regarded as the 3/2 electron compounds. Moreover, we found that the e / a value is not uniquely assigned to a given transition metal element but depends on its surrounding environments. Hence, it is difficult to use it as a universal parameter in an alloy design.
Fibroblast growth factor receptor 4 (FGFR4): a targetable regulator of drug resistance in colorectal cancer (2014)

The discovery of underlying mechanisms of drug resistance, and the development of novel agents to target these pathways, is a priority for patients with advanced colorectal cancer (CRC). We previously undertook a systems biology approach to design a functional genomic screen and identified fibroblast growth factor receptor 4 (FGFR4) as a potential mediator of drug resistance. The aim of this study was to examine the role of FGFR4 in drug resistance using RNAi and the small-molecule inhibitor BGJ398 (Novartis). We found that FGFR4 is highly expressed at the RNA and protein levels in colon cancer tumour tissue compared with normal colonic mucosa and other tumours. Silencing of FGFR4 reduced cell viability in a panel of colon cancer cell lines and increased caspase-dependent apoptosis. A synergistic interaction was also observed between FGFR4 silencing and 5-fluorouracil (5-FU) and oxaliplatin chemotherapy in colon cancer cell lines. Mechanistically, FGFR4 silencing decreased activity of the pro-survival STAT3 transcription factor and expression of the anti-apoptotic protein c-FLIP. Furthermore, silencing of STAT3 resulted in downregulation of c-FLIP protein expression, suggesting that FGFR4 may regulate c-FLIP expression via STAT3. A similar phenotype and downstream pathway changes were observed following FGFR4 silencing in cell lines resistant to 5-FU, oxaliplatin and SN38 and upon exposure of parental cells to the FGFR small-molecule inhibitor BGJ398. Our results indicate that FGFR4 is a targetable regulator of chemo-resistance in CRC, and hence inhibiting FGFR4 in combination with 5-FU and oxaliplatin is a potential therapeutic strategy for this disease.
The study of backside TSV reveal process by direct Si/Cu grinding and polishing (2013)

Despite the fact that manufacturing processes of through silicon via (TSV) have achieved great progresses, the backside via reveal process is still challenging and costly. The simplest TSV reveal method is using backside grinding (BG) and chemical mechanical polishing (CMP), by which the vias are revealed by CMP directly after wafer thinning with BG. However this method is not well accepted due to the Cu contamination concern. From the application point of view, if the Cu contamination is restrained in pretty low level with process optimization, it may be still possible to be applied to achieve the simple and economical process, especially for 2.5D interposer manufacturing which is more tolerant with Cu contamination. In this work, very low contamination level-copper atoms (lower than 0.000001%) were got in backside wafer surface after CMP of TSV vias, which is good enough for interposer or even 3DIC application.
The cost of labour : where are we headed? (2017)

The minimum wage system in South Africa has been with us for a number of years now and although there is quite some resistance against it from employer side, it is definitely here to stay. The minimum wage of employees in the farming and forestry sectors increased at the beginning of March 2017 and is currently at R15,39/hour or R3 001,13/month for employees who work a nine-hour day. This is an 8% increase from the minimum wage of 2016/17 and was based on consumer price index (CPI) (7%) plus 1%.
Secret handshakes from pairing-based key agreements (2004)

Consider a CIA agent who wants to authenticate herself to a server but does not want to reveal her CIA credentials unless the server is a genuine CIA outlet. Consider also that the CIA server does not want to reveal its CIA credentials to anyone but CIA agents - not even to other CIA servers. We first show how pairing-based cryptography can be used to implement such secret handshakes. We then propose a formal definition for secure secret handshakes, and prove that our pairing-based schemes are secure under the Bilinear Diffie-Hellman assumption. Our protocols support role-based group membership authentication, traceability, indistinguishability to eavesdroppers, unbounded collusion resistance, and forward repudiability. Our secret-handshake scheme can be implemented as a TLS cipher suite. We report on the performance of our preliminary Java implementation.
Sensitive Superoxide Detection in Vascular Cells by the New Chemiluminescence Dye L-012 (1999)

The detection superoxide production in vascular cells is usually limited by a low sensitivity of available assays. We tested the applicability of the luminol derivate L-012 ¿8-amino-5-chloro-7-phenylpyridol¿3,4-dpyridazine-1,4(2H,3H)dione to measure superoxide production in cultured endothelial cells (human umbilical vein endothelial cells) and rat aortic segments. Following stimulation with the protein kinase stimulator phorbol 12-myristate 13-acetate (PMA, 1 microM) there was an 2.8-fold increase of L-012 chemiluminescence, whereas incubation with angiotensin II (100 nM) did not result in a measurable increase. Addition of vanadate (100 microM) considerably increased the chemiluminescence (up to 17-fold) after PMA and made possible the detection of an enhanced superoxide production after stimulation with angiotensin II (by 1.7-fold). This was due to a approximately 9-fold increase in signal intensity of L-012 in the presence of vanadate. Prolonged incubation with vanadate also led to a tyrosine phosphorylation-dependent increase in superoxide formation which was predominantly produced by an NAD(P)H oxidase. Short-term vanadate-enhanced L-012 chemiluminescence represents a highly sensitive assay making it possible to detect small changes of superoxide formation in intact vascular cells.
Behaviour Profiling on Mobile Devices (2010)

Over the last decade, the mobile device has become a ubiquitous tool within everyday life. Unfortunately, whilst the popularity of mobile devices has increased, a corresponding increase can also be identified in the threats being targeted towards these devices. Security countermeasures such as AV and firewalls are being deployed, however, the increasing sophistication of the attacks requires additional measures to be taken. This paper proposes a novel behaviour-based profiling technique that is able to build upon the weaknesses of current systems by developing a comprehensive multilevel approach to profiling. In support of this model, a series of experiments have been designed to look at profiling calling, device usage and Bluetooth network scanning. Using neural networks, experimental results for the aforementioned activities’ are able to achieve an EER (Equal Error Rate) of: 13.5%, 35.1% and 35.7%.
Analysis of the chronic lymphocytic leukemia coding genome: role of <i>NOTCH1</i> mutational activation (2011)

The pathogenesis of chronic lymphocytic leukemia (CLL), the most common leukemia in adults, is still largely unknown. The full spectrum of genetic lesions that are present in the CLL genome, and therefore the number and identity of dysregulated cellular pathways, have not been identified. By combining next-generation sequencing and copy number analysis, we show here that the typical CLL coding genome contains <20 clonally represented gene alterations/case, including predominantly nonsilent mutations, and fewer copy number aberrations. These analyses led to the discovery of several genes not previously known to be altered in CLL. Although most of these genes were affected at low frequency in an expanded CLL screening cohort, mutational activation of NOTCH1, observed in 8.3% of CLL at diagnosis, was detected at significantly higher frequency during disease progression toward Richter transformation (31.0%), as well as in chemorefractory CLL (20.8%). Consistent with the association of NOTCH1 mutations with clinically aggressive forms of the disease, NOTCH1 activation at CLL diagnosis emerged as an independent predictor of poor survival. These results provide initial data on the complexity of the CLL coding genome and identify a dysregulated pathway of diagnostic and therapeutic relevance.