A mixed logit analysis of motorists’ right-of-way violation in motorcycle accidents at priority T-junctions

Research suggested that motorists’ right-of-way (ROW) violation in automobile-motorcycle gap-acceptance accidents at priority (i.e., stop-/yield-controlled) T-intersections has been a safety concern to motorcyclists. This study examines the characteristics of automobile-motorcycle gap-acceptance accidents that occurred at such locations. British Stats19 accident injury database during 1991-2005 are examined in detail. Automobile-motorcycle gap-acceptance accidents are classified into three crash scenarios: approach-turn, angle crossing, and angle merging crashes. Mixed (random parameters) logit models are estimated to investigate the contributory factors to motorists’ ROW violation in these three crash types. Crash features are also compared among gap-acceptance accidents and other crash scenarios. The methodological approach adopted allows for the individuals within the observations to have different parameter estimates as opposed to a single parameter representing all observations (i.e., accounts for unobserved heterogeneity potentially relating to roadway/environmental characteristics, and motorist behaviours). It was found that motorcycles’ ROW was more likely to be violated on non-built-up roads, and in diminished light conditions, with non-uniform effects across the observations. Elderly/female motorists appeared to be over-represented in gap-acceptance crashes. Implications of the findings are discussed.     

Minimum-power multicast routing in static ad hoc wireless networks

Wieselthier et al. (2000) proposed three greedy heuristics for Min-Power Asymmetric Broadcast Routing: SPT (shortest-path tree), MST (minimum spanning tree), and BIP (broadcasting incremental power). Wan et al. (2001) proved that SPT has an approximation ratio of at least (n/2) where n is the total number of nodes, and both MST and BIP have constant approximation ratios. Based on the approach of pruning, Wieselthier et al. also proposed three greedy heuristics for Min-Power Asymmetric Multicast Routing: P-SPT (pruned shortest-path tree), P-MST (pruned minimum spanning tree), and P-BIP (pruned broadcasting incremental power). In this paper, we first prove that the approximation ratios of these three heuristics are at least (n-1/2),n-1, and n-2-o(1), respectively. We then present constant-approxiation algorithms for Min-Power Asymmetric Multicast Routing. We show that any /spl rho/-approximation Steiner tree algorithm gives rise to a c/spl rho/-approximation heuristic for Min-Power Asymmetric Multicast Routing, where c is a constant between 6 and 12. In particular, the Takahashi-Matsuyama Steiner tree heuristic leads to a heuristic called SPF (shortest-path first), which has an approximation ratio of at most 2c. We also present another heuristic, called MIPF (minimum incremental path first), for Min-Power Asymmetric Multicast Routing and show that its approximation ratio is between (13/3) and 2c. Both SPF and MIPF can be regarded as an adaptation of MST and BIP, respectively, in a different manner than pruning. Finally, we prove that any /spl rho/-approximation Steiner tree algorithm also gives rise to a 2/spl rho/-approximation algorithm for Min-Power Symmetric Multicast Routing.     

Development of the LED measurement system of chromaticity coordinates correction

In this paper, we propose a procedure to adjust the chromaticity coordinates by using a few samples of the color measurement coordinate to do the error correction and choose the correction method of minimum color error difference average to be the procedure of measuring instruments, and to construct an efficient and predictable calibration procedure. This research adopts some engineering statistics methods, such as median and average methods, and corrects the experiments to obtain the chromaticity coordinates. The four calibration methods that we designed lower the average value of the color errors as 0.034. Moreover, the minimum average value of errors in the X-axis could be revised to 6.3% while the minimum average value of errors in the Y-axis 8.8%. The accuracy of best calibrated chromaticity coordinates could achieve to the percentage 71.1%.     

Missed joint induced by thermoelectric magnetic field in electron-beam welding dissimilar metals—Experiment and scale analysis

A missed joint, resulting from an induced thermoelectric magnetism in welding dissimilar metals with a high-intensity electron beam, is experimentally and analytically investigated. Election-beam welding is a very useful process for joining a wide range of dissimilar metals, which may be difficult or impossible to weld by other techniques. Certain combinations of materials, unfortunately, readily give rise to a missed-joint defect because of thermoelectric-magnetic deflection of the beam. Combinations of dissimilar metals chosen for this study are low-carbon steel and type 304 stainless steel, low-carbon steel and Ni-Cu alloy, and type 304 stainless steel and Ni-Cu alloy. The experimental results find agreement with a previous study showing that the electron beam deflects toward the metal with a larger Seebeck coefficient (denoted by metal 1). A general and algebraic expression for predicting deflection angle as a function of dimensionless beam power, accelerating voltage-to-Seebeck electromotive force (EMF) parameter, Peclet and Prandtl numbers, and electrical conductivity ratio between metals 1 and 2 has been derived from a scale analysis for the first time. The predicted results agree well with experimental data obtained from the literature, this work, and three-dimensional theoretical prediction.     

Programmable polymer thin film and non-volatile memory device

Building on the success of organic electronic devices, such as light-emitting diodes and field-effect transistors, procedures for fabricating non-volatile organic memory devices are now being explored. Here, we demonstrate a novel organic memory device fabricated by solution processing. Programmable electrical bistability was observed in a device made from a polystyrene film containing gold nanoparticles and 8-hydroxyquinoline sandwiched between two metal electrodes. The as-prepared device, which is in a low-conductivity state, displays an abrupt transition to a high-conductivity state under an external bias of 2.8 V. These two states differ in conductivity by about four orders of magnitude. Applying a negative bias of 1.8 V causes the device to return to the low-conductivity state. The electronic transition is attributed to the electric-field-induced charge transfer between the gold nanoparticles and 8-hydroxyquinoline. The transition from the low- to the high-conductivity state takes place in nanoseconds, and is non-volatile, indicating that the device may be used for low-cost, high-density memory storage.     

Monitoring the software development process using a short-run control chart

Techniques for statistical process control (SPC), such as using a control chart, have recently garnered considerable attention in the software industry. These techniques are applied to manage a project quantitatively and meet established quality and process-performance objectives. Although many studies have demonstrated the benefits of using a control chart to monitor software development processes (SDPs), some controversy exists regarding the suitability of employing conventional control charts to monitor SDPs. One major problem is that conventional control charts require a large amount of data from a homogeneous source of variation when constructing valid control limits. However, a large dataset is typically unavailable for SDPs. Aggregating data from projects with similar attributes to acquire the required number of observations may lead to wide control limits due to mixed multiple common causes when applying a conventional control chart. To overcome these problems, this study utilizes a Q chart for short-run manufacturing processes as an alternative technique for monitoring SDPs. The Q chart, which has early detection capability, real-time charting, and fixed control limits, allows software practitioners to monitor process performance using a small amount of data in early SDP stages. To assess the performance of the Q chart for monitoring SDPs, three examples are utilized to demonstrate Q chart effectiveness. Some recommendations for practical use of Q charts for SDPs are provided.     

State detection from local measurements in network synchronisation processes

The problem of detecting the initial state of a network dynamics from noisy local observations is examined. Specifically, a linear synchronisation dynamics defined on a graph is modelled as being initiated by two possible initial conditions (or hypotheses) with certain a priori probabilities, to capture two possible evolutions of the network dynamics; an external agent is modelled as measuring the network dynamics at one network component, and is tasked with determining which hypothesis is more likely. We find that the external agent's detection performance (specifically, probability of error in MAP detection) can be classified into three cases, depending on the network's spectrum and graph topology, the hypotheses, and the observation location. Specifically, the detector performance can be dichotomised into: (1) a no-improvement case, in which the measured data does not permit improved detection compared to an a priori detection; (2) an asymptotically-perfect case in which the error probability approaches 0 exponentially with increasing measurement horizon; and (3) an improved-but-imperfect estimation case in which measurements reduce error but do not eliminate it. Beyond this dichotomy, we obtain spectral characterisations of detector performance in the imperfect-estimation case, which can be translated into graph-theoretic results.     

Characterization and Catalytic Oxidation of Carbon Monoxide Over Supported Cobalt Catalysts

Three types of supported cobalt catalysts (CoO_x/SiO₂, CoO_x/TiO₂ and CoO_x/Al₂O₃) were prepared by incipient wetness impregnation with aqueous Co(NO₃)₂·6H₂O solution. The phase composition and the interactions of cobalt with supports under different calcined temperatures were investigated using thermogravimetry (TG), N₂-adsorption at −196 °C, X-ray diffraction (XRD), temperature-programmed reduction (TPR) and diffuse reflectance spectroscopy (DRS). Their catalytic activities towards the CO oxidation were further studied in a continuous flow micro-reactor. The results showed that the interaction of cobalt oxide with supports was much stronger in the kinds of Al₂O₃ and TiO₂, while no conclusive evidence of any interaction was found for SiO₂. Besides the crystalline Co₃O₄ which was formed in three supported catalysts, both high-temperature phases CoAl₂O₄ and CoTiO₃ spinel were also detected under XRD, DRS and TPR analysis. The degree of interaction between cobalt oxide and the support not only affected the surface area and reduction behavior of the catalysts, the catalytic activity toward the CO oxidation also affected simultaneously. As the CoAl₂O₄ and CoTiO₃ spinel formed, both the surface area and catalytic activity decreased significantly.     

Interactive Content-aware Video Streaming System with Fine Granularity Scalability

Video streaming with varying transmission bandwidth is becoming increasingly important. In this paper, an interactive video streaming system is proposed. Fine Granularity Scalability (FGS) is applied to be the streaming video format. The computational complexity of FGS coding is analyzed to explore an efficient FGS implementation. A new transmission model is proposed for the realization of a content-aware video streaming. At encoder side, the current MPEG-4 FGS coding flow is reordered such that the picture-level maximum can be acquired in advance and bit-plane data can be dynamically adapted. With these proposed hardware-oriented optimization approaches, a hardwired FGS block-level processing core is proposed to achieve a cost-effective solution to FGS implementation. The streaming server can adaptively decide quality-enhanced region by selective enhancement according to both object information from encoding side and user-defined region from receiver side. From the simulation results, it’s demonstrated that the proposed approach can provide better quality in users’ interest regions with no bit-rate or complexity overhead. Yung-Chi Chang was born in Kaohsiung, Taiwan, R.O.C., in 1975. He received the B.S., M.S., and Ph.D. degrees from the Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, R.O.C., in 1998, 2000, and 2005, respectively. He serves as senior engineer in SoC Solutions Dept., Vivotek Inc. now. His research interests include video coding algorithms and VLSI architectures for image/video processing. Chih-Wei Hsu was born in Taipei, Taiwan, in 1979. He received the B.S.E.E and M.S.E.E degrees from National Taiwan University (NTU), Taipei, in 2001 and 2003, respectively. He joined MediaTek, Inc., Hsinchu, Taiwan, in 2003, where he develops integrated circuits related to multimedia coding standard and digital consumer devices. His research interests include video coding, video processing and VLSI design. Wei-Min Chao was born in Taoyuan, Taiwan, R.O.C., in 1977. He received the B.S. and M.S. degrees from the Department of Electronics Engineering, National Taiwan University in 2000 and 2002 separately. His research interests include video coding algorithms and VLSI architecture for image and video processing. Liang-Gee Chen was born in Yun-Lin, Taiwan, in 1956. He received the B.S., M.S., and Ph.D. degrees in electrical engineering from National Cheng Kung University, Tainan, Taiwan, in 1979, 1981, and 1986, respectively. He was an Instructor (1981–1986), and an Associate Professor (1986–1988) in the Department of Electrical Engineering, National Cheng Kung University. In the military service during 1987 to 1988, he was an Associate Professor in the Institute of Resource Management, Defense Management College. In 1988, he joined the Department of Electrical Engineering, National Taiwan University. During 1993 to 1994 he was a Visiting Consultant of DSP Research Department, AT&T Bell Lab, Murray Hill. In 1997, he was a visiting scholar of the Department of Electrical Engineering, University of Washington, Seattle. During 2001 to 2004, he was the first director of the Graduate Institute of Electronics Engineering (GIEE) in National Taiwan University (NTU). Currently, he is a Professor of the Department of Electrical Engineering and GIEE in NTU, Taipei, Taiwan. He is also the director of the Electronics and Optoelectronics Research Laboratories in Industrial Technology Research Institute, Hsinchu, Taiwan. His current research interests are DSP architecture design, video processor design, and video coding systems. Dr. Chen has served as an Associate Editor of IEEE Transactions on Circuits and Systems for Video Technology since 1996, as Associate Editor of IEEE Transactions on VLSI Systems since 1999, and as Associate Editor of IEEE Transactions on Circuits and Systems II since 2000. He has been the Associate Editor of the Journal of Circuits, Systems, and Signal Processing since 1999, and a Guest Editor for the Journal of Video Signal Processing Systems. He is also the Associate Editor of the Proceedings of the IEEE. He was the General Chairman of the 7th VLSI Design/CAD Symposium in 1995 and of the 1999 IEEE Workshop on Signal Processing Systems: Design and Implementation. He is the Past-Chair of Taipei Chapter of IEEE Circuits and Systems (CAS) Society, and is a member of the IEEE CAS Technical Committee of VLSI Systems and Applications, the Technical Committee of Visual Signal Processing and Communications, and the IEEE Signal Processing Technical Committee of Design and Implementation of SP Systems. He is the Chair-Elect of the IEEE CAS Technical Committee on Multimedia Systems and Applications. During 2001–2002, he served as a Distinguished Lecturer of the IEEE CAS Society. He received the Best Paper Award from the R.O.C. Computer Society in 1990 and 1994. Annually from 1991 to 1999, he received Long-Term (Acer) Paper Awards. In 1992, he received the Best Paper Award of the 1992 Asia-Pacific Conference on circuits and systems in the VLSI design track. In 1993, he received the Annual Paper Award of the Chinese Engineer Society. In 1996 and 2000, he received the Outstanding Research Award from the National Science Council, and in 2000, the Dragon Excellence Award from Acer. He is a member of Phi Tan Phi.     

Earthen construction: an increase of the mechanical strength by optimizing the dispersion of the binder phase

Although of interest for its low embodied energy content for construction, earth is usually not used for modern construction due to the expensive, artisanal and complicated process and the high variability of the raw material. The transfer of techniques dedicated to cement concrete could help the industrialization of this material. The use of dispersant for an improved dispersion of the earth powder has been investigated for both dispersion of earth fine fraction and water (here named the binding phase) and mortar made with calibrated sand. An improvement of the rheology is observed with lower viscosity and yield stress. This leads to a very small improvement of the density however concomitant with a marked increase of the mechanical properties, Young modulus and compressive strength. The analysis of the microstructure of the mortar shows an increase of the largest pores, and a decrease of the clay platelets flocs. The evolutions of these properties are analyzed in terms of the Rumpf model at two different scales. The dispersant mainly acts on the platelet arrangement that defines the forces between particles, but also simultaneously decreases the permeability of this binding phase, therefore entrapping more air during the mixing of the powder and water. Clearly the use of a dispersant may be of interest for the processing of earth material on liquid state, decreasing the viscosity and/or allowing the reduction of the water content, and finally improving strength.