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排序方式: 共有331条查询结果,搜索用时 31 毫秒
321.
COMPUTATIONAL PROCESS MODELING OF HOUSEHOLD TRAVEL DECISIONS USING A GEOGRAPHICAL INFORMATION SYSTEM
ABSTRACT Household travel behaviour entails interdependent deliberate decisions, as well as the execution of routines not preceded by deliberate decisions. Furthermore, travel decisions are dependent on choices to participate in activities. Because of the complexity of the decision making process in which individuals are engaged, computational process models (CPMs) are promising means of implementing behavioral principles, which, unlike other disaggregate modeling approaches do not rely on a utility maximizing framework. A conceptual framework is proposed as the basis of a CPM interfaced with the geographical information system Arc/Info . How to model household' travel behaviour is illustrated in a case study of a single household in which one member started telecommuting. 相似文献
322.
A novel self-organizing map (SOM) based retrieval system is proposed for performing face matching in large database. The proposed system provides a small subset of faces that are most similar to a given query face, from which user can easily verify the matched images. The architecture of the proposed system consists of two major parts. First, the system provides a generalized integration of multiple feature-sets using multiple self-organizing maps. Multiple feature-sets are obtained from different feature extraction methods like Gabor filter, Local Autocorrelation Coefficients, etc. In this platform, multiple facial features are integrated to form a compressed feature vector without concerning scaling and length of individual feature set. Second, an SOM is trained to organize all the face images in a database through using the compressed feature vector. Using the organized map, similar faces to a query can be efficiently identified. Furthermore, the system includes a relevance feedback to enhance the face retrieval performance. The proposed method is computationally efficient. Comparative results show that the proposed approach is promising for identifying face in a given large image database. 相似文献
323.
The fast growing cellular mobile systems demand more efficient and faster channel allocation techniques. Borrowing channel
assignment (BCA) is a compromising technique between fixed channel allocation (FCA) and dynamic channel allocation (DCA).
However, in the case of patterned traffic load, BCA is not efficient to further enhance the performance because some heavy-traffic
cells are unable to borrow channels from neighboring cells that do not have unused nominal channels. The performance of the
whole system can be raised if the short-term traffic load can be predicted and the nominal channels can be re-assigned for
all cells. This paper describes an improved BCA scheme using traffic load prediction. The prediction is obtained by using
the short-term forecasting ability of cellular probabilistic self-organizing map (CPSOM). This paper shows that the proposed
CPSOM-based BCA method is able to enhance the performance of patterned traffic load compared with the traditional BCA methods.
Simulation results corroborate that the proposed method delivers significantly better performance than BCA for patterned traffic
load situations, and is virtually as good as BCA in the other situations analyzed. 相似文献
324.
Alexander Hammerschmidt Nikolaos Boukis Elena Hauer Eckhard Dinjus Tommy Larsen 《Fuel》2011,90(2):555-562
The purpose of the work presented here is the production of liquid biofuels from wet organic waste matter in a continuous one-step catalytic process under hydrothermal conditions. The catalytic reaction of wet organic matter at near-critical water conditions (T > 300 °C, p > 22.1 MPa) is used to produce a mixture of combustible organics which can be used as liquid biofuel. In order to achieve a good product quality in a continuous one-step process, two catalysts were applied, a homogeneous potassium carbonate catalyst and a heterogeneous ZrO2 catalyst. In addition, the reaction mixture was recirculated. The continuous flow of concentrated waste biomass feed at low flow rates and recirculation of the hot reaction mixture were the most challenging obstacles to overcome. The scale of the plant (0.1 l reactor volume) allowed for a variation of the feed, reaction temperature, and recirculation rate in order to optimise the process conditions. Still, the product quantity obtained was sufficient to perform a analytical characterisation. The experimental results confirmed the feasibility of the process. Hydrothermal treatment of waste biomass, after dewatering, resulted in a biocrude oil of high calorific value. 相似文献
325.
Judson RS Martin MT Egeghy P Gangwal S Reif DM Kothiya P Wolf M Cathey T Transue T Smith D Vail J Frame A Mosher S Cohen Hubal EA Richard AM 《International journal of molecular sciences》2012,13(2):1805-1831
Computational toxicology combines data from high-throughput test methods, chemical structure analyses and other biological domains (e.g., genes, proteins, cells, tissues) with the goals of predicting and understanding the underlying mechanistic causes of chemical toxicity and for predicting toxicity of new chemicals and products. A key feature of such approaches is their reliance on knowledge extracted from large collections of data and data sets in computable formats. The U.S. Environmental Protection Agency (EPA) has developed a large data resource called ACToR (Aggregated Computational Toxicology Resource) to support these data-intensive efforts. ACToR comprises four main repositories: core ACToR (chemical identifiers and structures, and summary data on hazard, exposure, use, and other domains), ToxRefDB (Toxicity Reference Database, a compilation of detailed in vivo toxicity data from guideline studies), ExpoCastDB (detailed human exposure data from observational studies of selected chemicals), and ToxCastDB (data from high-throughput screening programs, including links to underlying biological information related to genes and pathways). The EPA DSSTox (Distributed Structure-Searchable Toxicity) program provides expert-reviewed chemical structures and associated information for these and other high-interest public inventories. Overall, the ACToR system contains information on about 400,000 chemicals from 1100 different sources. The entire system is built using open source tools and is freely available to download. This review describes the organization of the data repository and provides selected examples of use cases. 相似文献
326.
Venskutonytė R Frydenvang K Valadés EA Szymańska E Johansen TN Kastrup JS Pickering DS 《ChemMedChem》2012,7(10):1793-1798
Continued efforts into the discovery of ligands that target ionotropic glutamate receptors (iGluRs) are important for studies of the physiological roles of the various iGluR subtypes as well as for the search for drugs that can be used in the treatment of diseases of the central nervous system. A new series of phenylalanine derivatives that target iGluRs was reported to bind AMPA receptors. Herein we report our studies of these compounds at the kainate receptors GluK1-3. Several compounds bind with micromolar affinity at GluK1 and GluK3, but do not bind GluK2. The crystal structure of the most potent compound in the ligand binding domain of GluK1 revealed different modes of binding to GluK1 and GluA2, due primarily to residues Ser741 (GluK1) and Met729 (GluA2). The compound was shown to be slightly more potent at GluK1 than at AMPA receptors and to induce a domain closure similar to that observed in GluK1 structures with partial agonists. 相似文献
327.
Devin K. Harris Tommy Cousins Thomas M. Murray Elisa D. Sotelino 《Canadian Metallurgical Quarterly》2008,22(5):305-315
This paper presents the results of a live-load test of the Shenley Bridge, the first bridge application of the sandwich plate system technology in North America. The investigation focused on the evaluation of in-service performance including lateral load distribution behavior and dynamic load allowance. Real-time midspan deflections and strain values were measured under both static and dynamic conditions and under various loading configurations to assess the in-service performance. Distribution factors were determined for interior and exterior girders subjected to single and paired truck loadings. In addition, dynamic load allowance was determined from a comparison of the bridge’s response under static conditions to the response under dynamic conditions. From a comparison of measured results to AASHTO LRFD, AASHTO standard, and CHBDC provisions, it was determined that the current provisions tend to produce conservative predictions for lateral load distribution, but can be unconservative for dynamic load allowance. As a result of the testing program containing a single field test, a finite-element model was also used for determination of lateral load distribution and yielded predictions similar to measured results. The results from the finite-element models were often less conservative than the code provisions. 相似文献
328.
肖赛君 ;Tommy MOKKELBOST ;Ove PAULSEN ;Arne P. RATVIK ;Geir M. HAARBERG 《中国有色金属学会会刊》2014,24(12):3917-3921
开发一种在低温电解质(850℃)铝电解中应用的新型二氧化锡基气体阳极以降低铝电解能耗和二氧化碳排放。在此种气体阳极中,氢气通入阳极后参与阳极反应,分别用石墨和铝作阴极和参比电极。采用循环伏安法研究此体系中铂和二氧化锡基电极上氧离子的电化学行为,并确定氧气的析出电势。然后,采用气体电极进行恒电流电解实验,相对于未通入气体和通入氩气,通入氢气后阳极出现明显的去极化现象(阳极电势约下降0.8 V)。实验结果表明,氢气已参与阳极三相界面(气体-电解质-电极)反应,为还原性气体阳极在铝电解上的应用提供了可行性。 相似文献
329.
Bosilevac JM Wheeler TL Rivera-Betancourt M Nou X Arthur TM Shackelford SD Kent MP Jaroni D Osborn MS Rossman M Reagan JO Koohmaraie M 《Journal of food protection》2004,67(2):303-309
The objective of this study was to establish the necessary protocols and assess the efficacy of cetylpyridinium chloride (CPC) as an antimicrobial intervention on beef cattle hides. Experiments using CPC were conducted to determine (i) the methods of neutralization needed to obtain valid efficacy measurements, (ii) the effect of concentration and dwell time after treatment, (iii) the effect of CPC on hide and carcass microbial populations when cattle were treated at a feedlot and then transported to a processing facility for harvest, and (iv) the effectiveness of spray pressure and two-spray combinations of CPC and water to reduce hide microbial populations. Residual CPC in hide sponge samples prevented bacterial growth. Dey-Engley neutralization media at 7.8% and a centrifugation step were necessary to overcome this problem. All dwell times, ranging from 30 s to 4 h, after 1% CPC application to cattle hides resulted in aerobic plate counts and Enterobacteriaceae counts 1.5 log CFU/100 cm2 lower than controls. The most effective dose of CPC was 1%, which reduced aerobic plate counts and Enterobacteriaceae counts 2 and 1 log CFU/100 cm2, respectively. Low-pressure application of 1% CPC at the feedlot, transport to the processing facility, and harvest within 5 h of application resulted in no effect on Escherichia coli O157 prevalence on hides or preevisceration carcasses. Two high-pressure CPC washes lowered aerobic plate counts and Enterobacteriaceae counts by 4 log CFU/100 cm2, and two medium-pressure CPC washes were only slightly less effective. These results indicate that under the proper conditions, CPC may still be effective for reducing microbial populations on cattle hides. Further study is warranted to determine if this effect will result in reduction of hide-to-carcass contamination during processing. 相似文献
330.
Ivan W.H. Fung Vivian W.Y. Tam Tommy Y. Lo Lori L.H. Lu 《International Journal of Project Management》2010
Problems on occupational health and safety are commonly occurred in the construction industry, including falling of materials or person from height, stepping on objects and injured by hand tools. Key of dealing with project safety and risk assessment in construction industry is important, thus, way on doing assessment and liability of assessment are necessary for all professionals. However, it is found that those professionals prone to heavily rely on their own experiences and knowledge on decision making on risk assessment, which lack of a systematic approach and lack of ways to check the reliability of the decisions. This paper investigates the need for people involved in construction to take systematic and effective risk assessments for different trades. 14 common types of trades, accidents, and accident causes are explored, in addition to suitable risk assessment methods and criteria. A Risk Assessment Model (RAM) is then developed for assessing risk levels as various project stages with various work trades. A case study is used to prove the workability and reliability of the developed RAM in the practical industry. The developed RAM is found to be benefit for predicting high-risk construction activities and thus preventing accidents occurred based on a set of historical accident data. 相似文献