Video-based measurement and data analysis of traffic flow on urban expressways

A new video-based measurement is proposed to collect and investigate traffic flow parameters. The output of the measurement is velocity-headway distance data pairs. Because density can be directly acquired by the reciprocal of headway distance, the data pairs have the advantage of better simultaneity than those from common detectors. By now, over 33 000 pairs of data have been collected from two road sections in the cities of Shanghai and Zhengzhou. Through analyzing the video files recording traffic movements on urban expressways, the following issues are studied：laws of vehicle velocity changing with headway distance, proportions of di0erent driving behaviors in the traffic system, and characteristics of traffic flow in snowy days. The results show that the real road traffic is very complex, and factors such as location and climate need to be taken into consideration in the formation of traffic flow models.

Activity Sequence Modes for Web Services and Verifications

Behavior requirement expression and its satisfiability verification for composite Web services is one of the ongoing issues in service computing. In this paper, the concept of behavior specifications based on activity sequence is proposed to express one kind of behavioral requirements for composite Web services. Its basic element is activity sequence. The method to express such behavioral requirements by behavioral modes is presented. Five behavioral modes used in this method are adopted. Through map- ping modes to Labeled Transition Systems （LTSs）, these modes are encoded with exact operation semantics. Then, the sufficient and necessary conditions as well as the checking algorithm for satisfiability of behavioral modes are given. Finally, an example analysis is presented. The result indicates that the behavioral requirements based on activity sequence are more suitable for the case of composite Web service than those based on activity or scenario. The behavioral modes expressions are concise and the satisfiability checking is effective by the given algorithm.

Behavior of single mode optic-fiber ring resonant hydrophone

The behavior of a single mode optic-fiber interferometric hydrophone with ring resonator is discribed in this paper. The optic-fiber ring resonant hydrophone has rery high optical finesse, and receiving sensitivity level about -130 dB (re 1 V/μPa).

Incorporating within- and between-patch resource selection in identification of critical habitat for brood-rearing greater sage-grouse

Introduction:Incorporating information on animal behavior in resource-based predictive modeling(e.g.,occurrence mapping)can elucidate the relationship between process and spatial pattern and depict habitat in terms of its structure as well as its function.In this paper,we assigned location data on brood-rearing greater sage-grouse(Centrocercus urophasianus)to either within-patch(encamped)or between-patch(traveling)behavioral modes by estimating a movement-based relative displacement index.Objectives were to estimate and validate spatially explicit models of within-versus between-patch resource selection for application in habitat management and compare these models to a non-behaviorally adjusted model.Results:A single model,the vegetation and water resources model,was most plausible for both the encamped and traveling modes,including the non-behaviorally adjusted model.When encamped,sage-grouse selected for taller shrubs,avoided bare ground,and were closer to mesic areas.Traveling sage-grouse selected for greater litter cover and herbaceous vegetation.Preference for proximity to mesic areas was common to both encamped and traveling modes and to the non-behaviorally adjusted model.The non-behaviorally adjusted map was similar to the encamped model and validated well.However,we observed different selection patterns during traveling that could have been masked had behavioral state not been accounted for.Conclusions:Characterizing habitat that structured between-patch movement broadens our understanding of the habitat needs of brood-rearing sage-grouse,and the combined raster surface offers a reliable habitat management tool that is readily amenable to application by GIS users in efforts to focus sustainable landscape management.