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11.
针对公路应急救援进行了较为全面而深入的研究,分析系统中的各个组成环节,提出依据救援呼叫(CFS)的概率建立ESSR应急救援单元的新思路,建立救援单元模型,进行仿真分析,得出救援设施数量安排策略。制定了ESSR系统整体最优化模型,并利用matlab软件进行仿真分析,获得紧急救援最佳方案。为公路和市政道路管理者全面收集和分析信息资料,管理应急救援系统提供依据。通过模型仿真可评估和优化管理设施,实现信息和决策支持,提高了配备资源,快速高效处理交通突发事件能力。  相似文献   
12.
Males of the parapatically distributed myobatrachid frogs Geocrinia laevis and G. victoriana have highly divergent advertisement calls. Furthermore, the two species differ strongly in the complexity of their vocal repertoires, with males of G. victoriana possessing, and those of G. laevis lacking, a distinct territorial vocalization (encounter call). We investigated the territorial vocal behavior of males in a persistent natural hybrid population. Most hybrid males possessed encounter calls functionally equivalent to those of G. victoriana, that were produced following exposure to playback of recorded advertisement calls presented at >110 dB peak sound pressure level. The territorial acoustic responses were not associated with an index of hybridity derived from the structure of the advertisement call, suggesting genetic and functional decoupling of the two components of the vocal repertoire; i.e., advertisement calls and encounter calls. This decoupling may be the result of sexual selection favouring those hybrids with pronounced territorial behavior and the associated vocalization, regardless of the structure of their advertisement calls.Communicated by A. Mathis  相似文献   
13.
Sequences of the advertisement calls produced by male Nathusius’ pipistrelles (Pipistrellus nathusii) during the autumn mating period were recorded from individuals at two separate sites in Antrim, Northern Ireland, in August 2004. Several male roosts were found at these sites in close proximity to a single maternity roost, each containing approximately 200 adult females and their young. Analysis of measured parameters of four identified call types revealed that there were significant differences in call structure between sites and between individuals. Playback experiments, performed outside the adult female and juvenile roost sites, comprised of experimental advertisement call sequences of P. nathusii, Pipistrellus pygmaeus and Pipistrellus pipistrellus and control sound recorded without bats present (silence). Response was measured by simultaneously recording ultrasound during playbacks and counting the number of echolocation pulses identified as those of P. nathusii above a predetermined amplitude threshold. Significantly greater numbers of P. nathusii echolocation pulses were recorded during playback of male P. nathusii advertisement calls than during playback of congeners’ advertisement calls and control sound. The number of echolocation pulses recorded was similar during playback of P. pipistrellus and P. pygmaeus advertisement calls and silence. We suggest that, due to call complexity, male P. nathusii advertisement calls should be classified as ‘song’. Species-specificity and individual variation suggests that the songs of male P. nathusii have the potential to play a role in mate attraction and mate assessment.  相似文献   
14.
Kleptoparasitism is a tactic used to acquire food opportunistically and has been shown to provide several benefits, including greater food intake rate and the acquisition of items not normally available during self-foraging. Host individuals may differ in their ability to defend themselves against kleptoparasitic attacks and therefore identifying those host individuals that are particularly vulnerable to attack could both provide energetic benefits and increase the efficiency of kleptoparasitism as a foraging strategy. Here, we show that the kleptoparasitic fork-tailed drongo (Dicrurus adsimilis) specifically targets juveniles when following groups of cooperatively breeding pied babblers (Turdoides bicolor). Drongos give alarm calls upon sighting a predator, thus providing extra predator vigilance to foraging pied babblers. However, drongos also use alarm calls to steal food items. During kleptoparasitic attacks, drongos give false alarm calls and then swoop down to steal food items dropped by alarmed babblers. Juvenile pied babblers are particularly vulnerable to attack because they (a) spend a longer period handling prey items prior to consumption and (b) respond to alarm calls primarily by immediately moving to cover, in contrast to adults who respond by looking up and visually scanning the surrounding area. Drongos attack juvenile babblers significantly more often than adults, with attacks on juveniles more likely to result in the successful procurement of a food item. This patterns of attack suggests that drongos are able to differentiate between individuals of different age when targeting pied babblers, thus increasing the efficiency of kleptoparasitism as a foraging strategy.  相似文献   
15.
Intensive study of arboreal forest-dwelling primates and their predators in Africa is increasingly revealing that crowned eagles (Stephanoaetus coronatus) are major predators of primates. Gray-cheeked mangabeys (Lophocebus albigena) are overrepresented in the diets of crowned eagles in Kibale National Park, Uganda, and adult male mangabeys are represented more than females. We focused on the behavior of adult male gray-cheeked mangabeys living in social groups in Kibale National Park (1) to clarify the interactions between mangabeys and eagles that might put adult males at greater risk and (2) to better understand individual variation in behavioral responses to predators. Adult male mangabeys in five groups responded to observer-confirmed presence of crowned eagles 88 times over a 13-month period. While all males gave alarm calls, only the highest-ranking male in each of four groups chased eagles. These males had elevated levels of fecal cortisol metabolites in the days immediately after they engaged in active defense, suggesting that they perceived such behavior as risky. In the one group where male ranks were unstable and there were no infants, no male was observed to chase eagles. We suggest that males pursue the dangerous tactic of chasing eagles only when they are likely to have offspring in the group. Males in larger groups also spent less time alarm calling to crowned eagles (from first to last call in a group), and our observations confirmed that the duration of their alarm calls was related to eagle presence. Thus, eagles spent less time around larger mangabey groups. Alarm calling by adult male mangabeys may signal to this ambush predator that it has been detected and should move on.  相似文献   
16.
基于交通事故紧急救援的现状,阐述建立车辆事故紧急呼救系统的新需求,提出了开发基于车辆事故严重等级分类的紧急呼救系统需要实现的功能;应用车辆碰撞安全性理论和研究成果、导航定位技术及通信技术,设计了基于事故严重等级分类的车辆事故紧急呼救决策流程;探讨车辆事故自动检测和等级分类及紧急救援的实施方案,以实现车辆事故紧急自动呼救,使车辆和伤员得到及时高效的紧急救助。  相似文献   
17.
20世纪90年代以来,班轮公司渐成影响港口体系演变的主导因素,班轮网络形成的内在机理成为学者们关注的热点领域。以长江三角洲为案例区,从基础设施、箱量规模、港口效率、港口费用、配套产业、扶持政策6个方面构建班轮公司挂靠港选择评价指标体系,利用多元线性回归模型,定量测度长江三角洲班轮公司挂靠港选择的影响因素。在此基础上,选取港口、班轮公司、货主和货代等港口物流节点进行访谈验证,结果显示定性分析与模型计算的结果基本吻合。箱量规模和港口费用是当前影响长江三角洲班轮公司挂靠港选择的主要因素,其次是港口基础设施与港口效率,最后是政策环境与航运配套产业,其中政策的影响越来越显著。  相似文献   
18.
为了合理区分和有效识别不同航班号,首先提出基于多标准的判断准则,使用主成分分析法量化得到统一的相似度;其次建立改进的Siamese网络模型,获得文本的语义信息;最后采用文本之间的Jaro-Winkler距离客观修正网络对比损失函数,综合网络输出判定2个航班号的相似情况。研究结果表明:多标准准则判定方法速度快且通用性强,改进后的Siamese网络虽受到训练样本的直接影响,但收敛速度明显提高,识别率比原网络平均提高约2.7%,比多标准判断准则提高约3%。研究结果可为相似航班号识别与预警提供理论依据。  相似文献   
19.
Background. The purpose was to study the test-retest reliability and internal consistency of questions in aquestionnaire concerning working conditions and health and the inter-rater reliability of observations andmeasurements according to an ergonomic checklist. Method. Fifty-seven operators participated in a retestquestionnaire and 58 operators participated in an inter-observer test. Results. The questions had fair to good or higher reliability in 142 of the total of 312. Twenty-seven of the total of 44 variables in the ergonomicchecklist were classified as having fair to good or higher reliability. Conclusions. About half of the questionshad fair to good or higher reliability and can be recommended for further analyses. The majority of variablesin the ergonomic checklist were classified as having fair to good or higher reliability. Low reliability does notnecessarily indicate that the reliability of the test, per se, is low but may signify that the conditions measuredvary over time or that the answers are aggregated in one part of the scale.  相似文献   
20.
Abstract

The discussion developed in this paper is based on the results of an ergonomic work analysis carried out with attendants at call centers. Some critical issues and difficulties, like working pace, inadequate tools and workstations, and software inadequacies were detected in working situations. Operator-customer interactions are presented, attempting to put in evidence working constraints, working conditions, and their connection with health problems.

The main conclusion is that serving clients, especially when the job is to provide information, is not a simple task, as information is not always available in the computerized system and is completely fragmented. The scope of workers’ actions is very restricted and complicated and recurrent requests are redirected to others. Workers (individually or as groups) have limited possibilities to make adjustments to be able to give more adequate and personalized treatment to clients and, at the same time, to work in a less stressful environment. In periods of increased workload and work intensification, the situation is very much favorable to the incidence of health disorders, such as work related musculoskeletal disorders (WMSD) and others. Some suggestions to improve the work situation are discussed.  相似文献   
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