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1.
鉴于高速铁路(HSRs)通信业务的多样性,侧重于单一类型业务的传输优化方案,已无法满足用户业务服务质量(QoS)差异性显著提升的需求。针对HSRs通信环境,将用户业务分为时延敏感业务和时延非敏感业务,以满足用户QoS需求且同时兼顾占用无线信道的公平性为优化目标,研究了基站(eNB)平均发射功率约束条件下的功率分配问题。根据eNB能否预先获知用户的期望速率,分别采用了基于用户期望和基于预分配的功率分配策略。仿真结果表明,ε-Optimal比例公平算法的eNB发射功率较高且用户满意度较低;信道反演算法只针对时延敏感用户能较好地满足其QoS(最大耐受时延映射的期望速率),并且固定功率分配算法仅能够满足时延非敏感用户的QoS,两种算法均无法保证用户间的公平性;所提算法既具有较高的用户满足度,又较好地保证了用户间的公平性。  相似文献   
2.
In China, many rural migrant workers experience residential segregation and live in urbanizing villages, due to China’s unique institutional context (e.g. land tenure system, hukou system) as well as exclusionary housing regulations. The purpose of this paper is to investigate whether these urbanizing villages provide good job accessibility for rural migrant workers. We explore this problem by investigating the commuting patterns of migrant workers. Through a survey conducted in 2009 across four mega-regions in China that are currently experiencing rapid urbanization, we collected individual level information on rural migrant workers’ commute distances and durations, demographics, household socioeconomic status, and whether the migrant worker is living in an urbanizing village or not. From residential address information collected in the survey, we constructed a group of built environment variables. Using IV Tobit models to address the endogeneity issues associated with residential location choice, our analyses show that these urbanizing villages actually provide relatively good accessibility to job opportunities. This result is different from what is suggested by the spatial mismatch literature based on U.S. data. This research helps to fill the gap in the literature on the relationship between residential segregation, built environment and travel behavior in the Chinese context. The findings have implications for policymaking, especially when many government officials are proposing to demolish urbanizing villages without fully realizing the benefits of these villages. This research could also provide useful information for other developing countries facing residential segregation of migrants or immigrants.  相似文献   
3.
文章基于汽车保险行业岗位要求,根据《汽车保险与理赔》课程特点和教学中存在的问题进行信息化教学改革,培养学生保险销售能力、承保核保能力以及查勘定损实际处理能力。此次改革增强了学生自主学习意识,提高了学习兴趣,实现以“学生为主,教师为辅”的教学模式,提升教学效果。  相似文献   
4.
王旭 《西部交通科技》2009,(11):135-138
市场经济所带来的多元化择业观念,使毕业生集体主义观念和社会责任感观念淡化,从而在就业选择上趋向于功利化、自我化。文章针对当前交通职业技术学院学生职业价值观的这一变化,分析学生现实型职业价值观与传统型职业价值观之旬的冲突,提出了交通职业技术学校在职业价值观教育方面应采取的措施。  相似文献   
5.
Attitudes play an important role in determining individual transit behaviour and the measurement of attitudes is relied on by public transit authorities’ world over. Given their role in behaviour and policy making, the accurate measurement of attitudes is of critical importance. Traditional satisfaction scales are prone to bias and on their own they are only a partial measure of attitudes. Given that satisfaction scales have been used to assist with large scale transport infrastructure investment decisions, to aid policy makers examining reactions to alternative policy changes and reform, and to measure the success of new initiatives, deriving robust satisfaction scales should be of critical importance. This paper introduces a dual version of best–worst scaling as an alternative measure of satisfaction. Best–worst scaling is free of the biases inherent in traditional response scales and is ideal for handling the comparative evaluation of large amount of attributes, particularly those which are inherently qualitative. The paper makes a further innovative contribution by proposing a model structure for the joint estimation of satisfaction and importance. Our model shows a better delineation between the attributes used to measure attitudes towards bus use and a more detailed understanding of the relationship between importance and satisfaction; enabling transport operators to better understand what counts most and assess their performance.  相似文献   
6.
Social equity is increasingly incorporated as a long-term objective into urban transportation plans. Researchers use accessibility measures to assess equity issues, such as determining the amount of jobs reachable by marginalized groups within a defined travel time threshold and compare these measures across socioeconomic categories. However, allocating public transit resources in an equitable manner is not only related to travel time, but also related to the out-of-pocket cost of transit, which can represent a major barrier to accessibility for many disadvantaged groups. Therefore, this research proposes a set of new accessibility measures that incorporates both travel time and transit fares. It then applies those measures to determine whether people residing in socially disadvantaged neighborhoods in Montreal, Canada experience the same levels of transit accessibility as those living in other neighborhoods. Results are presented in terms of regional accessibility and trends by social indicator decile. Travel time accessibility measures estimate a higher number of jobs that can be reached compared to combined travel time and cost measures. However, the degree and impact of these measures varies across the social deciles. Compared to other groups in the region, residents of socially disadvantaged areas have more equitable accessibility to jobs using transit; this is reflected in smaller decreases in accessibility when fare costs are included. Generating new measures of accessibility combining travel time and transit fares provides more accurate measures that can be easily communicated by transportation planners and engineers to policy makers and the public since it translates accessibility measures to a dollar value.  相似文献   
7.
高职市场营销专业的教育目标是培养社会适用的高技能营销人才,而社会上成功的营销人才应该具备哪些素质,则是高职院校人才培养过程中必须了解的问题。参照营销岗位能力素质模型,本文有针对性地提出了重构高职营销课程体系的思路与方法。  相似文献   
8.
A new local search method with hybrid neighborhood for Job shop scheduling problem is developed. The proposed hybrid neighborhood is not only efficient in local search, but also can help overcome entrapments while search procedure get trapped at local optima and carry the search to areas of the feasible set with better prospect. New strategies used for breaking out of entrapments are presented and they are helpful for the procedure to improve local optima. A performance comparison of the proposed method with some best-performing algorithms on all 10-job, 10-machine benchmark problems and the other two problems generated by Fisher and Thompson ( ie. , FT6 and FT20) is made. The experiment results show the better optimal performance of the proposed algorithm.  相似文献   
9.
This paper investigates the links between public transport and labor market outcomes in the French agglomeration of Bordeaux. Our objective is to analyze the effects and consequences of the construction of a tramway line in some neighborhoods and municipalities of the agglomeration. These localizations are confronted to isolation and concentration of unfavorable socio-economic characteristics. Among other things, this line has permitted to facilitate the access to the historical job center of Bordeaux for inhabitants concerned. We use difference-in-differences methods to compare labor market outcomes of inhabitants who benefit from this better access with others who do not, before and after the construction. Results show that if unemployment rate has globally decreased on the period observed, the decrease is more important for neighborhoods located close to tramway stations. More generally, it seems that the tramway project helped to reduce some socio-economic inequalities in the agglomeration of Bordeaux.  相似文献   
10.
During 10 years experience with competitive tendering of regional and local public transport in the Netherlands, national average trip satisfaction of passengers increased from 6.84 to 7.25 (+0.41). This is a remarkable improvement, but a closer look at the data reveals that also in regions without competitive tendering the improvement in satisfaction was substantial. The difference in the improvement for regions with and without tendering is only +0.06. Tendering led in the majority of concession areas to an improvement of average trip satisfaction, but in some 40% of the cases a deterioration was observed. A change of operator in general has a negative impact on satisfaction. We also find that the effect on satisfaction of early tendering is larger than of later tendering. This may well be the consequence of a shift in emphasis of authorities and operators from quality improvement to efficiency improvements. The model building and analysis is based on the comparison per year-pair of regions tendered versus regions non-tendered (in that specific year-pair). So we compare the effects on satisfaction of tendered regions relative to non-tendered regions.An analysis concerning the weighted satisfaction judgments of 15 underlying service attributes revealed that ‘service frequency, on-time performance, travel speed, and vehicle tidiness’ contribute the most to the effect on satisfaction in the tendered regions. We found that new vehicles impact highly on satisfaction with travel speed and vehicle tidiness. The emphasis in the tenders with increasing service frequency, led to an increase in satisfaction but, may have a deteriorating effect on (the satisfaction with) on-time performance.  相似文献   
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