超大规模基坑群开发模式选型

地上多单体独立开发、地下空间分区块联合开发的超大规模基坑群,面临总体工期及各地块的单体工期控制要求较严格的问题。结合工程实际情况,着重解决了基坑群开发模式选型问题,最大限度契合了技术、经济、工期以及环境保护的目标。总结的经验可供类似工程参考。

面向中小企业的云制造服务模式研究

云制造是近年来提出的一种面向服务、高效低耗和基于知识的网络化智能制造新模式。它融合了现有的信息化制造、云计算、物联网、语义Web、高性能计算等技术,我国中小企业普遍存在资金少、规模小、企业信息化程度低等问题,云制造服务平台能有效加以解决。通过对系统集成企业传统的新产品开发设计方法等进行研究,构建了面向云制造的零部件设计选型模式,提出了相应的零部件交易模式,设计了基于云制造的零部件设计选型与交易服务平台的运营主体、服务内容、盈利机制以及平台运行机制,为云制造服务平台实施和推广应用奠定了基础。

福建林区运材汽车评价模式的探讨

根据福建林区道路状况,结合农用货车性能特点,建立运材汽车评价模式,对福建林区四种有代表性的运材汽车进行了评价、并按综合性能优劣进行排序。研究结果发现:HFC1060为最优车型,NJ1060为次优型。

Combined model of trip mode and destination

This paper analyzes the characteristics of the destination distribution of trips and proposes a stratified sampling strategy for travel mode choice.The stratified sampling strategy can reduce the size of the alternative set;thus,the computation burden of simulation is decreased.Using the stratified sampling strategy,a combined choice model of the trip mode and destination is developed based on the Bayesian theory.Simulations are carried out to verify the proposed model.The results show that the combined choice model of the trip mode and destination can efficiently simulate travelers＇ choice behaviors.Furthermore,the forecasting accuracy of the combined choice model is higher than the one of the gravity model.Therefore,the proposed model is a powerful tool with which to analyze travelers＇ behaviors in selecting the trip mode.

Influence of land use characteristics and trip attributes on commuting mode choice: a case of Nanjing

The effects of socio-demographics, land use characteristics and trip attributes on the commute mode choice are studied with a nested logit （NL） model. Based on the random utility maximum theory, the NL model is formulated. The analysis is carried out in the main area of Nanjing. Direct and cross elasticities are calculated to analyze the effects of travel time and travel cost on the selection of travel mode choice. The results reveal that the non-motorized travel modes are more attractive in the areas with higher housing and employment accessibility and car owners are found to be more likely to commute to work by car. The bus and subway choice probabilities are more sensitive to changes in travel times than to changes in travel costs. In conclusion, a comprehensive public transit system and effective integration of land use and transportation policies help to relieve the traffic congestion levels caused by the increasing urban sprawl.

Investigation on transformation process of trip mode choice for planned special events

This paper aims to provide a decision-making method for the transportation management strategies in guiding the transformation of trip mode choice during planned special events. The Expo 2010 Shanghai is taken as an example, and a structural equation model is employed to analyze the dynamic mechanism of trip mode choice behavior and the effectiveness of the transportation management measures at different stages. Based on the difference between the objective-oriented stated preference （SP） survey results and the objectives, together with the feedback from the previous stage survey, some adjustments on the transportation management measures are made in the next stage of the planning process until the objectives are eventually achieved. The results indicate that the adjustments on transportation management measures at different stages can effectively raise the transit share to 88.6%. Nonlocal visitors are inclined to choose nonstop modes of transportation and the companion attributes have the most significant effects on the trip mode choices of visitors. The research method is proved to be an effective way to support the decision making process of transportation management measures during planned special events in the future.

Steam turbine rotor crack detection using sifting process of EMD and B-spline wavelet on the interval element model

A high-precision identification method for steam turbine rotor crack is presented. By providing me nrst three measured natural frequencies, contours for the specified natural frequency are plotted in the same coordi- nate, and the intersection of the three curves predicts the crack location and size. The cracked rotor system is mod- eled using B-spline wavelet on the interval （BSWI） finite element method, and a method based on empirical mode decomposition （EMD） and Laplace wavelet is implemented to improve the identification precision of the first three measured natural frequencies. Compared with the classical nondestructive testing, the presented method shows its effectiveness and reliability. It is feasible to apply this method to the online health monitoring for rotor structure.

The “Valley Economy” Model of Regional Development: A Case Study of Mountain Areas in Beijing, Northern China

A case study is presented of a regional development model for valley economies in the mountain areas of Beijing, China. The nature and framework of the valley economy model are described and the development of the model, which is specific to the mountain areas of Beijing, is analyzed. Five different valley economy models applied in the Beijing mountain areas are compared. The major purpose of the valley economy model is to develop the regional economy, including the selection of appropriate industries, the allocation of industrial space, the establishment of supply chains and the integration of various industries. Pilot experiments using the valley economy model have been conducted in seven counties(districts) in Beijing: Pinggu, Huairou, Changping, Mentougou, and Fangshan districts, and Yanqing and Miyun counties. Five models for developing the Beijing mountain areas have been explored, including: creative cultural industries, characteristic industry clusters, the promotion of large tourist areas, natural scenic tourism and folk cultural tourism. Each model has its own unique features and potential to help in the regional development of mountain areas.

Estimating walking access area for rail transit station based on discrete choice model

The discrete choice model is used to estimate the walking access area of rail transit stations while considering the influence of existing competition from other traffic modes. The acceptable walking access area is determined according to the willingness of passengers to walk who prefer rail transit compared with bus and automobile. Empirical studies were conducted using the survey data of six stations from the rail transit in Nanjing, China. The results indicate that the rail transit is more preferable compared with bus and private automobile in this case when excluding the influence of individual and environmental factors. It is found that passengers tend to underestimate their willingness to walk. The acceptable walking access area of every rail transit station is different from each other. Suburban stations generally have a larger walking access area than downtown stations. In addition, a better walking environment and a scarcer surrounding traffic environment can also lead to a larger walking area. The model was confirmed to be effective and reasonable according to the model validation. This study can be of benefit to the passenger transportation demand estimation in the location planning and evaluation of rail transit stations.

Dynamic Portfolio Choice under Uncertainty about Asset Return Model

The effect of uncertainty about stochastic diffusion model on dynamic portfolio choice of an investor who maximizes utility of terminal portfolio wealth was studied.It applied stochastic control method to obtain the closed-form solution of optimal dynamic portfolio,and used the Bayesian rule to estimate the model parameters to do an empirical study on two different samples of Shanghai Exchange Composite Index.Results show,model uncertainty results in positive or negative hedging demand of portfolio,which depends on investor's attitude toward risk;the effect of model uncertainty is more significant with the increasing of investment horizon,the decreasing of investor's risk-aversion degree,and the decreasing of information;predictability of risky asset return increases its allocation in portfolio,at the same time,the effect of model uncertainty also strengthens.

The theory of information images： Modeling based on diffusion equations

This work represents a formalized description of information and communicative interac- tions of individuals on the basis of theory of information images （II）. It also demonstrates how important it is to choose the models type adequate to the systems under research. It also introduces an explication of the possibility to create the model of information and communication interactions that can illustrate transmission of information between two and more individuals. Methods and approaches suggested in this paper allow us to compare different levels of the described processes depending on the chosen architecture of the model; the methods and approaches mentioned in the current work can be also used to simulate the processes of distortion and generation of information images while information and communication social interaction. Expansion and addition of informa- tion images theory in terms of transmission of information among individuals enables us to speak about the space of individual II. The existence of such a space and creation of correct formalized model help us to explain a number of characteristic phenomena of human thinking processes. As a result of this research, the authors introduce an equa- tion that describes the spatial and structural evolution of individual II. There is also an example of modeling on the basis of this theory taking into account the results of the experiment （bilingual Stroop test）.