Comprehensive decision-making method for optimal location of logistics hubs

A mathematical optimal model is developed to address the problem of logistics hubs location.The method integrates nonlinear programming models and fuzzy comprehensive evaluation,and handles both quantitative and qualitative factors that influence the location of logistics hubs.A mathematical programming model is used to find the optimal candidate sites of the logistics hub based on profit-maximizing criteria.Then a fuzzy comprehensive evaluation method is adopted to determine the final optimal location of those candidate sites by taking account of criteria including stability of policy environment,convenience of transportation(e.g.,easy access to highways/expressways,etc.),rationality of economy,competition and sustainability.Finally,the methodology is demonstrated by a case study of the Transfar Logistics Base in Zhejiang Province.The results verify the method application for logistics hub locations and show how to locate a logistics hub in practice from the case of Transfar Logistics Base.

Fractal features of size distribution of Chinese intercity bus hubs

Size distribution characteristics of intercity bus hubs in China from 1997 to 2（104 were analyzed regarding highway passenger volume as a size index of intercity bus hubs. Yearly fractal dimensions of intercity bus hub sizes were exactly calculated by a novel model. Fractal dimensions of the 200 biggest intercity bus hubs from 2000 to 2004 were 1. 486 2 to 1. 511 8, and that is consistent with fractal dimensions of Chinese urban system sizes. It showed that the size distribution of intercity bus hubs had fractal structure. Fractal dimensions from 1997 to 2004 indicated that intercity bus hub size distribution grew from bi-fractal to single fractal. It is concluded that the intercity bus hub system is in evolutionary progress, and the Central Government should support large intercity bus hubs more to optimize system structure.

A Comparison of Singapore and Hong Kong on Their Strategies for Developing Regional Education Hubs

This article examines the approaches that are adopted by both Singapore and Hong Kong in developing themselves as ＂regional hubs of higher education＂ through different strategies on the development of their higher education systems, and via developing transnational higher education. The article starts off with a delineation on how the process of globalization has structurally altered the landscape of the global higher education market, upon which these changes drive both Singapore and Hong Kong to become more competitive in the global education marketplace. By examining and evaluating the recent education reforms in the two Asian city-states, the author argues that the two places have significant differences and are using rather different strategies in developing their higher education sectors, which can then reflect upon their fundamental differences in terms of the basic mindsets, underlying philosophies and style of governance of higher education by the two governments.

Route optimization model for pedestrian evacuation in metro hubs

The route optimization problem for road networks was applied to pedestrian flow.Evacuation path networks with nodes and arcs considering the traffic capacities of facilities were built in metro hubs,and a path impedance function for metro hubs which used the relationships among circulation speed,density and flow rate for pedestrians was defined.Then,a route optimization model which minimizes the movement time of the last evacuee was constructed to optimize evacuation performance.Solutions to the proposed mathematical model were obtained through an iterative optimization process.The route optimization model was applied to Xidan Station of Beijing Metro Line 4 based on the actual situations,and the calculation results of the model were tested using buildingExodus microscopic evacuation simulation software.The simulation result shows that the proposed model shortens the evacuation time by 16.05%,3.15% and 2.78% compared with all or none method,equally split method and Logit model,respectively.Furthermore,when the population gets larger,evacuation efficiency in the proposed model has a greater advantage.

Integrated Layout and Transfer of Urban Rail Transit Hubs

This paper is engaged in the research of urban rail transit hub integration and transfer.Firstly,this paper focuses on the space division,the aggregation form of hub subsystems,the spatial layout of hub subsystems,and the design of integrated functions to achieve an integrated layout.In addition,this study also conducted a selection of transfer classification and transfer station layout of urban rail transit hubs,with the aims to promote the improvement of the functions of urban rail transit hubs,the rationality of transfers,and to improve the service quality of the hub system which meet the demand of the public travel.

Coordinated scheduling model for intermodal transit hubs based on GI/M^K/1 queuing system

Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of passengers from the dominant mode to the connecting mode was achieved. A GI/M K/1 bulk service queuing system was constituted by putting the passengers' reaching time distribution as the input and the connecting mode as the service institution. Through queuing theory, the relationship between average queuing length under steady-state and headway of the connecting mode was achieved. By putting the minimum total cost of system as optimization objective, the headway as decision variable, a coordinated scheduling model of multimode in intermodal transit hubs was established. At last, a dynamic scheduling strategy was generated to cope with the unexpected changes of the dominant mode. The instance analysis indicates that this model can significantly reduce passengers' queuing time by approximately 17% with no apparently increase in departure frequency, which provides a useful solution for the coordinated scheduling of different transport modes in hubs.

Bus coordination holding control for transit hubs under APTS

To increase the passenger transferring efficiency, the bus coordination holding control for transit hubs, which is as an important dynamic dispatching method for improving the service level of transit hubs, was studied in the framework of bus coordination dispatching mode. Firstly, the bus coordination holding control flow was studied based on Advanced Public Transportation Systems (APTS) environment. Then a control model was presented to optimize the bus vehicle holding time, and a genetic algorithm was designed as the solving method. In the end, an example was given to illustrate the effectiveness of the control strategy and the algorithm.

Day-ahead P2P Energy Sharing Strategy Among Energy Hubs Considering Flexibility of Energy Storage and Loads

Multi-energy systems are one of the key technologies to tackle energy crisis and environmental pollution.An energy hub(EH)is a minimum multi-energy system.Interconnection of multiple EHs through energy routers(ERs)can realize mutual energy assistance.This paper proposes a peer-to-peer(P2P)energy sharing strategy between EHs including ERs in an interconnected system,which is divided into two levels.In the lower level,a method of determining the charging/discharging constraints of energy storage devices is proposed.Based on the Lyapunov optimization method,virtual queues are used to model the energy storage devices and flexible loads in the system.The objective is to minimize the overall operating cost of the interconnected system.In the upper level,a non-cooperative game model is introduced to minimize the cost of purchasing power from other EHs for each EH.A best response-based method is adapted to find the Nash equilibrium.The simulation outcomes demonstrate that application of the proposed strategy can reduce operating costs of an interconnected system and each EH.On basis of a real-world dataset of interconnected EHs,both analytical and numerical results show the effectiveness of the proposed strategy.

A review on passenger emergency evacuation from multimodal transportation hubs

Multimodal transportation hubs serve as transfer points with the function of collecting,transferring,and distributing passengers and play a significant role in the entire multimodal transportation network.In an emergency,the development of an effective and efficient emergency evacuation strategy to evacuate passengers from multimodal transportation hubs is very important.This paper aims to conduct a comprehensive review on passenger emergency evacuations from multimodal transportation hubs,summarize the achievements,identify gaps in existing literature,thus to lay a solid foundation for future studies.This paper first reviewed studies on evacuee behavior characteristics in emergency evacuations,including pedestrian characteristics,pedestrian behavior characteristics,and pedestrian flow characteristics.Then evacuation models,including pedestrian evacuation models and multimodal transportation evacuation models,were investigated.In addition,a retrospective analysis was carried out for evacuation simulation.It is found that while many studies have been conducted on passenger emergency evacuations from multimodal transportation hubs,most of them focus more on evacuating pedestrians from inside to outside of hub buildings;the studies on evacuation at multimodal transfer points are limited.It is also found that most existing studies tried to establish a general model to handle all types of emergency evacuations;in fact,a model would be more efficient if it is just established for a specific emergency and for a specific type of hubs.Also,existing data collection methods may collect biased data;new data collection methods need to be explored to increase the accuracy of data collection.Future study directions include the evacuation at multimodal transfer points,interactive effects between individual pedestrian behavior and pedestrian group behavior,more specific types of emergency evacuations,more accurate data collection methods,and tradeoffs between cost and benefit in emergency evacuations.

First stirling-type cryocooler reaching lambda point of ~4He(2.17K) and its prospect in Chinese HUBS satellite project

The issue of "missing baryons” is always an unsolved mystery in galaxy cosmology, and an important reason for the great uncertainty of the galaxies' formation and evolution. To find the "missing" baryons, extra high-resolution spectral observation and imaging of the soft X-ray band (<1 kev) is required. However, the existing observation methods cannot meet this requirement. Therefore, Tsinghua University leads and proposes the Chinese "Hot Universe Baryon Surveyor (HUBS)" satellite program.

Comparison and Error Analysis of Off-design and Design Models of Energy Hubs

The accuracy of the simulation model has a pro-found impact on the optimal operation of the energy hubs(EHs).However,in many articles,the constant model of the efficiency of equipment is adopted to formulate the operation system,which would probably lead to a simplification of the simulation models.But,EHs are typically operated under off-design condition due to the fluctuations in cooling,heating,electricity requirement.More-over,even though the off-design characteristics are considered,few studies have suggested comparing the differences between those two models by considering the operation cost.In order to assess the effect of the off-design characteristics of EH on the optimal operation accuracy in this paper,two test cases are performed on the fixed and variable load conditions,respectively.In addition,the individual effect of off-design characteristics of each equipment on the optimal operation cost of the EH is also investigated through four optimization runs.It is worth mentioning that the optimal operation problem of the EH considering the off-design characteristics and on-off status of the equipment is a mixed integer non-linear programming problem(MINLP).By testing the design and off-design models on the two cases,the results of simulation demonstrate that the optimal operation cost for the off-design model is larger than that for the design model.Nonetheless,in the aspect of the authenticity of the system operation strategy,the off-design model performs better than the design model.Furthermore,a larger relative error of the system operation cost between the two models can be observed when the EH is operated under a relatively lower load condition,revealing that the influence of off-design characteristic on the optimal operation of EHs is too significant to be neglected.

Frequency-Resolved Connectome Hubs and Their Test-Retest Reliability in the Resting Human Brain

Functional hubs with disproportionately extensive connectivities play a crucial role in global information integration in human brain networks.However,most resting-state functional magnetic resonance imaging(R-fMRI)studies have identified functional hubs by examining spontaneous fluctuations of the blood oxygen level-dependent signal within a typical low-frequency band(e.g.,0.01–0.08 Hz or 0.01–0.1 Hz).Little is known about how the spatial distributions of functional hubs depend on frequency bands of interest.Here,we used repeatedly measured R-fMRI data from 53 healthy young adults and a degree centrality analysis to identify voxelwise frequency-resolved functional hubs and further examined their test-retest reliability across two sessions.We showed that a wide-range frequency band(0.01–0.24 Hz)accessible with a typical sampling rate(fsample=0.5 Hz)could be classified into three frequency bands with distinct patterns,namely,low-frequency(LF,0.01–0.06 Hz),middle-frequency(MF,0.06–0.16 Hz),and high-frequency(HF,0.16–0.24 Hz)bands.The functional hubs were mainly located in the medial and lateral frontal and parietal cortices in the LF band,and in the medial prefrontal cortex,superior temporal gyrus,parahippocampal gyrus,amygdala,and several cerebellar regions in the MF and HF bands.These hub regions exhibited fair to good test-retest reliability,regardless of the frequency band.The presence of the three frequency bands was well replicated using an independent R-fMRI dataset from 45 healthy young adults.Our findings demonstrate reliable frequency-resolved functional connectivity hubs in three categories,thus providing insights into the frequency-specific connectome organization in healthy and disordered brains.

HUBS1汇通天下巧借世博东风

3月24日,HUBS1汇通天下在上海召开新闻发布会,其Expotia世博官方旅游网正式上线。张滇表示,"借助世博会这一机会,我们将把国际上最先进的预订分销技术深入到中国,整体提升中国旅游服务的信息水平。"

Discussion on Development Mode of Large Railway Hubs in High-speed Rail Era:From Transportation Complex to Urban Complex

At present, most of China's railway hubs are developed to be transportation complexes, with some problems like unsmooth traffic circulation, mixed but disordered functions, separated spaces, etc. In high-speed rail era, high-speed railway hubs should be regarded as the catalyst to promoted urban development. The mode of urban complex should be developed, to closely connect the railway hub and the surrounding area within walking distance, so as people could get to their destinations in the most convenient way. Furthermore, it would strengthen people's aggregation, thus to bring about larger scale urban development by the successful development of urban complex.

Day-ahead Chance-constrained Energy Management of Energy Hubs:A Distributionally Robust Approach

The day-ahead management schedules of hybrid energy hubs are intricate and usually exposed to various uncertainties with the penetration of renewable sources and different demands.Furthermore,it is difficult to access to precise probability distribution functions and exact moment information of uncertain variables.To cope with these issues,an energy management scheme based on the distributionally robust optimization approach is developed for the energy hub.It makes no assumptions of certain probability distributions and can be implemented with limited empirical data and partial information of underlying uncertainties.The operational strategy can provide decision makers with a preliminary and robust optimal solution in the day-ahead market.Numerical results illustrate the economical benefit of the energy model,and the effectiveness of the proposed approach in chance-constrained energy management is demonstrated by comparing with other cases.Index Terms-Chance constraint,distributionally robust optimization,energy hub,energy management.

Effects of Comprehensive High-speed Transportation Hubs on Spatial Structure of Urban Development:A Case Study on Changsha-Zhuzhou-Xiangtan Area

This paper, by studying the mechanism of the spatial restructuring of urban development and the effects of comprehensive high-speed transportation hubs on it, analyzes the development trends of comprehensive high-speed transportation in Changsha-Zhuzhou-Xiangtan Area and the impacts of the growing urban area centered on comprehensive high-speed transportation hubs, like airport and high-speed railway station, on the urban development of this area. It also proposes some strategies for the spatial restructuring of Changsha-Zhuzhou-Xiangtan Area in view of the development of the comprehensive high-speed transportation hubs, like Huanghua Airport and Wuhan-Guangzhou High-speed Railway Station.

Philips iU22型及iE33型超声诊断设备故障维修案例分析

总结Philips iU22和iE33型超声诊断设备的结构及常见故障,分析其6例故障原因,确定故障维修方案更换相应元器件或重新安装系统软件等方法维修技术路线,为医院同行的日常维修工作提供一些参考。

脓毒症潜在相关基因的生物信息学分析及功能预测

目的 通过生物信息学方法筛选并分析与脓毒症相关的差异表达基因及关键(Hub)基因,以期为临床诊疗提供潜在靶点和生物标志物。方法 使用基因表达综合数据库(GEO)筛选脓毒症基因表达数据集,运用GEO自带在线分析工具(GEO2R)分析差异表达基因(DEGs);并结合STRING 12.0和DAVID数据库对DEGs进行富集分析;再通过Cytoscape 3.9.1软件筛选出Hub基因,并对其进行功能分析。结果 筛选出328个DEGs,其中上调基因2个,下调基因326个。富集结果显示,DEGs的功能主要与蛋白质修饰、分解代谢、蛋白酶复合物、线粒体及酶活性等有关。通过CytoHubba插件筛选出了核因子κB亚基1(NFKB1)、NEDD8、人NADH-泛醌氧化还原酶A8(NDUFA8)、POLR2F、延伸蛋白B(ELOB)、PSMB6、SEC61A1、COX4I1、人NADH-泛醌氧化还原酶B8(NDUFB8)及ATP5PD 10个Hub基因,经生物过程(BP)可视化发现这些Hub基因在生物过程中相互作用。结论 NFKB1、NEDD8、NDUFA8、POLR2F、ELOB、PSMB6、SEC61A1、COX4I1、NDUFB8及ATP5PD等10个Hub基因可能是脓毒症诊疗的潜在靶点和新型生物标志物,但部分基因对脓毒症发生发展的作用机制研究相对不足,仍需后续进一步验证。

基于HubGLasso注意力机制的脑网络分类研究

脑网络分类有助于脑疾病的早期诊断,也有益于理解脑疾病发病机理,具有重要的研究与应用价值。其中,卷积神经网络应用广泛,可以提取脑网络的拓扑特征,是脑网络分类中的一个前沿热点。然而,现有方法未考虑脑网络中Hub节点对脑功能的重要贡献,这可能会导致特征提取不充分,限制了它们的分类性能。为此,该文提出了一种基于HubGLasso注意力机制的卷积神经网络模型,用于进行脑网络分类任务。该方法包含了一种新的卷积层结构,首先利用GLasso模型去除脑网络中的冗余信息,然后引入Hub约束与注意力机制,使其能够提取与异常Hub结构相关的重要特征,并用于脑疾病诊断。实验结果表明,该方法在包含1112个被试的真实自闭症数据集上取得了68.67%的准确率,显著优于目前已有方法,证明了其应用价值。更进一步,通过对训练后的模型进行特征分析,能够得到与脑疾病相关的脑区信息与Hub节点结构信息,为脑疾病病理机制的研究提供了全新的视角。

Inhibitory effect of saffron on head and neck squamous cell carcinoma via targeting of ESR1 and CCND1 by its active compound crocetin

Background:Traditional Chinese medicine is promising for managing challenging and complex disorders,including cancer,and in particular,saffron is applied in treating various cancer types.However,its potential therapeutic efficacy and active components in managing squamous cell carcinoma of the head and neck(HNSCC)remain unclear yet.Methods:Using network pharmacology approaches,active ingredients of saffron,their target genes,and HNSCC-related genes were identified.Enrichment analyses were conducted for determining molecular functions and pathways enriched by genes that overlapped between the saffron target gene set and the HNSCC gene set.Among the four known active ingredients of saffron,crocetin was found to have the strongest inhibitory impact on HNSCC,based on the findings of cell viability and migration assays.Therefore,the potential target genes of crocetin in HNSCC cells were examined using molecular docking experiments and were confirmed by qPCR.Result s:Four active ingredients of saffron and 184 of their target genes were identified.Further,a total of 34 overlapping saffron-/HNSCC-associated targets related to the four active ingredients were screened,and crocetin was chosen for further investigation because it had the strongest inhibitory effect on HNSCC cells.Molecular docking experiments indicated that ESR1 and CCND1 were the target genes of crocetin.These results were confirmed through qPCR analysis,in which crocetin was found to lower the expression of the ESR1 and CCND1 genes in AMC-HN-8 and FaDu cells.Conclusion:According to our results,crocetin is a primary active anti-cancer component of saffron that may have potential in the development of novel HNSCC-treating medications.However,more thorough molecular research is necessary for confirming these results and elucidating the anti-cancer mechanism underlying saffron.