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1.
The capability automated warehouse in of a company to implement an an optimized way might be nowadays a crucial leverage in order to gain competitive advantage to satisfy the demand. The order picking is a warehouse function that needs to deal with the retrieval of articles from their storage locations. Merging several single customer orders into one, a picking order can increase efficiency of warehouse operations. The aim of this paper is to define throughout the use of ad-hoc genetic algorithm （GA） how better a warehouse can be set up. The paper deals with order batching, which has a major effect on efficiency of warehouse operations to avoid wastes of resources in terms of processes and to control possibility of unexpected costs in advance. 相似文献
2.
The response of dynamic wave pressures on structures would be more complicated and bring about new phenomena under the dynamic interaction between soil asnd structure.In order to better understand the response characteristics on deeply embedded large cylindrical structures under random waves,and accordingly to offer valuable findings for engineering ,the authors designed wave flume experiments to investigate comparatively dynamic wave pressures on a single and on continuous cylinders with two different cembedment depths in response to two wave spectra ,The time histories of the water surface elevation and the corresponding dynamic wave pressures exerted on the cylinder were analyzed in the frequency domain,By calculating the transfer function and spectral density for dynamic wave pressures along the height and around the circumference of the cylinder,experimental results of the single cylinder were compared with the theoretical results based on the linear diffraction theory ,and detailed comparisons were also carried out between the single and continuous cylinders ,Some new findings and the corresponding analysis are reported in present paoer,The investigation on continuous cylinders will be used in particular for reference in engineering applications becaus information is scarce on studying such kind of problem both analytically and experimentally. 相似文献
3.
Studies on optimization of nitrogen sources for astaxanthin production by <Emphasis Type="Italic">Phaffia rhodozyma</Emphasis> 总被引：2，自引：0，他引：2
Ni H Chen QH Ruan H Yang YF Li LJ Wu GB Hu Y He GQ 《Journal of Zhejiang University. Science. B》2007,8(5):365-370
Fermentation ofPhaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using （NH4）2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L （NH4）2SO4, 0.49 g/L KNO3 and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively. 相似文献
4.
Phenolic formaldehyde(PF)and epoxy(EP)resins are commonly used in electronic packaging. In this paper, high-ohmic resistors(2.2 M?, ±0.5%,)with Cr-Si film were coated by PF/EP paint, and the resulting coated resistors were used for heat and humid(HH)experiments. The experimental results show that the corrosion of bandlike resistive films is selective and isotropic, and that the corrosion spots in resistive films all form along grooves and extend in the same direction. It is revealed that OH~- ions are generated due to the electrochemical reactions of resistive film in HH experiments, so a NaOH aqueous solution with pH about 10 was used to study the effects of absorbed water and OH~- ions on PF/EP polymer film. The results indicates that the color of some part on PF/EP polymer film changes due to corrosion, and that the corrosion part of the polymer film is easy to be peeled off. It can be inferred that OH~- ions generated in HH experiments may play a catalytic role in the chemical reactions between polymer film and the absorbed water, which accelerates the degradation of PF/EP protection film for a resistor. 相似文献
5.
A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the control and sensor system.An electric energy storage system (ESS) is required which possesses high power density with good cycle life.Ultracapacitors which exhibit high power density and cycle life are considered as energy storage devices.Simulations based on a specific voyage condition indicate that ESS with ultracapacitors has positive effects on reducing the output power demand of PEMFC and lightening the power system.Experimental results show that the state of charge (SOC) is related to the capacitance and resistance in ultracapacitor ESS. 相似文献
6.
In this paper we introduce a novel energy-aware routing protocol REPU （reliable, efficient with path update）, which provides reliability and energy efficiency in data delivery. REPU utilizes the residual energy available in the nodes and the received signal strength of the nodes to identify the best possible route to the destination. Reliability is achieved by selecting a number of intermediate nodes as waypoints and the route is divided into smaller segments by the way-points. One distinct advantage of this model is that when a node on the route moves out or fails, instead of discarding the whole original route, only the two way-point nodes of the broken segment are used to find a new path. REPU outperforms traditional schemes by establishing an energy-efficient path and also takes care of efficient route maintenance. Simulation results show that this routing scheme achieves much higher performance than the classical routing protocols, even in the presence of high node density, and overcomes simultaneous packet forwarding. 相似文献
7.
A two-stage method is developed to solve a new class of multi-storage tank multi-source （MTMS） systems. In the first stage, the optimal storage policy of each tank is determined according to the electricity tariff, and the ground-level storage tank is modeled as a node. In the second stage, the genetic algorithm, combined with a repairing scheme, is applied to solve the pump scheduling problem. The objective of the pump scheduling problem is to ensure that the required volume is adequately provided by the pumps while minimizing the operation cost （energy cost and treatment cost）. The decision variables are the settings of the pumps and speed ratio of variable-speed pumps at time steps of the total operational time horizon. A mixed coding methodology is developed according to the characteristics of the decision variables. Daily operation cost savings of approximately 11% are obtained by application of the proposed method to a pressure zone of S. Y. water distribution system （WDS）, China. 相似文献
8.
Urban wastewater treatment techniques could not be applied to improve the pollutant removal efficiency,due to its characteristics of closed and quiescent conditions of the static lake water.In this study,natural zeolite and coal cinder were chosen as filler compounds of the ecological filter.Static and dynamic experiments were carried out to study the remediation efficiency.Experimental data show that removal efficiency of ammonia nitrogen （NH ＋ 4 -N） reaches 85% in both static and dynamic patterns and its removal efficiency reaches 97% when the recycling period is 1 h in dynamic condition.The maximum removal efficiency of nitrite nitrogen （NO-2 -N） reached 98%,and the removal efficiency of total nitrogen （TN） is a maximum of 84%.The final effluent concentration of total phosphorus （TP） is 0.079 mg/L.Effluent recycling could improve the nutrient （N,P） removal efficiently.Dissolved oxygen （DO） concentration could remain high with the water cycling.The filter works efficiently on regulating pH to the standard level of healthy water. 相似文献
9.
Shengli Zhan 《Frontiers of Education in China》2013,8(2):323-326
This is a book on policy study in the Chinese mainland by an insider with an outsider perspective.With contemporary policies on minban schooling in Shanghai as a case study,Ding illustrates and analyzes a case of policy metamorphosis in the contemporary Chinese mainland.
The book is based on a well-designed qualitative study with 65 in-depth interviews in 2001 and 2004.Ding tries to figure out the logic of policy implementation in Shanghai as an "insider" while having a clear awareness of the dilemma of studying a policy issue in her own culture.She makes the best use of her identity as an insider,not only as a Chinese but as someone who knows some "inside" stories concerning the issue interviewed.As Ding pointed out,"I had obtained some firsthand information about minban education in Shanghai,so that when I sensed that the informants were talking superficially,I let them know that I had heard some inside stories (which usually had very different versions).In this way,sensitive data emerged." (Ding,2011,p.145).This is true,since the views expressed in most interview data Ding collected cannot be found in public or official documents,and are also rarely found in the academic literature. 相似文献
10.
The combined use of dry cooling （DC） system and dedicated ventilation （DV） system to decouple cool-ing and dehumidification process for energy efficiency was proposed for subtropical climates like Hong Kong. In this study, the energy performance and condensation risk of the use of DCDV system were examined by analyzing its ap-plication in a typical office building in Hong Kong. Through hour-by-hour simulation using actual equipment per-formance data and realistic building and system characteristics, it was found that with the use of DCDV system, the annual energy consumption could be reduced by 54%in comparison with the conventional system （constant air vol-ume with reheat system）. In respect of condensation risk, it was found that the annual frequency of occurrence of con-densation on DC coil was 35 h. Additional simulations were conducted to examine the influence of different parame-ters on the condensation risk of DCDV system. Measures to ensure condensate-free on DC coil were also discussed. 相似文献
11.
为了改进网络存储设备的I/O速度和系统性能, 设计了一种新的专用存储服务器, 该服务器是一种基于iSCSI的附网存储服务器 (iSCSI-based network-attached storage server, iNAS). 在iNAS中, 利用iSCSI软件提供的模块, 使得iNAS同时提供file I/O 和block I/O服务, 实现了NAS和SAN (storage area network)的融合; 通过在RAID (redundant array of inexpensive disks)控制器和用户内存之间的直接数据传输(零拷贝), 极大地提高了iNAS的I/O响应速度; 通过一个多级分流的的设备驱动程序, 将多个RAID整合成单一的存储池, 从而实现了存储虚拟化. 实验结果显示, iNAS对文件I/O请求和块I/O请求都具有极高的响应速度. 相似文献
12.
存储网络是个大而复杂且昂贵的网络,使用传统的SCSI技术成本虽低,但传输数据时会受距离及路径的限制,先进的FC技术消除了这些弊端,提高了传输速率,但其结构复杂,投资大,管理难.用户期待更简单、成本低、能够充分利用已有以太网环境完成数据存储的工作,于是iSCSI技术应运而生.本文对iSCSI协议的工作原理、应用及特点等进行了论述. 相似文献
13.
Study on performance of a packed bed latent heat thermal energy storage unit integrated with solar water heating system 总被引：1，自引：0，他引：1
NALLUSAMY N. SAMPATH S. VELRAJ R. 《浙江大学学报(A卷英文版)》2006,7(8):1422-1430
INTRODUCTION Efforts of rational and effective energy man-agement, as well as environmental considerations, increase the interest in using renewable energy sources, especially solar energy. Because of discrep-ancy between the energy supply and demand in solar heating applications, a thermal energy storage (TES) device has to be used for the most effective utilization of the energy source. Energy storage combined with solar collectors and photovoltaic systems have been developed over the… 相似文献
14.
我国高等教育大众化政策的反思与展望 总被引：2，自引：0，他引：2
从政策分析的角度看,目前我国高等教育大众化政策还存在决策机制不健全、片面追求量的指标、路径单一等谤多问题。创新与健全高等教育大众化政策需要加强政策研究,健全科学决策机制;积、极发展民办高校,实现大众教育与精英教育的协调发展;贯彻科学发展观,追求量与质的和谐统一。 相似文献
15.
With development of networked storage and its applications, united storage network (USN) combined with network attached storage (NAS) and storage area network (SAN) has emerged. It has such advantages as high performance, low cost, good connectivity, etc. However the security issue has been complicated because USN responds to block I/O and file I/O requests simultaneously. In this paper, a security system module is developed to prevent many types of atl~cks against USN based on NAS head.The module not only uses effective authentication to prevent unauthorized access to the system data, but also checks the data integrity.Experimental results show that the security module can not only resist remote attacks and attacks from those who has physical access to the USN, but can also be seamlessly integrated into underlying file systems, with little influence on their performance. 相似文献
16.
潘旭 《闽西职业技术学院学报》2014,(3):115-120
从现有各种网络存储技术的基本原理出发,分析了每一种网络存储技术的优点和存在的问题,围绕目前的几种主流网络存储技术进行了讨论。结合大数据的基本概念进行剖析,并对大数据的主要应用和网络存储作简单对比。最后归纳总结大数据时代所面临数据存储的新挑战。 相似文献
17.
The article argues that there is no single globalisation of education systems, but rather multiple globalisations of each system taken in its individual context. We propose three explanatory factors to account for these vernacular globalisation processes, that is, for individual policy trajectories in each national context: path dependence on earlier policy choices and institutions, education policy-making through bricolage, and finally the translation by national actors of international-level ideas or tools as a function of the debate, institutions or national power dynamics in question. The research design is based on the study of a most-likely case: accountability policy in two school systems – France and Quebec – which show strong variations. Document analyses and semi-structured interviews were conducted in both cases. In the two countries, distinct vernacular globalisations are at work leading to different neo-statist accountability policies. In Quebec, the reinforcement of state power through a growing vertical accountability and the systematic development of regulation tools between policy actors and levels lead to a ‘centralisation by institutional linkage’. In France, we rather witness a ‘globalisation by discursive internalisation’ in which transnational imperatives are integrated in official discourses on the regulation of the education system, but without radically questioning the mainstays of this regulation. 相似文献
18.
政策评估、反思与重构是我国教育政策运行的一般性路径抉择.在对政策评估、反思与重构等相关要素分析的基础上,通过对我国高职院校评估政策更替的历史回顾提出,评估政策目标的转向必然导致对原政策"四大情结"的反思.从深度访谈、评估结论、数据平台等方面进行政策重构的解读后发现,针对旧方案存在的"四大情结"取向,新方案一方面删除了部分过时、无效的指标,改变了过去那种以查证、审核、抽检为主要任务的专家组做法;另一方面开发并形成了以数据采集平台为主要手段的评估体系,并采用了深度访谈的专家评估方式.评估政策的重构将引领新一轮高职评估的开展. 相似文献
19.
针对现有单一运营商提供的云存储方案,无法令用户跨运营商定制组建个人的云存储服务的缺陷,设计了一种模块化的存储方案.该方案涵盖了用户数据的传输安全、存储安全以及访问控制安全,并确保数据的机密性、可用性和完整性.该方案适用于云服务运营商面向用户提供高安全的网络存储服务,有利于用户在不同运营商之间迁移存储数据. 相似文献
20.
多路视频存储与检索容易造成I/O瓶颈,以及多用户回放的稳态性和连续性较差等问题,易导致整个监控系统的效率低下与不稳定性.基于组件化思想提出一种嵌入式Linux数字视频监控系统多维硬盘存储调度方案,有效地解决I/O瓶颈问题,提高了存储高效快捷性.同时通过采用η-dispatching方案提高网络数字视频监控系统的多路视频存储与并发用户检索的效率与模块化的通用性. 相似文献