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171.
选择供应商组构方案的DEA方法 总被引:8,自引:0,他引:8
以敏捷制造方式中制造资源的组构为背景 ,讨论了供应商组构问题的评价准则 ,并利用数据包络分析方法来解决供应商的评价问题 ,以及在非协作条件下组构方案的评价问题 相似文献
172.
173.
针对知识型服务企业面,临的人力需求多样性、知识更新速度快、客户响应要求高等问题,应用虚拟人力资源有助于知识型服务企业充分利用企业外智力资源,提升知识型服务企业的层次,降低人力资源管理的成本.通过应用方式及实例分析表明,虚拟人力资源是构建新型知识型服务业的一种有效途径. 相似文献
174.
NILS‐ARNE EKERHOVD 《Natural Resource Modeling》2008,21(4):582-606
Abstract In this paper, we use stock size, harvest quantity, and fishing effort as strategic variables. We model a two‐agent noncooperative fishery game, where the agents (nations) harvest a common fish stock. The planning horizon is infinite. The model is solved successively using one instrument at a time as the strategic variable in the game. The net present values of fishing and the escapement stock level from the three different models are compared to show how the choice of variables affects the results. The choice of strategic variable is not a trivial one, as the results are shown to be sensitive to the discounting, the stock's rate of growth, and the assumptions about the distribution of the fish in response to harvesting. 相似文献
175.
A new mathematical model for finding the optimal harvesting policy of an inland fishery resource under incomplete information is proposed in this paper. The model is based on a stochastic control formalism in a regime‐switching environment. The incompleteness of information is due to uncertainties involved in the body growth rate of the fishery resource: a key biological parameter. Finding the most cost‐effective harvesting policy of the fishery resource ultimately reduces to solving a terminal and boundary value problem of a Hamilton‐Jacobi‐Bellman equation: a nonlinear and degenerate parabolic partial differential equation. A simple finite difference scheme for solving the equation is then presented, which turns out to be convergent and generates numerical solutions that comply with certain theoretical upper and lower bounds. The model is finally applied to the management of Plecoglossus altivelis, a major inland fishery resource in Japan. The regime switching in this case is due to the temporal dynamics of benthic algae, the main food of the fish. Model parameter values are identified from field measurement results in 2017. Our computational results clearly show the dependence of the optimal harvesting policy on the river environmental and biological conditions. The proposed model would serve as a mathematical tool for fishery resource management under uncertainties. 相似文献
176.
ABSTRACTEvery year, a tremendous amount of meat is wasted, which may have adverse effects on the environment. Therefore, waste meat should be recycled. Building a recycling system for waste meat to reduce financial loss and careful treatment of life-based resources is essential. As meat contains abundant amino acids, it can be used as an immense source of amino acids for other industries following enzymatic hydrolysis. However, during the enzymatic hydrolysis process, the waste meat can easily get contaminated by microbes and therefore needs high temperature. In the present study, we applied high pressure carbon dioxide (HPCD) technology to prevent the contamination of meat by microbes during enzymatic hydrolysis process. According to our research, HPCD has a great potential to be adopted as a novel decontamination technology in the industrial enzymatic hydrolysis process at relatively lower temperature. 相似文献
177.
178.
Hongsheng Lu Lingling Yang Zhiyu Huang 《Journal of Dispersion Science and Technology》2016,37(2):159-165
The structure transitions of the aggregates in the sodium oleate (NaOA)/N-(3-(dimethylamino)propyl)-octanamide (DPOA) aqueous system was investigated upon CO2 stimuli. During the process of bubbling of CO2, three appearance states of sol, gel, and emulsion with little white precipitate were observed continuously. The cryo-transmission electron microscope characterization and rheological measurements exhibited that the sol–gel transition was attributed to a spherical-wormlike micelle transition. Moreover, this transition was switchable at least three cycles in the pH range of 10.91–9.56 by CO2 stimuli and pH regulation (adding NaOH), which could be explained by the protonation of DPOA and deprotonation of DPOA · H+. Bubbling of CO2 resulted in protonation of DPOA, which not only inserted into the OA– as a co-surfactant but also screened the electrostatic repulsion among OA–, corporately leading to the spherical-wormlike micelle transition. Adding NaOH caused the deprotonation of DPOA · H+ and hence reversed this transition. This surfactant system with switchable micelle transition not only displays tremendous application potential in various fields but also is of key importance in cyclic utilization of surfactant. 相似文献
179.
Kwan Wook Song Tae Ho Lee Eui Jin Ko Kyung Hun Back Doo Kyung Moon 《Journal of polymer science. Part A, Polymer chemistry》2014,52(7):1028-1036
A poly[benzodithiophene‐alt‐di‐2‐thienyl‐quinoxaline] series (PBDTDPQ‐EH, PBDTDPQ‐OD, and PBDTDPQ‐HDT) was synthesized via Stille coupling. Deep highest occupied molecular orbital (HOMO) levels were achieved by the introduction of 2‐decyl‐4‐hexyl‐thiophen‐yl (HDT) side chains. The introduction of the various side chains increased the molecular weight of the polymers, and the polymers dissolved well in common organic solvents at room temperature. The HOMO energy level (?5.20 to ?5.49 eV) decreased because of the 2D conjugated structure. X‐ray diffraction analysis showed that PBDTDPQ‐OD had a slightly edge‐on structure. In the case of PBDTDPQ‐HDT, however, the structure was amorphous due to the thiophene side chain, and the extent of π stacking increased. After fabricating bulk‐heterojunction‐type polymer solar cells, the OPV characteristics were evaluated. The values of open‐circuit voltage (Voc), short‐circuit current (Jsc), fill factor, and power conversion efficiency (PCE) were 0.88 V, 7.9 mA cm?2, 45.4%, and 3.2%, respectively. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1028–1036 相似文献
180.
吉林大学无机化学课程有着优良的历史传承和积淀。面对“互联网+”带来的教与学的新发展和新变革,围绕学生知识、能力和素质三方面的综合培养,教学团队以信息技术为支撑,将课程思政浸润教学,高阶思维贯通教学,建立了“三化、三融、三阶”的线上线下混合式教学模式:“三化”指教学内容层次化、教学资源多样化、评价体系多维化;“三融”指理论课与实验课相融合、专业知识与思政元素相融合、多种教学手段相融合;“三阶”指课前、课中、课后三环节进阶式教学过程。该教学模式可满足学生个性化学习的需求,提升了学生学习的主动性,增加了师生互动,学生的思辨、创新等高阶能力明显提高。 相似文献