1×4 MMI Splitter Based on Rib SOI Waveguide

In this paper, a 1×4 MMI splitter based on silicon-on-insulator (SOI) by effective index method and guide mode method is designed. The fabrication tolerance was analyzed. The device was fabricated and near-field output was obtained.     

Accurate Analysis of Microstrip Lines on Lossy Biaxial Anisotropic Substrates

We have studied the behavior of the microstrip lines on lossy biaxial anisotropic dielectric substrates. A spectral-domain moment method is used with the Galerkin testing procedure to determine the dispersion characteristics of single and coupled lines. Modes of both even and odd symmetries are included. It is found that the anisotropy of the substrate has a significant influence on the propagation characteristics. The theory is verified by comparison with previously published data.     

1×4 MMI Splitter Based on Rib SOI Waveguide

In this paper, a 1×4 MMI splitter based on silicon-on-insulator (SOI) by effective index method and guide mode method is designed. The fabrication tolerance was analyzed. The device was fabricated and near-field output was obtained.     

A mathematical model for a capacity reservation contract

It is common practice in many industries to use a replenishment contract with a mechanism of capacity reservation. In this paper, we focus on a multi-period capacity reservation contract practiced between a buyer, who buys a single type of product and sells it to end-customers, and two or more heterogeneous suppliers, who produce and replenish the product as agreed upon contractually.In this paper, a mathematical model including several key features of a real contract is developed for a single supplier situation from the buyer’s perspective. It is then extended to a multiple supplier model for a system in which there are several heterogeneous suppliers with different capacities and prices. A rolling-horizon implementation strategy is suggested for the efficient application of the models. Extensive computational experiments demonstrate that the model and strategy can produce cost effective contractual terms for the buyer within a few seconds.     

A tollbooth tandem queue with heterogeneous servers

We study a tandem queueing system with K servers and no waiting space in between. A customer needs service from one server but can leave the system only if all down-stream servers are unoccupied. Such a system is often observed in toll collection during rush hours in transportation networks, and we call it a tollbooth tandem queue. We apply matrix-analytic methods to study this queueing system, and obtain explicit results for various performance measures. Using these results, we can efficiently compute the mean and variance of the queue lengths, waiting time, sojourn time, and departure delays. Numerical examples are presented to gain insights into the performance and design of the tollbooth tandem queue. In particular, it reveals that the intuitive result of arranging servers in decreasing order of service speed (i.e., arrange faster servers at downstream stations) is not always optimal for minimizing the mean queue length or mean waiting time.     

A proposed model for measuring the aggregative risk degree of implementing an RFID digital campus system with the consistent fuzzy preference relations

An RFID digital campus system implementation can enhance convenience in teaching environment, teaching quality and administrative efficiency. When administrators decide to implement an RFID digital campus system, they often encounter unexpected internal and external risk factors and difficulties. Therefore, this study proposes a novel analytic hierarchy model for helping administrators to identify the critical risk factors affecting the RFID digital campus system initiation, and measuring the aggregative risk of implementing an RFID digital campus system. The importance weights of risk factors and possible occurrence ratings of four risk grades (high, medium, low and none) are determined by using consistent fuzzy preference relations. The relative priority weights of evaluators are considered simultaneously by using simple additive weighting method. Multiplying the importance weights of risk factors, the possible occurrence ratings of risk grades and the relative priority weights of evaluators, the aggregative risk degree of implementing an RFID digital campus system is derived. University A in Taiwan is used to demonstrate the computation procedures of this proposed methodology.     

Outsourcing suppliers as downstream competitors: Biting the hand that feeds

In this paper, we highlight an aspect of supplier opportunism in the outsourcing paradox that has largely been ignored by extant research – the supplier as a direct competitor of the buyer firm. In light of this paradox, we offer a game-theoretic framework in which we identify conditions under which firms could alleviate or mitigate this outsourcing problem. Our results show that apart from transaction costs, firm-level capabilities (both ordinary and dynamic) play important roles in determining the make only, buy only, or make-and-buy options a firm could exercise in countering the threat of the supplier as a potential competitor in the downstream marketplace.     

建立现代企业制度 发展水利综合经营

在简要分析水利综合经营作用的基础上，针对水利综合经营工作中存在的主要问题，对建立现代企业制度，发展水利综合经营这一问题进行了分析探讨。     

降低直接甲醇燃料电池浓差极化的含磺化碳管阻水夹层的构建

采用直接接枝法, 将来自对氨基苯磺酸的苯磺酸官能团引入氧化多壁碳纳米管, 制得磺化多壁碳纳米管(SO₃-MCNT). 再以SO₃-MCNT为填料, 以Nafion离聚物为黏结剂, 利用超声喷涂在商业N212质子交换膜一侧构建了新的膜层, 获得了一种复合膜(SO₃-MCNT?N212). 使用SO₃-MCNT?N212制备燃料电池膜电极(MEA), 并用于直接甲醇燃料电池(DMFC)测试. 与使用普通N212膜的膜电极相比, 该膜电极的性能得到明显提升. 进一步分析表明, SO₃-MCNT膜层的引入降低了阳极向阴极的跨膜水迁移作用, 缓解了阴极的水淹, 从而降低了浓差极化, 提升了膜电极的性能.