Product mix strategy and manufacturing flexibility

The manufacturing industry is facing a turbulent and constantly changing environment, with growing complexity and high levels of customisation. Any investment solution should address these problems for a dynamic market and within limited budget boundaries, so that companies try to remain competitive. The authors propose a real options model to support firms making important investment decisions, specifically decisions associated with the acquisition of new equipment aimed at allowing firms to increase their manufacturing flexibility for the production of both standard and customized products. This paper is partially based on a real operating experience related to visual finishing technology features in an industrial company that conforms to the definitions of the product mix. The authors’ motivation for this work is driven by firms’ desire to satisfy specific customer needs, and to respond to them quickly under uncertain demand. Our goal, using theories from finance, production management, and product offering management, is to conclude that there is a relevant difference between the evaluation of the technology that is to be chosen, and the potential value due to product mix adaptations that are able to provide the maximum return from investment. We address problems related to standard and customized production systems, and the decision to invest in a set of resources that will enable this choice.     

河北省职业教育集团化办学整体发展现状及发展策略研究

通过对于河北省职教集团化发展的现状分析,发现了当前河北省职教集团化发展过程中存在的阻碍职教集团化进一步发展的典型问题,提出了具有较强可操作性、针对性强的河北省职教集团化发展策略,对于政府,教育研究人员,职业院校管理人员有较强的借鉴意义。     

Energy management optimization of a hybrid power production unit based renewable energies

Hybrid power production units seem to be an interesting alternative for supplying isolated sites. This study proposes a new supervision strategy in order to ensure an optimized energy management of the hybrid system. The considered hybrid unit includes a wind generator (WG), a fuel cell (FC), an electrolyzer (EL) and a supercapacitor (SC). An overall power supervision approach was designed to guarantee the power flow management between the energy sources and the storage elements. The aim of the control system is to provide a permanent supply to the isolated site by adapting production to consumption according to the storage level. A mathematical analysis of the hybrid system using models implemented in Matlab/Simulink software was developed. Simulation results illustrate the performance of the control strategy for an optimal management of the hybrid power production unit under different scenarios of power generation and load demand.     

Bidding strategy of wind-thermal energy producers

This paper presents a stochastic mixed-integer linear programming approach for solving the self-scheduling problem of a price-taker thermal and wind power producer taking part in a pool-based electricity market. Uncertainty on electricity price and wind power is considered through a set of scenarios. Thermal units are modelled by variable costs, start-up costs and technical operating constraints, such as: forbidden operating zones, ramp up/down limits and minimum up/down time limits. An efficient mixed-integer linear program is presented to develop the offering strategies of the coordinated production of thermal and wind energy generation, having as a goal the maximization of profit. A case study with data from the Iberian Electricity Market is presented and results are discussed to show the effectiveness of the proposed approach.     

煤层气井试井测试中常见问题与技术对策

煤层气井与常规油气井储层在孔隙结构、赋存状态、产出机理上完全不同,试井方法亦不相同。针对煤层气产出特征、资料录取要求,重点探讨煤层气井注入/压降试井工艺技术中常见的问题与对策,结合测试井的不同情况,优化试井方案,采取单封、双封不同管柱结构工艺技术,可有效降低井筒储集效应对测试工作的影响,现场应用效果显著,对煤层气井试井测试具有借鉴意义。     

信息化条件下我国资产证券化研究

资产证券化凭借其独特的交易机制，已经成为发达国家资本市场的主流融资手段，更是全球领域最重要的金融创新之一。它不但为市场机制作用的发挥奠定了基础，而且充分体现了金融市场一体化的客观要求。信息化条件下，资产证券化快速渗透到社会经济领域的各个层面，对经济运行效率能够产生深远的影响。     

WLAN网络建设策略及其与3G网络融合分析

文章从联通运营商WLAN业务发展的现状出发，对WLAN建设过程中存在的问题进行详细的分析和研究，根据原因提出有效的建设策略，并对3G网络的融合进行全面的阐述。     

Aligning RFID applications with supply chain strategies

Many large retailers decided to adopt RFID as their new supply chain technology, but RFID adoption by all industries did not spread as rapidly as initially expected. We believe that its benefits constituted the major barrier to its adoption, and argued that a major contributor to the delay has been its inappropriate implementation. Our study reports the result of six in-depth case studies, which, together with case content analysis of 88 reported RFID applications, provided us with a clear view of the RFID implementation landscape, suggesting that organizations often mindlessly adopted RFID applications that were misaligned with their supply chain strategies, leading to unsatisfactory benefits. Insights into how organizations should adopt RFID were developed from our results and were discussed.     

Crisis response strategies in Finland and Spain

Crises are common in today's unpredictable environment rising the importance of crisis response strategies. Two societies in Europe are chosen: Finland, where trust in society is generalized to institutions, and Spain, where trust in society remains on the level of individuals. Using the results of the European Communication Monitor 2013 survey on crisis communication, we explored three hypotheses: “certain types of crises are often met with certain types of strategies,” “cultural context makes some crises more likely than others,” and “cultural context makes some response strategies more likely than others.” We find evidence for all three hypotheses and discuss our findings about perceived differences in the two societies. The results show that the cultural context plays an important role for crisis communication.     

Estimation of the state-of-charge of gel lead-acid batteries and application to the control of a stand-alone wind-solar test-bed with hydrogen support

In hybrid renewable energy systems, batteries act as a DC bus to provide constant voltage and to smooth out commutations between the generating devices. These batteries are usually of a lead-acid type and operate under harsh variable conditions due to fluctuations of both solar radiation and wind speed. Precise knowledge of the state-of-charge of the batteries, and hence of their available energy, play a key role in effecting efficient control and energy management of the installation. The present study had a twofold aim. One objective was to adjust and validate a method based on coulomb counting to estimate the state-of-charge (SOC) of a gelled lead-acid battery which is the DC bus of a hybrid wind-solar system with hydrogen storage. Other works evaluate SOC models based on several parameters, however, the present proposal based on experimental measurements involves only a few parameters. The second objective was to modify the installation's control algorithm to use the battery's calculated SOC as control parameter instead of its voltage. The results of a test-bed system, showing how the system evolved under real operating conditions, constitute a proof-of-concept of the validity of the method.