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Among the pillars of decarbonization of the global energy system, energy efficiency plays a key role in reducing energy consumption across end-use (industry, transport and buildings) sectors. In industrial processes, energy efficiency can be improved by exploiting heat recovery via heat exchange between process streams. This paper develops a stage-wise superstructure-based mathematical programming model for the optimization of heat exchanger networks. The model incorporates rigorous formulation to handle process streams with phase change (condensation or evaporation), and is applied to a case study of an ethylene glycol production plant in Taiwan for minimizing utility consumption. The results show a compromise between steam savings and process feasibility, as well as how the model is modified to reflect practical considerations. In the preliminary analysis, with a substantial potential steam saving of 15,476 kW (28%), the solution involves forbidden matches that pose a hazard to the process and cannot be implemented. In the further analysis without process streams that cause forbidden matches, although the space limitation in the plant renders the best solution infeasible, the compromise solution can achieve a considerable steam saving of up to 8448 kW (91%) and is being evaluated by the plant managers and operators. [ABSTRACT FROM AUTHOR]

An optimal planning model of the sectional switch and tie line for the distribution network is proposed considering the tradeoff between the system reliability and economy. First, the fault incidence matrices are established for the distribution network, and the explicit analytical expression of the system reliability index is realized by the algebraic operation of the fault incidence matrices and fault parameter vectors. Then, the 0–1 integer quadratically constrained optimization model is established for the sectional switch configuration considering the capacity constraint of the tie line. Finally, the sectional switches and tie lines are optimized jointly to ensure the economic investment and maximize the system reliability. The distribution network in Taiwan Power Company is used to verify the applicability of the proposed optimization method. Compared with the intelligent optimization algorithm, the mathematical programming method in this paper can always find the global optimal switch configuration quickly. In addition, the influence of the tie line capacity constraints on the sectional switch configuration is also considered, which can provide practical reference for the power network planners in the optimization design of the distribution network. [ABSTRACT FROM AUTHOR]

The annual output value of Taiwan’s wafer foundry and IC packaging test ranks first worldwide. The electronics industry has a complete industrial ecological chain in the supply chain system of global information and communication technology. In order to increase market competitiveness and increase the operational flexibility, manufacturing process outsourcing has become a trend in the business model of the electronics industry. The quality of the outsourcing affects the quality and function of the final product, the outsourcer selection is crucial to ensure the quality of the final product. This article takes the wire bonding process as an example, and proposes a fuzzy selection model of quality-based IC packaging process outsourcers. Then, this article selects the six standard deviation indicator that can fully reflect the process yield and quality level as the evaluation tool. Since the indicator contains unknown parameter, in order to improve the accuracy of estimation and overcome the uncertainty of measurement data, this paper applies mathematical programming to derive the confidence interval of six sigma quality index, and proposes a confidence-interval-based fuzzy testing meth as a green outsourcer selection tool to reduce the risk of misjudgment due to sampling errors and improve the accuracy of the selection. [ABSTRACT FROM AUTHOR]

In recent years, airlines have been expanding their fleets, but this has posed a challenge in terms of limited airport space for maintenance facilities. Maintenance, repair, and overhaul provider (MRO) enhances the efficiency of existing space utilization by reducing the distance between parked aircraft. However, it is often necessary to change the position of parked aircraft during maintenance and if there are other aircraft blocking this movement it is necessary to interrupt the original maintenance work to allow the aircraft to pass. Unnecessary relocation of aircraft could reduce maintenance efficiency and increase costs. This study adopts mathematical programming with a network flow technique to develop an MRO stand allocation model. The effectiveness of the proposed model is evaluated in a case study performed using the data collected from a Taiwan aircraft MRO service provider. The results demonstrate that the proposed model could be a useful and practical planning support tool. [ABSTRACT FROM AUTHOR]

Hotel competency is inherently intangible and multivariate. It involves a multiple-criteria decision-making problem. Particularly in the currently rapidly shrinking hotel market in Taiwan, what determines domestic chain hotel groups' (DCHGs') competence and survival involves more complex and multiple factors. A practical and effective tool is urgently required for making appropriate decisions. This paper thus proposes a combined consistent fuzzy preference relations (CFPR) and the VIKOR model, aiming to prioritize criteria and solution alternatives for hotel managers. In contrast to prior studies that have used mathematical programming, the model here is also tested using real-world hotel management cases and expert consultation. First, based upon the resource-based view, we propose 21 criteria and six dimensions as the determinants of DCHG competencies. Then, VIKOR is applied to produce the most appropriate alternatives with the corresponding weights obtained using the CFPR method. The combined method successfully manages the problems of linguistic ambiguity and consistency, determines the relative weights of the different factors and provides a ranking priority. The result is compared with some similar methods and is shown to be more useful and reliable. Finally, the verified model can be used to produce strategies. A decision-maker can make selection(s) from the solution formula. Our study may thus contribute to the hotel industry with the efficient decision-making tool of resource-based view (RSV) and two-phase methodologies. [ABSTRACT FROM AUTHOR]

"What is 5/24 + 3/16 + 7/40?" Many students have difficulty understanding operations with fractions, especially doing fraction addition and subtraction with different denominators. This paper offers a new perspective from Taiwan in this regard along with three different strategies, including applying the concepts of factors/common factors and multiples/common multiples to find equivalent fractions, decomposing numbers into prime numbers, and using short division with the idea of the least common multiple, for teaching students to find common denominators. This paper also presents how the topic of fraction is treated in Taiwan mathematics curriculum, with the comparison to the fraction treatment in US suggested in the Common Core State Standards (CCSSI, 2010). [ABSTRACT FROM AUTHOR]

In this paper, we develop an intercity bus scheduling model for a variable market share. The proposed model, unlike the past intercity bus scheduling models, does not assume a fixed market share. Instead, passenger choice behaviors in competitive markets are considered. The model is formulated as a nonlinear mixed integer program that is characterized as nondeterministic polynomial-time hard. We develop a solution algorithm to efficiently solve the model. The test results, which are based on a major Taiwan intercity bus carrier, show the good performance of the model and the solution algorithm. [ABSTRACT FROM AUTHOR]

To order to raise chickens for meat, chicken farmers must select an appropriate breed and determine how many broilers to raise in each henhouse. This study proposes a mathematical programming model to develop a production planning and harvesting schedule for chicken farmers. The production planning comprises the number of batches of chickens to be raised in each henhouse, the number of chicks to be raised for each batch, what breed of chicken to raise, when to start raising and the duration of the raising period. The harvesting schedule focuses on when to harvest and how many broilers to harvest each time. Our aim was to develop proper production and harvesting schedules that enable chicken farmers to maximise profits over a planning period. The problem is a highly complicated one. We developed a hybrid heuristic approach to address the issue. The computational results have shown that the proposed model can help chicken farmers to deal with the problems of chicken-henhouse assignment, chicken raising and harvesting, and may thus contribute to increasing profits. A case study of a chicken farmer in Yunlin County (Taiwan) was carried out to illustrate the application of the proposed model. Sensitivity analysis was also conducted to explore the influence of parameter variations. [ABSTRACT FROM AUTHOR]

Fossil fuels have been heavily exploited since the Industrial Revolution. The resulting carbon emissions are widely regarded as being the main cause of global warming and climate change. Key mitigation technologies for reducing carbon emissions include carbon capture and storage (CCS) and renewables. According to recent analysis of the International Energy Agency, renewables and CCS will contribute more than 50% of the cumulative emissions reductions by 2050. This paper presents a new mathematical programming model for multi-footprint energy sector planning with CCS and renewables deployment. The model is generic and considers a variety of carbon capture (CC) options for the retrofit of individual thermal power generation units. For comprehensive planning, the Integrated Environmental Control Model is employed in this work to assess the performance and costs of different types of power generation units before and after CC retrofits. A case study of Taiwan's energy sector is presented to demonstrate the use of the proposed model for complex decision-making and cost trade-offs in the deployment of CC technologies and additional low-carbon energy sources. Different scenarios are analysed, and the results are compared to identify the optimal strategy for the energy mix to satisfy the electricity demand and the various planning constraints. [ABSTRACT FROM AUTHOR]

Abstract: Unit load devices (pallets, containers, etc.) are used to move luggage and air cargo on wide-bodied aircraft. This paper examines a case study of the number of devices needed by an airline for international scheduled services. Unit load device movements between airports require planes to load and deliver. The stock of the unit load devices is thus influenced by the airline’s scheduled services. Based on a recurring weekly schedule, this study develops a time–space network to formulate mathematical programming models for minimizing device quantities. This model is applied to assess the preparation level of unit load devices for the various service networks for a Taiwanese airline. [Copyright &y& Elsevier]

Abstract: This paper examines the practicability and validity of the Multi-Objective Goal Programming (MOGP) model in designing a point-to-point airline network. The MOGP mathematical model is used in this study to identify and select a best central airport and its connecting airports providing the best overall optimal performance. By using the proposed model in the selection process, one can expect to achieve the following objectives: (1) an airline network designed at less cost, (2) an airline network that generates more revenues, and (3) an airline network that serves more passengers. Route data from Taipei to the Southeast Asian region were selected for this experiment to validate the model’s practicability. [Copyright &y& Elsevier]

A bikeway network design model was developed for recreational bicycling in scenic areas. The multi-objective 0-1 programming problem is to determine spatial layouts for networks of bikeways and service stations. The model objectives are maximizing bikeway service coverage, maximizing service station service coverage, minimizing cyclist risk and maximizing bikeway suitability. The model constraints are network connectivity, bikeway type, monetary budget, location relationships between bikeways and service stations, and value ranges of decision variables. The programming problem was solved by ε-constraint method in a case study of a bikeway network in North Coast & Guanyinshan National Scenic Area in northern Taiwan. Four of the six non-dominated alternatives generated in the case study were substantially superior to existing bikeways, and budget limits sensitively affected cyclist risk and bikeway suitability. The proposed network design model for recreational bikeways can assist planners in efficiently and systematically developing alternatives for further evaluation. [ABSTRACT FROM AUTHOR]

The consideration of fixed cost and time-varying operating cost associated with the simultaneous conjunctive use of surface and subsurface water should be treated as a multi-objective problem due to the conflicting characteristics of these two objectives. In order to solve this multi-objective problem, a novel approach is developed herein by integrating the multi-objective genetic algorithm (MOGA), constrained differential dynamic programming (CDDP) and the groundwater simulation model ISOQUAD. A MOGA is used to generate the various fixed costs of reservoirs' scale, generate a pattern of pumping/recharge, and estimate the non-inferior solutions set. A groundwater simulation model ISOQUAD is directly embedded to handle the complex dynamic relationship between the groundwater level and the generated pumping/recharge pattern. The CDDP optimization model is then adopted to distribute the optimal releases among reservoirs provided that reservoir capacities are known. Finally, the effectiveness of our proposed integrated model is verified by solving a water resources planning problem for the conjunctive use of surface and subsurface water in southern Taiwan. [ABSTRACT FROM AUTHOR]

This study investigated the effects of group personalization of instruction on the mathematics achievement and attitudes of 72 fifth-grade Taiwanese students. Personalization was accomplished by incorporating personal information and preferences provided by students into their mathematics word problems. Students were blocked by ability level, then randomly assigned to a personalized or nonpersonalized version of an instructional program on mathematics word problems. Students made significant pretest-to-posttest gains across treatments and scored significantly higher on personalized than on nonpersonalized posttest problems. However, the personalized treatment did not produce a significant achievement difference over the nonpersonalized one. Significant two-way interactions reflected greater pretest-to-posttest improvement for lower-ability than for higher-ability students and a greater difference between scores on personalized over nonpersonalized posttest problems for lower-ability students. The posttest scores of high-ability students were limited by a ceiling effect. Student attitudes were significantly more favorable toward the personalized instruction. [ABSTRACT FROM AUTHOR]