• Management Science and Financial Engineering
• /
• 제19권1호
• /
• pp.43-47
• /
• 2013

We investigate the effect of bank's market power on financing constraints of non-financial firms in 11 Asian countries between 1995 and 2009. Using firm-level data we analyze financial constraints with the Euler equation derived from the dynamic investment model. We find that with a highly concentrated banking sector firms which have high market power are less financially constrained. These results are consistent with an information-based hypothesis that more market power increases bank's advantage to produce information on potential borrowers.

• 가정과삶의질연구
• /
• 제15권4호
• /
• pp.81-102
• /
• 1997

This study intended to investigate factors shaping the styles for comsumers to express their dissatisfaction after comsuming goods(cloth and household appliance) and services(public and health) In particular this study examined what kinds of characteristics were crucial to distinguish three styles of consumers' and public complaints. The characteristics of consumer to be considered in this study included consumer knowledge consumer attitude consumer and several socio-economic characteristics. The sample used in this study were consumers whose age was grater than 20 years old living near Seoul in 1996. Discriminant analysis was conducted to investigate what factors discriminate the style of complaint. This study found that several consumer characteristics were sigificant in explaining different styles for consumers to response their dissatisfactions. The effects of consumer characteristics were more significant in explaining the complaining styles derived from public and health services rather than goods. Overall consumer attitude consumer knowledge and the degree of satisfaction of services were discriminant variables in explaining the styles of consumer complaint. Both consumer knowledge and budgeting skill were significant in explaining complaint styles to response dissatisfaction derived from consuming clothing while both consumer education and time constraint were significant in shaping the kinds of complaining styles derived from consuming household appliances.

• 대한전기학회논문지:전력기술부문A
• /
• 제54권12호
• /
• pp.597-602
• /
• 2005

The introduction of competition in electricity market emphasizes the importance of sufficient transmission capacities to guarantee various electricity transactions. Therefore, when dispatch scheduling, transmission security constraints should be considered for the economic and stable electric power system operation. In this paper, we propose an optimal dispatch scheduling algorithm incorporating transmission security constraints. For solving these constraints, the dispatch scheduling problem is decomposed into a master problem to calculate a general optimal power flow (OPF) without transmission security constraints and several subproblems to inspect the feasibility of OPF solution under various transmission line contingencies. If a dispatch schedule given by the master problem violates transmission security constraints, then an additional constraint is imposed to the master problem. Through these iteration processes between the master problem and subproblems, an optimal dispatch schedule reflecting the post-contingency rescheduling is derived. Moreover, since interruptible loads can positively participate as generators in the competitive electricity market, we consider these interruptible loads active control variables. Numerical example demonstrates efficiency of the proposed algorithm.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.98-101
• /
• 2004

Linear Programming(LP) is the term used for defining a wide range of optimization problems in which the objective function to be minimized or maximized is linear in the unknown variables and the constraints are a combination of linear equalities and inequalities. LP problems occur in many real-life economic situations where profits are to be maximized or costs minimized with constraint limits on resources. While the simplex method introduced in a later reference can be used for hand solution of LP problems, computer use becomes necessary even for a small number of variables. Problems involving diet decisions, transportation, production and manufacturing, product mix, engineering limit analysis in design, airline scheduling, and so on are solved using computers. This technique is called Sequential Linear Programming (SLP). This paper describes LP's problems and solves a LP's problems using the neural networks.

• KDI Journal of Economic Policy
• /
• 제43권2호
• /
• pp.1-22
• /
• 2021

The effects of social distancing measures on income distributions and aggregate variables are examined with an off-the-shelf heterogeneous-agent incomplete-market model. The model shows that social distancing measures, which limit households' labor supply, can decrease the labor supply of low-income households who hold insufficient assets and need income the most given their borrowing constraints. Social distancing measures can therefore exacerbate income inequality by lowering the incomes of the poor. An equilibrium interest rate can fall when the social distancing shock is expected to be persistent because households save more to prepare for rising consumption volatility given the possibility of binding to the labor supply constraint over time. When the shock is expected to be transitory, in contrast, the interest rate can rise upon the arrival of the shock because constrained households choose to borrow more to smooth consumption given the expectation that the shock will fade away. The model also shows that social distancing shocks, which diminish households' consumption demand, can decrease households' incomes evenly for every income quantile, having a limited impact on income inequality.

• Industrial Engineering and Management Systems
• /
• 제13권1호
• /
• pp.52-66
• /
• 2014

Promotion of a closed-loop supply chain requires disassembly systems that recycle end-of-life (EOL) assembled products. To operate the recycling disassembly system, parts selection is environmentally and economically carried out with non-destructive or destructive disassembly, and the recycling rate of the whole EOL product is determined. As the number of disassembled parts increases, the recycling rate basically increases. However, the labor cost also increases and brings lower profit, which is the difference between the recovered material prices and the disassembly costs. On the other hand, since the precedence relationships among disassembly tasks of the product also change with the parts selections, it is also required to optimize allocation of the tasks in designing a disassembly line. In addition, because information is required for such a design, the recycling rate, profit of each part and disassembly task times take precedence among the disassembly tasks. However, it is difficult to obtain that information in advance before collecting the actual EOL product. This study proposes and analyzes an optimal disassembly system design using integer programming with the environmental and economic parts selection (Igarashi et al., 2013), which harmonizes the recycling rate and profit using recyclability evaluation method (REM) developed by Hitachi, Ltd. The first stage involves optimization of environmental and economic parts selection with integer programming with ${\varepsilon}$ constraint, and the second stage involves optimization of the line balancing with integer programming in terms of minimizing the number of stations. The first and second stages are generally and mathematically formulized, and the relationships between them are analyzed in the cases of cell phones, computers and cleaners.

• 노동경제논집
• /
• 제23권2호
• /
• pp.1-37
• /
• 2000

1998~99년의 경제위기 상황에서 '경영상 이유에 의한 해고의 제한' 이 입법화되었다. 이 법은 이름 그대로 경영상 해고를 제한하기 위한 것이 아니라 계약상의 고용조정 제한을 완화시켜 노동시장 유연화를 달성하자는 취지에서 입법화되었다. 본 연구의 이론모형은 '코즈정리'의 관접에서, 이러한 공식 제약(formal constraint) 이 민간계약에 미치는 효과를 살펴본다. 즉 법의 고용보호 정도가 변화해 감에 따라 민간 주체들이 맺는 '암묵적 계약(implied contract)'의 경제효율성과 계약의 기회주의적 파기가 어떻게 변화하는가를 분석한다. 본고의 이론모형은 공식 제약의 변화가 민간 주체들의 암묵적 계약 비용을 최소화하는 방향으로 이루어지지 않는다면, 제약의 과도 혹온 과소함을 우회하기 위해 민간 주체들은 추가척인 암묵적 계약을 맺게 되고 이는 결국 계약의 경제효율성을 훼손시킬 수 있다는 합의를 제시한다. 이러한 이론모형의 합의를 한국 노동판결 자료를 통하여 검토해 본다. 사용자의 기회주의를 반영하는 대리변수로서 부당해고 사건의 원고승소율 혹은 근로자의 평균 근속연수의 시계열상 추이를 살펴봄으로써 공식 제약의 변화 이전과 이후에 기회주의적 계약파기의 변화를 실증적으로 살펴본다.

• 가정과삶의질연구
• /
• 제22권2호
• /
• pp.97-107
• /
• 2004

The purposes of this study were compare the leisure attitudes, leisure activities, and leisure constraint among three different generations - teenagers, adults, and elderly adults. Data were obtained from a Questionnaire completed by both male and female lived metropolitan, and aged over 13. Using the factor analysis, this study classified the types of leisure attitudes. The leisure attitude was divided to 4 factors - reducing stress, self-realization, family activity, and surplus time. In order to compare the attitudes, activities, and constraints of leisure among three different generations, ANOVA was used The findings of this study are as follows: First, there were significant differences between teenager group and the others. The teenagers (n=107) recognized the leisure as a mechanism of reducing stress, or as just surplus time. They liked sports, computer games, travels, and reading books, but were not likely to like leisure activities shared with family members. Their leisure constraints were significantly larger than those of the other groups. Teenagers' constraints of time, money, and skills could be leisure barriers. Second, adults group (n=123) attached importance to the family leisure activities. They liked to spend time with their family members, but they seemed to be relatively passive in most types of leisure activities. They like to read newspapers and magazines, and to participate in religious activities. Third, elderly adults' (n=86) purpose of leisure activities was to improve the health condition, and to develop relationships with their friends. They liked sports such as swimming and aerobic dance, travels, religious activities and community service activities. Their good health condition and economic resources could decrease the leisure constraints.

• 노동경제논집
• /
• 제35권3호
• /
• pp.51-81
• /
• 2012

본 연구는 저소득층의 4년제 대학진학을 제약하는 두 가지 요인, 즉 등록금 납부여력 부족과 불우한 성장환경의 누적적 영향에 따른 학업능력 부족 중 무엇의 영향이 더 큰지 살펴보았다. 희귀분석 결과, 중학교 시기의 학업성취와 몇몇 가정배경 변수들은 유의한 반면, 이들 변인 통제 시 대학진학 시기의 가구소득은 4년제 대학 진학에 거의 영향을 주지 못했다. 또한 Carneiro and Heckman(2003)이 미국 고등교육 격차 원인규명을 위해 수행한 분석을 한국 상황에 적용해 본 결과, 학업능력 및 가정배경의 격차로 4년제대에 진학하지 못하는 비율이 등록금 납부가 어려워 진학하지 못하는 비율을 크게 능가했다. 이는 등록금 인하와 같은 단기적 제약요인의 완화만으로는 대입격차문제 해결이 힘듦을 시사한다.

• 산학경영연구
• /
• 제6권
• /
• pp.135-152
• /
• 1993

The optional market segmentation pricing policy for rooms of hotels are investigated under the assumption of a linear demand function, and for four different situations: (1) single price market, (2) optimal segmentation of the unused capacity of a single-price-maeket, (3) optimal segmantation for all rooms, and (4) opimal segmentation for infiltration from higher priced to adjacent lower priced segments. The purpose of tis study is th show that with proper pricing policy, it would be possible to increase profits considerably. Such a profit increase might be achived by market segmentation coupled with product differentiation, where the different market segments are identified, sperated, and in each segment a different price per room is called for. The different prices are determined based on the specific price elasticity typical for each market segment and the relavant costs. The pricing model implied in this study is based on basic economic pricing theory and optimization techniques. While somewhat complex in its mathmatical solution, it can be easily programmed for use by practitioners, avoiding the need to cope with the technical aspects of the solution. In section II-1, the optimal single-market Single-price policy is evaluated. The optimal strategy under the constraint that only the previously unutilized rooms are segmented is analysed in section II-2, while the optimal strategy without this constraint is determined in section II-3. In section II-4, the optimal market-segmentation pricing policy is derived for the case in which market seperation is allowed for all the rooms under the assumption of custtomer infiltration from each market segment to the adjacent lower priced segment Finally, some considerations relating to the practicality of the model as a decision support tool and the requirements for its implementation are discussed in section III.