• 대한산업공학회지
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• 제32권1호
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• pp.42-50
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• 2006

The multi-criteria group decision making (MCGDM) problem is to determine the best compromise solution in a set of competing alternatives that are evaluated under conflicting criteria by decision maker (DM)s. In this paper, we propose a mixed-integer programming (MIP) model to solve MCGDM. The existing method based on minimizing a distance measure such as Median Approach can not guarantee the best compromise solution because the element of median point vector is defined with respect to each criteria separately. However, by considering all criteria simultaneously, we generate median point that is better for locating the best compromise solution. We also utilize the concept of spatial dispersion index (SDI) to produce a threshold value, which is used as a guideline to choose either the Utopian Approach or the Median Approach. And we suggest using CBITP (Convex hull of individual maxima Based Interactive Tchebycheff Procedure) to provide DMs with various Pareto-optimal solutions so that DMs have broad range of selection.

• 대한수학회보
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• 제49권6호
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• pp.1213-1222
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• 2012

The aim of this paper is to establish the existence of three solutions for a Sturm-Liouville mixed boundary value problem. The approach is based on multiple critical points theorems.

• 경영과학
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• 제33권2호
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• pp.75-87
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• 2016

Quality function deployment (QFD) is a widely adopted customer-oriented product development methodology by analyzing customer requirements. It is a main activity in QFD planning process to determine the optimal values of the technical attributes (TAs) so as to achieve the customer requirements (CRs) from the House of Quality (HoQ). In most of the previous research, all the TAs in QFD are assumed to have either continuous or discrete values. In the real world applications, the continuous TAs and the discrete TAs are often mixed in QFD. In this paper, a mixed integer linear programming model is formulated to obtain the optimal values for the continuous TAs and the discrete TAs in QFD planning as well as Branch and Bound (B and B) algorithm is proposed as the solution approach. Finally, the proposed model and solution approach are illustrated with an office chair under multi-segment market, and the sensitivity analysis is performed to study how the proposed model and its solutions respond to the variation for the two elements which are budget and CRs' weights.

• 한국전자거래학회지
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• 제23권3호
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• pp.1-12
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• 2018

혼합 중요도 시스템은 중요도가 다른 컴포넌트의 조합으로 이루어져 있다. 최근 자동차 시스템과 항공기 시스템에서 사용되는 ISO 26262와 DO-178B 표준에서는 컴포넌트를 중요도에 따라 분류하고 있다. 기존 혼합 중요도 시스템 연구에서는 시스템 모드를 통해서, 효율적이면서 안전한 스케줄링을 추구했다. 이러한 연구의 단점은 고중요도 모드에서 저중요도 작업의 성능저하이다. 이러한 문제를 개선하고자 작업별 중요도 모드를 도입하여 저중요도 작업의 성능을 개선하고 확률적 성능 지표를 설계했다. 시뮬레이션을 통해서 기존 연구 대비 성능 향상 효과를 보였다.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제25권4호
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• pp.440-446
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• 2023

Craniotomy is known as a cause of iatrogenic dural cerebral arteriovenous fistula (AVF). However, mixed pial and dural AVFs after craniotomy are extremely rare and require accurate diagnosis and prompt treatment due to their aggressiveness. We present a case of an iatrogenic mixed pial and dural AVF diagnosed 2 years after pterional craniotomy for surgical clipping of a ruptured anterior choroidal aneurysm. The lesion was successfully treated using single endovascular procedure of transvenous coil embolization through the engorged vein of Labbe and the superficial middle cerebral vein. The possibility of the AVF formation after the pterional approach should always be kept in mind because it usually occurs at the middle cranial fossa, which frequently has an aggressive nature owing to direct cortical venous or leptomeningeal drainage patterns. This complication is believed to be caused by angiogenetic conditions due to coagulation, retraction, and microinjuries of the perisylvian vessels, and can be prevented by performing careful sylvian dissection according to patient-specific perisylvian venous anatomy.

• 대한전기학회논문지:전력기술부문A
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• 제55권11호
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• pp.492-497
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• 2006

Nash Equilibrium (NE) is essential to investigate a participant's bidding strategy in a competitive electricity market. The transmission line constraints make it difficult to compute the NE due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The competition among multi-participants is modeled by a two-level hierarchical optimization problem. A mathematical programming approach is widely used in finding this equilibrium. However, there are difficulties to solving a mixed strategy NE. This paper presents two propositions to add heuristics to the mathematical programming method. The propositions are based on empirical studies on mixed strategies in numerous sample systems. Based on the propositions a new formulation is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the prepositions and the newly-formulated equations.

• Asian-Australasian Journal of Animal Sciences
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• 제33권9호
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• pp.1520-1532
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• 2020

Objective: Due to rapid economic return, mixed crop-swine farming systems in Korea have become more intensive. Intensive farming practices often cause nutrient surpluses and lead to environmental pollution. Nutrient budgets can be used to evaluate the environmental impact and as a regulatory policy instrument for nutrient management. This study was conducted to select a nutrient budgeting approach applicable to the mixed crop-swine farms in Korea and suggest an effective manure treatment method to reduce on-farm nutrient production. Methods: In this study, we compared current and ideal gross nutrient balance (GNB) approaches of Organisation for Economic Co-operation and Development and soil system budget (SSB) approach with reference to on-farm manure treatment processes. Data obtained from farm census and published literature were used to develop the farm nutrient budgets. Results: The average nitrogen (N) and phosphorus (P) surpluses were approximately 11 times and over 7 times respectively higher in the GNB approaches than the SSB. After solid-liquid separation of manure, during liquid composting a change in aeration method from intermittent to continuous reduced the N and P loading about 50% and 47%, respectively. Although changing in solid composting method from turning only to turning+aeration improved the N removal efficiency by 30.5%, not much improvement in P removal efficiency was observed. Conclusion: Although the GNB approaches depict the impact of nutrients produced in the mixed crop-swine farms on the overall agricultural environment, the SSB approach shows the partitioning among different nutrient loss pathways and storage of nutrients within the soil system; thus, can help design sustainable nutrient management plans for the mixed cropswine farms. The study also suggests that continuous aeration for liquid composting and turning+aeration for solid composting can reduce nutrient loading to the soil.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.751-753
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• 1996

The $H_{2}$/$H_{\infty}$ robust controller is designed by using polynomial approach. This controller can minimise a $H_{2}$ norm of error under the fixed bound of $H_{\infty}$ norm of mixed sensitivity function by employing the Youla parameterization and using polynomial approach at the same time. It is easy to apply this controller to adaptive system.

• 아태비즈니스연구
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• 제13권2호
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• pp.197-207
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• 2022

Purpose - This study reestablished the concept of mixed emotions experienced in online and offline shopping environments, and structuralized emotional responses which manifest mixed emotions in each channel, and developed a method of measuring overall mixed emotions in consideration of the asymmetry of emotions. Design/methodology/approach - This study conducted a focus in-depth interview based on phenomenological research and exploratory preliminary survey using questionnaires. In addition, a survey was conducted as a quantitative survey. Findings - Qualitative and quantitative researches were conducted to derive major emotional responses items which manifest mixed emotions in online and offline shopping environments and determine differential emotional structure in each channel. As a result, it was confirmed that mixed emotions consisted of 5 factors in each channel and 21 emotional responses. In addition, a method of measuring overall mixed emotions considering the asymmetric of emotions was developed to prove the difference in behavioral responses. Research implications or Originality - This study is meaningful in that it helps companies efficiently manage and understand customer responses to their products by classifying and systemizing the emotional responses experienced by consumers in online and offline purchase and consumption situations according to the purchase environment.

• Journal of Contemporary Eastern Asia
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• 제12권1호
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• pp.21-34
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• 2013

How do mixed legislative systems shape voter behavior and public perceptions? Through an analysis of the electoral systems in Japan, South Korea, and Taiwan, this paper evaluates the extent to which the public in these three countries understand their mixed systems and whether claims of voter ignorance translate into irrational voting behavior based on the institutional effects of mixed systems. Through a multi-method approach including data from outside of East Asia, this analysis seeks to determine whether these three cases exhibit patterns consistent with other mixed systems. Empirical analysis affirms levels of strategic voting consistent with comprehension of electoral rules. Furthermore, this analysis suggests a disconnect between practical knowledge and electoral expectations.