• 대한산업공학회지
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• 제34권1호
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• pp.98-107
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• 2008

The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unittime. This study considers a linear connected-(r, s)-ouI-of-(m, n):f lattice system whose components are orderedlike the elements of a linear (m, n)-matrix. We assume that all components are in the state 1 (operating) or 0(failed) and identical and s-independent. The system fails whenever at least one connected (r, s)-submatrix offailed components occurs. To find the optimal threshold of maintenance intervention, we use a simulatedannealing(SA) algorithm for the cost optimization procedure. The expected cost per unit time is obtained byMonte Carlo simulation. We also has made sensitivity analysis to the different cost parameters. In this study,utility maintenance model is constructed so that minimize the expense under full equipment policy throughcomparison for the full equipment policy and preventive maintenance policy. The full equipment cycle and unitcost rate are acquired by simulated annealing algorithm. The SA algorithm is appeared to converge fast inmulti-component system that is suitable to optimization decision problem.

• 한국관광식음료학회:학술대회논문집
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• 한국관광식음료학회 2005년도 학술논문발표집
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• pp.80-91
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• 2005

Recently, hotel industry has realized the importance of food and beverage sales for the profit maximization, and the focuses on restaurant management has been growing. Accordingly, menu management in the F/B department is one of the most key factors determining the success or failure of business. Therefore, in this study, entree menu items of french restaurant in the deluxe hotel was analysed with presently theorized model of menu analysis, classified into four menu items. Also it was analyzed how those classified menu items influence on sales, number of sold, food cost percentage, contribution margin And, proper ways was presented to make restaurant managers and menu planner in order to increase food operation sales through proper modifications and methods on various menu analysis matrix. In Pavesic's menu analysis method, all of menu items have impact on the sales, number of sold, contribution margin and Primes, Sleepers do so on the food cost. The finding of this study was that Pavesic's menu analysis is superior to menu analysis in terms of the sales, number of sold, food cost percentage, contribution margin. Therefore, Pavesic's menu analysis is useful and efficient method in order to conduct menu engineering.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.494-496
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• 2013

Cost-Benefit Analysis (CBA) is a systematic optimization process that allows users to compare different alternatives and to determine if a project is a solid investment. Many state DOTs have included CBA in their pavement management systems (PMSs) to help allocate state funds for maintenance, rehabilitation, resurfacing, and reconstruction of pavements. In a typical CBA, each pavement type has an assigned weight factor which represents the level of importance of this pavement type. To conduct an accurate CBA, it is essential to select appropriate weight factors. Arbitrarily assigning weights factors to pavements can lead to biased and inaccurate funding allocation decisions. The purpose for this paper is to outline a method to develop an ideal set of weight factors that can be utilized to conduct more accurate CBA. To this end, a matrix of all possible weight factors sets was developed. CBA was conducted for each set of weight factors to obtain a population of possible optimization solutions. Then a regression analysis was performed to establish the relationship between benefit and weight factors. Finally, a multi-objective genetic algorithm was applied to select the optimal set of weight factors. The findings from this study can be used by state DOTs to strategically manage their roadway systems in a cost effective manner.

• 대한치과보철학회지
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• 제38권3호
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• pp.366-374
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• 2000

FRC/ceromer system provides the clinician with a durable, flexible, and esthetic alternative to conventional porcelain fused to metal crowns. FRC is the matrix which is silica-coated and embedded in a resin matrix. The ceromer material which is a second generation indirect composite resin contains silanized, microhybrid inorganic fillers embedded in a light-curing organic matrix. FRC/ceromer restoration has a several advantages: better shock absorption, less wear of occluding teeth, translucency, color stability, bonding ability to dental hard tissues, and resiliency. It has versatility of use including inlay, onlay, single crown, and esthetic veneers. With adhesive technique, it can be used for single tooth replacement in forms of inlay adhesion bridge. In single tooth missing case, conventional PFM bridge has been used for esthetic restoration. However, this restoration has several disadvantages such as high cost, potential framework distortion during fabrication, and difficulty in repairing fractures. Inlay adhesion bridge with FRC/ceromer would be a good alternative treatment plan. This article describes a cases restored with Targis/Vectris inlay adhesion bridge. Tooth preparation guide, fabrication procedure, and cementation procedure of this system will be dealt. The strength/weakness of this restoration will be mentioned, also. If it has been used appropriately in carefully selected case, it can satisfy not only dentist's demand of sparing dental hard tissue but also patient's desire of seeking a esthetic restorations with a natural appearance.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2001년도 추계 컨퍼런스: 인터넷 비즈니스 환경에서의 디지털 컨텐츠 기술 발전 및 활용을 위한 컨퍼런스
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• pp.567-581
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• 2001

인터넷이 일반화된 지 불과 10년이 못되었지만, 기업뿐만 아니라 우리 사회 전반에 걸친 패러다임을 변화시키고 있다. 이와 같이 무선인터넷을 기반으로 한 모바일 비즈니스에 대한 관심은 높지만, 기존의 문헌들은 무선인터넷 서비스 수요, 사용자 만족도 등에 관한 연구가 주를 이루고 있다. 즉 모바일 비즈니스 모델을 통한 무선인터넷 서비스의 향후 진화방향에 관한 연구는 전무한 실정이다. 본 연구의 목적은 문헌고찰을 통하여 모바일 비즈니스의 모델들을 정리하고, 오재인(2000)의 The 2$\times$2 Matrix를 분석 툴을 활용하여 모바일 서비스별 현재 수요와 향후 수요를 분석함으로써 모바일 비즈니스의 진화방향을 실증적으로 규명하는 것이다. 1540명의 회수된 설문지 중 유효표본 786개를 대상으로 통계분석을 실시하여 분석된 주요 연구결과는 다음과 같다. 첫째, 모바일 서비스들을 The 2$\times$2 Matrix상에 매핑한 결과 예측에는 별다른 차이가 없는 것으로 나타났다. 둘째, 전체응답자, 사용자, 비사용자들의 모바일 서비스에 대한 순위는 The 2$\times$2 Matrix에서 Mobile Hub, Mobile Trade, Mobile Care, Mobile Support 순으로 나타났다. 셋째, 현재와 향후 각 서비스들 간에는 차이가 있고, 현재 모바일 서비스들 각각과 향후 모바일 서비스들 각각에 대하여 서비스들 순위에는 차이가 없는 것으로 나타났다. 넷째, 무선인터넷의 전반적인 만족도에 영향을 미치는 요인은 우수하고 독특한 컨텐츠, 패킷 과금으로 저렴한 서비스를 제공하는 Cost전략 등으로 나타났다.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.75-80
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• 2004

Vehicle structures are composed of many substructure connected to one another by various types of mechanical joints. In vehicle engineering it is important to study these connected structures under various dynamic forces for the evaluations of fatigue life and stress concentration exactly. It is difficult to obtain the accurate load history of specified positions because of the errors such as modeling, measurement and etc. In the beginning of design exact load data are actually necessary for the fatigue strength and life analysis to minimize the cost and time of designing. In this paper, the procedure of practical dynamic force determination is developed by the combination of the principal stresses of F. E. Analysis and experiment. Least square pseudo inverse matrix is adopted to obtain in inverse matrix of analyzed stresses matrix. The error minimization method utilizes the inaccurate measured error and the shifting error that the whole data is stiffed over real data. The least square criterion is adopted to avoid these non. Finally, to verify the proposed procedure, a bus is analyzed. This measurement and prediction technology can be extended to the structural modification of any geometric shape in complex structure.

• 대한기계학회논문집A
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• 제25권10호
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• pp.1621-1626
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• 2001

The structural optimization have been carried out in the continuous design space or in the discrete design space. Methods fur discrete variables such as genetic algorithms , are extremely expensive in computational cost. In this research, an iterative optimization algorithm using orthogonal arrays is developed for design in discrete space. An orthogonal array is selected on a discrete des inn space and levels are selected from candidate values. Matrix experiments with the orthogonal array are conducted. New results of matrix experiments are obtained with penalty functions leer constraints. A new design is determined from analysis of means(ANOM). An orthogonal array is defined around the new values and matrix experiments are conducted. The final optimum design is found from iterative process. The suggested algorithm has been applied to various problems such as truss and frame type structures. The results are compared with those from a genetic algorithm and discussed.

• 한국공작기계학회논문집
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• 제10권5호
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• pp.118-123
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• 2001

Most structures of automobile are composed of many substructures connected to one another by various types of mechanical joints. In automotive engineering, it is important to study these connected structures under various dynamic farces for the evaluations of fatigue life and stress concentration exactly. It is rarely obtained the accurate load history of specified positions because of the errors such as modeling, measurement, and etc. In the beginning of design, exact load data are actually necessary for the fatigue strength and life analysis to minimize the cost and time of designing. In this paper, the procedure of practical dynamic load determination is developed by the combination of the principal stresses of F.E. analysis and experiment. Inverse problem and least square pseudo inverse matrix are adopted to obtain an inverse matrix of analyzed stresses matrix. Pseudo-Practical dynamic load was calculated for Lab. Test of sub-structure. GUI program(PLODAS) was developed for whole of above procedure. This proposed method could be extended to any geometric shape of structure.

• 센서학회지
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• 제22권6호
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• pp.400-403
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• 2013

The piezoelectric composite film of ferroelectric PZT ceramic ($PbZr_xTi_{1-x}O_3$) and polymer (PDMS, Polydimethylsiloxane) was prepared to improve the flexibility of piezoelectric material. The bar coating method was applied to fabricate flexible nanocomposite film with large surface area by low cost process. In the case of using metal electrode on the composite film, although there is no problem by bending process, the electrode is usually broken away from the film by stretching process. However, the well-attached, flexible CNT electrode on PZT/PDMS film improved flexibility, especially stretchability. PZT particles was usually settled down into polymer matrix due to gravity of the weighty particle, so to improve the dispersion of PZT powder in polymer matrix, small amount of additives (CNT powder, Carbon nanotube powder) was physically mixed with the matrix. By stretching the film, an output voltage of PZT(70 wt%)/PDMS with CNT (0.5 wt%) was measured.

• 한국항공우주학회지
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• 제47권1호
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• pp.75-80
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• 2019

최근 항공우주 및 방위산업 분야에서 다양한 임베디드 시스템들의 소형화 및 저가화 개발이 많이 요구되고 있다. 본 논문에서는 고속 DSP를 이용하여 임베디드 시스템을 개발한다. 또한 비행 조종과 같은 고정밀 알고리즘의 연산시간을 줄이기 위해 행렬 곱을 위한 두 가지 알고리즘을 제안하고 구현한다. 개발한 임베디드 시스템을 이용하여 성능을 검증한 결과, $2{\times}2$ 단위 계산방법을 이용한 기존 방법과 성능을 비교했을 때 첫 번째 제안방법은 행렬의 사이즈가 작을 때 성능이 개선된다. 두 번째 제안방법은 $2{\times}2$ 단위 계산방법보다 전체적으로 성능이 우세하다.