• Management Science and Financial Engineering
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• 제19권2호
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• pp.19-29
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• 2013

Refuse collection network design, one of major decision problems in reverse logistics, is the problem of locating collection points and allocating refuses at demand points to the opened collection points. As an extension of the previous models, we consider capacity and maximum allowable distance constraints at each collection point. In particular, the maximum allowable distance constraint is additionally considered to avoid the impractical solutions in which collection points are located too closely. Also, the additional distance constraint represents the physical distance limit between collection and demand points. The objective is to minimize the sum of fixed costs to open collection points and variable costs to transport refuses from demand to collection points. After formulating the problem as an integer programming model, we suggest an optimal branch and bound algorithm that generates all feasible solutions by a simultaneous location and allocation method and curtails the dominated ones using the lower bounds developed using the relaxation technique. Also, due to the limited applications of the optimal algorithm, we suggest two heuristics. To test the performances of the algorithms, computational experiments were done on a number of test instances, and the results are reported.

• 한국전기전자재료학회논문지
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• 제23권2호
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• pp.169-173
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• 2010

Because of power consumption increase, global warming, and limitation of installation, not only high reliability and interruption capability but also compact and light power apparatuses are needed. In this paper, E field calculation and experiment were processed to identify the influence of the shape of end shield and gap distance. It is expected that the results of FEM simulation and experiments could be the basic data to develop VI. the results of FEM simulation and experiments are as following. Firstly, maximum E fields were compared by means of finite element method as a function of the shape of end shield. 3 types of models were used to analyze maximum E field of each model and the influence of shape of shield could be identified. As a result, proposed L type shield could reduce the maximum E field by 20%. Secondly, the influence of the gap distance between end shields on E field was analyzed. As the gap distance become short the gap distance between inner walls of ceramic also become short. And the maximum E field concentrated on inner wall of ceramic finally increased. Thirdly, the experiment was conducted by fabricating each prototype. As a result, no creepage occurred in shieldless model. In other words, creepage occurred in the shield-installed models. And creepage inception voltages were different from each other because of the difference of maximum E field. Fourthly, The equation that shows relation between calculated E field and measured creepage inception voltage was proposed as a result of FEM analysis and experiment. It is concluded that when designing VI this equation could be important data to reduce time and cost by identifying indirectly the optimal gap distance and the shape of shield required to prevent creepage.

• Journal of Magnetics
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• 제20권4호
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• pp.450-459
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• 2015

In this paper, the safety distances and maximum permissible power (MPP) of resonant wireless power transfer systems are defined and derived with regard to human exposure to electromagnetic field (EMF). The definition is based on the calculated induced current density and electric field in the standard human model located between the transmitting and receiving coil. In order to avoid the adverse health effects such as stimulation of nerve tissues, the induced current and electric field must not exceed the basic restriction values specified in EMF safety guidelines. The different combinations of diameters of the coils and the distance between the two coils are investigated and their effects are analyzed. Two versions of EMF safety guidelines (ICNIRP 1998 and ICNIRP 2010) are used as bases for safety distance calculation and the difference between the two guidelines are discussed.

• 한국정보통신학회논문지
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• 제19권2호
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• pp.287-292
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• 2015

본 논문에서는 사용자들의 밀집도 정보를 기반으로 설정된 목표지역과 릴레이 단말의 수를 제한한 환경에서 광고 확산을 위한 최대 거리 기반 릴레이 단말 선택 알고리즘과 최대 효율 기반 릴레이 단말 선택 알고리즘의 성능을 비교 분석하였다. 최대 거리 기반 릴레이 단말 선택 알고리즘은 단말간의 거리 정보만을 이용하여 릴레이 단말을 선택하고, 최대 효율 기반 릴레이 단말 선택 알고리즘은 설정된 목표지역들을 활용하여 최대 광고 효율을 위한 광고 확산 루트를 설정하였다. 시뮬레이션을 통해 광고를 섹터 수의 변화에 따른 성공적으로 수신한 전체 사용자 수와 전송 효율에 대한 성능을 비교하여, 최대 거리 기반 릴레이 단말 선택 알고리즘 보다 최대 효율 기반 릴레이 단말 선택 알고리즘 성능의 우수성에 대해 분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권3호
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• pp.932-951
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• 2021

The effectiveness of testing in Model-based Testing (MBT) for Software Product Line (SPL) can be achieved by considering fault detection in test case. The lack of fault consideration caused test case in test suite to be listed randomly. Test Case Prioritization (TCP) is one of regression techniques that is adaptively capable to detect faults as early as possible by reordering test cases based on fault detection rate. However, there is a lack of studies that measured faults in MBT for SPL. This paper proposes a Test Case Prioritization (TCP) approach based on dissimilarity and string based distance called Last Minimal for Local Maximal Distance (LM-LMD) with Dice-Jaro-Winkler Dissimilarity. LM-LMD with Dice-Jaro-Winkler Dissimilarity adopts Local Maximum Distance as the prioritization algorithm and Dice-Jaro-Winkler similarity measure to evaluate distance among test cases. This work is based on the test case generated from statechart in Software Product Line (SPL) domain context. Our results are promising as LM-LMD with Dice-Jaro-Winkler Dissimilarity outperformed the original Local Maximum Distance, Global Maximum Distance and Enhanced All-yes Configuration algorithm in terms of Average Fault Detection Rate (APFD) and average prioritization time.

• 자동차안전학회지
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• 제11권1호
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• pp.40-47
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• 2019

First, three point bending analysis for the inclined press door impact beam was carried out to investigate inclination angle effect on the maximum strength with varying support distance. Next, for the system model with spring elements representing body stiffness at door mounting area, the bending structural behavior of impact beam mounted on vehicle was estimated. The mounting distance and inclination angle were changed and the beam bending buckling strength was presumed at the head displacement below which spring stiffness change has little effect on the load. Finally strength ratio to predict the bending buckling strength of impact beam mounted on vehicle from three point bending maximum strength of fixed support distance was suggested.

• Journal of Pharmaceutical Investigation
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• 제30권2호
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• pp.85-91
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• 2000

We have studied the dissolution kinetics of two fast releasing tablets in four media, and the similarity of dissolution profiles was compared using 3 methods. Two of the methods were introduced from statistical algorithm of distance methods, which are maximum distance and Mahalanobis distance. The dissolution kinetics were also analysed using FDA method for similarity evaluation, and the results were compared with those obtained using the distance methods.

• Water Engineering Research
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• 제1권2호
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• pp.159-168
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• 2000

In this paper, the increment of the local scour depth at piers by constructing the bridge between existing bridges is examined through the experiments in which 5 piers in the non-cohesive bed material in the experimental flume were installed. In the experiments the maximum distance of 25 times of the pier length and the maximum distortion width of 8 times of the pier width were utilized. Through the experimental studies, it was indicated that low flow, which can be characterized as the flow having low Froude numbers, the maximum bed configuration change is obtained when the piers are installed in the straight line in the flor direction without any distortion. However, In the high flow, which can be characterized as the flow having high Froude numbers, the maximum bed configuration change is obtained when the piers are installed with some distortion from the flow direction. The influence of the bed configuration by interaction between bridge piers is changed depending upon the Froude numbers, the distance between piers, and the distortion width between adjacent bridge piers. Also, because the scour patterns are affected by the bed configuration, the maximum scour should be increased by about 60% compared to that in a single pier if the interaction between bridge piers exists. It can be suggested that the maximum scour depth at bridge piers predicted by applying the existing equations should be increased if the interaction between bridge piers exist. Those cases are found when new bridges are constructed successively in the river in the urban area.

• 대한디지털의료영상학회논문지
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• 제12권2호
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• pp.119-125
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• 2010

In order to demonstrate the value of long-distance radiography, we have studied how distance affects images in chest frontal radiography and compared short-distance and long-distance images in chest lateral radiography. Cardiothoracic ratio(CTR %) of 50 patients with no disease in the chest(10 each at the age of 20~60) were evaluated in Supine AP(100 cm), Sitting AP(100 cm), Sitting AP(180 cm), and Erect PA(180 cm). In lateral radiography, we evaluated and compared left lateral radiography(100 cm and 180 cm) of the patients based on the horizontal maximum of the heart. The average value of CTR(%) were 0.48 in Erect PA(180 cm), 0.52 in Supine AP(100 cm), 0.50 in Sitting AP(100 cm), 0.49 in Sitting AP(180 cm), which were Supine AP(100 cm) > Sitting AP(100 cm) > Sitting AP(180 cm) > Erect PA(180 cm). The average value of Maximum transverse diameter of left of the cardiac(MLD), which showed how much axis of spine was slanted to the left, was 90.67 mm in Erect PA(180 cm), 103.92 mm in Supine AP(100 cm), 93.54 mm in Sitting(100 cm), 89.84 mm in Sitting AP(180 cm), 58.11 mm in the minimum value and 118.79 mm in the maximum value. The average value of Maximum transverse diameter of right side of the cardiac(MRD), which suggested how much axis of spine was slanted to the right, was 47.18 mm in Erect PA(180 cm), 48.12 mm in Supine AP(100 cm), 44.98 mm in Sitting AP(180 cm), and the minimum value 26.84 mm and the maximum value 65.30 mm. There was no standard method to calculate; therefore, the horizontal maximum of the heart was used for lateral radiography. The average value was 121.07 mm in 100 cm and 109.76 mm in 180 cm. Sitting AP(180 cm) among the types was closest to C-PA(180 cm). As a result, during C-AP radiography, long-distance radiography lessened shadow of the heart more than that of short distance, Sitting position more than Supine position.

• 한국산학기술학회논문지
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• 제7권3호
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• pp.265-270
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• 2006

복합재로 된 판재에 대하여 동적 균열이 접합면을 따라서 진행되어 가면서 찢어져 나갈 때 그 계면 주위에서의 응력 상태 및 변형, 견인응력 등을 조사하였다. 최대의 등가응력 및 소성 변형율은 접촉이 바로 떨어지는 부분에서 그리고 판 끝부분의 휘어지는 부근에서 최대의 변형량이 되었다. 견인력은 0.015mm정도로 그 면이 떨어졌을 때 최대치 75 MPa로서 되었다가 서서히 낮아지면서 0.13mm이상 떨어졌을 때는 0으로 일정하게 되었다. 이러한 연구 자료로서 정확한 파괴강도 해석과 안전설계 및 새로운 고급재료의 개발에 필요한 자료를 제공할 수 있는 기초적인 연구를 수행함이 본 연구의 목적이다.