• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.53-63
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• 2016

Wheel dynamometers are used to measure dynamic load that is conveyed from the road to a vehicle while driving. In this paper, two types of six-component wheel dynamometers utilizing shear deformation and bending deformation were designed and evaluated. Prior to designing the shear and bending type wheel dynamometers, the shear and bending deformation behaviors of the basic structure of the wheel dynamometer itself were analyzed using finite element analysis. Strain analysis was performed repeatedly in order to obtain a similar output sensing strain for each load component. The design was modified with a bridge circuit in order to minimize coupling strain. The results indicated that the shear type dynamometer was expected to obtain stable characteristics due to uniform strain distribution while the bending type dynamometer was expected to obtain high-quality sensitivity performance due to consistent output sensitivity.

• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.187-193
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• 2014

One of the hottest challenges in automotive industry is related to weight reduction in sheet metal forming processes, in order to produce a high quality metal part with minimal material cost. Stamping is the most widely used sheet metal forming process; but its implementation comes with several fabrication flaws such as springback and failure. A global and simple approach to circumvent these unwanted process drawbacks consists in optimizing the initial blank shape with innovative methods. The aim of this paper is to introduce an efficient methodology to deal with complex, computationally expensive multicriteria optimization problems. Our approach is based on the combination of methods to capture the Pareto Front, approximate criteria (to save computational costs) and global optimizers. To illustrate the efficiency, we consider the stamping of an industrial workpiece as test-case. Our approach is applied to the springback and failure criteria. To optimize these two criteria, a global optimization algorithm was chosen. It is the Simulated Annealing algorithm hybridized with the Simultaneous Perturbation Stochastic Approximation in order to gain in time and in precision. The multicriteria problems amounts to the capture of the Pareto Front associated to the two criteria. Normal Boundary Intersection and Normalized Normal Constraint Method are considered for generating a set of Pareto-optimal solutions with the characteristic of uniform distribution of front points. The computational results are compared to those obtained with the well-known Non-dominated Sorting Genetic Algorithm II. The results show that our proposed approach is efficient to deal with the multicriteria shape optimization of highly non-linear mechanical systems.

• The Journal of Sustainable Design and Educational Environment Research
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• v.8 no.1
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• pp.23-33
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• 2009

The purpose of this study was to examine the basic academic achievement of technical high school students, their learning capability about major, their adaptability to school instruction and whether those factors of them was linked to their career in an effort to suggest workable reform measures. Technical high school seniors to grasp their basic learning capabilities and their opinions on the curricula. The findings of the study were as follows: First, the civil engineering students at technical high school weren't fully able to understand what they learned because of their poor basic achievement. They should take all the required courses to fix their academic deficiencies in the first year of high school, and client-centered additional education should be provided about particular subjects, such as mathematics, which they should learn to study their major. Second, many of the students chose technical high school through the advice of parents or since they weren't able to go onto academic high school. So they entered technical high school without knowing well about their major, and vocational education wasn't properly publicized. As students make a critical career decision in middle school, the government should build permanent pavilions for vocational-education exhibition where interested students can acquire information and explore their career without any restraints. Current fragrant vocational education that is based on experiential learning should be avoided. Third, the government substituted regular classroom teaching for field practice, and that resulted in providing just uniform instruction, destroying learning atmosphere and eventually holding teachers back from offering quality education. To remedy the situation, two different sorts of classes should be prepared. One type of classes are for college- bound students, and the others are for job-seeking students. College- bound students should receive education about humanities to improve their academic deficiencies, and job-seeking seniors should be allowed to take field-practice courses at authorized companies in the second semester. It's advisable personally and socially to help ensure their successful and immediate social adjustment.

• Journal of Sasang Constitutional Medicine
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• v.24 no.4
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• pp.17-27
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• 2012

Objectives : This study proposes developing Sasang Medical Diagnosis Program using Facial form for increase in Sasang Constitution Diagnosis objectivity and putting the Diagnosis Program into practical use. The author presents a review of extant research on Sasang constitution diagnosis utilizing facial feature analysis and suggests an agenda for further research. Methods : For this thesis, a collection of dissertations on the subject of 'Usage of facial form for constitution diagnosis' published until September of 2012 such as RISS4U, OASIS, KISTI, Korean TK were reviewed. The final 33 dissertations were classified into two categories, basic or clinical research and then analyzed. Results : 9 out of 33 dissertations were of basic research and 24 were of clinical research. 1) As result of review of references, a uniform tendency was found in facial form according to Sasang Constitution. 2) In the grade of practical use, facial element is repeatedly used and the facial element of important use has constitutional differences. 3) Standard faces per Sasang Constitution were derived as result of 2-dimensional research. 4) 3-dimensional research focused on improvement of accuracy and reliability of 3D-AFRA, and there has been an attempt to develop a prototype for identification. Conclusions : For practical use of facial feature in Sasang Constitution Diagnosis, 1) Standardization of diagnosis through establishing Sasang Medical Diagnosis clinical protocol must be preceded. After the standardization, practical purpose and direction of facial form in general may be decided. 2) Information on high quality facial form of constitutional and conditional patients must be collected to form extensive database. 3) Subdivided symptomatology, as well as Sasang Constitution must be considered for diagnosis in order for diagnosis technique to acquire clinical practicality.

• Fashion & Textile Research Journal
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• v.14 no.4
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• pp.597-606
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• 2012

To increase the productivity and product quality of customized baseball jerseys, this study developed a multi-variable system for a production process that efficiently controls diverse production management factors. The working time was measured through the establishment of a standard process where skilled workers and Chinese factory workers manufactured 5 sets of the same basic design jerseys. Based on the measured working time (1,136 seconds/per unit), the multi-variable process control system was developed, where hourly production management is possible according to the involved workers and equipment types. Each process was assigned accoding to the production management factors for a total of 28 standard processes. The processes were developed based on consideration of work characteristics according to the order of needlework of open-type set baseball jerseys with sleeves(the basic design of baseball jerseys)to result in a customized production system structure that could be set up with multi-variables. As a result, a total 12 types of systems were developed in consideration of the personnel involved and the number of equipments. The optimal production management system (with the highest efficiency compared to the number of workers)was A-2, B-1, C-1. D-2, E-2, F-1, and G-1. This system had extremely high efficiency and showed 99% assignment efficiency for the 7-person team. Though not optimal, possible process assignment for each working personnel is proposed as a reserve process in case work modification is inevitable due to malfunctions and the absence of equipments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3551-3567
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• 2016

The Low Earth Orbit satellite network has the unique characteristics of the non-uniform and time-variant traffic load distribution, which often causes severe link congestion and thus results in poor performance for delay-sensitive flows, especially when the network is heavily loaded. To solve this problem, a novel adaptive routing algorithm, referred to as the delay-oriented adaptive routing algorithm (DOAR), is proposed. Different from current reactive schemes, DOAR employs Destination-Sequenced Distance-Vector (DSDV) routing algorithm, which is a proactive scheme. DSDV is extended to a multipath QoS version to generate alternative routes in active with real-time delay metric, which leads to two significant advantages. First, the flows can be timely and accurately detected for route adjustment. Second, it enables fast, flexible, and optimized QoS matching between the alternative routes and adjustment requiring flows and meanwhile avoids delay growth caused by increased hop number and diffused congestion range. In addition, a retrospective route adjustment requesting scheme is designed in DOAR to enlarge the alternative routes set in the severe congestion state in a large area. Simulation result suggests that DOAR performs better than typical adaptive routing algorithms in terms of the throughput and the delay in a variety of traffic intensity.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.895-903
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• 2016

Spaceborne imaging sensors require periodic calibrations using an on-board calibration device for an image quality of observation satellites. The on-board calibration device consists of a blackbody to provide uniform radiance temperatures and calibration mechanism with a function of stow and deploy to target the blackbody during the calibration. Among these devices, the calibration mechanism is required to implement a fail-safe function to prevent blocking of the main optical path when the mechanism stops at a certain position during on-orbit calibration. In addition, structural safety of the mechanical driving part of the mechanism within the launch environment must be guaranteed. In this study, we proposed a deploy/stow-type calibration mechanism that provides launch-lock and fail-safe function. The effectiveness of the functionality of the proposed mechanism was validated through functional test using engineering model.

• Journal of the Korea Institute of Building Construction
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• v.9 no.5
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• pp.135-144
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• 2009

The primary focus of this study has been directed towards assessing the potential impact of construction method improvement on a reduction in project cost. A total of 90 actual application cases were collected from a public organization and private construction firms, and 32 cases were used in analysis by adopting a synthetic approach. The level of cost reduction was measured in terms of material and labor cost by comparing the existing method and the improved method. An analysis of the results indicates that project cost can be reduced by up to 5.26 percent compared to a normal project by adopting a synthetic approach. Additional benefits include the assurance of uniform quality, savings in terms of labor and/or materials, and improved productivity. The potential of the applicability of this approach to other types of buildings and the implications of research findings were discussed in detail.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1996.11a
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• pp.42-48
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• 1996

Glare phenomenon by sun's altitude and strong sunlight make a much visual handicap. And so, it reaches to unreadable situation although enough illumination in the fore site student of a window site and passage site. In school student seat arrange in the order of their height. So, cause the eyesight acuity according to distance is different, eyesight of backseat's student drop 1.0 and less in spite of 1.0, a learning effect reduces rather then that of the fore site student for site and Passage sitestudents. Therefore. in school, the conclusion's alteration of school structure, position's alteration and material quality's improvement of blackboard are needed, should be local lighting in blackboard. Therefore, we think that in other in improve the effect of lesson by the student, the student seats are not given by uniform disposition in the order of their height but change by a specified period.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.626-633
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• 2016

The objective of this study was to assess the effect of precooling and application of gaseous $ClO_2$ on the retention of freshness and quality of 'Maehyang' strawberry fruits intended for export. 'Maehyang' strawberry fruits (Fragaria ${\times}$ ananassa Duch.) were grown in commercial greenhouses and then harvested. Fruits of uniform and medium size at 60% ripeness were selected and assigned to one of four treatment groups: non-treatment (control), precooling only (PO), gaseous $ClO_2$ only (GCO) or precooling combined with gaseous $ClO_2$ (P + C). Weight loss was lowest in the PO treatment and greatest in the GCO treatment after export. Compared to the control and PO treatment groups, strawberry fruits in the GCO treatment group maintained high brightness and high chroma. Six days after shipping, fruits in the P + C treatment group had the highest soluble solids content, even as high as $10.05^{\circ}Brix$; the lowest value was observed in the PO treatment. The incidence rate of gray mold in strawberry fruits was 20% and 17% in the control and the PO treatment, respectively; in the GCO treatment, the incidence rate of gray mold amounted to 10%. No gray mold was observed in the P + C treatment group. These results indicate that gaseous $ClO_2$ treatment combined with precooling (P + C) was effective in maintaining the freshness of 'Maehyang' strawberry fruits intended for export from South Korea to Hong Kong.