• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.517-521
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• 2016

General industrial robots are difficult to use for precision assembly because they are operated based on position control. Their position accuracy is also usually higher than the assembly clearance (several tens of ${\mu}m$). In previous researches, force control was suggested as a robotic assembly solution. However, this method is difficult to apply in reality because of speed and cost problems. The RCC provides high speed, but applications are limited because the compliance is fixed, and it cannot detect an assembly condition during a task. A variable passive compliance device (VPCD) was developed herein. The VPCD can detect the assembly condition during tasks. This device can provide proper compliance for successful assembly tasks. The pneumatic system and the Stewart platform with an LVDT sensor were applied for measuring the displacement and variable compliance, respectively. The concept design and analysis were conducted to prove the effectiveness of the developed VPCD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.4
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• pp.337-345
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• 1991

This study was designed to investigate the effects of dietary protein ana calcium levels on hematological properties and renal functions of the Pb-administered rats. Male Sprague-Dawley rats were assigned to a 3$\times$3$\times$2 factorial design with 3 levels of protein (40％, 16％, 6％), 3 levels of Ca (1.2％, 0.6％, 0.12％) and 2 feeding Periods (3 and 7 Weeks). The Control group was included separately, The rats were exposed to the drinking water containing 2, 000ppm of lead. Hematocrit, hemoglobin content and RBC count were lower in the Pb-added groups than in the control group and were reduced with decreasing dietary protein and Ca levels. Urinary-aminolevulinic acid was higher in the Pb-added groups than in the control group and increased with decreasing dietary Ca level. However, urinary glucose was higher in the Pb-added groups than in the control group and enhanced with decreasing dietary protein and Ca levels. Creatinine celarance was not affected by the Pb administration when the rats fed the diet containing sufficient protein and Ca.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.23-29
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• 2001

An Obstacle Avoidance System(OAS) of Underwater Vehicle(UV) in diving and steering plane is investigated. The concept of Imaginary Reference Line(IRL), which acts as the seabed in the diving plane, is introduced to apply the diving plane avoidance algorithm to the steering plane algorithm. Furthermore, the distance to the obstacle and the slope information of the obstacle are used for more efficient and safer avoidance. As for the control algorithm, the sliding mode controller is adopted to consider the nonlinearity of the equations of motion and to get the robustness of the designed system. To verify the obstacle avoidance ability of the designed system, numerical simulations are carried out on the cases of some presumed three-dimensional obstacles. The effects of the sonar and the clearance factor used in avoidance algorithm are also investigated. Through these, it is found that the designed avoidance system can successfully cope with various obstacles and the detection range of sonar is proven to bea significant parameter to the performance of the avoidance.

• Bulletin of the Society of Naval Architects of Korea
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• v.11 no.2
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• pp.23-40
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• 1974

Semisubmersible 해양석유시추선의 기본설계에 필요한 파랑중(波浪中)에서 운동(運動)을 계산(計算)하는 이론적방법(理論的方法)을 제시하고 "MOHOLE"과 "SEDCO 1350-F" 석유시추선들의 운동(運動)을 해석하였다. 이 규칙파에서 운동계산을 불규칙해양파(波)에 적용하는 응용해석을 보여주었다. 현재 이론적 방법으로는 6자유도(自由度)의 운동을 해양파의 어떤 방향에 대해서도 정확히 계산할 수 있으며 계산의 정확성은 수조(水槽)에서의 모형선의 운동측정치와 실선(實船)의 운동측정치와 비교하여 증명되었다. 또 현재의 방법은 종전에 개발된 방법보다 더 일반적(一般的)인 경우를 다룰 수 있으며 결과치도 더 정확하다. 극소운동특성을 갖는 해양석유시추선과 부체(浮體)해양구조물의 설계는 경비가 비싸고 시간이 많이 드는 모형실험보다는 유체역학적(流體力學的) Parameters를 신속 정확히 자주 변경 검토해야 하는 기본설계단계에서는 정확한 이론적인 전자계산기에 의한 계산방법이 절실히 필요하다. 예상(豫想)과 같은 부가질량(附加質量)과 감쇠력(減衰力)은 Resonance 운동주기에서만 운동에 영향을 준다. 해양구조물에 작용하는 파력(波力)은 Froude-Krilov force, 부가질량(附加質量) 및 감쇠력(減衰力)과 Restoring force로 구성했으며 규칙파(規則波)에서의 6자유도(自由度) 운동방정식은 본 논문에 제시된 실험측정치(値)와 실험으로 정확도가 증명된 이론치(値)의 부가질량과 감쇠력 계수(係數)를 써서 풀었다. 규칙파(規則波)에서의 계산된 운동을 Pierson Moskowitz 해양파(海洋波) 스펙트럼과 linear superposition principle에 의해 불규칙해양파(不規則海洋波)에서의 운동을 계산하는데 사용했다. 불규칙파(不規則波)에서의 운동은 운동스펙트럼과 통계적 운동치로 나타냈다. 현재의 계산방법은 실제 기본설게에 사용되어 왔으며, 다른 응용분야는 파랑중(波浪中)에서의 파면(波面)과 Deck간(間)의 Clearance, 계류선(係留線)의 동장력(動張力)계산의 기본 Data 및 기본설계의 Draft 등 Parameters를 통(通)한 Optimum Design 등(等)이다. 파(波)의 한 방향(方向)에 대(對)한 전자계산기(電子計算機)(IBM 370 또는 CDC 6400)에 의한 운동계산은 10초(秒)미만밖에 안걸린다. 또 현재의 계산방법은 해양석유시추선뿐 아니라 이와 비슷한 부체(浮體)해양구조물과 Pipe-laying선(船) 또 Supply Boat설계(設計)에도 쓰여지고 있다.

• Korean Journal of Materials Research
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• v.19 no.7
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• pp.349-355
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• 2009

Metal thin film patterns on a LTCC substrate, which was connected through inner via and metal paste for electrical signals, were formed by a screen printing process that used electric paste, such as silver and copper, in a conventional method. This method brought about many problems, such as non uniform thickness in printing, large line spaces, and non-clearance. As a result of these problems, it was very difficult to perform fine and high resolution for high frequency signals. In this study, the electric signal patterns were formed with the sputtered metal thin films (Ti, Cu) on an LTCC substrate that was coated with protective oxide layers, such as $TiO_2$ and $SiO_2$. These electric signal patterns' morphology, surface bonding strength, and effect on electro plating were also investigated. After putting a sold ball on the sputtered metal thin films, their adhesion strength on the LTCC substrate was also evaluated. The protective oxide layers were found to play important roles in creating a strong design for electric components and integrating circuit modules in high frequency ranges.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.742-752
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• 2017

The bridge type of steel concrete composite rahmen or pre-flex has been applied where a lower depth girder is required due to vertical clearance restrictions caused by the crossing of rivers and roads. On the other hand, because these types are not only complicated to manufacture and construct, but also expensive, void slab bridges may be an alternative. In this study, prefabricated PSC-I shape girder was used to make a void slab and all procedures for bridge development, such as analysis, design, fabrication, and real-scale test, were included in the scope of research. The results of this study will provide sufficient background data to be applied to the field and the structural safety has been verified through experiments.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.2
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• pp.141-157
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• 2012

For the application TBM tunneling method, Both tunnel design standard and case study designed & constructed in domestic and foreign have been conducted. According to the study, the number of lane and inner shape (single or duplex) vary depending on the volume of traffic. Also extra space located in the top and bottom of tunnel is used for a multipurpose such as ventilation, disaster prevention, maintenance and administration. To find area ratio according to the components of road TBM tunnel, a standard section was considered as a two-lane road. Then, the analysis of area ratio of this section which consists of components for clearance, extra space in upper and lower tunnel was carried on two widths of shoulder. In addition, after a structural analysis, a thickness requirement of lower slab which is essential for road tunnel was derived on a few supporting types. Through correlation analysis, the ranges of available cross-sectional area between slab thickness and lower extra space of the tunnel was presented.

• Journal of the HCI Society of Korea
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• v.14 no.2
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• pp.83-91
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• 2019

These days, virtually every mobile game has a daily quest system. Daily quest is a great tool that can attract game players by providing daily rewards as the player conducts designated missions. However, conducting similar tasks repeatedly has a risk of becoming tedious duties, and maintaining an enjoyable daily quest is critical in enhancing the overall experience of a game. Based on the awareness on the need for academic research on daily quest systems, this study categorized the types of quests systems implemented in the current mobile games, observed how preferred type differs by player's propensity, and analyzed how motivation of a player can be improved using quest types. The results are (1) the staged rewards after each clearance of a task improve a player's motivation, (2) players with high autonomy should be given a freedom to choose their own quests, and (3) players who values their playing skills higher are motivated by providing a feedback on the completion of a task.

• Asia-Pacific Journal of Business
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• v.11 no.1
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• pp.145-165
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• 2020

Purpose - The purpose of this study is to suggest strategies and solutions for entering China in the tariff and non-tariff sectors of the cosmetic industry. Design/methodology/approach - This study analyzed the import tariff rate of cosmetics in China, and analyzed the export cost by actually interviewing the exporting companies to derive the economic effect of non-tariff measures. Findings - First, We proposed the use of the FTA business model (basic cosmetics), the use of Korea-China FTA tariffs (foam cleansing, toothpaste), and the use of APTA tariffs (perfume). Second, We proposed cooperation between the governments to facilitate customs clearance procedures and improvement of FTA awareness among corporate practitioners. Third, We proposed the expansion and support of the AEO MRA system and the expansion of Korea-China MOU conclusions regarding the certification system, and the international standardization of domestic licensing system and technical conditions. Fourth, We proposed the use of government-supported projects related to obtaining overseas certifications and overseas expansion through collaboration with the same industry. Research implications or Originality - HS3304 products excluded from the Korea-China FTA should take full advantage of the FTA business model. In addition, the non-tariff measure costs are fixed costs per year, so the ratio decreases as the number of exports and export volume increases.

• Journal of Korea Trade
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• v.23 no.7
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• pp.34-44
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• 2019

Purpose - The purpose of this study is to present what the port of Pyeongtaek, the hub of Korean trade with China, should improve in the current situation, wherein the e-commerce trade volume between Korea and China is increasing due to the development of online technology. Design/methodology - In this study, through prior research and expert interviews on e-commerce and port activation between borders, we derived the main improvement factors for 1) Administration and Systems, 2) Facilities, 3) Transport, and 4) Manpower, and selected 12 detailed variables for the major improvement factors. To identify the relative importance of the major improvement factors, the Analytic Hierarchy Process (AHP) method was applied, and a survey was conducted among 15 related experts. Findings - As a result, among the 12 detailed variables, Composition of Association (0.267) was the first factor to be improved, followed by Incentive Support (0.143) and E-Commerce Cluster (0.131). Based on these analyses, the main implications of this study are, first, in the current situation where the cross-border e-commerce market is growing, Pyeongtaek Port needs to form a consultative body among the government, local governments, and related businesses in connection with cross-border e-commerce and develop various support policies for the e-commerce market. Second, it will have to be able to provide differentiated services from competing ports by establishing e-commerce market-oriented clusters. Originality/value - In existing related studies, various improvements were presented to revitalize trade in line with the growth of the cross-border e-commerce market. However, with regard to most cross-border e-commerce businesses, one-dimensional improvement measures, such as improvement of payment systems, improvement of customs clearance services, and promotion of human resources, are presented in a piecemeal manner. In other words, none of the studies have proposed the importance and priority of each measure in terms of both the forward-looking and efficient allocation of resources, which is the purpose of this study. Therefore, this study contributed politically, practically, and academically by presenting countermeasures for ports to revitalize cross-border e-commerce and presenting strategic priorities using quantitative analysis methods.