• 전기학회논문지
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• 제64권1호
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• pp.136-142
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• 2015

In the paper, a design method of knee and pelvis joint in the biped robot is proposed for shock absorption and gravity compensation. Similarly to the human's body, the knee joints of the biped robot support most body weight and get a shock from the landing motion of the foot on the floor. The torque of joint motor is also increased sharply to keep the balance of the robot. Knee and pelvis joints with the spring are designed to compensate the gravity force and reduce the contact shock of the robot. To verify the efficiency of the proposed design method, we develope a biped robot with the joint mechanism using springs. At first, we experiment with the developed robot on the static motions such as the bent-knee posture both without load and with load on the flat ground, and the balance posture on the incline plane. The current of knee joint is measured to analyze the impact force and energy consumption of the joint motors. Also, we observe the motor current of knee and pelvis joints for the walking motion of the biped robot. The current responses of joint motors show that the proposed method has an effect on shock reduction and gravity compensation, and improve the energy efficiency of walking motions for the biped robot.

• 한국기계가공학회지
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• 제18권2호
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• pp.65-72
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• 2019

In long freight trains, there is a brake time delay in neighboring freight cars, which causes damage and fractures in the couplers, especially at their knuckle. A problem in the couplers of the cars can cause derailment and damages of human life and property. In this study, maximum forces on the couplers are studied when a long freight car brakes with the brake delay time and coupler gap. We make a dynamic model of 50 freight cars and couplers, applying contact between the couplers and a characteristic curve to express the force and displacement of the buffers using SIMPACK, which is a multi-body dynamics program. We use EN 14531-2, which is a standard of freight car brakes, to verify the dynamic model. Then, we compare the analyzed impact force with the coupler knuckle standard after applying the two carriages of a locomotive in the model based on the dispersed double head control system. The result shows that all coupler gap conditions satisfy the infinite lifetime of the material when the brake delay time is 0.1 second.

• 한국포장학회지
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• 제29권3호
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• pp.203-209
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• 2023

The increasing saturation challenges in storage facilities for Low- and Intermediate-Level Radioactive Waste call for a more efficient storage approach. Consequently, we have developed a square-structured container that features a storage capacity approximately 20% greater than that of conventional drum-type containers. Considering the need to contain various radioactive wastes from nuclear power usage securely until they no longer pose a threat to human health or the environment, this study focuses on evaluating the sealing efficacy of the newly designed rectangular container using finite element analysis. Since radioactive waste containers typically do not experience external forces except under special circumstances, our analysis simulated the impact of an external force, assuming a fall scenario. After fastening the bolts, we examined the vertical stress distribution on the container by applying the calculated external force. The analysis confirms the container's stable seal.

• Asia Pacific Journal of Business Review
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• 제4권2호
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• pp.23-33
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• 2020

Uzbekistan has been gradually integrating into the world economy since gaining its independence back in 1991. The need to integrate stems from the desire to advance the national economy and social well-being of population through importing advanced technologies or stimulating exports. However, opening up the country also meant exposure to increase in the mobility of its human capital. As a result, Uzbekistan has witnessed labor migration in and out of the country in the past couple of decades, driven by various causes, which is having inevitable social and economic implications for the country. Intensifying processes in contemporary international labor market make migration as a mechanism, which has a back-to-back impact onto and from economic development of a country. From developing countries' perspective, international labor migration is an instrument for reducing tension in national labor markets, decreasing high rates of unemployment and expanding sources of income. From developed countries' perspective, international labor migration helps solve demographic problems like decreasing number of population, aging of population and shortage of labor force. Thus, this processes turned into a mechanism or a system, which is not possible to ignore. Uzbekistan, in particular, is increasing its participation in the international labor market due to its high rates of population growth and young population.

• Advances in nano research
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• 제12권3호
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• pp.319-336
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• 2022

Evaluating the temporal and spatial changes in the ecosystem service value (ESV) of the Sanjiangyuan Nature Reserve is important for understanding the impact of human activities on natural ecosystem and guiding ecosystem restoration and environmental pollution control. In this study, remotely sensed land-cover data and the equivalent factor method were used to analyze the spatiotemporal evolution characteristics of the ESV in Sanjiangyuan Nature Reserve from 1992 to 2015, and regression analysis was employed to determine the factors driving changes in the ESV. The results show that grassland was the main type of ecosystem in the study area, and the transformation of grassland into bare areas was the primary change in land cover. Additionally, the ESV in the study area first decreased and then increased, with an annual growth rate of 0.69%. The ESV mainly increased in the north of the Yellow River's source area, and mainly decreased in the northwest of the Yangtze River's source area. Finally, the gross output value of agriculture, urbanization rate and proportion of secondary industry were found to be the main factors driving the ESV in the study area.

• 품질경영학회지
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• 제48권1호
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• pp.149-169
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• 2020

Purpose: This study analyzes the characteristics of the Quality Management performed by SMEs in the Defense Industry in supply chains and analyzes the effect of the continuous improvement activities based on cooperation. Especially, for Military Supplies, the suitability of products is usually decided by judging their conformity to the specification, and from this structural characteristic, this study would analyze the structural relationship of systematic improvement activities with Supply Chain Quality Management(SCQM) and Business Performance(BP). Methods: Continuous improvement activities(CI) have significance as the driver force for the promotion of Quality Management. Thus, this study analyzed the causal relationships from the perspective of the process among CI, SCQM and BP. For an analysis of the structural characteristics and causal relationships among the constituents, AMOS was used, and 297 companies in the Defense Industry were utilized as samples. Results: It turned out that CI had significant impacts on Management Infra(MGT_Infra), Process Management(PM), Human Resources Management(HRM) and Communication(COMU) and had an indirect impact on the enterprises' financial performance through the parameters of HRM and Communication. Meanwhile, it turned out that between CI and non-financial performance, there was a direct effect, and there was also an indirect effect through the variables of the Management Infra and Communication. Conclusion: It turned out that CI had a positive effect on SCQM as a proactive driver and that they had significant relationships with BP(financial, Non-financial), both financial performance and non-financial performance. However, PM did not have a significant relationship of effect with BP because of the character appearing by the evaluation method of military supplies for the conformity to the specifications.

• 대한기계학회논문집 C: 기술과 교육
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• 제3권2호
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• pp.131-140
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• 2015

하반신 마비환자가 스키를 탈 수 있도록 고안된 모노스키는 스키 플레이트 위에 좌석이 설치된 형태의 썰매이다. 스키를 탈 때 설면으로부터 전달되는 충격은 정상인의 경우 다리관절의 거동에 의하여 흡수되지만 모노스키의 경우에는 좌석에 탑승한 인체에 그대로 전달된다. 상용화된 대부분의 모노스키에는 이를 보완하기 위하여 스키 마운트와 시트 간에 링크 메커니즘과 충격완충장치가 설치되어 있다. 본 연구에서는 유압 실린더가 장착된 모노스키의 주행 시뮬레이션을 수행하고 불규칙한 표면 주행 중 발생하는 진동 충격 가속도를 분석하여 탑승자의 안락감을 평가할 수 있는 모델을 개발하였다. 안락감 평가방법은 국제 규격인 BS6841 을 사용하였다. 개발 모델을 이용하여 유압 완충장치의 노즐조절에 따른 안락감을 평가하였다.

• 무역상무연구
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• 제63권
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• pp.159-184
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• 2014

Climate change is one of the biggest dangers facing all living creatures in the earth. It has been understood that emissions of greenhouse gases from human activity is the cause of climate change. Cars are responsible for around 12% of total EU emissions of CO2, the main greenhouse gas. The United Nations Framework Convention on Climate Change (UNFCCC or FCCC) is an international environmental treaty adopted at the United Nations Conference on Environment and Development (UNCED) on 9 May, 1992, which entered into force on 21 March 1994. The European Commission first adopted a Community Strategy to reduce CO2 emissions from cars in 1995. On 19 December 2007, the European Commission proposed "Proposal for Setting emission performance standards for new passenger cars to reduce CO2 emissions", which was adopted on 23 April 2009 as "Regulation (EC) No 443/2009". Prior to submitting the Proposal, the European Commission performed impact assessment and prepared impact assessment report which was reviewed by the Impact Assessment Board. The objective of this Regulation is to set emission performance standards for new passenger cars registered in the Community, which forms part of the Community's integrated approach to reducing CO2 emissions from light-duty vehicles while ensuring the proper functioning of the internal market. In the event that a manufacturer fails to meet its target, it will be required to pay an excess emissions premium in respect of each calendar year from 2012 onwards. On 11 March 2014, Regulation (EC) No 333/2014 amending Regulation (EC) No 443/2009 was adopted. Regulation (EC) No 333/2014 amends Regulation (EC) No 443/2009 to implement the modalities of meeting the 95g CO2/km target for new passenger cars to be reached in 2020. As industry benefits from indications of the regulatory regime that would apply beyond 2020, the Regulation includes a further review to take place by, at the latest, 31 December 2014.

• 감성과학
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• 제26권1호
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• pp.65-78
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• 2023

항공기는 대표적인 인간-기계시스템이다. 인간의 조작과 기계의 작동 완료 시점 사이에는 기계가 작동되기 시작하는 시간과 기계에 힘이 전달되기 시작하여 완료되는 시간 등의 지연이 발생하며 항공기 조종은 시스템의 지연을 예측한 타이밍 작업을 통해 이루어진다. 시간지각은 타이밍 작업의 중요한 요소이며, 높은 각성작용과 관련된 불안에 영향을 받는 것으로 알려져 있다. 본 연구는 가상현실 환경에서 현직 조종사를 대상으로 기상, 비행 및 시간 조건이 조종사에게 발생하는 불안과 시간지각에 미치는 영향을 검증하였다. 기상조건은 시계비행 기상 상황과 악기상 상황으로 구분하였고 비행 및 시간 조건을 달리하여 실험 1, 2를 실시하였다. 실험 1은 비교적 운동량의 변화가 적고 지연이 적은 제자리비행과 수평비행 상황에서 조종간에 추가된 버튼을 사용하여 시간지각을 측정하였다. 실험 2는 운동량의 변화가 많고 지연이 많이 발생하는 이륙상황에서 조종간만을 사용하게 하여 자연스럽게 헬리콥터를 이륙시키는 과정에서 시간지각을 측정하였다. 실험결과 악기상 상황에서 불안과 심박수가 증가하는 것으로 나타났으며, 특히 실험 1, 2의 모든 비행조건 중 불안이 증가한 상황에서 시간을 과대 추정하는 것으로 나타났다. 이 결과는 불안의 영향으로 시간을 과대 추정하여 타이밍 작업을 실패할 수 있으며, 이로 인해 조종에 어려움을 겪고 사고로 연결될 가능성이 있음을 시사한다.

• 한국실내디자인학회논문집
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• 제24권3호
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• pp.15-29
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• 2015

Social and cultural impact of postmodernism in the seek for diversity and to respect the individual's personality and character was the center of human-centered thinking. This also affects the design area, as well as architecture, interior design. It is because of interactive interior design that reflects the lives and relationships with people. Thus, in modern society, people to meet the diverse needs have created a third space. Today's commercial space in the flow to a variety of users and is trying to provide comfort. To go to stores often offer lifestyle and proceeding to the next stage of life. Space for the creative force is trying to become getting better space. Collaboration is refer to phenomenon that two or more objects meet to collaborate. Collaboration is can be classified of space, art, low/high, high concept and star collaboration. And this study has been studied mainly collaboration. Space collaboration is can be classified of experiential, the third space, brand passes and landmark. Space collaboration elements rearranged to the standards of interior design theory, analysis, and marketing of space, commercial space, with previous studies of the spatial elements were extracted. The purpose of this study in the field of interior design space analysis method for the verification of collaboration theory is that to develop. Thus, the space collaboration has been developed to fit the field of interior design, and commercial interior spaces will be helpful for applying.