• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.459-465
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• 2011

Excessive heat may be generated during the semiconductor manufacturing process. Therefore, precise control of temperature is required to maintain a constant ambient temperature and wafer temperature in the chamber. Compared to an industrial chiller, a semiconductor chiller's power consumption is high because it is in continuous operation for a year. Because of this high power consumption, it is necessary to develop an energy-efficient chiller by optimizing the operation. The competitiveness of domestic products is low because of the high energy consumption. We experimentally investigated a domestic semiconductor by conducting load change, temperature rise and fall, and control precision experiments. The experimental study showed that the chiller had 2.1-3.9 kW of cooling capacity and 0.56-0.93 of EER. The control precisions were ${\pm}1^{\circ}C$ and ${\pm}0.6^{\circ}C$ when the setting temperatures were $0^{\circ}C$ and $30^{\circ}C$ respectively.

• Journal of Korea Ship Safrty Technology Authority
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• v.17
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• pp.24-43
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• 2005

최근 우리나라 어선어업은 한중일 어업협정, 연안 어업자원 감소 및 연안오염 등 사회적, 환경적 변화가 급변하고 있어 이들을 고려한 어선 선형개발이 필요로 한다. 현재 우리나라의 어선 중 연안지역에서 조업하는 5톤 미만의 소형어선은 전체 어선 중 $65\%$ 이상으로 구성되어 있으나 선박의 크기가 작고 부가가치가 낮은 관계로 지금까지 전문적인 연구는 거의 없었던 것이 현실이다. 한편, 서$\cdot$남해 연안에서 작업 및 항해하는 연안어선들의 해양사고 발생율은 전체사고의 $69.6\%$로 매년 증가하고 있는 추세이다. 전체 어선 안전사고 중 부유폐어망, 로프 등이 추진기에 감긴 사고는 전체 사고의 $10.4\%$로 매년 증가하고 있다. 이에, 추진기 손상에 의한 어선 사고와 연관하여 추진기를 보호하기 위한 장치로서 물분사 추진기(Water-Jet), 펌프제트(Pump-Jet)장치들이 있으나 이들은 고가 수입품으로서 영세한 어민들의 소형어선에 장착하기에는 한계가 있어, 본 연구에서는 폐그물, 로프 등 해상 부유물에 의한 추진기 손상이 발생되지 않는 프로펠러 보호터널 부착 추진장치를 개발을 목적으로 한다. 프로펠러 부착 추진장치는 기존 선미를 수정하여 추진기를 선체 안쪽으로 배치하며 돌출되는 부분은 덕트로 보호하고 있으며 이러한 추진기는 워터제트 추진기와는 달리 가격이 싸고 그물이나 부유물에 걸리지 않고 고장 시 신속한 대응이 쉬워 소형 연안어선에 적합할 뿐만 아니라 그물, 부유물, 갯벌이 많은 국내의 서$\cdot$남해 연안에서 작업 및 항해 시 매우 유용할 것으로 판단된다. 본 연구는 `프로펠러 보호터널 부착 연안어선의 선형개발`을 최종목표로 수행하였으며, 연구개발 내용은 기존 소형 연안어선의 분류 및 특성 조사 연구, 프로펠러 보호터널형 선미 선형 개발, 기존 선형 및 보호터널형 선형의 모형시험, 개발선의 구조강도 특성, 프로펠러 설계 및 단독시험, 보호터널 부착 추진기의 효율 검증 및 개발 대상 어선의 조선공학적 제 계산, 설계도작성 등을 실시하였다. 주요 요소 기술로서는 프로펠러 보호터널 부착 선형의 모형시험을 통하여 선미선형을 개발하며 FRP판부재의 구조강도 특성을 분석하고 그 결과를 활용하여 4톤급 연안어선의 시제선을 건조하고 시운전을 통하여 주요성능을 확인하였다.

• KDI Journal of Economic Policy
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• v.29 no.1
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• pp.79-112
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• 2007

Opening domestic market to international trade may enhance not only actual competition but also potential competition from foreign competitors. It seems that the competition authority has focused mainly on the actual competition (measured by the current market share) and has paid less attention to the potential competition. In this regards, this paper investigated the relation between potential foreign competition and domestic market structure. Using dynamic panel regression model, we analyzed the dynamic response of import penetration to the changes of domestic market condition in Korea as a proxy for the degree of potential foreign competition. The empirical results suggests that potential foreign competition does exist in the Korean manufacturing sector and this tendency is more stronger when the market is more concentrated. Thus, in order to effectively implement competition policy, it is necessary to consider both actual and potential competition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.322-328
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• 2012

This paper deals with a digital Desoldering system for removing lead-free solder. We proposed a Desoldering system that is to cope with the changed work environment of the solder materials changing from lead solder to lead-free solder, we can be quickly stable to the set temperature, and continuous operation is possible. Proposed system consists of a Desoldering station and a Desoldering gun. For the PID temperature control, we designed the 8bit MCU peripheral circuit. We had a few experiments to confirm the performance of the proposed system, and compared with the specification of same kind of imports. As a result, proposed system than the imported products showed good performance as follows: the time to reach operating temperature is 11 seconds faster, ripple temperature variation is $1.5^{\circ}C$ lower, temperature recovery rate is about $0.14^{\circ}C$/sec faster.

• Fashion & Textile Research Journal
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• v.5 no.4
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• pp.331-336
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• 2003

This study is to research the influence of Caesalpinia sappan which was imported through the exchanges between the Chosun dynasty and Japanese envoys during the early Chosun dynasty. Korea interchanged politically and culturally with Japan since ancient times. Particularly, the good-neighbor foreign policy toward Japan grew into trade relations. The diplomatic mission, under the name of Tongshinsa, was dispatched 12 times in total. Plenty of goods were exchanged through the visiting of Japanese envoys as well as through the activities of Korean envoys. In other words, the Korean-Japanese relations were at first focused on the political and diplomatic etiquette and gradually evolved into economic exchanges. Trading goods were various, including food, clothing, etc. Caesalpinia sappan, a red dye, was the most imported goods from Japan, but it was sold at a very high price, which caused luxurious trends in clothing. However, these sumptuous moods of the upper classes were decreased in the 16th century. Some of the reasons are : the difficulties of Japan's trade with the Caesalpinia sappan producing countries in South-east Asia, the transition of the high classes' preference from red clothing into Chinese BaecSa and SaraNeungDan, and the comparative decrease in the demand of Caesalpinia sappan by the changed understanding of Honghwa. Therefore, the early Chosun dynasty's clothing trends were due to the relationships between the Chosun dynasty and Japan.

• Journal of Korean Home Economics Education Association
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• v.16 no.4 s.34
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• pp.167-176
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• 2004

The purpose of this study was to identify the factors related to the propensity for conspicuous consumption of adolescent consumers. Data for this study were collected from 530 adolescent consumers who were in the 8th grade of middle school in Guri city. There were significant differences between boys and girls in the propensity for conspicuous consumption of adolescents. The propensity for conspicuous consumption of boys was higher than girls. The influences of friends and mass media. and self-esteem were found to predict the propensity for conspicuous consumption of adolescents.

• Korean Journal of Medicinal Crop Science
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• v.8 no.4
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• pp.319-326
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• 2000

This experiment was carried out to determine the effects of $GA_3$ treatment (concentration: period) to rhizomes before planting on their growth, morphology and yield. $GA_3$ treatment increased the number of shoots, leaves or latent buds, plant height, and leaf length per plant compared with non-treatment. The best treatment concentrations were 50 ppm in stem per plant, 100 ppm in latent bud and rhizome fresh weight per plant and 250 ppm in shoot fresh weight per plant. The number of leaves and roots per plant, plant height and fresh weights of shoot and root were the greatest in one day imbibition of $GA_3$. Numbers of stems and latent buds per plant and rhizome fresh weight, however, were the highest in two day imbibition. In addition, the most rhizomes per land unit were produced in one day imbibition treatment of 100 ppm $GA_3$.

• Information and Communications Magazine
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• v.25 no.4
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• pp.5-10
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• 2008

지능형 로봇은 자율적으로 이동할 수 있어야 한다는 것이 PC와 기본적으로 다른 점이다. 이동 로봇이 자율 주행할 때 꼭 필요한 기술이 위치 인식 기술과 장애물 감지 기술이다. 장애물 감지 기술은 이동 로봇이 다른 물체와 충돌하지 않도록 하기 위해 필요한 기술이지만 위치 인식 기술은 로봇이 현재 위치를 알고 목적지로 주행하기 위해 매우 중요한 기술이다. 지능형 로봇의 자율 주행 측면에서 위치 인식 기술은 필수적 핵심 기술이다. 위치 인식 센서는 로봇의 절대 위치 및 방향각 정보를 획득하여 실시간으로 관련 데이터를 지능형 로봇에 전달한다. 이로써 지능형 로봇의 이동 경로와 방향 제어가 가능해지고, 로봇을 보다 안정적으로 제어할 수 있다. 즉 로봇이 자기 위치를 인식한 후에야 안정적이고 지속적인 자율 주행이 가능해진다. (주)나인티시스템은 네트워크 기반 위치 파악용 indoor GPS 개념으로 로봇 위치 파악 센서 iGS를 개발하여 공급하고 있다. (주)나인티시스템이 개발한 iGS는 지능형 로봇의 거리, 위치, 방향을 파악하기 위해 초음파 송/수신부 및 RF 모듈로 Handware가 구성되어 있고 위치 추정 알고리즘, 장애물에 강건한 알고리즘 등이 Firmware를 구성하고 있다. 로봇 시장의 잠재적 성장 가능성을 고려할 때 로봇의 자율 운용에 필수적인 위치 파악 요소 기술을 선개발하여 상업화하는 것은 경제적으로도 큰 의미를 갖는다. 뿐만 아니라 위치 파악 요소 기술의 선도적 개발에 의해 미래 지능형 로봇시장을 주도할 수 있는 계기도 기대할 수 있다. Robot에 적정 가격대의 위치 인식 기술이 접목되면 Robot 산업의 활성화가 가능하다. 현재 청소용 Robot은 충돌 방지정도의 인식을 하고 있지만 위치 인식 기술이 접목되면 청소용 Robot이 더 많은 Service를 제공할 수 있다. 더 많은 Service의 실행으로 Robot 산업이 활성화되면 관련 요소기술 산업이 활성화된다. Robot 산업과 부품 산업이 활성화되면 Robot 관련 산업의 수익 Model이 다양해 진다. 위치 인식 기술은 Robot 산업뿐 아니라 산업 전반의 활성화에도 크게 기여할 것이다. 위치 인식 기술은 지능형 Robot의 자율 주행뿐 아니라 다양한 분야에 응용이 가능하다. 또한 위치 인식 기술을 국산화하면 기존 수입품을 대체할 뿐아니라 수출 시장의 진출에도 크게 기여할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.979-984
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• 2012

An antiroll-bar assembly is a precision component that is designed to control the rolling of railway cars. It is important for ensuring a safe and comfortable ride. A torsion bar is the main part of the antiroll-bar assembly. Now, this part is classified as a consumable, and it is imported into Korea from France. Therefore, there is a strong need to domestically develop a torsion bar suitable for Korean conditions and to reduce cost and improve quality. In this study, an antiroll bar is developed, and it is analyzed and tested by using a road histogram measured on Korean railroads. This bar shows satisfactory results in a comparison with the imported bar. It has a novel design featuring a ring cover made of SUS steels to prevent the corrosion of the torsion bar. Its safety is examined through CAE analysis and wear tests. It is found that its design does not result in a significant difference in static and fatigue safety. Two different SUS steels were investigated in terms of their wear resistance, and the best one was adopted.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.523-529
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• 2021

Medical service robots are variously defined and classified by researchers and related government departments, but surgical robots and rehabilitation robots are commonly included in medical service robots, and except for these, the robots are classified as other medical service robots. In this study, domestic and foreign development trends and use cases were considered, focusing on logistics, guidance, and drug processing robots among other medical service robots. Logistics and guidance robots were developed quite a lot in Korea and completed a pilot project, or are being commercialized in hospitals, and exported. However, although the drug prcocessing robots was developed in Korea, the robot being use in the hospital was an imported. In order to expand and activate the robot market, systematic follow-up studies such as demand prediction studies are needed.