• Journal of The Korean Association of Information Education
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• v.13 no.4
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• pp.497-508
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• 2009

As the educational use of intelligent service robots has been proved to be effective, educational service robots have been utilized in kindergarten. In addition, service robots will be used in elementary schools from 2010 for the after-school English program. This trend indicates that r-Learning using service robots will become a major educational paradigm in preparing for future education. This article consists of the following four parts. First, the concept and the type of educational robots were defined and the trend of previous research was examined. Second, the characteristics of robot-assisted learning were analyzed as a part of r-Learning, and difference between r-Learning and u-Learning was compared. Third, the contents and service using a robot-assisted learning system were discussed, the models and trend of service using the robot-assisted learning system were examined, and the aspects of viewing evolution were compared. Finally, suggestions for activating the service market of robot-assisted learning were made for the educational institution, research institution, government and robot companies.

• KSBB Journal
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• v.11 no.1
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• pp.100-106
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• 1996

The extraction of taxol and baccatin III from the ground needles of Taxus cuspidata were carried out by using supercritical carbon dioxide with and without cosolvents such as ethylacetate and methanol at 300 bar and 313K. Taxol is a promising anticancer agent and baccatin III is a precursor of semisysthesis of taxol. The taxol and baccatin III contents in the extracts were determined by a HPLC. The highest yields of taxol and baccatin III could be obtained by the supercritical extraction with 3wt% methanol and ethylacetate, respectively, as cosolvents. It was also found that the selectivity of taxol and baccatin III were 0.117 and 1.245wt%, respectively, with 0.7wt% ethylacetate, which demonstrated that the selectivity of taxol and baccatin III were increased about 1.8 and 19 times than those of conventional organic solvent extraction.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.6
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• pp.469-475
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• 2017

Workers in industrial fields are highly exposed to accidents or injuries caused by long working hours. An exoskeleton that is able to support the arm muscles of the worker and thereby reduce the probability of an accident and enhance working efficiency could be a solution to this problem. However, existing exoskeletons demand the use of high-priced sensors and motors, which makes them difficult to use in industrial fields. To solve this problem, we developed an arm assisting exoskeleton that consists only of mechanical components without any electronic sensors or motors. The exoskeleton follows the movement of the human arm by shoulder joint and ankle joint. In addition, counterbalance mechanisms are installed on the exoskeleton to support arm strength. The experimental validation of the exoskeleton was conducted using an EMG sensor, confirming the performance of the exoskeleton.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.67-73
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• 2016

With the rapid development of mobile services and the prevalence of education robots, robots are being developed to become a part of our lives and they can be utilized to assist teachers in giving education or learning to students. This standard has been proposed to define the degree of autonomy for education robot. The autonomy is an ability to perform a given work based on current state and sensor value without human intervention. The degree of autonomy is a scale indicating the extent of autonomy and it is determined in between 1 and 10 by considering the level of work and human intervention. It has been adapted as per standard and education robots can be utilized in teaching the students autonomously. Education robots can be beneficial in education and it is expected to contribute in assisting the teacher's education.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.33-38
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• 2002

A Ventricular Assist Device(YAD) is used to support the injured natural heart So. when considering a control algorithm for YAD. it is important to reduce a natural heart's load to enhance its recovery condition. To reduce natural heart's load, a counterpulsation algorithm is used commonly. In this study, we developed a counterpulsation control algorithm for moving-actuator type VAD and tested its usefulness using in vitro MOCK circulatory system. To notice a natural heart's Pumping status, electrocardiogram(ECG) signal was used and as a result of test. the counterpulsation effect between YAD and a natural heart was occurred and Automatic Control Mode Transition was occurred properly.

• The Journal of Korean Society for Radiation Therapy
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• v.7 no.1
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• pp.32-44
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• 1995

I. 제 목 고에너지 X-선 소조사야의 선량분포 및 계측에 관한 연구 II. 연구의 목적 및 중요성 최근 수술이 어려운 뇌종양등에 대한 방사선수술법(Radiosurgery)이 관심의 대상이 되고 있다. 방사선수술법은 크게 나누어 200여개의 Co-60이 장착된 장치(Gamma Knife)를 이용하는 방법과, X-선치료기를 이용하는 방법은 몇개의 보조기구를 설치하면 가능한 매우 경제적인 방법이다. 따라서 Microtron을 이용한 방사선수술의 기초자료확보를 위하여 소조사야에 대한 선량과 선량분포의 측정 및 계산을 실시하였다. III. 연구의 내용 및 범위 Microtron으로부터 조사되는 6MV, 10MV, 21MV X-선의 지름 3cm이하 소조사야에 대한 정확한 선량 및 선량분포 자료를 확보하기 위해, 가. Microtron치료기와 보조장치등에 대한 정밀도 계측 및 평가 나. 보조 Collimator의 적당한 크기와 재료의 선택 및 설계, 제작. 다. 에너지와 조사야 크기 각각에 대한 여러측정장치(Ion chamber, Diode detector, TLD 및 Film등)를 이용한 선량 및 선량분포 측정. 라. 측정값들의 비교, 검토 및 측정된 자료에 의한 선량 및 선량분포의 계산을 수행했다. IV. 연구결과 및 활용에 대한 건의 본 연구에서 얻은 결과는 다음과 같다. 가. Microtron치료기와 보조장치등의 정확도의 허용 오차범위내에서 잘 일치하였다. 나. 보조 collimater adpator는 총 길이 24cm로 하였으며 재질로는 두랄미늄을 사용하였고, 보조 collimator는 low melting alloy를 사용하였으며 소조사야 크기의 정확도는 0.5mm이내에서 매우 잘 일치 하였다. 다. 방사선 수술법의 에너지 선택에 중요한 요소중의 하나인 penumbra는 6MV X-선에서 가장 적게 나타났으며 라. 소조사면에 대한 깊이-선량 백분율곡선은 모든 에너지에서 조사면이 작아질수록 표면으로 이동하는 경향을 보였다. 이상의 결과로부터 방사선 수술을 시행할 경우 수십억원에 이르는 장비의 도입이나 새로운 시설 없이 Microtron에서 조사되는 고에너지 X-선을 이용할 수 있을 것으로 사료된다. 또한 새로 구입한 측정기나 보조 Collimator를 이용하여 소조사야에 대한 선량측정기술을 습득함으로써 일반적인 소조사야의 방사선치료나 회전치료등에 활용할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1191-1198
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• 2011

The use of a ventricular assist device (VAD) can raise the one-year survival rate without cardiac transplantation from 25% to 52%. However, malfunction of the VAD system causes 6% of VAD patients' deaths, which could possibly be avoided through the development of new VADs in which VAD malfunctions do not affect the patient's heart movement or hemodynamic state. A conventional VAD has an impeller or vane for propelling blood that can allow blood to regurgitate when the propelling force is weaker than the aortic pressure. In this paper, we developed a new pulsatile conduit-shaped VAD that has two valves. This device removes the possibility of blood regurgitation and has a small stationary area even when the pumping force is extremely weak. We estimated the characteristics of the device by measuring the outflow and the pressure of the pump in in-vitro and in-vivo experiments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.194-197
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• 2017

Aircraft engine and auxiliary power units are certified in processes of design, production according to airworthiness requirements. The aircraft engines shall demonstrate compliance with the design and production through the Type Certificate and the auxiliary power unit shall demonstrate compliance with the design and production through the Technical Standards Order Approval. MOLIT(Ministry of Land, Infrastructure and Transport) established the law and the airworthiness requirements for aircraft engines such as KAS Part 33 but didn't issue the Technical Standards Order for auxiliary power unit. In this paper, we proposed and explained the plan for improvement of our aircraft engines industry through building and expanding the certification infra-structure for aircraft engines and auxiliary power unit.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1057-1061
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• 2002

Effects of modifier and soaking on extraction of triterpenoid saponin (glycyrrhizin) from liquorice were examined using supercritical $CO_2(SC-CO_2)$ at 50 MPa, $60^{\circ}C$, and flow rate of 3 mL/min, and glycyrrhizin content was analyzed by HPLC. Additon of undiluted methanol, ethanol or isopropanol as modifier to $SC-CO_2$ had little influence on extraction yield of glycyrrhizin. Soaking process using water increased the extraction yield as the sample to solvent ratio was increased. Addition of 70% methanol, ethanol or isopropanol to $SC-CO_2$ significantly increased the extraction yields, with 70% methanol resulting in the highest yield. When water at 90% (w/w) of sample weight was used for soaking, the extraction yield and rate increased, 70% ethanol-modified $SC-CO_2$ was almost equal to that obtained using 70% methanol.

• Korean Journal of Social Welfare Studies
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• v.40 no.3
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• pp.99-124
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• 2009

This study investigates the problems of welfare decentralization reform implemented by Roh Mu-Hyun Administration and examines a policy direction for improving the decentralization. The reform has caused various problems. Local governments have suffered from heavy financial burden. Some social services, devolved into local governments, have not adequately provided as before. In addition, fiscal disparity among localities has increased. To deal with these problems, experts have proposed several plans, such as restoring the devolved programs to national subsidy programs, inventing a new social welfare grant, or introducing block grants. This study suggests that some of the devolved welfare programs should be restored to the national subsidies, since they cannot be maintained properly by local governments. Also, we need to adjust financial responsibilities between the central and local government in the national subsidy programs. Introducing block grant can be one satisfying solution to enhance local autonomy while maintaining the financial responsibility of central government. In some national subsidy programs, the financial contribution by the central government should be increased to alleviate financial burden of local governments.