• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.58-63
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• 2003

폐쇄형 묘생산 시스템(closed system for transplants production)은 자연광이 투과되지 않도록 단열재로 구성되어 있어 시스템 내부와 외부의 공기, 물, 열 등의 교환이 기본적으로 제한된다. 또한 식물 생육에 필요한 관수량, 내부에 적절한 습도를 유지시켜 주기 위한 가습량 및 공조기구에 의한 제습량 등이 시스템 내에서 평형을 이루며 순환한다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2004.08a
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• pp.208-215
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• 2004

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.118-123
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• 2000

Most quadruped walking robots under current research are individually controlling every joint ic make them step or walk according to an integrated strategy. Such methods are characterized by at least one pair of an actuator and a sensor installed per each 'oint so that the robots weigh execssively and move inefficiently in terms of energy expenditure. In addition, the task of controlling all the joints simultaneously is quite complex and prone to destabilize the robot motion. These respects keep the existing walking robots away from realistic applications such as transportation even if they have potentially, outstanding adaptability to swamps or uneven terrains as opposed to wheeled vehicles. So, this paper presents a new conceptual quadruped robot developed to walk and steer only with a minimal number of actuators owing to a closed-chain mechanism. To prove its actual performance including the adaptability to various types of terrains. experiments are done with the mammal-type prototype. And. it is also shown that the same concept can be easily extended to carry out different gait forms. for instance, that of spiders only with minor modifications.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.512-526
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• 2021

Peripheral arterial disease is an occlusive condition commonly involving the lower extremity vessels. When the aortoiliac region is affected by this disease, conventional management involves surgical bypass and endovascular treatment has been mainly recommended for patients with focal and simple lesions. It has been common strategy to perform endovascular treatment for selected patients with high surgical risk due to its minimally invasive nature. However, recent advances in the devices and techniques for endovascular treatment have resulted in its utilization for treating patients with various disease status and its clinical outcomes are comparable to those of conventional surgery. This review discusses the current diagnostic strategies for peripheral artery disease in the aortoiliac region, followed by the introduction of techniques and devices, and the role of endovascular treatment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.6
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• pp.871-883
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• 1997

Kinetodynamics of a cam driving slider mechanism consists of kinematic analysis and force analysis. The kinematic analysis is to determine the kinematic characteristics of a cam driving mechanism and a slider mechanism. The force analysis is to determine the joint forces of links, the contact forces of the cam and follower, and the driving torque of a main shaft. This paper proposes a close loop method and a tangent substitution method to formulate the relationships of kinematic chains and to calculate the displacement, velocity and acceleration of the cam driving slider mechanism. Also, and instant velocity center method is proposed to determine the cam shape from the geometric relationships of the cam and the roller follower. For dynamic analysis, the contact force and the driving torque of the cam driving slider mechanism are calculated from the required sliding forces, sliding motion and weight of the slider.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.1883-1897
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• 1993

Interactive computer-aided analysis of mechanical systems has recently been undergoing an evolution due to highly efficient computer graphics. The industrial implementation of state-of-the-art analytical developments in mechanisms has been facilitated by computer-aided design packages because these rigid-body mechanism analysis programs dramatically reduce the time required for linkage design. This paper proposes a component modular approach to computeraided kinematic motion analysis for general planar multiloop mechanisms. Most multiloop mechanisms can be decomposed into serveral components. The kinematic properties (position, velocity, and acceleration) of every node can then be determined from the kinematic analysis of the corresponding component modules by a closed-form solution procedure. In this paper, 8 types of modules are defined and formulations for kinematic analysis of the component modules are derived. Then a computer-aided kinematic analysis program is developed using the proposed approach and the solution procedure of an example shows the effectiveness and accuracy on the approach.

• Journal of Chest Surgery
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• v.34 no.4
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• pp.351-355
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• 2001

개흉술에 의한 수술적 폐쇄방법 및 경도관 동맥관 폐쇄술은 동맥관 개존중의 치료방법으로 발전되어 왔으나, 이러한 술식은 개흉술에 의한 합병증, 지속적인 단락 및 용혈의 가능성, 기구의 이동이나 색전증의 발생, 지속적인 단락시 세균성 심내막염 방지를 위한 지속적인 항생제 사용등의 단점이 있어 저자들은 흉강경을 이용한 수술을 시행하였다. 총 6례의 환자에서 흉강경을 이용한 동맥관 개존증 수술을 시행하였으며. 이중 대동맥 외막(adventitia) 박리중 지형이 잘 되지 않았던 1례에서는 소개흉술(minithoracotomy)로 전환하였다. 술 후 이시행한 이학적 검사상에서 모든 환아에 심잡음이 소실되었음을 확인할 수 있었으며, 흉부 방사선 검사상 점진적인 폐혈관음영의 감소를 관찰할 수 있었으며 수술중 동맥관 파열이나 불완전한 동맥관 폐쇄, 기흉, 애성(hoarseness) 등의 합병증은 발생되지 않았다. 환아들은 술후 평균 3.4일째 퇴원하였으며, 퇴원후 외래추적 관찰검사시 시행한 심초음파 검사상 동맥관의 재개통이나, 잔류단락은 관찰되지 않았다. 본원에서는 개흉술 및 경도관 동맥관 폐쇄술의 단점을 방지할수 있으며, 성공적인 동맥관 폐쇄, 작은 피부절개 반흔에 의한 미용적 효과, 짧은 재원기간등의 장점을 가진 흉강경을 이용항 동맥관 결찰술을 시해앟여 문헌 고찰과 함께 보고하는 바이다.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.401-408
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• 2008

Purpose : Transcatheter closure of atrial septal defects (ASD) is currently established therapy as an alternative to surgery. But rarely, complications are reported in some studies. We report early and intermediate term complications associated with transcatheter closure of atrial septal defects using the Amplatzer septal occluder (ASO). Methods : From June 2003 to May 2006, 64 patients underwent transcatheter closure of secundum ASD or patent foramen ovale using the ASO. The ratio of male to female was 1:2.4, the median age was 17 years (range: 2.6-64 years) and their median weight was 47.5 kg (range: 2.6-64 kg). Results : The median diameter of ASD measured with transthoracic or transesophageal echocardiography was 15 mm (range: 6-28 mm), the median balloon stretched diameter was 18 mm (range: 6.5-34 mm), and the median size of device was 19.5 mm (range: 6-36 mm), was little difference with balloon stretched diameter. There were 10 cases of complications: arrhythmia (2), device malformation (2), aorta to right atrial fistula (1), hemolytic anemia (1), mitral valve encroachment (1), malposition (1), residual shunt (1), and inferior vena cava perforation (1). Conclusion : Transcatheter closure of ASD using ASO is effective and safe therapy. However, significant complications such as aorta to atrial fistula, atrial erosion, or device embolization can happen, so an appropriate selection of patient and device in relevance to size and anatomy of ASD is important for successful closure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.846-855
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• 1994

An effective stiffness, analogous to that of a wound spring, can be created by antagonistic redundant actuation of general closed-chain mechanisms. The qualitative and quantitative characteristics of the effective stiffness are investigated through a Four-bar mechanism, and a load distribution method is introduced which simultaneously guarantees the required system motion and the effective stiffness of the Four-bar mechanism. Furthermore, a simulation is performed to understand the inter-relationship among the effective stiffness, the Four-bar geometry, and the actuation effort. Based on this analysis, the Four-bar synthesis problem for effective stiffness generation is discussed.

• Electronics and Telecommunications Trends
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• v.27 no.4
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• pp.73-82
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• 2012

디지털 사이니지는 사용 중인 대다수의 시스템이 폐쇄적이고 독자적이기 때문에 상호운용성이 부족하다. 따라서, 종단 사용자가 다른 제조업체나 오퍼레이터로부터 제품이나 서비스를 결합하여 사용하거나 다른 특징을 갖는 다양한 종류의 단말을 사용하기 위하여 산업체에서는 상호운용가능한 디지털 사이니지 솔루션을 위한 기술적인 표준을 정의한다. 현재 디지털 사이니지 기술에 대한 표준화는 ITU-T, POPAI(Point of Purchase Advertising International), W3C 등에서 진행되어 왔다. 따라서, 본고에서는 ITU-T, POPAI, W3C 등 디지털 사이니지 표준화 작업을 추진하고 있는 주요 국제 표준기구 및 포럼의 표준개발 현황에 대해 소개한다.