• Journal of Chest Surgery
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• v.47 no.4
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• pp.327-332
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• 2014

Single-port video-assisted thoracic surgery (VATS) has slowly established itself as an alternate surgical approach for the treatment of an increasingly wide range of thoracic conditions. The potential benefits of fewer surgical incisions, better cosmesis, and less postoperative pain and paraesthesia have led to the technique's popularity worldwide. The limited single small incision through which the surgeon has to operate poses challenges that are slowly being addressed by improvements in instrument design. Of note, instruments and video-camera systems that are narrower and angulated have made single-port VATS major lung resection easier to perform and learn. In the future, we may see the development of subcostal or embryonic natural orifice translumenal endoscopic surgery access, evolution in anaesthesia strategies, and cross-discipline imaging-assisted lesion localization for single-port VATS procedures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.865-868
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• 2002

This study investigated the shape deformation of ball projectile(5.56mn) under the low energy impact by the use of the drop weight impact tester. ball projectile(5.56mm) consisted of the copper face with a lead core. The impact conditions were changed with the variations of the mass and the drop height of the impact tup. Shape deformation of ball projectile(5.56mm) after low velocity impact was measured using a video microscope and CCD camera. The test result showed that impact energy by changing of drop height of the impact tup affected shape deformation of ball projectile(5.56mm). So, it is important to study the relativity between shape deformation of ball projectile(5.56mm) and ballistic protection of plate(such as hybrid composite laminates) under the high velocity impact.

• Journal of Mechanical Science and Technology
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• v.15 no.2
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• pp.172-179
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• 2001

The effects of the interface and two holes located near the crack path in the hybrid specimen on the dynamic crack propagation behavior have been investigated using dynamic photoelasticity with the aid of Cranz-Shardin type high speed camera system. The dynamic stress field around the dynamically propagating interface crack tip in the three point bending specimens under a dynamic load applied by a hammer dropped from 0.6m high without initial velocity are recorded. The complex stress intensity factors for the dynamically propagating interface crack are extracted by using a overdeterministic least square method. Theoretical dynamic interface isochromatic fringe loops generated by using the numerically determined complex stress intensity factors are compared with the experimental results. Furthermore, the influence of the hole to the dynamic interface crack velocities has been investigated experimentally.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.2
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• pp.247-254
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• 2003

The paper presents the influence of spring dynamics and friction on dynamic responses in a spring-driven cam system. The characteristics of the friction on the camshaft are analyzed using the nonlinear pendulum experiment while the parameters of the friction model are estimated using the optimization technique. The analysis reveals that the friction of the camshaft depends on stick-slip, Stribeck effect and viscous damping. Spring elements are found to have much influence on the dynamic characteristics. Hence, they are modeled as four-degree-of-freedom lumped masses with equivalent springs. The appropriateness of the derived friction model and spring model is verified by its application to a vacuum circuit breaker mechanism of the cam-follower type.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.4
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• pp.281-290
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• 2015

Human action recognition from a video scene has remained a challenging problem in the area of computer vision and pattern recognition. The development of the low-cost RGB depth camera (RGB-D) allows new opportunities to solve the problem of human action recognition. In this paper, we present a comprehensive review of recent approaches to human action recognition based on depth maps, skeleton joints, and other hybrid approaches. In particular, we focus on the advantages and limitations of the existing approaches and on future directions.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.112-113
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• 2013

서브 홀로그램 디스플레이는 디지털 홀로그래피 디스플레이의 제한된 시역을 관찰자의 동공 크기로 맞게 구현하여 사용자가 더 넓은 범위에서 더 큰 영상을 느끼도록 만드는 홀로그래픽 디스플레이이다. 본 논문에서는 서브홀로그램 방식에서 시야 창 문제를 해결하기 위해, Depth 카메라와 스테레오 카메라의 하이브리드 구성을 이용하여 정밀한 사용자 동공 추적 기법에 대해서 제안한다. 저해상도의 깊이 카메라의 얼굴 인식 정보를 바탕으로 고해상도 스테레오 카메라에서의 얼굴 및 눈의 후보영역을 찾고, 고해상도 스테레오 카메라에서 후보 영역 내의 동공 위치를 잦아서 빠르면서도 정밀한 동공 추적이 가능하도록 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.777-780
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• 2001

동영상 검색 및 관리 기술의 필요성 증가에 따라 동영상 검색 기법들이 제안되고 있으며, 특히 내용 기반 검색 기법에 대두되고 있다. 본 논문에서는 내용 기반 요소중의 하나인 카메라 동작 검출을 위한 시스템을 제안한다. 본 시스템은 영상의 평균값을 이용하여 제작된 투영 영상상에서 추출된 edge 의 방향 성분으로 구성된 optical flow 에 따라 적절한 카메라 동작을 검출한다. 효과적인 카메라 동작 요소 검출을 위하여 평균값으로 구성된 투영 영상을 검출하고자 하는 카메라 동작 요소에 따라 달리 제작한다. 투영 영상은 전체적인 영상에 대하여 제작하는 방법과 sub-block 으로 나눈 영상에 따라 각 블록별로 제작하는 방법으로 나누어진다.

• Journal of Auto-vehicle Safety Association
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• v.8 no.2
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• pp.30-36
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• 2016

According to revolutionary developments in automobile technologies, various electronically controlled components of vehicles are rapidly increasing. A variety of advanced vehicles (hybrid vehicle, hydrogen fuel-cell vehicle, electric vehicle, etc.) using electrical energy source are increasing, too. The electromagnetic compatibility is getting more important for development of a vehicle because those advanced vehicles are equipped with more new electronic systems. In general, electromagnetic compatibility tests consist of an electromagnetic interference (EMI) test and an electromagnetic susceptibility (EMS) test. In this paper, in order to investigate the electromagnetic interference in the cabin of vehicle by various electric and electronic components of vehicles, a series of narrowband electromagnetic emission tests are conducted. For comparison, the several digital home appliances (smartphone under charging, laptop compuer and digital camera), which are used a lot in daily lives, are tested.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.84-85
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• 2023

본 논문에서는 엣지 컴퓨팅에서 다수의 스마트 카메라를 클러스터링하여 협업하며 로드 밸런싱을 수행하는 알고리즘을 제안하고, Kubernetes 환경에서 시뮬레이션을 통해 여러 가지 상황에서 성능을 검증하여 엣지 컴퓨팅에서의 AI 연산을 보다 효율적으로 수행할 수 있는 방법을 제시한다.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.252-263
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• 2016

Road sign is an important street furniture that gives some information such as road conditions, driving direction and condition for a driver. Thus, road sign is a major target of image recognition for self-driving car, ADAS(autonomous vehicle and intelligent driver assistance systems), and ITS(intelligent transport systems). In this paper, an enhanced road sign recognition system is proposed for MMS(Mobile Mapping System) using the single camera and GPS. For the proposed system, first, a road sign recognition scheme is proposed. this scheme is composed of detection and classification step. In the detection step, object candidate regions are extracted in image frames using hybrid road sign detection scheme that is based on color and shape features of road signs. And, in the classification step, the area of candidate regions and road sign template are compared. Second, a Geo-marking scheme for geo-content that is consist of road sign image and coordinate value is proposed. If the serious situation such as car accident is happened, this scheme can protect geographical information of road sign against illegal users. By experiments with test video set, in the three parts that are road sign recognition, coordinate value estimation and geo-marking, it is confirmed that proposed schemes can be used for MMS in commercial area.