• Journal of Korea Game Society
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• v.10 no.2
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• pp.49-56
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• 2010

In this paper, we propose a control method of virtual hand by the recognition of a user's hand in the virtual reality game environment. We display virtual hand on the game screen after getting the information of the user's hand movement and the direction thru input images by camera. We can utilize the movement of a user's hand as an input interface for virtual hand to select and move the object. As a hand recognition method based on the vision technology, the proposed method transforms input image from RGB color space to HSV color space, then segments the hand area using double threshold of H, S value and connected component analysis. Next, The center of gravity of the hand area can be calculated by 0 and 1 moment implementation of the segmented area. Since the center of gravity is positioned onto the center of the hand, the further apart pixels from the center of the gravity among the pixels in the segmented image can be recognized as fingertips. Finally, the axis of the hand is obtained as the vector of the center of gravity and the fingertips. In order to increase recognition stability and performance the method using a history buffer and a bounding box is also shown. The experiments on various input images show that our hand recognition method provides high level of accuracy and relatively fast stable results.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.298-308
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• 1999

Experimental study on characteristics of direct contact condensation of steam discharged into a sub-cooled water pool has been performed using five different sizes of horizontal nozzle over a wide range of steam mass fluxes and pool temperatures. Steam condensation phenomena have been observed visually and by taking pictures of steam jets using a high speed video camera. Two different steam jet shapes such as ellipsoidal shape and conical shape were typically observed for a stable steam jet, depending on the steam mass flux and pool temperature. The steam jet expansion ratio and the steam jet length as well as the condensation heat transfer coefficients were determined. The effect of steam mass flux, pool temperature, and nozzle diameter on these parameters were also discussed. Empirical correlations for the steam jet lengths and the condensation heat transfer coefficients as a function of steam mass flux and condensation driving potential were established. The axial and radial temperature distributions in steam jet and in surrounding water were measured. The effect of steam mass flux, pool temperature, and nozzle diameter were also discussed. The condensation regime map, which consists of six regimes such as chugging, transient chugging, condensation oscillation, stable condensation, bubble condensation oscillation, and intermittent oscillation condensation, were established. In addition, the dynamic pressures at the pool wall were measured. The close relation of dynamic pressure and steam condensation mode, which is also dependent on steam mass flux and pool temperature, was found.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3833-3838
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• 2009

This paper introduces a measurement system for mechanical properties of sport shoes using an industrial robot. The robot system used in this paper is a commercial Puma type robot system(FARA AT2 made by SAMSUNG Electronics) with 6 joints and the end-effector is modified to produce a human walking motion. After analyzing human walking with a high speed video camera, each joint angle of the robot system is extracted to be used in the robot system. By using this system, ground impact forces were measured during stepping motion with 3 different shoe specimens made of 3 different hardness outsoles, respectively. As other mechanical properties, both bending moments to bend the toe part of the same specimen shoes and pronation quantities during walking motion were measured as well. In the impact test with the same depth of deformation under the ground level, the effect of the outsole hardness was clearly appeared such that the harder outsole produces the higher ground reaction force. The bending test and the pronation test also show proportional increments in the bending stiffness and the moment Mx according to the outsole hardness. Throughout such experiments, the robot system has produced consistent results so that the system could be used in obtaining valuable informations for a shoe designing process.

• 한국가시화정보학회:학술대회논문집
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• 2005.04a
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• pp.87-112
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• 2005

분무를 정량적으로 측정하는 것은 노즐의 설계와 개발을 위해서 뿐만 아니라 연소 시스템 전반의 효율 및 불안정성의 제거, 공해 저감 등의 요구 조건을 만족하기 위해서 중요하다. 이를 위해 이전에는 분무장 내에 수집관을 삽입하는 기계적 패터네이터(Mechanical Patternator)와 같은 삽입식 측정 방식을 이용하여 왔으나, 최근에는 고속카메라, Malvern particle analyzer, PDPA, 광학 패터네이터(Optical Patternator)와 같은 분무장을 교란시키지 않으면서도 빠른 측정이 가능한 가시화 기술들이 적용되고 있다. 특히 광학 패터네이터는 레이저 평면광을 이용하여 분무를 측정하는 비삽입식 기술로 단시간 내에 분무장 내 액체 연료의 질량 및 액적 크기의 단면 분포를 동시에 얻어낼 수 있는 장점을 갖고 있다. 그러나 분무 액적들의 수밀도가 증가하는 경우에는 이들 액적에 의한 입사광 및 신호 감쇠, 다중산란 등에 의한 오차가 심하게 발생하여, 기존의 PDPA, PLIF 등의 광학 기법으로는 충분히 신뢰할 만한 결과를 얻기가 어렵게 된다. 이러한 분무를 정량적으로 측정하기 위해서는 입사광의 감쇠뿐만 아니라 분무장 내 액적들에 의한 신호의 감쇠 과정에 대한 고려가 필요하다. 주면 액적들의 영향을 최소한으로 줄이기 위해서는 레이저 평면광을 사용하는 광학 패터네이터와 달리 레이저 광선을 분무장에 조사하여 고압에서 나타날 수 있는 다중 산란에 의한 오차를 최소화할 수 있다. 이러한 이미지 처리 기법을 이용하는 광학 선형 패터네이터(Optical Line Patternator)를 이용하여 기존 레이저 계측기법으로 측정이 곤란하였던 고압 환경 하에서의 스월 동축형 인젝터의 분무 특성을 해석할 수가 있다. 2015(년도) 6,388, 2025(년도) 13,367, 2035(년도) 18,756, 2045(년도) 22,595, 시장점유율 증가로 인한 수출액 증가분 누적(억원) : 2015(년도) 3,411, 2025(년도) 8,847, 2035(년도) 14,433, 2045(년도) 18,005 또한 시나리오 비교평가를 실시하여 본 결과, 본 연구에서 정의한 순편익 누적(Cumulative Net Profit) 변수를 적용하면 현재 연구비 추세 대비 $30\%$ 까지 연구비를 증가 시키는 것이 효율적임을 알 수 있었다.성, 생산 용이성, 제품 디자인의 우수한 정도가 a=0.01 수준 하에서 유의적으로 추정되었다. 이들 변수들 중에서 품질경쟁력에 가장 큰 영향을 미치는 측정변수는 제품의 기본 성능, 수명(내구성), 신뢰성, 제품 디자인의 순서로 추정되었다. 이것은 한국 제조업이 아직 산업 디자인이 품질경쟁력에 크게 영향을 미치는 성숙단계에 이르지 못하였음을 의미한다. (2) 제품 디자인에게 영향을 끼치는 유의적인 변수는 연구개발력, 연구개발투자 수준, 혁신활동 수준(5S, TPM, 6Sigma 운동, QC 등)이며, 제품 디자인은 우선 품질경쟁력을 높여 간접적으로 고객만족과 고객 충성을 유발하는 것으로 추정되었다. 상기의 분석결과로부터, 본 연구는 다음과 같은 정책적 함의를 도출하였다. 첫째, 신상품 개발과 혁신을 위한 포괄적인 연구개발 프로젝트를 품질 경쟁력의 주요 결정요인(제품의 기본성능, 신뢰성, 수명(내구성) 및 제품 디자인)과 연계하여 추진해야 할 것이다. 둘째, 기업은 디자인 경영 마인드 제고와 디자인 전문인력 양성을, 대학은 디자인 현장 업무를 통하여 창의력 증진과 기획 및 마케팅 능력 교육을, 정부는 디자

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.167-174
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• 2020

The purpose of this study was to investigate the kinematic comparison between successful and failed trials of Lopez vault techniques in male gymnastics. The subject, an Olympic gold medalist, was YHS (age: 27 years, height: 1.6 m, and mass: 53 kg) and fourteen high speed motion capturing cameras were used for data collection. The 26 reflective sensors were attached on major anatomical positions and 15 segment-body model was used to calculate the kinematic variables. According to results, the contact duration of the spring-board for successful trial(ST) was longer and that of failed trial(FT) and the range of motion of knee joint for ST was greater than that of FT. The movement times during pre-flight between ST and FT were same, but the movement time of horse contact period for ST was shorter than that of FT. The ST showed a longer movement time during post-flight and the longer horizontal distance than those of FT. Conclusively, YHS needs to approach the horse with a higher position of the body and higher incidence angle, as well as make faster twist angular velocity in an attempt to achieve ST.

• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.68-73
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• 2020

This purpose of this paper was to review the development trend of the VTOL MAVs with a ducted propellant that can fly like the VTOL at intermediate and high speeds, hovering, landing, and lifting off vertically over urban areas, warships, bridges, and mountainous terrains. The MAV differs in flight characteristics from helicopters and fixed wings in many respects. In addition to enhancing thrust, the duct protects personnel from accidental contact with the spinning rotor. The purpose of the U.S. Army FCS and DARPA's OAV program is spurring development of a the VTOL ducted MAV. Today's MAVs are equipped with video/infrared cameras to hover-and-stare at enemies hidden behind forests and hills for approximately one hour surveillance and reconnaissance. Class-I is a VTOL ducted MAV developed in size and weight that individual soldiers can store in their backpacks. Class-II is the development of an organic VTOL ducted fan MAV with twice the operating time and a wider range of flight than Class-I. MAVs will need to develop to perch-and-stare technology for lengthy operation on the current hover-and-stare. The near future OAV's concept is to expand its mission capability and efficiency with a joint operation that automatically lifts-off, lands, refuels, and recharges on the vehicle's landing pad while the manned-unmanned ground vehicle is in operation. A ducted MAV needs the development of highly accurate relative position technology using low cost and small GPS for automatic lift-off and landing on the landing pad. There is also a need to develop a common command and control architecture that enables the cooperative operation of organisms between a VTOL ducted MAV and a manned-unmanned ground vehicle.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.19-31
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• 2006

이 연구의 목적은 각 분절의 마커세트와 무릎관절 중심 정의가 3차원 무릎 관절각을 산출하는데 얼마나 민감하게 영향을 미치는지를 연구하였다. 자료수집은 1명을 실험대상자로 하여 두 가지 형태의 각기 다른 분절의 정의와 무릎관절의 중심을 나타내는 반사마커들을 동시에 오른쪽 하지에 부착시켜 실험을 실시하였다. 실험대상자의 달리기동작 중 좌측으로 45도 방향전환동작의 지지기를 분석하였다. 이를 위해서 8대의 고속카메라들을 이용하였고 달리기속도는 4m/$sec{\pm}(10%)$로 통제하였다. 하지분절의 발분절에는 하나의 마커세트를, 정강이와 대퇴분절에는 두 가지의 다른 마커세트들을 부착시켰다. 발분절에는 3개의 마커를 신발의 뒷부분에 부착하였고 정강이분절을 정의하기 위하여 첫 번째 마커세트는 경골을 중심으로 3개의 마커들을 두 번째 마커세트는 비골을 중심으로 3개의 마커를 부착하였다. 대퇴분절의 마커세트를 정의하기 위하여 첫 번째 마커세트에는 대퇴골을 중심으로 3개의 마커를 두 번째 마커세트에는 대퇴근육을 중심으로 3개의 마커들을 부착하였다. 무릎관절중심을 정의하는데 두 가지 다른 정의가 적용되었다. 첫 번째 무릎중심을 무릎의 내측과 외측의 마커들을 통해 두 마커의 중심을 무릎관절의 중심으로 정의하였다. 두 번째 무릎중심정의는 무릎의 외측부분과 슬개골의 중심에 부착된 마커들로부터의 교차점을 무릎관절중심으로 산출하였다. 무릎관절의 각도를 산출하기 위해서 JCS(Joint Coordinate System)의 정의가 적용되었고 연구의 결과는 다음과 같았다. 두 가지의 다른 분절마커세트 사이에서 무릎의 신전(extension)과 굴곡(flexion)은 유사한 형태를 나타냈으며 최대 무릎굴곡(peak knee flexion)각에서 $4.746^{\circ}$의 차이를 나타냈다. 다른 분절마커세트 사이의 회전(rotation)각과 내전(adduction)/외전(abduction)에서는 서로 다른 형태를 나타내었고, 두 마커세트간 최대무릎외측회전(peak knee external rotation)각도에서는 $15.628^{\circ}$의 차이를 나타냈다. 또한, 각 분절마커세트 내에서 두 가지의 다른 무릎관절 중심의 정의가 얼마나 무릎도 산출에 영향을 미치는지를 비교했을 때 무릎의 최대외측회전(peak external rotation)각에서 차이를 나타내었다. 첫 번째 분절마커세트의 무릎관절중심정의의 형태변화에 따라 최대외측회전각은 $0.549^{\circ}$의 차이를 나타냈고, 두 번째 분절마커 세트에서 무릎관절중심정의의 형태변화에 따라 최대외측회전각은 $0.309^{\circ}$의 차이를 나타냈다. 이와 같이 분절을 나타내는 마커세트와 무릎관절중심정의의 형태변화에 따라 무릎간을 계산하는데 있어서 결과가 다르게 산출되었다. 즉, 관절각의 계산이 분절에 부착되는 마커의 정의 혹은 위치에 매우 민감하게 영향을 받았다. 따라서 연구자가 여러 실험대상자들을 대상으로 실험시 마커세트 혹은 마커들을 동일한 위치에 가깝게 부착하는 것이 마커부착으로부터 발생하는 실험오차를 줄일 수 있을 것이다.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.243-249
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• 2007

In this paper we introduce a system that assists news reporters to easily edit source video anywhere, and transfer the result from a remote site to the station. Presently reporters are bothered to edit source materials, compress and transfer using several separate tools. Moreover such tools have lots of too complicated features to use only for news production. We have integrated file sending and video editing functions together for seamless workflow. News programs usually need promptness in production. For this reason our system is designed to make it possible the one-stop production of news items outside the TV station. Also the system reflects the demands of field workers, that is, easy usage for the beginner and features for speedy news production. One of the most focused is that the reliability of the system is guaranteed in the process of transfer. To achieve this end, we have implemented several error-resilient schemes for unexpected network errors. Our system consists of remote laptop editing terminals and a newsgathering server. DV-format based editing and analog-to-DV converting device are adopted to capture video from not only lightweight DV camcorders but also old-fashioned ENG cameras into laptop computers. We expect that news reporters and cameramen can take terminals anywhere the Internet is available and both editing and sending will be done on the spot. This will help increase the competitive power of our news production.

• Composites Research
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• v.29 no.2
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• pp.53-59
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• 2016

Aircraft wing structure is used as a fuel tank containing the fluid. Fuel tank and joint parts are consists of composite structure. Hydrodynamic Ram(HRAM) effect occurs when the high speed object pass through the aircraft wing or explosion and the high pressure are generated in the fuel tank by HRAM effect. High pressure can cause failure of the fuel tank and the joint parts as well as the aircraft wing structure. To ensure the aircraft survivability design, we shall examine the behavior of the joint parts in HRAM effect. In this study, static tensile tests were conducted on four kind of the composite T-Joints. The failure behavior of the composite T-joint was examined by strain gauges and high speed camera. We examine the validity of the Finite Element Modeling by comparing the results of FEA and static tensile tests. The failure stresses and failure pressure of the composite T-Joint were calculated by FEA.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.39-48
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• 2016

One of the major trends of automotive networking architecture is the introduction of automotive Ethernet. Ethernet is already used in single automotive applications (e.g. to connect high-data-rate sources as video cameras), it is expected that the ongoing standardization at IEEE (IEEE802.3bw - 100BASE-T1, respectively IEEE P802.3bp - 1000BASE-T1) will lead to a much broader adoption in future. Those applications will not be limited to simple point-to-point connections, but may affect Electric/Electronic(EE) Architectures as a whole. It is agreed that IP based traffic via Ethernet could be secured by application of well-established IP security protocols (e.g., IPSec, TLS) combined with additional components like, e.g., automotive firewall or IDS. In the case of safety and real-time related applications on resource constraint devices, the IP based communication is not the favorite option to be used with complicated and performance demanding TLS or IPSec. Those applications will be foreseeable incorporate Layer-2 based communication protocols as, e.g., currently standardized at IEEE[13]. The present paper reflects the state-of-the-art communication concepts with respect to security and identifies architectural challenges and potential solutions for future Ethernet Switch-based EE-Architectures. It also gives an overview and provide insights into the ongoing security relevant standardization activities concerning automotive Ethernet. Furthermore, the properties of non-automotive Ethernet security mechanisms as, e.g., IEEE 802.1AE aka. MACsec or 802.1X Port-based Network Access Control, will be evaluated and the applicability for automotive applications will be assessed.