Correlation between lower limb muscle asymmetry during the sit-to-stand task and spatiotemporal gait asymmetry in subjects with stroke

Sungkwang Ju 한국운동재활학회 2020 JER Vol.16 No.1

4WD 구동토크 배분에 따른 구동계 경량화에 관한 연구

신성광(Sungkwang Shin),고명수(Myungsoo Ko),성명호(Myung-Ho Sung) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

The target of SUV has been changed from an off-road performance to an on-road. A lot of SUV recently accept the electric couplings of on-demand type. Naturally the 4WD characteristics pursue not a traction performance on an off-road but a handling, a vehicle safety and a weight reduction for fuel-efficiency on an on-road. In the present work, we examine the 4WD driveline strength test for the weight-down and try to find the optimized torque distribution of rear wheel through changing the coupling limit torque. The measured rear wheel torque shows that transfer gear ratio is more efficient than the coupling limit torque to decrease the cost and weight of driveline.

물류기업의 관계특성이 협업 및 성과에 미치는 영향에 관한 연구

최성광(Sungkwang Choi),하명신(Myungshin Ha) 한국항만경제학회 2011 韓國港灣經濟學會誌 Vol.27 No.3

공급사슬관리에 관한 많은 선행연구들이 지속으로 공급사슬성과의 향상을 위해서는 협업이 필요하다고 주장하고 있다. 본 연구는 뭍류기업의 관계특성, 협업, 성과 간의 인과관계를 밝히는 것이며, 특히 관계특성과 성과 간의 관계에서 매개변수로서 두 종류의 협업(운영적 협업과 전략적 협업)에 초점을 맞추고 있다. 분석을 위해 물류기업 164개의 자료가 사용되었으며, PLS를 이용해 구조모형을 분석하였다. 분석결과 신뢰성, 정보공유는 운영적협업에 긍정적인 영향을 미쳤으며, 운영적 협업은 공급사슬 성과에 긍정적인 영향을 미치는 것으로 나타났다. 거래지속의지와 정보공유는 전략적 협업에 긍정적인 영향을 미쳤으나, 전략적 협업은 공급사슬 성과에 긍정적인 영향을 미치지 않는 것으로 나타났다. 따라서 관계특성과 공급사슬성과 사이에는 운영적 협업이 매개역할을 하는 것으로 나타났다. Many previous studies on the subject of supply chain have consistently claimed that they need collaboration among the partners of supply chains in order to enhance supply chain performance. The purpose of research is to examine the causal linkages among relational characteristics, collaboration, performance in the logistics firm and this research focuses on two types collaboration(operational collaboration and strategic collaboration) as the mediation variable between relational characteristics and supply chain performance. To test the above research questions, wc collected data from logistics firm(N=164). The proposed structural model was tested using the PLS(Partial Least Square) statistical program. The research results are as follows. Trust, and information sharing have positive influences on operational collaboration, and operational collaboration have also positive influences on supply chain performance. Duration and information sharing have positive influences on strategic collaboration. However, strategic collaboration has non-positive influences on supply chain performance. The effect of relational characteristics on supply chain performance is mediated by operational collaboration.

유한요소해석을 통한 Rack housing 설계변경에 따른 압축하중 특성 연구

조성광(Sungkwang Cho),김진용(Jinyoung Kim),나병철(Byungchul Na) 한국자동차공학회 2017 한국자동차공학회 부문종합 학술대회 Vol.2017 No.5

회전분리망 흡착선별기의 순환 굵은골재 이물질 제거효율에 관한 연구

조성광(Sungkwang Cho),김규용(Gyuyong Kim),김경욱(Kyungwuk Kim),선상원(Sangwon Seon),박진영(Jinyoung Park) 한국건설순환자원학회 2021 한국건설순환자원학회 논문집 Vol.9 No.1

건설폐기물에서 발생하는 순환골재의 분류 과정에서 발생하는 이물질을 순환골재 출하 전에 회수하기 위하여 회전분리망 흡착 선별기를 설계 및 제작하였다. 제작된 선별기의 성능을 평가하기 위하여, 순환골재에서 자체적으로 회수한 이물질 종류에 따라, 아크릴을 사용하여 규격화된 이물질 샘플을 제작하고, 선별기에서 작동하는 흡입팬의 제어주파수 및 분리망의 흡입구 위치에 따른 선별효율과 순환골재의 오분류율을 평가하여 적절한 운전점을 평가하였다. 순환골재 및 이물질을 입자로 가정한 유동해석을 통해 예측된 선별기의 운전점에서의 분류효율을 평가하였다. 성능 시험 결과 컨베이어 밸트와 흡입구의 거리가 0.2m일 때 95%의 선별효율을 보이는 것으로 나타났으나, 순환골재의 오분류율이 2% 이상으로 선별효율과 2% 이하의 오분류율을 만족하는 운전점은 흡입구 거리 0.254m에서 제어주파수 58Hz으로 나타났다. 유동해석 결과 이물질 선별기에서 순환골재의 오분류는 나타나지 않았다. 기존 순환골재 생산공정에서 이물질 저감을 위해 설치식으로 운용이 가능한 회전분리망을 이용한 풍력 선별시스템을 구축하였다. Aggregate waste separator with rotating separating net was designed for applying classification process of construction waste. In order to evaluate the performance of the aggregate waste separator, according to the type of waste, standardized waste samples are prepared using acrylic. The appropriate operating point was evaluated by the classification efficiency and misclassification rate of recycled aggregate according to the control frequency of the blower operating and inlet position of the separating net. The classification efficiency at the operating point of the aggregate waste separator was evaluated through flow analysis assuming recycled aggregate and waste sample as particles. As a result of the performance test, when the distance. between the conveyor belt and the inlet was 0.2m, the classification efficiency was 95%, but the misclassification rate of recycled aggregate was 2% or more, which satisfies the classification efficiency and the misclassification rate of less than 2%. The operating point was shown at a control frequency of 58Hz at a suction distance of 0.254m. As a result of flow analysis, there was no misclassification of recycled aggregate. In order to reduce construction waste in the existing recycled aggregate production process, adsorption system using a rotating separating net that can be operated as an installation type was built.

물질의 B-H 곡선에 따른 솔레노이드 밸브의 흡입력 특성 전자기적 수치 해석

조성광(Sungkwang Cho),김진용(Jinyoung Kim),나병철(Byungchul Na),설승윤(Seungyun Seol) 한국자동차공학회 2016 한국자동차공학회 부문종합 학술대회 Vol.2016 No.5

In this paper, we perform a three-dimensional electromagnetic finite element numerical analysis applied axially symmetrical shape of a typical solenoid valve. parts of the solenoid valve Inner Yoke, Outer Yoke, Armature was to change the material of the attraction force characteristics according to identify current and the stator and the plunger clearance derives an analysis result. According to an analysis result, attraction force in increasing as clearance decreasing and property of b-h curve greater. Especially, it was figured out that the armature made of materials with better B-H curve characteristics increases the attraction force more than the armature made of the same material as the Inner and Outer Yokes.

Incorporating Spatial Queries into Semantic Sensor Streams on the Internet of Things

Eom, Sungkwang,Lee, Kyong-Ho Idea Group Publishing 2017 Journal of database management Vol.28 No.4

<P>In the Internet of Things (IoT) environment, the use of sensors and sensor readings is significant in research and industry. The number of sensors is increasing exponentially, adding a tremendous amount of data to the Web. Therefore, the efficient management of sensors and observation data is becoming important. Especially, the location and time of observations are expected to play a vital role in IoT. However, existing researches mainly focus on the temporal properties of data stream. It is necessary to consider the spatial features in addition to the temporal ones. In this article, the authors propose a spatiotemporal query language which integrates spatial and temporal features. Also, they propose an efficient method of building a spatiotemporal index and processing the proposed query language. To evaluate the proposed method, the authors conduct experiments through implementation. The experimental results show that the proposed method deals with spatiotemporal queries within a reasonable time.</P>

ICT 표준화기관의 OSS 도입지원 플랫폼 분석

엄숭광(Sungkwang Eom),정해원(Hea Won Jung),이승윤(Seung Yun Lee) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.6

Autothermal reforming over a Pt/Gd-doped ceria catalyst: Heat and mass transport limitations in the steam reforming section

Lim, Sungkwang,Bae, Joongmyeon Elsevier 2010 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.35 No.13

<P><B>Abstract</B></P><P>Autothermal reforming (ATR) has several advantages for fuel cell applications, such as a compact reactor structure and fast response. Using oxidation reactions inside the reactor, ATR does not have the external heat transfer limitations associated with steam reforming. However, mass and heat transfer limitations inside and outside the catalyst particles are still anticipated. In this study, transport limitations in the steam reforming section of ATR over a Pt/Gd-doped ceria catalyst are analyzed by numerical simulations based on a reaction rate equation in which parameters are adjusted to measured kinetic data. The simulation results show that significant transport limitations characterize the steam reforming section of packed-bed ATR reactors. The activity per catalyst bed volume is highly dependent on the particle size, and only the thin exterior layer of the particles is involved in catalyzing the reactions. Based on the results, it is shown that an eggshell type catalyst particle could reduce catalyst material significantly without a considerable decline in the activity per catalyst bed volume.</P>

귀금속계열 WGS 촉매 연구

임성광(Sungkwang Lim),배중면(Joongmyeon Bae),김선영(Sunyoung Kim) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Water gas shift reactor in fuel processing is an important part that converts carbon monoxide into hydrogen. Fuel processing system for PEMFC usually has two stages of WGS reactors, which are high temperature and low temperature shifter. In this study we prepared noble metal catalysts and compared their performances with that of a commercial iron chromium oxide catalyst. Noble metal catalysts and the commercial catalyst showed quite different temperature dependence of carbon monoxide conversion. The conversion of carbon monoxide at the commercial catalyst was very low at medium temperature(~300℃) and increased rapidly as temperature increased while the conversion at noble metal catalysts was high in the medium temperature range and decreased as temperature increased, which is thermodynamically expected. Their characteristics agreed well with the literature published, and we are accomplishing further study for improvement of the noble metal catalysts.