다공질 압전소자로 제작한 초음파 트랜스듀서와 신경회로망을 이용한 3차원 수중 물체복원

조현철,박정학,사공건 ( Hyun Chul Cho,Jung Hak Park,Geon Sa Gong ) 한국전기전자재료학회 1996 전기전자재료학회논문지 Vol.9 No.8

3차원 수중 물체인식 실험에 의한 다공질 압전 초음파 센서의 성능평가

조현철,이수호,박정학,사공건 ( Hyun Chul Cho,Su Ho Lee,Jung Hak Park,Geon SaGong ) 한국전기전자재료학회 1997 한국전기전자재료학회 추계학술대회논문집 Vol.1997 No.1

Disciplinary Session 8 / Sport Physiology / Physiological Effects of Physical Training : 최대산소섭취량 , 환기역치 및 환기역치 20% 이하의 운동강도에서 과산화지질 ( LPO ) 생성 및 항산화효소 ( SOD ) 활성도의 변화

조현철,김학렬 ( Hyun Chul Cho,Hag Lyeol Kim ) 한국체육학회 1998 국제스포츠과학 학술대회 Vol.1998 No.2

교량의 경관조명연출디자인 평가항목 도출에 관한 연구

조현철,Cho, Hyun-Choul 한국조명전기설비학회 2004 조명·전기설비학회논문지 Vol.18 No.6

도시 공간에서의 교량경관 조명연출의 목적은 교량과 주변의 수변 공간을 아름답게 연출할 뿐만 아니라 사람과 자동차에 대하여 안전성 및 쾌적성을 확보함과 동시에 야간경관의 심미적 공간을 연출한다. 또한 환경과의 조화, 그리고 지역의 문화성, 역사성, 상징성과 융합하여 도시의 새로운 아이덴티티를 창출하기 위한 것으로서, 관광자원으로서의 부가가치를 높일 수 있으므로 최근에는 정부가 적극적으로 교량 경관조명을 활성화시키고 있으나 매뉴얼화 된 디자인과 설계기준의 부재로 교량의 예술적, 문화적 품위가 저하되고 있는 실정이므로 조속히 우리풍토에 적합한 교량 경관조명의 설계지침과 평가방법 등 이 확립되어야 하겠다. 이러한 이유로 본 연구에서는 도시미관을 향상시키기에 최적의 장소로 여겨지고 있는 한강의 교량 중 조명시설이 설치된 교량을 평가 대상으로 채택하여, 문헌고찰과 설문조사를 중심으로 예비평가항목 구성단계 및 전문가 검증 단계를 거쳐, 평가항목별 상관분석 및 인자분석 결과, 평가항목을 인자해석에 의해 중요변인으로 하고 분산 분석과 평균값 비교를 통해 중요 항목과 일반항목으로 구분하였고, 이를 바탕으로 전문적이고 표준화된 평가를 유도할 수 있는 교량형식별 경관조명의 평가항목을 도출하였다. It is an attempt to suggest the standard valuation method of the environmental illumination for the bridges across the Han-river from an aesthetic point of view, deviating from the technical and traditional viewpoint. In Korea the current evaluation criterion to verify the value of bridge design has a partiality for the technical and structural safety rather than the sentient beauty on the whole. However, the recently cultural reform of Korean mass society with the elevation of the standard of living forces the engineering designers for bridges to focus not only on competing physical structures but also on enhancing the formative beauty including the illumination effects for night view. Additionally, the new policy, which transforms the environments around the Han-river into the major tourist attractions has been executing strongly by the city authorities to revitalize the symbolic, historic, and cultural identity of the capital city with the introduction of the high-quality environmental illumination for the bridges. As a result, It becomes necessary to establish the manual and standardization of the environmental illumination planning for the city in terms of the formative beauty, and this study is to suggest the valuation model method of the environmental illumination for the bridges as the initial step of the standardization. In the study, the valuation items of the standard questionnaire are selected by the documentary records and the consultation of various experts in architecture, design, fine art, urban planning and even administration to verify the essential elements of the aesthetic beauty with the local amenity and the environmental harmony for the chosen bridges across the Han-river.

모델매칭 기법을 이용한 시스템 섭동을 갖는 비선형 크레인시스템 제어

조현철,이진우,이영진,이권순,Cho, Hyun-Cheol,Lee, Jin-Woo,Lee, Young-Jin,Lee, Kwon-Soon 한국항해항만학회 2007 한국항해항만학회지 Vol.31 No.6

크레인 시스템은 항만 터미널 등의 산업현장에서 무거운 물체를 이송하는데 사용되는 장비로서 그 정확성과 신속성을 동시에 만족시키기 위한 연구가 활발히 진행되고 있다. 본 논문은 적응제어기의 일종인 모델매칭 기법을 이용하여 복잡한 3 자유도 비선형 크레인의 제어 시스템에 대한 연구를 제안한다. 피드백 선형화(feedback linearization)를 통해 비선형 크레인 모델을 선형화한 후 PD 제어기를 적용하여 선형 공칭 모텔을 구한다. 이 모델은 시스템 섭동을 갖는 실시간 시스템 모델과 함께, 리아푸노브(Lyapunov) 이론을 적용하여 실시간 섭동에 의해 발생되는 제어오차를 감소하기 위한 보조 제어규칙의 산출에 이용된다. 또한 리아푸노브 안정성이론을 적용하여 구성한 크레인 제어시스템의 안정성 해석을 실시한다. 컴퓨터 시뮬레이션을 통해 제안한 알고리즘의 타당성을 검증하며 기존의 제어방식과 비교 분석하여 그 우수성을 입증한다. Crane systems are very important in industrial fields to carry heavy objects such that many investigations about control of the systems are actively conducted for enhancing its control performance. This paper presents an adaptive control approach using the model matching for a complex 3-DOF nonlinear crane system. First, the system model is linearized through feedback linearization method and then PD control is applied in the approximated model. This linear model is considered as nominal to derive corrective control law for a perturbed crane model using Lyapunov theory. This corrective control is primitively aimed to compensate real-time control deviation due to partially known perturbation. We additionally study stability analysis of the crane control system using Lyapunov perturbation theory. Evaluation of our control approach is numerically carried out through computer simulation and its superiority is demonstrated comparing with the classical control.

소비자의 제품 지각 위험에 대한 기업연상과 효과: 지식과 관여의 조절적 역활을 중심으로

조현철,강석후,김진용,Cho, Hyun-Chul,Kang, Suk-Hou,Kim, Jin-Yong 한국마케팅과학회 2008 마케팅과학연구 Vol.18 No.4

Brown and Dacin (1997) have investigated the relationship between corporate associations and product evaluations. Their study focused on the effects of associations with a company's corporate ability (CA) and its corporate social responsibility (CSR) on consumers' product evaluations. Their study has found that both of CA and CSR influenced product evaluation but CA association has a stronger effect than CSR associations. Brown and Dacin (1997) have, however, claimed that there are few researches on how corporate association impacts product responses. Accordingly, some of researchers have found the variables to moderate or to mediate the relationship between the corporate association and the product responses. In particular, there has been existed a few of studies that tested the influence of the reputation on the product-relevant perceived risk, but the effects of two types of the corporate association on the product-relevant perceived risk were not identified so far. The primary goal of this article is to identify and empirically examine some variables to moderate the effects of CA association and CSR association on the perceived risk of the product. In this articles, we take the concept of the corporate associations that Brown and Dacin (1997) had proposed. CA association is those association related to the company's expertise in producing and delivering its outputs and CSR association reflected the organization's status and activities with respect to its perceived societal obligations. Also, this study defines the risk, which is the uncertainty or loss of the product and corporate that consumers have taken in a particular purchase decision or after having purchased. The risk is classified into product-relevant performance risk and financial risk. Performance risk is the possibility or the consequence of a product not functioning at some expected level and financial risk is the monetary loss one perceives to be incurring if a product does not function at some expected level. In relation to consumer's knowledge, expert consumers have much of the experiences or knowledge of the product in consumer position and novice consumers does not. The model tested in this article are shown in Figure 1. The model indicates that both of CA association and CSR association influence on performance risk and financial risk. In addition, the effects of CA and CSR are moderated by product category knowledge (product knowledge) and product category involvement (product involvement). In this study, the relationships between the corporate association and product-relevant perceived risk are hypothesized as the following form. For example, Hypothesis 1a($H_{1a}$) is represented that CA association has a positive influence on the performance risk of consumer. Also, the hypotheses that identified some variables to moderate the effects of two types of corporate association on the perceived risk of the product are laid down. One of the hypotheses of the interaction effect is Hypothesis 3a($H_{3a}$), it is described that consumer's knowledges of the product moderates the negative relationship between CA association and product-relevant performance risk. A field experiment was conducted in order to examine our model. The company tested was not real but imagined to meet the internal validity. Water purifiers were used for our study. Four scenarios have been developed and described as the imaginary company: Type A with both of superior CA and CSR, Type B with superior CSR and inferior CA, Type C with superior CA and inferior CSR, and Type D with both inferior of CA and CSR. The respondents of this study were classified into four groups. One type of four scenarios (Type A, B, C, or D) in its questionnaire was given to the respondent who filled out questions. Data were collected by means of a self-administered questionnaire to the respondents, chosen in convenience. A total of 300 respondents filled out the questionnaire but 207 were use

확률론적 의사결정기법을 이용한 태양광 발전 시스템의 고장검출 알고리즘

조현철,이관호,Cho, Hyun-Cheol,Lee, Kwan-Ho 한국융합신호처리학회 2011 융합신호처리학회 논문지 (JISPS) Vol.12 No.3

태양광 발전 시스템의 고장검출은 고장으로 인해 발생되는 기술적 및 경제적 손실을 최대한 줄이기 위한 첨단 기술로 각광을 받고 있다. 본 논문은 푸리에 신경회로망과 확률론적 의사결정법을 이용한 태양광 발전 시스템의 새로운 고장진단 알고리즘을 제안한다. 우선 태양광 시스템의 동적 모델링을 위하여 최급강하 기반 최적화 기법을 통해 신경회로망 모델을 구성하며 GLRT 알고리즘을 이용하여 태양광 시스템의 확률론적 고장검출 기법을 제안한다. 제안한 고장검출 알고리즘의 타당성 검증을 위하여 태양광 고장검출 테스트베드를 제작하여 실시간 실험을 실시하였으며 이 때 태양광으로부터의 신호는 직류 전력선 통신을 이용하였다. Fault detection technique for photovoltaic power systems is significant to dramatically reduce economic damage in industrial fields. This paper presents a novel fault detection approach using Fourier neural networks and stochastic decision making strategy for photovoltaic systems. We achieve neural modeling to represent its nonlinear dynamic behaviors through a gradient descent based learning algorithm. Next, a general likelihood ratio test (GLRT) is derived for constructing a decision malling mechanism in stochastic fault detection. A testbed of photovoltaic power systems is established to conduct real-time experiments in which the DC power line communication (DPLC) technique is employed to transfer data sets measured from the photovoltaic panels to PC systems. We demonstrate our proposed fault detection methodology is reliable and practicable over this real-time experiment.

다공질 압전소자로 제작한 초음파 센서의 물체변위에 무관한 3차원 수중 물체인식 특성

조현철,이기성,박정학,이수호,사공건 ( Hyun Chul Cho,Kee Seong Lee,Jung Hak Park,Su Ho Lee,Geon SaGong ) 한국전기전자재료학회 1997 전기전자재료학회논문지 Vol.10 No.9

LiBr계 용액을 사용한 수직관 흡수기의 열 및 물질 전달에 관한 연구

조현철,김종보,정시영,강상우,이춘식,Cho, H.C.,Kim, C.B.,Jeong, S.Y.,Kang, S.W.,Lee, C.S. 대한설비공학회 1995 설비공학 논문집 Vol.7 No.2

Experimental investigations on heat and mass transfer characteristics in a vertical tube absorber have been carried out. Three different copper tubes with a length of 1.5m have been tested using LiBr solution and LiBr-$CaCl_2$ solution. The effects of solution flow rate, cooling water temperature, solution inlet temperature and evaporation temperature have been investigated in detail. It is found that heat transfer coefficient increases gradually with the increase of solution flow rate, but decreases rapidly for the flow rates less than 0.02kg/ms. The grooved tube generally shows better heat transfer performances than the smooth tube. LiBr solution shows almost no absorption capability for the cooling water temperatures over $40^{\circ}C$. LiBr-$CaCl_2$ gives less decreasing rate in absorption capability at these temperatures and the heat transfer coefficient becomes less dependent on the types of tubes in use. Considering heat and mass transfer rates, LiBr-$CaCl_2$ solution is found to be more suitable than LiBr solution for air cooled absorber, which operates at higher temperature than water cooled absorber.

한방통전약물요법을 이용한 섬유근통환자 치험 1례

조현철,장건,송윤경,임형호,조태영,Cho, Hyun-Chol,Jang, Gun,Song, Yun-Kyung,Lim, Hyung-Ho,Cho, Tae-Young 척추신경추나의학회 2005 대한추나의학회지 Vol.6 No.1

Objective : We got a good effect on one patient who was diagnosed Fibromyalgia. Method : We treated 1 case of Fibromyalgia with acupuncture, moxibustion, herbal medication, and iontophoresis. We measured the VAS(Visual Analog Scale) and ROM(Range of motion) of Lumbar. Results : Patient's met complain is low back pain, pain and hemiparesis of night lower limb, and Pantalgia After treatment, most symptoms decreased and ROM, ambulation improved. VAS score changed from 10 to 2 for 52 days. Conclusion : The Fibromyalgia were successfully treated by acupuncture, moxibustion, herbal medication, and iontophoresis.