참숯가마 열원을 활용한 비닐하우스 난방설비에 관한 연구

황용하,김범재,Hwang, Yongha,Kim, Beom-jae 한국교통대학교 융복합기술연구소 2012 융ㆍ복합기술연구소 논문집 Vol.2 No.2

This paper presents the study on applications of a surplus heat source. The heat is generated while hardwood charcoals are produced. We measure the temperature of the generated heat and analyze whether it can heat water or not. The analytic results show that the generated heat is useful as one of heat sources. In agricultural methods using a vinyl house, heating expenses will be saved by 10~20% when the surplus heat source is used.

볼-박판 스프링 형 체크밸브가 적용된 압전유압펌프의 가압 특성

황용하,황재혁,배재성,Hwang, Yong-Ha,Hwang, Jai-Hyuk,Bae, Jae-Sung 항공우주시스템공학회 2018 항공우주시스템공학회지 Vol.12 No.2

본 연구에서는 소형 압전유압펌프가 적용된 브레이크 시스템의 부하압 개선을 위해 체크밸브에 대한 연구를 수행하였다. 가압 과정에서 부하의 정상상태 압력은 챔버압과 부하압이 체크밸브에 작용하는 단면적 비에 영향을 받는다. 체크밸브 유로 덮개는 역류 방지를 위해 유로의 단면적보다 넓게 제작되었기 때문에 단면적 비 조절을 위해 박판 스프링 형 체크밸브에 부가질량을 부착하는 방식을 제안하였다. 부가질량 부착에 의한 부하압 개선 효과를 확인하기 위해 상용코드를 이용하여 소형 압전유압펌프가 적용된 단순 브레이크 시스템의 모델링을 수행하였다. 모델링의 검증을 위해 부가질량이 부착되지 않은 박판 스프링 형 체크밸브를 적용한 펌프의 가압 실험결과와 시뮬레이션 결과를 비교하였다. 검증된 아메심 모델링에 부가질량을 추가하였고 시뮬레이션을 통해 단면적 비 조절에 의한 고 부하압 형성 효과를 확인하였다. 부가질량 추가에 따른 소형 압전유압펌프 구성품을 새롭게 설계/제작한 후 브레이크 시스템의 가압 성능 실험을 수행하여 부하압 35% 의 성능 개선을 확인하였다. In this study, a new check valve was studied to improve the load pressure of a brake system with a small piezoelectric-hydraulic pump. During the pressurization process, the steady-state pressure at the load is affected by the ratio of the cross-sectional area of the check valve the chamber pressure and load pressure. Since the flow path cover of the check valve is made wider than the cross-sectional area of the output flow to prevent backflow, a method of reducing the area ratio is proposed for a higher load pressure by mounting an additional mass to a thin plate spring type check valve. To identify the effect of mounting an additional mass to the existing check valve on the load pressure, a simple brake system with a small piezoelectric-hydraulic pump was modeled using a commercial code AMESim. The AMESim modeling was verified by comparing the simulation results with the experimental results of the pump the existing check valve. The additional mass was added to the verified AMESim modeling and higher load pressure was able to be obtained through simulation. The 35% performance improvement in load pressure identified by carrying out pressurization test of the brake system after adopting the new check valve the small piezoelectric-hydraulic pump.

Solar Energy를 이용한 하수처리의 질소 제거에 관한 연구

황용하,Hwang, Yong Ha 한국교통대학교 융복합기술연구소 2011 융ㆍ복합기술연구소 논문집 Vol.1 No.2

The purpose of this research is to improve nitrogen removal efficiency in winter season through rise of water temperature of extraneous water by using solar energy which is estimated to have great potential among new regeneration energy and while operating Plug-Flow Reactor to improve nitrogen removal efficiency by selecting A/O process among sewage waste water treatment processes as the necessity of solving the problem of nitrogen removal efficiency according to reduced water temperature in winter season and strengthening of water quality criteria regarding discharged sewage waste water suggested in the research background. Summarizing the research result, supply of solar energy source improves the function outstandingly when removing nitrogen, (nitrogen removal rate before operating solar energy 55.4% ${\rightarrow}$ nitrogen removal rate after operating solar energy 84.1%).

다공성 물질을 이용한 공기용 태양열 집열기의 설계를 위한 이론 및 실험적 연구

황용하,박승호,Hwang, Yong-Ha,Park, Seung-Ho 대한기계학회 1996 大韓機械學會論文集B Vol.20 No.1

A theoretical and experimental study was conducted in order to design highly efficient solar air heaters using porous material. Radiative characteristics of glass windows and porous absorbing media were correlated through spectral transmittances measured by the UV-Visible and the FT-IR spectrometers. Using those characteristics the efficiencies of collectors were numerically calculated with the use of the two-flux radiation model. Based on the theoretical results, an experimental solar collector was designed and constructed. Experimental results under various conditions show that the daily efficiencies are over 60% in general and agree well with the theoretically calculated ones.

狂言台本における副詞ツヒニ

황용하(黃龍夏)(Hwang, Yong-Ha) 한일일어일문학회 2012 한일어문논집 Vol.16 No.-

본 논문에서는, 일본 중세의 狂言台本 자료를 이용하여 부사 ツヒニ의 사용실태를 조사 고찰해 다음과 같은 점을 밝혔다. 첫째, 狂言台本의 ツヒニ는 이전시대와 같은 용법이 있는 반면 다른 새로운 용법도 보이며 후속부의 피수식어 용법을 긍정·미래용법, 긍정·비미래용법, 부정·미래용법, 부정·비미래용법, 부정·중간용법, 부정·미경험용법과 같이 분류 조사 고찰한 결과 각 용법 사이에 사용빈도 등의 차이가 보였다. 둘째, 부사 ツヒニ 용법 가운데 부정·미경험용법이라는 새로운 용법이 狂言台本에서 발생하고 있으며 모든 대본에서 확인되었다. 또한 새로운 용법의 발생과 함께 그 과도기적인 부정·중간용법의 존재와 사용실태가 주목된다.

확대단면에서 폐쇄형 외부 띠철근 배근 방법에 따른 보강기둥의 중심축하중 거동 평가

황용하(Hwang, Yong-Ha),양근혁(Yang, Keun-Hyeok),심재일(Sim, Jae-Il),최용수(Choi, Yong-Soo) 대한건축학회 2019 大韓建築學會論文集 : 構造系 Vol.35 No.7

This study examined the effect of various arrangement methods for forming peripheral closed hoops in the jacket section on the axial behavior of section enlargement strengthening columns. Four types of peripheral closed hoops arranged in the jacket section were prepared as follows: 1) Closed connection of prefabricated bar units (column P); 2) V-clip installation across the overlapped legs of channel-type bars (column V); 3) Use of glass fiber mesh for an alternative of steel bars (column F); and 4) combination of prefabricated bar units and glass fiber mesh (column PF). The V-clip is designed to form the closed hoops in the jacket section using the overlapped channel-type bars, preventing the opening of the channel bar legs. The glass fiber mesh is to examine the feasibility to apply for closed hoops in the jacket section as an alternative for steel bars, considering the easy construction. In the jacket section of all the strengthened columns, V-ties were arranged for supplementary ties, avoiding the interruption of the existing column. The axial stiffness and strength of the strengthened columns were insignificantly affected by the arrangement methods of closed hoops in the jacket section. The axial ductility ratio of the strengthened columns P, V, and PF was enhanced more than twice of that measured in the non-seismic existing column. However, the column F exhibited a lower ductility than the other strengthened columns because of the fracture of the mesh at the ultimate strength of the column. The V-clip approach was favorable to enhance the ductility of the strengthened column, preventing the opening of the legs of channel-type bars.

스마트폰을 이용한 응급환자 인식 및 구조요청 시스템설계 및 구현

황용하(Hwang, Yong-Ha),김진모(Kim, Jin-Mo),남궁우진(NamgGung, Wu-Jin),김용석(Kim, yong-Seok) 강원대학교 산업기술연구소 2012 産業技術硏究 Vol.32 No.1

For emergency patients as heart disease, fast treatment is very important. This paper describes a smart phone software to detect emergency circumstance and request rescue. Detection of emergency condition of heart disease patients is based on physical motion and biological heart signals as electrocardiogram. Most smart phones have three axis acceleration sensor. On emergency condition, patients remain stationary. Thus the software detect stationary condition by using acceleration sensor data. For more precise detection, it combines electrocardiogram of patients. To request rescue, it sends help messages to designated persons. In addition, it generates emergency sound to surrounding people and plays a video of emergency measure that any person on the place can help the patient temporarily.

UPS용 배터리를 대체하는 열과 압축공기를 이용한 직류발전장치

황용하(Hwang yong Ha) 대한전기학회 2005 대한전기학회 학술대회 논문집 Vol.2005 No.11

축전지가 필요치 않은 무정전 전원장치

황용하(Y.H. Hwang) 대한전기학회 2004 대한전기학회 학술대회 논문집 Vol.2004 No.11

콘크리트의 전단마찰내력에 대한 시공줄눈의 영향

황용하(Hwang, Yong-Ha),양근혁(Yang, Keun-Hyeok) 대한건축학회 2016 大韓建築學會論文集 : 構造系 Vol.32 No.6

To evaluate the shear friction performance of concrete interfaces with construction joint, a total of 18 push-off specimens were tested under direct shear and constant axial compressive forces. The main parameters investigated were concrete unit weight, arrangement type of transverse reinforcement (V-type for perpendicular configuration to the shear plane and X-type for 45°-degree inclined configuration), and the magnitude of axial compressive stresses. The initial shear cracking stress and the slope at the ascending branch of the shear load-relative slip relationship were independent of the type of transverse reinforcement and concrete unit weight, whereas they tended to increase as the axial compressive stresses increases. The shear friction strength increased in proportion to the summation of the applied axial stresses and shear transfer capacity (pvffy) of transverse reinforcement. The X-type transverse reinforcement had higher shear transfer capacity than the V-type reinforcement. From the mechanical model derived using the upper bound theorem of concrete plasticity, the concrete cohesion and coefficient of friction at the interfaces with construction joint could be estimated to be 1.56 MPa and 36.3°, respectively.