내부 온도를 이용한 시스템 직류 접속반 진단용 인공 신경망 기반 예측기 설계

김홍성,김기복,이승요 대한전기학회 2020 전기학회논문지 Vol.69 No.6

A diagnosis model for DC junction block O&M(Operation and Maintenance) of PV system is proposed in this paper. The proposed diagnostic model is based on a bath tube failure rate function and requires a well-functioning predictor to generate a reference signal which evaluates the operating characteristics of the diagnostic junction block. Among the various ML(Machine Learning) techniques, ANN(Artificial Neural Network) is used as a technique for the predictor with design factors such as input, output variables and learning rates, and sufficient data are required to train the diagnostic model by ANN. However, it is difficult to obtain operational data related to the DC junction block that should be used to train and evaluate the proposed diagnostic model. In order to solve this problem, environmental data on outdoor temperatures and solar radiation are downloaded from the domestic meteorological data center in Korea, and the data needed to evaluate the proposed predictor are generated by appropriate assumptions using various references and numerical simulations. The accuracy and generality of the proposed predictor are evaluated by the   value and the RMSE(Root Mean Square Error).

키토산 고분자의 용액 물성(I) -초산수용액에서 온도와 경과시간에 따른 점도 변화-

김홍성,이순장 한국섬유공학회 2004 한국섬유공학회지 Vol.41 No.5

Viscosity variation ensuing from processing temperature and time elapsed in acetic solution of chitosan was investigated by rotary viscometer. The solution showed a typical behavior of pseudoplastic liquid where the gradient of shear stress decreases as strain rate increases. The apparent viscosity decreased as chitosan polymer degraded with temperature rise and time elapsed in the solution. And the decrease in viscosity occurred rapidly in a fixed time interval at each temperature. The proportionality of viscosity to temperature was confirmed by temperature superposition curve that was obtained with the temperature dependence shift factor a$_{T}$ in WLF equation. Intrinsic viscosity was linearly proportional to apparent viscosity within a fixed range depending on strain rate. The activation energy of chitosan was about 55.2 KJ/mole in the acetic solution, which was calculated from intrinsic viscosity based on the Andrade-Eyring equation.n.

병렬가시화 기법 조합을 통한 고해상도 타일가시화

김홍성,김선영,최윤혁,조진연 한국항공우주학회 2006 한국항공우주학회 학술발표회 논문집 Vol.- No.-

키토산 고분자의 용액 물성(II) -초산수용액에서 온도와 경과시간에 따른 평균분자량의 변화-

김홍성,Kim, Hong-Sung 한국섬유공학회 2005 한국섬유공학회지 Vol.42 No.3

Variation of weight average molecular weight ($\bar{M}_{w}$) with processing temperature and time elapsed in acetic solution of chitosan was investigated by high performance liquid chromatography(HPLC), rotary viscometer, and capillary viscometer. The molecular weight distribution on chromatographs suggested that molecular chains of chitosan were degraded continuously by acid hydrolysis in aqueous acetic solution. The $\bar{M}_{w}$, degree of deacetylation, apparent viscosity, and intrinsic viscosity decreased with increasing temperature and time in 2 wt$\%$ acetic solution. The $\bar{M}_{w}$ decreased rapidly with increasing temperature above $30^{\circ}C$, and decreased to less than $25\%$ within initial 12 hours at $50^{\circ}C$. Above $\bar{M}_{w}\;9.2\times10^{4}$, the apparent viscosity showed a linearly propertional relationship to $\bar{M}_{w}$. The intrinsic viscosity was determined in 0.1 M acetic acid/0.2 M sodium chloride solution in order to compare with $\bar{M}_{w}$. Gross solution conformation factor a in the Mark-Houwink equation suggests that chitosan molecular chains assume coil conformation in dilute acetic solution.

니트릴기의 가수분해 반응을 이용한 흡수성 아크릴 혼방사의 물성

김홍성 한국섬유공학회 2002 한국섬유공학회지 Vol.39 No.1

Super-absorbent hydrogel fiber was prepared from polyacrylonitrile(PAN)-based acrylic fiber by hydrolyzing its nitrile groups. Chemical reaction of PAN and physical properties of hydrolyzed acryl/cotton blended yarn were analyzed using FT-IR spectrophotometer, wide angle X-ray diffractometer, differential scanning calorimetry, universal testing machine, and static honestmeter to discuss nitrile group substitution mechanism, microstructure of the hydrolyzed fiber, and other physical properties. Most nitrile groups of PAN were hydrolyzed to ionic groups such as carboxyl group err And the crystalline phase of the acrylic fiber was disrupted to amorphous phase after processing, but the fiber retained its original shape. Water-absorption ratio and antistatic resistance of the hydrolyzed acryl/cotton blended yarn increased greatly, but tensile strength decreased by half.

공기연료비의 변화에 따른 제어자발화 가솔린기관의 배기 특성

김홍성,Kim, Hong-Wung 한국기계가공학회 2004 한국기계가공학회지 Vol.3 No.2

This work treats a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. Investigated are the engine emission characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet-air temperature. A controlled auto-ignition gasoline engine can be achieved the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxides had been significantly reduced by CAI combustion compared with conventional spark ignition engines.

복수개의 작업처리규칙을 이용한 Job Shop 스케쥴링

김홍성,오상봉 大田大學校 産業技術硏究所 2001 산업기술연구소 論文集 Vol.12 No.2

It is difficult to develop an optimal schedule for job shop problems due to computational complexities and also hard to incorporate dynamic nature of the manufacturing environment into the job shop schedules. This paper suggests a multiple dispatching rule based approach to job shop scheduling problems. Our approach generates a feasible job shop schedule according to the each dispatching rule and suggests a best solution from the multiple generated schedules. We tested the suggested method in static and dynamic environment.

CD8-dependent Tumor Growth Inhibition by Tumor Cells Genetically Modified with 4-1BBL

김홍성 대한의생명과학회 2021 Biomedical Science Letters Vol.27 No.4

We previously identified that tumor cells genetically modified with a 4-1BBL co-stimulatory molecule had anticancer effects in a CT26 mouse colorectal tumor model. To identify the distinction between immune cells in a mouse tumor model treated with tumor cells genetically modified with 4-1BBL or β-gal, we examined the immune cells in CT26-WT, CT26-βgal, and CT26-4-1BBL tumor bearing mice 21 days after tumor cell administration. The CD8+ T cells population in mice treated with tumor cells genetically modified with 4-1BBL was significantly increased on day 21 compared to that of tumor cells genetically modified with β-gal in the spleen and tumor tissue. The CD4+ T cell population was not different between the two mice groups. The Foxp3+CD25high CD4 T cell population decreased on day 21 in tumor tissues, but the decrease was not significant. We also found that CD8 T cells had pivotal roles in inhibiting tumor growth by treating mice with ant-CD4 and CD8 antibodies. These results suggest that tumor cells genetically modified with 4- 1BBL could inhibit tumor growth by affecting on CD8 T lymphocytes.

K-water 동남아 3개국 해외수자원학교(OWA : Overseas Water resources Academy) 운영을 마치고

김홍성,김주환,김정곤,이경혁,Kim, Hong-Seong,Kim, Ju-Hwan,Kim, Jeong-Gon,Lee, Gyeong-Hyeok 한국수자원학회 2014 물과 미래(한국수자원학회지) Vol.47 No.1

제어자발화 가솔린기관의 성능 특성

김홍성 한국기계가공학회 2005 한국기계가공학회지 Vol.4 No.1

In this study, A controlled auto-ignition (CAI) single cylinder gasoline engine is considered, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. Investigated are the engine performance characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to 180 in the inlet-air temperature. A controlled auto-ignition gasoline engine which has the super ultra lean-burn with self-ignition of gasoline fuel can be achieved by heating inlet air.