8풍향에 대한 지역별 풍향계수 추정

황규석,길용식,정석원 한국풍공학회 2011 한국풍공학회지 Vol.15 No.4

100 years return period wind speed is generally used for design basic wind speed which is applied regardless of wind direction. However, it is not true that wind speeds blown from all directions are identical in reality. Taking into account this condition, previous studies proposed wind directional factors or basic wind speeds which are based on meteorological observations with respect to 16 wind directions. However, these factors or speeds about 16 wind directions would make too many cases which designers should review. In addition, it might be too complicated if these factors or speeds are used in the codes strengthened for detailed design. To compensate this disadvantage, wind directional factors about eight wind directions were evaluated which are available to be applied in practice. 설계기본풍속은 100년 재현주기 풍속값으로 모든 풍향에 대하여 동일한 풍속을 사용하고 있으나 실제로 바람은 모든 방향에 대하여 동일하게 불어오는 것이 아니다. 이러한 점을 반영하여 기존 연구결과는 기상관측자료에 기인하여 16개 풍향에 대한 풍향계수 또는 풍향별 기본풍속을 제안하고 있다. 그러나 16개 풍향에 대한 풍향계수는 설계자가 검토해야 할 경우의 수가 너무 많다. 그리고 정밀설계를 위한 설계기준 강화시 16풍향에 대한 풍향계수는 기준에 도입하기 너무 복잡할 수 있다. 이러한 문제점을 보완하기 위한 해석기법 중에 본 논문에서는 실무적으로 적용이 용이한 8풍향에 대해서 풍향계수를 검토하였다.

저온도포열분해에 의해 제조된 Pb(Zr, Ti)O$_3$ 박막의 에피탁시와 결정화도에 미치는 전열처리 시간의 영향

황규석,이형민,김병훈 한국세라믹학회 1998 한국세라믹학회지 Vol.35 No.9

Pb(Zr, Ti)O3 (PZT) (Zr:Ti= 52: 48) thin films were prepared on MgO(100) substrates by dipping-py-rolysis process using metal naphthenates as starting materials. Thin films were fabricated by spin coating technique and the precursor films were prefired at 20$0^{\circ}C$ in air for 0.5, 1, 2, 3, and 24 h followed by final heat treatment at 75$0^{\circ}C$ for 30min. Film prefired for 24 h lost orientational properties and pole figure analysis showed the lost of the epitaxial relationship between the films and substrate while highly a/c-axis oriented thin films were obtained for the samples prefired for 1, 2, and 3h.

도포 열분해법을 이용한 Bi$_4$Ti$_3$O$_{12}$제조에 관한 연구

황규석,이형민,김병훈 한국세라믹학회 1998 한국세라믹학회지 Vol.35 No.9

Bismuth titanate thin films were prepared on {{{{ { SrTiO}_{3 } }}(100) and Si(100) substrates by dipping-pyrolysis pro-cess using metal naphthenates as starting materials. crystallinity and in-phase alignment of the films were analyzed by X-ray diffraction $\theta$-2$\theta$ scans and $\beta$ scans (pole-figures) respectively. Highly c-axis-oriented {{{{ { { {Bi }_{4 }Ti }_{3 }O }_{12 } }} thin films with smooth surfaces were obtained after heat treatment at 75$0^{\circ}C$ on {{{{ { SrTiO}_{3 } }}(100) sub-strate while the films grown of Si(100) exhibited polycrstalline characteristics. C-axis oriented film show-ed an epitaxial relationship with the {{{{ { SrTiO}_{3 } }} substrate.

화학공정의 위험상태 예측 전문가 시스템

황규석,안대명 한국화학공학회 1996 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.34 No.6

화학공장의 star-up. shutdown과 같은 비정상조업의 운전지원 시스템으로, 공정내 발생가능한 위험성을 예측할 수 있는 전문가 시스템을 개발하였다. 본 연구에서 취급하는 위험성은 공정장치의 운전전 제약조건과 운전 중 제약조건, 공정내 물질의 혼합, 접촉에 의한 위험 및 일반적으로 발생가능한 위험으로 구분하여 정리하고, 이를 이용하여 위험특성 데이터베이스를 작성하였으며, 공전의 결합구조와 상태의 표현규칙 및 공정내 위험성을 판별할 수 있는 추론기구를 재발하였다. 본 시스템을 구체적인 화학공정에 적용시킨 결과, 공정 내 존재하는 다양한 위험형태를 인지할 수 있었다. An expert system was developed to predict hazardous conditions in chemical plants as an operation-aid system for the automation of unsteady state process operation such as start-up and shutdown. In this paper, hazards were classified into three main groups; constraints for preoperation and main operation of process units, hazards by mixing of dangerous materials, and potential hazards in process. By using these three groups, Hazardous-Condition-Data-Base was organized, after that, the methodology to represent process topology and process states was developed. An inference engine was developed for evaluating hazards in process and applied to the practical chemical plant to identify various types of hazards.

스핀코팅으로 금속물질을 도핑한 TiO₂박막의 광학적 특성

황규석,김재민,정주현,Hwang, Kyu-Seong,Kim, Jai-Min,Jung, Ju-Hyun 한국안광학회 2007 한국안광학회지 Vol.12 No.1

Ti-나프텐산염과 금속을 출발원료로 사용하고, 스핀코팅-열분해법을 이용하여 실리카 유리위에 박막을 제조하였다. 도포된 박막은 $500^{\circ}C$ 공기에서 10min동안 열처리하였다. 이를 5회 코팅한 박막은 마지막으로 공기에서 $600^{\circ}C$에서 30min으로 하였다. 박막의 특성을 분석하기 위하여 X-선 회절 분석, 전자현미경, UV스펙트럼을 이용하여 분석하였다. 밴드갭에서 가장 큰 장파장 쪽으로 이동은 Fe을 도핑한 $TiO_2$ 박막이었다. Metal-doped $TiO_2$ thin films were prepared on soda-lime-silica glass substrates by using a spin coating-pyrolysis process. As-deposited films were prefired at $500^{\circ}C$ or 10 min in air. Five-coated films were finally annealed at $600^{\circ}C$ for 30 min in air. High resolution X-ray diffraction, field emission scanning electron microscope and UV spectrophotometer were used to analyze film's property. The largest red shift in optical energy gap is obtained in the Fe-doped $TiO_2$ film.

Combination of Light Emitting Diode at 375 nm and Photo-reactive TiO2 Layer Prepared by Electrostatic Spraying for Sterilization

황규석,Young-Sun Jeon,Tae-Il Choi,황보승 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.5

The objective of this work was to increase the efficiency of ultraviolet-light emitting diodes at 375 nm for sterilization. Since TiO2 had antibacterial properties, which were attributed to the appearance of hydroxyl radicals and superoxide radical anions on the surface species under ultra violet radiation at about 387 nm, photo-reactive layers such as Ag-doped TiO2 were coated on aluminum substrates by electrostatic spraying. Crystallinity and surface morphology of the coating layer were examined by X-ray diffraction θ-2θ scan and field emission-scanning electron microscope, respectively. In an antibacterial test, we observed above 99% reduction of Escherichia coli populations on 3 or 5 mol%Ag-doped TiO2 layers after irradiation for 2 hrs at 375 nm, while very low inactivation on bare aluminum substrates occurred after irradiation as the same condition.

졸-겔법에 의한 $TiO_2$ 박막의 특성에 관한 연구

황규석,김병훈 한국세라믹학회 1995 한국세라믹학회지 Vol.32 No.3

to prepare the TiO2 thin films, acetyl-acetone(2.4-pentanedione)(1 : 1 molar ratio) was dissolved in the propanol solution of titanium(IV)isopropoxide(Ti[OCH(CH3)2]4). Al, Cr and Sb in the form of soluble salt and niobium ethoxide were added s dopants, respectively. Thin films were coated by the dip-coating method and characteristics were investigated by XRD, SEM and conductance meter. As a result, viscosity of sol was maintained below 4 centi Poise more than 20 days, and crystal growth and diminution of resistivity occurred as the heat treatment temperature increased. The grains grew over 1${\mu}{\textrm}{m}$ and the lowest resistivity was obtained when Nb was added at 130$0^{\circ}C$.

기상자료에 근거한 설계풍속과 돌풍율에 의한 최대풍속의 추정에 관한 연구

황규석,김윤석 한국풍공학회 2003 한국풍공학회지 Vol.7 No.2

작업환경측정 커버리지 확대를 위한 대상 사업장 등록 방안

황규석 한국산업보건학회 2020 한국산업보건학회지 Vol.30 No.3

Objectives: The most important occupational health activity is work environment measurement(WEM) along with the health examination. The preventive function of the WEM system could be achieved on the assumption that all subjected workplaces are performing correctly the WEM. To achieve properly the original purpose of WEM, we suggested a policy for subjected workplaces that they should register whether subjected or not. Methods: We made registration draft through reviewing laws, reports and thesis for WEM. And we conducted Focus Group Interview for industrial health experts using structured questionnaire about the registration. Results: There were 412 occupational deaths from 2013 to 2017. And it was found that only 130(31.6%) workplaces which involved in these occupational deaths had conducted the WEM. In order to operate the WEM system with effect, the subjected workplaces should register the subject status. Such registration must be completed at the stage of industrial accident insurance enrollment. Conclusions: Conducting WEM is the first step to prevent intoxication accident in workpalces. To operate properly WEM we should correctly understand subjected workplaces. So it is needed for all subjected workplaces to register whether they are subjected or not.

부분순서 알고리즘을 이용한 화학공장의 운전절차 합성

황규석,허보경 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.3

운전절차 자동합성에 관한 기존 연구의 한계점을 극복하기 위해 본 연구에서는 운전절차 합성에 관한 새로운 접근법을 개발하였다. 이것은 부분순서 계획 알고리즘을 기반으로 하여 안전과 밸브의 시퀀스 문제를 해결하는 새로운 접근 방법이다. 제안된 시스템은 주어진 제약조건을 침해하지 않고 주어진 목표 세트를 만족시키기 위해 조작연산자로부터 조작을 선택하여 그 순서를 결정한다. 제안된 시스템으로 기존의 시스템이 풀 수 없었던 문제를 해결할 수 있음을 증명하였다. In this study we have proposed a new operating procedure synthesis (OPS) methodology to overcome the limitations of the earlier work. The proposed approach is based on partial order planning algorithm to solve the safety and valve sequencing problems, and choose and order actions from the operators so as to achieve a given set of operational goals with satisfying a given set of safety constraints. We have demonstrated that the proposed OPS system is capable of solving problems that no previous system could solve.