독성물질 사용 저장시설에 대한 개인적 위험성 산정에 관한 연구

김성빈,김윤화,이철,엄성인,고재욱,백종배 한국산업안전학회 1997 한국안전학회지 Vol.12 No.1

These days leakage incidents of toxic materials cause serious effects on the nearby residents as well as the workers around the accidents accompanying massive material losses and human damages through widening influencial areas. The risk measure through adequate quantitative analysis as well as the qualitative analysis of the leakage incidents of toxic materials becomes an urgent issue. The damage, of the leakage incident on the surrounding area of the dangerous toxic material facilities was calculated quantitatively by adopting several models in this research. First, the calculations of the leakage velocity from the factories were performed by using source model for the assessment of the influential area, and the damages on the nearly residents were calculated by using the dispersion model and the effect model. The probability of the incidents was computed based on $quot;The manual for classification and priorization of major incidents$quot; published by IAEA(International Atomic Energy Agency). Above calculated damage area and incident probability were further adopted in this study to induce the individual and societal risk, quantitatively. The calculated data of the real incident of the toxic material leakage showed reasonable agreements to the actual damage of the incidents, which showed a validity of this study. The result of this study might be a helpful measure for predicting damages and preparing safety systems for similar kinds of incidents.

데이터베이스를 이용한 산업시설의 위험성평가시스템 구축에 관한 연구

김성빈,김윤화,엄성인,고재욱,김기수,백종배 한국산업안전학회 1998 한국안전학회지 Vol.13 No.1

Recently, industrial accidents have occurred in various patterns due to the diversity of industries and the integration of facilities. Especially, the major accidents affect broad area and result in huge loss of lives and properties. Domestic researches on techniques for keeping away from such hazardous danger have been actively performed but their activities are limited in some institutes and universities. In advanced countries, integrated management systems like Seveso Directive of EU and OSHA(Occupational Safety and Health Act) of U.S.A. have been legislated along with the systematic research activities. In Korea, the integrated safety management systems called SMS(Safety Management System) and PSM(Process Safety Management) have been applied to major industries. These systems made chemical industries manage the process safety information by collecting and arranging safety data by themselves. In order to implement the system successfully, it is urgently required to prepare a tool for searching and accumulating process safety data systematically. In this study, a computerized prototype of Risk Assessment System which is essential to SMS and PSM was developed as a main system and data base as subsystem to handle safety information.

LPG 탱크로리 수송중 위험성 평가에 관한 연구

이재준,김윤화,엄성인,고재욱,백종배,윤성렬 한국산업안전학회 1997 한국안전학회지 Vol.12 No.4

Demand of LPG and LNG will increase continuously due to high calories, clearness, and convenience for usage. These gases are used widely for power plants, industrial plants, and domestic fuel. But accidents related with gas are increasing in proportion to increment of gas usage. Especially, LPG has high ignitability due to weak dispersion to air and accumulation at low place because LPG is heavier than air. There are many hazards during transportation as well as production, storage, and usage of LPG. Commonly, tank lorry is used for inland transportation of LPG. If tank lorry were to raise leakage incidents and then LPG released during transporting, the accidents cause serious effects on the environment as well as human damage of surrounding area. In this study, therefore, hazards which cause LPG of tank lorry to leak during transportation were identified and risk of LPG transportation was assessed quantitatively. Also, the result of this study might be a useful measure for predicting damage and preparing safe transportation strategies of LPG tank lorry.

식물성 사료원료 내 피틴태 인의 함량과 PHYTASE ACTIVITY 및 그 특성에 관한 연구

엄재상,백인기,이선재,남궁환 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.6

본 실험은 국내 사료회사들이 사용 중인 식물성 사료원료를 수집하여 phytate-P, total-P 그리고 phytase activity를 측정함으로써 가축이 필요로 하는 P의 적정 첨가량을 결정 할 수 있는 기초자료와 밀 phytase와 미생물 phytase의 pH 및 온도 변화에 따른 activity의 변화를 구명하고자 실시하였다. Phytate-P는 대부분 강피류에 많이 함유되어 있었다. 강피류 중에서도 미강 (1,201 ㎎/100g)과 탈지강 (1,077 ㎎/100g), corn gluten feed (896 ㎎/100g), 밀기울 (742㎎/100g) 그리고 채종박 (535 ㎎/100g)에 많이 함유되어 있었고, 다른 원료의 phytate-P는 500 ㎎/100g 이하였다. Total-P는 탈지강 (1,899 ㎎/100g), 미강 (1,886 ㎎/100g), 채종박 (1,016 ㎎/100g) 등에 많이 함유되어 있었다. Phytase activity는 밀 (1,121.9 U/㎏)과 밀기울 (2,935.1 U/㎏)에서 높은 활성을 보였다. pH와 온도의 변화에 따른 미생물 phytase와 밀 phytase의 activity는 모두 pH 5.5와 50℃를 전후하여 최고치를 나타내었다. 그러나 pH 6과 60℃ 이상에서 급격히 감소하는 경향을 보였다. 밀 phytase 보다는 미생물 phytase가 보다 더 급격히 감소하여 식물성 phytase가 pH와 온도변화에 대해서는 내성이 더 강한 것으로 나타났다. An experiment was conducted to measure the contents of phytate-P, total-P and phytase activity of cereals and cereal by-products. The effects of pH and temperature on the activity of wheat and microbial phytase were compared. Phytate-P content was higher in most cereal by-products than in cereal. Rice bran had the highest phytate-P (1,201 ㎎/100g) followed by defatted rice bran (1,077 ㎎/100g), corn gluten feed (896 ㎎/100g), wheat bran (742 ㎎/100g) and rapseed meal (535 ㎎/100g). The phytate-P contents of other ingredients were lower than 500 ㎎/100g. Total-P content was high in defatted rice bran (1,899 ㎎/100g), rice bran (1,886 ㎎/100g), and rapseed meal (1,016 ㎎/100g) compared to other ingredients. Wheat and wheat bran had the highest phytase activity (1,121.9 and 2,935.1 U/㎏) among ingredients tested. The activity of wheat and microbial phytase was gradually increased until pH and temperature reached at 5.5 and 50℃ respectively, then their activity remarkably decreased at pH 6 and 60℃. Wheat phytase was as stable, if not more, as microbial phytase under different pH and temperature.

화학공장의 중대사고에 따른 예상손실액 산정 및 대책연구

엄성인,고재욱,구남주 한국산업안전학회 1999 한국안전학회지 Vol.14 No.4

This study evaluated the effect of the accidents caused by fire, explosion, and toxic gas release by using SuperChems, quantitative hazardous material release modeling software, which estimates the potential area of damage. According to the loss severity, the appropriate risk management principles can be applied. Risk management is divided into the two methods which are risk control and risk financing. Risk control includes risk avoidance, risk spreading and diversification, and risk reduction. Risk financing includes risk retention and risk transfer. The results of this study can help the related company determine the appropriate reserve fund and the amount to be insured against the third party losses according to the estimated loss severity.

A Joint Agreement Measure Between Multiple Raters and One Standard

Um, Yong-Hwan The Korean Data and Information Science Society 2005 한국데이터정보과학회지 Vol.16 No.3

This article addresses the problem of measuring a joint agreement between multiple raters and a standard set of responses. A new agreement measure based on Um's approach is proposed. The proposed agreement measure is used for multivariate interval responses. Comparison is made between the proposed measure and other corresponding agreement measures using hypothetical data set.

A Measure of Agreement for Multivariate Interval Observations by Different Sets of Raters

Um, Yong-Hwan Korean Data and Information Science Society 2004 한국데이터정보과학회지 Vol.15 No.4

A new agreement measure for multivariate interval data by different sets of raters is proposed. The proposed approach builds on Um's multivariate extension of Cohen's kappa. The proposed measure is compared with corresponding earlier measures based on Berry and Mielke's approach and Janson and Olsson approach, respectively. Application of the proposed measure is exemplified using hypothetical data set.

Comparative Study of the Temperature-dependent Dielectric Properties of Au/PPy/n-Si (MPS)-type Schottky Barrier Diodes

Ahmet G¨um¨us¸,G¨ul¸cin Ers¨oz,˙Ibrahim Y¨uceda˘g,S¨umeyye Bayrakdar,S¸ emsettin Altındal 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.5

The dielectric properties of Au/PPy/n-Si metal-polymer-semiconductor (MPS)-type Schottky barrier diodes (SBDs) were investigated by using capacitance-voltage (C-V ) and conductancevoltage (G/!-V ) measurements at various temperatures and voltages at frequencies of 100 kHz and 500 kHz. Both the real and the imaginary parts of the complex dielectric constant and dielectric loss ("0, "00) and of the electric modulus (M0, M00), as well as the conductivity (ac), were found to depend strongly on the temperature and the voltage. Both the C and G/! values increased with increasing applied voltage and had inversion, depletion, and accumulation regions as with a metal-insulator-semiconductor (MIS) type behavior. Both the dielectric constant ("0) and the dielectric loss ("00) increased with increasing temperature and decreased with increasing frequency. The loss tangent (tan ) vs. temperature curve had a peak at about 200 K for both frequencies. The M0 and the M00 values decreased with increasing temperature and became independent of the frequency at high temperatures. The series resistance (Rs) of the diode decreased with increasing temperature for the two frequencies while the ac increased. Such behaviors of the dielectric properties with temperature were attributed to the restructuring and reordering of charges at interface states/traps due to the varying temperature, the interfacial polarization, and the interfacial polymer layer. ln(ac) vs. q/kT plots had two distinct linear regions with different slopes for the two frequencies. Such behaviors of these plots confirmed the existence of two different conduction mechanisms corresponding to low and high temperatures. The values of the activation energy (Ea) were obtained from the slopes of these plots, and its value at low temperatures was considerably lower than that at high temperatures.

On Assessing Inter-observer Agreement Independent of Variables' Measuring Units

Um, Yong-Hwan Korean Data and Information Science Society 2006 한국데이터정보과학회지 Vol.17 No.2

Investigators use either Euclidean distance or volume of a simplex defined composed of data points as agreement index to measure chance-corrected agreement among observers for multivariate interval data. The agreement coefficient proposed by Um(2004) is based on a volume of a simplex and does not depend on the variables' measuring units. We consider a comparison of Um(2004)'s agreement coefficient with others based on two unit-free distance measures, Pearson distance and Mahalanobis distance. Comparison among them is made using hypothetical data set.

Search Design of Resolution III.3 for $3^4$Factorial

Um, Jung-Koog 韓國統計學會 1990 Journal of the Korean Statistical Society Vol.19 No.1

The basic conditions for a parallel flats fraction to be a search design of resolution III.2 have been developed in Um (1980, 1981, 1983, 1984). A series of resolution III.2 search design for $3^n, n=4, 5, 6$ are presented in Um (1988). In this paper a resoultion III.3 search design for $3^4$ is presented.