• 인터넷정보학회논문지
• /
• 제23권4호
• /
• pp.11-19
• /
• 2022

본 논문은 컨볼루션 신경망(CNN)을 이용하여 폭발물 성분의 용량별로 분류할 때의 성능을 평가하는 연구이다. 기존의 폭발물 분류 방식 중에 IMS 증기 탐지기 방식은 폭발물의 농도가 사용자가 장비에서 설정한 임계치를 넘어야만 폭발물의 존재 여부를 판단한다. IMS 증기 탐지기는 폭발물이 존재하더라도 임계치를 넘지 않는 양이면 폭발물이 존재하지 않는다고 판단하는 문제가 있다. 따라서 폭발물 성분의 농도가 임계치를 넘지 않는 양일 때에도 폭발물 성분을 검출하는 방안이 필요하다. 이에 따라 본 논문에서는 폭발물 시계열 데이터를 Gramian Angular Field(GAF) 알고리즘으로 이미지화를 진행한 후 이미지와 영상처리뿐만 아니라 시계열 데이터 처리에도 뛰어난 성능을 보이는 딥러닝 모델인 컨볼루션 신경망(CNN)으로 직접 label을 설정해서 지도학습을 진행한 결과 폭발물 성분의 농도가 임계치를 넘지 않는 양일 때에도 폭발물 성분이 존재한다고 판단함과 동시에 폭발물 성분의 종류와 폭발물 성분의 농도의 양을 같이 판단할 수 있는지 성능평가를 진행했다.

• Korean Chemical Engineering Research
• /
• 제58권3호
• /
• pp.493-497
• /
• 2020

Hazardous area classification is designed to prevent chemical plant explosions in advance. Generally, the duration of the explosive atmosphere is used for zone type classification. Herein, IEC code, a quantitative zone type classification methodology, was used to achieve Zone 2 NE, which indicates a practical non-explosion condition. This study analyzed the operating pressure of a vessel handling propane to achieve Zone 2 NE by applying the IEC code via MATLAB. The resulting zone type and hazardous area grades were compared with the results from other design standards, namely API and EI codes. According to the IEC code, the operating pressure of vessels handling propane should be between 101325-116560.59 Pa. In contrast, the zone type classification criteria used by API and EI codes are abstract. Therefore, since these codes could interpret excessively explosive atmospheres, care is required while using them for hazardous area classification design.

• 분석과학
• /
• 제33권2호
• /
• pp.86-97
• /
• 2020

Reconstruction and separation of explosive-contaminated overlapping fingerprints constitutes an analytical challenge of high significance in forensic sciences. Laser-induced breakdown spectroscopy (LIBS) allows real-time chemical mapping by detecting the light emissions from laser-induced plasma and can offer powerful means of fingerprint classification based on the chemical components of the sample. During recent years LIBS has been studied one of the spectroscopic techniques with larger capability for forensic sciences. However, despite of the great sensitivity, LIBS suffers from a limited detection due to difficulties in reconstruction of overlapping fingerprints. Here, the authors propose a simple, yet effective, method of using chemical mapping to separate and reconstruct the explosive-contaminated, overlapping fingerprints. A Q-switched Nd:YAG laser system (1064 nm), which allows the laser beam diameter and the area of the ablated crater to be controlled, was used to analyze the chemical compositions of eight samples of explosive-contaminated fingerprints (featuring two sample explosive and four individuals) via the LIBS. Then, the chemical validations were further performed by applying the Raman spectroscopy. The results were subjected to principal component and partial least-squares multivariate analyses, and showed the classification of contaminated fingerprints at higher than 91% accuracy. Robustness and sensitivity tests indicate that the novel method used here is effective for separating and reconstructing the overlapping fingerprints with explosive trace.

• 한국안전학회지
• /
• 제16권4호
• /
• pp.103-108
• /
• 2001

Explosive limit is one of the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limits are used to classify flammable liquids according to their relative flammability. Such a classification is important for the safe handling of flammable liquids which constitute the solvent mixtures. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this paper, Raoult,s law and van Laar equation(activity coefficient model) are shown to be applicable for the prediction of the explosive limits in the flammable ethylacetate-toluene system. The values calculated by the proposed equations were a good agreement with literature data within a given percent. From a given results, by the use of the proposed equations, it is possible to predict explosive limits of the other flammable mixtures. It is hoped eventually that this method will permit the estimation of the explosive Properties of flammable mixtures with improved accuracy and the broader application for other flammable stances.

• 화약ㆍ발파
• /
• 제27권2호
• /
• pp.19-25
• /
• 2009

벽식구조 아파트에 대한 재개발의 수요가 증가함에 따라 RC구조 아파트와는 다른 새로운 해체기술이 요구되고 있다. 본 연구에서는 벽식구조 아파트의 발파해체를 위한 기초적인 자료를 제공하기 위해 실시설계 도면을 토대로 벽식구조 아파트를 주동 형태 및 규모에 따라 분류하고, 아파트의 높이(H), 폭(B), 길이(L)의 발파 패턴 요소를 이용하여 벽식구조 아파트의 발파해체에 적합한 발파해체공법을 분석하였다.

• 방재기술
• /
• 통권15호
• /
• pp.22-27
• /
• 1993

The classification of hazardous area is a method of analysing and classifying the environment where explosive gas or vapour atmosphere may be expected to be present. The object of area classification is to enable the proper selection and installation of electical apparatus and other equipments. This report is intended to serve a general reference about the classification procedure of hazardous area with explanations of related Korean Standard.

• 공업화학
• /
• 제32권1호
• /
• pp.102-109
• /
• 2021

Recently, an interest in risk calculation methods has been increasing in Korea due to the establishment of classification code for explosive hazardous area on gas facility (KGS CODE GC101), which is based on the international standard of classification of areas - explosive gas atmospheres (IEC 60079-10-1). However, experiments to check for leaks of combustible or toxic gases are very difficult. These experiments can lead to fire, explosion, and toxic poisoning. Therefore, even if someone tries to provide a laboratory for this experiment, it is difficult to install a gas leakage equipment. In this study we find out differences among actual experiments, CFD by using FLACS and calculation based on classification code for explosive hazardous area on gas facility (KGS CODE GC101) by comparing to each other. We develpoed KGS HAC (hazardous area classification) program which based on KGS GC101 for convenience and popularization. As a result, actual gas leak, CFD and KGS HAC are showing slightly different results. The results of dispersion of 1.8 to 2.7 m were shown in the actual experiment, and the CFD and KGS HAC showed a linear increase of about 0.4 to 1 m depending on the increase in a flow rate. In the actual experiment, the application of 3/8" tubes and orifice to take into account the momentum drop resulted in an increase in the hazardous distance of about 1.95 m. Comparing three methods was able to identify similarities between real and CFD, and also similarities and limitations of CFD and KGS HAC. We hope these results will provide a good basis for future experiments and risk calculations.

• 한국안전학회지
• /
• 제33권4호
• /
• pp.21-29
• /
• 2018

In many companies handling flammable liquids, explosion-proof electrical equipment have been installed according to the Korean Industrial Standards (KS C IEC 60079-10-1). In these standards, hazardous area for explosive gas atmospheres has to be classified by the evaluation of the evaporation rate of flammable liquid leakage. The evaporation rate is an important factor to determine the zones classification and hazardous area distance. However, there is no systematic method or rule for the estimation of evaporation rate in these standards and the first principle equations of a evaporation rate are very difficult. Thus, it is really hard for industrial workplaces to employ these equations. Thus, this problem can trigger inaccurate results for evaluating evaporation range. In this study, empirical models for estimating an evaporation rate of flammable liquid have been developed to tackle this problem. Throughout the sensitivity analysis of the first principle equations, it can be found that main factors for the evaporation rate are wind speed and temperature and empirical models have to be nonlinear. Polynomial regression is employed to build empirical models. Methanol, benzene, para-xylene and toluene are selected as case studies to verify the accuracy of empirical models.

• 한국가스학회지
• /
• 제23권4호
• /
• pp.46-64
• /
• 2019

폭발위험장소의 선정과 거리계산에 대한 상세기술기준 KGS GC101 2018(가스시설의 폭발위험장소 종류 구분 및 범위 산정에 관한 기준)이 제정되어, 2018년 7월 12일부터 시행되었다. IEC60079-10-1 2015 (Explosive atmospheres Part 10-1: Classification of areas - Explosive gas atmospheres)에 대한 전수 내용을 정리하고, 모호한 기준의 해석이나 기준에 대한 가이드라인을 추가하여 제정하였다. KGS GC101은 폭발위험장소 종류의 구분을 위한 방법으로 (1)누출등급의 결정 (2)누출 홀 크기의 결정 (3)누출유량의 결정 (4)희석등급의 결정 (5)환기유효성의 결정을 통하여 최종적으로 (6)위험장소의 결정 (7) 폭발위험장소 범위의 산정을 할 수 있다. 이 과정을 쉽게 계산하기 위하여 Visual Basic for Application (Excel) 언어로 구성한 프로그램(KGS-HAC, C-2018-020632)을 한국가스안전공사에서 제작하였고, 현재 시범 사용 중(2019년 4월 1일 현재 v1.14)에 있다. 그럼에도 불구하고 현장에서 어려워하여, 본 논문을 통하여 코드 및 프로그램의 사용법을 설명하는 것으로 해결코자 한다.

• 정보관리학회지
• /
• 제15권3호
• /
• pp.45-71
• /
• 1998

인터넷 정보자원의 폭발적인 증가에 따라 이를 효율적으로 조직화하고 체계화하는 시스템의 중요성이 증가하고 있다. 이에 따라 주제접근을 용이하게 하고 검색 효율성을 높이는 도구로서 분류체계에 대한 관심이 커지고 있다. 본 고에서는 문헌 분류체계와 인터넷기반 분류체계의 계층구조와 접근방법을 구조적 측면과 검색사례를 통하여 조사하고 이에 대한 비교 분석을 통해 인터넷 환경에 적합한 분류체계의 구성방안을 살펴보았다.