• 한국가스학회지
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• 제2권1호
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• pp.90-98
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• 1998

미래의 화재 사고에 대한 구체적인 대응과 사고를 줄이기 위하여 국내외 사고사례의 집적과 체계적인 자료 분류가 필요하다. 본 연구에서는 화재 사고사례 분류 모델을 제시하고 미국 NFPA의 분류 모델과 일본의 모델을 비교하여 향후 개선 방향을 제시하였다. 또한 PC의 Windows 환경에서 운영될 수 있는 사고사례에 관한 데이터베이스 프로그램(FADBS)을 개발하여 사고사례 분석을 쉽고 효과적으로 활용할 수 있도록 하였다.

• 센서학회지
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• 제33권3호
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• pp.139-146
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• 2024

Surface-enhanced Raman scattering (SERS) enables the detection of various types of π-conjugated biological and chemical molecules owing to its exceptional sensitivity in obtaining unique spectra, offering nondestructive classification capabilities for target analytes. Herein, we demonstrate an innovative strategy that provides significant machine learning (ML)-enabled predictive SERS platforms through surface-engineered graphene via complementary hybridization with Au nanoparticles (NPs). The hybridized Au NPs/graphene SERS platforms showed exceptional sensitivity (10^-7 M) due to the collaborative strong correlation between the localized electromagnetic effect and the enhanced chemical bonding reactivity. The chemical and physical properties of the demonstrated SERS platform were systematically investigated using microscopy and spectroscopic analysis. Furthermore, an innovative strategy employing ML is proposed to predict various analytes based on a featured Raman spectral database. Using a customized data-preprocessing algorithm, the feature data for ML were extracted from the Raman peak characteristic information, such as intensity, position, and width, from the SERS spectrum data. Additionally, sophisticated evaluations of various types of ML classification models were conducted using k-fold cross-validation (k = 5), showing 99% prediction accuracy.

• Journal of the Korean Wood Science and Technology
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• 제45권2호
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• pp.202-212
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• 2017

This study was to establish the interrelation between chemical compositions and near infrared (NIR) spectra for the classification on distinguishability of domestic gymnosperms. Traditional wet chemistry methods and infrared spectral analyses were performed. In chemical compositions of five softwood species including larch (Larix kaempferi), red pine (Pinus densiflora), Korean pine (Pinus koraiensis), cypress (Chamaecyparis obtusa), and cedar (Cryptomeria japonica), their extractives and lignin contents provided the major information for distinction between the wood species. However, depending on the production region and purchasing time of woods, chemical compositions were different even though in same species. Especially, red pine harvested from Naju showed the highest extractive content about 16.3%, whereas that from Donghae showed about 5.0%. These results were expected due to different environmental conditions such as sunshine amount, nutrients and moisture contents, and these phenomena were also observed in other species. As a result of the principal component analysis (PCA) using NIR between five species (total 19 samples), the samples were divided into three groups in the score plot based on principal component (PC) 1 and principal component (PC) 2; group 1) red pine and Korean pine, group 2) larch, and group 3) cypress and cedar. Based on the chemical composition results, it was concluded that extractive content was highly relevant to wood classification by NIR analysis.

• 한국축산식품학회지
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• 제21권2호
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• pp.97-102
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• 2001

The characteristic fitness of food to each Sa-sang constitution and the relationship between Han-Yeoul characteristics and chemical composition after classifying Samgye-tang ingredients and other food into Ohn-Yeoul-Ryang-Han characteristic were assessed. When the suitable constitution to the each characteristic was investigated after classifying Samgye-tang ingredients and other food into Han, Ryang, Pyound, Ohn and Yeoul of which fitness case for Soeumin was 44∼63% but fitness case for Soyangin and Taeyangin was only 0∼18%. When the relationship between Samgye-tang ingredients and other food classified into Ohn-Yeoul-Ryang-Han and chemical composition of fatty acid, amino acid, vitamin and mineral was investigated, the value of correlation coefficient was extremely low. There was not the relationship between chemical composition and Han-Yeoul classification. Therefore it should be further investigated the relationship between characteristic and chemical composition by additional analysis index.

• Korean Chemical Engineering Research
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• 제46권2호
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• pp.383-388
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• 2008

화학공정의 안전하고 효율적인 운전에 관심이 커지면서 공정이상의 원인을 조기에 진단하기 위한 다양한 이상진단방법이 연구되어 왔다. 최근에는 통계적 모델 등 정량적 데이터에 기반한 이상진단방법이 많이 연구되고 있으나, 특정 조업영역에서 얻어진 통계적 모델을 다른 조업영역에 적용하면 오진단이 많아지게 된다. 따라서 공정특성상 다양한 조업영역이 존재하는 화학공정에 데이터기반 방법론을 적용하기에는 어려움이 있어 화학공정의 조업영역 판별법이 요구되고 있다. 이 연구에서는 유클리드 거리(Euclidean distance), FDA(Fisher's discriminant analysis), PCA(principal component analysis)의 통계모델과 이 모델들에 공정변수의 동특성을 반영한 모델을 제안하였다. 6개의 조업모드를 가진 TE(tennessee eastman) 공정에 대한 사례연구를 통해 동특성을 반영한 PCA 모델의 성능이 가장 우수함을 확인하였다.

• 센서학회지
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• 제22권2호
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• pp.162-173
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• 2013

The purpose of this paper is to classify VOC gases by emulating the characteristics found in biological olfaction. For this purpose, we propose new signal processing method based a polymeric chemical sensor array consisting of 4096 sensors which is created by NEUROCHEM project. To remove unstable sensors generated in the manufacturing process of very large scaled chemical sensor array, we used discrete wavelet transformation and cosine similarity. And, to remove the supernumerary redundancy, we proposed the method of selecting candidates of representative sensor representing sensors with similar features by Fuzzy c-means algorithm. In addition, we proposed an improved algorithm for selecting representative sensors among candidates of representative sensors to better enhance classification ability. However, Classification for very large scaled sensor array has a great deal of time in process of learning because many sensors are used for learning though a redundancy is removed. Throughout experimental trials for classification, we confirmed the proposed method have an outstanding classification ability, at transient state as well as steady state.

• 한국화재소방학회논문지
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• 제34권1호
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• pp.89-102
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• 2020

인체 건강에 치명적인 위해를 가할 수 있는 독성 및 인화성 가스를 이용한 화학테러행위는 행위자인 테러범과 그 행위로 인한 피해자 간에 존재하는 현격한 정보의 비대칭성으로 인해 대다수의 선진국, 또는 국지적 분쟁을 겪고 있는 국가 및 지역사회에 대하여 중대한 안보위협이 되고 있다. 화학테러에 대한 대응기관의 대처방안은 크게 예방, 대응, 수습의 3단계로 나누어 볼 수 있고, 이 과정 중에서 화학테러의 피해 정도 및 피해 범위에 절대적인 영향력을 미치는 예방과 대응단계에 해당하는 각 전문대응기관과 요원들의 성공적인 임무수행을 위해서는 화학테러의 잠재적 대상이 되는 시설들에 대한 객관적이고 체계화된 취약성의 평가와 등급화가 무엇보다 중요하다. 본 연구에서는 기존 국내외의 화학테러관련 취약성 등급분류체계를 비교분석하고 현재 국내 등급분류체계의 개선방향에 대해 살펴보고 실제 국내 다중이용시설 표본에 대한 취약성 평가를 통해서 보다 과학적이고 체계화된 방법론을 제시하였다.

• 한국산업보건학회지
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• 제23권4호
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• pp.384-392
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• 2013

Objective: This study inspected incident cases, legal control levels, and GHS(Globally Harmonized System of Classification and Labeling of Chemicals) classification results of strong acids such as hydrogen fluoride, hydrogen chloride, nitric acid, and sulfuric acid, which have been responsible for many recent chemical accidents. As a result, it is deemed necessary for legal control levels of these strong acids to be revised and GHS classification be managed nation-wide. Methods: This study inspected incident cases and legal control levels for strong acids such as hydrogen fluoride, hydrogen chloride, nitric acid, and sulfuric acid. The study analyzed and compared chemical information status and GHS classification results. Results: There were 76 domestic incidents involving strongly acidic hazardous materials over the five years between 2007 and 2011. They include 37 leakage incidents(46.7%) within a workplace, 30 leakage incidents(39.5%) during transportation, and nine leakage incidents(13.8%) following an explosion. The strongly acidic materials in question are defined and controlled as toxic chemicals according to the classes of Substances Requiring Preparation for Accidents, Managed Hazardous Substance, Hazardous Chemical(corrosive) as set forth under the Enforcement Decree of the Toxic Chemicals Control Act and Rules on Occupational Safety and Health Standards of Occupational Safety and Health Act. Among them, nitric acid is solely controlled as a class 6 hazardous material, oxidizing liquid, under the Hazardous Chemicals Control Act. The classification results of the EU ECHA(European Chemicals Agency) CLP(Commission Regulation(EC) No. 790/2009 of 10 August 2009, for the purposes of its adaptation to technical and scientific progress, Regulation(EC) No 1272/2008 of the European Parliament and of the Council on classification, labeling and packaging of substances and mixtures) and NIER (National Institute of Environmental Research) are almost identical for the three chemicals, with the exception of sulfuric acid. Much of the classification information of NITE (National Institute of Technology and Evaluation) and KOSHA(Korea Occupational Safety and Health Agency, KOSHA) is the same. NIER provides 12(41.4%) out of 29 classifications, as does KOSHA.

• 품질경영학회지
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• 제30권1호
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• pp.152-161
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• 2002

The analysis of large data sets with hundreds of thousands observations and thousands of independent variables is a formidable computational task. A less parametric method, capable of identifying important independent variables and their interactions, is a tree structured approach to regression and classification. It gives a graphical and often illuminating way of looking at data in classification and regression problems. In this paper, we have reviewed and summarized tile methodology used to construct a tree, multiple trees and the sequential strategy for identifying active compounds in large chemical databases.

• 한국결정성장학회지
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• 제12권6호
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• pp.323-328
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• 2002

The model of the shortest chemical bonds is applied for the classification of acentric simple and binary Mo(VI) and W(VI) oxides. It is shown that on the plane of the shortest chemical bonds the compounds are located into the rosette of three intersected ellipses. The correlation between the optical nonlinearity and combination of the bond lengths is discussed.