• 한국산학기술학회논문지
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• 제18권4호
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• pp.216-223
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• 2017

화학물질은 전 세계적으로 1,500만 여종 이상 상업적으로 이용되고 있을 정도로 현대사회의 필수적인 요소이다. 그러나 이러한 화학물질 중에서 국민의 건강과 환경을 위협하는 위험성을 내포하고 있는 유해화학물질이 상당수 존재한다. 과거 사례를 통해 화학사고가 발생하면 인간의 생명에 얼마나 큰 위험성을 내포하고 있는지 알 수 있다. 화학물질사고의 특성상 짧은 시간에 큰 피해로 확산할 수 있으므로, 사전에 예방하고 사고발생 후에는 즉각적이고 신속한 대응이 매우 중요하다. 이에 국내의 화학물질에 대한 법제도가 2015년 기준으로 "유해화학물질관리법"에서 "화학물질의 등록 및 평가 등에 관한 법률"과 "화학물질관리법"의 체계로 이원화되었다. 그러나 현행법상 화학물질종합정보시스템과 화학물질정보처리시스템의 구축 및 운영을 하고 있지만, 여전히 화학사고는 지속적으로 발생하고 있다. 이러한 시스템은 화학물질사고 대응시스템이라기보다는 화학물질 정보에 그 목적을 둔 종합정보시스템이기에, 실질적인 사고대응에는 한계가 존재한다. 본 연구에서는 유해화학물질의 정보관리체계, 대응관리체계 및 화학물질 관리 지원 근거에 대해 분석하고, 이를 통한 현행 화학물질관리법 등의 개정방향과 지자체별 화학물질대응시스템을 개발 운영할 수 있도록 법제도 개선방안을 제안하고자 한다.

• Korea-Australia Rheology Journal
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• 제15권2호
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• pp.97-105
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• 2003

In the previous paper (Hyun et al.,2002), we have investigated the shape of storage modulus (G') and loss modulus (G") of complex fluids under large amplitude oscillatory shear (LAOS) flow. As the strain amplitude increases, owever, the stress curve becomes distorted and some important information may be smothered during data processing. Thus we need to investigate the stress data more precisely and systematically. In this work, we have obtained the stress data using high performance ADC (analog digital converting) card, and investigated the nonlinear response of complex fluids, 4wt% xanthan gum (XG), 2 wt% PVA/ 1 wt% Borax, and 1 wt% hyaluronic acid (HA) solutions, using Fourier transformation (FT) rheology. Comparing the strain signals in time domain with FT parameters in frequency domain, we could illustrate the sensitivity and importance of FT rheology. Diverse and unique stress patterns were observed depending on the material system as well as flow environment. It was found that they are not the outcome of experimental deficiency like wall slip but characteristics of the material system. When nonlinear response of complex fluids is analyzed, the intensity and phase angle of higher harmonic contributions should be considered together, and the shape of the stress signal was found to be strongly dependent upon phase angle.ngle.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.845-850
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• 2014

The rapid development of shotgun proteomics is paving the way for extensive proteome profiling, while providing extensive information on various post translational modifications (PTMs) that occur to a proteome of interest. For example, the current phosphoproteomic methods can yield more than 10,000 phosphopeptides identified from a proteome sample. Despite these developments, it remains a challenging issue to pinpoint the true phosphorylation sites, especially when multiple sites are possible for phosphorylation in the peptides. We developed the Phospho-UMC filter, which is a simple method of localizing the site of phosphorylation using unique mass classes (UMCs) information to differentiate phosphopeptides with different phosphorylation sites and increase the confidence in phosphorylation site localization. The method was applied to large scale phosphopeptide profiling data and was demonstrated to be effective in the reducing ambiguity associated with the tandem mass spectrometric data analysis of phosphopeptides.

• 대한본초학회지
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• 제31권5호
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• pp.25-39
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• 2016

Objectives : Atractylodes rhizomes, which have been widely used to treat gastrointestinal disorders, consist of numerous chemical compounds. Polyacetylenes are the parts of characteristic compounds of importance required to understand the therapeutic properties of Atractylodes rhizomes. It is necessary to understand the physicochemical and pharmacological properties of polyacetylenes in the Atractylodes rhizomes.Methods : The literatures from 1970 to January 2016 were searched using Korean and international electronic databases. The chemical structures of polyacetylenes were drawn by structure-drawing software.Results : The reported polyacetylenes were classified by their chemical skeletons and original resources, and their physicochemical and pharmacological features were discussed. Polyacetylenes with skeletal moieties were reported, such as diene-diyne types (two double and two triple carbon-bonds), triene-diyne types (three double carbon bonds and two triple carbon bonds), and monoene-diyne types (one double carbon bonds and two double carbon bonds), with various functional groups. Atractylodin was most frequently reported from many Atractylodes species. Atractylodin-related polyacetylenes showed chemical instability in both high and freezing temperatures. Processing of the Atractylodes rhizomes by stir-frying with bran could affect the contents of polyacetylenes and their bioavailability in vivo. Several polyacetylenes showed structure-related anti-inflammatory activities and gastrointestinal activities.Conclusion : Polyacetylene compounds in Atractylodes rhizomes were based on three chemical backbones and showed diverse physicochemical and pharmacological features. The present study provides structural, physicochemical, and pharmacological information of polyacetylene from Atractylodes rhizomes. This information provides fundamental data for further research.

• 한국가스학회지
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• 제7권3호
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• pp.24-31
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• 2003

화학공장은 수많은 장치들로 구성되어 있고 매우 복잡한 구조를 가지고 있다. 특히 분산 제어 시스템(Distributed Control System, DCS)이나 공정 정보 시스템(Process Information System, PIS) 등을 설치하여 매분 또는 매초 단위로 공정 데이터를 얻고 있다. 화학공장의 경우, 데이터들의 방대한 양 뿐 만 아니라 데이터들간의 상호 연관성이 크고 재순환이나 화학 반응 등으로 인하여 막대한 계산량 및 비선형성을 지니기 때문에 효과적 분석에 곤란한 점이 있다. 따라서 본 연구에서는 함수연결연상 신경망을 이용하여 입력변수들을 확장함으로써 신경망의 비선형성 표현능력과 학습능력이 뛰어난 프로그램의 개발에 주안점을 두고 있다. REFA (Real Time Fault Analyzer)는 실시간으로 공정정보를 입력받은 후 입력값을 PC로 매핑하고, 이를 다시 역으로 매핑하여 입력값을 예측하여 공정을 감시하는 시스템으로 개발되었으며, Tennessee Eastman 공정에 적용해 우수성을 입증하였다.

• 한국대기환경학회지
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• 제15권1호
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• pp.13-22
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• 1999

This study is carried out to investigate the chemical composition of atmospheric deposition in Cheju Island, Korea. For this purpose, dustfall matter samples are collected by dust jar from August, 1995 to July, 1996 at five sampling sites and total suspended particulate matters (TSP) and rain are also collected at one site from October, 1995 to July, 1996. All the samples collected are analyzed, and then the information of the 19 chemical species and deposition amount of each species is obtained. These data are used to determine the regional trends in dustfall chemistry and deposition, and compare the characteristics of chemical compositions between dustfall, TSP and rainwater.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.49-52
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• 1999

A subspace-based identification method of the Wiener model, consisting of a state-space linear block and a polynomial static nonlinearity at the output, is used to retrieve from discrete sample data the accurate information about the nonlinear dynamics. Wiener model may be incorporated into model predictive control (MPC) schemes in a unique way which effectively removes the nonlinearity from the control problem, preserving many of the favorable properties of linear MPC. The control performance is evaluated with simulation studies where the original first-principles model for a continuous MMA polymerization reactor is used as the true process while the identified Wiener model is used for the control purpose. On the basis of the simulation results, it is demonstrated that, despite the existence of unmeasured disturbance, the controller performed quite satisfactorily for the control of polymer qualities with constraints.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.501-506
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• 1998

A mathematical model is developed to describe the relationship between the manipulated variables (e.g. jacket inlet temperature and feed flow rate) and the important qualities (e.g conversion and weight average molecular weight (Mw)) in a continuous polymerization reactor. The subspace-based identification method for Wiener model is used to retrieve from the discrete sample data the accurate information about both the structure and initial parameter estimates for iterative parameter optimization methods. The comparison of the output of the identified Wiener model with the outputs of a non-linear plant model shows a fairly satisfactory degree of accordance.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1527-1535
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• 2012

Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms.

• 대기
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• 제33권3호
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• pp.319-330
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• 2023

As the need for PM type observation increases, Surface Particulate Matter Network (SPARTAN), PM samplers analyzes aerosol samples for PM mass concentration and chemical composition, were recently installed at two sites: Yonsei University at Seoul and Ulsan Institute of Science and Technology (UNIST) at Ulsan. These SPARTAN filter samplers and nephelometers provide the PM_2.5 mass concentration and chemical speciation data with aerosol type information. We introduced the overall information and installation of SPARTAN at the field site in this study. After installation and observation, both Seoul and Ulsan sites showed a similar time series pattern with the daily PM_2.5 mass concentration of SPARTAN and the data of Airkorea. In particular, in the case of high concentrations of fine particles, daily average value of PM_2.5 was relatively well-matched. During the Yonsei University observation period, high concentrations were displayed in the order of sulfate, black carbon (BC), ammonium, and calcium ions on most measurement days. The case in which the concentration of nitrate ions showed significant value was confirmed as the period during which the fine dust alert was issued. From the data analysis, SPARTAN data can be analyzed in conjunction with the existing urban monitoring network, and it is expected to have a synergetic effect in the research field. Additionally, the possibility of being analyzed with optical data such as AERONET is presented. In addition, the method of installing and operating SPARTAN has been described in detail, which is expected to help set the stage for the observation system in the future.