• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.412-417
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• 1999

The analytical results obtained by microwave digestion and acid digestion methods for sample pretreatment to determine metal impurities in silicon wafer by inductively coupled plasma-mass spectrometry (ICP-MS) were compared. In order to decompose the silicon wafer, a mixed solution of $HNO_3$ and HF was added to the sample and the metal elements were determined after removing the silicon matrix by evaporating silicon in the form of Si-F. The recovery percentages of Ni,Cr and Fe were found to be 95∼106% for both microwave digestion and acid digestion methods. The recovery percentage of Cu obtained by the acid digestion method was higher than that obtained by the microwave digestion method. For Zn, however, the microwave digestion method gave better result than the acid digestion method. Fe was added to a silicon wafer using a spin coater. The concentration of Fe in this sample was determined by lCP-MS, and the same results were obtained in the two pretreatment methods.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.704-708
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• 2009

We studied absorbance of tinted dye absorbed into tinted lenses by Spectrophotometric method. Used lenses and tinted dye were CR-39 plastic optical lenses and Ons & $Lavas^{(R)}$ Blue, respectively. Absorbance values of tinted dye absorbed into tinted lenses were obtained from the differences of absorbance values between tinted lenses and CR-30 lenses. Average concentrations of tinted dye absorbed into tinted lenses were obtained from the mass differences between tinted lenses and CR-30 lenses. The relationship between absorbance and average concentration for tinted dye absorbed into tinted lenses was also confirmed to follow Beer’s law. The absorption coefficient calculated from the tangent of the calibration curve was determined to be a=0.983 $Lg^{-1}cm^{-1}$.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.1-11
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• 1999

An immunohisochemical study on the cerebral ganglion of the African giant snail, Achatina fulica. was conducted by applying the AB/AY staining and the avidin-bovine-peroxidase complex staining methods. The followings are the results obtained throughout the study. The cerebral ganglion of Achatina fulica is an ellipsoidal body of 2 x 1 mm in size, which is connected by the cerebral commissure of 1 mm in diameter. The cross-section through the cerebral ganglion, shaped like a butterfly, is divided into the medio-dorsal parts, the latero-dorsal parts, the caudo-dorsal parts, and the lateral lobes. In the medio-dorsal and latero-dorsal parts, the LG cells and the DG cells are found mixed, although the LG cells are dominant. In lateral lobe, however, the Y cells are quite dominant, while the LG cells and the DG cells are seldom found. The LG cells are 20-70 $\mu\textrm{m}$ in sizes and circular or ellipsoidal in shapes. They are stained light green with the AB/AY. 1 - 3 nucleoli are found in karyolymph, where granular chromantins are evenly distributed. In cytoplasm, it is found that the secretory granules are evenly developed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.1
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• pp.1-5
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• 2019

The physical properties of ceramic materials including oxides are greatly influenced by the material density. Therefore, various efforts have been made to increase the material density. One of the most popular strategies is to use sintering additives in sintering materials. The conventional sintering additive was a spherical powder having a three-dimensional structure. In this study, sintering additive with 2-dimensional (2D) layer structure was used to increase the sintering density of cerium oxide and its effect was confirmed. In this study, 1 nm-thick $TiO_x$ and $MnO_x$ nanosheets were used as sintering additives.

• Journal of Korean Society for Quality Management
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• v.51 no.3
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• pp.363-379
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• 2023

Purpose: The main objective of this research is to construct an AI-based Composite Supplementary Index (ACSI) model to achieve accurate predictions of the Composite Index of Business Indicators. By incorporating various economic indicators as independent variables, the ACSI model enables the prediction and analysis of both the leading index (CLI) and coincident index (CCI). Methods: This study proposes an AI-based Composite Supplementary Index (ACSI) model that leverages diverse economic indicators as independent variables to forecast leading and coincident economic indicators. To evaluate the model's performance, advanced machine learning techniques including MLP, RNN, LSTM, and GRU were employed. Furthermore, the study explores the potential of employing deep learning models to train the weights associated with the independent variables that constitute the composite supplementary index. Results: The experimental results demonstrate the superior accuracy of the proposed composite supple- mentary index model in predicting leading and coincident economic indicators. Consequently, this model proves to be highly effective in forecasting economic cycles. Conclusion: In conclusion, the developed AI-based Composite Supplementary Index (ACSI) model successfully predicts the Composite Index of Business Indicators. Apart from its utility in management, economics, and investment domains, this model serves as a valuable indicator supporting policy-making and decision-making processes related to the economy.

• Journal of Korean Society for Quality Management
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• v.51 no.4
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• pp.573-588
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• 2023

Purpose: This study presents a research approach that utilizes deep reinforcement learning to construct optimal portfolios based on the business cycle for stocks and other assets. The objective is to develop effective investment strategies that adapt to the varying returns of assets in accordance with the business cycle. Methods: In this study, a diverse set of time series data, including stocks, is collected and utilized to train a deep reinforcement learning model. The proposed approach optimizes asset allocation based on the business cycle, particularly by gathering data for different states such as prosperity, recession, depression, and recovery and constructing portfolios optimized for each phase. Results: Experimental results confirm the effectiveness of the proposed deep reinforcement learning-based approach in constructing optimal portfolios tailored to the business cycle. The utility of optimizing portfolio investment strategies for each phase of the business cycle is demonstrated. Conclusion: This paper contributes to the construction of optimal portfolios based on the business cycle using a deep reinforcement learning approach, providing investors with effective investment strategies that simultaneously seek stability and profitability. As a result, investors can adopt stable and profitable investment strategies that adapt to business cycle volatility.

• LOGISTICS
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• s.17
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• pp.36-39
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• 2006

현재 대한민국은 물류산업을 이끌어갈 물류전문 컨설턴트가 절실히 필요하다. 글로벌 물류시대를 맞이하여 물류기업뿐만 아니라 각 제조업체도 물류전문가, 특히 글로벌 물류인재에 목말라 하고 있다. (사)한국물류협회(회장:서병륜)는 지난 6월 17일 협회 대강당에서 제2기 물류전문컨설턴트 29명을 배출하면서, 기업체들의 전문인력의 갈증에 조금이나마 해소하고 있다. 명지대학교와 산학협력 프로그램으로 실시되는 물류전문컨설턴트 양성과정은 물류분야 최고의 컨설턴트와 전문 교수진으로 구성하여, 회사 및 업계에서 물류컨설턴트로 활동할 물류지도자를 양성하는 자격 과정이다. 지난해 9월부터 시작한 이 과정은 우수한 강사진과 커리큘럼으로 국내기업으로부터 지대한 관심을 받으며 제1기 과정과 제2기 과정을 성공적으로 마쳤다. 한편, 오는 9월에 실시되는 제3기 과정에는 모집공고가 나오기도 전에 사전신청자가 11명에 이를 정도로 지원자가 급증하고 있다. 이는 교육 과정이 물류 전문가라면 알아야 될 내용들로 짜임새 있게 구성되어 있지만 더욱 중요한 것은 물류업계 전문가들과 인적 Network 구축이 큰 메리트로 작용하고 있다. 제2기 과정을 수료한 LG화학의 오태경부장은 "지금까지 수 많은 교육을 받아 봤고 여러 종류의 모임에도 참여해 봤지만 과거에는 경험해 보지 못한 전혀 색다른 교육 과정을 체험을 하였다."고 말했다.

• Electronics and Telecommunications Trends
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• v.27 no.1
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• pp.113-121
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• 2012

OLED는 두 개의 전극 사이에 유기물층을 배열하고 전계를 가하여 주입된 전자와 정공이 유기물 내에서 재결합하여 형성되는 여기자가 기저상태로 떨어지면서 빛을 내는 소자이다. 최근 OSRAM, Philips, LG화학, Panasonic 등의 기업에서 매우 우수한 특성을 보이는 OLED 패널 광원을 발표하고 있어 가까운 장래에 예전에 볼 수 없던 디자인의 OLED 조명이 일반조명 시장에 나올 것으로 예상됨에 따라 표준화 활동도 활발해지고 있다. OLED 조명은 기존 조명과 형태 및 특성이 다르기 때문에 기존 조명의 규격 사항을 그대로 적용할 수 없으며, 새로운 OLED 조명 표준 제정은 필수이다. 또한 국제표준화기구의 인증 마크의 유무는 자사 제품의 우수성과 안전성을 홍보하는 수단이고 해외로 진출하기 위해서는 해외의 주요 인증 획득이 필수적인 요소이므로 올바른 OLED 조명 표준 제정과 시험 방법 정립을 통하여 OLED 조명 제품의 국내외 신뢰를 확보하는 데 노력해야 할 것이다.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1003-1006
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• 2008

Highly efficient syntheses of cylindol A (1) and the proposed structure of cylindol B (2) have been accomplished using common synthetic transformations from symmetrical starting materials 7 and 11, respectively. The latter synthesis revealed that the proposed structure of the natural cylindol B was assigned incorrectly. Isomers of 2 such as 15 and 16 were synthesized as a possible candidate of the natural cylindol B. However, their spectral data also did not match that of the natural cylindol B. Therefore, the structure of the natural cylindol B is yet to be resolved.

• The monthly packaging world
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• s.310
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• pp.105-109
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• 2019

(사)한국포장협회(회장 임경호)가 지난해 9월 3일부터 11월 23일까지 총 11주간 진행한 제30기 포장기술관리사(Packaging Professional) 통신교육 결과, 43명의 포장기술관리사를 배출했다. 이번 제30기 포장기술관리사 통신교육에서는 (주)광진포장의 박한규 공장장이 총 1백점 만점에 94.5점을 획득해 최고 성적우수자로 선정됐으며, LG화학의 김현태 연구원은 93.9점으로 2등, (주)신원인팩의 이성구 대표이사와 (주)신명이노텍의 형재석 과장이 93.0점으로 3등으로 수료했다. 다음에 제30기 포장기술관리사 우수성적 수료자들로부터 포장기술관리사 통신교육에 대한 견해를 들어보도록 한다.