• 응용통계연구
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• 제10권2호
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• pp.227-239
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• 1997

분광학분야에서 측정되는 자료는 여러 파장에서 측정된 스펙트럼 행렬과 이 스펙트럼을 통하여 알고자하는 어떤 반응치들의 행렬 또는 벡터로 주어진다. 이 경우 측정 자료에의 많은 잡음(noise)과 파장간의 상관관계가 내재한다. 부분최소제곱회귀 방법은 여러 개의 파장에서 측정된 자료를 모두 이용하는데 자료축약과정을 통하여 자료의 잡음 문제와 상관관계 문제를 해결하는 다변량통계방법이다. 본 연구에서는 이러한 자료에 적합한 부분최소제곱회귀의 이론을 알아보고 실제로 측정된 자료를 통하여 주어진 스펙트럼에 대한 반응치의 예측을 부분최소제곱회귀 방법을 이용하여 고찰하였다.

• 정보화정책
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• 제27권2호
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• pp.20-39
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• 2020

본 논문은 분산원장기술을 기반으로 하여 암호화폐시장 잠재력지수를 개발하였다. 이 지수의 최대장점은 암호화폐의 개발과 실행 그리고 확산에 이르기까지 암호화폐시장의 전반적인 잠재력을 측정, 비교할 수 있다는 것이다. 본 논문은 암호화폐시장 잠재력지수의 개발과 측정을 위하여 요인분석기법을 이용한 213개 국가의 30개 변수를 분석 비교하였다. 그 결과 암호화폐의 분권화에도 불구하고 그 잠재력은 유럽, 북미, 아시아에 속한 일부 선진국, 그리고 일부 중동국가와 구 소련의 독립국가연합에 집중되어 있음을 밝혀내었다. 이는 암호화폐시장의 발전을 위해서 암호화폐의 확산 이전에 개발과 실행과정이 선행되어야 함을 보여준다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1123-1123
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• 2001

In recent years, a miniature spectrometer has been extensively developed due to the marriage of fiber optics and semiconductor detector array. This type of miniature spectrometer has advantages of low price and robustness due to the capability of mass production and no moving parts are required such as lenses, mirrors and scanning monochromator. These systems are ideal for use in teaching labs, process monitoring and field analyses. A portable near infrared (NIR) system has been developed for qualitative and quantitative analysis. This system includes a tungsten halogen lamp for light source, a fiber optics connected a light source, and a sample module to the microspectrometer, The size of spectrometer can be as small as 2.5 cm x 1.5 cm x 0.1 cm. Wavelength ranges can be chosen as 360-800 nm, 800-1100 nm and 1100-1900 nm depending on the type of detector. The software consists of various tools for multivariate analysis and pattern recognition techniques. To evaluate the system, long and short-term stability, wavelength accuracy, and stray light have been investigated and compared with conventional scanning type NIR spectrometer. This developed system can be sufficiently used for quantitative and qualitative analysis for various samples such as agricultural product, herbal medicine, food, petroleum, and pharmaceuticals, etc.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1284-1284
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• 2001

The transesterification of molten ethylene/vinylacetate (EVA) copolymers by octanol as a reagent and sodium methoxide as a catalyst in an extruder has been monitored by on-line near infrared (NIR) spectroscopy. A total of 60 NIR spectra were acquired for 37 minutes with the last spectrum recorded 31 minutes after the addition of octanol and catalyst was stopped. The experimental spectra show strong baseline fluctuations which are corrected for by multiplicative scatter correction (MSC). The chemometric methods of orthogonal projection approach (OPA) and multivariate curve resolution (MCR) were used to resolve the spectra and to derive concentration profiles of the species. The detailed analysis reveals the absence of completely pure variables that leads to small errors in the calculation of pure spectra. The initial estimation of a concentration that is necessary as an input parameter for MCR also presents a non-trivial task. We obtained results that were not ideal but applicable for practical concentration control. They enable a fast monitoring of the process in real-time and resolve the spectra of the EVA copolymer and the ethylene/vinyl alcohol (EVAL) copolymer to be very close to the reference spectra. The chemometric methods used and the decomposed spectra are discussed in detail.

• 산업공학
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• 제24권4호
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• pp.420-427
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• 2011

The present study developed an anthropometric design method accommodating physical human variabilities for user-centered product development. The proposed design method is based on the boundary zone method, a technique to generate a group of humanoids properly representing the body size diversity of thedesign target population. In addition, the anthropometric design method considers the variability of postures in the design process by incorporating the simulation of posture. The effectiveness of the proposed design method was evaluated in terms of multivariate accommodation percentage (MAP) by applying it to designing a computer workstation with 90% of accommodation percentage. The performance evaluation showed that the MAP (89%) of the computer workstation design produced by the proposed method was quite close to the designated accommodation percentage. The proposed design method can be of use to develop an effective anthropometric design for user-centered product development.

• Smart Structures and Systems
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• 제14권5호
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• pp.917-942
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• 2014

Multivariate statistics based damage detection algorithms employed in conjunction with novel sensing technologies are attracting more attention for long term Structural Health Monitoring of civil infrastructure. In this study, two practical data driven methods are investigated utilizing strain data captured from a 4-span bridge model by Fiber Bragg Grating (FBG) sensors as part of a bridge health monitoring study. The most common and critical bridge damage scenarios were simulated on the representative bridge model equipped with FBG sensors. A high speed FBG interrogator system is developed by the authors to collect the strain responses under moving vehicle loads using FBG sensors. Two data driven methods, Moving Principal Component Analysis (MPCA) and Moving Cross Correlation Analysis (MCCA), are coded and implemented to handle and process the large amount of data. The efficiency of the SHM system with FBG sensors, MPCA and MCCA methods for detecting and localizing damage is explored with several experiments. Based on the findings presented in this paper, the MPCA and MCCA coupled with FBG sensors can be deemed to deliver promising results to detect both local and global damage implemented on the bridge structure.

• Environmental Engineering Research
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• 제22권1호
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• pp.116-124
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• 2017

The study makes an attempt to investigate the causal nexus between carbon dioxide emissions, GDP per capita, industrialization and population with an evidence from Rwanda by employing a time series data spanning from 1965 to 2011 using the autoregressive distributed lag model. Evidence from the study shows that carbon dioxide emissions, GDP per capita, industrialization and population are co-integrated and have a long-run equilibrium relationship. Evidence from the Granger-causality shows a unidirectional causality running from industrialization to GDP per capita, population to carbon dioxide emissions, population to GDP per capita and population to industrialization. Evidence from the long-run elasticities has policy implications for Rwanda; a 1% increase in GDP per capita will decrease carbon dioxide emissions by 1.45%, while a 1% increase in industrialization will increase carbon dioxide emissions by 1.64% in the long-run. Increasing economic growth in Rwanda will therefore reduce environmental pollution in the long-run which appears to support the validity of the environmental Kuznets curve hypothesis. However, industrialization leads to more emissions of carbon dioxide, which reduces environment, health and air quality. It is noteworthy that the Rwandan Government promotes sustainable industrialization, which improves the use of clean and environmentally sound raw materials, industrial process and technologies.

• 디지털융복합연구
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• 제14권4호
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• pp.33-42
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• 2016

본 연구는 원격대학원생들의 성별에 따른 차이가 학습 만족요인(콘텐츠, 시스템, 상호작용, 교수자이미지, 교수학습)에 어떠한 영향을 주는지 확인하고자 수행되었다. 이를 위해 서울 소재 원격대학원에서 강좌를 수강한 원격대학원생 88명을 대상으로 설문을 진행하였으며, 그 중 유효한 64개의 응답에 대해 SPSS 21.0 통계 패키지 프로그램을 활용하여 다변량분산분석(MANOVA)을 실시하였다. 분석 결과 5개의 학습만족요인 중 상호작용요인에서 유의미한 결과가 나타나는 것을 확인하였으며, 연구 결과의 원인을 분석하고 향후 방향에 대한 논의 및 시사점 등을 기술하였다.

• Advances in environmental research
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• 제2권4호
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• pp.291-308
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• 2013

In the present study, an experimental design methodology was used to optimize the adsorptive removal of Basic Yellow 13 (BY13) using Turkish coal powder. A central composite design (CCD) consisting of 31 experiments was employed to evaluate the simple and combined effects of the four independent variables, initial dye concentration (mg/L), adsorbent dosage (g/L), temperature ($^{\circ}C$) and contact time (min) on the color removal (CR) efficiency (%) and optimizing the process response. Analysis of variance (ANOVA) showed a high coefficient of determination value ($R^2=0.947$) and satisfactory prediction of the polynomial regression model was derived. Results indicated that the CR efficiency was not significantly affected by temperature in the range of $12-60^{\circ}C$. While all other variables significantly influenced response. The highest CR (95.14%), estimated by multivariate experimental design, was found at the optimal experimental conditions of initial dye concentration 30 mg/L, adsorbent dosage 1.5 g/L, temperature $25^{\circ}C$ and contact time 10 min.

• 대한화학회지
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• 제57권1호
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• pp.109-114
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• 2013

The effects of aluminum nanoparticles (AlNs) on the thermal decomposition of ammonia perchlorate (AP) were investigated by DSC, TG-DSC and DSC-TG-MS-FTIR. Addition of AlNs resulted in an increase in the temperature of the first exothermic peak of AP and a decrease in the second. The processing of non-isothermal data at various heating rates with and without AlNs was performed using Netzsch Thermokinetics. The dependence of the activation energy calculated by Friedman's isoconversional method on the conversion degree indicated the decomposition process can be divided into three steps. They were C1/D1/D1 for neat AP, determined by Multivariate Non-linear Regression, and changed to C1/D1/F2 after addition of AlNs into AP. The isothermal curves showed that the thermal stability of AP in the low temperature stage was improved in the presence of AlNs.