• 한국대기환경학회지
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• 제19권6호
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• pp.719-731
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• 2003

In order to maintain and manage ambient air quality, it is necessary to identify sources and to apportion its sources for ambient particulate matters. The receptor methods were one of the statistical methods to achieve reasonable air pollution strategies. Also, receptor methods, a field of chemometrics, is based on manifold applied statistics and is a statistical methodology that analyzes the physicochemical properties of gaseous and particulate pollutant on various atmospheric receptors, identifies the sources of air pollutants, and quantifies the apportionment of the sources to the receptors. The objective of this study was 1) after obtaining results from the PMF modeling, the existing sources of air at the study area were qualitatively identified and the contributions of each source were quantitatively estimated as well. 2) finally efficient air pollution management and control strategies of each source were suggested. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols, the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided quantitative source contributions (scaled G matrix) and source profiles (scaled F matrix). The results of the PMF modeling showed that the sources were apportioned by secondary aerosol related source 28.8 ％, soil related source 16.8％, waste incineration source 11.5%, field burning source 11.0%, fossil fuel combustion source 10%, industry related source 8.3％, motor vehicle source 7.9%, oil/coal combustion source 4.4％, non-ferrous metal source 0.3％. and aged sea- salt source 0.2％, respectively.

• 말소리와 음성과학
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• 제3권2호
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• pp.89-96
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• 2011

In this paper, details of the design and implementation of a voice source simulator using Simulink and Matlab are discussed. This simulator is an implementation by model-based design concept. Voice sources can be analyzed and manipulated through various factors by choosing options from GUI input and selecting pre-defined blocks or user created ones. This kind of simulation tool can simplify the procedure of analyzing speech signals for various purposes such as voice quality analysis, pathological voice analysis, and speech coding. Also, basic analysis functions are supported to compare the original signal and the manipulated ones.

• Journal of Biosystems Engineering
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• 제26권6호
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• pp.503-508
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• 2001

In this paper, time-fiequency analysis and multi-dimensional spectral analysis methods are applied for source identification and diagnosis of non-stationary sound/vibration signals. Sound or vibration problems of general vehicle and agricultural machinary are under 500 Hz. So We used linearly increased chirp signals under 500 Hz. By checking the coherences on concerned time, fur time-variant non-stationary signals, this simulation it very well coincident to expected results.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.36-38
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• 2003

In order to understand the basic knowledge on the model of heat source in hybrid welding, authors have conducted finite element analysis to calculate heat distribution using three heat source models of non-split type and split type(Volume, Volume-Volume, Volume-Surface). From the research result, we can confirm that Volume-Volume heat source of split type is suitable for the analysis of heat distribution.

• 한국정보통신학회논문지
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• 제13권2호
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• pp.437-444
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• 2009

유엔을 비롯한 국제단체와 각국의 정부에서는 공개 소프트웨어 보급을 위해 많은 노력을 기울이고 있다. 우리나라에서도 공개 소프트웨어를 활성화하기 위한 노력의 일환으로 공개소프트웨어 시범 사업을 시행하고 정보화 사업 평가 항목에 공개 소프트웨어 사용하면 가점을 부여하고 있다. 그러나 잠재적인 공개 소프트웨어 사용자들인 중등학교 학생을 대상으로 공개 소프트웨어에 대한 홍보와 교육이 부족한 상태이다. 본 연구에서는 현재 중등학교에서 학생들의 공개 소프트웨어에 대한 인지도를 파악하고 분석한다. 그리고 공개소프트웨어를 중등학교의 개정된 7차 교육과정 의 정보 교과에서 활용할 수 있는 방안을 제시한다.

• 설비공학논문집
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• 제11권3호
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• pp.391-400
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• 1999

The efficiency and capacity of an air source heat pump system decrease as the ambient temperature drops. One strategy of avoiding the decrease of the efficiency and capacity in air source heat pump system is to switch to another thermal energy source. Water can be a good candidate for the heat source. This paper presents the results of the performance analysis of heat pump system with a single unit dual source(SUDS) evaporator The heat exchanger combines two separated evaporators into a single evaporator and the object of the SUDS evaporator is to recover energy from dual heat sources, i.e. air and water. Simulation program is developed for the dual source heat pump system with a SUDS evaporator and experimental data are obtained and compared with the simulation results. Differences in heating capacity and COP are 7% and 8% respectively. Simulation results are in good agreement with the test results. Therefore, the developed program is effectively used for the design and performance prediction of the dual source heat pump system with a SUDS evaporator.

• 한국병원경영학회지
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• 제22권1호
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• pp.1-9
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• 2017

Purpose : Many studies showed that having a usual source of care improved the efficient access of healthcare service. However in Korea there have been few studies on the usual source of care. So this study aims to find whether having a usual source of care affect the medical utilization and expense. Methodology/Approach : We used the Korean Health Panel data in 2012, 2013 to examine the change of utilization and expenses in ambulatory care affected by having a usual source of care. We selected 1,215 hypertension patients without usual source of care in 2012 and performed linear regression analysis to identify the difference between treatment group(with usual source of care in 2013) and control group(without usual source of care in 2013). Then we performed analysis again separated by the age group. Findings : Among study population, 711(58.5%) reported that they have a usual source of care in 2013. Treatment group reported 1.85 less increase in outpatient visits and 69,234 won less increase in expense than control group with weak significance(visit ${\beta}$ -1.85 p-value 0.0807, expense ${\beta}$ -69,234 p-value 0.0541). People under the age of 65 showed significant change in outpatient visits for tertiary hospital (visit ${\beta}$ -0.78 p-value 0.0154, expense ${\beta}$ -91,462 p-value 0.0168). The analysis which focused outpatient for mild disease showed similar trend. Practical Implications : This study supports the positive effect of having usual source of care which decrease inefficient outpatient utilization. Promoting physician-patient relationships is important for efficiency of healthcare service.

• 한국소프트웨어감정평가학회 논문지
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• 제17권2호
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• pp.31-38
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• 2021

소스코드 감정목적물의 유사성을 판단하는 경우, 양측의 비교대상 소스코드는 컴파일과 실행이 가능 해야 한다. 또한 시스템 소스의 경우에는 하드웨어와의 인터페이스가 일치하는지 확인이 되어야 한다, 그러나 현실적으로 분쟁당사자의 소스코드가 완전하지 않은 상태로 제공되는 경우가 발생하고 있다. 분쟁을 제기하는 측에서는 동작 특성이 자사의 기능과 유사하고, 출력되는 표현과 기능이 유사한 이유로 소스코드의 핵심부분이 유사한 것으로 판단하고, 감정을 요청하고 있다. 분석과정에서 소스코드의 컴파일 오류 발생 시, 감정인은 소스코드의 흐름도를 작성하고, 함수별 코드의 흐름을 추적하는 방법을 적용하게 된다. 그러나 이 방법은 간접적이고, 감정인의 주관적인 판단이 적용되어 유사성 분석결과에 객관성에 대한 다툼이 우려된다. 본 연구에서는 임베디드 시스템에 적용된 소스코드분쟁의 감정사례를 통해 검증되지 않은 소스코드 유사성 도출의 문제점과 개선 방향을 다룬다.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.807-812
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• 2020

본 논문은 여러 음원신호가 혼합된 환경에서 목적으로 하는 음원신호만을 분리하기 위하여 마이크로폰을 사용한 블라인드 음원분리 알고리즘을 제안한다. 제안하는 알고리즘은 독립성분분석 방법을 기반으로 한 주파수영역 표현모델이다. 따라서 2 음원에 대한 주파수영역 독립성분분석의 실제 환경에서의 유효성 검증을 목적으로, 음원의 종류를 변경하여 주파수영역 독립성분분석을 실행하여 음원분리를 실시하여 그 향상효과를 검증한다. 파형에 의한 실험결과로부터 원래의 파형과 비교하여 2채널의 음원신호를 깨끗하게 분리할 수 있음을 명확히 하였다. 또한 목표 신호 대 간섭 에너지비율을 사용하여 비교한 실험 결과로부터 본 논문에서 제안한 알고리즘의 음원분리 성능이 기존의 알고리즘에 비하여 성능이 향상되었다는 것을 알 수 있었다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권1호
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• pp.128-141
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• 2015

Independent Component Analysis (ICA), one of the blind source separation methods, can be applied for extracting unknown source signals only from received signals. This is accomplished by finding statistical independence of signal mixtures and has been successfully applied to myriad fields such as medical science, image processing, and numerous others. Nevertheless, there are inherent problems that have been reported when using this technique: instability and invalid ordering of separated signals, particularly when using a conventional ICA technique in vibratory source signal identification of complex structures. In this study, a simple iterative algorithm of the conventional ICA has been proposed to mitigate these problems. The proposed method to extract more stable source signals having valid order includes an iterative and reordering process of extracted mixing matrix to reconstruct finally converged source signals, referring to the magnitudes of correlation coefficients between the intermediately separated signals and the signals measured on or nearby sources. In order to review the problems of the conventional ICA technique and to validate the proposed method, numerical analyses have been carried out for a virtual response model and a 30 m class submarine model. Moreover, in order to investigate applicability of the proposed method to real problem of complex structure, an experiment has been carried out for a scaled submarine mockup. The results show that the proposed method could resolve the inherent problems of a conventional ICA technique.