• 대한의용생체공학회:의공학회지
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• 제11권1호
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• pp.89-96
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• 1990

The numerical evaluation of Rayleigh's integral for the sound source reconstruction can be speeded up by the use of angular frequency propagation method and the FFT. However, are several source of errors involved during the reconstruction. Besides the aliasing error due to undersampling in space, the wrap around error. which is caused by undersampling the kernel functionin frequency domain, and windowing effect are present. We found that there is no replicated source problem and the windowing effect is due to the windowing the kernel function In frequency domain, and, xero padding is always required to improve the quality of reconstruction.

• 대한인간공학회지
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• 제16권1호
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• pp.119-126
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• 1997

Most of human factors experiments in nuclear industry domain produe lots of experimental data, thus much time is reauired to analyze the data. DAEXESS was developed to reduce resource demands necessary for the analysis work through systematic data analysis requirements and automated data processing based on computer technology. Physilolgical data, human behavior recording data, system log data and verbal protocl can be collected, synthesized and easily analyzed with with respect to time domain in DAEXESS so that analyser is able to look into inte- grated information on operating context. DAEXESS assists analyser to carry out qualitative and quantitative data analysis easily.

• 한국ITS학회 논문지
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• 제21권5호
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• pp.197-217
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• 2022

자율주행자동차(Automated vehicle, AV) 교통사고가 지속적으로 발생하면서 자율주행시스템(automated driving system, ADS)의 안전성 및 신뢰성을 확보하기 위한 안전성 검증의 중요성이 강조되고 있다. 안전성 및 신뢰성을 확보하기 위해서는 ADS의 운행가능영역(operational design domain, ODD)을 정의하고 ODD를 벗어나는 상황에서의 대응 능력을 평가하면서 ADS의 안전성을 검증해야 할 필요가 있다. 이를 위해 SAE, BSI, NHTSA, ISO 등의 국제 기구에서는 ODD 분류 기준 및 표준을 규정하고 있으나 국내의 경우 ODD 기준이 부재하여 AV의 ODD 표현 방법 및 안전성 검증 및 평가가 적절히 이루어지지 않고 있다. 이에 본 연구에서는 해외 ODD 분류 기준을 분석하고 안전성 검증 및 평가에 적합한 분류 기준을 선정하였다. 선정된 ODD를 기반으로 ADS 안전성 검증 및 평가에 필요한 평가요소를 제시하였다. 특히, ADS 기술 개발을 지원하는 자율주행 실험도시(K-City)의 평가환경을 분석하여 평가요소를 제시하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권10호
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• pp.539-545
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• 2004

In this paper, we consider the problem of capacitance matrix calculation for strip-line and other interconnects crossings. The problem is formulated in the spectral domain using the method of moments. Sinc-functions are employed as basis functions. Conventionally, such a formulation leads to a large, non-sparse system of linear equations in which the calculation of each of the coefficient requires the evaluation of a Fourier-Bessel integral. Such calculations are computationally very intensive. In the method proposed here, we provide simplified expressions for the coefficients in the moment method matrix. Using these simplified expressions, the coefficients can be calculated very efficiently. This leads to a fast evaluation of the capacitance matrix of the structure. Computer simulations are provided illustrating the validity of the method proposed.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
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• pp.214-217
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• 1996

Early decision support systems (DSS) were the "passive" decision support systems in the sense that the systems only able to do what the users explicitly direct them to do. But some researchers such as Raghav Rao et al. [51 showed architectures to suggest general idea of the innovative DSS systems which offer active form of decision support, say, "active Intelligent Decision Support Systems(active IDSS)". The system can perform not only what the users want to do but some voluntary (or involuntary) intelligent works. This paper presents the issues in the design of the active IDSS in the domain of investment evaluation, a domain area where few researchers have suggested frameworks or architectures to discriminate good investment from bad one. We propose a new paradigm, by utilizing historical investment results using neural network and Multivariate Discriminant Analysis(MDA), to identify goodness of investment. A new active IDSS architecture which consists of neural network, expert system and three components of the traditional passive DSS is suggested with some scenario based results.nario based results.

• 센서학회지
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• 제16권3호
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• pp.202-210
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• 2007

The aim of this study is to acquire useful information of lower urinary tract symptom (LUTS) diagnosis through urophonography signal as a noninvasive method. The hardware and software which could evaluate the function of compensatory hypertrophy with noninvasive and comfortable method was implemented to measure uroflow and urophonography signal during urination. The PSD (power spectrum density) and the log-log plot gradient analysis were accomplished in frequency domain. For evaluation of the system and analysis method, a model system for the lower urinary system of men was used. From the evaluation of the model system, the PDS and the log-log plot gradient were dependent on the occlusion degree significantly. In a pilot study on normal and abnormal male subjects, the PSD and the log-log plot gradient were highly correlated with the artificial urethral obstruction.

• Journal of the Optical Society of Korea
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• 제13권4호
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• pp.439-444
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• 2009

Accurate evaluation of polarization characteristics in the integrated optic chip (IOC) for interferometric fiber optic gyroscope was performed. Spatial distribution of optical wavetrains caused by the polarization parameters such as local polarization cross-coupling and polarization rejection coefficient of the IOC were measured utilizing the path-matched optical coherence domain polarimetry (PM-OCDP). With the analytic model deduced from Jones matrix representation, we could accurately identify the polarization characteristics of the IOC. Both degree of measurement error due to the imperfect equipment conditions in PM-OCDP and birefringence of IOC chip were also characterized.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.984-990
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• 1994

In this paper a new speech synthesis method in the time domain using mono-syllables is proposed. It is to overcome the degradation of the synthetic speech quality by the synthesis method in the frequency domain and to develop an algorithm in the time domain for the prosodic control. In particular when we use a method in a time domain with mono-syllable as a synthesis unit it will be the main issues which are to control th pitch period and to smooth the energy pattern. As a solution to the pitch control, a method using Lagrange interpolation is suggested. As a solution to the other problem, an algorithm which can control the amplitude envelop shape of mono-syllable is proposed. As the results of experiments it was possible to synthesize unlimited Korean speeches including the prosody control. Accoding to the MOS evaluation the quality and the naturality in them was improved to be a good level.

• 한국환경교육학회지:환경교육
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• 제22권3호
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• pp.136-151
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• 2009

The purpose of this study was to analyze changes in perceptions of the categories of environmental education and environmental education professionalism of teachers participating in a in-service teacher training programs for environmental education. For this study, surveys and interviews were conducted before and after participation of 20 elementary and secondary school teachers who had participated in 'in-service teacher training program for professional development in environmental education' in August of 2005. Before participation, most of teachers answered that 'Education for Environment' was essential factor among the categories for environmental education. After participation, 15 teachers retained their perception but 5 teachers had changed to 'Education about Environment' or 'Education for Environment'. Environmental professionalism was conducted in '5 ability categories of environment teachers' of Hungerford et al.(1994). Categories has goal domains such as 'Goal domain I (level of basic)', 'Goal domain II (level of conceptual perceptions)', 'Goal domain III (level of investigating and evaluation)', 'Goal domain IV(level of environmental action skill)', 'Goal domain V(level of educational apply)'. Before participation, teachers had a low level of professionalism in environmental areas, but after participation environmental education professionalism improved significantly into the all 'Goal domains'.

• 한국빅데이터학회지
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• 제3권2호
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• pp.11-18
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• 2018

본 연구는 빅데이터 품질 진단의 핵심 요소인 도메인 기반 품질 진단을 위한 도메인 자동 판별에 관한 연구다. 빅데이터의 가치와 활용도의 증가와 4차 산업혁명의 대두로, 법률, 의료, 금융 등 IT와 융합된 다양한 분야에서 빅데이터를 활용하여 새로운 가치를 창출하려는 노력을 진행중이다. 하지만, 신뢰도가 낮은 데이터에 기반한 분석은 과정과 결과 모두에서 치명적인 문제를 발생하며, 분석 결과에 따른 판단 또한 신뢰하기 어려워 진다. 이처럼 신뢰도가 높은 데이터의 필요성 또한 증가하였지만, 데이터의 품질 확보에 대한 연구와 그에 대한 결과는 미비하다. 본 연구는 데이터 품질 향상을 위한 진단 평가의 핵심적 요소인 도메인 기반 품질 진단에서, 수작업으로 진행되었던 도메인 판별 작업을 머신러닝을 이용하여 자동화 함으로써, 작업시간을 단축하는 것을 목표로 한다. 데이터 베이스에 저장된, 도메인이 판별되어 있는 데이터의 특성에 관한 정보들을 추출하여 변수화하고, 이를 머신러닝을 이용하여 도메인 판별을 자동화 한다. 이를 빅데이터 품질 진단에 활용하고, 품질 향상에 기여하도록 한다.