• 한국정보통신학회논문지
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• 제3권4호
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• pp.907-914
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• 1999

This paper studies on the model identification of electro-hydraulic servo systems, which are composed of servo valves, double-rod cylinder and load mass. The identified plant is described as a discrete-time ARX or ARMAX model which is respectively obtained from the identification algorithms of least square error method, instrumental variable method and prediction error method. where a nominal model and the variation of model parameters are quantitatively evaluated.

• 분석과학
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• 제18권6호
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• pp.520-528
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• 2005

Two biological Certified Reference Materials (CRMs), KRISS 108-04-001 (oyster tissue) and 108-05-001 (water dropwort stem), were prepared by Korea Research Institute of Standards and Science (KRISS)during FY '01. The certified values of these materials had been determined by Isotope Dilution Mass Spectrometry (IDMS) for six elements (Cd, Cr, Cu, Fe, Pb and Zn). Additional analytical works are now progressing to certify the concentrations of a number of the environmental and nutrimental elements in these CRMs. The certified values in a CRM are usually determined by using a single primary method with confirmation by other method(s) or using two independent critically-evaluated methods. Instrumental Neutron Activation Analysis (INAA) plays an important role in the determination of certified values as it can eliminate the possibility of common error sources resulting from sample dissolution. In this study INAA procedure was used in determination of 23 elements in these two biological CRMs to acquire the concentration information and the results were compared with KRISS certified values.

• 한국의류학회지
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• 제21권1호
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• pp.194-205
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• 1997

The typical instrumental assessment of ununiform natural soils has been carried out by yellowing of the specimens instead of the surface reflectance or the calculated formula. However, the regular instrumental area of sample holder is necessary for the measure of yellowing. Therefore, this study attempted to apply image analysis which had full color image by scanning of one time without limitation of instrumental area. The test samples were analyzed pseudo and full color image. This paper evaluated soil with hue of yellowing and gradation of gray level with color image analysis. Then, it was studied propriety of image analysis with correlation of yellowing, hue and gray level. Ultimately, the proposed image analysis in this paper was advanced method against the typical instrumental assessment.

• 한국대기환경학회지
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• 제23권4호
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• pp.420-429
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• 2007

In this study, we attempted to evaluate the relationship between air dilution sensory test and instrumental detection method for individual odorous compound. For the purpose of our comparative study, we conducted the analysis of malodor on total of 46 samples collected from both industrial and food waste sectors using the two independent approaches. The results of instrumental analyses were explained after modification to several parameters such as: the sum of odor concentration (SOC), sum of odor quotient (SOQ) and sum of odor intensity (SOI). When we compared dilution ratio values (DRV) of threshold limit (TL) with the modified instrumental data sets, pearson coefficient of SOC, SOQ, and SOI were 0.556 (p=5.83E-05), 0.911 (p=9.64E-19) and 0.847 (p=8.93E-14), respectively. The results of this study thus suggest that the DRV of TL sensitively reflects odor strength measured intuitive.

• 분석과학
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• 제8권4호
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• pp.815-820
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• 1995

Instrumental neutron and gamma activation analysis of coal and combustion products, determination of platinum content in natural samples by radiochemical gamma activation analysis and high-sensitive track method of thorium determination has been studied with the use of the MT-25 microtron.The optimal conditions for complete elemental analysis of coal and combustion products, isolation and determination of platinum and thorium are recommended.

• 노동경제논집
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• 제44권2호
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• pp.33-69
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• 2021

본 연구는 2010~2018년 기간 동안의 16개 시도 지역 패널데이터를 구축하여 내외국인근로자의 고용관계를 추정한다. 산업별(제조업과 건설업), 규모별(5~29인, 5~99인, 5~299인 그리고 5인 이상) 분석을 시도하고 외국인근로자의 내생성을 통제하기 위하여 지역 내 외국인근로자의 출신 국가 점유율(Foreigner's Concentration Index: FCI)을 도구변수로 사용한다. 최종적으로는 외국인근로자의 내생성을 고려하지 않는 패널 GLS와 이를 고려한 도구변수법의 결과를 비교한다. 분석 결과, 패널 GLS 분석에서는 내외국인근로자 사이에 보완관계가 확인되었다. 그러나 도구변수법에서는 내외국인근로자의 고용관계가 통계적으로 유의하지 않았지만, 정(+)에서 부(-)로 바뀌었으며, 제조업과 건설업을 결합한 분석에서는 통계적으로 유의한 대체관계가 나타났다. 본 연구는 내외국인근로자의 고용관계를 추정하는 데 있어서 내생성 통제 여부의 중요성을 확인하고 이를 통제하기 위해 도구변수를 국내 최초로 고안했다는 점에서 높은 평가를 받을 수 있다.

• 소음진동
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• 제6권5호
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• pp.679-684
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• 1996

The Instrumental Variable Method(IVM), modified from least square algorithm, is applied to parameter identification of a noise contaminated bearing test rig. The signal to noise ratio included in Frequency Response Function(FRF) can cause significant errors in parameter identification. Therefore, among several candidates of parameter identification method, results of the applied IVM were compared with noise-contaminated least square method. This study shows that the noise-contaminated least square method can have indonsistent accuracy depending on the degree of noise level, while the IVM has robuster performance to signal to noise ratio than least square method.

• 여성건강간호학회지
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• 제9권4호
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• pp.449-456
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• 2003

Purpose: The purpose of this study was investigate the relationships among perceived social support, instrumental support needs, and depression of healthy, community dwelling elderly women. Method: This study was designed to examine whether the perceived social support and instrumental support were correlated with depression in elderly women. Data were cross-sectional and community-dwelling elderly individuals. The subject was 98 elderly women recruited from Elderly Welfare Center and Community center for Elderly. The instruments for this study were Personal Resource Questionnaire-part II, Geriatric Depression Scale (Short Form), and Instrumental Support Activities Checklist. Data were gathered by means of structured personal interviews. The internal consistency of the instruments was relatively good. Result: The participants' perceived social support was moderately high and instrumental support needs was low. Depression was mild and moderate relatively. The correlation analysis showed that the perceived social support was negatively related to depression and negatively related with instrumental support needs. Conclusion: The findings suggested that more perceived social support, less their depressive symptom in elderly women. It also revealed that the age, marital status, and socioeconomic status of elderly women also are important indicator of the elderly depression. Therefore nursing assessment and the design of intervention that incorporate the determinants supported in this study, such as perceived social support of the elderly women are needed in adopting and maintain health promoting lifestyle for the mental health and effective functioning in later life in women.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.688-693
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• 2002

Identification method is formulated to evaluate the dynamic characteristics of air bearings under NFR(Near Field Recording) sliders. Impulse responses and frequency response functions of NFR sliders are obtained on numerical non-linear models including rigid motion of slider and fluid motion of air bearing under the slider. Modal parameters and system parameters are identified by modal analysis method and instrumental variable method. The parameters of sliders are utilized to evaluate the dynamic characteristics of air bearings. Also, this study shows the difference between the dynamic characteristics of NFR and HDD slides, and squeeze effect of air bearings.

• Communications for Statistical Applications and Methods
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• 제24권5호
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• pp.421-441
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• 2017

In this survey, estimation methods for structural vector autoregressive models are presented in a systematic way. Both frequentist and Bayesian methods are considered. Depending on the model setup and type of restrictions, least squares estimation, instrumental variables estimation, method-of-moments estimation and generalized method-of-moments are considered. The methods are presented in a unified framework that enables a practitioner to find the most suitable estimation method for a given model setup and set of restrictions. It is emphasized that specifying the identifying restrictions such that they are linear restrictions on the structural parameters is helpful. Examples are provided to illustrate alternative model setups, types of restrictions and the most suitable corresponding estimation methods.