• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.202-203
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• 2010

발전용 연료전지 시스템에서 PCS는 계통에 고장 발생시 MBOP등 전용부하에 지속적인 전력을 공급하기 위하여 모드 전환하여 단독운전을 해야 한다. 기존의 제어방식은 계통연계시 전류제어를, 단독운전 시 전압제어를 하기 때문에 이러한 모드 전환 시 전용부하는 심각한 과도상태에 놓이게 된다. 본 논문에서는 모드 전환에 따른 전압의 과도현상을 최소화하기 위한 개선된 간접전류제어 알고리즘을 제안한다. 제안한 방식은 기존의 알고리즘보다 연산량이 작아 구현이 간단하며 제어기의 모델링이 가능해져 제어 파라미터 설정이 용이해졌다.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.207-209
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• 2010

연료전지 시스템의 경우 계통에 Sag 및 Swell 같은 이상이 발생하더라도 계통과 분리되기 전 MBOP등 독립부하에는 안정적인 전원을 공급하는 것이 중요하다. 기존의 직접전류제어방식으로는 계통이상 시 전압을 제어할 수 없으므로 독립부하에 계통이상전압이 그대로 걸리게 된다. 본 논문에서는 계통에 Sag 및 Swell 같은 상황이 발생하더라도 무효전류를 제어하여 자체 부하전압을 보상할 수 있는 간접전류제어 전압보상기법을 이용한 계통 연계형 인버터의 동작을 분석하고 이에 맞는 소자 및 새로운 LCL필터 설계방법을 제안한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.269-272
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• 2003

The importance of the improving quality of electric power is being strongly raised, owing to an increasing use of sensitive and small-sized electronic devices and system. The transient overvoltage on low-voltage AC power distribution system are induced by direct or indirect lightning return strokes, and those can cause damage and/or malfunction of the utility system for borne automation, office automation and factory automation as well as medical equipments. The behavior of lightning surge transferred to the primary side from the primary side in distribution transformers were experimentally investigated the protection effect of low voltage SPD installed at the secondary side of distribution transformers was analyzed.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.704-712
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• 2010

Porcine circovirus-2 (PCV2) has been implicated in many clinical diseases/syndromes that are now referred to as PCV-associated diseases (PCVAD). Due to significant economic losses caused by PCVAD, many swine operations have launched extensive monitoring programs for PCV2. Traditional serum sampling is, however, rather expensive and laborious, hampering effective large scale pathogen surveillance. A field-based longitudinal study was conducted to assess the utility of pen-based oral fluid sample as an alternative to serum for herd PCV2 testing. Six pens (25 pigs/pen) at each of 3 different sites were used in the study. One oral fluid and 5 random serum samples per pen were collected at 3, 5, 8, 12, and 16 weeks of age, and the sera were pooled by pen for testing. All samples were tested for PCV2 by real-time PCR and for antibodies by indirect fluorescent antibody test (for both anti-PCV2 IgG and IgA) and 3 ELISA assays (blocking ELISA, indirect ELISA, and IgG/IgM sandwich ELISA). PCV2 DNA was detected in oral fluid samples sporadically until 8 weeks and in all pens at 16 weeks. PCV2-specific IgG was detected in oral fluid samples at 3 weeks and persisted until 5 to 8 weeks in all sites. Anti-PCV2 IgG and IgA were detectable in oral fluid samples collected at 16 weeks from all of the pens at 1 site. The detection of PCV2 and anti-PCV2 antibody in oral fluid samples correlated positively with results on pooled sera, suggesting that oral fluids can be a cost-effective alternative to serum for herd monitoring of PCV2 infection.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.1
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• pp.81-89
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• 1997

The size and shape of the human body has been an important factor not only in anthropology but in integration of designs aimed for daily use. Although the three-dimensional measurements have been proposed and obtained introducing new methods, there still remains many problems concerning how to analyze and evaluate the results. In this study, we have got the internal and external orientation factors, image coordinates from the ac-quired photographs, have calaulated the object coordinates through Bundle Adjustment, have matched multi-images. have drawn the object in the computer, and smoothly handled the surface of the body model using the Au-to-CAD system or graphic processing utility then we could generate the digital model of human body. The. results show that once digital modeling of the body is generated. the information which a designer needs can be acquired and the adequate calculations for many application fields can be done easily and many geometrical properties could be extracted. Therefore we propose the possibility of indirect human body measurement through digital model generation.

• Environmental and Resource Economics Review
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• v.16 no.3
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• pp.701-721
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• 2007

A key issue in the development and application of stated preference nonmarket valuation is the incorporation of unobserved heterogeneity in utility models. Two approaches to this task have dominated. The first is to include individual-specific characteristics into the estimated indirect utility functions. These characteristics are usually socioeconomic or demographic variables. The second employs generalized models such as random parameter logit or probit models to allow model parameters to vary across individuals. This paper examines a third approach: the inclusion of psychological or 'latent' variables such as general attitudes and behaviour-specific attitudes to account for heterogeneity in models of stated preferences. Attitudinal indicators are used as explanatory variables and as segmentation criteria in a choice modelling application. Results show that both the model significance and parameter estimates are influenced by the inclusion of the latent variables, and that attitudinal variables are significant factors for WTP estimates.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.16 no.2
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• pp.97-105
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• 2021

Objectives This study is aimed to evaluate cost-effectiveness of treatment of Korean Medicine for whiplash associated disorders (WAD) and to suggest the direction of future research. Methods We searched papers in Pubmed database to use some keywords indicating whiplash injury syndrome, treatment of Korean Medicine and cost-effectiveness. After searching, appropriate papers were selected depending on the exclusion criteria. The selected papers were analyzed in the sections of author, publication year, intervention and control groups, outcome measurement, the list including in the cost, cost-effectiveness, cost-utility and study design. Results Four studies about effect of Korean medicine and 3 studies about economic evaluation were finally included. Acupuncture was effective for balance disorder and neck pain. Economic evaluation studies used analytical decision model or cost-consequence analysis. Cost-effectiveness analysis using visual analog scale and cost-utility analysis using quality adjusted life years were performed. Initiating timing of proper management affected the consequence of treatments. Direct and indirect medical costs including supportive devices, and non-medical costs such as litigation were considered. Conclusions We conclude that studies haven't been conducted so far to evaluate the cost-effectiveness of Korean Medicine in whiplash injury syndrome. Thus, future studies are needed in this section.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.2
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• pp.13-25
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• 2022

Purpose : This study compared the cost-effectiveness ratio of physical therapy in health centers and home physical therapy, two physical therapy methods for home-bound stroke patients, and clarified the economic validity regarding the effect of home physical therapy. Methods : To measure and compare the cost and effectiveness of the two physical therapy methods for stroke patients, subjects were recruited based on in-hospital and home physical therapy. Among the entire data collected, 82 and 90 participants were selected for in-hospital and home physical therapy, respectively. To measure costs, regarding both in-hospital and home physical therapy, direct cost and indirect cost for patients, family, medical institutes, and the government were measured. In addition, activities of daily living were measured in both methods to measure their effectiveness. Through collected data, the cost-effectiveness and incremental cost-effectiveness ratios were analyzed. Results : Based on the analysis of cost-effectiveness, home physical therapy showed lower cost-effectiveness than in-hospital physical therapy. Furthermore, the incremental cost-effectiveness ratio also showed a difference, which implied home physical therapy could have high effectiveness compared to cost. Conclusion : Based on these results, home physical therapy could be considered as an alternativeto other methods of physical therapy, for home-bound stroke patients. In addition, the result of thisstudy contribute by providing evidence that home physical therapy offers economic benefits and canbe more effective in treating home-bound patients when policy decisions are made to establish a home physical therapy system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.11
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• pp.944-951
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• 2018

Artificial icing test and wind tunnel test can be performed to reduce the development period when a rotorcraft is required operation under icing situations. Artificial icing test of the KUH(Korean Utility Helicopter) was performed in advance to verify anti-icing and de-icing performance before natural icing test. Although high-precision sensor, the CCP(Cloud Combination Probe) is used to measure icing test condition parameters such as LWC(Liquid Water Content) and MVD(Median Volume Diameter), the measured values need to be verified in various methods due to the possibility of uncertainties which are the test atmosphere environment, sensor errors, and etc. The calculated LWC from the ice thickness cumulated on the fuselage of the KUH is compared to the measured value by CCP, and the results show the effective indirect method to check the test conditions.

• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.356-360
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• 2005

Background : This study examined the clinical utility of using indirect chest radiography during a physical examination of new conscripts for determine the presence of pulmonary tuberculosis. Methods : Over an eight-month period, this study examined 25386 people who underwent a physical examination after conscription. The abnormal findings on mass miniature radiography were followed-up using direct chest radiography. The positive predictive value of mass miniature radiography and direct chest radiography was compared. The incidence, degree of infiltration and clinical outcome of active pulmonary tuberculosis were also evaluated during a follow-up examination. Results : The positive rate of mass miniature radiography was 1.19% (n=302). Various lesions were identified: Parenchymal lesions (n=109), mediastinal lesions (n=6), cardiovascular lesions (n=45), pleural lesions (n=49), bony lesions (n=90) and miscellaneous lesions (n=7). The incidence of active pulmonary tuberculosis by mass miniature radiography was 0.26% (n=67). The first diagnosis was made in 50 people; active pulmonary tuberculosis (n=42), pneumonia (n=1), a mediastinal mass (n=1), a rib fracture (n=2) and a pneumothorax (n=4). Most cases of active pulmonary tuberculosis were mildly infiltrated and either improved or were cured by the follow-up examination. Conclusion : Although mass miniature radiography in a physical examination after conscription has limitations, but it is a useful means for detecting the presence of early disease, particularly in active pulmonary tuberculosis.