• 대한안전경영과학회지
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• 제12권2호
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• pp.55-64
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• 2010

This study tried to focus on nontraditional job that has not been studied in terms of the subjects associated with MSDs(Musculoskeletal Disorders). Specifically, dental procedure was the job to be analyzed in this study. An alternative method as well as a traditional method for viewing teeth while performing simulated dental procedures. Four graduated students did both methods(direct view and indirect view) as the subjects in this study. The method based on indirect view used a video camera and monitor to view the teeth. The experiment was conducted five times for each subject. The major findings in this study were as follows; 1) Job speed was increased with the repetitions for both methods, 2) Difference of Neck flexion between direct and indirect methods was statistically siginificant(Neck flexion for indirect method was dramatically decreased), 3) Difference of job speed between direct and indirect methods was statistically significant(Job speed for direct method was faster than that of indirect method), 4) Difference of error rate between direct and indirect methods was statistically significant(error rate for direct method was lower than that of indirect method), 5) Even though indirect method did not provide better performance in terms of job speed and error rate yet, it seemed to need a trade-off between two methods in the future since indirect method provided better working postures than that of direct method.

• 대한토목학회논문집
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• 제33권4호
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• pp.1361-1375
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• 2013

Lee et al. (2011)이 제시한 목감천 유역의 하천복원 설계절차에 근거하여 수리구조물의 설계와 관련 있는 설계홍수량을 산정에 있어 비정상성을 고려하여 산정하였다. 본 연구의 목적은 목감천 유역에서 비정상성을 고려한 새로운 설계홍수량을 제안하기 위함이다. 설계홍수량 산정방법인 설계-호우단위도법과 직접 홍수빈도해석법을 적용하였으며, 각각의 방법에 사용되는 빈도분석은 NCAR (National Center for Atmospheric Research)에서 개발된 extRemes 모형을 통하여 비정상성을 고려하였다. 직접 홍수빈도해석의 방법은 유량으로부터 직접 빈도해석을 수행한다는 점에서 신뢰성이 기대되지만, 설계-호우단위도법보다 다소 과소 추정되었다. 따라서 가장 크게 산정된 설계호우-단위도법의 100년 빈도 설계홍수량을 목감천 유역의 설계홍수량으로 결정하였다.

• 한국약용작물학회지
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• 제22권1호
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• pp.17-22
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• 2014

Ginsenosides of roots in Panax ginseng were analyzed by metabolic-targeting HPLC using the partial least squares discriminant analysis (PLS-DA) and compared depending on sowing methods between direct seeding and transplanting method. Score plots derived from PLS-DA could identify the sowing method between the direct seeding and transplanting method in P. ginseng roots. The ginsenoside compounds were assigned as Rg1, Re, Rf, Rg2, Rb1, Rc, Rb2, Rb3, and Rd. Contents of Re, Rf, Rg2, Rb1, Rc, Rb3, and Rd of main roots produced from the transplanting method were relatively higher than those of samples produced from direct seeding method. Also, contents of Rg1, Re, Rf, Rg2, Rb1, Rc, Rb2, Rb3, and Rd of lateral roots from the transplanted samples were relatively higher than those of samples produced from direct seeding method. Therefore, HPLC with PLS-DA analysis can be a straightforward tool for identification of ginsenosides in main or lateral roots of P. ginseng obtained from two different seeding methods between direct and transplanting methods.

• KIEAE Journal
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• 제17권3호
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• pp.35-44
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• 2017

Purpose: This study questioned the efficiency of daylight factor as a daylight adequacy and investigated a method of how to complement its weakness by considering a direct sunlight component under a clear sky condition. Method: The Snowdon visitor centre cafe was chosen as a case study building and various techniques such as BRE formula, BRE sky protractor, Pilkington dot diagram and mock-upscale model under the artificial sky simulator were used to analyse and compare daylight factor values. An analysis of direct sunlight component under the clear sky condition was carried out by Climate Consultant 5.5, sun path diagram, and the artificial sky simulator. Result: The result of daylight factor analysis differed by the adopted techniques and it was also contradictory to the results on a direct sunlight penetration. The result not only showed the limitation of daylight factor as a metric but also suggested an improvement by combining it with direct sunlight analysis. The techniques used in this study had a merit of being applied in the early design stage and thus be beneficial to many design professions in order for early daylight performance analysis.

• 대한임상검사과학회지
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• 제47권1호
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• pp.17-23
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• 2015

A fine needle aspiration biopsy (FNAB) is the primary means of distinguishing benign from malignant in thyroid nodules. However, between 10 and 30% of the FNABs of thyroid nodules are diagnosed as 'indeterminate'. A molecular method is needed to reduce unnecessary surgery in this group. In Korea, most thyroid cancer is classic papillary type and BRAFV600E mutation is highly prevalent. Thus, this study compared the pyrosequencing method with the conventional direct DNA sequencing and PCR-RFLP analysis and investigated the evaluation of preoperative BRAFV600E mutation analysis as an adjunct diagnostic method with routine FNABs. Sixty-five (78.3%) of 83 histopathologically diagnosed malignant nodule revealed positive BRAFV600E mutation on pyrosequencing analysis. In detail, 65 (83.8%) of 78 papillary thyroid carcinomas sample showed positive BRAFV600E mutation. None of 29 benign nodules had in pyrodequencing, direct DNA sequencing and PCR-RFLP. Out of 31 thyroid nodules classified as 'indeterminate' on cytological examination preoperatively, 28 cases turned out to be malignant: 24 papillary thyroid carcinomas. Among that, 16 (66.7%) classic papillary thyroid carcinomas had BRAFV600E mutation. Among 65 papillary thyroid carcinomas with positive BRAFV600E mutation detected by pyrosequencing analysis, each 3 cases and 5 cases did not show BRAFV600E mutation by direct DNA sequencing and PCR-RFLP analysis. Therefore, pyrosequencing was superior to direct DNA sequencing and PCR-RFLP in detecting the BRAFV600E mutation of thyroid nodules (p =0.027). Detecting BRAFV600E mutation by pyrosequencing was more sensitivity, faster than direct DNA sequencing or PCR-RFLP.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.112-122
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• 2013

Current status of soil contamination with fluorine and its source were investigated. The basic principles and procedures of various techniques for the analysis of fluorine contents in soil and solid phase samples were summarized in this review. Analysis of fluorine in solid matrices can be achieved by two types of techniques: (i) UV/Vis spectrophotometer or ion selective electrode (ISE) analysis after performing appropriate extraction steps and (ii) direct solid analysis. As the former cases, the standard method of Korean ministry of environment, alkali fusion-ISE method, pyrohydrolysis, oxygen bomb combustion, aqua regia digestion-automatic analysis, and sequential extraction-ISE method were introduced. In addition, direct analysis methods (i.e., X-ray fluorescence spectrometry and proton induced gamma-ray emission spectrometry) and atomic spectrometry combining with the equipment for introducing solid phase sample were also reviewed. Fluorine analysis techniques can be reasonably selected through site-specific information such as matrix condition, contamination level, the amount of samples and the principles of various methods for the analysis of fluorine presented in this review.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 춘계학술대회 논문집
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• pp.125-128
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• 2002

The automotive industry have made an effort to reduce the weight of vehicle structures with increased safety, while initial model of the final product does not contain any prehistoric effects in a design stave. It takes lots of time to calculate forming effects that have great influences on the energy absorption of structures. In this paper, finite element inverse analysis is adopted to calculate forming effects, such as thickness variation and effective plastic strain as well as an initial blank shape with small amount of computation time. Crash analysis can be directly performed after inverse analysis of the forming process without remeshing scheme. The direct mesh mapping method is used to calculate an initial guess from the sliding constraint surface that is extracted from the die and punch set. Analysis results show that energy absorption of structures is increased with consideration of forming effects and finite element inverse analysis is usefully applicable to calculate forming erects of vehicle structures for the crash analysis.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1549-1557
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• 2018

Optimizing the design of large-scale electric machines based on nonlinear finite element analysis (FEA) requires longer computation time than other applications of FEA, mainly due to the huge size of the machines. This paper addresses a new region decision method (RDM) with mesh adaptive direct search (MADS) for the optimal design of wind generators in order to reduce the computation time. The validity of the proposed algorithm is evaluated using Rastrigin and Goldstein-Price benchmark function. Moreover, the algorithm is employed for the optimal design of a 5.6MW interior permanent magnet synchronous generator to minimize the torque ripple. Additionally, mechanical stress analysis as well as electromagnetic field analysis have been implemented to prevent breakdown caused by large centrifugal forces of the modified design.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.398-401
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• 2001

There are two methods to calculate design sensitivity such as direct differentiation method and adjoint method. A sort of direct differentiation method for design sensitivity analysis costs too much when number of design variables is much larger than the number of response functions whose design sensitivity analyses are required. Therefore, an adjoint method is suggested for the case that the dimension of design variables is lager than the number of response function. An adjoint method is required to compute adjoint variables from the simultaneous linear system equation, the so-called adjoint equation, requiring only the eigenvalue and its associated eigenvectors for mode being differentiated. This method has been extended to the repeated eigenvalue problem. In this paper, we propose an adjoint method for deign sensitivity analysis of damped vibratory systems with distinct eigenvalues.

• 한국정보통신학회논문지
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• 제5권4호
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• pp.668-675
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• 2001

최근, 상업적인 pcs시스템은 매우 발전되어 있으며, 결국 차세대 이동통신은 멀티미디어 서비스를 제공하는 IMT-2000에 의해 실현될 것이다. 그러므로 , 새로운 형태의 수신 시스템 연구가 활발히 진행되고 있고, 이중하나가 Direct conversion 방식이다 Direct conversion은 차세대 이동통신 시스템에 필요한 저전력, 소형, MMIC, 저가에 적합한 방식이다. 이 시스템을 사용할 경우 DC-offset의 문제가 발생하게 된다. DC-offset은 시스템에서 주파수 합성기의 누설신호에 의해 원하는 신호의 증폭을 억압한다. 본 논문에서 DC-offset을 제거하는 방법에 대해 고려한다. DC-offset의 제거법에는 AC-coupling, 대용량 capacitor, DC-feedback loop, DC-free coding의 4가지 방법이 있다. 이중에서 AC-coupling법은 가장 간단하며, DC-feedback법은 최고의 성능을 가진다. AC-coupling법과 DC-feedback법을 HP사의 ADS를 사용하여 시뮬레이션 하였다.