• The Optical Journal
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• s.101
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• pp.57-63
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• 2006

지금까지 재현성이나 안정성이 문제가 되어온 경면 연삭이나 연성 모드 연삭도 ELID 연삭법의 개발에 따라 실용화되기 시작하고 있다. 부드러운 지석으로 피삭재 표면을 문지르듯이 가공한 기존의 다듬질 연삭은 예리하게 돌출된 미세한 지립에 의해 삭둑삭둑 잘리며 능률적으로 경면화되고 초정밀화 될 수 있는 신가공 기술로 변해 왔다. 또 절삭 가공의 이미지로 난가공재를 깎는 고능률 연삭도 실용 단계로 들어섰다. ELID 법의 본격적인 보급을 위해 관련된 제조업체의 협력으로 주변 기술의 정비가 진행되고 있지만 ELID 연삭 조건을 최적화하려면 작업 목적의 설정과 구성 요소의 선정을 좀더 명확하게 한 다음 적용할 기계 정밀도·성능, 기능과의 적합성을 검토할 필요가 있다.

• Journal of Korea Society of Industrial Information Systems
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• v.3 no.1
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• pp.101-116
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• 1998

혼합·이산 비선형 최적화문제 해결을 위한 전역적 최적화 알고리즘이 개발되었으며 이 알고리즘은 확률적 최적화기법인 유전알고리즘을 사용한다. 유전알고리즘은 다양한 설계변수를 처리하는데 적합하다. 그러나 기존의 유전알고리즘이 특별히 잘 수행되지 않는 상황이 많이 존재하기 때문에 혼합화에 대한 다앙한 방법이 개발되어지고 있다. 따라서 이 논문은 유전알고리즘에서 최적해 주위에 대한 국고수수렴기법과 정밀 탐색법을 구체화시킨 새로운 혼합유전알고리즘(NHGA)을 개발했다. 사례연구에서는 혼합·이산 비선형 최적화문제를 해결하는데 있어서 NHGA가 상당한 능력을 제공하며 효율적이고 우수한 해를 제공할 수 있다는 것을 보여주고 있다.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.859-864
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• 1995

중수형발전로의 가동에 따라 중수는 삼중수소로 오염된다 오염된 중수의 정화에 적합한 공정으로 평가되는 기액촉매교환과 초저온증류공정으로 이루어진 촉매복합공정에 대하여 탑내의 유속비 및 이론단수의 변화에 따른 촉매탑과 증류탑에서의 삼중수소 제거율 및 농축률 그리고 탑내의 수소동위원소의 농도분포변화를 Newton-Raphson 방법을 사용하여 전산모사를 수행하여 구하였다. 이러한 해석은 본격적 최적화 설계의 기초입력자료로 활용될 것이다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.9
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• pp.1091-1096
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• 2017

The aim of this study was the validation of a modified analytical method for determination of oxypaeoniflorin and paeoniflorin in Moutan Cortex Radicis extract. For validation of the analytical method, we modified established analytical methods and validated improvement. For validation, the specificity, linearity, precision, accuracy, limit of detection (LOD), and limit of quantification of oxypaeoniflorin and paeoniflorin were measured by high performance liquid chromatography. The results show that the correlation coefficients of the calibration curve for oxypaeoniflorin and paeoniflorin were 1.0000 and 0.9998, respectively. The LOD for oxypaeoniflorin and paeoniflorin were $0.23{\mu}g/mL$ and $0.25{\mu}g/mL$, respectively. The inter-day and intra-day precision values of oxypaeoniflorin and paeoniflorin were 0.70~3.19% and 1.74~2.43%, and 0.32~0.92% and 0.62~2.28%, respectively. The inter-day and intra-day accuracies of oxypaeoniflorin and paeoniflorin were 98.33~102.11% and 97.72~118.12%, and 98.44~101.56% and 97.10~112.00%, respectively. Therefore, the analytical method was validated for the detection of oxypaeoniflorin and paeoniflorin in Moutan Cortex Radicis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1419-1425
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• 2013

The aim of this study was to investigate the method validation for the determination of eleutherosides (B and E) and ${\beta}$-glucan in Acanthopanax (A.) koreanum. This medicinal plant reportedly mainly included eleutherosides which exhibit the pharmacological effects, and ${\beta}$-glucan substantially enhances the function of the immune system by activating macrophages. The specificity, linearity, precision, accuracy, limit of detection (LOD, S/N=3), and limit of quantification (LOQ, S/N=10) were measured by HPLC and enzymatic methods. Our results showed that the coefficient of calibration correlation ($R^2$) for eleutheroside B and E were 0.9997 and 0.9999, respectively. The limits of detection (LOD) for eleutheroside B and E were $0.050{\mu}g/mL$ and $0.025{\mu}g/mL$, respectively. The recovery rate of eleutheroside B and E were revealed in the high range of 100.66~110.04% and 94.26~111.62%, respectively. The inter-day precision of eleutheroside B and E in the root and stem in A. koreanum were 1.4~5.0% and 1.1~2.5%, respectively. The intra-day precision of eleutheroside B and E in the root and stem in A. koreanum were 2.8~2.9% and 0.4~1.1%, respectively. Furthermore, the inter-day and intra-day precision of ${\beta}$-glucan in the stem, leaf, and fruit of A. koreanum were 1.32~5.67% and 8.01~11.76%, respectively. In conclusion, the methods were validated for the detection of eleutherosides and ${\beta}$-glucan in A. koreanum.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.352-359
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• 2010

The objective of this paper is to study on the property transformation for materials and to evaluate the precision through marginal gap depending on heat-treatment of metal-porcelain by the gold electro-forming system. Specimens for evaluating property of hardness treat non-treat(HC), once(H1), twice(H2), and three times(H3) by heating, respectively. Specimens for marginal gap classified as each groups of special bonder(FS), special bonder, opaque(FO), special bonder, opaque, body(FB) and non-treatment(FC). As a result for micro-hardness test, the level of hardness on each groups of H1, H2, H3 decreased rather than HC group(p<0.05). In addition, marginal gap was not affected by the number of times being treated by heating. Therefore, the marginal fitness and the precision for mterials were not affected by the heat-treatment on the process to make GES metal-porcelain.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.89-103
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• 2006

This study develops the tire/pavement noise measuring trailer that can minimize the effect of various environmental noise and evaluate road noise characteristics without regard to time and spots. As literature reviews, it is examined into road noise characteristics and case studies of various CPX Trailer, and made a development plan of device. Based on these, HEART CPX Trailer is developed and conduct experiments for verification of the semi-anechoic chamber suitability, precision and field application of device. In the result of the experiment for verification of semi-anechoic chamber suitability, we can make sure that it is suitable and reliable among frequency bands. In the test of repetition measurement, we can verify excellent measurement accuracy among speeds and microphone's locations. In case of field tests using HEART CPX Trailer, it is founded that the result is similar to CPB test result carried out by Chung-Ang university in 2003. It can be concluded caused that the effect of environmental noise in and around the road including mechanical noise of a tow car was excluded. This paper confirmed and suggested that HEART CPX Trailer is suitable for evaluation of real road noise characteristics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1604-1609
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• 2016

An HPLC analysis method was developed for standard determination of marmesin as a functional health material in Broussonetia kazinoki extract. HPLC was performed on a $C_{18}$ Kromasil column ($4.6{\times}250mm$, $5{\mu}m$) with a gradient elution of 0.1% (v/v) trifluoroacetic acid and acetonitrile at a flow rate of 1.0 mL/min at $30^{\circ}C$. The analyte was detected at 330 nm. The HPLC method was validated in accordance with International Conference on Harmonization guidelines for analytical procedures with respect to specificity, precision, accuracy, and linearity. The limit of detection and quantitation were 6.2 and $18.6{\mu}g/mL$, respectively. Calibration curves showed good linearity ($r^2$>0.9999), and the precision of analysis was satisfactory (less than 0.3%). Recoveries of quantified compound ranged from 100.35 to 101.18%. This result indicates that the established HPLC method is very useful for the determination of marker compounds in B. kazinoki extracts.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.135-142
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• 2017

Adoption of CAD/CAM milling in dentistry has allowed production of more analytic and precise prosthesis. Such precision enables definite path of insertion and undercut to be provided in removable partial denture especially when designing a surveyed crown on an abutment tooth. This case is about the production of surveyed crown with proper path of insertion utilizing CAD/CAM electronic surveying method on a patient with edentulous maxilla. Resulting removable partial denture fit well and showed acceptable stability and retention with no clinical problem.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.279-288
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• 2012

The material removal mechanism in machining is significantly affected by the cutting edge geometry. Its effect becomes even more substantial when the depth of cut is relatively small as compared to the characteristic length which represents the shape and size of the cutting edge. Conventionally, radius or focal length has been employed as the characteristic length with the assumption that the shape of cutting edge is round or parabolic. However, in reality, there could be various ways to determine the radius or focal length even for the same tool edge profile, depending on the region to be considered as cutting edge in the measured profile and the constraints to be set in constructing the best fitted circle or parabola. In this regard, the present study proposes various models to determine the characteristic length in terms of radius or focal length. Their physical compatibility are validated by carrying out 2D orthogonal cutting experiments using inserts with a wide range of characteristic length ($30{\sim}180\;{\mu}m$ in terms of radius) and then by investigating the correlation between the characteristic length and the cutting forces. Such validation is based on the common belief that the larger the characteristic length is, the blunter the cutting edge is and the higher the cutting forces are. Interestingly, the results showed that the correlation is higher for the radius or focal length obtained with a constraint that the center of best fitted circle or the focus of the best fitted parabola should be on the bisectional line of the wedge angle of tool.