• 한국수산과학회지
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• 제39권2호
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• pp.78-84
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• 2006

A high performance liquid chromatography assay method for spiramycin in fish muscle was developed. The developed method was evaluated and validated by monitoring spiramycin in olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli) and in live conger eel (Anguilla japonica) in fish farms and distribution centers. Using the developed method, the recovery rate was up to 82.4-88.8%, which was higher than that of conventional methods (77.6-87.1%). In particular, the proposed sample treatment protocol was suitable for use with fish samples to remove low molecular weight materials and pigments that could interfere an accurate analysis. The prepared stock solution was very stable, and it remained chemically stable for 5 weeks at $4^{\circ}C$. The performance limit of the developed method for spiramycin acid in fish muscle was 0.05 ppm. One hundred thirty-four fish samples including olive flounder, black rock fish and live conger eel were analyzed to evaluate the overall efficiency of the modified method and to monitor the actual condition of spiramycin usage in fish farms. Olive flounder and black rock fish were collected from fish farms in coastal areas of Korea, and live conger eels were purchased from a fish market in the Busan area from September 2001 to March 2002. According to the overall performance of the developed method, it was considered suitable for the monitoring of spiramycin in fish muscle. The suggested method of analysis for spiramycin in fish muscle is registered in the Korean Official Methods of Food Analysis and is currently tieing utilized for fishery products inspection by the Korea Food and Drug Administration and the National Fisheries Products Quality Inspection Service.

• Journal of Biosystems Engineering
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• 제40권1호
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• pp.35-46
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• 2015

Purpose: To present a flexible and accurate autonomous solution for creating any desired row spacing value between the hydroponic gullies in multilayer growing units, and evaluate the capabilities and performance of the relevant automated system through the use of virtual prototyping technique. Methods: To build the virtual prototype of the system, CAD models of its different parts, including an autonomous vehicle and the mechanical mechanisms embedded in the multilayer growing unit, were developed and imported into the RecurDyn simulation software. In order to implement the automated row spacing operation, three spacing modes with different loading cycles and working steps were defined, and the operation of the system was simulated to obtain the target row spacing values specified for each of these modes. Results: Motion profiles related to the horizontal displacement of: 1) the lower and upper sliding bars installed in the cultivation layers, and 2) the hydroponic gullies, during the simulation of the system operation, were generated and analyzed. No deviation from the specified target spacing values was observed at the end of simulations for all spacing modes. Conclusions: The results of the motion analysis obtained by simulating the system operation confirm the effectiveness of the control scheme proposed for automated row spacing of gullies. It was also found that proper sequencing of the loading cycles and the precision of the working strokes of the upper bars are the critical factors for establishing a certain row spacing value. Based on the simulation results, precise control of the back and forth motions of the upper bars is highly necessary for sound operation of the real system.

• 분석과학
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• 제24권3호
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• pp.159-167
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• 2011

식물 체중에 포함되어 있는 항산화제로서 주목받고 있는 게르마늄과 셀레늄의 극미량 분석에 있어서의 재현성 있는 분석방법을 제시하고자 수소화물생성장치와 유도결합플라스마질량분석기를 이용하여 분석하였다. 유도결합플라스마질량분석기에 일반적으로 사용되는 torch 대신 에너지 밀도를 높여 이온 간섭, 분자이온 생성 등의 간섭현상을 줄일 수 있는 mini torch를 사용하여 산 종류와 농도의 영향, 수소화물의 생성을 위한 환원조건, 시료 전처리 방법의 차이 등 다양한 조건하에서 상추 중의 게르마늄과 셀레늄을 분석하였다. 분석의 정확성을 평가하기 위하여 회수율 검증과 셀레늄의 표준시료인 SRM-1547, 1570a을 분석하여 기준 값과 비교함으로서 분석의 정확성을 평가하여 다음과 같은 결론을 얻었다.

• 대한기계학회논문집A
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• 제39권8호
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• pp.823-830
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• 2015

구조최적설계는 구조물의 성능 개선을 추구하며, 최근에는 구조최적설계는 항공기와 같이 복잡하고 대형인 구조물의 설계에 적용되고 있다. 해석의 정확도를 높이기 위해 유한요소의 수가 증가하는 추세이나 이는 설계 비용의 증가로 이어진다. 이에 부분구조합성법으로써 구분모드합성법이 해석시간 단축을 위해 종종 사용되어 왔다. 본 연구에서는 구조물의 동적특성을 고려하고 해석의 정확도는 유지하면서, 설계에 소요되는 시간과 비용을 줄일 수 있는 설계방법을 제안한다. 제안한 방법은 등가정하중을 이용한 동적응답 최적설계에, 부분구조합성법을 적용하여 설계영역만을 고려한 구조최적설계를 수행하는 것이다. 제안한 방법의 유용성 검증을 위하여 선형 및 비선형 동적응답 최적설계의 예제를 풀이하고, 그 결과에 대해 토의한다.

• 한국측량학회지
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• 제29권6호
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• pp.593-599
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• 2011

지리정보에 대한 사용자의 활용도가 높아지면서 더 새롭고 고품질인 지리정보 자료에 대한 요구 역시 함께 증가하고 있다. 새로운 콘텐츠를 제작하는데 있어 기 구축된 자료간의 융합을 통한 방법은 기존의 자료들이 가진 장점만을 취하여 새로운 지리정보 콘텐츠를 생성할 수 있다는 점에서 효율적이다. 그러나, 서로 다른 자료를 융합하면 위치편차와 형상불일치가 나타나는데 이는 이종의 자료가 가진 정보의 정확도는 그대로 유지한 채 자료 간 불일치되는 부분을 개선하는 합성 기술로 해결이 가능하다. 본 연구에서는 선행연구를 통해 위치편차가 최소화된 도로지도와 항공사진간에 형상불일치를 제거하는 것을 목적으로 하여 항공사진에서 도로 후보 영상을 생성한 후 이를 도로일 가능성으로 표현한 그래프를 제작하였다. 여기서 도로일 가능성이 높은 것만을 추출하여 합성 시 형상불일치를 제거할 수 있었다.

• 한국정밀공학회지
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• 제24권4호
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• pp.138-146
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• 2007

Some biodegradable polymers and other materials such as hydrogels have shown the promising potential for surgical applications. Post surgical adhesion caused by the natural consequence of surgical wound healing results in repeated surgery and harmful effects. Recently, scientists have developed absorbable anti-adhesion barriers that can protect a tissue from adhesion in case they are in use; however, they are dissolved when no longer needed. Although these approaches have been attempted to fulfill the criteria for adhesion prevention, none can perfectly prevent adhesions in all situations. Overall, we developed a new method to fabricate an anti-adhesion membrane using biodegradable polymer and hydrogel. It employed a highly accurate three-dimensional positioning system with pressure-controlled syringe to deposit biopolymer solution. The pressure-activated microsyringe was equipped with fine-bore nozzles of various inner-diameters. This process allowed that inner and outer shapes could be controlled arbitrarily when it was applied to a surgical region with arbitrary shapes. In order to fulfill the properties of the ideal barriers f3r preventing postoperative adhesion, we adopted the pre-mentioned method combined with surface modification with the hydrogel coating by which anti-adhesion property was improved.

• 대한원격탐사학회지
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• 제27권3호
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• pp.303-314
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• 2011

Surface albedo is an important parameter of the surface energy budget, and its accurate quantification is of major interest to the global climate modeling community. Therefore, in this paper, we consider the direct solution of kernel based bidirectional reflectance distribution function (BRDF) models for retrieval of normalized reflectance of high resolution satellite. The BRD effects can be seen in satellite data having a wide swath such as SPOT/VGT (VEGETATION) have sufficient angular sampling, but high resolution satellites are impossible to obtain sufficient angular sampling over a pixel during short period because of their narrow swath scanning when applying semi-empirical model. This gives a difficulty to run BRDF model inferring the reflectance normalization of high resolution satellites. The principal purpose of the study is to estimate normalized reflectance of high resolution satellite (RapidEye) through BRDF components from SPOT/VGT. We use semi-empirical BRDF model to estimated BRDF components from SPOT/VGT and reflectance normalization of RapidEye. This study used SPOT/VGT satellite data acquired in the S1 (daily) data, and within this study is the multispectral sensor RapidEye. Isotropic value such as the normalized reflectance was closely related to the BRDF parameters and the kernels. Also, we show scatter plot of the SPOT/VGT and RapidEye isotropic value relationship. The linear relationship between the two linear regression analysis is performed by using the parameters of SPOTNGT like as isotropic value, geometric value and volumetric scattering value, and the kernel values of RapidEye like as geometric and volumetric scattering kernel Because BRDF parameters are difficult to directly calculate from high resolution satellites, we use to BRDF parameter of SPOT/VGT. Also, we make a decision of weighting for geometric value, volumetric scattering value and error through regression models. As a result, the weighting through linear regression analysis produced good agreement. For all sites, the SPOT/VGT isotropic and RapidEye isotropic values had the high correlation (RMSE, bias), and generally are very consistent.

• 대한지하수환경학회지
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• 제5권4호
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• pp.210-214
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• 1998

담수나 해수와 같은 자연수중의 우라늄(U)의 농도는 0.0l∼5 ppb 수준으로서 극미량 원소분석법을 필요로 한다. 본 연구는 고감도의 비파괴법인 중성자방사화분석법을 이용하여 지하수중의 우라늄을 신속, 정확하게 정량할 수 있는 방법에 대하여 시료를 증발농축 전처리하는 방법과 직접 분석하는 방법을 비교 검토하였다. 표준용액(0.5∼100 ppb)을 이용하여 분석법을 검증하였다. 주어진 농도범위에서 검정곡선의 평균편차는 2% 이하를 나타냈으며, 각 측정값의 상대표준편차는 2∼l2% 이내이었다. 동일시료에 대한 시기별 농도의 편차는 10.3%이었다 본 방법을 이용하여 충청지역의 17개 관정으로부터 지하수시료를 채취하여 우라늄 농도를 정량한 결과 1 ppb에서 80 ppb수준인 것으로 확인되었다.

• 대한수의학회지
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• 제52권2호
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• pp.69-74
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• 2012

The analytical method of trace toxic metals in livestock products was confirmed and validated through certified reference material (CRM) and the international proficiency tests. There are some difficulties to determine low levels of toxic metals in livestock products because of interferences due to the matrix. The recoveries of CRM (NIST 1577c) ranged from 73.9 to 119% for lead and from 86.4 to 111% for cadmium in bovine liver. The international proficiency tests were carried out with the milk powder and cocoa powder samples including metals provided by Food Analysis Performance Assessment Scheme (FAPAS$^{(R)}$, UK). The test samples were prepared by microwave digestion using solution of $HNO_3:H_2O_2:H_2O$ (v/v/v = 5 : 2 : 4) and analyzed by ICP/MS. The analytical result of cadmium in milk powder was $121{\mu}g/kg$ with -0.3 of the z-score compared to the assigned value of $131{\mu}g/kg$ by FAPAS$^{(R)}$. The analytical results of lead and cadmium in cocoa powder were $29.2{\mu}g/kg$ and $97.6{\mu}g/kg$, respectively, which satisfied the assigned values of $34.2{\mu}g/kg$ for lead and $126{\mu}g/kg$ for cadmium by FAPAS$^{(R)}$. It is verified that the analytical method is accurate and reliable to determine trace lead and cadmium in livestock products by microwave digestion and ICP/MS.

• 한국치위생학회지
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• 제10권6호
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• pp.1095-1105
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• 2010

Objectives : This paper is designed to help the public prevent their future dental caries, based on the studies of xylitol about it's efficacy and effectiveness, and its appropriate usage. Methods : This study of xylitol on the basis of existing research papers and literature is not only to learn about the mechanism of what xylitol acts, but also to search the effectiveness of incompleteness of xylitol-containing foods, bacterial infection between xylitol and mother-baby, and the side-effects of xylitol. Results : 1. Xylitol's continuous intake of teeth effects the decrease of calculus amount, cleanness of teeth, as well as the remineralization process. The xylitol effect varies depending on the weight of xylitol, which has no effect on root caries. 2. Mouth gargle solution is higher resistant against acids; recalcification is significantly reduced; and remineralization effect represents. 3. It is reported that regular consumption of xylitol by mothers just during two years after birth has significantly decreased the spread possibility of mutans streptococcei. 4. The reduction of dental caries by xylitol is happened by its restraining the growth of bacteria resource caries, with their presence in amount of uncontrolled growth. 5. When a small amount of eating xylitol is absorbed slowly into gastrointestinal tract, being followed by glucose metabolism in the liver, while its excessive amount of eating can cause gastrointestinal problems. Conclusion : Dental hygienists should be required to provide dental information to the public on the basis of academic knowledge. In situation that one is not yet sure of xylitol on solid and multifaceted researches, there must be needed more accurate and detailed reviews on the side-effects of xylitol and the overall impact on the oral environments.