• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.86-93
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• 1997

Purpose: To assess the ability of in vivo H-1 MRS to determine the degree of malignancy and to characterize the histopathologic type of intracranial solid tumors. Materials and Methods: In vivo H-1 MR spectra of the pathologically-proven 81 intracranial soild tumors (low-grade glioma 17 cases, high-grade glioma 31 cases, lymphoma 9 cases, meningioma 8 cases, central neurocytoma 4 cases, medulloblastoma 3 cases, PNET 3 cases, metastasis 2 cases, others 4 cases) were analyzed. H-1 MR spectroscopy was performed on a 1.5T MR unit using PRESS sequence with a TR of 2000ms, a TE of 270 or 135ms and a voxel size of $2{\times}2{\times}2cm^3$ for all spectra. N-acetyl aspartate (NAA)/Creatine complex(Cr), Choline complex (Cho)/Cr, and lactate (Lac)/Cr ratios were measured on the peak heights of each resonance and compared among the different tumors. Results: All intracranial solid tumors demonstrated decreased NAA, elevated Cho and lactate, and variable Cr levels. All tumors showed increased Cho/Cr and Lac/Cr, whereas NAA/Cr level was decreased. Mean Cho/Cr and Lac/Cr ratios were significantly higher in high-grade gliomas than in low-grade gliomas. However, NAA/Cr ratio showed no significant difference between low-grade and high-grade gliomas. Very high Cho peaks were seen in lymphomas, meningiomas, medulloblastomas, and neurocytomas in addition to high-grade gliomas. Conclusion: H-1 MRS may be useful in differentiating between low-grade and high-grade gliomas, however cannot characterize the histologic types or subtypes of tumors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.585-592
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• 2017

Most sewer lines buried in the city are likely to be collapsed due to serious aging. Also, due to the high concentration of development and high population density and traffic, the collapse of the sewer will cause enormous social and economic damage. Therefore, proactive maintenance is required to prevent accidents caused by deteriorated sewer pipe. In order to utilize limited budget effectively, risk-based prioritization methods should be proposed that simultaneously consider the consequence of failure and the probability of failure. In this study, the method of risk-based prioritization of sewer was examined by reviewing various cases of overseas studies and applied to the urban sub-catchment. First, the impact factors that can be secured through the sewer GIS DB in Seoul were derived, and the weight, sub-criteria, and impact score of each impact factor were determined and the consequence of failure was calculated by weight sum method. In addition, the probability of failure was calculated by dividing the service life by the estimated useful life, and the consequence of failure and the probability of failure were classified into five grades by the Jenks natural breaks classification method. The prioritization method was applied to sub-catchment in the Seoul to derive a risk matrix and a risk grade. As a result, 26% of all subjects were selected as the inspection priority subjects with 4-5 risk grade. Therefore, using the risk-based CCTV prioritization methodology, it will be possible to systematically determine the objects that need investigation first.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.132-139
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• 2009

The objective of this study was to investigate the most effective analysis methods for palatability grading of Hanwoo beef by comparing the results of discriminant analysis with sensory data. The sensory data were obtained from sensory testing by 1,300 consumers evaluated tenderness, juiciness, flavor-likeness and overall acceptability of Hanwoo beef samples prepared by boiling, roasting and grilling cooking methods. For the discriminant analysis with one factor, overall acceptability, the linear discriminant functions and the non-parametric discriminant function with the Gaussian kernel were estimated. The linear discriminant functions were simple and easy to understand while the non-parametric discriminant functions were not explicit and had the problem of selection of kernel function and bandwidth. With the three palatability factors such as tenderness, juiciness and flavor-likeness, the canonical discriminant analysis was used and the ability of classification was calculated with the accurate classification rate and the error rate. The canonical discriminant analysis did not need the specific distributional assumptions and only used the principal component and canonical correlation. Also, it contained the function of 3 factors (tenderness, juiciness and flavor-likeness) and accurate classification rate was similar with the other discriminant methods. Therefore, the canonical discriminant analysis was the most proper method to analyze the palatability grading of Hanwoo beef.

• Economic and Environmental Geology
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• v.41 no.4
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• pp.383-392
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• 2008

This study aims to evaluate the mechanical-chemical stability of used coal ash blocks, for improving fishing grounds. The surface of weathered ash blocks in seawater showed a decrease in the Ca and an increase in the Mg contents, compared to that of fresh blocks. This result reflects the substitution of Ca by Mg in seawater. The compressive strengths of ash blocks submerged into seawater during 12 months ranged from 235.23 to $447.43\;kgf/cm^2$; this is higher than the standard strength of wave-absorbing blocks($180\;kgf/cm^2)$ that are used for harbor construction. In addition, the compressive strength of ash blocks tends to increase with increasing installation time in seawater. The result of leaching experiments on coal ash blocks by Korean Standard Leaching Test(KSLT) method showed that leached concentrations of most metals except Cr(that leached up to 50 ppb, approaching standard concentration) do not exceed the seawater quality standards. A long-term(112 days) heavy metal leaching test to analyze seawater without mixing-dilution also showed that the concentrations of leached heavy metals, except for Cu, under anaerobic conditions do not exceed the seawater quality standards. Accordingly, the use of coal ash blocks in marine environments appears to be safe from chemical and mechanical factors that decrease the efficiency of concrete. Also, leaching concentration of Cu seems to be stable by decrease of leaching concentration due to dilution of seawater.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.835-842
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• 2022

Several countries are establishing management systems for aquaculture environment, and fishery environment assessment is one of them. The fishery management law amended in 2013 stipulates that a fishery environment assessment should be performed when a fish cage farm's license is extended. The purpose of the fishery environment assessment is to promote sustainable fishery, increase the fishery production capacity, and increase the fishermen incoming by implementing evaluation and improvement measures through scientific methods. The analysis items of fishery environment assessment include the Benthic Health Index (BHI), which is a biological index based on the macrobenthic polychaetes community, and total organic carbon (TOC), and the two items are scored and used for evaluation as a single grade. This study explains the selection process of BHI and TOC, which are evaluation items for fishing ground, and ecological significance of the calculated evaluation grades.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1819-1824
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• 2014

The vacuum-glazing panel is a panel that keeps two glasses completely sealed in a vacuum condition. It is the high function insulation material of having the wall level minimizing the heat loss by the conduction and convection heat transmission coefficient. The edge sealing is a very important process of vacuum glass on the strength, thickness and air tightness. In this study, by using the hydrogen mixture gas torch, two sheets of glass was sealing in the furnace. The thickness and strength of the glass according to the process parameters is measurement and analysis, and predicting the edge sealing strength of glass by using taguchi method of experiment. We verified the validity of the experiment by checking the error rate through additional experiment.

• Journal of Embryo Transfer
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• v.19 no.1
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• pp.67-73
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• 2004

본 연구는 우리나라 고유의 유전자원인 재래산양의 체내수정란 생산기술을 확립하고자 수행하였다. 흡입법(aspiration)과 세절법(slicing)에 의해 난소 한 개당 회수된 난자의 수는 3.9개와 4.1개를 나타내어 slicing방법이 aspiration방법보다는 많은 숫자의 난자를 회수하였으나 유의적인 차이는 나타내지 않았다. 회수된 난자의 등급별 분포는 aspiration방법에서 Grade I, Grade II, Grade III, Grade IV의 비율이 10.3%, 20.5%, 38.5%, 30.8%를 나타내었으며, slicing법에서는 9.8%, 22.0%, 39.0%, 29.3%를 나타내어 Grade III과 Grade IV의 비율이 70% 이상을 차지하였다. 회수된 난자를 체외성숙 시킨 결과 Grade I과 Grade II에서는 85% 이상이 metaphase H (MII)까지 도달하였으나, Grade III과 Grade IV는 40% 이하의 체외성숙율을 나타내었다. 체외수정용 배양액으로 BO를 사용하였을 경우 Grade I 및 II에서 84.4%의 난분할율을 나타내어 TALP를 사용하였을 때의 58.8%보다 높은 난할율을 보였다. 또한 배양액의 종류별 체외발달율에 있어서는 상실배 및 배반포기배로의 발달은 mSOF를 배양액으로 이용하였을 경우 15.0%의 발달율을 나타내었으며, 체외배양 시 항산화물질인 glutathione (GSH)을 첨가함으로서 26.8%의 상실배 및 배반포배로의 발달율을 나타내었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.11
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• pp.2083-2088
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• 2017

This study aims to explore the problems of the VR content industry, which is the core of the newly emerging fourth industrial revolution and convergence new industry, and to find alternatives to solve them. Through in-depth interviews with experts, we collected elements that impeded the development of VR content industry. As a result, the simplification of the VR simulator's content changes, the regulation of the VR simulator was newly established within the Game Industry Act, and the diversification of the input amount were the reasons. Simplification of deliberation provides the basis for new platform business. The new law is to reflect the characteristics of VR content properly and to avoid unnecessary regulation by existing laws. The adoption of various input methods is intended to actively expand the market for new industries. This study is expected to contribute the safe ecosystem by reviewing the factors that impede the development of the new industry as suggesting alternatives.

• Journal of Sensor Science and Technology
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• v.11 no.2
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• pp.93-101
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• 2002

The quality of agricultural products is classified with various factors which are measured and determined by destructive and/or nondestructive method. NIR spectrum analysis method is used to determine internal qualities such as a brix and an acidity. CCD color camera is used to measure external quality like color and a size of fruit. Today, nondestructive methods are widely researched. The quality and the grade of fruit loaded into a cup automatically and measured in real time by camera and NIR system is determined by infernal and external factors. This paper proposes modified boundary tracking algorithm which detects the contour of fruit's color image and make chain code faster than conventional method. The chain code helps compute a size of fruit image and find multiple loading of a fruit in single cup or fruit between two cups. The designed classification system sorts a citrus at speed of 8 fruit/s, with evaluating a brix, an acidity and a size grade.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1375-1379
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• 2010

물관리 주무부처인 국토해양부(이하 국토부)는 최근의 전 세계적인 기후변화와 더불어 유역의 도시화 등으로 인해 급격한 하천환경 및 사회적 여건변화에 맞추어 "하천법"을 전부개정(법률 제8338호)하여 2008년 4월 7일부터 시행하고 있다. 개정 "하천법"에서는 하천수 사용 관리 조정기능이 크게 강화되어 국가 및 지방하천에서 하천수를 취수하여 특정용도로 사용하려는 경우, 그 취수량에 관계없이 누구나 관할 홍수통제소장에게 허가를 받아야한다. 따라서 국토부 소속기관이자 국가 물관리 전문기관인 홍수통제소는 수문조사, 이수(하천유량 관리 등) 및 치수(홍수예보 등) 등의 주요업무 중 기존 국가하천에 국한되었던 하천수사용 관리를 지방하천까지 확대하게 되었다. 본 연구에서는 하천법에 따라 집행된 2009년 국가하천, 지방하천 및 일시적인 하천수 사용 인 허가 행위 등 하천수관리 현황자료를 조사 정리하였다. 현황 자료를 토대로 행정구역(시 도)별, 수계별, 용도별, 허가량별, 월별 분석을 수행하고 그 특성을 파악하였다. 그리고 일시적인 하천수사용은 상기 분석 이외에 하천등급별, 공사종별 분석을 수행하였다. 2009년 총 152건(반려, 취소 등을 제외한 행위는 총 131건 : 국가하천 43건, 지방하천 33건, 일시적인 하천수 55건)의 기본적인 통계분석을 통하여 낙동강유역의 하천수사용 특성을 제시하고, 파악된 하천수사용 특성 결과는 낙동강유역의 물관리정책에 소중한 기초자료로 활용될 것으로 판단된다.