• Journal of the Korean Society of Radiology
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• v.14 no.6
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• pp.827-832
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• 2020

X-ray equipment, which is frequently used in radiology and treatment, is the most common and most used equipment in clinical practice. Equipment must provide accurate information to patients through continuous quality control. In case of manual quality control measurement, reproducibility may be poor and there may be a problem with reliability of evaluation results. In this study, an automated program was developed and attempted to measure how much the central ray between the focus of the X-ray tube and the variable aperture of the diagnostic X-ray generator used in clinical practice coincides. As a result of the experiment, it succeeded in calculating the coordinates of the two center points, and the distance between the two points was calculated in pixels and applied to the judgment and the automatic judgment value for whether the center line coincidence is within the normal angle or the abnormal angle is presented. The results of this study are considered to be very helpful in the quality control of the X-ray apparatus.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2906-2910
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• 2015

The alignment modifications after completion of railway construction entail a lot of efforts and time as well as high additional costs. In the process of renewal of the existing railway alignment to offer higher-speed services, the effect of initial design parameters(e.g., intersection angle) on determination of allowable degree of improvement of horizontal curves under consideration of economic efficiency is investigated in this study. From the analysis results, in the case that there are obstacles at the tangent line, it was found that the larger angle of intersection has a significant effect on the permissible zone. In addition, as the intersection angle is increased, the permissible values of maximum curve radius and the length of transition curve becomes smaller and longer, respectively. It is expected that this study can contribute to the efficient and accurate prediction of the permissible zone according to the locations of obstacles and the size of intersection angle as well as improvement in the railway alignment without any additional costs.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.108-119
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• 2018

"The Collection of Yi Chungmugong" manuscript is a hand-written manuscript of the volume 1 consisting of the Collection, published in 1795 and it seems to have completed the contents of the book by correcting the first part of the book before print. The book adopted a form of Seonjangbon(線裝本) of Ochimanjeongbeop(五針眼訂法) and was urgently needed some measures to preserve because it has been much damaged by stains, loss and oxidation due to moisture on the bottom of it. In addition, a scientific investigation was applied to find out the features of the quality of paper and fiber used for the book, which would be reflected in the process of the preservation. The characteristics of paper were measurmented for size(cm), thickness(mm), weight(g), basis weight($g/m^2$), density($g/cm^3$), chain line and laid lines($3{\times}3cm$). The measurement showed that the characteristics of paper used in royal books published in the late Joseon Dynasty. For the paper-fiber of the book, C stain was used and the technique revealed that the book is made of bast fibre of paper mulberry and its binding strings are cotton. SEM-EDS analysis was performed to verify the existence of additives in paper. As a result of the analysis, The crystallized calcium was detected in addition to the main components carbon(C) and oxygen(O). This artifact is the unique final version of "The collection of Yi Chungmugong", which has considerable value in terms of academic research, besides it helps to understand how to print books of Joseon Dynasty. And it also has a very accurate information of when and where the book was made, which primarily could be resources to conserve and restore for other book heritage.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.141-147
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• 2015

On July 1 2012, the carriage requirement for ECDIS became mandatory in a phased-in manner. The system has since been widely used as a core bridge navigation system and as a replacement for paper charts with a back up arrangement. However operational anomalies have been found in the system internationally. IMO and IHO have recognised these anomalies and seek for solution. This study has been conducted on a survey of seafarers on the use of ECDIS with regard to anomalies identification, level of the seafarer satisfaction and requirements for further functional improvement. From the results, the ECDIS user focused requirements suggested on strengthening the level of navigational safety and efficiency. The efficiency of using main functions of ECDIS was positively evaluated. However, there were concerns regarding its operational safety.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1471-1478
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• 2010

Microforming processes have recently attracted considerable attention from industry and academia since they enable the production of microscale parts using various materials at a high production rate, minimize material loss, and provide parts with excellent mechanical properties. However, for successful development and applications of the microforming process it is critical to take the tribological size effect into consideration because previous studies have shown that traditional friction models for macroscale forming generate significantly erroneous results in the case of microforming. In this paper, we performed scaled ring compression experiments to investigate the tribological size effect of aluminum and brass materials in microforming. The sensitivity of the interfacial friction to the deformation characteristics of the ring was quantitatively analyzed by the finite element analysis. In addition, a friction model based on slip line field and upper boundary techniques was used to theoretically explain the friction mechanism in microforming.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.329-336
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• 2010

This study deals with the measurement of reflectivity as well as the distance accuracy with Terrestrial Laser Scanner(TLS) using time of flight methods and near infrared wave length, for a variety of user-made targets. Especially, point clouds' reflection to several targets was measured with Gretag Macbeth il spectrophotometer in the office. And the distance accuracy in comparison to reference distance for TLS performance evaluation, was tested after scanning the user-made targets and measuring the inter-pillars distances over the precise EDM calibration baseline. The results of test was shown that except white resin objects, with approx. 10m and 170m inter-pillar distances, other targets achieved the distance accuracy of several millimeters(mm) with respect to standard distances. Future work should be concentrate on a few parameters influencing on the distance accuracy such as atmospheric correction, instrument correction, the additive constant or zero/index correction, etc.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.369-387
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• 2012

Based on the survey data, this study focused venture firms examines how organizational resources and capabilities along with its external environmental conditions have an effect on its strategy and performance. In particular, this article attempts, by performing a binary logistic regression analysis, to identify the venture-specific importance and priority of the factors that may influence firms' strategy patterns, with multiple regression analysis on the relationships between some variables included in the model. The survey was conducted from October 1, 2010 through October 30, 2010. The results of this study are the following. First, the more firms are exposed to high industry growth and low competitive intensity, the higher chance they get to pursuit aggressive strategy. And then a firm seeks aggressive strategy, when it has more technological resources and human resources. Third, environmental uncertainty, industry growth, technological resources, human resources, financial resources and marketing capabilities have positive effects on firm's performance. But, competitive intensity has no direct influence firm's performance. Finally, CEO competence directly influences firm's performance, but the interaction. of CEO competence with other variables is not significant.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.213-217
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• 2014

Medical operations and diagnosis using interventional radiology techniques have been increased. The management and monitoring of occupational radiation exposure to the staff of interventional radiology become important, specially because they stand in close proximity to the patient. The operational radiation protection quantity, Hp(10) which can be obtained from personal dosimeter do not always represent the effective dose to the staff. So, in this study, to estimate the critical organ doses to the staff of interventional radiology, Monte Carlo calculations with mathematical human phantom and dose measurements with personal dosimeters were carried out for the major interventional radiology procedures using C-arm. Results showed that the values of Hp(10) measured by personal dosimeters were higher than critical organ doses which were calculated. And the calculated dose to thyroids was much higher than those of other critical organ doses. For the proper radiation protection of the medical staff of interventional radiology, additional radiation protection for thyroids as well as for whole body shielding like wearing a lead apron should be considered.

• Journal of Digital Contents Society
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• v.16 no.6
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• pp.871-882
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• 2015

AIS-ASM is one of the studies to provide a variety of maritime safety information as well as the information on a ship's position that is their own function, and AIS-ASM has been implemented with adjustment of the relevant regulations since 2004. However, it was reported that the increased use of ASM message on the existing AIS channel affects the part of the existing AIS own function such as the transmission of the ship's position and safe-related information. Also, seamless MSP service is difficult to provide at a low transmission rate of the existing AIS channel. This study aims to reduce the marine officer's workload through automating captain's mandatory reporting items using the one of the next maritime digital communication technology (ASM2.0). For this purpose, we designed and realized the ASM2.0 protocol through analyzing domestic regulations about passenger flight and AIS-ASM message.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.158.1-158
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• 2003

손바닥 선인장 (Opuntia ficus-indica)은 백년초라고도 불리어지는 다년생 식물로 멕시코가 그 원산지이며, 우리나라에는 약 200년 전에 들어와 제주도 월령마을과 마라도 남쪽해변 산지에 자연상태로 착생되어 제주도 지방 기념물 제 35호로 지정되어 있다. 현재는 북제주군의 월평리를 중심으로 노지에서 재배되고 있으며, 열매는 서양배 모양을 하고 점질물과 함께 다량의 적색계 색소를 함유하고 있다. 열매는 공복에 갈아 마시면 변비치료, 이뇨효과, 장운동 활성화 및 식욕증진에 효과가 있으며, 당뇨, 고혈압, 천식에도 효능이 있다고 하여 민간요법으로 사용되어 왔다. 또한 라디칼 소거, tyrosinase 활성 억제, 항알레르기 활성, 항산화 및 항균활성, 스트레스 항위궤양 효과 등 다양한 기능성이 보고되고 있다. 색소성분은 함질소 anthocyanin의 일종인 betalaines로 적색의 betacyanines과 황색의 betaxanthines 로 구성되어 있으며 75~95%가 betacyanines에 속하는 것으로 알려져 있다. 지금까지 손바닥 선인장에 관한 연구로는 색소의 안정성, 품종별 아미노산 조성, 성분 특성, 추출물을 첨가한 면류의 품질 특성 등으로 상당히 단편적인 연구에 그치고 있다. 본 연구는 최근 식생활의 서구화로 쌀 위주의 식생활에 많은 변화를 가져와 쌀 소비량은 해마다 줄어들고 있는 반면 기능성을 가미한 쌀의 소비가 늘고 있음을 감안하여, 손바닥 선인장 물추출물로 코팅한 유색미의 취반특성을 조사하였다. 그 결과 유색미는 자청색을 띠었으나 그 취반은 연한 황색을 띠었다. 손바닥 선장의 유리아미노산은 $\alpha$-aminoadipic acid가 83.22 mg%, tyrosine이 75.61 mg%로 주 아미노산을 이루었다. 유색미 취반에는 백미 취반에는 검출되지 않는 $\alpha$-aminoadipic acid가 1.66 mg% 함유되었으며, 백미 취반에 비하여 arginine과 leucine은 2배, histidine과 Iysine은 각각 2.3배 및 4.2배, tyrosine은 3.4배가 함유되었다. 손바닥 선인장의 주요 무기질은 Ca, K및 Mg으로 전체 무기질 함량의 약 95%를 차지하였으며 이들 무기질의 함량은 유색미 취반이 백미취반에 비하여 10~45%가 높았다. 밥알의 견고성, 점착성 및 깨짐성은 유색미 취반에서 낮았으나 응집성은 높았다. 단맛은 유색미 취반과 백미 취반 간의 뚜렷한 차이가 없었으나 구수한 맛과 쫄깃한 맛은 유색미 취반에서 높았다. 취반의 종합적인 기호도 및 색상에 대한 기호도는 유의적인 차이가 없었다.