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Dosimetric Characteristics of 6 MV Modified Beams by Physical Wedges of a Siemens Linear Accelerator

  • Zabihzadeh, Mansour;Birgani, Mohammad Javad Tahmasebi;Hoseini-Ghahfarokhi, Mojtaba;Arvandi, Sholeh;Hoseini, Seyed Mohammad;Fadaei, Mahbube
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1685-1689
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    • 2016
  • Physical wedges still can be used as missing tissue compensators or filters to alter the shape of isodose curves in a target volume to reach an optimal radiotherapy plan without creating a hotspot. The aim of this study was to investigate the dosimetric properties of physical wedges filters such as off-axis photon fluence, photon spectrum, output factor and half value layer. The photon beam quality of a 6 MV Primus Siemens modified by 150 and 450 physical wedges was studied with BEAMnrc Monte Carlo (MC) code. The calculated present depth dose and dose profile curves for open and wedged photon beam were in good agreement with the measurements. Increase of wedge angle increased the beam hardening and this effect was more pronounced at the heal region. Using such an accurate MC model to determine of wedge factors and implementation of it as a calculation algorithm in the future treatment planning systems is recommended.

The analysis of causal relationship of SCM performance based on BSC framework (BSC에 기반한 SCM 성과간의 인과관계 분석)

  • Kim, Mi-Ae;Suh, Chang-Kyo
    • The Journal of Information Systems
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    • v.23 no.4
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    • pp.75-91
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    • 2014
  • The effective supply chain management(SCM) is a matter of survival in many firms because successful supply chains will effectively coordinate their processes, focus on delivering customer value, eliminate unnecessary costs in key functional areas, and create performance measurement systems. The balanced scorecard(BSC) is widely used to measure the performance of the SCM. The BSC framework suggests that balance is obtained by adopting performance measures from four different areas. In this study, we analyzed the causal relationship of SCM performance based on BSC framework. First, we reviewed the nested causal relationships among four different perspective of the BSC, namely, business process perspective, customer perspective, financial perspective, and innovation and learning perspective. Then, we used the chi-square difference test to identify the best model to fit the causal relationship of SCM performance. Of the 800 questionnaires posted, a total of 265 questionnaires were returned after one follow-up. A total of 66 questionnaires were eliminated due to largely missing values. The major finding says alternative model 3 is dominant to other models to fit causal relationships among four different perspective of the BSC. Innovation and learning perspective positively influence on customer perspective, business process perspective, and financial perspective. Business process perspective also positively influence on customer perspective and financial perspective whereas customer perspective does not influence on financial perspective significantly.

Improvement of Accuracy in Evaluating Hue Change Time in the Hue Detection Based Transient Liquid Crystals Technique (색상 검출방식의 천이 액정법에서 색상 변화 시간 산정의 정확도 향상)

  • Shin, So-Min;Jeon, Chang-Soo;Jung, Yong-Wun;Kwak, Jae-Su
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.11
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    • pp.918-925
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    • 2007
  • In this paper, different criteria fur determining hue change time in the hue detection based transient liquid crystals technique were compared. Results showed that methods utilizing threshold of intensity or saturation gave many missing points and quality of the calculated results were strongly depends on the value of threshold. Wider bandwidth in the hue bandwidth method showed better distribution of calculated hue change time, but induced ambiguity in the hue change time. In the time-hue curve fitting method, the distribution of evaluated hue change time was smooth and reasonable, and, by the nature of curve fitting, the noise effect on the hue was successfully considered in calculating of the hue change time. Compared to other methods, it is expected that the time-hue curve fitting method would provide better and accurate hue change time in the hue detection based transient liquid crystals technique.

A Study on the Kimchi Recipe in the Early Joseon Dynasty through 「Juchochimjeobang」 (「주초침저방(酒醋沈菹方)」에 수록된 조선 전기(前期) 김치 제법 연구 - 현전 최초 젓갈김치 기록 내용과 가치를 중심으로 -)

  • Park, Chae-Lin;Kwon, Yong-min
    • Journal of the Korean Society of Food Culture
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    • v.32 no.5
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    • pp.333-360
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    • 2017
  • This study aims to examine the contents of "Juchochimjeobang", a cookbook about Jeotgal kimchi, and review its value in the history. This cookbook was published between about 1500s and early 1600s, and its book title is unknown because both the front and the back covers thereof are missing. However, the cookbook contains many wine and kimchi recipes, accounting for 66%, and "Juchochimjeobang" was thus named after the recipes. "Juchochimjeobang" has 126 recipes in 120 categories, and this study examines 20 kimchi recipes and 7 recipes for preserving vegetables. "Juchochimjeobang" has a specific recipe for making Jahajeot and Baekajeot kimchi which are described in literature published between 1400s and 1500s. Although the recipes for making the aforementioned two types of Jeotgal kimchi are simple because jeotgal is just mixed with main materials, they are different from the recipe for Seokbakji described in Gyuhapchongseo, a cookbook written in the 19th-century Joseon Dynasty. Seokbakji described in Gyuhapchongseo is made by mixing spices of ginger, spring onion, chili powder with other materials. This implies changes of making Seokbakji over time. Moreover, "Juchochimjeobang" is a very valuable historical cookbook because it has unique recipes, for example, adding sesame liquid, chinese pepper, willow and the like.

Relationship between the Flow data on the Unit Watersheds and on the Stream Flow Monitoring Network (수질오염총량관리 단위유역 유량자료와 하천유량 측정망 자료의 연계성 분석)

  • Park, Jun Dae;Oh, Seung Young
    • Journal of Korean Society on Water Environment
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    • v.29 no.1
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    • pp.55-65
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    • 2013
  • It is very difficult to apply stream flow data directly to the management of Total Maximum Daily Loads because there are some differences between the unit watershed and the stream flow monitoring network in their characteristics such as monitoring locations and its intervals. Flow duration curve can be developed by linking the daily flow data of stream monitoring network to 8 day interval flow data of the unit watershed. This study investigated the current operating conditions of the stream flow monitoring network and the flow relationships between the unit watershed and the stream flow monitoring network. Criteria such as missing and zero value data, and correlation coefficients were applied to select the stream flow reference sites. The reference sites were selected in 112 areas out of 142 unit watersheds in 4 river basins, where the stream flow observations were carried out in relatively normal operating conditions. These reference sites could be utilized in various ways such as flow variation analysis, flow duration curve development and so on for the management of Total Maximum Daily Loads.

COMPLICATIONS OF THE IMPLANT-SUPPORTED POSTERIOR MANDIBULAR SINGLE RESTORATIONS WITH MESIAL CANTILEVER (하악구치 임플란트 지지 단일수복에서 근심 캔틸레버가 임플란트 합병증에 미치는 영향)

  • Shin, He-Sung;Kim, Myung-Rae;Kim, Sun-Jong
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.35 no.4
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    • pp.248-252
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    • 2009
  • Purpose: This retrospective study was performed to analyze the relationship between complications of the posterior mandibular single crowns and distance from the adjacent teeth to the implant. Subjects and Methods: Of the patients who presented Ewha Womans University Mokdong Hospital & Yonsei University Dental Hospital with missing of the posterior mandibular molar and restored with implant-supported 18 Single crowns between 1996 thru 2007, 115 patients had been followed after crown delivery. The subjects were divided into complication-followed group and a control without any problems. The distance from the most distal tooth to the implant were measured. The prosthetic & biologic complications were reviewed by the cantilever distance and analyzed by abutment type, age & gender statistically using SAS version 9.1 (SAS Inc., USA). Results and Conclusion The results were as follows; 1) The posterior mandibular single crown with cantilever showed higher incidence of follow-up complications upon logistic analysis (p<0.05). 2) The prosthetic and biologic complications are related with the cantilever distance with 2.1 odds ratio and 3.39 cut-off value of specificity & sensitivity by SPSS 12.0. 3) The complications are neither significant in abutment types nor age & gender.

A Study on the Investment Portfolios of Stocks using DEA (DEA를 활용한 주식 포트폴리오 구성에 관한 연구)

  • Gu, Seung Hwan;Jang, Seong Yong
    • Korean Management Science Review
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    • v.31 no.3
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    • pp.1-12
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    • 2014
  • This study suggests the two types DEA models such as DEA CCR model and Super Efficiency model to evaluate the value of a company and to apply them for the investments. 14 kinds of real data of companies such as EV/EBITDA, EPS growth rate, PCR, PER, dividend yield, PBR, stock price/net current asset, debt ratio, current ratio, ROE, operating margin, inventory turnover, accounts receivable turnover, and sales growth ratio were used as input variables of DEA models. 12 year data from December 30, 2000 up to December 30, 2012 were collected, and the data with negative, missing and 0 values were removed reflecting the characteristics of the DEA. In order to verify the effectiveness of the models, we compared the historical variability and rate of return of both models those of the market. Study results are as follows. First, two DEA models are more stable than market in terms of rate of return because the historical variability of both models are less than that of market. Second, Super Efficiency model is more stable than CCR model. Lastly, the cumulative rate of return of Super Efficiency model (434%) is greater than that of the CCR model (420%) and that of the market (269%).

A Note on Relationship between Strengths of Heavy Metals Contamination in Scalp Hair and Organs from Autopsy Subjects (부검체 두발과 장기의 중금속 오염농도 관련성)

  • Lee, Won-Kee;Song, Myung-Unn;Song, Jae-Kee;Lee, Sung-Kook;Park, Sung-Hwa
    • Journal of the Korean Data and Information Science Society
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    • v.10 no.1
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    • pp.215-222
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    • 1999
  • It is well known to use scalp hair as a signal of strengths of heavy metals contamination. In this paper, using the multivariate methods we examine the relationship between strengths of cadmium and mercury in scalp hair and cerebellum, cerebrum, heart, kidney, liver, lung and spleen from 61 korean autopsy subjects. As a result, there is statistically singnificant relationship between strengths of mercury contamination in scalp hair and secondary contaminated organs.

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Effect of Eating-Out Consumption Propensity on Selection Attributes for Dessert Cafe (외식소비성향이 디저트 카페 선택속성에 미치는 영향)

  • Yoon, Jung-Suk
    • Culinary science and hospitality research
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    • v.23 no.7
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    • pp.31-41
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    • 2017
  • The purpose of this study was to verify the relationship of eating-out consumption propensity and selection attributes by consumers have been used dessert cafe and to provide the useful data for efficient establishing marketing strategies to dessert cafe managers. This survey was conducted from 7th to 22th on April, 2017 and a total of 250 responses were distributed, of which 232 were used for analysis, after excluding responses containing missing data. The results from this study are as follows. First, it was found that eating out enjoyment pursuit type and health pursuit type had significant effects on menu and service factor of selection attributes for dessert cafe. Second, only eating out enjoyment pursuit type had significant effects on visual factor of selection attributes for dessert cafe. Third, only health pursuit type had significant effects on health menu factor of selection attributes for dessert cafe. Fourth, economic value pursuit type and atmosphere pursuit type had significant effects on price factor of selection attributes for dessert cafe. This study contributes to useful results for establishing efficient marketing strategies to dessert cafe marketers by examining selection attribution of dessert cafe as recognizing eating-out consumption propensity.

A New Method to Find Bars

  • Lee, Yun Hee;Ann, Hong Bae;Park, Myeong-Gu
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.40.1-40.1
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    • 2014
  • We have classified barred galaxies for 418 RC3 sample galaxies within z < 0.01 from SDSS DR7 using the visual inspection, ellipse fitting method and Fourier analysis. We found the bar fraction to be ~60%, 43% and 70% for each method and that the ellipse fitting method tends to miss the bar when a large bulge hides the transition from bar to disk in early spirals. We also confirmed that the Fourier analysis cannot distinguish between a bar and spiral arm structure. These systematic difficulties may have produced the long-time controversy about bar fraction dependence on Hubble sequence, mass and color. We designed a new method to fine bars by analyzing the ratio map of bar strength in polar coordinates, which yields the bar fraction of ~27% and ~32% for SAB and SB, respectively. The consistency with visual inspection reaches around 70%, and roughly 90% of visual strong bar are classified as SAB and SB in our classification. Although our method also has a weakness that a large bulge lowers the value of bar strength, the missing bar fraction in early spirals is reduced to the level of ~1/4 compared to the ellipse fitting method. Our method can make up for the demerits of the previous automatic classifications and provide a quantitative bar classification that agrees with visual classification.

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