• Title/Summary/Keyword: depth adjustment

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Verification of Mechanical Leaf Gap Error and VMAT Dose Distribution on Varian VitalBeamTM Linear Accelerator

  • Kim, Myeong Soo;Choi, Chang Heon;An, Hyun Joon;Son, Jae Man;Park, So-Yeon
    • Progress in Medical Physics
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    • v.29 no.2
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    • pp.66-72
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    • 2018
  • The proper position of a multi-leaf collimator (MLC) is essential for the quality of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) dose delivery. Task Group (TG) 142 provides a quality assurance (QA) procedure for MLC position. Our study investigated the QA validation of the mechanical leaf gap measurement and the maintenance procedure. Two $VitalBeam^{TM}$ systems were evaluated to validate the acceptance of an MLC position. The dosimetric leaf gaps (DLGs) were measured for 6 MV, 6 MVFFF, 10 MV, and 15 MV photon beams. A solid water phantom was irradiated using $10{\times}10cm^2$ field size at source-to-surface distance (SSD) of 90 cm and depth of 10 cm. The portal dose image prediction (PDIP) calculation was implemented on a treatment planning system (TPS) called $Eclipse^{TM}$. A total of 20 VMAT plans were used to confirm the accuracy of dose distribution measured by an electronic portal imaging device (EPID) and those predicted by VMAT plans. The measured leaf gaps were 0.30 mm and 0.35 mm for VitalBeam 1 and 2, respectively. The DLG values decreased by an average of 6.9% and 5.9% after mechanical MLC adjustment. Although the passing rates increased slightly, by 1.5% (relative) and 1.2% (absolute) in arc 1, the average passing rates were still within the good dose delivery level (>95%). Our study shows the existence of a mechanical leaf gap error caused by a degenerated MLC motor. This can be recovered by reinitialization of MLC position on the machine control panel. Consequently, the QA procedure should be performed regularly to protect the MLC system.

Application of Sediment Yield Estimation Methods for an Urbanized Basin (도시유역에 대한 토사유출량 모의기법 적용성 검토)

  • Son, Kwang-Ik;Roh, Jin-Wook
    • Journal of Korea Water Resources Association
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    • v.42 no.9
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    • pp.737-745
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    • 2009
  • Field measured sediment yield from an experimental urbanized basin was compared with the predicted sediment yields with RUSLE (Revised Universal Soil Loss Equation), and MUSLE (Modified Universal Soil Loss Equation). The experimental basin is 3.1km2 in area and fifty six percent of the total area had been urbanized. The hydrological data have been measured with T/M at the outlet of the experimental basin. Runoff from the basin and rainfall depth of the basin were measured every minute. Bed load and suspended load were also measured for a given flow rate. Runoff rating curves and sediment rating curve were developed for the last three years. RUSLE showed scattered prediction results but the average of the prediction values was close to the measured one. Meanwhile, MUSLE showed linear correlation between the measured sediment yield and predicted one with high correlation coefficient. But MUSLE predicts high values than the real one. Therefore, adjustment is necessary to apply MUSLE in estimation of sediment yield from the experimental urbanized basin.

Development of the Blouse Block Pattern for 7 Years Old Girls (7세 여아 블라우스 원형 개발에 관한 연구)

  • Song, Yun-Hwa;Jo, Jin-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.2
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    • pp.187-199
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    • 2009
  • Recently, the quality and design of the children's wear is being improved remarkably. Following the trend, the need for the research on the pattern making of children's wear is growing. At first, we tried to find out how the industry is doing the pattern making job through interview. Results are as follows. The target age ranges from 5 to 11 years old. For the sample size of pattern making, 7 years of age is preferred. It is not usual to develop the design pattern from the bodice block pattern. Instead, they use middle block pattern for each item, such as blouse, shirt, pants, skirt or jacket. Starting from these middle block pattern, they prepare individual designs. With the results, the aim of the research became to develop one of most frequently used middle block pattern. The blouse block pattern was selected for that purpose. To look into the existing patterns, we selected 4 methods, i.e. NM-method, T-method, O-method, E-methods. Theses patterns were compared through wearing test for the evaluation of comfort and fit using trial garments. The results indicated the NM-method was best among them. Specially waist line position, shoulder shape and size allowance was adequate. Alteration and adjustment of pattern draft was made onto the NM-method. Allowances for the bust circumference, across chest, across back and depth of arm was adjusted for better comfort as well as fine fit. Sidelines of the bodice and the underarm seam of the sleeves were curved for styling. After another wearing test, the final pattern was suggested as a blouse block pattern for 7 years old girl.

A Study on the Spatial Cognition and the adjustment of Intermarriage Couples Regarding Transnational Migration Backgrounds (국제결혼 부부의 초국적 이주배경에 대한 공간인지와 적응에 관한 연구)

  • Lee, Kyung Ja
    • Journal of the Korean association of regional geographers
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    • v.19 no.4
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    • pp.712-736
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    • 2013
  • Since the 1990s, the international married couple, who were transnational migration has increased. therefore, there has been many studies on this approaches in the meanwhile, but enough analysis is not being done on the background of female marriage migrant and the adaptation of international marriage couples, because there is limits of the approach method. With the awareness of these issues, this study is about the analysis on the background and adaptation of them, based the data of surveys and in-depth interviews targeted international marriage couples in the area of Daegu and Gyeongbuk. The result of analysis survey on background of international migration was very high level about the recognition of the international marriage couple's global thinking, and analyzed this macro-background does not affect much about the international marriage couple's adaptation. However, this study were analyzed that the advance cognition degree to the other side, which are expected affect directly to the life and adaptation of all the couples is very low level.

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Adaptation to Motherhood in Central Asian-Korean Immigrants to Korea: A Grounded Theory Study (한국으로 이주한 고려인 여성의 모성 적응과정: 근거이론연구)

  • Kim, Su Hyun;Cho Chung, Hyang-In
    • Journal of Korean Academy of Nursing
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    • v.49 no.6
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    • pp.677-689
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    • 2019
  • Purpose: This qualitative study aimed to develop a substantive theory of the process of adaptation to motherhood in Central Asian-Korean immigrants to Korea. Methods: Individual, in-depth interviews were conducted from July to September 2017, with 18 women who emigrated of Korean ethnicity from Central Asia to Korea, and took care of their baby for at least a year after their first delivery in Korea. The interviews were audio-recorded and transcribed verbatim. Data from the transcriptions were analyzed through Strauss and Corbin's grounded theory method, and data analysis was conducted simultaneously with data collection. Results: As a result of categorizing the interview data through the process of open coding, 10 categories, with 31 subcategories and 102 concepts were drawn, and "growth as a Central Asian-Korean mother in an unfamiliar, historical hometown" was found to be the core category of the process of adaptation to motherhood in Central Asian-Korean immigrants to Korea. Conclusion: A characteristic of the process of adaptation to motherhood in Central Asian-Korean immigrants to Korea, drawn from this study, is that it differs according to the level of initiative to carry out interaction strategies, and the use of various supportive social resources. The findings indicate the need for Medicare eligibility adjustment for antenatal care, the extension of the visa renewal period during childbirth, the development of web- or mobile application-based educational programs in Russian language, and the establishment of integrated visiting healthcare services, community service resources, and policy support to enable these women to utilize various supportive social resources.

Mediated Effects of Self-esteem and Moderated Mediation Effects of Job Stress in the Process of Effect of Ex-prisoners's Job Satisfaction on Occuapational Adaptation (출소자의 직무만족과 직업적응의 관계에서 자존감의 매개효과와 직무스트레스의 조절된 매개효과 검증)

  • Gong, Jung-Sik;Kwon, Joon-Sung
    • The Journal of the Korea Contents Association
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    • v.19 no.12
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    • pp.93-100
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    • 2019
  • this study aims to analyze causality on the effect of job satisfaction on vocational adaptation of ex-prisoners through empirical study and to verify the moderated effect of self-esteem and the Moderated Mediation effect of the job stress. According to the analysis, job satisfaction have a static effect on Vocational Adjustment and the self-esteem have a mediated effect in this process. also, the indirect effects of job satisfaction on vocational adaptation by self-esteem are moderated by job stress. advanced researchs study that job-related emotions affect vocational adaptation and maintenance, but psychological factors affecting vocational adaptation is not dealt with in depth, and what factors actually moderate this process is not explored in detail. also, becausea there are few studies related to the job of ex-prisoner, this study carried out full-fledged exploration and verification of it.

Illness Experience of People with Chronic Hepatitis B in Korea (한국 만성 B형 간염 환자들의 질병 경험)

  • Yi, Myung-Sun;Choi, Eun-Ok;Paik, Seung-Woon;Kim, Keum-Soon;Kwak, Sang-Man;Lee, Hwa-Jin
    • Journal of Korean Academy of Nursing
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    • v.37 no.5
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    • pp.665-675
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    • 2007
  • Purpose: The purpose of this study was to explore the experiences of people with chronic hepatitis B (CHB) in Korea. The specific aim was to identify major problems that people with CHB face and strategies that they are dealing with. Methods: A grounded theory method was utilized. The data were collected by individual in-depth interviews from 12 CHB patients from one of the major hospitals in Korea. Results: After constant comparative analysis, a core category emerged as "illness management with self-reliance and will." Seven major strategies that were identified in dealing with the illness were maintaining receptive and positive attitudes; restraining excessive work and greed; searching for information; controlling illness information; adhering to practices for not spreading the viral disease; abstaining from alcohol and smoking and maintaining healthy eating habits; nd using alternative therapies. The outcomes that result from employing these strategies were identified as burden, depression and helplessness, stress for maintaining compliance, and dispirited interpersonal relationships. Conclusion: The results of this study suggest that most people with CHB in Korea have problems in psychosocial area. Thus health professionals need to provide not only informational support but also emotional one to improve quality of life of the people with CHB.

Factors that Affect Self-esteem among Vietnam War Veterans (베트남전 참전용사의 자아존중감에 영향을 미치는 요인)

  • 이인수
    • Journal of Families and Better Life
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    • v.22 no.1
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    • pp.11-25
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    • 2004
  • This study was conducted to explore the impacts of involvement in the Vietnam War on the self-esteem of the veterans in their later lives. In this study, 14 Korean male Vietnam War veterans from 55 to 63 years old were asked about the impacts of their war experiences on their self-esteem. From the analysis of the in-depth interviews the following conclusions were drawn: First, the veterans perceived that their self-esteem improved with both internal and external impacts of their activities in Vietnam. The internal aspects that improved the veterans' self-esteem were recalling their positive memories of Vietnam War, such as being on duty at a war front for the sake of our country, doing volunteer work for the villagers, and becoming a masculine heroic figure in the family legend. The external aspects were positive attitudes and responses toward their war activities from their family, friends, and neighbors. Second, they also felt persistently frustrated with their recurring memories of involvement in killing human beings, experiences of negative family and social responses, and the side effects of herbicidal cyanide they suffer. In this article, the following suggestions were made. First, standardized images and good-will episodes of the Vietnam War need to be provided by the government, in order to improve public images on the veterans. Second, intensive adjustment programs for the families of older veterans in special needs should be developed in collaboration with various veterans' societies and family counseling institutions, so that the spouses and children can be relieved from tension-laden contacts with the veterans and prevent violent incidents.

A Study on Acculturation of North Korean Defectors in South Korea (북한이탈주민의 한국 내 문화적응)

  • Han, Jin-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.11
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    • pp.5027-5033
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    • 2011
  • The purpose of this study was to analyze a qualitative research on the essential structure of the acculturation of North Korean defectors, who settled in South Korea. The participants in this study were nine North Korean defectors who had resided in the city of D, South Korea, for three years or more after defecting from North Korea. After an in-depth interview, collected data were analyzed by applying Colaizzi's phenomenological method. As a result, their acculturation were classified into three categories : 'heterogeneity coming from different cultures', 'undergoing various sufferings after defection', and 'trying to tide over the difficulties in the actuality'. And 11 clusters of theme were selected. It's basically meant in this study to find out problems North Korean Defectors encountered and their process of overcoming the difficulties in an effort to step up the acculturation of the new settlers and ease their difficulties. And it's suggested that adjustment programs should be provided for them to fit into South Korean society.

Admittance Model-Based Nanodynamic Control of Diamond Turning Machine (어드미턴스 모델을 이용한 다이아몬드 터닝머시인의 초정밀진동제어)

  • Jeong, Sanghwa;Kim, Sangsuk
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.10
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    • pp.154-160
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    • 1996
  • The control of diamond turning is usually achieved through a laser-interferometer feedback of slide position. The limitation of this control scheme is that the feedback signal does not account for additional dynamics of the tool post and the material removal process. If the tool post is rigid and the material removal process is relatively static, then such a non-collocated position feedback control scheme may surfice. However, as the accuracy requirement gets tighter and desired surface cnotours become more complex, the need for a direct tool-tip sensing becomes inevitable. The physical constraints of the machining process prohibit any reasonable implementation of a tool-tip motion measurement. It is proposed that the measured force normal to the face of the workpiece can be filtered through an appropriate admittance transfer function to result in the estimated dapth of cut. This can be compared to the desired depth of cut to generate the adjustment control action in additn to position feedback control. In this work, the design methodology on the admittance model-based control with a conventional controller is presented. The recursive least-squares algorithm with forgetting factor is proposed to identify the parameters and update the cutting process in real time. The normal cutting forces are measured to identify the cutting dynamics in the real diamond turning process using the precision dynamoneter. Based on the parameter estimation of cutting dynamics and the admitance model-based nanodynamic control scheme, simulation results are shown.

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