• Title/Summary/Keyword: Depth of Interaction

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Neutron Generation from a 24 MV Medical Linac (24 MV 의료용 선형가속기의 중성자 발생에 관한 연구)

  • Jeong Dong Hyeok;Kang Jeong Ku;Lee Jeong Ok
    • Progress in Medical Physics
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    • v.16 no.2
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    • pp.97-103
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    • 2005
  • The energy spectra and dose calculations were performed for secondary neutrons from a 24 MV LINAC using MCNPX code (V2, 4, 0). The energy spectra for neutrons and photons emitted from the LINAC head, and absorbed dose to water were calculated in water phantom. The absorbed doses calculated with Monte Carlo were $0.66\~0.35$ mGy/photon Gy at the surface to d=5 cm, and calculated with interaction data was 0.52 mGy/photon Gy at the depth of electron equilibrium in water. We have shown that this work can be applied to dose estimation of neutrons from high energy LINAC through the comparison of our results with other results.

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Music Therapy Students' Experience as a Supervisee in Peer Supervision (음악치료 전공생의 동료 수퍼비전에서 수퍼바이지로서의 경험)

  • Lee, Yeon Mee;Suh, Eun Sil
    • Journal of Music and Human Behavior
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    • v.11 no.2
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    • pp.41-57
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    • 2014
  • The purpose of this study was to analyze music therapy students' experience of peer supervision as supervisee. A total of 17 participants in a university in Seoul, participated two times in structured dyadic peer supervision with a different student. In-depth, semi-structured interviews with the students were conducted and content analysis was used for analyzing the data. The results showed that peer supervision was recognized as an important technique as students experienced an accepting and supportive emotional climate that increased their motivation in terms of their professional growth. However, the students also experienced anxiety and dissatisfaction when they could not get a definitive answer from their peer or their peer could not solve their problem. The structure of peer supervision could help the participants by facilitating the process, providing directions, and promoting interaction between peer. This study is significant that it provides actual content in music therapy students' experiences as a supervisee, and enables students to apply peer supervision to their professional growth.

Development of Urban Inundation Analysis Model Using Dual-Drainage Concept (Dual-Drainage 개념에 의한 도시침수해석모형의 개발)

  • Lee, Chang Hee;Han, Kun Yeun;Noh, Joon Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4B
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    • pp.379-387
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    • 2006
  • An urban inundation model coupling an one-dimensional stormwater model, SWMM(Storm Water Management Model), and a two-dimensional inundation model was developed to simulate inundation caused by the surcharge of storm sewers in urban areas. The limitation of this model which can not simulate the interaction between drainage systems and surcharged flow was resolved by developing Dual-Drainage inundation analysis model which was based upon hydraulic flow routing procedures for surface flow and pipe flow. The Dual-Drainage inundation analysis model can simulate the effect of complex storm drainage system. The developed model was applied to Dorim, catchment. The computed inundated depth and area have good agreement with the observed data during the flood events. The developed model can help the decision support system of flood control authority for redesigning and constructing flood prevention structures and making the potential inundation zone, and establishing flood-mitigation measures.

Numerical investigation on 3D behavior of 2-Arch tunnel (2-Arch 터널의 3차원 거동 특성 - 수치해석 연구)

  • Yoo, Chung-Sik;Kim, Joo-Mi;Kim, Hee-Chul
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.3
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    • pp.255-264
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    • 2009
  • This paper concerns the behavior of 2-Arch tunnel constructed under various conditions. A 2-Arch tunnel section adopted in a subway tunnel construction site is considered in this study. A calibrated 3D finite element model was adopted to conduct parametric studies on a variety of construction scenarios including lagged distance between left and right tunnels, overburden, and geological condition. The results of analyses were examined in terms of crown settlement, shotcrete lining stress, and load on center column in relation to the lagged distance, cover depth, and the ground condition. The results indicate that the shotcrete lining stress and the center pillar load are more influenced by the second tunnel excavation than the tunnel deformation. Also shown is that a greater lagged distance is required to minimize the interaction between two tunnels when the ground condition becomes weaker. Fundamental mechanisms of 2-arch tunnel were also discussed based on the results.

Numerical Simulation of Wave Deformation due to a Submerged Structure with a Second-order VOF Method (2차 정확도 VOF기법을 활용한 수중구조물에 의한 파랑변화 예측)

  • Ha, Tae-Min;Cho, Yong-Sik
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.1
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    • pp.111-117
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    • 2010
  • A three-dimensional numerical model is employed to investigate wave deformation due to a submerged structure. The three-dimensional numerical model solves the spatially averaged Navier-Stokes equations for two-phase flows. The LES(large-eddy-simulation) approach is adopted to model the turbulence effect by using the Smagorinsky SGS(sub-grid scale) closure model. The two-step projection method is employed in the numerical solutions, aided by the Bi-CGSTAB technique to solve the pressure Poisson equation for the filtered pressure field. The second-order accurate VOF(volume-of-fluid) method is used to track the distorted and broken free surface. A simple linear wave is generated on a constant depth and compared with analytical solutions. The model is then applied to study wave deformation due to a submerged structure and the predicted results are compared with available laboratory measurements.

Thermal Structure of the East China Sea Upper Layer Observed by a Satellite Tracked Drifter Experiment (위성추적부이를 이용한 동중국해 상층 수온구조 관측)

  • Lee, Seok;Lie, Heung-Jae;Cho, Cheol-Ho;Song, Kyu-Min;Lee, Jae-Hak
    • Ocean and Polar Research
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    • v.30 no.3
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    • pp.361-372
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    • 2008
  • A satellite tracked drifter experiment was conducted to observe thermal structure and surface circulation in the northeastern East China Sea. For this experiment, four ADOS buoys, assembled with surface float and thermister chain, were deployed on August 2007 in southern Jeju-do, where the Kuroshio Branch Current is separated from the main stream. Thermal structure in the upper layer of the northeastern East China Sea was successfully observed during the following $1{\sim}3$ months. Strong thermo-haline front in a northeast-southwest direction was observed. In the frontal zone, warm and saline Kuroshio origin water intermixes with fresher coastal water and flows toward the Korean Strait. Typhoon Nari, which passed over the East China Sea 20 days after commencement of study, caused distinct signals in the thermal structure and trajectory of buoys. During the typhoon, surface temperature abruptly dropped to about $4^{\circ}C$, while the thermocline formed at $30{\sim}50$ m depth vanished due to strong vertical mixing. Internal inertial oscillation occurred several days after the typhoon. The fortuitous occurrence of typhoon Nari showed that ADOS buoys can provide useful and accurate air-sea interaction data during typhoons.

A Surface Modeling Algorithm by Combination of Internal Vertexes in Spatial Grids for Virtual Conceptual Sketch (공간격자의 내부정점 조합에 의한 가상 개념 스케치용 곡면 모델링 알고리즘)

  • Nam, Sang-Hoon;Kim, Hark-Soo;Chai, Young-Ho
    • Journal of KIISE:Software and Applications
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    • v.36 no.3
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    • pp.217-225
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    • 2009
  • In case of sketching a conceptual model in 3D space, it's not easy for designer to recognize the depth cue accurately and to draw a model correctly in short time. In this paper, multi-strokes based sketch is adopted not only to reduce the error of input point but to substantiate the shape o) the conceptual design effectively. The designer can see the drawing result immediately after stroking some curves. The shape can also be modified by stroking curves repeatedly and be confirmed the modified shape in real time. However, the multi-strokes based sketch needs to manage the great amount of input data. Therefore, the drawing space is divided into the limited spatial cubical grids and the movable infernal vertex in each spatial grid is implemented and used to define the surface by the multi-strokes. We implemented the spatial sketching system which allows the concept designer's intention to 3D model data efficiently.

A Process Analysis on the Experiences of Preliminary Child Care Teachers in Child Care Practice (예비보육교사의 실습 경험에 관한 과정 분석)

  • You, Byoungye;Yang, Sungeun
    • Korean Journal of Childcare and Education
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    • v.9 no.3
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    • pp.95-119
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    • 2013
  • The study uses a qualitative research method for an in-depth study on child care practice for preliminary child care teachers. The study shows firstly that prior to practice, a preliminary child care teacher expects to perform a dual role. The preliminary child care teacher conceives an unequal, vertical relationship with a practice guidance teacher and serves as someone between a teacher and a friend to children, while perceiving the facility head as a mediator and practice colleagues as companions. Secondly, the preliminary child care teacher performed a triple role, while the practice guidance teacher played the role of a preliminary child care teacher. A preliminary child care teacher has mutually supportive interaction with a practice guidance teacher and serves as someone between a teacher and a friend, while acting as an important supporter to the facility head and as an uncomfortable competitor to a practice colleague. Thirdly, when a practice is completed, a preliminary child care teacher feels satisfied and sorry, while emphasizing a balance between theory and practice in a curriculum. The purpose of the current study lies in figuring out the needs for child care practice for a preliminary child care teacher who is the subject in child care practice to suggest improvements for a qualitative enhancement of child care practice.

Radio and Senior Generation: Focused on Radio Program for Senior (라디오와 노인: 라디오 노인 대상 프로그램을 중심으로)

  • Hong, Myungshin
    • 한국노년학
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    • v.30 no.4
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    • pp.1329-1344
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    • 2010
  • This study is intended to find out how production people have been creating senior radio program. For this purpose, the study set up the three research questions and employed in-depth interviews with ten production people: First, production people find out senior radio listeners who have been very royal attendance of the program for a long time. And they examined senior listeners prefer to listen about health care, information about elderly life and singing contest. They have been made para-social interaction with master of ceremonies (MC). Second, unlike other radio program, the senior radio program has concentrated on the radio station's image and public interest rather than financial profit and viewing rate. Normally, it was known that radio program for senior used carried on break of the day. But some program has been broadcasted on prime time in the afternoon. Target audience of senior radio program has been expanded over the forties and the fifties from sixties. Thirdly, in general the role of producer is critically important to produce program. However, MC and scriptwriter are far more experienced and specialized on the field than producer in radio program for senior.

Development of Multi-purpose Marine Wastes Cleaning Systems for the Shallow Waters(PART II : System Development and Performance Evaluation) (천수용 다기능 해양폐기물 수거시스템 개발(PART II : 시스템 구성 및 성능시험))

  • Cho Yong-Jin;Moon Il-Sung;Shin Myung-Soo;Yu Jeong-Seok;Kang Chang-Gu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.5 no.2
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    • pp.62-67
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    • 2002
  • This paper - following 'Development of multi-purpose marine waste cleaning systems for the shallow waters (Part I : preliminary conceptual design)'- describes on the system development and the sea trial performance evaluation(Cho[2003]). The multi-functional seabed waste collecting system and the towing hook system were developed. The maximum working depth of these systems are 15 and 100 meters, respectively(MOMAF[2001]). For the multi-purpose use to collect the marine waste, this system contains floating waste collecting device for the waste on seawater and remained waste collecting device for the waste on seabed, while steel wire cutting system is added for higher efficiency In order to evaluate the system performance, the prototype of multi-functional system was constructed and the sea trial test at shallow water were carried out. As a result, this system operated well with safe and without any interaction so that the developed systems are practicable and applicable.

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