• 제목/요약/키워드: Multi Agent Simulation

검색결과 147건 처리시간 0.024초

Head and neck extra nodal NHL (HNENL) - Treatment Outcome and Pattern of failure - A Single Institution Experience

  • Giridhar, Prashanth;Mallick, Supriya;Bhasker, Suman;Pathy, Sushmita;Mohanti, Bidhu Kalyan;Biswas, Ahitagni;Sharma, Atul
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권15호
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    • pp.6267-6272
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    • 2015
  • Background: Extra nodal lymphoma (ENL) constitutes about 33 % of all non-Hodgkin's lymphoma. 18-28% develops in the head and neck region. A multimodality treatment with multi-agent chemotherapy (CT) and radiotherapy (RT) is considered optimum. Materials and Methods: We retrieved the treatment charts of patients of HNENL treated in our institute from 2001-2012. The charts were reviewed and the demographic, treatment details and outcome of HNENL patients were retrieved using predesigned pro-forma. Results: We retrieved data of 75consecutive patients HNENL. Median age was 47years (Range: 8-76 years). Of the 75 patients 51 were male and 24 were female. 55patients were evaluable. The patient and tumor characteristics are summarized in Table 1. All patients were staged comprehensively with contrast enhanced computed tomography of head, neck, thorax, abdomen, pelvis and bone marrow aspiration and biopsy 66 patients received a combination multi-agent CT with CHOP being the commonest regimen. 42 patients received 4 or lesser number of cycles of chemotherapy whereas 24received more than 4 cycles chemotherapy. Post radiotherapy, 41 out of 42 patients had a complete response at 3 months. Only 21patients had a complete response after chemotherapy. All patients received radiation (mostly involved field radiation) as a part of the treatment. The median radiation dose was 45 Gray (Range: 36 Gray-50 Gray). The radiation was planned by 2D fluoro simulation based technique in 37cases and by 3 Dimensional conformal radiation therapy (3DCRT) in 36 cases. Two patients were planned by the intensity modulated radiation therapy (IMRT) technique. IMRT was planned for one thyroid and one nasal cavity primary. 5 patients experienced relapse after a median follow up of 19 months. The median survival was not reached. The estimated two and three year survival were 92.9% (95%CI- 68.6- 95.35) and 88% (95%CI- 60.82 - 92.66) respectively. Univariate analysis revealed higher stage and poorer baseline performance status to be significantly associated with worse progression free survival. 5 patients progressed (relapse or primary disease progression) after treatment. Of the 5 patients, two patients were primary orbital NHL, two patients had NHL nasal cavity and one was NHL thyroid. Conclusions: Combined modality treatment in HNENL confers excellent disease control with acceptable side effects.

원격탐사자료를 이용한 공간적 현상의 모형화 및 시뮬레이션 : 자연화재발생의 경우 (Development of Stochastic Model and Simulation for Spatial Process Using Remotely Sensed Data : Fire Arrival Process)

  • 정명희
    • Spatial Information Research
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    • 제6권1호
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    • pp.77-90
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    • 1998
  • 자연적이거나 인위적인 여러 요인의 복합적인 상호작용에 의해 지표는 계속 변화해간다. 자연재해는 생태계의 다양한 군집이 서로 상호작용을 하는데 결정적 영향을 미치는 요소로 이런 변화의 직접적인 원인이 되는 특정 사건의 발생과정이나 공간적 분포에 대한 연구는 환경과 자원관리 측면에서 중요하다. 본 논문에서는 지표변화에 영향을 미치는 자연화재의 경우를 중심으로 공간적 분포를 모형화하는 방법론을 설명하였다. 자연화재는 주로 번개에 의해 발생되어 몇 주에 결쳐 수만 킬로미터의 지역을 태우면서 새롭고 다양한 서식지를 만들어 가는 주된 자연재해중의 하나로 생태계관리차원에서 연구되고 있다. 오스트리아 빅토리아사막을 예로 이곳에서의 자연화재 발생지역을 20년동안의 원격탐사자료(MSS data)로부터 추출하여 이를 바탕으로 자연화재발생에 대한 공간적 모형을 개발하였고 모형에 입각한 시뮬레이션 방법을 논의하였다. 화재발생과정은 불규칙적으로 분포된 공간상의 point pattern에 의해 특징지어질 수 있는데 이의 모형화를 위해서 Nonhomogeneous Planar Poissin Process가 이용되었다.

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근접 정책 최적화 기반의 적 대공 방어 위협하 수리온 에이전트의 최적 기동경로 도출 연구 (Proximal Policy Optimization Reinforcement Learning based Optimal Path Planning Study of Surion Agent against Enemy Air Defense Threats)

  • 김재환;김종환
    • 한국시뮬레이션학회논문지
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    • 제33권2호
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    • pp.37-44
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    • 2024
  • 한국형 헬기 개발사업의 성공적인 결과로 인하여 노후화된 UH-1및 500MD 헬기를 대체하는 수리온(Surion)에 대한 연구가 활발히 진행되고 있다. 특히, 높은 기동성을 보유한 수리온은 미래 전장에서의 병력수송 및 특수작전 등 다양한 임무를 수행할 것으로 예상되며 이를 지원하기 위한 저고도 전술기동 능력이 요구되고 있다. 그러나 수리온 운용시, 대공 위협 요소를 고려한 최적 저고도 전술기동에 대한 연구는 아직까지 미흡한 실정이다. 본 연구는 강화학습 기반의 알고리즘 중에 하나인 Proximal Policy Optimization(PPO) 알고리즘과 적 대공위협을 고려하여 수리온이 작전 목표지역까지 도달하도록 하는 저고도 상에서의 최적화된 기동 경로를 산출하는 방법론을 제안한다. 이를 위해, Unity 환경과 ML-Agents 라이브러리 상에서 실사화된 수리온 모델을 기초로 약 2×107 회의 강화학습을 진행하였고, 제안하는 방법을 적용하여 수리온의 최단시간 및 최소피해를 달성하는 최적 저고도 전술기동 경로를 산출하는 정책을 도출하였다. 그 결과, '최단 시간' 및 '최소 피해'라는 두 가지 기준을 충족하는 최적 경로가 도출되었다. 본 연구의 결과는 수리온 및 수리온 무인체계를 운용하는 다양한 작전에 활용되어 기동계획을 수립할 시 기동성, 작전성공율, 그리고 생존율을 예측하는데 보탬이 되기를 기대한다.

우두머리가 있는 두 생물무리의 가로지르기 동역학 (Crossing Dynamics of Leader-guided Two Flocks)

  • 이상희
    • 한국시뮬레이션학회논문지
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    • 제19권3호
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    • pp.37-43
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    • 2010
  • 우리는 두 생물무리가 서로 가로지르거나 결합하는 현상을 주변에서 흔히 볼 수 있다. 예로, 하천의 물고기 무리가 운동하다 바위나 돌같은 장애물을 만나 두 무리로 나누어졌다가 장애물 뒤에서 다시 하나로 합쳐지는 현상이 있다. 우두머리를 가지는 두 생물 무리가 각도${\theta}$를 가지고 서로 충돌하면서 가로질러 지나갈 때의 동역학을 연구하였다. 두 무리의 각 우두머리 개체는 다른 개체에 의해 영향을 받지 않는다. 이에 비해 무리의 개체들은 우두머리의 운동방향을 쫓아 가도록 시뮬레이션 되었다. 이 두 무리의 가로지르기 동역학을 이해하기 위해서, 무리개체의 평균 단위속도의 합으로 정의되는 질서매개변수${\phi}$를 조사하였다. 두 무리가 서로 만나는 순간, 두 무리의 운동량 균형이 무너지면서 ${\phi}$값이 급격히 올라갔다. 그리고 두 무리가 서로 분리되어질 때, 두 번째로 ${\phi}$값이 피크를 보였다. 무리개체들은 서로 충돌하면서 그들의 우두머리 개체를 쫓아가는데 방해를 받게 되는데 이로 인해 두 번째 피크이후에 불규칙적인 작은 피크들이 관측되었다. 두 피크값, $d_1$ (첫번째) 그리고 $d_2$ (두번째), 은 서로 다른 충돌각도 ${\theta}$에 대해서 동기화 현상을 보였다. 이 시뮬레이션 모델은 생물행동을 연구하거나 다개체 로봇 시스템 개발에 유용하게 사용되어 질수 있다.

Collaboration to Enhance Development and Application of Shiphandling Simulators

  • Shi, Chaojian;Chen, Jinbiao;Xiao, Baojia;Ding, Baocheng
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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    • pp.459-464
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    • 2006
  • It has been well proved that shiphandling simulators are efficient and useful facilities for training and education of cadets and seafarers. Most of the maritime universities and many maritime training institutes all over the world have installed shiphandling simulators, which play important roles in maritime education and training. However, most of the Shiphandling simulators are standalone facilities with diversities on system architectures, layouts and functions. STCW78/95 requires simulators used for simulator-based training shall be suitable for the selected objectives and training tasks. To ensure the shiphandling simulator facilities meet the requirements of STCW convention and other expanded applications, collaborated research and coordination are needed in development and application of shiphandling simulators. Performance standard should be established for shiphandling simulator systems considering the advanced research needs as well as the needs in education, training, and assessment of competence. Standardizing and exchanging shiphandling mathematical models will improve critical performance of the system. Cooperated research on model course and training assessment approaches will enhance the training standard. In addition, the rapid spread of the internet technology has shown a promising future of application of shiphandling simulators through internet. Research has been carried out on internet based integration of multiple shiphandling simulators. A multi-agent based system, including necessary hardware, has been developed. Collaborated operation of the system can be of benefit in filling the gaps of the technical and operational level and methodology between maritime universities, enhancing mutual understanding of the navigation customs and culture background among cadets and seafarers from different countries, facilitating communication and maritime English training, and extending the functions of shiphandling simulators.

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교통 접근성 변동에 따른 도시 토지이용 변화에 관한 연구 (A Study on the Change of Urban Land Use According to the Change of Transportation Accessibility)

  • 원석환;황철수
    • 지적과 국토정보
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    • 제47권1호
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    • pp.127-142
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    • 2017
  • 수도권의 도시화는 서울로의 교통 접근성의 변화에 따라 급속하게 진행되었다. 도시화 과정 속에 교외화, 주택 수의 증가, 도심용지 토지이용 증대 등의 다양한 공간적 변화가 이루어지고 있다. 본 연구의 목적은 2001~2008년 간 경기도 남양주시의 도시화 경관현상을 살펴보고 교통(도로 및 철도) 접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하는데 있다. 상관성 분석 결과를 토대로 멀티 에이전트 시스템(MAS)을 이용하여 교통접근성과 토지이용 에이전트 간 상호작용의 관점에서 시뮬레이션 하였다. 이런 과정을 통하여 교통접근성의 변화로 인한 주변 토지이용 변화를 시공간적으로 예측하고자 한다. 도시화 현황을 살펴보기 위해서 위성영상 자료와 지적도 자료를 이용하여 거시적 미시적 경관 분석을 실시한 후 교통접근성의 변화에 따른 주변 토지이용 변화의 상관성을 분석하기 위해 교통자료와 토지이용 자료를 활용하여 GIS분석 및 통계 분석, 시뮬레이션 분석을 하였다. 본 연구를 통해 신규 도로 및 철도가 생성됨에 따라 주변 500m 이내에서 도심 토지용지로 변경되는 패턴을 확인할 수 있었으며, 향후 도로 및 철도가 생성됨에 따라 발생하는 토지용지 변화 현상을 예측할 수 있는 시스템을 구축하였다. 이를 통해 교통시설 입지 대상지역 선정 시 기초자료로 활용할 수 있는 근거가 될 수 있을 것으로 기대된다.

중학교 "환경" 교과의 교수.학습 및 평가 방법 연구 (A Study on Teaching-Learning and Evaluation Methods of Environmental Studies in the Middle School)

  • 남상준
    • 한국환경교육학회지:환경교육
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    • 제7권1호
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    • pp.1-17
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    • 1994
  • This study was performed to determine appropriate teaching-learning and evaluation methods for Environmental Studies. To promote the relevance of our study to the needs of the schools and concerned educational communities of environmental education, we reviewed related literature, conducted questionnaire surveys, interviewed related teachers and administrator, held meetings with experts, and field-tested our findings. For selecting and developing teaching-learning methods of Environmental Studies, findings of educational research in general are considered. moreover, principles of environmental education, general aim of environmental education, orientations of environmental education, and developmental stages of middle school students in educational psychology were attended. In addition, relevance to the purpose of the Environmental Studies curriculum, appropriateness for value inquiry as well as knowledge inquiry, small group centered class organization, social interaction centered teaching-learning process, regional environmental situation, significance of personal environment, evaluation methods of Environmental Studies, multi- and inter-disciplinary contents of the Environmental Studies textbook, suitability to the evaluation methods of Environmental Studies, and emphasis on the social interaction in teaching-learning process were regarded. It was learned the Environmental Studies can be taught most effectively in via of holding discussion sessions, conducting actual investigation, doing experiment-practice, doing games and plate, role-playing and carrying out simulation activities, and doing inquiry. These teaching-learning methods were field-tested and proved appropriate methods for the subject. For selecting and developing evaluation method of Environmental Studies, such principles and characteristics of Environmental Studies as objective domains stated in the Environmental Studies curriculum, diversity of teaching-learning organization, were appreciated. We categorized nine evaluation methods: the teacher may conduct questionnaire surveys, testings, interviews, non-participatory observations; they may evaluate student's experiment-practice performances, reports preparation ability, ability to establish a research project, the teacher may ask the students to conduct a self-evaluation, or reciprocal evaluation. To maximize the effect of these methods, we further developed an application system. It considered three variables, that is, evaluates, evaluation objectives domains, and evaluation agent, and showed how to choose the most appropriate methods and, when necessary, how to combine uses of different methods depending on these variables. A sample evaluation instrument made on the basis of this application system was developed and tested in the classes. The system proved effective. Pilot applications of the teaching-learning methods and evaluation method were made simultaneously; and the results and their implications are as follows. Discussion program was applied in a lesson dealing with the problems of waste disposal, in which students showed active participation and creative thinking. The evaluation method used in this lesson was a multiple-choice written test for knowledge and skills. It was shown that this evaluation method and device are effective in helping students' revision of the lesson and in stimulating their creative interpretations and responces. Pupils showed great interests in the actual investigation program, and this programme was proved to be effective in enhancing students' participation. However, it was also turned out that there must be pre-arranged plans for the objects, contents and procedures of survey if this program is to effective. In this lesson, non-participatory observation methods were used with a focus on the attitudes of students. A scaled reported in general description rather than in grade. Experiment-practice programme was adopted in a lesson for purifying contaminated water and in this lesson, instruction objectives were properly established, the teaching-learning process was clearly specified and students were highly motivated. On the other hand, however, it was difficult to control the class when some groups of students require more times to complete their experiment, and sometimes different results. As regards to evaluation, performance observation test were used for assessing skills and attitudes. If teachers use well-prepared Likert scale, evaluation of all groups within a reasonablely short period of time will be possible. The most effective and successful programme in therms of students' participation and enjoyment, was the 'ah-nah-bah-dah-market' program, which is kind of game of the flea market. For better organized program of this kind, however, are essential, In this program, students appraise their own attitudes and behavior by responding to a written questionnaire. In addition, students were asked to record any anecdotes relating to self-appraisal of changes on one's own attitudes and behaviours. Even after the lesson, students keep recording those changes on letters to herself. Role-playing and simulation game programme was applied to a case of 'NIMBY', in which students should decide where to located a refuse dumping ground. For this kind of programme to e successful, concepts and words used in the script should be appropriate for students' intellectual levels, and students should by adequately introduced into the objective and the procedures of the lessons. Written questionnaire was used to assess individual students' attitudes after the lesson, but in order to acquire information on the changes of students' attitudes and skills, pre-test may have to be made. Doing inquiry programme, in which advantages in which students actually investigated the environmental influence of the areas where school os located, had advantages in developing students' ability to study the environmental problems and to present the results of their studies. For this programme to be more efficient, areas of investigation should be clearly divided and alloted to each group so that repetition or overlap in areas of study and presentation be avoided, and complementary wok between groups bee enhanced. In this programme, teacher assessed students' knowledge and attitudes on the basis of reports prepared by each group. However, there were found some difficults in assessing students' attitudes and behaviours solely on the grounds of written report. Perhaps, using a scaled checklist assessing students' attitudes while their presentation could help to relieve the difficulties.

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