• 대한방사선치료학회지
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• 제26권1호
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• pp.91-98
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• 2014

목 적 : 본 연구에서는 기존의 방사선 치료 기법인 3D-CRT 방법을 기반으로 치료 Energy와 Wedge를 변형 시킨 Hybrid 치료계획을 세워, open rectangular field를 사용한 2D-RT와 현재 가장 많이 시행되고 있는 방사선치료의 형태인 3D-CRT, 그리고 Hyrid paln 의 각각의 치료계획에 따른 선량분포, 선량-체적 히스토그램을 이용하여 산출된 값들을 비교, 분석하여 Hybrid 치료계획의 유용성을 평가하고자 한다. 대상 및 방법 : 본원에서 방사선 치료를 받은 환자 5명을 대상으로 전산화 단층촬영장치(RT-16GE)를 이용해 CT모의치료를 시행하여 영상을 획득하였다. 치료계획실에서는 이미지 관심영역표시는 종양은 CTV으로, 정상장기는 폐, 심장으로 나타냈다. 치료계획은(pinncle-ver 9.2)은 표적에는 충분한 선량을 정상장기에는 선량이 최소화 되도록 치료계획을 세웠다. 결 과 : Homogeneity Index의 선량비교는 2D-RT (open rectangular field): 38.32, TW(conformal wedge field): 32.01 FIF(field in field): 29.22, HYBRID(energy combine, wedge combine): 30.57으로 나타났다. 2D-RT, TW, FIF Hybrid $V_{75_-lung}$은 각각 112.33, 125.14, 121.3, 123.78. $V_{50_-lung}$은 155.43, 159.62, 157.96, 159.06. $V_{25_-lung}$은 199.86, 200.22, 198.65, 200.31. $V_{50_-heart}$는 각각 26.07, 27.1, 26.85, 27.17 $V_{30_-heart}$ 33.71, 34.37, 34.15, 34.65로 나타났다. 결 론 : HYBRID planning에서 표적에는 3D-CRT 에 비해 비교적 뛰어난 선량분포와 유방을 보호함을 보여주지만 폐와 심장에 많은 선량이 조사됨을 치료계획 시 주의해야 하고 앞으로 해결해야 할 과제라 생각된다. HYBRID 으로 Energy를 혼합하여 사용한다면, 타겟에 보다 더 적절한 coverage가 이루어질 수 있을 것으로 보인다. breast 뿐만 아닌 Lung cacner 치료와 같이 불균질한 부위의 치료에 적용한다면 보다 더 최적을 결과를 이루어낼 수 있을 것으로 사료된다.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.428-437
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• 2017

최근 지자체는 난개발과 도시경관 저해, 기존 관련법에 따른 제어한계등의 과제를 해결하기 위해서 각 지역의 특성에 맞는 추진전략을 수립하고 있다. 이를 위해서 사업승인을 위한 별도 기준을 마련하여 경관, 색채, 외관, 층수계획등을 준수하도록 유도하고 있다. 층수계획은 도시경관과 계획밀도 및 외부공간의 질을 결정하는 중요한 인자이고 지구여건에 따라 매우 다른 양상을 나타내는 변화요인이다. 또한 각 지구의 용적률이나 건설호수에 따른 지하주차장 설치비율, 녹지율 등에 따라 매우 다른 경향을 보이는 주요인자이다. 그러나 지자체는 지역특성을 감안하지 않고 일률적으로 저층화 지향의 층수를 규제하여 지구특성을 살리지 못하고 있다. 따라서 본 연구에서는 지구별 사례분석과 가배치안 검토를 통하여 각 지표간 상관관계를 규명하여 다음과 같은 결론에 도달하였다. 첫째, 관련법과 제도에 밀도지표제, 평균층수제, 주거환경성능제 등을 도입해 융통성을 확보하여야 한다. 둘째, 계획초기부터 인접불럭 또는 도시까지 개념을 확대하는 광역적인 계획기법을 개발하여야 한다. 셋째, 지역별 특화전략 수립과 권장형의 규제방안 등 규제완화 조치를 시행하여야 한다.

• 한국경영과학회지
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• 제38권2호
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• pp.43-63
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• 2013

Remanufacturing is a process of recovering end-of-life products into serviceable parts for producing new products. Due to the limited supply of recovery cores to remanufacture, a remanufacturing firm also needs to produce or procure new parts for fulfilling the demand. This paper is targeted for solving the problem of determining the optimal amount of newly produced and remanufacturing parts, which is called production and remanufacturing planning (PRP) problem, under uncertain supply of recovery cores. The new production mitigates the risk of insufficient core supply while it takes more costs than the remanufacturing. The PRP model in this paper also considers disassemble-to-order (DTO) environment, in which multiple kinds of parts are remanufactured from multiple products on order of the parts. Whereas existing studies presents only heuristic solutions for DTO remanufacturing, this paper provides an exact solution for this problem and analytical sensitivity of the involved cost parameters, adopting multi-dimensional newsvendor modeling and stochastic linear programming techniques. The result shows that production and remanufacturing plans for multiple products are mutually dependent, and a change of cost parameters involved in only one part is propagated to all other parts.

• 한국수자원학회논문집
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• 제45권4호
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• pp.383-391
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• 2012

본 연구는 다기준 의사결정 문제에서 항상 발생하는 가중치와 대안들의 평가치에 대한 불확실성을 최소화하기 위해 민감도 분석을 수행하는 절차를 제시하였다. 제기되는 가중치에 대한 불확실성을 극복하기 위해 일반적으로 순위가 뒤바뀔 수 있는 가장 민감한 평가기준의 결정과 대안의 효과 측정자료의 결정이 있다. 본 연구는 유량확보와 수질개선을 위한 수자원 계획수립을 위해가중합계법을 이용한 문제에 두 경우의 민감도분석을 모두수행하였다. 이 과정에서 결정계수와 민감도 계수를 산정하여 이용하였다. 본 연구에서 제시한 민감도 분석 과정은 향후 수자원 계획 수립에 폭넓게 활용될 수 있다.

• 대한예방한의학회지
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• 제16권2호
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• pp.53-65
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• 2012

Objectives : This study aimed to analyze the fundamentals of a Korea-China FTA and suggest strategies for Korean medicine market that correspond with each scenario selected from foreseen circumstances after the conclusion of the FTA through the scenario planning, which is one of management techniques. Methods : Four scenarios have been established by means of key questions : the scope of FTA, health care policies, and the combination of western medicine(WM) and Korean medicine(KM). Each scenario is defined as the Maximized Competitive Market, Neutral Market, General Completive Market, and Conservative Market. This study suggests brand marketing, extending of health insurance coverage, launching local network, and strategy for Korean medicine based health promotion programs. Results and Conclusions : Although Korean medicine could be prompted by the trade policies between countries, related studies are very limited. Therefore, more research is needed to suggest the detailed strategies for change of Korean medicine market through various strategic analysis tools.

• 대한교통학회지
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• 제12권1호
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• pp.25-42
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• 1994

The traffic forecast is one of the most important analysis objects in the urban transportation planning process. The results of traffic forecast are the most widely used informations and give a critical influence on the major decision makings in the transportation planning process. Thus, they should be as much accurate and credible data, and evaluated to determine whether they are enough reliable to directly use in the planning process. However, the evaluation process is usually overlooked or abbreviated with a few exceptions according to the size and character of the project. Even though a planner or engineer tries to evaluate the assignment results, he/she is usually faced with certain difficulties since there are no established criteria and methods for the accuracy evaluation. Accordingly, the main purpose of this research placed on establishing the criteria and methods for the accuracy evaluation of the assignment results. The secondary purpose was to evaluate which assignment technique produces the most accurate assignment results by applying the established evaluation criteria and methods to an actual network. The research found that the proposed evaluation methods well operated in testing the accuracy of assignment results with few limits on application. Also, the incremental assignment was found to provide the best assignment results of existing assignment techniques (Stochastic, Iterative, Incremental, Equilibrium assignment) for the Seoul city network applied.

• 한국경영과학회지
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• 제26권4호
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• pp.133-141
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• 2001

Rapid development in computer and network technology these days has created in environment in which decisions for manufacturing companies can be made in a much broader perspective. Especially, better decisions on production and distribution planning(PDP) problems can be made laking advantage of real time information from all the parties concerned. However, since the PDP problem-a core part of the supply chain management- is known to be the so-called NP-hard problem, so heuristic methods are dominantly used to find out solutions in a reasonable time. As one of those heuristic techniques, many previous studios considered genetic a1gorithms. A standard genetic a1gorithm applies rules of reproduction, gene crossover, and mutation to the pseudo-organisms so the organisms can pass along beneficial and survival-enhancing trails to a new generation. When it comes to representing a chromosome on the problem, it is hard to guarantee an evolution of solutions through classic a1gorithm operations alone, for there exists a strong epitasis among genes. To resolve this problem, we propose a hybrid genetic a1gorithm based on Silver-Meal heuristic. Using IMS-TB(Intelligent Manufacturing System Test-bed) problem sets. the good performance of the proposed a1gorithm is demonstrated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2237-2242
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• 2005

The original RRT is iteratively expanded by applying control inputs that drive the system slightly toward randomly-selected states, as opposed to requiring point-to-point convergence, as in the probabilistic roadmap approach. It is generally known that the performance of RRTs can be improved depending on the selection of the metrics in choosing the nearest vertex and bias techniques in choosing random states. We designed a path planning algorithm based on the RRT method for a remote-controlled mobile robot. First, we considered a bias technique that is goal-biased Gaussian random distribution along the command directions. Secondly, we selected the metric based on a weighted Euclidean distance of random states and a weighted distance from the goal region. It can save the effort to explore the unnecessary regions and help the mobile robot to find a feasible trajectory as fast as possible. Finally, the constraints of the actuator should be considered to apply the algorithm to physical mobile robots, so we select control inputs distributed with commanded inputs and constrained by the maximum rate of input change instead of random inputs. Simulation results demonstrate that the proposed algorithm is significantly more efficient for planning than a basic RRT planner. It reduces the computational time needed to find a feasible trajectory and can be practically implemented in a remote-controlled mobile robot.

• 농촌계획
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• 제10권3호
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• pp.41-51
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• 2004

This study aims to develop a potential evaluation method for urban spatial expansion using remote sensing (RS) and geographic information system (GIS). A multi-criteria evaluation method with several criteria and their weighting values was introduced to evaluate the score and quantification of the potential surface around the existing cities. The six criteria with one geographic factor, slope, and five accessibility factors, time distance from center of the city, national road, interchange of expressway, a big city, and station, were defined for the potential. RS techniques were applied for classification of the actual urban expansion maps between two periods, and GIS functions were used for score of accessibility criteria with a distance decay function from geographic, road and several point maps, which was developed in this study. The new methodology was applied to a test area, Suwon, between 1986 and 1996. In order to optimize the six weighting values, this study made new findings to search the optimal combination of the weighting values from new methodology, weighted scenario method for intensity order (WSM), combined with intensity order and AHP method, including a trial and error method for sensitivity analysis to make the intensity order. The optimal combination of the weighting values by the new method generated the optimal potential surface, considering spatial trend of urban expansion in the test area.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2005년도 제30회 춘계학술대회
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• pp.47-50
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• 2005

The aim of radiosurgery cures a patient to deliver the lower dose at the normal organ and the higher dose at the tumor. Therefore accuracy of the dose is required to gain effect of radiosurgery in surgical planning. In this paper, we developed the methods of target approximation for a fast treatment planning. Nominally, the stereotactic radiosurgery(SRS) using Linac and Gamma knife produces spherical dose distribution through circular collimators using multiple arcs and 201 holes on semi-spherical helmet by $^{60}Co$. We developed an automatic radiosurgical plan about spherical packing arrangement. To automatically plan the SRS, new planning methods based on cylinder and cube structure for target shaping was developed. This approach using heuristic and stochastic algorithm is a useful radiosurgical plan without restrictions in the various tumor shapes and the different modalities.