• International Journal of Naval Architecture and Ocean Engineering
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• 제2권2호
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• pp.96-103
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• 2010

A concept of preliminary design for mid-size superyachts is explored. First, the profile of a superyacht is interactively designed with the help of freeform curve functionality and graphical user interface (GUI) based interaction. The hull form is then constructed using major characteristic curves such as design waterline, deck sideline, and sections in addition to the predefined profile curve. After exterior hull modeling is done, the arrangement of significant interior spaces of all decks is carried out. A genetic algorithm is exploited to find a space arrangement by considering space fitness values, space proximity, and stairs connectivity of relevant spaces. A goal of the paper is to offer a step-by-step procedure for superyacht design from scratch or when initial information is not sufficient for complete design. For this purpose, a GUI based superyacht design system is developed. This design approach is expected to help users interactively design mid-size superyachts.

• 한국해양공학회지
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• 제30권1호
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• pp.10-17
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• 2016

This paper reports a simulation-based design method for the optimized arrangement design of buoyancy modules in a marine riser system. A buoyancy module is used for the safe operation and structural stability of the riser. Engineers design buoyancy modules based on experience and experimental data. However, they are difficult to design because of the difficulty of conducting real sea experiments and quantifying the data. Therefore, a simulation-based design method is needed to tackle this problem. In this study, we developed a simulation-based design algorithm using a multi-body dynamic simulation and genetic algorithm to perform optimization arrangement design of a buoyancy module. The design results are discussed in this paper.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.286-289
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• 2001

This paper deals with the procedures of effective mid-term Operation Planning establishment for painting shop in shipbuilding. and develop prototype system. In general, the block painting process consists of two stages such as blasting operation for surface preparation and painting operation for paint application for blocks. Weather condition is a potent Influence on those operations. The procedures consists of four steps, Load analysis, Generate alternative simulation plan. Implementation of Allocation automation module and Compare result of each simulation plan. Explain of each step. as follows, 1.step, Load analysis measure amount of assigned workload and manhour. 2.step, simulation scheme include alterable control variable such as overtime, weather. Auto allocating module carry out feasibility of simulation plan. 3.step, Allocation automation module are composed of three algorithms, as followings: - the block allocation algorithm that determines the number of blocks to be processed each day, - the team allocation algorithm that allocates blocks to worker groups. - the block arrangement algorithm that arrange blocks in blasting and painting cells. Since the block arrangement algorithm is conducted simultaneously with the team allocation algorithm, the total structure of the operating algorithms is considered to have two phases: first, daily load balancing with capacity limit and second, team allocation considering arrangement each day 4 step, Comparing result of each simulation plan. and select best simulation plan.

• Journal of Information Processing Systems
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• 제13권5호
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• pp.1149-1157
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• 2017

The satisfiability problem is always a core problem in artificial intelligence (AI). And how to improve the efficiency of algorithms solving the satisfiability problem is widely concerned. Algorithm IER (Improved Extension Rule) is based on extension rule. The number of atoms and the number of clauses affect the efficiency of the algorithm IER. DPLL rules are helpful to reduce these numbers. Then a complete algorithm CIER based on splitting rule and extension rule is proposed in this paper in order to improve the efficiency. At first, the algorithm CIER (Complete Improved Extension Rule) reduces the scale of a clause set with DPLL rules. Then, the clause set is split into a group of small clause sets. In the end, the satisfiability of the clause set is got from these small clause sets'. A strategy MOAMD (maximum occurrences and maximum difference) for the algorithm CIER is given. With this strategy, a better arrangement of atoms could be got. This arrangement could make the number of small clause sets fewer and the scale of these sets smaller. So, the algorithm CIER will be more efficient.

• 한국항해항만학회지
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• 제27권4호
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• pp.397-402
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• 2003

컨테이너 시큐어링 시스템은 컨테이너 운반선 상갑판에 적재되는 컨테이너의 배치 설계를 위한 시스템이다. 컨테이너의 배치는 각 선급의 가이드라인에 기초하여 설계되어지며, 주어진 배치에 따른 반력들과 변력의 한계값을 제공하고 있다. 컨테이너 설계를 위해서는 컨테이너 구속 교량(lashing bridge)과 수직 구속 장치(vertical lashing) 등을 고려해야 하며, 최대 수직 중량 중심(vertical center of gravity, VCG)과 최대 화물 중량(stack weight)을 갖는 배치안을 제시할 수 있어야 한다. 본 연구에서는 이를 위한 평형방정식을 정립하였으며, 배치안 계산을 위해 등식 제한조건(equality constraint)을 처리할 수 있는 최적화 알고리즘을 적용하여 새로운 컨테이너 시큐어링 시스템을 개발하였다. 개발된 시스템은 컨테이너 배치 설계 시간을 크게 줄여주며, 설계자가 원하는 배치 설계안을 제시해 준다.

• 한국CDE학회논문집
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• 제17권4호
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• pp.262-273
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• 2012

We present a novel GPU algorithm to compute outer cell boundaries of 3D arrangement subdivided by a given set of triangles. An outer cell boundary is defined as a 2-manifold surface consisting of subdivided polygons facing outward. Many geometric problems, such as Minkowski sum, sweep volume, lower/upper envelop, Bool operations, can be reduced to finding outer cell boundaries with specific properties. Computing outer cell boundaries, however, is a very time-consuming job and also is susceptible to numerical errors. To address these problems, we develop an algorithm based on GPU with a robust scheme combining interval arithmetic and multi-level precisions. The proposed algorithm is tested on Minkowski sum of several polygonal models, and shows 5-20 times speedup over an existing algorithm running on CPU.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1821-1826
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• 2003

In this study, we discuss CIP method, which can treat compressible/incompressible problem and multi-phase problem. We can apply this method to the general equations by using CCUP. In this paper, non-staggered grid arrangement and predictor-corrector method are used to enhance later development and the solution accuracy and convergence performance. To validate the numerical algorithm proposed in this paper, the two-dimensional unsteady flow in the driven cavity is simulated. The numerical results of this subject using the present algorithm are compared with other numerical results. As a result, it is prived that the present scheme gives stable and improved solutions, and the results even coarse grid are in good agreement with other result using a fine grid arrangement.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.548-554
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• 1996

A new method to locate modular fixtures using an optimization technique is proposed. The optimal fixture arrangement is derived to minimize the elastic deformation of a workpiece. That is, a fixture arrangement is regarded better if it minimized the elastic deformation of the workpiece while fixing a workpart of course. In this approach, the workpiece is projected into two dimensional domain to simplify the 3-dimensional fixture arrangement problem into 2-dimensional one. Thus the problem is reduced to find the optimal positions of one horizontal clamp and three locators which minimize the total deformation of the workpiece and the design variables are the location of the contact points between the boundary of the workpiece and the 4-fixels. The Genetic Algorithm is used for the optimization by mapping each design variables to a gene of a chromosome. The fitness value is the total strain energy of the workpiece calculated by the fin element analysis.

• 산업공학
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• 제13권2호
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• pp.266-272
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• 2000

This paper deals with a computer-aided product arrangement system in the plant industry. The arrangement schedule may be performed manually. But this is inadaptable to change and difficult to store the results, which eventually requires time consuming and ineffective works. Using computerbased scheduling system, problems mentioned above can be resolved. In the system, the products can be arranged in a workarea with an automatic algorithm as well as manual operation using mouse dragging. In the automatic scheduling algorithm, the position of a product is determined by considering the existing products and material handling costs. Then the scheduled results are stored in DB and can be manipulated at any time.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.483-484
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• 2013