• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.35-39
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• 2004

In a shipyard, there exist various critical decision making components pertaining to various production hindrances. The most prominent one is best-fit spatial arrangement for the minimal spatial occupancy with better pick-ability for the erection of the ship in the dock. During the present research, a concept have been conceived to evade the gap between the identification oj inter-relationships among a set of blocks to be included on a pre-erection area, and a detailed graphical layout of their positions, is called an Optimal Block Relationship Diagram A research has been performed on generation of optimal (or near Optimal) that is, with minimal scrap area. An effort has been made in the generation of optimal (or near-optimal) Optimal Block Relationship Diagram with the Goldberg's Genetic Algorithms with a representation and a set of operators are 'trained' specifically for this application. The expected result to date predicts very good solutions to test problems involving innumerable different blocks to place. The suggested algorithm could accept input from an erection sequence generator program which assists the user in defining the nature and strength of the relationships among blocks, and could produce input suitable for use in a detailed layout stage.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.559-563
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• 1996

선박 건조는 선체를 수십에서 많게는 이백여개에 블럭으로 분활하여 각 블럭에 해당하는 원자재를 처리 가공한 후 소조립, 중조립, 그리고 대조립의 과정을 거쳐 블럭으로 완성하여 이들 블럭을 정해진 순서에 맞추어 탑재하는 과정을 거치면서 기타 공정을 완료하여 마지막으로 진수에 이르게 된다. 본 연구에서는 선박 건조 과정에서 탑재 공정 계획을 위한 블럭의 접속 관계를 체계적으로 확립하여 탑재 순서를 생성하는 방법론을 제시하고 이러한 방법론을 바탕으로 초기 탑재 네트워크을 생성 방안을 제시한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.265-268
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• 2008

본 논문에서는 새로운 교량 형식인 U-Channel Bridge(UCB)의 시공단계를 고려하여 그 거동 및 슬래브의 설계방법에 대한 연구를 수행하였다. UCB는 각각의 세그먼트를 공장에서 제작하여 현장에서 조립하여 시공하므로 각 시공단계별로 지지 조건에 변화가 발생한다. UCB의 시공단계를 지지 조건이 변화하는 제작, 운반, 가설빔 거치, 완공의 네 단계로 구분하여 각 단계마다 프레임 요소와 판 요소를 적용하여 적합한 구조해석 모델을 제시하였으며, 구조해석을 수행하고 그 결과를 검토하였다. 검토 결과 슬래브의 해석은 네 단계를 모두 고려하여 수행되어야 하는 것으로 나타났으며 구성된 모델을 적용하여 타당한 슬래브의 설계방법을 제안하였다.

• 한국공간구조학회논문집
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• 제14권2호
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• pp.69-78
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• 2014

The purpose of this study is to increase applicability of high strength steel, HSA800 to the structure. Selected study of structure is to consider high strength steel, and following parts, 1) Tensile member with no consider of buckling, 2) Truss existing both tension and compression members with small slenderness ratio. This studied structure is included tension column hang on to the upper bridge truss. The structure element quantity with apply HSA800 instead of SM570 is reduced about 38.9% of tension column and 29.7% of bridge truss. In addition, the number of element's division is reduced about two sections due to reduction of self weight that the crane is able to lift up. This improves to reduce erection sequence and construction period which can save about a month. All connections are reviewed as welding and bolt. Also, the cost of welding is reduced about 41.3% due to apply HSA800. In conclusion, applying HSA800 to the hanging structure aggressively can secure economic and constructability.

• 대한산업공학회지
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• 제41권1호
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• pp.1-9
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• 2015

In shipbuling processes, a quay wall is a major resource for additional operations after an erection operation at dock. A quay wall is becoming a new bottleneck instead of docks, while ship types with long operation time at quay wall are increasing recently. We developed a quay wall scheduling algorithm for the quayside operations of ships in this paper. The objective function is to minimize the sum of not assigned days of ships which have to be assigned to any quay wall under limited numbers of quay walls. The scheduling algorithm is based on an assignment method to assign each ship to a quay wall among its alternative quay walls at the time of launching or moving to another quay wall. The scheduling algorithm is also using Tabu Search algorithm to optimize assignment sequence of ships. The experiment shows that the algorithms in this paper are effective to make schedule of the quayside operations of ships.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권1호
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• pp.83-101
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• 2016

This paper suggests an event-based scenario manager capable of creating and editing a scenario for shipbuilding process simulation based on multibody dynamics. To configure various situation in shipyards and easily connect with multibody dynamics, the proposed method has two main concepts: an Actor and an Action List. The Actor represents the anatomic unit of action in the multibody dynamics and can be connected to a specific component of the dynamics kernel such as the body and joint. The user can make a scenario up by combining the actors. The Action List contains information for arranging and executing the actors. Since the shipbuilding process is a kind of event-based sequence, all simulation models were configured using Discrete EVent System Specification (DEVS) formalism. The proposed method was applied to simulations of various operations in shipyards such as lifting and erection of a block and heavy load lifting operation using multiple cranes.

• 한국CDE학회논문집
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• 제17권1호
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• pp.17-25
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• 2012

Recently, requests for accurate process planning using simulation have been increasing in many engineering fields including the shipbuilding industry, and many application systems for simulation have been developed. It is difficult, however, for a user to reuse the developed systems, because simulation models in the system are defined by its own method. In addition, the simulation model should be modified whenever a simulation sequence, which is called simulation scenario, is changed. Therefore, in this study, an elementary simulation object is proposed to modularize a simulation model. And the management scheme of simulation scenario is proposed to manage the scenario outside of the simulation models. Also, a simulation template is proposed to increase the development efficiency. To verify the efficiency of the proposed methods, application examples for shipbuilding process planning are implemented.

• Journal of Construction Engineering and Project Management
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• 제7권1호
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• pp.37-49
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• 2017

The Jinshanling section of the Great Wall of China is a series of fortifications in northern China that was constructed for strategic military defenses. This section was first built in the beginning of the Ming Dynasty in AD 1368 and then underwent major construction, reconstruction and renovation during the late Ming Dynasty, approximately in AD 1569. The Jinshanling section is 10.5 km long, a very short section compared with the entire 21,200 km wall. The wall section is located in Luanping County, Hebei province, China. This research paper focuses on the construction methods and materials of the wall and the towers in the area. The research methodology includes site visits, knowledge acquisition of experts and 3D graphic modeling. This study reveals that the materials selected for the structure include rubbles and rammed earth, bricks, stones, timber, and mortar. The erection sequence of the wall and the towers was a bottom-up fashion using various ancient construction techniques, such as the fire-setting rock blasting techniques and the surveying techniques from the Sea Island Mathematical Manual.

• Steel and Composite Structures
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• 제22권3호
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• pp.647-662
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• 2016

This study aims to monitor the variation of modal frequencies of steel buildings during their construction sequence. In this respect, construction of a steel building is followed by vibration based measurements. The monitored building is a three-story educational building within a building group whose structural system consists of steel moment resisting steel frames and eccentric braces. Five different acceleration measurements in two perpendicular directions are taken on five different construction stages, starting from the erection of the columns and beams ending with the completion of the construction. The recorded measurements are transferred into frequency domain and the dominant frequencies for each case have been determined. The change in the dominant frequencies is evaluated with the existing construction stages and performed constructional works between the stages. The last measurement, performed on the building in service, revealed the first two dominant frequencies as mutual in X and Y direction, showing that these dynamic modes are torsional modes. This result is investigated by numerical analysis performed with finite element model of the building constructed for design purpose. Lower frequencies and different mode shapes are determined from numerical analysis. The reason of lower frequencies is discussed and the vibration survey is extended to determine the effects of an adjacent building. The results showed that the building is in strong relation with an adjoining building in spite of a designed construction joint.

• 대한건축학회논문집:구조계
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• 제35권7호
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• pp.147-156
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• 2019

The purpose of this study is to consider structural issues and analyze construction sequences when constructing hanging floors supported by Mega truss. Since suspended structures were supported by the Mega truss, vertical load on suspended structures was needed to transfer from low to high. Deflection management of structures was the primary point under construction. The results of this study were as follows; The steel structures, which has relatively lighter self-weight, were constructed upwards after the base floor steel truss erection. Concrete Placing, which has relatively heavier self-weight, were performed in two phases to minimize structure's deflection. Slab was placed downwards from the top floor to lower floor whereas column was places upwards. Deflection measurements were carried out at every construction sequences.