• Title/Summary/Keyword: Erection Process

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Bay and Machine Selection for the Parts Fabrication of Ship Hull Construction (조선 선각가공공정에서 부재가공을 위한 Bay 및 가공기계의 선택)

  • Park, Chang-Kyu;Seo, Yoon-Ho
    • IE interfaces
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    • v.12 no.3
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    • pp.395-400
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    • 1999
  • Shipbuilding process is composed of hull construction, in which the structural body of a ship is formed, and outfitting, in which all the non-structural parts such as pipes, derricks, engines, machinery, electrical cable, etc. are manufactured, added and assembled. Hull construction can be classified into parts fabrication, block assembly and hull erection. Among them, the parts fabrication is the first manufacturing stage that produces components or zones needed for block assembly and hull construction. More specifically, the parts fabrication is performed through machining processes including marking, cutting, pressing, and/or forming. When material is entering into the parts fabrication stage, it is important for achieving the total efficiency of production to select one of production division, so-called 'bay,' as well as machine tools on which the part is fabricated. In this paper, given production quantities of parts in the fabrication stage, the problem is to optimally select machine tools and production division, such that the total flow-time is minimized as well as the workload among machines is balanced. Specifically, three mathematical models for flow-time minimization, load balance, and simultaneously considering both objectives, and a numerical example are analyzed and presented.

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The Weld Strength and Design Tables for the Unstiffened Seated Connections (비보강받침접합의 용접강도와 설계도표)

  • Choi, Sun-Kyu;Yoo, Jung-Han;Lee, Kang-Min;Park, Jai-Woo
    • Journal of Korean Society of Steel Construction
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    • v.24 no.2
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    • pp.199-206
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    • 2012
  • Unstiffened seated connections (USC) ensure easy installation and safety during erection, thereby making the process more economical. USCs consist of a seat angle for carrying the beam's reactions and a top angle to provide beam stability. These angles are bolted or welded to the beam and supporting member. This paper sought to propose a design table for the weld strength of such connections obtained from the elastic vector method (EVM) and the instantaneous center-of-rotation method (ICM) in terms of calculating the eccentricity. Also, the proposed design table is compared with both AISC and KBC specifications.

A Study on Actual Condition of the Noise in a Factory (일 제조업체의 작업장 소음실태에 관한 연구)

  • Shin Soo Ok
    • Journal of Korean Public Health Nursing
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    • v.9 no.2
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    • pp.43-51
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    • 1995
  • Many poeple has been engaged in industry is aware of the dangers from exposure to high intensity nose levels. The exposure to high intensity noise is encountered in a large number of situations. Laws governing the safety and health of employed people being to create a suitable working environment and eliminate unsafety practices and processes. Work areas should be designed and laid out so that they are satisfactory both from the environmental and safety points of view. In this connection safety also implies that noise is kept at a level which is not likety to cause hearing damage. This study was performed to measure the noise of press and assembly process in an automobile factory. and suggested the method of noise control. Consequently the effect ways of reducing level in working environment are as follows; 1. Changes to machines which would reduce noise generation. 2. Alteration of equipment to avoid impact in machinery and handing materials. 3. Enclosure of noisy machines or machine parts. 4. Mounting of attenuators on gas and air outlets as well as ventilation ducts. 5. Erection of sound absorbing screens. linings. and baffles in work areas. 6. The personal ear protectors can be chosen to protect the workers.

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Simulation Based Production Using 3-D CAD in Shipbuilding

  • Okumoto, Yasuhisa;Hiyoku, Kentaro;Uesugi, Noritaka
    • International Journal of CAD/CAM
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    • v.6 no.1
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    • pp.3-8
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    • 2006
  • The application of three-dimensional (3-D) CAD has been popularized for design and production and digital manufacturing has been spreading in many industrial fields. By simulation of the production process using 3-D digital models, which are the core of CIM (Computer Integrated Manufacturing) system, the efficiency and safety of production are improved at each stage of work, and optimization of manufacturing can be achieved. This paper firstly describes the concept of "simulation based production" in shipbuilding and also digital manufacturing; the 3-D CAD system is indispensable for effective simulation because ship structure is three dimensionally complex. By simulation, "computer optimized manufacturing" can be possible. The most effective fields of simulation in shipbuilding are in jobs where many parties have to cooperate, while existing two-dimensional drawings are hardly observed the whole structures due to interference between structures or equipment of complex shape. In this paper some examples of the successful application in IHIMU (IHI Marine United Inc.) are shown: assembly of a pipe unit, erection of a complex hull block, carriage of equipment, installation of a propeller, and access in an engine room.

A Study on the Erection of the Palaces during the Reign of Kwang Hae Kun (광해군(光海君) 대(代)의 궁궐(宮闕) 영건(營建)에 관한 연구)

  • Hong, Seok-Joo;Park, Eon-Kon
    • Journal of architectural history
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    • v.8 no.4 s.21
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    • pp.25-38
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    • 1999
  • After Japanese Invasion of Korea in 1592 was over and the situation was coped with, Chang-Kyoung Palace and Chang-Duk Palace were rebult, and In-Kyung Palace and Kyung-Duk Palace were built during the reign of Kwang Hae Kun. Many utilitarians were engaged with the construction as a manager, and they devoted themselves to improve technology. As a result, craftsmen were treated so valuable, compared to the past, that they were consulted about the technical problems under construction, the process of making an estimate, and the management of construction materials. Moreover, famous craftsmen obtained the government service. And there were various attempts on organizing and compensating workmen in order to manage them efficiently. In addition, the know-how of manufacturing a blue tile, which had been failed to succeed due to the war, was revived, and manufacturing a yellow tile, which had not been used, was studied by utilitarians. Finally, There were many kind of technical attempts and development under the construction of palaces, which gave utilitarians a chance to express their ideas, expected practical science, and assembled craftsmen who had scattered due to the war, during the reign of Kwang Hae Kun

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A System for Thermal Distortion Analysis of Hull Structures by Solar Radiation (선체의 태양복사 열변형 해석을 위한 전처리시스템)

  • Ha, Yunsok;Lee, Donghoon
    • Journal of the Society of Naval Architects of Korea
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    • v.53 no.4
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    • pp.275-281
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    • 2016
  • One of the most important things for quality to meet ship-production schedule is an accuracy control. A ship is assembled by welding through whole production process, so it is important that loss by correction will not happen as much as possible by using some engineering skills like reverse design, reverse setting and margin for thermal shrinkage. These efforts are a quite effective in fabrication stages, but not in erection stages. If a ship block which consists of common steel is exposed to directional solar radiation, its dimensional accuracy will change high as time by its thermal expansion coefficient. Therefore, the measuring work would be often done at dawn or evening even with having a very accurate device. In this study, an FE analysis method is developed to solve this problem. It can change measured data affected by solar thermal distortion to ones not, even though ship-block is measured at an arbitrary time. It will use the time when measuring, the direction of block and the weather record by satellites. It is confirmed by a comparison between measured data of a ship-block and the result by suggested analysis method. Furthermore, a pre-processing system is also developed for fast application of the suggested analysis method.

A Study on the Practical Suggestions in the Contract for the Turnkey Supply of an Industrial Plant - Focused on the Commentary of ICC Model Contract - (턴키방식 플랜트계약의 실무상 유의점에 관한 연구 - ICC 표본 계약서의 해설을 중심으로 -)

  • Oh, Won-Suk;Lee, Ki-Ok
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.53
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    • pp.3-29
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    • 2012
  • This article examines the Practical Suggestions in the Contract for the Turnkey Supply of an Industrial Plant based on a study focused on the commentary of "ICC Model Contract" clause which is encouraged by ICC. Especially practical issues are inquired into on business and legal perspective as follows. First, in regard to supply of technical documentation, equipment and spare parts, it is important to supplier and purchaser to agree on obtaining technical documents necessary for installing and operating plant, and also components necessary for it's maintenance. Second, it is about erection, testing, taking over and training chapter. Both parties need to agree about the process of the arrival of equipments and assembly conducted by the supplier and following examination and also training purchaser to operate it Third, when it comes to price, payment conditions, bank guarantees, parties are to make decision on the pricing, payment conditions and currency of contract-payment. Lastly, it is necessary to reach an agreement of the issue of whether it is to be defined as delay or non-performance of the contract and also it's consequences about rights and obligation.

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A Case Report of Hypospadias Repaired by Radial Forearm Free Flap (요측전완유리피판을 이용한 요도하열의 교정 1례 보고)

  • Park, Sung Ho;Chung, Chul Hoon;Lee, Jong wook
    • Archives of Plastic Surgery
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    • v.36 no.2
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    • pp.225-228
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    • 2009
  • Purpose: Urethral reconstruction following failed hypospadias repair is difficult because of a severe shortage of the skin on ventral surface of the penis. We experienced a successful reconstruction of a failed hypospadias repair using the radial forearm free flap. So we present our case. Methods: A 16 - year - old boy had a proximal shaft hypospadias and had been taken a transverse preputial island flap but it completely broke down. There was no spare skin on the shaft of the penis. So we reconstructed a neo - urethra and the ventral skin of the penis with the radial forearm free flap. Results: Postoperatively he made relatively good process. The urethral catheter was maintained for 10 days and self - voiding was started. The suprapubic catheter was removed at the postoperative 30th day after control of cystitis. The postoperative appearance of the penis is acceptable and a straight erection is achieved. Conclusion: In the scarred penis with hypospadias, the radial forearm free flap transfer is a reliable reconstructive method for the neo - urethra and the ventral skin of the penis.

Development of Distortion Analysis Method for Multi-pass Butt-welding Based on Shell Element (다층 맞대기용접의 쉘 요소 기반 변형해석법 개발)

  • Ha, Yun-Sok;Yang, Jin-Hyuk
    • Journal of Welding and Joining
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    • v.28 no.1
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    • pp.54-59
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    • 2010
  • Ship Blocks are assembled by welding, and among them, welding between large blocks (Pre-erection stage) is used as feature of butt. In this process, local material has a experience of thermal cycle and become finally shrunk. As for inconsistency of shrunk weldments and adjacent regions, ship structure would be deformed locally and globally. Thermal distortion analyses are done for control of these processes, and methodologies capable of ship block size among them are using 2-D shell element in FEM. A shell element takes charge of plate, so it has its thickness which is important for angular distortion by welding. By the way, a butt-welding consists normally of several passes, and weldment thickness are different at each pass. If a calculated final one-time welding shrinkage is acting on the shell element whose thickness is same as it of plate, then deformation value must be underestimated. This research developed a methodology that total deformation after multi-pass welding can be analyzed by one time at shell element having original thickness of its plate. We use the SDB thermal distortion analysis method and verified by several experiment. The both experimental and analysis results showed good agreements.

Decision Supporting Methodology and System Based on Theory of Constraints for Optimal Product Portfolio Strategy in Shipbuilding Industry (제약이론을 기반으로 한 최적제품조합 의사결정 지원 방법론 및 시스템)

  • Kim, In-Il;Han, Seong-Hwan;Kwon, Min-Chull
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.3
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    • pp.362-371
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    • 2009
  • Shipbuilding is a typical 'build to order' industry. It has a business model that generates revenues from building various ships and offshore products in accordance with owner's requirements at each production stage. Under uncertainty in shipping market, it is very essential for the shipbuilder to prepare the fast and competitive decision for product portfolio strategy in order to maximize contribution margin by exploiting production facilities and constraints. In this study, we introduce the unique decision supporting methodology for the optimal product portfolio sets based on Theory of Constraints(TOC). This methodology is established by adopting the concept of Drum Buffer Rope(DBR) in constraints planning and Throughput Accounting (TA) in management accounting of TOC. In addition, Decision Supporting System(DSS) is implemented. This DSS system provides a throughput estimator with reflecting the cost structure of shipbuilding industry and a resource simulator built on heuristic algorithms to operate major constraint-resources in shipyard such as dock, quay and pre-erection area etc. Several examples are presented to show that the proposed methodology and system can effectively support the strategic decision-making process of a global shipbuilding company.