• Title/Summary/Keyword: Finishing Work Process

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Investigation of Thermo-mechanical Behavior of Work Roll and Roll Life in Hot Strip Rolling

  • C.G.Sun;Yun, C.S.;Chung, J.S.;Hwang, S.M.
    • Transactions of Materials Processing
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    • v.6 no.2
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    • pp.161-175
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    • 1997
  • The effects of various process paramenters on the detailed aspects of the thermo-mechanical behavior of work roll and on the roll life are investigated via a series of process simulation, using a mathematical model presented previously. The process conditions are discussed that are favorable or optimal in terms of reducing roll wear in the front finishing stands.

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Study on the Defects of Finishing Works of Apartment Houses during Warranty Liability Period and its Correlation (공동주택 마감공사의 하자보수기간 현황 및 연관성 연구)

  • Lee, Ung-Kyun;Seo, Deok-Seok
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.4
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    • pp.385-391
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    • 2017
  • The warranty liability period for defects in apartment buildings by work type is not based on scientific analysis, making the appropriateness of the term a culprit behind the lawsuits. Therefore, this research aims to evaluate the appropriateness of the warranty liability term of apartment buildings by identifying the current status of defects, in particular, caused by finishing works. That is because the number of defects, caused during the finishing works, accounted for the largest portion of the total defect cases of apartment buildings reported to the Apartment Defect Dispute Mediation Committee under the Ministry of Land, Infrastructure, and Transport of Korea between 2010 and 2011. The result from analyzing claims for defect repairs of the finishing works showed that most cases by work type continued to be made after two years, and only about 60% were charged within the warranty period. And, defects by work type have correlation, which needs to be considered for a better construction technique. Considering a low correlation between the possibility of defects and the construction performance rankings, which are highly relevant to the apartment preference. It is believed that there needs to be a qualification process for agencies that actually performs finishing works.

Automatic Tool Selection and Path Generation for NC Rough Cutting of Sculptured Surface (자유곡면의 NC 황삭가공을 위한 자동 공구 선정과 경로 생성)

  • Hong, Sung Eui;Lee, Kun woo
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.6
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    • pp.28-41
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    • 1994
  • An efficient algorithm is proposed to select the proper tools and generate their paths for NC rough cutting of dies and molds with sculptured surfaces. Even though a milling process consists of roughing, semi-finishing, and finishing, most material is removed by a rough cutting process. Therfore it can be said that the rough cutting process occupy an important portion of the NC milling process, and accordingly, an efficient rough cutting method contributes to an efficient milling process. In order work, the following basic assumption is accepted for the efficient machining. That is, to machine a region bounded by a profile, larger tools should be used in the far inside and the region adjacent to relatively simple portion of the boundary while smaller tools are used in the regions adjacent to the relatively complex protion. Thus the tools are selected based on the complexity of the boundary profile adjacent to the region to be machined. An index called cutting path ratio is proposed in this work as a measure of the relative complexity of the profile with respect to a tool diameter. Once the tools are selected, their tool paths are calculated starting from the largest to the smallest tool.

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A Study on the Turning System for Processing a Large Ship Propeller (대형 선박 프로펠러 가공 공정용 터닝 시스템에 관한 연구)

  • Do-Hun Chin
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.5
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    • pp.825-831
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    • 2023
  • The propellers used for big ships have a large diameter and are very heavy. In order to apply a precise and safe work process to them, it is necessary to use an exclusive turning system. For this reason, various techniques are applied to produce them. However, workers' convenience and safety are not taken into consideration enough at production sites. Conventionally, these propellers are designed to be separated as their turning system is loaded and rotated by empty weight. Therefore, it is necessary to replace such a design. This study tries to find the weaknesses of the design and structure of a conventional propeller turning system for large ships, to verify structure integrity of a structure in structural analysis, and to devise a plan for designing a new type of turning system. In the basic concept design and structural analysis for the turning system used in the propeller finishing process for large ships, this study drew the following conclusions. It was possible to develop the work process of the turning system for the propeller finishing process used for large ships, to obtain the dimensions for exterior design through a basic design. Structural analysis was conducted to find the structure integrity of the turning system. As a result, in the rail installed to transfer a gantry, the maximum stress was about 45MPa, about 5.5 times lower than the yield strength 250MPa. Therefore, the turning system was judged to be safe structurally.

The Improvement Plan of Design Process by Case Study of Steel Structural Work (철골공사 현장조사를 통한 설계프로세스 개선방안)

  • 방성원;오승준;김진호;임남기
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.121-126
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    • 2003
  • Steel frame construction is divided into subsidiary materials with column, beam, girder and bracing. After these are processed in factory for using installing in construction field. These prefabricated furniture is very important in accordance with design drawing about processing and prefabricating. In the case of design process using information transmission in blueprint, omission of material number, processing measure and finishing material, or discordance of each structure drawing and selecting incongruent structural material generated an error in the process of design. These error caused delaying tine and increasing cost and increasing safety accident in the steel-structure work operating process. therefore, design process should consider problem of operating process.

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The Improvement Plan of Design Process by Case Study of Steel Structural Work (현장조사를 통한 철골공사 설계프로세스 개선방안)

  • Bang, Sung-Won;Kim, Jin-Ho;Lim, Nam-Gi
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.2
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    • pp.111-118
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    • 2003
  • Steel frame construction is divided into subsidiary materials with column, beam, girder and bracing. After these are processed in factory for using installing in construction field. These prefabricated furniture is very important in accordance with design drawing about processing and prefabricating. In the case of design process using information transmission in blueprint, omission of material number, processing measure and finishing material, or discordance of each structure drawing and selecting incongruent structural material generated an error in the process of design. These error caused delaying time and increasing cost and increasing safety accident in the steel-structure work operating process. therefore, design process should consider problem of operating process.

Safety Management Information System in Plants Construction Work (플랜트 건설공사의 안전관리 정보시스템 개발)

  • Park, Jong-Keun
    • Journal of the Korea Safety Management & Science
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    • v.14 no.4
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    • pp.23-29
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    • 2012
  • There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as appurtenant works, temporary works, structural works, equipment work, finishing work and etc based on accident examples and investigation on actual condition in plants construction work. In addition, the safety management system was developed to perform risk assessment of plants construction and use it for effective safety training for labor.

A Study on Analysis and Improvement of the Process of Furniture Work for High-rise Residential Building (초고층주거건축의 가구공사 프로세스 분석 및 개선방안에 관한 연구)

  • Kim Hyun-Woo;Song Young-Woong;Choi Yoon-Ki
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.446-449
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    • 2003
  • Recently, large residental buildings including high-rise apartment and a multi-business and commercial-residential building are appearing in the form of Korean construction work. According to this large-size trend a tenn and cost of construction works was largely increased. Therefore, studies of techniques construction management for successful project are lively being progressed. This study introduced Just-In-Time form and Lean Construction concept in order to establish management system of a house construction work taking up much portion on aspects of work scale and materials transportation in finishing works of high-rise residental building architecture. The process of house construction works will be analyzed with these two principles for productivity improvement and then the improvement plan will be suggested. This analysis and proposal can induce the flow of finishing works smoothly and contribute to success of project through saving of a tenn and cost of construction works.

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Studies on Silk Textile Wash and Wear Finishing (絹織物 Wash and Wear 加工硏究)

  • Choe, Byong-Hee;Lee, Yang-Hoo
    • Journal of Sericultural and Entomological Science
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    • v.23 no.1
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    • pp.47-55
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    • 1981
  • Silk textile finishing has been studied for many years by many workers in order to meet more utilities for various endusers. Such studies, however, could not be successful because any natural fibers are hardly change their natures by artificial treating methods. Textile finishing is of course to improve the mechandise qualities and the poor natures of silk so that it may be available as the best textile fiber in the world. Sometimes, famous trade marked textile plays more power than its quality in the silk market, nevertheless, this should be over line of research activities. Meantime, the silk demand has been also transferred from ladies stocking to other clothes since nylon or other synthetic fibers were developed. That is why, the extension of silk demand should be developed by various research works. Specially, silk is known as difficult textile to handle it during washing or ironing process which happened to depress down the silk usage for house wives. In order to solve such problems, the reporter has been worked for many years and now, he believes that he has developed a proper finishing method to coversuch problems. The developed finishing method may be said to eligible with economical aspect and shorten the dry duration after water washing in half against normal silk textile without harming the specific silk nature. As all of us know, silk fiber starts to denature since it was spinned by silkworm and the fiber is formed as overlapped "S" type curves during its concooning process. After it is made as raw silk or sericin silk, it shows as straight line form, but it changes in to waved form in case refining or degumming process in order return to its original spinned form. Such nature is continued during its textile form and ends with hard ironing nature than other textile fibers. Mean while, the silk fiber keeps to continue its denaturing and this is iniciated by repeat of washing and drying which takes many years to reach its final stage, The reporter has found the iniciating denature of silk by his finishing process, with out heat, decreasing the swollen nature which ended with shortening the drying duration after wash. Each washing was carried out by soaking the previously weighed sample in cold water for one hour, then pressed the sample for ten minutes to eliminate its free water component before weighing with same condition. According to this, the treated silk showed much denaturing after the finishing, but the standard silk progressed the denaturing by and by with the repeat of washing and drying, finally reached the same swollen degree of treated silk, Such treating result explains that the treated silk happened to be stebilized nature by the treating immediately. On the other that the treated silk happened to be stebilized nature by the treating immediately. On the other hand, standard silk may reach to such condition by the time of worn out clothes after repeat of washing and drying for many years while the clothes will be no more useful. The decreased swelling nature has brought about the drying period in half against standard silk after all. Not only the tests of tenacity and elongation but also crease resistance recovery, stiffness and shrinkage tests were carried out after each washing and drying which he has found better result on the treated silk textile against the standard silk. The most important thing was to keep the textile feeling of silk by such finishing work before improve any poor nature of silk. The general silk has a nature to absorb smoke or dirt from its surrounding air and reaches to dirty color shade upon such exposure, but the treated one has improved such nature because of its artificial denaturing, another word, it keeps clean longer than the normal silk. Many previous finishing works could improve some specific nature of silk, but it happened to deprave other important natures. The reporters work is, however, specialized to improve the silk to be useful as Wash and Wear Silk without harming its standard natures. So far, this work happened to be a overall innovative finishing method of silk textile.

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Analysis of Delay Factors Based on Importance of Construction Subject-classified in Apartment Finishing Works (공동주택 마감공사 공사주체별 작업지연 요인 분석)

  • Lee, Seung-Hoon;Kim, Yong-Man;Kim, Ju-Hyung;Kim, Jae-Junn
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.1
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    • pp.73-81
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    • 2011
  • The ultimate goal of construction is to complete the given work in the most economical and safest way within the required construction period while meeting the quality standards specified in the design drawing. There are a few characteristics of finish work. First, executed in subdivided processes, finish work involves a very diverse and complex structure. Second, there are no criteria for each segmented process with regard to the appropriate time of input. Third, it is not very necessary to set priorities for lead and lag works. This study intends to provide information on the completion of a project in accordance with the required duration by setting priorities in the delay of each detailed process of finish work to minimize delay in finish work. In this study, finish work is divided into wet work and other types of finish work, and the importance of each process is classified based on the given details of each process. In addition, the study employs a survey to analyze delay factors of a designer, a constructor, and a supplier. Using the survey results, the study sets priorities in delay of final work to provide information on the completion of an apartment project within the planned construction period.