• Title/Summary/Keyword: construction excellence

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Mechanical properties of friction stir welded aluminum alloys 5083 and 5383

  • Paik, Jeom-Kee
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.1 no.1
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    • pp.39-49
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    • 2009
  • The use of high-strength aluminum alloys is increasing in shipbuilding industry, particularly for the design and construction of war ships, littoral surface craft and combat ships, and fast passenger ships. While various welding methods are used today to fabricate aluminum ship structures, namely gas metallic arc welding (GMAW), laser welding and friction stir welding (FSW), FSW technology has been recognized to have many advantages for the construction of aluminum structures, as it is a low-cost welding process. In the present study, mechanical properties of friction stir welded aluminum alloys are examined experimentally. Tensile testing is undertaken on dog-bone type test specimen for aluminum alloys 5083 and 5383. The test specimen includes friction stir welded material between identical alloys and also dissimilar alloys, as well as unwelded (base) alloys. Mechanical properties of fusion welded aluminum alloys are also tested and compared with those of friction stir welded alloys. The insights developed from the present study are documented together with details of the test database. Part of the present study was obtained from the Ship Structure Committee project SR-1454 (Paik, 2009), jointly funded by its member agencies.

Rajakudakan Wat Chotikaram: From Ruins to The Reconstruction of The Grand Stupa, Wat Chedi Luang, Chiang Mai

  • Kirdsiria, Kreangkrai;Buranautb, Isarachai;Janyaemc, Kittikhun
    • SUVANNABHUMI
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    • v.13 no.2
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    • pp.167-186
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    • 2021
  • The Grand Stupa is mentioned in historical text as 'Rajakudakan', which means a royal building with a multitiered superstructure. This Grand Stupa is the principal construction of Wat Chedi Luang, and marks the center of the Chiang Mai City Plan. This study argues that the Grand Stupa was built in 1391 during Phaya Saen Mueang Ma's reign, possibly inspired by the construction of Ku Phaya in Bagan. Thereafter, in 1545, the Grand Stupa's superstructure collapsed after the great earthquake, resulted in the irreparable damage since then. Therefore, a survey using a 3D laser scanner is conducted to collect the most precise data on the current condition of the Grand Stupa, yielding an assumption of its reconstruction. Other simultaneous stupas or those that show a close architectural relationship (e.g. stupas in Wat Chiang Man and Wat Lok Moli and the stupa of King Tilokaraj in Wat Chet Yot in Chiang Mai) are also employed as research frameworks for the reconstruction. As a result, the architectural research on the Grands Stupa, compared with simultaneous stupas, yields a fruitful argument that the pre-collapse superstructure form of the Grand Stupa marks the most architectural similarity to the stupa of Wat Chiang Man.

A Study on Ceramic Insert and Anchor Application for Railway Structures (철도구조물에 대한 세라믹 인서트 및 앵커의 적용 방안 연구)

  • Suh, Chang-Beom;Oh, Myoung-Ryoul;Li, Guang-Ri
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1177-1184
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    • 2011
  • Ceramic insert and anchor has many advantages compared with existing steel products, therefor widely applied for concrete bridge, tunnel, railroad and building etc. in Japan. Ceramic insert and anchor start-to-used in Korea is no longer, but the product has already been applied to various construction sites and have been recognized for excellence. But now in Korea, the ceramic insert and anchor are not yet widely use like in Japan. This paper was an introduction to the ceramic insert and anchor, and detailed explained the product excellent performance. Ceramic insert and anchor can be applied to many areas, but in this case the focus was the application of ceramic insert and anchor for railway structures. In this paper we detailed compared the ceramic products with existing steel products in their respective characteristic, and analyzed on their application in domestic and foreign.

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An Implementation of Inference-Based Web Ontology for Intelligent Image Retrieval System (지능형 이미지 검색 시스템을 위한 추론 기반의 웹 온톨로지 구축)

  • Kim, Su-Kyoung;Ahn, Kee-Hong
    • Journal of the Korean Society for information Management
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    • v.24 no.3
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    • pp.119-147
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    • 2007
  • Actually a diffusion of a semantic web application and utilization are situations insufficient extremely. Technology most important in semantic web application is construction of the ontology which contents itself with characteristics of semantic web. Proposed a suitable a method of building web ontology for characteristics or semantic web and web ontology as we compared the existing ontology construction ana ontology construction techniques proposed for web ontology construction, and we analyzed. And modeling old ontology to bases to description logic and the any axiom rule that used an expression way of SWRL, and established inference-based web ontology according to proposed ways. Verified performance of ontology established through ontology inference experiment. Also established an web ontology-based intelligence image retrieval system, to experiment systems for performance evaluation of established web ontology, and present an example of implementation of a semantic web application and utilization. Demonstrated excellence of a semantic web application to be based on ontology through inference experiment of an experiment system.

Web Ontology Modeling Based on Description Logic and SWRL (기술논리와 SWRL 기반의 웹 온톨로지 모델링)

  • Kim, Su-Kyoung;Ahn, Kee-Hong
    • Journal of the Korean Society for information Management
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    • v.25 no.1
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    • pp.149-171
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    • 2008
  • Actually a diffusion of a Semantic Web application and utilization are situations insufficient extremely. Technology most important in Semantic Web application is construction of the Ontology which contents itself with characteristics of Semantic Web. Proposed a suitable a Method of Building Web Ontology for characteristics of Semantic Web and Web Ontology as we compared the existing Ontology construction and Ontology construction techniques proposed for Web Ontology construction, and we analyzed. And modeling did Ontology to bases to Description Logic and the any axiom rule that used an expression way of SWRL, and established Inference-based Web Ontology according to proposed ways. Verified performance of Ontology established through Ontology inference experiment. Also, established an Web Ontology-based Intelligence Image Retrieval System, to experiment systems for performance evaluation of established Web Ontology, and present an example of implementation of a Semantic Web application and utilization. Demonstrated excellence of a Semantic Web application to be based on Ontology through inference experiment of an experiment system.

An Experimental Study on the Durability of High-Ductile Mortar (고인성 모르타르의 내구특성에 관한 실험적 연구)

  • Rho, Hyoung-Nam;Kim, Ju-Sang;Hwang, Nam-Soon;Kim, Jae-Hwan;Lee, Sang-Soo;Song, Ha-Young
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.11a
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    • pp.71-74
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    • 2007
  • With the changes of times the building materials tend to extend the demand for application under the special environment. Since high-ductile mortar is developed, the building materials show excellent performance like toughness, compression, tensile, and bending, etc. in the general concrete from the existing brittle point. And, recently they are widely used as repairing and reinforcing materials both at home and abroad because they are recognized as excellence like durability and fire-resistance. However, it is in a situation of creating problems in durability because it frequently happened deterioration of buildings that have already repaired and reinforced at a time when it requires reconstruction of recently deteriorated construction structure recently. Therefore, in this study improved with a more repair Material development and reinforcement of the second high-ductile mortar products for a variety of basic materials were presented want, research plans used include traditional repair materials and the newly developed PCM (polymer cement mortar) structural reinforcement type indicated that comparison. PCM analysis in order to present a rate depending on the types fiber 0, 1.2 and 2.0(%) at three levels and mixture water according to ratios of weight to Plain in the 2.0 and 1.85(kg) at two levels is set, the results were as follows. 1) This study has shown that PCM had excellent strain hardening behavior at the same time that the bending stress increased according to the fiber contents. 2) This study has shown that it had the durability performance due to the high substance transmission according to the fiber contents.

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Network separation construction method using network virtualization (네트워크 가상화를 이용한 망 분리 구축 방법)

  • Hwang, Seong-Kyu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.8
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    • pp.1071-1076
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    • 2020
  • The importance of network separation is due to the use of the Internet with existing business PCs, resulting in an internal information leakage event, and an environment configured to allow servers to access the Internet, which causes service failures with malicious code. In order to overcome this problem, it is necessary to use network virtualization to separate networks and network interconnection systems. Therefore, in this study, the construction area was constructed into the network area for the Internet and the server farm area for the virtualization system, and then classified and constructed into the security system area and the data link system area between networks. In order to prove the excellence of the proposed method, a network separation construction study using network virtualization was conducted based on the basis of VM Density's conservative estimates of program loads and LOBs.

Improvement Plan for Construction Management and Legislation of Donation Collection Facilities (기부채납 시설의 건설관리 및 법제에 관한 개선방안)

  • Lee, Juyong;Jung, Youngchul
    • Korean Journal of Construction Engineering and Management
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    • v.25 no.1
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    • pp.3-12
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    • 2024
  • The donation collection system to secure infrastructure and land necessary for public development projects has been actively applied as an effective means of realizing public interest and the concept of recovering development profits, and has contributed greatly to society in public difficult financial conditions. However, due to the ambiguous legal standards and lack of legal grounds for the operation of the donation collection system, it has been arbitrarily used for administrative convenience in the form of granting a donation collection assistant to install infrastructure. In addition, infrastructure is a facility that is constructed and donated within development profits to obtain licenses, and is promoted to minimize construction costs to improve profitability, posing a risk of poor infrastructure planning, design, and construction, resulting in increased safety and maintenance costs for citizens. Continuous system and legal improvement are needed to improve the excellence, convenience, and safety of facilities that citizens will use for half a century through the improvement of the donation system.

Determination of plastic hinge properties for static nonlinear analysis of FRP-strengthened circular columns in bridges

  • Amiri, Gholamreza Ghodrati;Jahromi, Azadeh Jaberi;Mohebi, Benyamin
    • Computers and Concrete
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    • v.10 no.5
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    • pp.435-455
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    • 2012
  • In the recent years, rehabilitation of structures, strengthening and increasing the ductility of them under seismic loads have become so vital that many studies has been carried out on the retrofit of steel and concrete members so far. Bridge piers are very important members concerning rehabilitation, in which the plastic hinging zone is very vulnerable. Pier is usually confined by special stirrups predicted in the design procedure; moreover, fiber-reinforced polymers (FRP) jackets are used after construction to confine the pier. FRP wrapping of the piers is one of the most effective ways of increasing moment and ductility capacity of them, which has a growing application due to its relative advantages. In many earthquake-resistant bridges, reinforced concrete columns have a major defect which could be retrofitted in different ways like using FRP. After rehabilitation, it is important to check the strengthening adequacy by dynamic nonlinear analysis and precise modeling of material properties. If the plastic hinge properties are simplified for the strengthened members, as the simplified properties which FEMA 356 proposes for non-strengthened members, static nonlinear analysis could be performed more easily. Current paper involves this matter and it is intended to determine the plastic hinge properties for static nonlinear analysis of the FRP-strengthened circular columns.

Evaluation of Cost-Effectiveness on High-Strength Steel Pipe Strut and Its Application (고강도 강관버팀보 현장적용 및 경제성 평가)

  • La, Seung-Min;Lee, Jong-Gu;Lee, Yong-Joo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.511-520
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    • 2008
  • The steel pipe strut for a means of the retaining structure has been used generally in North America, Europe and China so far. However, Korea and Japan, two countries are much familiar with H-shape steel strut having its anisotropic strength on two different axes(named as strong and weak axes), even though they recognize the steel pipe's excellence of structural function associated with its compressive ability. This trend is mainly due to a number of its field application, accumulated know-hows and workmanship etc. This paper introduces particular features of a high-strength steel pipe strut in comparison with the H-shape steel strut and its application for two excavation sites in Seoul. As a result of field verification, the high-strength pipe steel strut is more effective than the H-shape steel strut in terms of construction costs, schedules, constructibility and structural stability.

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