• Title/Summary/Keyword: 기성

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Development of the Pilot Type Machine for Automation of PHC Pile Cutting Work (PHC 파일 두부정리 자동화를 위한 파일롯타입 장비의 개발)

  • Lee Jeong-Ho;Park Sang-Jun;Jeong Myung-Hoon;Kim Young-Suk
    • Korean Journal of Construction Engineering and Management
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    • v.4 no.4 s.16
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    • pp.173-181
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    • 2003
  • During the last few years, the use of Pre-tensioned spun high strength concrete piles(PHC pile) has been gradually increased in many construction sites. Cutting work of the concrete pile is an important task to crush a part of pile head which is compressed with more than 800$\cal{kg}f/cm^2$. It is usually performed by a crusher and three to four skilled workers. Recent analysis results of the pile cutting work reveal that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is labor-intensive work. The primary objective of this study is to propose conceptual designs for developing an automated pile cutting machine. It is anticipated that the development of the automated pile cutting machine would be able to bring improvements in safety, productivity, quality as well as cost saving.

Study on the Development of the Customized Ready-Made Hull Forms according to the Retrofit (선박개조에 따른 고객 맞춤형 기성품 선형 개발)

  • Park, Dong-Woo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.4
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    • pp.432-438
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    • 2017
  • The primary objective of the current work was to develop a standardized retrofit hull form capable of saving energy based on existing vessels. The bow shape of existing vessels was investigated, giving consideration to design draft and speed. Resistance performances were assessed for existing vessels according to operating conditions. Commercial CFD codes and model test materials were used for assessment of effective power. Three retrofit hull forms with minimum resistance were selected given real operating conditions. These vessels were named after customized ready-made hull forms to enable ship owners to make easier choices. The effective power of each vessel was estimated under real operating conditions. Subjects were operated with the lowest draft, and performance for retrofit No. 3 showed an 11-16% improvement in effective power at low speed ranges of 16-18 knots compared to existing vessels. When operated with a middle draft, performance for retrofit No. 3 showed a 6-11% improvement in effective power at low speed ranges compared to existing vessels. When operated with the highest draft, performance for all vessels showed little difference in effective power.

Ultrastructure of the Digestive Diverticulum of Saxidomus purpuratus (Bivalvia: Veneridae) (개조개, Saxidomus purpuratus 소화맹낭의 미세구조)

  • Ju, Sun-Mi;Lee, Jung-Sick
    • The Korean Journal of Malacology
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    • v.27 no.3
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    • pp.159-165
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    • 2011
  • The anatomy and ultrastructure of the digestive diverticulum of Saxidomus purpuratus were described using light and electron microscopy. The digestive diverticulum of dark green color was situated on the gonad and connected to stomach by a primary duct. Digestive diverticulum is composed of numerous digestive tubules. The epithelial layer of digestive tubule, which is simple, is composed of basophilic cells and digestive cells. Basophilic cells are columnar in shape, and the electron density is higher than that of the digestive cell. The cytoplasm has a well-developed endoplasmic reticulum, tubular mitochondria, Golgi complex and membrane-bounded granules of high electron density. Digestive cells are columnar in shape, with development of microvilli on the free surface. Pinocytic vasicles, lysosomes and numerous mitochondria were observed in the apical cytoplasm of digestive cells. The results of this study suggest that basophilic cells and digestive cells in the digestive tubule are specialized in the extracellular and intracellular digestions, respectively.

A Study on the Contractor's Liability for Defect in Public Construction Project - through comparing Civil Law with Government Contract Law - (공공건설사업 하자에 대한 수급인의 책임에 대한 연구- 민법과 국가계약법령의 비교를 통하여 -)

  • Cho Young-Jun;Hyun Chang-Taek
    • Korean Journal of Construction Engineering and Management
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    • v.2 no.4 s.8
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    • pp.69-79
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    • 2001
  • Characteristics of Contactor's Defect Liability was too many discussed. But it's not clearly defined yet. Because recent Government Construction Projects are very complex and executed through long time, too many conflicts were appeared related to Contactor's Defect Liability. Therefore to analyse and to resolve the conflicts legal aspects of Contactor's Defect Liability stated in Civil Law and Government Contract Act was systematically compared. The result of this research is as follows : (1) Characteristic of Contactor's Defect must be regarded as a breach of Contract and be an incomplete contract implementation. (2) To decide the range of Damage, Characteristic of Defect must be regarded. (3) Contactor's Defect Liability must be effectual from the day of delivery. (4) Retainage must be added to secure the completion during the Contract Period and Defect Repairing Liability must be omitted in the Contract performance Security.

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Microanatomical Structure of the Digestive Diverticulum of Mytilus galloprovincialis (Bivalvia: Mytilidae) (지중해담치, Mytilus galloprovincialis 소화맹낭의 미세해부학적 구조)

  • Ju, Sun-Mi;Lee, Jung-Sick
    • Applied Microscopy
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    • v.41 no.4
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    • pp.257-263
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    • 2011
  • The microanatomy and ultrastructure of the digestive diverticulum of Mytilus galloprovincialis were described using light and electron microscopy. The digestive diverticulum of tawny color was surrounded the stomach and connected to stomach by a primary duct. Digestive diverticulum is composed of numerous digestive tubules. The epithelial layer of a simple digestive tubule, which is simple, is composed of basophilic cells and digestive cells. Basophilic cells are columnar in shape, and has a well-developed endoplasmic reticula, tubular mitochondria, Golgi complex and membrane-bounded granules of high electron density in the cytoplasm. Whereas digestive cells are columnar in shape, with development of microvilli and cilia on the free surface. Pinocytic vasicles, active lysosomes and numerous mitochondria were observed in the apical cytoplasm of digestive cells. The results of this study suggest that basophilic cell and digestive cell of the digestive tubule are specialized in the extracellular and intracellular digestion, respectively.