• Title/Summary/Keyword: Cold-Form

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Temperature History of Wall Concrete with Heat Insulating Curing Method Subjected to Severly Cold Climate (혹한온도 조건에서의 양생방법 변화에 따른 벽체 콘크리트의 온도이력 특성)

  • Son, Ho-Jung;Han, Sang-Yoon;Cheong, Sang-Hyeon;Ahn, Samg-Ku;Han, Cheon-Goo;Han, Min-Cheol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.51-52
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    • 2011
  • This study is to propose a curing method for a concrete wall structure under severe cold climate. The curing methods of using heated cable, heated panel and insulated form were applied. Results showed that the concrete cured by the heated cable resulted in the highest temperature history and the highest strength development at 28 days. Further, it is believed that the curing methods of the heated panel and insulated form are also recommendable for the resistance of the early frost damage on the concrete in practice.

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Densification Behavior of Metal Powder under Cold Compaction (냉간 압축 하에서 금속 분말의 치밀화 거동)

  • Lee, Sung-Chul;Kim, Ki-Tae
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.652-657
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    • 2001
  • Densification behavior of aluminum alloy(A16061) powder was investigated under cold compaction. Experimental data were obtained under triaxial compression with various loading conditions. A special form of the Cap model was proposed from experimental data of A16061 powder under triaxial compression. The proposed yield function and several yield functions in the literature were implemented into a finite element program (ABAQUS) to compare with experimental data for densification behavior of A16061 powder under cold isostatic pressing and die compaction. The agreement between finite element calculations from the proposed yield function and experimental data is very good under cold isostatic pressing and die compaction.

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Densification Behavior of Metal Powder Under Cold Compaction (냉간 압축 하에서 금속 분말의 치밀화 거동)

  • Lee, Seong-Cheol;Kim, Gi-Tae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.1
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    • pp.95-104
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    • 2002
  • Densification behavior of aluminum alloy(A16061) powder was investigated under cold compaction. Experimental data were obtained under triaxial compression with various loading conditions. A special form of the Cap model was proposed from experimental data of A16061 powder under triaxial compression. The proposed yield function and several yield functions in the literature were implemented into a finite element program (ABAQUS) to compare with experimental data for densifcation behavior of A16061 powder under cold isostatic pressing and die compaction. The agreement between finite element calculations from the proposed yield function and experimental data is very good under cold isostatic pressing and die compaction.

Provenance and Concept of 10 Symptoms of Para-cold Damage(類傷寒) from Yixuerumen(醫學入門) (『의학입문(醫學入門)·상한편(傷寒篇)』 유상한(類傷寒) 병증(病症) 10종의 유래와 개념에 대한 연구)

  • Jo, Hak-jun
    • Journal of Korean Medical classics
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    • v.29 no.4
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    • pp.17-36
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    • 2016
  • Objectives : This paper seeks to study the provenances of 10 Symptoms of Para-cold damage from Yixuerumen, and discovers the rationality and originality of para-cold damages recognized by Li Chan. Methods : The paper looks through the books referenced by Yixuerumen to investigate the source text for Yixuerumen's Para-cold Damage chapter, and the contents of the referenced books will be compared to that of Yixuerumen. Results : The sources of the 10 symptoms of para-cold damage from Yixuerumen Chapter of Cold Damage can be traced to Leizhenghuorenshu (expectoration, indigestion, rising temperature due to lack of energy, and beriberi), Wang Zhen's Shanghanzhengzhimingtiao Xinzengxuleishanghansizheng(the infection in a boil, blood sattis, caused overexertion, and pox), and Liu Chun's Yujiweiyi's chapter on Common Cold. Here, Li Chan made his own addition of internal damage and damage of overworking. Li Chan seems to have considered para-cold damage not as a type of cold damage but as a "concept relative to the broader range of cold damage." In reflection of this understanding, Li Chan limited the number of categories to ten in accordance with the developmental trace leading from Leizhenghuorenshu to Shanghanzhengzhimingtiao. When we understand para-cold damage as a "concept relative to the narrower range of cold damage," it could be used as a mean as for "Wenbin diagnosis," but Yixuerumen's para-cold damage is only utilized for the "diagnosis of a broader concept of cold damage." Conclusions : Li Chan deserves credits for his academic rationality and originality displayed by the method he used to form para-cold damages where he used real cold damage and para-cold damage as principles, by the division of para-cold damage symptoms into ten provenances, by the creation of the concept of para-cold damage, and by his broad collection of prescription and treatment corresponding to each type.

Estimation of the Emission form Passenger Car Considering Cold Start and Evaporative VOC Emission in the Capital Area (수도권지역 승용차에 의한 Cold Start와 Evaporative VOC를 고려한 배출량 추정)

  • 장영기;최상진;홍영실
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.157-158
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    • 2003
  • 급증하는 자동차 수요로 인해 발생되는 배출량 증가는 자동차 운행의 특성상 대도시 대기오염의 주원인으로 작용하고 있다. 자동차 배출오염물질의 배출량 추정 및 관리에 있어 연간 배출량 뿐만 아니라 월별 기온변화에 따른 배출량의 시간분포 또한 고려되어야 한다. 본 연구에서는 Hot emission에 부가되는 Cold start emission과 Evaporative VOC emission의 산정에 있어서 차종/차령에 대해서 월별 배출량을 추정하여 보았다. (중략)

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A Study on the System Identification of Cold Tandem Mills using the Subspace Method (부분 공간법을 이용한 연속 냉간 압연기의 시스템 규명에 관한 연구)

  • 장유신;김인수;이만형
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.299-303
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    • 1995
  • This paper charcterizes dynamics of cold tandem minns, and constructs it state-space model of which are linear time invariant, using subspace method. Step responses particularly show the influence on mass transfer delay. Input-output data set are obtained form nonlinear differential equations including mass transfer delay and nonlinearity. It is shown that the identified state-apace model well approximates the original systems dynamics.

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Forging of Long Hollow Shafts of Hard-to-Form Material by Hollow Shaft Extrusion after Piercing with Back Pressing (후방 가압식 피어싱 및 중공축 압축 공법에 의한 난성형 재료 중공장축의 단조)

  • Jun, B.Y.;Lee, J.H.;Eom, J.G.;Park, J.H.;Joun, M.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.10a
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    • pp.338-343
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    • 2007
  • We presented a special method of forging hollow shafts of hard-to-form material, which is composed of piercing with back pressing and hollow shaft extrusion. The presented method was applied to cold forging a bushing of an excavator. The finite element simulation technology was employed for developing the optimized process and the predictions were compared with the experiments. The method was also applied to an automotive part and was verified to be powerful for manufacturing the cold forged hollow shafts of the hard-to-form materials.

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Supervised Learning-Based Collaborative Filtering Using Market Basket Data for the Cold-Start Problem

  • Hwang, Wook-Yeon;Jun, Chi-Hyuck
    • Industrial Engineering and Management Systems
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    • v.13 no.4
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    • pp.421-431
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    • 2014
  • The market basket data in the form of a binary user-item matrix or a binary item-user matrix can be modelled as a binary classification problem. The binary logistic regression approach tackles the binary classification problem, where principal components are predictor variables. If users or items are sparse in the training data, the binary classification problem can be considered as a cold-start problem. The binary logistic regression approach may not function appropriately if the principal components are inefficient for the cold-start problem. Assuming that the market basket data can also be considered as a special regression problem whose response is either 0 or 1, we propose three supervised learning approaches: random forest regression, random forest classification, and elastic net to tackle the cold-start problem, comparing the performance in a variety of experimental settings. The experimental results show that the proposed supervised learning approaches outperform the conventional approaches.

A Study on the Fluctuation of Bottom Cold Water in the Western Channel of Korea Strait

  • Jong-Hwui Yun;Kyu-Dae Cho
    • Journal of the Korean Institute of Navigation
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    • v.21 no.4
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    • pp.39-47
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    • 1997
  • We researched the mechanism on th flucturain of Bottom Cold Water in the western channel of Korea Strait, using 13 years(1981~1933) oceanographic data of FRDA. The bottom cold water in the western channel appears more often in summer and fall than in winter and spring, and its year-to-year variation of temperature is very large. Such variation seems to be closely related with the variations of cold waters in the subsurface layer of the southwestern East Sea. According to the longitudinal temperature distribution along the korean southeastern coast, a density difference occurs all the time at the still deepth between the western channel and the southwestern East Sea. Thus, it is inferred that the cold waters would intrude into the western channle form the subsurface layer in the southwestern East Sea as a density-driven current, and it intensity depends upon the density difference.

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A Study on Relationship between Cold Water Appearance and Fog Formation in the Southwest Coastal Waters of Korea (한국남서연안해역의 저수온 출현과 안개 형성과의 관련성에 관한 연구)

  • Yun Jong-Hwui;Jeong Hee-Dong;Cho Kyu-Dae;Lee Chung-Il
    • Proceedings of KOSOMES biannual meeting
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    • 2004.11a
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    • pp.123-127
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    • 2004
  • It is known that cold water appears and fog frequently forms in the southwest coastal waters of Korea in summer. The authors investigate the time and place. of cold water existence, and also whether the cold water affects the occurrence of fog formation. As a result, cold water begins to appear around Daeheugsando at the early summer. It gets colder with times and cold water area moves toward southwest of Jindo in mid-summer, then disappears in this area around mid-Oct. Fog mostly forms in April through August and most frequently occurs at Chukdo(Jindo) where sea surface temperature shows lower than that at the adjacent area. Accordingly it is taken that the cold water is considerably contributed to form the dense and frequent fog around Jindo area.

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