• Title/Summary/Keyword: Break-In

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Estimation on Clamping Force of High Strength Bolts Considering Temperature Variable of Both Site conditions and Indoor Environments (실내환경과 건설현장 온도변수를 고려한 고력볼트 체결력 예측)

  • Nah, Hwan-Seon;Lee, Hyeon-Ju
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.3
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    • pp.32-40
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    • 2015
  • The torque shear high strength bolt is clamped normally at the break of pin-tail specified. However, the clamping forces on slip critical connections do not often meet the required tension, as it considerably fluctuates due to torque coefficient dependent on lubricant affected temperature. In this study, the clamping tests of torque shear bolts were conducted independently at indoor conditions and at construction site conditions. During last six years, temperature of candidated site conditions was recorded from $-11^{\circ}C$ to $34^{\circ}C$. The indoor temperature condition was ranged from $-10^{\circ}C$ to $50^{\circ}C$ at each $10^{\circ}C$ interval. As for site conditions, the clamping force was reached in the range from 159 to 210 kN and the torque value was from 405 to $556 N{\cdot}m$. The range of torque coefficient at indoor conditions was analyzed from 0.126 to 0.158 while tensions were indicated from 179 to 192 kN. The torque coefficient at site conditions was ranged from 0.118 to 0.152. Based on this test, the variable trends of torque coefficient, tension subjected temperature can be taken by statistic regressive analysis. The variable of torque coefficient under the indoor conditions is $0.13%/^{\circ}C$ while it reaches $2.73%/^{\circ}C$ at actual site conditions. When the indoor trends and site conditions is combined, the modified variable of torque coefficient can be expected as $0.2%/^{\circ}C$. and the modified variable of tension can be determined as $0.18%/^{\circ}C$.

Flood Inundation Analysis from Levee Failure in Nakdong River (낙동강 제방 붕괴에 따른 범람홍수 해석)

  • Jeon, Min-Woo;Han, Kun-Yeun;Choi, Kyu-Hyun
    • Journal of Korea Water Resources Association
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    • v.38 no.4 s.153
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    • pp.259-269
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    • 2005
  • One- and two-dimensional coupling model has been developed to analyze the flood inundation aspect of protected lowland. One-dimensional model solves the Saint-Venant equations by the Preissmann method, and two-dimensional model solves the shallow water equation by the integrated finite difference method. The coupling model approximates unsteady supercritical and subcritical flow, backwater flooding effects, and escaping and returning flow from two-dimensional flow model to channel system. The model has been applied to the levee failure in the Nakdong river during September 13 through 15, 2000. Velocity distributions and inundated depths were presented to demonstrate model simulation results.

Deterioration State and Behavior of Discontinuity System of the Seosan Maaesamjonbulsang (Rock-carved Triad Buddha in Seosan), Korea (서산 마애삼존불상의 훼손상태 및 불연속면의 거동특성)

  • Lee, Sun-Myung;Lee, Chan-Hee;Choi, Seok-Won;Yun, Seok-Bong
    • Journal of Conservation Science
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    • v.19
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    • pp.85-98
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    • 2006
  • Rock property of the Seosan Maaesamjonbulsang is composed of biotite granite with medium grained texture. The triad Buddha is highly deteriorated by the joint, fracture, break-out, exfoliation, dew condensation of the surface and discoloration of the secondary pollutant. Host rock of the triad Buddha is divided dozens of rock blocks with various shape, and developed irregular discontinuity planes. Besides, the host rock is promoted biological pollution due to the surrounding crowded vegetation and high humidity environment. As the results of structural stability, it is confirmed that developed discontinuity system in the host rock is exposed instability sloping environment. Therefore, the host rock and surroundings are required maintenance, and required preservation by continuance monitoring for understand behavior of discontinuity system.

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Development of a Rough Rice Handling Equipment for In-Bin Drying and Storage System (개량 곳간용 벼이송장치(移送裝置) 개발(開發))

  • Chang, D.I.
    • Journal of Biosystems Engineering
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    • v.13 no.3
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    • pp.44-51
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    • 1988
  • The objective of this study is to develop a grain handling system for loading, unloading and transporting of rough rice stored at the in-bin drying and storage (IBDS) developed by the Korea Advanced Institute of Science and Technology(KAIST). A mechanized Fain handling system consisted of a portable auger and a gate was developed and tested. The test results can be summarized as the following: 1) The loading capacity of the handling system developed is $16.2m^3/h$ (8.3 ton/h) for the Indica type rice and $13.0m^3/h$(7.3 ton/h) for the Japonica type. It is greater than that of manual handling as much as 2.5 - 2.7 times. 2) The unloading capacity of the handling system developed is $16.0m^3/h$(8.2 ton/h) for the Indica type rice and $12.6m^3/h$(7.0 ton/h) for the Japonica type. It is greater than that of the manual as much as 4.7 - 5.5 times. 3) For 3-ton capacity of the storage, the loading and unloading can be performed for 20 and 30 minutes by one man operation of equipment. while 60 and 120 minute for the manual of 2 men, respectively. 4) The volumetric efficiency of the system developed is 0.42 - 0.54 and the power efficiency is 4.0 - 4.4. 5) The break-even quantity of the handling system developed is about 38.6 ton($68.7m^3$) of rough rice and the initial investment for the system would be returned within five years for the most owners of the KAIST IBDS system.

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Aesthetic Study of Film Sound in Godard's (고다르 <카르멘이라는 이름(Prénom Carmen)>에 나타난 영화 사운드의 미학적 고찰)

  • Park, Byung-Kyu
    • The Journal of the Korea Contents Association
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    • v.18 no.8
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    • pp.82-91
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    • 2018
  • This paper examines the sound of Godard's <$Pr{\acute{e}}nom$ Carmen> from Deleuze's film aesthetics and Merleau-Ponty's phenomenological point of view. The rehearsal scene of a string quartet is a mirror-image that illuminates the music itself, and becomes a crystal-image with the indiscernibility of the present and the past in the break with the main narrative. On the other hand, urban noise and waves are the seeds composed of pure optical (sound) images and grow into pure sound crystals that collide with what is seen through the juxtaposition, substitution, and intentional connection of sound. However, these sound contradictions also lead to the integrated sound category as a 'sole movement' through Merleau-Ponty's dialectical thought, and even the dialectical sound management of pop and classical music is no longer a confrontation of the genre, but is integrated into the materialistic category of sound. This study is differentiated from the existing research by solving the sound aesthetics of the Godard's film through philosophical thought.

A Study on the Wealth of Seller and Buyer in Asset Sales (자산매각의 가치창출 효과: 매각기업과 매수기업의 비교분석)

  • Lee, Sang-Lae;Oh, Hyun-Tak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1625-1632
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    • 2012
  • The purpose of this study is to analyze whether asset sales contributed to increase of the shareholder value of the seller and the buyer in Japan. The period of analysis is 2000-2007. As a result of event study, Although the stockholder of the seller earn positive abnormal returns at the announcement of a asset sales, most stockholders of the buyer were break even. However, the buyer which purchase related asset get positive abnormal returns. Furthermore, when using a matched seller-buyer, we find that asset sales are firm value enhancing for the seller and buyer. Furthermore, we verify whether the excess return depends on the financial condition, and the managerial performance. we find that seller gains are related to the seller's managerial performance, leverage ratio, and buyer gains are related to the leverage ratio, foreigner holdings ratio. we conclude that lender and outside monitoring lead to increase of firm value.

Breakaway Fracture Energy(BFE) of Indented Type Bolt for Breakaway Sign Supports (분리식 지주 단부장치에 이용되는 인덴티드 타입 볼트의 분리파괴에너지)

  • Ko, Man-Gi;Kim, Kee-Dong;Jun, Sung-Min;Sung, Jung-Gon
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.4
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    • pp.39-45
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    • 2008
  • Breakaway support for small signs of size $0.293\;m^2{\sim}0.360\;m^2$ using indented tube type bolt of D12 mm with 6 mm inner diameter has been developed and the structural strength of the support system for the wind load was verified through static shear and tension tests. One important value in understanding the dynamic behavior of sign post and impact vehicle is the fracture energy of the sign support. In this study, fracture energy needed to break the sign support was estimated by pendulum test and computer simulation using LS-DYNA program. Support system composed of 3 indented bolts was found to sustain the 43.1 kg$\sim$51.2 kg wind load safely. Fracture energy for one indented bolt was measured as 163.3J from the pendulum test, and was calculated as 153J from the LS-DYNA simulation. The closeness between these two values verified the validity of the simulation model.

User-Focused Package Contents Application System for Interactive IPTV Services (대화형 IPTV 서비스를 위한 사용자 중심의 패키지 콘텐츠 운용 시스템)

  • Kim, Kwang-Yong;Lee, Young-Il;Yoo, Jeong-Ju;Lyu, Won;Jeong, Jae-Gil;Jung, Hoe-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.11
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    • pp.2323-2329
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    • 2009
  • Recent IPTV services still remain as simple broadcasting services that cannot make the most of interactive features together with various content-associated data. So, IPTV providers are making efforts to break from monopolistic style, so as increasing the user's participation m service. However there is an interoperability problem because no common solution is employed across different providers. To solve this problem, there needs to be a framework for a framework for generating, sharing and distributing package contents. In this paper, we propose user-centered package contents application framework for interactive IPTV services. We also design a package content authoring and consuming system which plays core parts in the proposed framework.

Development of Korean Condition Based Maintenance Systems to Monitor Naval Weapon Systems (해군 무기체계 한국형 상태진단시스템 발전방향 연구)

  • Oh, Kyungwon
    • Journal of Aerospace System Engineering
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    • v.10 no.4
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    • pp.67-74
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    • 2016
  • The primary aim for using a Korean Condition Based Maintenance (CBM) system is to maintain military operational readiness using Interactive Collection Analysis Systems (ICAS) installed on naval vessels. Other aims are to preemptively provision maintenance and supply functions, to guarantee economical management of logistical assets, and to implement data driven equipment life cycle management. In order to accomplish these aims, it is necessary to establish standard system conditions. However, because manufacturers do not provide the technology necessary for maintenance management, it is required to retain component performance maps for each piece of equipment, and to accumulate data about frequently occurring fault patterns. This study confirms the validity of component performance maps using micro gas turbines and provides accumulated data on machine break downs. This would allow real time equipment performance checks and present performance trends. Then analysis would provide solutions for maintaining the best machine operating conditions with detailed maintenance manuals for operators. This study is a basis for further research to investigate additional ways to develop CBM using data obtained from naval vessels used in actual military operations.

A Study on the Development of a Training Program to Reinforce the Teachers' Performance as Facilitators (교원의 퍼실리테이터 수행지원 강화를 위한 연수 프로그램 개발 연구)

  • Jung, Ju-Young;Hong, Kwang-Pyo
    • Journal of Fisheries and Marine Sciences Education
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    • v.22 no.3
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    • pp.431-444
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    • 2010
  • This research aims at developing a teachers' training program to reinforce teachers' capability to perform the action learning program. To accomplish this goal, the key value of the training program based on action learning, the process of the core learning activities, and the elements to support learners and facilitators respectively were deducted on the foundation of documentary research and case study, based on which, the program was developed through the formative test by professionals and application to the field. This research was applied to 105 middle or high school teachers, the participants of the in-service training on creative problem solving hosted by B metropolitan city for one week (30 hours) from 9 a.m. on Monday, January 25th, 2010 to 4 p.m. on Friday, January 29th. The result of this research is as follows. First, as for the key values of this study, (1) the team-based learning centered on the trainees, not lecturers-oriented, knowledge-transmitting training, is possible, (2)for each process, guidelines, related information, tools, and various kinds of media are supported just in time, and (3)a focus is given on fostering facilitators centered on teachers. Second, the process of the core learning activities of the teachers' training program based on action learning consists of the procedure of a prior lecture${\rightarrow}$break${\rightarrow}$investigation into problems${\rightarrow}$clarification of problems${\rightarrow}$drawing possible solutions${\rightarrow}$decision on the priority${\rightarrow}$making an action plan${\rightarrow}$performance${\rightarrow}$evaluation, and on each stage, the contents for the activities of teachers and learners and detailed supportive elements are offered.