• Title/Summary/Keyword: 체결체

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A Study on Characteristics of Chinese Civil Aviation Market (중국 항공운송시장특성에 관한 연구)

  • Sun, Zhanfang
    • The Journal of the Korea Contents Association
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    • v.14 no.6
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    • pp.397-406
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    • 2014
  • Recently, China has expanded enormously its economic trade exchange bilaterally with other nations and developed as the second largest aviation market in the world. While open skies bilateral agreements were signed between China and other countries, the agreement processes influenced the aviation market structure and market sharing heavily. This paper analyzed the Chinese aviation market by such three angles as market scale, competitive situation, and market concentration. It is concluded that the Chinese aviation market is the oligopolistic market structure tested by the Herfindahl-Hirschman Index. Finally, suggestions are given to the airlines operating in China such as joining the air alliance, paying attention to a different frequent flyer program (FFP) etc.

Evaluation of Pull-Out Strength of Connections with Roof Cladding using Honey Comb Panel Secured Cool Roof Performance (Cool Roof 성능을 확보한 Honey Comb Panel 지붕 접합부의 인발 성능 평가)

  • Lee, In Ho;Park, Sang Woo;Ko, Kwang Il;Chung, Mi Ja;Lee, Eun Taik
    • Journal of Korean Society of Steel Construction
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    • v.28 no.3
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    • pp.139-149
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    • 2016
  • Roof cladding of buildings are required for the measures about the 'screw pull-out' which causes the casualties and the property damage by typhoons. In this study, the pull-out resistance was increased by increasing the penetration depth of the screw installing a ironware called 'insert nut' on the roof cladding frame. Tensile tests were conducted to compare the pull-out strengths of a general screw-joint and a nut insert joint. Roof cladding that is actually being used in the field was produced using the 'solid work' and then the roof claddings using a general screw-joint and a nut insert joint were compared by a static test and dynamic test.

Experimental Study of the End-plate Gap Effect on the Performance of Extended End-plate Type Splice (이음면 이격이 확장형 단부판 이음부 성능에 미치는 영향에 대한 실험적 연구)

  • Kim, Cheol Hwan;Lee, Myung Jae;Kim, Hee Dong;Kim, Sa Bin
    • Journal of Korean Society of Steel Construction
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    • v.28 no.6
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    • pp.427-438
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    • 2016
  • This study is experimental research for the effect of gap at the end plate on the performance of extended end-plate type splice. For this research, simple beam type specimens by using extended end-plate type splice are planned. Main variables are the initial gap between end-plates, the installation of finger shim plate before the installation of high tension bolts, the final gap between end-plates, and the installation of finger shim plate after the installation of high tension bolts. The static loading tests results show that the maximum bending strength of splice is not dependent on the gap, but the vertical displacement, initial stiffness and elastic stiffness are affected by the gap. In addition to that, the possibility of brittle fracture is increased when the torque of high tension bolt is used to control the gap. Thus, careful consideration is needed in this case.

Development of Connection Details for a Double Split Tee Connection Without a Shear Tab (전단탭이 없는 상·하부 스플릿 티 접합부의 접합부상세 개발)

  • Yang, Jae Guen;Kim, Yong Boem
    • Journal of Korean Society of Steel Construction
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    • v.28 no.1
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    • pp.53-64
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    • 2016
  • The double split tee connection, a type of beam-to-column moment connection, exhibits different behavioral characteristics according to changes in the thickness of the T-stub flange, the gauge distance of the high-strength bolt, and the number and diameter of high-strength bolts. In general, the double split tee connection is idealized and designed so that a T-stub fastened to the top and bottom supports a flexural moment, and a shear tab supports a shear force. However, if the double split tee connection is applied to low-and medium-rise steel structures, the size of the beam member becomes small, and thus the shear tab cannot be bolted to the web of a beam. In this regard, this study was conducted to propose connection details to ensure that the double split tee connection with a geometric shape can display sufficient shear resisting capacity. To this end, experiments were conducted using full-scale specimens for the double split tee connection.

Experimental Study on Characteristics of Deformation for Concrete Track on Railway Bridge Deck End induced by Bridge End Rotation (철도교량 단부 회전에 따른 콘크리트 궤도의 변형특성에 관한 실험적 연구)

  • Lim, Jongil;Song, Sunok;Choi, Jungyoul;Park, Yonggul
    • Journal of the Korean Society for Railway
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    • v.16 no.3
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    • pp.217-225
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    • 2013
  • In this study, by considering the rail fastening support distance and the distance between the bridge and the abutment, the behavior of concrete track installed on a railway bridge end deck and the bridge end rotation were analyzed. In order to analyze the track-bridge interaction, bridge and abutment specimens with concrete track structures were designed and used in laboratory testing. At a constant fastening support distance, an increase in the bridge end rotation caused an increase in the displacement of the rail. Therefore, the displacement of the rail directly affects the rail and clip stress. Further, it is inferred that the results of multiple regression analysis obtained using measured data such as angle of bridge end rotation and fastening support distance can be used to predict the track-bridge interaction forces acting on concrete track installed on railway bridge deck ends.

The Satisfaction of the Students, Teachers, and Smaller businesses who participate in the 「Apprenticeship」 (「도제학교」에 참여하는 학생, 교사, 중소기업의 만족도)

  • Kim, Su won;Kim, Moon Seup;Kim, Jin Sook
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.3
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    • pp.177-183
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    • 2019
  • The purpose of this study was to identify and analyze the satisfaction of students, teachers, and smaller businesses who participate in the apprenticeship. To get answers, it analyzed students and teachers in 4 technical high schools in Daegu city and 4 technical high schools in small and midium sized city in Gyeongsangbuk-do province, and analyzed field teachers and people in charge in the smaller businesses which entered into the program. This study results are as follows. First, It is shown that participation in apprenticeship school is helpful for emplyment and that apprenticeship system is helpful for student's career choice because the respondents who are willing to make aggressive invitation to juniors are high. Second, Satisfaction with teachers was company discovery to be difficult, but the need for the system was relatively positively evaluated. Third, when it comes to the satisfaction of the smaller businesses, The participating companies's matter of primary concern is continuous business growth and they have will to participate in the apprenticeship program depending on the demand for manpower.

Empirical Analysis on Trade Pattern of Korean Motor Industry and Effect of Free Trade Agreement through Panel Gravity Model (패널중력모형을 통한 한국 자동차산업의 교역패턴과 자유무역협정의 영향 분석)

  • Kim, Seog-Min;Jun, Eui-Cheon
    • International Area Studies Review
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    • v.14 no.2
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    • pp.251-272
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    • 2010
  • This study was done through Panel Gravity Model to analyze the trade pattern of Korean motor industry and empirical analysis was also performed on the effect of regional economies joining to the Korean trade is to draw out some implications. Compared with per capita pattern regarding the income levels of both the countries, the results indicated that trade of Korean motor industry followed GDP pattern in accordance with the overall market. The results of effect on regional economic integration to Korean motor industry reflected 179% and 198% increase in motor trade industry and motor parts trade, respectively. To expand the trade of Korean motor industry at the international competitiveness level, focus should be made on smaller, smarter and greener car with lesser impact on the environment. Hence, the present investigation suggested that government should not delay in retaining the core technology as well as private sector should also aggressively invest in the market.

Splice Performance Evaluation of Fastening Coupler According to the Slope Length of Internal Fasteners (조임쇠 경사길이에 따른 체결식 커플러의 이음성능 평가)

  • Jung, Hyun-Suk;Choi, Chang-Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.4
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    • pp.11-19
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    • 2022
  • In this study, in order to improve the splice performance of mechanical couplers, two new mechanical couplers with different connection modes were developed with rebar(SD400). The stress analysis of mechanical couplers with two different connection modes was carried out. Uniaxial tensile tests were carried out with type of steel, connection mode and the slope length of internal fastener as variables to analyze the influence on the maximum tensile strength. Building upon this previous work, the specimens that met the code in uniaxial tensile test were fabricated and static loading test and cyclic loading test were performed on the basis of Korean code(KS D 0249). The results of this research are as follows; (1) The tensile strength of steel and the slope length of internal fasteners have a certain influence on the maximum tensile strength. (2) The connection mode has some influence on the stiffness, slip and stiffness reduction rate of the connecting rebars. The results verify the feasibility of the proposed enhanced mechanical coupler in the field.

Development of Static Seal for a Liquid Rocket Engine (액체 로켓 엔진 스태틱 실 개발)

  • Jeon, Seong Min;Yoon, Suk-Hwan;Chung, Taegeum
    • Journal of Aerospace System Engineering
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    • v.16 no.4
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    • pp.53-59
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    • 2022
  • Static seals are used to seal high temperature gas and cryogenic fluid under high pressure, at interfaces between liquid rocket engine components such as combustion chamber, turbopump, gas generator, valves, etc. As thermal expansion and contraction at assembly interfaces cause undesirable leakage under cryogenic and high temperature environments, static seals applied for sealing of joint interfaces without relative motion should be designed properly. The additional function of rotation at the sealing face is also required for static seals, when the spherical flange is used for improvement of assembly at misalignment interfaces. In this study, structural analysis and leak tightness test of simulating test rig for several important interfaces are performed, to verify structural integrity of static seals.

Cultural Discount Analysis of Chinese and Korean Co-production Movies (한중 합작 영화의 문화 할인 분석)

  • Yang, Li-Juan
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.6
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    • pp.103-111
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    • 2019
  • Under the background of globalization, the borderless nature of film and television language makes the exchange of film as the carrier become an important part of cultural exchanges in various countries. Therefore, film co-production between China and the United States, China and Japan, China and South Korea and other countries has become an important part of the current Chinese film industry. Among them, China and South Korea are close neighbors, and the exchanges between the two countries' films are also increasing. Korean movies have recovered since the 1990s, and they prospered at the beginning of the 21st century, and have formed a unique influence in the international community, especially in crime, suspense, love and other types of films. The co-production of Chinese and Korean films began to appear in 2000, and the signing of the "China-Korea Co-production Film Agreement" in 2014 prompted the rapid convergence of Chinese and Korean film co-productions. However, the co-productions of China and South Korea did not achieve good expectations in terms of communication effects and market evaluation. This article will use the "cultural discount" theory in cross-cultural communication to analyze the reasons for the cultural discounts produced by Chinese and Korean co-productions and how to avoid this phenomenon to the maximum extent.