• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.531-536
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• 2003

It is generally known that RC flexural members strengthened by GFRP(Glass Fiber Reinforced Polymers) tend to be failed by premature bond failure near the flexural-shear cracks happened at the mid-span of beams. It is therefore strongly recommended that premature bond failure must be avoided to insure the intended strengthening effects sufficiently. The various methodologies such as increasing bonded length of GFRP and bonding details including U-shape wrappings and epoxy shear-keys are examined in this study. The bonded length of GFRP are calculated based on the assumed bond strengths of epoxy saturating resin. Total six half scale RC beam specimens were constructed and tested to investigate the effectiveness of each methodologies to prevent the bond failure of GFRP. Test results of each specimens are discussed in this paper.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.188-196
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• 2007

A composite case was designed to satisfy the required condition of KSLV-I kick motor system. we performed the structure and combustion tests to insure the reliability of the case before the production of the flight model. The hydraulic, vacuum and non destruction testes as the structure test were carried out to confirm the strength of the components of the case and the characteristics of the thermal and structure were investigated through the ground combustion test.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.473-480
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• 2005

A three axes marine satellite antenna has been developed. As a design step, a CAD model for the antenna has been created according to the design requirements. Kinematic analyses are carried out to insure design specification and to check collision detection of the CAD model. Marine satellite antennas experience base motions, and a relevant control system should control the three antenna axis to point to the satellites accurately. A sensor fusion algorithm and a PIDA (Proportional, Integral, Derivative, Acceleration) control algorithm are designed and implemented to control the yaw, level, and cross-level angle of a small size satellite marine antenna. Antenna stabilization control experiments are performed using a test simulator which gives the antenna base motions. Experimental results show small pointing errors, which is less than 0.2 degree for the level, cross-level, and yaw axis.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.18-22
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• 2014

A new concept tractor is developed, which can conduct multi-functional complex tasks such as excavating and working with attached various equipments. A cabin of the agricultural tractor is designed to protect the driver from vibration transmitted due to the irregular ground and overturning of the tractor. In this paper, the dynamic characteristic of the cabin is identified through finite element analysis and effects of configurational parameters are investigated to insure the dynamic stiffness of the cabin.

• International Commerce and Information Review
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• v.10 no.4
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• pp.533-551
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• 2008

Export Credit Agency(ECA) plays a role of importance in international trade and investment flows. The first ECA, the Export Credits Guarantee Department(ECGD) of the United kingdom, was established in 1919. Its original purpose was to encourage and support exports that would not otherwise have taken. Similar motivations led to the establishment, most of those in operation today. Their traditional role is to support and encourage exports and outward investment by insuring international trade and investment transactions, and in some cases by providing trade finance directly. ECA come in all shapes and sizes, and there in no such thing as a typical ECA model. Most of them insure both political and commercial risks on exports and until the last decade. They operated as government entities or on the account of their government, and many of them have changed and are still changing. This study focuses and analyzes the changes of those four major countries' ECAs, which are the U.S.A.(EXIM), France(COFACE), Japan(JBIC), and Canada(EDC).

• Journal of the Korean Institute of Educational Facilities
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• v.10 no.3
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• pp.15-26
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• 2003

The purpose of this study is to describe the planning and applied safety facility layout for a technology laboratory in a middle school. A technological teaching facility has its essential purpose in meeting students' needs and achieving educational objectives efficiently and effectively. Practice-related appliances were selected through investigation of the current middle school laboratory, and analysis of the technology textbooks of the 7th curriculum. Laboratory layout was achieved with consideration of the teacher's and students need of safety and close proximity to laboratory facilities and equipment. Our recommendation takes the SLP survey results into consideration. The results of this study are as follows: The following floor plan is recommended. The facility layout will insure that students are able to work safely, in full view of academic instructors. Students will have easy access to all equipment due to the efficient floor plan and logical sequencing of equipment.

• Journal of Welding and Joining
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• v.8 no.3
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• pp.39-52
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• 1990

The research is to insure the soundness of the stainless steel overlaid weld metal(21/4Cr-IMo steel + SUS 309L) for a pressure vessel application. Detail studies were conducted for the PWHT influence on the micrstructure and intergranular corrosion characteristics of the overlaid weld metal as well as initiation of hydrogen embrittlement crack(or Disbonding) when welded metal are exposed to the hydrogen atmosphere. Hydrogen was experimentally charged to the overlaid weld metal in order to study PWHT effect on the susceptibility of hydrogen embrittlement crack. The results of this research are as follows: 1. At the bond region, austenite grain of the stainless steel side became coarsed and Cr23C6 type carbide was precipitated at the coarsed austenitic grain boundaries. Intergranular Corrosion width(by Straiss test) increased with increasing PWHT temperature and PWHT time.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.240-248
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• 1999

This paper presents a lane-change collision avoidance control algorithm for autonomous vehicles that will be used in AHS(Automated Highway System). In the proposed control algorithm, nominal control inputs are generated by solving the inverse vehicle dynamic equations of motion for a lane-change maneuver. In addition, a corrective steering input from preview as well as DYC (Direct Yaw Moment Control) may be included to reduce unpredictable errors and to insure yaw directional stability, respectively. The performance of the algorithm is evaluated with an ABS HILS system which consist of 17 DOF vehicle model and real ABS hardware parts. The HILS simulation results show that the proposed algorithm may be used for emergency lane-change maneuvers for autonomous vehicles.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.3
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• pp.6-14
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• 2007

In this research, vibration reduction and aeroelastic stability of a composite hingeless rotor hub flexure with viscoelastic constrained layer damping treatment(CLDT) were investigated. The composite flexures with viscoelastic CLDT were applied to hingeless rotor system to improve the in-plane stability of the lead-lag motion causing resonance. The modal test was performed and dynamic properties(natural frequency and loss factor) were acquired. Also, complex eigenvalue analysis(SOLlO7) in the NASTRAN structural analysis module was performed and compared with results of the modal test. To insure aeroelastic stability, damping ratio analyses of the hingeless rotor system with CLDT were accomplished at hovering condition due to collective pitch angle changes. Satisfactory results of increasing structural damping and stability were obtained.

• Health Policy and Management
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• v.28 no.3
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• pp.251-256
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• 2018

The origin of hospital accreditation in Korea is the Hospital Standardization Program of the Korea Hospital Association. Current accreditation program implemented by the Korea Institute for Healthcare Accreditation has succeeded in stimulating quality improvement activities of participating hospitals since its launching in 2010. However it has been criticized due to some unintended consequences of accreditation. In order to fully enjoy the benefit of the accreditation program in Korea, national efforts to expand accreditation scheme and coverage, upgrade accreditation standards, insure substantiality of accreditation process, provide consumers with more useful information, and strengthen the professional capacity of accreditation organization will be needed.