• Journal of The Korean Association of Information Education
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• v.8 no.1
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• pp.1-13
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• 2004

A new on-line essay test system that write the articles to manuscript paper which has two hundred squares for characters, look over and correct the manuscript paper in environment of on-line network like the real essay test is designed and implemented in this thesis. Using this system, a participant can write the articles to manuscript paper, a scorer look over and can correct the articles on manuscript paper directly. When looking over and correcting manuscript paper in this system, scorer can use a pen-mouse and a tablet. To reduce the network traffic, bitmap format of the manuscript paper is compressed to JPEG format before it is transmitted to server. The system is cost-effective and has lots of advantages in efficiency and usability. Furthermore, it is expected that the developed system can be used to improve the field of on-line subjective examinations as a counterproposal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.3
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• pp.155-161
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• 1993

It is usually very expensive and often impractical to extend a load test on a large pile until collapse. Many graphical or mathematical methods have been attempted to estimate the bearing capacity from the results of a vertical load test without having to load the pile to failure. According to Fellenius, the failure value must be based on some mathematical rule and generate a repeatable value that is independent of scale relations and the opinions of the individual interpreter. This study presents the method which may estimate the failure load using the maximum curvature to apply Kondner's theory from the results of a loading test which cannot be extended until the failure load is reached.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1669-1674
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• 2012

A commonly analytical estimation of fatigue life on rubber components is using fatigue life equation based on various fatigue test results. However, such method has very restricted applicability in actual designing processes because performing fatigue tests requires a lot of time and money. In addition, non-standard rubber materials and their randomness make it hard to make databases. In this paper, the other fatigue life estimation method using tearing energy was suggested. We performed static and dynamic tearing test about automotive vibration rubber materials and a finite element formulation using a virtual crack to calculate the tearing energy of rubber components with complicated shapes. To using the suggested method, fatigue life of an automotive motor mount has been estimated and verified the reliability of this method by using comparison between the estimated values and the actual fatigue life.

• Tunnel and Underground Space
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• v.28 no.1
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• pp.72-96
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• 2018

Accurate estimation of the uniaxial compressive strength of rock is very crucial for the safety of construction activities occurring in the rock mass. However, the uniaxial compressive strength test is expensive and time consuming. Moreover, the uniaxial compressive strength test cannot be performed in the field. In order to solve this kind of problem, many foreign researchers investigated the use of the point load strength test for the estimation of uniaxial compressive strength of rock. However, the result of research obtained for rocks from other countries may not be directly applicable for rocks in Korea. The correlation between the point load strength index and the uniaxial compressive strength for rocks in Korea is suggested in the form of table by using the results of the extensive literature reviews and laboratory tests. The suggested result is expected to be used for the simple and quick estimation of uniaxial compressive strength of rocks in Korea.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.731-738
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• 2015

The rapid prototyping process and development tool which enable the control law evaluation efficiently are needed to minimize the development cycle, cost and risk of aircraft flight control system. This paper describes a development process that integrates the designed control law into HETLAS to evaluate simulation effectively using nonlinear mathematical models. The desktop engineering simulator was developed using HETLAS for the piloted simulation evaluation of a various control modes and the procedure was developed, which quickly integrates the HETLAS into HQS(Handling Quality Simulator) and HILS(Hardware In the Loop Simulation) environments. This paper presents a rapid prototyping process using HETLAS that significantly shortens the integration process of the control law into the nonlinear math model, HETLAS, and allows the control law designs to be quickly tested in the piloted simulation and HILS environments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.165-170
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• 2020

In the rapidly growing new and renewable ESS parts and materials market, there is a limit for domestic SMEs to cope with the rapidly changing global new and renewable ESS market. There is a growing need to build a new and renewable ESS convergence commercialization support center. Therefore, through the establishment of a new and renewable ESS convergence professional evaluation center base, performance evaluation and standardization of new and renewable ESS products enhance product reliability. And By securing the reliability of new and renewable ESS, it is possible to promote domestic supply business and export activation. In addition, by supporting domestic research institutes and manufacturers to enhance their development capabilities and strengthen their competitiveness, and shortening the test cost and testing period according to the total-test evaluation system, it is possible anti-spill effect can be expected. Therefore, in this paper, we intend to study the establishment of a test certification center beyond the level of developed countries that can establish standardization for performance evaluation and demonstration.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.552-562
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• 1997

This paper proposes a formal method on confromance testing for INAP(AIN) test sequence generation by optimization technique.In order to implement and prove the dffectiveness of the proposed method,we specify the SRSM of INAP protocol SRF in SDL and generate I/O FSM by using our S/W tool. We generate an opti-mal test sequence by applying our method our method to this reference I/O FSM. We prove experimentally that the length of the generated test sequence by our method is more effective and shorter(i.e 32% improved)than the one geverated by UIO method,and estimate that The test coverage space of our test sequence is larger that of UIO method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.979-984
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• 2012

An antiroll-bar assembly is a precision component that is designed to control the rolling of railway cars. It is important for ensuring a safe and comfortable ride. A torsion bar is the main part of the antiroll-bar assembly. Now, this part is classified as a consumable, and it is imported into Korea from France. Therefore, there is a strong need to domestically develop a torsion bar suitable for Korean conditions and to reduce cost and improve quality. In this study, an antiroll bar is developed, and it is analyzed and tested by using a road histogram measured on Korean railroads. This bar shows satisfactory results in a comparison with the imported bar. It has a novel design featuring a ring cover made of SUS steels to prevent the corrosion of the torsion bar. Its safety is examined through CAE analysis and wear tests. It is found that its design does not result in a significant difference in static and fatigue safety. Two different SUS steels were investigated in terms of their wear resistance, and the best one was adopted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2553-2558
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• 2014

Military rotorcraft should be designed taking into account the condition of the fuel cell bullet impact. The internal fluid pressure, stress of metal fitting and fuel cell, bullet kinetic energy can be included as the design factor for the fuel cell. The best way to obtain the important design data is to conduct the verification test with actual product. But, the verification test requires huge cost and long-term effort. Moreover, there is high risk to fail because of the sever test condition. Thus, the numerical simulation is required to reduce the risk of trial-and-error together with prediction of the design data. In the present study, the bullet impact simulation based on SPH(smoothed particle hydrodynamics) is conducted with the commercial package, LS-DYNA. As the result of the numerical simulation, the internal pressure of fuel cell is calculated as 350~360MPa and the equivalent stress caused by hydro-ram effect is predicted as 260~350MPa on metal fittings.

• Journal of the Korean GEO-environmental Society
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• v.23 no.7
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• pp.5-10
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• 2022

The industrial waste is becoming a big problem in the aspect of spatial and environmental in domestic and international. Therefore, the waste reduction and recycling policy has been being implemented as a way to solve this problem. The engineered stone sludge, which is waste, is generated duing the engineered stone production process. since engineered stone sludge is mostly treated by landfill, an increase in the amount of the sludge leads to an increase in landfill sites and treatment costs. therefore, there is a need for a method of resourcization with engineered stone sludge. So, laboratory tests (Plastic and liquid limits, compaction, unconfined compression and permeability test) were conducted to confirm the possibility of using engineered stone sludge mixed with weathered granite soil as a cover material for landfill in this study. The result shows that the mixed soil material with less that 62.5% of engineered stone sludge can be used as a cover material for landfill.