• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.776-779
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• 2003

To reduce the storage space of spent fuel used at the atomic power plants in the over the world, the uranium elements contained in the spent fuel is being extracted and effectively stored. For this, the spent fuel are oxidized and deoxidized. In this study, it is produced the heat-resisting methods about the spent fuel management technology research and test facility for the spent fuel waste for spent fuel minimized. The first considered processes in the facility are the electrolytic metal reduction reactor process. Since the electrolytic metal reduction reactor is operated at the high temperature range, we have to consider the heat-resisting methods for the devices. For the heat-resisting methods, we have searched and analyzed technical reference for the heat-resisting methods. We have calculated thermal stress and strain of each devices by the commercial analysis software, ANSYS. D.S. It is experimented for inspecting confidence rate of analysis results. By using the results, we have analyzed the problems of parts and determined the heat-resisting material, commercial parts, and the size of parts and O-ring. Based on these results, it is produced the heat-resisting methods of magnesia filter, cathode, and reactor for the electrolytic metal reduction reactor.

• Steel and Composite Structures
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• v.23 no.2
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• pp.153-160
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• 2017

It is extremely important to be aware of the ballistic performances of engineering materials in order to be able to choose the lightest armor providing full ballistic protection in civil and military applications. Therefore, ballistic tests are an important part of armor design process. In this study, ballistic performance of plates made of carbon steel and cold worked tool steel against 7.62 mm AP (armor-piercing) bullets was examined experimentally and numerically in accordance with NIJ standards. Samples in different sizes were prepared to demonstrate the effect of target thickness on ballistic performance. Some of these samples were coated with titanium nitride using physical vapor deposition (PVD) method. After examining all successful and unsuccessful samples at macro and micro levels, factors affecting ballistic performance were determined. Explicit non-linear analyses were made using Ls-Dyna software in order to confirm physical ballistic test results. It was observed that the ballistic features of steel plates used in simulations comply with actual physical test results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.10
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• pp.1841-1861
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• 2011

The advance in Service-Oriented Architecture (SOA) and web services has led to the development of new types of a system in which heterogeneous service components can connect and compose to solve a complex business problem. In the SOA, even though these service components are valid in their functionality, there is a need to test their behaviors when those services are composited. In recent years, WS-BPEL has received a wide acceptance as a means of integrating distributed service components. To test the composite service, the existing testing techniques have been focused on the functional features based on the WS-BPEL process. However as SOA approach is applying to real-time software development, the performance of composite service becomes one of important issues. This paper proposes a technique to the performance testing of a composite service with WS-BPEL extension which combined with the concept of aspect. Our WS-BPEL extension has been made towards annotating aspect component which is measuring the response time of the composite service. This paper also explains the procedure of performance testing with on-line transaction system. Our technique can apply to choose an adequate component in service composition with considering the performance among several candidate web service components.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.9
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• pp.381-388
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• 2014

In this paper, we deal with implementation issues of an unknown word classifier for middle-school level English writing test. We define the type of unknown words occurred in English text and discuss the detection process for unknown words. Also, we define the type of swear words occurred in students's English writings, and suggest how to handle this type of words. We implement an unknown word classifier with a swear detection module for developing an automatic English writing scoring system. By experiments with actual test data, we evaluate the accuracy of the unknown word classifier as well as the swear detection module.

• Earthquakes and Structures
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• v.17 no.1
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• pp.39-48
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• 2019

This paper presents an experimental study on a 1/2 scale steel frame with archaized-style under the pseudo-dynamic loading. Four seismic waves, including El Centro wave, Taft wave, Lanzhou wave and Wenchuan wave, were input during the test. The hysteresis characteristic, energy dissipation acceleration response, displacement response, strength, stiffness and strain were analyzed. Based on the experiment, the elastoplastic dynamic time-history analysis was carried out with the software ABAQUS. The stress distribution and failure mode were obtained. The results indicate that the steel frame with archaized-style was in elastic stage when the peak acceleration of input wave was no more than 400 gal. Under Wenchuan wave with peak acceleration of 620 gal, the steel frame enters into the elastoplastic stage, the maximum inter-story drift was 1/203 and the bearing capacity still tended to increase. During the loading process, Dou-Gong yielded first and played the role of the first seismic fortification line, and then beam ends and column bottom ends yielded in turn. The steel frame with archaized-style has good seismic performance and meets the seismic design requirement of Chinese code.

• Computers and Concrete
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• v.28 no.5
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• pp.497-506
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• 2021

Steel-concrete composite structures and precast concrete elements have a common prefabrication process and allow fast construction. The use of hollow-core slabs associated with composite floors can be advantageous. However, there are few studies on the subject, impeding the application of such systems. In this paper, a numerical model representing the considered system using the FE (finite element)-based software DIANA is developed. The results of an experimental test were also presented in Souza (2016) and were used to validate the model. Comparisons between the numerical and test results were performed in terms of the load versus displacement, load versus slip, and load versus strain curves, showing satisfactory agreement. In addition, a wide parametric study was performed, evaluating the influence of several parameters on the behaviour of the composite system: The strength of the steel beam, thickness of the web, thickness and width of the bottom flange of the steel beam and concrete cover thickness on top of the beam. The results indicated a great influence of the steel strength and the thickness of the bottom flange of the steel beam on the capacity of the composite floor. The remaining parameters had limited influences on the results.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.2
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• pp.65-70
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• 2015

In the PCB(Printed Circuit Board) manufacturing industry, the yield is an important management factor because it affects the product cost and quality significantly. In real situation, it is very hard to ensure a high yield in a manufacturing shop because products called chips are made through hundreds of nano-scale manufacturing processes. Therefore, in order to improve the yield, it is necessary to analyze main fault process and equipment that cause low PCB yield. This paper proposes a systematic approach to discover fault-causing processes and equipment by using a logistic regression and a stepwise variable selection procedure. We tested our approach with lot trace records of real work-site. A lot trace record consists of the equipment sequence that the lot passed through and the number of faults for each fault type in the lot. We demonstrated that the test results reflected the real situation of a PCB manufacturing line.

• Design & Manufacturing
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• v.14 no.4
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• pp.71-77
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• 2020

Various manufacturing technologies, including over-molding and insert-injection molding, are used to produce hybrid plastics and metals. However, there are disadvantages to these technologies, as they require several steps in manufacturing and are limited to what can be reasonably achieved within the complexities of part geometry. This study aims to determine a practical approach for producing metal/plastic hybrid components by combining plastic injection molding and metal die casting to create a new hybrid metal/plastic molding process. The integrated metal/plastic hybrid injection molding process developed in this study uses the proven method of multi-component technology as a basis to combine plastic injection molding with metal die casting into one integrated process. In this study, the electrical conductivity and ampacity were verified to qualify the new process for the production of parts used in electronic devices. The electrical conductivity was measured, contacting both sides of the test sample with constant pressure, and the resistivity was measured using a micro ohmmeter. Also, the specific conductivity was subsequently calculated from the resistivity and contact surface of the conductor path. The ampacity defines the maximum amount of current a conductive path can carry before sustaining immediate or progressive deterioration. The manufactured hybrid multi-components were loaded with increasing currents, while the temperature was recorded with an infrared camera. To compare the measured infrared images, an electro-thermal simulation was conducted using commercial CAE software to predict the maximum temperature of the power loaded parts. Overall, during the injection molding process, it was demonstrated that multifunctional parts can be produced for electric and electronic applications.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.5
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• pp.688-699
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• 2017

Model-based test, a well-known method of the black box tests, is consisted of the following four steps : model construction using requirement, test case generation from the model, execution of a SUT (software under test) and detection failures. Among models constructed in the first step, state-based models such as UML standard State Machine are commonly used to design event-based embedded systems (e.g., weapon control systems). To generate test cases from state-based models in the next step, coverage-based techniques such as state coverage and transition coverage are used. Round-trip path coverage technique using W-Method, one of coverage-based techniques, is known as more effective method than others. However it has a limitation of low failure observability because the W-Method technique terminates a testing process when arrivals meet states already visited and it is hard to decide the current state is completely same or not with the previous in the case like the GUI environment. In other words, there can exist unrevealed faults. Therefore, this study suggests a Extended W-Method. The Extended W-Method extends the round-trip path to a final state to improve failure observability. In this paper, we compare effectiveness and efficiency with requirement-item-based technique, W-Method and our Extended W-Method. The result shows that our technique can detect five and two more faults respectively and has the performance of 28 % and 42 % higher failure detection probability than the requirement-item-based and W-Method techniques, respectively.

• Journal of Ocean Engineering and Technology
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• v.21 no.2 s.75
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• pp.67-74
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• 2007

Maritime and Ocean Engineering Research Institute (MOERI), a branch of KORDI, has designed and manufactured a model of an autonomous underwater vehicle (AUV) named ISiMI (Integrated Submergible for Intelligent Mission Implementation). ISiMI is an AUV platform to satisfy the various needs of experimental test required for development of challenging technologies newly investigated in the field of underwater robot; control and navigational algorithms and software architectures. The main design goal of ISiMI AUV is downsizing which will reduce substantially the operating cost compared to other vehicles previously developed in KORDI such as VORAM or DUSAUV. As a result of design and manufacturing process, ISiMI is implemented to be 1.2 m in length, 0.17 m in diameter and weigh 20 kg in air. A series of tank test is conducted to verify the basic functions of ISiMI in the Ocean Engineering Basin of MOERI, which includes manual control with R/F link, auto depth, auto heading control and a final approach control for underwater docking. This paper describes the implementation of ISiMI system and the experimental results to verify the function of ISiMI as a test-bed AUV platform.