• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.79-90
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• 2008

This paper introduces how we have designed and implemented an efficient starting line-up system of professional baseball players, using the forward chaining technology which is an expert system technology. The knowledge base adopted holds 286 players and 148 evaluation Items. Each player's competitiveness is measured as a numerical value in points through 2 different phases. The 1st phase point represents the static information of the target player and the 2nd his dynamic information. This paper gets a representative value of the player, which is used as the basis on which an efficient line-up system in views of both game environments and counterparts is constructed.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.20-30
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• 2005

In the anaerobe identification, when we develop the clinical decision support system for department of laboratory medicine, we must consider expression of an incomplete knowledge structure and addition of an evolving knowledge based on an expert's informal and heuristic knowledge is very complicated work flow. In the present study, we developed the system for anaerobe identification to advise on identification of unknown bacillus using knowledge base and inference engine. In the future, we are planning to develop the clinical decision support system for the whole bacteria not only an anaerobe but also aerobe to offer an expert's static and dynamic knowledge.

• Transactions of Materials Processing
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• v.12 no.1
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• pp.60-65
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• 2003

HIP diffusion bonding of Ni-based superalloys, cast Mar-M247 (MM247) and Udimet 720 (U720) powder, was experimentally and numerically studied. Subsolvus HIP treatment was optimized by investigating the variations of high temperature tensile properties of HIP-bonded specimens with powder size, HIP'ing time, etc. While the tensile strength at high temperatures showed no detectable changes, the tensile elongation and reduction in area were slightly increased as the powder size decreased from -140 mesh to -270 mesh. While as-HIP'ed U720 showed a high tensile strength comparable to that of lorded U720 alloy, the HIP diffusion-bonded specimen showed a strength lower than the forged U720 alloy and the cast MM247 alloy The increase of HIP'ing tune from 2 hours to 3 hours resulted in a rapid risc of tensile strength and elongation due to the disappearence of microvoids in the cast MM247. FEM simulation for HIP process was conducted by applying the McMeeking micromechanical model, which uses power-law creep model as constitutive equations. ABAQUS user subroutine CREEP with an implemented microscopic model was used for the simulation. Numerical simulation was shown to be essential for the near-net shape manufacturing as well as the HIP process optimization.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.68-74
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• 2011

This papers investigated the mechanical characteristics and the weldability of identical as well as dissimilar welding by GTAW for STS 304 and STS 316L. It is applied to double wall gas pipe of duel fuel engine for LNG carrier. Consequently, the weldability of dissimilar and identical welded zone of STS 304 decreased compared to base metal significantly. The result of microstructure observation for welded zone, a degree of acicular ferrite in welding zone for STS 304 presented more than STS 316L. The hardness of welding zone for STS 304 presented higher value than that for STS 316L by this effect.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1312-1316
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• 2007

Strip casted and rolled magnesium sheet is become exiting material for car manufacturer, due to its better formability and specific strength compare with conventional extruded sheet. TWB technology was attractive for car body designer, because it saves the weight of the car without strength loss. In this study, the laser welding performance of magnesium sheet was investigated for Mg TWB panel manufacturing. The material was strip casted and rolled magnesium alloy sheet contains 3 wt% Al and 1 wt% Zn (AZ31). Lamp pumped Nd:YAG laser of 2kW was used and its laser light was delivered by optical fiber of 0.6mm core diameter to material surface with focusing optics of 200mm focal length for TWB welding. The microstructure of weld bead was investigated to check internal defects such as inclusion, porosity and cracks. Also mechanical properties and formability were evaluated for press forming of car body. For the results, there was no crack but inclusion or porosity on weld at some conditions.The tensile strength of weld was over 95% of base metal. Inner and outer panel of engine hood were press formed and assembled at elevated temperature.

• Advances in materials Research
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• v.8 no.4
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• pp.275-293
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• 2019

The engine parts material used in gas turbines (GTs) should be resistant to high-temperature variations. Thermal barrier coatings (TBCs) for gas turbine blades are found to have a significant effect on prolonging the life cycle of turbine blades by providing additional heat resistance. This work is to study the performance of TBCs on the high-temperature environment of the turbine blades. It is understood that this coating will increase the lifecycles of blade parts and decrease maintainence and repair costs. Experiments were performed on the gas turbine blade to see the effect of TBCs in different combinations of materials through the air plasma method. Three-layered coatings using materials INCONEL 718 as base coating, NiCoCrAIY as middle coating, and La₂Ce₂O₇ as the top coating was applied. Finite element analysis was performed using a two-dimensional method to optimize the suitable formulation of coatings on the blade. Temperature distributions for different combinations of coatings layers with different materials and thickness were studied. Additionally, three-dimensional thermal stress analysis was performed on the blade with a commercial code. Results on the effect of TBCs shows a significant improvement in thermal resistance compared to the uncoated gas turbine blade.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.283-289
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• 2006

This study is a preparation for the application of FSA (Formal Safety Assessment) to the fire safety of ships. FSA is the new-fashioned methodology proposed to prevent ships from the accidents. To make a base of the fire safety assessment about ship's fire protection design and Classification Society rule, statistical informations for the fire safety engineering are investigated. From results, the necessity of new criterion for ship's fire safety design, the need to study the human behavior in the evacuation from fire, and the development of new fire progress model considering special situations in ships are acknowledged.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.280-285
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• 2007

This paper proposes a technique improving performance using word senses and user feedback in web information retrieval, compared with the retrieval based on ambiguous user query and index. Disambiguation using word senses is very important processing for improving performance by eliminating the irrelevant pages from the result. According to semantic categories of nouns which are used as index for retrieval, we build the word sense knowledge-base and categorize the web pages. It can improve the performance of retrieval system with user feedback deciding the query sense and information seeking behavior to web pages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.1965-1971
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• 2010

A ship propulsion thruster platform which is used by safety sailing takes charge of remote control of a main engine in ship. This system not only guarantees safety and reliable flight sailing but also require remote control technology of a ship. Accordingly, in this paper it deals with a telegraph lever control unit system which is a part of propulsion thruster system as localization technology. Also it makes sure of knowledge and core technology through analysis and designing and developing a telegraph lever control unit system. Moreover, it is sure of acquisition of base technology for integration of a ship propulsion thruster platform.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1329-1332
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• 1987

This paper describes a design of the expert system for diagnosis of abnormal gait patients. This system makes the rule-based representation that can easily extend the knowledge-base and naturally represent the uncertainty, and the inference engine that uses forward chaining which covers the reasoning from the first condition to the goal. The results of inferring various maladies using this system are as follows: 1) In cases of progressive muscular dystrophy, cerebral vascular accident, peripheral neuropathic lesion and peroneal nerve injury, the result of inference is the same as that of medical specialists' with 100% accuracy. 2) In cases of Neuritis, Paralysis agitan and Brain tumor, the accuracy of inference is less than 50% compared to that of medical specialists. With above results, we decide that the rule-based representations of some maladies ard accurate relatively, but that the correction and the extention of some rules and some methods of problem solving are required in order to construct the complete expert system for diagnosis of abnormal gait patients.