• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.4
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• pp.331-338
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• 1992

The application of Connectionist expert system using neural network to fault diagnosis of power system is presented and compared with rule-based expert system. Also, the merits of Connectionist model using neural network is presented. In this paper, the neural network for fault diagnosis is hierarchically composed by 3 neural network classes. The whole power system is divided into subsystems, the neural networks (Class II) which take charge of each subsystem and the neural network (Class III) which connects subsystems are composed. Every section of power system is classified into one of the typical sections which can be applied with same diagnosis rules, as line-section, bus-section, transformer-section. For each typical section, only one neural network (Class I) is composed. As the proposed model has hierarchical structure, the great reduction of learning structure is achieved. With parallel distributed processing, we show the possibility of on-line fault diagnosis.

• Journal of The Korean Association For Science Education
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• v.14 no.1
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• pp.70-84
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• 1994

This study tried to find the effect to cognitive structure upon the momentum effect. The previous studies showed that the momentum effect is influenced by students' cognitive levels and the abstractness of test items. The cognitive structure is examined by cognitive level and cognitive style. Cognitive levels and cognitive styles are determined by GALT and GEFT respectively. The research method used in this study is time series design. The period is 50 days. The period is divided into "pre-test", "intervention-test", "post-test". Pre-test period is 5 days and in this period class instruction does not exist Intervention-test period is 30 days and in this period class instruction exist Post-test period is 15 days and in this period class instruction does not exist. Field independent students showed longer momentum effect than field dependent students. Formal level students showed less ratio of decrease on post-test than nonformal level students. Momentum effects is not artifact but the essential characteristics of science study.

• Korean Journal of Computational Design and Engineering
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• v.13 no.2
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• pp.98-108
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• 2008

Plant, civil engineering and construction equipment data of overseas construction are obtained and then analyzed, classified and integrated by experts. With those refined data set, we built classification system and defined property information with reference to international standard (ISO 15926, IRDL). If class in ISO 15926 is predefined for equipment of interest, we used the class as is. If not, we created and defined new classes on the basis of ISO 15926 classes. If there is similar class for equipment of interest, extension or inheritance methods were used. As a result, classification system of five levels and 637 classes were built and construction equipment information were expressed in open structure of XML such as tree structure of classification system and detailed information with number equipments for each specific equipment. We also developed the electronic catalog system which is basically equipment information management system providing various product search functions.

• Journal of Integrative Natural Science
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• v.6 no.1
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• pp.57-63
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• 2013

Histone deacetylase (HDACs) is an enzyme family that deacetylates histones and non-histones protein. Availability of crystal structure of HDAC8 has been a boosting factor to generate target based inhibitors. Hydroxamic class is the most studied one to generate potent inhibitors. HDAC class I and class II enzymes are emerging as a therapeutic target for cancer, diabetes, inflammation and other diseases. DNA methylation and histone modification are epigenetic mechanism, is important for the regulation of cellular functions. HDACs enzymes play essential role in gene transcription to regulate cell proliferation, migration and death. The aim of this article is to provide a comprehensive overview about structure and function of HDACs enzymes, histone deacetylase inhibitors (HDACi) and HDACs enzymes as a therapeutic target for cancer, inflammation and diabetes.

• The Journal of the Acoustical Society of Korea
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• v.18 no.7
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• pp.67-73
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• 1999

We constructed a class Ⅳ Flextensional transducer, and analyzed the effects of the variation in its material properties and structure on the resonance frequency of the transducer. We used the FEM for the analysis. Major axis length, minor axis length, thickness and material properties of the shell turned out to have large effects, while volume of the insert material, material properties and thickness of the ceramic bar have little. Thickness of the nodal-plate has no effect on the resonance frequency. Results of the present work can be utilized to design Class W Flextensional transducers of various resonance frequency.

• Communications of the Korean Mathematical Society
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• v.32 no.2
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• pp.353-359
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• 2017

Starting from a t-norm T, it is possible to construct a class of new t-norms, so-called T-generalized t-norm. The purpose of this paper is to describe some properties of this class of generalized t-norms. An algebraic structure as well as a binary relation among t-norms are also investigated. Some open problems are discussed as well.

• Communications of the Korean Mathematical Society
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• v.35 no.4
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• pp.1255-1267
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• 2020

The class of isotropic almost complex structures, J_𝛿,𝜎, define a class of Riemannian metrics, g_𝛿,𝜎, on the tangent bundle of a Riemannian manifold which are a generalization of the Sasaki metric. This paper characterizes the metrics g_𝛿,0 using the geometry of tangent bundle. As a by-product, some integrability results will be reported for J_𝛿,𝜎.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.4
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• pp.208-211
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• 2018

This paper details the design of a 1,200 V class trench gate field stop IGBT (insulated gate bipolar transistor) with a nano gate structure smaller than 1 um. Decreasing the size is important for lowering the cost and increasing the efficiency of power devices because they are high-voltage switching devices, unlike memory devices. Therefore, in this paper, we used a 2-D device and process simulations to maintain a gate width of less than 1 um, and carried out experiments to determine design and process parameters to optimize the core electrical characteristics, such as breakdown voltage and on-state voltage drop. As a result of these experiments, we obtained a wafer resistivity of $45{\Omega}{\cdot}cm$, a drift layer depth of more than 180 um, an N+ buffer resistivity of 0.08, and an N+ buffer thickness of 0.5 um, which are important for maintaining 1,200 V class IGBTs. Specially, it is more important to optimize the resistivity of the wafer than the depth of the drift layer to maintain a high breakdown voltage for these devices.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2707-2715
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• 2010

This paper suggests a implements and a design of class diagram authorization tool based on the MVC pattern. It defines and descries the structure of ClassInformation, ScreenDisplay and ToolManager. ClassInformation is responsible for processing or handling information of a diagram. ScreenDisplay is responsible for GUI to configure the screen of the authorization tool. ToolManager is responsible for event handling to process I/O of the authorization tool. Based on MVC pattern, ClassInformation, ScreenDisplay and ToolManager of the authorization tool are assigned each role independently. It is flexible to new requirement, because of loose coupling.

• Educational Technology International
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• v.19 no.2
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• pp.175-197
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• 2018

Flipped classroom (FC) has gained attention as an active learning approach. Designing effective out-of-class activities to help prepare students for in-class activities is fundamental for successful implementation of FC. This study investigated the effectiveness of Goal-Based Scenarios (GBS) for out-of-class learning in FC. Four out of twelve units in a medical humanities course for Year 2 medical students was redesigned into a FC format, where e-learning modules were designed using a GBS approach for out-of-class activities and classroom debates were implemented for in-class activities. The other eight units were delivered in a conventional classroom debate format, which included reading text materials as pre-class assignments. A formative evaluation study was conducted using questionnaires and interview methods and students' academic achievements were evaluated by comparing their pre- and post-test scores between FC and conventional units. Students had positive perceptions of the e-learning modules in GBS approach and preferred the structure of learning in the FC format. Students' pre-test scores were slightly higher in the FC units, yet their post-test scores were comparable with conventional units. This study illustrates students' perceptions that the learning was bettered structured in FC and that the out-of-class learning using the GBS approach helped them better prepared for in-class activities.