• Journal of Computational Design and Engineering
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• 제3권1호
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• pp.1-13
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• 2016

The increase of consumer needs for quality metal cutting related products with more precise tolerances and better product surface roughness has driven the metal cutting industry to continuously improve quality control of metal cutting processes. In this paper, two different approaches are discussed. First, design of experiments (DOE) is used to determine the significant factors and then fuzzy logic approach is presented for the prediction of surface roughness. The data used for the training and checking the fuzzy logic performance is derived from the experiments conducted on a CNC milling machine. In order to obtain better surface roughness, the proper sets of cutting parameters are determined before the process takes place. The factors considered for DOE in the experiment were the depth of cut, feed rate per tooth, cutting speed, tool nose radius, the use of cutting fluid and the three components of the cutting force. Finally the significant factors were used as input factors for fuzzy logic mechanism and surface roughness is predicted with empirical formula developed. Test results show good agreement between the actual process output and the predicted surface roughness.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.103-106
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• 2009

Fracture characteristics of plate shape using shock tube for glass filled ceramics was carried out. Glass filled ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role separating solid and liquid fuel, and needs the frangible characteristics that the fracture of a part should not affect the internal components of combustion. The objectives of this study are to evaluate the fracture pressures for various thicknesses and diameters of shock impact area. Also fracture phenomena of separated membrane using a shock tube are observed. The experimental apparatus of shock tube consists of a driver, a driven section and a dump tank. The used material is glass filled ceramic made from Corning company. Specimens are used 3, 4.5 and 6mm thickness. Also diameters of shock wave area are chosen 70, 60 and 50 mm. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.353-358
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• 2001

Turbo-charging or Super-charging has been used to boost engine power for Gasoline Engine and Diesel Engine came to the world at the beginning of $20^{th}$ century. So far Turbo-Charger has enjoyed a high reputation in the charging filed for its technical advantages such as no demand of operation power from engine and an excellent charging effect in the event of a static operation at mid- and high engine speed. A mechanically driven Super-Charger, however, is now emerging in order to meet demands of the age of speed such as high engine power for a quick change of the driving mode - high engine torque even at low engine speed. Since Super-Charger needs driving power from engine, it cannot improve its relatively higher fuel consumption against that of Turbo-Charger. This negative point is still an obstacle to the wide use of Super-Charger. Super-Charger using Screw-type compressor which has already had a considerable base in air compressor market will fulfill this purpose of improving fuel consumption by minimizing operation power owing to no charging at idling or partially loading driving. This study aims to develop power control concept to achieve this minimization of operation power.

• 대한기계학회논문집A
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• 제33권11호
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• pp.1274-1278
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• 2009

Fracture characteristics for plate and dome shapes of glass filled ceramics using shock tube were carried out. Glass filled ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role as separated membrane between combustion and external air, and needs the frangible characteristics that the particles of fractured glass filled ceramics should not affect the internal components of combustion. The objectives of this study are to evaluate the fracture pressures for various thicknesses and diameters of shock impact area. Also fracture phenomena of separated membrane using a shock tube compare with analytical method. The experimental apparatus consists of a driver, a driven section and a dump tank. The used material is glass filled ceramic made from Corning company. Specimens have the thickness of 3, 4.5 and 6mm. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.

• 한국인터넷방송통신학회논문지
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• 제14권3호
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• pp.163-169
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• 2014

현재 범용 컴퓨터 시스템을 구축할 때 성능을 높이기 위하여 멀티코어 프로세서가 널리 이용되고 있으며, 멀티코어 프로세서의 구조는 크게 대칭적 구조와 비대칭적 구조로 나뉜다. 비대칭적 멀티코어 프로세서는 크고 복잡한 고성능의 코어와, 작고 간단한 저성능의 프로세서들로 구성되며, 대칭적 멀티코어 프로세서에 비하여 더욱 성능과 효율이 높은 것으로 알려져 있다. 본 논문에서는 다양한 구성을 갖는 비대칭적 쿼드코어 및 옥타코어 프로세서에 대하여 SPEC 2000 벤치마크를 통하여 모의실험을 수행하여 그 성능을 측정하고, 대칭적 쿼드코어 및 옥타코어 프로세서와 그 성능을 비교하였다.

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.889-896
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• 2012

Recent progress in the computational fluid dynamics methods of two- and multiphase phase flows has already started opening up new exciting possibilities for using complete multidimensional models to simulate boiling systems. Combining this new theoretical and computational approach with novel experimental methods should dramatically improve both our understanding of the physics of boiling and the predictive capabilities of models at various scale levels. However, for the multidimensional modeling framework to become an effective predictive tool, it must be complemented with accurate mechanistic closure laws of local boiling mechanisms. Boiling heat transfer has been studied quite extensively before. However, it turns out that the prevailing approach to the analysis of experimental data for both pool boiling and forced-convection boiling has been associated with formulating correlations which normally included several adjustable coefficients rather than based on first principle models of the underlying physical phenomena. One reason for this has been the tendency (driven by practical applications and industrial needs) to formulate single expressions which encompass a broad range of conditions and fluids. This, in turn, makes it difficult to identify various specific factors which can be independently modeled for different situations. The objective of this paper is to present a mechanistic modeling concept for both pool boiling and forced-convection boiling. The proposed approach is based on theoretical first-principle concepts, and uses a minimal number of coefficients which require calibration against experimental data. The proposed models have been validated against experimental data for water and parametrically tested. Model predictions are shown for a broad range of conditions.

• 한국언어정보학회지:언어와정보
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• 제13권1호
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• pp.77-92
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• 2009

Geis (1973) has provided various properties of the subjects and by + Gerund Phrase (GerP) in English causative constructions. Among them, the two main issues of Geis's analysis are as follows: unlike Lakoff (1965; 1966), the subject of English causative constructions, including causative-inchoative verbs such as liquefy, first of all, should be acts or events, not persons, and the by + GerP in the construction is a complement of the causative verbs. In addition to these issues, Geis has provided various data exhibiting other idiosyncratic properties and proposed some transformational rules such as the Agent Creation Rule and rule orderings to explain them. Against Geis's claim, I propose that English causative verbs require either Proper nouns or GerP subjects and that the by + GerP in the constructions as a Verbal Modifier needs Gerunds, whose understood Affective-agent subject is identical to the subject of causative verbs with respect to the semantic index value. This enables us to solve the two main issues. At the same time, the other properties Geis mentioned also can be easily accounted for in Head-driven Phrase Structure Grammar (HPSG) by positing a few lexical constraints. On this basis, it is shown that given the few lexical constraints and existing grammatical tools in HPSG, the constraint-based analysis proposed here gives a simpler explanation of the properties of English causative constructions provided by Geis without transformational rules and rule orderings.

• 대한수의학회지
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• 제55권2호
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• pp.125-131
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• 2015

A total of 11,395 animals were impounded in shelters in Seoul in 2013. The Animal Protection Division of the Seoul metropolitan government has annual contracts with local veterinary associations as well as Korean animal rescue and management organizations for providing shelter to animals, and collects monthly statistics from these groups. In 2013, the collected intake and outcome data for 25 districts were reviewed to analyze shelter capacity in terms of housing capacity (monthly daily average intake, required holding capacity, and adoption-driven capacity), staff capacity (staff hours required for daily care), and live release rate. Seasonal variations in the monthly daily average intake were observed, indicating that management of these shelters requires various strategies. This study was performed to analyze and interpret meaningful statistics for improving the efficiency of animal shelters in Seoul. However, inconsistent collection of animal statistics limited data compilation. Creation of a basic animal statistics matrix with reference to well-designed matrices from recognized professional animal shelters is essential. These complied statistical data will help plan for future animal shelter needs in Seoul.

• 한국초등과학교육학회지:초등과학교육
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• 제30권4호
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• pp.442-458
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• 2011

Digital textbook project is one of government-driven project to improve education due to integrating technology. Digital textbook need to be universally designed to fit for each student. Recently, universal design for learning( UDL) gains great attention as one of promising approaches for the development of the digital textbook through giving various options and flexibility to all students. UDL has three main principles, first provide multiple means of representation, second provide multiple means of action and expression, third provide multiple means of engagement. The purpose of the study is to analyze fourth grade science textbook according to three UDL guidelines and suggest implications to improve an existing science textbook. The results indicated that fourth grade science digital textbook has been partly applied UDL guidelines like implementing multimedia and multi- mode contents, learning and communication tools, and motivation strategies. But options which students can choose according to their needs and styles are insufficient and tools for expression and communication need to enhance for helping each student to overcome his/her obstacles for learning and need to be more and elaborate to support learner-centered science digital textbook.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.338-343
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• 2008

Fracture characteristics of plates and dome shapes for machinable glass ceramics using compressed shock wave. Machinable glass ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role separating solid and liquid fuel, and needs the frangible characteristics whereby the fracture of a part should not affect the internal components of combustion. The objective of this study are to evaluate the fracture pressure and phenomena of separated membrane using a shock tunnel. The experimental apparatus consists of driver, a driven section and a dump tank. The used material is machinable glass ceramic from Corning company. Specimens are used 3, 4.5 and 6mm thickness with plates and dome shapes. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.