• 한국세라믹학회지
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• 제35권3호
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• pp.264-272
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• 1998

The effect of catalytic condition on the properties of SiO2 aerogels has been investigated and then the dri-ed aerogels were partially densified to induce mechanical strength by heat treatment in order to prepare Type-VI silica by Sol-Gel method. Aerogel made by 1-step base process had the highest skeletal density lowest shrinkage and the smallest particle size. But in case of using acid catalyst in both 1st and 2nd step had the lowest skeletal density highest shrinkage and the largest particle size The aerogel synthesized by 1-step base process was most transparent because of its homogeneous microstructure. During heat treatments cracks occurred below 200$^{\circ}C$ for aerogel with the skeletal density lower than 1.9 g/cm3 but the with the higher skeletal density did not cracked up to 800$^{\circ}C$ shrinkage and skeletal density increased as heating temperature increased due to condensation and viscous sintering mechanism.

• 품질경영학회지
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• 제31권2호
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• pp.131-142
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• 2003

QFD(Quality Function Deployment) is design method which is focused to guarantee of quality and function to satisfy for customer’s need. QFD are used entire manufacturing, specially new production development and design. HOQ(House of Quality) are important tool of QFD, which is implement that complex function and communications of customer. Actually implementation of HOQ are difficult by HOQ's size. It is well known that complexity of HOQ are exponentially increasing by increasing of HOQ’s size. In this Paper, we study of HOQ Complexity reduction by Quantification Method of Type Ⅲ. That method is efficiency and minimize of loss information by reduction HOQ. We give example and prove our suggestion method is better than other methods.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
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• pp.307-309
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• 1996

This paper analyses a deterministic scheduling problem concerned with manufacturing two types of components at a pre-assembly stage which consists of two independent feeding machines each producing its own type of component. Each type represents a unique component which may have variations in its size or quality. Therefore, the completion time of each component depends on both its type and quality (size) variations. Such manufactured components are subsequently assembled into various component dependent products. The problem has the objective measure of minimizing the total weighted completion time of a finite number of jobs(products) where the completion time of each job is measured by the latest completion time of its two components at the pre-assembly stage. The problem is shown to be NP-complete in the strong sense. A WSPT rule coupled with a machine-aggregation idea is developed for good heuristics which show the error bound of 2.

• 한국인쇄학회지
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• 제16권3호
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• pp.43-60
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• 1998

The photosensitive properties and spectroscopic characteristics in the organic photoconductor(OPC) with carrier generation layer(CGL) of poly(vinylbutyral)(PVB) and polycarbonate(PC) doped with titanyl phthalocyanine(TiOPc) were investigated. The change of crystal structure of TiOPc dispersed with PVB and PC was shown by UV-visible reflective spectrum and FT-IR spectrum and mainly caused by the difference of solubility of solvent and the interaction between TiOPc and binder. The particle size of TiOPc dispersed with PVB measured by SEM was smaller than in PC. The crystal structure of TiOPc dispersed with PVB was amorphous type and in PC was $\alpha$type. It was found that the photosensitive properties of OPC were dependent on the change of absorbance and ionization potential of TiOPc occurred from the difference of crystal structure. In this work, the photosensitivity of OPC of TiOPc dispersed with PVB was better than PC due to the crystal type and the smaller particle size.

• 한국동물위생학회지
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• 제31권3호
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• pp.369-374
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• 2008

The objective of this study was to differentiate the beef species between Hanwoo and Holstein from a total of 1,081 beef samples using PCR-RFLP of MC1R gene. When a PCR product of 403 bp specific band amplified from bovine MC1R gene sequence was digested with restriction enzyme MspA1I, Hanwoo type showed 2 bands, 220 bp and 183 bp size bands. Holstein type, however, showed three bands, 220 bp, 138 bp and 45 bp size band, respectively. The results of the differential test for beef species were as following; 7 samples (0.64%) were determined to Holstein type, of which 4 were submitted from administrative authorities, other 3 from self-collection planing, and none from civilian clients including school.

• Tribology and Lubricants
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• 제11권1호
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• pp.20-26
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• 1995

Most magnetic bearings are based on the attractive force between the magnets and ferrous materials. One of the disadvantages of such attractive type magnetic bearings is the instability so that an active control device is necessary to operate bearing successfully. In this study a repulsive type magnetic bearing is analyzed which uses eddy current as a force source. The load capacities are analyzed for the various gap sizes, the rotor velocities and the frequencies of current supplied to electromagnet. Analytic Results show that as the gap size decreases, the levitation and drag forces increase, while the number of poles increasqs, the drag force decreases in the higher linear velocity region. Experimental results show that as the gap size decreases the levitation and the drag force increase, and as the velocity of rotor increases, the drag is larger than the levitation force up to certain velocity. But after that, the levitation is larger than the drag force. As the frequency of the current increases the levitation and drag decreases while the thickness of rotor gets thicker the forces decrease because of increase in eddy current loss.

• 한국주거학회논문집
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• 제10권4호
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• pp.11-21
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• 1999

The purpose of this study is to analyze the interrelation of architectural composition and type of windows and doors in Korean traditional architecture. Windows and doors type, in Korean traditional architecture, is one of the important element which used to playa great role in building's physical fasade, so that used to subjected the building as a whole. In this study, the investigations on the totally 88 Korean Buddhist Temples are made, and the analysis are made according to the physical size of buildings (length and height of JUGAN), composition of JUGAN, and existence of RUGAK. The result of this study indicates that there are outstanding typical differences of traditional windows and doors in advance to variation in the physical size of building, though there are numerous interrelation between typical differences of traditional windows and doors and composition of building as a whole.

• 가정과삶의질연구
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• 제11권1호
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• pp.35-45
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• 1993

The purpose of this study is to investigate the changes of housing characteristics and the degree of attainment of housing norms. The major findings are as follows: 1) There are significant differences in changes of housing characteristics. A size of house and the number of room have been improved according to hosing experience and housing expects. Type of tenure has been improved according to housing experience and housing expects. Type of tenure has been improved gradually according to moving. The family with higher socio-economic status prefers apartments. Although about a half of household hopes to live in a high-rising apartments. more than 40 persentage of the household still hopes to live in single detached houses. As a result apartment are though not to satisfy their housing well-being 2) As socio-economic status is higher and family life cycle is longer the degree of their attainment of housing norms appear higher. The household attaining higher housing norms has the higher housing satisfaction but needs to move is lower The family attains housing norms as the following orders: type of tenure\longrightarrowtype of house\longrightarrowthe nmber of rooms\longrightarrowa size of house.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.813-819
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• 2006

The state of the art for the design of swing ann actuators for optical disc drives is to obtain the high efficient dynamic characteristics, especially for the small size for the mobile information devices, It is affected by the need of consumers who wants the portable digital storage devices maintaining highly functional and removable characteristics of the optical disk drive (ODD). As a necessary consequence, the need of the small form factor (SFF) storage device has been considered as an important part in the information storage technology. In this paper. we suggest a new conceptual miniaturized swing arm type actuator that has high efficient dynamic characteristics as well as satisfies the sensitivity and the heat emission requirements for the SFF-ODD. It also uses a tracking electromagnetic (EM) circuit for a focusing motion. Due to the size constraint, the thermal problem of optical head arises; therefore, we design an efficiently heat emitted structure for the actuator.

• 대한화장품학회지
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• 제27권1호
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• pp.29-42
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• 2001

We had prepared MLV liposome with Hibiscus Esculentus Ext.(HEE) which have fluorescent light in order to evaluate its percutaneous absorption about hairless rat skin. Then we investigated particle size of MLV using confocal laser scanning microscope(CLSM) and transmission electron microscope(TEM), respectively. Stability of MLV liposome and penetration of MLV liposome to hairless rat skin was measured by CLSM. As a result of experiments, MLV was globular shape and the rage of particle size was 0.3-0.5$\mu\textrm{m}$ mostly. Cream-type MLV had high stability comparatively. When we treated with MLV to rat skin, skin penetration was enhanced, especially, the optimum concentration of MLV on penetration to rat skin was 10%. Optimum penetration time was 6hr-12hr. And MLV-type HEE was more effective on percutaneous absorption than HEE-cream or liposome-type HEE.