• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.440-445
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• 1999

One of the important technical issues is how to decrease thermal expansion of ballscrew in proportion to the increase of machining speed. When measuring force of stretch of ballscrew, since not only actual expansion and the value of bending have to be considered, it's impossible to definite the exact value of expansion. In addition, support bearings of ballscrew gain considerable force in axial direction. It also generates thermal expansion on the ballscrew, and deteriorates the bearings. In conclusion, it's impossible to give the pretension enough to absorb the all elongation due to thermal expansion generated during machine running. If gave, bed, column and saddle are all bent to change machine accuracy, and the pretension of support bearing of ballscrew in machine tool.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.51-56
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• 2002

In order to achieve high precision machine tools, Performance enhancement of feed drive systems is required. One of the important technical issues is how to decrease thermal expansion of ball screw in proportion to the increase of machining speed. When measuring force of stretch of ball screw, since not only actual expansion and the value of bending have to be considered, it is impossible to define the exact value of expansion. In addition, support bearings of ball screw gain considerable force in axial direction. It also generates thermal expansion on the ball screw, and deteriorates the performances of the hearings. In conclusion, it is impossible to give the pretension enough to absorb all the elongation due to thermal expansion generated during machine is running. If given bed column and saddle are all bent to chance machine accuracy, and the support bearings of ball screw is damaged.

• Language and Information
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• v.9 no.2
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• pp.107-126
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• 2005

The impersonal or psyc-predicate construction in Old English (=OE) poses a special challenge for most case theories in generative linguistics. In the OE impersonal construction, the experiencer argument is marked by dative, accusative, or nominative, whereas the theme is marked by nominative, genitive, or accusative, or by a PP. The combinations of possible cases for experiencer and theme are not random, bringing about daunting complexity for possible and impossible case frames. In this paper, I develop a conceptual semantic case theory (a la Jackendoff 1990, 1997, 2002; Yip, Maling, and Jackendoff 1987) to provide a unified account for the complicated case frames of the OE impersonal construction. In the conceptual semantic case theory, syntax and semantics have their own independent case assignment principles. For impersonal verbs in OE, I propose that UG leave an option of determining either syntactic or semantic case to lexical items. This proposal opens a new window for the OE impersonal construction, in that it naturally explains both possible and impossible case frames of the construction.

• Journal of Korean Association for Spatial Structures
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• v.17 no.3
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• pp.91-98
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• 2017

Most of the cultural assets in Korea are wooden structures. Due to the material characteristics of wood, the preservation of traditional wooden structure is impossible by simple maintenance. Damaged member is replaced with new member or completely dissolve and restore them. But member has a cultural value, so that it is impossible to arbitrarily replace each member. Although the preservation treatment method using synthetic resin is emphasized, there is no exact standard for proper reinforcement ratio. This paper is experimental study for reinforcement ratio of wooden flexural member with synthetic resins, Reinforced ratio on section area of flexural member. As a result, synthetic resin reinforcement are selected as experimental variables by proper ratio enhanced flexural capacity of reinforced wooden member than new wooden member.

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.88-92
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• 2001

The crossabilities among 3 wild mulberry species and 3 cultivars growing in the Korean Peninsula had been studied. The result of the crossabilities of Moms tiliaefolia with Moms bombycis and 3 cultivars were possible, but with Morus mongolica was impossible. Those of Moms mongolica with Moms bombycis, Morus tiliaefolia and 2 cultivars except Daeryukppong were possible too. And those of Morus bombycis with Moms titiaefolia, Moms mongolica were impossible, but with 3 cultivars were possible moderately.

• Korean Journal of Community Nutrition
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• v.15 no.2
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• pp.253-265
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• 2010

The purpose of this study was to examine the designs of the menu books as an important tool of marketing and then present its improvement strategies. For this, the investigator comparatively examined the current status of menu book designs of the restaurants in Incheon area with 295 managers and then analyzed menu book designs by its designers. Menu book designers were printing houses (42.0%), specialized business (31.9%) and managers/employees (26.1%). 51.5% of menu books were impossible to substitute partially. Even there were seasonal menus or event menus, 27.5% of them were impossible to replace menu books partially; therefore, it was impossible to take a prompt action for seasonal or event menus. The easiness of understanding the terminology in menu books was average $2.74{\pm}0.45$(3-point scale). The harmony of menu book design with restaurants was average $2.46{\pm}0.51$ (3-point scale). Comparing to the menu books designed in specialized business, the menu books designed in printing houses or by managers/employees were uniform in type sizes (p < 0.001), had no menu photos (p < 0.001) and explanations (p < 0.001), and did not classify menus by groups (p < 0.001) in general. In addition, profit-making menus were not properly emphasized (p < 0.001), thus making the design of menu books a little improper. Therefore, it is necessary to educate managers in the restaurants to understand the importance of menu books and thus improve it. In addition, by maintaining close communication with designers of menu books, managers in the restaurants must ensure for their menu books to be designed appropriately, thus making their menu books play the role of an important marketing tool.

• Convergence Security Journal
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• v.21 no.1
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• pp.3-7
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• 2021

In quantum cryptographic communication based on quantum mechanics, each piece of information is loaded onto individual photons and transmitted. Therefore, it is impossible to eavesdrop on only a part, and even if an intruder illegally intercepts a photon and retransmits it to the recipient, it is impossible to send the same information to the photon by the principle of quantum duplication impossible. With the explosive increase of various network-based services, the security of the service is required to be guaranteed, and the establishment of a quantum cryptographic communication network and related services are being promoted in various forms. However, apart from the development of Quantum Key Distribution (QKD) technology, a lot of research is needed on how to provide network-level services using this. In this paper, based on the quantum encryption device, we propose an integrated data structure for transferring quantum keys between various quantum encryption communication network devices and realizing an encrypted transmission environment.

• Journal of the Korean Professional Engineers Association
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• v.44 no.2
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• pp.39-42
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• 2011

The main concern at the moment is securing rare earth(RE) resources, because the RE is the essential elements in green technology such as hybrid car, wind power plant, LED, display etc. It's impossible Korea will be a advanced country without securing RE. The importance of investment radically in the securing RE resources and professional engineers can not be overinvested.

• Tribology and Lubricants
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• v.8 no.1
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• pp.38-43
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• 1992

In solving the Reynolds equation in dynamically loaded bearing problem, it is almost impossible to find the squeeze velocity and the cavitation region by analytical method. Finite Element Method was applied to the piston-ring lubrication analysis to solve the complementary problem. The method was very efficient and any convergence problem was not encountered.

• Journal of Advanced Marine Engineering and Technology
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• v.14 no.1
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• pp.72-82
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• 1990

It is impossible to directly analyse stress distribution on thin bevel Gear. On this Paper, the author propose a method to analyse the stress of thin bevel gear boundary element method and develope a computer program. The propriety of this program is verified by comparing the numerical calculating results with theoretical results.