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        검색결과 9

        1.
        2016.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have investigated the crystallization mechanism of the lithium disilicate (Li2O-2SiO2, LSO) glass particles with different sizes by isothermal and non-isothermal processes. The LSO glass was fabricated by rapid quenching of melt. X-ray diffraction and differential scanning calorimetry measurements were performed. Different crystallization models of Johnson- Mehl-Avrami, modified Ozawa and Arrhenius were adopted to analyze the thermal measurements. The activation energy E and the Avrami exponent n, which describe a crystallization mechanism, were obtained for three different glass particle sizes. Values of E and n for the glass particle with size under 45 μm, 75~106 μm, and 125~150 μm, were 2.28 eV, 2.21 eV, 2.19 eV, and ~1.5 for the isothermal process, respectively. Those values for the non-isothermal process were 2.4 eV, 2.3 eV, 2.2 eV, and ~1.3, for the isothermal process, respectively. The obtained values of the crystallization parameters indicate that the crystallization occurs through the decreasing nucleation rate with a diffusion controlled growth, irrespective to the particle sizes. It is also concluded that the smaller glass particles require the higher heat absorption to be crystallized.
        4,000원
        2.
        2012.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A Li2O-2SiO2 (LS2) glass was investigated as a lithium-ion conducting oxide glass, which is applicable to a fast ionic conductor even at low temperature due to its high mechanical strength and chemical stability. The Li2O-2SiO2 glass is likely to be broken into small pieces when quenched; thus, it is difficult to fabricate a specifically sized sample. The production of properly sized glass samples is necessary for device applications. In this study, we applied spark plasma sintering (SPS) to fabricate LS2 glass samples which have a particular size as well as high transparency. The sintered samples, 15mmφ×2mmT in size, (LS2-s) were produced by SPS between 480˚C and 500˚C at 45MPa for 3~5mim, after which the thermal and dielectric properties of the LS2-s samples were compared with those of quenched glass (LS2-q) samples. Thermal behavior, crystalline structure, and electrical conductivity of both samples were analyzed by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and an impedance/gain-phase analyzer, respectively. The results showed that the LS2-s had an amorphous structure, like the LS2-q sample, and that both samples took on the lithium disilicate structure after the heat treatment at 800˚C. We observed similar dielectric peaks in both of the samples between room temperature and 700˚C. The DC activation energies of the LS2-q and LS2-s samples were 0.48±0.05eV and 0.66±0.04eV, while the AC activation energies were 0.48±0.05eV and 0.68±0.04eV, respectively.
        4,000원
        3.
        2010.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The current study examined Ag migration from the Ag paste bump in the SABiT technology-applied PCB. A series of experiments were performed to measure the existence/non-existence of Ag in the insulating prepreg region. The average grain size of Ag paste was 30 nm according to X-ray diffraction (XRD) measurement. Conventional XRD showed limitations in finding a small amount of Ag in the prepreg region. The surface morphology and cross section view in the Cu line-Ag paste bump-Cu line structure were observed using a field emission scanning electron microscope (FE-SEM). The amount of Ag as a function of distance from the edge of Ag paste bump was obtained by FE-SEM with energy dispersive spectroscopy (EDS). We used an electron probe micro analyzer (EPMA) to improve the detecting resolution of Ag content and achieved the Ag distribution function as a function of the distance from the edge of the Ag paste bump. The same method with EPMA was applied for Cu filled via instead of Ag paste bump. We compared the distribution function of Ag and Cu, obtained from EPMA, and concluded that there was no considerable Ag migration effect for the SABiT technology-applied printed circuit board (PCB).
        4,000원
        5.
        2006.09 KCI 등재 서비스 종료(열람 제한)
        This study has been conducted to perform the survey on the ecological systems, scenary, and water quality change for agriculturally purposed drainage channels constructed with the application of environment-friendly methods and thus to evaluate the environment-friendly redevelopment effects of them. The main results of this study are as follow: 1. The channels not looking good aesthetically before redevelopment had changed into graceful scenic views from the aspect of landscape architecture as natural-type gently waterside to the channel and naturally-looking water stream. In the village parks developed for the rest of residents, an enough view was secured and thus a wide prospect scope could be obtained. 2. The flora in the channels have increased to 35 families and 82 species from 19 families and 32 species before renovation. As the growth speed of them are slower than externally-brought plants, they can cause some risks to the stability of land slope, including scour by erosion. From that reason, it is necessary to adequately combine the species of the plants both natively growing there and externally-brought planted. 3. In case of water quality, it turned out that, from more than a year after redevelopment, plants began to take roots and the water quality improved. On the contrary, there have been some cases, partly found, that aggravated the quality of water due to the causes like as retention of floating matters by withered plants or plant bodies after the growth of plants in the channels under survey became active, and therefore it is judged that a periodic maintenance of waterways is needed. 4. In case of fishes, all species before renovation have revived, and the population and the number of species have increased after works the formation of puddles in the channels. In waterside grasslands, amphibia and reptiles have not only increased but also been diversified.
        6.
        2006.03 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to verify the result of the previous studies and to clarify the types and activation factors of maintenance activities of the naturally favorable water space through the participation of residents in rural areas, through a further survey of the area proposed as a program in the existing study review and previous study related to the participation of residents. The survey was conducted through the survey of 1,242 households and 1,335 persons intended for Japanese rural areas. The study result is summarized as follows. The types of the maintenance activities in the areas intended for the survey have been classified into 'rural type' and 'combination type' through the analysis results by the references like the comparison analysis, job percentage and main utilization purpose of facilities for each type of maintenance and operation activities. In case of the 'rural type' area, residents were doing maintenance activities centered on the group activities rather than personal maintenance activities. Also, the activities of maintenance & operation group members were more active than non-members, and the water-friendly utilization to the facilities was not directly affecting the maintenance activities of residents. In case of the 'combinational type' area, there was no common characteristic according to each area, and the participation percentage in the maintenance activities was low compared with the 'rural type' area. According to the analysis result based on the participation degree of personal maintenance activities, the repair of facilities as a naturally favorable water space, implementation of projects reflecting the opinions of residents, educational programs conducted in order to motivate the participation of residents, etc. have been analyzed as the factors affecting the activation of maintenance activities of residents. Through the above results, for continuous maintenance activities to be made with residents as a main body in the future, it is necessary to support maintenance groups on an administrative level and procure experts for the production and operation of programs that can increase the participation percentage of residents.
        7.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        For the purpose of finding correlation between the characteristics of the rural residents and the maintenance activities of naturally favorable waterside spaces, this paper has conducted a research with the focus on the three model case regions in Japan. The methods of the research included surveys, interviews, and documents. The research confirmed that the three regions in focus have characteristics distinct from one another. The rate of participation in group activities was high in a region, with members that belong to groups most active in the maintenance activities. Reasons for their participation included: to manage the local area themselves; and to promote cooperation and friendships among the residents. This proves that participation in the maintenance activities has also attributed to the formation of close communities in the regions. According to the analytic conclusion of the factors related to participation, the residents' experience to have been involved in a professional education program which induces communal participation, acted more as the major factor than the individual ones.
        8.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        In 1980s, studies on the river environment and the management techniques to maintain the quality of water achieved actively. From the beginning of 1990s, the concept considering the river ecology and conservation in urban area have been introduced in Korea. Recently, some environment friendly projects on the rivers have been executed and some are under way. Many small rivers in rural areas have been maintained considering landscape and partly ecology. However until the pilot project named Songsam drainage channel project started in 1998, there were no studies and projects on the irrigation and drainage channels considering environment friendly maintenance. Korea Agricultural and Rural Infrastructure Corporation (KARICO) is going to introduce environment friendly and naturally favorable maintenance technique when the new projects to reform the irrigation and drainage channels are planned. Irrigation channel in O-dong project site in Yeomsan-myeon, Younggwang-gun was designed considering environment friendly consolidation and maintenance.
        9.
        2000.03 KCI 등재 서비스 종료(열람 제한)
        Jung, In-Gyo & Yang, Yong-seok. 2000. A Study on the Productivity of Neologism. Studies in Modern Grammar 19, 109-138. The aim of this study is to analyze the morphological structure of neologisms in the novel of X-generation (1991) written by Douglas Coupland on the basis of the framework of Word Syntax (Lieber, 1992), and to suggest the paradigm of morphological derivatives and spelling module between lexicon and grammatical components. X-bar theory works well in explaining the combinational process of affixes, but the nonhead of a lexical item can be bound near its adjacent category. The results obtained are as follows.: 1) several suffixes which form ]{_(N,A)}_]N such as -ism, -ing, -ness, -ification, -tion, and -phobia have high productivity as well as syntactic adequacy. 2) the addition of formatives such as -ozo, -job, -chondria, and Quelle by a sort of blending has lower productivity. 3) the root compounding word, `-slumming` may be formulated as [[[N₁+al]+N₂]+A_(fi)] in the deep structure, and used as a pejorative. 4) spelling variations of -vul-, -o-, -to, -o- are the outcomes realized by some phonological conflations.