• Education of Primary School Mathematics
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• v.7 no.1
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• pp.31-41
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• 2003

Representation has been main topic in teaching and learning mathematics for a long time. Moreover, teachers' deficiency of representation about fraction results in teaching algorithms without conceptual understanding. So, this paper was conducted to investigate and analysize the elementary preservice mathematics teachers' representation about fraction. 38 elementary preservice mathematics teachers participated in this study. This study results showed that, the only model of a fraction that was familiar to the preservice teachers was the part of whole one. And research showed that, they solved the problems about fraction well using algorithms but seldom express the sentence which illustrates the meaning of the operation by a fraction. Specially, the division aspect of a fraction was not familiar nor readily accepted. It menas that preservice teachers are used to using algorithms without a conceptual understanding of the meaning of the operation by a fraction. This results give us some implications. Most of all, teaching programs in preservice mathematics teachers education have to devise to form a network among the concepts in relation to fraction. And we must emphasize how to teach and what to teach in preservice mathematics teachers education course. Finally, we have to invent the various materials which can be used to educate both preservice teachers and elementary school students. If we want to improve the mathematical ability of students, we will concentrate preservice teachers education.

• Polymer(Korea)
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• v.25 no.5
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• pp.707-718
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• 2001

Polypropylene (PP) exhibits many beneficial properties such as low density high thermal stability, chemical resistance, good processability and recyclability. However, only limited research has been done on expanded polypropylene (EPP). In this study, we were trying to prepare EPP with chemical blowing agent. Ethylene-octene copolymer (mPE) was melt blended with PP to enhance melt fluidity of PP at processing temperature and to make more flexible foamed material. Prior to foaming, phase morphology of PP/mPE blends were investigated to examine the effect of phase morphology on the foaming ratio and cell structure of foams. Phase morphology of PP/mPE blends were affected by the content of mPE and mixing torque ratio. At the same composition, it was affected by mixing rpm. High blowing ratio and stable cell structure were obtained in the blend which has the continuous PP matrix with dispersed droplets of mPE.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.687-697
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• 2010

This study was designed to carry out studies on critical seepage velocity and critical hydraulic gradient using a piping test targeting SM and ML which are widely distributed ahead of and behind the depth of E.L(-)10m in Saemangeum area in order to examine stability of embankment built on the ground vulnerable to piping. The effects of relative densities on critical hydraulic gradient and critical velocity were also compared and analyzed using empirical formula and theoretical formula, and relative densities were set up as respectively 9%, 25%, 50%, and 75% for this experiment. As a result, for critical hydraulic gradient, most of specimens detected piping at lower values than the empirical formula of Terzaghi(1922). It is, therefore, considered that the empirical formula devised by Kalin(1977) or Hayashi(1978) is more reasonable to be conservative. It was also found that critical velocity decreased as relative density increased, and critical velocity predicted was mostly lower than the theoretical formula.

• Journal of Korean Library and Information Science Society
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• v.42 no.1
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• pp.51-72
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• 2011

This work investigated the social, cultural, and economical impacts of the services that S Children's Library provides to local community and its residents. In this study I analyzed the user statistics by using Korean Library Automation System III, practiced a comparative analysis with other libraries over circulation efficiency, and reviewed the user's evaluation through user survey. The achievement of this study is to find out the value of S Children's Library by verifying the service status of S Children's Library based on the analyzed data, assessing the role and meaning of the children's library within the community, and measuring the economical contribution through user evaluation.

• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.89-111
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• 2012

The purpose of this study was to identify ways in which to improve assistance of reading culture promotion for reading disables in Busan Metropolitan City. The research conducted a survey on reading culture promotion works which were conducted through related public institutions, private organizations and facilities for disadvantaged class, including public libraries. This study analyzed the situations in Busan. The Results indicated promotional strategies are needed in reading culture for the handicapped. This study suggest ways in which to improve assistance through analytical research which are models of mutual cooperation for reading culture promotion in Busan.

• The Korean Journal of Nuclear Medicine
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• v.22 no.1
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• pp.27-31
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• 1988

In Graves' disease, changes in orbital tissue and structure are casued by inflammatory infiltation, which induces increase of capillary permeability and breakdown of blood-tissue barriers. Using the uptake of $^{99m}Tc-DTPA$ in inflammatory lesion, Eye/Brain radioactivity ratios in brain scintigraphy were evaluated in 15 normal controls and 40 Graves' patients. The results were as follows; 1) Eye/Brain radioactivity ratio was significantly higher in Graves' ophthalmopthy group than in control group (p < 0.005). 2) In Graves' ophthalmopathy, Eye/Brain radioactivity ratio was significantly higher in active (progressive) group than in inactive (non-progressive) group (p < 0.05). 3) There was no correlation between class of ATA classification of Graves' ophthalmopathy and Eye/Brain radioactivity ratio. 4) There was no correlation between Eye/Brain radioactivity ratio and serum activity of TBII. In conclusion, Eye/Brain radioactivity ratio using $^{99m}Tc-DTPA$ brain scintigraphy may be useful to determine the activity of Graves' ophthalmopathy and whether treatment of Graves' ophthalmopathy is necessary or not.

• Journal of the Korean Society for information Management
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• v.32 no.3
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• pp.295-316
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• 2015

This study analyzed the policy making process by finding factors of a back-in phenomenon appeared in contracting out of public library using advocacy coalition framework. The coalitions were divided into 'agreement of direct management', 'opposition of direct management' and 'keep the contract out'. Considering their belief and activity, to share core belief could make a change of secondary belief. It suggests that activating public sphere is necessary for enforcement of their strategies throughout the library policy.

• School Mathematics
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• v.10 no.1
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• pp.105-121
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• 2008

Even though the 7th national curriculum based on learner-centered instruction as fundamental spirit has been operated for 10 years or so, still the instruction style nation widely implemented in current classrooms is closer traditional style than it. It is a big challenge for a teacher who is used to a traditional one to try to fully make learner-centered instruction. The paper describes the teacher's cognizance change on it with the point of views of children's ability to construct knowledge, instructional materials, questioning techniques, and children's achievements.

• The Journal of Korean Medicine
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• v.21 no.4
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• pp.227-235
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• 2000

Background and Purpose : Medical and Neurological complications in patients with acute stroke may affect their prognosis including death rate, function and admission period. Some of these complications may be preventable. But few data exist regarding complications occurring in the first weeks. So we sought to observe the type, timing, and frequency of complications in hospitalized patients after stroke. Methods : We retrospectively examined the case notes of patients admitted in Won Kwang Oriental Medical Hospital after stroke. Two observers inspected the case notes using predifined diagnostic criteria and recorded the type, timing, and frequency of complications that occurred during the inpatient period. Results : Complications were recorded in 43 patients(82.7%). The most common medical complications were constipation(25.0%) and shoulder pain(21.2%). The most frequent serious medical problems were pulmonary infection(9.6%) and UTI(7.7%). The most common neurological complications were insomnia(34.6%) and dysphagia(23.7%). The most frequent serious medical problem was mental deterioration(7.7%). Conclusion : Complications after acute stroke are common. There were more medical complications than neurological complications. So we should compile much knowledge about medical complications and treat them actively. The differences between our study and previous studies are attributable to the different methods including patient selection and diagnostic criteria.

• Journal of Korean Library and Information Science Society
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• v.37 no.2
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• pp.273-290
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• 2006

Recently, a digital divide has gotten worse in the information age. So LG Sangnam library developed the ubiquitous library for the improvement of information accessability of the blind. It utilizes a mobile phone applied with NFC (Near Field Communication) technology and automates a user's identification process and serve library services at anytime from anywhere. Users can use three access points of a web service, a mobile service and a telephone library service. As a conclusion of this paper. Several recommendations were proposed. For the development of ubiquitous library, various instruments should be considered to diversify user's access points and a usability test and analysis about user's environmental context should be done simultaneously.