• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.227-231
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• 1996

The reflection spectrum of a $2H-PbI_2$ single crystal grown by vapour phase method were measured at 10 K near the fundamental absorption edge. The n= 1,2,3 Wannier exciton series and $A_{EP}$ reflection line were obtained from the reflection spectrum. Based on the 2nd phonon energy in the Raman spectrum, which is different from Nagamune's report, we suggest that $A_{EP}$ line is due to the bound state between the n=2 exciton and the 2nd phonon which surmise that this is LO phnon due to the second Raman process. The L-T splitting energy of n=1 exciton line was 6.56 meV and was consistent with the emission spectrum. The temperature dependence of the reflection spectrum showed that n=1 exciton peak was shifted to longer wavelength while, as the temperatre is raised, the sharpness of that with the increase of the L-T splitting energy decrease. From Wannier exiton series, the exciton binding energy and exciton radius was 30 meV and 14$\AA$, respectively.

• Journal of Surface Science and Engineering
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• v.37 no.2
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• pp.71-75
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• 2004

The technology of $C_{60}$ fullerite films preparation by means of gas-phase deposition and structure of fullerite films are described. A three-channel flow plant was used to obtain fullerite films. The films were deposited in the flow of inert gas under reduced pressure onto a cooled silicon or sapphire substrate placed inside the reaction chamber of the plant. The plant allows one to obtain the films of pure fullerenes and to synthesise the films from fullerene compounds and doped fullerenes. The structure of two types of films were investigated by FE-SEM and SEM techniques: pure fullerite films onto silicon and sapphire substrates as well as compound films were studied by FE-SEM technique. All samples have shown columnar structure with high level of porosity. The synthesis of films composed of fullerene and its compounds for use in electronics is demonstrated to be promising. For example, experiments confirm the possibility to use fullerite films in sensor electronics to produce humidity and thermal sensors. It is also possible to use the sensitivity of these films to isotropic pressure. The experiments with $C_{60}$-Cu-J films have shown quite strong dependence of their resistance on pressure of different sort of medium-gas that could be used in gas-sensitive sensors. The structure and preparation technology of resistive sensor based on fullerite films are described.bed.

• Journal of The Korean Association For Science Education
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• v.24 no.2
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• pp.287-297
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• 2004

In this study, students' understanding of the analogies used for chemical concepts in science textbooks, misconceptions induced by the analogy, and the factors affecting conceptual understanding were investigated. In addition to the tests of field independency and logical thinking ability, tests of students' understanding of concepts and analogies on three states of matter, pressure-volume relation, molecular motion, and changing state depending upon energy were administered. The results revealed that half of the subjects understood the analogies differently from the textbook writers' intention and that students' conceptual understanding was significantly correlated with the degree of understanding on corresponding analogies, field independency, logical thinking ability, and prior achievement of science. The results of analyzing the direct and indirect effects of each variable on conceptual understanding showed that the direct effect of prior achievement was significant and that field independency and logical thinking ability had indirect effects through understanding of analogies and prior achievement of science. The limitations and implications of using analogies in science education were discussed on the basis of the results.

• The Korean Journal of Rehabilitation Nursing
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• v.14 no.1
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• pp.5-12
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• 2011

Purpose: The purpose of this study was to evaluate the association among of Activity of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), depression and isolation in disabled people. Method: The subjects consisted of 761 disabled people in Korea. Data were analyzed using descriptive statistics, t-test, ANOVA, and Pearson's correlational statistics. Results: There were significant differences in age, cause of disability, type of disability, degree of disability, education, job, perceived health condition, and economic status between disabled people with high and low levels of ADL and IADL. Depression showed significant differences in type of disability, degree of disability, education, job, perceived health condition, and economic state; isolation showed significant differences in age, cause of disability, type of disability, education, job, residence, perceived health condition, and economic status. A significant association was identified between depression and isolation (r=.69, p<.001). Conclusion: There was a high incidence of depression in disabled men with high levels of isolation and ADL and IADL dependence. An effort to increase disabled people's ADL, IADL, and independence levels is needed, and nursing interventions should be designed and tested to increase their community involvement and decrease the sense of isolation and depression.

• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.439-454
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• 1993

The phase sequence of codeposited Co-Si alloy and Co/si multilayer thin film was investigated by differential scanning calormetry(DSC) and X-ray diffraction (XRD) analysis, The phase sequence in codeposition and codeposited amorphous Co-Si alloy thin film were CoSilongrightarrow Co2Si and those in Co/Si multilayer thin film were CoSilongrightarrowCo2Silongrightarrow and CoSilongrightarrowCo2Si longrightarrowCoSilongrightarrowCoSi2 with the atomic concentration ration of Co to Si layer being 2:1 and 1:2 respectively. The observed phase sequence was analyzed by the effectvie heat of formatin . The phase determining factor (PDF) considering structural facotr in addition to the effectvie heat of formation was used to explain the difference in the first crystalline phase between codeposition, codeposited amorphous Co-Si alloy thin film and Co/Si multilayer thin film. The crystallinity of Co-silicide deposited by multitarget bias cosputter deposition (MBCD) wasinvestigated as a funcion of deposition temperature and substrate bias voltage by transmission electron microscopy (TEM) and epitaxial CoSi2 layer was grown at $200^{\circ}C$ . Parameters, Ear, $\alpha$(As), were calculate dto quantitatively explain the low temperature epitaxial grpwth of CoSi2 layer. The phase sequence and crystallinity had a stronger dependence on the substrate bias voltage than on the deposition temperature due to the collisional daxcade mixing, in-situ cleannin g, and increase in the number of nucleation sites by ion bombardment of growing surface.

• Research in Community and Public Health Nursing
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• v.18 no.2
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• pp.252-265
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• 2007

Purpose: This study was attempted to provide basic data required to develop community-base rehabilitation program for disabled persons at home by investigating their characteristics. ADL, and perceived health status. Method: The subjects were 146 disabled persons at home in rural areas. Data were collected from January 22 to January 31, 2004. Data were analyzed using frequencies, percentages, means, standard deviations, minimums, maximums, $\chi^2$-test, Fisher's exact test, t-test, one-way ANOVA, Scheffe test, Contingency coefficient, Pearson's correlation, Stepwise multiple regression. Results: The average score of ADL was $5.51{\pm}1.92$: sphincter control $(5.85{\pm}2.10)$, communication $(5.66{\pm}2.02)$, transfers $(5.67{\pm}2.21)$, self care $(5.44{\pm}2.05)$, social cognition $(5.33{\pm}2.08)$, and locomotion $(4.85{\pm}2.32)$. This means that the respondents were in the state of dependence. The main items requiring others' help were 'bathing' (57.7%) and 'going up and down stairs' (51.1%) ADL was significantly different according to age, sender, occupation, medical fee payer, type, severity and duration of disability, BMI, and alcohol drinking. Among the respondents, 82.8% perceived that their health status was bad. Main factors influencing the perceived health status of disability were age and ADL$(R^2=.343)$. Conclusion: Perception of health status among the disabled is related to their characteristics and ADL, so it is necessary to develop community-base rehabilitation programs in order to improve ADL and the perception of health status.

• The KIPS Transactions:PartD
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• v.10D no.4
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• pp.655-660
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• 2003

The cache used by mobile host is an important device that recovers the weak points of limited power and bandwidth, in mobile computing environments. However, it has to stand and maintain the consistency with the server data. In this paper, we propose a 'Selective Cache Consistency Scheme'. The server allows an effective broadcasting by selecting data of high usability using 'Cache State Table' and 'Data Access Table'. Moreover, this scheme prevents the loss of data that nay occur by a long period of disconnection, by asynchronous broadcasting and transmitting those broadcast data preserved in the server. This also allows user to possess the latest data. Through experiments, we have found that the enlargement of autonomy is possible by reducing the dependence of server.

• Clinical and Experimental Pediatrics
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• v.57 no.11
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• pp.496-499
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• 2014

Wernicke's encephalopathy is an acute neurological disorder characterized by mental confusion, oculomotor dysfunction, and ataxia. It has been reported in individuals with alcohol dependence, hyperemesis gravidarum, and prolonged parenteral nutrition without vitamin supplementation. Here we present the case of a 13-year-old male patient with neuroblastoma and a history of poor oral intake and nausea for 3 months. After admission, he showed gait disturbances, nystagmus, and excessive dizziness; his mental state, however, indicated he was alert, which did not fit the classical triad of Wernicke's encephalopathy. A diagnosis of Wernicke's encephalopathy was made only after brain magnetic resonance imaging and serum thiamine level analyses were performed. The patient's symptoms remained after 5 days of treatment with 100-mg thiamine once daily; thus, we increased the dosage to 500 mg 3 times daily, 1,500 mg per day. His symptoms then improved after 20 days of replacement therapy. This case report describes a pediatric patient who was promptly diagnosed with Wernicke's encephalopathy, despite only 2 suspicious symptoms, and who completely recovered after high doses of thiamine were given intravenously.

• Journal of Korean Library and Information Science Society
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• v.45 no.4
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• pp.139-164
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• 2014

Analyzing research schools' reports on school library activities, this paper identifies the characteristics and problems of library assisted instruction (LAI), and proposes areas and ways for improvement. Twenty three reports of secondary schools in Edunet were analyzed and their content were categorized into 13 educational activities. Most frequently implemented activities were collection development, reading programs, LAI, and Digital Library System (DLS). The verified positive impact of LAI include enhanced motivation for reading and improved ability for self-directed learning. Areas for improvement include LAI's excessive dependence on DLS and reading activities, insufficient time and library materials which hindered students' information activities. In order for LAI to be more effective in enhancing self-directed learning ability, it is suggested to connect LAI to specific educational experiences and develop customized and detailed content.

• Advances in Energy Research
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• v.5 no.2
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• pp.91-105
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• 2017

Thermal hydraulic (TH) analysis of nuclear power reactors is utmost important. In this way, the numerical codes that preparing TH data in reactor core are essential. In this paper, a subchannel analysis of a Russian pressurized water reactor (WWER1000) core with enhanced numerical code is carried out. For this, in fluid domain, the mass, axial and lateral momentum and energy conservation equations for desired control volume are solved, numerically. In the solid domain, the cylindrical heat transfer equation for calculation of radial temperature profile in fuel, gap and clad with finite difference and finite element solvers are considered. The dependence of material properties to fuel burnup with Calza-Bini fuel-gap model is implemented. This model is coupled with Isotope Generation and Depletion Code (ORIGEN2.1). The possibility of central hole consideration in fuel pellet is another advantage of this work. In addition, subchannel to subchannel and subchannel to rod connection data in hexagonal fuel assembly geometry could be prepared, automatically. For a demonstration of code capability, the steady state TH analysis of a the WWER1000 core is compromised with Thermal-hydraulic analysis code (COBRA-EN). By thermal hydraulic parameters averaging Fuel Assembly-to-Fuel Assembly method, the one sixth (symmetry) of the Boushehr Nuclear Power Plant (BNPP) core with regular subchannels are modeled. Comparison between the results of the work and COBRA-EN demonstrates some advantages of the presented code. Using the code the thermal modeling of the fuel rods with considering the fission gas generation would be possible. In addition, this code is compatible with neutronic codes for coupling. This method is faster and more accurate for symmetrical simulation of the core with acceptable results.