• Journal of the Korean Society for information Management
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• v.35 no.2
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• pp.89-114
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• 2018

Research on changes in research trends in academic disciplines is a method that enables observation of not only the detailed research subject and structure of the field but also the state of change in the flow of time. Therefore, in this study, in order to observe the changes of research trend in library and information science field in Korea, co-word analysis was conducted with Korean author keywords from three types of journals which were listed in the Korea Citation Index(KCI) and have top citation impact factor were selected. For the time series analysis, the 15-year research period was accumulated in 5-years units, and divided into 2003~2007, 2003~2012, and 2003~2017. The keywords which limited to the frequency of appearance 10 or more, respectively, were analyzed and visualized. As a result of the analysis, during the period from 2003 to 2007, the intellectual structure composed with 25 keywords and 8 areas was confirmed, and during the period from 2003 to 2012, the structure composed by 3 areas 17 sub-areas with 76 keywords was confirmed. Also, the intellectual structure during the period from 2003 to 2017 was crowded into 6 areas 32 consisting of a total of 132 keywords. As a result of comprehensive period analysis, in the field of library and information science in Korea, over the past 15 years, new keywords have been added for each period, and detailed topics have also been subdivided and gradually segmented and expanded.

• Analytical Science and Technology
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• v.7 no.3
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• pp.361-369
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• 1994

Voltammetric behavior of some light lanthanide ions($La^{3+}$, $Pr^{3+}$, $Nd^{3+}$, $Sm^{3+}$ and $Eu^{3+}$) in acetonitrile(AN) and dimethylformamide(DMF) has been investigated by direct current, differential pulse polarography and cyclic voltammetry. The reduction of $La^{3+}$, $Pr^{3+}$ and $Nd^{3+}$ in 0.1M TEAP proceeded directly to the metallic state through three-electron charge transfer of irreversible process where as $Sm^{3+}$ and $Eu^{3+}$ proceeded by charge transfer of two steps. As the results of the cyclic voltammetric investigation, the first step reduction of $Sm^{3+}$ and $Eu^{3+}$ were a quasireversible reaction, the second step reductions were an irreversible reaction. The cathodic peak currents of the differential pulse polarogram showed adsorptive properties at lower sweep rates and high concentrations of these metal ions. The peak potenital was shifted to a negative petential and the peak current decreased with the increase of percentage of water in AN. On the other hand, the peak potential was shifted to a positive potential and the peak current decreased with an increased percentage of water in DMF.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.447-455
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• 2018

This study examined the effects of work values and the career decision level on the major commitment of the university students majoring in social welfare. For this purpose, a survey of 351 undergraduate students majoring in social welfare at 4 universities located in Kangwon-do was conducted and the data were analyzed. The work values consisted of intrinsic values and extrinsic values. The career decision level was measured by the career decision scale (CDS) and the major commitment was measured by the flow state scale (FSS). The research findings are as follows. First, the career decision level (3.43) and major commitment (3.58) of the university students majoring in social welfare were slightly higher than the mid-point on the 5 point Likert scale. In addition, the intrinsic work value (4.05) were higher than the extrinsic work value (3.34). Second, the intrinsic work values and career decision level were positively correlated with the major commitment. Third, the extrinsic work value had a negative effect on the major commitment (${\beta}=-.34$, p<.001); however, the intrinsic work value (${\beta}=.31$, p<.001) and career decision level (${\beta}=.18$, p<.001) had a positive effects on the major commitment. This paper also discusses the theoretical and practical implications for university student's work values, career decision level, and major commitment based on the research findings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7443-7450
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• 2014

To resolve shortcomings of high-rate anaerobic processes, such as high upward flow velocity, this study sought to improve the structure of the high-rate anaerobic reactor and evaluate its performance. The improved reactor was manufactured by adjusting the diameter and dividing the reactor into three parts. The evaluation of the structurally improved reactor revealed that the reactor could stabilize a single circuit, and prevent the accumulation of solid matter and leakage of microbes, thereby stabilize the microbes. In the process of anaerobic digestion, an increase in pH and alkalinity within the reactor was presumably attributed to bicarbonate created in the process of organic matter decomposition and due to the re-dissolution of some biogas. To maintain a high rate of organic matter removal, the reactor should be operated with more than 9 hrs of HRT and an organic matter load of under $10.kgTCODcr/m^3{\cdot}d$. The methane gas generated in the anaerobic digestion process showed a high content of 65~83 % at the organic matter load of over $7.7kgTCODcr/m^3{\cdot}d$. per removal of CODcr. The methane quantity was generated at $0.10{\sim}0.23m^3CH_4/kgCOD_{rem}$, showing that it was smaller than the theoretical methane generation amount (0.35) in the STP state. In the latter part of high-rate anaerobic process, an advanced treatment process was required to remove nitrogen.

• Ocean Systems Engineering
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• v.6 no.3
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• pp.245-264
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• 2016

The iterative boundary element method (IBEM) developed originally before for cavitating two-dimensional (2-D) and three-dimensional (3-D) hydrofoils moving under free surface is modified and applied to the case of 2-D (two-dimensional) airfoils and 3-D (three-dimensional) wings over water. The calculation of the steady-state flow characteristics of an inviscid, incompressible fluid past 2-D airfoils and 3-D wings above free water surface is of practical importance for air-assisted marine vehicles such as some racing boats including catamarans with hydrofoils and WIG (Wing-In-Ground) effect crafts. In the present paper, the effects of free surface both on 2-D airfoils and 3-D wings moving steadily over free water surface are investigated in detail. The iterative numerical method (IBEM) based on the Green's theorem allows separating the airfoil or wing problems and the free surface problem. Both the 2-D airfoil surface (or 3-D wing surface) and the free surface are modeled with constant strength dipole and constant strength source panels. While the kinematic boundary condition is applied on the airfoil surface or on the wing surface, the linearized kinematic-dynamic combined condition is applied on the free surface. The source strengths on the free surface are expressed in terms of perturbation potential by applying the linearized free surface conditions. No radiation condition is enforced for downstream boundary in 2-D airfoil and 3-D wing cases and transverse boundaries in only 3-D wing case. The method is first applied to 2-D NACA0004 airfoil with angle of attack of four degrees to validate the method. The effects of height of 2-D airfoil from free surface and Froude number on lift and drag coefficients are investigated. The method is also applied to NACA0015 airfoil for another validation with experiments in case of ground effect. The lift coefficient with different clearance values are compared with those of experiments. The numerical method is then applied to NACA0012 airfoil with the angle of attack of five degrees and the effects of Froude number and clearance on the lift and drag coefficients are discussed. The method is lastly applied to a rectangular 3-D wing and the effects of Froude number on wing performance have been investigated. The numerical results for wing moving under free surface have also been compared with those of the same wing moving above free surface. It has been found that the free surface can affect the wing performance significantly.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2527-2532
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• 2012

Objectives: The aim of the present study was to explore mechanisms underlying the effects of down-regulating ${\beta}$-catenin expression on esophageal carcinoma (EC) cells. Methods: Cell cycle distribution and apoptosis were determined using flow cytometry and annexin V apoptosis assay, respectively. Transmission electron microscopy (TEM) was used to examine changes in ultrastructure, while expression of cyclin D1 protein and mRNA was detected by western blot and real-time PCR. Proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated kinase (ERK) 1-2 were evaluated by Western blot analysis. PCNA labeling index (LI) was determined by immunocytochemistry. Results: Compared with pGen-3-con transfected and Eca-109 cells, the percentage of G0/G1-phase pGen-3-CTNNB1 transfected cells was obviously increased (P<0.05), with no significant difference among the three groups with regard to apoptosis (P>0.05). pGen-3-CTNNB1 transfected cells exhibited obvious decrease in cyclin D1 mRNA and protein expression (P<0.05) and the ultrastructure of Eca-109 cells underwent a significant change after being transfected with pGen-3-CTNNB1, suggesting that down-regulating ${\beta}$-catenin expression can promote the differentiation and maturation. The expression of PCNA and the ERKI/2 phosphorylation state were also down-regulated in pGen-3-CTNNB1 transfected cells (P<0.05). At the same time, the PCNA labeling index was decreased accordingly (P<0.05). Conclusion: Inhibition of EC Eca-109 cellproliferation by down-regulating ${\beta}$-catenin expression could improve cell ultrastructure by mediating blockade in G0/G1 through inhibiting cyclin D1, PCNA and the MAPK pathway (p-ERK1/2).

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1099-1104
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• 2014

Aims and Background: Ginsenoside Rh2, which exerts the potent anticancer action both in vitro and in vivo, is one of the most well characterized ginsenosides extracted from ginseng. Although its effects on cancer are significant, the underlying mechanisms remain unknown. In this study, we sought to elucidate possible links between ginsenoside Rh2 and phosphoglucose isomerase/autocrine motility factor (PGI/AMF). Methods: $KG1{\alpha}$, a leukemia cell line highly expressing PGI/AMF was assessed by western blot analysis and reverse transcription- PCR (RT-PCR) assay after transfection of a small interfering (si)-RNA to silence PGI/AMF. The effect of PGI/AMF on proliferation was measured by typan blue assay and antibody array. A cell counting kit (CCK)-8 and flow cytometry (FCM) were adopted to investigate the effects of Rh2 on PGI/AMF. The relationships between PGI/AMF and Rh2 associated with Akt, mTOR, Raptor, Rag were detected by western blot analysis. Results: KG1${\alpha}$ cells expressed PGI/AMF and its down-regulation significantly inhibited proliferation. The antibody array indicated that the probable mechanism was reduced expression of PARP, State1, SAPK/JNK and Erk1/2, while those of PRAS40 and p38 were up-regulated. Silencing of PGI/AMF enhanced the sensibility of $KG1{\alpha}$ to Rh2 by suppressing the expression of mTOR, Raptor and Akt. Conclusion: These results suggested that ginsenoside Rh2 suppressed the proliferation of $KG1{\alpha}$, the same as down-regulation of PGI/AMF. Down-regulation of PGI/AMF enhanced the pharmacological effects of ginsenoside Rh2 on KG1${\alpha}$ by reducing Akt/mTOR signaling.

• Journal of the Korean association of regional geographers
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• v.17 no.2
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• pp.181-203
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• 2011

Transformation towards multicultural society requires discussion on new concepts of citizenship which would overcome some limits of national citizenship developed on the basis of the nation-state. Citizenship can be defined as a relationship between individuals and their community, and conceptualized in a relation with identity. Citizenship also includes its spatial elements such as site and movement, place and public/private space, boundary and territory, flow and network, level and scale, etc. and in particular implies a multi-scalability of local, national, and global level. A new discussion on citizenship has emerged in Japan in shift to multicultural society, especially focusing on activities of local governments and grassroots social movements to support and ensure welfare services to and human rights of foreign immigrants in local communities, hence develops a concept of local citizenship. This concept seems to be highly significant for both foreign immigrants and Japanese dwellers for multicultural coexistence, but raises serious problems of separating local citizenship from formal national citizenship and from universal global citizenship. In order to resolve these problems, a new multiscalar concept of glocal citizenship which links interrelationally local, national and global citizenship. The concept of glocal citizenship is suggested to lead academically a new version of cosmopolitanism which embraces the universal and the particular in a dialectic manner, and to give strategically an alternative to multicultural coexistence policy and discourse and local citizenship discussion in Japan.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.729-734
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• 2008

The higher valence state of iron i.e., Fe(VI) was employed for the treatment of Cu(II)-EDTA in the aqueous/waste waters. The ferrate(VI) was prepared through wet oxidation of Fe(III) by sodium hypochlorite. The purity of prepared Fe(VI) was above 93%. The stability of Fe(VI) solution decreased as solution pH decreased through self decomposition. The reduction of Fe(VI) was obtained by using the UV-Visible measurements. The dissociation of Cu(II)-EDTA complex through oxidation of EDTA using Fe(VI) and subsequent treatment of organic matter and metal ions by Fe(III) reduced from Fe(VI) in bench-scale of continuous flow reactor were studied. The removal efficiencies of copper were 69% and 79% in pH control basin and reactor, respectively, at 120 minutes as retention time. In addition, Cu(II)-EDTA in the reactor was decomplexated more than 80% after 120 minutes as retention time. From this work, a continuous treatment process for the wastewater containing metal and EDTA by employing Fe(VI) as muluti-functional agent was developed.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.33-37
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• 2009

Purpose: To examine the coloring condition of titanium spectacle frames with various colors by using anodization method. Methods: We made an anodization coater. Platinum plate with $3{\times}3cm^2$ was used for a cathode and titanium spectacle frame specimens was mounted on an anode in an electrolyte. An electric source device were designed to supply steady state current. The color of the coated spectacle frame specimens were measured by a spectrophotometer equipped with an integrating sphere. We use CIE $L^*a^*b$ color system as chromaticity coordinates. Results: The thickness of $TiO_2$ of titanium spectacle frame specimens was varied as controlling current flow time for electrodes. The specimens with various kinds of color as a walnut, a yellow brown, a navy blue, a blue, a light blue, a mung bean, a yellowish green, a light purple, a purple, a flower pink, a bluish green, an emerald, and a green color etc. were obtained. The values of CIE $L^*a^*b^*$ for these specimens were measured and analyzed to be changed clockwise in chromaticity coordinates as the thickness of $TiO_2$ increases. Conclusions: We identified the coloring mechanism by anodization method in titanium spectacle frame specimens.