• Clean Technology
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• v.22 no.4
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• pp.308-315
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• 2016

$SiO_x/ZnO$ composites were prepared from sol-gel method for excellent cycle life characteristics. The composites were coated by PVC as a carbon precursor. ZnO removal to create a void space therein was able to buffer the volume change during charge and discharge. To determine the crystal structure and the shape of the synthesized composite, XRD, SEM, TEM analysis was performed. The carbon contents in the composites were confirmed by TGA. The pore structure and pore size distribution of the composite was measured with the BET specific surface area analysis and BJH pore size distribution. Enhanced electric conductivity by carbon addition was determined from powder resistance measurement. Electrochemical properties were measured with the AC impedance and the charge and discharge cycle life characteristics. When carbon was coated on the $SiO_x/ZnO$ sample, the electrical conductivity and the discharge capacity were increased. After removal of ZnO with HCl the surface area of the sample was increased, but the discharge capacity was decreased. $SiO_x/ZnO$ sample without acarbon coating showed very low discharge capacity, and after carbon coating the sample showed high discharge capacity. For cycle life characteristics, $C-SiO_x/ZnO$ composite (Zn : Si : C = 1 : 1 : 8) with a capacity of $815mAh\;g^{-1}$ at 50 cycle and 0.2 C has higher capacity than existing graphite-based anode materials.

• Korean Journal of Social Welfare
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• v.58 no.3
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• pp.313-340
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• 2006

The purpose of this study was to examine predictors of move intention to silver town in Jeju Island. Participants were 449 middle age and elderly who live in Seoul, Gyungido, Inchun Metropolitan and Jeju island. Participants were completed a questionnaire and/or structured interview that included measures of socioeconomic variables, motivation to move, determinants of move selection, conditions of location, and preparation for old age. Results of descriptive analysis revealed that cognition level of sliver industry and silver town was relatively high and medical service was the best necessary field, followed by field of leisure activity, house, life and finance. Logistic regression analyses on the effects of socioeconomic variables on move intention indicated that region, occupation and house ownership had significant effects on move intention to silver town. Result of motivational effect on move intention revealed that solution of offspring's burden was the most important factor, followed by convenient life of the aged, enjoyment of freedom for the elderly life. Result on the influence of determinants of move selection indicated that medical service facilities, resort facilities and leisure, cultural service facilities had significant effect on move intention. Among conditions of location for Jeju island, mild climate, comfort environment and low-price were significant predictors on move intention. Overall, result on relative influence of individual factors indicated that low price factor was the most important predictor, followed by resort facilities, cognition on necessity of silver town, enjoyment of freedom for the elderly life, leisure cultural service facilities, and medical service facilities.

• Korean Journal of Social Welfare
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• v.63 no.1
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• pp.29-55
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• 2011

This study aims to understand the experiences of rights-based social work practice in a residential facility for people with intellectual disabilities. A representative residential facility practicing a human rights perspective was selected by recommendation of professional groups. Using a qualitative case study method, data was collected and analysed. In detail, it explores the experiences of rights-based social work practice at both organizational and individual levels respectively, and then discusses ethical dilemmas that arise from workers in the process of rights-based social work practice. According to results at the organizational level, rights-based social work practice of the residential facility began from workers' interests in needs of users with intellectual disabilities. Some trials to apply human rights in social work practice resulted in regulations for people with intellectual disabilities and stepped up organizational culture on human rights perspectives. And, at the individual level, self determination and choice of users with intellectual disabilities were stressed among various forms of human rights. As the results of rights-based social work practice, it appeared to be improved for the participation of the users, workers' human rights sensitivity, and qualities of rights-based activities. However, ethical dilemmas still existed. Hence, rights-based social work practice should understand a process of dynamic interaction between users and workers, which require workers to endeavor continuously. This study is significant in that it explored rights-based social work practice, focusing on field experiences for the first time in Korea, and suggested practical tasks to settle it down in the future.

• Journal of the Korean Magnetics Society
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• v.9 no.1
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• pp.41-47
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• 1999

$Buffer/[NiFe/Cu/CoFe(Co)/Cu]_N$ spin valve multilayers prepared by dc magnetron sputtering on a corning glass substrate using NiFe and CoFe(Co) posses different coercivities. Dependence of magnetoresistance on the type and thickness of buffer layer, thickness of Cu, NiFe, stacking number of multilayer, substrate temperature and annealing temperature in the form $[NiFe/Cu/CoFe(Co)/Cu]_N$ spin-valve multilayers were investigated. To evaluate effect of magnetoresistance for this samples, X-ray diffraction analysis, vibrating sample magnetometer analysis, and magnetoresistance measurement (4-probe method) were performed the maximum magnetoresistance ratio and coercivity were 7.5 % and 140 Oe, respectively for $Cr-50{\AA}/[NiFe-20{\AA}/Cu-{\AA}/Co-20{\AA}/Cu-50{\AA}]_10$ at substrate temperature of 9$0^{\circ}C$. Magnetoresistance slope maintained 0.25%/Oe until 15$0^{\circ}C$ of annealing temperature, and then decreased to 0.03%/Oe at 20$0^{\circ}C$. It was confirmed that the main factor of thermal stability was deteriorating of soft magnetic properties in the NiFe layer.

• Food Science and Preservation
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• v.14 no.3
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• pp.269-275
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• 2007

This paper was study to develop an extract of Elaeagnus multiflora as a beverage component, and was part of a broader research project for at the development of processed foods using extract of Elaeagnus multiflora. Acceptable mixing properties of the beverage were significantly related to brix values, pH, total acidity, and total phenol contents. When brown rice vinegar was used as a supplement, the vinegar contributed only 1% of total acidity content, and the brix was below 5% of acceptable level. Maximal total acidity of the mixed beverage was attained which added 19.2%(v/v) of Elaeagnus multiflora extract and 7.6%(v/v) of brown rice vinegar. The mixed beverage contributed 0.88% of the total acidity content. The maximum condition of brix(11.5) of the mixed beverage was arrived to 24.7%(v/v) of Elaeagnus multiflora extract and 4.9%(v/v) of brown rice vinegar. The maximum polyphenol contents of beverage(14.47 mg%) was achieved which added 25.0%(v/v) of Elaeagnus multiflora extract and 4.3%(v/v) of brown rice vinegar.

• Korean Journal of Materials Research
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• v.8 no.10
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• pp.961-968
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• 1998

In order to investigate the effects of substrate bias voltage on the formation of$ZnS-SiO_2$ protective film in phase change optical disk by R.F. magnetron sputtering method, thin dielectric film was formed on Si wafer and Corning glass by using ZnS(80mol%)-$SiO_2$(20mol%)t arget under argon gas. In this study, the Taguchi experimental method was applied in order to obtain optimum conditions with reduced number of experiments and to control numerous variables effectively. At the same time this method can assure the reproducibility of experiments. Optimum conditions for film formation obtained by above method were target RF power of 200 W. substrate RF power of 20 W, Ar pressure of 5 mTorr. sputtering time of 20 min.. respectively. The phase of specimen was determined by using XRD and TEM. The compositional analysis of specimen was performed by XPS test. In order to measure the thermal resistivity of deposited specimen, annealing test was carried out at $300^{\circ}C$ and $600^{\circ}C$. For the account of void fraction in thin film, the Bruggeman EMA(Effective Medium Approximation) method was applied using the optical data obtained by Spectroscopic Ellipsometry. According to the results of this work, the existence of strong interaction between bias voltage and sputtering time was confirmed for refractive index value. According to XRD and TEM analysis of specimen, the film structure formed in bias voltage resulted in more refined structures than that formed without bias voltage. But excess bias voltage resulted in grain growth in thin film. It was confirmed that the application of optimum bias voltage increased film density by reduction of void fraction of about 3.7%.

• KSBB Journal
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• v.21 no.3
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• pp.224-229
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• 2006

FEMLAB is a powerful interactive environment for modeling, solving all kinds of scientific and engineering problems based on partial differential equations(PDEs). Separation process of chiral compound in HPLC columns was simulated by FEMLAB. To study change of elution profile with isotherm models, non-competitive and competitive Langmuir adsorption isotherm were adopted. Separated material was (R, S)-ibuprofen [(R, S)-2-(4-isobutyl phenyl) propionic acid], an anti-inflammatory agent, which retain the pharmacological activity in the (S)-(+)-enantiomer. Sample concentrations were changed from 0.5 mg/ml to 2.0 mg/ml at a flow rate of 1 ml/min and flow rate varied from 1 ml/min to 3 ml/min at an ibuprofen concentration of 2.0 mg/ml and $20{\mu}l$ of injection volume. Simulated results were well fitted with experimental data.

• The Korean Journal of Financial Management
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• v.8 no.2
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• pp.209-255
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• 1991

This paper develops a simple model to explain the reasons why foreign acquirers pay significantly higher premiums for U.S. target firms than do U.S. buyers. We also provide empirical work on the valuation effect of foreign takeovers and the determinants of the wealth gains of U.S. target shareholders involved in foreign takeovers. The results indicate that target wealth gains are significantly higher in foreign takeovers than in domestic takeovers, after controlling for the wealth effects of payment method, acquisition type, tax status, size and time period of bids. This confirms the valuation effect of foreign takeovers. Furthermore, the results of cross-sectional regression analysis show that the variation in U.S. target wealth gains is explained by extra tax benefits stemming from double tax deductions for acquisition-related interest expenses incurred by foreign acquirers. These findings imply that differential taxation across tax jurisdictions is the main source of the valuation effect of foreign takeovers. In addition, we find that there exists a valuation effect of the nationality of the foreign acquirers. Japanese companies pay significantly higher premiums than do non-Japanese acquirers. The finding also indicates that competition among bidders increases the abnormal returns to U.S. target shareholders in foreign takeovers.

• Korean Journal of Construction Engineering and Management
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• v.7 no.4 s.32
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• pp.137-145
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• 2006

Calculating non-working days is very important element for the accurate estimation of construction time. And non-working days are largely affected by weather factors such as rainfall, wind velocity, snowfall and temperature. In the case of concrete works, there are lots of referable information for the calculation of non-working days due to the weather factors. However, for the structural steel works, there are very limited information only. Through literature survey and interviews with a few engineers, this paper established the weather factors that affect steel structural works and the impact of those factors. Based on the factors and the expected impact of the factors together with the weather data during the last 15 years in Seoul region gathered from Korea Meteorological Administration, this paper suggests the monthly non-working day of structural steel work due to weather factors. This information can be used for the early estimation of construction time.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.331-336
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• 2007

The importance of a building management is embossed at construction industry and the concernment about a lengthening longevity and a efficient management of construction project is concentrated. At present, a study about maintenance management of existing building is progressed and normal papers concentrate in partial construction project for showing management method. This paper proposes Management method that make use of RFID/USN at the whole course of construction project that is composed plan, design, supply, construction, operation, maintenance management and so on. First of all, this paper analyzes process and applicable scope of RFID/USN at construction project. At each step, use scope, location, method and so on are decided at plan, design step and equipment, human power, materials and so on are established at supply step. real time progress, human power, safety, material, equipment management and so on put in operation at construction step and building is managemented real time by established sensor tag and wireless sensor network. This paper want to helps efficient project progress and management and presents convenience of maintenance management.