• Journal of the Korea Concrete Institute
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• v.17 no.3 s.87
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• pp.473-480
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• 2005

In this study, a mix design for self compacting concrete was based on Okamura's method and concrete incorporated just a ground granulated blast furnace slag. Replacement ratio of slag is in the range of $20-80\%$ of cement matrix by volume. For the optimal self compactability in mixture incorporating ground granulated blast furnace slag, the paste and mortar tests were first completed. Then the slump flow, elapsed time of 500mm slump flow, V funnel time and filling height by U type box were conducted in concrete. The volume of coarse aggregate in self compacting concrete was in the range of $50-60\%$ to the solid volume percentage of coarse aggregate. Finally, the compressive and splitting tensile strengths were determined in the hardened self compacting concrete incorporating ground granulated blast furnace slag. From the test results, it is desirable for self compacting concrete that the replacement of ground granulated blast furnace slag is in the range of $40-60\%$ of cement matrix by volume and the volume of coarse aggregate to the solid volume percentage of coarse aggregate with a limit of $55\%$.

• Health Policy and Management
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• v.18 no.1
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• pp.21-42
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• 2008

This study investigates economies of scale, cost complementarity and economies of scope for healthcare organizations using econometric approaches. The economies of scale appear to exist in each service provided by a hospital such as inpatient treatment services, outpatient treatment services, and other patient treatment services, respectively. When we test all services in aggregate level, it also indicates that the healthcare industry on average exhibits the economies of scale of 6 percent, which implies that scaling up hospital sizes will bring substantial cost savings to them Evidence shows that cost complementarity exists between outpatient services and other services for patients and, i.e., these other services for patients experience the reduction in marginal costs as the outputs of the outpatient services increase. For the economies of scope, they are present in most service areas; aggregate level services, outpatient services, and other services for patients, respectively. Inpatient treatment services, however, do not show any evidence of the economies of scope. Results show that the economies of scope are achieved by the general hospital type that provides all service areas such as inpatient treatments, outpatient treatments, and other services for patients. The existence of the economies of scope provides the rationale for extending the existing line of business in a hospital into more diverse areas of services where its benefit comes in the form of cost savings. In sum, it overall provides evidence that the M&As in this industry are encouraged to achieve cost reductions from the economies of scale and scope by changing the size and the output mix.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.59.2-59.2
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• 2010

We have carried out VLBI test observations of the Korean VLBI Network (KVN) at 22/43-GHz in collaboration with Japanese VLBI Exploration of Radio Astrometry (VERA). In order to evaluate the VLBI system of KVN, we have observed several sources using KVN+VERA. They consist of Active Galactic Nuclei (AGNs), which are expected to be compact and to have very well-known structures at spatial resolutions of 50-250 Mega-wavelengths, and Galactic star-forming regions and late-type stars, which have bright H2O and SiO maser emission regions. We have investigated baseline and imaging sensitivities of KVN+VERA. In this talk we report the preliminary results.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.281-283
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• 2016

The Cholangiocarcinoma is a. The risk of development of cholangiocarcinoma, generally a rare type of a liver tumor, increases during infection of Opisthorchiasis. For this reason the timely detection of Opisthorchiasis is important for Cholangiocarcinoma prevention. There are many studies which concern the detection of pathogenesis of Opisthorchis viverrini infection but a little known about Opisthorchis felineus. In this study we investigate a correlation of the eggs which are found in a faeces and are comparable with a serum Ig G and Ig M antibody level that were detected with ELISA test in a large group of patients. The result is showing positive correlation between evidence of the Opisthorchis felineus eggs that were found in a faeces and antibody Ig G and Ig M level in a serum. Moreover the combination of two methods can improve the Opisthorchiasis diagnostic: the serum antibody and faeces investigation of eggs.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.2
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• pp.92-92
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• 1996

Recently, with the rapid development in the oceanic systems such as the oceanic structures and vessel, there occurs much interest in the impingement erosion-corrosion. In this paper, Cu-metal was tested by using of erosion apparatus with water-jet type and was investigated under the behaviour of impingement erosion-corrosion according to various environmental conditions, and the properties of Cu-metal were evaluated through the measurement by weight loss, weight loss rate, protective efficiency. The results were compared with those obtained using Cu-metal applied to cathodic protection and Cu-alloys added to Zn or Al-metal. As a basis of those results, the best protective efficiencies could be taken as using cathodic protection method and Cu-alloy with Al & Zn material addings, and will be suggested as the fundamental data of the anti-impingement erosion-corrosion on Cu-metal of impeller material for oceanic centrifugal pump.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11b
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• pp.149-155
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• 2005

The $ACP^1$ is under development for effective management of spent fuel by converting $UO_2$ into U-metal. For demonstration of this process, $\alpha-\gamma$ type new hotcell was built in the $IMEF^2$ basement. To secure against radiation hazard, this facility needs radiation monitoring system which will observe the entire operating area before the hotcell and service area at back of it. This system consists of 7 parts; Area Monitor for $\gamma$-ray, Room Air Monitor for particulate and iodine in both area, Hotcell Monitor for hotcell inside high radiation and rear door interlock, Duct Monitor for particulate of outlet ventilation, Iodine Monitor for iodine of outlet duct, CCTV for watching workers and material movement, Server for management of whole monitoring system. After installation and test of this, radiation monitoring system will be expected to assist the successful ACP demonstration.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.160-165
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• 2004

MPA (Multi-Point Averaging) flow element is a new type of differential pressure (DP) flow-sensing device that was developed by Seojin Instech to improve the operating characteristics of the conventional Averaging Pilot Tube (APT) flow elements. Operating characteristics of a flowmeter in general can be defined in terms of measurement accuracy and range. Improvement of accuracy and expanding the range of flow measurement were the two main objectives of the development. To achieve these dual objectives several upstream and downstream pressure-sensing holes were placed in MPA flow element. During the course of the development it was found that certain arrangements of the pressure-sensing holes improved measurement accuracy but did not expand operating flow range of Averaging Pilot Tubes. Development tests were performed with water between Reynolds number of 50,000 and 1,000,000 in the four-inch test line at the Alden Research Laboratory, U.S.A. Purpose of this paper is to present the relationship between the various locations of the pressure-sensing holes and the performance characteristics of MPA flow element. Furthermore, the operating characteristics of the best performing MPA are compared with those of typical orifice and APT.

• Journal of Auto-vehicle Safety Association
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• v.12 no.2
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• pp.7-13
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• 2020

Recently, there is a big issue of downsizing on brake system according to fuel efficiency and regenerative braking cooperation control. Especially, small cars have improved in a variety ways such as electric vehicle and smart car compared to previous small cars. So, small brake system is strongly required in the car industry. A new small brake system for light compact vehicles was proposed in this paper. For this system, the solid type disc and caliper were newly developed. And the important design factors were considered to reduce brake size. First, we calculated the temperature rise of disc through heat capacity formula and CAE analysis. Second, we analyzed the housing and carrier stiffness of caliper to select the reasonable condition. Finally, the superiorities of the developed brake system were verified by heat capacity, consumption liquid level, braking feeling, judder, wear test and regenerative braking cooperation control analysis. A developed brake system is expected to be useful for brake system of light compact platform.

• Nuclear Engineering and Technology
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• v.37 no.2
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• pp.201-206
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• 2005

Fretting, which is a special type of wear, is defined as small amplitude relative motion along the contacting interface between two materials. The structural integrity of steam generators in nuclear power plants is very much dependent upon the fretting wear characteristics of Inconel 690 U-tubes. In this study, a finite element model that can simulate fretting wear on the secondary side of the steam generator was developed and used for a quantitative investigation of the fretting wear phenomenon. Finite element modeling of elastic contact wear problems was performed to demonstrate the feasibility of applying the finite element method to fretting wear problems. The elastic beam problem, with existing solutions, is treated as a numerical example. By introducing a control parameter s, which scaled up the wear constant and scaled down the cycle numbers, the algorithm was shown to greatly reduce the time required for the analysis. The work rate model was adopted in the wear model. In the three-dimensional finite element analysis, a quarterly symmetric model was used to simulate cross tubes contacting at right angles. The wear constant of Inconel 690 in the work rate model was taken as $K=26.7{\times}10^{-15}\;Pa^{-1}$ from experimental data obtained using a fretting wear test rig with a piezoelectric actuator. The analyses revealed donut-shaped wear along the contacting boundary, which is a typical feature of fretting wear.

• Korean Journal of Occupational Health Nursing
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• v.23 no.2
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• pp.115-122
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• 2014

Purpose: This study was to identify the relations of interpersonal attitude and communication competence of new community health nurses. Methods: The research design was a correlational study. The data were collected from 136 visiting nurses using a structured questionnaire and analyzed using independent t-test, Pearson's correlation coefficient, and multiple regression with the SPSS/WIN 20.0 program. Results: The type of interpersonal attitude in subjects was I+U+ and the score of communication competence was 3.6. Among 15 sub-dimensions, the highest score was responsiveness and the lowest was assertiveness. There were no significant differences in communication competence by general characteristics. Factors influencing on communication competence in new visiting nurses were interpersonal attitude I+(I am OK) (${\beta}$=.34) and I-(I am not OK) (${\beta}$=-.28). Conclusion: Education program, stressing the self-awareness, is necessary to increase positive interpersonal attitude and communication competence for reemployment of community health nurses. Furthermore, in order to reinforce assertiveness, institutional support should be accompanied with the efforts of individual level.