• Proceedings of the Korean Geotechical Society Conference
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• 1998.12a
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• pp.85-94
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• 1998

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.178-183
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• 2012

To simulate space thermal environment in thermal vacuum test, direct or in-direct heater has been applied on the radiator. Both of them, direct heater attached on the radiator and indirect heater with a distance from the radiator, simulate the heat fluxes from the Sun radiation, the Earth IR and Albedo. They also supply the heat fluxes to the radiator of spacecraft to achieve the target temperature according to thermal test conditions. In general, indirect heater is used when the heater is not allowed to attach on the radiator directly due to constraints of coating property or contamination. For in-direct heater design, it is needed to estimate the heat power to make the extreme test conditions and minimize the interference with heat exchange of radiator and shroud. In this study, optimized thermal design of in-direct heater is proposed and investigated by commercial S/W SINDA. The effective values of design factors are also derived.

• Journal of Korean Home Economics Education Association
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• v.14 no.1
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• pp.87-95
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• 2002

The purposel of this study was to examine the effects which the direct and the indirect instructions at a Home Economics class have on improving the learning achievements and attitudes. To accomplish these goals. 90 students. the number of two classes of the first tirade at p high school at Anyang city of Kyonggi province were selected. They are composed of the experimental group and the comparative group. Each group contained 40 students. The former was implemented by indirect instructions and the latter direct instructions. The 'Family and Domestic Life' unit of the first tirade was selected as the study subject to take effects and 30 periods of class were enforced. For the experimental measure of this study. the researcher used a pre-learning test. a learning attitude test. and a learning achievement test as means of measure. The two groups were confirmed as the group having the same quality, So after the experimental measure, the results of the post tests(included a learning achievement test and a learning attitude test) were verified by T-test in order to research the problematic subject. and SPSS/win statistics package was used for the processing of the statistics. The results are following: 1. The direct and the indirect instructions represented the meaningful differences in the learning achievements (p <.05). They represented the meaningful differences in improving the learning achievements of knowledge and understanding(p <.05). It was verified that the (order is more effective than the latter in improving the learning achievements of knowledge and understanding, and They represented the meaningful differences in the improving learning achievements of application (p <.05) 2. They represented the meaningful differences in the learning attitudes at a domestic class(p <.05) The latter is more effective than the former in changing into the positive learning attitudes. In the light of these result7. the direct instructions are effective in improving the learning achievements of knowledge and understanding. and the indirect instructions are effective in improving the learning achievements of application. Also the indirect instructions are more effective than the direct instructions in changing into the positive learning attitude.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6007-6010
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• 2015

Background: Chronic lymphoid leukemia (CLL) is a malignant hematopoietic disorder, the most common of all adult leukemias with a distinctive immunophenotype. It is well established that CLL patients can have autoimmune complications, amongst them autoimmune hemolytic anemia as the most frequent. This study was carried out to determine the frequency of direct Coombs Test positivity in CLL patients and its possible correlation with Rai staging, hematological parameters and biochemical markers. Materials and Methods: This descriptive cross sectional study was carried at Liaquat National Hospital from January 2011 to June 2013. Sixty untreated patients with B- chronic lymphoid leukemia were enrolled. Complete blood count, direct Coombs test, serum urea, creatinine, uric acid and LDH levels were determined. Data were compiled and analyzed using SPSS version 21. Results: Out of 60 patients, 42(70%) were males and 18(30%) were females. Mean age was $59{\pm}9.2years$. Male to female ratio was 2.1: 1. The frequency of direct antiglobulin test (DAT) positivity was found to be 23.3%. The monospecific IgG was positive in 11 patients (18.3%); C3d positivity was evident in 1 patient (1.6%) and 2 patients (3.3%) had dual IgG and C3d positivity. The mean hemoglobin was $10.8{\pm}2.4gm/dl$. Significantly low mean hemoglobin of $8.3{\pm}3.0gm/dl$ was seen in Coombs positive patients compared with negative patients having a mean hemoglobin level of $11.7{\pm}1.6gm/dl$ (P<0.001). DAT positivity also demonstrated a positive association with advanced Rai stage III disease (P<0.01). No associations were noted with age, gender and biochemical markers. Conclusions: Direct Coombs test positivity in CLL in our patients, unlike in Western studies, appears relatively high, indicating significant autoimmune hemolytic anemia and advanced Rai stage in our setting. DAT positivity can be considered as a surrogative marker for advanced clinical disease.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.160-168
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• 2003

Statement of problem : Direct denture reline resins tend to discolor during service in the oral environment by intrinsic and extrinsic factor. Purpose : This study was designed to evaluate the color stability of direct denture reline resins. Material and methods : Mild Rebaron(GC Corp., Japan), Meta Base M(Sun medical Co., Japan), Mild Rebaron LC(GC Corp., Japan) and as a control group, Vertex SC(Dentimex Zeist, Holland) were chosen for this study. Ten specimens of each direct denture reline resins were fabricated. Treatment methods designed for this study were the coffee staining test(7days) and the accelerated aging test(100hours). The color changes before and after treatment were measured by Tristimulous colorimeter(Yasuda seiki seisakusho, Ltd. Japan) and analyzed. Results All the direct denture reline resins subjected to the coffee staining test and the accelerated aging test showed noticible difference in color change. After coffee staining test, Meta Base M showed the highest color change followed by Vertex SC. Mild Rebaron LC and Mild Rebaron. There were no statistical differences between Meta Base M and Vertex SC and between Mild Rebaron LC and Mild Rebaron(p>0.05). After accelerated aging test. Mild Rebaron LC showed the highest color change followed by Vertex SC, Meta Base M and Mild Rebaron. There were no statistical differences only between Mild Rebaron and Mata Base M(p>0.05) but among the others, there were statistical differences(p<0.05). Conclusion : Within the limitation of this study, all the direct denture reline resins subjected to the extrinsic and intrinsic factors showed noticible difference in color change, and there were differences among manufacturers.

• Nuclear Engineering and Technology
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• v.34 no.5
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• pp.421-432
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• 2002

As one of the advanced design features of the APR1400, direct vessel injection (DVI) system is being considered instead of conventional cold leg injection (CLI) system. It is known that the DVI system greatly enhances the reliability of the emergency core cooling (ECC) system. However, there is still a dispute on its performance in terms of water delivery to the reactor core during the reflood phase of a large-break loss-of-coolant accident (LOCA). Thus, experimental validation is under progress. In this paper, test results of direct ECC bypass performed in the steam-water test facility tailed MIDAS (Multi-dimensional Investigation in Downcomer Annulus Simulation) are presented. The test condition is determined, based on the preliminary analysis of TRAC code, by applying the ‘modified linear scaling method’with the l/4.93 length scale . From the tests, ECC direct bypass fraction, steam condensation rate and information on the flow distribution in the upper annulus downcomer region are obtained.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.813-820
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• 2003

The shear friction tests using large direct shear test units were performed to evaluate the friction properties of fiber-mixed soil. The used materials and test conditions were flowing. Soils : SM and ML; mixing fibers : three types of polypropylene fibers(net type 38mm and 60mm, and line type 60mm), reinforcement : geogrid; mixing ratio：0.2% and 0.3%; degree of compaction : 85% and 95%. In the test results, the reinforcing effect of fiber mixed soil was confirmed.

• Journal of information and communication convergence engineering
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• v.6 no.1
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• pp.43-46
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• 2008

This paper proposes an advanced test circuit for detecting the connectivity between a drum ring of laser printer and PCB. The detection circuit of charge sharing is proposed, which minimizes the influences of internal parasitic capacitances. The test circuit is composed of precharge circuit, analog comparator, level shifter. Its functional operation is verified using $0.6{\mu}m$ 3.3V/40V CMOS process parameter by HSPICE. Access time is100ns. Layout of the drum contact test circuit is $465{\mu}m\;{\times}\;117{\mu}m$.

• Geomechanics and Engineering
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• v.37 no.6
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• pp.615-627
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• 2024

Direct simple shear test is an effective method to measure strength and deformation properties of soil. However, existing direct simple shear apparatus have some shortcomings. The paper has developed a novel dual stress/strain-controlled direct simple shear apparatus. The novel apparatus has the following advantages: A rectangular specimen is used that effectively avoid common issues associated with conventional cylindrical specimens, such as specimen tilting. The utilization of deformation control rods ensures a uniform shear deformation of the specimen. Vertically integrated force transmission structure is improved that avoids issues arising from changes in pivot points due to lever tilting. Incorporating this novel direct simple shear apparatus, shear strength and shear creep tests of clay were performed. Shear strength parameters and shear creep behaviors are analyzed. The results of these experiments show that the novel apparatus can measure accurately the shear rheological properties of soil. This study provides strong guidance for studying the mechanical properties of soil in engineering practice.

• Tunnel and Underground Space
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• v.29 no.5
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• pp.292-304
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• 2019

Limestone joint surfaces with smooth roughness were experimented by means of both the individual direct shear tests based on the KSRM standard test method and the multi-stage direct shear test to apply the stepwise vertical stresses. Changes in the roughness of the joint surfaces before and after the shear tests were examined and the difference between the two kinds of tests mentioned above was analyzed. In both tests, the shear resistance increased as the joint roughness increased and the maximum shear stress required for shearing the joint surface increased as the vertical stress increased. The peak friction angle obtained by the multi-stage direct shear tests was only 63% of that obtained by the individual direct shear tests. In the multi-stage direct shear test, the initial engagement of the concave-convex parts changes frequently during stepwise shearing process, which deforms the original roughness of a joint surface. Accordingly, the individual direct shear test is thought to be more effective when obtaining the friction angle of the rock joint surfaces. Limestone joint surfaces with smooth roughness of JRC value 4~8 were found to have peak friction angle of $47^{\circ}$, residual friction angle of $38^{\circ}$ and cohesion of 37 kPa.