• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.52-59
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• 2015

The aim of the paper is to introduce the statistical definition of the specified compressive strength of the concrete to be used for safety evaluation of the existing structure in domestic practice and to present the practical method to obtain the specified strength by utilizing the non-destructive test data as well as the limited number of core test data. The statistical definition of the specified compressive strength of concrete in the design codes is reviewed and the consistent formulations to statistically estimate the specified strength for assessment are described. In order to prevent estimating an unrealistically small value of the specified strength due to limited number of data, it is proposed that the information from the non-destructive test data is combined to that of the minimum core test data. The the sample mean, standard deviation and total number of concrete test are obtained from combined test data. The proposed procedures are applied to an example test data composed of the artificial numerical values and the actual evaluation data collected from the bridge assessment reports. The calculation results show that the proposed statistical estimation procedures yield reasonable values of the specified strength for assessment by applying the non-destructive test data in addition to the limited number of core test data.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.5
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• pp.657-665
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• 2003

Combined De-NOx Process in which $NH_3$ SCR (Selective Catalytic Reduction) and non-thermal Plasma Process are simultaneously used, has been investigated with a pilot test facility. The pilot test facility treats the combustion flue gases exhausted from a diesel engine that generates 240 kW of electrical power. Test results show that up to 80 % of NOx (NO and NO2) can be removed at 100 - $200^{\circ}C$. None of conventional De-NOx techniques works under such low temperature range. In addition to NOx. the Pilot test results show that soot can be simultaneously treated with the present non-thermal plasma technique. The present pilot test shows that the electrical power consumption to operate the non-thermal plasma reactor is equivalent to 3 - 4 % of the electrical power generated by the diesel engine.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.4
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• pp.501-510
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• 1996

The gas-turbine generator of Seo-Incheon combined-cycle plant was tested for derivation of a model for dynamic analysis. Load rejection and AVR step test was performed to get the dynamic response of generator. The parameters of generator/control system model were determined by these measured data. No-load saturation test was performed for the saturation characteristics of the generator under steady state. V-curve test was also performed so as to find exact generator parameters. Q-axis parameters of generator was derived by measuring power angle. AVR and governor constants have been tuned by their oscillatory period and setting time characteristics. The derived parameters of generator control system is verified by one-machine infinite bus system simulation. (author). 7 refs., 20 figs., 5 tabs.

• Steel and Composite Structures
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• v.42 no.2
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• pp.265-275
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• 2022

A new type of precast steel reinforced concrete (PSRC) column was put forward in this paper. In order to study the static performance of PSRC column and hollow precast steel reinforced concrete (HPSRC) column subjected to combined compression and shear loading, a parametric test was carried out and effects of axial compression ratio, concrete strength and shear ratio on the mechanical behavior of composite PSRC column and HPSRC column were explored. In addition, the cracks development, load-span displacement relationship, strain distribution and shear bearing strength of column specimens were emphatically focused. Test results implied that shear failure of all specimens occurred during the test, and higher strength of cast-in-place concrete, smaller shear ratio and larger axial compression ratio could lead to greater shear resistance, but when the axial compression ratio was larger than 0.36, the shear capacity began to decrease gradually. Furthermore, truss-arch model for determining the shear strength of PSRC column and HPSRC column was proposed and the calculated results obtained from proposed method were verified to be valid.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.587-595
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• 2015

The purpose of this study was to demonstrate exploring the field application of combined cognitive-motor learning program based on proprioceptive neuromuscular facilitation and Bartenieff Fundamental program. The combined cognitive-motor learning program(CC) was applied to the 10 MCI elder while 10 elder in occupational therapy(OT) took cognitive learning class. MMSE-K, Time up & go test(TUG), Tandem gait test(TA), GQOL-D were measured and analyzed. The collected data were analyzed by Independent & Paired T-test. The results were as follows: Both groups showed similar learning effect in MMSE-K test. However, in TA & GQOL-D test, CC group showed significant learning effect than OT group. From these result, we conclude that combined cognitive-motor learning program is valuable as alternative program for cognitive development and social development as well as physical development of MCI elder.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.1-1
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• 2005

Japan Aerospace Exploration Agency(JAXA) has been conducting research and development of the Scramjet engines and their derivative combined cycle engines as hypersonic propulsion system for space access. Its history will be introduced first, and its recent advances, focusing on the engine performance progress, will follow. Finally, future plans for a flight test of scramjet and ground test of combined cycle engine will be introduced. Two types of test facilities for testing those hypersonic engines. namely, the 'Ramjet Engine Test Facility (RJTF)' and the 'High Enthalpy Shock Tunnel (HIEST)' were designed and fabricated during 1988 through 1996. These facilities can test engines under simulated flight Mach numbers up to 8 for the former, whereas beyond 8 for the latter, respectively. Several types of hydrogen-fueled scramjet engines have been designed, fabricated and tested under flight conditions of Mach 4, 6 and 8 in the RJTF since 1996. Initial test results showed that the thrust was insufficient because of occurrence of flow separation caused by combustion in the engines. These difficulty was later eliminated by boundary-layer bleeding and staged fuel injection. Their results were compared with theory to quantify achieved engine performances. The performances with regards to combustion, net thrust are discussed. We have reached the stage where positive net thrust can be attained for all the test coditions. Results of these engine tests will be discussed. We are also intensively attempting the improvement of thrust performance at high speed condition of Mach 8 to 15 in High Enthalpy Shock Tunnel (HIEST). Critical issues for this purposemay be air/fuel mixing enhancement, and temperature control of combustion gas to avoid thermal dissociation. To overcome these issues we developed the Hypermixier engine which applies stream-wise vortices for mixing enhancement, and the M12-engines which optimizes combustor entrance temperature. Moreover, we are going to conduct the flight experiment of the Hypermixer engine by utilizing flight test infrastructure (HyShot) provided by the University of Queensland in fall of 2005 for comparison with the HIEST result. The plan of the flight experiment is also presented.

• Korean Journal of Biological Psychiatry
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• v.4 no.2
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• pp.272-278
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• 1997

Many investigators are trying to elucidate the pathogenesis of psychiatric disorders on the basis of neuroendocrine responses to stimulation or perturbation. Dexamethasone(DEX) suppression has been the most widely utilized as the prototypical challenge test. Dexamethasone suppression test(DST) has proven to be valuable in diagnosing the depressive spectrum disorder. Reported specificity of diagnosis of depression is relatively high, but sensitivity is limited. Some researchers used the combination of dexamethasone and corticotropin releasing hormone(CRH) in order to improve the sensitivity. They reported that combined DEX/CRH test is more sensitive than DST alone. In this study the authors modified the DEX/CRH test, i.e., we administered the insulin instead of CRH. Total subjects were 28(7 normal controls, 10 manic patients, 11 schizophrenic patients). Subjects were taken DEX(1.5mg p.o.) at 11 p.m., insulin 16 hours later(0.1 unit/kg i.v.). Five blood samples for the determination of cortisol and ACTH were serially drawn at 15 minute interval. The results are as followings : 1) The cortisol and ACTH levels of manic subjects increased following insulin administration. Manic subjects showed higher levels of cortisol and ACTH than schizophrenic and normal control subjects. The cortisol and ACTH levels of schizophrenic and normal control subjects did not show gross changes. 2) The sensitivity of the test was lower than that of reported DEX/CRH test.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.243-249
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• 2001

In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature liquid metal reactor was simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The inelastic deformation of the reactor baffle cylinder can occur due to the moving temperature distribution along the axial direction as the hot free surface moves up and down under the cyclic heat-up and cool-down of reactor operations. The ratchet deformations were measured with the laser displacement sensor and LVDTs after cooling the structural specimen which experiences thermal load up to $550^{\circ}$ and the temperature differences of about $500^{\circ}C$. During structural thermal ratchet test, the temperature distribution of the test cylinder along the axial direction was measured from 28 channels of thermocouples and the temperatures were used for the ratchet analysis. The thermal ratchet deformation analysis was performed with the NONSTA code whose constitutive model is nonlinear combined kinematic and isotropic hardening model and the test results were compared with those of the analysis. Thermal ratchet test was carried out with respect to 9 cycles of thermal loading and the maximum residual displacements were measured to be 1.8mm. It was shown that thermal ratchet load can cause a progressive deformation to the reactor structure. The analysis results with the combined hardening model were in reasonable agreement with those of the tests.

• Journal of the Korean Data and Information Science Society
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• v.23 no.4
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• pp.787-796
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• 2012

The aim of this study is to closely examine the changes in their metabolic syndrome index and autonomic nerve systems after the 16-weeks's combined exercise program is carried out on low-level physical strength group (PAPS 4-5 level students). They were divided into two groups; exercise training group (15) and control group (15). This program consisted of five-times-a-week's warm-ups, main activities and warm-downs and it takes 50 minutes per trial. Through SPSS 19.0, all averages and standard deviations of dependent variables were calculated. We first performed Shapiro-Wilk's normality test of the variables. Before verifying the effect of combined exercise program, we tested the equality of means of the variables between combined-exercise-programmed-group and control group through a two-sample t-test and carried out a paired t-test to check if the changes in the variables of two groups before and after 16 weeks are statistically significant. Every statistical test is performed at a significance level of ${\alpha}$=.05. The results are as follows. When it came to metabolic syndrome index, there were statistically meaningful changes in waist measurement, triglyceride, glucose with empty stomach and HDL-C. Also, when it came to autonomic nerve system, there were meaningful changes in all variables. Consequently, it seems that the 16-weeks combined exercise program has positive effects on low level physical strength students.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1241-1251
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• 2013

The purpose of this study was to investigate and compare the effects of aerobic and complex exercise on body composition and blood lipids in the middle-aged women. Sixteen women whose ages ranged in 40 to 50 years were included in the sample of the study. The sample was divided into two groups: (a) aerobic exercise group (n = 8) and (b) combined exercise training group (n = 8). The aerobic exercise program consisted of bicycle ergometer, stepper, and treadmill, whereas; the combined exercise program was designed to improve muscular strength and aerobic capacity. Both programs took place 4 times a week for 12 weeks with the gradual increase of intensity (HRmax 60% 75% and 1 RM 60% 80%). Data were analyzed by nonparametric methods for pre-post within group mean differences (Wilcoxon signed rank test) and for between group mean differences (Wilcoxon rank sum test). Results indicated that there were statistically significant differences in BMI, body fat mass, and triglyceride within the sample of combined exercise; whereas, no significance existed in any variables within the aerobic exercise group. Results also revealed that statistical significance did exist in body fat mass between the combined and aerobic exercise group. These results implies that the combined exercise may be superior to aerobic only excercise for the body composition and blood lipid of the middle-aged women.