• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.17-23
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• 2009

Dihexyloctanamide(DHOA) was used as an extractant or phase modifier with the diamide extractants in a solvent extraction process for a radioactive liquid waste treatment. The degradation compounds of the DHOA extractant, irradiated with $^{60}Co$ gamma ray, were octanoic acid and dihexylamine which are identified by a Fourier transform infrared(FT-IR) and gas chromatograph/mass spectrometer(GC/MS) analysis, and determined by the GC/MS with selected ion monitoring(SIM) mode. Retention behavior of octanoic acid, tridecane (internal standard) and dihexylamine in total ion chromatogram (TIC) were 8.65 min., 9.79 min., and 10.27 min., respectively. With increasing the absorbed dose of the $\gamma$-ray irradiated DHOA, the concentration of octanoic acid was decreased and that of dihexylamine was increased.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.2
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• pp.102-114
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• 2004

The present work has been developed the interpretation processor including the behavior of material failure and the separation phenomena under transient dynamic loading (the operation of explosive bolt) using AUTODYN V4.3, SoildWork 2003 and TrueGrid V2.1 programs. It has been demonstrated that the interpretation in ridge-cut explosive bolt under dynamic loading condition should be necessary to the appropriate failure model and the basic stress of bolt failure is the principal stress. The use of this interpretation processor developing the present work could be extensively helped to design the shape and the amount of explosives in the explosive bolt having a complex geometry. It is also proved that the interpretation processor approach is an accurate and effective analysis technique to evaluate the separation mechanism in explosive bolts.

• Structural Engineering and Mechanics
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• v.67 no.4
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• pp.347-358
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• 2018

The main aim of this research was to investigate the shear strength of non-prismatic steel fiber reinforced concrete beams under monotonic loading considering different parameters. Experimental program included tests on fifteen non-prismatic reinforced concrete beams divided into three groups. For the first and the second groups, different parameters were taken into consideration which are: steel fibers content, shear span to minimum depth ratio ($a/d_{min}$) and tapering angle (${\alpha}$). The third group was designed mainly to optimize the geometry of the non-prismatic concrete beams with the same concrete volume while the steel fiber ratio and the shear span were left constant in this group. The presence of steel fibers in concrete led to an increase in the load-carrying capacity in a range of 10.25%-103%. Also, the energy absorption capacity was increased due to the addition of steel fibers in a range of 18.17%-993.18% and the failure mode was changed from brittle to ductile. Tapering angle had a clear effect on the shear strength of test specimens. The increase in tapering angle from ($7^{\circ}$) to ($12^{\circ}$) caused an increase in the ultimate shear capacity for the test specimens. The maximum increase in ultimate load was 45.49%. The addition of steel fibers had a significant impact on the post-cracking behavior of the test specimens. Empirical equation for shear strength prediction at cracking limit state was proposed. The predicted cracking shear strength was in good agreement with the experimental findings.

• Journal of the Korean Society for information Management
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• v.23 no.2
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• pp.5-19
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• 2006

The purpose of this study is to observe and analyze information searching behaviors of various user groups in different access modes for designing user-centered query interface of content-based Music Information Retrieval System(MIRS). Two expert groups and two non-expert groups were recruited for this research. The data gathering techniques employed in this study were in-depth interviewing, participant observation, searching task experiments, think-aloud protocols, and post-search surveys. Expert users, especially majoring in music theory, preferred to input exact notes one by one using the devices such as keyboard and musical score. On the other hand, non-expert users preferred to input melodic contours by humming.

• Korean Journal of Human Ecology
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• v.18 no.5
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• pp.1123-1133
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• 2009

This study attempted to analyze the general and physical characteristics, the status of physical function, the type and number of current diagnosis and self-reported symptoms, healthy life mode and food preference according to self-rated health (SRH) of older adults (135 men and 270 women). It also attempted to assess the factors affecting the SRH standards in agricultural and fishery areas located in southwestern Korea. The subjects considered themselves as being 'good'(57.6%), 'normal'(29.6%) or 'poor'(12.85) SRH, meaning positive self-rating of health and it was found that the correlation between factors such as the gender, current marriage status, monthly wage, the reception of the government's livelihood subsidy and subjective economical status and the SRH were significant. Regardless of the categories of obesity, a large number of the participants rated themselves as 'healthy', but not statistically significant. The subjects who reported poor ADL and IADL capacities, indicators of the status of physical function, were significantly more classified to the 'poor' health category and vice versa (P<0.001). The reported chronic diseases in this study that have lasted more than three months, were lumbago, sciatica, arthritis, high blood pressure and peptic ulcer. The current ratios of smoking, drinking and exercise were 85.3, 39.0 and 18.6%, respectively. The less drinking and exercising there was, the higher the 'good' SRH categories obtained (P<0.05). The respondents who had less chance of eating sour and hot foods estimated their health status as being better.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.6
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• pp.465-471
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• 2007

The system efficiency of the proposed Buck-Boost AC-DC converter is increased by soft switching method. The converter includes to merit of power factor correction (PFC) from sinusoidal control of input current. The switching behavior of control switches operates with soft switching by partial resonance, and then the proposed converter has high system efficiency with decrement of switching power loss. The input current waveform in proposed converter is got to be a sinusoidal form of discontinuous quasi-pulse row in proportion to magnitude of AC input voltage under the constant duty cycle switching. Therefore, the input power factor is nearly unity. The output voltage of the converter is regulated by PWM control technique. The discontinuous mode action of current flowing into inductor makes to simplify control method and control components. The proposed PFC Buck-Boost converter is analyzed to compare with the conventional PFC Buck-Boost converter. Some computer simulative results and experimental results confirm to the validity of the analytical results.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.12
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• pp.641-652
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• 2016

This paper proposes a method to generate test scripts in an automatic manner, based on checklist used for testing embedded systems in the fields. The proposed method can reduce the mistakes which may be introduced during manual generation. In addition, it can generate test scripts to test various mode combinations, which is not possible to be tested by the typical checklist. The test commands in a checklist are transformed into a test script suit referencing the signal values defined in a test command dictionary. In addition, the method to generate test scripts in sequential, double permutation and random manners is proposed useful to test the inter-operations between modes, a series of operations for a specific behavior. The proposed method is implemented and the feasibility is shown through the experiments.

• Tunnel and Underground Space
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• v.28 no.4
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• pp.343-357
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• 2018

Algorithm which can analyze the slope failure behavior utilizing the comprehensive information of the dense point of joint poles and the joint set orientations, both of which are obtained statistically, and the defect pattern of pole distribution has been developed. This method overcomes the potential incorrectness of the hemispheric projection method utilizing the joint set orientations only and also enhances the reliability of slope failure analysis. To this end a method capable of calculating the joint dispersion index directly from the joint pole distribution, instead of contour map, has been devised. The representative orientations for the slope failure analysis has been determined by considering the number and orientations of cone angle-dependent joint sets as well as the joint dispersion index. By engaging these representative orientations to the hemispheric projection analysis more reliable slope failure examination has been carried out. Sensitivity analysis for the potentially unstable slope of plane failure mode has been performed. Significance of joint strength index and the external seismic loading on the slope stability has been fully analyzed.

• Journal of Korean Society of Steel Construction
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• v.28 no.3
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• pp.185-194
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• 2016

This paper presents the finite element method results for HSS(Hollow Square Section) steel columns strengthened with Carbon Fiber Reinforced Polymer Plastic(CFRP) sheets. 6 specimens were fabricated and the specimen groups were non-compact short columns, slender short columns, and non-compact long columns. Test parameter was the number of CFRP ply. The finite element analysis was performed by using ANSYS Workbench V.14.0 and the results of FEM were compared with those of Test for failure mode, load-displacement curve, maximum load, and initial stiffness. The comparisons between experimental observations and computed results show that the analyses provided good correlation to actual behavior. Finally, the buckling stress were calculated according to the AISC cold-formed structure provision and the retrofitting effect were verified for each section type.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.7-16
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• 2008

There are unique aspects of truck vehicle movements compared with the personal travel in trip chaining. This paper reports an analysis on the truck vehicle trip chaining which intercity/metropolitan/intraregional trips are classified. Data collected from the travel dairy survey is used the truck trip-chaining analysis. The pattern of trip chaining classes is classified by the GIS mapping based on orgin-destination trip information. The physical index and efficiency index for each trip diary is used to the truck vehicle activity. Truck trips lengths and time differs from its truck type, service type and travel patterns. It is shown that the efficiency of the truck trip chaining depends on vehicle types and its delivery patterns. There are many other topics for research on trip chaining modeling such as the classification of trip chain, time use and mode choice by trip chaining.