• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.53-61
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• 2013

A new deformation of reinforcing bar in coils was proposed to improve a machinability of straightening process, which has crescent-shaped transverse ribs with an inclination angle of 50 degrees, a crest width of $0.15d_b$, and a flank inclination of 55 degrees. The proposed deformation can increase contact area between a surface of re-bar and a groove of a roller during a straightening process and, therefore, it might reduce a damage of ribs, improve a final straightness, and enhance an efficiency of the straightening process. Splice tests were conducted to evaluate bond strengths of three types of re-bar in coils including the proposed re-bar, of which the inclination angles of transverse ribs were 50, 60, and 90 degrees, respectively. Test results show that the re-bars in coils have higher bond strengths than predicted strengths by equations of Orangun et al., ACI 408, and KCI by at least 10%. Correlation coefficients of bond strengths between a straight bar and re-bars in coils are 0.94 and more. Consequently, equations of the KCI code for determining development and splice lengths can be applied to the tested re-bars in coils.

• Journal of the Korea Concrete Institute
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• v.25 no.3
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• pp.295-304
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• 2013

Ultra-High Performance Concrete (UHPC) has recently been one of the most active research fields in Korea as well as in foreign countries, because it can contribute to a longer life and economic efficiency of structures. Although precast-type UHPC fabricated in a factory is preferable in terms of quality control and reduction of construction period, there exist, even in the precast structure, some parts that need to be cast in-place such as the joints between precast segments. In the cast-in-place UHPC, however, it is probable that an optimum curing condition can hardly be realized in contrast to the factory production. In this study, therefore, the trend of compressive strength development of UHPC was experimentally investigated by assuming various inferior curing conditions that may be anticipated at a construction site. Concrete specimens were fabricated and cured under different conditions with the variables such as curing temperature, delay time before the initiation of curing, duration of curing time and moisture condition. The strengths were compared with those of the specimens cured by standard high temperature steam. Through the analysis of the test results, some minimum requirements for curing have been proposed that are required when the UHPC is cast in-place. It is expected, through this study, that practical use of UHPC in construction sites can be increased.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.141-146
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• 2016

HEVC/H.265 is the latest joint video coding standard proposed by ITU-T SG 16 WP and ISO/IEC JTC 1/SC29/WG 11. In H.265, pictures are divided into a sequence of coding tree units(CTUs), and the CTU further is partitioned into multiple CUs to adapt to various local characteristics. Its coding efficiency is approximately two times high compared to previous standard H.264/AVC. However according to the size of extended CU(coding unit) and transform block, the hardware size of PMR(prediction/mode decision/reconstruction) block within video encoder is about 4 times larger than previous standard. In this study, we propose a new less complex hardware architecture of PMR block which has the most high complexity within encoder without any noticeable PSNR loss. Using this simplified block, we can shrink the overall size the H.265 encoder. For FHD image, it operates at clocking frequency of 300 MHz and frame rate of 60 fps. And also for the test image, the Bjøntegaard Delta (BD) bit rate increase about average 30 % in PMR prediction block, and the total estimated gate count of PMR block is around 1.8 M.

• Journal of the Korean Society of Fashion and Beauty
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• v.3 no.3 s.3
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• pp.31-40
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• 2005

The reason that aromatherapy began to draw attention again as the alternative therapy is because the essential oils that are used for aromatherapy not only allow the human body to maintain homeostasis but also have an effect on curing a mental feeling of fatigue and because these efficacies and effects are proceeding with being proved scientifically. Also, with coming to be high in a voice of concern about severally side effects that the modern medicine and the synthetic chemistry have, the aromatherapy came to be paid attention as the replacement therapy that can substitute for and supplement this. In particular, at the time of requiring a study on a substance to substitute for this after having been announced in Japan for 1998 a risk of Zincpyrithione that is being used as a component of dandruff treatment, it is thought that the aroma oil that was known for having an anti-dandruff effect has a merit of being easy in a user's access, thus it will be effective in curing the symptom of dandruff. Accordingly, this study conducted the following experiment in a bid to examine whether the aroma oil has the anti-microbial effect on the actual malassezia. First of all, it measured the minimum concentration of aroma oil in which the growth of malassezia is inhibited, by carrying out MIC(Minimum Inhibition Concentration) test in terms of anti-microbial activity against Malassezia furfur KCTC 7744 while using oils of Patchouli, Rosemary, Lavender, and Tea tree among aroma oils that are being used for dandruff treatment. As a result of that, Tea tree oil has the most excellent anti-microbial activity, and the measurement result of anti-microbial activity was shown in order of Lavender oil>Rosemary oil>Patchouli oil. Next, it carried out the is actually eased by applying Tea tree oil directly to the scalp of dandruff. In consequence of the experiment, the massage of Tea tree oil indicated the result of relieving the symptoms of dandruff such as scale, itch, pain, inflammation, and sebum, and among these symptoms of dandruff, it was shown to be most effective in easing itch. Especially, this clinical experiment was indicated that the massage of Tea tree oil has the most effect on relieving itch of targets with a dry-skin type who had no experience of dandruff treatment.

• Journal of Radiation Protection and Research
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• v.37 no.1
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• pp.10-15
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• 2012

Design and performance test results of a newly developed optically stimulated luminescence (OSL) measurement system are presented in this paper. Generally, different types of optical filters are used in OSL reader system to minimize the interference of the stimulation light in the OSL signal. For optically stimulation of $Al_2O_3:C$, we have arrived at an optimal combination of the filters, i.e., GG420 filter for filtering the stimulating light source, and a combined UG11 and BG39 filter at the detecting window (PMT). By using a high luminance blue LED (Luxeon V), sufficient luminous intensity could be obtained for optically stimulation. By using various control boards, the OSL reader device was successfully interfaced with a personal computer. A software was developed to deliver required commands to operate the OSL reader by using the LabView program (National Instruments, Inc.). In order to evaluate the reliability and the reproducibility of newly designed-OSL reader. Performance testing of the OSL reader was carried out for OSL efficiency, OSL decay curve and signal to noise ratio of the standard $Al_2O_3:C$ OSL material. It was found to be comparable with that of commercial Riso reader system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.11
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• pp.1034-1046
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• 2011

In this paper, a design and fabrication of 40 W power amplifier for the X-band using load-pull measurement of GaN HEMT chip are presented. The adopted active device for power amplifier is GaN HEMT chip of TriQuint company, which is recently released. Pre-matched fixtures are designed in test jig, because the impedance range of load-pull tuner is limited at measuring frequency. Essentially required 2-port S-parameters of the fixtures for extraction optimal input and output impedances is obtained by the presented newly method. The method is verified in comparison of the extracted optimal impedances with data sheet. The impedance matching circuit for power amplifier is designed based on EM co-simulation using the optimal impedances. The fabricated power amplifier with 15${\times}$17.8 $mm^2$ shows the efficiency above 35 %, the power gain of 8.7~8.3 dB and the output power of 46.7~46.3 dBm at 9~9.5 GHz with pulsed-driving width of 10 usec and duty of 10 %.

• The Korean Journal of Emergency Medical Services
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• v.4 no.1
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• pp.35-46
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• 2000

The results of analyzing the cognition of CPR by college students who major in public health or not order to enhance the educational efficiency of first aid ability and its expansion are as follows. 1. In case of students majoring in public health, the students who have the knowledge of term 'CPR' are 95.3% of total 300 students and 62.6% of the students who don't major in public health know it. In the item test of examining the degree of theoretical knowledge of CPR, the cases who know all 12 items are 5.2% and 1.6% respectively in cases who major in public health and don't major in it and it is judged that the extension of educational opportunity for them should be urgent. 2. The students who have experienced the practice of CPR are 20.6% in case who major in public health and 7.4% in other case. Therefore it seems to desirable that indirect field experience should be obtained by strengthening practice centered education. 3. The order of practice to examine the CPR ability is asked and the students who show very good remark are just 21~22% in both cases and they conducted very ineffective CPR and it is examined that they did first aid which may a serious damage to patients. Then the cases who recovered pulse and respiration after CPR were very low as 28.8% in the students who major in public health and 35.7% in others. It is therefore considered that the exact education of conducting the maintenance of respiratory trace, artificial respiration and CPR is necessary. 4. The cases who had the education of CPR were 51% in the students who major in public health and 39.4% in others, who had little opportunities to have CPR and 92.5~93.2% in both groups fee the necessity of continuous education and it is very encouraging to extend the education of CPR. 5. The education of CPR is mainly done at school (70.3~79.4%) and from teachers (52.7~55.4%) and 71.2% of the students majoring in public health responded that it is good for them to have education of CPR at school and lecture by first-aider and 58.9% of others did it. The cases who ask for lecture by the Professors of Dept. of First-Aid are 11.8 in students majoring in public health and 13.1% in others and it is judged that lecture by them having the theoretical foundation and first-aider with practical ability will be desirable. 6. On teaching methods, 57.5% of the cases majoring in public health and 63.3% of others ask for practice and 20% of both groups need theory centered teaching. 7. On lecture fee, 83% of the cases majoring in public health and 83.3% of others consider it should be free and 8~11.8% who are to pay for 10,000 won and it is judged that it should be opened and operated as liberal arts by college in the dimension of lifelong education. 8. On the objects of education, 83% of cases majoring in public health and 66.6% of others consider it should be conducted in people of all ages and both sexes and it is known that everyone recognizes the necessity of popularizing the education of first-aid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1608-1617
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• 2013

This study is performed to evaluate the effectiveness of a weight management program for overweight and obesity office workers; comparing their changes in the anthropometry, biochemistry, nutrient intakes, and exercise performance before and after the obesity management program. This program was performed on 39 workers, who are overweight or obese, over BMI 23 for 6 months in Jeollabuk-do public institution. As the results of this study suggests, triceps thickness (TT) of male subjects was significantly decreased (P<0.05). Waist circumference (WC), and hip circumference (HC) of the total subjects were significantly decreased after the weight management program (P<0.05). The biochemical result of the Total cholesterol (TC) (P<0.05) and LDL cholesterol (LDL-C) (P<0.01) was significantly decreased in male subjects. The results of abdominal computed tomography (CT) also showed that subcutaneous fat area (SFA) of male subjects was significantly decreased after the weight management program (P<0.01). The nutrient intake's results of female subjects, who took Fe, Vit B2, and niacin, were increased significantly after the weight management program (P<0.05). The nutrition knowledge score of male subjects was significantly increased (P<0.05), and a muscular endurance of the physical test was significantly increased after the obesity management program (P<0.01). At the work place, workers need a systemic health and obesity management program to improve their work efficiency and quality of life. After this study, the program should be developed and supported continuously to maintain positive results from this study.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.74.2-74.2
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• 2017

Faint quasars are important to test the possibility that quasars are the main contributor to the cosmic reionization. However, it has been difficult to find faint quasars due to the lack of deep, wide-field imaging data. In this poster, we present our efforts to find faint quasars in the ELAIS-N1 field through the deep data (iAB ~ 25) obtained by the Subaru Hyper Suprime-Cam (HSC) Strategic Program survey. To select reliable quasar candidate, we also use the near-infrared (NIR) data of the Infrared Medium-deep Survey (IMS) and the UKIRT Infrared Deep Sky Survey (UKIDSS) - Deep Extragalactic Survey (DXS). Using multiple-band color cuts, we select high redshift quasar candidates. To confirm them as high redshift quasars, candidates are observed by the SED camera for QUasars in EArly uNiverse (SQUEAN) instrument in several medium band filters that can sample the redshifted Lyman break efficiency. The quasar sample will be used to study the growth of BH and stellar mass, the relation between the quasar activity and the host galaxy, and their contribution to the cosmic re-ionization.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.153-162
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• 2011

Composite box-girder with corrugated steel webs has been widely used in civil engineering practice as an alternative of conventional pre-stressed concrete box-girder because the efficiency of pre-stressing can be increased and weight reduction of superstructure can be achieved by replacing concrete webs as a corrugated steel webs. However, most of previous researches were limited in shear and flexural behavior of such girder so that the torsional behaviors of composite box-girder with corrugated steel webs are not fully understood yet and it needs to be investigated. Some of previous researchers developed the nonlinear theory for torsional analysis of composite box-girder with corrugated steel webs. However, their theories were developed by ignoring the tensile behavior of concrete. Thus, there are certain limitations in analysis of serviceability such as cracking moment and torsional stiffness of the girder. This paper presents the analytical model for torsional behavior of composite box-girder with corrugated steel webs considering tensile behavior of concrete. Based on the proposed analytical model, nonlinear torsional analysis program of composite box-girder with corrugated steel webs was developed. Then, for verification of validation of the developed model, test for the girder was conducted and the results were compared with those of analytical model. Finally, parametric study was conducted and the effects of tensile behavior of concrete on the torsional behavior of the girder were discussed.