• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.250-256
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• 2014

This study was carried out in order to seek social support direction by allowing them to recognize necessity of preparing for their stably old age life and by inquiring into the preparation for old age life targeting dental hygienists who work at dental clinics. It sent questionnaire by post to dental hygienists of 1,560 dental clinics, which were sampled with a stratified sampling method, and then conducted a cross-sectional study based on self-administration. As a result of a problem of being worried in old age life, the ratio with the response as saying of being 'economy' was indicated to be the highest. The ratio of financial preparation for old age was shown to be high with 84.3%. Its method was the highest in 'fixed deposit and installment savings' with 62.6%. The satisfaction with financial preparation for old age stood at averagely 2.60, thereby having shown to be dissatisfied. It was shown to be low with 2.97 in the mean score of physical preparation for old age life, 3.59 in emotional preparation, and 2.56 in preparation for leisure. In conclusion, the satisfaction with financial preparation for old age life in our country's dental hygienists was low. Even the physical, emotional, and leisure-based preparations were shown to be low. Hence, it is considered to be likely needed to be planned preparation for old age life from the 30s. Also, for this, Korean Dental Hygienists Association needs to positively develop several kinds of programs such as education, policy and system for old age life following these people's retirement.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.107-114
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• 2011

This study was conducted to investigate the effect of feeding whole crop barley silage (WBS) on the growth performance, carcass grade, and beef quality of Hanwoo steers. Twelve Hanwoo steers (12-mon-old) were allocated into either a control (rice straw fed) or WBS (whole crop barley silage fed) group (six animals per group) and fed for 540 d until the animals reached 30-mon-old. Concentrates and roughage were fed according to the feeding stage phases; finisher I (12.16-monold), II (17.21-mon-old), and III (22.30-mon-old). A significant increase in growth was observed during the finisher I stage for the steer fed WBS, whereas a significant increase in growth occurred during the finisher II stage in the control group. The yield grade of the WBS group increased significantly with a 15.6% increase in the longissimus dorsi area and a 25.7% reduction in back fat thickness. Marbling scores improved 52.4% in the WBS group compared with the control group. A significant difference in treatments was observed for the proximate chemical composition of the crude fat content. The results regarding palatability traits in the WBS group showed a significant improvement in appearance. The results indicate that the WBS group had improved longissimus muscle and marbling scores on carcass grading compared to the control.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.269-274
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• 2003

The purpose of this study was to determine the effect of rbST treatment on progesterone concentration, volume of luteal tissue and pregnancy rate following embryo transfer. Recipient cows were assigned to control and rbST group, of which was given a single injection of rbST (500 mg. sc) at estrus detection. The concentration of progesterone was not significantly different between control and at 0, 3, 6 days after rbST treatment. However, the concentration of progesterone at 9, 12 days was significantly higher than in control group (4.6 and 6.8 vs. 3.9 and 4.5 ng/ml P4). The pregnancy rate after embryo transfer in rbST treatment was significantly higher than in control group (64.0 vs. 47.1 %; p<0.05). The results indicated that rbST treatment in recipient cows could be improved the efficiency of pregnancy rate after embryo transfer.

• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.245-255
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• 2001

Existing cut-and-cover tunnels are designed regardless of cut-slope under the assumption that the overburden weight of backfill soil acts on tunnel arch and the earth pressure at rest acts on tunnel walls. However, actual earth pressures acting on the tunnel lining depend on open-cut size composed of cut-slope and cut-width, and thus the tunnel lining shows a different structural behavior. This study investigated the effect of cut-slope on structural behavior of the cut-and-cover tunnel lining as follows; Firstly, a comprehensive numerical analysis method using FLAC2D code was used and verified by field measurements of tunnel profile. Secondly, based on the verified numerical analysis technique, earth pressure acting on the lining, and displacement and sectional force developed on the lining were estimated with various shapes of cut-slopes$30^{\circ}\;, 456{\circ},\; 60^{\circ},\; and\;75^{\circ}%). Numerical analysis results indicate that the steeper cut-slope shows the more displacement and moment of the tunnel lining.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.160-168
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• 2010

An experimental study has been conducted to investigate the effects of forcing amplitude on the tone-excited non-premixed jet flame of the resonance frequency. Visualization techniques are employed using the laser optic systems, which are RMS tomography, PLIF and PIV system. There are three lift-off histories according to the fuel flow rates and forcing amplitudes; the regime I always has the flame base feature like turbulent flame when the flame lift-off, while the flame easily lift-off in the regime II even if a slight forcing amplitude applied. The other is a transient regime and occurs between the regime I and regime II, which has the flame base like the bunsen flame of partial premixed flame. In the regime I and II, the characteristics of the mixing and velocity profile according to the forcing phase were investigated by the acetone PLIF, PIV system. Particular understanding is focused on the distinction of lift-off history in the regime I and II.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.321-330
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• 2014

This study was performed to investigate relation between riparian vegetation and environmental factor and to predict riparian vegetation succession in Nakdong river, which is typical sand river in Korea Peninsula. We searched 5 natural levee and installed 84 quadrats in Nakdong river near by Andong city. Also, We analyzed flora, vegetation cover degree, topography, soil moisture, organic content, pH, electrical conductivity and soil texture. According to the result of CCA (canonical correspondence analysis), which considered both investigated vegetation data and environmental factor, vegetation were divided down three groups, and each group was difference by height above ordinary water level, organic content and sand. In addition, the most powerful factor was indicated the height above ordinary water level.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.6 s.46
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• pp.31-39
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• 2005

The purpose of this study was to investigate the nonlinear behavior of a cold-formed steel (CFS) shear panel, which was composed of built-up columns and tension-only diagonal straps for bracing, when excited by earthquake motions. For the purpose, shaketable tests of a full-scale two-story cold-formed steel (CFS) shear panel were conducted. in the shear panel, the diagonal strap is a major lateral force resisting system, which is a very ductile member, and the columns, which are gravity resisting members, are fabricated by wooing studs, which can't develop their full flexural strength because they may buckle locally. The test results showed that the straps dissipate most of energy of the shear panel in a tension-only and pinched way and the columns dissipate it relatively smaller than the straps but they still contribute to overall dissipation. As a result of this study, investigating real nonlinear behavior of a structure in earthquakes is a very important process by shaketable tests even though it is simple.

• Geophysics and Geophysical Exploration
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• v.5 no.3
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• pp.178-184
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• 2002

For economy and convenience, seismic refraction survey is widely used in surveying for large civil engineering work. The purpose of this study is to obtain the numerical responses of various models using Kirchhoff migration, and to analyze its application to the real data processing. Synthetic traveltime curve was calculated by vidale's algorithm, and various models such as 2 or 3 layer model and irregular topography model are tested to simulate the response of real structure. In order to compare the effect of initial velocity model, true velocity models, inversion results by tomography, smooth velocity models are used as an initial guess. The responses of model data show that the algorithm of this study is more sensitive to initial velocity model than the reflection survey, so choosing a suitable initial velocity model will be the most important thing in real data processing.

• The Journal of Korean Society for School & Community Health Education
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• v.21 no.3
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• pp.21-34
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• 2020

배경 및 목적: 본 연구는 학교 내 응급상황(천식 위기, 알레르기 반응, 저혈당 위기, 발작, 심폐정지, 출혈/골절, 머리/목 상해, 열성질환, 중독, 질식)에 대한 행정 차원과 물품구비 차원에서의 준비 실태, 그리고 응급처치 수행자신감을 파악하는데 목적이 있다. 방법: 단면조사연구로 274명의 보건교사를 대상으로 하였으며, 자가보고형 조사지를 이용하여 대상자와 학교의 일반적 특성, 학교 내 응급상황에 대한 행정·물품 준비 실태, 그리고, 응급처치 수행자신감 등 3개 영역의 자료를 수집하였다. 자료수집은 2018년 2월 1일부터 2018년 7월 31일까지 실시하였고, 자료분석은 기술통계, t-검정과 분산분석을 이용하였다. 결과: 대부분의 학교에서 응급상황 관리계획이 있었으나, 응급상황별로 천식 위기는 46.7%, 알레르기 반응은 58.4%에서만 관리계획을 갖추고 있었다. 산소, 혈당측정기, 자동제세동기, 경추고정장치 등은 85% 이상의 학교에서 보유하고 있었으나, 기관확장제 흡입기, 에피네프린 주사제, 흡인기 등은 거의 갖추고 있지 않았다. 응급상황 수행자신감은 5점 만점에 2.67점 (발작관리) 에서 3.55점 (심폐정지관리)이었으며, 일부 응급상황에 대해서 의료기관 근무경력이 증가함에 따라 수행자신감이 증가하였다. 결론: 대부분의 학교에서 응급관리계획을 수립하고 있었으나, 응급상황별 관리계획을 수립한 경우는 반 정도에 불과하였다. 보건교사의 학교 내 응급상황에 대한 응급처치 수행자신감은 전체적으로 낮게 나타남에 따라, 이들의 역량강화를 위한 체계적인 교육과 멘토링 프로그램이 요구된다.

• Tunnel and Underground Space
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• v.25 no.6
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• pp.496-504
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• 2015

Roadheader that excavates ground using pick cutters installed on the cutting head is one of the partial-face machines. A conical cutter among pick cutters is excavation tool decreasing the loss of cutter using tungsten carbide insert at the tip of the cutter and it has been widely used in the roadheaders. In this study, durability performance for three kinds of conical cutters was evaluated in copper mines composed of Manto and conglomerate. After field test, the visual inspection as well as the weight loss measurement of pick cutters was carried out to investigate the damage of pick cutters. In addition, CT scan and SEM were performed to check whether or not crack and apertures in pick cutters. As results, the conical cutter with hardfacing was evaluated as having the best durability performance and it was unable to find cracks in all cutters investigated.