• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.58-66
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• 1979

동력경운기용 두류의 무경운 파종기에 부착하여 사용하는 구절기중에서 소요견인력이 작고 구절작업정도가 양호한 구절기의 개발을 위한 기초자료를 얻기 위하여 구동식 토조에 인공강토를 채우고 원판형 및 호우형 구절기의 소요견인력과 이에 영향을 미치는 인자들의 관계를 구명코자 실내모형 확험을 실시하여 다음과 같은 결과를 얻었다. 원판형 구절기에 대하여 직경별로 조립각을 $8^{\circ}$ 와 $16^{\circ}$, 경심을 3 cm 와 6cm로 변화시키면서 2.75cm/sec의 속도로 견인력을 측정한 결과 원판의 직경이 약 28cm인 경우에 견인력이 최소로 나타났고, 직경이 이보다 크거나 작은 때는 견인력이 증가하는 경향을 나타냈으며 비저항도 대체로 비슷한 경향이었으나 원판의 직경이 약 30cm 일 때 최소로 나타났다. 종자파종의 심도조절을 목적으로 작구심(3cm 및 6 cm)과 견인력과의 관계를 조사하였던바, 경심과 견인력과의 관계는 거의 직선적인 변화를 나타냈으며 견인력에 영향을 미치는 인자중에서 경심의 영향이 가장 컸음을 알 수 있었다. 일반적으로 조립각 미 주행속도에 별 영향없이 경심 3cm 및 6 cm 공히 견인력은 직경 약 28 cm에서 , 비저항은 약 30cm에서 최소의 값을 나타내었다. 파종기의 작업성능과 관계가 깊은 주행속도 및 파시의 조절을 목적으로 원판의 조립각과 주행속도가 견인력에 미치는 영향을 조사했던 바, 조립각과 주행속도가 증가함에 따라 모두 견인력이 증가하는 경향을 나타내었으나 견인력에 미치는 영향은 주행속도가 더욱 크게 나타났다. 원판형 구절기와 호우형 구절기를 비교하기 위하여 쐐기각이$16^{\circ}$ 이고 리프트 각이 $20^{\circ}$ 인 호우형 구절기와 조건이 비슷한 조립각$16^{\circ}$ 의 원판형 구절기의 견인특성을 비교한 결과 직경 30cm 인 원판형의 경우는 비저항이 0.35-0.5kg/$cm^2$인데 비해 호우형의 경우는 0.71-1.02kg/$cm^2$로 나타나 호우형의 견인저항력이 평균 2 배정도 크게 나타났고 작구상태고 원판형의 경우보다 불량하였다.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.193-201
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• 2013

Recently there has been insignificant growth in the Korean construction management (CM) market, in comparison to the previous year. However, despite stagnation or even decreasing growth trends, the number of domestic companies participating in the CM market has increased rapidly. As follows, market movements of CM despite trending in stagnant growth or decrease, the market has been increasing firms which entry the market. The reasons for such dynamic change must be examined first, in order to facilitate analysis of its competitive structure. This study aims to examine the market competition structure and analyze the reason for proliferation of companies in the sick CM market. This study employs market concentration ratio and DEA-based Malmquist productivity indices to analyze the competitive structure of the CM market. Results reveal that the CM market has been monopolized by a few companies, but this is gradually changing. In addition, these companies were not productive, but there has been a gradual increase in the productivity index. Therefore, this study, which provides the direction index of the CM market, has implications for all major stakeholders in this market.

• Korean Journal of Medicinal Crop Science
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• v.28 no.2
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• pp.136-141
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• 2020

Background: The leaves of the goji berry (Lycium chinense Mill.) are used as raw materials in processing and by replace fruits to some extent. The reason is that the leaves are cheaper, however, betaine content is higher than in the fruits. These experiments were conducted to determine the planting density and cutting height for producing a large number of leaves. Methods and Results: The cultivar 'Myeongan' with many branches was used. When the shoot height reached 50 cm - 70 cm, harvesting was possible four times a year. The time to next harvest was approximately 38 days after regeneration of new shoots. Leaf quantity was in the order of 1st > 2nd > 4th > 3rd harvest. Insect damage occurred during the third harvest in late July and early August, therefore, eco-friendly control was necessary. The total yield was higher at the planting density 60 cm × 30 cm than that of 60 cm × 20 cm or 60 cm × 40 cm. The yield at cutting for shoot height of 60 cm was increased by 6.3 percent compared to that of 50 cm, At the cutting height of 70 cm, harvest was difficult owing to hardening of stems and thorns. Betaine content, an indicator component of goji berry, was not significantly different according to planting densities and cutting height. Conclusions: The ideal cutting period to produce leaves of goji berry for processing is when the shoots grow to approximately 60 cm, and the leaves can be harvested 4 times a year. The dried-leaf yield was highest at the planting density of 60 cm × 30 cm.

• The Research Journal of the Costume Culture
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• v.21 no.2
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• pp.246-260
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• 2013

This research was carried out on women in their 20s and 30s who have overweight lower body. The subjects selected for this study were women a Rohrer index of 1.6 or higher, a waist circumference 78.5cm to 83.5cm, and a lower drop of at least 18cm. The aim is to propose a prototype of bi-stretch pants meeting demands for both functionality and aesthetic appeal. Various clothing patterns ease amount of the waist and hip circumferences and crotch depths and were developed. They had different crotch widths, and center back line angles. The results showed that the best pants patterns were ease 1cm to the total hip circumference. The front hip circumference was H/4-0.5cm, and the back hip circumference was H/4+1cm. The front crotch width was H/20+1cm, the back crotch width was H/10+3cm. No additional ease was given to the total waistline. The front waist circumference was W/4+0.5cm. The back waist circumference was W/4-0.5cm. The knee circumference was set at 44cm, the pant hem width was set at 36cm, and the pant length was set at 100cm-5cm. The findings of this research can be used as basic data for stretch pants that fit the abdomen, hips, and thighs for women in their 20s and 30s with overweight lower body.

• The Korean Journal of Emergency Medical Services
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• v.12 no.3
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• pp.27-41
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• 2008

Purpose : The purpose of this study was to supply basic data for the impact on the accuracy of basic CPR according to position and foot-board height of basic CPR provider. Methods : Study design was within - group design. Subjects were 25 EMT-P Students in K city. Interventions was basic CPR performed on a resuscitation manikin placed on a hospital bed, kneeling on the bed adjacent to the manikin. Data was analyzed using descriptive statistics and Friedman test. Results : In case of the basic CPR performed on a resuscitation manikin placed on a hospital bed, ventilation accuracy was the highest in less than 160 cm height, foot-board height : $34.2{\pm}1.48cm$, 91.4% and in 161-165 cm height, foot-board height : $26.0{\pm}2.14cm$, 88.4% and in 171-175 cm height, foot-board height : $23.0{\pm}1.41cm$, 91.3% and in the above 176 cm, kneeling on the bed, 95%. Chest compression accuracy was the highest in less than 160 cm height, foot-board height : $30.2{\pm}1.48cm$, 95.6% and in 161-165 cm height, kneeling on the bed, 97.6% and in 171-175 cm height, kneeling on the bed, 98.5% and in the above 176 cm, kneeling on the bed, 98.7% and foot-board height : $20.5{\pm}1.91cm$, 98.7%. Chest compression error was due to too weak : 2.0-35.4 times. There were ststistically significant differences in 191-195 cm group according to chest compression mean depths($x^2=10.824$, p = .013) and chest compression error (p = .040). Conclusion : In contrast to current guidelines, the position and foot-board height of basic CPR provider are very important to the accuracy of the basic CPR. Furthermore, we recommend that a using real time audiovisual feedaback system significantly improve the quality of chest compression and ventilation during resuscitation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.1
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• pp.2853-2877
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• 1973

Models of cross-sections and channels were made in order to measure seepage losses. Cross-sections were made of sand, sandy clay loam and loam, their thicknesses being 30cm and 40cm, respectively. Flow depths kept in the cross-sections were 4cm, 6cm, 8cm and 10cm. Straight and curved channel models were provided so as to measure seepage losses, when constant water depths maintained at the heads of the channels were 7.3cm and 5.7cm, respectively. The results obtained in this experiment are presented as follows: 1) A cumulative seepage loss per unit length at a point in the channel varies in accordance with time and flow depth. The general equation of cumulative seepage loss may be as follows(Ref. to Table V.25): $$q_{cum}=\int_{o}^aq(a)dt+\int_a^bq(b)dt+\int_b^tq(c)dt$$ 2) In case that the variation of water depth through the channel is slight, the total seepage loss may be computed by applying the following general equation: $$\={q}_{cum}{\cdot}x=\int_o^tq_{cum}\frac{{\partial}x}{{\partial}t}dt$$ 3) Because seepage loss varies considerably according to water depth in case that the variation of flow depth through the channel is great, seepage loss should be computed by taking account of the change of flow depth. 4) The relation between time and traveling distance of water flow may be presented as the following general equation(Ref. to Table V.29): $$x=pt^r$$ 5) The ratios of the seepage losses of the straight channel to the curved channel are 1:1.03 for a flow depth of 7.3cm and 1:1.068 for that of 5.7cm. 6) The ratios of the seepage losses occurring through the bottom to those through the inclined plane in the channel cross-section are 1:2.24 for a water depth of 8cm and 1:2.47 for a depth of 10cm in case that soil-layer is 30cm in thickness. Similarly, those ratios are 1:2.62 and 1:2.93 in case of a soil-layer thickness of 40cm(Ref. to Table V.5).

• Journal of the Korean Geosynthetics Society
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• v.18 no.1
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• pp.55-65
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• 2019

This paper describes results of experimental and numerical analyses, in order to analyze a reinforcement effect of concrete mat on open cut restoration of underground cavity. The plate loading tests were conducted to evaluate a reinforcement effect of concrete mat, at reinforcement depths from the ground surface of 10 cm, 20 cm, and 30 cm. The result showed that the reduction ratio of stress (earth pressure) was about 60% at all reinforcement depth. The reinforcement effect considering ground surface settlement and reduction ratio of stress based on laboratory tests and numerical analysis was significant, at reinforcement depths from the ground surface of 10 cm~20 cm. LFWD test results showed that subgrade modulus was the largest when concrete mat was installed 20 cm below ground surface. Therefore, it is effective to reinforce concrete mat within 20 cm from the surface, when the underground cavity due to damage of underground utilities was formed in the height direction to the bottom of the pavement layer.

• Smart Structures and Systems
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• v.23 no.5
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• pp.479-493
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• 2019

In this paper, the interaction between notch and micro pore under uniaxial compression has been performed experimentally and numerically. Firstly calibration of PFC2D was performed using Brazilian tensile strength, uniaxial tensile strength and biaxial tensile strength. Secondly uniaxial compression test consisting internal notch and micro pore was performed experimentally and numerically. 9 models consisting notch and micro pore were built, experimentally and numerically. Dimension of these models are 10 cm*1 cm*5 cm. the length of joint is 2 cm. the angularities of joint are $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$. For each joint angularity, micro pore was situated 2 cm above the lower tip of the joint, 2 cm above the middle of the joint and 2 cm above the upper of the joint, separately. Dimension of numerical models are 5.4 cm*10.8 cm. The size of the cracks was 2 cm and its orientation was $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$. Diameter of pore was 1cm which situated at the upper of the notch i.e., 2 cm above the upper notch tip, 2 cm above the middle of the notch and 2 cm above the lower of the notch tip. The results show that failure pattern was affected by notch orientation and pore position while uniaxial compressive strength is affected by failure pattern.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.533-538
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• 2021

^99mTcO₄^- is used to measure thyroid uptake. When measuring background radioactivity of the thigh, the distance between the detector and the thigh was 20 cm at a position 10 cm above the knee from the knee to the pelvis. At 25 cm, many hospitals are measuring at different distances. The purpose of this study was to study the difference in effectiveness in obtaining the thyroid uptake rate by quantitatively analyzing the uptake rate measurement at two distances. As a result, the average thyroid uptake rate measured at 20 cm in the thigh of 50 patients was 3.532±4.312%, and the average thyroid uptake rate measured at 25 cm was 3.680±4.304%. As a result of the thyroid uptake rate test result, the femoral background radioactivity value measured at a distance of 20 cm was relatively higher than the background radioactivity value measured at a distance of 25 cm, and as a result, the thyroid uptake rate was 0.148% lower.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.162-168
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• 2022

This study was carried out to investigate the effects of planting densities on the growth characteristics, dry matter yield, and feed value of "Geukdong 6" (a new variety of corn for feed). The experimental design was arranged in a randomized block design with three replications. Treatments consisted of six planting densities, 60 cm × 25 cm (T1), 60 cm × 30 cm (T2), 70 cm × 25 cm (T3), 70 cm × 30 cm (T4), 80 cm × 25 cm (T5) and 80 cm × 30 cm (T6). All treatments were sown on May 14, 2021, and the harvest was on October 3 (late flowering). Plant length and the number of tillers were the highest in T5 (p<0.05), but the number of leaves and stem diameter were the highest in T6 than in the other treatments (p<0.05). Leaf length, leaf width, and dead leaf were not significantly different among the treatments. Organic matter was highest in T6, and crude protein was highest in T5 (p<0.05). The ether extract was not significantly different among the treatments. Crude fiber, NDF, and ADF were highest in T2 with relatively higher planting density (p<0.05). Calcium and phosphorus were not significantly different among the treatments. TDN content was the highest in T3 (p<0.05). Sugar degree (Brix), fructose, glucose, dextran, isomerose, and inverted sugar were not significantly different among the treatment. Fresh yield, dry matter yield and TDN yield were higher in order of T6 > T5 > T4 > T3 > T2 > T1 (p<0.05). Relatively feed value was higher in order of T3 > T6 > T5 > T1 > T4 > T2 (p<0.05). Based on the above results, planting density could be recommended from 80 cm × 30 cm for efficient production of "Geukdong 6".