• Korean Journal of Poultry Science
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• v.38 no.1
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• pp.51-57
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• 2011

This study was conducted to investigate the effects of supplementation diets of pine needle powder on performance, proximate composition, carcass characteristics, blood cholesterol concentration, TBARS (thiobarbituric acid reactive substance), WHC (water holding capacity), and shear force of chicken meat. Broiler chicks were fed diets for five weeks containing 0% pine needle powder (Control), 0.3% pine needle powder (T1), 0.6% pine needle powder (T2), and 0.9% pine needle powder (T3). Performance was no significant difference among treatment groups, but mortality was decreased in diets by the supplementation of pine needle powder than that of T1 and control. The moisture, crude protein, crude fat, and crude ash were no significant difference. The liver weight and abdominal fat was significantly decreased by the supplementation of pine needle powder compare to the T1 and control (P<0.05). The total cholesterol and LDL-cholesterol concentration of control was higher than treatment groups, and the HDL-cholesterol concentration and glucose of control was lower than treatment groups (P<0.05). The TBARS value was significantly decreased by the supplementation of pine needle compared to the control (P<0.05). In conclusion, these data indicate that 0.6% pine needle powder supplementation (T2) was most effective in decreasing mortality, total cholesterol and LDL-cholesterol and increasing HDL-cholesterol concentration.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.121-141
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• 2017

The thermal analysis of an underground power conduit for electrical cables is essential to determine their current capacity with an increasing number of demands for high-voltage underground cables. The temperature rises around a buried cable, caused by excessive heat dissipation, may increase considerably the thermal resistance of the cables, leading to the danger of "thermal runaway" or damaging to insulators. It is a key design factor to develop the mechanism on thermal behavior of backfilling materials for underground power conduits. With a full-scale field test, a numerical model was developed to estimate the temperature change as well as the thermal resistance existing between an underground power conduit and backfill materials. In comparison with the field test, the numerical model for analyzing thermal behavior depending on density, moisture content and soil constituents is verified by the one-year-long field measurement.

• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.33-40
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• 2020

The purpose of this research was to find out the relation between Korean learners' English proficiency and the ratio of the length of the stressed vowel in a monosyllabic noun to that of the unstressed vowel in an article of the noun phrases (e.g., "a cup", "the bus", etcs.). Generally, the vowels in monosyllabic content words are phonetically more prominent than the ones in monosyllabic function words as the former have phrasal stress, making the vowels in content words longer in length, higher in pitch, and louder in amplitude. This study, based on the speech samples from Korean-Spoken English Corpus (K-SEC) and Rated Korean-Spoken English Corpus (Rated K-SEC), examined 879 English noun phrases, which are composed of an article and a monosyllabic noun, from sentences which are rated on 4 levels of proficiency. The lengths of the vowels in these 879 target NPs were measured and the ratio of the vowel lengths in nouns to those in articles was calculated. It turned out that the higher the proficiency level, the greater the mean ratio of the vowels in nouns to the vowels in articles, confirming the research's hypothesis. This research thus concluded that for the Korean English learners, the higher the English proficiency level, the better they could produce the stressed and unstressed vowels with more conspicuous length differences between them.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.24-31
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• 2016

This study investigated the effects of flower and fruit thinning agents on fruit set and harvested fruit quality attributes in 'Gamhong' apples. Lime sulfur, MaxCel (1.9% BA), and Fruitone (3.5% NAA) were applied either at post-bloom or fruitlet stages to mature 'Gamhong/M.9' trees. In 2011, the numbers of fruits per cluster in terminal flowers were 1.74, 0.82, and 1.15 for the control, lime sulfur, and Maxcel (applied at 10-mm fruit stage) treatments, respectively. The percentages of single fruit per cluster were 36.0, 47.9, and 48.7% for the control, lime sulfur, and Maxcel (10 mm) treatments, respectively, while the percentages of clusters with three fruits per cluster were 22.9, 1.4, and 5.8%. In lateral flowers, fruit numbers per cluster were 1.20, 0.36, and 0.50 for the control, lime sulfur, and Maxcel (10 mm) treatments, respectively. In 2012, all the thinning treatments showed a positive effect on flower and fruit thinning, compared with the control. Moreover, the treatment with thinning agents did not affect fruit quality. Overall, the results suggest that a single application of flower or fruit thinning agents would be sufficient, rather than the mixed application of thinning agents, based on the observed decrease in fruit setting.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.50-50
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• 2008

본 연구에서는 전방항성 초음파 액추에이터의 제작, 시뮬레이션, 구동 드라이버 제작, 제어 방법에 대하여 연구하였다. 우선, 시뮬레이션 툴인 ATILA를 사용하여 전방향성 초음파 액추에이터를 설계하였고 구동 주파수, 어드미턴스 특성 그리고 액추에이터의 움직임을 분석하여 최적의 구동 주파수 영역을 파악하였다. 실제 구동을 확인하기 위하여 액추에이터 스테이지와 구동 드라이버를 개발 하였다. 전방항성 액추에이터 스테이지의 구조는 액추에이터와 4개의 볼 베어링이 알루미나 볼을 압착하는 형태이며 세라믹에 인가되는 사인파의 위상차에 의하여 4개의 방향으로 구동 할 수 있다. 또한, 액추에이터를 위치 제어를 위하여 로터리 엔코더 두 개를 사용하여 구의 움직임을 파악하였고 PID 제어기법을 사용하여 액추에이터의 움직임을 제어하였다. 스테이지 구조상 엔코더의 $70^{\circ}$ 내에서만 구동 가능하며, 실험 결과를 통하여 전방향성 초음파 액추에이터는 약 $1.2^{\circ}$의 분해능을 가지고 구동영역 내 원하는 좌표로의 이동이 가능했고, 향후 고 정밀 관절 및 인공 눈에 응용 가능할 것으로 사료된다.

• The Korean Journal of Rheology
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• v.9 no.2
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• pp.81-87
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• 1997

비상용성 고분자는 그 계면의 특성에 의해서 복잡한 유변학적 거동을 갖는데 그러 한 거동을 해석하기 위해서 최근에 제안된 구성방정식을 토대로 소폭 진동 전단 흐름장에서 의 유변학적 물성과 몰폴로지 전개를 예측한 바 있다. Takahashi[2]등은 이런 흐름하에서의 계면은 거의 변하지 않음을 보여주었고 따라서 이경우는 상대적으로 쉬운편이었다. 본연구 에서는 정상전단흐름장하에서의 몰폴로지 전개에 대한 구성방정식을 간단한 형태로 표현함 으로써 실제 산업계에서 이용될수 있도록 하였다. 그러한 해석을 통하여 원래의 모델에서 제시되었던 3개의 실험변수를 2개로 줄일수 있었으며 계면의 특성을 잘 나타내 주는 새로운 변수($textsc{k}$)를 도입하였다. 계면의 특성을 잘 나타내 주는 이새로운 변수를 통하여 그 계면의 영향을 예측할수 있었다. 한편 분산상의 파괴, 변형, 합체 메카니즘을 모델에 제시되었던 변 수값들을 통하여 해석하였고 이를 실험적인 데이터와 비교해 보았다.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.305-312
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• 2010

The effects of dietary supplementation with Kalopanax pictus branch, leaves, and extracts on performance, proximate composition, pH, total phenol and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, cholesterol and fatty acid composition of chicken meat. Broiler chicks were fed for 5 weeks with a diet containing 5% Kalopanax pictus branch (T1), 2% Kalopanax pictus leaves (T2), and 5% Kalopanax pictus extracts (60% leaves + 40% branch) (T3). T1 and T3 resulted in much better feed conversion than T2. In proximate composition, crude fat of chicken meat was increased, but not signi-ficantly (p>0.05) in Kalopanax pictus-supplemented diets than control diet. Total phenol contents and DPPH radical scavenging activity were significantly increased (p<0.05) by the dietary-supplementation with Kalopanax pictus branch and leaves compared to the control diet. Total and high density lipoprotein cholesterols of treatment groups were higher than the control group, and control group low density lipoprotein cholesterolwas higher than treatment groups (p<0.05). Especially, T3 was significantly (p<0.05) more effective in improving cholesterol compared to other treatment groups. The treatment groups (especially T3) showed significantly higher total fatty acid and unsaturated fatty acid compositions compare to the control group.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.230-237
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• 2011

In this study, the characteristic of fluid flow in the new type lung assist devices has been established using computational fluid dynamics(CFD). For the modeling, the hollow fiber was ignored, and vertical types and tangential types were used for the model. Which was to analyze the flow characteristics of the fluid flow model when there exists 1 and 2 input/output ports, and when the input/output ports is located at the center of the cylinder and at the tangential direction with the cylinder wall. The modeling results showed that it was possible to eliminate no-flow region(stagnant layer) as shown in the vertical type when an inlet and an outlet were installed on the tangential direction of the cylinder as shown in the tangential type. Also, in the tangential type, vortex-type flow appeared as dominant, and it showed a complicated flow not deviated to one side. When the number of input/output was two, there was no deviated flow, and complicated flows were generated all across the tube. From the test result, it was found that input/output of flow was tangential type and complicated flows with no stagnant layer would be generated when there are two inputs/outputs, respectively.

• Journal of The Korean Association For Science Education
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• v.29 no.4
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• pp.373-387
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• 2009

The purpose of the study was to investigate the roles of parents in science learning at the Everyday Science Classroom (ESC). Discourses of 20 parent-child dyads were analyzed to identify the roles of the parents and their significance. Data were also gathered through questionnaires that were made to survey the perception of parents and students of the Everyday Science Classroom (ESC) in Gwanak-gu. The results showed that parents played the role of Guide as well as Learner. Parents as the Guide showed roles of Process guide, Cognitive facilitator, Participation inducer, and Authoritative manager. Parents helped their children to accomplish the experiment successfully (34.5%) and offered cognitive scaffolds (21.3%) and affective scaffolds (8.7%) for children to reach a level of understanding that they could not reach by themselves. However, parents who helped their own children without considering their needs repressed children's autonomous learning (1.6%). The roles of parents as the Learner were categorized into Active learner (16.1%), Collaborative fellow learner (15.1%), and Authoritative leading learner (2.7%). The multiple roles of parents can influence the children's understanding of science in both positive and negative ways. This study can provide basic information on the roles of parents and their interaction with their children. Reflection on positive aspects of parent participation in program development will promote the understanding of science in both parents and children.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.357-360
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• 1997

Multiple shoot formation was obtained from excised axillary buds of Achyranthes japonica NAKAI cultured on MS media containing various growth regulators such as auxin and cytokinin. The highest average number of shoots was obtained in 1 mg/L NAA and 2 mg/L BA after 6 weeks (25.8 adventitious shoots per node). Although the regeneration rate was less than the former condition, optimal combination for the production of more shoots with a suitable size was 0.5 mg/L NAA and 1 mg/L BA (19.7 adventitious shoots per node). Roots were induced from regenerated shoots after 3 weeks culture, transferred to 1/2 MS medium supplemented with 0.1 mg/L IBA. Micropropagated plants were successfully transferred to soil.