• 한국과학교육학회지
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• 제19권1호
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• pp.78-90
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• 1999

본 연구에서는 실험에 포함된 이상조건의 이해를 조사하기 위해 수행되었다. 주요 연구질문은 다음과 같다. (1) 실제 실험 상황에는 어떠한 이상조건이 포함 되어 있다고 생각하는가? (2) 실험에 포함된 이상조건들이 실제 실험에서 얼마나 만족되고 있다고 생각하는가 ? (3) 실험에 포함된 이상조건들이 실험 결과에 얼 마나 영향을 준다고 생각하는가 ? (4) 교사들은 실험에 포함된 이상조건에 대해 일반적으로 어떠한 관점을 가지고 있는가 ? 연구질문 1, 2, 3을 위해서 6개의 설문을 개발하여 총 85명의 고등학생과 과학교사에게 직접 실험과 함께 제시하여 응답하도록 하였으며, 연구질문 4를 위해서 과학교사 42명을 대상으로 4개의 설문을 개발하여 응답하도록 하였다. 응답결과는 연구 질문에 따라 분류되어 요약 제시되었으며, 물리 실험 지도를 위한 시사점 추출을 위해 사용되었다.

• 한국환경과학회지
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• 제31권2호
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• pp.117-129
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• 2022

In this study, we investigated the characteristics of the meteorological and environmental conditions for a cloud seeding experiment over the Korean peninsula and estimated the available days for the same. The conditions of available days appropriate for a cloud seeding experiment were classified according to four purposes: water resources, drought relief, forest fire prevention, and air quality improvement. The average number of available days for a cloud seeding experiment were 91.27 (water resources), 45.93-51.11 (drought relief), 40.28-46.00 (forest fire prevention), and 42.19-44.60 days/year (air quality improvement). If six experiments were carried out per available day for a cloud seeding experiment, the number of times cloud seeding experiments could be conducted per year in a continuously operating system were estimated as 547.62 (water resources), 275.58-306.66 (drought relief), 241.68-276.00 (forest fire prevention), and 253.14-267.60 times/year (air quality improvement). From this result, it was possible to determine the appropriate meteorological and environmental conditions and statistically estimate the available days for a cloud seeding experiment. The data on the available days for a cloud seeding experiment might be useful for preparing and performing such an experiment.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.109-114
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• 2005

The large injection molded parts technology such as instrument panel, front and rear bumper are presented for a precision molding. Some lead time and cost are required to product these part from design to mass product. Recently, CAE is widely used in product design, mold design and analysis of molding conditions to reduce time and cost. The optimal molding conditions can be obtained by DOE(Design of Experiment). The optimal design applications with CAE and DOE have been used in small molded parts. However, application to the large molded body is not reported. In this paper, optimization of injection molding process is studied for quality control in mass production of automobile bumper. Mold temperature difference is chosen through robust design of injection molding process, the molding process being optimized in term of shrinkage and deflection. The optimal conditions through DOE are validated by using injection molding analysis.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2010년도 심포지엄 및 추계학술발표회
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• pp.189-190
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• 2010

• Journal of Oral Medicine and Pain
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• 제23권4호
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• pp.309-326
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• 1998

In general, the major causative factor of halitosis is thought to be a sulfated compounds. Clusterin, a sulfated glycoprotein-2(SGP-2), is frequently found in diabetic conditions and cold stress conditions. The same result is werum glucose level to diabeteic and cold stress conditions that founded Clusterin. Therefore, this study was performed to examine Clusterin in the slivary glands under stress conditions before insulin injection I.M. Fourty rats were diveded into 3 groups ; 1) 10 rats of gorup I were selected as a control 2) 15 rats beloning to group II were bathed in cold water for 30 seconds twice a day 3) 15 rats in group III received cold stress and injected I.M. with insulin. The rats were sacrifeced at day 0, 3, 5, 7 and 10 of the experiment and the submandibular glands and parotid galnds were removed. RNAs were purified from the salivary of the salivary glands were subjected to Hematoxillin-Eosin stainings and examined under the light microscope. The obtained results were as follows : 1. With immunohistochemistric method, in normal control goup, Clusterin was moderately stained in the intercalated ductal cell of the submandibualr glands, mild stained in the striated ductal cell of the submandibular glands, heavily stained on the cytoplasm of the intercalated ductal cell in the mucous submandibular glands nad slightrly stained in the intercalated ductal cell of the paroted gland, expressed negativity in the acina cell. 2. With immunohistochemistric method, Clusterin slightly increased in the acina cell of the submandibular glands under stress condition at 3 days after experement, moderately stained at 5 days after experiment so revealed positive response. And hearily in the intercalated ductal cell and mildly lin the acina celluar eytoplasm of the parotid glands under stress condition at 3 days experiment. 3. With immunohistochemistric method, no remarkable differences are found between the normal control group and stress conditioned group that insulin administration was performed before. 4. In the stressor-giving group, Clusterin mRNA was porminently expressed in submandibular gland after 5 days after experiment, in parotid gland after 3 days after experiment, performed in immunoelectrophoresis method. 5. In the insulin-injected nad stressor-giving group, Clusterin mRNA was not observed in all experimental submandibular and parotid gland, performed in immunoelectrophoresis method.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2000년도 제14회 학술강연논문집
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• pp.8-8
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• 2000

In this paper are presented main power and gasdynamic characteristics of C-l6VK hypersonic test cell of Research Test Center of CIAM. Gasdynamic adjustment of the C-l6VK test cell was carried out with the working section constructed on scheme of Ramjet/scramjet test in free stream. Gasdynamic adjustment was conducted stage by stage in tile following sequence. First, check and preparation of all technical systems and checking measuring system. Than determination of the characteristics of test cell on cold (without the heating of air at entrance) regime and determination of the characteristics of test cell on regimes with the heating of air. Finally determination of tile characteristics of test cell with the loading of the working part by object. On tile final stage of gasdynamic adjustment two experiments with tile axisymmetric Scramjet model loaded into the working part of test cell were conducted. The first experiment was conducted with the purpose of determination of flow parameters with the object leaded into the working part and verification of experiment cyclogram. The second experiment was conducted with injection of hydrogen into the combustion chamber of object, that is tile conditions on test cell simulated Scramjet flight Mach number M = 6. Such methodology of gasdynamic adjustment allows to determine influence of experimental object on flow parameters in the working part at different conditions of experiment (with the burning in combustion chamber of object and without the homing), and also to compare flow characteristics in the object duct.

• 환경위생공학
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• 제4권2호
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• pp.91-99
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• 1989

An anaerobic acidogenic fermentation experiment was carried out in order to investigate the distribution of volatile acid products and gas generations with varing temperatures and pH values. The experiment was carried out using $1\%$ glucose as substrate and a pair of 3.5 liter vessle as bench scale batch reactors. The reactors were operated for 7 days at 25, 30 and $35^{\circ}C$ and at pH values of 4.0, 4.5, 5.0, 5.5 and 6.0 at each temperature conditions. Major products at all experiment pH's at $35^{\circ}C$ were acetic acids and butyric acids which together composed around $90^{\circ}F$ of total product acids. At higher pH values at $35^{\circ}C$, propionic acid reached around $10\%$. At all experiment conditions, 52 to $55\%$ of generated gases comprised of hydrogen gas and 45 to $48\%$ of carbon dioxide. With temperature increase from 25 to $35^{\circ}C$, the production rate of acetic acid increased 2.9 fold, butyric acid 22 fold, hydrogen gas 2.0 fold and carbon dioxide gas 2.3 fold. Optimum reaction conditions for highest production of acetic acid and hydrogen gas was determined to be pH 5.5 at $35^{\circ}C$.

• International Journal of Aeronautical and Space Sciences
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• 제13권2호
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• pp.229-237
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• 2012

In this study, the failure mechanism of sandwich-to-laminate T-joints under pull-off loading was investigated by experiment and the finite element method. A total of 26 T-joint specimens were manufactured and tested in order to investigate the effects of both adhesive thickness (0.4, 2.0, and 4.0 mm) and environmental conditions on the failure of the joints. The results showed that failure occurred mainly as intralaminar failure in the first layer of the sandwich face, which was contacted to the paste adhesive. The failure load did not significantly change with increasing adhesive thickness in both RTD (Room Temperature and Dry) and ETW (Elevated Temperature and Wet) conditions. In the case of ETW conditions, however, the failure load increased slightly with an increase in adhesive thickness. The joints tested in ETW conditions had higher failure loads than those tested in RTD conditions. In addition to the experiment, a finite element analysis was also conducted to investigate the failure of the joint. The stress inside the first ply of the sandwich face was of interest because during the experiment, failure always occurred there. The analysis results showed good agreement with the trend of experimental results, except for the case of the smallest adhesive thickness. The highest stress was predicted in the regions where initial failure was observed in the experiment. The maximum stress was almost constant when the adhesive thickness was beyond 2 mm.

• 한국작물학회지
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• 제25권1호
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• pp.25-30
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• 1980

수도 6개품종과 육도 7개품종을 동시에 논재배와 밭재배 하였을 때 양조건하에서 일어나는 변이를 수량과 수최구성요소 및 미질면에서 검토한 바 다음과 같은 결과를 얻었다. 1. 수량은 수도나 육도 모두 논재배에서 증가하였는데 그 증가정도가 육도보다 수도에서 현저하였으며 논재배에서는 수도가, 밭재배에서는 육도가 더 높은 수량을 내었다. 2. 1ℓ중, 1000입중 및 수당입수에 있어서 수도는 전체적으로 논재배에서 높았으나 육도는 품종간에 변이의 차리가 있었으며 주당수수는 대부분 논재배에 서 증가하였다. 3. Amylose 함량은 메벼의 대부분이 밭재배에서 증가하였으나 찰벼에서는 논재배에서 증가하였으며 Alkali 붕괴도와 단백질함량은 전반적으로 밭재배에서 증가하는 경향이었다.

• 한국작물학회지
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• 제44권3호
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• pp.214-220
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• 1999

Rice production in Korea has markedly increased during the last two decades due to newly developed high yielding varieties and improved production technology. This experiment was conducted to determine the potential of tropical japonica germplasm in enhancing the yield of temperate japonica. The yield performance of two tropical japonicas (IR 65597-29-3-2 and IR66154-52-1-2) and one temperate japonica (Dongjinbyeo) was compared at different plant densities and nitrogen levels under Korean environmental conditions. Although tropical japonicas showed low tillering habit and large panicles, they had similar leaf area index and dry weight at heading stage to Dongjinbyeo of the high tillering type indicating that there was not much difference between tropical and temperate japonica in terms of biomass production. The highest milled rice yield of 6.15 t/ha was obtained from Dongjinbyeo at a high nitrogen level with less planting density (220 kg N/ha and 30 $\times$ 15 cm). However, those of the two tropical japonicas were 5.36 t/ha at the condition of 165 kg N/ha and 30 x 10 cm planting density and 5.06 t/ha at the condition of 165kgN/ha and 15 x 15 cm planting density, respectively. Ripened grain of tropical japonicas ranged from 65 to 87%, while that Dongjinbyeo ranged from 82 to 97% under Korean conditions.