• 수산해양기술연구
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• 제36권3호
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• pp.186-194
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• 2000

계획어군심지기를 이용하여 자원량을 추정할 경우 해저검출은 매우 중요한 요소이다. 특히 어군이 해저에 가까이 분포하면 할수록, 해저와 어군을 분리하여 책분하는 것은 자원량의 추정정도의 신뢰도를 좌우하게 한다. 본 연구에서는 종래의 해저검출법을 보완하기 위해, 새로운 해저검출법을 개발하여, 그 유효성에 대하여 고찰하였으며, 다음과 같은 결과를 얻었다. 1) 에코레벨의 최대변화점을 이용하여 해저검출을 행한 경우 고정도로, 나아가 레벨 변동과 무관하여 안정한 해저검출법으로서 유효하다. 2) 전압최대변화율법에 의하면, 해저 오프셋는 해저검출위치로부터 0.45m이내에서 설정가능하고, 펄스파형, 해저지형과 음향 빔 등에 의존하여 결정된다.

• 한국농공학회논문집
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• 제55권5호
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• pp.9-16
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• 2013

This study finds the characteristics of long-term settlement of Bottom Ash and to review the application of Singh-Mitchell creep equation and Burgers Model to the creep behavior of Bottom Ash. In the undrained state, it was confirmed that creep behavior appeared in the range to 30-80 % of the maximum deviator stress by applying condition in other three stresses through triaxial compression test after isotropically consolidation. By using sieve analysis, it was compared to each sample that was passed through 9.5 mm, 2 mm, 0.25 mm sieves. Also, using Singh-Mitchell creep equation and Burgers Model, it was compared between the theoretical behavior and the observed behavior for each sample. In the result, it is found that creep behavior of Bottom Ash is similar to the theoretical behavior of Singh-Mitchell creep equation and Burgers Model in early stage and it is possible to predict creep behavior of Bottom Ash by these models.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.713-716
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• 2008

본 연구는 잔골재 부분 대체 Bottom-Ash 활용에 관한 기초 물성치 연구로서 Bottom-Ash의 잔골재 대체 콘크리트의 압축강도 테스트와 이들 실험을 통한 내구성능(노후화) 영향지수를 분석하였다. 잔골재 대체 Bottom-Ash 콘크리트 압축강도 실험의 경우 잔골재로 대체 시 발생하는 콘크리트의 초기경화시간의 단축 및 Ash 내 유해물질 방지를 위하여 고화제(GRG-21)를 활용, 40, 50, 60%의 W/C 비율별로 콘크리트를 배합 압축강도 실험을 실시하였다. 각각의 실험체에 대한 강도-내구공극 상관관계 조사를 위하여 압축강도 실험 후 활용되어진 공시체는 내부공극 측정을 위한 적절한 사이즈로 샘플링, 분석되었다. 분석요소로는 각종 내부 공극의 크기, 모양 직경별 함유량의 분포상태 등이 고려되었으며 이들 조사를 통하여 압축강도-내부공극 간 상호관계를 예측하였다. 부가적으로 콘크리트 재료변화는 콘크리트 내구성 자체의 변화를 가져 올 것으로 판단하여 상용프로그램(ATENA)을 활용, 콘크리트 압축실험에 따른 구조물의 균열패턴을 예측,조사하였다.

• KIEAE Journal
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• 제12권2호
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• pp.125-129
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• 2012

With the development of the industry, such as homes and industries of electric energy usage and thereby increase the supply of electrical energy for power generation facilities were also increased. Among them an increase in thermal power plants, such as Bottom Ash was accompanied by an increase in industrial waste. If fly ash is recycled, some ten thousand Fly Ash and Bottom Ash Landfill, the recycling rate is low in most. In this study, in order to resolve the problem of fly ash recycling Bottom Ash to take advantage of low physical and chemical characteristics were analyzed. Evaluation of Physical Properties of Bottom Ash In addition, through the evaluation of functional properties of additives chogyeol condensation of 1 hour or more, within 3 hours of closing, Flow has more than 190mm of wheel load resistance value is less than 3mm flooring developed to study the subsequent emphasis on the Properties is based. Through these studies by developing a functional flooring help with the problem of resource depletion, and losses due to reclamation and pollution is to prevent.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.889-892
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• 2003

Effects of $N_{2}$ plasma treatment of the Al bottom cathode on the characteristics of top emission inverted organic light emitting diodes (TEIOLEDs) were studied. TEIOLEDs were fabricated by depositing an Al bottom cathode, a tris-(8-hydroxyquinoline) aluminum $(Alq_{3})$ emitting layer, an N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-diphenyl-4,4'diamine (TPD) hole transport layer, and an indium tin oxide (ITO) top anode sequentially. The Al bottom cathode layer was subjected to $N_{2}$ plasma treatment before deposition of the $Alq_{3}$ layer. X-ray photoelectron spectroscopy suggested that the existence of and the amount of $AIN_x$ between the $Alq_{3}$ emitting layer and the Al bottom cathode significantly affect the characteristics of TEIOLEDs. The maximum external quantum efficiency of the TEIOLED with an Ai bottom cathode subjected to $N_{2}$ plasma treatment for 30 s was about twice as high as that of the TEIOLED with an untreated Al bottom cathode.

• 한국안전학회지
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• 제31권1호
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• pp.54-60
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• 2016

The bottom of dikes must be kept impermeable to control hazardous chemicals spilled from storage tanks. Currently, insufficient related chemical control laws lead to a possibility to spread through the bottom. Generally, due to the high cost of installation and periodical maintenance, many businesses prefer to install the bottom with general concrete. But, since the impermeability of concrete is dependent on the kind of materials and chemical reaction, all concrete cannot be considered as impermeable material. Thus, it is necessary to make the installation standards of the dike bottom clear in order to avoid the argument over the impermeability and prevent the chemical accident. This study has suggested the standards of impermeable concrete by conducting 7-day exposure test to crude oil with the pilot dikes. The results have showed that the standards have the better impermeable performance compared with the germany standard, which have been penetrated at the maximum penetration depth of 1.9 cm. This study is expected to contribute to both the risk reduction of penetrating into the bottom and the cost reduction of spending to make the bottom of dikes impermeable.

• 한국음향학회지
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• 제22권1호
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• pp.78-87
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• 2003

고주파 (126-㎑) 음향 신호를 이용하여 퇴적층의 구성 매질 및 표면 형태에 따른 산란 신호 변화를 측정하였다. 퇴적층은 구성 매질에 따라 사니질 (sandy mud), 사질 (sand), 자갈 (gravel)의 세가지 경우와 이를 혼합한 경우로 하였으며, 표층 연흔 (ripple) 형태에 따라 연흔과 음파 진행방향이 직각을 이루는 경우 및 평행한 경우를 모의하였다. 평면입사각 변화 및 연흔 구성 형태에 따른 후방산란 강도는 평면입사각에 비례하여 증가하였으며, 연흔 형성 방향과 음파 진행 방향이 이루는 각이 작을수록 삼차원적인 측방산란이 강하게 나타났다. 연흔과 음파가 이루는 각이 증가할수록 후방산란은 증가하였으며, 지음향적 요소 외에도 연흔 형성과 방향에 음파 산란이 강하게 의존함을 알 수 있었다.

• 한국가시화정보학회지
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• 제18권2호
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• pp.35-38
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• 2020

Airfryer is used to heat a food up by convecting hot air upward around the food. In this study, we investigated the effect of the bottom-shape of the food container in airfryer on the upward convection velocity of hot air to find an optimal bottom-shape by computational fluid dynamics. Numerical experiments were performed by solving the incompressible Navier-Stokes equations with turbulence model. We found that the maximum upward velocity with concave flow-passage on the bottom was bigger than that with the flat bottom and that the maximum upward convection velocity was achieved when the number of concave flow-passage with fan-shape is around six. The pressure drop by the internal flow was found to increase as the number of the concave flow-passage on the bottom increased probably due to increase of the surface area of the bottom. Therefore, it can be said that the optimal number of the concave flow-passage is around six for the flow rate considered in this study.

• 한국의상디자인학회지
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• 제19권1호
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• pp.91-105
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• 2017

A literature review and survey were conducted regarding the silhouette changes in bell bottom pants and the overall visual evaluation in accordance with the changes. The survey was disseminated from December 2015 to January 2016 to 245 women in their 20s living in Busan. The variables used for the silhouette changes in bell bottom pants were the volume of flare and the flare's starting point, and 20 pairs of terms were selected for visual evaluation. The results of the study are as follows: 1. Visual evaluations according to the volume of flare in bell bottoms indicated that females in their 20s appraised pants with a flare volume of 54 cm close to a straight silhouette and flare volume of 62 cm (recognized clearly as characteristic of bell bottom pants) to be more attractive and sophisticated than pants with flare volumes of 70 cm and 78 cm. 2.Visual evaluations according to the starting point of the flare in bell bottom pants showed that women appraised their legs as looking thinner when the flare started near the thighs. In a vertical visual evaluation, women appraised that their legs looked longer when the flare started near the knees and pants fit tightly around them. 3.The analysis of silhouette factors affecting the visual evaluation of bell bottom pants indicated that the volume of flare has more effect visually than the starting point of the flare.

• 콘크리트학회논문집
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• 제16권6호
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• pp.751-757
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• 2004

화력 발전소에서 발생하는 석탄회(fly ash, bottom ash)를 안정적으로 재활용하기 위하여 알칼리 활성화된 석탄회 경화체 및 인공경량골재를 제조하였으며, 알칼리 활성화 석탄회 인공경량골재의 콘크리트 적용을 위한 실험적 연구를 수행하였다. 따라서, 알칼리 활성화된 석탄회 경화체의 최적 배합비, 알칼리 활성화 석탄회 경화체와 인공경량골재의 기본적 특성, 역학적 특성과 환경안전성, 알칼리 활성화 석탄회 인공경량골재를 사용한 콘크리트의 역학적 특성과 동결음해저항성을 파악하였다 실험결과 알칼리 활성화 석탄회 인공경량골재를 제조하기 위한 경화체의 최적 배합비는 시멘트 $10\%$, Water glass $15\%$, NaOH $10\%$, $MnO_2\;5\%$였으며, 혼합물을 $50^{\circ}C$ 항온습윤양생 24k후 상온 공기중 양생을하여, 7일 압축강도 36.4MPa를 얻을 수 있었다. 제조된 골재의 폴리머 함침 결과 $10\%$ 파쇄강도를 $150\%$ 향상시킬 수 있었으며, 콘크리트용 굵은 골재로의 활용 가능성을 파악할 수 있었다.