• 한국해양공학회지
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• 제33권2호
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• pp.178-188
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• 2019

When burying underwater cables using robots, heading control is one of the key functions for the robots to improve task efficiency. This paper addresses the heading control issue for URI-T, an ROV for underwater construction tasks, including the burial and maintenance of cables or small diameter pipelines. Through modeling and identifying the heading motion of URI-T, the dynamic characteristics and input limitation are analyzed. Based on the identification results, a PD type controller with appropriate input treatment is designed for the heading control of URI-T. The performance of the heading controller was verified in water tank experiments. The field applicability of the proposed controller was also evaluated through the sea trial of URI-T at the East Sea, with a water depth of 500 m.

• 환경위생공학
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• 제22권4호
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• pp.119-130
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• 2007

Sea food wastewater including high concentration of organics and nutrients is hard to treat stably by established traditional activated sludge process. This research is aimed to obey more and more of strengthened the law and to secure stable effluents by using advanced treatment process applied membrane filter in aeration tank for treatment of wastewater from marine products. It must maintain pH of influent over 6.0 to keep up stably biological sludge of advanced treatment process. At 38hr of HRT, removal rates of TBOD and TCOD were 99.9% and 99.4% respectively and TSS also removed with high efficiency. Most organics in the effluent was constituted with soluble type materials, it caused that membrane filter installed aeration tank should remove minute suspended particles. The reactor was operated well to get stable treatment results for operation period, in spite of high loading of organics like that $0.67{\sim}1.67\;kgTBOD/m^3/day$ of organics loading and $0.10{\sim}0.21\;kgBOD_5/kgMLSS/day$ of F/M ratio. At $36{\sim}48hr$ of HRT, removal rates of T-N and T-P were $89.7{\sim}90.7%\;and\;91.5{\sim}96.0%$ respectively. It means this treatment process also work to remove nutrients of high concentration. Upon investigation of advanced treatment's operation factors, optimum SRT was about 30days and average SNR that showed tendency to increase according to increase water temperature was calculated 0.014 gN/g MLVSS/d. SDNR was risen in conformity to increase F/M ratio of Non-aeration tank and investigated as $0.038{\sim}0.051\;gN/gMLVSS/d$.

• 한국산학기술학회논문지
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• 제17권11호
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• pp.186-195
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• 2016

동해 울릉도-독도 2정점에서 식물플랑크톤의 군집조성 및 수직적 영양염분포 특성과 표층 현장수를 이용하여 N, P, NP, Fe을 첨가하여 식물플랑크톤의 영양염소비 및 성장특성을 파악하였다. 현장에서 영양염류농도는 유광층 상부에서 낮았고, 100 m보다 깊은 수심에서 증가하였다. N:P비는 Redfield비(16)보다 표층에서 21-25로 높았고, 조사 최대심도인 400 m 층에서는 6 전후로 극히 낮게 관찰되었다. 식물플랑크톤의 총개체수는 St.UD3과 St.50에서 각각 $4.9{\times}10^5cells\;L^{-1}$과 $1.9{\times}10^5cells\;L^{-1}$로 관찰되었다. 주요 우점종은 St.UD3에서 침편모조류 Heterosigma akashiwo, 은편모조류 Crytomonas spp., 규조류 Leptocylindrus danicus로 파악되었고, St.50에서는 규조류 Chaetoceros socialis, H. akashiwo, L. danicus로 각각 관찰되었다. 영양염첨가실험의 +N과 +NP실험군에서 빠른 식물플랑크톤의 성장반응을 보였고, +P실험군에서는 대조군과 유사하게 식물플랑크톤 성장이 관찰되지 않았다. 아울러 Fe을 첨가한 대조군, +N, +P, +NP실험군에서 Fe을 첨가하지 않은 다른 실험군과 비교하여 형광값의 유의한 차이를 보이지 않았다는 것은 Fe첨가에 따른 식물플랑크톤의 성장반응이 명확하지 않다는 것을 의미한다(p>0.05). 결과적으로 현장에서 우점한 H. akashiwo 와 L. danicus는 영양염이 추가적으로 공급된 환경의 생물검증실험에서도 빠르게 반응하여 높은 개체수로 우점한 것을 파악하였고, 특히 +Fe 실험군에서 L. danicus의 빠른 성장이 두드려졌다.

• 혜화의학회지
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• 제13권2호
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• pp.259-265
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• 2004

Objective; This study was designed to investigate the effect of Sa-am acupuncture and Arctii Fructus water extract on Post-herpetic Neuralgia. Method: We have treated them with acupuncture treatment of Sa-am acupuncture and Arctii Fructus water extract and evaluated the effect by Pain Rating Score(P.R.S.) and Visual Analogue Scale(V.A.S.) scale. Result: Before theraphy, the grades of Song's scale were P.R.S. 80 and V.A.S. 100, Kim's sclae's P.R.S. 77 and V.A.S. 100. After theraphy, the grades of song's scale were P.R.S. 5 and V.A.S. 10, Kim's scales's P.R.S. 10 and V.A.S. 10 Conclusion: The treatment of Sa-am-acupuncture and Arctii Fructus water extract on Post-herpetic Neuralgia was effective and will be attempted to the patients with it.

• 한국수산과학회지
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• 제32권2호
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• pp.165-169
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• 1999

포말분리 장치를 이용한 해수 중의 단백질 제거 특성을 조사한 결과, 단백질 농도가 높을 수록 또한 폭기량이 높을수록 단백질의 제거속도는 증가하는 것으로 나타났다. 이러한 각각의 제거특성을 통계학적으로 비선형 회귀분석하여 각각의 인자의 변화에 따른 단백질 농도의 변화를 다음의 식으로 나타낼 수 있었다. $$f\;(Co,\;u)=1.5712\times10^{-7}\timesCo^{3.061}\timesu^{1.258}$$ 위 식을 이용하여 유한차분법으로 시뮬레이션을 수행한 결과 실제 포말분리 운전에서 나타난 결과와 상관성이 아주 높은 결과를 얻을 수 있었다.

• 한국가금학회지
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• 제32권1호
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• pp.55-60
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• 2005

본 연구는 성게 껍질 분말을 사료내 첨가하여 그 첨가 수준(0, 1, 3, $5\%$)에 따라 계육의 관능검사, 육색, 지방산 및 아미노산 조성 등의 이화학적 특성을 검토하고자 broiler 160수를 공시하여 실시하였다. 전단력은 대조구보다 처리구에서 높고, 보수성은 대조구에서 높았으며(P<0.05), 가열감량, pH는 유의성이 인정되지 않았다. 관능검사 결과 성게 껍질 분말 급여구에서 연도, 다즙성, 풍미가 높은 점수를 나타내었는데 특히 T2에서 유의적인 (P<0.05) 차이를 나타내었다. 육색은 처리구에서 대조구보다 비교적 L$\ast$ 값이 낮고, a$\ast$ 값이 높아 육색이 어두운 편이었다. 대조구에 비해 처리구에서 oleic acid 함량이 유의하게 높거나 높은 경향을 나타내었으며, 총아미노산 함량은 대조구보다 처리구에 많은 함량을 나타내었다. 본 실험 결과 육계사료 내에 성게 껍질 분말의 급여는 관능검사의 결과를 개선할 것으로 사료된다.

• 전력전자학회논문지
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• 제18권6호
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• pp.530-539
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• 2013

In large vessels, proper water level must be maintained with a balance for right and left equilibrium by absorbing or draining sea water in ballast water tank. However, this ship's ballast-water can be drained marine organisms to local sea area by world trade and this can be a source of ecological disturb. In order to solve these problems, marine organisms must be removed in accordance with the international covenant for the emission of microorganisms. By this reason, the seawater electrolysis rectifier of low-voltage high-current rectifiers with excellent ability for microbial treatment is required. In this paper, PSFB converter will be discussed for the seawater electrolysis rectifier. Furthermore, a new output control method with the power limit operation under the limited maximum voltage condition is proposed for this rectifier. The simulation for the proposed current control method for PSFB Converter is shown using MATLAB/SIMULINK. Finally the usefulness of the proposed control method is presented by the experimental results.

• 한국물환경학회지
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• 제20권5호
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• pp.466-472
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• 2004

Red mud is formed as a waste during bauxite refining known as Bayer's process. Its main constituents are iron, aluminium, sodium and silica. The disposal of large quantities of wasted red mud causes a serious ecological problem. In this study, the red mud wasted from the bauxite refinery was studied for phosphate removal from aqueous solution according to activation methods. The influence of heat treatment, and neutralization with sea water and acid treatment level for the optimum conditions for phosphate removal have been determined. Heat treatment combined with acid treatment is most suitable for the removal of phosphate from aqueous solution. The optimal condition was activated with 1 N HCl solution after heating in $600^{\circ}C$ during 4 hours. Acid and heat treatment causes sodalite compounds which hinder the phosphate adsorption to leach out. The adsorption data obtained followed a first-order rate expression and fitted well with the Freundlich Isotherm well.

• 한국수산과학회지
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• 제17권5호
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• pp.398-404
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• 1984

단백질 폐수처리시의 세균학적 변동을 조사하기위해 연제품 가공공장 폐수중 기계적인 세정수를 시료로 하여 회분 및 연속배양을 행하여 얻은 결과는 다음과 같다. 1. 활성스럿지에 의한 연제품 폐수처리에서의 BOD및 COD 제거율은 모두 $90\%$이상으로 양호한 결과를 얻었다. 2. 단백질폐수의 질산화과정에서 $NH_4-N$와 $NO_2-N$은 48시간까지 계속 증가하는 경향을 나타냈으나 $NO_3-N$는 별 변동이 없었다. 3. 원료폐수중의 세균을 회분배양에서 10 일간 순양해서 얻은 활성스럿지 가운데는 질산화능이 우수한 균은 나타나지 않았다. 4. 분리균 120균주 가운데서 Enterobacteriaceae가 $25\%$, Pseduomonas가 $23\%$로 이 이속이 우점종이었고 암모니아가 다량생산되는 폭기후기에는 Pseudomonas는 감소하는 경 향을 보였고 Enterobacteriaceae와 Aeromonas가 출현율이 높았다. 5. 염분요구성은 120 세주중 $50\%$가 $0\%,\;3\%$ NaCl, $75\%$ ASW의 식염농도하에서 생육가능한 균이었음으로 농후한 단백질폐수의 희석수로 해수를 이용할 수 있다는 것을 알 수 있었다.

• 해양환경안전학회지
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• 제3권2호
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• pp.69-76
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• 1997

Each factor for the most effective electrolytic reaction in treating shipboard sewage was enhanced by means of batch electrolyitc reactor using DSA electrode. The effective clearance was 6mm and pH was 5-6. In such case, more than 20% of sea water concentration was needed to attain 90% of COD removal rate. The suspended solids was effectively removed by electro-floatation in proportion as charged current density. The nitrogen and posporous were effectively removed in the electrolytic device when mixed seawater.