• 한국농촌건축학회논문집
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• 제10권1호
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• pp.101-109
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• 2008

It is very hard to find out Tongbanga-millhouse installed nearby a streamlet to use water with Tongbanga(a kind of water-mill) to polish cereals by pounding like a visage of its old days. It plays an important part in folkloric, architectural and educational aspects. The purpose of this study is to analyse the architectural features of Tongbanga and millhouse itself so that to find the way how to build and fabricate the materials and frame members. Therefore this study has been focused on the composition principle and fabrication method of Tongbanga-millhouse on the side of architecture. The fabrication methods of its house in accordance with regular sequences are as follows. ${\cdot}$ Firstly the decision of location of Tongbanga-millhouse and Hwak(a big mortar made of stone). ${\cdot}$ Slantly three rafter installation at an angle of $50^{\circ}$ to err on the safe side and then slantly fifteen rafter installation making a circular cone shape. ${\cdot}$ Installation of twigs to be circles from bottom to top. ${\cdot}$ Manifoldly covering of trunks peeling the barks from flax plants. ${\cdot}$ Threefoldly thatching with upside barks of oak trees. ${\cdot}$ Placing woods alike rafter on the bark thatches as a weight not to fly away by wind. ${\cdot}$ Binding woods alike rafter with vines of arrowroots to maintain the proper place. The decayed Tongbanga-millhouse by means of upper ways was restored out of all recognition.

• 농약과학회지
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• 제17권2호
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• pp.126-132
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• 2013

본 실험은 방역살충제 살포에 따른 수생태계의 위해성을 평가하는데 필요한 기초자료를 제공하고자 deltamethrin의 하천 방역시 풍속에 따른 하천수 중 약제의 잔류변화(A)와 하천표면으로 유입되는 잔류량 조사(D) 그리고 소여울에서의 수중 잔류변화(B) 및 상류지역인 반석천변에서 관행 살포시, 하류지역인 유성천 합류지점에서의 deltamethrin 잔류변화(C)를 조사하였다. A지점에서 풍속에 따른 결과를 비교해 볼 때, 각각의 최대 잔류량은 $0.17{\mu}g/L$(0 m)와 $4.42{\mu}g/L$(25 m)로 나타났으며, 약제가 검출된 시료 중 살포지점으로부터 가장 멀리 떨어진 지점은 각각 100 m(5 min)과 200 m(15 min)으로 나타났다. B지점의 하천 여울의 잔류량은 0 min ~ 480 min(8 hr)까지 $0.15{\sim}0.26{\mu}g/L$의 범위를 유지하다 720 min(12 hr) 이후부터 정량한계 미만인 $0.04{\mu}g/L$ 이하로 감소하는 것으로 나타났다. 반석동과 죽동 하천변 일대에서 관행법으로 방역 후 유성천 합류지점(C)에서 최대 48시간까지 시료를 채취하였는데, deltamethrin이 최초로 유입되는 것은 0 min과 1 min에서 각각 $0.15{\mu}g/L$, $0.11{\mu}g/L$로 나타났으며, 이후 12 hr 지점($0.10{\mu}g/L$)을 제외하고는 모든 지점에서 정량한계 미만으로 나타났다. 이는 상류에서 방역을 실시할 경우 하천으로 투입된 약제가 합류지점까지 이동하면서 유량의 증가, 저니토 및 부유물에 의한 흡착으로 인해 잔류량이 낮아졌기 때문이라고 보여 진다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.889-901
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• 2021

The tension of cables and motion response significantly affect safety of an immersed tunnel element in the immersion process. To investigate those, a hydrodynamic scale-model test was carried out and the model experiments was conducted under wind, current and wave loads simultaneously. The immersion standby (the process that the position of the immersed tunnel element should be located before the immersion process) and immersion process conditions have been conducted and illustrated. At the immersion standby conditions, the maximum force of the cables and motion is much larger at the side of incoming wind, wave and current, the maximum force of Element-6 (6 cables directly tie on the element) is larger than for Pontoon-8 (8 cables tie on pontoon of the element), and the flexible connection can reduce the maximum force of the mooring cables and motion of element (i.e. sway is expecting to decrease approximate 40%). The maximum force of the mooring cables increases with the increase of current speed, wave height, and water depth. The motion of immersed tunnel element increases with increase of wave height and water depth, and the current speed had little effect on it. At the immersion process condition, the maximum force of the cables decrease with the increase of immersion depth, and dramatically increase with the increase of wave height (i.e. the tension of cable F4 of pontoons at wave height of 1.5 m (83.3t) is approximately four times that at wave height of 0.8 m). The current speed has no much effect on the maximum force of the cables. The weight has little effect on the maximum force of the mooring cables, and the maximum force of hoisting cables increase with the increase of weight. The maximum value of six-freedom motion amplitude of the immersed tunnel element decreases with the increase of immersion depth, increase with the increase of current speed and wave height (i.e. the roll motion at wave height of 1.5 m is two times that at wave height of 0.8 m). The weight has little effect on the maximum motion amplitude of the immersed tunnel element. The results are significant for the immersion safety of element in engineering practical construction process.

• 대한조선학회논문집
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• 제47권3호
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• pp.321-327
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• 2010

During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For estimating resistance and moment prediction of a real ship by changing of running attitude, a model test of the ship has to be carried out. This study aims at establishing experimental techniques for a catamaran sailing yacht by changed attitude during running direction. Through the model test, drag and side force of the real ship are predicted. Also through experiment, rolling and yawing moments were considered.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1686-1691
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• 2004

The effect of recirculated exhaust gas on performance and exhaust emissions with FGR rate are investigated by using a natural circulation, pressurized draft and water tube boiler with FGR system operating at several boiler loads and over fire air(OFA) damper openings. The purpose of this study is to apply the FGR system to a power plant boiler for reducing $NO_{x}$ emissions. To activate the combustion, the suction damper of two stage combustion system installed in the upper side of wind box is opened by handling the lever between $0^{\circ}$ and $90^{\circ}$ , and the OFA with 0 to 20% into the flame is supplied, as the combustion air supplied to burner is reduced. It is found that the fuel consumption rate divided by evaporation rate does not show an obvious tendency to increase or decrease with rising the FOR rate, and $NO_{x}$ emissions are decreased, at the same OF A damper opening, as FOR rates are elevated and boiler loads are dropped.

• Journal of Biosystems Engineering
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• 제32권3호
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• pp.145-152
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• 2007

Uniformity of spray deposit is one of the important factors in spray performance affecting efficacy of pest management. Distributions of spray deposit on artificial targets were measured and analyzed to enhance the efficiency of spray application. The research was studied to understand the deposition characteristics of spray droplets and to determine the optimum conditions of chemical application. The deposit and its pattern by the lower fan speed was more uniform and higher than that by the higher fan speed. The upward blasting distance was limited within 3 m, but the limit to the ground level was expanded the distance more than 3.5 m because of the accumulated droplets. When the fan speed was higher at the distance of 2.5 m, deposit reached to maximum. When the distance increased, deposit was getting lower. At the both fan speeds, the deposit was concentrated below $30^{\circ}$ because of the gravitation and the resistance of wind. This research can be useful in designing an orchard sprayer and its operation for various tree canopies. To achieve a uniform distribution of deposit using the air-blast type orchard sprayer, the application rate from the middle boom should be increased as the air velocity to the upward increased. The spray rate to the side boom should be limited in a minimal level.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.132-138
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• 2016

Korea Aerospace Research Institute (KARI) is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Based on the flight tests and design experiences of the previously developed electric-driven UAVs, KARI has designed EAV-3, a solar-powered HALE UAV. EAV-3 weighs 53kg, the structure weight is 22kg, and features a flexible wing of 19.5m in span with the aspect ratio of 17.4. Designing the main wing and empennage of the EAV-3 the amount of the bending due to the flexible wing, 404mm at 1-G flight condition based on T-800 composite material, and side wind effects due to low cruise speed, $V_{cr}=6m/sec$, are carefully considered. Also, unlike the general aircraft there is no center of gravity shift during the flight because of the EAV-3 is the solar-electric driven UAV. Thus, static margin cuts down to 28.4% and center of gravity moves back to 31% of the Mean Aerodynamic Chord (MAC) comparing with the previously designed the EAV-2 and EAV-2H/2H+ to upgrade the flight performance of the EAV-3.

• 대한한의학원전학회지
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• 제30권2호
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• pp.31-43
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• 2017

Objectives : Written by Yoongdongri in the 18th century Chosun, Chochangkyeul is a book that specially deals in Ungi. Yoon understood a person's body constitution by taking into factor the person's birth year, and used this information to determine his Ungi type, and understood his disease mechanism. Methods : Following the study on the first part of Chochangkyeul, named Ungiyeonron, the paper tries to study the book's second part, called Yongyakgwon. The book's core messages are summarized upon a thorough inspection. Results & Conclusions : Yoondongri was a highly-acclaimed doctor in the 18th century Chosun, and also an Ungi practitioner who utilized the theory of Ungi in his clinical practices. His practices were mainly based on the prescription of Ungi found in Chenwuze's Sanyinfang, coupled with almost all parts of Donguibogam's Husebang. He had an extensive clinical experience which helped him describe his methods of quickly responding to the side effects that sometimes occur due to misuse of medicine. Such detailed descriptions are never found in past medical books, which gives Yoon's book a great level of historical importance. Yongyakgwon divides the scripts between Gabsin, Muui, Byungye, Gyungjeong, and Yimgi in accordance with the theory of Ounhabgi, and also introduces treatments based on Yukisachun. Jangbupasuyak also introduces about six external organs and six internal organs with relation to treating wind medicine, treating heat medicine, treating cold medicine, treating dry dampness medicine, dryness-moistening medicine, pulling meridian medicine. All of these can be applied to patients easily.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.166.1-166.1
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• 2011

The rotor design is fundamental to the performance and dynamic response of the Counter-rotating marine tidal current turbine. The wind industry has seen significant advancement single rotor blade technology, offering considerable knowledge and making it easy to transfer to tidal stream energy converters. In this paper, 3D flow and performance an alysis on a 100 kW counter-rotating marine current turbine blade was carried out by using the 3-D Navier-Stokes commercial solver(ANSYS CFX-11.0) to provide more efficient design techniques to design engineers. The front and rear rotor diameter is 8m and the rotating speed is 24.72rpm. Hexahedral meshing was generated by ICEM-CFD to achieve better quality of results. The rated power and its approaching stream velocity for design are 100 kW and 2 m/s respectively. The pressure distribution on the blade's suction side tells us that the pressure becomes low at the leading edge of the airfoil as it moves from the hub to the tip.

• Journal of the korean society of oceanography
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• 제38권3호
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• pp.143-155
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• 2003

Current and sea level were observed in spring 1999 by a bottom mounted ADCP and tide gauge in the central part of the South Sea of Korea. With respect to the front, the distribution of isotherms is prograde in the offshore region whereas that of isohalines is retrograde, especially in the coastal area. The combined effect results in shoaling of isopycnals at the front. This distribution corresponds to a westward coastal flow on the northern side of the front and the eastward Tsushima Warm Current (TWC) to the south, determined by vessel-mounted ADCP observations. The low-frequency current shows either alternating clockwise-counterclockwise rotation or else persistent eastward motion depending on the frontal motion. Fluctuations of wind, sea level and current are coherent at period of 3-4 days and show some characteristics of Ekman-like dynamics.