• 상하수도학회지
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• 제26권4호
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• pp.497-502
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• 2012

Anaerobic Digestion Process is evaluated as efficient wastewater treatment process with the removal of high concentrations of organic waste and production of biogas. This study was performed using hybrid anaerobic hybrid reactor (AHR) which consists of anaerobic sludge blanket (UASB) and biofilm-coated filter media was applied for Palm Oil Mill Effluent (POME) for 80 days to know optimum removal efficiency and production of biogas by comparing each part which divided changing Organic Loading Rate (OLR). As a result of this study, the removal efficiency was 90.4 % when the organic loading rate of influent was 15 kg COD/$m^3$/day. Since organic loading rate was up to 20 kg COD/$m^3$/day, the removal rate declined 80.7%. Over loading of influent caused sludge expansion and overproduction of microorganism. Amount of biogas was collected 82.3 L/day and pH was remained 6.9 constantly with balance of alkalinity.

• Plant Resources
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• 제8권3호
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• pp.281-285
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• 2005

In order to select suitable fertilizer level and sowing rate of Dangyo $^{#8}$(hybrid) rapeseed at the southern area of Korea, two varieties of Naehanyuchae (Normal) and Dangyo $^{#8}$(hybrid) rapeseed currently grown for oil production by two fertilizer level with 10-8-8 kg/10a and 15-8-8 kg/10a and three sowing rate with 500 g/10a, 1,000g/10a and 1,500g/10a with relatively high yield was grown at the same condition yield and yield components were observed. Dangyo $^{#8}$(hybrid) rapeseed was superior to oil-eed rapeseed for yield at the 15-8-8 kg/10a of fertilizer and 1,500 g/10a of sowing rate. Fertilizer level, $N-P_{2}O_5-K_{2}O$ = 15-8-8 kg/10a and sowing rate, 1,500 g/10a showed somewhat higher value in two varieties of Naehanyuchae(Normal) and Dangyo $^{#8}$(hybrid).

• 한국잠사곤충학회지
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• 제4권
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• pp.51-55
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• 1965

가잠의 교배별 잡종강세율의 비교를행한 결과. 1. 이계통간의 $F_1$($가_{육}$ $\times$$중_{백}$ )과 ($일_{백}$ $\times$$중_{백}$ )은 동계통간의 $F_1$보다 기잠체중의 V.R 및 타계량형질의 V.R에 있어서 높은 잡종강세율(V.R)를 나타냈다. 2. 이계통간의 $F_1$($가_{육}$ $\times$$중_{백}$ )과 ($일_{백}$ $\times$$중_{백}$)의 비교에서는 $가_{육}$ $\times$$중_{백}$ 교배형식이 전반적으로 우수한 잡종강세율(V.R)을 나타냈다. 3. 기잠체중의 잡종강세율(V.R)은 모체의 영향을 받아 의잠부터 용까지의 추이가 Smooth하게 나타나지 않고 계통간에 상당한 차이를 보였다.

• Journal of Welding and Joining
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• 제33권2호
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• pp.85-90
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• 2015

Recently many studies for improvement of productivity and automation of process are in progress, and among others, laser-arc hybrid welding that combined laser and arc has attracted much attention. Since parameters by interactions as well as the parameters of each heat source should be considered, There are a lot of hardship in actual application, even though many researches have been done so far. Therefore in this study, bead welding was done to examine the effects of the flow rate of shield gas and the distance between laser and arc during laser-arc hybrid welding. As for hybrid heat source, disk laser and MIG were used. As experiment result, sound bead and weld with no defect were formed when the flow rate of front and rear shield gas were respectively 20 l/min and 15 l/min, and deep penetration was done at DLA=3 mm.

• 한국추진공학회지
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• 제16권1호
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• pp.9-15
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• 2012

하이브리드 연소실의 국부 압력과 속도변화를 고려하는 비정상 내탄도 해석모델을 제안하고 이를 바탕으로 연소실 내 국부영역에서 내탄도 특성인자의 변화를 도출하였다. 해석 모델 검증을 위하여 연소실 전후단의 압력을 측정한 실험결과와 해석결과를 비교하여 실험과 해석결과가 유사함을 확인하고 연소 효율을 평가 하였다. 하류방향으로 산화제 유량이 변화하므로 이에 따른 연소실 국부영역의 압력, 온도, 연료의 후퇴율 및 연소가스의 유속 변화를 정량적으로 고찰하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.337-340
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• 2005

In this study, an effect of fiber blending on material property of Hybrid Fiber Reinforced Concrete (HFRC) was evaluated. Also, Compare and evaluates collating and mechanical property by the mixing rate of fiber for HFRC was determine. Modulus of rupture and strength effectiveness of Hybrid Fiber Reinforced Concrete mixed with macro-fiber(steel fiber) and micro-fiber(glass fiber, carbon fiber, cellulose fiber). Test result shows, in the case of mono fiber reinforced concrete. As the steel fiber mixing rate increases to 1.5$\%$, the strength effectiveness promotion rate rises. However, when is 2.0$\%$, strength decreases. In the case of hybrid fiber reinforcement concrete, synergy effect of micro fiber and macro fiber happens and higher Modulus of rupture and strength effectiveness appears than mono-fiber reinforcement concrete. Use of hybrid fiber reinforcement in concrete caused a significant influence on its fracture behavior; consequently, caused increase by mixing rate of steel fiber + carbon fiber and contributed by steel fiber + glass fiber, steel fiber + celluloid fiber in reinforcement effect in order. And was expose that steel fiber(1.5$\%$) + carbon fiber(0.5$\%$) is most suitable association.

• 한국전자파학회논문지
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• 제10권6호
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• pp.879-888
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• 1999

보다 선뢰적인 정보전송을 위하여 데이터 에러를 제어하기 위한 ARQ 기법의 연구는 중요하다. 특히 위성 통신에서는 긴 전송 지연시간에 의하여 성능의 차이가 크게 나타나므로 본 논문에서는 전송 지연시간을 중심으로 프레임의 길이. 채널용량, BER의 변화에 따른, SR ARQ와 기존의 고정된 코딩율을 갖는 type- I h hybrid ARQ 방식의 성능분석을 하였다. Type-I hybrid ARQ 방식에 사용되는 FEC(Forward Error Control) 방식으로는 BCH 코드를 사용하였고 BCH 코드율과 Window 크기. 데이터 속도 등 여러 가지 파라미터에 따 른 throughput을 분석하였다. 특히 기존의 SA W(Stop and Wait) ARQ의 식을 바탕으로 전송지연시간이 고 려된 type-I hybrid ARQ의 성능 관계식을 유도하였다. 다양한 전송 지연시간이 고려된 type-I hybrid ARQ 의 성능을 수치해석과 더불어 시뮬레이션을 통해 분석하여, 중요한 특성 결과를 얻게 되었다.

• 한국철도학회논문집
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• 제3권3호
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• pp.101-108
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• 2000

In this study, we tested hybrid pilot system combined with soil vapor extraction and bioventing methods on the contaminated railroad soil. So, we found out the remediability and operating conditions. Air permeability(k) and gas phase(O$_2$/CO$_2$/VOCs) level trend are very important to determine the remediation rate of the contaminated sites. Throughout hybrid pilot test on different conditions, the range of air permeability(k) was 1985∼1194 darcy. The tests results in hybrid system was appropriate on this test sites, and the suitable injection air flow rate was 3.5㎥/hr. So, we suggested a basic data for the remediation and management of contaminated railroad soil.

• 한국항공운항학회지
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• 제14권4호
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• pp.17-23
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• 2006

This paper describes the preliminary design procedure for the hybrid propulsion system. For a given mission defined by velocity increment, the design of a polyethylene/LOX hybrid rocket was implemented. In addition, Seven-cluster multi-port fuel-grain was considered. After determining the system size including the combustion chamber, the performance parameters such as specific impulse, thrust, characteristic velocity, and thrust coefficient can be predicted by using empirical regression rate correlation, though most of preliminary design code assume constant regression rate. The results of the performance prediction indicated that besides the widely used HTPB/LOX, polyethylene/LOX hybrid motor can be a viable alternative to the more widely used SRMs.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2001년도 제17회 학술발표회 논문초록집
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• pp.61-67
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• 2001

Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. The recent research efforts are focused on the improvement of volume limitation and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the eddy breakup model and Hiroyasu and Nagle and Strickland-Constable model are used for soot formation and soot oxidation. Radiative heat transfer is modeled by finite volume method. To reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect, the Low Reynolds number k-$\varepsilon$ turbulent model is employed. Based on numerical results, the detailed discussion has been made for the turbulent combustion processes in the vortex hybrid rocket engine.