• Title/Summary/Keyword: 최적 에너지 효율

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Evaluation of the Optimum Dietary Protein to Energy Ratio of Juvenile Japanese eel, Anguilla japonica (뱀장어 치어의 사료내 에너지에 대한 적정 단백질 비 평가)

  • Han, Kyung-Min;Bae, Jun-Young;Eme Okorie okorie;Go Su-Hong;Yoo Jin-Hyung;Bai SungChul-C.
    • Journal of Aquaculture
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    • v.18 no.3
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    • pp.135-141
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    • 2005
  • A 16-week feeding trial was conducted to estimate the optimum dietary protein to energy ratio (P/E ratio, mg/kcal) in juvenile Japanese eel, Anguilla japonica. Six experimental diets were formulated with three energy levels and two protein levels at each energy level. Three energy levels of 3800, 4150 and 4500 kcal per kg diets were included at 45 and 50% crude protein (CP) levels, respectively $(_{120}P_{45},\;_{110}P_{45},\;_{100}P_{45},\;_{130}P_{50},\;_{120}P_{50},\;and\;_{110}P_{50})$. After four weeks of the conditioning period, fish initially averaging $15.0{\pm}3g\;(means{\pm}SD)$ were randomly distributed into each tank as groups of 20 fish. Each diet was fed to fish in three randomly selected tanks at a rate of $2{\sim}3%$ wet body weight per day in the recirculated system. Weight gain (WG) and specific growth rate of fish fed diet $_{100}P_{45}$ were significantly higher (P<0.05) than those of fish fed the other diets. WG of fish fed diet $_{120}P_{50}$ was also significantly higher than those of fish fed diets $_{130}P_{50}$ and $_{110}P_{50}$. Feed efficiency ratio of fish fed diets $_{100}P_{45}$ and $_{110}P_{45}$ were significantly higher (P<0.05) than those of fish fed other diets. These results suggest that the optimum P/E ratio may be 100 mg/kcal with 45% protein diets, and 120 mg/Kcal 50% protein diets for the maximum growth of juvenile Japanese eel under the experimental condition.

The Efficient Dynamic Modeling of a Manipulator Robot System (제조 공정용 로봇 매니퓰레이터의 효율적 다물체 동역학 해석 모델링 기술 개발)

  • Song, In-Ho;Ryu, Han-Sik;Choi, Jin-Hwan
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.2
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    • pp.155-164
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    • 2015
  • Recently, the robot manipulators are needed more slim size and longer reach and more accurate movement for increasing productivity. So, in this paper, the simulation modeling method and the efficient modeling method for new slim & long reach robot has been investigated for forecasting the slim robot performance before making prototype. To do this investigation, the major parts of robot driving system such as motor, belt and reducer devices and parts assembly method have been investigated mainly. And then, using this developed modeling method the new designed robot will be forecasted about the dynamic performance of new designed robot.

The Effect of Working Angle of Non-power Disc Harrow on Traction (무동력 디스크 해로우의 작업각도가 견인력에 미치는 영향)

  • Jung, Ho Jun;Kim, Seong Sik;Jo, Jae Min;Kang, Dae Sik;Kim, Hyeon Tae
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.72-72
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    • 2017
  • 국내 농업에서 토양의 반전, 쇄토, 배토, 가능한 복합작업기인 무동력 디스크해로우 방식의 경운과 배토 고효율 복합작업기의 수요가 증가 하고 있다. 경운작업에서 일련의 과정은 작물의 생육과 관리차원에서 큰 의미를 지니며 작물재배의 첫 단계로 중요시 다루어져야할 과정이다. 이러한 작업기의 성능 시험에서 포장시험을 통해 복합기의 신뢰도와 실제 필드에서 발생하는 문제들을 포괄적으로 해결 할 수 있는 방안이 필요하다. 토양 경작을 위한 농업기기의 작업 저항은 식물 생산에서 유용성을 평가하는 가장 중요한 지표중 하나이다. 작업 저항(수평, 수직 방향의 힘)은 트랙터의 힘에 의해 생성된 동작을 방해하므로 토양 경운 시 에너지 소비를 결정하고 설계 매개 변수 측면에서 최적의 작업 조건을 결정하는 데 중요한 영향을 미친다. 따라서 본 연구에서는 경상대학교 내 위치한 실험동에서 Soil-bin에 이송장치를 설치한 후, 이송장치에 디스크 해로우 (Multidisc Vario, Tulip Agri., Netherlands)를 부착하여 실험을 진행하였다. 디스크 해로우의 원주 평면과 수직 평면 사이의 각 a(토양 표면에 수직)와 디스크의 해로우의 원주 평면과 작업 방향 사이의 각 b의 값을 독립 변수로 두고 a, b를 변화 시키면서 발생하는 이송장치의 견인력을 측정하여 농가 및 효율적인 경운작업 시 기초자료로 활용하고자 한다.

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Effective Utilization of Waste Landfill by Dynamic Compaction Pilot Test (동다짐에 의한 폐기물 매립장의 유효활용에 관한 연구)

  • Chun, Byung-Sik
    • Journal of the Korean GEO-environmental Society
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    • v.1 no.1
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    • pp.71-78
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    • 2000
  • In this study, the evaluation for effective utilization of waste landfill was performed by field test to use waste landfill as construction site(Nangido in Seoul). This site had been formed by dredging the household waste, building debris and industrial waste for fifteen years(78'3~93'3). The site where dynamic compaction test was divided by 4 yards. Yard-1, 2 were not eliminated widening of cover soil and Yard-3, 4 were eliminated it. Dynamic Compaction Pilot Test was carried out by the 15ton heavy tamper with drop height of 20m in Yard-1, 3 and with drop height of 15m in Yard-2, 4. We evaluated the compaction efficiency, optimum compaction number and noise vibration through field test, monitoring. As a result, if the countermeasures against vibration and noise by the method utilize, the dynamic compaction method is suitable for using in waste landfill as a construction site among the ground improvement method.

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Microbe Adhesion and Organic Removal from Synthetic Wastewater Treatment using Polypropylene Media Modified by Ion-Assisted Reactions (이온 보조 반응에 의하여 활성화된 폴리프로필렌 담체를 이용만 합성폐수 처리시 미생물 부착 및 유기물의 제거)

  • Seon, Yong-Ho;Han, Sung;Koh, Seok-Keun
    • KSBB Journal
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    • v.17 no.3
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    • pp.235-240
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    • 2002
  • The surface of polypropylene was modified by 1 keV $Ar^+$ ion beam in an $O_2$ environment in order to enhance wettability. Contact angle of deionized water on modified polypropylene was reduced from $78^{\circ}$to $22^{\circ}$. The enhanced wettability is originated from newly formed functional groups such as ether, carbonyl, and carbonyl groups. During immersion in deionized water, the enhanced wettability has remained nearly same. After washing in water, the hydrophilic functional groups on the polymer surface have been very stable. The modified polypropylene was adopted as bio-film media to remove organics in synthetic wastewater. Microbe adhesion on the polypropylene surface was improved due to the newly formed hydrophilic groups.

Application of Cardiac Electromechanical FE Model for Predicting Pumping Efficacy of LVAD According to Heart Failure Severity (심부전 정도에 따른 좌심실보조장치의 박동효율예측을 위한 심장의 전기역학적 유한요소 모델의 응용)

  • Jung, Dae Hyun;Lim, Ki Moo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.8
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    • pp.715-720
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    • 2014
  • In order to maximize the effect of left ventricular assist device (LVAD) on ventricular unloading, the therapy should be begun at appropriate level of heart failure severity. We predicted pumping efficacy of LVAD according to the severity of heart failure theoretically. We used 3 dimensional finite element model of ventricle coupled with 6 Wind-kessel compartmental model of vascular system. Using the computational model, we predicted cardiac responses such as contractile ATP consumption of ventricle, left ventricular pressure, cardiac output, ejection fraction, and stroke work according to the severity of ventricular systolic dysfunction under the treatments of continuous LVAD. Contractile ATP consumption, which indicates the ventricular energetic loading condition decreased maximally at the $5^{th}$ level heart-failure under LVAD therapy. We conclude that optimal timing for LVAD treatment is $5^{th}$ level heart-failure when considering LVAD treatment as "bridge to recovery".

Circuit Model Based Analysis of a Wireless Energy Transfer System via Coupled Magnetic Resonances (결합된 자기공명을 통한 무선에너지 전력 전송 시스템의 회로 해석)

  • Cheon, Sang-Hoon;Kim, Yong-Hae;Lee, Myung-Lae;Kang, Seung-Youl
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.2
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    • pp.137-144
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    • 2011
  • A Simple equivalent circuit model is developed for a wireless energy transfer system via coupled magnetic resonances and a practical design method is also provided. Node equations for the resonance system are built with the method, expanding on the equations for a transformer, and the optimum distances of coils in the system are derived analytically for optimum coupling coefficients for high transfer efficiency. In order to calculate the frequency characteristics for a lossy system, the equivalent model is established at an electric design automation tool. The model parameters of the actual system are extracted and the modeling results are compared with measurements. Through the developed model, it is seen that the system can transfer power over a mid-range of a few meters and impedance matching is important to achieve high efficiency. This developed model can be used for a design and prediction on the similar systems such as increasing the number of receiving coils and receiving modules, etc.

An Operation Scheme of Local Sink in Geographic Routing for Wireless Sensor Networks (무선 센서 네트워크를 위한 위치 기반 라우팅에서 로컬 싱크 운영 기법)

  • Lee, Eui-Sin;Park, Soo-Chang;Jin, Min-Sook;Park, Ho-Sung;Kim, Tae-Hee;Kim, Sang-Ha
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.3
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    • pp.201-205
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    • 2009
  • This paper addresses issues to efficiently collect and aggregate data of sources within a local and adjacent region in geographic routing for wireless sensor networks. We first introduce the concept of a local sink which collects and aggregates data form source nodes in the region and delivers the aggregated data to a global sink. We also design a model to determine an optimal location of the local sink and propose a mechanism to collect data through the local sink. Simulation results show that the proposed mechanism with the local sink is more efficient in terms of the energy and the data delivery ratio than the existing mechanism without the local sink in a geographic routing.

Designing a Path Management Method in Large-scale Multiple Sensor Networks (대규모 다중 센서 네트워크에서 효과적인 경로 관리 기법)

  • Lim, Yu-Jin;Park, Jae-Sung;Ahn, Sang-Hyun
    • The KIPS Transactions:PartC
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    • v.15C no.3
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    • pp.205-212
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    • 2008
  • In the environment with multiple heterogeneous wireless sensor networks with a single point of sensed data collection or a gateway (GW), relay points (RPs) may be required for the energy efficient delivery of sensed data from static or mobile sinks to the GW. The optimal placement of RPs becomes an even more difficult problem if static sinks are dynamically added or the trajectory of mobile sinks can not be known in advance. In order to resolve this problem, we propose a mechanism to deploy RPs in a grid pattern and to use the tree-based relaying network for reducing the cost of the RP and for reducing the control overhead incurred by the route setup from sinks to the GW. For the performance evaluation of our proposed mechanism, we have carried out a numerical analysis on a single route setup from a sink to the GW and, for more general performance evaluations, ns-2 based simulations have been carried out. According to the performance evaluation results, our tree-based relaying network mechanism outperforms that based on AODV in terms of the data delivery time, the network service time and the control overhead.

A study on Zigbee Authentication Protocol Using System IDs in Environments of Smart Grid (스마트 그리드 환경에서 시스템 ID를 이용한 지그비 인증 프로토콜에 관한 연구)

  • Kim, Kyoung-Mok;Im, Song-Bin
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.4
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    • pp.101-110
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    • 2011
  • A smart grid networks delivers electricity from suppliers to consumers using digital technology with two-way communications to control appliances at consumers' homes to save energy, reduce cost and increase reliability and transparency. Security is critically important for smart grid networks that are usually used for the electric power network and IT environments that are opened to attacks, such as, eavesdroping, replay attacks of abnormal messages, forgery of the messages to name a few. ZigBee has emerged as a strong contender for smart grid networks. ZigBee is used for low data rate and low power wireless network applications. To deploy smart grid networks, the collected information requires protection from an adversary over the network in many cases. The security mechanism should be provided for collecting the information over the network. However, the ZigBee protocol has some security weaknesses. In this paper, these weaknesses are discussed and a method to improve security aspect of the ZigBee protocol is presented along with a comparison of the message complexity of the proposed security protocol with that of the current ZigBee protocol.