• Title/Summary/Keyword: energy saving efficiency

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Comparison of Production Structure of Purse Seine Fishery in Korea and Norway (우리나라와 노르웨이의 선망어업 현황 및 생산구조 비교)

  • Kim, Dae-Young
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.1
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    • pp.308-318
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    • 2015
  • In order to improve the competitiveness of Korean large purse seine fishery, the purpose of this study is to find out the problems and present the improvement of the production structure of Korean large purse seine fishery by comparing to the production structure of Norwegian purse seine fishery. Norwegian purse seine fishery has been operating labor and energy-saving systems through a single wire operation and avoiding fishing competition through the introduction of IVQ system with different types of fishing vessel and obtaining benefits from Leading fishery management integrated with fish pumps and cooling water systems. In contrast, our country has a large purse seine fishery issues such as high cost and low efficiency of production structures, the volatility of mackerel resources, the lack of leading fishery management after catching fishes, the reduction of fishing ground in accordance with the North East Asia EEZ system. To solve these problems, initiatives to improve the structure of our large purse seine fishery are as follows: First, Implementing the promotion of the effective immature fishes management and establishing Korea-China-Japan resource management system. Second, the promotion of reduction of fleet size, the review of possible single fishing operation, leading out to strengthen its competitiveness by switching to energy-efficient production systems through enhanced efforts at fisheries catches steps. Third, it is necessary to realize corporate through the diversification of business areas and the large-scale commercialization of production structure.

New Memristor-Based Crossbar Array Architecture with 50-% Area Reduction and 48-% Power Saving for Matrix-Vector Multiplication of Analog Neuromorphic Computing

  • Truong, Son Ngoc;Min, Kyeong-Sik
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.3
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    • pp.356-363
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    • 2014
  • In this paper, we propose a new memristor-based crossbar array architecture, where a single memristor array and constant-term circuit are used to represent both plus-polarity and minus-polarity matrices. This is different from the previous crossbar array architecture which has two memristor arrays to represent plus-polarity and minus-polarity connection matrices, respectively. The proposed crossbar architecture is tested and verified to have the same performance with the previous crossbar architecture for applications of character recognition. For areal density, however, the proposed crossbar architecture is twice better than the previous architecture, because only single memristor array is used instead of two crossbar arrays. Moreover, the power consumption of the proposed architecture can be smaller by 48% than the previous one because the number of memristors in the proposed crossbar architecture is reduced to half compared to the previous crossbar architecture. From the high areal density and high energy efficiency, we can know that this newly proposed crossbar array architecture is very suitable to various applications of analog neuromorphic computing that demand high areal density and low energy consumption.

Removal of nitrogen and phosphorus of the secondary effluent by electro-coagulation (전기응집을 이용한 2차 유출수의 질소.인 제거 공정 연구)

  • Han, Song-Hee;Chang, In-Soung
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.4
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    • pp.579-589
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    • 2012
  • To reduce extensive energy costs of the internal recycling for the purpose of denitrification in the advanced wastewater treatment, a post-treatment process using an electro-coagulation to treat nitrate in the secondary effluents is evaluated in this study. Removals of phosphorus and organics in the secondary effluents by the electro-coagulation were also evaluated to propose an alternative advanced wastewatert treatment process. A series of experiments of the electro-coagulation were carried out with the following 4 different samples: synthetic solution containing nitrate only, synthetic solution containing nitrate as well as phosphorus, secondary effluents from activated sludge cultivated in laboratory, and secondary effluents from real wastewater treatment plants. Removals of nitrate and phosphorus in the synthetic solution were 30 and 97 % respectively, which verified the feasibility of the process. Removals of nitrate, phosphorus and COD in the secondary effluents from the cultivated sludge in laboratory were 49, 90 and 19 % respectively. Removal efficiency of the total nitrogen, nitrrate, phosphorus and COD in the secondary effluent from real wastewater treatment plant were 50, 61, 98 and 80 % respectively. The removal of the total nitrogen was less than the nitrate as expected, which is due to the formation of ammonia nitrogen in the cathode. But the proposed scheme could be an energy saving and alternative process for the advanced wastewater treatment if further studies for the process optimization are carried out.

A study on the selection of optimal marine engine and its techno- economical evaluation method (최적박용기관의 선정 및 그의 경제성 평가방법에 관한 연구)

  • 전효중;조기열
    • Journal of Advanced Marine Engineering and Technology
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    • v.8 no.2
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    • pp.51-66
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    • 1984
  • The cost percentage of engine part in the total building cost of a ship is about 30-40% and the main engine occupies about 50% of the engine part cost. For certain ships the fuel bill can be as high as about 60-70% of the total operating cost after two oil shocks and its amount for one year is nearly equivalent to her main engine price. This fact has further increased the pressure on the engine builders to develop engines of higher efficiency and better possibilities to burn further deteriorated fuel qualities. But the energy-saving plants are ordinarily more expensive and their available amount of exhaust gas energy is less and therefore, they are not always profitable and optimum systems. This paper is prepared to decide the most economical and efficient engine systems by presenting reasonable selecting and economical evaluation methods of the main engine, which is the largest single unit and the most expensive, and its auxiliaries. In order to demonstrate the application of investigated methods in a practical case, a 46, 000 DWT class bulk carrier is selected as a model ship and her main engine and its auxiliaries are selected and evaluated. The result shows that the optimum determined has one year three months POP, 0.903 IRR at a year, 4, 116, 000 dollars PW in 15 years (for 5% escalation rate of fuel cost) and 9.522 BCR for same condition, when the engine plant of a same existing ship is taken as the basis.

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The Design of Fuse in High Efficient Inverter Control System using Ceramic Radiant Heat and Metal Film Laminated Plating (세라믹 방열과 박막 적층 도금을 이용한 고효율 인버터 제어 회로용 퓨즈 설계)

  • Kim, Eun-Min;Kim, Shin-Hyo;Cho, Dae-Kweon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.11
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    • pp.1538-1544
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    • 2014
  • In recent years, The electronic and energy industries demand low power consumption and high efficiency, so under their demands, the white goods industries which are represented for refrigerator and air conditioner system be implemented energy-saving power suppling structure with inverter control system. As inverter control system is different from step control type, when switching system is optimizing temperature control during short period, the inrush plus current can be flown in the circuit. In despite of these characteristics, there is no fuse which can be applied to this type until now. For this reason, we suggest the method of manufacturing protector in the high efficient inverter control system using the alumina-based ceramic radiated heat characteristics and metal films laminated plating. And through the evaluating electrical characteristics, we make a possible to utilize the method when designing overall fuses.

A Numerical Study for the Heat and Mass Transfer in Silica gel/Water Adsorption Chiller's Adsorber (흡착식 냉동기의 흡착탑에서 열 및 물질전달에 관한 수치적 연구)

  • Kwon, Oh-Kyung;Yun, Jae-Ho;Kim, Joung-Ha;Kim, Yong-Chan;Joo, Young-Ju
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.341-346
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    • 2005
  • Nowadays, adsorption chillers have been receiving considerable attentions as they are energy-saving and environmental1y benign systems. A Fin & tube type heat exchanger in which adsorption/desorption take place is required more compact size. The adsorption chiller is expected to have high energy-efficiency in utilizing the waste heat exhausted from a process. The objectives of this paper are to investigate the effect of fin pitch of fin & tube on the adsorption performance and to develop an optimal design fin & tube heat exchanger in the silica gel/water adsorption chiller. Previous study concluded that optimal particle size selected 0.5mm, type HO silica gel, and fundamental heat transfer & mass transfer experiments carried out. From the numerical results, the adsorption rate for the fin pitch 2.5mm is the highest than that for the fin pitch 5mm, 7.5mm and 10mm. Also cooling water & hot water temperature affect the adsorption rate.

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Study on Indoor Thermal Environment Controlled by Portable Cooler (실험을 통한 이동형 냉방기의 실내 온도분포 특성의 검토)

  • Choi, Dong-Kyun;Song, Doosam;Kim, Jung-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.2
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    • pp.49-54
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    • 2016
  • The purpose of this study is to analyze the indoor temperature distribution of a room controlled by a personal and portable cooler. As an energy saving strategy, the personal air-conditioning or task conditioning system was developed and installed in office buildings in the 90 s. Many research results regarding the personal air-conditioning (PAC) system were focused on thermal comfort, localized ventilation efficiency and energy savings. However, the conventional PACs were only developed for application in office buildings. In this study, as a type of PAC, a portable cooler was analyzed in terms of indoor temperature distribution changes with the passage of time. The measurement was performed in a bedroom in an apartment house. The results showed that indoor temperature was controlled at about $24^{\circ}C$ around the human body. However, the ambient zone up to 1.5 m away from the the human body stayed at about $27.5^{\circ}C$.

Study on The Throughput Unfairness of High-power transmission in The Transmission Power Controlled Wireless Networks Considering Green Computing (그린 컴퓨팅을 위한 무선 네트워크 전송 파워 조절에서 고출력 전송의 성능 불공평성에 대한 연구)

  • Lee, Hee-Jin;Kim, Jong-Kwon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.10
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    • pp.27-35
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    • 2010
  • In wireless packet networks, energy and wireless resource efficiency is critical issue to addressed for wide deployment. To achieve the both goals of saving the mobile station's energy and increasing the wireless capacity, transmission power control is introduced to wireless packet networks. In the transmission power controled networks, it is not deeply studied on unfairness among transmissions with different power levels that reaches starvation. Through the performance analysis, this paper explains the throughput unfairness of high power transmission with the unfair media access probability owing to the contending node number difference and proposes a simple PHY-MAC cross layer approach.

New Active Snubber Boost PFC Converter for Efficiency Improvement in Home Appliances Applications

  • Jeong, In Wha;Park, Mingyu;Um, Kee-Ju;Heo, Chang Jae;Lee, JunHo;Kim, Kwangsoo;Suh, Bum-Seok;Kim, Yong-Wook;Kim, Rae-Young
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.289-290
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    • 2012
  • This paper proposes a new active snubber boost PFC converter to provide a zero-voltage-switching (ZVS) turn-on condition and reduce electromagnetic interference (EMI) noise in home appliances and renewable energy applications, including solar or fuel cell electric systems. The proposed active snubber circuit enables a main boost switch of the boost-type PFC or grid converter to turn on under a ZVS condition and reduce the switching losses of the main boost switch. Moreover, for the purpose of a specialized intelligent power module (IPM) fabrication, the proposed boost circuit is designed to satisfy some design aspects such as space saving, low cost, and easy fabrication. Simulation and experimental results of a 2kW IPM boost-type PFC converter are provided to verify the effectiveness of the proposed active snubber boost circuit.

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Simulation of Dynamic Characteristics of a Trigenerative Climate Control System Based On Peltier Thermoelectric Modules

  • Vasilyev, G.S.;Kuzichkin, O.R.;Surzhik, D.I.
    • International Journal of Computer Science & Network Security
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    • v.21 no.6
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    • pp.252-257
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    • 2021
  • The application of the principle of trigeneration allows to simultaneously provide electricity to power electronic devices, as well as heat and cold to create the necessary microclimate of the premises and increase efficiency compared to separate cooling and heating systems. The use of Peltier thermoelectric modules (TEM) as part of trigenerative systems allows for smooth and precise control of the temperature regime, high manufacturability and reliability due to the absence of moving parts, resistance to shock and vibration, and small weight and size parameters of the system. One of the promising areas of improvement of trigenerative systems is their modeling and optimization based on the automatic control theory. A block diagram and functional model of an energy-saving trigenerative climate control system based on Peltier modules are developed, and the transfer functions of an open and closed system are obtained. The simulation of the transient characteristics of the system with varying parameters of the components is performed. The directions for improving the quality of transients in the climate control system are determined, as well as the prospects of the proposed methodology for modeling and analyzing control systems operating in substantially nonlinear modes.