• Title/Summary/Keyword: Consumed-Power

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The Analysis of heating performance of heat pump system for agricultural facility using underground air in Jeju area - Focused on the Jeju Area - (제주지역 지하공기를 이용한 농업시설용 히트펌프시스템의 난방 성능 분석 - 제주지역을 중심으로 -)

  • Kang, Youn-Ku;Lim, Tae-Sub
    • KIEAE Journal
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    • v.16 no.6
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    • pp.109-114
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    • 2016
  • Purpose: The underground air is the warm air discharged from the porous volcano bedrock 30-50m underground in Jeju, including excessive humidity. The temperature of the underground air is $15-20^{\circ}C$ throughout the year. In Jeju, the underground air was used for heating greenhouses by supplying into greenhouses directly. This heating method by supplying the underground air into greenhouses directly had several problems. The study was conducted to develop the heat pump system using underground air as heat source for resolving excessive humidity problem of the underground air, adopting the underground air as a farm supporting project by Ministry of Agriculture, Food and Rural Affairs(MAFRA) and saving heating cost for agricultural facilities. Method: 35kW scale(10 RT) heat pump system using underground air installed in a greenhouse of area $330m^2$ in Jeju-Special Self-Governing Province Agricultural Research & Extension Services, Seogwipo-si, Jeju. The inlet and outlet water temperature of the condenser, the evaporator and the thermal storage tank and the underground air temperature and the air temperature in the greenhouse were measured by T type thermocouples. The data were collected and saved in a data logger(MV200, Yokogawa, Japan). Flow rates of water flowing in the condenser, the evaporator and the thermal storage tank were measured by an ultrasonic flow meter(PT868, Panametrics, Norway). The total electric power that consumed by the system was measured by a wattmeter(CW240, Yokogawa, Japan). Heating COP, rejection heat of condenser, extraction heat of evaporator and heating cost were analyzed. Result: The underground air in Jeju was adopted as a farm supporting project by Ministry of Agriculture, Food and Rural Affairs(MAFRA) in 2010. From 2011, the heat pump systems using underground air as a heat source were installed in 12 farms(16.3ha) in Jeju.

A Study on the Infrastructure of All-electric Houses in the Viewpoint of Hydrogen Economy (수소경제 관점의 전기에너지주택 보급기반 구축에 관한 연구)

  • Hwang, Sung-Wook;Lee, Hyeon-Ju;Kim, Kang-Sik;Nah, Hwan-Seon;Kim, Jung-Hoon
    • Transactions of the Korean hydrogen and new energy society
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    • v.23 no.1
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    • pp.100-109
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    • 2012
  • In this paper, some ideas are proposed to establish the infrastructure of all-electric houses which are able to reduce primary energy consumption and $CO_2$ emission by adopting heat pump systems and induction heating cookers excluding the use of fossil fuel energy. This electrification concept is based on the consumption of only one type of energy which means electricity as secondary energy and the conventional fossil fuel energy is just consumed to generate electricity as primary energy. All-electric house is laid on the extension of the hydrogen economy in a long-term viewpoint so that the effectiveness of this new conceptual house is estimated analyzing the reduction of $CO_2$ emission. In this analysis, the balance of electricity supply and demand is considered including the construction of new power plants by renewable energy such as nuclear, IGCC and fuel cell because decarbonization is an essential element of hydrogen technology and economy and this action is accomplished in both supply and demand side of electricity. The results are able to contribute to develop various useful hydrogen policies and strategies and some detail researches are required previously to make the best application of this new conceptual house.

Development and Evaluation of the Attrition Coupled Bioreactors for Enzymatic Hydrolysis of Biomass ; Tumbling-Drum Type Bioreactor for Enzymatic Hydrolysis of Cellulose (Biomass의 고효율 효소당화에 적합한 Attrition Coupled Bioreactor 개발에 관한 연구 ; Tumbling Drum Type Bioreactor를 활용한 섬유소 당화)

  • 이용현;조구형;박진서
    • KSBB Journal
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    • v.4 no.2
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    • pp.87-93
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    • 1989
  • To develop high dfficiency-low energy consumption attrition coupled bioreactor for enhanced enzymatic hyerolysis of insoluble biomass, a tumbling drum type bioreactor was installed, and its efficiency was evaluated. The effects of drum structure and poerational conditions were investigated. The optimal saccharification at 3L drum was obtained at 8 baffled drum, drum diameter to baffle height ratio of 1:0.05, 100rpm, and addition of 600g of 3mm glass bead per liter. The consumed power for rolling of drum and energy consumption for half digestion of cellulose were measured, and compared with enhanced rate and yield to predict the economic prospect of the process. The tumbling drum type bioreactor seems to have appropriated structure for industrial scale operation, and further investigation for scale-up need to be conducted.

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A Comparative study on the pricing mechanism and social welfare in the Natural Gas Market (국내 천연가스산업의 도매가격결정방식 비교 분석)

  • Namgoong Yoon;Choi Kiryun;Kim Boyung;Lee Kiho
    • Journal of the Korean Institute of Gas
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    • v.2 no.3
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    • pp.18-24
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    • 1998
  • This paper attempts to improve domestic natural gas pricing system, thereby optimizing social welfare. This is done by deriving theoretical frameworks of natural gas pricing, which make use of both Ramsey component pricing rule and Efficient component pricing rule based on the theory of marginal cost. Allocative efficiency and social welfare between gas prices derived from the three pricing mechanism, present Cost-based pricing, Ramsey component pricing rule and Efficient component pricing rule, are analysed and compared in the case study. For the city gas, allocative efficiency of Cost-based pricing is higher than that of Ramsey component pricing rule and Efficient component pricing rule. In contrast, for the natural gas consumed for power generation, allocative efficiency of Cost-based pricing is lower than the other two pricing systems. It also turns out that social welfare is improved by the prices driven from Ramsey component pricing rule and Efficient component pricing rule rather than present Cost-based pricing.

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Antioxidant Activity and Acetylcholinesterase Inhibitory Activity of Ark shell (Scapharca broughtonii) (피조개의 항산화 활성과 Acetylcholinesterase 저해 활성)

  • Kim, Jeong-Been;Kim, Jae-Min;Lee, Young-Min;Baek, In-Seok;Lee, Seung-Cheol
    • Korean journal of food and cookery science
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    • v.30 no.2
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    • pp.212-218
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    • 2014
  • Ark shell (Scapharca broughtonii; Korean name, pijogae) is one of the most widely cultivated and consumed shellfishes in Korea. The purpose of this study was to evaluate the antioxidant activity and acetylcholinesterase inhibitory activity of ark shell. After preparing the methanol extract of ark shell powder, the extract was subsequently fractionated by hexane, diethyl ether, ethyl acetate and water. The antioxidant activity evaluated by DPPH radical scavenging activity, ABTS radical scavenging activity and reducing power was relatively higher in the water fraction; however, the activity was spread out in all fractions. Acetylcholinesterase inhibitory activity was the highest in the diethyl ether fraction. Taken together with the results of both antioxidant and acetylcholinesterase inhibitory activities, it can be suggested that different kinds of physiological compounds were contained in the ark shell.

Cluster Based Multi-tier MAC Protocol for Dense Wireless Sensor Network (밀집된 무선센서네트워크를 위한 클러스터 기반의 멀티티어 MAC 프로토콜)

  • Hwan, Moon-Ji;Mu, Chang-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.2
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    • pp.101-111
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    • 2011
  • A new MAC protocol, MT-MAC(Multi-Tier Medium Access Control) by name, is proposed for dense sensor networks. Depending on the density of nodes in a virtual cluster, the cluster header performs the splitting to several tiers in nodes of virtual cluster. MT-MAC split the tiers to use modfied-SYNC message after receiving the beacon message from the cluster header. Because only the sensor nodes in the same tier communicate each other, less power is consumed and longer network life time is guaranteed. By a simulation method with NS-2, we evaluated our protocol. In dense nodes environments, MT-MAC protocol shows better results than S-MAC in terms of packet delivery rates throughput and energy consumption.

Operational Characteristics of Methanol Reformer for the Phosphoric Acid Fuel Cell System (인산형 연료전지용 메탄올 연료개질기의 운전 특성)

  • 정두환;신동열;임희천
    • Journal of Energy Engineering
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    • v.2 no.2
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    • pp.200-207
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    • 1993
  • A methanol reformer was designed and fabricated using a CuO-ZnO low temperature shift catalyst, and its operation characteristics have been studied for the phosphoric acid fuel cell (PAFC) power generation system. The type of reactor was annular Methanol was consumed both for heating and for reforming fuel. Contents of carbon monoxide produced from the reformer increased as the reaction temperatures increased, but decreased as the mole ratios of water to methanol(H$_2$O/CH$_3$OH) increased. At steady state operating conditional, temperature profile of the catalytic reactor of the reformer was well coincide with the model equation, and it took 50 minutes from start to the rated condition of the reformer. When the system was operated at 4/4 and 1/4 of load, thermal efficiencies of the system were 72.3% and 77%, respectively. When the PAFC system was operated with reformed gas in the range of 62 V-37.6 V and 0-147 A, the trend of I-V curve showed a typical fuel tell characteristic. At steady state condition, the flow rates of reforming and combustion methanol were 88.1 mol/h and 50.1 mol/h, respectively.

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On Optimizing Route Discovery of Topology-based On-demand Routing Protocols for Ad Hoc Networks

  • Seet, Boon-Chong;Lee, Bu-Sung;Lau, Chiew-Tong
    • Journal of Communications and Networks
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    • v.5 no.3
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    • pp.266-274
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    • 2003
  • One of the major issues in current on-demand routing protocols for ad hoc networks is the high resource consumed by route discovery traffic. In these protocols, flooding is typically used by the source to broadcast a route request (RREQ) packet in search of a route to the destination. Such network-wide flooding potentially disturbs many nodes unnecessarily by querying more nodes than is actually necessary, leading to rapid exhaustion of valuable network resources such as wireless bandwidth and battery power. In this paper, a simple optimization technique for efficient route discovery is proposed. The technique proposed herein is location-based and can be used in conjunction with the existing Location-Aided Routing (LAR) scheme to further reduce the route discovery overhead. A unique feature of our technique not found in LAR and most other protocols is the selective use of unicast instead of broadcast for route request/query transmission made possible by a novel reuse of routing and location information. We refer to this new optimization as the UNIQUE (UNIcast QUEry) technique. This paper studies the efficacy of UNIQUE by applying it to the route discovery of the Dynamic Source Routing (DSR) protocol. In addition, a comparative study is made with a DSR protocol optimized with only LAR. The results show that UNIQUE could further reduce the overall routing overhead by as much as 58% under highly mobile conditions. With less congestion caused by routing traffic, the data packet delivery performance also improves in terms of end-to-end delay and the number of data packets successfully delivered to their destinations.

Theoretical Design for the Production of Quinoa (Chenopodium quinoa Willd.) in a Closed Plant Factory

  • Bae, Jong Hyang;Austin, Jirapa;Jeon, Yoon-A;Cha, Mi-Kyung;Cho, Young-Yeol
    • Horticultural Science & Technology
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    • v.34 no.6
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    • pp.840-844
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    • 2016
  • Quinoa (Chenopodium quinoa Willd.) is a grain crop with high nutritional value. The leaves and sprouts of quinoa can also be consumed either raw or cooked, providing considerably nutritional value as well as high antioxidant and anticancer activities. This study was carried out to obtain basic data to assist in the practical design of a plant factory with artificial lighting for the cultivation of quinoa as a leafy vegetable. We estimated the energy content of the quinoa and the electrical energy required to produce this crop. The yield was 1,000 plants per day, with a planting density and light intensity of $0.015m^2$ ($15{\times}10cm$) and $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The total number of plants, cultivation area, and electricity consumption were estimated to be 25,000, $375m^2$, and $93,750{\mu}mol{\cdot}s^{-1}$, respectively. White fluorescent lamps were used at a power of 20.4 kW from 1,857 fluorescent lamps (FL, 55 W), and the cost for electricity was approximately 1,820 dollars (exchange rate of $1 = 1,200 won) per month. For a daily harvest of 1,000 plants per day in a closed plant factory, the estimated light installation cost, total installation cost, and total production cost would be 15,473, 46,421, and 55,704 dollars, respectively. The calculated production cost per plant, including labor costs, would be 27 cents for the 25-day cultivation period, with a marketable ratio of 80%. Considering the annual total expenses, income, and depreciation costs, the selling price per plant was estimated to be approximately 56 cents.

Usages of Mobile Views for Battery Efficiency of a Smart Phone (스마트폰 배터리 효율을 위한 모바일 뷰의 활용)

  • Ban, ChaeHoon;Kim, DongHyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2418-2423
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    • 2012
  • A smart phone which is one of the new IT technologies can be viable on various enterprise applications since it provides easily information and services. Especially, a smart phone can request queries to a server which finds massive data for decision making and receive the results of the queries from the server. However, a smart phone has a drawback that its battery is consumed easily due to the 4G communication. In this paper, we propose mobile views in order to reduce the easy consumption of a battery on mobile client-server environment. The proposed mobile view scheme reduces the number of communication which is leading to power consumption using materialized views for processing queries. We also classify the methods to control the consistency of the mobile view as the sources of the view are changed and present the cost of each method based on the cost model of battery consumption.