• Title/Summary/Keyword: Energy Consumption Efficiency

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The impact of Foreign direct investment on Energy intensity: absorptive capacity as moderator (외국인 직접투자가 에너지 집약도에 미치는 영향분석-흡수능력의 조절효과를 중심으로)

  • Wang, Xiao Xue;Hwang, Yun-Seop
    • International Commerce and Information Review
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    • v.16 no.5
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    • pp.179-201
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    • 2014
  • The complementary effect between FDI and its absorptive capacity has drawn more attention than before. This paper intended to explore the relationship between energy intensity and such complementary effect. The absorptive capacity of FDI shows various aspects among which we focus on the human capital, the financial system and the infrastructure in this paper. Using the panel data from 1990 to 2011, the study is processed between the 20 OECD and 20 Non-OECD countries. The empirical results shown that for OECD country, a complementary effect exists between FDI and its absorbability and it has the controlling effect on energy reduction. But the effect is only significant in the human capital and the financial system. The infrastructure variable is less important in OECD country due to their high development level. However, for non-OECD country, the complementary effect between infrastructure and FDI reduces energy consumption significantly, it can get to the point that the process for infrastructure to attract FDI and also benefits from it only blow its way to the Non-OECD, developing countries, without andy special effects for the OECD countries which has already highly build up their infrastructure. Also, the financial system in Non-OECD countries is at the primary stage yet, which is not easy to contribute efficiency. To make a conclusion, the complementary effect between infrastructure and FDI in OECD country and which between finical system and FDI in non-OECD country cannot enhance energy efficiency as expected.

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Performance Evaluation of Traffic Adaptive Sleep based MAC in Clustered Wireless Sensor Networks (클러스터 기반 무선 센서 망에서 트래픽 적응적 수면시간 기반 MAC 프로토콜 성능 분석)

  • Xiong, Hongyu;So, Won-Ho
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.5
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    • pp.107-116
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    • 2011
  • In this paper, a traffic adaptive sleep based medium access control (TAS-MAC) protocol for wireless sensor networks (WSNs) is proposed. The protocol aims for WSNs which consist of clustered sensor nodes and is based on TDMA-like schema. It is a typical schedule based mechanism which is adopted in previous protocols such as LEACH and Bit-Map Assisted MAC. The proposed MAC, however, considers unexpected long silent period in which sensor nodes have no data input and events do not happen in monitoring environment. With the simple traffic measurement, the TAS-MAC eliminates scheduling phases consuming energy in previous centralized approaches. A frame structure of the protocol includes three periods, investigation (I), transmission (T), and sleep-period (S). Through the I-period, TAS-MAC aggregates current traffic information from each end node and dynamically decide the length of sleep period to avoid energy waste in long silent period. In spite of the energy efficiency of this approach, the delay of data might increase. Thus, we propose an advanced version of TAS-MAC as well, each node in cluster sends one or more data packets to cluster head during the T-period of a frame. Through simulation, the performance in terms of energy consumption and transmission delay is evaluated. By comparing to BMA-MAC, the results indicate the proposed protocol is more energy efficient with tolerable expense in latency, especially in variable traffic situation.

The Secure Path Cycle Selection Method for Improving Energy Efficiency in Statistical En-route Filtering Based WSNs (무선 센서 네트워크에서 통계적 여과 기법의 에너지 효율을 향상시키기 위한 보안 경로 주기 선택 기법)

  • Nam, Su-Man;Sun, Chung-Il;Cho, Tae-Ho
    • Journal of the Korea Society for Simulation
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    • v.20 no.4
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    • pp.31-40
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    • 2011
  • Sensor nodes are easily exposed to malicious attackers by physical attacks. The attacker can generate various attacks using compromised nodes in a sensor network. The false report generating application layers injects the network by the compromised node. If a base station has the injected false report, a false alarm also occurs and unnecessary energy of the node is used. In order to defend the attack, a statistical en-route filtering method is proposed to filter the false report that goes to the base station as soon as possible. A path renewal method, which improves the method, is proposed to maintain a detection ability of the statistical en-route filtering method and to consume balanced energy of the node. In this paper, we proposed the secure path cycle method to consume effective energy for a path renewal. To select the secure path cycle, the base station determines through hop counts and the quantity of report transmission by an evaluation function. In addition, three methods, which are statistical en-route filter, path selection method, and path renewal method, are evaluated with our proposed method for efficient energy use. Therefore, the proposed method keeps the secure path and makes the efficiency of energy consumption high.

Analysis of the Low-Carbon Economy of China on the Emissions of Carbon (탄소 배출량에 대한 중국 저탄소 경제의 분석)

  • Chen, Si Jia;Ahn, Jong-Chang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.528-534
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    • 2019
  • This study analyzes the factors affecting China's carbon emissions from 1985 to 2016. In recent years, the whole industries of China are in the midst of industrialization and have several problems. Now, the low-carbon economy has become the main task of China's economic development. This study analyzes the factors affecting China 's carbon emissions by selecting relevant data onto the Chinese yearbook and using a time series model. The analysis shows that related industries continue to innovate and increase the use of green energy such as electricity, but coal is still the largest share of the energy consumed. As energy use efficiency increases and industrial R&D investment increases year by year, carbon emissions are increasing every year. In addition, there is a stereotype that industry is the biggest factor affecting carbon emissions. The research found that the impact of the industry on China's carbon emissions is declining gradually. While controlling industrial carbon emissions, keeping continue to improve technology development and focusing on carbon emissions from other industries are critical to reduce overall carbon emissions. Based on the empirical results, if we can change stereotypes starting from the nature of the data, we will quickly reach a low carbon sustainable development economy.

Simulation and Sensitivity Analysis of the Air Separation Unit for SNG Production Relative to Air Boosting Ratios (SNG 생산용 공기분리공정의 공기 재 압축비에 따른 민감도 분석)

  • Kim, Mi-yeong;Joo, Yong-Jin;Seo, Dong Kyun;Shin, Jugon
    • KEPCO Journal on Electric Power and Energy
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    • v.5 no.3
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    • pp.173-179
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    • 2019
  • Cryogenic air separation unit produces various gases such as $N_2$, $O_2$, and Ar by liquefying air. The process also varies with diverse production conditions. The one for SNG production among them has lower efficiency compared to other air separation unit because it requires ultrapure $O_2$ with purity not lower than 99.5%. Among factors that reduce the efficiency of air separation unit, power consumption due to compress air and heat duty of double column were representatives. In this study, simulation of the air separation unit for SNG production was carry out by using ASEPN PLUS. In the results of the simulation, 18.21 kg/s of at least 99.5% pure $O_2$ was produced and 33.26 MW of power was consumed. To improve the energy efficiency of air separation unit for SNG production, the sensitivity analysis for power consumption, purities and flow rate of $N_2$, $O_2$ production in the air separation unit was performed by change of air boosting ratios. The simulated model has three types of air with different pressure levels and two air boosting ratio. The air boosting ratio means flow rate ratio of air by recompressing in the process. As increasing the first air boosting ratio, $N_2$ flow rate which has purity of 99.9 mol% over increase and $O_2$ flow rate and purity decrease. As increasing the second air boosting ratio, $N_2$ flow rate which has purity of 99.9 mol% over decreases and $O_2$ flow rate increases but the purity of $O_2$ decreases. In addition, power consumption of compressing to increase in the two cases but results of heat duty in double column were different. The heat duty in double column decreases as increasing the first air boosting ratio but increases as increasing the second air boosting ratio. According to the results of the sensitivity analysis, the optimum air boosting ratios were 0.48 and 0.50 respectively and after adjusting the air boosting ratios, power consumption decreased by approximately 7% from $0.51kWh/O_2kg$ to $0.47kWh/O_2kg$.

A Vehicle-to-Vehicle Communication Protocol Scheme for Forwarding Emergency Information in Intelligent Cars Transportation Systems (지능형 차량 전송시스템에서 긴급정보 전송을 위한 Vehicle-to-Vehicle 통신 프로토콜)

  • Kim, Kyung-Jun;Cha, Byung-Rae;Kim, Chul-Won
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.6 no.2
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    • pp.70-80
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    • 2007
  • Inter-vehicular communication suffers from a variety of the problem on the road, resulting in large delay in propagating emergency warning. An energy depletion as well as a transmission delay may induced by traffic accident. A transmission delay are caused by direct contention from nodes that can hear each other or indirect contention from nodes that can not hear each other, but simultaneously transmit to the same destination. A variety of works have been researched to solve the transmission delay and energy consumption problem in intelligent cars transportation systems. We consider a vehicle-to-vehicle communication protocol for disseminating an emergency information that include end-to-end and energy efficient transmission. In this paper, we propose A vehicle-to-vehicle communication protocol scheme for dissemination emergency information in intelligent cars communication based on IEEE 802.15.3 wireless personal area networks. Results from a simulation study reveal that our scheme can achieves low latency in delivering emergency warnings, and efficiency in consuming energy in stressful road scenarios.

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An Energy Awareness Congestion Control Scheme based on Genetic Algorithms in Wireless Sensor Networks (무선 센서 네트워크에서의 유전자 알고리즘 기반의 에너지 인식 트래픽 분산 기법)

  • Park, Jun-Ho;Kim, Mi-Kyoung;Seong, Dong-Ook;Yoo, Jae-Soo
    • The Journal of the Korea Contents Association
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    • v.11 no.7
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    • pp.38-50
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    • 2011
  • For energy-efficiency in Wireless Sensor Networks (WSNs), when a sensor node detects events, the sensing period for collecting the detailed information is likely to be short. The lifetime of WSNs decreases because communication modules are used excessively on a specific sensor node. To solve this problem, the TARP decentralized network packets to neighbor nodes. It considered the average data transmission rate as well as the data distribution. However, since the existing scheme did not consider the energy consumption of a node in WSNs, its network lifetime is reduced. The proposed scheme considers the remaining amount of energy and the transmission rate on a single node in fitness evaluation. Since the proposed scheme performs an efficient congestion control it extends the network lifetime. The simulation result shows that our scheme enhances the data fairness and improves the network lifetime by about 27% on average over the existing scheme.

The Routing Algorithm for Wireless Sensor Networks with Random Mobile Nodes

  • Yun, Dai Yeol;Jung, Kye-Dong;Lee, Jong-Yong
    • International Journal of Internet, Broadcasting and Communication
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    • v.9 no.4
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    • pp.38-43
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    • 2017
  • Sensor Networks (WSNs) can be defined as a self-configured and infrastructure-less wireless networks to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location or base-station where the data can be observed and analyzed. Typically a wireless sensor network contains hundreds of thousands of sensor nodes. The sensor nodes can communicate among themselves using radio signals. A wireless sensor node is equipped with sensing and computing devices, radio transceivers and power components. The individual nodes in a wireless sensor network (WSN) are inherently resource constrained: they have limited processing speed, storage capacity, communication bandwidth and limited-battery power. At present time, most of the research on WSNs has concentrated on the design of energy- and computationally efficient algorithms and protocols In order to extend the network life-time, in this paper we are looking into a routing protocol, especially LEACH and LEACH-related protocol. LEACH protocol is a representative routing protocol and improves overall network energy efficiency by allowing all nodes to be selected to the cluster head evenly once in a periodic manner. In LEACH, in case of movement of sensor nodes, there is a problem that the data transmission success rate decreases. In order to overcome LEACH's nodes movements, LEACH-Mobile protocol had proposed. But energy consumption increased because it consumes more energy to recognize which nodes moves and re-transfer data. In this paper we propose the new routing protocol considering nodes' mobility. In order to simulate the proposed protocol, we make a scenario, nodes' movements randomly and compared with the LEACH-Mobile protocol.

Thermoelectric Energy Harvesting Circuit Using DC-DC Boost Converter (DC-DC 부스트 변환기를 이용한 열전에너지 하베스팅 회로)

  • Yoon, Eun-Jung;Park, Jong-Tae;Yu, Chong-Gun
    • Journal of IKEEE
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    • v.17 no.3
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    • pp.284-293
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    • 2013
  • This paper describes a DC-DC boost converter for thermoelectric energy harvesting. The designed converter boosts the VDD through a start-up block from a low-output voltage of a thermoelectric device and the boosted VDD is used to operate the internal control block. When the VDD reaches a predefined value, a detector circuit makes the start-up block turn off to minimize current consumption. The final boosted VOUT is achieved by alternately operating the DC-DC converter for VDD and the main DC-DC converter for VOUT according to the comparator outputs. Simulation results shows that the designed converter generates 2.65V from an input voltage of 200mV and its maximum power efficiency is 63%. The area of the chip designed using a 0.35um CMOS process is $1.3mm{\times}0.7mm$ including pads.

Cooperative Multipath Routing Protocol for Wireless Sensor Networks (무선 센서 네트워크를 위한 협력 다중경로 라우팅 프로토콜)

  • Jung, Kwansoo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.5
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    • pp.419-428
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    • 2015
  • Multipath routing technique is recognized as one of the effective approaches to improve the reliability of data forwarding. However, the traditional multipath routing focuses only on how many paths are needed to ensure a desired reliability. For this purpose, the protocols construct additional paths and thus cause significant energy consumption. These problems have motivated the study for the energy-efficient and reliable data forwarding. Thus, this paper proposes an energy-efficient cooperative multipath routing protocol with a small number of paths based on an inter path communication. The inter path communication (namely, cooperative multipath routing) in the proposed protocol helps to reinforce the multipath reliability and reduce the use of network resources. In addition, the proposed protocol provides a reliable end-to-end transmission time by using a transmission recovery method based on the local decision for the path or transmission failures.