• Smart Structures and Systems
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• 제22권5호
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• pp.509-525
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• 2018

Sensors and systems in Civionics technology play an important role for continuously facilitating real-time structure monitoring systems by detecting and locating damage to or degradation of structures. An advanced materials, design processes, long-term sensing ability of sensors, electromagnetic interference, sensor placement techniques, data acquisition and computation, temperature, harsh environments, and energy consumption are important issues related to sensors for structural health monitoring (SHM). This paper provides a comprehensive survey of various sensor technologies, sensor classes and sensor networks in Civionics research for existing SHM systems. The detailed classification of sensor categories, applications, networking features, ranges, sizes and energy consumptions are investigated, summarized, and tabulated along with corresponding key references. The current challenges facing typical sensors in Civionics research are illustrated with a brief discussion on the progress of SHM in future applications. The purpose of this review is to discuss all the types of sensors and systems used in SHM research to provide a sufficient background on the challenges and problems in optimizing design techniques and understanding infrastructure performance, behavior and current condition. It is observed that the most important factors determining the quality of sensors and systems and their reliability are the long-term sensing ability, data rate, types of processors, size, power consumption, operation frequency, etc. This review will hopefully lead to increased efforts toward the development of low-powered, highly efficient, high data rate, reliable sensors and systems for SHM.

• 수산해양기술연구
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• 제59권2호
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• pp.155-163
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• 2023

This study deals with the maximum thermal load analysis and optimal capacity determination method of tank culture system for applying seawater source heat pump to save energy and realize zero energy. The location of the fish farm was divided into four sea areas, and the heat load in summer and winter was analyzed, respectively. In addition, two representative methods, the flow-through aquaculture system and the recirculation aquaculture system were reviewed as water treatment methods for fish farms. In addition, the concept of the exchange rate was introduced to obtain the maximum heat load of the fish farms. Finally, power consumption for heat pumps was analyzed in the view point of sea areas, tank capacity, and exchange rate based on the calculated maximum thermal load.

• 교육녹색환경연구
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• 제6권2호
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• pp.25-52
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• 2007

This paper is focused on the economical efficiency of the geothermal heat pump system in school. As the importance of problems of environment and energy becomes larger, the development and distribution of energy-saving technology in the whole nation has become influential. This paper is intended, targeting on school buildings scattered all over the country, to evaluate the introduction and possibility of a terrestrial heat system which is in the first stage of introduction in the country, through energy consumption and efficiency in case where a terrestrial heat system is introduced. To do that, the author performed a qualitative analysis of the heat pump system using various terrestrial heat energy and the system introduced to existing school buildings and, through the analysis, made tentative evaluation on the most environment-friendly and energy saving type system. Also, the author performed simulation analysis using a currently typical school building standard and, on the basis of this result, conducted efficiency analysis of various heat pump systems. The conclusion according to synthetical analysis & evaluation can be summarized as follows. In case a heat pump system is introduced to a school building, it was deemed the investment in the early stage would increase, but the investment could be collected within 5~6 years through reduction of large operation expenses. Also, it was analyzed in case of terrestrial heat contracted heat mode using midnight electric power among heat pump systems, not only early investment but also operation expenses could be reduced to a great extent. Accordingly in case the system using terrestrial heat energy is applied to the school buildings that are to be newly built or repaired in the future, it will provide an object-lesson to students as well as contributing to energy saving.

• 한국멀티미디어학회논문지
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• 제19권10호
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• pp.1808-1815
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• 2016

TPSN(Timing-sync Protocol for Sensor Networks), the representative of time synchronization protocol, has been already developed to provide time synchronization among nodes in wireless sensor networks. Even though the TPSN's method has been referenced by so many other time synchronization schemes for resource-constrained networks like wireless sensor networks or low power personal area networks, it has some inefficiency in terms of power consumption and network-wide synchronization time (or called convergence time). The main reason is that each node in TPSN needs waiting delay to solve the collision problem due to simultaneous transmission among competing nodes, which causes more power consumption and longer network convergence time for a network-wide synchronization. In this paper an improved scheme is proposed by changing message exchange method among nodes. The proposed scheme not only shortens network-wide synchronization time, but also reduce collision traffic which lead to needless power consumption. The proposed scheme's performance has been evaluated and compared with an original scheme by simulation. The results are shown to be better than the original algorithm used in TPSN.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.159-162
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• 2007

Comparative study on a low cost sustaining driver with single and dual path energy recovery circuits for plasma display panels (PDPs) is shown in this paper. The cost of PDPs has been still high and about half of the cost has been occupied by driving circuit. A simple sustaining driver is proposed to reduce the cost and size of driving circuit. The proposed driver has small number of devices and reactive components and there are two methods for charging and discharging PDPs such as single and dual path energy recovery circuits. A comparative research on two-types of energy recovery path is practiced to evaluate performance. As a result, the dual energy recovery path circuit has low power consumption, low surge current and high performance. To verify those results, experiment will be shown with 42-inch HD panel.

• 한국통신학회논문지
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• 제37C권12호
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• pp.1222-1229
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• 2012

가정 및 빌딩에서의 에너지 소비 절감 및 효율 향상을 위한 에너지 절감 시스템(ESS)의 새로운 구조와 기능 요구사항을 정의하는 신규 국제표준 제안서를 2009년에 IEC TC 100에 제안하고 최종 IEC PT 62654라는 신규 프로젝트로 채택이 되었다. 최근 표준 발간을 위한 최종 투표에서 만장일치로 통과함에 따라 2012년 8월 IEC TS 62654 규격이 발간되었다. 표준의 검증을 위해 ESS 서버, ESS 클라이언트, 휴대용 ESS 터미널로 구성되는 ESS 시스템의 프로토타입을 표준화 과정과 병행하여 구현하였으며, 또한 ESS 서버와 클라이언트간 통신을 위한 EPCM 프로토콜을 구현하였다. EPCM 프로토콜은 ESS 네트워크의 자동 구성, 전력 소비 모니터링, 원격 전원 제어 및 지능적인 에너지 절감 서비스를 위한 부가 기능들을 지원한다.

• 한국컴퓨터정보학회논문지
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• 제26권8호
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• pp.1-11
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• 2021

본 논문에서는 HPC 시스템의 에너지 효율을 향상시키기 위해 Event-driven Uncore Frequency Scaler (eUFS)라는 새로운 전력관리 메커니즘을 제안한다. eUFS는 LAPI (LLC accesses Per Instructions) 및 CPI (Clock Cycles Per Instruction)와 같은 하드웨어 이벤트를 활용하여 언코어 주파수를 동적으로 조정한다. 기준 시간을 주기로 해당 하드웨어 이벤트를 취합하고, 취합한 이벤트와 이전 언코어 주파수를 이용해 목표 언코어 주파수를 결정한다. NPB 벤치마크를 사용한 실험을 통해 본 논문에서 제안하는 UFS 메커니즘은 C/D class NPB 벤치마크에 대해 평균 6%의 에너지 소비를 감소시키는 것으로 확인되었고 실행시간 증가는 평균 2% 수준인 것으로 확인되었다.

• KIEAE Journal
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• 제10권1호
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• pp.57-64
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• 2010

Electric energy is indispensible of the development of the industrial and living sector. Among the energy sectors, the building area shares 20% of the produced electric power in Korea. As we plan to supply the apartment, we need to forecast the required amount of the electric energy and supply the infrastructure to apartment for the lighting, cooling. Nonetheless, it is not easy to forecast the required amount of the electric energy, considering the management aspect, building physical aspect and social-geographic aspect. In this paper, it studied the estimation model of the electric energy, reflecting the affecting variables such as total area, number of household, geography and so on. The estimation model is proposed in 3-types which explained in central heating, individual heating and district heating, and each type have two estimation model, reflecting the affecting variable and corelation between variables to eliminate the muticolinearity. The unit of electric energy consumption per area and year is similar in three heating type and the results are as follows; the central heating is $34.446kWh/yr{\cdot}m^2$, individual type is $35.756446kWh/yr{\cdot}m^2$ and district heating is $34.285446kWh/yr{\cdot}m^2$.

• Current Photovoltaic Research
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• 제5권1호
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• pp.15-19
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• 2017

The fossil fuel power consumption generates $CO_2$, which causes the problems such as global warming. Also, the increase in energy consumption has accelerated the depletion of the fossil fuels, and renewable energy is attracting attention. Among the renewable energies, the solar energy gets a lot of attention as the infinite clean energy source. But, the supply level of solar cell is insignificant due to high cost of generation of electric power in comparison with fossil fuels. Thus several researchers are recently doing the research on ultra-low-cost solar cells. Also, $Cu_2O$ is one of the applied materials as an absorption layer in ultra-low-cost solar cells. Cuprous oxide ($Cu_2O$) is highly desirable semiconductor oxide for use in solar energy conversion due to its direct band gap ($E_g={\sim}2.1eV$) and a high absorption coefficient that absorbs visible light of wavelengths up to 650 nm. In addition, $Cu_2O$ has several advantages such as non-toxicity, low cost and can be prepared with simple and cheap methods on large scale. In this work, we fabricated the $Cu_2O$ thin films by reactive sputtering method. The films were deposited with a Cu target with variable parameters such as substrate temperature, rf-power, and annealing condition. Finally, we confirmed the structural properties of thin films by XRD and SEM.

• 대한기계학회논문집B
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• 제35권5호
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• pp.459-465
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• 2011

반도체 제조를 위한 공정에서는 과도한 열이 발생한다. 따라서 Chamber 내의 웨이퍼나 주변온도를 일정하게 유지할 수 있도록 온도의 정밀제어가 요구된다. 반도체 칠러는 산업용 칠러와는 다르게 운전조건이 24시간 년중 지속되므로 반도체 칠러는 전력소비량이 대단히 크며, 냉동기의 최적 운전제어를 통한 저소비전력 칠러 개발이 대단히 필요하다. 국내에서 판매되고 있는 반도체 칠러는 수입품에 비해 전력소비가 높아 제품 경쟁력이 낮은 실정이다. 이에 따라 본 연구에서는 국내에서 개발된 반도체 칠러에 관한 실험적 연구를 통하여 칠러의 부하변화 실험, 온도 상승 하강실험, 제어정밀도 실험 등을 통하여 칠러의 에너지절감 방향을 제시하고자 한다. 실험을 통하여 칠러의 냉각능력은 2.1~3.9 kW, EER은 0.56~0.93으로 측정되었다. 제어정밀도는 $0^{\circ}C$에서 ${\pm}1^{\circ}C$, $30^{\circ}C$ 이상 설정에서는 ${\pm}0.6^{\circ}C$로 향상되는 것으로 나타났다.