• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.1-17
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• 2017

Mobile Cloud Computing has become a promising computing platform. It moves users' data to the centralized large data centers for users' mobile devices to conveniently access. Since the data storage service may not be fully trusted, many public verification algorithms are proposed to check the data integrity. However, these algorithms hardly consider the huge computational burden for the verifiers with resource-constrained mobile devices to execute the verification tasks. We propose an energy-efficient algorithm for assigning verification tasks (EEAVT) to optimize the energy consumption and assign the verification tasks by elastic and customizable ways. The algorithm prioritizes verification tasks according to the expected finish time of the verification, and assigns the number of checked blocks referring to devices' residual energy and available operation time. Theoretical analysis and experiment evaluation show that our algorithm not only shortens the verification finish time, but also decreases energy consumption, thus improving the efficiency and reliability of the verification.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.28-31
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• 2009

This paper is a report of designing for high efficient LED lights driver. The main purpose of driver designing is meet the requirement the high efficient energy regulation for light of Korea. To meet the regulation the high efficient the circuit adapted wide range resonant power supply and current regulate circuit to adjust LED current. This product archived excellent performance as well as reliable operation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.724-726
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• 1996

In this paper, we propose an optimal daily operation model for the total energy system which includes cogeneration, thermal storage and electrical charger and ice storage facilities. Storing and utilizing the surplus thermal and electrical energy, the daily operation cost could be reduced and more efficient use of thermal energy could be achieved. The ice storage cooling system has a merit of reduce the electricity cost by time of day rate(peak/off-peak). And also, refrigerator can be down sized compare to the other cooling system From this model, operation costs of the sample cogeneration system with/without auxiliary facilities are obtained and compared to each other. In case study, the sensitivity of operating cost is simulated according to the variation of cogeneration production cost, electricity rate, etc.

• Nuclear Engineering and Technology
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• 제25권1호
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• pp.1-7
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• 1993

핵연료 밀집공정의 조업을 보조하는 전문가시스템 모형을 개발하였다. 시스템의 지식기반은 3개의 데이타베이스와 60개의 규칙을 객체지향 방법에 의해 설계되었다. 본 전문가시스템은 핵연료 밀집시설의 물질계량관리 영역에서 핵물질의 이동 상황을 추적하여 체계적으로 데이터베이스화하고, 정상 및 비정상조업 조건하에서 현 운전상황을 진단하며, 비정상 조업상황을 적절히 회복할 수 있게 조업자에게 필요한 정보를 제공하여, 효과적으로 핵연료 밀집시설의 공정조업을 이룰 수 있도록 하였다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1110-1116
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• 1993

A study on optimum operation performances of power efficiency, economy and exhaust emissions for a tractor was conducted. A mathematical model of multiple degree polynomial equation was applied to established the function of solid multiple parameter curves for specific fuel consumption (ge), cabon monoxide (CO) ,hydrcarbons (HC) and cabonaceous smoke (Rb). The optimum operation theorems for economy operation indicated by ge and for exhaust emissions described by Co , HC and Rb were obtained from analytical method and performance test data. The optimum operation theorems could exhibit optimum operation working points, curves, and regions. The optimum matching relations of engine speed and transmission parameters were analyzed by using computer simulation methods in accordance with the tractor specifications , actual farm working conditions in a typical drawbar pull work such as plowing , the optimum operation objective function, the ideal transmission ratio, practical gear shif ing positions and practical travel speed of the tractor TN55 medel. The results of the anlayzes indicated clearly that the optimum power efficient operation, energy saving and pollution reducing would be realized if the tractor would be operated according to theoptimum operation methods.

• 설비공학논문집
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• 제20권12호
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• pp.775-780
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• 2008

A dynamic model to simulate LNG reliquefaction process has been developed. The model was applied to two candidate cycles for LNG reliquefaction process, which are Reverse Brayton and Claude cycles. The simulation was intended to simulate the pilot plant under construction for operation of the two cycles and evaluate their feasibility. According to the simulation results, both satisfy control requirements for safe operation of brazed aluminum plate-fin type heat exchangers. In view of energy consumption, the Reverse Brayton cycle is more efficient than the Claude cycle. The latter has an expansion valve in addition to the common facilities sharing with the Reverse Brayton cycle. The expansion valve is a main cause to the efficiency loss. It generates a significant amount of entropy associated with its throttling and increases circulation flow rates of the refrigerant and power consumption caused by its leaking resulting in lowered pressure ratio. It is concluded that the Reverse Brayton cycle is more efficient and simpler in control and construction than the Claude cycle.

• International Journal of Air-Conditioning and Refrigeration
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• 제17권4호
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• pp.135-140
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• 2009

A dynamic model to simulate LNG reliquefaction process has been developed. The model was applied to two candidate cycles for LNG reliquefaction process, which are Reverse Brayton and Claude cycles. The simulation was intended to simulate the pilot plant under construction for operation of the two cycles and evaluate their feasibility. According to the simulation results, both satisfy control requirements for safe operation of brazed aluminum plate-fin type heat exchangers. In view of energy consumption, the Reverse Brayton cycle is more efficient than the Claude cycle. The latter has an expansion valve in addition to the common facilities sharing with the Reverse Brayton cycle. The expansion valve is a main cause to the efficiency loss. It generates a significant amount of entropy associated with its throttling and increases circulation flow rates of the refrigerant and power consumption caused by its leaking resulting in lowered pressure ratio. It is concluded that the Reverse Brayton cycle is more efficient and simpler in control and construction than the Claude cycle.

• International journal of advanced smart convergence
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• 제8권1호
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• pp.82-86
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• 2019

We aim to use public data different from the remote BEMS energy diagnostics technology and already established and then switch the conventional operation environment to a big-data-based integrated management environment to operate and build a building energy management environment of maximized efficiency. In Step 1, various network management environments of the system integrated with a big data platform and the BEMS management system are used to collect logs created in various types of data by means of the big data platform. In Step 2, the collected data are stored in the HDFS (Hadoop Distributed File System) to manage the data in real time about internal and external changes on the basis of integration analysis, for example, relations and interrelation for automatic efficient management.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.294-298
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• 2008

The major threats that human being is facing nowadays are the Climate change, depletion of the fossil fuels at a rapid rate and energy costs. A significant portion of world energy consumption is consumed by domestic heating and cooling. And heat pumps, due to their higher utilization efficiencies as compared to conventional heating and cooling systems, offer an attractive solution to this problem. Among the types of heat pumps, the Geothermal heat pump or Ground-source heat pump is a highly efficient, renewable energy technology for space heating and cooling. The Ground-source heat pump uses the Earth as a heat sink in the summer and a heat source in the winter. And the Earth, having a relatively constant temperature, warmer than the air in winter and cooler than the air in summer, offers an excellent heat source in winter and heat sink in summer.. This paper will discuss an overview of the types of heat pumps, its operation, benefits of using geothermal heat pumps, soil characteristics, and overview of some experimental works. Finally it will briefly discuss the opportunity of using these energy efficient systems (EES) in the HVAC market of South Korea.

• International journal of advanced smart convergence
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• 제7권1호
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• pp.42-47
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• 2018

Recently, as the demand for limited resources continues to rise and problems of resource depletion rise worldwide, the importance of renewable energy is gradually increasing. In order to solve these problems, various methods such as energy conservation and alternative energy development have been suggested, and biogas, which can utilize the gas produced from biomass as fuel, is also receiving attention as the next generation of innovative renewable energy. New and renewable energy using biogas is an energy production method that is expected to be possible in large scale because it can supply energy with high efficiency in compliance with energy supply method of recycling conventional resources. In order to more efficiently produce and manage these biogas, a biogas plant has emerged. In recent years, a large number of biogas plants have been installed and operated in various locations. Organic wastes corresponding to biogas production resources in a biogas plant exist in a wide variety of types, and each of the incoming raw materials is processed in different processes. Because such a process is required, the case where the biogas plant process is inefficiently operated is continuously occurring, and the economic cost consumed for the operation of the biogas production relative to the generated biogas production is further increased. In order to solve such problems, various attempts such as process analysis and feedback based on the feedstock have been continued but it is a passive method and very limited to operate a medium/large scale biogas plant. In this paper, we propose "CNN-based production yield prediction algorithm for increasing process efficiency of biogas plant" for efficient operation of biogas plant process. Based on CNN-based production yield forecasting, which is one of the deep-leaning technologies, it enables mechanical analysis of the process operation process and provides a solution for optimal process operation due to process-related accumulated data analyzed by the automated process.