• 대한건축학회논문집:계획계
• /
• 제34권8호
• /
• pp.23-30
• /
• 2018

A necessity of increasing the energy efficiency of the buildings is rising due to global warming and high energy demands prices. Commissioning is an effective way to increase the energy efficiency of the building and reduce maintenance costs. In this study, a case study was conducted to derive the commissioning process of green building and propose management factors that can be used in domestic commissioning projects. The case was a university renovation project that received a LEED Glod certification and conducted the enhanced commissioning. The commissioning is divided into planning, design, construction, and post-construction phases. In the planning stage, commissioning company selection, commissioning goal setting, tasks and responsibilities for each subject are set. In the design phase, preparations are made for inspection and construction steps to prevent design errors. In the construction phase, problems are solved through periodic on-site inspections. In the post-construction phase, a final report with all the details of the commissioning will be created and future maintenance strategies will be proposed. Based on the findings of this study, it will be a basis for the management factors that can be used in the implementation of domestic commissioning projects.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권2호
• /
• pp.462-483
• /
• 2016

The research on optimization of cellular network's energy efficiency (EE) towards environmental and economic sustainability has attracted increasing attention recently. In this survey, we discuss the opportunities, trends and challenges of this challenging topic. Two major contributions are presented namely 1) survey of proposed energy efficiency metrics; 2) survey of proposed energy efficient solutions. We provide a broad overview of the state of-the-art energy efficient methods covering base station (BS) hardware design, network planning and deployment, and network management and operation stages. In order to further understand how EE is assessed and improved through the heterogeneous network (HetNet), BS's energy-awareness and several typical HetNet deployment scenarios such as macrocell-microcell and macrocell-picocell are presented. The analysis of different HetNet deployment scenarios gives insights towards a successful deployment of energy efficient cellular networks.

• 한국정밀공학회지
• /
• 제30권5호
• /
• pp.480-485
• /
• 2013

Enhancing energy efficiency of machine tools causes substantial impacts on the manufacturing industries, to cope with the competitive introduction of the total energy management strategies. Real-time energy monitoring is essential to identify energy consumption patterns of the machine tools and correlate them with the energy management strategy. Integrated analysis of machine tool's operation status and the corresponding energy usage is most important to accurately evaluate the energy efficiency under the various machining process environments. This paper proposes a system architecture to realize the online energy monitoring system and the embedded energy monitoring approach interconnected with the CNC kernel. The shop-floor operation management system is presented to integrate the proposed online energy monitoring approach.

• 한국해양환경ㆍ에너지학회지
• /
• 제14권1호
• /
• pp.65-71
• /
• 2011

국제해사기구의 해양환경보호위원회에서 CO₂ 배출량 감축의 지구적 노력에 동참하기 위해 최근 선박에서 대기로 방출하는 CO₂의 양을 지수화 하고자 하는 논의가 활발히 진행중이다. 그 대표적인 지수로서 신조선 설계 건조시에 적용하는 에너지 효율지수(EEDI : Energy Efficiency Design Index for new ships)와 현재 또는 건조 후 항행시에 운항선에 적용되는 에너지 효율지표(EEOI : Energy Efficiency Operational Indicator), 그리고 운항선의 에너지 효율관리 계획(SEEMP : Ship Energy Efficiency Management Plan)등이다. 본 지수는 선박을 설계 건조시부터 각 선박당 CO₂의 배출값을 산정하고 운항시에도 CO₂배출을 개량하고 이를 감축하는 방안을 모색하도록 유도하는 조치가 될 것이다. 향후 3년내에 발효될 수 있는 임박한 CO₂선박 배출 규제를 조사 분석하고 향후 발전방향을 모색해 보고자 한다.

• 한국수소및신에너지학회논문집
• /
• 제19권6호
• /
• pp.552-560
• /
• 2008

In 1997, Korean government established the National Energy and Resources Plan, which targeted from 1997 to 2005 with strategic energy technology development. At the end of 2005, Korean government built a New National Energy and Resources Plan preparing for upcoming 10 years from 2006 until 2015 based on energy technology trees comparing with the previous plan, which based on the energy R&D projects. In this research, we prioritize the relative preferences and efficiency by an AHP/DEA CCR-I and BCC-I integrated model approach considering scale efficiency for well focused R&D and efficiency of developing Greenhouse Gas technologies as an extended research from a view point of econometrics as an extended research.

• 전기학회논문지
• /
• 제56권10호
• /
• pp.1763-1769
• /
• 2007

To improve the cycle-life and efficiency of an energy storage system for HEV, a dynamic control system consisted of a switch between a battery and an ultracapacitor module is proposed, which is appropriate for mild hybrid vehicle with 42V power net. The switch can be controlled based on the status of the battery and the ultracapacitor module, and a control algorithm that could largely decrease the number of high charging current peak is also implemented. Therefore the cycle life of the battery can be improved such that it is suitable for a mild hybrid vehicle with frequent engine start-stop and regenerative-braking. Also, by maximizing the use of the ultracapacitor, the system efficiency during high current charging and discharging operation is improved. Finally, this system has the effects that improves the efficiency of energy storage system and reduces the fuel consumption of a vehicle. To verify the validity of the proposed system, this paper presented cycles test results of different energy storage systems: a simple VRLA battery, hybrid energy Pack (HEP, a VRLA battery in Parallel with Ultracapacitor) and a HEP with a switch that controlled by energy management system (EMS). From the experimental result, it was proved the effectiveness of the algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제5권4호
• /
• pp.626-648
• /
• 2011

Energy consumption of wireless access networks is in permanent increase, which necessitates development of more energy-efficient network management approaches. Such management schemes must result with adaptation of network energy consumption in accordance with daily variations in user activity. In this paper, we consider possible energy savings of wireless local area networks (WLANs) through development of a few integer linear programming (ILP) models. Effectiveness of ILP models providing energy-efficient management of network resources have been tested on several WLAN instances of different sizes. To cope with the problem of high computational time characteristic for some ILP models, we further develop several heuristic algorithms that are based on greedy methods and local search. Although heuristics obtains somewhat higher results of energy consumption in comparison with the ones of corresponding ILP models, heuristic algorithms ensures minimization of network energy consumption in an amount of time that is acceptable for practical implementations. This confirms that network management algorithms will play a significant role in practical realization of future energy-efficient network management systems.

• 한국경영공학회지
• /
• 제23권4호
• /
• pp.73-86
• /
• 2018

Most electric products produced during the manufacturing process are produced after design and mass production under a given control standard. In particular, the development phase should present the criteria for the production process by setting appropriate limits based on the performance being targeted. Even if the standard of performance is set considering the performance of the process, measuring the performance of the product after actual production results will cause nonconformities with the expected results. Among the performance of electrical products, Energy standards represented by energy consumption efficiency continue to be of importance, and are mandatory standards that correspond to national standards in most countries. Therefore, statistical quality control of these standards shall basically have a large number of test equipment for each product, ensure sufficient test time and continuous sampling of product samples. In the end, companies that produce and sell electric appliances are striving to control mass production at a great cost, but this is not acceptable. This study presents basic characteristics of the energy efficiency of electrical products and proposes and conducts a case study on statistical production control methods for performance variation across products under the standards about domestic and international regulations.

• 품질경영학회지
• /
• 제12권1호
• /
• pp.31-34
• /
• 1984

The industrial sector is the largest energy consumer, accounting for 44% of the total energy consumption of Korea in 1981. Energy conservation in the industrial processes is one of the most important strategies to the energy conservation to the nation. This paper introduces principles of energy conservation which is the maximum thermodynamic efficiency in energy use. Two important factors considered are how much heat is available and how good is the heat available (the quality of energy).

• 전력전자학회논문지
• /
• 제24권4호
• /
• pp.279-285
• /
• 2019

This study proposes an enhanced switching pattern that can improve energy transfer efficiency in an active cell-balancing circuit using a multiwinding transformer. This balancing circuit performs cell balancing by transferring energy stored in a specific cell with high energy to another cell containing low energy through a multiwinding transformer. The circuit operates in flyback and buck-boost modes in accordance with the energy transfer path. In the conventional flyback mode, the leakage inductance of the transformer and the stray inductance component of winding can transfer energy to an undesired path during the balancing operation. This case results in cell imbalance during the cell-balancing process, which reduces the energy transfer efficiency. An enhanced switching pattern that can effectively perform cell balancing by minimizing the amount of energy transferred to the nontarget cells due to the leakage inductance components in the flyback mode is proposed. Energy transfer efficiency and balancing speed can be significantly improved using the proposed switching pattern compared with that using the conventional switching pattern. The performance improvements are verified by experiments using a 1 W prototype cell-balancing circuit.