• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.17-20
• /
• 2008

HYOSUNG manufactured and tested 1kW class PEFC systems to generate electrical and thermal energy for each residential usage. In particular, HYOSUNG developed power conditioning system that performs over 91% electrical conversion ratio specified in 1kW class PEFC systems. Prior to system integration, we tested each performances of components to derive control issues from it. In addition, we have been developing the adequate simulator to describe and predict system performance. In this paper, we verified HYOSUNG's 1kW class PEFC systems are valid for residential energy sources by testing the characteristics of systems and performances of main components.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.5
• /
• pp.688-695
• /
• 2013

Networked Control Systems(NCS) contain the structure which controllers, actuators and sensors are connected to communication network. And they have been adopted in large and complicated plant area due to the advantages of mitigating computational bottleneck and maintenance. Although this structure provides many benefits, it brings in problems of unpredictable communication delay, data loss and corruption. This phenomena have to be considered in designing NCSs since it affects on overall control system stability. This paper introduces network traffic test method for ethernet based NCSs to find out maximum network usage which guarantee stable control operation. Test results shows this methods can be adopted in various types of NCSs and contributes economical system design and effective system operation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.6
• /
• pp.63-69
• /
• 2015

Energy Storage Systems (ESSs) are essential in the future power systems because they can improve power usage efficiency. In this paper, we propose the countermeasure for improving the power quality using coordinated control of BESS(Battery Energy Storage System) on EV connected system. To verify the performance of proposed scheme, we simulate on the actual power system of KEPCO and compare the results of voltage variation, frequency variation, and load factor with those of uncoordinated control. From the simulation results, we confirm that frequency and voltage deviation are significantly reduced with proposed coordinated control of BESS.

• Structural Engineering and Mechanics
• /
• v.59 no.6
• /
• pp.1055-1070
• /
• 2016

The aim of this experimental study is to investigate the free vibration and buckling behaviors of hybrid composite beams having different span lengths and orientation angles subjected to different impact energy levels. The impact energies are applied in range from 10 J to 30 J. Free vibration and buckling behaviors of intact and impacted hybrid composite beams are compared with each other for different span lengths, orientation angles and impact levels. In free vibration analysis, the first three modes of hybrid beams are considered and natural frequencies are normalized. It is seen that first and second modes are mostly affected with increasing impact energy level. Also, the fundamental natural frequency is mostly affected with the usage of mold that have 40 mm span length (SP40). Moreover, as the impact energy increases, the normalized critical buckling loads decrease gradually for $0^{\circ}$ and $30^{\circ}$ oriented hybrid beams but they fluctuate for the other beams.

• Journal of the Korean Home Economics Association
• /
• v.35 no.2
• /
• pp.401-413
• /
• 1997

The objectives of this study were to measure the characteristics of environmentally conscious behavior in the private household focused on energy consumption, money expenditure and time usage, and to determine the socioeconomic variables, environmental consciousness and environmental education which are associated with the environmentally conscious behavior of private households. The data for this study were collected in a personal interview and the final sample consisted of 178 respondents and the statistics employed to analyze the data are discriminant analysis $\chi$2-test. As a result of the discriminant analysis, it was shown that environmentally conscious private households consumed less energy, had lower transportation costs, but spent more time in purchasing behavior in the market compared with those who did not exhibit environmentally conscious behavior. Environmentally conscious behavior of private households differed significantly according to the education of housewives, and also to the level of environmental consciousness and environmental education of the respondents.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.10 no.6
• /
• pp.391-397
• /
• 2015

Nonvolatile memories in memory hierarchy have been investigated to reduce its energy consumption because nonvolatile memories consume zero leakage power in memory cells. One of the difficulties is, however, that the endurance of most nonvolatile memory technologies is much shorter than the conventional SRAM and DRAM technology. This has limited its usage to only the low levels of a memory hierarchy, e.g., disks, that is far from the CPU. In this paper, we study the use of a new type of nonvolatile memories - the Phase Change Memory (PCM) with a DRAM buffer system as the main memory. Our design reduced the total energy of a DRAM main memory of the same capacity by 80%. These results indicate that it is feasible to use PCM technology in place of DRAM in the main memory for better energy efficiency.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.717-719
• /
• 2013

Building Energy Management System application not only helps maintain internal environment comfortable, but also maximizes energy efficiency and extends an expected life of facility system. Due to generalized computer usage, development of communication system, and bigger and more complex of building in 1990s, automation and comprehensive management system were acknowledged to be important; and these have been widely applied in domestic market. This paper study the design of the BEMS project.

• Journal of Drive and Control
• /
• v.9 no.2
• /
• pp.46-53
• /
• 2012

This paper explains how eliminating contamination from the manufacturing processes will lead to better product quality and hence the need for reworking, a trouble free commissioning period and greatly improved production efficiency. All of these will reduce costs and energy usage. It will also ensure that the product is delivered to the customer in a condition that will ensure improved reliability and longer life, again reducing both energy and other operating costs. Correctly designing the contamination control measures will achieve and maintain the level of fluid cleanliness that is required by the end user. The filter is critical to cleanliness management and should be selected with the same degree of thought and consideration as for other major components. This paper explains the role that Cleanliness Management plays in the reducing the carbon footprint of systems and processes by making them perform more efficiently for longer periods. It also examines two differing ways of selecting filters to incorporate the features of newer designs, and shows how significant savings in the costs of ownership can be achieved using these approaches.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.10 no.4
• /
• pp.8-14
• /
• 2014

With the advancement of the industry such as information technology, residential facilities has been consistently achieved high standard. Ubiquitous system has been introduced in apartments nowadays, and it will be general facilities in the near future. However elderly people is not generally accustomed to ubiquitous or internet environment, so degree of ubiquitous system usage is able to be less than young people. This study aims to grasp the relative importance of ubiquitous environment, and offer materials to realize residential environment's improvement of silver towns under investigation through a questionnaire survey. Skin recognition system was most preferred among various functions. Energy management system, protection system of solitude elderly person and security system by CCTV was also preferred at a high rate. Housework part such as cooking aid, height control of sink and basin etc., was not less important system relatively.

• International Journal of High-Rise Buildings
• /
• v.4 no.2
• /
• pp.103-107
• /
• 2015

China's rapidly growing cities offer a unique opportunity to create highly sustainable communities. Architects and their clients, typically real estate developers, are highly focused on strategies that are effective at reducing energy and water usage at the scale of the individual building or within a master plan of multiple related buildings. However, a closer look at energy consumption reveals that transportation uses more energy worldwide than residential and commercial buildings combined. In light of this, it is appropriate that China is making massive investments in transportation infrastructure like heavy rail rapid transit and grade separated expressways, but the end result of these investments to date has been to enable people to live further from where they work and shop rather than closer - while simultaneously not creating walkable communities. Using positive and negative examples from Asia and the rest of the world, this article will investigate the specific urban design policies such as height limits, setbacks, land use restrictions, parking ratios, and parcel size which might change to enable the creation of truly sustainable communities for China's 21st century.