• Journal of Engineering Education Research
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• v.13 no.3
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• pp.11-17
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• 2010

Korea plans to be the world's first country to transform its electricity network into "smart grids," which use information and operational technologies to help to facilitate the reduction of carbon emissions, make more efficient use of existing infrastructure/resources through meeting customer demand/less generation, and support renewable resources with real time monitoring and controls. In this situation, universities do the needful on priority to nurture smart grid engineers who will be responsible for state-of-the-art technologies as today's electric grid transitions to a digital network. This paper thus attempts to permanently turn out high-quality human resources in electrical engineering by fleshing out strategies for training smart electric grid engineers, based on lessons from a national undertaking of nurturing qualified power IT engineers starting on February 1 of 2007.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.407-412
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• 2016

The design in this study containing a consideration of children's free fantasy and experiential acquisition, is convergence in terms of its external use of Solar thermal energy and human friendly software, and is about public design based on eco-friendly playing equipments. Despite several flaws, the modularized solar-light power generation equipment is suitable for realizing the concept of the relationship between the Sun and the life thanks to its being versatile. Playing is equivalent to the world for children in itself, therefore; it should be something flexible to stimulate their fantasy and I imagined the sun, which should be something more than a mere source of power generation, and the children interact with each other by the medium of this equipment.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.1
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• pp.53-58
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• 2020

Korea Electric Power Corporation (KEPCO) uses large amount of SF₆, one of the potent greenhouse gases, in electric equipment for electrical insulation. KEPCO is developing SF₆ recovery and purification technology to minimize the release of SF₆ into the environment, to secure certified emission reduction, and to save purchase cost of new SF₆ by reusing the refined SF₆. A prototype SF₆ purification system using cryogenic solidification technology has been built in demonstration scale. To evaluate the feasibility of the commercialization, the system has been operated to purify large amount of used SF₆ in a long-term operation and the performance has been economically evaluated. The system was stable enough for commercial operation such that it was able to purify 5.4 tons of used SF₆ from power transmission equipment in 2-month operation. Over 99% of the SF₆ was recovered from the used gas and the purity of the purified gas was over 99.7 vol%. The operation cost, which is the cost of refrigerant (liquid nitrogen), electricity and labor, per kilogram of purified SF₆ was 6,526 KRW. Considering the price of new SF₆ in Korea is about 15,000 KRW per kilogram this year, about 56% of the purchase cost can be saved.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.638-644
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• 2010

This paper presents ideas of service scenarios for home residents using electric power monitoring system per appliance, the implementation of the monitoring system, and analysis of acquired electric power usage pattern. By acquiring and analyzing electric power usage pattern, home residents can get information of power usage pattern of every legacy (non-Demand Response-ready) appliance. Further they can get pieces of recommendation how to reduce energy consumption, intelligent standby power blocking service, and alarming service to abnormality of appliances. In order to check the feasibility of the ideas, a system that can acquire electric power pattern per appliance is implemented, and electric power pattern of some appliances are stored to a database and it was analyzed to show if auto-identification of a type of a device is possible, which is a basic required function for the scenarios presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.4
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• pp.23-30
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• 2000

Cogeneration systems are seen as a significant innovation for dispersed energy generation since they are both environmentally friendly and has comparatively high degrees of efficiency. It is especially suited for the decentralized provision of electricity and heat. However, it causes operational problems such as voltage regulation, voltage variation, protection and safety. Especially, it is expected that the interconnection/disconnection operation of cogeneration system has an effect on distribution voltage regulation and variation. Recently, with the increased use of customer-owned computers and other sensitive electronic equipment, electric power quality has become an important concerns. Therefore, the voltage quality problems with cogeneration system should be investigated because the voltage quality is an important part of electrical power quality. In this paper, the momentary voltage dips associated with the interconnection/disconnection operation of cogeneration system are analyzed, including restraint solutions at the customer level. In addition, the unit capacity of cogeneration systems per feeder are evaluated from the view point of momentary voltage variations. The results of this paper are useful analysis data for interconnection standards/guidelines of cogeneration systems and dispersed generation (DG)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9B
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• pp.1390-1398
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• 2010

We present the concept of applying Wireless Mesh Networking (WMN) technology into Smart Grid, which is recently rising as a potential technology in various areas thanks to its advantages such as low installation costs, high scalability, and high flexibility. Smart Grid is an intelligent, next-generation electrical power network that can maximize energy efficiency by monitoring utility information in real-time and controlling the flow of electricity with IT communications technology converged to the existing power grid. WMNs must be designed for Smart Grid communication systems considering not only the high level of reliability, QoS support and mass-data treatment but also the properties of the traditional power grid. In addition, it is essential to design techniques based on international standards to support interoperability and scalability. In this paper, we evaluate the performance of IEEE 802.11s based Smart Grid Mesh Networks by conducting preliminary simulation studies with the ns-3 simulator. We also outline some challenging issues that should be reviewed when considering WMNs as the candidate for Smart Grid communication infrastructure.

• Resources Recycling
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• v.16 no.6
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• pp.28-33
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• 2007

Coal is the most abundant energy source and deposited in every area of world. Combustion process with lower efficiency has been mainly used. Therefore, implementation of more efficient technologies, involving gasification, combined cycles and fuel cells, would be a key issue in the plans for more efficient power generation. In these technologies, gasification has been studied for decades. However, coal gasification to high value combustible gas such as hydrogen and carbon monoxide is focused again due to high oil price. The gaseous product, called syngas, can be effectively utilized in a variety of ways ranging from electricity production to chemical industry (as feedstock). In this study, coal gasification with ultra high temperature steam has been performed. The effect of steam/carbon ratio on the produced gas concentrations, gasification rate and additional products like tar, ammonia and cyan compounds has been determined.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.147-155
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• 2008

The economics of most chemical plants are heavily dependent upon the management of the utilities used in the plants. The utilities are supplied by the centralized utility system of the plant. Among the various utilities the steam is by far the most important energy source and the management of the electricity and the process water are greatly affected by the steam. Therefore it is necessary to educate students and new employees the basic concepts about the effective distribution of the utilities and the fundamental strategies to apply the concepts in actual plant operations. The OOUS (Optimal Operation of Utility System) is an GUI educational system designed to educate the effective generation of the steam and the optimal steam distribution schemes within short period. The OOUS deals with various utility equipments and processes and shows how to save operation costs by displaying the optimal operation conditions based on the process models and the operational knowledgebase.

• Advances in environmental research
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• v.1 no.1
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• pp.37-55
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• 2012

Here we show that perchlorate reduction during pitting corrosion of zero-valent titanium (ZVT) is likely caused by dissolved titanium species, especially Ti(II). Several possible mechanisms were suggested based on the literature and were evaluated based on experimental observations. Direct reduction of perchlorate on the bare metal of the ZVT electrode was thermodynamically infeasible due to the high anodic potential that was applied. Other potential mechanisms were considered such as reduction by small ZVT metal particles released from the electrode and direct reduction on the oxide layer of the electrode where potential was sufficiently reduced by a high ohmic potential drop. However, these mechanisms were not supported by experimental results. The most likely mechanism for perchlorate reduction was that during pitting corrosion, in which ZVT is partially oxidized to form dissolved ions such as Ti(II), which diffuse from the electrode surface and react with perchlorate in solution. This mechanism is supported by measurements of the dissolution valence and the molar ratio of ZVT consumed to perchlorate reduced (${\Delta}Ti(0)/{\Delta}ClO_4{^-}$). The results shown in this study demonstrate that ZVT undergoing pitting corrosion has the capability to chemically reduce perchlorate by producing dissolved Ti(II) and therefore, it has the potential to be applied in treatment systems. On the other hand, the results of this research imply that the application of ZVT undergoing pitting corrosion in treatment systems may not be feasible now due to several factors, including material and electricity costs and possible chloride oxidation.

• Journal of the Korean Dietetic Association
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• v.24 no.1
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• pp.1-18
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• 2018

Sustainable practices of school foodservices are gaining more attentions. The study aimed to investigate dietitians' performance levels of sustainable practices in school foodservice settings in Gyeonggi Provinces. Using a survey method was used, and data were collected from 358 participants (response rate 59.7%) to be analyzed using the SPSS program. The evaluation tool for sustainable practices of school foodservices consisted of four sections and 34 criteria with 100 points. Employment status of the respondents was as follows: nutrition teachers 40.9%, dietitians (permanent) 45.1%, and temporary position dietitians 13.2%. Dietitians' performance for sustainable practices marked 65.67 points out of 100 (performance rate 66%) and were in the following order by section: sustainable foodservice management criteria (69%), support activities (69%), planning and evaluation (68%), and outcome management (52%). Regarding sub-sections, criteria that acquired higher performance rates were labelling of food origin (99%), use of seasonal vegetables and fruits (98%), food waste management by contract dealer (98%), and planning for reducing of food waste and solid waste (91%). Meanwhile, criteria that showed the lowest scores were installing water conservation devices on equipment (19%), operating food donation programs for communities (21%), use of sensor lights for electricity conservation (24%), planning for annual energy conservation (40%), and implementation of education programs for foodservice workers on sustainable activities (42%). Performance scores differed according to school levels and working experience of dietitians, indicating that dietitians at elementary school foodservices or with work experience of 15 to 20 years showed higher performance than those at high schools or with less than 5 years of work experience (P<0.001, P<0.05). Based on the results, action plans for improvement were suggested.