• ETRI Journal
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• v.42 no.4
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• pp.585-595
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• 2020

Integration of multiple communication technologies in a smart grid (SG) enables employing cognitive radio (CR) technology for improving reliability and security with low latency by adaptively and effectively allocating spectral resources. The versatile features of the CR enable the smart meter to select either the unlicensed or the licensed band for transmitting data to the utility company, thus reducing communication outage. Demand response management is regarded as the control unit of the SG that balances the load by regulating the real-time price that benefits both the utility company and consumers. In this study, joint allocation of the transmission power to the smart meter and consumer's demand is formulated as a two stage multi-armed bandit game in which the players select their optimal strategies noncooperatively without having any prior information about the media. Furthermore, based on historical rewards of the player, a real-time pricing adaptation method is proposed. The latter is validated through numerical results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.4
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• pp.278-287
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• 2009

Plug-in hybrid electric vehicle (PHEV) with capability of being recharged from the power-grid will reduce oil consumption. Also, the PHEV will affect the utility operations by adding additional electricity demand for charging. In this research, the power-grid impact by demand of PHEV charging is presented and the optimal charging control strategy for utility operators is proposed with simulated data. The penetration of PHEV is assumed to be 50% in the circumstances of Korean passenger car market and Korean power-grid market limitedly. To obtain smooth load shape and utilize the surplus electricity in power-grid at midnight and dawn, the peak of charging demand should be controlled to be located before 4:00 a.m., and the time slot which can supply the electricity power to PHEV should be allowed between 1:00 a.m.$\sim$7:00 a.m.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.202-203
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• 2006

The equipment using the Power electronic device is recently increased in the distribution system, so power utility and customers increase in concerning about harmonics level. Accordingly, The power utility which prepares a measure for the harmonic public standard and manege process must analysis of the harmonics level and the effect on equipment interconnecting distribution system. In the past, the measurement equipment and technique is imperfect, so very difficult to investigate the harmonics and trend. But the improvement of the measurement equipment recently is possible to obtain the data realtime for harmonic analysis. In this paper, we research the measuring domestic harmonic and constructing of DB based on the IEC standard.

• Journal of Korean Home Economics Education Association
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• v.15 no.4
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• pp.87-103
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• 2003

This study aimed to research the cognition of Technologyㆍ Home Economics curriculum by the middle and high school students in Kyungnam area. Data were collected from 646 middle school students and 589 high school students by the self-questionnaire. The results were following; 1. The overall cognition of TechnologyㆍHome Economics were evaluated lower middle school students than high school students, especially the variety of lessons the lowest. The variety of lessons and satisfaction was correlated highly. 2. The practices of lessons were more frequently Home Economics than Technology. The most complains were the insufficiency of interests and practice lessons. 3. The overall evaluation of subject´s matters and subject´s goals were highly positive levels, but the item of the interrelatedness of Technology and Home Economics was a little low level. 4. The utility and the importance of subject´s matters were evaluated higher the Home Economics and Computer than Technology revealed sex differences obviously.

• Journal of the Korean Home Economics Association
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• v.25 no.2
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• pp.1-11
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• 1987

The purpose of the study is to researdch clothing consumer behavior of men and women over age of 20 years and to find out the reasonable maximum utility on clothing behavior. The factors are eight distinguished parts such as sex, age, monthly income, occupation, floor space, number of room, number of family and place of residence. A common questionaire is introduced to survey the clothing consumption activity and the home background. Sources to measure them are gathered in the whole country including major cities. The questionaire of 915 correspondents of 368 males and 547 females is investigated for this research. Some of the data are analyzed by correlation, frequency, percentage, mean, and S.D. Others are investigated by ANOVA Test, x2-Test, and Multiple Range Test. The results from the survey are as followings: 1. Only four factors such as sex, monthly income, occupation, and floor space have a significance in the clothing consumption activity. 2. This survey reveals that many cloths have been kept in dead storage and concerns of utility have risen high. 3. This survey has shown that the correspondents have deep concerns about using colthing exchange store, clothing lending store, and trunk room to utilize dead storage clothing efficiently.

• Journal of Technology Innovation
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• v.7 no.1
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• pp.176-186
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• 1999

This paper starts out by reviewing the literature that in different ways utilizes patent data as an output of Research ＆ Development (R&D) investment. The main focus, however, is an analysis of time-lag between industrial R&D input and its output. To achieve this research's purpose, the basic data associated with the industrial R&D input (expenditure, researchers) and output (applied patent and utilities) for the past 15 years, from 1980 to 1994, in the areas of electrical-electronic, mechanical and chemical industries have been collected. And the raw input data were altered into real flow data (but stock data) using Laspeyres approach and analyzed using multiple regression analysis, especially stepwise regression analysis. The result of this study can be summarized as follows: a) The time-lag; between industrial R&D input and its output is within 1 to 3 years. b) The time-lag: of patents was longer than that of utility models. c) The time-lag: in electrical-electronic, chemical industry was longer than that of the mechanical industry.

• KIEAE Journal
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• v.13 no.5
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• pp.51-57
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• 2013

Energy saving starts by knowing how much energy is being consumed. A building factor is easier than any other things in energy saving. Since, especially, it is closely connected with user's space-use-patterns and manager's utility-operation-style. An energy metering system lets building users know about energy consumption pattern in buildings and measure energy in real time. Development and materialization of metering systems need more careful plans, so that they depend on a demand of individual facilities and available infrastructures they used to use. But, so far, there is no guidelines how to install metering systems. This paper suggested how to install meters and researched a method for how to analyze by using metered data. For that, Green Building in KIER is used as a test bed. As the results, nevertheless the smallest number of meters is basically one for the whole building energy measuring, it is too limited in analysis. So we needed to add the sort of fuel and utility types and found that it depends on all cases. For this reasons, a guideline should be created in order to install meters as soon as possible. It would be suggest a way to save more energy in building factor.

• Journal of information and communication convergence engineering
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• v.7 no.1
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• pp.35-40
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• 2009

Many researchers strive to research on ways on how to improve the performance of RFID system and many papers were written to solve one of the major drawbacks of potent technology related with data management. As RFID system captures billions of data, problems arising from dirty data and large volume of data causes uproar in the RFID community those researchers are finding ways on how to address this issue. Especially, effective data management is important to manage large volume of data. Data reduction techniques in attempts to address the issues on data are also presented in this paper. This paper introduces readers to a new data reduction algorithm that might be an alternative to reduce data in RFID Systems. A process on how to extract data from the reduced database is also presented. Performance study is conducted to analyze the new data reduction algorithm. Our performance analysis shows the utility and feasibility of our categorization reduction algorithms.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.29-39
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• 2017

In this research, thermal design data such as heat transfer coefficient on the wall surface required for ventilation system design which is to prevent the temperature rise in the underground utility tunnel that three sides are adjoined with the ground was investigated in numerical analalysis. The numerical model has been devised including the tunnel lining of the underground utility tunnel in order to take account for the heat transfer in the tunnel walls. The air temperature in the tunnel, wall temperature, and the heating value through the wall based on heating value(117~468 kW/km) of the power cable installed in the tunnel and the wind speed in the tunnel(0.5~4.0 m/s) were calculated by CFD simulation. In addition, the wall heat transfer coefficient was computed from the results analysis, and the limit distance used to keep the air temperature in the tunnel stable was examined through the research. The convective heat transfer coefficient at the wall surface shows unstable pattern at the inlet area. However, it converges to a constant value beyond approximately 100 meter. The tunnel wall heat transfer coefficient is $3.1{\sim}9.16W/m^2^{\circ}C$ depending on the wind speed, and following is the dimensionless number:$Nu=1.081Re^{0.4927}({\mu}/{\mu}_w)^{0.14}$. This study has suggested the prediction model of temperature in the tunnel based on the thermal resistance analysis technique, and it is appraised that deviation can be used in the range of 3% estimation.

• Proceedings of the Technology Innovation Conference
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• 1997.07a
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• pp.160-171
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• 1997

This paper starts out by reviewing the literature that in different ways utilizes patent data as a output of R&D investment. The main focus, however, is an analysis of time-lag between R&D input and output. To achieve this research objective, the basic data associated with the R&D input(expenditure, researchers) and output(patent, utilities) for the past 15 years, from 1980 to 1994, in the areas of electrical-electronic, mechanical and chemical industries have been collected. And the raw output data were altered it to objective data using Laspeyres approach and analyzed using multiple regression analysis, especially stepwise regression analysis. The result of this study can be summarized as follows: a) The time-lag between R&D input and output is from 1 to 4 years. This result is equal to the research conclusion of the existing foreign studies. b) It was found that the time-lag of patents was longer than of utility models. c) It was showed that the time-lag of electrical-electronic, mechanical industry was longer than the chemical one.