• Educational Technology International
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• v.17 no.2
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• pp.229-251
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• 2016

This study was designed to investigate the relationship between middle school students' smart media competency and online learning outcomes. The context of this study was on online inquiry-based mathematics and science learning environment, and four-hundred and fifty-five (455) 7^th to 9^th grade students in Korea participated in this research. To assess students' smart device competency, Smart Media Literacy Quotient (SMLQ) which consisted of 18 items regarding the operation ability of smart media and its application (14 items) and positive beliefs of smart media (4 items) was administered to each student. The findings of this study first showed that students' smart media literacy varied according to their characteristics such as gender, grade, class (subject), and socio-economic status. Female students' scores were higher in overall smart media literacy operation and learning ability of smart media than male students. 7^th grade middle school students represented lower smart media literacy scores, compared to 8^th and 9^th graders. Also, minority students were significantly lower in smart media literacy, operation and learning ability of smart media, and positive belief of smart media than the non-minority students. Second, overall smart media literacy and operation and learning ability of smart media varied among high, medium, and low score achievers in inquiry tasks. Low scored students in inquiry tasks were significantly lower in overall smart media literacy and operation and learning ability of smart media than medium scored students. Lastly, smart media literacy also varied by students' dropout/completion. Students who dropped out reported significantly lower scores in overall smart media literacy, operation and learning ability of smart media, and positive belief of smart media.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.273-280
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• 2001

In this study, a comparison between the structural design criteria for a catenary system with the maximum design speed of 100km/h and that of 300km/h was performed in order to establish that of 200km/h. According to the result, catenary design criteria for 300km/h operation is more conservative than that for 100km/h operation. This result shows that higher wind pressure and safety factor are adopted to catenary design for 300km/h operation. So, for the purpose of the economic structural design for catenary system, it is necessary to review the adoption possibility of catenary system for 100km/h operation first. In order to review the adoption possibility for catenary system for 100km/h operation, design criteria for 300km/h operation should be chosen for safer catenary structure.

• Journal of Korea Port Economic Association
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• v.20 no.1
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• pp.57-77
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• 2004

The meaning of seaport has always been translated into something concerned with nation-wide goals and viewpoints, which used to be in developing country. The time developing countries have tried to be in pursuit of their economic development, one of important sectors is SOC investment that is needed into huge capital input which they couldn't easily afford to it. Another one which we have to mention in terms of seaport at contemporary maritime matters is privatization of port, that is strongly connected with efficiency to achieve port productivity. All these factors can produce high quality of service, and port co-operation and diversification of their business areas, etc. Therefore we then have to think of private port management companies such as P&O Ports, Hutchison Whampoa in HK, etc. in order to provide better port service to the customers, and they can also get involved into capital port investment as well. This kind of concept already comes from Denholm Ship management companies in shipping. So, it is necessary for us to look into port management company in our side, which means, we have to be involved into such a business to invest and manage foreign ports as well as our ports. Then, port competitiveness will follow in our ports.

• International Journal of Highway Engineering
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• v.15 no.3
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• pp.85-92
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• 2013

PURPOSES: The purpose of this paper is to estimate expected effects on traffic operational and economic aspects of 2+1 roads application in Korea. METHODS : Micro simulation study using VISSIM 5.0 was used to analyze the operation efficiency of 2+1 roads compared to two-lane highways and four-lane highways. Some scenarios for various traffic volumes were set up in order to analyze the effect of 2+1 roads under various traffic situations. Also imaginary road networks were set up for each type of roads. The MOEs to measure the operation efficiency were selected with average travel speed and delay. For analyzing economic effect of 2+1 roads, construction cost of a specific imaginary 2+1 road was compared to construction cost of a four-lane highway with same conditions. RESULTS: The results of study show that a 2+1 road is more effective with 19 percents higher average travel speed and 39 percents lower average delay than a two-lane highway. In the economic analysis, construction costs to construct a 2+1 road are saved as approximately 26.4~40.7 percents when compared to construction of four-lane highway. CONCLUSIONS: It can be concluded that 2+1 roads can improve the traffic operational level of service for two-lane highways and 2+1 roads can be applied as an effective design alternative for higher-volume two-lane highways in Korea.

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.272-284
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• 1996

The present study has quantitatively assessed the regional production, income and employment impact resulting from the construction and operation of nuclear power plant (NPP) upon the domestic local areas by applying the regional input-output analysis model to the case of Wolsong unit-l site. The conclusions regarding the most likely regional economic impacts upon the wolsong site are summarized as follows: 1. The income multipliers are calculated to be 1.563 for the construction phase and 1.500 for the operation phase. These values are relatively high compared with those of other conventional facilities. 2. The level of total employee's wage induced employment associated with the construction phase has been estimated to be 37,000 while that with the operational phase in 1990 to be 5,610. 3. With relation to the aspect of resident welfare it is found that the industrial sector associated with electricity, gas and water supply have remarkably improved with the construction of the NPP. 4. The NPP siting has induced substantial changes in interindustry (input-output) structures of the Wolsong unit-l site which is one of the rural areas where all the domestic NPPs are sited. Such changes are attributed to the industrial recomposition of the region. 5. With the application of other regional economic analysis models and the use of more sufficient regional data, other detailed studies on the economic impact analysis of domestic NPP-related facility sitings are suggested to be carried out further since the influence of NPP sitings is significant to the national economic impact as well as the regional economic impact.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.732-737
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• 2001

The mathematical method was developed and numerical analyses were carried out with various parameters to provide substantial data for optimal design and operation of urban utility systems. The composition of systems and their specifications, such as co-generation system, heat pump system, incineration system and other heating and cooling system could be obtained through these analyses for various resource and energy requirements in urban area. As results the system constituents and operating characteristics, and their economic performances such as the value of objective function, initial and an operating costs were discussed for various load patterns. The effective system design method and the excepted effects of the several unused energy recovery systems were also briefly discussed with the variation of the buildings and facilities species and their capacities.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.13-16
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• 1988

As the automic power plant is increased, load leveling energy storage system becomes more important. Pumped hydroelectric storage, used in the present, has too storage efficiency and difficulty in selecting site. But SMES(Superconducting Magnet Energy Storage) has high storage efficiency (90%), fast time response characteristics and ease of location. The general object of SMES with electric power system is the minimization overall production cost. This paper presents a method for the economic operation of SMES by Dynamic Programming.

• Journal of Agricultural Extension & Community Development
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• v.15 no.4
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• pp.577-597
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• 2008

The purpose of this study is to examine the effects of residents' perceptions of tourism impact and conflicts on residents' participation in rural tourism village. Method of analysis involves factor analysis and regression analysis in this study. In order to measure the level of perception, three factors(economic benefits, social benefits, social and environmental cost) are derived from the factor analysis. And also in order to measure the level of conflict, two factor(openness of information, leading of operation) are derive from the factor analysis. The result of regression analysis indicate that perceived economic benefits and social benefits are rather greater impacts on residents' participation than social and environmental cost, and also openness of information is rather greater impacts on residents' participation than leading of operation.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1088-1090
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• 1997

This paper presents an effective methodology of optimal environmental and economic operation using evolution strategy. In power systems, evolution strategy, based on natural selection and genetics, can analyze non-linear and discontinuous functions in global search techniques. The formulation using this search techniques is multi-objective function, which consists of fuel cost and environmental effects concerning the pollution of the Earth's atmosphere caused by the emission of $SO_2$ and $NO_x$ from thermal generator plants. The proposed algorithms are applied on system with 6 generator.

• Journal of the Korean Professional Engineers Association
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• v.30 no.5
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• pp.82-95
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• 1997

A Study of Improvement in Reactor Thermal Power Measurement Method using Kalman Filter. The objectives of the safety analysis of nuclear power plants are to maintain the surface temperature of fuel and fuel cladding within limit value in case of Loss of Coolant accident (LOCA) so that it ensures the safety and reliability of nuclear power plants. The new technique evaluating the reactor power and improvement of existing plant system increase the safety margin of nuclear power plant operation, and accordingly, economic effect will be anticipated. Hereby, 1 would like to introduce reactor power measurement method using Kalman filter that enables to calculate the reactor power more precisely combining the parameters, for example, turbine output as the 1 st stage pressure of high pressure turbine, and reactor power using energy equilibrium relation. It is expected that the new technique will enhance the accuracy of measurement of reactor power and maintain the reliability of nuclear power operation by increasing operational safety margin, and gain the economic benefit