• International Journal of Highway Engineering
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• v.18 no.5
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• pp.83-93
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• 2016

PURPOSES : The aim of this article is to compare and identify eco-friendly competitiveness between (regional) motorway and high-speed rail(HSR) from the perspective of $CO_2$ emission in the Republic of Korea. METHODS : In order for an analysis of low-carbon competitiveness between the two modes, $CO_2e$ emission, $CO_2eppk$ (equivalent $CO_2$ gram per passenger kilometer), is employed as a comparison index. As for HSR, the index is calculated based on the passenger transport data and the gross of $CO_2e$ produced by Kyungbu high-speed line in 2013. Additionally, the gross of $CO_2e$ is computed by the greenhouse gas emission factors of domestic electricity generation mix. Regarding the index of motorway, it is directly calculated using both the official $CO_2e$ emission factor and the passenger-car occupancy of motorway. RESULTS : The results revealed, in the case of inter-regional transport, that the $CO_2e$ emission of displacement-based cars is 54.9% less than that of HSR, as the domestic electric power systems heavily relies on the thermal power plants over 66%. Note that internal combustion engines commonly used for vehicles are more energy-efficient than steam-driven turbines usually utilized for thermal power generation. CONCLUSIONS : It can be seen, at the very least in our study, that HSR has no superiority over motorway in the case of $CO_2e$ emission under the situations of domestic electricity generation mix. In addition, advanced eco-friendly vehicles have strong advantages over HSR. Therefore, all-out efforts should be made to develop and harvest renewable energy sources in order to achieve low-carbon HSR, sparing fossil fuels.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.502-507
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• 2014

In this paper, performance characteristics of cycles were studied when mixed working fluid was used for ocean thermal energy conversion (OTEC). Among the various mixed refrigerants for industrial heat-pump, R32/R152a used in ocean thermal energy conversion system. For simulations, R32/R152a were used in existing closed cycle and Kalina cycle which is used only ammonia and water as mixed refrigerant. Temperature of the warm heat source was 26 and 29 celsius degree, temperature of the cold heat source was 5 celsius degree. In results of simulation, Gross power of the closed cycle on R32 was 22kW, and efficiency of the cycle was 2.02%. When the mixed refrigerant of R32/R152a, in the ratio of 90 to 10, gross power of the closed cycle was 29.93kW, and efficiency of the cycle was 2.78%. Gross power and cycle efficiency of R32/R152a increased by 36% and 37% than those of existing single refrigerant. Additionally, the same simulations were conducted in Kalina cycle with the same various composition ratio of mixed refrigerant.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.8
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• pp.380-389
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• 2000

This paper presents a method for the regional long-term load forecasting in metropolitan area considering econimic indicator with the assumption that energy demands propoprtionally increases under the economic indicators. For the accurate load forecasting, it is very important to scrutinize the correlation among the regional electric power demands, economic indicator and other characteristics because load forecasting results may vary depending on many different factors such as electric power demands, gross products, social trend and so on. Three steps for the regional long-term load forecasting are microscopically and macroscopically used for the regional long -term load forecasting in order to increase the accuracy and practicality of the results.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.65-72
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• 2018

This study analyzed the condition of marine accident and disaster rate of crew of Korean fishing vessels by vessel type, and checked the Australian safety management system and relevant regulation in Korea to suggest measures to build coastal/offshore fishing vessel safety management system in Korean coastal/offshore fishery. As a result, the power and production amount of Korean coastal/offshore fishing vessel is consistently decreasing while marine accident is increasing. Disaster rate of crew was higher than land industry, especially, the disaster rate of coastal/offshore fishing vessel was very high (100.0‰). Australia applies safety management system differed by vessel type and operation waters which fully considers the characteristics of pertinent vessel. The average accident rate of fishing vessels with gross tonnage over 20 tons among the Korean coastal/offshore fishing vessel was 13.6%, which was significantly higher than fishing vessels with gross tonnage below 20 tons (1.4%). Such result indicates it is urgent to implement safety management system to fishing vessel with gross tonnage over 20 tons and introduce fishing vessel safety supervisor. Establishing safety management system of coastal/offshore fishing vessel will contribute to consistent industrial development by achieving the general goal of reducing marine accident and spreading safety culture.

• Journal of Environmental Science International
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• v.15 no.7
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• pp.689-694
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• 2006

To examine inshore radioactive contamination caused by nuclear power plants, nuclear testing, hospital and laboratory, both gross ${\beta}$-radioactivity and ${\upsilon}$-spectrometry were measured. The measurements were taken with the Abalone and Top shell, which had been collected from the four different sites at the coast in Jeju-do (Seongsan, Deajeong, Wimi, Dodu). The activity ranges of concentration were respectively 0.11-0.29 Bq/kg-wet for $^{90}Sr$, 0.01-0.04 Bq/kg-wet for $^{137}Cs$, 36 - 53 Bq/kg-wet for $^{40}K$ in shellfish on the Jeju island. The radioactivities of $^{90}Sr$, $^{137}Cs$ and $^{40}K$ were similar to those in sampling location of shellfish in the coastal on the Jeju island. The radioactivity of $^{90}Sr$ for the Abalone was lower level than that for Top shell. The radio- activity of $^{137}Cs$ for the Abalone was similar to that for the Top shell. But the radioactivity of $^{40}K$ for the Abalone was higher level than that for the Top shell. As a result, the gross ${\beta}$-radioactivity observed was similar to that in nature. Among radionuclides, only $^{90}Sr$, $^{137}Cs$ and $^{40}K$ were detected in a very small amount, and each was also close to the natural levels.

• The Korean Journal of Pain
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• v.34 no.1
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• pp.82-93
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• 2021

Background: This study used bibliometric analysis of articles published about the topic of regional anesthesia from 1980-2019 with the aim of determining which countries, organizations, and authors were effective, engaged in international cooperation, and had the most cited articles and journals. Methods: All articles published from 1980-2019 included in the Web of Science database and found using the keywords regional anesthesia/anaesthesia, spinal anesthesia/anaesthesia, epidural anesthesia/anaesthesia, neuraxial anesthesia/anaesthesia, combined spinal-epidural, and peripheral nerve block in the title section had bibliometric analysis performed. Correlations between the number of publications from a country with gross domestic product (GDP), gross domestic product (at purchasing power parity) per capita (GDP PPP), and human development index (HDI) values were investigated with the Spearman correlation coefficient. The number of articles that will be published in the future was estimated with linear regression analysis. Results: Literature screening found 11,156 publications. Of these publications, 6,452 were articles. The top 4 countries producing articles were United States of America (n = 1,583), Germany (585), United Kingdom (510), and Turkey (386). There was a significant positive correlation found between the GDP, GDP PPP, and HDI markers for global countries with publication productivity (r = 0.644, P < 0.001; r = 0.623, P < 0.001, r = 0.542, P < 0.001). The most productive organizations were Harvard University and the University of Toronto. Conclusions: This comprehensive study presenting a holistic summary and evaluation of 6,452 articles about this topic may direct anesthesiologists, doctors, academics, and students interested in this topic.

• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.124-130
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• 2010

Ocean Thermal Energy Conversion(OTEC) power plants have been examined as a viable option for supplying clean energy. This paper evaluated the thermodynamic performance of the OTEC Power system for the production of electric power and desalinated water. The results show that newly developed fluids such as R32, R125, R143a, and R410A that do not cause stratospheric ozone layer depletion perform as well as R22 and ammonia. Overall cycle efficiency of open cycle is the lowest value of 3.01% because about 10% of the gross power is used for pumping out non-condensable gas. Also, the hybrid cycle is an attempt to combine the best features and avoid the worst features of the open and closed cycles. The overall cycle efficiency of hybrid cycle is 3.44% and the amount of desalinated water is 0.0619 kg/s.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.2
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• pp.42-47
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• 2014

The urban railway station is a structure that consumes a large amount of electric energy. Thus, the rationalization of using electric power is acutely demanded, but statistical data and design criteria that consider operating power load characteristics and structures, are very insufficiency. Therefore, this study investigated and analyzed that electricity consumption a year, characteristics, gross floor area of the station, structure, and etc, on the basis of Seoul metro station 1~4 line. Through regression analysis theory, we verified the overall features and the main tendency by analysis of specific parameter value(average, maximum, minimum, etc). The object of this study is the analysis about power density considering structure of the urban railway station, managing electric energy for the rationalization and setting a new standard of maintenance and construction.

• Korean Management Science Review
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• v.32 no.2
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• pp.37-50
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• 2015

The number of contracts for bundling services in a domestic telecommunication market records 1.3 miilion as of the first half year in 2007, and steadily increased to 8.97 million in 2010, to 12.76 million in 2013. In 2014, 70.4% of telecommunication service consumers are found to subscribe to bundling service. Bundling services provide consumers with benefits such as price discount, convenience, increase ARPU. However, a market dominant player in a specific market may transfer its market power to another market by selling bundling services. SSNIP has been adopted to provide a market definition. However, SSNIP is not suitable to measure the effect of market power transition through bundling services because SSNIP cannot measure the effect of changeover sales of bundling services. Thus, in this study, we have investigated the effect of market power transition through bundling services reflecting market power effect and quality upgrade using Gross Upward Market Power Pressure Index metho and reviewed UPP and derivative UPP models.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.363-371
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• 2019

Thousands of demersal fishes inhabit in the waters around Korea and most of them are overexploited. One of reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the Danish seine fishery from 1960s to 2010s. Gross tonnage was decreased stably, but the horse power was increased annually. The length of ground rope, warp and hand rope was somewhat longer, but changed a little. Color fish finder was utilized from the mid-1960s and positioning system was used five years later. A hydraulic line hauler were introduced in the mid-1980s, and supply rate was gradually increased. Surveys on the supply and upgrading of fishing equipment utilized visiting researchers. Therefore, the relative fishing power index in the Danish seine fishery increased stably from 1.0 in 1970 to 1.0 in 1980, to 1.2 in 1990, to 1.3 in 2000 and to 1.3 in 2010. The results are expected to contribute to reasonable fisheries stock management.