• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.582-588
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• 2014

IMO and IALA have undertaken projects that GMDSS Modernization and E-navigation, which refer to "Future digital communications systems" for a more efficient transmission of voice and data communications in the VHF maritime mobile service. ITU has also resolved in WRC-07 Resolution 357 to study the use of spectrum-efficient technologies in order to provide for the operation of ship and port security and maritime safety systems. IALA and ITU WP5B have coordinated for the technical developments and the spectrum issues. Recommendation ITU-R M.1842-1 has approved by WP5B meeting. This revision provides a wideband data service both 50kHz and 100kHz in the VHF maritime mobile service. This paper has studied E-navigation, its needs for data exchange that includes explanations of the current methods for transmitting data by VHF that based in land mobile radio service. A further technologies trend is estimated for Recommendation ITU-R M.1842-1, that is based on the land mobile radio standards with some tailored to fit the needs of the maritime mobile service.

• 대한공업교육학회지
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• v.36 no.2
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• pp.111-130
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• 2011

The purpose of this study was to identify a causal relationship among commitment to change, needs of technology education innovation, communication and self-efficacy of technology teachers. A total of 300 copies of questionnaires were used for data analysis except for 117 copies like the one where insincerely responds to any question was found. To ensure the reliability and validity of questions, I performed technical statistics like average, standard deviation, skewness, and kurtosis via PASW 18.0, item-total correlation and the totality, and reliability analysis. I undertook a confirmatory factor analysis via AMOS 7.0 to ensure the validity of items together with a structural analysis to perform a path analysis among variables and assess the suitability of model. The major finding of this study were as follows: First, because fit index of hypothetical model generally met standards in this study, a hypothetical model was judged appropriately. Second, needs of technology education innovation had a positive effect on communication and commitment to change of technology teachers. And, communication among technology teachers had a positive effect on commitment to change of technology teachers. This result means that communication among technology teachers is important to activation of technology education. Third, self-efficacy had a positive effect on commitment to change of technology teachers. This result means that it needs to raise self-efficacy level through teacher education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6167-6175
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• 2012

This study is experimental analysis to verify heating efficiency of Ondol in floor heating panel developed. For this one, an experiment tests producing an each test speciment and measuring heating efficiency. The result of an experiment, supplying hot water temperature is $45^{\circ}C$ and the result of measuring on parts temperature of test speciment on supplying for 8 hours, mortar surface that is superstructure plumbing of heating system developed is $49.4^{\circ}C$, the gap of piping on center of mortar surface is $44.1^{\circ}C$ and airspace is proved $25.3^{\circ}C$. In floor structure of standards, mortar surface is $46.2^{\circ}C$, the gap of piping on center of mortar surface $37.7^{\circ}C$ and airspace is $24.7^{\circ}C$. On the other hand, energy consumption accumulating of development technology is identified, in case of hot-water supply on $45^{\circ}C$ as 4,646 kcal and in existing technology, as 4,814 kcal. developing technology is verified and lower than existing technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.600-608
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• 2017

This study analyzed the management index, debt ratio, and business performance of livestock agricultural farming corporations since the Korea international financial reporting standards (K-IFRS) was introduced in 2011. In addition, this study was based on credible accounting reports by the financial supervisory service's DART (data analysis, retrieval and transfer) system. First, after analyzing the key management index, the results showed that the current ratio, debt ratio, and current liabilities ratio decreased and the ratio of the owners increased on the safety index. Regarding the profitability index, the ROA (return on total assets), ROE (return on equity), and ROS (return on sales) increased slightly in 2014 compared to 2013. The overall growth and external growth on the growth index have not increased. Second, an analysis of the debt ratio and business performance, the debt ratio has a negative effect on the ROA and ROS. These results show that the use of debt of livestock agricultural farming corporations contributes to the external growth but it has a negative effect on business performance. These results show that management should consider solutions for the increase in sales to achieve cost reductions. In addition, the debt ratio should be reduced and solutions for an increase in revenue are needed to reduce management expenses, such as propagation of technical development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.738-744
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• 2017

Recently, the installation of energy storage systems (ESSs) has increased in parallel with the extension of renewable energy resources. However, there has been no concrete analysis ofthe performance verification and economic evaluation of ESSs,which makes it difficult to perform aneffective installation and operation of an ESS. In particular, there are no international technical standards and guidelines on electric ESS for frequency regulation applications. Therefore, acomprehensive study on the power quality, impact on grid, extent of contribution, and cost benefit study of ESS are strongly being required. Under these backgrounds, this paper proposes a performance verification algorithm on ESS for frequency regulation application based on ananalysis of the AGC(Automatic Generation Control) performance verification method of PJM in USA. In addition,this paper proposes an economic evaluation algorithm on a 500 MW installation of ESS for frequency regulation applications using the account settlement of an expensive gas-fired generation plant and coal-fired power generation plant. From the simulation with real ESS operation data and 500 MW installation case, it wasconfirmed that the ESS showssuperior performance toany other conventional generators and provides anannual benefit of 500 MW ESS are between 345~429 billon won.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.723-737
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• 2017

In order to decide the national technical standards policy for national policy/market economy activities, the people in charge commonly make policy decisions based on the current technology level/concentration/utilization by means of major common technology field analysis using patent data. One possible source of such patent data is the domestic mobile carriers through the Korea Intellectual Property Rights Information System (KIPRIS) of the Korean Intellectual Property Office (KIPO). Using this system, we collected 20,294 patents and 152 International Patent Classification (IPC) types and confirmed KTs (9,738 cases / 47.98%), which perform relatively high technology retention activities compared to other mobile carriers through the KIPRIS of KIPO. Based on these data, we performed three analyses (SNA, PCA, ARIMA) and extracted 30 IPC types from the SNA and 4 IPC types from the PCA. Based on the above analysis results, we confirmed that 4 IPC (H04W, H04B, G06Q, H04L) types are the major common technology field of the domestic mobile carriers. Finally, the number of 4 IPC (H04W, H04B, G06Q, H04L) forecast averages of the ARIMA forecast result is lower than the number of existing time series patent data averages.

• Resources Recycling
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• v.27 no.1
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• pp.14-21
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• 2018

The rapid increase in the consumption of products that contain rare metals has highlighted the importance of recycling and recovering resources from these products when they enter the waste stream. Among various metal resources that can be recovered, this study analyzes the waste streams of cobalt and palladium to determine how their waste resource circulation can be improved at each stage of the waste stream. The findings of this study point to improvements and strategies that can be made at individual stages. First, at the discharge/import stage, the implementation of tariff quotas for specific recycled metal resources is suggested to allow the systemic categorization of waste metals as resources. At the collection/discarding stage, a major problem is the instability in the supply of scrap metals, which may be better managed by changing the bidding process for the scrap metals. At the pretreatment stage, possible areas for improvement are uncovered concerning technical areas, such as technological development and improving the efficiency of material recycling, as well as policy-wise, for instance, expanding the regulation for manufacturers to produce products that are designed to facilitate resource recovery, increasing incentive for closed recycling, and refining the guidelines and standards for recycling. At the resource recovery stage, as the waste metal recycling industry consists of businesses that vary in size, policies to promote cooperation and coexistence between large and smaller enterprises will benefit the industry in the long-run. Lastly, at the product production/export stage, a tariff on exporting waste resources that contain cobalt and palladium will help control the amount of waste metals that are shipped abroad.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.207-214
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• 2017

High voltage electric power transmitter GIS(Gas Insulated Switchgear) above 72.5kV needs to satisfy domestic Korean peninsular standard(ES-6110-0002) in KEPCO with respect to normal and special operation conditions which include internal gas pressure, dead weight, wind and seismic load. Some other requirements not described in Korean standard can be applied from other international standards such as IEC(International Electronical Committee) 62271-203 and 62271-207. The GIS is a kind of pressure vessel structure made of aluminum and filled with SF6 gas of internal pressure 0.4~0.5MPa. Finite element analysis of GIS is performed with such operational loads including seismic loading and the stability and reliability is determined according to ASME BPVC(Boiler and Pressure Vessel Code) SEC. VIII standard where the allowable stress level of the pressure vessel is suggested. The result shows that the stress of GIS is satisfied the allowable stress level and the safety factor is about 2.3 for Korean peninsular standard.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.313-327
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• 1996

As an at-reactor(AR) storage method o( spent fuel, there are horizontal concrete module type, metal storage cask type, concrete storage cask type, dual purpose (transportation and storage) cask type and multi-purpose (transportation, storage and disposal) cask type. All other types except multi-purpose one have been already used for AR dry storage of spent fuels after obtaining operation license in various foreign countries. Also the development of multi-purpose type has been continued for operation license. In America, Japan, Germany, Canada, Spain, Switzerland, and Czech Republic, etc., AR dry storage facilities are under operation or on propulsion, and spent fuels are transported to interim storage facility or reprocessing plant after dry storage at reactor temporarily. At Wolsung site, in case of Korea, concrete silo type has already been introduced, and it is believed to be inevitable to store spent fuels at reactor temporarily, considering the reality that storage capacity of spent fuel is approaching to the limit in some nuclear power plants. In this report, the system characteristics, design requirements, technical standards and status of AR storage system, which is suitable for domestic site such as Kori, have been studied. In most cases, the licensed period of storage cask is limited up to 20 years and the integrity of material and maintenance of leaktightness are required during the whole service life.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.4
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• pp.384-392
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• 2013

Objective: This study inspected incident cases, legal control levels, and GHS(Globally Harmonized System of Classification and Labeling of Chemicals) classification results of strong acids such as hydrogen fluoride, hydrogen chloride, nitric acid, and sulfuric acid, which have been responsible for many recent chemical accidents. As a result, it is deemed necessary for legal control levels of these strong acids to be revised and GHS classification be managed nation-wide. Methods: This study inspected incident cases and legal control levels for strong acids such as hydrogen fluoride, hydrogen chloride, nitric acid, and sulfuric acid. The study analyzed and compared chemical information status and GHS classification results. Results: There were 76 domestic incidents involving strongly acidic hazardous materials over the five years between 2007 and 2011. They include 37 leakage incidents(46.7%) within a workplace, 30 leakage incidents(39.5%) during transportation, and nine leakage incidents(13.8%) following an explosion. The strongly acidic materials in question are defined and controlled as toxic chemicals according to the classes of Substances Requiring Preparation for Accidents, Managed Hazardous Substance, Hazardous Chemical(corrosive) as set forth under the Enforcement Decree of the Toxic Chemicals Control Act and Rules on Occupational Safety and Health Standards of Occupational Safety and Health Act. Among them, nitric acid is solely controlled as a class 6 hazardous material, oxidizing liquid, under the Hazardous Chemicals Control Act. The classification results of the EU ECHA(European Chemicals Agency) CLP(Commission Regulation(EC) No. 790/2009 of 10 August 2009, for the purposes of its adaptation to technical and scientific progress, Regulation(EC) No 1272/2008 of the European Parliament and of the Council on classification, labeling and packaging of substances and mixtures) and NIER (National Institute of Environmental Research) are almost identical for the three chemicals, with the exception of sulfuric acid. Much of the classification information of NITE (National Institute of Technology and Evaluation) and KOSHA(Korea Occupational Safety and Health Agency, KOSHA) is the same. NIER provides 12(41.4%) out of 29 classifications, as does KOSHA.