• Economic and Environmental Geology
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• v.32 no.6
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• pp.575-584
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• 1999

Through alkaline hydrothermal activation processes, zeolite minerals were synthesized from fly ashes produced at Youngwol and Boryoung power plants. The syntheses were performed in a closed teflon vessel with a teflon-coated magnetic bar for continuous stirring during the reaction periods. The experiments were caeeied out at three different reaction temperatures ($100^{\circ}C$,$200^{\circ}C$, and $250^{\circ}C$), with varying NaOH concentations (0.5~8N) and reaction time (24 to 288 hours). Mineralogical characterization of the reaction products indicated that Na-p1, analcime, and hydroxysodalite were dominant zeolites formed from the both fly ashes at the given experimental conditions, The highest amount of zoelites produced from the Youngwol and Boryoung fly ash were:60 and 45wt%for Na-P1, 70 and 45wt% for analicime, 50 and 40wt% for hydroxysodalite, respectively. A small amount of zeolite A was present in NaP-dominant dample is about 250 meq/100g. This suggests the possibility of its utilization as an ion-absorbent.

• Journal of Advanced Marine Engineering and Technology
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• v.7 no.1
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• pp.40-48
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• 1983

Nowadays electromagnetic contactors are used for power on-off in various electrical loads. If the severe arc are occurred when power off, the magnetic contactor can not long run because of damage of contactor. In this paper, Authors indicate a method of how to minimize the arc when power off, Authors contrived a electronic circuit which can adjust the demagnetizing point of electro magnetic contactor, and control the demagnetizing point, utilizing our circuit, so as to occur the extinguish of arc at near the AC current zero point which is indispensibly exists. From the results of study, Authors could get confirmations the AC circuit could cut off with occurrence of mininum arc, and that possibility of extensive utilization of our method to hightension circuit.

• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.32-37
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• 2019

In this paper, we have designed a solar photovoltaic system to attach solar photovoltaic modules to each module and develop the best efficiency in each module. The efficiency of the designed solar panel optimizer was more than 99.27% and MPPT efficiency of 99.66%. In addition, the monitoring of power generation and abnormal operation phenomenon in each optimum period and tracking for failure location of specific photovoltaic module have improved the utilization rate of photovoltaic power generation. Wired and wireless communication methods has been proposed to monitor the power generation and operation status of the solar panel optimizer. For this purpose, the RS485 communication was used for wire communication and Zigbee communication was used for wireless communication to monitor the status of each module in real time. It is shown that communication redundancy can be achieved through the proposed method, and the possibility of commercialization is suggested.

• Journal of the Korea Society of Computer and Information
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• v.24 no.6
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• pp.151-158
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• 2019

In this paper, we analyzed the relationship between employment stability, wage level, welfare system, working condition, job satisfaction and organizational commitment in order to find out ways to develop and competitiveness of the nano-convergence industries. Through this study, we conducted the possibility of deriving organizational commitment by job satisfaction which is given through employment stability, wage level, welfare system, and working condition for continuing their work life. In order to find relationships between each concepts, we used a multiple regression analysis with job satisfaction and commitment as dependent variable and employment stability, wage level, welfare system, and working condition as independent variables. Through this study, it was expected to increase the organizational commitment through the job satisfaction of the employees if a changing method of employees management is centered on some tasks suggested for the sound working condition and efficient utilization policies.

• Journal of Engineering Education Research
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• v.23 no.6
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• pp.51-59
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• 2020

ABEEK's professional liberal arts education reflecting critical thinking, has been well received by professors and students in the engineering discipline. Also, the demand for further utilization of critical thinking within the engineering curriculum is increasing. To meet such demand, there is a need for experts in the area of critical thinking education and engineering education to come together and search for the most effective method in using critical thinking in engineering design education courses. In this paper, we were able to confirm, through specific application cases, that the problem-solving process of critical thinking can be effectively transferred to an engineering design process, and the elements and criteria of critical thinking can be used as a successful design tool. Also, we explore the possibility of further improving engineering education on the basis of critical thinking.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.151-152
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• 2020

There is a possibility of failure as a result of field application in the planning and execution process to change the operating policy for operating terminals, so a lot of time and effort are required to reduce trial and error. In the planning stage to change the terminal operation policy, simulation technology can be used to support decision making. This study introduces a case of using a virtual terminal system among simulation technologies.

• Korea Trade Review
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• v.46 no.4
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• pp.219-234
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• 2021

Armington elasticity has been a methodology for analyzing how much imports could increase in response to importing price cuts, assuming the possibility of incomplete substitution of domestic and imported products. This study calculates Armington elasticity values in Korean fisheries sector and presents an analysis method for classifying items based on price and preference differences. The model is modified reflecting the characteristics of the fisheries market along with the typical OLS, PAM, and ECM models. The result's implication is that products with a high import growth rate do not necessarily show a high Armington value, but it could be seen that price is not the only factor facilitating fisheries imports increase. Considering the items of which demand increases due to importing price cuts have an indiscriminate demand between domestic and imported products, the results could be interpreted that the Korean fisheries importing market has been easily affected by the changes in import prices. Fisheries grouping by price and preference demonstrates that explanatory variables other than price should be considered when estimating import demand.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.201-208
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• 2011

Today's highly competitive construction scenario forces all the major players in the field to take up multiple projects which have put an undue pressure on the resources available within the organization. Under such a situation, there are many instances where in the resource requirement exceeds its availability due to multiple activities (with same resource requirement) which are scheduled to start simultaneously and thus results in the constrained resource becoming a bottleneck of the project. As a consequence of sharing resources, this paper studies the impact on the completion date of two similar projects under two different conditions, the first one resulting in a postponed end date and the second without any postponement. The resource utilization, the possibility of substitution of a resource and its subsequent impact on the deadline of the project is analyzed under these two circumstances. The study is done on a Critical Chain Project Management (CCPM) platform instead of leaving the schedule with a traditional Critical Path Method (CPM) finish, which gives an added advantage of validating the robustness of the emerging CCPM trend in the field of resource management.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.11-22
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• 2005

It is necessary to arrange and analyze the collected research date to get regularity such as characteristics, merits and demerits, and possibility in city when constructing land information by analyzing linkage and utilization of cadastral information as the fundamental data for land information around the acreage of a lot and by expressing the purpose of each digital data construction with map. In short, that is the work to classify data, to make chart or map, or to analyze using statistical technique. Some information in land utilization had been used by computerization, but several problems were found in common use of total divisions. The most important problem is, in the case of drawing information, that topographical map with building boundary and land registration map with acreage boundary cannot be used together. In the case of property information, common utilization of property information that is basically needed and standard measurement of usage classification are necessary. The characteristics of the land usage data by the rearrangement of the cadastral information. etc. is presented as the basic data for the land information orientation, and the analyzing result of the data should be expressed and controlled on the map as the fundamental survey for the establishment of the land information oriented planning supports the physical space planning of the land cadaster finally. In this research, the problem in establishing current land information around acreage of a lot was found to research data to be needed in land information for utilizationof space based digital information, and was studied the method in relation to GIS.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.701-706
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• 2004

The objective of this experiment was to compare the dry matter intake, nutrients digestibility and nitrogen and energy utilization of herbages harvested from turf type mixtures {tall fescue(Rebell Jr.) 40%+ perennial ryegrass(Palmer II) 20%+ Kentucky bluegrass(Newport) 10%+ redtop(Banicuda) 10%+ red fescue(Salem) 10%+ creeping bentgrass(Crenshaw) 10%} and tall type mixtures {orchardgrass(Potomac) 40%+ tall fescue(Fawn) 20%+ Festuloium braunii(Paulita) 10%+ perennial ryegrass(Reveille) 10%+ timothy(Climax) 10%+ red clover(Kenblue) 10%+ alfalfa(Vernal) 10%} by Korean native goats. This experiment was conducted by total collection method in laboratory, 2001. The voluntary DM intake per body weight were slightly higher for turf type mixtures(28.9g) than that of tall type mixtures(26.2g), but there was no significant difference. The digestibility of cellular constituents was slightly higher for turf type mixtures than that of tall type mixtures(p<0.05), but digestibility of DM, NDF and ADF did not differ between two mixtures. The retained nitrogen percent(apparently biological value) was slightly higher for turf type mixtures(56.7%) than that of tall type mixtures(56.4%), but there was no significant difference between two mixtures. Apparently retained digestible energy was slightly higher for turf type mixtures(58.3%) than that of tall type mixtures(57.9%), but there was no significant difference between two mixtures. Based on the results, the herbage utilization by Korean native goats did not showed any significant difference between two mixtures, therefore there is a possibility that herbages of turf type mixtures can be used as a roughages by livestock.