• Membrane Journal
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• v.30 no.6
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• pp.395-408
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• 2020

Polymer electrolyte membrane fuel cells (PEMFCs) have gained much attention as eco-friendly energy conversion devices without emission of environmental pollutant. Polymer electrolyte membrane (PEM) that can transfer proton from anode to cathode and also prevent fuel cross-over has been regarded as a key component of PEMFCs. Although perfluorinated polymer membranes such as Nafion® were already commercialized in PEMFCs, their high cost and toxic byproduct generated by degradation have still limited the wide spread of PEMFCs. To overcome these issues, development of hydrocarbon based PEMs have been studied. Incorporation of cross-linked structure into the hydrocarbon based PEM system has been reported to fabricate the PEMs showing both high proton conductivity and outstanding physicochemical stability. This study focused on the various cross-linking strategies to the preparation of cross-linked PEMs based on hydrocarbon polymers with ion conducting groups for application in PEMFCs.

• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.341-352
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• 2008

The dedicated line linked up with the internet maintains generally the efficiency of network by using Best Effort Model. But it is the problem that we allocate the higher bandwidth to services which request high bandwidth regardless of service types or purposes. To overcome this weak point, we use the Session QoS System which distinguish between business services such as E-mail, Web, etc. and non-business services. But, a recent session QoS system is not adequate to the environment similar to university, because that has many users who have various requests. In this paper, to satisfy various requirements of many user's in session QoS system which support services of research, education, business, etc., we analyze types of service in the environment of education and research network and propose a necessity of management strategies of session Qos system.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1184-1187
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• 1996

A simple and rapid detection system for $aflatoxin\;M_1\;(AFM_1)$ in cow's milk by an enzyme-linked immunosorbent assay (ELISA) was developed. Specific antibodies against $AFM_1$, conjugated to bovine serum albumin $(AFM_1-BSA)$ were raised in rabbits and purified. The cross-reactivities of the antibodies against aflatoxin analogs were less than 29.9%. When a competitive direct ELISA (cdELISA) for $AFM_1$, established by use of the antibodies was applied to the spike test of $AFM_1$ onto uncontaminated cow's milk, the assay recovery was unstable unless cow's milk was diluted to 40% (2:3) with phosphate buffered saline (PBS). In that condition of sample dilution, the mean ELISA recovery of $AFM_1$, from the cow's milk was 113% (coefficient of variation (CV) of each recovery percentage, 8.2%) in the range of $0.3{\sim}3.0\;ppb$. These results showed that the ELISA system could be a convenient tool to monitor the contamination of AFM1 more than 0.5 ppb in cow's milk (FDA allowance limit) easily.

• Journal of Korean Society on Water Environment
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• v.33 no.2
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• pp.219-229
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• 2017

A watershed-river linked modeling system was developed to forecast the water quality, particularly weekly changes in chlorophyll-a concentration, of the Yeongsan River, Korea. Hydrological Simulation Program-Fortran (HSPF) and Environmental Fluid Dynamics Code (EFDC) were adopted as the basic model framework. In this study, the EFDC model was modified to effectively simulate the operational condition and flow of multi-functional weirs constructed in the main channel of rivers. The model was tested against hydrologic, water quality and algal data collected at the right upstream sites of two weirs in 2014. The mean absolute errors (MAEs) of the model calibration on the annual variations of river stage, TN, TP, and algal concentration are 0.03 ~ 0.10 m, 0.65 ~ 0.67 mg/L, 0.03 ~ 0.04 mg/L, and $9.7{\sim}10.8mg/m^3$, respectively. On the other hand, the MAE values of forecasting results for chlorophyll-a level at the same sites in 2015 range from 18.7 to $22.4mg/m^3$, which are higher than those of model calibration. The increased errors in forecasting are mainly attributed to the higher uncertainties of weather forecasting data compared to the observed data used in model calibration.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.381-396
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• 2023

Purpose - The purpose of this study was to analyze environmental and labor issues and related norms, which are new trade issues that are expanding in bilateral and multilateral trade agreements, and examine the possible impact of these norms on domestic fisheries policies. Design/methodology/approach - In this study, literature research was used as the main research methods. The comparative analysis of international norms and multilateral trade agreements texts related to the environment, labor and trade were conducted. Findings - The new trade norms in the fisheries sector can be represented by labor and environment issues. Since domestic environmental and labor standards do not fully meet the standards of the multilateral trade agreements, it is necessary to ensure that domestic norms are supplemented and relevant policies are newly established through a review of international law on environment and labor. Research implications or Originality - This study confirmed that international norms related to labor and environment in the fisheries sector are mixed with soft norms and binding norms, and each norm is linked in a multi-layered and mutual way. Such international norms are being strengthened in connection with trade agreements and issues.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.581-590
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• 2022

It is important to create a decent pedestrian space in order to realize a public space that can ultimately improve the quality of life based on guaranteeing people's right to move while also enhancing urban activity. The goal of this study is to develop a pedestrian path evaluation system in order to lay the foundation for data construction leading to the creation of such elegant walking space. First, a basic system was established in keeping with factors and the space, and this system was used as the basic framework of the study. The trends identified in the literature can be divided into eight categories, denoted here as: Walking safety policy, Walking focused plan, Recognition transition, Transportaion system, Activity-linked walking, Facility utilization walking, Nature and history linked walking and Content convergence walking. The macro- and micro-indices and factors mentioned in related studies were synthesized and classified, and the basis for universality and differentiation was established by integrating them. Next, according to the basic composition of the walking system, Walking potential and slope safety in the Safety category, Basic walking connectivity and Traffic linkage in the Efficiency category, Walking arrangement and Rest convenience in the Health category, and Resource connectivity and Activity abundance in the Comfortability category macro evaluation system of the eight categories were established and a corresponding measurement method was developed.

• Journal of Science Education
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• v.32 no.1
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• pp.61-72
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• 2008

The purpose of the study is to research students' proficiency with systems-thinking approach concerning water cycles and to acquire data on Earth System-related concepts based on students' feedback. To achieve the purpose of the study, I chose 4 mid-level high school juniors living in Pohang, where the high school equalization policy has not been implemented, and the students answered a questionnaire about water cycles. Then, based on the results, I created a causal map and evaluated it using systems-thinking analysis. The results of the study are as follows: First of all, among the answers of the subjects, there were 21 concepts related to the conception of the earth system : 14 of the conceptions were linked scientifically, and 7 of the conceptions were not linked scientifically. Secondly, results of the causal map of what the subjects described showed that only two students'(A and C) feedback loops were completed, and that student C's feedback loop included unscientific reasoning. In conclusion, this study indicated that the students failed to understand the water cycle with the systems-thinking approach, or alternatively they applied low-level systems-thinking approach and had a lower understanding of it.

• Korean Educational Research Journal
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• v.37 no.1
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• pp.1-18
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• 2016

'The Training for School Organization Management' is a essential teacher training system in order to develop qualification and ability of teachers who have to be the flexible to the recent changeable society. The concept which the school management issue is only belong to the principle is changed now. The thought that 'the school as a team' is broadly accepted. As a result, every teachers including the parents, community people are thinking the solution about the management issues of the school. The changes in the framework of these thoughts is from the recognition that the school management is no longer the preservation only to the manager such as the principle. 'the school linked to the community', 'the school which information is open to all public', the school which is thinking about the curriculum' are highlighted as an alternative which can solve the current education issue. The new curriculum of 'The Training for School Organization Management' is necessary to be in accordance to the new school curriculum because we have to run a new school system in the complex educational circumstance.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.308-309
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• 2022

The Ministry of Oceans and Fisheries is providing maritime safety services using combine limited artificial intelligence technologies through the operation of the Korean e-Navigation service, and research is needed to improve reliability and quality to secure the competitiveness of the system. However, linking real-time operating systems requires a separate system configuration that can be linked after processing personal information security with minimal performance impact. To solve this problem, this study will make a basic design of a big-data maritime information gateway system of the Korean e-Navigation service that minimizes the impact of performance and reflects the security of personal information.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.31-36
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• 2020

This research study designed a location image collecting technology. It provides the exact location information of an image which is not given in the photo to the user. Deep learning technology analysis and collects the images. The purpose of this service system is to provide the exact place name, location and the various information of the place such as nearby recommended attractions when the user upload the image photo to the service system. Suggested system has a deep learning model that has a size of 25.3MB, and the model repeats the learning process 50 times with a total of 15,266 data, performing 93.75% of the final accuracy. This system can also be linked with various services potentially for further development.