• Journal of Engineering Education Research
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• v.11 no.1
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• pp.24-33
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• 2008

The purpose of the study was to analyze system of accreditation for mechanical engineering education between A university in Korea and M university in U.S.A. which were evaluated in 2007 under EC2000. Literature review through self-study report and homepage of two programs was used to accomplish objectives of the study. Strengths of U.S.A for accreditation evaluation system were systematic curriculum operation, design education with cooperation system, course-based evaluation system for program outcome, supportive circumstances for research of faculty and guidance to students. On the other hands, strengths of Korea were likely to use quantitative data for educational improvement and were able to systematic guide to students with portfolio. In the future, plan and research for design education, curriculum operation and program outcome evaluation are needed to establish ABEEK evaluation.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.3
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• pp.205-216
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• 2017

Carbonaceous aerosols such as the equivalent black carbon (eBC), the elemental carbon (EC) and the organic carbon (OC) were monitored at the Seoul Olympic Park site ($37.521^{\circ}N$, $127.124^{\circ}E$) during the KORUS-AQ 2016 campaign using a Multi Angle Absorption Photometer (MAAP) and an OCEC Analyzer. Averaged mass concentrations of eBC, EC and OC were presented as $2.46{\pm}1.52{\mu}g/m^3$, $1.01{\pm}0.60{\mu}g/m^3$ and $4.85{\pm}2.60{\mu}g/m^3$, respectively. OC/EC ratio and mass absorption cross-section (MAC) of light absorbing aerosols were calculated as 2.32 and $14.8m^2/g$, respectively. Diesel OC concentrations were estimated from a source profile of diesel vehicles as well. eBC mass concentrations measured from May $26^{th}$ to May $27^{th}$, 2016 showed 40% higher than averaged eBC mass concentrations during campaign period. $PM_{2.5}$ concentrations measured in this period were also higher than average $PM_{2.5}$ concentrations. High eBC concentrations were observed from May $29^{th}$ to May $31^{st}$, 2016 and from June $9^{th}$ to June $11^{th}$, 2016, possibly due to morning rush hour and the effect of temperature inversion at night. Diurnal variations of eBC, EC and Diesel OC showed a typical pattern of metropolitan area. In the weekend, however, diurnal variations of eBC, EC and Diesel OC mass concentrations were different from those measured in the weekday. It is expected that this study can help to understand the relationship between carbonaceous aerosols in a metropolitan area.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.3
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• pp.256-266
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• 2012

The purpose of this study is to use DARTs (Directed Activities Related to text) to foster inquiry problems while actively engaging accelerated gifted elementary students in the field of earth sciences. This study is continually evolving in the classroom on the proposition that accelerate the scientific thought whether inquiry problems show any change according to the extent of prior background knowledge through DARTs. Researchers appointed the accelerated gifted elementary students with 14 investigation problems and it was their duty to not only classify the inquiry problems, but to analyze using interviewing methods according to type classification framework. Many scientific terms were used concretely in the inquiry problems that were propose after DART. The students gave a direct effect to the inquiry problem to be proposed according to the level of the content that it is presented in the DARTs worksheet. As a result, the NP-IP type and the EC-IP, NC-IP inquiry problem type proposed above much as a whole in DARTs former and prior. Particularly, the EMC-IP type and etc. was variously proposed after the DARTs. And the students proposing the inquiry problem of above average proposed the inquiry problem of the EP-IP type much unlike the general average student after the DARTs. The EC-IP, NC-IP and NF-IP type were changed much after DARTs used. Particularly, the EC-IP and NC-IP type were changed much.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.4
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• pp.1147-1161
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• 2023

The Internet of Things (IoT) requires a new processing model that will allow scalability in cloud computing while reducing time delay caused by data transmission within a network. Such a model can be achieved by using resources that are closer to the user, i.e., by relying on edge computing (EC). The amount of IoT data also grows with an increase in the number of IoT devices. However, building such a flexible model within a heterogeneous environment is difficult in terms of resources. Moreover, the increasing demand for IoT services necessitates shortening time delay and response time by achieving effective load balancing. IoT devices are expected to generate huge amounts of data within a short amount of time. They will be dynamically deployed, and IoT services will be provided to EC devices or cloud servers to minimize resource costs while meeting the latency and quality of service (QoS) constraints of IoT applications when IoT devices are at the endpoint. EC is an emerging solution to the data processing problem in IoT. In this study, we improve the load balancing process and distribute resources fairly to tasks, which, in turn, will improve QoS in cloud and reduce processing time, and consequently, response time.

• Steel and Composite Structures
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• v.33 no.6
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• pp.877-889
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• 2019

The developments of double skin composite (DSC) walls with novel enhanced C-channel connectors (DSCW-EC) were reported. Followed axial compression tests on prototype walls were carried to evaluate structural performances of this novel DSC composite structures. The testing program consists of five specimens and focused on the layout of the novel enhanced C-channel (EC) connectors, which include the web direction of C-channels, steel-faceplate thickness, vertical and horizontal spacing of C-channels. Crushing in concrete core and buckling of steel faceplate were two main observed failed modes from the compression tests. However, elastic or plastic buckling of the steel faceplate varies with designed parameters in different specimens. The influences of those investigated parameters on axial compressive behaviors of DSCW-ECs were analyzed and discussed. Recommendations on the layout of novel EC connectors were then given based on these test results and discussions. This paper also developed analytical models for predictions on ultimate compressive resistance of DSCW-ECs. Validation against the reported test results show that the developed theoretical models predict well the ultimate compressive resistance of DSCW-ECs.

• Journal of Environmental Science International
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• v.32 no.10
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• pp.741-744
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• 2023

This study focused on high school laboratory research and the main purpose was to develop alternative additives for livestock waste and ammonia volatilization methods with high school students as participants and to provide information to business owners based on the results. Compared to the control groups, The bentonite and illite treatment groups had similar ammonia volatilization, pH, EC, and total nitrogen content. In particular, the alum and aluminum chloride mixed treatment group showed low pH and ammonia volatilization, and high EC and total nitrogen content for poultry litter. As a result, when focusing on high school laboratory research, the alum and aluminum chloride mixed agent treatment fulfilled its role as an alternative additive for ammonia reduction. In addition, this approach can be suggested as a method to solve difficulties in adapting to the field through a practical cooperative relationship with livestock farms.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.731-739
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• 2007

In this study, water quality monitoring focused on TOC was performed at 5 points in Mihocheon (Stream) from January to December 2006. And 10 parameters (water temperature, pH, DO, EC, turbidity, SS, BOD, $PO_4-P$, TOC, TN) were monitored every month for one year. According to this study, TOC increased towards the lower stream (#4~#5). Correlation coefficients between TOC and DO, EC, turbidity, SS, BOD, $PO_4-P$, TN were -0.126, 0.351, 0.320, 0.286, 0.711, 0.525, 0.666. TOC was highly related to BOD. As a result of linear regression analysis, regression equation between BOD and TOC was BOD=0.58TOC+1.90 ($R^2=0.506$). In Mihocheon (Stream), BOD/TOC ratio decreased towards the lower stream. This results show decrease of ratio of biodegradable organic material to total organic pollutants towards the lower stream. This study is significant since it has revealed the potential value of TOC as organic material indicator for inquiry of water quality characteristics in the natural water system.

• Industrial Engineering and Management Systems
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• v.14 no.4
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• pp.335-346
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• 2015

The electronic commerce site (EC site) has become an important marketing channel where consumers can purchase many kinds of products; their access logs, including purchase records and browsing histories, are saved in the EC sites' databases. These log data can be utilized for the purpose of web marketing. The customers who purchase many product items are good customers, whereas the other customers, who do not purchase many items, must not be good customers even if they browse many items. If the attributes of good customers and those of other customers are clarified, such information is valuable as input for making a new marketing strategy. Regarding the product items, the characteristics of good items that are bought by many users are valuable information. It is necessary to construct a method to efficiently analyze such characteristics. This paper proposes a new latent class model to analyze both purchasing and browsing histories to make latent item and user clusters. By applying the proposal, an example of data analysis on an EC site is demonstrated. Through the clusters obtained by the proposed latent class model and the classification rule by the decision tree model, new findings are extracted from the data of purchasing and browsing histories.

• Elastomers and Composites
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• v.52 no.1
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• pp.17-21
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• 2017

The optimum mixing conditions of silica and silane containing rubber composites were evaluated by investigating the properties of rubber composites prepared with a silica composition of 10, 20, 40, 60, and 80 g, respectively. The crosslinking rate decreased with increasing silica content, with he promoters being adsorbed on the silica surface with in the rubber composite. As a result, the increase in crosslinking time resulted in the destruction of the silica structure. The increase of the bound rubber content due to the destruction of the silica structure inhibited the chain motion of the polymer molecules and reduced the cohesion of the silica itself. Finally, the increase of silica content showed the increase of hardness, tensile strength, and storage modulus of rubber composites.

• Research in Mathematical Education
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• v.15 no.1
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• pp.93-104
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• 2011

Sixty-four EC-6 teacher candidates were asked to elaborate on the method they used when interrupting seven mathematical pictorial models. The instrument used was research designed but modeled after a 4th grade released state tests. This study was conducted in the southern part of the United States. A panel of experts worked with the researcher to determine the most appropriate initial approach to interrupting the mathematical pictorial model. The pictorial models examined such concepts as measurement, place value and time. Since the questions were on a 4th grade level, it was expected that the teacher candidates would score 100%, however, this was not the case. The results will be given in the paper as each question is discussed. The results of the survey are being used to develop teaching modules for teacher candidates in mathematics methodology classes.