• Journal of Digital Contents Society
• /
• v.19 no.7
• /
• pp.1263-1270
• /
• 2018

We investigated the e-learning platforms for higher education in developing countries. First, we introduced e-learning environmental factors such as ICT technology as well as ASEAN Cyber University (ACU) project for developing countries. And then, we presented Cambodian case as an example of e-learning platform for developing countries. We analyzed the national education policy and ICT environment as well as the demands and obstacles of e-learning in Cambodia. We derived e-learning strategies and plans based on the analysis results, and finally proposed e-learning platform C-MOOC Net. In order to verify the proposed scheme, we developed prototype of C-MOOC Net system which is implemented based on open software. As a result, we have met the requirement of networking the C-MOOC hub, supporting localization of local language and personalization of favorite courses respectively.

• Journal of Navigation and Port Research
• /
• v.41 no.4
• /
• pp.243-250
• /
• 2017

Seaports are not longer considered to be single entities for which the main activity is to load and discharge cargo, but rather as fundamental hubs within a complex supply chain serving global production networks. From a public perspective, they hold a key role in terms of their economic impact at the local, regional and national level by generating value added activity and employment. This issue is becoming increasingly pivotal for ports and their stakeholders. The objective of the study is to estimate a regression model of the value added activity and employment figures of 17 Italian ports for which there are no publications available. Concerning port system reform in Italy, the research intends to provide policy makers with a tool to measure the effects produced by ports and their importance to local communities and regions. The paper finds that in all Italian ports, the direct effects are larger than the indirect effects, and the bigger socio-economic effects are found in the biggest ports.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.2 no.3
• /
• pp.1-9
• /
• 1998

The exhaustion of fossil fuels and serious environmental pollution put the concern about non-po llution energy into the world. On the developments of technology, wind energy has been spotlighted as a non-pollution energy in many countries. This study has carried out the aerodynamic and structural design procedure of the lightweight composite rotor blades with an appropriate aerodynamic performance and structural strength for the 500㎾ medium class wind turbine system. The previous design, which is shell-spar structure, is redesigned to shell-spar- sandwich structure for light weight. Large deformation problem from light weight is examined by non-linear analysis. Local buckling occurred under lower stress than failure stress. The buckling analysis is accomplished to confirm the safety of the composite blade. The stress analysis around pin hole joint part at hub is carried out and it is confirmed that the pin hole is not failed. The results show that the resonance of redesigned blade does not happen in operation range.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.2
• /
• pp.221-233
• /
• 2008

In general, we use a Parallel processing computer manufactured specially for the purpose of parallel processing to do high performance computings. But we can depoly and use a PC cluster composed of several common PCs instead of the very expensive parallel processing computer. A common way to get a PC cluster is to adopt the star topology network connected by a switch hub. But in this paper, we grope efficient implementations of hypercube networks based on TCP/IP to connect 8 PCs directly for more useful parallel processing environment, and make evaluations on functionality and efficiency of them using ping, netperf, MPICH. The two proposed methods of implementation are IP configuration based on link and IP configuration based on node. The results of comparison between them show that there is not obvious difference in performance but the latter is more efficient in simplicity of routing table. For verification of functionality, we compare the parallel processing results of an application in them with the same in a star network based PC cluster. These results also show that the proposed hypercube networks support a perfect parallel processing environment respectively.

• Journal of Korea Port Economic Association
• /
• v.36 no.4
• /
• pp.1-16
• /
• 2020

Since Korea has excellent port infrastructure and competitive petrochemical complexes, there is plenty of potential for creating an oil hub in Northeast Asia. In particular, Ship-to-Ship (STS), which creates high added values, contributes greatly to the national economy. In this study, the liquid cargo volumes of chemical industrial products, refined petroleum products, and crude oil were analyzed at the national and regional (Busan, Ulsan, and Yeosu/Gwangyang) levels. Additionally, a Granger causality analysis was performed between imports, exports, and transshipments, in pairs. ADF, PP, and KPSS were analyzed for the unit root test. In addition, the VAR model and expanded VAR model suggested by Toda and Yamamoto were used for further analyses. Findings revealed a difference in Granger causality depending on the region or cargo type. These findings suggest that policies and incentive schemes for ports need to be differentiated according to the region and cargo types. In addition, the different patterns in the relationship between transshipments and import-export petrochemical cargoes should be considered.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.8
• /
• pp.1018-1023
• /
• 2019

Since 2010, vehicle black boxes have become popular with many people, if there is no record of the vehicle accident scene, or if the offender deliberately deletes the image data, the victim succeeds. The biggest advantage of blockchain is that it is impossible to modify and delete data by data distribution storage. The biggest disadvantage is that sensitive data is also distributed. In this paper, we propose a blockchain method for the black box by using the advantage of shared block data and we intend to solve the problem of personal information leakage which is a disadvantage of blockchain by storing sensitive information stored in a blockchain in a private server by LINK blockchain with a private server. We also attached code(Github) and demonstration video(Youtube) linking LINK blockchain with the private server in this paper.

• Journal of the wind engineering institute of Korea
• /
• v.22 no.4
• /
• pp.163-169
• /
• 2018

In this study, wind loads exerted on the offshore wind turbine rotor in parked condition were predicted with variations of wind speeds, yaw angles, azimuth angle, pitch angles, and power of the atmospheric boundary layer profile. The calculated wind loads using blade element theorem were compared with those of estimated aerodynamic loads for the simplified blade shape. Wind loads for an NREL's 5 MW scaled offshore wind turbine rotor were also compared with those of NREL's FAST results for more verification. All of the 6-component wind loads including forces and moments along the three axis were represented on a non-rotating coordinate system fixed at the apex of rotor hub. The calculated wind loads are applicable for the dynamic analysis of the wind turbine system, or obtaining the over-turning moment at the foundation of support structure for wind turbine system.

• Journal of Korea Port Economic Association
• /
• v.38 no.2
• /
• pp.123-138
• /
• 2022

Korea has been huge investments in its port system, annually upgrading its infrastructure to turn the ports into Asian hub port. However, while Busan port is ranked fifth globally for container throughput, Other Korean ports are ranked much lower. This article applies Data Envelopment Analysis (DEA) and Malmquist Productivity Index (MPI) to evaluate selected major Korean seaports' operational efficiency and productivity from 2010 to 2018. It further integrates Principal Component Analysis (PCA) into DEA, with the PCA-DEA combined model strengthening the basic DEA results, as the discriminatory power weakens when the variable number exceeds the number of Decision Making Units(DMU). Meanwhile, MPI is applied to measure the seaports' productivity over the years. The analyses generate efficiency and productivity rankings for Korean seaports. The results show that except for Gwangyang and Ulsan port, none of the selected seaports is currently efficient enough in their operations. The study also indicates that technological progress has led to impactful changes in the productivity of Korean seaports.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.25 no.2
• /
• pp.99-107
• /
• 2023

Recently, the abnormal weather events and crop damages occurred frequently likely due to climate change. The importance of meteorological data in agricultural research is increasing. Researchers can download weather observation data by accessing the websites provided by the KMA (Korea Meteorological Administration) and the RDA (Rural Development Administration). However, there is a disadvantage that multiple inquiry work is required when a large amount of meteorological data needs to be received. It is inefficient for each researcher to store and manage the data needed for research on an independent local computer in order to avoid this work. In addition, even if all the data were downloaded, additional work is required to find and open several files for research. In this study, data collected by the KMA and RDA were uploaded to GitHub, a remote storage service, and a package was created that allows easy access to weather data using Python. Through this, we propose a method to increase the accessibility and usability of meteorological data for agricultural personnel by adopting a method that allows anyone to take data without an additional authentication process.

• Journal of Environmental Policy
• /
• v.7 no.1
• /
• pp.81-100
• /
• 2008

This paper reviewed the main characteristics of Web 2.0 and discussed the possible applications related to National Geographic Information Systems. In general, Web 2.0 refers to a next generation World Wide Web environment that let people participate and share information and data. The recent examples using Web 2.0 with geo-spatial information are convincing us apply Web 2.0 into National Geographic Information Systems. In order to imply Web 2.0 into National Geographic Information Systems, we should consider not only technological advancements related to providing the services but also shifting the relationship between information provider(government agencies) and end-users. In other words, new platform should be provided to users so that users can easily create, share, and mash-up data, which was previously managed and owned only by government agencies. Successful integration Web 2.0 platform into National Geographic Information Systems require some important points such that; 1) the consideration for the data should be changed from closed and agency owned data to opened and shared data. 2) data standards should be established to integrate all data from different sources. 3) real change need to be happened rather than different naming on the same system.