• Bulletin of the Korean Chemical Society
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• v.10 no.3
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• pp.238-242
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• 1989

The relations between the repulsive interactions and the electron density overlaps are investigated for various closed shell-closed shell pairs, including the systems containing alkali and halide ions. It is found that the repulsive interaction($V_{rep}$) depends on the overlap of the electron density($S_{\rho}$) according to a simple exponential relation, $V_{rep}$ = $As_{\rho}\;^{\alpha}$. Furthermore, for most of the closed shell systems the $\alpha$ values are near unity and the A values do not vary much. The same tests are also performed for the open shell-closed shell, and the open shell-open shell pairs. Although the results for these systems also show exponential dependences of the repulsive interactions on the density overlaps, the details of the dependence differ greatly from those for the closed shell systems and also vary widely from one individual system to another.

• Asia pacific journal of information systems
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• v.26 no.3
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• pp.339-366
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• 2016

National and local governments around the world have been allowing access to administrative data to increase transparency, motivate civic engagement of citizens, and improve collaboration between the public and the government. This study reviews and classifies existing literature on open government data (OGD). To create a structure to organize the existing studies, the researchers devised a framework based on socio-technical theory and summarized the significance of studies along four major points: (1) readiness, (2) implementation, (3) emerging effects, and (4) actors of open data. Studies in OGD have been growing steadily in the recent years because of the rapid development of adoptable technologies that have enabled easier access to government data. Nonetheless, an examination of existing research not only shows a disparity in research and development of OGD across countries in the Open Government partnership program but also reveals pertinent issues that have arisen in different stages of the OGD initiative. The growing number of studies and expanding body of knowledge show the importance of organizing existing literature. This step is timely and significant to map out the current breadth and depth of OGD research. According to existing research, current open governments fall short in encouraging citizen participation and collaborations among citizens and the government. This study pointed out how studies on OGD actors might be the reason as well as the solution to existing findings. This paper aims to provide a framework for organizing OGD studies, present the status of OGD research, and provide recommendations on current gaps that must be addressed.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.6
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• pp.325-334
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• 2016

Recently, Open Computing Language (OpenCL) has been proposed to provide a framework that supports heterogeneous computing platforms. By using an OpenCL framework, digital communication systems can support various protocols in a unified computing environment to achieve both high portability and high performance. This article introduces a parallel software decoder of Low Density Parity Check (LDPC) codes for China Multimedia Mobile Broadcasting (CMMB) on a heterogeneous platform. Each step of LDPC decoding has different parallelization characteristics. In this paper, steps suitable for task-level parallelization are executed on the CPU, and steps suitable for data-level parallelization are processed by the GPU. To improve the performance of the proposed OpenCL kernels for LDPC decoding operations, explicit thread scheduling, loop-unrolling, and effective data transfer techniques are applied. The proposed LDPC decoder achieves high performance by using heterogeneous multi-core processors on a unified computing framework.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2236-2245
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• 2009

This paper proposes the process for evaluating the impact of charging the PHEV(Plug-In Hybrid Electric Vehicle) on the distribution systems, and analyzes the study results employing the actual systems as the PHEV is highly expected to increase in the automobile industries in North America in the near future. Since the charging load of the PHEV directly connected to the distribution systems would consume electric power much more than any other existing electric product of residential customers, the new modeling and process would be required to consider the PHEV in distribution systems planning. The EPRI(Electric Power Research Institute) is collaboratively conducting the impact study of PHEV on the distribution systems with power utilities in North America. This study models distribution systems and the charging load of the PHEV using OpenDSS software, and analyzes the impact of PHEV on the distribution systems by assuming various scenarios with different charging time and PHEV types.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.1
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• pp.15-26
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• 2022

3D open-field farm model developed from UAV (Unmanned Aerial Vehicle) data could make crop monitoring easier, also could be an important dataset for various fields like remote sensing or precision agriculture. It is essential to separate crops from the non-crop area because labeling in a manual way is extremely laborious and not appropriate for continuous monitoring. We, therefore, made a 3D open-field farm model based on UAV images and developed a crop segmentation model using a supervised machine learning algorithm. We compared performances from various models using different data features like color or geographic coordinates, and two supervised learning algorithms which are SVM (Support Vector Machine) and KNN (K-Nearest Neighbors). The best approach was trained with 2-dimensional data, ExGR (Excess of Green minus Excess of Red) and z coordinate value, using KNN algorithm, whose accuracy, precision, recall, F1 score was 97.85, 96.51, 88.54, 92.35% respectively. Also, we compared our model performance with similar previous work. Our approach showed slightly better accuracy, and it detected the actual crop better than the previous approach, while it also classified actual non-crop points (e.g. weeds) as crops.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.2
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• pp.260-269
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• 2000

Oil-film flow visualizations and three-dimensional flow measurements have been conducted in the downstream region of a butterfly-type valve used in air-conditioning systems, with the variation of a disk open angle. The flow visualizations in the flow symmetry plane show that there are a pair of counter-rotating separation/recirculation zones as wall as two jet-like near-wall flows. These flow disturbances are strongly depends on the disk open angle. Based on the flow visualization, a qualitative flow model is suggested in the near-field and downstream region of the valve disk. For a small disk open angle, the mean velocities and turbulent intensities have relatively small values in the near-field of the valve disk, but they do not show uniform distributions even in some downstream region. With an increment of the disk open angle, mean velocity variations and turbulent intensities are greatly increased in the immediate downstream region, but uniform distributions are quickly resumed as departing from the valve disk. The mass flow rate remains nearly constant for the disk open angles less than 30 degrees, meanwhile it strongly depends on the disk open angles between 45 and 75 degrees. The pressure loss is found to be about zero for the disk open angles less than 45 degrees, but is substantially increased for those larger than 75 degrees.

• Smart Structures and Systems
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• v.23 no.6
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• pp.553-564
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• 2019

Modeling of magnetorheological (MR) dampers for cable vibration control to facilitate the design of even more effective and economical systems is still a challenging task. In this study, a parameter-adaptive three-element model is first established for a full-scale MR damper based on laboratory tests. The parameters of the model are represented by a set of empirical formulae in terms of displacement amplitude, voltage input, and excitation frequency. The model is then incorporated into the governing equation of cable-damper system for investigation of open-loop vibration control of stay cables in a cable-stayed bridge. The concept of optimal voltage/current input achieving the maximum damping for the system is put forward and verified. Multi-mode suboptimal and Single-mode optimal open-loop control method is then developed. Important conclusions are drawn on application issues and unique characteristics of open-loop cable vibration control using MR dampers.

• Asia pacific journal of information systems
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• v.16 no.4
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• pp.49-70
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• 2006

In recent, Open markets are booming up rapidly. Open markets are one of the online marketplaces which mainly concentrated on spot transactions of commodities, and are differentiated from integrated internet shopping stores with market participants, trading rules and so on. This study investigated on factors affecting satisfaction with and preference on open markets by comparing open markets with integrated internet shopping stores, and aimed to figure out the reasons why open markets are growing up so rapidly and to forecast the future of open markets. To investigate the factors affecting buyers' satisfaction with and preference on internet shopping channel. I extracted several factors through literature reviews. The factors include the pros (cost saving and time saving), the cons (security concerns and privacy concerns), and decision making support suggested by Simon's research as well. Then, I constructed research model and related research hypotheses. To verify research hypotheses, I conducted field survey targeting on online buyers and analyzed research data using structural equation model. According to data analysis result, open markets have competitive advantages over integrated internet shopping stores with respect to cost saving, time saving, and decision making support. However, online buyers are still concerning privacy issues within open markets. In summary, buyers are considering that open markets are cheaper, faster, and more efficient internet shopping channel, compared with integrated internet shopping stores. However, open markets are required to dedicate to lessen buyers' privacy concerns to rebirth as more satisfying and preferable internet shopping channel and to prosper in the future.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.919-943
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• 2019

Distributed ledger technology, which is attracting attention as an emerging technology related to the 4th Industrial Revolution, is implemented as an open source based distributed ledger technology system and widely used for development with various applications (or services), but the security functions provided by the distributed general ledger system are very insufficient. This paper proposes security enhancements for distributed ledger technology systems based on open source. To do so, potential security threats that may occur under running an open source based distributed ledger technology systems are identified and security functional requirements against the security threats identified are provided by analyzing legislation and security certification criteria (ISMS-P). In addition, it proposes a method to implement the security functions required for an open source based distributed ledger technology systems through analysis of security functional components of Common Criteria (CC), an international standard.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.280-292
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• 2021

Enterprise Resource Planning (ERP) is a software that manages and automate the internal processes of an organization. Process speed and quality can be increased, and cost reduced by process automation. Odoo is an open source ERP platform including more than 15000 apps. ERP systems such as Odoo are all-in-one management systems. Odoo can be suitable for small and medium organizations, but duo to efficiency limitations, Odoo is not suitable for the large ones. Furthermore, Odoo can be implemented on both local or public servers in which each has some advantages and disadvantages such as; the speed of internet, synced data or anywhere access. In many cases, there is a persistent need to have more than one synchronized Odoo instance in several physical places. We modified Odoo to support this kind of requirements and improve its efficiency by replacing its standard database with a distributed one, namely CockroachDB.