• Korean Journal of Computational Design and Engineering
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• v.5 no.1
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• pp.61-70
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• 2000

The design and development of a Web-based Workflow Management System (WfMS) is described in this paper. WfMSs are employed by many organizations to manage their business processes efficiently. The goal of this research is to provide an effective management of design processes in a distributed and heterogeneous environment-an environment in which workflow participants are geographically dispersed and use different computing platforms. We identify the requirements of WfMSs for the distributed and heterogeneous environment. We present an approach to applying the Web technology to was. The developed system is composed of three main modules: Worflow Engine, Web-based clients, and Process Designer. The workflow engine is implemented in pure Java for portability to heterogeneous platforms. furthermore, the client interfaces are all programmed using applets, and thus they can be readily accessed through the Internet/intranet. The Process Designer provides a build-time function of generating process specifications. Some important functions of the developed system are explained in this paper. A prototype system has been developed and applied to design processes. The system allows effective cooperation among designers who may be geographically separated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3171-3191
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• 2016

Due to growing demand on wireless data traffic, a large number of different types of base stations (BSs) have been installed. However, space-time dependent wireless data traffic densities can result in a significant number of idle BSs, which implies the waste of power resources. To deal with this problem, we propose an active state control algorithm based on semi-Markov decision process (SMDP) for a heterogeneous network. A MDP in discrete time domain is formulated from continuous domain with some approximation. Suboptimal on-line learning algorithm with a random policy is proposed to solve the problem. We explicitly include coverage constraint so that active cells can provide the same signal to noise ratio (SNR) coverage with a targeted outage rate. Simulation results verify that the proposed algorithm properly controls the active state depending on traffic densities without increasing the number of handovers excessively while providing average user perceived rate (UPR) in a more power efficient way than a conventional algorithm.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2419-2421
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• 2009

A simple and efficient method has been developed for Knoevenagel condensation between aldehydes or ketones and active methylene group by stirring in methylene chloride at 60 ${^{\circ}C}$ under heterogeneous conditions using silica supported ammonium acetate. The products are obtained in excellent yields and are in a state of high purity. The structures of the products were confirmed by IR, $^1H$ NMR and mass spectral data and comparison with authentic samples available commercially.

• ETRI Journal
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• v.40 no.5
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• pp.604-612
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• 2018

To solve the problem of unbalanced loads and the short network lifetime of heterogeneous wireless sensor networks, this paper proposes a node-selection algorithm based on energy balance and dynamic adjustment. The spacing and energy of the nodes are calculated according to the proximity to the network nodes and the characteristics of the link structure. The direction factor and the energy-adjustment factor are introduced to optimize the node-selection probability in order to realize the dynamic selection of network nodes. On this basis, the target path is selected by the relevance of the nodes, and nodes with insufficient energy values are excluded in real time by the establishment of the node-selection mechanism, which guarantees the normal operation of the network and a balanced energy consumption. Simulation results show that this algorithm can effectively extend the network lifetime, and it has better stability, higher accuracy, and an enhanced data-receiving rate in sufficient time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2147-2154
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• 2014

JXTA does not need to be managed by the central server, and has the property that can communicate with any device that is connected to the network. Thus, JXTA can be applied to the communication between heterogeneous P2P systems. This paper deals with the design of a data exchange system utilizing the JXTA's foregoing property, which is able to connect P2P systems with different protocols and APIs.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.1-14
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• 2023

To secure national future competitiveness, the Korean government announced the 『National Ultra-High Performance Computing (HPC) Innovation Strategy (2021.5.28.)』 and set three innovation strategy goals throughout establishing an innovation ecosystem. This study presented a heterogenous data-based strategic support framework that allowed to understand both the current status of domestic & foreign R&D areas and domestic industrial economy areas in terms of strategic fields related to ultra-high performance computing, and the empirical research was conducted in the life science and public health area. The HPC innovation ecosystem platform based on the connection of heterogeneous data (domestic R&D project-technology-industry-overseas R&D project) presented in this study provided useful and essential information that allowed establishing a specific action plan for the national HPC innovation strategy and contributing to vitalizing the innovation ecosystem. Since the evidence-based policy assumes that a more reasonable consensus is reached through a non-biased decision- making process among stakeholders, the proposed platform may contribute to enhancing policy momentum by increasing legitimacy and trust of planning of the national HPC strategy.

• Computers and Concrete
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• v.29 no.2
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• pp.93-105
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• 2022

The degrees of freedom (DOFs) of high-rise structures increase rapidly due to the need for refined analysis, which poses a challenge toward a computationally efficient method for numerical analysis of high-rise structures using the finite element method (FEM). This paper presented an efficient iterative method, an algebraic multigrid (AMG) with a Jacobi overrelaxation smoother preconditioned conjugate gradient method (AMG-CG) used for solving large-scale structural system equations running on heterogeneous platforms with parallel accelerator graphics processing units (GPUs) enabled. Furthermore, an AMG-CG FEM application framework was established for the numerical analysis of high-rise structures. In the proposed method, the coarsening method, the optimal relaxation coefficient of the JOR smoother, the smoothing times, and the solution method for the coarsest grid of an AMG preconditioner were investigated via several numerical benchmarks of high-rise structures. The accuracy and the efficiency of the proposed FEM application framework were compared using the mature software Abaqus, and there were speedups of up to 18.4x when using an NVIDIA K40C GPU hosted in a workstation. The results demonstrated that the proposed method could improve the computational efficiency of solving structural system equations, and the AMG-CG FEM application framework was inherently suitable for numerical analysis of high-rise structures.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.55-61
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• 2020

The communication issues expected for SMEs are that 1) IT systems are not easy to connect, 2) data collection and integration by heterogeneous systems are difficult, and 3) various fieldbuses and protocols make interfaces difficult. Usually, SMEs often have automation built before the introduction of smart factories. It is necessary to provide communication technology such as Sensing to meet the heterogeneous system level with the old aged sensors in the automation equipment and communication network of SMEs. We will consider how to improve the network interface before applying the latest network technology at the time of preparation using PI.

• Korean Membrane Journal
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• v.6 no.1
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• pp.61-69
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• 2004

Small angle light scattering (SALS) and field emission scanning electron microscope (FE-SEM) have been used to investigate the effects of alcohol on phase separation of chlorinated poly(vinyl chloride) (CPVC)/tetrahydrofuran (THF)/alcohol (9/61/30 wt%) solution during water vapor induced phase separation. A typical scattering pattern of nucleation & growth (NG) was observed for all casting solutions of CPVC/THF/alcohol. In the case of the phase separation of CPVC dope solution containing 30 wt% ethanol or n-propanol, the demixing with NG was observed to be heterogeneous. Meanwhile, the phase separation of CPVC dope solution with 30 wt% n-butanol was found to be predominantly homogeneous NG. Although the different phase separation behavior of NG was observed with types of alcohol additives, the resultant surface morphology had no remarkable differences. That is, even though the NG process by water vapor is either homogeneous or heterogeneous, this difference does not play a main role on the final surface morphology. However, it was estimated from the result of hydraulic flux that the phase separation by homogeneous NG provided the membrane geometry with lower resistance in comparison with that by heterogeneous one.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.112-122
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• 2016

Cognitive radio (CR) is considered an attractive technology to deal with the spectrum scarcity problem. Multi-radio access technology (multi-RAT) can improve network capacity because data are transmitted by multiple RANs (radio access networks) concurrently. Thus, multi-RAT embedded in a cognitive radio network (CRN) is a promising paradigm for developing spectrum efficiency and network capacity in future wireless networks. In this study, we consider a new CRN model in which the primary user networks consist of heterogeneous primary users (PUs). Specifically, we focus on the energy-efficient resource allocation (EERA) problem for CR users with a special location coverage overlapping region in which heterogeneous PUs operate simultaneously via multi-RAT. We propose a two-tier crossover genetic algorithm-based search scheme to obtain an optimal solution in terms of the power and bandwidth. In addition, we introduce a radio environment map to manage the resource allocation and network synchronization. The simulation results show the proposed algorithm is stable and has faster convergence. Our proposal can significantly increase the energy efficiency.