• Journal of the Korean Society for Precision Engineering
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• v.31 no.12
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• pp.1115-1119
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• 2014

In this article, a 20 kHz ultrasonic waveguide for nano-surface treatment was designed and manufactured. When designing the system, finite element analysis with ANSYS software was performed to find optimal dimensions of the waveguide, which can raise energy efficiency. Consequently an anti-resonance frequency of an Al waveguide with a piezoelectric actuator was 20 kHz, which predicted the experimentally obtained value of 18 kHz well. For the assessment of the performance, Steel Use Stainless (SUS) 304 and chromium molybdenum steel (SCM) 435 specimens were tested. Cross-sectional microscopies of SUS304 were taken and they showed that the treated thickness was $30{\mu}m$. Additionally, hardness tests of SCM435 were done and the hardness before the process was 14.0 Rockwell Hardness-C scale (HRC) and after the process was 20.5 HRC, respectively, which means 46% increase. Considering these results, the developed ultrasonic system is thought to be effective in the nano-surface treatment process.

• The Journal of Society for e-Business Studies
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• v.13 no.2
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• pp.181-194
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• 2008

Process mining aims at extracting useful information from system log of business process execution. As process-aware information systems, such as BPMS, ERP, and SCM, spread, researches on process mining get more significance. In this paper, we propose the methodology of clustering process log before process mining and also present the prototype system. The proposed methodology can be used in accompany with the existing process mining algorithms to improve their performance. The process log clustering system PROCLE, presented in this paper, supports to classify the process instances in the system log in order to extract the appropriate level of process model according to the users' need. The proposed methodology was implemented on the open platform for process mining, ProM.

• Korean Management Science Review
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• v.30 no.2
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• pp.43-61
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• 2013

With the recent introduction of supply chain management (SCM), quality management has extended from within companies to between companies. As a result, supply chain quality management (SCQM) has received increased attention. However, existing SCQM studies only focus on what impact quality control in supply chains have on company performance while virtually no studies examine quality control efficiencies. This paper, therefore, evaluated the SCQM efficiency of a parent company and its partner companies by using Data Envelopment Analysis (DEA) based on the Quality Collaboration Index for Supply Chain Management (QCI-SCM) conducted by the Korean Standards Association for its 'Quality Innovation-Based Building and Expansion of Business.' Study results showed that a parent company and its partners showed an overall average efficiency of approximately 80% (parent company 80.37%, partner company 79.05%). By also performing a discriminant analysis based on the calculated efficiency scores using DEA, factors that made companies efficient or inefficient were different between the two groups. In parent companies, efficiency and inefficiency were determined by factors such as communication, infra-structure, support, delivery of quality, and benefit sharing, whereas in partner companies, talent development, infrastructure, crisis management, and delivery of quality were the determining factors. In this paper, we examined the efficiency of SCQM and analyzed them from the perspective of both the parent company and partner companies to offer strategic SCQM insights.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.792-798
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• 2008

Supply chain management (SCM) has been drawn increasing attention in industries and academia. The attention is mainly due to a need to integrate the multiple activities in a process network from the overall perspective under the constantly varying economic environment. While many researchers have been addressing various issues of SCM, there is not much research explicitly handling the overall dynamics of supply chain entities from PSE literature. In this two-part series paper, it is investigated how the overall supply chain processing times vary in response to the variation of individual entities using Monte Carlo simulation. Instead of figuring out the operation levels of individual entities, the overall operation time called TAT(Turn-Around-Time) is proposed as a performance indicator. An example of 7 entity-supply chain is presented to illustrate the proposed methodology.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.7
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• pp.24-30
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• 2000

In this paper, we proposed an fiber-optic transceivers based on the analog optical transmission techniques of incorporating the SCM (subcarrier multiplexing) and WDM (wavelength-division multiplexing ) method, which can be used to transmission of IMT-2000 and PCS wireless frequency band and analyzed overall those parameters related with fabrication. Especially in the impedance matching network between RF signal and LD, we proposed the method of deriving optimal performance using simulation techniques. In the frequency band of 1.7GHz∼2.25GHz, experimental data for the gain flatness and the noise floor of the optical link were also presented $\pm$1.5dB and -130dBm respectively when the link Rain was 0dB.

• IE interfaces
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• v.24 no.1
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• pp.78-86
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• 2011

To mitigate space restriction and to raise productivity, some shipbuilding companies use floating-docks on the sea instead of dry-docks on the land. In that case, a floating-crane that can lift very heavy objects (up to 3,600 tons) is used to handle the blocks which are the basic units in shipbuilding processes, and so, very large blocks (these are called the mega-blocks) can be used to build a ship. But, because these mega-blocks can be made only in the area near the floating-dock and beside the sea, the space is very important resource for the process. Therefore, our problem is to make an efficient spatial schedule for the mega-block assembly yard. First of all, we formulate this situation into a mathematical model and find optimal solution for a small problem using a commercial optimization software. But, the software could not give optimal solutions for practical sized problems in a reasonable time, and so we propose a GA-based heuristic algorithm. Through a numerical experiment, finally, we show that the spatial scheduling algorithm can provide a very good performance.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.4
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• pp.203-209
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• 2009

Dual mass flywheel is the newly developed flywheel system which reduces the noise and vibration and make a better and comfortable ride of cars by adding inertia mass and damping device. However, verification of performance for this system should be carried out since this system is under developing status in our country. Especially, the durability for each part of this system should be guaranteed. Durable properties of driver plate which is the key component of dual mass flywheel were first investigated both in the raw (SCM435 in JIS) and heat-treated material. In addition, fatigue life analysis of driver plate was preformed in the real condition and the results were verified by comparison with the results of rig test.

• Advances in concrete construction
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• v.5 no.1
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• pp.31-48
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• 2017

Supplementary cementitious materials (SCM) have turned out to be a vital portion of extraordinary strength and performance concrete. Metakaolin (MK) is one of SCM material is acquired by calcinations of kaolinite. Universally utilised as pozzolanic material in concrete to enhance mechanical and durability properties. This study investigates the fresh and hardened properties of conventional concrete (CC) and self compacting concrete (SCC) by partially replacing cement with MK in diverse percentages. In CC and SCC, partial replacement of cement with MK varies from 5-20%. Fresh concrete properties of CC are conducted by slump test and compaction factor tests and for SCC, slump flow, T500, J-Ring, L-Box, V-Funnel and U-Box tests. Hardened concrete characteristics are investigated by compressive, split tensile and flexural strengths at age of 7, 28 and 90 days of curing under water. Carbonation depth, water absorption and density of MK based CC and SCC was also computed. Fresh concrete test results indicated that increase in MK replacement increases workability of concrete in a constant w/b ratio. Also, outcomes reveal that concrete integrating MK had greater compressive, flexural and split tensile strengths. Optimum replacement level of MK for cement was 10%, which increased mechanical properties and robustness properties of concrete.

• Korean Management Science Review
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• v.20 no.2
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• pp.151-163
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• 2003

Although there has been growing interests in outsourcing the logistics sectors in the industry, not much research was undertaken to provide the processes and standards in choosing the right 3PL for the company. In this research, we attempt to provide the 3PL selection criteria and its priority orders. We surveyed and interviewed the various industry experts and analyzed results using Analytic Hierarchy Process(AHP). The study reveals that manufactures and logistics companies have different understanding of the selection criteria and priorities in outsourcing the 3PL.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.58-62
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• 2016

Due to the rapidly changing global business environment and global management environment, companies must actively act for competitiveness. By examining the development process of Enterprise Resource Planning (ERP), there is a chance to optimize the organization and find measures to improve the company competitiveness. It seems examining task process, and studying the influence of ERP introduction to management performance by considering whether the excessive maintenance cost or repetitive investment toward ERP is quiet significant. The companies which instituted ERP uses "business process model" provided by "Best Practice" compare own task to choose much efficient method. This allows simultaneous realization of ERP institution and Business Reengineering (BR).