• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.29-36
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• 2003

Reducing the energy consumption while maintaining pulp quality is an important objective of today's paper industry. Enzymatic treatment of fibers and the application of dry strength agent were investigated as methods to reduce energy consumption during refining and to upgrade fiber characteristics. Modification of recycled fibers with an enzyme was effective in improving relining efficiency and reducing refining energy. Optimization of dry strength agent application conditions including stock pH, cationic demand, zeta potential, etc. were found to be very important for improving its effectiveness.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.99.4-99
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• 2001

PMAC(Permanent magnet AC) motor drives are widely used in the industrial applications and home appliances because of high torque ratio, high efficiency and precise control performance. In recent years there has been a significant development of PMAC motors of various kinds. Improvements in the properties of permanent magnet materials have increased the viability of related types of motors. However, precise speed and position information is essential for the good control performance. In order to produce correct torque, the rotor flux position information from position sensor has to be identified. In this paper, a low cost position sensor is proposed for improving of starting and low speed performance of PMAC. The proposed position ...

• Asia pacific journal of information systems
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• v.20 no.3
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• pp.91-114
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• 2010

An IT system within a company play increasingly important role as a significant part of corporate assets. The IT system possesses an extraordinary ability to improve an organization's efficiency, effectiveness and productivity by providing competitive advantages and improving strategic business decision capabilities. Indeed, providing a more secure IT environment, improving employee productivity and enhancing business process and strategic decision capabilities are key areas to improve corporate performance. However, existing research on IT ROI of return on IT investments does not provide solid justification to stakeholders. In this paper, we analyze the IT investment during the past 28 years from 1982 to 2009 and present the results in two dimensions. First, we show the IT solution implementation analysis by years and industries based on 1,240 IT success cases from 8 different sources such as major Korea IT newspaper, IT magazines, and IT vendors. Then, the paper presents the relationship between IT capability through IT success cases and corporate business performance among 32 industries.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.332-335
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• 1995

A simple and effective method for improving Euclidean norm condition number for chemical processing system is presented. The singular value sensitivities of Freudenberg et al. (1982) is used to estimate the behavior of singular values of process transfer function matrix when design parameter is changed, then the condition number can be calculated straightforwardly. The method requires explicit dependencies of each transfer function matrix elements on design parameters. These dependencies can be obtained either by symbolic differentiation in the form of explicit function of design parameters, or by numerical perturbation studies for units with large and complicated models. Gerschgorin-type lower bound for minimum singular value is introduced to detect the large divergencies near singular point due to linearity of sensitivities. The case studies are performed to show the efficiency of the proposed method.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.61-67
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• 2000

Many research works for improving a boundary lubrication performance have been executed by using solid lubricants, and been tried to apply an engine lubrication. However those general lubricants like MoS$_2$ or PTFE have not been applied on engines due to the extreme conditions such as very high temperature and pressure by combustion process in a cylinder. A copper nickel alloy fine particle has been introduced and studied. In this Paper the lubricant using the alloy Particles is applied on a marine diesel engine and assessed by the engine performance test The results showed the increase of cylinder pressure related strongly to the engine efficiency as well as the improving the engine lubrication performance.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.3
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• pp.107-113
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• 2011

An OFDMA(Orthogonal Frequency Division Multiple Access) includes a MIMO(Multi-Input Multi-Output) scheme for improving spectral efficiency and data throughput. Recognizing that the performance of MIMO system is heavily dependent upon the accuracy of channel estimation, we propose a novel channel estimation for the MIMO scheme based on OFDMA. Conventional interpolation-based channel estimation suffers from poor estimation error at specific subcarriers. Proposed scheme makes use of a planar interpolation instead of linear interpolation for those subcarriers of bad accuracy. Simulation results show that the proposed scheme improves the performance of MIMO system by improving the accuracy in channel estimation especially for the adverse subcarrier positions. It is observed that the proposed scheme outperforms the conventional method by about 2dB in terms of both mean squared error and overall bit error rate with a reasonable computational complexity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.725-731
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• 2003

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-.oiling system (MD-ARS) might be one candidate of several systems against the ship's rolling. As the movable range of the mass on the ship is finite, the control system must include restriction on the mass position to protect the device and the ship. This restriction usually causes windup phenomenon and control performance is deteriorated seriously. We adopt anti-windup technique to improve the control performance and demonstrate its efficiency by simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.6
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• pp.566-572
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• 2015

This study introduces an LCC resonant converter operating on a continuous conduction mode. The LCC resonant converter has the advantage of improving system efficiency, especially under the rated load condition, because it can reduce conduction loss by improving the resonance current shape and switching loss by increasing the lossless snubber capacitance. The proposed LCC resonant converter is applied to various applications, including a 60 kW EV fast charger, a 24 kJ/s high-voltage capacitor charger, and a 20 kV, 20 kW high-precision DC power supply. Experimental results prove that the proposed LCC resonant converter topology can be effectively used as a converter topology for these applications.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.272-279
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• 2003

There are two methodologies to increase transport capacity of railway. One is to invest railroad equipment or vehicles, and the other is to improve operation efficiency through optimization. All of these is intended to increase transport capacity by improving the line capacity, So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. Korea Railroad Research Institute(KRRI) proposed a new line capacity estimation system based on the probability simulation method. In this research. we perform analysis of line capacity for the railway improvement alternatives, and to represent the results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.295-297
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• 2013

Reinforcing bar coupling method has a variety of ways including lap-splice method. However, there are problems that need to be improved in terms of constructability, economics analysis. We should be improved about the problems of the existing methods. Accordingly, this study were developed a new type of staggered grip type reinforcing bar coupling. The proposed method show the following effects than existing methods. First, this method can be reduce time through improved workability. Second, increasing safety through the slip removal. Third, improving economic efficiency by reduce the manufacturing costs.