• Advances in nano research
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• v.14 no.2
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• pp.117-126
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• 2023

This experimental study investigated friction stir welding (FSW) of the acrylonitrile-butadiene-styrene (ABS) T-joint in the presence of various nano-silica levels. This study aim to handle the drawbacks of the friction stir welding (FSW) of an ABS T-joint with various quantity of nanoparticles and assess the performance of nanoparticles in the welded joint. Moreover, the relationship between the nanoparticle quantity and FSW was analyzed using response surface methodology (RSM) Box-Behnken design. The input parameters were the tool rotation speed (400, 600, 800 rpm), the transverse speed (20, 30, 40 mm/min), and the nano-silica level (0.8, 1.6, 2.4 g). The tensile strength of the prepared specimens was determined by the universal testing machine. Silica nanoparticles were used to improve the mechanical properties (the tensile strength) of ABS and investigate the effect of various FSW parameters on the ABS T-joint. The results of Box-Behnken RSM revealed that sound joints with desired characteristics and efficiency are fabricated at tool rotation speed 755 rpm, transverse speed 20 mm/min, and nano-silica level 2.4 g. The scanning electron microscope (SEM) images revealed the crucial role of silica nanoparticles in reinforcing the ABS T-joint. The SEM images also indicated a decrease in the nanoparticle size by the tool rotation, leading to the filling and improvement of seams formed during FSW of the ABS T-joint.

• Journal of the Korea Society of Computer and Information
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• v.3 no.1
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• pp.47-62
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• 1998

The needs and practical use of multimedia authoring tools in education are increasing. In the paper. we analyze essential elements and the functional features of an authoring tool which may be required for developing multimedia CAI programs. Based on a review of popular authoring tools in the market, GREAT-II, Artware, Authorware professional, ToolBook and IconAuthor, we present the improvement direction of next generation multimedia authoring tools.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.206-214
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• 1988

To improve the surface waviness in the peripheral milling, the feedrate is controlled so that the cutting force measured in the normal direction to the workpiece is constant. A discrete time first order model between the feedrate and the tool deflection is derived for the control. It has been shown by the analysis that the tool deflection is directly related to the feedrate and largely affects the surface waviness during cutting. The experimental results shown that the surface waviness is drastically improved by the proposed methods.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.64-69
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• 2004

The work presented here deals with controller design using error model constructed with proportional control ramp response. The design aims at the improvement of transient response, steady-state error reduction with stability preservation, generation of the consistent contour error through the proportional gain regulation of a mismatched system. The first step is to generate tracking-error curve with proportional control only and decide the added error signal shape on the error curve. The next is to construct a table for the steady-state loop gain with step input. The table is used for selecting the proportional gain. The effectiveness of the proposed controller is confirmed through the simulation and experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.73-77
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• 2002

The requirements for higher productivity call for high speed of the machine tool axes. Iron core type linear DC motor is growly accepted far a viable candidate of the high speed machine tool feed unit. LDM, however, has inherent disturbance force components: cogging and force ripple. These disturbance force directly affects tracking accuracy of the carrage and must be eliminated or reduced. Reducing motor ripple, this paper adapted the feed forward compensation method and neural network control. Experiments carried 7ut on the linear motor test setup show that this control methods is usable in order to reduce the motor ripple.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.4
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• pp.358-368
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• 2006

The significance of intellectual property in the knowledge-based society has been increasing and as a result, the patent customer's demand for a top quality patent administration service has increased as well. Therefore, Korean Intellectual Property Office(KIPO) adopted 6 sigma as a tool for KIPO's innovation to improve the quality of patent administration and enhance customer satisfaction. KIPO's steadfast promotion of 6 sigma resulted in many successful outcomes such as improvement of policy and service process from customer's point view, streamlining the administrative procedures, increased work efficiency, capability enhancement of core personnel, and so on. Since 6 sigma has proved itself to be equipped with features suitable for innovation in public sector, it can be used as an extensible innovation tool to meet the challenges in rapidly changing administration environment and to achieve a competitive edge.

• IE interfaces
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• v.3 no.1
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• pp.1-11
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• 1990

The purpose of this study is to develop the decision support model for the investment in the operation and maintenance in telecommunication networks. First, we analyze the relation between the cost of quality and the quality of service, and then establish and analysis tool of the investment alternatives for the improvement of the quality of service. This study will offer a decision tool to enhance an efficiency of the operation and maintenance for telecommunication facilities, and will contribute to shaping a policy of network performance management.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.28-34
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• 1999

According to the development of tool material and the improvement of machinability of cutting material like aluminium alloy, the higher spindle speed is needed. However, the higher speed causes the heat generation of bearings, the deformation of spindle unit parts, and the rotational accuracy of spindle to be worse. Therefore, it is essential to analyze and control the heat generation and the thermal behavior of spindle unit in order to have higher speed and better rotational accuracy. This paper shows the analogy between the analyzation of heat generation and thermal behavior of high speed spindle system by finite element method and the test results of actual temperature rise through running test, and shows the necessity of cooling the spindle and inner ring side of bearings for the thermal balance of high speed spindle system.

• Tribology and Lubricants
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• v.19 no.2
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• pp.59-64
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• 2003

In this study, the hydraulic breaker system was analyzed and the analysis tool using GUI was developed. The analysis on the system with the accumulator was included. From the parametric analysis, the effects of each factor were revealed. Through the simulation with varying parameters, the method to improve the performance of the hydraulic breaker system was presented. The analysis tool will help a man without special knowledge about programming analyze the hydraulic breaker system. The result of this study will help improve the hydraulic breaker system in sight of Blow energy and Blows per minute.

• Structural Engineering and Mechanics
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• v.34 no.3
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• pp.301-317
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• 2010

This paper studies the reliability of an analytical tool for predicting the lateral load-deformation response of RC columns while subjected to lateral cyclic displacements and axial load. The analytical tool in this study is based on a fiber element model implemented into the program DRAIN-2DX (fiber element). The response of RC column under cyclic displacement is defined by the behavior of concrete, and reinforcing steel under general reversed-cyclic loading. A tri-linear stress-strain relationship for the cyclic behavior of steel is proposed and the improvement in the analytical results is studied. This study only considers the behavior of columns with flexural dominant mode of failure. It is concluded that with the implementation of appropriate constitutive material models, the described analytical tools can predict the response of the columns with reasonable accuracy when compared to experimental data.