• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.3
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• pp.112-118
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• 2007

Recently, the machine tools called multi-task machines, which mounted rotary axes on the table or spindle are used increasingly. Accordingly, multi-task machine tool takes a growing interest on the motion accuracy of feed drive system. In this study, measurement and diagnosis of motion errors ware attempted from circular pattern obtained by using DBB (Double ball bar) device. Those were obtained at both clockwise and counter clockwise motions in mutually perpendicularly intersecting three planes. The reliability of error measurement system for multi-task machine tool was verified by the direct test cutting.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.3
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• pp.31-37
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• 2007

Recently, the machine tools called multi-task machines, which mounted rotary axes on the table or spindle are used increasingly. Accordingly, multi-task machine tool takes a growing interest on the motion accuracy of feed drive system. In this study, measurement and diagnosis of motion errors ware attempted from circular pattern obtained by using DBB (Double ball bar) device. Those were obtained at both clockwise and counter clockwise motions in mutually perpendicularly intersecting three planes. The reliability of error measurement system for multi-task machine tool was verified by the direct test cutting.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.117-126
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• 1992

This study proposes a new interactive multicriteria method for determining the best levels of the decision variables needed to optimize a stochastic computer simulation with multiple response variables. The method, called the Pairwise Comparison Stochastic Cutting Plane (PCSCP) method, combines good features from interactive multiple objective mathematical programming methods and response surface methodology. The major characteristics of the PCSCP algorithm are: (1) it interacts progressively with the decision maker (DM) to obtain his preferences, (2) it uses good experimental design to adequately explore the decision space while reducing the burden on the DM, and (3) it uses the preference information provided by the DM and the sampling error in the responses to reduce the decision space. This paper presents the basic concepts of the PCSCP method along with its performance for solving randomly selected test problems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.818-822
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• 2000

The low density, sustained high temperature strength and excellent resistivity to acid materials have made them strong candidate materials for future aerospace or medical applications. Nowadays their usage has already been broaden to everyday's commercial applications such as golf club heads, finger rings and many decorative items, Anticipating the general use of this material and development of the titanium alloys in domestic furnaces, the review and the study of the machining parameters for those alloys are deemed necessary. The present studies are concentrated to the machining parameters of the Ti-6Al-4V alloys due to their dominant position in the production of titanium alloys.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.4
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• pp.55-63
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• 1991

This paper deals with development of a Computer Aided Process Planning System based on knowledge base in addition to database for injection mold as a part of Computer Integrated Manufacturing System for injection mold manufacture. The prposed system consists of four modules such as manufacturing feature code generation module machine tool selection and sequencing module, operation and cutting tool selection mudule and standard time estimation module. The system is programmed by using Turbo Pascal on the IBM-PC/AT. The performance of the system is evaluated by using real problems and the test results indicate that the proposed system is a practical and efficient system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.873-877
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• 1997

This paper presents experimental results to know the charcteristics of machined surface due to cutter runout. Cutter runout is a common but undesirable phenomenon in multi-tooth machining such as end-milling process because it introduces variable chip loading to insert which results in a accelerated tool wear, amplification of force variation and hence enargement vibration amplitude. To develop in-proess cutter runout compensation system, set-up the micro-positoning mechanism which is based on piezoelectric translator embeded in the work holder to manipulate the depth of cut in real-time. And feasibility test of system was done under the various experimental cutting conditions. This results provide lots of information to build-up the precision machining technology.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1491-1494
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• 2003

A specific experimental method, the Split Hopkinson Pressure Bar (SHPB) technique has been widely used to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of 103/s∼104/s. This type of test procedure has been used to examine the dynamic response of materials in various modes of testing. In this paper, dynamic deformation behaviors of rubber materials widely used for the isolation of vibration from varying structures under dynamic loading are determined using a Split Hopkinson Pressure Bar technique.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.135-142
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• 1998

The performances of cutting process is mostly affected by the characteristics of closed loop system constructed with machine tool structure, work piece and tools. The chucking system is very important component in this system to hold work piece correctly in various static and dynamic load condition. Therefore, chucking force and accuracy must be considered carefully, from these reason, this paper describes the stability of chucking system which preserve high stiffness and accuracy of machine tool system.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.5
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• pp.287-298
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• 2016

This paper proposes an effective smart plug system capable of monitoring power, cutting off standby power and overload current. The key design concept is focused on measurement accuracy, self power consumption and controlling via smart phone application. The system is composed of several plugs and a hub, and adopts a star-topology-styled TDMA wireless protocol for communication between plug and hub. The test result shows that the implemented smart plug system meets K10026 regulation and is worth in electrical safety, energy saving, easy living.

• MALSORI
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• no.45
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• pp.1-14
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• 2003

This paper criticizes S. Kim (1992), claiming that the perception of place cues in the reduced stop consonant clusters ('reducing' means 'cutting off' the acoustic silence in stop clusters) largely depends on the acoustic characteristics such as formant transition and noise frequency distribution of stop burst, rather than the closure duration time as advocated by S. Kim (1992). The claim is based on the perception test conducted upon 111 stimuli over 10 subjects. The finding is that, when the closure duration is cut off up to the point where only one stop is perceived, place of the second stop, not the first one, in the cluster is in most cases perceived regardless of the places of the first and second stops. It is likely that the place cues of the stop in the prevocalic position mask those in the postvocalic position.