• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.10-12
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• 2014

In ISO 10140-5:2010, defines the reverberation time conditions of the receiving room. The sound absorption side of test specimen is installed in the source room generally. In this study, examined at the change in the sound insulation characteristics for the test specimen of asymmetric structure attached sound absorbing material by changing the installed position. A difference of sound insulation performance was maxium Rw 1 dB, it is preferable to place the larger sound absorption area in source room.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.18-20
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• 2004

An interior permanent magnet synchronous motor (IPMSM) is receiving increased attention for many industrial applications because of its high torque to inertia ratio, superior power density, and high efficiency. IPMSM is necessary to use the accurate information of the inductace for the precise torque control owing to the reluctance torque. This paper presents two method to measure the each-axis inductance. The first method uses the peak current that is measured by applying the pulsewise voltage on the each position of IPMSM. The second uses the hysteresis loop of the flux and current measured by applying the positive and negative pulsewise voltage alternately on the each-axis.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.353-362
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• 2008

Operation data and fault data are recorded at the TCMS(Train Control and Monitoring System) of train are very important record for repairs and inspection of train. there are two ways to transfer the data today. one is using memory card and the other is using wireless communications. This paper is proposed about TCMS wireless depot analytical equipment that transfers data recorded in train to depot equipment via wireless method. The TCMS wireless depot equipment configuration is an AP(Access Point) and a central server PC at depot equipment. This method has the advantage of decrease of personnel expenses, collection time and convenience of staffs. This paper is verified about the utility of use, efficient establishment position of an AP at depot, the safety of data receiving, the exactitude of data and the shortening of transmission time. and this equipment is now operating at shin-jeong depot of SeoulMetro.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1835-1838
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• 2002

This paper presents the statistical analysis and the effects of the ionospheric scintillation to the satellite communication system. By receiving 1.694 GHz carrier wave of telemetry signal transmitted from Geostationary Meteorological Satellite (GMS-5) at both of King Mongkut's Institute of Technology Ladkrabang, Bangkok. and Chiang Mai University, Thailand, in order to study the characteristics of Ionospheric scintillation in case of different geomagnetic latitude Position; the statistical analysis of S$_4$, fade duration. message reliability and fade rate can be obtained . The data was analyzed from february 2000 to January 2001

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.11-13
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• 2005

An interior permanent magnet synchronous motor (IPMSM) is receiving increased attention for many industrial applications because of its high torque to inertia ratio, superior power density, and high efficiency. IPMSM is necessary to use the accurate information of the inductance for the precise torque control owing to the reluctance torque. This paper presents two method to measure the each-axis Inductance. The first method uses the peak current that is measured by applying the pulsewise voltage on the each position of IPMSM. The second uses the hysteresis loop of the flux and current measured by applying the positive and negative pulsewise voltage alternately on the each-axis.

• Proceedings of the KIEE Conference
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• summer
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• pp.827-829
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• 2004

A characteristic of the rotating machine that has been receiving relatively little attention is the axial force on the rotor versus its axial displacement from magnetic neutral position. A knowledge of this force is essential to the economic application of thrust bearings for rotating machine and their connected loads. In this paper this axial force is analyzed and calculated and test values are verified with two different machines.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.49-50
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• 2023

The purpose of this study was to review ways to increase mechanical performance and apply to actual structures by reinforcing AL perforated sheets, which are industrial by-products generated after capacitor production, with mortar to reinforce the stress of structural members. The AL perforated sheet was reinforced so that it behaves integrally at the position receiving compression, tension, and bending stress. It was confirmed that the stress received by the AL perforated sheet increased according to the number of reinforcements, and as a result, the mechanical properties were improved.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.243-251
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• 2010

Based on theories and case analysis, the present research concerns the deduction of useful results about the basic stage for setting up a planar plan for children's play therapy facility, which cures children's psychological problems such as social maladaptation by means of play rather than language. The case analysis was sub-categorized into movement in each area, relative position among areas, and the size of each room. Detailed investigations were made concerning: First, Adjacent areas of each area. Second, Movement plan, which was sub-categorized into the movement of therapists and that of the children receiving therapy and guardians; area was sub-categorized into management area, therapy area and service area. Third, the size of each area measured was calculated to be expressed as the percentage of the total size. The result is as follows: (1) As for adjacent areas, in some cases management area and service area were adjacent, with isolated therapy area; whereas in the other cases, service area and information area, which is a part of management area, were placed along the doorway, with therapy area between them and therapist area, which is the other part of management area, behind them. (2) As for movement, the movement of therapists and that of children receiving therapy were same; whereas the movement of guardians was allowed only up to the middle part of the therapy facilities, and there was almost no entry of guardians into the play therapy rooms located in the inner parts. This is because they do not show the details of their therapy for children to guardians. (3) As for size, the area of independent facilities were similar; whereas institutional facilities in general had larger waiting room and unlike independent facilities, were of diverse size.

• Journal of Multimedia Information System
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• v.5 no.3
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• pp.163-170
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• 2018

We developed a multicast communication packet radio protocol using a time-sharing tablet system ("wireless token ring") to achieve the efficient exchange of files among packet radio terminals attached to swans. This paper provides an overview of the system and the protocol of the packet communications. The packet device forming the main part of the transceiver developed is the Texas Instruments CC2500. This device consists of one call-up channel and one data transmission channel and could improve error frame correction using FEC (forward error correction) with 34.8 kbps MSK and receiving power of at least -64 dBm (output 1 dBm at distance of 200 m using 3 dBi antenna). A time-sharing framework was determined for the wireless token ring using call sign ordinals to prevent transmission right loss. Tests using eight stations showed that resend requests with the ARQ (automatic repeat request) system are more frequent for a receiving power supply of -62 dBm or less. A wireless token ring system with fixed transmission times is more effective. This communication protocol is useful in cases in which frequency resources are limited; the energy consumed is not dependent on the transmission environment (preset transmission times); multiple terminals are concentrated in a small area; and information (position data and vital data) is shared among terminals under circumstances in which direct communication between a terminal and the center is not possible. The method allows epidemiological predictions of avian influenza infection routes based on vital data and relationships among individual birds based on the network topology recorded by individual terminals. This communication protocol is also expected to have applications in the formation of multiple in vivo micromachines or terminals that are inserted into living organisms.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.1
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• pp.40-46
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• 2011

In the field application of the conventional acoustic nonlinear technique using through transmission of bulk waves to evaluate the contact acoustic nonlinearity(CAN) in solid-solid contact interfaces like as in the closed crack, it has difficulty to access inner position for attaching the pulsing or receiving transducer. In the present study, a new reflection technique has been suggested to measure the acoustic nonlinearity in solid-solid contact interfaces, which uses both of pulsing and receiving transducers on the same side of target and so that it will be very useful for the field application. For this, based on the linear and the nonlinear contact stiffness estimated by the power-model of the contacting pressure, the nonlinear parameter of the reflected ultrasonic wave at the interfaces has been theoretically calculated. Experimental results in contact interfaces of A1606l-T6 alloy specimens with loading pressure showed good agreement with the theoretical predictions, which proves the validity of the suggested reflection mode technique.