• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.2
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• pp.176-181
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• 1988

In this paper, the LPC speech synthesizer with Multipulsse excitation is implemented using general-purpose DSP \ulcornerD7720. As the driving function for synthesis filter is used in the amplitude and position of pulse, the Voice/Unvoice decision and pitch period detectioncan be excluded. The synthesizer is implemented with DSP device which is operated on the interrupt mehtod with main computer and on the DMA mehtod with D/A converter. The comparision of synthetic and original waveform, alogn with the listening test, proves the validity of this system.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.285-286
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• 2014

Recently, the unipolar gate power source is preferred in inverter system because of cost reduction reason. In this case, designer uses 0V source for turning-off the switching devices instead of negative voltage at Vee source. If the gate driver circuit has some stray inductance, the gate voltage would happen a surge voltage. This paper analyzes that of stray inductance effect during the switching behavior in the circuit and the proposed solutions were verified by pulse test.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.176-177
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• 2016

본 논문에서는 효율적인 배터리 팩 설계를 위해 300개의 18650 리튬이온 셀의 전기적 특성을 비교분석하였고 통계적 분석을 기반으로 스크리닝 기법을 적용하였다. 300개의 고출력 원통형 18650 리튬이온 배터리 셀을 사용하여 전류적산법 기반 방전 용량(discharged capacity)과 HPPC(hybrid pulse power Characterization) test 기반 충전저항과 방전저항을 추출하였다. 추출한 파라미터를 바탕으로 통계적 분석을 수행하고 스크리닝 기법을 적용하였다. 스크리닝 기법을 적용한 셀과 랜덤으로 추출된 셀을 비교 및 분석하였다.

• Journal of Korean Biological Nursing Science
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• v.15 no.1
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• pp.1-7
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• 2013

Purpose: The research was to investigate the effect of line dance programs on oxygen saturation level and happiness of elderlies. Methods: Researchers had conducted a series of test to measure peripheral blood vessel oxygen saturation level, pulse and happiness level of 47 elderlies from the D district of G city. Collected data were analyzed with ${\chi}^2$-test and independent t-test, equipped with SPSS WIN 17.0. Results: As a result of serial tests, Pre-test and Post-test of line dance performance showed that oxygen saturation of the Experimental group had significant increase following the program and happiness of the Experimental group also had significant increase following the program. Conclusion: In conclusion, with many advantages such as its easiness to access and emulate as well as its ubiquitousness as an aerobic exercise, line dance cannot only be very beneficial to cardiovascular function and relation of elderlies, but also to emotional and psychological effect, considered as a great breakthrough to improve comprehensive well-being in both physical and mental aspects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2583-2588
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• 2009

This study deals with the shock response analysis of HDD subjected to a half-sine shock pulse and its experimental verification. Comparatively, accurate computer simulation allows designers to determine complete mechanical information during the product impact time period, compared with only segmental messages by sensors in a test, to predict potential failures. But, impact/shock simulation technology is rather sensitive to various factors to predict the shock behavior without validation. In our shock simulation, the methodology of analysis with LS-DYNA3D and test validation is adopted to predict the shock behavior of HDD. We can confirm the soundness of the present shock simulation through the comparison with electromagnetic shock test(200G/1ms) and linear drop test(300G/2ms).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.11-16
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• 2006

The object of this study is to develop new examination techniques for detecting the debonds in adhesive interface of different kinds of the material. Ultrasonic signal was modeled by theoretically analyzing ultrasonic propagation phenomenon of the adhesive interface and debonding interface. The test method using the phase reversal of the debonding interface applied to the FRP/Rubber test block. Aluminum/Rubber test block with the flat bottom hole was manufactured to quantitatively evaluate the minimum detection ability of the defects. The pulse echo reflection method and the phase reversal method were mutually compared and it was estimated that the phase reversal method could detect the debonds on the basis of the theoretically predicted ultrasonic signal and ultrasonic test data.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.263-268
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• 2004

In the present study, a Nd;YAG Laser (pulse type) was used to emit ultrasonic signals to a test material. In addition, a total ultrasonic investigation system was designed by adopting a Fabry-Perot interferometer, which receives ultrasonic signals without any contact. For non-destructive test SM45C, which contains some flaws was used as a test material. Because it is easy to align light beam in receiver, and the length of the light beam does not change much even if convex mirror leans towards one side, confocal Fabry-Perot interferometer, which has stable frequency, and PI control are used to correct interfered and unstable signals from temperature, fluctuation and time shift of laser frequency. Stable signals are always obtained by the feedback of PI circuit signals in the confocal Fabry-Perot interferometer. The type, size and position of flaws inside the test material were examined by achieving the stabilization of an interferometer. This study presented a useful method, which could quantitatively investigate the fault of objects by using a Fabry-Perot interferometer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.540-544
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• 2017

In this study, we analyzed the effects of TID(Total Ionizing Dese) and TREE(Transient Radiation Effects on Electronics) on nMOSFET and pMOSFET fabricated by 0.18um CMOS process. The size of nMOSFET and pMOSFET is 100um/1um(W/L). The TID test was conducted up to 1 Mrad(Si) with a gamma-ray(Co-60). During the TID test, the nMOSFET generated leakage current proportional to the applied dose, but that of the pMOSFET was remained in a steady state. The TREE test was conducted at TEST LINAC in Pohang Accelerator Laboratory with a maximum dose-rate of $3.16{\times}10^8rad(si)/s$. In that test nMOESFET generated a large amount of photocurrent at a maximum of $3.16{\times}10^8rad(si)/s$. Whereas, pMOSFETs showed high TREE immunity with a little amount of photocurrent at the same dose rate. Based on the results of this experiment, we will progress the research of the radiation hardening for CMOS unit devices.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.2
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• pp.9-16
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• 2009

The object of this study is to develop new examination technique for detecting debond in adhesive interface of different kinds of materials. Ultrasonic signal was modeled by theoretically analyzing ultrasonic propagation phenomenon of the adhesive interface and debonding interface. The test method using the phase reversal of the debonding interface applied to the FRP/Rubber test block. Aluminum/Rubber test block with the flat bottom hole was manufactured to evaluate quantitatively the minimum detection ability of defects. The pulse echo reflection method and the phase reversal method were mutually compared and it was estimated that the phase reversal method could detect the debond on the basis of the theoretically predicted ultrasonic signal and ultrasonic test data.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1858-1868
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• 2021

Resisting an accidental impact of large commercial aircrafts is an important aspect of advanced nuclear power plant (NPP) design. Especially after the 9·11 event, some regulations were enacted, which required the design of NPPs should consider the accidental impact of large commercial aircrafts. Normal working of equipment is important for stopping reactor under an impact when an NPP is in operation. However, there is a lack of reliable analysis and research on the impact test of nuclear prototype equipment. Therefore, in order to study the response of the equipment under high acceleration impact, a centrifugal pump is selected as the research object to perform the impact test. A horizontal half-sinusoidal pulse wave was applied to the working pump. The test results show that the horizontal response of the motor and flange is greater compared to other parts, as well as the vertical response of the coupling. The stress response of the pump body support and motor support is high, hence these parts should be considered in the design of the pump. Finally, combined with the damage and stress evaluation results of the pump under different amplitudes, the ultimate impact acceleration that the pump can withstand is given.