• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.257-259
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• 2008

Acceleration time history (ATH) used in the seismic analysis should envelop a target power spectral density (PSD) function in addition to the design response spectrum in order to have sufficient energy at each frequency for the purpose of ensuring adequate load. Even though design regulations require the ATH used in seismic analysis to meet a target PSD function, the reason that ATHs meet to a target PSD function is not described. Thus, artificial ATHs for high PSD function and artificial ATHs for low PSD function are generated. And then elastic and inelastic single-degree-of-freedom (SDOF) systems are loaded with these artificial time histories as the earthquake load. As a result, linear response and inelastic response of SDOF systems are affected by PSD function.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.637-644
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• 2006

Acceleration time history used in the seismic analysis of nuclear porter plant structure should envelop a target power spectral density (PSD) function in addition to design response spectrum. Current regulation guide defines the target PSD function only for the U.S. URC RG 1.60 Design Response Spectrum. This paper proposes a technical scheme to obtain the target PSD function compatible with generally defined design response spectrum. The scheme includes the methodology for design-spectrum compatible motion history in order to minimize the variation of the derived target PSD function. The PSD calculation procedure follows simple and practical methods allowed within regulation. Effectiveness of the proposed scheme is identified through an example problem. The design response spectrum In the example is based on U.S. NRC RG 1.60 but amplifies the spectral acceleration amplitudes above 9Hz. The target PSD function with little variation can be constructed with the reduced time history ensemble.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1A
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• pp.59-67
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• 2008

Acceleration time history used in the seismic analysis of nuclear power plant structures should envelop a target power spectral density (PSD) function in addition to the design response spectrum in order to have sufficient energy at each frequency for the purpose of ensuring adequate load. The safety for complex long-span highway bridges cannot be over-emphasize. An alternative method to improve the seismic capacity is to ensure the minimum PSD function of the applied seismic load. This study proposes a technical scheme to obtain the reference power spectral density function by using artificial earthquakes which are compatible with the highway bridge design spectrum.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.6
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• pp.668-672
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• 2005

In this paper, a distance measuring system using a PSD sensor in proposed, which in suitable for low-cost localization sensor of a mobile robot. Because the distance-voltage output of PSD sensor has a non-linear property, the linearizing function is proposed through the experimental characteristics of the sensor. And the characteristics are tested and the distance-voltage data are measured in various colors and materials of object. The parameters of the proposed function are extracted by using the measured data. Finally, the performance and the accuracy of the developed system are verified according to the comparison of the distance by the proposed function with the real distance.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1427-1430
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• 2005

In this paper, the range finder system using a PSD sensor suitable for low-cost localization sensor of a mobile robot. Because the distance-voltage output of a PSD sensor has a non-linear property, the linearizing function is proposed through the experimental characteristics of the sensor. And the characteristics are tested and the distance-voltage data are measured in various colors and materials of object. For a known environment, a mobile robot scans the surroundings using a PSD sensor that can rotate $360^{\circ}$. Finally, the performance and accuracy of the developed system are verified according to the comparison the distance by proposed function with real distance

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.23-30
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• 2007

The effectiveness of a pogo suppression device (PSD) on the response of piping system simulating the propellant supply lines of the rocket engines was investigated experimentally by other researchers. In this study, the simplified analytical model was made, and the key parameters which are difficult to derive theoretically were identified in combination with the previous experimental work. In other words, the flow transient equations for a PSD system and the key parameters used to decide the instability of the system from the linearized transfer function including inertance, compliance, and resistance were derived. From the analysis, the values of key parameters could be determined from the experimental results.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1397-1404
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• 2011

Metro serves more than a basic function of transporting passengers between short distances but became a crucial part of civic culture due to the fact that citizens demand various facilities for better life style. Therefore, domestic metro cuts off train noise and air dust, provides pleasant platform surroundings by offering effective HVAC, and establishes PSD (Platform Screen Door) system to prevent falls into train tracks. To control and interlock EMU Door and PSD to avoid passenger complaint and revenue service obstructions, stability and reliability of on-board & wayside equipment are required foremost and each line needs to build optimum interface between on-board & wayside equipment. To control PSD, we would like to introduce examples of Busan Metro(BTC : Busan Transportation Corporation) which already utilizes interface between on-board & wayside equipment in various ways and consider optimum interface between on-board & wayside equipment in future PSD system.

• Journal of Pharmacopuncture
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• v.13 no.2
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• pp.67-73
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• 2010

Objective : The purpose of this study is to determine the efficacy and safely of Hwangryunhaedok-tang Pharmacopuncture (HHT-PA) therapy on post-stroke depression (PSD) in stroke patients. Methods : Fifteen PSD patients has been recruited and evaluated with liver function test (LFT) and renal function lest (RFT) and depression scales, Beck Depress ion Inventory (BDI) and Hamilton Depression Rating Scale (HAM-D) before and after HHT-PA treatment. Results : HAM-D score significantly decreased after HHT-PA treatment regard less of improving of motor function. But BDI score did not decrease significantly. All results of LFT and RFT were in normal range before and after HHT-PA treatment Conclusion : These results showed that HHT-PA decrease PSD symptoms and has safety on stroke patients, although has no effect on improving of motor impairment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.917-922
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• 2009

This paper presents a technique to generate road surface profiles in a spatial domain using a power spectral density function. A single track power spectral density function is proposed to describe a road surface profile, which is also applicable for multi-track vehicle response analysis. The roads in lateral direction makes the relation between the coherence of the lateral tracks. The derived road surfaces are compared to ISO(International Organization for Standardization) standards. Generated road profiles are in good agreements with the target road PSD shape and measured coherence relation.

• Proceedings of the KSRS Conference
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• v.1
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• pp.344-347
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• 2006

China Coastal Water (CCW) usually appears in the seas surrounding Jeju Island annually (June?October) and is very pronounced in August. The power spectrum density (PSD), sea level anomalies (SLAs), and sea surface temperatures (SSTs) were found to peak annually and semiannually. The peaks at intervals of 80-, 60-, and 43-days are considered to be influenced by CCW and the Kuroshio Current. Generally, low-salinity water appears to the west of Jeju Island from June through October and gradually propagates to the east, where CCW meets the Tsushima Current. Empirical orthogonal function (EOF) analysis of SLAs and SSTs indicated that the variance in SLAs and SSTs was 55.70 and 98.09% in the first mode, respectively. The PSD for the first mode of EOF analysis of SLAs was stronger in the western than in the eastern waters because of the influence of CCW. The PSD for the EOF analysis of SSTs was similar in all areas (the Yangtze Estuary and the waters to the west and east of Jeju Island), with a period of approximately 260 days.