• Title/Summary/Keyword: Shock response

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Shock Test Signal Analysis using Wavelets (웨이블렛을 이용한 충격신호분석)

  • 안호일
    • Journal of the Korea Institute of Military Science and Technology
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    • v.4 no.1
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    • pp.147-154
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    • 2001
  • The underwater explosion shock test is performed for the evaluation of the shock-resistant capability which is a very critical factor considering the survivability of the battle ship. Some measured signals have impulsive noise and gaussian white noise because of the unstable power supply system and the transient movement of cables during the underwater explosion shock test. The advanced shock signal analysis method which remove the noise of measured signal using the threshold policy of the median filter and the orthogonal wavelet coefficients are proposed. It is verified that the signal-to-noise ratio was improved about 30㏈ by the numerical simulation.

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Hydraulic Shock of Apartment Sewage in Inverse Fluidized Bed Biofilm Reactor (역유동층 생물막 반응기에서 수리학적 충격에 따른 아파트 오수의 처리)

  • 박영식;나영수
    • Journal of Environmental Science International
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    • v.6 no.1
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    • pp.17-24
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    • 1997
  • The objective of this study was to examine the transient response to hydraulic shocks in an Inverse fluidized bed bioflm reactor(IFBBR) for the treatment of apartment sewage. The hydraulic shock experiments, when the system were reached at steady state with each HRT 12, 7, and 4hr, were conducted by chancing twice HRT per day during 3days. The SCOD, SS, DO, and pH of the effluent stream were increased with hydraulic shock, but easily recovered to the steady state of pre-hydraulic shock condition. In spite of hydraulic shock, there were not much variation of biomass concentration, biofilm thickness and biofilm dry density.

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Experiment of a Simple Feed-forward Active Control Method for the Shock Response of a Flexible Beam and Performance Analysis (유연빔의 충격응답에 대한 단순 피드포워드 능동제어 실험 및 성능분석)

  • Pyo, Sang-Ho;Shin, Ki-Hong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.634-639
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    • 2006
  • Active control method is applied to a flexible beam excited by a shock impulse in order to reduce the residual vibrations after the shock event. It is assumed that the shock input can be measured and is always occurred on the same point of the beam. If the system is well identified and the corresponding inverse system is designed reliably, it has shown that a very simple feed-forward active control method may be applied to suppress the residual vibrations without using error sensors and adaptive algorithm. Both numerical simulations and experimental results show a promising possibility of applying to a practical problem. Also, the performance of the method is examined by considering various practical aspects : shock duration, shock magnitude, and control point.

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A Simple Feed-forward Active Control Method for the Shock Response of a Flexible Beam: Experiments and Its Performance Analysis (유연보의 충격응답에 대한 단순 피드포워드 능동제어 실험 및 성능분석)

  • Pyo, Sang-Ho;Shin, Ki-Hong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.6 s.111
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    • pp.651-657
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    • 2006
  • Active control method is applied to a flexible beam excited by a shock impulse in order to reduce the residual vibrations after the shock event. It is assumed that the shock input can be measured and is always occurred on the same point of the beam. If the system is well identified and the corresponding inverse system is designed reliably, it has shown that a very simple feed-forward active control method may be applied to suppress the residual vibrations without using error sensors and adaptive algorithm. Both numerical simulations and experimental results show a promising Possibility of applying to a practical problem. Also, the performance of the method is examined by considering various practical aspects : shock duration, shock magnitude, and control point.

Preliminary Study on Market Risk Prediction Model for International Construction using Fractal Analysis

  • Moon, Seonghyeon;Kim, Du Yon;Chi, Seokho
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.463-467
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    • 2015
  • Mega-shock means a sporadic event such as the earning shock, which occurred by sudden market changes, and it can cause serious problems of profit loss of international construction projects. Therefore, the early response and prevention by analyzing and predicting the Mega-shock is critical for successful project delivery. This research is preliminary study to develop a prediction model that supports market condition analysis and Mega-shock forecasting. To avoid disadvantages of classic statistical approaches that assume the market factors are linear and independent and thus have limitations to explain complex interrelationship among a range of international market factors, the research team explored the Fractal Theory that can explain self-similarity and recursiveness of construction market changes. The research first found out correlation of the major market factors by statistically analyzing time-series data. The research then conducted a base of the Fractal analysis to distinguish features of fractal from data. The outcome will have potential to contribute to building up a foundation of the early shock warning system for the strategic international project management.

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Characterization of a Cadmium-resistant Yeast Strain in Response to Cadmium or Heat Shock Stress

  • Huh, Nam-Eung;Choi, Nack-Shick;Seo, Young-Kyo;Yu, Tae-Shick
    • Journal of Microbiology and Biotechnology
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    • v.4 no.1
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    • pp.30-35
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    • 1994
  • A varient strain of budding yeast, Hansenula anomala B-7 which had been identified to be highly resistant to cadmium ions, were observed by transmission electron microscopy. It was shown that the cells accumulated excess amounts of cadmium ions throughout inside the cell rather than on the cell surface. The cell growth in response to cadmium or heat shock stress has also been investigated. It was observed that the cells precultured in the presence of 500 $\mu$ g/ml of Cd ions grew slower than those precultured at 1, 000 $\mu$ g/ml of the metal ions, when they were cultivated in the media containing 1, 000 $\mu$g/ml of the metal ions. Heat shock, however, stimulated the cell growth transiently, when the cells were allowed to grow in the presence of 1, 000 $\mu$g/ml of the metal ions. But the cells given heat shock for more than 100 min received permanent damage to growth. Effects of both stresses on budding rate was also examined. It revealed that the stresses did not change the budding ratio much, which was contradictory to that observed from the same budding yeast, Saccharomyces cerevisiae. Furthermore, the cells treated with 1, 000 $\mu$g/ml of the metal ions not only induced, but also switched off the expression of several new proteins. Some of the cadmium stress-inducible proteins were estimated to be also induced by heat shock stress.

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Heat Shock Induces Necrosis in Cisplatin-resistant Gastric Cancer Cells through Suppressing JNK1/2 Activation and HSP27 Induction (시스플라틴 내성세포주에서 열충격에 의한 세포사멸에 관한 연구)

  • Lim, Sung-Chul;Choi, Cheol-Hee;Han, Song-Iy
    • Journal of Life Science
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    • v.19 no.12
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    • pp.1705-1711
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    • 2009
  • Carcinoma cells that had acquired resistance to a chemotherapeutic drug often show cross-resistance to various other cytotoxic drugs. In the present study, we explored the effect of heat shock in cisplatin-resistant gastric cancer cells SNU601/Cis2 to figure out the efficacy of hyperthermia in drug-resistant carcinoma. While SNU601/WT cells showed a high-sensitivity response to heat shock by dying through apoptosis, SNU601/Cis2 cells were considerably resistant to mild heat shock, but died by necrosis upon treatment with harsh heat shock. The occurrence of necrosis in SNU601/Cis2 cells was linked to the suppression of both JNK1/2 activation and HSP27 induction in response to heat shock. Since necrosis is closely associated with tumor malignancy and poor prognosis through inflammatory responses, our result suggests that hyperthermic treatment should be carefully applied when it is combined with chemotherapy.

Regulation of $CO_2$ Fixation Gene Expression in Acidithiobacillus ferrooxidans ATCC 23270 by Lix984n Shock

  • Wang, Wei;Xiao, Shuiming;Chao, Jing;Chen, Qijiong;Qiu, Guanzhou;Liu, Xueduan
    • Journal of Microbiology and Biotechnology
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    • v.18 no.11
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    • pp.1747-1754
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    • 2008
  • Acidithiobaeillus ferrooxidans ATCC 23270 is an important model organism for bioleaching and bioremediation studies owing to its diverse metabolic capabilities, whereas lix984n is a widely used extractant. Little is known about the response of cbb genes in A. ferrooxidans to lix984n shock. Thus, to elucidate the response of the $CO_2$ fixation genes in A. ferrooxidans ATCC 23270 to the addition of lix984n, the gene expression of cbb genes was examined using a real-time PCR. Although a natural increase or decrease in the expression of most cbb genes was observed after 5 min of shock with 3% (v/v) lix984n, sdhC and cbbR exhibited quick responses to the shock. Ten min of shock had a greater effect on the cbb gene expression, yet 15 min of shock had a significant effect on the Calvin cycle in A. ferrooxidans ATCC 23270, as the expression of all the cbb genes reached a very high level. Therefore, after a short lix984n shock, a solution of A. ferrooxidans can be re-used for bioleaching.

Effect of Arsenic on Heat Shock Protein and Vascular Contractility of Rat Aorta (횐쥐 대동맥의 수축반응과 열충격단백질에 대한 비소의 영향)

  • 박태규;권윤정;김중영
    • Journal of Environmental Science International
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    • v.12 no.6
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    • pp.651-657
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    • 2003
  • In order to examine if arsenic, one of environmental stresses, contributes to hypertension as one of cardiovas cular pathological factors, this study was perfarmed in vivo and in vitro, using intacted or pithed rats and aorta ring preparation, respectively. And also the relationship between expression of heat shock protein (HSP) 90 and vasoactives-induced contractile response was elucidated. To measure blood pressure, the carotid arterial pressure was recorded on physiograph(Grass Co. 79E) connected to strain gauge. On the other hand, contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And HSP was detacted by Western blotting whole cell Iysis. Preganglionic nerve stimulation was increased by 26.0% in arterial pressure of rat treated with arsenic. Vascular contractile response was monitored and HSP were measured by Western blotting of whole Iysis prepared from samples exposed with 0, 0.5, 1, 2 and 4 mM of arsenic for 8 hours. The dose-vascular responses of potassium chloride were augmented by increasing dose of arsenic in the strips exposed to arsenic for 8 hours, and were not augmented for 1, 3, 5 hours. And the response of relaxation of rat aorta induced by histamine was not influenced by arsenic stress. The increase of HSP 90 expression in rat aorta was pronounced at 8 hours after 4 mM of arsenic treatment, but HSP 60 expression was not. Arsenic stress not only increased the expression of HSP 90 in the rat aorta, but also augmented contractions to potassium chloride. These results indicated that arsenic stress was sufficient to induce heat shock protein 90, resulting in increased vascular contractility in rat aorta.

Characterization of Heat Shock Protein 70 in Freshwater Snail, Semisulcospira coreana in Response to Temperature and Salinity (담수산다슬기, Semisulcospira coreana의 열충격단백질 유전자 특성 및 발현분석)

  • Park, Seung Rae;Choi, Young Kwang;Lee, Hwa Jin;Lee, Sang Yoon;Kim, Yi Kyung
    • Journal of Marine Life Science
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    • v.5 no.1
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    • pp.17-24
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    • 2020
  • We have identified a heat shock protein 70 gene from freshwater snail, Semisulcospira coreana. The freshwater snail HSP70 gene encode a polypeptide of 639 amino acids. Based on bioinformatic sequence characterization, HSP70 gene possessed three classical signature motifs and other conserved residues essential for their functionality. The phylogenetic analysis showed that S. coreana HSP70 had closet relationship with that of golden apple snails, Pomacea canaliculata. The HSP70 mRNA level was significantly up-regulated in response to thermal and salinity challenges. These results are in agreement with the results of other species, indicating that S. coreana HSP70 used be a potential molecular marker in response to external stressors and the regulatory process related to the HSP70 transcriptional response can be highly conserved among species.