• 제목/요약/키워드: stress signals

검색결과 329건 처리시간 0.025초

Structural health monitoring using piezoceramic transducers as strain gauges and acoustic emission sensors simultaneously

  • Huo, Linsheng;Li, Xu;Chen, Dongdong;Li, Hongnan
    • Computers and Concrete
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    • 제20권5호
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    • pp.595-603
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    • 2017
  • Piezoceramic transducers have been widely used in the health monitoring of civil structures. However, in most cases, they are used as sensors either to measure strain or receive stress waves. This paper proposes a method of using piezoelectric transducers as strain gauges and acoustic emission (AE) sensors simultaneously. The signals received by piezoceramic transducers are decomposed into different frequency components for various analysis purposes. The low-frequency signals are used to measure strain, whereas the high-frequency signals are used as acoustic emission signal associated with local damage. The b-value theory is used to process the AE signal in piezoceramic transducers. The proposed method was applied in the bending failure experiments of two reinforced concrete beams to verify its feasibility. The results showed that the extracted low-frequency signals from the piezoceramic transducers had good agreement with that from the strain gauge, and the processed high-frequency signal from piezoceramic transducers as AE could indicate the local damage to concrete. The experimental results verified the feasibly of structural health monitoring using piezoceramic transducers as strain gauges and AE sensors simultaneously, which can advance their application in civil engineering.

원격측정장치를 이용한 설치류의 생체신호 측정 및 분석 (Measurement and Analysis of Rodent Biological Signals using Telemetry System)

  • 김창환;허경행
    • 한국군사과학기술학회지
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    • 제14권6호
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    • pp.1159-1165
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    • 2011
  • Telemetry techniques of rats have been used for assessing safety pharmacology of drugs and chemicals. Biological signals including blood pressure and heart rate measured under anesthesia were significantly different from those obtained under normal conditions. The stress of restraint in awake animals can also affect the accuracy of physiological evaluation. This paper details the surgery required to allow key cardiovascular parameters to be determined. The telemetric measurement of cardiovascular parameters such as blood pressure, heart rate, electrocardiograph(ECG) established. We carried out the continuous monitoring of cardiovascular parameters using the telemetry system in F344 rats. During the measurement, no significant changes were observed in the heart rate and blood pressure. ECG signals and body temperature were also constant during the measurement of biological signals. With the results of this study, we conclude that this telemetry system can be applied usefully for the assesment of biological parameters in the rats.

산림 산책 전후 뇌파 및 맥파 분석을 통한 치유효과 검증 연구 (Study on the Verification of Healing Effect through Brain and Pulse Wave Analyses before and after Forest Walking)

  • 김민수;염정헌
    • 한국환경과학회지
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    • 제33권4호
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    • pp.249-256
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    • 2024
  • This study aimed to verify the healing effect through brain and pulse wave analyses before and after a forest walk to the university students. Bio-signals of brain and pulse waves were measured using Omnifit Mindcare. After analyzing four brain wave items such as concentration and four pulse wave items such as heart health, it is identified that the stress level of university students was higher than that of the general public, and the brain stress level was approached to the normal range for 19 people with clear improvement. For pulse waves, a statistically significant decrease in sympathetic nerve activity (%) was confirmed. Although the slight fluctuations within the normal range were caused by short term and individual differences, it showed that the forest walking is partially effect on the relieving stress.

HRV를 이용한 자기공명영상 소음의 시간 변화에 따른 스트레스 평가 (Evaluation on the stress using HRV according to elapsed time of MRI noise)

  • 예수영;김동현
    • 융합신호처리학회논문지
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    • 제16권2호
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    • pp.50-55
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    • 2015
  • 자기공명영상 촬영시 발생되는 소음은 100 dB정도의 큰 소리로 인체에 심리적 생리적으로 많은 영향을 미친다. 따라서 본 연구는 자기공명영상 소음에 따른 성인 남녀의 심박동변이률 신호의 주파수 분석을 통해 스트레스 정도를 분석하였다. 실험 방법은 귀마개를 착용하여 안정상태에서 15분간 심전도 신호를 측정하였다. 그 후 자기공명영상 장비에서 측정한 약 100dB의 음원을 30분동안 들으면서 동시에 심전도 신호를 측정하였다. 약 100 dB정도에서의 자기공명영상 소음은 HRV 분석 결과 교감신경과 부교감신경간의 불균형을 초래하여 스트레스 상태를 유발하였다. 안정 상태에서 10분까지 최대의 스트레스 상태를 나타내고, 15분부터는 스트레스 정도가 줄어들어 30분에는 안정 상태 보다 높은 스트레스 상태를 나타내었다. 본 연구를 기초 자료로 하여 자기공명영상 촬영 종사자들은 환자의 청각보호에 관심을 가지고, 자기공명영상 소음에 관한 객관적인 지표연구가 필요할 것으로 사료된다.

스트레스 내성 식물 호르몬인 앱시스산의 산업적 활용 전망 (Future Prospects for Industrial Application of Abscisic acid, a Stress-resistant Phytohormone)

  • 이정호;김승희;유하영
    • Korean Chemical Engineering Research
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    • 제58권4호
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    • pp.514-523
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    • 2020
  • 이동성이 없는 식물은 주위 환경에서 다양한 형태의 스트레스를 받게 되는데 이를 대응하기 위한 방어 기작으로 스트레스 저항성 단백질과 조절 단백질이 생성된다. 앱시스산은 이러한 신호전달 역할을 하는 호르몬 분자로 잘 알려져 있으며, 잎의 노화, 종자의 휴면 등 식물의 생리적 반응에도 관여한다. 특히 식물이 아닌 동물, 조류(algae) 등 다른 생물계에서도 다양한 기능을 수행하는 것으로 밝혀졌다. 본 총설에서는 앱시스산의 생합성 및 신호전달 과정 그리고 그 기능에 대하여 조사하였고, 농생명공학, 의생명공학, 산업생명공학을 포함한 다양한 생명공학분야에서 앱시스산을 활용한 작물량 증대, 질병 치료제 개발, 바이오에너지 생산 등 최신 응용 연구 및 산업적 활용에 대한 동향을 살펴보았다.

A NOTE ON NEW METALLIC BONDING ORBITAL

  • Oh, Hung-Kuk
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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    • pp.156-162
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    • 1994
  • The existence of the elastic anisotropic channeling is based on the experimental evidences. The rotating electron pairs orbits play the role of basic bonding orbitals. The abnormal signals from ligand domain and train-membrane in cancer cell, Deformation in fatigue and creep at low stress, con duction, superconduction and semiconduction are all from the new metallic bonding orbital.

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Computational Identification and Comparative Genomic Analysis of Soybean Oxidative Stress-Related Genes

  • Arti, Sharma;Mun, Bong-Gyu;Yun, Byung-Wook
    • Current Research on Agriculture and Life Sciences
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    • 제32권1호
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    • pp.43-52
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    • 2014
  • Reactive oxygen and nitrogen species (ROS and RNS, respectively) are messengers that carry signals to alter the redox state in order to activate plant responses and other physiological processes, such as differentiation, aging, senescence, and pathogen defense. Quite a large number of genes are involved in this signaling and lead to oxidative stress in plants. Although the role of ROS/RNS during stress conditions is well documented, a comprehensive list of genes and comparative study of these genes has not yet been completed. Accordingly, the in silico identification of oxidative stress-related genes was performed for soybeans and Arabidopsis. These genes were also studied in relation to multiple domain prediction. The presence of domains like dehydogenase and ATPase suggests that these genes are involved in various metabolic processes, as well as the transportation of ions under optimal environmental conditions. In addition to a sequence analysis, a phylogenetic analysis was also performed to identify orthologous pairs among the soybean and Arabidopsis oxidative stress-related genes based on neighbor joining. This study was also conducted with the objective of further understanding the complex molecular signaling mechanism in plants under various stress conditions.

Development of a System Observing Worker's Physiological Responses and 3-Dimensional Biomechanical Loads in the Task of Twisting While Lifting

  • Son, Hyun Mok;Seonwoo, Hoon;Kim, Jangho;Lim, KiTaek;Chung, Jong Hoon
    • Journal of Biosystems Engineering
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    • 제38권2호
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    • pp.163-170
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    • 2013
  • Purpose: The purpose of this study is to provide analysis of physiological, biomechanical responses occurring from the operation to lifting or twist lifting task appears frequently in agricultural work. Methods: This study investigated the changes of physiological factors such as heart rate, heart rate variability (HRV) and biomechanical factors such as physical activity and kinetic analysis in the task of twisting at the waist while lifting. Results: Heart rates changed significantly with the workload. The result indicated that the workload of 2 kg was light intensity work, and the workload of 12 kg was hard intensity work. Physical activity increased as the workload increased both on wrist and waist. Besides, stress index of the worker increased with the workload. Dynamic load to herniated discs was analyzed using inertial sensor, and the angular acceleration and torque increased with the workload. The proposed measurement system can measure the recipient's physiological and physical signals in real-time and analyzed 3-dimensionally according to the variety of work load. Conclusions: The system we propose will be a new method to measure agricultural workers' multi-dimensional signals and analyze various farming tasks.

7구역진단기의 임상응용에 대한 고찰 (2) - 각 제품에 따른 원리와 판독의 비교 - (A Study on the Clinical Use of 7-zone-Diagnostic System (2) - the Comparative Analysis of the Rule and the Decipher for each Equipment -)

  • 송범용
    • Journal of Acupuncture Research
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    • 제23권5호
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    • pp.11-21
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    • 2006
  • The 7-zone-diagnostic system(ABR-2000, BIO MEDIC 700Plus, CP-6000A, OMD 3000, VEGA-DFM 722) is a diagnostic device which applies pulse signals to predetermined bodily locations. Applying alternating positive and negative stress to tissues with positive and negative pulses first manifests itself as negative and positive wave forms. This system make a diagnosis of functional disorder or some typical organic diseases include stress of the mind or the body, and the energetic situation, reserves. We are known a disorder or disease throw the result charts. And these result represents various characteristic signals are assisted diagnosis and care. These result chart contains disorder flow wave forms and some valuable diagnostic hints or marks. But we have several various products for the 7-zone-diagnostic system. I think that we need the comparative analysis of the general rule and the decipher for each equipment. Because these letters(marks) each product are different, we necessary various plentiful research and suitable statistics in these points. And we must carry out many various research in the future.

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Backbone NMR Assignments of a Prokaryotic Molecular Chaperone, Hsp33 from Escherichia coli

  • Lee, Yoo-Sup;Won, Hyung-Sik
    • 한국자기공명학회논문지
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    • 제16권2호
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    • pp.172-184
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    • 2012
  • The prokaryotic molecular chaperone Hsp33 achieves its holdase activity upon response to oxidative stress particularly at elevated temperature. Despite many structural studies of Hsp33, which were conducted mainly by X-ray crystallography, the actual structures of the Hsp33 in solution remains controversial. Thus, we have initiated NMR study of the reduced, inactive Hsp33 monomer and backbone NMR assignments were obtained in the present study. Based on a series of triple resonance spectra measured on a triply isotope-[$^2H/^{13}C/^{15}N$]-labeled protein, sequence-specific assignments of the backbone amide signals observed in the 2D-[$^1H/^{15}N$]TROSY spectrum could be completed up to more than 96%. However, even considering the small portion of non-assigned resonances due to the lack of sequential connectivity, we confirmed that the total number of observed signals was quite smaller than that expected from the number of amino acid residues in Hsp33. Thus, it is postulated that peculiar dynamic properties would be involved in the solution structure of the inactive Hsp33 monomer. We expect that the present assignment data would eventually provide the most fundamental and important data for the progressing studies on the 3-dimensional structure and molecular dynamics of Hsp33, which are critical for understanding its activation process.