• 제목/요약/키워드: Critical Spectrum

검색결과 251건 처리시간 0.024초

고압 배터리 팩의 임피던스 스펙트럼 측정용 휴대용 임피던스 분광기 (A Portable Impedance Spectroscopy Instrument for the Measurement of the Impedance Spectrum of High Voltage Battery Pack)

  • 굴 라힘;최우진
    • 전력전자학회논문지
    • /
    • 제26권3호
    • /
    • pp.192-198
    • /
    • 2021
  • The battery's State of Health (SOH) is a critical parameter in the process of battery use, as it represents the Remaining Useful Life (RUL) of the battery. Electrochemical Impedance Spectroscopy (EIS) is a widely used technique in observing the state of the battery. The measured impedance at certain frequencies can be used to evaluate the state of the battery, as it is intimately tied to the underlying chemical reactions. In this work, a low-cost portable EIS instrument is developed on the basis of the ARM Cortex-M4 Microcontroller Unit (MCU) for measuring the impedance spectrum of Li-ion battery packs. The MCU uses a built-in DAC module to generate the sinusoidal sweep perturbation signal. Moreover, it performs the dual-channel acquisition of voltage and current signals, calculates impedance using a Digital Lock-in Amplifier (DLA), and transmits the result to a PC. By using LabVIEW, an interface was developed with the real-time display of the EIS information. The developed instrument was suitable for measuring the impedance spectrum of the battery pack up to 1000 V. The measurement frequency range of the instrument was from 1 hz to 1 Khz. Then, to prove the performance of the developed system, the impedance of a Samsung SM3 battery pack and a Bexel pouch module were measured and compared with those obtained by the commercial instrument.

Management and rehabilitation of moderate-to-severe diabetic foot infection: a narrative review

  • Chi Young An;Seung Lim Baek;Dong-Il Chun
    • Journal of Yeungnam Medical Science
    • /
    • 제40권4호
    • /
    • pp.343-351
    • /
    • 2023
  • Diabetic foot is one of the most devastating consequences of diabetes, resulting in amputation and possibly death. Therefore, early detection and vigorous treatment of infections in patients with diabetic foot are critical. This review seeks to provide guidelines for the therapy and rehabilitation of patients with moderate-to-severe diabetic foot. If a diabetic foot infection is suspected, bacterial cultures should be initially obtained. Numerous imaging studies can be used to identify diabetic foot, and recent research has shown that white blood cell single-photon emission computed tomography/computed tomography has comparable diagnostic specificity and sensitivity to magnetic resonance imaging. Surgery is performed when a diabetic foot ulcer is deep and is accompanied by bone and soft tissue infections. Patients should be taught preoperative rehabilitation before undergoing stressful surgery. During surgical procedures, it is critical to remove all necrotic tissue and drain the inflammatory area. It is critical to treat wounds with suitable dressings after surgery. Wet dressings promote the formation of granulation tissues and new blood vessels. Walking should begin as soon as the patient's general condition allows it, regardless of the wound status or prior walking capacity. Adequate treatment of comorbidities, including hypertension and dyslipidemia, and smoking cessation are necessary. Additionally, broad-spectrum antibiotics are required to treat diabetic foot infections.

제주 연안에서 어획된 두툽상어의 청각 특성 (Auditory Characteristics of Tiger shark Scyliorhinus torazame caught in the Coast of jeju Island)

  • 안장영;최찬문;이창헌
    • 수산해양기술연구
    • /
    • 제47권3호
    • /
    • pp.234-240
    • /
    • 2011
  • In order to obtain the fundamental data about the behavior of sharks by underwater audible sound, this experiment was carried out to investigate the auditory characteristics of tiger shark Scyliorhinus torazame which was caught in the coast of Jeju Island by heart rate conditioning method using pure tones coupled with a delayed electric shock. The audible range of tiger shark extended from 80Hz to 300Hz with a peak sensitivity at 80Hz including less sensitivity at 300Hz. The mean auditory thresholds of tiger shark at the frequencies of 80Hz, 100Hz, 200Hz and 300Hz were 90dB, 103dB, 94dB and 115dB, respectively. The positive response of tiger shark was not evident after the sound projection of over 300Hz. At the results, the sensitive frequency range of tiger shark is narrower than that of fish that has swim bladder. In addition, it is assumed that the most sensitive frequency in auditory thresholds of Chondrichthyes is lower than that of Osteichthyes. Critical ratios of tiger shark measured in the presence of masking noise in the spectrum level range of about 60-70dB (0dB re $1{\mu}Pa/\sqrt{Hz}$) increased from minimum 27dB to maximum 39dB at test frequencies of 80-200Hz. The noise spectrum level at the start of masking was distributed at the range of about 65dB within 80-200Hz.

제주 연안에서 어획된 붕장어의 청각 능력 (Hearing Ability of Conger eel Conger myriaster caught in the Coast of jeju Island)

  • 안장영;박용석;최찬문;김석종;이창헌
    • 수산해양기술연구
    • /
    • 제48권4호
    • /
    • pp.479-486
    • /
    • 2012
  • In order to obtain the fundamental data about the behavior of conger by underwater audible sound, this experiment was carried out to investigate the hearing ability of Conger eel Conger myriaster which was in the coast of Jeju Island by heartbeat conditioning method using pure tones coupled with a delayed electric shock. The audible range of conger eel extended from 50Hz to 300Hz with a peak sensitivity at 80Hz including less sensitivity over 200Hz. The mean auditory thresholds of conger eel at the frequencies of 50Hz, 80Hz, 100Hz, 200Hz and 300Hz were 105dB, 92dB, 96dB, 128dB and 140dB, respectively. The positive response of conger eel was not evident after the sound projection of over 200Hz. At the results, the sensitive frequency range of conger eel is narrow in spite of swim bladder. Auditory masking was determined for Conger eel by using masking stimuli with the spectrum level range of about 60~70dB (0dB re $1{\mu}Pa/\sqrt{Hz}$). According to white noise level, the auditory thresholds increased as compared with thresholds in a quiet background noise including critical ratio at 68dB of white noise from minimum 26dB to maximum 30dB at test frequencies of 80Hz and 100Hz. The noise spectrum level at the start of masking was distributed at the range of about 68dB within 80~100Hz.

EXPERIMENTAL ANALYSES OF SPALLATION NEUTRONS GENERATED BY 100 MEV PROTONS AT THE KYOTO UNIVERSITY CRITICAL ASSEMBLY

  • Pyeon, Cheol Ho;Azuma, Tetsushi;Takemoto, Yuki;Yagi, Takahiro;Misawa, Tsuyoshi
    • Nuclear Engineering and Technology
    • /
    • 제45권1호
    • /
    • pp.81-88
    • /
    • 2013
  • Neutron spectrum analyses of spallation neutrons are conducted in the accelerator-driven system (ADS) facility at the Kyoto University Critical Assembly (KUCA). High-energy protons (100 MeV) obtained from the fixed field alternating gradient accelerator are injected onto a tungsten target, whereby the spallation neutrons are generated. For neutronic characteristics of spallation neutrons, the reaction rates and the continuous energy distribution of spallation neutrons are measured by the foil activation method and by an organic liquid scintillator, respectively. Numerical calculations are executed by MCNPX with JENDL/HE-2007 and ENDF/B-VI libraries to evaluate the reaction rates of activation foils (bismuth and indium) set at the target and the continuous energy distribution of spallation neutrons set in front of the target. For the reaction rates by the foil activation method, the C/E values between the experiments and the calculations are found around a relative difference of 10%, except for some reactions. For continuous energy distribution by the organic liquid scintillator, the spallation neutrons are observed up to 45 MeV. From these results, the neutron spectrum information on the spallation neutrons generated at the target are attained successfully in injecting 100 MeV protons onto the tungsten target.

제주 연안에서 양식된 참조기의 청각 능력 (Hearing Ability of Redlip croaker Pseudosciaena polyactis cultured in the Coastal Sea of Jeju)

  • 안장영;김석종;최찬문;박용석;이창헌
    • 수산해양교육연구
    • /
    • 제28권2호
    • /
    • pp.384-390
    • /
    • 2016
  • The purpose of this paper is to improve the availability of underwater sound by the fundamental data on the hearing ability of Redlip croaker Pseudosciaena polyactis, which is cultured according to the cultivation technology, recently. The auditory thresholds of Redlip croaker were determined at 6 frequencies from 80Hz to 800Hz by heartbeat conditioning method using pure tones coupled with a delayed electric shock. The audible range of the Redlip croaker extended from 80Hz to 800Hz with the best sensitive frequency range including little difference in hearing ability from 80Hz to 500Hz. In addition, the auditory thresholds over 800Hz increased rapidly. The mean auditory thresholds of the Redlip croaker at the test frequencies from 80Hz to 800Hz were 90.7dB, 93.4dB, 92.9dB, 94.4dB, 95.5dB and 108dB, respectively. Auditory masking for the redlip croaker was measured using masking stimuli with the spectrum level range of about 66, 71, 75dB (0dB re $1{\mu}Pa/{\sqrt{Hz}}$). According to white noise level, the auditory thresholds increased as compared with thresholds in a quiet background noise. The Auditory masking by the white noise spectrum level was stared over about 70dB within 80~500Hz. Critical ratio ranged from minimum 20.7dB to maximum 25.5dB at test frequencies of 80Hz~500Hz.

TCNQ가 흡착된 N-docosylquinolium-TCNQ LB 유기 초박막의 물리적특성 (Physical properties for the LB films of the N-docosylquinolium-TCNQ incorporated with TCNQ)

  • 최강훈;신동명;손병청;강도열
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1993년도 하계학술대회 논문집 B
    • /
    • pp.1197-1199
    • /
    • 1993
  • The molecular electronic devices of organic materials are of current interest. Langmuir-Blodgett(LB) method is the most possible candidate for the development of the molecular electronic devices. One of the critical problems for applications of the LB films to the commercial products will be an electrical conductivity within a LB film. We studied the monolayer characteristics and electrical conductivity of the 1:1 mixture LB films of N-docosylquinolium-TCNQ and $TCNQ^0$. There were some differences in the $\pi-A$ isotherm and UV-visible absorption spectrum of N-docosylquinolium-TCNQ and 1:1 mixture. The small critical area of the $\pi-A$ isotherm for 1:1 mixture may result from the bilayer formation. We confirmed the incorporation of the $TCNQ^0$ with the N-docosylquinolium-TCNQ from the UV-visible absorption spectrum. But the electrical conductivity measured was $10^{-7}$ S/cm for the 1:1 mixture film layered at the surface pressure of 35 mN/m. We couldn't gain any electrical conductivity by mixing the $TCNQ^0$ into the N-docosylquinolium-TCNQ layer. We supposed that $TCNQ^0$ mixed in was not packed parallel to the TCNQ anion radical faces.

  • PDF

자폐장애 아동을 위한 애착증진치료 프로그램의 개발 (Development of Attachment Promotion Therapy Program for the Children with Autistic Spectrum Disorder)

  • 홍강의;주세진;임숙빈
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
    • /
    • 제17권2호
    • /
    • pp.79-90
    • /
    • 2006
  • Social deficits are the most critical and core deficits of the children with Autistic Spectrum Disorder(ASD) and they are qualitatively as well as qualitatively different from typically developing children. It is proposed that the attachment between the mother and the autistic child should be promoted foremost and early as possible, to improve social deficits, just like early social developments in normal children depend largely on interactions between the mother and the child who are attached to each other we have developed an interventional program, 'Attachment Promotion Therapy', largely based on the attachment theory. The Attachment promotion Therapy mandates the participation of both the mother and the autistic child, and consists of mutually enjoying play activities, close physical contacts and parental training on intense mother-child interactions, focusing on improving maternal sensitivity, responsiveness, and nurturing behaviors during their interactions. The program was found to be effective in improving attachment behaviors, attachment security and acquiring joint attention skills. Attachment Promotion Therapy is therefore proposed here as the important earliest intervention method for children with ASD and could become the base for many other educational and therapeutic interventions.

  • PDF

Primary user localization using Bayesian compressive sensing and path-loss exponent estimation for cognitive radio networks

  • Anh, Hoang;Koo, Insoo
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제7권10호
    • /
    • pp.2338-2356
    • /
    • 2013
  • In cognitive radio networks, acquiring the position information of the primary user is critical to the communication of the secondary user. Localization of primary users can help improve the efficiency with which the spectrum is reused, because the information can be used to avoid harmful interference to the network while simultaneity is exploited to improve the spectrum utilization. Despite its inherent inaccuracy, received signal strength based on range has been used as the standard tool for distance measurements in the location detection process. Most previous works have employed the path-loss propagation model with a fixed value of the path loss exponent. However, in actual environments, the path loss exponent for each channel is different. Moreover, due to the complexity of the radio channel, when the number of channel increases, a larger number of RSS measurements are needed, and this results in additional energy consumption. In this paper, to overcome this problem, we propose using the Bayesian compressive sensing method with a calibrated path loss exponent to improve the performance of the PU localization method.

Robust Cognitive-Radio-Based OFDM Architecture with Adaptive Traffic Allocation in Time and Frequency

  • Kim, Nak-Myeong;Kim, Mee-Ran;Kim, Eun-Ju;Shin, Su-Jung;Yu, Hye-In;Yun, Sang-Boh
    • ETRI Journal
    • /
    • 제30권1호
    • /
    • pp.21-32
    • /
    • 2008
  • Cognitive radio (CR) has been proposed as an effective technology for flexible use of the radio spectrum. The interference between primary users and CR users, however, becomes a critical problem when they are using adjacent frequency channels with different transmission power levels. In this paper, a robust CR orthogonal frequency division multiplexing (OFDM) architecture, which can effectively suppress interference to nearby primary users and overcome adjacent channel interference (ACI) to the CR user, is proposed. This new approach is characterized by adaptive data repetition for subcarriers under heavy ACI, and adaptive time spreading for subcarriers near the borders of the CR user's spectrum. The data repetition scheme provides extra power gain against the ACI coming from primary users. Time spreading guarantees an acceptable interference level to nearby primary users. By computer simulation, we demonstrate that, under a CR environment, the proposed CR OFDM architecture outperforms conventional OFDM systems in terms of throughput and BER performance.

  • PDF