• 제목/요약/키워드: cut off level

검색결과 314건 처리시간 0.033초

The prognostic value of median nerve thickness in diagnosing carpal tunnel syndrome using magnetic resonance imaging: a pilot study

  • Lee, Sooho;Cho, Hyung Rae;Yoo, Jun Sung;Kim, Young Uk
    • The Korean Journal of Pain
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    • 제33권1호
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    • pp.54-59
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    • 2020
  • Background: The median nerve cross-sectional area (MNCSA) is a useful morphological parameter for the evaluation of carpal tunnel syndrome (CTS). However, there have been limited studies investigating the anatomical basis of median nerve flattening. Thus, to evaluate the connection between median nerve flattening and CTS, we carried out a measurement of the median nerve thickness (MNT). Methods: Both MNCSA and MNT measurement tools were collected from 20 patients with CTS, and from 20 control individuals who underwent carpal tunnel magnetic resonance imaging (CTMRI). We measured the MNCSA and MNT at the level of the hook of hamate on CTMRI. The MNCSA was measured on the transverse angled sections through the whole area. The MNT was measured based on the most compressed MNT. Results: The mean MNCSA was 9.01 ± 1.94 ㎟ in the control group and 6.58 ± 1.75 ㎟ in the CTS group. The mean MNT was 2.18 ± 0.39 mm in the control group and 1.43 ± 0.28 mm in the CTS group. Receiver operating characteristics curve analysis demonstrated that the optimal cut-off value for the MNCSA was 7.72 ㎟, with 75.0% sensitivity, 75.0% specificity, and an area under the curve (AUC) of 0.82 (95% confidence interval [CI], 0.69-0.95). The best cut off-threshold of the MNT was 1.76 mm, with 85% sensitivity, 85% specificity, and an AUC of 0.94 (95% CI, 0.87-1.00). Conclusions: Even though both MNCSA and MNT were significantly associated with CTS, MNT was identified as a more suitable measurement parameter.

태양광(PV) 셧다운(Shutdown)기술 'NEC Article 690' 표준화 분석 (Standardization Analysis of 'NEC Article 690' for Photovoltaic Shutdown Technology)

  • 윤용호
    • 한국인터넷방송통신학회논문지
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    • 제22권3호
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    • pp.171-176
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    • 2022
  • 신속한 차단 사양을 위한 통신 신호는 시스템 구성과 관계없이 NEC 2014, NEC 2017 또는 해당 UL 규격에서는 "적용되는 모든 태양광(PV) 시스템의 빠른 차단 요구사항을 지원하도록 설계한다"라고 규정되어 있다. 한편 신재생에너지 관련 국내 규정 등을 보면 각 기관에서 정한 기준이나 규정, 지침 등은 일반적이거나 해당 기관이 필요한 부분만 제정해서 운영 중이다. 이러한 것들을 태양광 시설에 적용하기에는 미흡한 점이 많아 설계, 감리자와 검사기관의 검사 기준, 검사자의 기술 수준에 따라 과도하게 설비를 하는 경우 등이 발생하고 있다. 국제적으로 통용되는 IEC 규격은 각종 시설규격을 자세히 다루고 있다. 유럽 각국에서는 IEC를 근간으로 별도의 시설 규정이 있는데, 특히 기기의 성능, 안전성 등을 상세하게 다루고 있고, 미국 등 북미에서 적용하는 'NEC Article 690'인 경우 각 항목이 매우 상세하게 기술하고 있다. 따라서 본 논문에서는 국제적으로 통용 및 현재 적용되고 있는 태양광(PV) 셧다운(Shutdown) 기술에 대한 세부 내용들을 살펴보고자 한다.

Serum Beta-2 Microglobulin: a Possible Marker for Disease Progression in Egyptian Patients with Chronic HCV Related Liver Diseases

  • Ouda, SM;Khairy, AM;Sorour, Ashraf E;Mikhail, Mikhail Nasr
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권17호
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    • pp.7825-7829
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    • 2015
  • Background: Egypt has the highest prevalence of HCV infection in the world (~14.7%). Around 10-15% of HCV-infected persons will advance to cirrhosis within the first 20 years. The incidence of HCC is expected to grow in the next two decades, largely due to HCV related cirrhosis, and detection of HCC at an early stage is critical for a favorable clinical outcome. No simple reliable non-invasive marker has been available till now. B2M, a non-glycosylated polypeptide composed of 99 amino acids, is one of the components of HLA class I molecules on the surfaces of all nucleated cells. It has been reported that the level of serum B2M is elevated in patients with chronic hepatitis C and HCV-related HCC when compared to HCV-negative patients or healthy donors. Determining the clinical utility of serum B2M as a marker for disease progression in Egyptian patients with HCV related chronic hepatitis, cirrhosis and hepatocellular carcinoma was the aim of the present study. Materials and Methods: In this analytical cross sectional study 92 participants were included in 4 equal groups: Group (1) non cirrhotic chronic HCV; Group (2) HCV related liver cirrhosis; Group (3) HCC on top of HCV,; and Group (4) healthy controls. History taking, clinical examination, routine labs and abdominal ultrasound were conducted for all patients, PCR and Metavir scores for group (1) patients, and triphasic CT abdomen and AFP for Group (3) patients. B2M levels were measured in serum with a fully-automated IMX system. Results: The mean serum B2M level of Group (1) was $4.25{\pm}1.48{\mu}g/ml$., Group (2) was $7.48{\pm}3.04$, Group (3) was $6.62{\pm}2.49$ and Group (4) was $1.62{\pm}0.63$. Serum B2M levels were significantly higher in diseased than control group (p<0.01) being significantly higher in cirrhosis ($7.48{\pm}3.04$) and HCC groups ($6.62{\pm}2.49$) than the HCV group ($4.25{\pm}1.48$) (p<0.01). There was a significant correlation between B2M Level and ALK, total and direct bilirubin and INR (p<0.05), and a significant inverse correlation between B2M level and albumin, total proteins, HB andWBCS values (p<0.05). There was no significant correlation between B2M level and viral load or Metavir score, largest tumour size or AFP (p>0.05). The best B2M cut-off for HCV diagnosis was 2.6 with a sensitivity of 100%, a specificity of 92%, a positive predictive value (PPV) of 97% and a negative predictive value (NPV) of 100%. The best B2M cut-off for HCC diagnosis was 4.55 which yielded sensitivity, specificity, positive predictive value, negative predictive values of 74%, 62%, 39.5, 87.8% respectively (p-value <0.01) while best cut-off for cirrhosis was 4.9, with sensitivity 74 % and specificity 74%.The sensitivity for HCC diagnosis increased upon B2M and AFP combined estimation to 91%, specificity to 79%, NPV to 95% and accuracy to 83%. Conclusions: Serum B2M level is elevated in HCV related chronic liver diseases and may be used as a marker for HCV disease progression towards cirrhosis and carcinoma.

IC 신뢰성 향상을 위한 내장형 고장검출 회로의 설계 및 제작 (Design and fabrication of the Built-in Testing Circuit for Improving IC Reliability)

  • 유장우;김후성;윤지영;황상준;성만영
    • 한국전기전자재료학회논문지
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    • 제18권5호
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    • pp.431-438
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    • 2005
  • In this paper, we propose the built-in current testing circuit for improving reliability As the integrated CMOS circuits in a chip are increased, the testability on design and fabrication should be considered to reduce the cost of testing and to guarantee the reliability In addition, the high degree of integration makes more failures which are different from conventional static failures and introduced by the short between transistor nodes and the bridging fault. The proposed built-in current testing method is useful for detecting not only these failures but also low current level failures and faster than conventional method. In normal mode, the detecting circuit is turned off to eliminate the degradation of CUT(Circuits Under Testing). The differential input stage in detecting circuit prevents the degradation of CUT in test mode. It is expected that this circuit improves the quality of semiconductor products, the reliability and the testability.

척수손상환자의 우울성향에 관한 연구

  • 강순희
    • 대한물리치료사협회지
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    • 제13권1호
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    • pp.5-17
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    • 1992
  • Depression in Spinal Cord Injury Patients Kang, Soon Hee, M.Ed., R.P.T. Dept. of Rehabilitation Medicine, Kyung-Hee University Medical Center Depressions have the potential to affect adversely the rehabilitation of patients with spi-nal cord iniury. The present study examined depression, functional independence, and demographic and medical characteristics for 49 spinal cord injury(SCI) patients. This investigation involved the administration of the Beck Depression Inventory, the Modified Barthel Index, and aquestionnaire consisted of 14 items, The results were as follows .1. Compared to normal subjects, SCI patients had significantly higher BDI scores.2. When the cut-off point of HDI scores was assumed 21, 26.1% of normal subjeets and 75.5% of SCI patients appeared to be depressed. Depression in SCT patients were not related with age, sex, marital status, injury evel, severity, duration, pain, functional independence and medical charge. Depression in SCI patients were related with education level, economic level, age at injury, motivation. Depression in normal subjects were related with age, education level, economic level, but not related with sex, marital status. There were significant differences at 30 items of BDI between normal subjects and SCI patients. The items were as fellows . 1 sadness, 2 pessimism, 3 failure, 4 dissat-isfaction, 5 guilt, 6 punishment. 7 self-dislike 9 suicidal, 10 crying, 11 irritability, 12withdrawl, 13 indecisive, 14 self-image, IS work inhibition, 16 insomnia, 17 fatigue,18 anorexia, 19 weight loss, 20 hypochondria, 21 libido loss.

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고정밀 전류센서를 이용한 이중 차단용 전기화재 방재장치에 관한 연구 (A Study on Electrical Fire Disaster Prevention Device used in Double Circuit Break)

  • 박동필;곽동걸;정도영;김춘삼;신호준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.2102-2103
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    • 2008
  • The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device(RCD) of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms](KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this paper is proposed to a electrical fire disaster prevention device(EFDPD) for a RCD trip or a self circuit-breaking function on electric arc or spark due to electrical fire. Some experimental results of the proposed apparatus is confirmed to the validity of the analytical results.

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저압 배전선로의 누전 및 배선용 차단기의 오동작 방지를 위한 고속형 전기안전 보호장치 (Electric Safety Protection Device of High Speed for Incapable Operation of ELB and MCCB Using the Low Voltage Distribution Line)

  • 곽동걸;정도영
    • 전기학회논문지
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    • 제56권11호
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    • pp.1925-1929
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    • 2007
  • This paper is studied on a novel Electric Safety Protection Device (ESPD) of high speed for incapable operation of Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB) using the low voltage distribution line. The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device (RCD), that is ELB and MCCB, of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this research development is proposed to a novel ESPD of high speed to trip of distribution line on electric arc or spark due to electrical fire. Some experimental results of the proposed ESPD are confirmed to the validity of the analytical results.

진공차단기 3상 동시 차단시의 서지 특성 분석 (Surge Characteristics Analysis of Three-phase Virtual Chopping at Vacuum Circuit Breaker)

  • 김종겸
    • 전기학회논문지
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    • 제67권9호
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    • pp.1159-1164
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    • 2018
  • Vacuum circuit breakers(VCB) are widely used for current interruption of high-voltage inductive loads such as induction motors. This VCB can be chopped off before the current zero due to its high arc-extinguishing capability. One of the outstanding features of VCB is that it can cut off high frequency re-ignition current more than other circuit breakers. If the transient recovery voltage generated in the arc extinguishing is higher than the dielectric strength of the circuit breaker, a re-ignition phenomenon occurs. The surge voltage of the re-ignition is very high in magnitude and the steepness of the waveform is so severe that it can act as a high electrical stress on the winding. If the high frequency current of one phase affects the other two phases when the re-ignition occurs, it may cause a high surge voltage due to the virtual current chopping. If the magnitude of the voltage allowed in the motor winding is high or the waveform level is too severe, it may lead to insulation breakdown. Therefore, it is necessary to reduce the voltage to within a certain range. In this study, we briefly explain the various phenomena at the time of interruption, analyzed the magnitude of the dielectric strength and the transient recovery voltage at the simultaneous three-phase interruption that can give the greatest influence to the inductive load, proposed a method to reduce the impact.

미디어 스트림 전송을 위한 적응형 멀티미디어 동기화 기법에 관한 연구 ((A Study on an Adaptive Multimedia Synchronization Scheme for Media Stream Transmission))

  • 지정규
    • 한국컴퓨터산업학회논문지
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    • 제3권9호
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    • pp.1251-1260
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    • 2002
  • 실시간 응용 프로그램은 미디어 데이터간에 만족되어야 할 동기화 제약조건을 가지고 있다. 클라이언트의 버퍼를 버퍼레벨기법의 가상버퍼와 네트워크 상태를 포함한 피드백기법을 제안한다. 가변적 전송 지연 시간을 흡수하면서 피드백 제어에 의한 동기화를 수행한다. 버퍼의 수위가 정상레벨을 유지하는가에 대한 문제는 재생률과 QoS 서비스에 중요한 영향을 주게 된다. 본 논문에서는 이러한 문제를 해결하기 위해서 필터링함수, 제어함수, 네트워크 평가 함수 등을 적용하여 멀티미디어 서버에서 전송 시작시점을 결정하고 미디어의 재생 시 끊어짐이 없는 유연한 재생을 처리하게 된다. 주 미디어인 오디오 프레임이 상위임계레벨에 버퍼의 수위가 존재 할 경우는 점차적으로 재생시간을 줄이고, 오디오 프레임이 하위임계레벨에 버퍼의 수위가 있을 경우는 점차적으로 재생시간을 늘리는 시스템을 제안한다.

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멀티미디어 통신에서 미디어스트림 전송을 위한 적응형 멀티미디어 동기화 기법 (An Adaptive Multimedia Synchronization Scheme for Media Stream Delivery in Multimedia Communication)

  • 이기성
    • 정보처리학회논문지C
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    • 제9C권6호
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    • pp.953-960
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    • 2002
  • 실시간 응용 프로그램은 미디어 데이터간에 만족되어야 할 동기화 제약조건(synchronization constraints)을 가지고 있다. 멀티미디어 데이터의 가변적 전송 시연 시간을 흡수하여 피드백 제어와 재생정책에 의한 동기화 기법을 수행한다. 버퍼의 수위가 정상레벨을 유지하는가에 대한 문제는 재생률과 QoS 서비스에 중요한 영향을 주게 된다. 본 논문에서는 버퍼의 수위를 안정상태고 유지하기 위해 피트백을 위한 필터링함수를 적용하고, 재생시간을 적응적으로 적용하여 미디어의 재생 시 끊어짐이 없는 유연한 재생을 한다. 또한 버퍼의 주 미디어인 오디오 프레임의 버퍼가 상위임계레벨에 수위가 존재 할 경우는 적응적으로 재생시간을 줄이고, 하위임계레벨에 버퍼의 수위가 있을 경우는 점차적으로 재생시간을 늘리는 시스템이다.