• 제목/요약/키워드: Transit Time Difference

검색결과 44건 처리시간 0.03초

지하철의 사상사고 및 운전장애 분석에 관한 연구 (An Analysis of Death Injuries and Operational Troubles of Urban Transit)

  • 권혁무;윤원영;장성록;옥영석;목연수;이동훈;최용석;배동철
    • 한국안전학회지
    • /
    • 제14권3호
    • /
    • pp.168-173
    • /
    • 1999
  • The purpose of this study is to analyze death injuries and operation troubles of urban transit. No difference was shown in death rates between Line 1 of Pusan urban transit and Line 5, 7, And 8 of Seoul metropolitan transit. And relief time by another train did not depend upon the number of crews. We concluded that thorough inspection and preventive maintenance of trains and facilities are necessary for safe and timely service of urban transit.

  • PDF

전달 시간차 방식 초음파 가스 유량계 (Development of an Ultrasonic Gas Flow Meter Using Transit Time Difference)

  • 박상국;황원호
    • 제어로봇시스템학회논문지
    • /
    • 제9권9호
    • /
    • pp.707-713
    • /
    • 2003
  • We investigate the ultrasonic gas flow meter for the measurement of gas volume quantity, which passing through pipe, using the transit time difference method. We have designed a receiving system of an ultrasonic signal and hardware system of a flow meter Also, we have designed an experimental system for the characteristic test and calibration of a gas flow meter system. We have developed an ultrasonic gas flow meter, which has a measurement uncertainty within $\pm$ 1.7 %. For the test, we have compared our system with a difference pressure type flow meter for a few months in the real field. Through the test, we have confirmed that our system have a good reliability and durability. Also, we have confirmed that our system follows very well the variation of gas volume quantity, which was measured by a difference pressure type flow meter.

The Effects of Neuromuscular Electrical Stimulation on Swallowing Function in Acute Stroke Patients with Dysphagia

  • Kim, Myung-Kwon;Lee, Chang-Ryeol;HwangBo, Gak
    • International Journal of Contents
    • /
    • 제7권4호
    • /
    • pp.98-102
    • /
    • 2011
  • In this study, we investigated the effects of neuromuscular electrical stimulation (NMES) on the treatment of 20 acute stroke patients with dysphagia. For both the treated and control groups, the basic facial stimulation training was conducted for 30 minutes, five times a week, for four weeks. NMES was performed on the treated group only, for 30 minutes each time. Both groups were evaluated according to the functional dysphagia scale (FDS) using a videofluoroscopic swallowing study (VFSS). After the treatment was performed for four weeks, the FDS results of the treated group showed a significance difference in oral transit time in the oral phase and in the triggering of pharyngeal swallow fluid, laryngeal elevation and epiglottic closure, nasal penetration, residue in valleculae, coating of pharyngeal wall after swallow fluid, and pharyngeal transit time in the pharyngeal phase. In addition, the treated group showed a significant difference in laryngeal elevation and epiglottic closure, nasal penetration, and pharyngeal transit time in the pharyngeal phase after the treatment compared to the control group. The results of this study showed that neuromuscular electrical stimulation may be an effective method of treating dysphagia in acute phase stroke patients.

유동식 및 고형식을 이용한 동위원소 식도통과검사의 임상적 의의에 대한 연구 (Clinical Evaluation of Radionuclide Esophageal Transit Studies using Liquid and Solid Foods)

  • 최재걸;이민재;서원혁;송치욱;현진해
    • 대한핵의학회지
    • /
    • 제29권1호
    • /
    • pp.61-72
    • /
    • 1995
  • The author performed radionuclide esophageal transit studies(RETS) with liquid and solid boluses using the same day protocol in 90 normal controls and 164 patients with various primary esophageal motility disorders who were diagnosed by manometric criteria and clinical courses. The authors calculated mean esophageal transit time(MTT) and mean residual retention(MRR) in each of the liquid and solid studies, and classified time-activity curve(TAC) patterns. The normal criteria of RETS with liquid bolus were MTT<24 sec, MRR<9%, and the TAC pattern that showed rapid declining slope and flat low residual(Type 1). The normal criteria of RETS with solid bolus were MTT<35 sec, MRR<9% and TAC of type 1. With these normal criteria, the sensitivity and the specificity of the liquid study were 62.2 % and 97.8%, respectively. The sensitivity increased to 75.4% with the solid study. The author also found that the RETS was highly reproducible. The achalasia typically showed no effective emptying of both liquid and solid boluses during the whole study period, and was well differentiated by its extremely long transit time and high retention from the other motility disorders. The diffuse esophageal spasm (DES) and nonspecific esophageal motility disorder(NEMD) showed intermediate delay in transit time and increased retention. In the groups of hypertensive lower esophageal sphincter(LES), hypotensive LES and nutcracker, there noted no significant difference with the normal control group in terms of MTT and MRR. The DES and NEMD could be more easily identified by solid studies that showed more marked delay in MTT and increased MRR as compared with the liquid study. In conclusion, esophageal scintigraphy is a safe, noninvasive and physiologic method for the evaluation of esophageal emptying.

  • PDF

전신 마취 중 심박동변이도와 맥파전달시간 변화의 비교 (Comparison of Heart Rate Variability with Pulse Transit Time during General Anesthesia)

  • 백승완;김태균;김재형;전계록;예수영
    • 한국전기전자재료학회논문지
    • /
    • 제21권8호
    • /
    • pp.770-775
    • /
    • 2008
  • Autonomic nervous system of the anesthetized patients can be influenced by the many kinds of stimulations such as intubation, surgical incision and so on. The changes of the heart rates and blood pressures are surrogates of responses of the autonomic system to the external stimulations. Recently, the power spectral analysis of the heart rate variability (HRV) made it easy to know the fractions and changes of sympathetic and parasympathetic autonomic systems. In this study, the changes of pulse transit time, one of the response of vessels to stimulations, was investigated in relation to the HRV. Ten patients were examined and average age is 22.5 $\pm$ 11.04, average weight is 63 $\pm$ 14.4 kg. The patients were anesthetized only by sevoflurane inhalation. Pulse transit time is determined by calculating the difference of the time between the R peak of ECG and the characteristic point of the plethysmography. Power spectral density (PSD) of the HRV was achieved in the frequency of 0.04-0.15 (LF) and 0.15-0.4 (HF). Compared to preanesthetic period the values of LF and LF/HF ratio of HRV were decreased (p<0.05). HF and PTT was increased in anesthetic state with sevoflurane. Otherwise, after intubation, the HF was decreased and LF, LF/HF ratio and PTT were increased. PSD of the HRV is well-known for the index of the autonomic nervous activity. Not only HRV but PTT analysis also is a useful index reflecting the autonomic responses to various stimulations. And this analysis is useful in bed side monitoring because the calculating method is simple and it takes shorter processing time compared to the HRV analysis.

경제성분석시 통행시간절감편익 개선방안에 관한 연구 (A Study on Ways to Improve Benefits of Travel-time in Analyzing the Economic Efficiency)

  • 이수일;이승재
    • 대한토목학회논문집
    • /
    • 제30권3D호
    • /
    • pp.263-270
    • /
    • 2010
  • 본 연구는 경제분석기법에서 편익항목의 통행시간절감편익의 개선안을 살펴보았다. 기존의 경제성분석 시 통행시간절감편익의 계산방법은 피크시간대의 O/D를 이용하여365를 곱하여 산정하고 있다. 이 계산방법의 문제점은 요일에 대한 교통량변화, 달에 대한 교통량변화를 고려하지 못하는 것이다. 이러한 분석점을 개선하기 위하여, 군집분석과 t-검증을 통하여 달별, 요일별 비슷한 교통량 패턴이 가지는 것끼리 묶었다. 이러한 결과값은 요일별과 월별로 교통량의 차이가 발생하는 것으로 나타났다. 본 연구에서는 이러한 요일별, 월별 가중치를 적용하여 pilot 예제를 통해 통행시간절감분을 계산하였더니 기존의 방법에 비해 다소 적게 도출되는 것을 알 수 있었다. 본 연구는 교통량의 변화패턴을 고려한 가중치 연구에 의의를 둘 수 있다.

말초혈관 혈류 측정을 이용한 비관혈적 혈압 추정법에 대한 연구 (Estimation of Non- Invasive Blood Pressure Using Peripheral Plethysmograph)

  • 정인철;신태민;윤형로
    • 대한전기학회논문지:시스템및제어부문D
    • /
    • 제54권8호
    • /
    • pp.504-509
    • /
    • 2005
  • This paper presents a new method for obtaining the noninvasive and unrestrained blood pressure readings noninvasively and unrestrainedly using based on reflected wave arrival time(RAT) in the volume of pulse. Since this new method employs only volume pulse, is more rapider and simpler than the method using pulse transit time(PTT) because it only employs the volume of pulse. Blood pressure, PTT and RAT were acquired from 15 healthy subjects. Each subjects were performed forty trials of each measurement. As a result of those trials, the mean error between oscillometric and RAT measurements for systolic blood pressure was $4.55\pm5.64mmHg$. This result showed quite equal with the mean error between oscillometric and PPT measurf:ments, $4.22\pm5.30mmHg$, However, it was not obtained a satisfactory result in the relativity of oscillometric to both RAT and PPT measurements for diastolic blood pressure because of personal difference. To conclude, the method of systolic blood pressure estimation noninvasively and unrestrainedly using by RAT may be used as the method by PTT. Nevertheless, additional studies would be necessary for the RAT/PTT estimation of diastolic blood Pressure measurement.

The Effect of Soybean Galactooligosaccharides on Nutrient and Energy Digestibility and Digesta Transit Time in Weanling Piglets

  • Zhang, Liying;Li, Defa;Qiao, Shiyan;Wang, Jituan;Bai, Lu;Wang, Zongyi;Han, In K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제14권11호
    • /
    • pp.1598-1604
    • /
    • 2001
  • Eight $12.4{\pm}0.6kg$ initial body weight crossbred barrows were used to determine the effect of soybean galactooligosaccharides on nutrient and energy digestibility, and digesta transit time. Four dietary treatments were utilized in this trial. Treatment one was a corn-soybean meal based diet (SBM) containing raffinose and stachyose at the levels of 0.16% and 0.75%, respectively. Treatment two (control) was a corn-HP300 (soybean concentrate protein) diet. In treatments three and four, 1.1% and 2.2% commercial stachyose was added to the control diet to provide total dietary stachyose at the levels of 1% and 2%, respectively. The soybean galactooligosaccharides (raffinose + stachyose) level in treatment one was slightly lower compared to that in treatment three. Three collection periods were run with two pigs for each treatment/period. There was a 4 d adjustment period followed by a 3 d collection period. The results showed that the nitrogen retention (86.79%) of pigs fed treatment two diet was higher than that of pigs fed treatment one by 5.2% (p<0.05). The nitrogen retention of treatment three was intermediate 83.09%. The apparent fecal digestibility of all amino acids in treatment two was numerically highest, followed by treatments three and four. However, there were no significant difference among groups (p>0.05). The dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) digestibility numerically decreased as the soybean galactooligosaccharides level increased, but were not significantly different (p>0.05). Chromium content in feces (from the inclusion of 0.3% chromic oxide in the diets) differed among treatments (p<0.05) at 15 h, 18 h, and 21 h after eating. This showed that the digesta transit time was differed significantly among treatments. Treatment four was the shortest, followed by treatment three, SBM and control. The results demonstrated that in the absence of antinutritional factors and soybean antigen protein, inclusion of 1% and 2% stachyose in corn-HP300 diet has no significant effect on the digestibility of DM, OM, CP, CF and amino acids. When the soybean galactooligosaccharide level in diet one and diet three were adjusted to be almost the same, antinutritional factors such as trypsin inhibitor and soybean antigen protein could decrease the nutrient digestibility and nitrogen retention rate of diet. High levels of soybean galactooligosaccharides shortened the digesta transit time in the intestinal tract. This trial suggested that the total level of soybean galactooligosaccharides (stachyose+raffinose) in the weanling piglet diet is better not to exceed 1% when common soybean meal is used as main protein source.

안전한 도시철도를 위한 통합 화재 경보 시스템 구축의 연구 (A Study on Integrated Fire Alarm System for Safe Urban Transit)

  • 장일식;안태기;전지혜;조병목;박구만
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
    • /
    • pp.768-773
    • /
    • 2011
  • Today's urban transit system is regarded as the important public transportation service which saves passengers' time and provides the safety. Many researches focus on the rapid and protective responses that minimize the losses when dangerous situation occurs. In this paper we proposed the early fire detection and corresponding rapid response method in urban transit system by combining automatic fire detection for video input and the sensor system. The fire detection method consists of two parts, spark detection and smoke detection. At the spark detection, the RGB color of input video is converted into HSV color and the frame difference is obtained in temporal direction. The region with high R values is considered as fire region candidate and stepwise fire detection rule is applied to calculate its size. At the smoke detection stage, we used the smoke sensor network to secure the credibility of spark detection. The proposed system can be implemented at low prices. In the future work, we would improve the detection algorithm and the accuracy of sensor location in the network.

  • PDF

Unusual Radar Echo from the Wake of Meteor Fireball in Nearly Horizontal Transits in the Summer Polar Lower-Thermosphere

  • Lee, Young-Sook;Kirkwood, Sheila;Kwak, Young-Sil
    • Journal of Astronomy and Space Sciences
    • /
    • 제35권2호
    • /
    • pp.83-92
    • /
    • 2018
  • The summer polar lower thermosphere (90-100 km) has an interesting connection to meteors, adjacent to the mesopause region attaining the lowest temperature in summer. Meteors supply condensation nuclei for charged ice particles causing polar mesospheric summer echoes (PMSE). We report the observation of meteor trail with nearly horizontal transit at high speed (20-50 km/s), and at last with re-enhanced echo power followed by diffusive echoes. Changes in phase difference between radar receivers aligned in meridional and zonal directions are used to determine variations in horizontal displacements and speeds with respect to time by taking advantage of radar interferometric analysis. The actual transit of echo target is observed along the straight pathway vertically and horizontally extended as much as a distance of at least 24 km and at most 29 km. The meteor trail initially has a signature similar to 'head echoes', with travel speeds from 20 - 50 km/s. It subsequently transforms into a different type of echo target including specular echo and then finally the power reenhanced. The reenhancement of echo power is followed by fume-like diffusive echoes, indicating sudden release of plasma as like explosive process probably involved. We discuss a possible role of meteor-triggered secondary plasma trail, such as fireball embedded with electrical discharge that continuously varies the power and transit speed.