• Title/Summary/Keyword: Flow duration function

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Study of the Lower Duration Curve Characteristic by Reservoir and Weir Couple-operating System in Geum River Basin (금강수계 댐과 보의 운영에 의한 하류 유황특성 연구)

  • Ahn, Jung-Min;Cha, Kee-Uk;Ryoo, Kyong-Sik;Lyu, Si-Wan
    • Journal of Korea Water Resources Association
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    • v.44 no.4
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    • pp.285-293
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    • 2011
  • This study presents effects of downstream control point by coupled operation of dams and multi function weirs in the Geum River. Geum river basin that study area did authoritativeness high quality data to acquisition possibility. We applied the flow duration curve, flow regime coefficient, impounded flow index analysis to investigate the quantitative changes in natural flow regimes. In sphere that water supply is possible, this study applied believability that satisfy 95% at estimation year. Impounded flow index was calculated 0.292 by dam coupled operation and 0.297 by dam-weir coupled operation. The results indicate that the storage amount is increased by 29.7% as being added. Duration flow of downstream control point was improved because became coupled operation by regulation of dam and weir in the geum river.

A Study on Construction of the CMELDC at Load Points (각 부하지점별 유효부하지속곡선 작성법에 관한 연구)

  • Kim, Hong-Sik;Mun, Seung-Pil;Choe, Jae-Seok
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.4
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    • pp.195-198
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    • 2000
  • This paper illustrates a new method for constructing composite power system effective load duration curve(CMELDC) at load points. The main concept of proposed method is that the CMELDC can be obtain from convolution integral processing of the outage probabilistic distribution function of not supplied power and the load duration curve given at each load point. The effective load duration curve (ELDC) at HLI plays an important part in probabilistic production simulation, reliability evaluation, outage cost assessment and power supply margins assesment for power system planning and operation. And also, the CMELDC at HLII will extend the application areas of outage cost assessment and reliability evaluation at each load point. The CMELDC at load points using the Monte Carlo method and a DC load flow constrained LP have already been developed by authors. The effective load concept at HLII, however, has not been introduced sufficiently in last paper although the concept is important. In this paper, the main concept of the effective load at HLII which is proposed in this study is defined in details as the summation of the original load and the probabilistic loads caused by the forced outage of generators and transmission lines at this load point. The outage capacity probabilistic distribution function at HLII can be obtained by combining the not supplied powers and the probabilities of the not supplied powers at this load point. It si also expected that the proposed CMELDC can be applied usefully to research areas such as reliability evaluation, probabilistic production cost simulation and analytical outage cost assessment, etc. at HLII in future. The characteristics and effectiveness of this methodology are illustrated by case study of IEEE-RTS.

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Thrust Measurement in a Impulse Facility (충격파 시험장치를 이용한 추력 측정)

  • Jin, Sangwook;Hwang, Kiyoung;Park, Dongchang;Min, Seongki
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.310-319
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    • 2017
  • This paper introduces the method how to measure the thrust in impulse facility. In a Facility having such a short duration time of steady flow, there's no time to reach a steady state of the forces acting on model so that the test model vibrates until the end of the flow. The forces exerted on an engine exist with vibration so that the usual force balance can not be used. SWFB(Stress Wave Force Balance) technique is utilized in a shock tunnel to get the thrust. As an example, a model force balance has been calculated its strain against impulse force by using FEM(Finite Element Method). A transfer function between the impulse force and strain has been obtained by the way of de-convolution.

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A Study on the Optimum Design Flowrate for Tunnel-Type Small Hydro-Power Plants (터널식 소수력 발전소의 최적 설계유량에 관한 연구)

  • 이철형;박완순
    • Water for future
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    • v.24 no.1
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    • pp.63-71
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    • 1991
  • This study represents the methodology for feasibility analysis of small hydro power plants. Cumulative density function of Weibull distribution and Thi-essen method were adopted to beside flow duration curve at candidate sites. The performance prediction model and construction cost estimation model for tunnel-type small hydro power plants were developed. Eight candidate sites existing on Han river selected and surveyed for actual sites reconnaissance. The performance characteristics and economical feasibility for these sites were analyzed by using developed models. As a result, it was found that the optimum design flowrates with the lowest unit generation cost for tunnel-type small hydro power plants were the flowrate concerning with between 20 % and 30 % of time ratio on the flow duration curve. Additionally, primary design specifications such as design flowrate, effective head, capacity, annual average load factor, annual electricity production were estimated and discussed for surveyed sites.

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Effect of Laparoscopic Nerve-sparing Radical Hysterectomy on Bladder Function, Intestinal Function Recovery and Quality of Sexual Life in Patients with Cervical Carcinoma

  • Chen, Long;Zhang, Wei-Na;Zhang, Sheng-Miao;Yang, Zhi-Hao;Zhang, Ping
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.24
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    • pp.10971-10975
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    • 2015
  • Objective: To investigate bladder and intestinal function recovery and quality of sexual life after laparoscopic nerve-sparing radical hysterectomy (LNRH) for treatment of early invasive cervical carcinoma. Methods: Subjects included patients who underwent radical hysterectomy by laparotomy who were randomly assigned to 2 groups: 30 patients who underwent LNRH and 35 classical laparoscopic radical hysterectomy (LRH). We assessed the patients general clinical information, surgical characteristics, pathological findings, and adjuvant therapies. A urodynamic study was used to assess bladder function. Intestinal function recovery and quality of sexual life were evaluated by questionnaire. Results: No significant differences were found in age, surgery characteristics, pathological findings, adjuvant therapies, and main adverse effects between the 2 groups. The mean duration of the postoperative catheterization (DPC) in group LNRH was shorter than that in group LRH (P < 0.001). The maximum flow rate, maximum cystometric capacity, maximum detrusor pressure and urinary complications in group LNRH were better than those in group LRH. The quality of sexual life evaluated according to the female sexual function index (FSFI) was better in group LNRH than in those who underwent LRH. The intestinal function of patients in group LNRH also recovered better compared with patients in group LRH.

Effects of Sagittal Spinopelvic Alignment on Motor Symptom and Respiratory Function in Mild to Moderate Parkinson's disease

  • Kang, DongYeon;Cheon, SangMyung;Son, MinJi;Sung, HyeRyun;Lee, HyeYoung
    • The Journal of Korean Physical Therapy
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    • v.31 no.2
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    • pp.122-128
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    • 2019
  • Purpose: This study examined the effects of sagittal spinopelvic alignment on the clinical parameters, motor symptoms, and respiratory function in patients with mild to moderate Parkinson's disease (PD). Methods: This study was a prospective assessment of treated patients (n=28, Hoehn and Yahr (H&Y) stage 2-3) in a PD center. Twenty-eight subjects ($68.5{\pm}5.7yrs$) participated in this study. The clinical and demographic parameters, including age, sex, symptoms duration, treatment duration, and H&Y stage, were collected. Kinematic analysis was conducted in the upright standing posture with a motion capture system. A pulmonary function test (PFT) was performed in the sitting position using a spirometer. The motor symptoms were assessed on part III of the movement disorder society sponsored version of the unified Parkinson's disease rating scale (MDS-UPDRS). SPSS 18.0 was used to analyze the collected data. Results: The exceeding 12 degrees group of the lower trunk showed significantly higher on the clinical parameters than the below 12 degrees group. In addition, the exceeding 12 degrees group of the lower trunk showed a significantly lower forced expiratory volume at one second (FEV1) / forced vital capacity (FVC) (%) and 25-75% forced mid-expiratory flow (FEF) (L/s) than in the below group. On the other hand, there was no difference in the upper trunk and the cervical pelvis between the groups. Conclusion: These findings suggest that the sagittal balance in the lower trunk is related to the clinical parameters and respiratory function, but not the motor symptoms in patients with mild to moderate PD.

The Characteristics related to Pulmonary Rehabilitation in Patients with Chronic Obstructive Pulmonary Disease: A Cross-sectional Study, Data from the Korea National Health and Nutrition Examination Survey 2015-2019.

  • Kyeongbong Lee
    • Physical Therapy Rehabilitation Science
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    • v.12 no.3
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    • pp.229-239
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    • 2023
  • Objective: Patients with chronic obstructive pulmonary disease (COPD) may experience reduced physical activity and quality of life (QoL) due to decreased pulmonary function. The purpose of this study was to investigate the level of pulmonary function, physical activity, and QoL of COPD patients. Design: Cross-sectional observational study. Methods: This study examined the published data of the Korea National Health and Nutrition Examination Survey in 2015-2019. Among 39,759 subjects who participated for 5 years, data from 151 patients diagnosed with COPD were analyzed separately. For the pulmonary function, the results of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV6, forced expiratory flow 25-75%, and peak expiratory flow were observed. Physical activity was identified as frequency and duration. For the QoL, EQ-5D-3L evaluation results were examined, and the frequency and index of the Korean version were investigated. Results: In pulmonary function, all variables were found to be lower than age and weighted matched normal values. COPD patients showed to perform very low levels of high/medium physical activity and sitting time was confirmed to be more than 8 hours a day. In QoL, it was found that the highest reporting rate of some problems was the "pain and discomfort" and "mobility". Conclusions: It was found that COPD patients showed that the prevalence of circulatory disease was relatively high, lowered pulmonary function, and QoL. These can be improved through regular physical activity, and it is thought that this can be achieved through optimization of pulmonary rehabilitation.

Determination of Instreamflow Requirement for Upstream Urban Watershed Using SWAT Model (SWAT 모형을 이용한 도시하천 상류유역의 하천유지유량 산정방안)

  • Lee Kil-Seong;Chung Eun-Sung;Shin Mun-Ju;Kim Young-Oh
    • Journal of Korea Water Resources Association
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    • v.39 no.8 s.169
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    • pp.703-716
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    • 2006
  • The flow duration curves in the present and the ideal hydrologic cycle were derived using SWAT model. The present situation is the landuse and the groundwater withdrawal in the year of 2000 and the ideal situation is the landuse of 1975 and no groundwater withdrawal. These results were compared with the previous instream flow requirements which are the larger flow between the average drought flow and environmental control flow. As a result, the present and ideal drought flows of Ojeoncheon, Hakuicheon, Samseongcheon, and Sammakcheon, were the same and the drought flows of Samseongcheon and Sammakcheon were even zero since the baseflow is very little due to the small and mountainous watersheds. The previous instream flow requirement for the riverine function is also larger than the low flow of the ideal hydrologic cycle. The present method to set the instream flow requirement is not proper for the small mountainous watershed since it can be usually overestimated and drive the artificial measures to secure the streamflow Therefore, another method should be developed such as the low flow and the average flow between the drought flow and the low flow of the ideal hydrologic cycle using the proper hydrologic simulation model such as SWAT which can consider the landuse.

Development of Portable Arrhythmia Moniter Using Microcomputer(I) (마이크로 컴퓨터를 이용한 휴대용 부정맥 모니터의 개발(I)-하드웨어 설계를 중심으로-)

  • 이명호;안재봉
    • Journal of Biomedical Engineering Research
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    • v.7 no.2
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    • pp.169-182
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    • 1986
  • Pulsed ultrasonic Doppler system is a useful diagnostic instrument to measure blood-flow-velocity, velocity profile, and volume-blood-flow. This system is more powerful compare with 2-dimensional B-scan tissue image. A system has been deve- loped and ii being evaluated using TMS 32010 DSP. We use this DSP for the purpose of real-time spectrum analyzer to obtain spectrogram in singlegate pulsed Doppler system and for the serial comb filter to cancel clutter and zero crossing counter to estimate Doppler mean frequency in multigate pulsed Doppler system. The Doppler shift of the backscattered signals is sensed in a phase detector. This Doppler signal corresponds to the mean velocity over a some region in space defined by the ultrasonic beam dimensions, transmitted pulse duration, and transducer ban(iwidth. Multi- gate pulsed Doppler system enable the transcutaneous and simultaneous assessment of the velocities in a number of adjacent sample volumes as a continuous function of time. A multigate pulsed Doppler system processing the information originating from presented.

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A Study of Effect on Pulmonary Function of Pleural Effusion in Tuberculous pleurisy patients (결핵성 흉막염 환자에서 흉수가 폐기능에 미치는 영향에 대한 연구)

  • Yim, Jeong Yoon;Lee, Kee Hyun;Jung, Hye Kyung;Chang, Jung Hyun;Cheon, Seon Hee
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.4
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    • pp.491-499
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    • 1996
  • Background : Pleural effusion is a common disease in clinical practice but its effect on pulmonary function and altered pulmonary mechanics after removal of effusion are not still largely understood. Previous studies have shown that there is little or a relatively small improvement in pulmonary function and arterial blood oxygenation after therapeutic thoracentesis. The present study was designed to assess the effect on pulmonary function of pleural effusion and to test whether there was a significant improvement in pulmonary function and arterial oxygenation after thoracentesis and to observe long tenn effect after thoracentesis. Method : We examined flow-volume curve, body box and arterial blood gas analysis according to severity of effusion, present symptom, and symptom duration. Then, we measured changes of pulmonary function after thoracentesis and observed longterm effect after thoracentesis. Result: 1) Pleural effusion cause restrictive pulmonary insufficiency. Not only functional impairment of small airway but also large airway is provoked. 2) MMFR, FEV1, Raw, POz are earlier improved than FVC and TLC after thoracentesis and patients without complication have mild restrictive pulmonary insufficiency after longterm observation. 3) FVC, FEV1, & TLC are similarly restricted as severity of pleural effusion and po, is relatively decreased. 4) Cases with symptom duration 1 week or less and cases with dyspnea have more severe pulmonary insufficiency than others. 5) The flow volume curves show a relatively greater improvement in flow rates at large lung volumes than small airway. 6) Significant relationship is shown between first thoracentesis amount and changes of FEV1, FVC, TLC. Conclusion: Pleural effusion cause restrictive pulmonary insufficiency and not only functional impairment of small airway impairment but also large airway is provoked. Then, Pulmonary function is progressively improved after thoracentesis and remained mild restrictive pulmonary insufficiency after recovery.

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