• 제목/요약/키워드: Effective time interval

검색결과 312건 처리시간 0.025초

Fault Location and Classification of Combined Transmission System: Economical and Accurate Statistic Programming Framework

  • Tavalaei, Jalal;Habibuddin, Mohd Hafiz;Khairuddin, Azhar;Mohd Zin, Abdullah Asuhaimi
    • Journal of Electrical Engineering and Technology
    • /
    • 제12권6호
    • /
    • pp.2106-2117
    • /
    • 2017
  • An effective statistical feature extraction approach of data sampling of fault in the combined transmission system is presented in this paper. The proposed algorithm leads to high accuracy at minimum cost to predict fault location and fault type classification. This algorithm requires impedance measurement data from one end of the transmission line. Modal decomposition is used to extract positive sequence impedance. Then, the fault signal is decomposed by using discrete wavelet transform. Statistical sampling is used to extract appropriate fault features as benchmark of decomposed signal to train classifier. Support Vector Machine (SVM) is used to illustrate the performance of statistical sampling performance. The overall time of sampling is not exceeding 1 1/4 cycles, taking into account the interval time. The proposed method takes two steps of sampling. The first step takes 3/4 cycle of during-fault and the second step takes 1/4 cycle of post fault impedance. The interval time between the two steps is assumed to be 1/4 cycle. Extensive studies using MATLAB software show accurate fault location estimation and fault type classification of the proposed method. The classifier result is presented and compared with well-established travelling wave methods and the performance of the algorithms are analyzed and discussed.

그린키위와 골드키위 과실무름병 예방약제의 적정 살포시기, 간격 및 횟수 (Optimal Spray Time, Interval and Number of Preventive Fungicides for the Control of Fruit Rots of Green and Gold Kiwifruit Cultivars)

  • 김경희;이영선;정재성;허재선;고영진
    • 식물병연구
    • /
    • 제19권1호
    • /
    • pp.1-6
    • /
    • 2013
  • 그린키위 품종 'Hayward'와 골드키위 품종 'Hort16A'가 같은 과수원에서 나란히 재배되고 있는 제주도 서귀포시 성산읍 신산리에 있는 키위 재배농가 포장에서 2009년과 2010년 국내에서 키위 과실연부병(무름병) 방제약제로 등록되어 있는 살균제인 베노밀 수화제 및 지오판 수화제와 키위 재배농가에서 관행적으로 많이 사용하는 카벤다짐 디에토벤카브 수화제의 적정 살포시기, 살포간격 및 살포횟수를 조사하였다. 약제간 방제효과는 베노밀 수화제, 티오파네이트메틸 수화제, 카벤다짐 디에토펜카브 수화제 순이었다. 개화 전부터 약제를 살포하는 것보다 수정 후 약제를 살포하는 것이 방제효과가 높았으나 수정 후 약제살포하는 시기가 늦어질수록 방제효과는 낮아졌다. 약제살포 횟수가 증가함에 따라 방제효과는 증가하는 경향이었으나 'Hayward'와 'Hort16A' 모두에서 과실무름병 방제를 위한 예방약제의 적정 살포시기, 살포간격 및 살포횟수는 수정 후 2주일 간격 4회 처리로 판단된다.

국제 해상 컨테이너의 운용방안에 관한 연구 (A Study on the Effective Management for the International Sea-borne Container)

  • 김성국;신한원
    • 한국항해학회지
    • /
    • 제19권1호
    • /
    • pp.33-48
    • /
    • 1995
  • In the process of containerization, the problem of regional maldistribution of container management plan arises seriously due to several factors like a number of unbalances of containers between loading and discharging ports. This study focus on the minimizing cost. This study is composed of two models which in effective management decision making show decision of the number of containers and transfer of empty containers. One is decision of the number of containers which carriers should possess by appropriate forecasting and the other is effective management decision making which includes the transfer of empty containers on calling ports. This study has suggested as follows, First, the Time Series analysis method, especially the "Exponential Smooting with Trend Adjustment" was used to forecast the trade volumes for the designated traffic route. Second, the Time Series analysis method in deciding the optimal number of owned container at the unbalances trade situation between East Bound and West Bound service, most important variables were found such as total traffic volume, the calling interval at a port, the number of days of voyage and the length of stay on shore of container for the optimal number of owned container. Third, effective management decision making model, which makes it possible to analyze the impacts of change in important matters such as lease and positioning policy, and actually influence decision making.on making.

  • PDF

정관(精管) 정관(精管) 문합술(吻合術)의 경험(經驗) (CLINICAL EXPERIENCES OF VASOVASOSTOMIES)

  • 이희영
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제2권1호
    • /
    • pp.19-38
    • /
    • 1975
  • A total of 185 vasovasostomies were carried out for 11 years. Various factors which are of importance in fluencing the successful vasovasostomies are analysed and presented as follows: In recent years, demand of reanastomosis of the vas deferens increased considerably. An average age of the subjects is 39, and that of their wives, 33 in this series. An average interval between vasectomy and vasovasostomy is 4 years. An average number of living chidren is 2.6 at the time of vasectomy. and 2.1 at the time of time of vasovasostomy. Merchant and public official are the most commonly encounterd occupation in the present series. Coital frequencies are 2.2/week after vasovasostomy. The most common reasons for requesting the vasovasostomy are remarriage and deaths of children, especially son. Success rate is considerably higher among younger group than that of the older. Success rate is somewhat higher among groups of shorter interval between the operations (vasectomy and vasovasostomy) than that of longer interval group. Success rate is higher among bilateral vasovasostomy group than that of any others. Success rate is higher in solid splint group and no splint group than hollow splint group. The closed dressing technique of the end of splint on the scrotum is found to be reasonably effective in preventing infection. Ordinary end-to-end anastomosis and folded side-to-side anastomosis techniques are proved to be the most ideal form of modified operation for the successful vasovasostomies. The most common causes of failure are infection, injuries of blood supply, avascular necrosis due to extensive mobilization, inadequate approximation of both vasal end, hematoma, changes of epididymal environment, and early ambulation in this series. Overall success rate of the author's series is found the 81 per cent, and impregnation rate is 35 per cent. Overall results reported by other workers are that success rate regarding appearance of sperm in the semen after operation is 64 per cent, and that of impregnation after vasovasostomy is 33 per cent. The results of semen assessment performed on same cases prior to vasectomy and following vasovasostomy showed that post-vasovasostomy sperm count scarcely reached three-quaters of pre-vasectomy count.

  • PDF

전오존이 세라믹 막의 차압에 미치는 영향 (Effect of Pre-ozonation on the Trans-membrane Pressure of Ceramic Membrane)

  • 배병욱
    • 대한환경공학회지
    • /
    • 제33권9호
    • /
    • pp.656-661
    • /
    • 2011
  • 본 연구에서는 공경 $0.1{\mu}m$, 막여과 유속$3.0m^3/m^2{\cdot}d$의 국산 세라믹 막을 이용하여 음용수를 생산하는 기술에 대해 조사하였다. 세라믹 막의 성능 평가를 위해 $1m^3/d$ 규모의 pilot-scale 실험장치를 제작하였으며, 역세주기에 따른 차압변화와 전오존이 차압변화에 미치는 영향을 조사하였다. 차압상승률은 역세주기에 비례하여 증가하였으나, 전오존 주입을 통해 차압상승률을 낮출 수 있었다. 이 결과는 전오존이 파울링 감소에 효과가 있음을 의미한다. 1 mg/L의 전오존을 주입하고 5 min간 접촉하였을 때, 역세주기 1시간에서 차압상승률은 약 30% 감소하였다. 전오존 접촉시간을 5~15 min으로 변경하면서 운전한 결과, 접촉시간에 따른 차압상승률에는 차이가 없었다. 그러나, 차압상승률은 오존 주입농도가 증가하면 감소하는 경향을 보였다.

Birth Patterns and Delayed Breastfeeding Initiation in Indonesia

  • Tama, Tika Dwi;Astutik, Erni;Katmawanti, Septa;Reuwpassa, Jauhari Oka
    • Journal of Preventive Medicine and Public Health
    • /
    • 제53권6호
    • /
    • pp.465-475
    • /
    • 2020
  • Objectives: This study was conducted to examine the association between birth patterns (defined in terms of birth order and interval) with delayed breastfeeding initiation in Indonesia. Methods: A cross-sectional study was carried out using data from the Indonesian Demographic and Health Survey 2017. The weighted number of respondents was 5693 women aged 15-49 years whose youngest living child was less than 2 years old. Multivariable logistic regression was conducted to evaluate associations between birth patterns and delayed breastfeeding initiation after adjusting for other covariates. Results: This study found that 40.2% of newborns in Indonesia did not receive timely breastfeeding initiation. Birth patterns were significantly associated with delayed breastfeeding initiation. Firstborn children had 77% higher odds of experiencing delayed breastfeeding initiation (adjusted odds ratio, 1.77; 95% confidence interval, 1.02 to 3.04; p<0.05) than children with a birth order of 4 or higher and a birth interval ≤ 2 years after adjusting for other variables. Conclusions: Firstborn children had higher odds of experiencing delayed breastfeeding initiation. Steps to provide a robust support system for mothers, especially first-time mothers, such as sufficient access to breastfeeding information, support from family and healthcare providers, and national policy enforcement, will be effective strategies to ensure better practices regarding breastfeeding initiation.

목적함수가 고려된 적응샘플링기법에 의한 샘플링효율에 관한 연구 (On the Sampling Efficiency by the Adaptive Sampling Technique based on Performance Index)

  • 고명삼;김창은
    • 전기의세계
    • /
    • 제25권6호
    • /
    • pp.89-96
    • /
    • 1976
  • In this paper we deal with that the performance indices by the three adaptive sampling control laws are computed and compared. It shows that the most effective control law is the integral input difference method. The techniques of simulation by Analog/Hybrid computer are presented and the results of the output illustrate that the maximum and minimum sampling interval can be applied to the time sharing of digital controller or computer.

  • PDF

이산형 변수 시스템의 설계를 위한 시뮬레이션 활용 기법 연구 (A Method for Design of Discrete Variable Stochastic Systems using Simulation)

  • 박경종
    • 한국시뮬레이션학회논문지
    • /
    • 제8권3호
    • /
    • pp.1-16
    • /
    • 1999
  • This paper deals with a discrete simulation optimization method for designing a complex probabilistic discrete event system. The proposed algorithm in this paper searches the effective and reliable alternatives satisfying the target values of the system to be designed through a single run in a relatively short time period. It tries to estimate an autoregressive model, and construct mean and confidence interval for evaluating correctly the objective function obtained by small amount of output data. The experimental results using the proposed method are also shown.

  • PDF

PDA를 활용한 홍수예보시스템의 효율적 관리방안에 대한 연구 (A Study on Effective Management Method of the Flood Forecast System using PDA)

  • 정승백;양승인
    • 정보처리학회논문지A
    • /
    • 제17A권4호
    • /
    • pp.197-202
    • /
    • 2010
  • 관측소의 기록저장 장치는 수위계와 우량계로부터 5분 간격으로 측정된 데이터를 저장한다. 그리고 관측소의 RTU(Remote Terminal Unit)는 VHF와 위성통신을 이용하여 10분 간격으로 홍수통제소의 TM(Telemetering)으로 측정된 데이터를 전송한다. 이때 전송되는 데이터는 레코더에 저장된 전체 데이터가 아니라 10분 간격으로 측정된 데이터이다. 홍수 통제소에서는 수신된 데이터를 홍수예보를 위해 분석한다. 또한 중요한 점은 관측소의 유지보수이다. 본 논문에서는 홍수예보를 위한 효과적인 유지보수 시스템을 제안한다. 그것은 PDA의 CDMA와 Blutooth 기술을 사용하였다. 제안된 시스템은 휴대용이며 관측소에 저장된 데이터를 RTU없이 쉽게 홍수통제소로 전송할 수 있다. 또한 홍수통제소로 부터 전송 받아서 다른 지역의 관측소 데이터를 원격으로 볼 수 있다. 따라서 제안하는 시스템은 인력과 시간의 낭비를 줄여서 관측소의 유지 보수 업무를 효율적으로 할 수 있다.

Effects of 20% Aluminum Chloride in Axillary Hyperhidrosis not Accompanying Osmidrosis

  • Kim, Seok-Won;Lee, Seung-Myung
    • Journal of Korean Neurosurgical Society
    • /
    • 제37권4호
    • /
    • pp.272-274
    • /
    • 2005
  • Objective: Surgical treatment of focal axillary hyperhidrosis is often unsatisfactory because of compensatory hyperhidrosis. The purpose of this study is to evalute the effect of decreased sweating production using 20% aluminum chloride on axillary hyperhidrosis. Methods: From February to December, 2002, 10 patients (mean age 25.2 male 2, female 8) with clinical diagnosis of axillary hyperhidrosis were treated by 20% aluminum chloride solution. Until the desired degree of symptom relief was obtained, they were educated to apply every day and thereafter, the agent would be applied as often as is necessary. We analyzed patient's satisfaction and application time at onset of desired dryness, application interval to maintain the relief of symptom and side effects. Results: Aluminum chloride solution was effective in treatment of axillary hyperhidrosis showing excellent result in 60% of patients and good in 40%. Application time at onset of desired dryness ranged from 1 to 6 days(mean 3 days). Application interval to maintain the relief of symptom ranged from 5 to 45 days(mean 12 days). There were no significant complications but just mild irritation and miliaria in seven patients. Conclusion: 20% aluminum chloride solution is the simple, safe and less expensive method for initial treatment for axillary hyperhidrosis not accompanying osmidrosis.