• 제목/요약/키워드: Repeat time

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초신속궤도력 기반 GPS 위성 repeat time 산출 및 궤도 예측 (GPS Satellite Repeat Time Determination and Orbit Prediction Based on Ultra-rapid Orbits)

  • 이창문;박관동;김혜인;박재민
    • 한국측량학회지
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    • 제27권4호
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    • pp.411-420
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    • 2009
  • GPS 측량 계획을 수립하기 위해서는 GPS 위성의 예측궤도력을 이용하여 측량자가 원하는 시간과 측점에서 측량이 가능한지 여부를 판단해야 한다. 이 연구에서는 예측궤도력을 생성하기 위한 방법으로 GPS 위성의 repeat time을 이용하였다. Repeat time은 초신속궤도력에 포함된 48시간 GPS 궤도력에서 제공하는 3차원 위성좌표의 상관관계를 분석하여 산출하였다. 그리고 계산된 repeat time을 이용하여 13차 Lagrange 보간 다항식으로 7일간 예측 궤도를 생성하였다. 그 결과, 각 위성의 X, Y, Z 성분별 최대오차의 RMS 평균은 각각 39.8km, 39.7km, 19.6km로 나타났다. 그리고 3차원 오차의 최대값은 119.5km 평균값은 48.9km로 나타났다. 또한 위성의 가시성 분석을 위해 3차원 최대 오차 값인 119.5km를 시야각 오차로 변환한 결과, 방위각과 고도각의 오차는 각각 9.7', 14.9'으로 나타났다.

STABILITY CONDITION OF DISCRETE-TIME $GEO^x$/G/1 QUEUE WITH PREEMPTIVE REPEAT PRIORITY

  • Lee, Yutae
    • Journal of applied mathematics & informatics
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    • 제12권1_2호
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    • pp.291-297
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    • 2003
  • This paper considers discrete-time two-class Ge $o^{X/}$G/1 queues with preemptive repeat priority. Service times of messages of each priority class are i.i.d. according to a general discrete distribution function that may differ between two classes. Completion times are derived for the preemptive repeat identical and different priority disciplines. By using the completion time, the stability condition for our system is investigated.d.

저수태 한우에 대한 성선자극 호르몬 방출호르몬 투여 효과 (Effect of Gonadotropin-releasing Hormone Administration in Repeat-breeder Hanwoo)

  • 임석기;우재석;윤상보;전기준
    • 한국수정란이식학회지
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    • 제12권1호
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    • pp.117-122
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    • 1997
  • The objective of this study was to enhance the pregnancy rate of repeat-breeder Hanwoo with gonadotropin-releasing hormone(Gn-RH) at the time, dose and site of administration.The results obtained were summaried as fallows:1.Ovulation time and pregnancy rate following GnRH administration time was 46.0, 27.4, 42.0 and 43.2hr and 33.3, 57.1, 37.5 and 40.0% at non-treatment, estus, 1st A' and 2nd Al treatment, respectively.2. Ovulation in repeat-breeder was induced 100% within 24hr with GnRH administration at the time of estrus.3. Ovulation time and pregnancy rate following GnRH adminstration dose and site was 25.2, 32.6, 17.6 and 27.6hr, and 28.6, 42.9, 75.0 and 66.7% at 50$\mu$g+IU, 50$\mu$g+IM, 100$\mu$g+IU and 100$\mu$g+IM treatments, respectively. It is concluded that GnRH administration for repeat-breeder was enhanced the pregnancy rate when treated with 100$\mu$g intrauterine at the time of estrus.

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무선 채널에서의 Selective Repeat ARQ 프로토콜의 Delay 성능 분석 (Delay Analysis of Selective Repeat ARQ for a Markovian Source Over a Wireless Channel)

  • 김정근;김영수;이계산
    • 한국통신학회논문지
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    • 제29권11B
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    • pp.930-937
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    • 2004
  • 이 논문에서는 시간에 따라 채널 상태가 변화는 무선 채널 상에서 Markov 소스의 딜레이 성능을 분석하였다. 무선 링크의 양단에서 Selective-repeat (SR) ARQ 프로토콜을 사용한다고 가정했다. 이 논문에서는 대기 시간과 전송 및 재전송 시간 그리고 재 정렬 시간으로 구성된 단대단 평균 패킷 딜레이에 대한 근사화된 분석 방식을 제안하였다. 수치적인 분석과 시뮬레이tus 결과와의 분석을 통해서, 이 연구에서 제안한 분석 방식이 대부분의 경우 정확한 결과를 예측하고 있음을 증명하였다.

Risk factors for repeat breeder dairy cows and their impacts on reproductive performance

  • Jeong, Jae-Kwan;Kim, Ill-Hwa
    • 대한수의학회지
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    • 제62권2호
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    • pp.15.1-15.8
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    • 2022
  • The objective of this study was to identify risk factors for repeat breeder dairy cows and their impact on reproductive performance. The characteristics of 1,504 cows, including their peripartum health, nutrition, production, and reproduction, were collected. Cows with metabolic disorder were significantly more likely (odds ratio [OR], 2.47; p < 0.001) and cows with clinical endometritis tended to be more likely (OR, 1.35; p < 0.1) to become repeat breeders than cows without metabolic disorder and clinical endometritis, respectively. Cows initially inseminated > 80 days after calving were less likely (OR, 0.78; p < 0.05) to become repeat breeders than cows initially inseminated ≤ 80 days after calving. As a result, repeat breeding in dairy cows resulted in a 90 day longer (p < 0.0001) mean interval from calving to pregnancy. In conclusion, postpartum metabolic disorder, clinical endometritis, and a short interval from calving to initial insemination were risk factors for repeat breeder dairy cows, resulting in a severely impaired reproductive performance.

Repeat analysis of intraoral digital imaging performed by undergraduate students using a complementary metal oxide semiconductor sensor: An institutional case study

  • Yusof, Mohd Yusmiaidil Putera Mohd;Rahman, Nur Liyana Abdul;Asri, Amiza Aqiela Ahmad;Othman, Noor Ilyani;Mokhtar, Ilham Wan
    • Imaging Science in Dentistry
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    • 제47권4호
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    • pp.233-239
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    • 2017
  • Purpose: This study was performed to quantify the repeat rate of imaging acquisitions based on different clinical examinations, and to assess the prevalence of error types in intraoral bitewing and periapical imaging using a digital complementary metal-oxide-semiconductor(CMOS) intraoral sensor. Materials and Methods: A total of 8,030 intraoral images were retrospectively collected from 3 groups of undergraduate clinical dental students. The type of examination, stage of the procedure, and reasons for repetition were analysed and recorded. The repeat rate was calculated as the total number of repeated images divided by the total number of examinations. The weighted Cohen's kappa for inter- and intra-observer agreement was used after calibration and prior to image analysis. Results: The overall repeat rate on intraoral periapical images was 34.4%. A total of 1,978 repeated periapical images were from endodontic assessment, which included working length estimation (WLE), trial gutta-percha (tGP), obturation, and removal of gutta-percha (rGP). In the endodontic imaging, the highest repeat rate was from WLE (51.9%) followed by tGP (48.5%), obturation (42.2%), and rGP (35.6%). In bitewing images, the repeat rate was 15.1% and poor angulation was identified as the most common cause of error. A substantial level of intra- and inter-observer agreement was achieved. Conclusion: The repeat rates in this study were relatively high, especially for certain clinical procedures, warranting training in optimization techniques and radiation protection. Repeat analysis should be performed from time to time to enhance quality assurance and hence deliver high-quality health services to patients

(N, n)-선점 재샘플링-반복 우선순위 대기행렬 ((N, n)-Preemptive Repeat-Different Priority Queues)

  • 김길환
    • 산업경영시스템학회지
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    • 제40권3호
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    • pp.66-75
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    • 2017
  • Priority disciplines are an important scheme for service systems to differentiate their services for different classes of customers. (N, n)-preemptive priority disciplines enable system engineers to fine-tune the performances of different classes of customers arriving to the system. Due to this virtue of controllability, (N, n)-preemptive priority queueing models can be applied to various types of systems in which the service performances of different classes of customers need to be adjusted for a complex objective. In this paper, we extend the existing (N, n)-preemptive resume and (N, n)-preemptive repeat-identical priority queueing models to the (N, n)-preemptive repeat-different priority queueing model. We derive the queue-length distributions in the M/G/1 queueing model with two classes of customers, under the (N, n)-preemptive repeat-different priority discipline. In order to derive the queue-length distributions, we employ an analysis of the effective service time of a low-priority customer, a delay cycle analysis, and a joint transformation method. We then derive the first and second moments of the queue lengths of high- and low-priority customers. We also present a numerical example for the first and second moments of the queue length of high- and low-priority customers. Through doing this, we show that, under the (N, n)-preemptive repeat-different priority discipline, the first and second moments of customers with high priority are bounded by some upper bounds, regardless of the service characteristics of customers with low priority. This property may help system engineers design such service systems that guarantee the mean and variance of delay for primary users under a certain bounds, when preempted services have to be restarted with another service time resampled from the same service time distribution.

Analysis of Factors Contributing to Repeat Surgery in Multi-Segments Cervical Ossification of Posterior Longitudinal Ligament

  • Jeon, Ikchan;Cho, Yong Eun
    • Journal of Korean Neurosurgical Society
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    • 제61권2호
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    • pp.224-232
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    • 2018
  • Objective : Cervical ossification of the posterior longitudinal ligament (OPLL) can be treated via anterior or posterior approach, or both. The optimal approach depends on the characteristics of OPLL and cervical curvature. Although most patients can be successfully treated by a single surgery with the proper approach, renewed or newly developed neurological deterioration often requires repeat surgery. Methods : Twenty-seven patients with renewed or newly developed neurological deterioration requiring salvage surgery for multi-segment cervical OPLL were enrolled. Ten patients (group AP) underwent anterior approach, and 17 patients (group PA) underwent posterior approach at the initial surgery. Clinical and radiological data from initial and repeat surgeries were obtained and analyzed retrospectively. Results : The intervals between the initial and repeat surgeries were $102.80{\pm}60.08months$ (group AP) and $61.00{\pm}8.16months$ (group PA) (p<0.05). In group AP, the main OPLL lesions were removed during the initial surgery. There was a tendency that the site of main OPLL lesions causing renewed or newly developed neurological deterioration were different from that of the initial surgery (8/10, p<0.05). Repeat surgery was performed for progressed OPLL lesions at another segment as the main pathology. In group PA, the main OPLL lesions at the initial surgery continued as the main pathology for repeat surgery. Progression of kyphosis in the cervical curvature (Cobb's angle on C2-7 and segmental angle on the main OPLL lesion) was noted between the initial and repeat surgeries. Group PA showed more kyphotic cervical curvature compared to group AP at the time of repeat surgery (p<0.05). Conclusion : The reasons for repeat surgery depend on the type of initial surgery. The main factors leading to repeat surgery are progression of remnant OPLL at a different segment in group AP and kyphotic change of the cervical curvature in group PA.

남한산성도립공원 등산객과 비등산객의 장소 가치인식 비교 연구 (Comparison between Hiker and Non-hiker's Sense of place value at Namhansanseong Provincial Park)

  • 김예은;김현;백난영
    • 농촌계획
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    • 제21권4호
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    • pp.127-137
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    • 2015
  • This Study attempted to comprehend difference between hiker and non-hiker's sense of place value at Namhansanseong Provincial Park. Especially, it was analyzed after visitors, who were divided into local residents & tourists and first time visitors & repeat visitors. Out of 600 visitors, who were over 19 years old, participated in the survey, 587 responses were used for data analysis. Consequently, Sense of place value at Namhansanseong Provincial Park were classified into three factors: Health Culture, Ecology Environment, and Connectedness. Hikers feel higher value on promotion of health, relaxation, environment than non-hikers. Among hikers, local residents feel higher value on ecology environment and connectedness than tourists. Among non-hikers, however, they have no difference between local residents and tourists, only repeat visitors and first time visitors. On this result, possibility of resident participation management on natural environment and trail was considered, and when the program, which is for raising cultural and traditional value, would develop, increasing number of repeat visitor should be considered as a high priority.

문자열의 최장 공통 부분문자열과 최대 반복자를 구하기 위한 상수시간 RMESH 알고리즘 (Constant Time RMESH Algorithm for Computing Longest Common Substring and Maximal Repeat of String)

  • 한선미;우진운
    • 정보처리학회논문지A
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    • 제16A권5호
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    • pp.319-326
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    • 2009
  • 문자열 연산이 계산 생물학 분야에 응용되면서 효율적인 문자열 연산을 위한 다양한 자료구조와 알고리즘이 연구되고 있다. 최장 공통 부분 문자열 문제는 두 개 이상의 문자열에서 가장 길게 일치하는 부분문자열을 찾는 연산이며, 최대 반복자 문제는 하나의 문자열에서 두 번 이상 반복되는 부분문자열을 찾는 연산이다. 이 연산은 패턴 매칭, 유사도 측정 등의 문자열 처리 분야에서 중요하게 사용되고 있다. 본 논문에서는 RMESH(Reconfigurable MESH) 구조에서 3-차원 $n{\times}n{\times}n$ 프로세서를 사용하여 두 문자열의 최장 공통 부분문자열을 구하는 알고리즘과 주어진 문자열의 최대 반복자를 찾는 알고리즘을 제안하며, 이 알고리즘들은 모두 O(1) 시간 복잡도를 갖는다.