• 제목/요약/키워드: Multiple Period

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A Model of Organizational Decision Process

  • Kim, Woo-Youl
    • 한국국방경영분석학회지
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    • 제7권2호
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    • pp.63-99
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    • 1981
  • The generalized goal decomposition model proposed by Ruefli as a single period decision model is presented for the purpose of a review and extended to make a multiple period planning model. The multiple period planning model in the three level organization is formulated with, linear goal deviations by introducing the goal programming method. Dynamic formulation using the generalized goal decomposition model for each single period problem is also presented. An iterative search algorithm is presented as an appropriate solution method of the dynamic formulation of the multiple period planning model.

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다중 해시함수 기반 데이터 스트림에서의 아이템 의사 주기 탐사 기법 (Finding Pseudo Periods over Data Streams based on Multiple Hash Functions)

  • 이학주;김재완;이원석
    • 한국IT서비스학회지
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    • 제16권1호
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    • pp.73-82
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    • 2017
  • Recently in-memory data stream processing has been actively applied to various subjects such as query processing, OLAP, data mining, i.e., frequent item sets, association rules, clustering. However, finding regular periodic patterns of events in an infinite data stream gets less attention. Most researches about finding periods use autocorrelation functions to find certain changes in periodic patterns, not period itself. And they usually find periodic patterns in time-series databases, not in data streams. Literally a period means the length or era of time that some phenomenon recur in a certain time interval. However in real applications a data set indeed evolves with tiny differences as time elapses. This kind of a period is called as a pseudo-period. This paper proposes a new scheme called FPMH (Finding Periods using Multiple Hash functions) algorithm to find such a set of pseudo-periods over a data stream based on multiple hash functions. According to the type of pseudo period, this paper categorizes FPMH into three, FPMH-E, FPMH-PC, FPMH-PP. To maximize the performance of the algorithm in the data stream environment and to keep most recent periodic patterns in memory, we applied decay mechanism to FPMH algorithms. FPMH algorithm minimizes the usage of memory as well as processing time with acceptable accuracy.

분산 제어 시스템에서의 태스크와 메시지 기반 스케줄링을 이용한 최적 주기와 우선순위 할당 (Optimal Period and Priority Assignment Using Task & Message-Based Scheduling in Distributed Control Systems)

  • 김형육;이철민;박홍성
    • 제어로봇시스템학회논문지
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    • 제8권6호
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    • pp.506-513
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    • 2002
  • Distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks. An assignment method of the optimal period of each loop and a heuristic assignment rule of each message's priority are proposed and the integrated scheduling method is developed based on them.

다발성 경화증 환자 5례에 대한 임상보고 (Clinical Studies on 5 Cases of Multiple Sclerosis by Acupuncture Therapies)

  • 강계성;권기록
    • Journal of Acupuncture Research
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    • 제20권1호
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    • pp.209-217
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    • 2003
  • Background : Multiple Sclerosis is characterized by chronic inflammation, demyelinization and neurogliosis(plaque) in optic nerve, brain and spinal cord, which is recurrent visual disturbance, sensory disturbance, motor disturbance and sphincter disturbance, etc. Objective : This study was performed to evaluate the treatment of acupuncture therapy including Herbal Acupuncture and Bee venom Herbal Acupuncture in Multiple Sclerosis. Methods : We treated 5 cases of Multiple Sclerosis patients with mainly Bee venom Herbal Acupuncture therapy, and herbal Acupuncture, sa-am acupuncture form 18th september, 2001 to december, 2002. Results : 1 Of 5 cases who were treated with above, 3 patients were mildly reduced symptoms and 2 patients were no changes. 2. There are two patients who were definitely appeared the recurrent symptoms on treatment period, but decreased the remission period than before. 3. It has not shown noticeable recurrent symptoms of 3 patients. Conclusions : Bee Venom Herbal Acupuncture therapy and other acupuncture therapies were effective in reducing the recurrent symptoms and remission perod, but it was not evaluated the chief complaints on 5 cases of Multiple Sclerosis. We think that it need the further study and clinical trial for Multiple Sclerosis and other neurological diseases.

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다중 지역기후모델로부터 모의된 월 기온자료를 이용한 다중선형회귀모형들의 예측성능 비교 (Inter-comparison of Prediction Skills of Multiple Linear Regression Methods Using Monthly Temperature Simulated by Multi-Regional Climate Models)

  • 성민규;김찬수;서명석
    • 대기
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    • 제25권4호
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    • pp.669-683
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    • 2015
  • In this study, we investigated the prediction skills of four multiple linear regression methods for monthly air temperature over South Korea. We used simulation results from four regional climate models (RegCM4, SNURCM, WRF, and YSURSM) driven by two boundary conditions (NCEP/DOE Reanalysis 2 and ERA-Interim). We selected 15 years (1989~2003) as the training period and the last 5 years (2004~2008) as validation period. The four regression methods used in this study are as follows: 1) Homogeneous Multiple linear Regression (HMR), 2) Homogeneous Multiple linear Regression constraining the regression coefficients to be nonnegative (HMR+), 3) non-homogeneous multiple linear regression (EMOS; Ensemble Model Output Statistics), 4) EMOS with positive coefficients (EMOS+). It is same method as the third method except for constraining the coefficients to be nonnegative. The four regression methods showed similar prediction skills for the monthly air temperature over South Korea. However, the prediction skills of regression methods which don't constrain regression coefficients to be nonnegative are clearly impacted by the existence of outliers. Among the four multiple linear regression methods, HMR+ and EMOS+ methods showed the best skill during the validation period. HMR+ and EMOS+ methods showed a very similar performance in terms of the MAE and RMSE. Therefore, we recommend the HMR+ as the best method because of ease of development and applications.

Throughput Analysis and Optimization of Distributed Collision Detection Protocols in Dense Wireless Local Area Networks

  • Choi, Hyun-Ho;Lee, Howon;Kim, Sanghoon;Lee, In-Ho
    • Journal of Communications and Networks
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    • 제18권3호
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    • pp.502-512
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    • 2016
  • The wireless carrier sense multiple access with collision detection (WCSMA/CD) and carrier sense multiple access with collision resolution (CSMA/CR) protocols are considered representative distributed collision detection protocols for fully connected dense wireless local area networks. These protocols identify collisions through additional short-sensing within a collision detection (CD) period after the start of data transmission. In this study, we analyze their throughput numerically and show that the throughput has a trade-off that accords with the length of the CD period. Consequently, we obtain the optimal length of the CD period that maximizes the throughput as a closed-form solution. Analysis and simulation results show that the throughput of distributed collision detection protocols is considerably improved when the optimal CD period is allocated according to the number of stations and the length of the transmitted packet.

워킹 휴가형 GI/M/1 대기행렬의 바쁜기간 분석 (Busy Period Analysis for the GI/M/1 Queue with Working Vacations)

  • 채경철;임대은
    • 한국경영과학회지
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    • 제32권2호
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    • pp.141-147
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    • 2007
  • We consider a GI/M/1 queue with vacations such that the server works with different rate rather than completely stops working during a vacation period. We derive the transform of the joint distribution of the length of a busy period, the number of customers served during the busy period, and the length of the subsequent idle period.

자원제약을 고려하며 기간단축이 가능한 복수의 양식을 지닌 단일 프로젝트의 일정문제:자원 가용량이 시간에 따라 변하는 경우의 휴리스틱 기법 (Resource Constrained Project Scheduling Problem with Multiple Crashable Modes: A Heuristic Procedure for the Resource Availabilities Varying from Period to Period)

  • 안태호
    • 한국컴퓨터정보학회논문지
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    • 제3권4호
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    • pp.154-163
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    • 1998
  • In this paper a heuristic procedure for a resource constrained project scheduling problem with multiple crashable modes is presented. A similar heuristic procedure by Ahn and Erengue was recently introduced, but the procedure assumes the resource capacities constant over the project life. The Procedure of this paper is able to deal with the resource capacities varying over the project life. The computational results with a set of 110 test problems demonstrate the efficacy of the heuristic procedure.

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혈역학적으로 불안정한 골반외상 환자의 치료를 통해 본 외상전문의의 필요성 (The Importance of the Trauma Surgeon: A Reflection on the Management of Hemodynamically Unstable Pelvic Trauma Patients)

  • 신성;경규혁;김지완;김정재;홍석경
    • Journal of Trauma and Injury
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    • 제22권2호
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    • pp.254-259
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    • 2009
  • Purpose: Pelvic trauma is a serious skeletal injury with high mortality. Especially in cases of severe injury trauma, treatment outcomes depend on early diagnosis and intervention. We expect trauma surgeon to play an important role in the management of severe multiple trauma patients. Methods: A retrospective study was performed on pelvic trauma patients with hemodynamic instability between March 2005 and September 2009. We divided the time period into period I (March 2005~Feburary 2009) and period II (March 2009~September 2009). The trauma surgeon and team started to work from period II. Data were collected regarding demographic characteristics, mechanism of injury, type of pelvic fracture, ISS(injury severity score), treatment modality, transfusion requirement, time to definitive treatment, and mortality. Results: During period I, among 7 hemodynamically unstable patients, 4(57.1%) patients died. However during Period II, only one of 6(16.6%) patients died. The demographic data and injury scores showed no differences between the two time periods, but the time to definitive treatment was very short with trauma team intervention(14.4 hrs vs. 3.9 hrs). Also, the amount of transfusion was less(41.1 U vs. 13.9 U). With arterial embolization, early pelvic external fixation led to less transfusion and made patients more stable. Conclusion: This study demonstrated the importance of the trauma surgeon and the trauma team in cases of hemodynamically unstable pelvic trauma. Even with the same facility and resources, an active trauma team approach can increase the survival of severely injured multiple trauma patients.

몬테소리와 일반 어린이집 유아의 다중지능 영역비교와 사회성 (A Comparison of Young Children's Multiple Intelligence Area and Social Behaviors in Montessori and General Programs of Day Care Centers)

  • 전오숙;정영숙;장혜자
    • 한국생활과학회지
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    • 제15권1호
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    • pp.71-81
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    • 2006
  • The purpose of this study is to examine the differences in young children's multiple intelligence and social behaviors based not only on Montessori and general programs of day care centers but also on their gender and social- demographic factors. The subjects were 329 young children (182 boys and 147 girls aged from four to five) from two day care centers in Cheongju city. The instruments used in this study were HAPI (Hillside assessment of Perceived Intelligence) to measure the surveyee's multiple intelligence and Park & Lee's scale to measure their social behaviors. The frequencies, percentiles, mean, standard deviations, Cronbach a, t-teat, F and LSD were used to analyze the collected data through SPSS WIN program. The results of this study are as follows: 1) As for young children's multiple intelligence, there are differences according to young children's gender, order of birth, parents' level of education and teacher's working period out of social-demographic factors. 2) As for the young children's social behavior, there are differences according to young children's gender, mother's level of education and teacher's working period out of social-demographic factors.

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