• 제목/요약/키워드: Group synchronization

검색결과 123건 처리시간 0.06초

A Synchronization Scheme for Hierarchical Video Streams over Heterogeneous Networks

  • Sohn, Yejin;Cho, Minju;Seo, Minjae;Paik, Jongho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권8호
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    • pp.3121-3135
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    • 2015
  • Owing to the increase in consumption of multimedia content and the improvement of device capacity, user demand for high-quality content has increased. However, it is difficult to transport such large amounts of content over the existing broadcasting network with limited bandwidth. To provide high-definition broadcasting, some studies suggest methods of transporting multimedia over heterogeneous networks after encoding content hierarchically. MPEG Media Transport (MMT), standardized by Moving Picture Experts Group (MPEG), is a solution that enables large-volume media transport over heterogeneous networks such as digital broadcasting networks and packet-switched networks. In the case of delivering a scalable encoded video over different networks, synchronization of each stream is an important issue. MMT defines a synchronization scheme, but does not contain sufficient functions to implement it. In this paper, we propose a synchronization scheme for media streams that are encoded hierarchically, divided into layers, and transported over heterogeneous networks. We implement our scheme using MMT and HTTP, and experimented using three encapsulated video streams with different durations. As a result, we show that the proposed scheme can reduce the waiting time to display high-quality video, relative to Dynamic Adaptive Streaming over HTTP-Scalable Video Coding (DASH-SVC) by requesting segments of enhanced layers after calculating the transmission time. Additionally, we find out that the selection of durations have a relation to the characteristics of the video.

Use of Two Estrus Synchronization Protocols and Their Success on Pregnancy in Zebu and Crossbred Heifers at Char Areas of Bangladesh

  • Ghosh, Tapas;Paul, Ashit Kumar;Talukder, Anup Kumar;Alam, M. Golam Shahi;Bari, Farida Yeasmin
    • Journal of Embryo Transfer
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    • 제27권4호
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    • pp.223-228
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    • 2012
  • This study was designed to adopt two estrus synchronization protocols in zebu and crossbred heifers and their effects on pregnancy rate after timed artificial insemination (TAI). A number of 120 cyclic heifers were allotted for two different treatment groups and one control group. Heifers under protocol A were injected with GnRH at first day followed by a single dose of $PGF_{2{\alpha}}$ at Day 11 and injection of GnRH at the day of AI; and heifers belonged to protocol B were treated with GnRH, two $PGF_{2{\alpha}}$ injections at 11 days apart and injection of GnRH at AI. AI was done at fixed time (within 72~96 hours after $PGF_{2{\alpha}}$ injection) in both protocols and pregnancy was confirmed by rectal palpation on 80~120 days of post AI. In control group; local heifers were conceived higher (30%) proportion than that of crossbred heifers (25%; p<0.05). In protocol A, the local breed were conceived higher (38.9%) proportion compared with crossbred (25%; p<0.05). In protocol B, local breed heifers were conceived higher (38.9%) proportion compared with crossbred heifers (33.3%; p<0.05). The overall pregnancy rate in protocol A and protocol B was 33.3% and 36.6%, respectively. The proportion of pregnancy rate of local heifers (38.9%; Protocol A) was significant (p<0.05) in comparison with local heifers (30%) in control group (p<0.05). The overall pregnancy rate between pooled control group (28.3%) and treatment group (35%) was significantly (p<0.05) differ from each other's. Results of present study concluded that estrus synchronization followed by fixed time AI could be applied for higher pregnancy rate in zebu and crossbred heifers.

Effects of Different Hormone Treatments on the Estrus Synchronization and Superovulation of Gilts I. Effects of Altrenogest and PG600 Treatments on the Estrus Synchronization of Gilts (미경산돈의 발정 동기화 및 과배란시 호르몬 처리간의 효과 I. 미경산돈의 발정 동기화에 있어 Altrenogest와 PG600 처리 효과)

  • 장원경;박진기;이장형;김도형;이훈택;정길생
    • Korean Journal of Animal Reproduction
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    • 제19권2호
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    • pp.147-152
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    • 1995
  • The purpose of this study was to examine the estrus synchronization and superovulation of pigs with hormone treatments. Three different kinds of procedures for synchronization and superovulation were used as follow: I) gilts in natural estrus behavior (control): 2) gilts synchronized with 20mg altrenogest for 9 days regardless of the estrus cycle; 3) gilts received PG600 (400IU PMSG + 200 IU hCG) in 15 day of the estrus cycle; and then gilts administrated with PMSG (1,500 IU) and hCG (750 IU) after altrenogest and PG600 treatment for superovulation. Estrus was checked daily with a boar, in estrus synchronization, the intervals from hormone treatment to estrus were different between PG600 (43/47) and altrenogest (13/53) within 6 days. The percentage of animals displaying a estrus response were not different by hormone treatments. The average number of corpora lutea (C.L) and ovulated embryos were similar between PG600 25.4${\pm}$13.1, 19.0$\pm$12.8 and altrenogest 25.5${\pm}$0.7, 15.0${\pm}$4.2, respectively, but was increased (P<0.05) by hormone treatment compared to that 12.9${\pm}$1.8, 12.7${\pm}$3.9 in the control. The number of normal embryos after ovulation was higher in the control than hormone treatment. Therefore, these results suggest that altrenogest and PG600 treatment could be a valuable for cut down the labour and cost by synchronization.

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Implementation of a Remote Group Lighting Control System using ICT (ICT를 활용한 원격 그룹조명 제어시스템 구현)

  • Na, Cheol-hun;Boo, Su-il
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 한국정보통신학회 2021년도 추계학술대회
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    • pp.606-608
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    • 2021
  • Humans and various devices are interconnected using the Internet of Things and are used in various ways. In this study, a synchronization control system with remote locations was constructed using ICT, and a signal system for pedestrians was implemented using the system. PLC circuits were used to implement controllers, through which wireless control signal transmission and reception, LED lamp emission control, and power control were performed. It was confirmed that signal synchronization from the main controller to the remote sub-controller was possible by establishing a controller and pedestrian traffic light system, and lamp signal synchronization of the pedestrian traffic light system installed on both sides of the road was implemented. As a result, it was confirmed that 1:1 remote control or 1:N remote group control was possible, and this result can be used in various fields.

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A Case Study of Synchronization-Based Group Music Therapy for Promoting Peer Interaction of Children With Autism Spectrum Disorder (자폐범주성장애 아동의 또래 간 상호작용 촉진을 위한 동기화 기반 그룹 음악치료 사례)

  • Kim, Jiyun
    • Journal of Music and Human Behavior
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    • 제17권1호
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    • pp.97-125
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    • 2020
  • This case study examined the effects of synchronization-based group music therapy for improving peer interaction of children with autism spectrum disorder (ASD). The participants were five children between the ages of 6 and 10 with ASD. A total of eight 30-minute music therapy sessions were conducted two times a week. During sessions, target behaviors (i.e., engagement in joint action, synchronized movements, eye contact, and initiation of social interaction) were observed and analyzed. Also, the PIPPS-P was completed by parents to identify behavioral changes in real-life environments from pretest to posttest. Following the intervention, all of the participants showed increases in synchronized movements with peers and attempts to initiate social interaction. In addition, parents rated their children's play behavior as being improved in their everyday living environment. These results support that synchronous movements between children with ASD, which were facilitated with rhythmic cueing, led to enhanced engagement in joint action. Considering that those movements are the basis for further social skills (e.g., play behavior), this study also indicates that synchronization-based group music therapy could be an effective therapeutic approach for improving the peer interaction of this population.

Task Synchronization Mechanism for Round Robin based Proportional Share Scheduling (라운드 로빈 기반 비례지분 스케줄링을 위한 동기화 기법)

  • Park, Hyeon-Hui;Yang, Seung-Min
    • Journal of KIISE:Computer Systems and Theory
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    • 제36권4호
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    • pp.291-303
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    • 2009
  • Round robin based proportional share scheduling(RRPS) defines weight which determines share for each task and allocates CPU resource to each task in proportional to its respective weight. RRPS uses fairness as the measure of performance and aims at high fairness of scheduling. However, researches for scheduling fairness problem due to synchronization among tasks have been rarely investigated. In this paper, we discuss that scheduling delay due to synchronization may result high unfairness in RRPS. We explain such a situation as weight inversion. We then propose weight inheritance protocol(WIP), a synchronization mechanism, that prevents weight inversion. We also show that WIP can reduce unfairness using fairness analysis and simulation.

CoAP-based Time Synchronization Algorithm in Sensor Network (센서 네트워크에서의 CoAP 기반 시각 동기화 기법)

  • Kim, Nac-Woo;Son, Seung-Chul;Park, Il-Kyun;Yu, Hong-Yeon;Lee, Byung-Tak
    • Journal of the Institute of Electronics and Information Engineers
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    • 제52권3호
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    • pp.39-47
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    • 2015
  • In this paper, we propose a new time synchronization algorithm using CoAP(constrained-application protocol) in sensor network environment, which handles a technique that synchronizes an explicit timestamp between sensor nodes not including an additional module for time-setting and sensor node gateway linked to internet time server. CoAP is a standard protocol for sensor data communication among sensor nodes and sensor node gateway to be built much less memory and power supply in constrained network surroundings including serious network jitter, packet losses, etc. We have supplied an exact time synchronization implementation among small and cheap IP-based sensor nodes or non-IP based sensor nodes and sensor node gateway in sensor network using CoAP message header's option extension. On behalf of conventional network time synchronization method, as our approach uses an exclusive protocol 'CoAP' in sensor network, it is not to become an additional burden for synchronization service to sensor nodes or sensor node gateway. This method has an average error about 2ms comparing to NTP service and offers a low-cost and robust network time synchronization algorithm.

A Cell Search with Reduced Complexity in a Mobile Station of OFCDM Systems (OFCDM 시스템의 이동국에서의 복잡도 감소 셀 탐색)

  • Kim, Dae-Yong;Park, Yong-Wan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • 제11권1호
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    • pp.139-149
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    • 2007
  • Asynchronous OFCDM(Orthogonal Frequency and Code Division Multiplexing) systems must have a cell search process necessarily unlike synch개nous systems. this process is hewn initial synchronization and a three-step cell search algorithm is performed for the initial synchronization in the following three steps: OFCDM symbol timing, i.e., Fast Fourier Transform(FFT) window timing is estimated employing guard interval (GI) correlation in the first step, then the frame timing and CSSC(Cell Specific Scrambling Code) group is detected by taking the correlation of the CPICH(Common Pilot Channel) based on the property yielded by shifting the CSSC phase in the frequency domain. Finally, the CSSC phase within the group is identified in the third step. This paper proposes a modification group code with two or three block of the conventional CPICH based cell search algorithm in the second step which offers MS(Mobile Station) complexity reductions. however, the effect of the reduction complexity leads to degradation of the performance therefore, look for combination to have the most minimum degradation. the proposed block type group code with suitable combinations is the nearly sane performance as conventional group code and has a complexity reduction that is to be compared and verified through the computer simulation.

Development of Machine Learning Model to Predict Hydrogen Maser Holdover Time (수소 메이저 홀드오버 시간예측을 위한 머신러닝 모델 개발)

  • Sang Jun Kim;Young Kyu Lee;Joon Hyo Rhee;Juhyun Lee;Gyeong Won Choi;Ju-Ik Oh;Donghui Yu
    • Journal of Positioning, Navigation, and Timing
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    • 제13권1호
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    • pp.111-115
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    • 2024
  • This study builds a machine learning model optimized for clocks among various techniques in the field of artificial intelligence and applies it to clock stabilization or synchronization technology based on atomic clock noise characteristics. In addition, the possibility of providing stable source clock data is confirmed through the characteristics of machine learning predicted values during holdover of atomic clocks. The proposed machine learning model is evaluated by comparing its performance with the AutoRegressive Integrated Moving Average (ARIMA) model, an existing statistical clock prediction model. From the results of the analysis, the prediction model proposed in this study (MSE: 9.47476) has a lower MSE value than the ARIMA model (MSE: 221.2622), which means that it provides more accurate predictions. The prediction accuracy is based on understanding the complex nature of data that changes over time and how well the model reflects this. The application of a machine learning prediction model can be seen as a way to overcome the limitations of the statistical-based ARIMA model in time series prediction and achieve improved prediction performance.

Error Correction of Digital Data in Radio Data System (라디오 데이터 시스템의 디지털 데이터 에러 정정)

  • 김기근
    • Proceedings of the Acoustical Society of Korea Conference
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    • 한국음향학회 1991년도 학술발표회 논문집
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    • pp.78-81
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    • 1991
  • Digital radio data is composed of groups which are divided into 4 blocks of 26 bits. And each block is made up of information word and check word. Check word of digital radio data that is composed ofcode word and offset word is used for group/block synchronization and error correction. In this paper, we have investigated the group/block synchronizer using offext word and shortened cyclic decoder for correcting error produced during the radio data transimission. Also, we have simulated the decoding process of the proposed decoder. From the simulation results, we have confirmed that the proposed decoder most with the required coding capcbility.

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