• Title/Summary/Keyword: Asynchronous data

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SPMC-MAC : Slim Preamble Multi-Channel MAC Protocol with Transmission Power Control in Wireless Sensor Networks (무선 센서 네트워크에서 다중 채널과 전송세기 제어를 이용한 맥 프로토콜)

  • Yoon, Jang-Muk;Bahk, Sae-Woong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.10B
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    • pp.876-884
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    • 2008
  • In this paper, we propose an asynchronous MAC protocol to minimize energy usage and to maximize data throughput for a wireless sensor network in multi channel environments. Our proposed SPMC-MAC (Slim Preamble Multi-Channel Media Access Control) adopts the preamble sliming mechanism proposed in [6] that takes advantage of the knowledge about the wakeup time of the receiver node. The preamble contains the receiver's ID and a randomly selected channel ID for data communication, and it is transmitted over a dedicated common channel. The power control has the benefit of keeping an appropriate number of nodes with the communication range, resulting in reduced collision and interference. We compare our SPMC-MAC and X-MAC extensively in terms of energy consumption and throughput using mathematical analysis and simulation.

Social Network Games' Commitment Between 2012 and 2016 (2012년과 2016년 소셜네트워크 게임의 몰입)

  • Lee, Sae Bom;Moon, Jae Young;Suh, Yung Ho
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.07a
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    • pp.262-264
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    • 2018
  • Many of users play Mobil Social Network Games (M-SNG). M-SNGs are played through social network, and typically features multiplayer and asynchronous gameplay mechanics. It is most often implemented as mobile devices with mobile instant messenger app. Kakaotalk provids mobile game platform. The purpose of this study is to find significant factors that have effects on the commitment of M-SNGs. We also conduct multi-group comparison test to study the difference in factors of models between time t and time t1. Time t is October, 2012 and time t1 is April, 2016. This study is to empirically test the research model using data collected from M-SNGs' users. We survey two different groups of time t and time t1 people with the same model. We use structural equation model analysis with AMOS 18.0 and compare two models of different times. This study is to give academicians and practitioners insight about its effects and implications

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A Study on Dual-rate MC-CDMA Systems (이중전송률 다중반송파 CDMA 시스템)

  • Kim Nam-Sun
    • Journal of Korea Society of Industrial Information Systems
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    • v.10 no.1
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    • pp.1-8
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    • 2005
  • Multicarrier code division multiple access(MC-CDMA) Is a scheme that combines multicarrier modulation with CDMA. It offers robustness to frequency selective fading and can support higher rate data transmission with higher spectral efficiency. The objective of this article to proposed a new asynchronous ME-CDMA system to implement multiple data rate communications. It can be accomplished by changing the number of parallel branch(.p). For the analysis of average BER performance, numerical method and computer simulation were used. After MAI power of received signal calculated, the average BER can be acriuired using Gaussian approximation to MAI. We also compare the system performance with that of a single rate MC-CDMA system.

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A Study on Butter Managment Mechanism for Efficient Cell Transmission in ATM Network (ATM망에서 효율적인 셀 전송을 위한 버퍼 관리 기법에 관한 연구)

  • 양신현;서진교;김준년;김영일
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.4
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    • pp.782-792
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    • 1997
  • Asynchronous transfer mode (ATM) provides the means to support with variety of multimedia serivices in broadband network. For the support of multimedia services, various data traffic with priortes should be controlled errectively and congestion function is required in the network to carry out the control operation. To accomplish this in a flexible and effective manner, priorty classes for the different services are commonly used. In this paper, we suggested a buffer managment algorithm in ATM network to improve overall network performance with separated buffer which consists of existing buffer with threshold andauxiliary buffer whose input consists of superposition of voice and data traffic. To evaluate the proposed buffer managment algorithms, simulations are excuted with two proiorities and the results are provied that network throughput is improved better than the existing parital buffer method.

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A Study on Optimization of W-CDMA System Reverse Link Power Ratio using Multiple Access Interference Cancellation (역방향 채널 전력비에 따른 IMT-2000용 비동기 W-CDMA 시스템의 성능 분석)

  • 강명구;조장묵;진용옥
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.1
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    • pp.227-232
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    • 2000
  • This study applied asynchronous W-CDMA(3GPP) system that is suggested as an access method of IMT-2000, multimedia communication in next generation, and estimated fading channel by using pilot symbol different from traditional IS-95. And then, it applied PIC(Parallel Interference Cancellation) as multiple access interference cancellation and analyzed performance depending on the power rate between DPCCH(Control) and DPDCH(Data). As a result of simulation, it showed the best performance in C:D = 3:7 and 4:6, where set up as five users in case of hand design, and showed the best performance in C:D = 3:7, where did as ten users.

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An Implementation of the Labeling Auto.ation system for Hot-coils using a Robot Vision System (로봇비젼 시스템을 이용한 핫코일의 자동라벨링 시스템 구현)

  • Lee, Yong-Joong;Kim, Hak-Pom;Lee, Yang-Bum
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1266-1268
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    • 1996
  • In this study an automatic roiling-coli labeling system using robot vision system and peripheral mechanism is proposed and implemented, which instead of the manual labor to attach labels Rolling-coils in a steel miil. The binary image process for the image processing is performed with the threshold, and the contour line is converted to the binary gradient which detects the discontinuous variation of brightness of rolling-coils. The moment invariants algorithm proposed by Hu is used to make it easy to recognize even when the position of the center are different from the trained data. The position error compensation algorithm of six degrees of freedom industrial robot manipulator is also developed and the data of the position of the center rolling-coils, which is obtained by floor mount camera, are transfered by asynchronous communication method. Therefore even if the position of center is changed, robot moves to the position of center and performs the labeling work successfully. Therefore, this system can be improved the safety and efficiency.

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Motion Recognition of Mobile Phone for data sharing based on Google Cloud Message Service (Google 클라우드 메시지 서비스 기반의 데이터 공유를 위한 모바일 폰의 모션 인식)

  • Seo, Jung-Hee;Park, Hung-Bog
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.1
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    • pp.205-212
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    • 2019
  • With the rapid spread of mobile phones, users are continuously interested in using the mobile phone in connection with personal activities. Also, increasingly users want to share (transmit and receive) and save data more easily and simply in the mobile environment. This paper suggests motion recognition of mobile phone to share personal information with any people located within a certain distance using location-based service with GCM service. The suggested application is based on Google Cloud Messaging which enables asynchronous communication with the mobile applications executed in Android operating system. The requirements of light-weight mechanism can be satisfied as it is possible to access sharing of personal information easily, simply and in real time through all mobile devices anywhere.

A Case Study of Rapid AI Service Deployment - Iris Classification System

  • Yonghee LEE
    • Korean Journal of Artificial Intelligence
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    • v.11 no.4
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    • pp.29-34
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    • 2023
  • The flow from developing a machine learning model to deploying it in a production environment suffers challenges. Efficient and reliable deployment is critical for realizing the true value of machine learning models. Bridging this gap between development and publication has become a pivotal concern in the machine learning community. FastAPI, a modern and fast web framework for building APIs with Python, has gained substantial popularity for its speed, ease of use, and asynchronous capabilities. This paper focused on leveraging FastAPI for deploying machine learning models, addressing the potentials associated with integration, scalability, and performance in a production setting. In this work, we explored the seamless integration of machine learning models into FastAPI applications, enabling real-time predictions and showing a possibility of scaling up for a more diverse range of use cases. We discussed the intricacies of integrating popular machine learning frameworks with FastAPI, ensuring smooth interactions between data processing, model inference, and API responses. This study focused on elucidating the integration of machine learning models into production environments using FastAPI, exploring its capabilities, features, and best practices. We delved into the potential of FastAPI in providing a robust and efficient solution for deploying machine learning systems, handling real-time predictions, managing input/output data, and ensuring optimal performance and reliability.

Selective Cache Consistency Scheme to Enlarge Autonomy of Mobile Host in Mobile Computing Environments (이동 컴퓨팅 환경에서 이동 호스트의 자치성 증대를 위한 선택적 캐쉬 일관성 유지 기법)

  • Kim, Hee-Sook;Hwang, Byung-Yeon
    • The KIPS Transactions:PartD
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    • v.10D no.4
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    • pp.655-660
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    • 2003
  • The cache used by mobile host is an important device that recovers the weak points of limited power and bandwidth, in mobile computing environments. However, it has to stand and maintain the consistency with the server data. In this paper, we propose a 'Selective Cache Consistency Scheme'. The server allows an effective broadcasting by selecting data of high usability using 'Cache State Table' and 'Data Access Table'. Moreover, this scheme prevents the loss of data that nay occur by a long period of disconnection, by asynchronous broadcasting and transmitting those broadcast data preserved in the server. This also allows user to possess the latest data. Through experiments, we have found that the enlargement of autonomy is possible by reducing the dependence of server.

Fixed Time Synchronous IPC in Zephyr Kernel (Zephyr 커널에서 고정 시간 동기식 IPC 구현)

  • Jung, Jooyoung;Kim, Eunyoung;Shin, Dongha
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.4
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    • pp.205-212
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    • 2017
  • Linux Foundation has announced a real-time kernel, called Zephyr, for IoT applications recently. Zephyr kernel provides synchronous and asynchronous IPC for data communication between threads. Synchronous IPC is useful for programming multi-threads that need to be executed synchronously, since the sender thread is blocked until the data is delivered to the receiver thread and the completion of data transfer can be known to two threads. In general, 'IPC execution time' is defined as the time duration between the sender thread sends data and the receiver thread receives the data sent. Especially, it is important that 'IPC execution time' in the synchronous IPC should be fixed in real-time kernel like Zephyr. However, we have found that the execution time of the synchronous IPC in Zephyr kernel increases in proportion to the number of threads executing in the kernel. In this paper, we propose a method to implement a fixed time synchronous IPC in Zephyr kernel using Direct Thread Switching(DTS) technique. Using the technique, the receiver thread executes directly after the sender thread sends a data during the remaining time slice of the sender thread and we can archive a fixed IPC execution time even when the number of threads executing in the kernel increases. In this paper, we implemented synchronous IPC using DTS in the Zephyr kernel and found the IPC execution time of the IPC is always 389 cycle that is relatively small and fixed.