• Title/Summary/Keyword: Cellular System

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A Novel Power-Efficient BS Operation Scheme for Green Heterogeneous Cellular Networks

  • Kim, Jun Yeop;Kim, Junsu;Kang, Chang Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.12
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    • pp.1721-1735
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    • 2016
  • Power-efficient base station (BS) operation is one of the important issues in future green cellular networks. Previously well-known BS operation schemes, the cell zooming scheme and the cell wilting and blossoming scheme, require tight cooperation between cells in cellular networks. With the previous schemes, the non-cooperative BSs of a serving cell and neighboring cells could cause coverage holes between the cells, thereby seriously degrading the quality of service as well as the power saving efficiency of the cellular networks. In this paper, we propose a novel power-efficient BS operation scheme for green downlink heterogeneous cellular networks, in which the networks virtually adjust the coverage of a serving macrocell (SM) and neighboring macrocells (NMs) without adjusting the transmission power of the BSs when the SM is lightly loaded, and the networks turn off the BS of the SM when none of active users are associated with the SM. Simulation results show that our proposed scheme significantly improves the power saving efficiency without degrading the quality of service (e.g., system throughput) of a downlink heterogeneous LTE network and outperforms the previous schemes in terms of system throughput and power saving efficiency. In particular, with the proposed scheme, macrocells are able to operate independently without the cooperation of a SM and NMs for green heterogeneous cellular networks.

The Implementation of Digital Input System for Cellular-phone using the Accelerometer and PIC (Accelerometer Sensor와 PIC를 이용한 Cellular-phone용 Digital Input System 구현)

  • 여영호;손수국;윤나서
    • Proceedings of the IEEK Conference
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    • 2003.07d
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    • pp.1495-1498
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    • 2003
  • This paper has been studied about designed digital-pen using PIC and Accelerometer and about calculated acceleration by the measure analog signal from accelerometer Finally, we calculate the coordinates and the tilt about the acceleration and discuss the possibility of using the digital-pen from cellular phone. And we discuss about the full-duplex communication of input data that displayed in cellular phone.

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A Study on the Formation of Cellular Manufacturing Line for Construction JIT System's Basis (JIT 시스템 운용의 출발점 - Cellular 제조라인의 구축)

  • 구일섭;신현표
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.17 no.31
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    • pp.43-48
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    • 1994
  • In an effort to become more competitive and cost efficient many companies have shifted from traditional job-shop production to production using group technology (GT) and cell manufacturing (CM). Cellular manufacturing is critical to implementing Just-in-Time (JIT) production which pointed out in the previous articles. and adopt the U-shaped cell which allows for entry at one end of the U and exist at the other. This paper looks at the availability of cellular manufacturing, by applying those concepts to the small and medium sized industry.

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Efficient Backup methods for Location Register System in Cellular Network

  • Kim, Jang-Hwan
    • International journal of advanced smart convergence
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    • v.7 no.3
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    • pp.61-65
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    • 2018
  • A Location Register(LR) system manages each subscriber's location information, which continuously changes in mobile cellular network. For this purpose, the LR database system provides backup management facilities. The objectives of this paper are to identify the problems of the current LR system through rigorous analysis, to suggest solutions to them. I proposed efficient backup methods that takes into account the characteristics of LR database transactions. In the proposed backup method, I use two kinds of dirty flags in order to solve the performance degradation problem caused by frequent registration- location operations.

A One-Step System for Convenient and Flexible Assembly of Transcription Activator-Like Effector Nucleases (TALENs)

  • Zhao, Jinlong;Sun, Wenye;Liang, Jing;Jiang, Jing;Wu, Zhao
    • Molecules and Cells
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    • v.39 no.9
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    • pp.687-691
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    • 2016
  • Transcription activator-like effector nucleases (TALENs) are powerful tools for targeted genome editing in diverse cell types and organisms. However, the highly identical TALE repeat sequences make it challenging to assemble TALEs using conventional cloning approaches, and multiple repeats in one plasmid are easily catalyzed for homologous recombination in bacteria. Although the methods for TALE assembly are constantly improving, these methods are not convenient because of laborious assembly steps or large module libraries, limiting their broad utility. To overcome the barrier of multiple assembly steps, we report a one-step system for the convenient and flexible assembly of a 180 TALE module library. This study is the first demonstration to ligate 9 mono-/dimer modules and one circular TALEN backbone vector in a one step process, generating 9.5 to 18.5 repeat sequences with an overall assembly rate higher than 50%. This system makes TALEN assembly much simpler than the conventional cloning of two DNA fragments because this strategy combines digestion and ligation into one step using circular vectors and different modules to avoid gel extraction. Therefore, this system provides a convenient tool for the application of TALEN-mediated genome editing in scientific studies and clinical trials.

Determining Appropriate Production Conditions in Cellular Manufacturing Systems (셀생산(生産)의 효율적(效率的)인 운용(運用)을 위한 시뮤레이션 연구(硏究))

  • Song, Sang-Jae;Choi, Jung-Hee
    • Journal of Korean Institute of Industrial Engineers
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    • v.19 no.2
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    • pp.23-34
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    • 1993
  • Although there are numerous studies that address the problem of optimal machine grouping and part family classification for cellular manufacturing, little research has been reported that studies the conditions where cellular manufacturing is appropriate. This paper, in order to evaluate and compare the job shop with the GT cellular shop, the performance of those shops were simulated by using SIMAN. We tested the effect of independent variables including changes of product demands, intercell flow level, group setup time, processing time variability, variety of material handling systems, and job properties (ratio of processing time and material handling time). And also performance measures (dependent variables), such as machine utilization, mean flow time, average waiting time, and throughput rate, are discussed. Job shop model and GT cellular shop written in SIMAN simulation language were used in this study. These systems have sixteen machines which are aggregated as five machine stations using the macro feature of SIMAN. The results of this research help to better understand the effect of production factors on the performance of cellular manufacturing systems and to identify some of the necessary conditions required to make these systems perform better than traditional job shops. Therefore, this research represents one more step towards the characterization of shops which may benefit from cellular manufacturing.

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Mobile College Synthesis System Implementation for Ubiquitous (유비쿼터스를 위한 모바일 학사종합시스템 구현)

  • Han, Sang Hwan;Lee, Hye Rim;Kim, Yu Doo;Moon, Il Young
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.4 no.4
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    • pp.63-69
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    • 2008
  • Recently, every student would take lessons without knowing no lecture in campus life. And, If you are a university student, you tired a course to register in a crowded. For solving this problem, we choose the cellular phone. Nowadays peoples have one cellular phone to one person in korea. Using cellular phone, you can use cellular phone anywhere any time. In this paper, we studied mobile synthesis system using mobile cellular phone. According to use mobile campus system, the university and students can use easy an one to one service in ubiquitous.

Inversion of Spread-Direction and Alternate Neighborhood System for Cellular Automata-Based Image Segmentation Framework

  • Lee, Kyungjae;Lee, Junhyeop;Hwang, Sangwon;Lee, Sangyoun
    • Journal of International Society for Simulation Surgery
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    • v.4 no.1
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    • pp.21-23
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    • 2017
  • Purpose In this paper, we proposed alternate neighborhood system and reverse spread-direction approach for accurate and fast cellular automata-based image segmentation method. Materials and Methods On the basis of a simple but effective interactive image segmentation technique based on a cellular automaton, we propose an efficient algorithm by using Moore and designed neighborhood system alternately and reversing the direction of the reference pixels for spreading out to the surrounding pixels. Results In our experiments, the GrabCut database were used for evaluation. According to our experimental results, the proposed method allows cellular automata-based image segmentation method to faster while maintaining the segmentation quality. Conclusion Our results proved that proposed method improved accuracy and reduced computation time, and also could be applied to a large range of applications.

Development of CDMA Hierarchical Cellular Simulator using Object-Oriented-Program (객체지향프로그램을 이용한 CDMA 계층 셀 시뮬레이터 개발)

  • Kim, Ho-Joon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.29 no.3
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    • pp.111-118
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    • 2006
  • This paper presents design and development of a simulator evaluates the performance of a hierarchical cellular system. The proposed hierarchical cellular simulator, consisting of macro, micro, and pico cells, applies the wrap-around technique to reduce simulation time. The simulator is implemented as object oriented class models by using the C++ language in a PC environment. The resulting application can evaluate the interference, SIR(Signal to Interference Ratio), and capacity of a hierarchical cellular system in various configurations. Moreover, it can be used in other applications such as power control, call admission control, hand over scheme.

D2D Utility Maximization in the Cellular System: Distributed Algorithm

  • Oh, Changyoon
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.3
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    • pp.57-64
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    • 2019
  • We consider the D2D sum utility maximization in the cellular system. D2D links reuse the uplink resource of cellular system. This reuse may cause severe interference to cellular users. To protect the cellular users, interference limit from the D2D links is required. In this setting, D2D sum utility maximization problem is investigated. Each D2D link has limited transmit power budget. Because optimum solution may require global information between links and computational complexity, we propose the distributed algorithm which only require the local information from each D2D link and simple broadcasting. Simulation results are provided to verify the performance of the proposed algorithm.