• Title/Summary/Keyword: Primary link

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Reverse link performance evaluation with sync-CDMA in PCS environment (PCS 환경에서 Sync-CDMA를 적용한 역방향링크의 성능평가)

  • 김병균;김근대;김신재;암병철;최형진
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.10-23
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    • 1996
  • In this paper, the reverse link performance evaluation with synchronous CDMA is analyzed in the PCS system, which is the schem based on proposed method of KMT-PCS to increase the capacitance of cellular CDMA system. We make the baseband system model of CDMA reverse link, and then analyze system performance and subsystem techniques considering effect of channel and power control that are improtant factor influencing system performance in the PCS system. Based on this result, the paper presents primary technique analyses required at synchronous reverse link proposed by the KMT, which compose of initial synchronization range in initial synchronization step and control signal period in the synchronization maintenance step.

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Shape Finding of Unstable Link Structures (불안정(不安定) Link 구조물(構造物)의 형태해석(形態解析)에 관(關)한 연구(硏究))

  • Kim, Jae-Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.2 s.8
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    • pp.101-107
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    • 2003
  • There exists a structural problem for link structures in the unstable state. The primary characteristics of this problem are in the existence of rigid body displacements without strain, and in the possibility of the introduction of prestressing to change an unstable state into a stable state. When we make local linearized incremental equations in order to obtain knowledge about these unstable structures, the determinant of the coefficient matrices is zero, so that we face a numerically unstable situation. This is similar to the situation in the stability problem. To avoid such a difficult situation, in this paper a simple and straightforward method was presented by means of the generalized inverse for the numerical analysis of stability problem.

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Optimized stiffener detailing for shear links in eccentrically braced frames

  • Ozkilic, Yasin O.
    • Steel and Composite Structures
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    • v.39 no.1
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    • pp.35-50
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    • 2021
  • Eccentrically braced frames (EBFs) are utilized as a lateral resisting system in high seismic zones. Links are the primary source of energy dissipation and they are exposed to high deformation, which may lead to buckling. Web stiffeners were introduced to prevent buckling of shear link. AISC 341 provides the required vertical stiffeners for a shear link. In this study, different stiffener configurations were examined. The main objective is to improve the behavior of short links using different stiffener configurations. Pursuant to this goal, a comprehensive numerical study is conducted using ABAQUS. Shear links with different stiffener configurations were subjected to cyclic loading using loading protocol mandated by AISC 341. The results are compared in terms of energy dissipation and shear capacities and rupture index. The proposed stiffener configurations were further verified with different link length ratios, I-shapes and thickness of stiffener. Based on the results, the stiffener configuration with two vertical and two diagonal stiffeners perpendicular to each other is recommended. The proposed stiffener configuration can increase the shear capacity, energy dissipation capacity and the ratio of energy/weight up to 27%, 38% and 30%, respectively. Detailing of the proposed stiffener configuration is presented.

The Distribution of Research Framework on Exsheetlink Module Development for Accounting Education

  • Nor Sa'adah, JAMALUDDIN;Rohaila, YUSOF;Noor Lela, AHMAD
    • Journal of Distribution Science
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    • v.21 no.2
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    • pp.45-52
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    • 2023
  • Purpose: The Malaysia Education Blueprint is primarily concerned with the transformation of students' minds through the curriculum offered at the school level (2013-2025). Diversity in the application of teaching and learning methods is one means of achieving the transformation of students' minds through the Secondary School Standard Curriculum. Consequently, the production of ExSheetLink's Module for Accounting Education is the primary outcome of this study, which had three objectives: the need for ExSheetLink's Module in the process of producing financial statements for Accounting Students in secondary school to the Accounting Teacher; and the design of ExSheetLink's Module that meets the entire process in the production of financial statements for Accounting Students in secondary school based on the Documents Curriculum and the Accounting Students' needs. Research design, data and methodology: This study outlines the research framework for module development in accordance with the Design and Development Research Method, which combines multiple research techniques (Mixed Method). Results: The development of ExSheetLink's Module is completed and can be used for the level of effectiveness purposes. Conclusion: The transformation of Accounting Students' minds is a success thanks to the ExSheetLink Module. Researchers also suggested that all Malaysian Secondary School accounting students test the ExSheetLink Module.

New DC/AC Soft Switched PWM Converter Having a DC-Link Commutation Circuit (직류측에 Commutation 회로를 갖는 영전압 스위칭 PWM 인버터)

  • Chung, J.H.;Park, S.S.;Goo, T.H.
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.1158-1160
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    • 1992
  • A new dc/ac soft switched PWM convert having a dc-link commutation circuit is proposed. The commutation circuit implemented by utilizing a series resonant circuit while preparing for zero voltage switching of primary inverter. The converter provides both variable pulse width and position which is fundamentally different than converters. In this paper, the operating principles, design and control considerations analysis of a such a soft switched converter is analyzed.

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Scheduling and simulation for FMC systems (FMC 시스템의 스케쥴링 및 시뮬레이션)

  • 서기성;이노성;안인석;박승규;이규호;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.370-375
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    • 1992
  • This paper deals with the scheduling and simulation for FMC(Flexible Manufacturing Cells). In order to achieve CIM, there is a critical need to link factory level and machine level. The primary functions performed by this link for all jobs issued to the shop floor and cell include short-term scheduling and dynamic operational scheduling. Here, hierarchical control structure is introduced to define these functions. And Intelligent scheduling through expert module is adopted for efficiency of FMC operation. Computer simulation reveals that expert scheduling method is better than heuristics in various performance index.

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An Experimental Implementation of a Cross-Layer Approach for Improving TCP Performance over Cognitive Radio Networks

  • Byun, Sang-Seon
    • Journal of Information Processing Systems
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    • v.12 no.1
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    • pp.73-82
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    • 2016
  • In cognitive radio networks (CRNs), the performance of the transmission control protocol (TCP) at the secondary user (SU) severely drops due to the mistrigger of congestion control. A long disruption is caused by the transmission of primary user, leading to the mistrigger. In this paper, we propose a cross-layer approach, called a CR-aware scheme that enhances TCP performance at the SU. The scheme is a sender side addition to the standard TCP (i.e., TCP-NewReno), and utilizes an explicit cross-layer signal delivered from a physical (or link) layer and the signal gives an indication of detecting the primary transmission (i.e., transmission of the primary user). We evaluated our scheme by implementing it onto a software radio platform, the Universal Software Radio Peripheral (USRP), where many parts of lower layer operations (i.e., operations in a link or physical layer) run as user processes. In our implementation, we ran our CR-aware scheme over IEEE 802.15.4. Furthermore, for the purpose of comparison, we implemented a selective ACK-based local recovery scheme that helps TCP isolate congestive loss from a random loss in a wireless section.

Link-Disjoint Embedding of Complete Binary Trees into 3D-Meshes using Dimension-Ordered Routing (순위차원라우팅을 사용한 완전 이진트리의 3차원 메쉬로의 링크 충돌 없는 임베딩)

  • Park, Sang-Myeong;Lee, Sang-Kyu;Moon, Bong-Hee
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.2
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    • pp.169-176
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    • 2000
  • This paper is considered with the problem of embedding complete binary trees into 3-dimensional meshes using dimension-ordered routing with primary concern of minimizing link congestion. The authors showed that a complete binary tree with $2^P-1$ nodes can be embedded into a 3-dimensional mesh with optimum size, $2^P$ nodes, if the link congestion is two[14], (More precisely, the link congestion of each dimension is two, two, and one if the dimension-ordered routing is used, and two, one, and one if the dimension-ordered routing is not imposed.) In this paper, we present a scheme to find an embedding of a complete binary tree into a 3-dimensional mesh of size no larger than 1.27 times the optimum with link congestion one while using dimension-ordered routing.

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A MAC Protocol for Link Maintenance in Multichannel Cognitive Radio Ad Hoc Networks

  • Li, Jingye;Luo, Tao;Gao, Jing;Yue, Guangxin
    • Journal of Communications and Networks
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    • v.17 no.2
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    • pp.172-183
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    • 2015
  • To provide an efficient link maintenance approach, we propose a cross layer medium access control (LM-MAC) protocol for multichannel cognitive radio ad hoc networks. Link establishment and reliable transmission are two key problems for a perfect link maintenance mechanism. Since the cognitive user (CU) pairs have to reestablish their links each frame, in the proposed MAC protocol, three different access modes are designed to guarantee transmission efficiency in continuous frames. To enhance the transmission reliability, each CU will create a father spectrum list (FSL) after joining in the network. FSL is divided into three groups of sub-channels with different functions to compensate the packet loss caused by the primary users' appearance and the deep fading. Meanwhile, since the transmitter and the receiver will share the same FSL, periodical cooperative sensing is adopted to further optimize the former problem. Finally, compared with the existing opportunistic multichannel (OMC)-MAC protocol, the proposed LM-MAC protocol achieves better system performance in terms of saturation throughput, continuity and access delay.

Biomass and secondary production of the three dominant amphipods (Crustacea) in a temperate sandy shore, southern Korea

  • Hwan, Yu-Ok;Rip, Seo-Hae
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.05a
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    • pp.435-436
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    • 2001
  • In sand beaches the benthic macrofauna feeding on primary food sources such as detritus and phytoplankton and being prey in turn for top predators such as fishes occupies a key position in the center of food chains. Amphipods are the most productive bentho-pelagic animals (Barnard, 1963) and are commonly consumed by fishes and larger crustaceans (Vetter, 1995). Consequently, amphipods play an important role in energy flow as a trophic link from primary producers to higher consumers(Chiaravalle et al., 1997).

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