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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Electronics and Telecommunications Research Institute
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Volume 22, Issue 4 - Dec 2000
Volume 22, Issue 3 - Sep 2000
Volume 22, Issue 2 - Jun 2000
Volume 22, Issue 1 - Mar 2000
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Rate Proportional SCFQ Algorithm for High-Speed Packet-Switched Networks
Choi, Byung-Hwan ; Park, Hong-Shik ;
ETRI Journal, volume 22, issue 3, 2000, Pages 1~1
Self-Clocked Fair Queueing (SCFQ) algorithm has been considered as an attractive packet scheduling algorithm because of its implementation simplicity, but it has unbounded delay property in some input traffic conditions. In this paper, we propose a Rate Proportional SCFQ (RP-SCFQ) algorithm which is a rate proportional version of SCFQ. If any fair queueing algorithm can be categorized into the rate proportional class and input is constrained by a leaky bucket, its delay is bounded and the same as that of Weighted Fair Queueing (WFQ) which is known as an optimal fair queueing algorithm. RP-SCFQ calculates the timestamps of packets arriving during the transmission of a packet using the current value of system potential updated at every packet departing instant and uses a starting potential when it updates the system potential. By doing so, RP-SCFQ can have the rate proportional property. RP-SCFQ is appropriate for high-speed packet-switched networks since its implementation complexity is low while it guarantees the bounded delay even in the worst-case input traffic conditions.
An Adaptive Learning Rate with Limited Error Signals for Training of Multilayer Perceptrons
Oh, Sang-Hoon ; Lee, Soo-Young ;
ETRI Journal, volume 22, issue 3, 2000, Pages 10~10
Although an n-th order cross-entropy (nCE) error function resolves the incorrect saturation problem of conventional error backpropagation (EBP) algorithm, performance of multilayer perceptrons (MLPs) trained using the nCE function depends heavily on the order of nCE. In this paper, we propose an adaptive learning rate to markedly reduce the sensitivity of MLP performance to the order of nCE. Additionally, we propose to limit error signal values at out-put nodes for stable learning with the adaptive learning rate. Through simulations of handwritten digit recognition and isolated-word recognition tasks, it was verified that the proposed method successfully reduced the performance dependency of MLPs on the nCE order while maintaining advantages of the nCE function.
Green-Function Calculations of Coherent Electron Transport in a Gated Si Nanowire
Ko, Young-Jo ; Shin, Min-Cheol ; Ha, Jeong-Sook ; Park, Kyoung-Wan ;
ETRI Journal, volume 22, issue 3, 2000, Pages 19~19
We describe a detailed numerical scheme to calculate electron transport in quantum wires using the Green function formalism combined with tight-binding orbital basis. As an example of the application, we study the electron transport in a Si nanowire containing a finite potential barrier. The effects of nonzero bias, temperature, and disorder on the barrier-induced oscillatory conductance are investigated within the context of coherent transport model. The oscillatory behavior of the conductance as a function of the Fermi energy is found to be highly sensitive to sample disorder and limited to a very low temperature and a small bias range.
Web-Enabled Collaborative Design Environment
Kim, Hyun ; Yoo, Sang-Bong ; Lee, Hyun-Chan ;
ETRI Journal, volume 22, issue 3, 2000, Pages 27~27
Recently, advanced information technologies have opened new possibilities for collaborative designs. In this paper, a web-enabled collaborative design environment is proposed, where the product data based on STandard for the Exchange of Product model data (STEP) is managed in a hierarchical database and the product metadata is used to efficiently search and utilize information scattered over the network. Several integrity constraints are depicted using EXPRESS to validate the combination of data from different sources. The knowledge represented as metadata and constraints on the interacting features differentiate this environment from previous ones. The collaborative conferencing system is also introduced to communicate and collaborate simultaneously among the related designed. As a result, the proposed environment allows the distributed designers to more efficiently obtain, exchange and communicate the design information throughout the design process.
TATS: an Efficient Technique for Computing Temporal Aggregates for Data Warehousing
Shin, Young-Ok ; Park, Sung-Kong ; Baik, Doo-Kwon ; Ryu, Keun-Ho ;
ETRI Journal, volume 22, issue 3, 2000, Pages 41~41
An important use of data warehousing is to provide temporal views over the history of source data. It is significant that nearly all data warehouses are dependent on relational database technology, yet relational databases provide little or no real support for temporal data. Therefore, in is difficult to obtain accurate information for time-varying data. In this paper, we are going to design a temporal data warehouse to support time-varying data efficiently. For this purpose, we present a method to support temporal query by combining a temporal query process layer with the relational database which is used as a source database in an existing data warehouse. We introduce the Temporal Aggregate Tree Strategy (TATS), and suggest its algorithm for the way to aggregate the time-varying data that is changed by the time when the temporal view is created. In addition, The TATS and the materialized view creation method of the existing data warehouse have been evaluated. As a result, the TATS reduces the size of the fact table and it shows a good performance for the comparison factor in case of processing the query for time-varying data.