Browsing by Author "Chen, Chun-Ting"

Now showing 1 - 4 of 4

On-Demand Density-Aware UAV Base Station 3D Placement for Arbitrarily Distributed Users With Guaranteed Data Rates
(2019-06-01)
Lai, Chuan-Chi
;
Chen, Chun-Ting
;
Wang, Li-Chun
;
電機工程學系
;
Department of Electrical and Computer Engineering
In this letter, we study the on-demand unmanned aerial vehicle mounted base stations (UAV-BS) placement problem for arbitrarily distributed users. This UAV-BS placement problem is modeled as a knapsack-like problem, which is NP-complete. We propose a density-aware placement algorithm to maximize the number of covered users subject to the constraint of the minimum required data rates per user. Simulations are conducted to evaluate the performance of the proposed algorithm in a real environment with different user densities. Our numerical results indicate that for various user densities our proposed solution can service more users with guaranteed data rates compared to the existing method, while reducing the transmit power by 29%.
OPTUNS: Optical Edge Datacenter Network Architecture and Prototype Testbed for Supporting 5G
(2019-01-01)
Yuang, Maria
;
Tien, Po-Lung
;
Ruan, Wei-Zhang
;
Lin, Tien-Chien
;
Wen, Shao-Chun
We present the architecture/testbed of an SDN-based optical-tunnel-network system (OPTUNS) for 5G edge-datacenters. Benchmarking results show that, compared to electrical-spine-leaf datacenter-network, OPTUNS achieves 82.6% power saving and significantly lower mean/p99 latency under high traffic load/locality.
OPTUNS: Optical intra-data center network architecture and prototype testbed for a 5G edge cloud [Invited]
(2020-01-01)
Yuang, Maria
;
Tien, Po-Lung
;
Ruan, Wei-Zhang
;
Lin, Tien-Chien
;
Wen, Shao-Chun
An edge data center (EDC) network infrastructure is required to flexibly deliver massive bandwidth and ultralow latency for a 5G edge cloud. Existing electrical-switching-based infrastructure, however, has been shown incapable of meeting such requirements. In this paper, we present an EDC network architecture and prototype testbed, referred to as the intelligence-defined optical tunnel network system (OPTUNS). OPTUNS consists of a set of optical switching subsystems that operate collectively to facilitate packet transport through logical wavelength-based optical tunnels. These optical tunnels are governed by a software-defined-networking-based intelligent tunnel control system, in a proactive manner. As such, optical tunnels are always made available whenever needed. In essence, OPTUNS boasts several crucial features, including high scalability, massive wavelength reuse (yielding high bandwidth), proactive optical tunnel control (yielding ultralow latency), and fault tolerance. We have built an OPTUNS testbed, including 30 optical switching subsystem prototypes, that interconnect a total of 25 racks (400 servers). Benchmarking results show that OPTUNS achieves 82.6% power saving compared with electrical spine-leaf networks. Further, our NetPipe-based experimental results show that OPTUNS invariably achieves mean and p99 end-to-end latencies of less than 17 mu s, regardless of traffic load and locality. (C) 2019 Optical Society of America
THE EFFECTIVENESS OF SCIENTIFIC INQUIRY WITH/WITHOUT INTEGRATION OF SCIENTIFIC REASONING
(2015-02-01)
Chen, Chun-Ting
;
She, Hsiao-Ching
;
教育研究所
;
Institute of Education
This study examines the difference in effectiveness between two scientific inquiry programs-one with an emphasis on scientific reasoning and one without a scientific reasoning component-on students\' scientific concepts, scientific concept-dependent reasoning, and scientific inquiry. A mixed-method approach was used in which 115 grade 5 students were administered the scientific concept test, scientific concept-dependent reasoning test, and scientific inquiry test before, 1 week after, and 8 weeks after instruction. In addition, students\' scientific inquiry worksheets in the classroom were collected and evaluated. Results indicated that the experimental group outperformed the control group, regardless of scientific concept test, scientific concept-dependent reasoning test, and scientific inquiry test. Moreover, the classroom inquiry worksheets results demonstrated that the experimental group generated a significantly greater number of testable hypotheses, correct hypotheses, and correct evidence-based scientific explanations and a higher level of scientific reasoning than did the control group.