Browsing by Author "Lin, Wei-Chu"

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A New Gas Sensor of a Thin-Film Diode and Low-Power, Area-Efficient Readout Circuit
(2013)
Chen, Hung-Che
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Chao, Paul C. -P.
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Lin, Wei-Chu
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Sun, Hsiang-Fang
;
Dai, Ming-Zhi
The study presents a new gas sensor made of a novel organic diode with vertical nano-junctions and its low-power, area-efficient readout circuit. There are seven parts included in the readout system. First part is a preamplifier, which is composed of trans-impedance to convert the output current of a gas sensor into voltage. Second part is a peak-detect-and-hold circuit. It can detect the maximum voltage and holds its value, the initial value. Third part is a divider, which is used to calculate the ratio of saturation current to initial current. Fourth part is the saturation detector, which is used to detect when the output current of the VNJ-P3HT diode doesn\'t change anymore (that is, the responses are saturated). Fifth part is the auto-reset circuit, which is used to detect when the sensor device starts to react with gas and reset the voltage value of the peak detect-and-hold circuit. Sixth part is a logic gate and a buffer. When the sensor device is reacting with gas and the responses are saturated, the response result is outputted through the logic gate and buffer. Otherwise, the zero is outputted. Seventh part is a micro-processor control unit (MCU). STM32 is the CPU of proposed MCU by ALIENTEK. The ADC of MCU is used to transform the output data of readout circuit. Then the LCD displays the results. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mu m 2P4M 3.3V mixed-signal CMOS process.
(DENDIST)-E-2-FM: Flow Migration in Routing of OpenFlow-based Cloud Networks
(2013-01-01)
Lin, Wei-Chu
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Liu, Gen-Hen
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Kuo, Kuan-Tsen
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Wen, Charles H. -P.
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電機資訊學士班
A prior layer-2 routing algorithm-(DENDIST)-E-2 demonstrates advantages in throughput improvement, reroute period and failure recovery. Moreover, with the invention of software-defined networking (SDN), a revolutionary networking concept, dynamic routing protocols can embrace more flexible policy on per-flow basis. However, due to runtime complexity of dynamic routing, many issues on the practicality emerge and await to be resolved. Therefore, in this paper, we first apply (DENDIST)-E-2 to a SDN architecture and compare performances between dynamic-routing and flow-control mechanisms in a OpenFlow-based cloud network. Then, the flow-migration (FM) scheme, showing a better flow-control management, can be combined with (DENDIST)-E-2, and evolved into (DENDIST)-E-2-FM. At last, experimental results demonstrate that (DENDIST)-E-2-FM enables better feasibility in real-world applications, throughput improvement, sensitivity to reroute period and reduction in failure recovery time.
Flow-and-VM Migration for Optmizing Throughput and Energy in SDN-based Cloud Datacenter
(2013-01-01)
Lin, Wei-Chu
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Liao, Chien-Hui
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Kuo, Kuan-Tsen
;
Wen, Charles H-P.
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電機資訊學士班
Minimizing energy consumption and improving performance in datacenters are critical to cost-saving for cloud operators, but traditionally, these two optimization objectives are treated separately. Therefore, this paper presents an unified solution combining two strategies, flow migration and VM migration, to maximize throughput and minimize energy, simultaneously. Traffic-aware flow migration (FM) is first incorporated in dynamic reroute (DENDIST), evolving into DENDIST-FM, in a software-defined network (SDN) for improving throughput and avoiding congestion. Second, given energy and topology information, VM migration (ETA-VMM) can help reduce traffic loads and meanwhile save energy. Our experimental result indicates that compared to previous works, the proposed method can improve throughput by 42.5% on average with only 2.2% energy overhead. Accordingly, the unified flow-and-VM migration solution has been proven effective for optimizing throughput and energy in SDN-based cloud datacenters.