Browsing by Author "Liu, Jiang"

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An All-Solid-State Carbon-Air Battery Reaching an Output Power over 10 W and a Specific Energy of 3600 Wh kg-1
(2021-01-15) Yan, Xiaomin; Zhou, Mingyang; Zhang, Yapeng; Qiu, Qianyuan; Chen, Qianyang; Cai, Weizi; Tang, Yubao; Liu, Jiang
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Carbon-air batteries have a very high theoretical specific energy. However, they have not been given sufficient attention because of the challenges associated with optimizing the battery design and making it rechargeable. Here we report a novel carbon-air battery stack based on solid oxide electrolyte which enables high operating temperature. The battery is composed of a tubular membrane electrode assembly (MEA), with a solid oxide electrolyte layer sandwiched between two porous electrodes, and carbon powder filled inside the MEA tube. By introducing a row of holes along the length direction of the MEA tube for current collection, the performance of the battery can be significantly enhanced because of shortened current paths. By using a removable quartz plug to stuff the open end of the MEA tube, the battery becomes mechanically rechargeable. Several batteries can be assembled into a stack by connecting the batteries in electrical series through the holes for current collection. A 3-battery-stack operating at 800 °C displays an output power of 11.0 W, corresponding to ∼160 mW cm-2. With an overall carbon powder of ∼10 g, the stack discharges at 0.5 A and ∼2.75 V for 26 h, revealing a specific energy of ∼3600 Wh kg-1, which is significantly higher than those of the state-of-the-art metal-air batteries.
PPCS: A Progressive Popularity-Aware Caching Scheme for Edge-Based Cache Redundancy Avoidance in Information-Centric Networks
(2019-02-01) Nguyen, Quang Ngoc; Liu, Jiang; Pan, Zhenni; Benkacem, Ilias; Tsuda, Toshitaka; Taleb, Tarik; Shimamoto, Shigeru; Sato, Takuro
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This article proposes a novel chunk-based caching scheme known as the Progressive Popularity-Aware Caching Scheme (PPCS) to improve content availability and eliminate the cache redundancy issue of Information-Centric Networking (ICN). Particularly, the proposal considers both entire-object caching and partial-progressive caching for popular and non-popular content objects, respectively. In the case that the content is not popular enough, PPCS first caches initial chunks of the content at the edge node and then progressively continues caching subsequent chunks at upstream Content Nodes (CNs) along the delivery path over time, according to the content popularity and each CN position. Therefore, PPCS efficiently avoids wasting cache space for storing on-path content duplicates and improves cache diversity by allowing no more than one replica of a specified content to be cached. To enable a complete ICN caching solution for communication networks, we also propose an autonomous replacement policy to optimize the cache utilization by maximizing the utility of each CN from caching content items. By simulation, we show that PPCS, utilizing edge-computing for the joint optimization of caching decision and replacement policies, considerably outperforms relevant existing ICN caching strategies in terms of latency (number of hops), cache redundancy, and content availability (hit rate), especially when the CN's cache size is small.