Against the background of rapid urbanization, city memories have been gradually lost. In view of this, historic blocks and ancient buildings are taken as the key points of restoring collective memory spaces of cities,...Against the background of rapid urbanization, city memories have been gradually lost. In view of this, historic blocks and ancient buildings are taken as the key points of restoring collective memory spaces of cities, and Temple of Lord Fan Wenzheng in ancient Huishan Town, Wuxi City as a typical case to define tangible landscape elements in memory spaces. By analyzing the process of restoring buildings, pavements, waters, stone layouts and plants in the temple, practical means of restoring tangible landscapes in city memory spaces were summarized, so as to provide references for protecting original town landscapes, repairing damaged memory spaces, and inheriting city memories.展开更多
Utilizing commercial off-the-shelf(COTS) components in satellites has received much attention due to the low cost. However, commercial memories suffer severe reliability problems in radiation environments. This paper ...Utilizing commercial off-the-shelf(COTS) components in satellites has received much attention due to the low cost. However, commercial memories suffer severe reliability problems in radiation environments. This paper studies the low-density parity-check(LDPC) coding scheme for improving the reliability of multi-level-cell(MLC) NAND Flash memory in radiation environments. Firstly, based on existing physical experiment works, we introduce a new error model for heavyion irradiations; secondly, we explore the optimization of writing voltage allocation to maximize the capacity of the storage channel; thirdly, we design the degree distribution of LDPC codes that is specially suitable for the proposed model; finally, we propose a joint detection-decoding scheme based on LDPC codes, which estimates the storage channel state and executes an adaptive log-likelihood ratio(LLR) calculation to achieve better performance. Simulation results show that, compared with the conventional LDPC coding scheme, the proposed scheme may almost double the lifetime of the MLC NAND Flash memory in radiation environments.展开更多
The excellent climbing performance of the gecko is inspiring engineers and researchers for the design of artificial systems aimed at moving on vertical surfaces. Climbing robots could perform many useful tasks such as...The excellent climbing performance of the gecko is inspiring engineers and researchers for the design of artificial systems aimed at moving on vertical surfaces. Climbing robots could perform many useful tasks such as surveillance, inspection, repair, cleaning, and exploration. This paper presents and discusses the design, fabrication, and evaluation of two climbing robots which mimic the gait of the gecko. The first robot is designed considering macro-scale operations on Earth and in space. The second robot, whose motion is controlled using shape memory alloy actuators, is designed to be easily scaled down for micro-scale applications. Proposed bionic systems can climb up 65 degree slopes at a speed of 20 mm·s^-1.展开更多
基金Sponsored by National Natural Science Fund(41401152)Humanities and Social Sciences Youth Fund of the Ministry of Education(14YJCZH228)+1 种基金Philosophical and Social Sciences Fund of Universities and Colleges in Jiangsu(2012SJB790028)Key Humanities and Social Sciences Program of Nanjing Institute of Industry Technology(YK13-05-03)
文摘Against the background of rapid urbanization, city memories have been gradually lost. In view of this, historic blocks and ancient buildings are taken as the key points of restoring collective memory spaces of cities, and Temple of Lord Fan Wenzheng in ancient Huishan Town, Wuxi City as a typical case to define tangible landscape elements in memory spaces. By analyzing the process of restoring buildings, pavements, waters, stone layouts and plants in the temple, practical means of restoring tangible landscapes in city memory spaces were summarized, so as to provide references for protecting original town landscapes, repairing damaged memory spaces, and inheriting city memories.
基金supported by the National Basic Research Project of China(973)(2013CB329006)National Natural Science Foundation of China(NSFC,91538203)the new strategic industries development projects of Shenzhen City(JCYJ20150403155812833)
文摘Utilizing commercial off-the-shelf(COTS) components in satellites has received much attention due to the low cost. However, commercial memories suffer severe reliability problems in radiation environments. This paper studies the low-density parity-check(LDPC) coding scheme for improving the reliability of multi-level-cell(MLC) NAND Flash memory in radiation environments. Firstly, based on existing physical experiment works, we introduce a new error model for heavyion irradiations; secondly, we explore the optimization of writing voltage allocation to maximize the capacity of the storage channel; thirdly, we design the degree distribution of LDPC codes that is specially suitable for the proposed model; finally, we propose a joint detection-decoding scheme based on LDPC codes, which estimates the storage channel state and executes an adaptive log-likelihood ratio(LLR) calculation to achieve better performance. Simulation results show that, compared with the conventional LDPC coding scheme, the proposed scheme may almost double the lifetime of the MLC NAND Flash memory in radiation environments.
文摘The excellent climbing performance of the gecko is inspiring engineers and researchers for the design of artificial systems aimed at moving on vertical surfaces. Climbing robots could perform many useful tasks such as surveillance, inspection, repair, cleaning, and exploration. This paper presents and discusses the design, fabrication, and evaluation of two climbing robots which mimic the gait of the gecko. The first robot is designed considering macro-scale operations on Earth and in space. The second robot, whose motion is controlled using shape memory alloy actuators, is designed to be easily scaled down for micro-scale applications. Proposed bionic systems can climb up 65 degree slopes at a speed of 20 mm·s^-1.