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高原被动式太阳能建筑透明围护结构的阶跃传热特性 被引量:6
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作者 石利军 戎向阳 +1 位作者 司鹏飞 李鹏宇 《暖通空调》 2019年第2期107-110,57,共5页
介绍了一种具有阶跃传热特性的被动式太阳能建筑透明围护结构及其控制策略,结合实测进行了验证。透明围护结构的阶跃传热特性主要表现在两方面:白天实现了直接受益窗太阳得热系数的阶跃升高,使得太阳能容易进入室内;夜间实现了直接受益... 介绍了一种具有阶跃传热特性的被动式太阳能建筑透明围护结构及其控制策略,结合实测进行了验证。透明围护结构的阶跃传热特性主要表现在两方面:白天实现了直接受益窗太阳得热系数的阶跃升高,使得太阳能容易进入室内;夜间实现了直接受益窗综合换热热阻的阶跃上升,使得热量可以保存住。实测表明:在该控制策略下,即使在室外最低温度为-12.5℃的恶劣气候条件下,宿舍楼室内温度也可维持在13~14℃,比非阶跃控制提高了4.5~10℃;传统墙体蓄放热速率难以满足被动式太阳能利用要求,这是造成被动式太阳能建筑蓄热能力不足的主要原因。 展开更多
关键词 被动式太阳能建筑 透明围护结构 阶跃传热 太阳得热系数 综合换热热阻 蓄热 放热 热平衡
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A New Segmentation Model—Combined Mumford-Shah Model with Narrow Band
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作者 王峥 Yang +2 位作者 Xin Shi pengfei 《High Technology Letters》 EI CAS 2004年第1期17-21,共5页
A segmentation model that combines the Mumford-Shah (M-S) model and narrow band scheme of level set is presented. The M-S model is a desirable model for image segmentation, but computationally time-consuming. This pap... A segmentation model that combines the Mumford-Shah (M-S) model and narrow band scheme of level set is presented. The M-S model is a desirable model for image segmentation, but computationally time-consuming. This paper introduces a fast segmentation model, which combines the M-S model and narrow band scheme using new initialization method. The new initialization method is based on fast marching method, and the computing time is O(n). In each iteration step, the new segmentation model only deals with the data in narrow band instead of the whole image. Comparing M-S model and new narrow band M-S, experiments show that the two models can obtain almost the same segmentation result, but the computing time of new narrow band M-S model is much less than M-S model. 展开更多
关键词 MUMFORD-SHAH模型 M-S模型 分割模型 窄带 初始化 水平集 计算机图形学
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A New Approach for Lossless Image Compression Based on Fuzzy Adaptive Prediction
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作者 吴颖谦 Fang +2 位作者 Tao Shi pengfei 《High Technology Letters》 EI CAS 2004年第2期38-41,共4页
This paper proposes a novel approach for image lossless compression based on fuzzy logic and adaptive prediction. By a flexible strategy, the method can acquire a set of original predictors describing the more detail ... This paper proposes a novel approach for image lossless compression based on fuzzy logic and adaptive prediction. By a flexible strategy, the method can acquire a set of original predictors describing the more detail characteristic. Using a neural network, the proposed method can more efficiently organize the training of original predictors and implement adaptive prediction in fuzzy style. In entropy coding phase, the context-based conditional adaptive arithmetic encoding is adopted. The experiments demonstrate the characteristics make the approach achieve good tradeoff between computational complexity and efficiency of prediction and good performance for lossless compression. 展开更多
关键词 自适应回归预测 模糊逻辑 FOSART神经网络 内容基条件算术编码 无损图像压缩
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A New Algorithm of Sub-pixels Image Matching
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作者 吴建明 Xu +2 位作者 Zhiyang Shi pengfei 《High Technology Letters》 EI CAS 2004年第1期22-25,共4页
This paper discusses a new algorithm of sub-pixels image matching and analyzes the characteristics of resampling and surface fitting methods. In order to meet the matching demands and to alleviate the computation work... This paper discusses a new algorithm of sub-pixels image matching and analyzes the characteristics of resampling and surface fitting methods. In order to meet the matching demands and to alleviate the computation workload, the following improvement algorithms are used. First, resample the model n-times, putt out (2n-1) sub-models, and calculate the NCs between each sub-model and image. Then choose the maximum between the sub-model and the displacement corresponding to this sub-model which requires the sub-pixel displacement. Finally, put forward a new algorithm that combines the resampling with surface fitting methods. Experimental results show the validity of the algorithm. 展开更多
关键词 算法 图像匹配 低像素图像 再取样 表面适合方法
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Medical Image Dynamic Collaborative Processing on the Distributed Environment
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作者 张全海 Shi pengfei 《High Technology Letters》 EI CAS 2003年第1期51-57,共7页
A new trend in the development of medical image processing systems is to enhance the shar-ing of medical resources and the collaborative processing of medical specialists. This paper presents an architecture of medica... A new trend in the development of medical image processing systems is to enhance the shar-ing of medical resources and the collaborative processing of medical specialists. This paper presents an architecture of medical image dynamic collaborative processing on the distributed environment by combining the JAVA, CORBA (Common Object Request and Broker Architecture) and the MAS (Multi-Agents System) collaborative mechanism. The architecture allows medical specialists or applications to share records and cornmunicate with each other on the web by overcoming the shortcut of traditional approach using Common Gateway Interface (CGI) and client/server architecture, and can support the remote heterogeneous systems collaboration. The new approach im-proves the collaborative processing of medical data and applications and is able to enhance the in-teroperation among heterogeneous system. Research on the system will help the collaboration and cooperation among medical application systems distributed on the web, thus supply high quality medical service such as diagnosis and therapy to practicing specialists regardless of their actual geo-graphic location. 展开更多
关键词 medical image distributed processing COLLABORATION MULTI-AGENT Web computing
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Prescribed-time stabilisation control of differential driven automated guided vehicle
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作者 Qiyuan Chen pengfei 《IET Cyber-Systems and Robotics》 EI 2023年第1期143-153,共11页
The position control problem of differential-driven automated guided vehicles(AGVs)based on the prescribed-time control method is studied.First,an innovative orientation error function is proposed by an auxiliary arcs... The position control problem of differential-driven automated guided vehicles(AGVs)based on the prescribed-time control method is studied.First,an innovative orientation error function is proposed by an auxiliary arcsine function about the orientation angle.Thus,the problem of position control of AGV is transformed into the stabilisation control of the kinematic system.Second,by introducing a reserved time parameter and a smooth switching function,a novel time-varying scaling function is proposed.This novel scaling function avoids the risk of infinite gain in the conventional prescribed-time control method while ensuring the smoothness of control laws.Then,an improved velocity constraint function is proposed using the Gaussian function.Compared with the existing constraint function,the proposed method not only has more smoothness but also solves the balance point errors caused by the large AGV orientation errors.The presented method ensures that the AGV reaches the target position in a prescribed time.Hence,the upper bound of the AGV system state can be determined by adjusting parameters.Matlab simulation results show that the proposed controller can effectively make the AGV system state satisfy the prescribed bound. 展开更多
关键词 Automated guided vehicle kinematic system position control prescribed-time stabilisation
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