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排序方式: 共有524条查询结果,搜索用时 15 毫秒
91.
Xin Guan Min Chen Tomoaki Ohtsuki 《Wireless Communications and Mobile Computing》2015,15(12):1633-1648
In sparse mobile wireless networks, normally, the mobile nodes are carried by people, and the moving activity of nodes always happens in a specific area, which corresponds to some specific community. Between the isolated communities, there is no stable communication link. Therefore, it is difficult to ensure the effective packet transmission among communities, which leads to the higher packet delivery delay and lower successful delivery ratio. Recently, an additional ferry node was introduced to forward packets between the isolated communities. However, most of the existing algorithms are working on how to control the trajectory of only one ferry work in the network. In this paper, we consider multiple ferries working in the network scenario and put our main focus on the optimal packet selection strategy, under the condition of mutual influence between the ferries and the buffer limitation. We introduce a non‐cooperative Bayesian game to achieve the optimal packet selection strategy. By maximizing the individual income of a ferry, we optimize the network performance on packet delivery delay and successful delivery ratio. Simulation results show that our proposed packet selection strategy improves the network performance on packet delivery delay and successful delivery ratio. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
92.
Bit‐length of digital images is decided by the Analog‐to‐Digital (AD) converter. The bit‐length expansion technique is necessary for high‐quality displays such as the liquid crystal display (LCD) and the plasma display. Bit‐length expansion is also necessary for low‐bit length images, which are degraded by the pseudo‐contour. In this paper, we propose a bit‐length expansion method from M‐level to N‐level [N=3(M−1)+1]. This operation means that two quantization levels are introduced between existing levels. The bit‐length expansion method results in the estimation problem of an error image between an M‐level's image and an N‐level's image. The error image is the pattern image which consists of three values. We show the estimation method of the three values pattern image and that the proposed method can remove the pseudo‐contour of digital images through several application results. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(10): 32–40, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ecj.10105 相似文献
93.
Diabetes mellitus is a major cause of chronic kidney disease and end-stage renal disease. However, the management of chronic kidney disease, particularly diabetes, requires vast improvements. Recently, sodium-glucose cotransporter-2 (SGLT2) inhibitors, originally developed for the treatment of diabetes, have been shown to protect against kidney injury via glycemic control, as well as various other mechanisms, including blood pressure and hemodynamic regulation, protection from lipotoxicity, and uric acid control. As such, regulation of these mechanisms is recommended as an effective multidisciplinary approach for the treatment of diabetic patients with kidney disease. Thus, SGLT2 inhibitors are expected to become key drugs for treating diabetic kidney disease. This review summarizes the recent clinical evidence pertaining to SGLT2 inhibitors as well as the mechanisms underlying their renoprotective effects. Hence, the information contained herein will advance the current understanding regarding the pleiotropic effects of SGLT2 inhibitors, while promoting future research in the field. 相似文献
94.
Yasushi Sumi Yutaka Ishiyama Fumiaki Tomita 《Computer Vision and Image Understanding》2007,105(3):218-230
This paper presents a new robot-vision system architecture for real-time moving object localization. The 6-DOF (3 translation and 3 rotation) motion of the objects is detected and tracked accurately in clutter using a model-based approach without information of the objects’ initial positions. An object identification task and an object tracking task are combined under this architecture. The computational time-lag between the two tasks is absorbed by a large amount of frame memory. The tasks are implemented as independent software modules using stereo-vision-based methods which can deal with objects of various shapes with edges, including planar to smooth-curved objects, in cluttered environments. This architecture also leads to failure-recoverable object tracking, because the tracking processes can be automatically recovered, even if the moving objects are lost while tracking. Experimental results obtained with prototype systems demonstrate the effectiveness of the proposed architecture. 相似文献
95.
96.
To unlock the full potential of evolution in digital media, a Tierra-like system using network-type assembly-like language has been constructed. In the system, like Avida, digital creatures, self-replicating programs, live in a discrete 2D torus space and an interaction between creatures is restricted locally. Bearing a genetic network in mind, network structure is introduced. In the previous works, it is shown that the possibility that the network-type model has more potential of evolution than a linear-type model like Avida in a simple environment. In this paper, to study the potential of evolution more precisely, we model the effects of environment other than creatures. As one of the simplest models of such environment, the cost of execution, i.e. executing time, is introduced. The difficult environment to live in costs high to execute instructions, the easy environment does low. In computer experiments, we have investigated the influence of change in environment by analyzing the process of evolution and diversity of the system. Experimental results show that the network-type system keeps more stable diversity than the linear-type system does, even when the environment changes drastically. This indicates the possibility that the network-type system has more potential of evolution than the linear-type system has. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008 相似文献
97.
Most control methods of underwater vehiclemanipulator systems (UVMS) are based on the computed torque method that is used
for underwater robotic vehicles. We have proposed a resolved acceleration control (RAC) method for UVMS. In this article,
we propose a disturbance compensation control method for both vehicle and manipulator based on the RAC method. Experimental
results using an underwater robot with a vertical planar 2-link manipulator show that the proposed control method has good
control performance. 相似文献
98.
Fumiaki Shiraishi 《程序员》2006,(9):34-39
对于如何提供补丁下载,单机PC游戏开发人员已经是轻车熟路了,这些补丁包里通常包含玩家需要手动更新的数据和二进制文件.但基本上.他们很少会为了补丁下载而创建一个“更新系统”。 相似文献
99.
A numerical simulation of an instrument that is used to measure the charging state of PM2.5 is conducted in order to clarify its measurement uncertainty and to improve its performance. The instrument, a parallel-plate particle separator (PPPS), is designed to classify aerosol particles according to their charging states and measure their quantities. The trajectories of submicron particles in the PPPS are numerically analyzed using the Lagrangian particle tracking method, taking into account the Brownian force and the electrostatic force. First, it is confirmed that the deterioration in the classification accuracy observed in the experiment is due to Brownian diffusion. The optimal condition that improves the accuracy is investigated through a parametric study by varying the balance of flow rates at the inlets, the geometry of the inlet and exit sections, and the applied voltage. It is found that decreasing the flow rate of the central inlet for aerosol or narrowing the central inlet improves the accuracy. The dependence of the accuracy on the flow rate is found to be in accordance with the experimental results. For charged particles, an optimum voltage that maximizes the classification accuracy is found. On the basis of the simulation results, we propose a method to determine the charge distribution of aerosol from the number of particles counted at each exit of the PPPS. In the test assuming aerosol in the air, the charge distribution determined from the number count at the exits is found to perfectly agree with the charge distribution specified at the inlet.
Copyright © 2019 American Association for Aerosol Research 相似文献
100.
Aoi Sugiyama Shunji Araki Naonori Sakamoto Tomoaki Watanabe Masahiro Yoshimura 《Journal of Electroceramics》2006,17(1):71-74
Ceramics have generally been fabricated from powders by shape forming & sintering methods except for glasses and glass ceramics.
Glasses and glass ceramics can be fabricated by melting methods. The melting method has not only higher productivity but also
higher shape forming ability than powder processes via forming & sintering methods. Thus we have reinvestigated melting methods
in binary and ternary oxides systems to fabricate amorphous bulk ceramics and bulk nano composites. We have successfully fabricated
amorphous phases by simple melt solidification methods in ternary eutectic melts in the HfO2-Al2O3-Gd2O3system. The present study demonstrates the formation of the amorphous phases in quaternary systems HfO2-Al2O3-Gd2O3-Eu2O3. Furthermore, we have also succeeded to fabricate nano-structured bulk ceramics, which consisted of constituent oxide grains
with 20–100 nm in size, by post annealing of the amorphous phase. 相似文献