A mobile edge cloud provides a platform to accommodate the offloaded traffic workload generated by mobile devices.It can significantly reduce the access delay for mobile application users.However,the high user mobilit...A mobile edge cloud provides a platform to accommodate the offloaded traffic workload generated by mobile devices.It can significantly reduce the access delay for mobile application users.However,the high user mobility brings significant challenges to the service provisioning for mobile users,especially to delay-sensitive mobile applications.With the objective to maximize a profit,which positively associates with the overall admitted traffic served by the local edge cloud,and negatively associates with the access delay as well as virtual machine migration delay,we study a fundamental problem in this paper:how to update the service provisioning solution for a given group of mobile users.Such a profit-maximization problem is formulated as a nonlinear integer linear programming and linearized by absolute value manipulation techniques.Then,we propose a framework of heuristic algorithms to solve this Nondeterministic Polynomial(NP)-hard problem.The numerical simulation results demonstrate the efficiency of the devised algorithms.Some useful summaries are concluded via the analysis of evaluation results.展开更多
The detection of Oracle Bone Inscriptions (OBIs) is one of the most fundamental tasks in the study of Oracle Bone, which aims to locate the positions of OBIs on rubbing images. The existing methods are based on the sc...The detection of Oracle Bone Inscriptions (OBIs) is one of the most fundamental tasks in the study of Oracle Bone, which aims to locate the positions of OBIs on rubbing images. The existing methods are based on the scheme of anchor boxes, involving complex network design and a great number of anchor boxes. In order to overcome the problem, this paper proposes a simpler but more effective OBIs detector by using an anchor-free scheme, where shape-adaptive Gaussian kernels are employed to represent the spatial regions of different OBIs. More specifically, to address the problem of misdetection caused by regional overlapping between some tightly distributed OBIs, the character regions are simultaneously represented by multiscale Gaussian kernels to obtain regions with sharp edges. Besides, based on the kernel predictions of different scales, a novel post-processing pipeline is used to obtain accurate predictions of bounding boxes. Experiments show that our OBIs detector has achieved significant results on the OBIs dataset, which greatly outperforms several mainstream object detectors in both speed and efficiency. Dataset is available at http://jgw.aynu.edu.cn.展开更多
The method to cool a high heat flux device is an important research direction for the heat exchanger design.Micro-channels are an eflfective heat exchange structure both for single-phase and two-phase flow.In this pap...The method to cool a high heat flux device is an important research direction for the heat exchanger design.Micro-channels are an eflfective heat exchange structure both for single-phase and two-phase flow.In this paper,the heat transfer correlations of single-phase,two-phase and nanofluid in a micro-channel are discussed and analyzed.The correlations of pressure drop for single-phase and two-phase fluids are also presented.Excluding the different working fluids used in the micro-channel,the diameter and aspect ratio,shape and structure,surface roughness,internal and external factor and layout of micro-channel pipe are considered to analyze their influence on the heat transfer performance and pressure drop.Micro-channel technology applications include industry,air-conditioning,solar energy systems,heat pipe technology and computer data center cooling.Compared to the conventional heat exchangers used in these fields,a micro-channel heat sink showed a much better heat transfer coefficient and low volume,indicating that it is a good choice and has huge potential for cooling application.Finally,existing problems and future scopes are described,and drawing up design standard,experimental and simulated methods for evaluating its performance are the urgent actions which need to be carried out.This review paper serves as guidance for researchers to design and predict the performance of micro-channel heat sinks.展开更多
基金partially supported by JSPS KAKENHI under Grant Number JP16J07062
文摘A mobile edge cloud provides a platform to accommodate the offloaded traffic workload generated by mobile devices.It can significantly reduce the access delay for mobile application users.However,the high user mobility brings significant challenges to the service provisioning for mobile users,especially to delay-sensitive mobile applications.With the objective to maximize a profit,which positively associates with the overall admitted traffic served by the local edge cloud,and negatively associates with the access delay as well as virtual machine migration delay,we study a fundamental problem in this paper:how to update the service provisioning solution for a given group of mobile users.Such a profit-maximization problem is formulated as a nonlinear integer linear programming and linearized by absolute value manipulation techniques.Then,we propose a framework of heuristic algorithms to solve this Nondeterministic Polynomial(NP)-hard problem.The numerical simulation results demonstrate the efficiency of the devised algorithms.Some useful summaries are concluded via the analysis of evaluation results.
文摘The detection of Oracle Bone Inscriptions (OBIs) is one of the most fundamental tasks in the study of Oracle Bone, which aims to locate the positions of OBIs on rubbing images. The existing methods are based on the scheme of anchor boxes, involving complex network design and a great number of anchor boxes. In order to overcome the problem, this paper proposes a simpler but more effective OBIs detector by using an anchor-free scheme, where shape-adaptive Gaussian kernels are employed to represent the spatial regions of different OBIs. More specifically, to address the problem of misdetection caused by regional overlapping between some tightly distributed OBIs, the character regions are simultaneously represented by multiscale Gaussian kernels to obtain regions with sharp edges. Besides, based on the kernel predictions of different scales, a novel post-processing pipeline is used to obtain accurate predictions of bounding boxes. Experiments show that our OBIs detector has achieved significant results on the OBIs dataset, which greatly outperforms several mainstream object detectors in both speed and efficiency. Dataset is available at http://jgw.aynu.edu.cn.
基金sponsored by National Key Research and Development Program of China(Grant No.2018YFC0705306)National Natural Science Foundation of China(Project No.51678488)Applied Basic Research Project of Sichuan Province(Project No.2017JY0253)。
文摘The method to cool a high heat flux device is an important research direction for the heat exchanger design.Micro-channels are an eflfective heat exchange structure both for single-phase and two-phase flow.In this paper,the heat transfer correlations of single-phase,two-phase and nanofluid in a micro-channel are discussed and analyzed.The correlations of pressure drop for single-phase and two-phase fluids are also presented.Excluding the different working fluids used in the micro-channel,the diameter and aspect ratio,shape and structure,surface roughness,internal and external factor and layout of micro-channel pipe are considered to analyze their influence on the heat transfer performance and pressure drop.Micro-channel technology applications include industry,air-conditioning,solar energy systems,heat pipe technology and computer data center cooling.Compared to the conventional heat exchangers used in these fields,a micro-channel heat sink showed a much better heat transfer coefficient and low volume,indicating that it is a good choice and has huge potential for cooling application.Finally,existing problems and future scopes are described,and drawing up design standard,experimental and simulated methods for evaluating its performance are the urgent actions which need to be carried out.This review paper serves as guidance for researchers to design and predict the performance of micro-channel heat sinks.