Time filter

Source Type

Chengdu, China

Zhang J.,University of Wisconsin - Madison | Zhang X.,University of Wisconsin - Madison | Wu G.,UESTC
Proceedings - IEEE INFOCOM | Year: 2015

Visible Light Communications (VLC) is emerging as an appealing technology to complement WiFi in indoor environments. Yet maintaining VLC performance under link dynamics remains a challenging problem. In this paper, we build a VLC software-radio testbed and examine VLC channel dynamics through comprehensive measurement. We find minor device movement or orientation change can cause the VLC link SNR to vary by tens of dB even within one packet duration, which renders existing WiFi rate adaptation protocols ineffective. We thus propose a new mechanism, DLit, that leverages two unique properties of VLC links (predictability and full-duplex) to realize fine-grained, in-frame rate adaptation. Our prototype implementation and experiments demonstrate that DLit achieves near-optimal performance for mobile VLC usage cases, and outperforms conventional packet-level adaptation schemes by multiple folds. © 2015 IEEE.

Shi K.,Shanghai JiaoTong University | Li L.,UESTC | Liu H.,Shanghai JiaoTong University | He J.,Zhejiang University | And 2 more authors.
CCIS2011 - Proceedings: 2011 IEEE International Conference on Cloud Computing and Intelligence Systems | Year: 2011

Text classification has gained booming interest over the past few years. As a simple, effective and nonparametric classification method, KNN method is widely used in document classification. However, the uneven distribution in training set will affect the KNN classified result negatively. Moreover, the uneven distribution phenomenon of text is very common in documents on the Web. To tackling on this, this paper proposes an improved KNN method denoted by DBKNN. Experimental results show that the DBKNN algorithm can better serve classification requests for large sets of unevenly distributed documents. © 2011 IEEE.

Zhang Z.,UESTC | Zhang Z.,Ecole Polytechnique Federale de Lausanne | Mara O.,Ecole Polytechnique Federale de Lausanne | Argyraki K.,Ecole Polytechnique Federale de Lausanne
SIGCOMM 2014 - Proceedings of the 2014 ACM Conference on Special Interest Group on Data Communication | Year: 2014

When can we reason about the neutrality of a network based on external observations? We prove conditions under which it is possible to (a) detect neutrality violations and (b) localize them to specific links, based on external observations. Our insight is that, when we make external observations from different vantage points, these will most likely be inconsistent with each other if the network is not neutral. Where existing tomographic techniques try to form solvable systems of equations to infer network properties, we try to form unsolvable systems that reveal neutrality violations. We present an algorithm that relies on this idea to identify sets of non-neutral links based on external observations, and we show, through network emulation, that it achieves good accuracy for a variety of network conditions. © 2014 ACM.

Yun-Sheng W.,UESTC
AIAA/IEEE Digital Avionics Systems Conference - Proceedings | Year: 2012

IMA is an embedded version of a centralized time-shared 'mainframe', which provides: shared high performance common computing resources, high speed communication network, open architecture for both software and hardware. © 2012 IEEE.

Liu Z.,University of California at Riverside | Tan S.X.-D.,University of California at Riverside | Wang H.,UESTC | Swarup S.,University of California at Riverside | Gupta A.,Intel Corporation
Proceedings of the Asia and South Pacific Design Automation Conference, ASP-DAC | Year: 2013

This paper proposes a new thermal nonlinear modeling technique for packaged integrated systems. Thermal behavior of complicated systems like packaged electronic systems may exhibit nonlinear and temperature dependent properties. As a result, it is difficult to use a low order linear model to approximate the thermal behavior of the packaged integrated systems without accuracy loss. In this paper, we try to mitigate this problem by using piecewise linear (PWL) approach to characterizing the thermal behavior of those systems. The new method (called ThermSubPWL), which is the first proposed approach to nonlinear thermal modeling problem, identifies the linear local models for different temperature ranges using the subspace identification method. A linear transformation method is proposed to transform all the identified linear local models to the common state basis to build the continuous piecewise linear model. Experimental results validate the proposed method on a realistic packaged integrated system modeled via the multi-domain/physics commercial tool, COMSOL, under practical power signal inputs. The new piecewise models can lead to much smaller model order without accuracy loss, which translates to significant savings in both the simulation time and the time required to identify the reduced models compared to applying the high order models. © 2013 IEEE.

Discover hidden collaborations