Pervasive needs for data explorations at all scales have populated modern distributed platforms with workloads of different characteristics. The growing complexities and diversities have thereafter imposed distinct challenges to execute them on shared clusters in corporate or public clouds. This paper presents Fangorn, an adaptive execution framework built on an enriched graph model. As the underlying infrastructure for core computation platforms at Alibaba, Fangorn supports various execution modes and caters to heterogeneous workloads. With the capability to orchestrate graph executions with both long-running and requested-on-demand resources at the same time, Fangorn allows exploration of tradeoffs between latency and resource efficiency, for jobs of all scales. By modeling distributed job executions as mutable graphs with pluggable components, Fangorn offers a systematic framework to adjust job executions adaptively, according to data statistics collected during run-time. Fangorn supports an array of different computation engines ranging from relational to deep learning, and is fully deployed on production clusters across Alibaba. It manages tens of millions of distributed jobs daily, with job size scaling from one to half-million. PVLDB Reference Format: Yingda Chen, Jiamang Wang, Yifeng Lu, Ying Han, Zhiqiang Lv, Xuebin Min, Hua Cai, Wei Zhang, Haochuan Fan, Chao Li, Tao Guan, Wei Lin, Yangqing Jia and Jingren Zhou. Fangorn: Adaptive Execution Framework for Heterogeneous Workloads on Shared Clusters. PVLDB, 14(12): 2972 -

Pervasive needs for data explorations at all scales have populated modern distributed platforms with workloads of different characteristics. The growing complexities and diversities have thereafter imposed distinct challenges to execute them on shared clusters in corporate or public clouds. This paper presents Fangorn, an adaptive execution framework built on an enriched graph model. As the underlying infrastructure for core computation platforms at Alibaba, Fangorn supports various execution modes and caters to heterogeneous workloads. With the capability to orchestrate graph executions with both long-running and requested-on-demand resources at the same time, Fangorn allows exploration of tradeoffs between latency and resource efficiency, for jobs of all scales. By modeling distributed job executions as mutable graphs with pluggable components, Fangorn offers a systematic framework to adjust job executions adaptively, according to data statistics collected during run-time. Fangorn supports an array of different computation engines ranging from relational to deep learning, and is fully deployed on production clusters across Alibaba. It manages tens of millions of distributed jobs daily, with job size scaling from one to half-million.

Randomized network coding (RNC) has greatly reduced complexity of implementing network coding in large-scale, heterogeneous networks. Two tradeoffs are studied here that further reduce the overhead in applying RNC. The first examines how RNC performance varies with a node's randomizing capabilities. Specifically, a limited randomized network coding (L-RNC) scheme - in which intermediate nodes perform randomized encoding based on only limited number of random coefficients - is proposed and its performance bounds are analyzed. L-RNC is applicable to networks in which nodes have either limited computation/storage capacity or have ambiguity about downstream edge connectivity (e.g., as in ad hoc sensor networks). A second tradeoff studied here examines the relationship between reliability and capacity gains of RNC, i.e., how the outage probability of RNC relates to the transmission rate at source node. This tradeoff reveals that significant reductions in outage probability are possible when the source deliberately transmit at (only slightly) below network capacity. It therefore provides an effective alternative to improve RNC feasibility when the size of finite field is fixed.

Response surface methodology Was Used to analyze the effect of amylase level (X-1) and glycerol level (X-2) on the objective [water solubility index (WSI), water absorption index (WAI), and Max. loading] attributes of a poly(vinyl alcohol)-/cornstarch-blended composite. A rotable central-composite design (CCD) was used to develop models for the objective responses. The experiments were run at die temperature 100 degrees C with a feed rate of 25 g/min and a screw speed of 35 rpm. Responses were most affected by changes in the amylase level (X-1) and to a lesser extent by glycerol level (X-2). Individual contour plots of the different responses were overlaid, and regions meeting the optimum WSI of 3.03 (%), WAT of 5.08 (g gel/g dry wt), and Max. loading of 29.36 (N) were identified at the amylase level of 2.8 (mL) and the glycerol level of 92.2 (mL), respectively. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 258-264, 2009

A game-theoretic analysis of decode and forward cooperative communications is presented for additive white Gaussian noise (AWGN) and Rayleigh fading channels. Cooperative communications is modeled as a repeated game in which the two participating terminals are selfish and seek to maximize their own payoff, a general utility function that monotonically increases with signal-to-noise ratio. Results show a Nash Equilibrium in which users mutually cooperate can be obtained for AWGN channels when strict power control is enforced and users care about future payoff. However, such power control may not be necessary to achieve cooperative Nash Equilibrium when the game is played in Rayleigh fading channels. We study the Rayleigh fading channel as a two state Markov model in this paper. In this case, a mutually cooperative Nash Equilibrium 1) always exists when the utility function is convex and users care somewhat about future payoff; and 2) may not always exist when the utility function is concave, especially in adverse channel conditions. Examinations of several widely-used concave functions, however, demonstrate that mutual cooperation is more likely when users increase their value on future payoff. Additionally, it is shown that improving the effective uplink channel conditions of users, e.g., by using multiple transmit antennas, further encourages cooperation.

We develop a game theoretic framework for effective and adaptive inter-cell interference management in the OFDMA-based WiMAX/3GPP-LTE systems. Such approach requires no fixed spectrum planning beforehand and does not affect the spectrum usage for users that are not subject to inter-cell interference. Based on the handoff mechanisms in WiMAX systems, we also examine means of categorizing users who are, or are not, subject to potential interference. Different optimization opportunities for BSs are identified and analyzed. The interactions between BSs are modeled by a Stackelberg game in which BSs can make intelligent and rational decisions to reduce interference with minimum optimization cost. The algorithm to attain stable Nash Equilibrium is investigated and the behaviors of BSs with different preferences in the game are examined.

A game theoretic framework is developed in this paper to facilitate inter-cell interference management through cognitive sensing distributively performed by mobile stations (MSs). Using stochastic geometry, we reveal the relationship between the effectiveness of interference management and MS's "willingness" to perform cognitive sensing. Such cognitive sensing performed by MS is motivated by the associated beneficial results as well as by the rewards from base station(BS) that encourage sensing. Different tradeoffs for BS and MSs exist in their interactions, which are modeled as a Stackelberg game in this paper. While both BS and MS seek to manage interference at its own minimum cost, we design algorithm to achieve Nash Equilibrium in such a game and investigate the optimal strategies taken by the players (BS and MSs).

The unreliability of network edges in wireless networks invalidates some fundamental assumptions used in most studies on network coding and may present a performance bottleneck in its application. Particularly, wireless systems that are designed based on randomized network coding (RNC) would face two layers of uncertainty when receivers attempt to retrieve source information, among which the uncertainty brought by wireless fading can have a major impact on the system performance. In this paper, we approach the RNC scheme in wireless networks with both layers of uncertainty in mind, and we look at the joint impact of channel fading and broadcasting on the performance of RNC in the wireless setting. We show that the compromising effect of fading can be elevated when the wireless broadcasting medium is properly utilized. Furthermore, by exploiting the capacity-reliability inherent in the application of RNC, we demonstrate additional improvements in the performance of RNC over wireless network edges.

A game-theoretic analysis of decode-and-forward user cooperation is presented. Cooperative communications is modeled as a game in which the two participating terminals are selfish and seek to maximize their own payoff, a general utility function that monotonically increases with signal-to-noise ratio. The terminals communicate to a common destination terminal using orthogonal additive white Gaussian noise (AWGN) channels. Both deterministic and mixed-strategy Nash Equilibria are studied. Results show the selfish nature drives users away from a mutually cooperative equilibrium in a one-shot game. However, when the communication scenario is modeled as a repeated game, a Nash Equilibrium in which users cooperate can be achieved. The requirement for such an equilibrium is that users value future payoff and a proper power control scheme is utilized. Examinations of two possible payoffs (i.e., channel capacity and transmission reliability) show that such a power control scheme can be easily implemented.

Adopting ultra-short impulses in ultra-wide bandwidth (UWB) transmission make systems vulnerable to timing-jitter. To overcome this challenge, we propose a timing-hopping high-order waveform modulation scheme in this letter. Central to our design is the adaptation of a high-order monocycle (HOM) that can provide timing-jitter robust UWB communications

This paper investigates the diversity gain offered by implementing network coding (R. Ahlswede et al., 2000) over wireless communication links. The network coding algorithm is applied to both a wireless network containing a distributed antenna system (DAS) as well as one that supports user cooperation between users. The results show that network-coded DAS leads to better diversity performance as compared to conventional DAS, at a lower hardware cost and higher spectral efficiency. In the case of user cooperation, network coding yields additional diversity, especially when there are multiple users