THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

What will 5G be? What it will not be is an incremental advance on 4G. The previous four generations of cellular technology have each been a major paradigm shift that has broken backward compatibility. Indeed, 5G will need to be a paradigm shift that includes very high carrier frequencies with massive bandwidths, extreme base station and device densities, and unprecedented numbers of antennas. However, unlike the previous four generations, it will also be highly integrative: tying any new 5G air interface and spectrum together with LTE and WiFi to provide universal high-rate coverage and a seamless user experience. To support this, the core network will also have to reach unprecedented levels of flexibility and intelligence, spectrum regulation will need to be rethought and improved, and energy and cost efficiencies will become even more critical considerations. This paper discusses all of these topics, identifying key challenges for future research and preliminary 5G standardization activities, while providing a comprehensive overview of the current literature, and in particular of the papers appearing in this special issue.

What Will 5G Be

Recommender systems have developed in parallel with the web. They were initially based on demographic, content-based and collaborative filtering. Currently, these systems are incorporating social information. In the future, they will use implicit, local and personal information from the Internet of things. This article provides an overview of recommender systems as well as collaborative filtering methods and algorithms; it also explains their evolution, provides an original classification for these systems, identifies areas of future implementation and develops certain areas selected for past, present or future importance.

http://romisatriawahono.net/lecture/rm/survey/information%20retrieval/Bobadilla%20-%20Recommender%20Systems%20-%202013.pdf

Recommender systems survey

Cloud data centers host diverse applications, mixing workloads that require small predictable latency with others requiring large sustained throughput. In this environment, today's state-of-the-art TCP protocol falls short. We present measurements of a 6000 server production cluster and reveal impairments that lead to high application latencies, rooted in TCP's demands on the limited buffer space available in data center switches. For example, bandwidth hungry "background" flows build up queues at the switches, and thus impact the performance of latency sensitive "foreground" traffic.To address these problems, we propose DCTCP, a TCP-like protocol for data center networks. DCTCP leverages Explicit Congestion Notification (ECN) in the network to provide multi-bit feedback to the end hosts. We evaluate DCTCP at 1 and 10Gbps speeds using commodity, shallow buffered switches. We find DCTCP delivers the same or better throughput than TCP, while using 90% less buffer space. Unlike TCP, DCTCP also provides high burst tolerance and low latency for short flows. In handling workloads derived from operational measurements, we found DCTCP enables the applications to handle 10X the current background traffic, without impacting foreground traffic. Further, a 10X increase in foreground traffic does not cause any timeouts, thus largely eliminating incast problems.

/pdf/data-center-tcp-dctcp-4d3pj8xdal.pdf

Data center TCP (DCTCP)

This paper presents and evaluates two principles for wireless routing protocols. The first is datapath validation: data traffic quickly discovers and fixes routing inconsistencies. The second is adaptive beaconing: extending the Trickle algorithm to routing control traffic reduces route repair latency and sends fewer beacons.We evaluate datapath validation and adaptive beaconing in CTP Noe, a sensor network tree collection protocol. We use 12 different testbeds ranging in size from 20--310 nodes, comprising seven platforms, and six different link layers, on both interference-free and interference-prone channels. In all cases, CTP Noe delivers > 90% of packets. Many experiments achieve 99.9%. Compared to standard beaconing, CTP Noe sends 73% fewer beacons while reducing topology repair latency by 99.8%. Finally, when using low-power link layers, CTP Noe has duty cycles of 3% while supporting aggregate loads of 30 packets/minute.

/pdf/collection-tree-protocol-selhhlblmq.pdf

Collection tree protocol

Methods, systems, and computer program products for distributed phase balancing are provided herein. A method of use in connection with a distribution network having a phase imbalance includes determining one or more power consumption parameters associated with a given entity of the distribution network; determining one or more power supply parameters associated with the given entity of the distribution network; and computing, based on said one or more power consumption parameters and said one or more power supply parameters, at least one of (i) a level of power consumption increase and/or decrease and (ii) a level of power supply increase and/or decrease associated with one or more devices of the given entity to remedy the phase imbalance within the distribution network.

Distributed Phase Balancing

In this paper we evaluate rate distributions between competing flows in a network of droptail queues. Specifically we look at the case when some of the flows are non-conformant or mis-behaving and it's effect on conformant flows. Our results show in a network of droptail queues mis-behaving flows can have significantly higher bandwidth allocations at the cost of conformant flows. Further this unequal sharing worsens in a multi-bottleneck scenario where conformant flows may consistently time-out. However the distribution of rates improves if RED is used at the bottleneck thus suggesting deployment of RED. In this paper we also look at the fairness from the network's perspective rather then end-user's. As such we propose an analytical model for managing non-conformant or mis-behaving flows by manipulating congestion penalties conveyed to them. We show that this penalty transformation can map a user's utility function, U/sub s/, to any objective utility function, U/sub obj/. These penalty transformation modules can be completely implemented at the edge and can also work with droptail queues. We have analyzed the framework and evaluated it for both single and multi bottleneck scenarios.

On impact of non-conformant flows on a network of droptail gateways

In this paper, we propose a multicast congestion control called GMCC. It provides multi-rate features at low complexity by encompassing a set of independent single-rate sub-sessions (a.k.a layers). Various receivers can subscribe to different subsets of these layers to achieve different throughput. The sending rate in each layer is adjusted without boundary by a single-rate multicast congest control algorithm. The set of layers offered to receivers is also dynamically adapted to need. In summary, GMCC is fully adaptive.

Generalized multicast congestion control an efficient multi-rate scheme using single-rate control

In this paper, we investigate a distributed fine grain adaptive FEC (FGA-FEC) scheme for scalable video streaming
to heterogeneous users over a congested multihop network, where we do FGA-FEC decode/recode at selected
intermediate overlay nodes, and do FGA-FEC adaptation at remaining nodes. In order to reduce the overall
computational burden, we propose two methods: (1) a coordination between optimization processes running at
adjacent nodes to reduce the optimization computation, and (2) extension of our overlay multihop FEC (OM-FEC 1,
2 ) to reduce the number of FGA-FEC decode/recode nodes. Simulations show that the proposed scheme
can greatly reduce computation, and can provide near best possible video quality to diverse users.

Distributed fine grain adaptive-FEC scheme for scalable video streaming

Wireless networks suffer from high packet loss-rates and variations in delay and bandwidth. This makes it difficult for conventional transport protocols like TCP to operate efficiently over such networks. We presented Multi-Path LOss Tolerant transport protocol (MPLOT) in [1] to counter such lossy and volatile conditions. MPLOT uses multiple paths for data transfer such that at an aggregate level, the volatilities of individual paths are averaged out to yield a smooth stable transmission. MPLOT also employs Forward Error Correction (FEC), which adapts to the changing conditions in the network, to control the amount of re-transmissions. We showed in [1] that MPLOT is able to achieve significantly higher goodput (data rate) than traditional TCP-SACK even with packet losses as high as 50%. The goodput attained by MPLOT actually increases with the number of paths (while the total bandwidth across paths remains fixed). However, a protocol that yields high goodput and a high delay cannot be used by several applications that not only demand a high goodput, but a low packet delay as well(e.g. Skype). In this paper, we aim to show that MPLOT can be used for applications that need low delay. We show that MPLOT is able to use multiple paths effectively to yield a low average packet delay with small variation in the lossy and volatile conditions. We also study how MPLOT behaves with conventional TCP flows in lossless conditions. We then study the conditions under which MPLOT is able to reduce transfer time of small sized files (10Kb–100Kb), which is important for interactive web applications.

Shivkumar Kalyanaraman

Papers

Distributed Phase Balancing

On impact of non-conformant flows on a network of droptail gateways

Generalized multicast congestion control an efficient multi-rate scheme using single-rate control

Distributed fine grain adaptive-FEC scheme for scalable video streaming

Exploiting multiple paths and diversity in wireless networks for high goodput and low latency