A distributed scheduling framework based on selfish autonomous agents for federated cloud environments

In global supply chain, the scheduling problems of large products such as ships, airplanes, space shuttles, assembled constructions, and/or automobiles are complicated by nature. New scheduling systems are often developed in order to reduce inherent computational complexity. As a result, a problem can be decomposed into small sub-problems, problems that contain independently small scheduling systems integrating into the initial problem. As one of the authors experienced, DAS (Daewoo Shipbuilding Scheduling System) has adopted a two-layered hierarchical architecture. In the hierarchical architecture, individual scheduling systems composed of a high-level dock scheduler, DAS-ERECT and low-level assembly plant schedulers, DAS-PBS, DAS-3DS, DAS-NPS, and DAS-A7 try to search the best schedules under their own constraints. Moreover, the steep growth of communication technology and logistics enables it to introduce distributed multi-nation production plants by which different parts are produced by designated plants. Therefore vertical and lateral coordination among decomposed scheduling systems is necessary. No standard coordination mechanism of multiple scheduling systems exists, even though there are various scheduling systems existing in the area of scheduling research. Previous research regarding the coordination mechanism has mainly focused on external conversation without capacity model. Prior research has heavily focuses on agent-based coordination in the area of agent research. Yet, no scheduling domain has been developed. Previous research regarding the agent-based scheduling has paid its ample attention to internal coordination of scheduling process, a process that has not been efficient. In this study, we suggest a general framework for agent-based coordination of multiple scheduling systems in global supply chain. The purpose of this study was to design a standard coordination mechanism. To do so, we first define an individual scheduling agent responsible for their own plants and a meta-level coordination agent involved with each individual scheduling agent. We then suggest variables and values describing the individual scheduling agent and meta-level coordination agent. These variables and values are represented by Backus-Naur Form. Second, we suggest scheduling agent communication protocols for each scheduling agent topology classified into the system architectures, existence or nonexistence of coordinator, and directions of coordination. If there was a coordinating agent, an individual scheduling agent could communicate with another individual agent indirectly through the coordinator. On the other hand, if there was not any coordinating agent existing, an individual scheduling agent should communicate with another individual agent directly. To apply agent communication language specifically to the scheduling coordination domain, we had to additionally define an inner language, a language that suitably expresses scheduling coordination. A scheduling agent communication language is devised for the communication among agents independent of domain. We adopt three message layers which are ACL layer, scheduling coordination layer, and industry-specific layer. The ACL layer is a domain independent outer language layer. The scheduling coordination layer has terms necessary for scheduling coordination. The industry-specific layer expresses the industry specification. Third, in order to improve the efficiency of communication among scheduling agents and avoid possible infinite loops, we suggest a look-ahead load balancing model which supports to monitor participating agents and to analyze the status of the agents. To build the look-ahead load balancing model, the status of participating agents should be monitored. Most of all, the amount of sharing information should be considered. If complete information is collected, updating and maintenance cost of sharing information will be increasing although the frequency of communication will be decreasing. Therefore the level of detail and updating period of sharing information should be decided contingently. By means of this standard coordination mechanism, we can easily model coordination processes of multiple scheduling systems into supply chain. Finally, we apply this mechanism to shipbuilding domain and develop a prototype system which consists of a dock-scheduling agent, four assembly- plant-scheduling agents, and a meta-level coordination agent. A series of experiments using the real world data are used to empirically examine this mechanism. The results of this study show that the effect of agent-based platform on coordinated scheduling is evident in terms of the number of tardy jobs, tardiness, and makespan.

We present in this paper a novel distributed solution to a security-aware job scheduling problem in cloud computing infrastructures. We assume that the assignment of the available resources is governed exclusively by the specialized brokers assigned to individual users submitting their jobs to the system. The goal of this scheme is allocating a limited quantity of resources to a specific number of jobs minimizing their execution failure probability and total completion time. Our approach is based on the Pareto dominance relationship and implemented at an individual user level. To select the best scheduling strategies from the resulting Pareto frontiers and construct a global scheduling solution, we developed a decision-making mechanism based on the game-theoretic model of Spatial Prisoner’s Dilemma, realized by selfish agents operating in the two-dimensional cellular automata space. Their behavior is conditioned by the objectives of the various entities involved in the scheduling process and driven towards a Nash equilibrium solution by the employed social welfare criteria. The performance of the scheduler applied is verified by a number of numerical experiments. The related results show the effectiveness and scalability of the scheme in the presence of a large number of jobs and resources involved in the scheduling process.

Cloud computing has become pervasive due to attractive features such as on-demand resource provisioning and elasticity. Most cloud providers are centralized entities that employ massive data centers. However, in recent times, due to increasing concerns about privacy and data control, many small data centers (SDCs) established by different providers are emerging in an attempt to meet demand locally. However, SDCs can suffer from resource in-elasticity due to their relatively scarce resources, resulting in a loss of performance and revenue. In this paper we propose a decentralized cloud model in which a group of SDCs can cooperate with each other to improve performance. Moreover, we design a general strategy function for the SDCs to evaluate the performance of cooperation based on different dimensions of resource sharing. Through extensive simulations using a realistic data center model, we show that the strategies based on reciprocity are more effective than other involved strategies, e.g., those using prediction on historical data. Our results show that the reciprocity-based strategy can thrive in a heterogeneous environment with competing strategies.

With advances in semiconductor technology, power management has increasingly become a very important design constraint in processor design. In embedded processors, instruction fetch and decode consume more than 40% of processor power. This calls for development of power minimization techniques for the fetch and decode stages of the processor pipeline. For this, filter cache has been proposed as an architectural extension for reducing the power consumption. A filter cache is placed between the CPU and the instruction cache (I-cache) to provide the instruction stream. A filter cache has the advantages of shorter access time and lower power consumption. However, the downside of a filter cache is a possible performance loss in case of cache misses. In this article, we present a novel technique---decode filter cache (DFC)---for minimizing power consumption with minimal performance impact. The DFC stores decoded instructions. Thus, a hit in the DFC eliminates instruction fetch and its subsequent decoding. The bypassing of both instruction fetch and decode reduces processor power. We present a runtime approach for predicting whether the next fetch source is present in the DFC. In case a miss is predicted, we reduce the miss penalty by accessing the I-cache directly. We propose to classify instructions as cacheable or noncacheable, depending on the decode width. For efficient use of the cache space, a sectored cache design is used for the DFC so that both cacheable and noncacheable instructions can coexist in the DFC sector. Experimental results show that the DFC reduces processor power by 34% on an average and our next fetch prediction mechanism reduces miss penalty by more than 91%.

Modern client processors typically use one of three commonly-used power delivery network (PDN) architectures: 1) motherboard voltage regulators (MBVR), 2) integrated voltage regulators (IVR), and 3) low dropout voltage regulators (LDO). We observe that the energy-efficiency of each of these PDNs varies with the processor power (e.g, thermal design power (TDP) and dynamic power-state) and workload characteristics (e.g., work-load type and computational intensity). This leads to energy-inefficiency and performance loss, as modern client processors operate across a wide spectrum of power consumption and execute a wide variety of workloads. To address this inefficiency, we propose FlexWatts, a hybrid adaptive PDN for modern client processors whose goal is to provide high energy-efficiency across the processor's wide range of power consumption and workloads. FlexWatts provides high energy-efficiency by intelligently and dynamically allocating PDNs to processor domains depending on the processor's power consumption and workload. FlexWatts is based on three key ideas. First, FlexWatts combines IVRs and LDOs in a novel way to share multiple on-chip and off-chip resources and thus reduce cost, as well as board and die area overheads. This hybrid PDN is allocated for processor domains with a wide power consumption range (e.g., CPU cores and graphics engines) and it dynamically switches between two modes: IVR-Mode and LDO-Mode, depending on the power consumption. Second, for all other processor domains (that have a low and narrow power range, e.g., the IO domain), FlexWatts statically allocates off-chip VRs, which have high energy-efficiency for low and narrow power ranges. Third, FlexWatts introduces a novel prediction algorithm that automatically switches the hybrid PDN to the mode (IVR-Mode or LDO-Mode) that is the most beneficial based on processor power consumption and workload characteristics. To evaluate the tradeoffs of PDNs, we develop and open-source PDNspot, the first validated architectural PDN model that enables quantitative analysis of PDN metrics. Using PDNspot, we evaluate FlexWatts on a wide variety of SPEC CPU2006, graphics (3DMark06), and battery life (e.g., video playback) workloads against IVR, the state-of-the-art PDN in modern client processors. For a 4 W thermal design power (TDP) processor, FlexWatts improves the average performance of the SPEC CPU2006 and 3DMark06 workloads by 22% and 25%, respectively. For battery life workloads, FlexWatts reduces the average power consumption of video playback by 11% across all tested TDPs (4W-50W). FlexWatts has comparable cost and area overhead to IVR. We conclude that FlexWatts provides high energy-efficiency across a modern client processor's wide range of power consumption and wide variety of workloads, with minimal overhead.

Cost effectiveness of commercial computing clouds

A protocol has been developed to obtain two-dimensional kinematic shoe data of football players in their training environment through high-speed video analysis. Such kinematic data can provide an understanding of how to better replicate the boundary conditions of football movements when simulated using mechanical traction and penetration test devices. As part of a pilot study, 11 youth academy players from a Premiership football club performed football-specific movements which were filmed at 1000 frames s-1. The protocol required minimal set-up time and the area of the pitch to be filmed could be positioned in any part of the playing area, causing low disruption to the players. This aimed to ensure that the movements performed were representative of those carried out during competitive play. Results in this study are concerned with the kinematics of the shoe during contact with the ground for movements identified to be important in terms of injury risk and loss of performance (slipping). Shoe velocities and orientations were measured for subjects wearing shoes of different stud types (traditional round studs versus contemporary bladed studs) on two surfaces (artificial turf, in-filled with rubber and sand, versus a natural surface). All the parameters measured from the relatively small population of subjects had high variances and therefore few significant effects of studs and surface could be found. The data does however provide insight into the appropriate boundary conditions to be used in mechanical test devices. For example, in the forefoot push-off movement it can be seen that test devices should measure the traction forces when the shoe first starts to move, as this is when the player would lose performance, as opposed to the maximum traction which can occur after significant displacement of the shoe through the surface. Analysis of the orientation and velocity path of the studs just before contact with the ground shows that the studs could be aligned to enhance their penetration into the surface and optimise the traction properties of the studs. In order to determine the orientation and velocity of the shoes at crucial phases in movements force-plate data obtained in the laboratory should be utilised in future studies.

Accurate and reliable results in orthodontics heavily depend on selecting the right impression materials. With the rise of digital technology and additive manufacturing techniques, it has become necessary to characterize experimentally the materials used to design prosthetic bases. In this study, the mechanical properties of Polyetheretherketone, Nylon6, Nylon12, and Polypropylene are analyzed, as impression materials commonly used in dentistry applications. Specifically, the effect on their flexural elastic modulus of the exposure to working environment conditions is also investigated by means of 3-point bending test performed on virgin materials and samples immersed in saliva for 72 hours. The proposed approach revealed significant behavior in terms of loss in mechanical performances. These findings have significant implications for the proper selection and use of AM materials in dental applications.

An adaptive threshold mechanism for accurate and efficient deep spiking convolutional neural networks

A wavelength division multiplexing based multicast Benes switching network considers an input signal on inlets with the given wavelength to one or more fiber outlets with wavelength conversion in the optical domain. The main challenge in the design of multicast routing and wavelength assignment is to reduce the complexity of wavelength conversion without affecting switch capability and no cross-talk signal quality using the Benes network. The proposed design of multicast routing and wavelength assignment wavelength conversion using Benes network complexity is 4Flog2W/2 and switching complexity of O(Flog2W/2). The performance loss in terms of throughput, delay, and packet loss of the proposed low-complexity method using output queuing multicast interconnection network. We prove that W > 64 conversion complexity of the optimal design is strictly lower than the existing system Copy route single channel and multicast channel. When we compare with different conversion techniques, the add/drop multicast Benes network and Mach---Zehnder Interferometer using Benes network complexity is higher because 2N × 2N design switching elements are required, and so double the amount of conversion is required. The proposed Multicast routing Wavelength assignment Benes technique achieves more than 80 % reduction in conversion complexity for the design of Benes network as compared to different wavelength conversion techniques.

An energy, performance efficient resource consolidation scheme for heterogeneous cloud datacenters

With reference to light railways transportation systems, in the paper a comparison is carried out between vehicles equipped with either Induction Motor Drive or Permanent Magnet Brushless Motor Drive. The attention is particularly focused on energetic performance, in term of losses and efficiency. The main characteristics of the traction units of the two compared vehicles have been chosen in accordance with the real constraints, usually imposed or suggested by the motor type, which influences mechanical and electrical configurations, control architectures and techniques. Thus, the analysis has not the aim to compare specific devices, which are different for the two considered cases, but the whole traction units, each one with its own proper characteristics. Based on both assigned characteristic of the railways sections and vehicle mission, an extensive numerical analysis has been carried out in various operating conditions, with the aim to comparatively evaluate either fast dynamic performance, in response to the PWM modulation, or slow dynamic performance, concerning the time constant of mechanical quantities, or losses and energy efficiency.

Over the last decades, Content Delivery Networks (CDNs) have been developed to overcome the limitation of user perceived latency by replicating contents from origin server to its content servers around the globe close to clients. As some contents occupy most of the storage capacity and processing power in traditional private content servers, cloud computing can provide a pool of storage and processing power resources for caching contents. By adopting cloud computing to CDN, the content provider can use the cloud infrastructure by distributing the contents to cloud servers which will then deliver to near clients. In this paper, we propose a cloud-based CDN framework designed by two schemes 1) UDP/TCP-based content distribution from origin server to cloud servers and 2) SDN-based cloud server coordination. In addition, we also formulate the optimal content placement problem using binary integer programming to minimize the total cost of renting resources including storage, processing power, and network bandwidth in cloud providers for hosting contents from origin server. Then, the optimal solution obtained from binary integer programming is evaluated by greedy algorithm and simulations. The proposed framework helps content provider to offer high quality of services to clients while minimizing the cost of rented cloud resources.

Nowadays, big media healthcare data processing in cloud has become an effective solution for satisfying QoS demands of medical users. It can support various healthcare services such as pre-processing, storing, sharing, and analysis of monitored data as well as acquiring context-awareness. However, to support energy and cost savings, the union of cloud data centers termed as cloud confederation can be an promising approach, which helps a cloud provider to overcome the limitation of physical resources. However, the key challenge in it is to achieve multiple contradictory objectives, e.g., meeting the required level of services defined in service level agreement, maintaining medial users'application QoS, etc. while maximizing profit of a cloud provider. In this paper, for executing heterogeneous big healthcare data processing requests from users, we develop a local and global cloud confederation model, namely FnF, that makes an optimal selection decision for target cloud data center(s) by exploiting Fuzzy logic. The FnF trades off in between profit of cloud provider and user application QoS in selecting federated data center(s). In addition, FnF enhances its decision accuracy by precisely estimating the resource requirements for the big data processing tasks using multiple linear regression. The proposed FnF model is validated through numerical as well as experimental evaluations. Simulation results depict the effectiveness and efficiency of the FnF model compared to state-of-the-art approaches.

Cloud server farms global organization empowers expansive-scale logical job procedures to strengthen execution and transmit rapid responses. This exceptional topographical appropriation of the calculation is enhanced by associated expansion within the range of the information taken care of by such apps, conveying title new problems recognized crosswise over locations with efficient info administration. High quantity, low potential or price-related exchange offers area unit only one or two concerns intended to take care of information cross-sectional over server farms along with cloud providers and buyers. Cloud-gave capacity that provides low execution in lightweight fixed cost plans is impacted by existing provisions. Work process motors therefore necessitate the formation of alternates, carrying out execution at the cost of negative framework set-ups, maintaining costs, reducing strong quality and reusability. We tend to give overflow, associate unchanging information management structure for logical job procedures running across topographically disseminated locations, desiring to obtain economic benefits from these geo-differing characteristics. Our response is conscious of the condition, as it screens and displays the global cloud framework, the contribution of extraordinary and expected info taking care of execution for exchange value and quantity, within and across sites. Overflow suggests a meeting of pluggable administrations, assembled in an info-scientific cloud set. They provide an opportunity for applications to screen the essential framework, to endeavor to swish info pressure, reduplication and geo-replication, to assess info administration costs, to align the exchange between costs and periods and, consequently, to improve the exchange procedure.