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The rise of the network economy and E-commerce has pushed the rapid development of logistics market. The Multi-tier Shuttle Warehousing System (MSWS) as a new autonomous unit load storage/retrieval system, which flexibility and work efficiency is much-improved compared with the conventional AS/RS, has attracted more and more attention of logistics enterprises both at home and abroad. MSWS is composed...
Model slicers are tools which provide two services: (a) finding parts of interest in a model and (b) displaying these parts somehow or extract these parts as a new, autonomous model, which is referred to as slice or sub-model. This paper focuses on the creation of editable slices, which can be processed by model editors, analysis tools, model management tools etc. Slices are useful if, e.g., only...
This paper describes a dynamical nonlinear data center model. It is a principle-based continuous time model, aimed at testing and evaluating control and optimization algorithms. The model is based on a module in data center used by RISE, Research Institute of Sweden. The data center modelled is a small scale slab floor data center. It contains four computer-room-air-handling units, two rows of five...
Mobile device features such as camera and other sensors are evolving rapidly nowadays. Supported by a reliable communications network, it raises new methods in information retrieval. Mobile devices can capture an image with its camera and pass it to the retrieval systems to get the information needed. This system, called Mobile Content-Based Image Retrieval (MCBIR), generally consists of two parts:...
The paper presents the Big data definition and the main characteristics description The model of association between entities and characteristics is constructed. The method of heterogeneous data sharing and bringing to relational data model “entity-characteristic” was created. The testing results of developed methods and algorithms are presented.
Most load balancing techniques implemented in current data centers tend to rely on a mapping from packets to server IP addresses through a hash value calculated from the flow five-tuple. The hash calculation allows extremely fast packet forwarding and provides flow `stickiness', meaning that all packets belonging to the same flow get dispatched to the same server. Unfortunately, such static hashing...
Smart Grids have nowadays gained wide diffusion and relevance. Due to the complexity of the grid, many Smart Grids laboratories have emerged over the years to provide partially virtualized environments for testing and co-simulation testbeds for the modern grid. However, the costs for setting-up Smart Grids laboratories are substantial, representing a barrier for newcomers and for educational purposes...
This paper proposes a new version of the Power of Two Choices, SQ(d), load balancing algorithm that improves the performance of the classical model based on the power of two choices randomized load balancing. This model considers jobs that arrive to a dispatcher as a Poisson stream of rate λn, λ 1, at a set of n servers. Using the power of two choices, the dispatcher chooses for each job some d constant...
It is well known that load balancing and low delivery communication cost are two critical issues in mapping requests to servers in Content Delivery Networks (CDNs). However, the trade-off between these two performance metrics has not been yet quantitatively investigated in designing efficient request mapping schemes. In this work, we formalize this trade-off through a stochastic optimization problem...
Typical traffic scheduling is to use special load balancers distributing client requests to different application servers, but this technique requires not only the dedicated hardware support, but also has many other shortcomings, such as high price, lack of flexibility and easier to become a single point of failure. This paper presents a cheap, flexible solution. Based on SDN, this method adopts the...
In large-scale data stream management systems, sampling rate of different sensors can change quickly in response to changed execution environment. However, such changes can cause significant load imbalance on the back-end servers, leading towards performance degradation and data loss. To address this challenge, in this paper, we present a model-driven middleware service (i.e., Arion) that uses a two-step...
Metal additive manufacturing (AM) processes are very complex and the process parameters required to fabricate quality parts can be very complicated and challenging to determine. For this reason, there is a continuous demand for AM simulations which can assist users to determine optimal process parameters in a timely manner. However, current commercial simulation packages are expensive and not designed...
We study a two-hop cache-aided network, where a layer of relay nodes connects a server and a set of end users, i.e., a combination network. We consider the case where both the relay nodes and the end users have caching capabilities. We provide upper and lower bounds which are applicable to any combination network, noting that previous work had focused on models where the relays do not have caches...
The unprecedented complexity of modern power systems has created a need for analyzing the interactions between different power system areas, which requires detailed physical models of all involved grids. However, a single institution seldom has access to enough information to build a complete model of a multi-area system. Additionally, such a model would be too labor-intensive to build and too computationally...
Network functions virtualization (NFV) is increasingly adopted by telecommunications (telecos) service providers for cost savings and flexible management. However, deploying virtual network functions (VNFs) in geo-distributed central offices (COs) is not straightforward. Unlike most existing centralized schemes in clouds, VNFs of a service chain usually need to be deployed in multiple COs due to limited...
Memcached is a widely used in-memory caching solution in large-scale searching scenarios. The most pivotal performance metric in Memcached is latency, which is affected by various factors including the workload pattern, the service rate, the unbalanced load distribution and the cache miss ratio. To quantitate the impact of each factor on latency, we establish a theoretical model for the Memcached...
Load balancing algorithms play a crucial role in delivering robust application performance in data centers and cloud networks. Recently, strong interest has emerged in Join-the-Idle-Queue (JIQ) algorithms, which rely on tokens issued by idle servers in dispatching tasks and outperform power-of-d policies. Specifically, JiQ strategies involve minimal information exchange, and yet achieve zero blocking...
Network Function Virtualization (NFV) is enabling the softwarization of traditional network services, commonly deployed in dedicated hardware, into generic hardware in form of Virtual Network Functions (VNFs), which can be located flexibly in the network. However, network load balancing can be critical for an ordered sequence of VNFs, also known as Service Function Chains (SFCs), a common cloud and...
Predicting resource requirements for cloud services is critical for dimensioning, anomaly detection and service assurance. We demonstrate a system for real-time estimation of the needed amount of infrastructure resources, such as CPU and memory, for a given service. Statistical learning methods on server statistics and load parameters of the service are used for learning a resource prediction model...
In this paper, we address cloud VoIP scheduling strategies to provide appropriate levels of quality of service to users, and cost to VoIP service providers. This bi-objective focus is reasonable and representative for real installations and applications. We conduct comprehensive simulation on real data of twenty three on-line non-clairvoyant scheduling strategies with fixed threshold of utilization...
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