scholarly journals On Bandwidth Tiered Service

2009 ◽  
Vol 17 (6) ◽  
pp. 1780-1793 ◽  
Author(s):  
George N. Rouskas ◽  
Nikhil Baradwaj

Many network operators offer some type of tiered service, in which users may select only from a small set of service levels (tiers). Such a service has the potential to simplify a wide range of core network functions, allowing the providers to scale their operations efficiently. In this work, we study a number of problem variants related to service tier selection. Our contributions include: (1) a faster algorithm for obtaining optimal service tiers; (2) a new formulation and optimal algorithm to optimize jointly the number and magnitude of each service tier; and (3) the concept of ??TDM emulation?? in which all service tiers are multiples of the same (software-configurable) bandwidth unit, and a suite of algorithms to select jointly the basic unit and service tiers. Our work provides a systematic framework for reasoning about and tackling algorithmically the general problem of service tier selection, and has applications to a number of networking contexts, including access networks (e.g., determining the tiers for ADSL, cable modem networks or PONs) and core networks (e.g., LSP sizing for MPLS networks).

Agriculture ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 324 ◽  
Author(s):  
Huanyong Zhang ◽  
Huiyuan Xu ◽  
Xujin Pu

Preselling strategies have been a common marketing tool, but research on this selection is limited. Thus, we examine three pre-sale strategies of a manufacturer who produces and sells a seasonal product to a retailer: (1) supplier pre-sale strategy—the supplier carries out preselling by opening a direct channel; (2) retailer pre-sale strategy—the retailer purchases pre-sale products from the supplier and sells them in online and offline channels; and (3) joint pre-sale strategy—the retailer acts as a pre-sale platform, providing order information and pre-sale services. For each preselling mode, we construct the Stackelberg game model aiming to maximize profits and obtain optimal service levels and pricing decisions. We find that the two latter scenarios, that is, to cooperate with the retailer (retailer pre-sale and joint pre-sale strategies), could highly gain more profit for the supplier compared with the former. For the supplier, the joint pre-sale strategy will likely be the dominant strategy because of its wide-range applicability. On the contrary, the retailer is swaying between retailer pre-sale and joint pre-sale strategies under different conditions. For the supplier, leadership always guarantees a high profit, but if the joint pre-sale strategy is adopted, then the existence of a profit-sharing ratio will narrow the profit gap between the two players.


2020 ◽  
Author(s):  
Josep Arús-Pous ◽  
Atanas Patronov ◽  
Esben Jannik Bjerrum ◽  
Christian Tyrchan ◽  
Jean-Louis Reymond ◽  
...  

Molecular generative models trained with small sets of molecules represented as SMILES strings are able to generate large regions of the chemical space. Unfortunately, due to the sequential nature of SMILES strings, these models are not able to generate molecules given a scaffold (i.e. partially-built molecules with explicit attachment points). Herein we report a new SMILES-based molecular generative architecture that generates molecules from scaffolds and can be trained from any arbitrary molecular set. This is possible thanks to a new molecular set pre-processing algorithm that exhaustively cuts all combinations of acyclic bonds of every molecule, obtaining a large number of scaffold-decorations combinations. Moreover, it serves as a data augmentation technique and can be readily coupled with randomized SMILES to obtain even better results with small sets. Two examples showcasing the potential of the architecture in medicinal and synthetic chemistry are described: First, models were trained with a training set obtained from a small set of Dopamine Receptor D2 (DRD2) active modulators and were able to meaningfully decorate a wide range of scaffolds and obtain molecular series predicted active on DRD2. Second, a larger set of drug-like molecules from ChEMBL was selectively sliced using synthetic chemistry constraints (RECAP rules). Moreover, the resulting scaffold-decorations were filtered to only allow decorations that were fragment-like. This allowed models trained with this dataset to selectively decorate diverse scaffolds with fragments that were generally predicted to be synthesizable and attachable to the scaffold using known synthetic approaches. In both cases, the models were already able to decorate molecules using specific knowledge without the need to add it with other techniques, such as reinforcement learning. We envision that this architecture will become a useful addition to the already existent architectures for de-novo molecular generation.


Author(s):  
Anna Kuchciak

MUNICIPAL COUNCIL OF SENIORS - THE ROLE OF " THE VOICE OF EXPERIENCE" IN THE MATTERS OF LOCAL COMMUNITIESUnder the Act dated 11 October 2013 amending the Act on Municipal Self- Government, the ability to create municipal councils of seniors was introduced. The considered amendment is one of the wide range of legislative changes resulting from the process of population aging. The article attempts to assess how this optional collective body, aimed primarily at the civic activation of the elderly people and identification of their needs, works in the structure of the basic unit of the territorial system.


2012 ◽  
Vol 198-199 ◽  
pp. 1733-1738
Author(s):  
Xiao Wei Qin ◽  
Feng Chen

With the explosive growth of wireless applications, the subscribers’ requirements of QoS (Quality of Service) are increasing as well. In this paper, the upper bound of the tolerant delay of services in wireless access network is investigated, by mapping core network onto a cost-variable directed graph, where the cost is construed as the average service delay of the flows traveling in core network that depends on the current load. A multicommodity minimal cost flow mathematics problem is then derived and solved by Price-directive Decomposition and Lagrangian Relaxation. Simulations are carried out in two typical core networks and some valuable conclusions are gained.


2018 ◽  
Vol 10 (10) ◽  
pp. 1155-1165 ◽  
Author(s):  
Md. Jubaer Alam ◽  
Mohammad Rashed Iqbal Faruque ◽  
Rezaul Azim ◽  
Mohammad Tariqul Islam

AbstractA modified H-shaped metamaterial is imparted in this paper that has a multiple band coverage for reflection and transmission coefficient. The proposed structure exhibits triple band coverage for the permittivity and permeability. Two split ring resonators (SRR) are connected with the substantial H-shaped structure. The 12 × 12 mm2 structure has been printed on FR-4 and a correlation is made between the basic unit-cell and array structures. A comparison is made among 1 × 2, 2 × 2, and 4 × 4 array structures with 1 × 2, 2 × 2, and 4 × 4 unit-cell configurations to validate the performance of the proposed metamaterial. A great transmission coefficient having a band of 13 GHz with a 500 MHz band gap in the middle is demonstrated for all of these configurations. The effective parameters of the resonators cover C, X, and Ku bands independently with double-negative phenomena at X and Ku bands with a frequency range of about 2.5 GHz. The reflection and transmission coefficients of the unit cell are obtained by CST microwave studio. Having an auspicious design and wide range double-negative characteristics, this structure can be applied to satellite communication.


2018 ◽  
Vol 6 ◽  
pp. 421-435 ◽  
Author(s):  
Yan Shao ◽  
Christian Hardmeier ◽  
Joakim Nivre

Word segmentation is a low-level NLP task that is non-trivial for a considerable number of languages. In this paper, we present a sequence tagging framework and apply it to word segmentation for a wide range of languages with different writing systems and typological characteristics. Additionally, we investigate the correlations between various typological factors and word segmentation accuracy. The experimental results indicate that segmentation accuracy is positively related to word boundary markers and negatively to the number of unique non-segmental terms. Based on the analysis, we design a small set of language-specific settings and extensively evaluate the segmentation system on the Universal Dependencies datasets. Our model obtains state-of-the-art accuracies on all the UD languages. It performs substantially better on languages that are non-trivial to segment, such as Chinese, Japanese, Arabic and Hebrew, when compared to previous work.


2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Hongyi Xu ◽  
Ruoqian Liu ◽  
Alok Choudhary ◽  
Wei Chen

In designing microstructural materials systems, one of the key research questions is how to represent the microstructural design space quantitatively using a descriptor set that is sufficient yet small enough to be tractable. Existing approaches describe complex microstructures either using a small set of descriptors that lack sufficient level of details, or using generic high order microstructure functions of infinite dimensionality without explicit physical meanings. We propose a new machine learning-based method for identifying the key microstructure descriptors from vast candidates as potential microstructural design variables. With a large number of candidate microstructure descriptors collected from literature covering a wide range of microstructural material systems, a four-step machine learning-based method is developed to eliminate redundant microstructure descriptors via image analyses, to identify key microstructure descriptors based on structure–property data, and to determine the microstructure design variables. The training criteria of the supervised learning process include both microstructure correlation functions and material properties. The proposed methodology effectively reduces the infinite dimension of the microstructure design space to a small set of descriptors without a significant information loss. The benefits are demonstrated by an example of polymer nanocomposites optimization. We compare designs using key microstructure descriptors versus using empirically chosen microstructure descriptors as a demonstration of the proposed method.


Author(s):  
Husein Elkeshreu ◽  
Otman Basir

Many medical applications benefit from the diversity inherent in imaging technologies to obtain more reliable diagnoses and assessments. Typically, the images obtained from multiple sources are acquired at distinct times and from different viewpoints, rendering a multitude of challenges for the registration process. Furthermore, different areas of the human body require disparate registration functional capabilities and degrees of accuracy. Thus, the benefit attained from the image multiplicity hinges heavily on the imaging modalities employed as well as the accuracy of the alignment process.  It is no surprise then that a wide range of registration techniques has emerged in the last two decades. Nevertheless, it is widely acknowledged that despite the many attempts, no registration technique has been able to deliver the required accuracy consistently under diverse operating conditions.  This paper introduces a novel method for achieving multimodal medical image registration based on exploiting the complementary and competitive nature of the algorithmic approaches behind a wide range of registration techniques. First, a thorough investigation of a wide range of registration algorithms is conducted for the purpose of understanding and quantifying their registration capabilities as well as the influence of their control parameters. Subsequently, a supervised randomized machine learning strategy is proposed for selecting the best registration algorithm for a given registration instance, and for determining the optimal control parameters for such algorithm. Several experiments have been conducted to verify the capabilities of the proposed selection strategy with respect to registration reliability, accuracy, and robustness.


2015 ◽  
Vol 12 (7) ◽  
pp. 6799-6830 ◽  
Author(s):  
P. Greve ◽  
L. Gudmundsson ◽  
B. Orlowsky ◽  
S. I. Seneviratne

Abstract. Water availability is of major importance for a wide range of socio-economic sectors. Over land, the partitioning of precipitation (P) into evapotranspiration (E) and runoff (Q) is the key process to assess hydrological conditions. For climatological averages, the Budyko framework provides a simple first order relationship to estimate the evaporative index E / P as a function of the aridity index (Ep / P, with Ep denoting potential evaporation). However, a major downside of the Budyko framework is its limitation to steady state conditions, being a result of the assumption of a closed land water balance. Nonstationary processes coming into play at other than mean annual catchment scales are thus not represented. Here we propose an analytically derived new formulation of the Budyko curve including an additional parameter being implicitly related to the nonlinear storage term of the land water balance. The new framework is comprehensively analysed, showing that the additional parameter leads to an upward rotation of the original supply limit and therefore implicitly represents the amount of additional water available for evaporation. The obtained model is further validated using standard datasets of P, E and Ep. It is shown that the model is capable to represent first-order seasonal dynamics within the hydroclimatological system.


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