Adaptive Resource Management Platform for Reconfigurable Networks

Users’ expectations towards technology, in terms of quality, service availability and accessibility are ever increasing. Aligned with this, the wireless world is rapidly moving towards the next generation of systems, featuring cooperating and reconfiguring capabilities for coexisting (and upcoming) Radio Access Technologies (RATs), so that to improve connectivity and reduce costs. In this respect, conventional planning and management techniques ought to be replaced by advanced schemes that consider multidimensional characteristics, increased complexity and high speeds. To this effect, means are needed capable to support scalability and to cater for advanced service features, provided to users at high rates and cost-effectively. This article provides a scheme to optimize resource management in future systems, by describing a platform that accommodates engineering mechanisms that deal with dynamic, demand driven planning and managing of spectrum and radio resources in reconfigurable networks. To do so, it first discusses the fundamentals and the approach followed in the proposed architecture and then investigates the basic functional modules. The architecture is validated through a set of use-cases that exemplify the operational applicability and efficiency in a wide range of communication scenarios.

Gene expressions of Collagen type I,ALP and BMP-4 in osteo-inductive BCP implants show similar pattern to that of natural healing bones

Osteo-inductive materials give rise to ectopic bone formation in vivo either in muscles or in subcutaneous tissue. However, the underlying molecular mechanism is totally unclear. To investigate the expression pattern of bone related genes in osteo-inductive materials, we performed quantitative PCR (qPCR) to detect the expressions of type I collagen, alkaline phosphatase (ALP) and bone morphogenetic protein 4 (BMP-4) in biphasic calcium phosphate (BCP) ceramics implanted in dorsal muscle of dogs. Bone formation in mandibular alveolus defects served as controls showing the expression patterns of these genes in natural healing bones. Histological examinations were performed to show the bone formation in osteo-inductive BCP implants. Data of qPCR indicated that all tested genes had a similar expression pattern with two peaks during the bone formation either in BCP implants or natural healing bones. Type I collagen and ALP were expressed at lower levels with delayed peak in BCP implant than that in natural healing bone. Higher BMP-4 expression level was detected in BCP ceramic implant than in natural healing bone at all the time points. These results demonstrated that expression patterns of bone-related genes in the inductive bone formation are similar to that of natural healing bone formation. As these three genes are important parameters for osteoblast activity in bone formation, our data provide clue to uncover the molecular mechanism of bone formation in osteo-inductive materials.     

Comment on the paper “Controlling intermetallic compound formation reaction between Sn and Ni-P by Zn addition” by X.F. Zhang, J.D. Guo, J.K. Shang, J. Alloys Compd. 479 (2009) 505–510

Zhang et al. recently reported about the formation of Ni₄(Sn,Zn) in the interlayer of a Sn–Zn/Ni(P) solder joint. This phase is claimed to be based on the binary Ni₄Sn phase. However, this phase as described in the literature by Mikulas and Thomassen, was ruled out for any existing phase diagram version. It could be proved that the diffraction pattern from Mikulas and Thomassen was composed of Ni and Ni₃Sn low-temperature phase. Thus the interpretation of their X-ray diffraction results is incorrect and the phase “Ni₄Sn” is an artefact. The indexing of Ni₄(Sn,Zn) by Zhang et al. is based on this artefact and therefore is incorrect, too. Furthermore, Tai et al. investigated IMC formation in Sn–3Ag–0.5Cu/Ni–8Zn–8P joints and could not observe any interdiffusion of Zn as stated by Zhang et al.     

Univariate statistical analysis of environmental (compositional) data: Problems and possibilities

For almost 30 years it has been known that compositional (closed) data have special geometrical properties. In environmental sciences, where the concentration of chemical elements in different sample materials is investigated, almost all datasets are compositional. In general, compositional data are parts of a whole which only give relative information. Data that sum up to a constant, e.g. 100 wt.%, 1,000,000 mg/kg are the best known example. It is widely neglected that the “closure” characteristic remains even if only one of all possible elements is measured, it is an inherent property of compositional data. No variable is free to vary independent of all the others.Existing transformations to “open” closed data are seldom applied. They are more complicated than a log transformation and the relationship to the original data unit is lost. Results obtained when using classical statistical techniques for data analysis appeared reasonable and the possible consequences of working with closed data were rarely questioned. Here the simple univariate case of data analysis is investigated. It can be demonstrated that data closure must be overcome prior to calculating even simple statistical measures like mean or standard deviation or plotting graphs of the data distribution, e.g. a histogram. Some measures like the standard deviation (or the variance) make no statistical sense with closed data and all statistical tests building on the standard deviation (or variance) will thus provide erroneous results if used with the original data.     

Vom Damaststahl zum Scharsachstahl

Verbesserung der Schwertklingen durch Damaszierung. Nachweis des Übergangs auf eine andere Schmiedetechnik in der Ritterzeit (11. bis 14. Jh.) an Hand von zwölf mittelalterlichen Schwertern, die aus in der Steiermark hergestellten Stählen nach der Gärbtechnik gefertigt wurden. Kennzeichnung des sogenannten Scharsachstahles mit rd. 0,80% C und seine Verarbeitung zu Schwertklingen mit hoher Elastizität.     

The development of peat-oil (POM) and peat-alcohol (PAM) slurries as alternative fuels

The preparation and evaluation of peat/No. 2 fuel oil mixtures (POM) and peat/methanol mixtures (PAM) is described. POM and PAM prepared using North Carolina peat and having varied peat loadings, peat moisture contents, and peat particle sizes have been studied by measuring slurry sedimentation ratios and drain times from sedimentation tubes. The peat moisture content was particularly crucial in forming stable slurries. The effect of a variety of additives at 0.5–1.0 wt.% on sedimentation ratios, drain times, and viscosities was studied. Calorimetric studies of several PAM and POM slurries as well as preliminary combustion tests of POM slurries in a salamander burner are also reported.     

17-4PH不锈钢纳米析出物的磁小角中子散射研究

本文充分发挥中子对磁灵敏、穿透力强等技术优势,利用加载磁场小角中子散射实验技术研究核电站实际服役14年的阀杆17 4PH不锈钢样品。结果表明,与不加磁场时相比,加载磁场条件下二维散射图谱呈明显各向异性,在散射矢量垂直于磁场方向上散射强度显著增强。利用多分散球模型对数据进行拟合,结合原子探针实验结果分析得出,衬度的增加降低了Cu析出物周围元素分布不均匀对散射的相对贡献,从而有助于更加准确地获得Cu纳米析出物的尺寸。     

An effective quantum potential for particle–particle interactions in three-dimensional semiconductor device simulations

The classical Coulomb potential and force can be calculated efficiently using fast multi-pole methods. Effective quantum potentials, however, describe the physics of electron transport in semiconductors more precisely. Such an effective quantum potential was derived previously for the interaction of an electron with a barrier for use in particle-based Monte Carlo semiconductor device simulators. The method is based on a perturbation theory around thermodynamic equilibrium and leads to an effective potential scheme in which the size of the electron depends upon its energy and which is parameter-free. Here we extend the method to electron-electron interactions and show how the effective quantum potential can be evaluated efficiently in the context of many-body problems. Finally several examples illustrate how the momentum of the electrons changes the classical potential.     

Adapted random sampling patterns for accelerated MRI

Objective  

Variable density random sampling patterns have recently become increasingly popular for accelerated imaging strategies, as they lead to incoherent aliasing artifacts. However, the design of these sampling patterns is still an open problem. Current strategies use model assumptions like polynomials of different order to generate a probability density function that is then used to generate the sampling pattern. This approach relies on the optimization of design parameters which is very time consuming and therefore impractical for daily clinical use.