Primary decomposition and the fractal nature of knot concordance

For each sequence of polynomials, P=(p_1(t),p_2(t),...), we define a characteristic series of groups, called the derived series localized at P. Given a knot K in S^3, such a sequence of polynomials arises naturally as the orders of certain submodules of the sequence of higher-order Alexander modules of K. These group series yield new filtrations of the knot concordance group that refine the (n)-solvable filtration of Cochran-Orr-Teichner. We show that the quotients of successive terms of these refined filtrations have infinite rank. These results also suggest higher-order analogues of the p(t)-primary decomposition of the algebraic concordance group. We use these techniques to give evidence that the set of smooth concordance classes of knots is a fractal set. We also show that no Cochran-Orr-Teichner knot is concordant to any Cochran-Harvey-Leidy knot.Comment: 60 pages, added 4 pages to introduction, minor corrections otherwise; Math. Annalen 201

Diagnosis and combined treatment of patients with locally advanced prostate cancer

Prostate cancer is one of the most urgent problems of modern oncology. The article provides an overview of the methods of treatment of locally advanced prostate cancer, comparative characteristics, the advantages of both independent and combined methods. The results of multicenter studies have been stated

On analyzing the intra-frame power saving potentials of the IEEE 802.16e downlink vertical mapping

Worldwide Interoperability for Microwave Access (WiMAX) is generally considered as a competitive candidate networking technology for the realization of the 4G vision. Among the key factors towards its successful and widespread deployment are the effective support of mobility and the provision of mechanisms for enabling service access at a high quality level in an efficient and cost-effective manner. Nonetheless, this effort should take into account and adequately address strict and severe energy limitations that the mobile devices are currently facing. Power saving constitutes an issue of vital importance, as mobile terminals continue to incorporate more and more functionalities and energy-hungry features in order to support the ever increasing user requirements and demands. The standard employs variations of power saving classes in a frame-to-frame basis, while recent power saving mechanisms proposed in related research literature limit their activity in whole frames, neglecting, thus, the intra-frame power saving capabilities. In this work, the intra-frame energy conservation potentials of the mobile WiMAX network are studied and a novel analytical approach is provided, focusing on the downlink direction where the bandwidth allocation involves idle intervals and dynamic inactivity periods. Specifically, we endeavour to accurately analyse the potential energy conservation capabilities in an intra-frame point of view, applying the well-known simple packing algorithm to distribute the available bandwidth to the various subscribers. Our analytical findings are thoroughly cross-validated via simulation, providing clear insights into the intra-frame energy reduction capabilities

The theta^+ baryon in soliton models: large Nc QCD and the validity of rigid-rotor quantization

A light collective theta+ baryon state (with strangeness +1) was predicted via rigid-rotor collective quantization of SU(3) chiral soliton models. This paper explores the validity of this treatment. A number of rather general analyses suggest that predictions of exotic baryon properties based on this approximation do not follow from large Nc QCD. These include an analysis of the baryon's width, a comparison of the predictions with general large Nc consistency conditions of the Gervais-Sakita-Dashen-Manohar type; an application of the technique to QCD in the limit where the quarks are heavy; a comparison of this method with the vibration approach of Callan and Klebanov; and the 1/Nc scaling of the excitation energy. It is suggested that the origin of the problem lies in an implicit assumption in the that the collective motion is orthogonal to vibrational motion. While true for non-exotic motion, the Wess-Zumino term induces mixing at leading order between collective and vibrational motion with exotic quantum numbers. This suggests that successful phenomenological predictions of theta+ properties based on rigid-rotor quantization were accidental.Comment: 19 pages; A shorter more readable versio

Creative professional users musical relevance criteria

Although known item searching for music can be dealt with by searching metadata using existing text search techniques, human subjectivity and variability within the music itself make it very difficult to search for unknown items. This paper examines these problems within the context of text retrieval and music information retrieval. The focus is on ascertaining a relationship between music relevance criteria and those relating to relevance judgements in text retrieval. A data-rich collection of relevance judgements by creative professionals searching for unknown musical items to accompany moving images using real world queries is analysed. The participants in our observations are found to take a socio-cognitive approach and use a range of content and context based criteria. These criteria correlate strongly with those arising from previous text retrieval studies despite the many differences between music and text in their actual content

In-medium pion weak decay constants

In nuclear matter, the pion weak decay constant is separated into the two components $f_t, f_s$ corresponding to the time and space components of the axial-vector current. Using QCD sum rules, we compute the two decay constants from the pseudoscalar-axial vector correlation function in the matter $i \int d^4x~ e^{ip\cdot x} < \rho| T[{\bar d}(x) i \gamma_5 u (x)~ {\bar u}(0) \gamma_\mu \gamma_5 d (0)] | \rho>$. It is found that the sum rule for $f_t$ satisfies the in-medium Gell-Mann--Oakes--Renner (GOR) relation precisely while the $f_s$ sum rule does not. The $f_s$ sum rule contains the non-negligible contribution from the dimension 5 condensate $_N + {1\over 8} _N$ in addition to the in-medium quark condensate. Using standard set of QCD parameters and ignoring the in-medium change of the pion mass, we obtain $f_t =105$ MeV at the nuclear saturation density. The prediction for $f_s$ depends on values of the dimension 5 condensate and on the Borel mass. However, the OPE constrains that $f_s/f_t \ge 1$, which does not agree with the prediction from the in-medium chiral perturbation theory. Depending on the value of the dimension 5 condensate, $f_s$ at the saturation density is found to be in the range $112 \sim 134$ MeV at the Borel mass $M^2 \sim 1$ GeV$^2$.Comment: 19 pages including two postscript figures, substantially revise

Theory of Two-Dimensional Josephson Arrays in a Resonant Cavity

We consider the dynamics of a two-dimensional array of underdamped Josephson junctions placed in a single-mode resonant cavity. Starting from a well-defined model Hamiltonian, which includes the effects of driving current and dissipative coupling to a heat bath, we write down the Heisenberg equations of motion for the variables of the Josephson junction and the cavity mode, extending our previous one-dimensional model. In the limit of large numbers of photons, these equations can be expressed as coupled differential equations and can be solved numerically. The numerical results show many features similar to experiment. These include (i) self-induced resonant steps (SIRS's) at voltages V = (n hbar Omega)/(2e), where Omega is the cavity frequency, and n is generally an integer; (ii) a threshold number N_c of active rows of junctions above which the array is coherent; and (iii) a time-averaged cavity energy which is quadratic in the number of active junctions, when the array is above threshold. Some differences between the observed and calculated threshold behavior are also observed in the simulations and discussed. In two dimensions, we find a conspicuous polarization effect: if the cavity mode is polarized perpendicular to the direction of current injection in a square array, it does not couple to the array and there is no power radiated into the cavity. We speculate that the perpendicular polarization would couple to the array, in the presence of magnetic-field-induced frustration. Finally, when the array is biased on a SIRS, then, for given junction parameters, the power radiated into the array is found to vary as the square of the number of active junctions, consistent with expectations for a coherent radiation.Comment: 11 pages, 8 eps figures, submitted to Phys. Rev

Carbon Nanotubes as Nanoelectromechanical Systems

We theoretically study the interplay between electrical and mechanical properties of suspended, doubly clamped carbon nanotubes in which charging effects dominate. In this geometry, the capacitance between the nanotube and the gate(s) depends on the distance between them. This dependence modifies the usual Coulomb models and we show that it needs to be incorporated to capture the physics of the problem correctly. We find that the tube position changes in discrete steps every time an electron tunnels onto it. Edges of Coulomb diamonds acquire a (small) curvature. We also show that bistability in the tube position occurs and that tunneling of an electron onto the tube drastically modifies the quantized eigenmodes of the tube. Experimental verification of these predictions is possible in suspended tubes of sub-micron length.Comment: 8 pages, 5 eps figures included. Major changes; new material adde

Yang-Lee Zeros of the Two- and Three-State Potts Model Defined on ϕ3\phi^3 Feynman Diagrams

We present both analytic and numerical results on the position of the partition function zeros on the complex magnetic field plane of the $q=2$ (Ising) and $q=3$ states Potts model defined on $\phi^3$ Feynman diagrams (thin random graphs). Our analytic results are based on the ideas of destructive interference of coexisting phases and low temperature expansions. For the case of the Ising model an argument based on a symmetry of the saddle point equations leads us to a nonperturbative proof that the Yang-Lee zeros are located on the unit circle, although no circle theorem is known in this case of random graphs. For the $q=3$ states Potts model our perturbative results indicate that the Yang-Lee zeros lie outside the unit circle. Both analytic results are confirmed by finite lattice numerical calculations.Comment: 16 pages, 2 figures. Third version: the title was slightly changed. To be published in Physical Review

An experience on natural sciences augmented reality contents for preschoolers

[EN] Early education is a key element for the future success of students in the education system. This work analyzes the feasibility of using augmented reality contents with preschool students (four and five years old) as a tool for improving their learning process. A quasi experimental design based on a nonequivalent groups posttest-only design was used. A didactic unit has been developed around the topic animals by the participant teachers. The control group followed all the didactic activities defined in the developed didactic materials, while the experimental group was provided in addition with some augmented reality contents. Results show improved learning outcomes in the experimental group with respect to the control group.The Spanish Ministry Economy and Competitiveness partially supported this work (Project ref. TIN2010-21296-C02-01).Cascales, A.; Laguna, I.; Pérez López, DC.; Perona Ruiz, PD.; Contero, M. (2013). An experience on natural sciences augmented reality contents for preschoolers. Lecture Notes in Computer Science. 8022:103-112. https://doi.org/10.1007/978-3-642-39420-1_12S1031128022Barnett, W.S.: Effectiveness of Early Educational Intervention. Science 333(6045), 975–978 (2011)OECD: Investing in high-quality early childhood education and care (ECEC). OECD Publishing, http://www.oecd.org/dataoecd/0/28/48980282.pdf (retrieved)Campos, P., Pessanha, S.: Designing Augmented Reality Tangible Interfaces for Kindergarten Children. In: Shumaker, R. (ed.) Virtual and Mixed Reality, HCII 2011, Part I. LNCS, vol. 6773, pp. 12–19. Springer, Heidelberg (2011)Lim, J., Kim, S.: A Study on Markerless AR-based Infant Education System using CBIR. Communications in Computer and Information Science 78, 52–58 (2010)Chen, C.H., Su, C.C., Lee, P.Y., Wu, F.G.: Augmented Interface for Children Chinese Learning Technologies. In: 7th IEEE International Conference on Advanced Learning Technologies, pp. 268–270. IEEE Press, New York (2007)Azuma, R.: A Survey of Augmented Reality. Presence: Teleoperators and Virtual Environments 6(1), 355–385 (1997)Winkler, T., Herczeg, M., Kritzenberger, H.: Mixed Reality Environments as Collaborative and Constructive Learning Spaces for Elementary School Children. In: Barker, P., Rebelsky, S. (eds.) Proceedings of World Conference on Educational Multimedia, Hypermedia and Telecommunications 2002, pp. 1034–1039. AACE, Chesapeake (2002)Hsieh, M.C., Lee, J.S.: AR Marker Capacity Increasing for Kindergarten English Learning. In: International Multi Conference of Engineers and Computer Scientists, vol. 1, pp. 663–666 (2008)Hsieh, M.C., Lin, H.C.K.: Interaction Design Based on Augmented Reality Technologies for English Vocabulary Learning. In: Wong, S.L., et al. (eds.) Proceedings of the 18th International Conference on Computers in Education, vol. 1, pp. 663–666. Asia-Pacific Society for Computers in Education (2010)Lee, H., Lee, J.: Mathematical Education Game Based on Augmented Reality. Technologies for E-Learning and Digital Entertainment, 442–450 (2008)Hyun, E., Choi, K., Kim, G.J., Han, J., Jo, M., Kim, N.: Delphi Survey on the Use of Robot Projector based Augmented Reality in Dramatic Activity for Young Children. International Journal of Digital Content Technology and its Applications 5(11), 272–282 (2011)Kim, H.M., Song, T.H., Jung, S.M., Kwon, K.H., Jeon, J.W.: Virtual Storyteller Using Marker Based AR and FPGA. In: IEEE 54th International Midwest Symposium on Circuits and Systems, pp. 1–4. IEEE Press, New York (2011)Dunleavy, M., Dede, C., Mitchell, R.: Affordances and Limitations of Immersive Participatory Augmented Reality Simulations for Teaching and Learning. Journal of Science Education and Technology 18, 7–22 (2009)Martín-Gutiérrez, J., Saorín, J.L., Contero, M., Alcañiz, M., Pérez-López, D., Ortega, M.: Design and validation of an augmented book for spatial abilities development in engineering students. Computers & Graphics 34(1), 77–91 (2010)Cook, T.D., Campbell, D.T., Day, A.: Quasi-experimentation: Design and Analysis Issues for Field Settings, pp. 19–21. Houghton Mifflin, Boston (1979)Buendía, L., Colás, P., Hernández-Pina, F.: Métodos de Investigación en Psicopedagogía. McGraw Hill, Madrid (1997