Cell loss dynamics and output process in a finite-buffer discrete-time queue with correlated arrivals

This paper analyzes the performance of an ATM switching node considering cell arrival correlation. An ATM switching node is modeled as a discrete-time finite-buffer queue. Cell arrivals are assumed to follow a semi-Markovian process, where the number of cell arrivals in a lot depends on the states of the underlying (M-state) Markov chain in the current and previous slots. This paper presents analyses for various characteristics of the cell loss, as well as the distribution function of the cell output process from an ATM switching node. Obtained results include the cell loss probability, the consecutive loss probability, the distribution of loss period lengths, the joint distribution of successive cell interdeparture times, and the distribution of busy and idle periods. Through the numerical results, it is shown that both the correlation and the variation of cell arrivals significantly affect the cell loss and the output process characteristics

Commuting difference operators arising from the elliptic C_2^{(1)}-face model

We study a pair of commuting difference operators arising from the elliptic C_2^{(1)}-face model. The operators, whose coefficients are expressed in terms of the Jacobi's elliptic theta function, act on the space of meromorphic functions on the weight space of the C_2 type simple Lie algebra. We show that the space of functions spanned by the level one characters of the affine Lie algebra sp(4,C) is invariant under the action of the difference operators.Comment: latex2e file, 19 pages, no figures; added reference

Direct observation of magnetic domains in phase separated Nd0.7Ca0.3MnO3 single crystals

The magnetic properties of single-crystalline Nd0.7Ca0.3MnO3 were studied with both macroscopic and microscopic probes. The magnetization shows large irreversibility behavior between zero-field-cooled and field-cooled data at low field, suggesting a phase separation driven by competition between ferromagnetic and antiferromagnetic phases. The scanning superconducting quantum interference device microscope observations under zero field gave clear evidence that the compound includes ferromagnetic regions as the ground state below Tc. It was also found that two different phase-separated states appear, depending on temperature. At T∼125 K, weak but finite spontaneous magnetization develops, while the magnetization is abruptly enhanced below 95 K, possibly reflecting an increase of the volume fraction of the ferromagnetic region. The present results support the phase separation scenario that fine ferromagnetic particles embedded in an antiferromagnetic matrix are magnetostatically coupled to each other to form a network of macroscopic sizes

Do people who highly value happiness tend to ruminate?

Previous studies have suggested that an extremely strong desire for happiness might ironically reduce a person’s well-being, particularly among Western people. According to the goal progress theory and the theory of valuing happiness, rumination might explain the relationship between valuing happiness and well-being. Based on these theoretical rationales, this study examined the following hypotheses: (1) valuing happiness is significantly associated with rumination, (2) people who experience low life stress have a stronger association between valuing happiness and rumination, and (3) people with more interdependent self-construal have a weaker association between valuing happiness and rumination. University students in Japan participated in a cross-sectional study (N = 350; Study 1) and a 4-weeks longitudinal study (N = 329; Study 2). They responded to a packet of questionnaires assessing valuing happiness, trait rumination, depressive symptoms, negative events, and interdependent self-construal. Consistent with our hypothesis, valuing happiness was concurrently and longitudinally associated with increased rumination after controlling for depressive symptoms. However, negative events did not moderate the association between valuing happiness and rumination. Furthermore, Study 1, but not Study 2, indicated that the association between valuing happiness and rumination was stronger among students with highly interdependent self-construal than those with less interdependent self-construal. The preset findings indicated that valuing happiness might be a factor that perpetuates rumination. More sophisticated evidence on the influence of valuing happiness on rumination can lead to effective psychotherapies for decreasing rumination and depression

Transition in electron scattering mechanism in atomic layer deposited Nb:TiO2 thin films

We characterized transport and optical properties of atomic layer deposited Nb:TiO2 thin films on glass substrates. These promising transparent conducting oxide (TCO) materials show minimum resistivity of 1.0 × 10−3 Ω cm at 300 K and high transmittance in the visible range. Low-temperature (2–300 K) Hall measurements and the Drude fitting of the Vis-NIR optical spectra indicate a transition in the scattering mechanism from grain boundary scattering to intra-grain scattering with increasing Nb content, thus underlining enhancement of the grain size in the low doping regime as the key for further improved TCO properties.Peer reviewe