The structure and electronic transport properties of polymerderived pristine and boron-doped silicon carbonitride ceramics have been studied, with particular emphasis on understanding the effect of annealing treatments. Structural analysis using the radial distribution function formalism showed that the local structure is comprised of basic building blocks of Si tetrahedra with B, C, and N at the corners. Comparison of the electrical properties of pristine and boron-doped ceramics shows that boron doping leads to enhanced p-type conductivity, with a small positive thermopower. The postpyrolysis annealing treatments at elevated temperatures have a significant effect on the conductivity. The conductivity variation with temperature for these ceramics shows Mott's variable range hopping (VRH) behavior, characteristic of a highly defective semiconductor.

We present the four-year survey results of monthly submillimeter monitoring of eight nearby (<500 pc) starforming regions by the JCMT Transient Survey. We apply the Lomb-Scargle Periodogram technique to search for and characterize variability on 295 submillimeter peaks brighter than 0.14 Jy beam −1 , including 22 disk sources (Class II), 83 protostars (Class 0/I), and 190 starless sources. We uncover 18 secular variables, all of them protostars. No single-epoch burst or drop events and no inherently stochastic sources are observed. We classify the secular variables by their timescales into three groups: Periodic, Curved, and Linear. For the Curved and Periodic cases, the detectable fractional amplitude, with respect to mean peak brightness, is ∼4% for sources brighter than ∼0.5 Jy beam −1 . Limiting our sample to only these bright sources, the observed variable fraction is 37% (16 out of 43). Considering source evolution, we find a similar fraction of bright variables for both Class 0 and Class I. Using an empirically motivated conversion from submillimeter variability to variation in mass accretion rate, six sources (7% of our full sample) are predicted to have years-long accretion events during which the excess mass accreted reaches more than 40% above the total quiescently accreted mass: two previously known eruptive Class I sources, V1647 Ori and EC 53 (V371 Ser), and four Class 0 sources, HOPS 356, HOPS 373, HOPS 383, and West 40. Considering the full protostellar ensemble, the importance of episodic accretion on few years timescale is

Temporal data mining is the activity of finding interesting correlations or patterns in large temporal data sets. On the other hand, utility mining aims at identifying the itemsets with high utilities. In 2006, Tseng et al. introduced the temporal utility mining which is extended from both temporal association rule mining and utility mining. In this study, we investigated the incremental utility mining which can identify all high temporal utility itemsets in a specified time period on an incremental transaction database. Two efficient algorithms, Incremental Utility Mining (IUM) and Fast Incremental Utility Mining (FIUM), were proposed. The experimental results also showed that both algorithms are efficient.

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