On the expected diameter, width, and complexity of a stochastic convex-hull

We investigate several computational problems related to the stochastic convex hull (SCH). Given a stochastic dataset consisting of $n$ points in $\mathbb{R}^d$ each of which has an existence probability, a SCH refers to the convex hull of a realization of the dataset, i.e., a random sample including each point with its existence probability. We are interested in computing certain expected statistics of a SCH, including diameter, width, and combinatorial complexity. For diameter, we establish the first deterministic 1.633-approximation algorithm with a time complexity polynomial in both $n$ and $d$. For width, two approximation algorithms are provided: a deterministic $O(1)$-approximation running in $O(n^{d+1} \log n)$ time, and a fully polynomial-time randomized approximation scheme (FPRAS). For combinatorial complexity, we propose an exact $O(n^d)$-time algorithm. Our solutions exploit many geometric insights in Euclidean space, some of which might be of independent interest

The diffuse X-ray spectrum from 14-200 keV as measured on OSO-5

The measurement of energy spectrum of the diffuse component of cosmic X-ray flux made on the OSO-5 spacecraft is described. The contributions to the total counting rate of the actively shielded X-ray detector are considered in some detail and the techniques used to eliminate the non-cosmic components are described. Positive values for the cosmic flux are obtained in seven energy channels between 14 and 200 keV and two upper limits are obtained between 200 and 254 keV. The results can be fitted by a power law spectrum. A critical comparison is made with the OSO-3 results. Conclusions show that the reported break in the energy spectrum at 40 keV is probably produced by an erroneous correction for the radioactivity induced in the detector on each passage through the intense charged particle fluxes in the South Atlantic anomaly

Identification of miR-379/miR-656 (C14MC) cluster downregulation and associated epigenetic and transcription regulatory mechanism in oligodendrogliomas

Introduction Although role of individual microRNAs (miRNAs) in the pathogenesis of gliomas has been well studied, their role as a clustered remains unexplored in gliomas. Methods In this study, we performed the expression analysis of miR-379/miR-656 miRNA-cluster (C14MC) in oligodendrogliomas (ODGs) and also investigated the mechanism underlying modulation of this cluster. Results We identified significant downregulation of majority of the miRNAs from this cluster in ODGs. Further data from The Cancer Genome Atlas (TCGA) also confirmed the global downregulation of C14MC. Furthermore, we observed that its regulation is maintained by transcription factor MEF2. In addition, epigenetic machinery involving DNA and histone-methylation are also involved in its regulation, which is acting independently or in synergy. The post- transcriptionally regulatory network of this cluster showed enrichment of key cancer-related biological processes such as cell adhesion and migration. Also, there was enrichment of several cancer related pathways viz PIK3 signaling pathway and glioma pathways. Survival analysis demonstrated association of C14MC (miR-487b and miR-409-3p) with poor progression free survival in ODGs. Conclusion Our work demonstrates tumor-suppressive role of C14MC and its role in pathogenesis of ODGs and therefore could be relevant for the development of new therapeutic strategies

Precise time and frequency intercomparison between NPL, India and PTB, Federal Republic of Germany via satellite symphonie-1

A time and frequency intercomparison experiment conducted using Earth stations in New Delhi, India and Raisting, FRG is described. The NPL clock was placed at New Delhi Earth Station and the Raisting Clock was calibrated with PTB/Primary standard via LORAN-C and travelling clocks. The random uncertainity of time comparisons, represented by two sample Allan Variance sigma (30 seconds), was less than 10 nanoseconds. The relative frequency difference between the NPL and Raisting Clocks, SNPL, RAIS, as measured over the 44 days period was found to be -15.7 x 10 to the -13th power. The relative frequency difference between PTB Primary Standard and Raisting Clock, SPTB, RAIS, during this period, was measured to be -22.8 x 10 to the -13th power. The relative frequency difference between NPL clock and PTB Primary Standard, SNPL, PTB, thus, is +7.1 x 10 to the -13th power. The clock rate (UTC, India) of +7.1 + or - 0.5 x 10 to the -13th power, agrees well with that obtained via VLF phase measurements over one year period and with USNO travelling clock time comparisons made in September, 1980

Documentation of the data analysis system for the gamma ray monitor aboard OSO-H

The programming system is presented which was developed to prepare the data from the gamma ray monitor on OSO-7 for scientific analysis. The detector, data, and objectives are described in detail. Programs presented include; FEEDER, PASS-1, CAL1, CAL2, PASS-3, Van Allen Belt Predict Program, Computation Center Plot Routine, and Response Function Programs

Decoupling a Cooper-pair box to enhance the lifetime to 0.2 ms

We present a circuit QED experiment in which a separate transmission line is used to address a quasi-lumped element superconducting microwave resonator which is in turn coupled to an Al/AlO$_{x}$/Al Cooper-pair box (CPB) charge qubit. In our measurements we find a strong correlation between the measured lifetime of the CPB and the coupling between the qubit and the transmission line. By monitoring perturbations of the resonator's 5.44 GHz resonant frequency, we have measured the spectrum, lifetime ($T_{1}$), Rabi, and Ramsey oscillations of the CPB at the charge degeneracy point while the CPB was detuned by up to 2.5 GHz . We find a maximum lifetime of the CPB was $T_{1} = 200\ \mu$s for $f = 4$ to 4.5 GHz. Our measured $T_{1}$'s are consistent with loss due to coupling to the transmission line, spurious microwave circuit resonances, and a background decay rate on the order of $5\times 10^{3}$ s$^{-1}$ of unknown origin, implying that the loss tangent in the AlO$_{x}$ junction barrier must be less than about $4\times 10^{-8}$ at 4.5 GHz, about 4 orders of magnitude less than reported in larger area Al/AlO$_{x}$/Al tunnel junctions

Prediksi Luasan Optimal Hutan Kota Sebagai Penyerap Gas Karbondioksida (CO2) Di Kota Medan

City is the center of government and human activities. The tendency of all activities centered in the city results increasing of city development. This impacts the reduction of Green Open Space especially the urban forest, the increasing of carbondioxide concentration and the reduction of oxygen in the air. Such condition can reduce the urban environment quality, because one of the functions of urban forest is to absorb carbondioxide. This study aims to analyze the needs of urban forest width based on the function of carbondioxide absorber in Medan up to 2050. The method used was by collecting primary and secondary datas, then data analysis was performed to determine the optimal width for urban forest. The results showed that in 2012 Medan city need urban forest width for carbondioxide absorber about 4.304,21 ha and in 2050 is 9.880,06 ha

Sikap dan Motivasi Remaja dalam Mengikuti Kesenian Tradisional Kuda Lumping di Pesawaran

This research aims to explain and describe the attitude and adolescent motivation in following traditional artistry of kuda lumping in Pesawaran. The problem of this research is how the attitude and adolescent motivation in following traditional artistry of kuda lumping in Pesawaran. The method of this research is descriptive. Data collecting technique use question form, interview, observation and documentation. The sample of this research amount 54 respondents. Based on the result of research which have been done, it can be seen that adolescent behave neutral to traditional artistry of kuda lumping and have good enough motivation in following traditional artistry of kuda lumping.Penelitian ini bertujuan untuk menjelaskan dan mendeskripsikan sikap dan motivasi remaja terhadap kesenian tradisional kuda lumping di Pesawaran. Rumusan masalah dalam penelitian ini adalah bagaimanakah sikap dan motivasi remaja terhadap kesenian tradisional kuda lumping di Pesawaran. Metode penelitian ini adalah deskriptif. Teknik pengumpulan data mengggunakan angket, wawancara, observasi dan dokumentasi. Sampel dalam penelitian ini berjumlah 54 responden. Berdasarkan hasil penelitian yang telah dilakukan bahwa remaja bersikap netral terhadap kesenian tradisional kuda lumping dan memiliki motivasi yang cukup baik dalam mengikuti kesenian tradisional kuda lumping