10,016 research outputs found

    Scale-free network growth by ranking

    Full text link
    Network growth is currently explained through mechanisms that rely on node prestige measures, such as degree or fitness. In many real networks those who create and connect nodes do not know the prestige values of existing nodes, but only their ranking by prestige. We propose a criterion of network growth that explicitly relies on the ranking of the nodes according to any prestige measure, be it topological or not. The resulting network has a scale-free degree distribution when the probability to link a target node is any power law function of its rank, even when one has only partial information of node ranks. Our criterion may explain the frequency and robustness of scale-free degree distributions in real networks, as illustrated by the special case of the Web graph.Comment: 4 pages, 2 figures. We extended the model to account for ranking by arbitrarily distributed fitness. Final version to appear on Physical Review Letter

    Fault identification using multidisciplinary techniques at the Mars/Uranus Station antenna sites

    Get PDF
    A fault investigation was performed at the Mars and Uranus antenna sites at the Goldstone Deep Space Communications Complex in the Mojave desert. The Mars/Uranus Station consists of two large-diameter reflector antennas used for communication and control of deep-space probes and other missions. The investigation included interpretation of Landsat thematic mapper scenes, side-looking airborne radar transparencies, and both color-infrared and black-and-white aerial photography. Four photolineaments suggestive of previously undocumented faults were identified. Three generally discrete morphostratigraphic alluvial-fan deposits were also recognized and dated using geomorphic and soil stratigraphic techniques. Fourteen trenches were excavated across the four lineaments; the trenches show that three of the photolineaments coincide with faults. The last displacement of two of the faults occurred between about 12,000 and 35,000 years ago. The third fault was judged to be older than 12,000 years before present (ybp), although uncertainty remains. None of the surface traces of the three faults crosses under existing antennas or structures; however, their potential activity necessitates appropriate seismic retrofit designs and loss-prevention measures to mitigate potential earthquake damage to facilities and structures

    The dynamics of loop formation in a semiflexible polymer

    Get PDF
    The dynamics of loop formation by linear polymer chains has been a topic of several theoretical/experimental studies. Formation of loops and their opening are key processes in many important biological processes. Loop formation in flexible chains has been extensively studied by many groups. However, in the more realistic case of semiflexible polymers, not much results are available. In a recent study (K. P. Santo and K. L. Sebastian, Phys. Rev. E, \textbf{73}, 031293 (2006)), we investigated opening dynamics of semiflexible loops in the short chain limit and presented results for opening rates as a function of the length of the chain. We presented an approximate model for a semiflexible polymer in the rod limit, based on a semiclassical expansion of the bending energy of the chain. The model provided an easy way to describe the dynamics. In this paper, using this model, we investigate the reverse process, i.e., the loop formation dynamics of a semiflexible polymer chain by describing the process as a diffusion-controlled reaction. We perform a detailed multidimensional analysis of the problem and calculate closing times for a semiflexible chain which leads to results that are physically expected. Such a multidimensional analysis leading to these results does not seem to exist in the literature so far.Comment: 37 pages 4 figure

    Perancangan Mekanisme Penggerak pada Mesin Pembilah Bambu

    Full text link
    Bamboo is widely used as a product application material. More and more enthusiasts of products produced with bamboo laminate materials require special equipment with good performance for production. The existing bamboo laminate production equipment still requires much innovation for that purpose, which required improvement and addition of mechanism to improve its performance. The addition of a motion mechanism to the bamboo splitting tool improved the tool performance by 54%, and decrease in rolling time for bamboo from 23 seconds to 0.85 seconds. Increased performance of bamboo splitter will have a positive impact on production costs for small and medium enterprises, thereby increasing profits and increasing the competitiveness of products

    Penerapan Teknopreneurship pada Proses Pengawetan Bambu untuk Sektor USAha Kecil Menengah

    Full text link
    Bamboo is a new favourite material in the world of eco buildings in Indonesia. Design innovation of buildings will impact the high demand for bamboo that must be balanced with the rate of production in preserved bamboo supply. Existing problems in small and medium enterprises will be overcome by applying technopreneursip. Among them is by developing the tools that will help in improving the production. The application of technology must be balanced with education to small medium enterprises owner and the labor. Preservation by the boucherie-morisco method can increase production by the same amount of labor and time by 2.8 times than Vertical Soak Diffusion Method. Technologically supported enterprises will further strengthen the bargaining position in the bamboo supply business. The partnership pattern between academia and small and medium business sector will create synergy in developing technopreneurship in Indonesian grassroots

    Evaluasi Penempatan Lokasi Jembatan Penyeberangan di Kota Pekanbaru (Studi Kasus Implementasi Perda Nomor 2 Tahun 2009)

    Full text link
    Increassingly mobility in Pekanbaru demands facility preparation for pedestrian such an overpass. The purpose is to help pedestrian to cross the road safely and comfortable. Beside that an overcross also can minimize traffic jam and minimize accident over the road. In fact, 11 overcross which spread in Pekanbaru couldnt solve circulation transportation problem because overpass placement location is not appropriate.The concept of theory is Evaluation. Evaluatin consist of effectiveness, efficient, adequace, equity, responsiveness, and accuracy. The genre of tihs research is qualitative with descriptive method. In data collecting the writer applies interview technique observation and library research. By using ke informan and infrman as information sources.Based on tehe result of this research by observation and interview, conclude that overpass placement location in Pekanbaru is not maximal, less for human resources to run the policy, and weak sanction given.Key Word : Theory Of Evaluation, Overpas

    Pengaruh Event Sponsorship terhadap Brand Image Rokok Sampoerna A-mild (Survei pada Mahasiswa Fakultas Ilmu Administrasi Universitas Brawijaya)

    Full text link
    The purpose of this research was to determine the influence of event sponsorship to sampoerna a-mild brand image. Research type used is explanatory research with quantitative approach and using survey method. Sampel in this research are 96 respondents using accidental sampling. Questionnaire date research collection. Date analysis used is descriptive analysis and simple linear regression analysis. Simple linear regression analysis result shows that independent variable Event Sponsorship (X) influence to dependent variable Brand Image (Y). It is shown by probability value t (0,000) < α = 0.05. Contribution from independent variable can be seen from the coefficient regression value of 46.5%, while rest 53.5% influenced by other variable which is not studied in this research

    The puzzling symbiotic X-ray system 4U1700+24

    Full text link
    Symbiotic X-ray binaries form a subclass of low-mass X-ray binary systems consisting of a neutron star accreting material from a red giant donor star via stellar wind or Roche lobe overflow. Only a few confirmed members are currently known; 4U 1700+24 is a good candidate as it is a relatively bright X-ray object, possibly associated with the late-type star V934 Her. We analysed the archive {\it XMM}-Newton and Swift/XRT observations of 4U 1700+24 in order to have a uniform high-energy (0.3100.3-10 keV) view of the source. We confirmed the existence of a red-shifted O VIII Ly-α\alpha transition (already observed in the 2002 {\it XMM}-Newton data) in the high-resolution spectra collected via the RGS instruments. The red-shift of the line is found in all the analysed observations and, on average, it was estimated to be 0.009\simeq 0.009. We also observed a modulation of the centroid energy of the line on short time scales (a few days) and discuss the observations in the framework of different scenarios. If the modulation is due to the gravitational red-shift of the neutron star, it might arise from a sudden re-organization of the emitting XX-ray matter on the scale of a few hundreds of km. Alternatively, we are witnessing a uni-polar jet of matter (with typical velocity of 100040001000-4000 km s1^{-1}) possibly emitted by the neutron star in an almost face-on system. The second possibility seems to be required by the apparent lack of any modulation in the observed XX-ray light curve. We also note also that the low-resolution spectra (both {\it XMM}-Newton and Swift/XRT in the 0.3100.3-10 keV band) show the existence of a black body radiation emitted by a region (possibly associated with the neutron star polar cap) with typical size from a few tens to hundreds of meters. The size of this spot-like region reduces as the overall luminosity of 4U 1700+24 decreases.Comment: In press on A&
    corecore