1,460 research outputs found

    Performance of Direct Displacement Based Design on Regular Concrete Building Against Indonesian Response Spectrum

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    The renewal of Indonesian seismic code from SNI 1726-2002 into SNI 1726-2012 brings significant change in the design spectrum. Focused on several regular plan concrete building which have been design using displacement based design method, the aim of this study is to verify their performance using nonlinear time history analysis based on parameters: drift, damage indices, and plastic mechanism determined by FEMA 356. The excitation is spectrum consistent accelerogram based on El-Centro 1940 N-S, to match with the new Indonesian response spectrum for soft soil in low- and high intensity area. It is found that the code-designed buildings are not suitable for the targeted design of level-2 with maximum drift of 2.5% due to major. This is caused by improper selection of SNI spectrum as the design major earthquake. In fact, it is only equivalent to small earthquake. Although buildings survive up to a very rare earthquake without collapse but they suffer excessive damage and rotation due to small- to major-earthquake. The capacity design procedure is able to maintain ductile mechanism, but some columns experience yielding at prohibited locations

    Evaluasi Kinerja Bangunan Yang Didesain Secara Ddbd Terhadap Gempa Rencana

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    Salah satu dari prosedur untuk mendesain bangunan terhadap gempa adalah Direct Displacement Based Design (DDBD) yang merupakan varian dari Displacement Based Design (DBD). Beberapa penelitian telah menggunakan DDBD dengan beban gempa sesuai SNI 2002 dan 2012. Semuanya menunjukan bahwa DDBD memiliki kinerja yang sangat baik. Padahal beban rencana tersebut jauh lebih rendah daripada target desain yang diharapkan (gempa dengan periode ulang 2500 tahun) Oleh karena itu pengujian dilakukan cara non-linier time history analysis dengan gempa El-Centro 1940 N-S yang sudah dimodifikasi untuk wilayah Surabaya dan Jayapura menurut SNI 1726-2012 untuk berbagai periode ulang gempa. Untuk mengetahui kinerja bangunan tersebut, digunakan parameter drift, momen rotasi dan mekanisme keruntuhan. Hasil penelitian ini menunjukan bahwa kinerja bangunan sangat baik untuk level gempa tinggi (2500 tahun). Dari letak sendi plastis yang terjadi, dapat disimpulkan bahwa capacity design pada bangunan tidak terjamin dengan sempurna, karena muncul sendi plastis pada kolom selain pada kolom lantai paling bawah dan kolom lantai paling atas. Namun side sway mechanism tetap terjamin, karena balok selalu leleh terlebih dahulu sebelum kolom

    Using impression data to improve models of online social influence

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    Influence, the ability to change the beliefs and behaviors of others, is the main currency on social media. Extant studies of influence on social media, however, are limited by publicly available data that record expressions (active engagement of users with content, such as likes and comments), but neglect impressions (exposure to content, such as views) and lack “ground truth” measures of influence. To overcome these limitations, we implemented a social media simulation using an original, web-based micro-blogging platform. We propose three influence models, leveraging expressions and impressions to create a more complete picture of social influence. We demonstrate that impressions are much more important drivers of influence than expressions, and our models accurately identify the most influential accounts in our simulation. Impressions data also allow us to better understand important social media dynamics, including the emergence of small numbers of influential accounts and the formation of opinion echo chambers

    Fitting pseudo-Sérsic (Spergel) light profiles to galaxies in interferometric data: The excellence of the uυ-plane

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    Modern (sub)millimeter interferometers, such as ALMA and NOEMA, offer high angular resolution and unprecedented sensitivity. This provides the possibility to characterize the morphology of the gas and dust in distant galaxies. To assess the capabilities of the current software in recovering morphologies and surface brightness profiles in interferometric observations, we tested the performance of the Spergel model for fitting in the uυ-plane, which has been recently implemented in the IRAM software GILDAS (uv_fit). Spergel profiles provide an alternative to the Sérsic profile, with the advantage of having an analytical Fourier transform, making them ideal for modeling visibilities in the uυ-plane. We provide an approximate conversion between the Spergel index and the Sérsic index, which depends on the ratio of the galaxy size to the angular resolution of the data. We show through extensive simulations that Spergel modeling in the uυ-plane is a more reliable method for parameter estimation than modeling in the image plane, as it returns parameters that are less affected by systematic biases and results in a higher effective signal-to-noise ratio. The better performance in the uυ-plane is likely driven by the difficulty of accounting for a correlated signal in interferometric images. Even in the uυ-plane, the integrated source flux needs to be at least 50 times larger than the noise per beam to enable a reasonably good measurement of a Spergel index. We characterized the performance of Spergel model fitting in detail by showing that parameter biases are generally low (<10%) and that uncertainties returned by uv_fit are reliable within a factor of two. Finally, we showcase the power of Spergel fitting by reexamining two claims of extended halos around galaxies from the literature, showing that galaxies and halos can be successfully fitted simultaneously with a single Spergel model

    Comparison of On-Site Versus Remote Mobile Device Support in the Framingham Heart Study Using the Health eHeart Study for Digital Follow-up: Randomized Pilot Study Set Within an Observational Study Design

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    BACKGROUND: New electronic cohort (e-Cohort) study designs provide resource-effective methods for collecting participant data. It is unclear if implementing an e-Cohort study without direct, in-person participant contact can achieve successful participation rates. OBJECTIVE: The objective of this study was to compare 2 distinct enrollment methods for setting up mobile health (mHealth) devices and to assess the ongoing adherence to device use in an e-Cohort pilot study. METHODS: We coenrolled participants from the Framingham Heart Study (FHS) into the FHS-Health eHeart (HeH) pilot study, a digital cohort with infrastructure for collecting mHealth data. FHS participants who had an email address and smartphone were randomized to our FHS-HeH pilot study into 1 of 2 study arms: remote versus on-site support. We oversampled older adults (age \u3e /=65 years), with a target of enrolling 20% of our sample as older adults. In the remote arm, participants received an email containing a link to enrollment website and, upon enrollment, were sent 4 smartphone-connectable sensor devices. Participants in the on-site arm were invited to visit an in-person FHS facility and were provided in-person support for enrollment and connecting the devices. Device data were tracked for at least 5 months. RESULTS: Compared with the individuals who declined, individuals who consented to our pilot study (on-site, n=101; remote, n=93) were more likely to be women, highly educated, and younger. In the on-site arm, the connection and initial use of devices was \u3e /=20% higher than the remote arm (mean percent difference was 25% [95% CI 17-35] for activity monitor, 22% [95% CI 12-32] for blood pressure cuff, 20% [95% CI 10-30] for scale, and 43% [95% CI 30-55] for electrocardiogram), with device connection rates in the on-site arm of 99%, 95%, 95%, and 84%. Once connected, continued device use over the 5-month study period was similar between the study arms. CONCLUSIONS: Our pilot study demonstrated that the deployment of mobile devices among middle-aged and older adults in the context of an on-site clinic visit was associated with higher initial rates of device use as compared with offering only remote support. Once connected, the device use was similar in both groups

    You Can?t Win If You Don?t Fight: The Role of Regime Type in Counterinsurgency Outbreaks and Outcomes

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    What effect, if any, does democracy have on outcomes of counterinsurgency wars? Previous studies have provided inconclusive answers mainly because of the challenges involved in testing the question empirically: First, insurgencies are not accidental and the anticipated outcomes also affect whether they break out in the first place. Second, regimes are non-random and their determinants can also affect insurgency incidence and its outcomes. Moreover, different aspects of democracy can have opposite effects on the government's chances of winning. I address these challenges by conducting a critical test to distinguish between different causal mechanisms. I find that domestic institutions that are associated with public goods provision make insurgency onsets less likely. I also show that once we control for this selection effect, domestic political institutions do not influence insurgency outcomes

    Noema formIng Cluster survEy (NICE): Discovery of a starbursting galaxy group with a radio-luminous core at z=3.95

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    The study of distant galaxy groups and clusters at the peak epoch of star formation is limited by the lack of a statistically and homogeneously selected and spectroscopically confirmed sample. Recent discoveries of concentrated starburst activities in cluster cores have opened a new window to hunt for these structures based on their integrated IR luminosities. Hereby we carry out the large NOEMA (NOrthern Extended Millimeter Array) program targeting a statistical sample of infrared-luminous sources associated with overdensities of massive galaxies at z>2, the Noema formIng Cluster survEy (NICE). We present the first result from the ongoing NICE survey, a compact group at z=3.95 in the Lockman Hole field (LH-SBC3), confirmed via four massive (M_star>10^10.5M_sun) galaxies detected in CO(4-3) and [CI](1-0) lines. The four CO-detected members of LH-SBC3 are distributed over a 180 kpc physical scale, and the entire structure has an estimated halo mass of ~10^13Msun and total star formation rate (SFR) of ~4000Msun/yr. In addition, the most massive galaxy hosts a radio-loud AGN with L_1.4GHz, rest = 3.0*10^25W/Hz. The discovery of LH-SBC3 demonstrates the feasibility of our method to efficiently identify high-z compact groups or forming cluster cores. The existence of these starbursting cluster cores up to z~4 provides critical insights into the mass assembly history of the central massive galaxies in clusters.Comment: 7 pages, 7 figures, submitted to A&

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
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