12,170 research outputs found
Politics and Strategy in Judicial Decision-Making: Evidence from federal human trafficking sentencing
This thesis investigates the effects of judicial ideology and judge characteristics on sentencing in human trafficking cases. Despite research on federal prosecutions of human trafficking, almost nothing is known about sentencing for federal human trafficking offenders. Previous research on sentencing has been limited by the lack of data linking judges to specific sentencing decisions. Using new data that matches judges to defendants convicted of federal human trafficking offenses, I observe that judicial ideology has an effect on overall sentence length—but only for district court judges appointed by Democratic presidents. I also find that partisan composition of the circuit court, rather than ideology of the sentencing judge, affects the likelihood of downward departures from the Sentencing Guidelines. When Democrat-appointed judges make up a majority of the circuit court, district court judges are 2.1 times as likely to depart below the Sentencing Guidelines. These findings confirm positive political theories of sentencing that model judges as strategic decision makers within a "judicial hierarchy."Undergraduate Research ScholarshipNo embargoAcademic Major: PhilosophyAcademic Major: Political Scienc
Parallel repetition for entangled k-player games via fast quantum search
We present two parallel repetition theorems for the entangled value of
multi-player, one-round free games (games where the inputs come from a product
distribution). Our first theorem shows that for a -player free game with
entangled value , the -fold repetition of
has entangled value at most , where is the answer length of any
player. In contrast, the best known parallel repetition theorem for the
classical value of two-player free games is , due to Barak, et al. (RANDOM 2009). This
suggests the possibility of a separation between the behavior of entangled and
classical free games under parallel repetition.
Our second theorem handles the broader class of free games where the
players can output (possibly entangled) quantum states. For such games, the
repeated entangled value is upper bounded by . We also show that the dependence of the exponent
on is necessary: we exhibit a -player free game and such
that .
Our analysis exploits the novel connection between communication protocols
and quantum parallel repetition, first explored by Chailloux and Scarpa (ICALP
2014). We demonstrate that better communication protocols yield better parallel
repetition theorems: our first theorem crucially uses a quantum search protocol
by Aaronson and Ambainis, which gives a quadratic speed-up for distributed
search problems. Finally, our results apply to a broader class of games than
were previously considered before; in particular, we obtain the first parallel
repetition theorem for entangled games involving more than two players, and for
games involving quantum outputs.Comment: This paper is a significantly revised version of arXiv:1411.1397,
which erroneously claimed strong parallel repetition for free entangled
games. Fixed author order to alphabetica
Perception of Waiting Time at Signalized Intersections
Perceived waiting time at signalized intersections differs from the real value, and varies with signal design. The onerousness of delay depends on the conditions under which it is experienced. Using weighted travel time time may contribute to optimal signal control if its use can improve upon assuming that all time is weighted equally by users. This research explores the perception of waiting time at signalized intersections based on the results of an online survey, which directly collected the perceived waiting time and the user ratings of the signal designs of each intersection on an arterial including 3 intersections. Statistically analyzing the survey data suggests the perception of waiting time is a function of the real time; and a quadratic model better can describes relationship. The survey also indicates that there exists a tradeoff between the total waiting time and the individual waiting time of each intersection. It turns out that drivers prefer to split the total waiting time at different intersections at the price of a longer total wait if the difference of the total waiting time of two signal designs is within 30 seconds. The survey data shows that the perceived waiting time, instead of the real waiting time, better explains how users will rate the individual signal designs for both intersections and arterials including multiple intersections.Traffic Signal, Stated Preference, Virtual Experience Stated Preference, Signalized Intersection, Value of Time, Perception of Time
Data Analytics for Humanities and Historical Analysis
Historical text and images feed the complex narrative we view history with today. In some cases, references to recurring situations in the form of a diary or a series of maps can become quantifiable data in the form of a visual record. Analytics can be performed on maps of military campaigns tracking the movement of troops over time, a form of time series data, and on casualty lists recording the when, where and from which individual soldiers fell in battle. Our project utilizes primary data from maps and casualty reports concerning World War II battles, specifically from the Eastern Front, to reconstruct one of the largest military clashes recorded in human history: 1941 Operation Barbarossa. We transformed multiple maps into one central database recording the place and time of troops as well as their losses. The data set was not only checked for accuracy and completeness, but also interpreted for various military postures such as: attack, defense, movement, or reserve. Finally the data was mapped into an animated environment. The team created a new type of “weather” map displaying the movement of troops as if they were a weather front. Graphic representation using mathematical modeling allowed for detailed accounts of areas with concentrated troops and the direction of movement. A demo of the work can be found at URL http://visiblepast.org/apps/OPMAPS/OPMAPS_FINAL_DEMO/OPMAPS_BETA.ipynb?appmode_scroll=
Steady state risetimes of shock waves in the atmosphere
A square wave shape is used in the Pestorius algorithm to calculate the risetime of a step shock in the atmosphere. These results agree closely with steady shock calculations. The healing distance of perturbed shocks due to finite wave effects is then investigated for quasi-steady shocks. Perturbed 100 Pa shocks require on the order of 1.0 km travel distance to return to within 10 percent of their steady shock risetime. For 30 Pa shocks, the minimum recovery distance increases to 3.0 km. It is unlikely that finite wave effects can remove the longer risetimes and irregular features introduced into the sonic boom by turbulent scattering in the planetary boundary layer
Non-volatile, high density, high speed, Micromagnet-Hall effect Random Access Memory (MHRAM)
The micromagnetic Hall effect random access memory (MHRAM) has the potential of replacing ROMs, EPROMs, EEPROMs, and SRAMs because of its ability to achieve non-volatility, radiation hardness, high density, and fast access times, simultaneously. Information is stored magnetically in small magnetic elements (micromagnets), allowing unlimited data retention time, unlimited numbers of rewrite cycles, and inherent radiation hardness and SEU immunity, making the MHRAM suitable for ground based as well as spaceflight applications. The MHRAM device design is not affected by areal property fluctuations in the micromagnet, so high operating margins and high yield can be achieved in large scale integrated circuit (IC) fabrication. The MHRAM has short access times (less than 100 nsec). Write access time is short because on-chip transistors are used to gate current quickly, and magnetization reversal in the micromagnet can occur in a matter of a few nanoseconds. Read access time is short because the high electron mobility sensor (InAs or InSb) produces a large signal voltage in response to the fringing magnetic field from the micromagnet. High storage density is achieved since a unit cell consists only of two transistors and one micromagnet Hall effect element. By comparison, a DRAM unit cell has one transistor and one capacitor, and a SRAM unit cell has six transistors
Witten Diagrams for Torus Conformal Blocks
We give a holographic description of global conformal blocks in two
dimensional conformal field theory on the sphere and on the torus. We show that
the conformal blocks for one-point functions on the torus can be written as
Witten diagrams in thermal AdS. This is accomplished by deriving a general
conformal Casimir equation for global conformal blocks, and showing that Witten
diagrams obey the same equation. We study the semi-classical limit of n-point
conformal blocks, and show that these equal the action of a network of bulk
world-lines obeying appropriate geodesic equations. We give an alternate
description in the Chern-Simons formulation of 3D gravity, where the conformal
blocks are described by networks of Wilson lines, and argue that these
formulations are equivalent.Comment: 32 pages, 6 figure
Assessing replicated coral trace element (Sr/Ca and Mg/Ca) variability and skeletal growth records from the tropical Pacific
To gain a more complete history and understanding of the full amplitude of climate variability prior to instrumental records, science must rely on natural proxy archives that are sensitive to fluctuations in key climate parameters. Calcium carbonate skeletons of long-living hermatypic corals in some locations have been shown to be natural archives of surface ocean variability. This study investigated the fidelity and reproducibility of coral derived Sr/Ca time series from Clipperton Atoll, Fiji, and Tonga as accurate proxies of sea surface temperature (SST). The replicated high-resolution Sr/Ca time series record monthly and bimonthly SST changes, though with a greater magnitude of variability than instrumental records. Coupled measurements of coral Sr/Ca and δ18O records were also used to reconstruct δ 18O of seawater from each region, and showed good agreement with in situ sea surface salinity (SSS) measurements. Longer-term, lower-frequency trends in the proxy records appear to reflect the changing position of the Intertropical Convergence Zone (ITCZ) and the South Pacific Convergence Zone (SPCZ). Coral skeletal growth parameters were then examined for possible effects of ocean acidification. These results showed some coral colonies with increasing calcification while others showed decreasing calcification, suggesting other effects play an important role. The results of the analyses of growth and paleoclimatology proxy reconstructions were also inconclusive, since slight influences were present in some but not all colonies. Finally, inter- and intra-colony comparisons were made using Mg/Ca as the proxy results in the Fiji and Tonga colonies. However, because of alterations and discontinuities in the skeletal material, Mg/Ca lacked coherence at long timescales and should not be considered as a reliable SST proxy
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