Cross-language Wikipedia Editing of Okinawa, Japan

This article analyzes users who edit Wikipedia articles about Okinawa, Japan, in English and Japanese. It finds these users are among the most active and dedicated users in their primary languages, where they make many large, high-quality edits. However, when these users edit in their non-primary languages, they tend to make edits of a different type that are overall smaller in size and more often restricted to the narrow set of articles that exist in both languages. Design changes to motivate wider contributions from users in their non-primary languages and to encourage multilingual users to transfer more information across language divides are presented.Comment: In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, CHI 2015. AC

Distributed space-time block code over mixed Rayleigh and Rician frequency-selective fading channels

This paper proposes a new distributed space-time block code (DSTBC) over frequency-selective fading channels for two-hop amplify and forward relay networks, consisting of a source node (S), two relay nodes (R1 and R2), and a destination node (D). The proposed DSTBC is designed to achieve maximal spatial diversity gain and decoupling detection of data blocks with a low-complexity receiver. To achieve these two goals, S uses zero-sequence padding, and relay nodes precode the received signals with a proper precoding matrix. The pairwise error probability (PEP) analysis is provided to investigate the achievable diversity gain of the proposed DSTBC for a general channel model in which one hop is modeled by Rayleigh fading and the other by Rician fading. This mixed Rayleigh-Rician channel model allows us to analyze two typical scenarios where {Ri} are in the neighborhood of either S or D

Network coding-based retransmission for relay aided multisource multicast networks

This paper considers the reliable transmission for wireless multicast networks where multiple sources want to distribute information to a set of destinations with assistance of a relay. Basically, the reliability of a communication link is assured via automatic repeat request (ARQ) protocols. In the context of multisource multicast networks, the challenge is how to retransmit the lost or erroneous packets efficiently. In traditional approaches, the retransmission of lost packets from a single source is treated separately, and thus it may cause a considerable delay. To solve this problem, we propose the relay detects, combines, and forwards the packets which are lost at destinations using network coding. In the proposed ARQ protocol, the relay detects packets from different sources and combines the lost packets using NC. In particular, two packet-combination algorithms are developed to guarantee that all lost packets are retransmitted with the smallest number of retransmissions. Furthermore, we analyze the transmission bandwidth and provide the numerical results to demonstrate the superior performance of the proposed ARQ protocol over some existing schemes

Resonant Leptogenesis and Verifiable Seesaw from Large Extra Dimensions

In the presence of large extra dimensions, the fundamental scale could be as low as a few TeV. This yields leptogenesis and seesaw at a TeV scale. Phenomenologically two TeV-scale Majorana fermions with a small mass split can realize a resonant leptogenesis whereas a TeV-scale Higgs triplet with a small trilinear coupling to the standard model Higgs doublet can give a verifiable seesaw. We propose an interesting scenario where the small parameters for the resonant leptogenesis and the type-II seesaw can be simultaneously generated by the propagation of lepton number violation from distant branes to our world.Comment: 5 pages. More discussions and references. Published in PR

Double Type-II Seesaw, Baryon Asymmetry and Dark Matter for Cosmic e^\pm Excesses

We construct a new realization of type-II seesaw for neutrino masses and baryon asymmetry by extending the standard model with one light and two heavy singlet scalars besides one Higgs triplet. The heavy singlets pick up small vacuum expectation values to give a suppressed trilinear coupling between the triplet and doublet Higgs bosons after the light singlet drives the spontaneous breaking of lepton number. The Higgs triplet can thus remain light and be accessible at the LHC. The lepton number conserving decays of the heavy singlets can generate a lepton asymmetry stored in the Higgs triplet to account for the matter-antimatter asymmetry in the Universe. We further introduce stable gauge bosons from a hidden sector, which obtain masses and annihilate into the Higgs triplet after spontaneous breaking of the associated non-Abelian gauge symmetry. With Breit-Wigner enhancement, the stable gauge bosons can simultaneously explain the relic density of dark matter and the cosmic positron/electron excesses.Comment: 9 pages, 4 figures, minor rewording, final PRD version (in Press

Low thrust orbit determination program

Logical flow and guidelines are provided for the construction of a low thrust orbit determination computer program. The program, tentatively called FRACAS (filter response analysis for continuously accelerating spacecraft), is capable of generating a reference low thrust trajectory, performing a linear covariance analysis of guidance and navigation processes, and analyzing trajectory nonlinearities in Monte Carlo fashion. The choice of trajectory, guidance and navigation models has been made after extensive literature surveys and investigation of previous software. A key part of program design relied upon experience gained in developing and using Martin Marietta Aerospace programs: TOPSEP (Targeting/Optimization for Solar Electric Propulsion), GODSEP (Guidance and Orbit Determination for SEP) and SIMSEP (Simulation of SEP)

What \u3cem\u3eMatter of Soram\u3c/em\u3e Got Wrong: “Child Abuse” Crimes that May Trigger Deportation Are Constantly Evolving and Even Target Good Parents

Many are surprised to learn that crime-based deportations do not necessarily make intuitive sense. Under the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 (IIRIRA), a misdemeanor drug offense for which probation was imposed 20 years ago can be an “aggravated felony,” a category reserved for the presumably most serious offenses that result in detention, deportation, and denial of most forms of immigration relief. But a felony conviction for kidnaping may have no consequences at all. The crime of “child abuse, child neglect, or child abandonment” removal ground created by IIRIRA similarly leads to illogical results. This deportability ground, first created in 1996 by IIRIRA, is causing federal circuit courts (and arguably the Board of Immigration Appeals itself) to split over whether this deportability ground is narrow or broad. We contend that the narrow interpretation, best defended by the Tenth Circuit, is the proper one. Not only does the legislative history support a narrow reading, but the ground’s broad interpretation adopted by the Second Circuit improperly includes civil actions (not just crimes) and does not even require acts that cause injury to a child. As a result, the broad interpretation sweeps too far. It includes parents with civil violations for leaving their child unattended, either out of circumstances arising from the lack of child care for the working poor or from deliberate parenting choices known as “free-range” parenting in which children are encouraged to function independently and with limited parental supervision. The deportability ground should be interpreted narrowly—as intended by Congress— to trigger deportation only for those who are harming and preying on children

Mission Analysis Program for Solar Electric Propulsion (MAPSEP). Volume 2: User's manual

A user's manual which describes input/output routines and recommended operating procedures relating to MAPSEP is presented. Samples runs are included

Mission Analysis Program for Solar Electric Propulsion (MAPSEP). Volume 1: Analytical manual

The mission analysis program for solar electric propulsion (MAPSEP) is comprised of the basic modes: TOPSEP (trajectory generation), GODSEP (linear error analysis), and SIMSEP (simulation). The program is designed to analyze any low thrust mission with respect to trajectory performance, guidance and navigation, and to provide system related requirements for the purpose of vehicle design. The MAPSEP organization is described along with all models and algorithms. Topics discussed include: trajectory and error covariance propagation methods, orbit determination processes, thrust modeling, and trajectory correction (guidance) schemes

Mission Analysis Program for Solar Electric Propulsion (MAPSEP). Volume 3: Program manual

The internal structure of MAPSEP is described. Topics discussed include: macrologic, variable definition, subroutines, and logical flow. Information is given to facilitate modifications to the models and algorithms of MAPSEP