Compressing Word Embeddings

Recent methods for learning vector space representations of words have succeeded in capturing fine-grained semantic and syntactic regularities using vector arithmetic. However, these vector space representations (created through large-scale text analysis) are typically stored verbatim, since their internal structure is opaque. Using word-analogy tests to monitor the level of detail stored in compressed re-representations of the same vector space, the trade-offs between the reduction in memory usage and expressiveness are investigated. A simple scheme is outlined that can reduce the memory footprint of a state-of-the-art embedding by a factor of 10, with only minimal impact on performance. Then, using the same `bit budget', a binary (approximate) factorisation of the same space is also explored, with the aim of creating an equivalent representation with better interpretability.Comment: 10 pages, 0 figures, submitted to ICONIP-2016. Previous experimental results were submitted to ICLR-2016, but the paper has been significantly updated, since a new experimental set-up worked much bette

Space spider crane

A space spider crane for the movement, placement, and or assembly of various components on or in the vicinity of a space structure is described. As permanent space structures are utilized by the space program, a means will be required to transport cargo and perform various repair tasks. A space spider crane comprising a small central body with attached manipulators and legs fulfills this requirement. The manipulators may be equipped with constant pressure gripping end effectors or tools to accomplish various repair tasks. The legs are also equipped with constant pressure gripping end effectors to grip the space structure. Control of the space spider crane may be achieved either by computer software or a remotely situated human operator, who maintains visual contact via television cameras mounted on the space spider crane. One possible walking program consists of a parallel motion walking program whereby the small central body alternatively leans forward and backward relative to end effectors

Identifying Retweetable Tweets with a Personalized Global Classifier

In this paper we present a method to identify tweets that a user may find interesting enough to retweet. The method is based on a global, but personalized classifier, which is trained on data from several users, represented in terms of user-specific features. Thus, the method is trained on a sufficient volume of data, while also being able to make personalized decisions, i.e., the same post received by two different users may lead to different classification decisions. Experimenting with a collection of approx.\ 130K tweets received by 122 journalists, we train a logistic regression classifier, using a wide variety of features: the content of each tweet, its novelty, its text similarity to tweets previously posted or retweeted by the recipient or sender of the tweet, the network influence of the author and sender, and their past interactions. Our system obtains F1 approx. 0.9 using only 10 features and 5K training instances.Comment: This is a long paper version of the extended abstract titled "A Personalized Global Filter To Predict Retweets", of the same authors, which was published in the 25th ACM UMAP conference in Bratislava, Slovakia, in July 201

Xeno-Free Derivation of Retinal Pigmented Epithelium from Human Pluripotent Stem Cells

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly and is characterized by the death of the retinal pigmented epithelium (RPE), the cell layer located behind the retina. The RPE maintains the health of the primary cells responsible for vision, the photoreceptors. As AMD progresses, the RPE degrades, which causes the death of the photoreceptors and a debilitating loss of sight. Human embryonic stem cells (hESCs) can generate a limitless source of RPE for cellular therapies, therefore efforts to derive RPE from human embryonic stem cells (hESCs) to graft into AMD patients are under development. This thesis addresses two of the obstacles that hinder the production of these therapeutical cells. First, to manufacture cells for clinical use, it is desirable for procedures to be performed under defined conditions free of non-human reagents (xeno-free). Therefore, a novel, biomimetic, xeno-free RGD-containing copolymer designed for cell culture was investigated and found to support healthy hESC cultures and permit their differentiation into functional RPE. These stem cells and hESC-RPE demonstrate similar gene expression, protein localization and phagocytic function as cultures grown on a xenogeneic substrate. The second obstacle pertains to the intense time requirement needed to differentiate hESCs into RPE. Therefore, we recapitulated the signaling events during early embryonic development to expedite the production of hESC-RPE from 1-3 months to 14 days. However, this protocol employs full length recombinant growth factors and animal derivatives. These components represent a challenge in employing these cells as therapies due to the risk of exposure to non-human immunogens. Preliminary work to replace the xenogeneic substrate and recombinant growth factors with small molecules is presented. These pilot studies demonstrate that a xeno-free substrate and dual-Smad inhibition via small molecules can rapidly and efficiently differentiate hESCs into a population of cells expressing a pigmentation marker. These studies contribute to the development of defined, xeno-free methods for cellular manufacture which can further the translation of stem cell therapies to the clinic

Classification and Biogeography of Panicoideae (Poaceae) in the New World

Panicoideae (Poaceae) in the New World comprise 107 genera (86 native) and 1357 species (1248 native). As circumscribed herein, Panicoideae include eight tribes: Andropogoneae, Arundinelleae, Centotheceae, Gynerieae, Isachneae, Paniceae, Steyermarkochloeae, and Thysanolaeneae. The two major tribes are Andropogoneae with 230 species (16.95% of all New World panicoids), and Paniceae with 1082 species (79.73%). Andropogoneae are divided into nine subtribes (Andropogoninae, Anthistiriinae, Coicinae, Germainiinae, Ischaeminae, Rottboelliinae, Saccharinae, Sorghinae, and Tripsacinae), while Paniceae are divided into seven subtribes (Arthropogoninae, Cenchrinae, Digitariinae, Melinidinae, Panicinae, Paspalinae, and Setariinae). Brazil is the center of diversity of New World panicoids with 741 species (54.6% of all species). The distributions of endemic and restricted taxa were analyzed in terms of biogeographical regions and Kranz syndrome. Amphitropical disjuncts and widespread species are also discussed

少人数グループでの語彙と読解の学習と、それが有する Beglar&Hunt によって改訂されたI.S.P.ネイションによる語彙レベルテストとの関連

本論文は、2002年9月から2003年3月にかけて、英会話クラスで実施した読解力・語彙力の実験に関するものである。教材として使用した小説は、I.S.P. Nation 語彙レベルテスト (Beglar and Hunt 改正) に基づいて分析、評価を行った。当該グループ・レッスンは、週に一回、少人数制で行っており、対象は40歳代前半から60歳代前半の主婦である。全員が日本の大学を卒業しており、アメリカまたはカナダで数年間の居住経験を持つ。また、全員が日本英語検定1級保持者であって、英会話力は、「優秀な上級者」レベルである。生徒は積極的に発言をするため会話には活気があり、日本人の生徒の間で通常見られる遠慮した態度、文化的バリアなどは、ほとんど感じられない

Detection by NMR of a "local spin-gap" in quenched CsC60

We present a 13C and 133Cs NMR investigation of the CsC60 cubic quenched phase. Previous ESR measurements suggest that this phase is metallic, but NMR reveals contrasting electronic behavior on the local scale. The 13C spin-lattice relaxation time (T1) exhibits a typical metallic behavior down to 50 K, but indicates that a partial spin-gap opens for T<50 K. Unexpectedly, 133Cs NMR shows that there are two inequivalent Cs sites. For one of these sites, the NMR shift and (T1T)^{-1} follow an activated law, confirming the existence of a spin-gap. We ascribe this spin-gap to the occurrence of localized spin-singlets on a small fraction of the C60 molecules.Comment: 4 figure

Anomalous Normal-State Properties of High-Tc_c Superconductors -- Intrinsic Properties of Strongly Correlated Electron Systems?

A systematic study of optical and transport properties of the Hubbard model, based on Metzner and Vollhardt's dynamical mean-field approximation, is reviewed. This model shows interesting anomalous properties that are, in our opinion, ubiquitous to single-band strongly correlated systems (for all spatial dimensions greater than one), and also compare qualitatively with many anomalous transport features of the high-T$_c$ cuprates. This anomalous behavior of the normal-state properties is traced to a ``collective single-band Kondo effect,'' in which a quasiparticle resonance forms at the Fermi level as the temperature is lowered, ultimately yielding a strongly renormalized Fermi liquid at zero temperature.Comment: 27 pages, latex, 13 figures, Invited for publication in Advances in Physic

Eccentric Exercise Program Design: A Periodization Model for Rehabilitation Applications

The applied use of eccentric muscle actions for physical rehabilitation may utilize the framework of periodization. This approach may facilitate the safe introduction of eccentric exercise and appropriate management of the workload progression. The purpose of this data-driven Hypothesis and Theory paper is to present a periodization model for isokinetic eccentric strengthening of older adults in an outpatient rehabilitation setting. Exemplar and group data are used to describe the initial eccentric exercise prescription, structured familiarization procedures, workload progression algorithm, and feasibility of the exercise regimen. Twenty-four men (61.8 ±6.3 years of age) completed a 12-week isokinetic eccentric strengthening regimen involving the knee extensors. Feasibility and safety of the regimen was evaluated using serial visual analog scale (VAS, 0-10) values for self-reported pain, and examining changes in the magnitude of mean eccentric power as a function of movement velocity. Motor learning associated with the familiarization sessions was characterized through torque-time curve analysis. Total work was analyzed to identify relative training plateaus or diminished exercise capacity during the progressive phase of the macrocycle. Variability in the mean repetition interval decreased from 68% to 12% during the familiarization phase of the macrocycle. The mean VAS values were 2.9 ±2.7 at the start of the regimen and 2.6 ±2.9 following 12 weeks of eccentric strength training. During the progressive phase of the macrocycle, exercise workload increased from 70% of the estimated eccentric peak torque to 141% and total work increased by 185% during this training phase. The slope of the total work performed across the progressive phase of the macrocycle ranged from -5.5 to 29.6, with the lowest slope values occurring during microcycles 8 and 11. Also, mean power generation increased by 25% when eccentric isokinetic velocity increased from 60 deg s-1 to 90 deg s-1 while maintaining the same workload target. The periodization model used in this study for eccentric exercise familiarization and workload progression was feasible and safe to implement within an outpatient rehabilitation setting. Cyclic use of higher eccentric movement velocities, and the addition of active recovery periods, are featured in the proposed theoretical periodization model for isokinetic eccentric strengthening

Phase diagram of YBa2_2Cu3_3O7−y_{7-y} at T<<Tc_c based on Cu(2) transverse nuclear relaxation

Two maxima in transverse relaxation rate of Cu(2) nuclei in YBa$_2$Cu$_3$O$_{7-y}$ are observed, at T = 35 K and T = 47 K. Comparison of the $^{63}$Cu(2) and $^{65}$Cu(2) rates at T = 47 K indicates the magnetic character of relaxation. The enhancement at T = 47 K of fluctuating local magnetic fields perpendicular to the CuO$_2$ planes is connected with the critical fluctuations of orbital currents. Maximum at T = 35 K is connected with the appearance of inhomogeneous supeconducting phase. Together with data published to date, our experimental results allow to suggest a qualitatively new phase diagram of the superconducting phase.Comment: 4 LaTEX pages + 3 figures in *.ps forma