On binary correlations of multiplicative functions

We study logarithmically averaged binary correlations of bounded multiplicative functions $g_1$ and $g_2$. A breakthrough on these correlations was made by Tao, who showed that the correlation average is negligibly small whenever $g_1$ or $g_2$ does not pretend to be any twisted Dirichlet character, in the sense of the pretentious distance for multiplicative functions. We consider a wider class of real-valued multiplicative functions $g_j$, namely those that are uniformly distributed in arithmetic progressions to fixed moduli. Under this assumption, we obtain a discorrelation estimate, showing that the correlation of $g_1$ and $g_2$ is asymptotic to the product of their mean values. We derive several applications, first showing that the number of large prime factors of $n$ and $n+1$ are independent of each other with respect to the logarithmic density. Secondly, we prove a logarithmic version of the conjecture of Erd\H{o}s and Pomerance on two consecutive smooth numbers. Thirdly, we show that if $Q$ is cube-free and belongs to the Burgess regime $Q\leq x^{4-\varepsilon}$, the logarithmic average around $x$ of the real character $\chi \pmod{Q}$ over the values of a reducible quadratic polynomial is small.Comment: 33 pages; Referee comments incorporated; To appear in Forum Math. Sigm

Practical approaches to exploiting body dynamics in robot motor control

Motor control systems in the brain of humans and mammals are hierarchically organised, with each level controlling increasingly complex motor actions. Each level is controlled by the higher levels and also receives sensory and/or proprioceptive feedback. Through learning, this hierarchical structure adapts to its body, its sensors and the way these interact with the environment. An even more integrated view is taken in morphological or embodied computation. On the one hand, there is both biological and mechanical (robotics) evidence that a properly chosen body morphology can drastically facilitate control when the body dynamics naturally generate low level motion primitives. On the other hand, several papers have used robot bodies as reservoirs in a reservoir computing setup. In some cases, reservoir computing was used as an easy way to obtain robust linear feedback controllers for locomotion. In other cases, the body dynamics of soft robots were shown to perform general computations in response to some input stimulation. In general, very specific highly compliant bodies were used. At Ghent University’s Reservoir Lab, we have previously used reservoir computing to generate locomotion on quite different robot platforms: the highly compliant tensegrity robot Recter and the far less compliant quadruped robot Oncilla and a new low cost modular quadruped puppy robot. In all cases, we succeeded in generating stable gaits. However, not surprisingly, not all robot bodies are equally suitable to help generating their own motor actuations. As a result, the reservoir computing principle alone was not always sufficient. We present an overview of our experience with these different robot platforms and give practical guidelines for applying physical reservoir computing to new robots. We finally discuss some perspectives on a more systematic evaluation between body morphology, compliance and the complexity of generating stable gaits for locomotion

Partially embodied motor control: towards a natural collaboration between body and brain

Motor control systems in the brain humans and mammals are hierarchically organised, with each level controlling increasingly complex motor actions. Each level is controlled by the higher levels and also receives sensory and/or proprioceptive feedback. Through learning, this hierarchical structure adapts to its body, its sensors and the way these interact with the environment. An even more integrated view is taken in morphological or embodied computation. On the one hand, there is both biological and mechanical (robotics) evidence that a properly chosen body morphology can drastically facilitate control when the body dynamics naturally generate low level motion primitives. On the other hand, several papers have used physical bodies as reservoirs in a reservoir computing setup. In some cases, reservoir computing was used as an easy way to obtain robust linear feedback controllers for locomotion. In other cases, the body dynamics of soft robots were shown to perform general computations in response to some input stimulation. In general, very specific highly compliant bodies were used. We present recent results on two open questions regarding the way morphological computation could be exploited in biological motor control. Generally, when reservoir computing has been used to exploit body dynamics for computation, the desired output signals were known. Clearly, in biological locomotion, the learning does not enforce specific muscle actuation signals. Instead, it rewards desirable forms of motion and penalizes undesirable ones. We show how a biologically plausible learning rule, reward modulated Hebbian learning, can enable the incorporation of compliant body dynamics into the control hierarchy, resulting in robust motor control. Despite the many successes with using physical bodies as reservoirs, the relationship between compliance and computational power has hardly been investigated. Although biological bodies are partially compliant, they also have a very specific structure and many rigid parts. It therefore remains unclear to what extent this type of bodies can help in motor control. In our research, we use compliant four legged robots to address this issue. We present first results that indicate that for such robots, linear feedback of proprioceptive signals alone is often not sufficient to result in stable gait control. In addition, a first comparison of different levels of compliance indicate that a well chosen level of compliance can drastically simplify motor control, compared to both, too little and too much compliance, and that the body should therefore be considered as an integral part of the control

The Fossilization Error Made by the Second Semester Students of Islamic Communication and Broadcasting Prody (Kpi) at Stai Bumi Silampari Lubuklinggau

Kesalahan yang memfosilisasi didalam mengucapkan kata dalam Bahasa Inggris didalam Penelitian ini difokuskan pada kesalahan mereka mengucapkan kata yang mempunyai huruf vocal (/i:/, /I/, /e/, /ӕ/) mahasiswa semester II, Prodi KPI (Komunikasi Penyiaran Islam), dalam penelitian ini ditemukan ada enam kata yang sangat memfosil siswa mengucapkannya yaitu kata: 1) Listening  /lis:ning/ 2) She  /sh:i/ 3) Pizza /fɪ:tzaʃ/ 4) Mosque /mos:k/, 5) Eight /eɪt/ and 6) Accent /æksent . Penelitian ini mengunakan metode Descriptive. Hasil penelitian menunjukkan bahwa fosilisasi terjadi karena tiga sumber kesalahan dari guru, kawan, dan buku paket

Did the CDC guidelines for suicide reports affect the New York Times?

The CDC informed the American media of the best way to avoid contributing to imitative suicides by releasing guidelines for suicide reports in 2001. In this study, suicide reports in the New York Times were examined to establish if these guidelines affected the reporting. To determine if there was any change, all suicide reports from five years before, the year of guideline release, and five years after were extracted from the Times database. To determine compliance, articles were coded using a coding sheet that operationalized the guidelines into 12 yes–or–no questions. The New York Times observed nearly one and a half guidelines more in 2006 than 10 years before, from about 5 to nearly 6.5 observed. Some guidelines were observed differently in 2001, suggesting greater focus on the topic. However, only some of the changes were in line with the guidelines, and none of them lasted five years

Request formation in Ecuadorian Quichua

published or submitted for publicationis peer reviewe

Preaching with all you\u27ve got: embodying the word

Title: Preaching with all you\u27ve got: embodying the word. Author: Day, David Preaching with all you\u27ve got 186 p. Publisher: Peabody, Mass : Hendrickson, 2006

Improving Students' Skill to Write Islamic Historical Texts Through Dicstom Technique, the Trial Web Shift Design, and Engagement Strategy at Stai Bumi Silampari Lubuklinggau

This study aims to find the ability of third semester students, Prodi PAI (Islamic Religious Education) in writing texts of Islamic history in English. Students are taught 3 ways to write; (1) Dicstom, (2) Web Shift Trial, (3) Engagement, and (4) without technique. This research uses Quasi-experimental design method, and one-way ANOVA. The results showed that there is a difference between the students' ability in writing Islamic history text in English using the 3 ways mentioned above

Optimizing Teaching English as Efl in Novice Level Through Students' Optimism

Mengoptimalkan pengajaran bahasa inggris dengan menanamkan rasa optimisme pada siswa mempunyai pengaruh sangat penting dalam belajar bahasa inggris terutama dalam tingkat dasar. Siswa akan mempunyai inisiatif, berani mengambil resiko dan akan lebih banyak terlibat dalam setiap kegiatan sehingga mereka dapat meningkatkan kemampuan bahasa serta mempunyai kemampuan akademik yang tinggi