Uniform semiglobal practical asymptotic stability for non-autonomous cascaded systems and applications

It is due to the modularity of the analysis that results for cascaded systems have proved their utility in numerous control applications as well as in the development of general control techniques based on ``adding integrators''. Nevertheless, the standing assumptions in most of the present literature on cascaded systems is that, when decoupled, the subsystems constituting the cascade are uniformly globally asymptotically stable (UGAS). Hence existing results fail in the more general case when the subsystems are uniformly semiglobally practically asymptotically stable (USPAS). This situation is often encountered in control practice, e.g., in control of physical systems with external perturbations, measurement noise, unmodelled dynamics, etc. This paper generalizes previous results for cascades by establishing that, under a uniform boundedness condition, the cascade of two USPAS systems remains USPAS. An analogous result can be derived for USAS systems in cascade. Furthermore, we show the utility of our results in the PID control of mechanical systems considering the dynamics of the DC motors.Comment: 16 pages. Modifications 1st Feb. 2006: additional requirement that links the parameter-dependency of the lower and upper bounds on the Lyapunov function, stronger condition of uniform boundedness of solutions, modification and simplification of the proofs accordingl

Characterization of the Transition State of Functional Enzyme Dynamics

Through characterization of the solvent isotope effect on protein dynamics, we have examined determinants of the rate limitation to enzyme catalysis. A global conformational change in Ribonuclease A limits the overall rate of catalytic turnover. Here we show that this motion is sensitive to solvent deuterium content; the isotope effect is 2.2, a value equivalent to the isotope effect on the catalytic rate constant. We further demonstrate that the protein motion possesses a linear proton inventory plot, indicating that a single proton is transferred in the transition state. These results provide compelling evidence for close coupling between enzyme dynamics and function and demonstrate that characterization of the transition state for protein motion in atomic detail is experimentally accessible

Characterization of the Transition State of Functional Enzyme Dynamics

Through characterization of the solvent isotope effect on protein dynamics, we have examined determinants of the rate limitation to enzyme catalysis. A global conformational change in Ribonuclease A limits the overall rate of catalytic turnover. Here we show that this motion is sensitive to solvent deuterium content; the isotope effect is 2.2, a value equivalent to the isotope effect on the catalytic rate constant. We further demonstrate that the protein motion possesses a linear proton inventory plot, indicating that a single proton is transferred in the transition state. These results provide compelling evidence for close coupling between enzyme dynamics and function and demonstrate that characterization of the transition state for protein motion in atomic detail is experimentally accessible

Editorial

CIENCIA ergo sum es la revista científica multidisciplinaria de prospectiva de la Universidad Autónoma del Estado de México (UAEM); su periodicidad es cuatrimestral y en este 2012 cumple diecinueve años de aparecer puntual e ininterrumpidamente, respondiendo a los más estrictos requerimientos de las revistas académicas internacionales. Un logro muy importante de la revista es que en octubre de 2012 ha ingresado al Índice de Revistas Mexicanas de Divulgación Científica y Tecnológica de CONACyT, lo cual corrobora la calidad académica de la publicación.CIENCIA ergo sum es la revista científica multidisciplinaria de prospectiva de la Universidad Autónoma del Estado de México (UAEM); superiodicidad es cuatrimestral y en este 2012 cumple diecinueve años de aparecer puntual e ininterrumpidamente, respondiendo a los más estrictos requerimientos de las revistas académicas internacionales. Un logro muy importante de la revista es que en octubre de 2012 ha ingresado al Índice de Revistas Mexicanas de Divulgación Científica y Tecnológica de CONACyT, lo cual corrobora la calidad académica de la publicación

Control of the chaotic Duffing equation with uncertainty in all parameters

In this work, we deal with the open problem of controlling the periodically forced Duffing equation with uncertainty in all parameters. To date, several control schemes have been proposed to adapt for the linearly appearing unknown parameters but no solution exists for the case when the frequency of the periodic forcing is also unknown. We prove for the state feedback control case, global, asymptotic convergence for constant and time-varying references. We extend these results to the position feedback case and prove global ultimate boundednes

Robust output stabilization: improving performance via supervisory control

We analyze robust stability, in an input-output sense, of switched stable systems. The primary goal (and contribution) of this paper is to design switching strategies to guarantee that input-output stable systems remain so under switching. We propose two types of {\em supervisors}: dwell-time and hysteresis based. While our results are stated as tools of analysis they serve a clear purpose in design: to improve performance. In that respect, we illustrate the utility of our findings by concisely addressing a problem of observer design for Lur'e-type systems; in particular, we design a hybrid observer that ensures ``fast'' convergence with ``low'' overshoots. As a second application of our main results we use hybrid control in the context of synchronization of chaotic oscillators with the goal of reducing control effort; an originality of the hybrid control in this context with respect to other contributions in the area is that it exploits the structure and chaotic behavior (boundedness of solutions) of Lorenz oscillators.Comment: Short version submitted to IEEE TA

Coherence in monoidal track categories

We introduce homotopical methods based on rewriting on higher-dimensional categories to prove coherence results in categories with an algebraic structure. We express the coherence problem for (symmetric) monoidal categories as an asphericity problem for a track category and we use rewriting methods on polygraphs to solve it. The setting is extended to more general coherence problems, seen as 3-dimensional word problems in a track category, including the case of braided monoidal categories.Comment: 32 page

SISTEM INFORMASI MANAJEMEN HUBUNGAN PELANGGAN PADA SALON MUSLIMAH DAN SPA DESI KHADIJAH PALEMBANG

Salon Muslimah dan SPA Desi Khadijah Palembang merupakan tempat kecantikan perawatan tubuh yang di khususkan untuk perempuan. SPA sendiri merupakan suatu rangkaian perawatan yang terdiri dari terapi pijat seluruh badan, lulur/body scrub, masker, pemutih, mandi susu dan aromatherapy. Permasalahan yang terdapat pada Salon Muslimah dan SPA Desi Khadijah adalah pelanggan terlalu lama menunggu layanan jasa perawatan dikarenakan belum adanya informasi status terapis sehingga terdapat keluhan pelanggan, tidak ada pengklasifikasian dalam pencatatan data regular dan data member, dan pelanggan tidak dapat memilih terapis yang diinginkan. Tujuan skripsi ini adalah untuk membangun dan membuat sistem informasi manajemen hubungan pelanggan pada Salon Muslimah dan SPA Desi Khadijah Palembang. Metodologi yang digunakan dalam penulisan laporan ini adalah metode Rational Unified Process (RUP) yang memiliki 4 fase yang di dalamnya terdiri dari beberapa tahapan. Diharapkan hasil implementasi dari sistem ini adalah dapat mempermudah salon dalam menyampaikan informasi kepada pelanggan sehingga dapat meningkatkan suatu hubungan yang baik dengan pelanggan dan mengurangi kemungkinan pelanggan berpindah ke salon lai