651 research outputs found

    A search method for optimal control of a flow shop system of traditional machines

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    Cataloged from PDF version of article.We consider a convex and nondifferentiable optimization problem for deterministic flow shop systems in which the arrival times of the jobs are known and jobs are processed in the order they arrive. The decision variables are the service times that are to be set only once before processing the first job, and cannot be altered between processes. The cost objective is the sum of regular costs on job completion times and service costs inversely proportional to the controllable service times. A finite set of subproblems, which can be solved by trust-region methods, are defined and their solutions are related to the optimal solution of the optimization problem under consideration. Exploiting these relationships, we introduce a twophase search method which converges in a finite number of iterations. A numerical study is held to demonstrate the solution performance of the search method compared to a subgradient method proposed in earlier work. 2010 Elsevier B.V. All rights reserved

    Constrained Optimal Hybrid Control of a Flow Shop System

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    Cataloged from PDF version of article.We consider an optimal control problem for the hybrid model of a deterministic flow shop system, in which the jobs are processed in the order they arrive at the system. The problem is decomposed into a higher-level discrete-event system control problem of determining the optimal service times, and a set of lower-level classical control problems of determining the optimal control inputs for given service times. We focus on the higher-level problem which is nonconvex and nondifferentiable. The arrival times are known and the decision variables are the service times that are controllable within constraints. We present an equivalent convex optimization problem with linear constraints. Under some cost assumptions, we show that no waiting is observed on the optimal sample path. This property allows us to simplify the convex optimization problem by eliminating variables and constraints. We also prove, under an additional strict convexity assumption, the uniqueness of the optimal solution and propose two algorithms to decompose the simplified convex optimization problem into a set of smaller convex optimization problems. The effects of the simplification and the decomposition on the solution times are shown on an example problem

    Patologi Anatomi Ikan Komet (Carassius Auratus Auratus) Akibat Infestasi Argulus Japonicus Jantan Dan Betina Pada Derajat Infestasi Yang Berbeda [Anatomic Pathology of Comet Fish (Carassius Auratus Auratus) as Result of Males and Females Argulus Japonicus Infestation in Different Degree ]

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    Usaha perikanan terutama ikan hias air tawar merupakan alternatif USAha untuk menjalankan perekonomian. Salah satu kendala dalam budidaya ikan komet adalah penyakit, terutama parasit. Infestasi ektoparasit Argulus japonicus dapat mengakibatkan kematian dan kerugian ekonomi bagi pembudidaya. Tujuan dari penelitian ini adalah untuk dapat mengetahui Perubahan atau kelainan pada kulit ikan komet yang disebabkan oleh ektoparasit Argulus japonicus jantan dan betina. Penelitian ini dilaksanakan pada bulan Agustus-September 2015 di Laboratorium Pendidikan Fakultas Perikanan dan Kelautan Universitas Airlangga. Metode yang digunakan dalam penelitian ini adalah metode eksperimental. Pengaruh perlakuan terhadap Perubahan patologi anatomi diolah dengan analisis statistik Analisis Variansi Rancangan Acak lengkap Pola Faktorial. Penelitian ini menggunakan dua kelompok perlakun yaitu kelompok satu menggunakan Argulus japonicus jantan dan kelompok dua menggunakan Argulus japonicus betina. Masing-masing kelompok menggunakan empat perlakuan dan lima ulangan. Variabel yang diamati dalam penelitian ini adalah Perubahan patologi anatomi pada kulit ikan komet. Skoring dilakukan untuk menentukan derajat kerusakan patologi anatomi kulit ikan komet. Hasil penelitian ini menunjukkan bahwa infestasi ektoparasit Argulus japonicus jantan dan betina dapat mengakibatkan Perubahan patologi anatomi pada ikan komet, tingkat kerusakan patologi anatomi ikan komet yang terjadi mengikuti derajat infestasi ektoparasit Argulus japonicus, perlakuan infestasi masing-masing Argulus japonicus jantan dan betina juga berpengaruh terhadap kerusakan patologi anatomi ikan komet, dan kondisi pemeliharaan ikan komet yang baik selama penelitian dapat meminimalkan pengaruh lain di luar pengaruh infestasi Argulus japonicus

    First CNGS events detected by LVD

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    The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band νμ\nu_{\mu} beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the ντ\nu_{\tau} appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of 7.6 10177.6~10^{17} protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations.Comment: Accepted for publication by the European Physical Journal C ; 7 pages, 11 figure

    Study of the effect of neutrino oscillation on the supernova neutrino signal with the LVD detector

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    We present an update of our previous study (astro-ph/0112312) on how ν\nu oscillations affect the signal from a supernova core collapse observed in the LVD detector at LNGS. In this paper we use a recent, more precise determination of the cross section (astro-ph/0302055) to calculate the expected number of inverse beta decay events, we introduce in the simulation also the ν\nu-{\rm Fe} interactions, we include the Earth matter effects and, finally, we study also the inverted mass hierarchy case.Comment: 4 pages, 4 figures, to appear in the Proceedings of ICRC 200

    On-line recognition of supernova neutrino bursts in the LVD detector

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    In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated to a supernova explosion, in the absence of an "external trigger", e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and electron anti-neutrino intensity at the source.Comment: Accepted for pubblication on Astroparticle Physics. 13 pages, 10 figure

    The Extreme Energy Events HECR array: status and perspectives

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    The Extreme Energy Events Project is a synchronous sparse array of 52 tracking detectors for studying High Energy Cosmic Rays (HECR) and Cosmic Rays-related phenomena. The observatory is also meant to address Long Distance Correlation (LDC) phenomena: the network is deployed over a broad area covering 10 degrees in latitude and 11 in longitude. An overview of a set of preliminary results is given, extending from the study of local muon flux dependance on solar activity to the investigation of the upward-going component of muon flux traversing the EEE stations; from the search for anisotropies at the sub-TeV scale to the hints for observations of km-scale Extensive Air Shower (EAS).Comment: XXV ECRS 2016 Proceedings - eConf C16-09-04.

    Search for low energy neutrinos in correlation with the 8 events observed by the EXPLORER and NAUTILUS detectors in 2001

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    We report on a search for low-energy neutrino (antineutrino) bursts in correlation with the 8 time coincident events observed by the gravitational waves detectors EXPLORER and NAUTILUS (GWD) during the year 2001. The search, conducted with the LVD detector (INFN Gran Sasso National Laboratory, Italy), has considered several neutrino reactions, corresponding to different neutrino species, and a wide range of time intervals around the (GWD) observed events. No evidence for statistically significant correlated signals in LVD has been found. Assuming two different origins for neutrino emission, the cooling of a neutron star from a core-collapse supernova or from coalescing neutron stars and the accretion of shocked matter, and taking into account neutrino oscillations, we derive limits to the total energy emitted in neutrinos and to the amount of accreting mass, respectively.Comment: Accepted for publication in Astronomy and Astrophysic

    Dark Matter Results from 100 Live Days of XENON100 Data

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    We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows to select only the innermost 48 kg as ultra-low background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in a pre-defined signal region with an expected background of 1.8 +/- 0.6 events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic WIMP-nucleon scattering cross-sections above 7.0x10^-45 cm^2 for a WIMP mass of 50 GeV/c^2 at 90% confidence level.Comment: 5 pages, 5 figures; matches accepted versio

    Implications on Inelastic Dark Matter from 100 Live Days of XENON100 Data

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    The XENON100 experiment has recently completed a dark matter run with 100.9 live-days of data, taken from January to June 2010. Events in a 48kg fiducial volume in the energy range between 8.4 and 44.6 keVnr have been analyzed. A total of three events have been found in the predefined signal region, compatible with the background prediction of (1.8 \pm 0.6) events. Based on this analysis we present limits on the WIMP-nucleon cross section for inelastic dark matter. With the present data we are able to rule out the explanation for the observed DAMA/LIBRA modulation as being due to inelastic dark matter scattering off iodine at a 90% confidence level.Comment: 3 pages, 3 figure
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