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Vieira, Andre Mozart de Miranda
2008-07-01
In this work, absorbed dose to water produced by the radiation beam of a clinical linear accelerator - CLINAC 600C{sup TM} (Varian), with a photon beam of 6 MV, were evaluated both theoretically and experimentally. This determination includes square and circular field configurations, the last one obtained with a micro multi leaf collimator - mMLC m3{sup TM} (Brain Lab). Theoretical evaluation was performed throughout Monte Carlo method. Experimental measurements of Percentage Depth Dose - PDD and derived Tissue Maximum Ratio - TMR curves from CLINAC 600C were validated by comparison with reference values as well as with measurements using different detectors. The results indicate local differences smaller than 5% and average differences smaller than 1,5% for each evaluated field, if they are compared to the previous commissioning values (made in 1999) and to the values of literature. Comparisons of ionization chamber and diode result in an average local difference of -0,6% for PDD measurements, and within 1% for lateral dose profiles, at depth, in the flat region. Diode provides measurements with better spatial resolution. Current output factors of open fields agree with reference values within 1,03% of discrepancy level. Current absorbed dose distributions in water are, now, considered reference values and allow characterization of this CLINAC for patient dose calculation. The photon spectra resulting from simulations with PENELOPE and MCNP codes agree approximately in 80% of the sampled points, in what average energies of (1,6 {+-} 0,3)MeV, with MCNP, and of (1,72 {+-} 0,08)MeV, with PENELOPE, are coincident. The created simple source model of the CLINAC 600C, using the PENELOPE code, allows one to calculate dose distributions in water, for open fields, with discrepancies of the order of {+-} 1,0% in dose and of {+-} 0,1 cm in position, if they are compared to experimental measurements. These values met the initial proposed criteria to validate the simulation
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Sérgio Carlos Barros Esteves
2008-04-01
variables no statistically significant correlation was observed between occlusion and treatment complications.OBJETIVO: Analisar os resultados obtidos com radiocirurgia e as suas complicações do procedimento, no tratamento das malformações arteriovenosas com acelerador linear. MÉTODOS: Este é um estudo retrospectivo. Entre Outubro de 93 e Dezembro de 96, sessenta e um pacientes com malformações arteriovenosas foram tratados, utilizando um acelerador linear com 6MV de energia. As idades variaram de 6 a 54 anos (média: 28,3 anos, 32 pacientes mulheres e 29 pacientes homens. O sintoma inicial mais freqüente foi cefaléia (45,9%, seguido de déficit neurológico (36,1%. Hemorragia cerebral diagnostica por exame de imagem foi observada em 35 pacientes (57,3%. A maioria das malformações arteriovenosas (67,2% eram graus III e IV de Spetzler. Estenose venosa (21,3% e aneurisma (13,1% foram as mais freqüentes alterações da arquitetura vascular. A dose administrada variou de 12 a 27,5Gy na periferia da lesão. RESULTADOS: Dos vinte e oito pacientes que se submeteram a controle angiográfico conclusivo, 18 tiveram obliteração completa (72% e 7 falharam ao tratamento (ausência de oclusão com mais de três anos de seguimento. Quatro pacientes foram submetidos a uma segunda radiocirurgia, e um paciente deste grupo apresentou obliteração em 18 meses de seguimento. DISCUSSÃO: Vários fatores foram analisados em relação ao grau de oclusão (sexo, idade, volume, localização, Spetzler, fluxo, embolização, total de isocentros, dose prescrita e isodose escolhida e complicações (total de isocentros, localização, volume, dose máxima, dose prescrita e isodose escolhida. As variáveis analisadas não mostraram significância estatística para a obliteração do vaso, bem como para as complicações de tratamento. O maior diâmetro da malformação arteriovenosa, seu volume e a dose administrada não influenciaram no tempo de obliteração. CONCLUSÃO: Radiocirurgia
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Oliva, Jose de Jesus Rivero, E-mail: rivero@con.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Departamento de Engenharia Nuclear; Sousa, Fernando Nuno Carneiro de, E-mail: fernandonunosousa@gmail.com [Aceletron Irradiacao lndustrial, Rio de Janeiro, RJ (Brazil)
2013-07-01
The electron linear accelerators can be used in industrial applications that require powerful sources of ionizing radiation. They have the important characteristic of not representing a radiation hazard when the accelerators remain electrically disconnected. With the plant in operation, a high reliability defense in depth reduces the risk of radiological accidents to extremely small levels. It is practically impossible that a person could enter into the radiation bunker with the accelerators connected. Aceletron Irradiacao Industrial, located in Rio de Janeiro, offers services of irradiation by means of two powerful electron linear accelerators, with 15 kW power and 10 MeV electron energy. Despite the high level of existing radiation safety, a simplified risk study is underway to identify possible sequences of radiological accidents. The study is based on the combined application of the event and fault trees techniques. Preliminary results confirm that there is a very small risk of entering into the irradiation bunker with the accelerators in operation, but the risk of an operator entering into the bunker during a process interruption and remaining there without notice after the accelerators were restarted may be considerably larger. Based on these results the Company is considering alternatives to reduce the likelihood of human error of this type that could lead to a radiological accident. The paper describes the defense in depth of the irradiation process in Aceletron Irradiacao Industrial, as well as the models and preliminary results of the ongoing risk analysis, including the additional safety measures which are being evaluated. (author)
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Lívia Almeida Fortunato
2015-12-01
Full Text Available A radioterapia é um tratamento eficaz contra o câncer de mama que tem a finalidade de destruir as células neoplásicas. Entretanto, pode produzir efeitos adversos causando alterações importantes na qualidade de vida (QV das pacientes durante e após o tratamento. Assim, essa pesquisa que tem por objetivo comparar a qualidade de vida de mulheres com câncer de mama no início e após se submeterem a radioterapia com acelerador linear. O estudo foi realizado no hospital denominado OncoBeda, na cidade de Campos dos Goytacazes - RJ. A amostra foi composta por 20 pacientes do gênero feminino, com idade entre 33 a 87 anos. As mesmas responderam nos momentos pré e pós tratamento ao Instrumento WHOQOL-bref, composto por 26 questões, sendo 2 questões gerais sobre auto avaliação da QV e as outras 24 questões que envolvem 4 domínios, sendo eles “físico”, “psicológico”, “relações sociais” e “meio ambiente”. Os resultados obtidos revelam que houve uma diferença ligeiramente significativa no domínio “físico”, influenciando na avaliação geral da QV dessas pacientes. Sendo assim, conclui-se que mesmo não tendo um valor elevado de diferença entre os dois momentos avaliados, as pacientes apresentaram alteração na sua QV durante o tratamento.
Sérgio Carlos Barros Esteves; Wladimir Nadalin; Ronie Leo Piske; Salomon Benabou; Evandro de Souza MD; Antonio Carlos Zuliani de Oliveira
2008-01-01
OBJECTIVE: To evaluate results achieved with radiosurgery and complications of the procedure when treating arteriovenous malformations with linear accelerator. METHODS: This retrospective study was conducted between October 1993 and December 1996. Sixty-one patients with arteriovenous malformations were treated with radiosurgery utilizing a 6MV energy linear accelerator. Ages of the 32 female and 29 male patients ranged from 6 to 54 years (mean: 28.3 years). The most frequent initial symptom ...
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Maria da Penha Silva
2001-10-01
Full Text Available Um programa de garantia da qualidade é um pré-requisito obrigatório para a exatidão necessária em radioterapia. Este trabalho relata parte dos testes de rotina mensal do controle da qualidade dos aceleradores lineares do Instituto Nacional do Câncer, relativos à calibração dos feixes de fótons e elétrons, no período de dois anos. Os resultados foram comparados com as recomendações do protocolo AAPM TG-40. Na análise do fator de calibração para o feixe de fótons foi encontrado um desvio máximo de 12%; para o feixe de elétrons o maior desvio encontrado foi 10%. A flutuação observada no indicador da qualidade do feixe para os feixes de elétrons foi maior que para os feixes de fótons. Os resultados confirmam a importância de um programa de garantia da qualidade em um serviço de radioterapia, permitindo correções rápidas da dose administrada ao paciente.A quality assurance program is a mandatory prerequisite for obtaining the high level of accuracy required for radiotherapy. This paper reports the results of part of the routine quality control tests for linear accelerators at the National Cancer Institute, Brazil, performed monthly over a period of two years. These tests included dose output and beam quality indicator. The results were compared with the guidelines of the AAPM TG-40 protocol. The results for the photon beams have shown dose output variations of up to 12%; for electron beams, the largest deviation found was 10%. The fluctuations observed in the beam quality indicator for the electron beams were greater than for the photon beams. These results strongly emphasize the importance of a quality assurance program in radiotherapy services in order to allow prompt corrections of the dose delivered to the patient.
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Goncalves, Leandro R.; Santos, Gabriela R.; Menegussi, Gisela; Silva, Marco A.; Passaro, Anderson M.; Rodrigues, Laura N., E-mail: leandrorg11@hotmail.com [Instituto do Cancer do Estado de Sao Paulo (ICESP), Sao Paulo, SP (Brazil)
2013-08-15
Radiotherapy techniques like VMAT allow complex dose distributions modulating the beam intensity within the irradiation field from the handling of multi-blade collimators, variations in dose rate, different speeds of rotation of the gantry and collimator angle allowing greater conformation of the dose to the tumor volume and a lower dose to healthy tissues. To ensure proper dose delivery, the linear particle accelerator must be able to monitor and perform all the variation in these parameters simultaneously. In this work dosimetric tests obtained in the literature that aims to commission, implement and ensure the quality of VMAT treatments were performed performed in the Institute of Cancer of Sao Paulo State (ICESP). From the results obtained it was established a program of quality control for the linear accelerator studied. The linearity and stability response of ionization chamber monitoring, leafs accuracy positioning, flatness and symmetry of beam to VMAT irradiations were evaluated. The obtained results are in agreement with the literature. It can be concluded that the accelerator studied is able to satisfactorily control the variation of all necessary parameters to perform the VMAT treatments. (author)
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Piriz, Gustavo H.; Lozano, Enrique; Banguero, Yolma; Varon, Carlos Fernando; Mancilla, Claudio S. [Instituto Nacional del Cancer, Santiago (Chile). Radioterapia; Parra, Cristian [Universidad de la Frontera, Temuco (Chile); Pacheco, P. [Universidad Nacional Mayor de San Marcos, Lima (Peru)
2011-07-01
The aim of this paper is to present the experience on intraoperative radiotherapy, which has as the reference center the network of radiotherapy in Chile. It is detailed the construction of a system of applicators with an easy coupling on a linear accelerator collimator. It is also detailed the cost and the measurements set up with their corresponding percentage depth dose and isodose curves. This technique was implemented in a Varian Clinac 21EX for beams with 6, 9 and 12 MeV electron energy. The coupling system provides a good dose distribution both laterally and in depth for different energies. This provides a good coverage of treatment planning volume. (author)
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Soares, Alessandro Facure Neves de Salles
2006-04-15
Medical linear accelerators, with maximum photon energies above 10 MeV, are becoming of common use in Brazil. Although desirable in the therapeutic point of view, the increase in photon energies causes the generation of undesired neutrons, which are produced through nuclear reactions between photons and the high Z target nuclei of the materials that constitute the accelerator head. In this work, MCNP simulation was undertaken to examine the neutron equivalent doses around the accelerators head and at the entrance of medical linear accelerators treatment rooms, some of them licensed in Brazil by the National Regulatory Agency (CNEN). The simulated neutron dose equivalents varied between 2 e 26 {mu} Sv/Gy{sub RX}, and the results were compared with calculations performed with the use of some semi-empirical equations found in literature. It was found that the semi-empirical equations underestimate the simulated neutron doses in the majority of the cases, if compared to the simulated values, suggesting that these equations must be revised, due to the increasing number of high energy machines in the country. (author)
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Gutt, F.; Silva, P.; Guerrero, R.; Diaz, J.; Colmenares, J. [Instituto Venezolano de Investigaciones Cientificas (IVIC), Laboratorio Secundario de Calibracion Dosimetrica (LSCD), Apartado 21827, Caracas 1020 A (Venezuela)
1998-12-31
The objective of the present work is to find a physical mathematical model based on the reason of the dose percentages at 10 and 20 cm depth, at 100 cm DFS and a 10 x 10 cm{sup 2} field. It was utilized literature data of new manufactured accelerators and those are in use in hospitals, which allow to prove the model under different conditions. Our objective consists only to obtain a model that verifies the nominal potential for a linear accelerator, but without pretending that such a model to be used to calculate any one factor to determination of absorbed dose. (Author)
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Sansogne, R.; Palacios, V.; Arbiser, S. [Vidt Centro Medico- CETRO. Vidt 1924- (1428) Buenos Aires (Argentina)
1998-12-31
This work come along of the necessity to utilize an unique High-Energy Electron Linear Accelerator (10 MV) for radiant treatments which require higher doses in the surface levels of tissue. It is analyzed the interposition of acrylic degraders (spoilers) in the beam, especially for opposed and parallel fields in the cases of head and neck. It was analyzed the possible combinations of the following parameters: 1) Field sizes defined at isocenter (100 cm) 6 x 6 cm{sup 2}, 8 x 8 cm{sup 2} and 10 x 10 cm{sup 2} ; 2) Surface-spoiler distance (DSS) of 4, 7 and 10 cm; 3) Spoilers with different thickness 1.1 and 1.5 cm. It was observed a displacement of the maximum dose toward the surface, and an increase in the percentile doses in the build-up zone when the spoiler is nearing and/or increasing its thickness. It is verified that the use of spoilers, support the symmetry and plane of the beam inside of the clinically acceptable margins. When the results obtained are analyzed then it is proposed as a calculation method to incorporate an attenuation factor. (Author)
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Cruz, Jose Carlos da [Hospital Israelita Albert Einstein, Sao Paulo, SP (Brazil). Servico de Radioterapia; Segreto, Roberto Araujo; Segreto, Helena R. Comodo [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Medicina. Setor de Radioterapia]. E-mail: josecarlos@einstein.br
2003-07-01
Three dosimetric systems were compared regarding dosimetry of small circular x ray fields used in radiosurgery. The dosimetric parameters for circular cones, with diameters ranging from 7 to 30 mm, were acquired using a 6 MV Clinac 600 C linear accelerator. For the measurement of tissue maximum ratios, total scatter factor and radiation field profile, Kodak X-Omat type V radiographic films, and ionization chamber of 0.1 cm{sup 3} and a plane parallel ionization chamber type Markus were used. The plane parallel ionization chamber showed satisfactory results for measurement of tissue maximum ratios and total scatter only for cone sizes larger than 11 mm in diameter. Beam profile showed better spatial resolution when films ere used. The main physical parameters of small circular fields used in radiosurgery can be obtained by combining the dosimetry results of radiation therapy equipment used in current clinical practice. (author)
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Passaro, Bruno M.; Rodrigues, Laura N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Videira, Heber S., E-mail: bruno.passaro@gmail.com [Universidade de Sao Paulo (HCFMRP/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas
2013-04-15
The aim of this study is to assess and analyze the stability of the calibration factor of three linear accelerators, as well as the other dosimetric parameters normally included in a program of quality control in radiotherapy. The average calibration factors of the accelerators for the period of approximately four years for the Clinac 600C and Clinac 6EX were (0.998±0.012) and (0.996±0.014), respectively. For the Clinac 2100CD 6 MV and 15 MV was (1.008±0.009) and (1.006±0.010), respectively, in a period of approximately four years. The data of the calibration factors were divided into four subgroups for a more detailed analysis of behavior over the years. Through statistical analysis of calibration factors, we found that for the 600C and Clinacs 2100CD, is an expected probability that more than 90% of cases the values are within acceptable ranges according to TG-142, while for the Clinac 6EX is expected around 85% since this had several exchanges of accelerator components. The values of TPR20,10 of three accelerators are practically constant and within acceptable limits according to the TG-142. It can be concluded that a detailed study of data from the calibration factor of the accelerators and TPR{sub 20},{sub 10} from a quantitative point of view, is extremely useful in a quality assurance program. (author)
Directory of Open Access Journals (Sweden)
Mafalda F. Berdaky
2001-10-01
Full Text Available Este trabalho apresenta a parte operacional do processo final envolvido na implantação de um programa de controle de qualidade por meio de testes rotineiros mecânicos e de radiação. O programa de controle de qualidade, durante 35 meses, mostrou a estabilidade excelente deste acelerador.This paper describes the operational characteristics of the final process of implementation of a quality control program using routine mechanical and radiation tests. The quality control program was performed during 35 months and demonstrated the excellent stability of this accelerator.
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Ordiales, J. M.; Alvarez, F. J.; Falero, B.
2011-07-01
For quality control of the virtual wedge there are several systems on the market as arrays of detectors or ionization chambers, linear or 2D configuration, radiochromic films or digital imaging systems incorporated in electron linear accelerators (ALE ). The present work aims at implementing a system of Computed Radiography (CR) for a routine check of the virtual wedge.
Un ano de retraso para el acelerador europeo LHC
CERN. Geneva
2002-01-01
"Debido a las dificultades presupuestarias que sufre el Laboratorio Europeo de Fisica de Particulas (CERN) para construir el nuevo acelerador LHC, la puesta en marcha de esta gran instalacion se retrasara un ano, entrando en funcionamiento en 2007, segun el plan elaborado por la direccion del centro" (1/2 page).
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Ordiales, J. M.; Falero, B.; Vazquez, M.; Alvarez, F. J.
2013-07-01
The use of bags of rice as dispersion medium in irradiation of blood products for medical use is less effective than the immersion from the point of view dosimetric water. However, given the wide range of dose values for a valid result and once subjected to quality control procedure, the method provides the necessary work for the irradiation of blood products in a linear electron accelerator. (Author)
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Ruiz Egea, E.; Sanchez Carrascal, M.; Torres Pozas, S.; Monja Ray, P. de la; Perez Molina, J. L.; Madan Rodriguez, C.; Luque Japon, L.; Morera Molina, A.; Hernandez Perez, A.; Barquero Bravo, Y.; Morengo Pedagna, I.; Oliva Gordillo, M. C.; Martin Olivar, R.
2011-07-01
In order to try to determine the high dose in the bunker of a Linear Accelerator clinical use trying to measure the spatial dependence of the same from the isocenter to gateway to the board cheeking to establish the origin of it. This dose measurements performed with an ionization chamber at different locations inside the bunker after an irradiation of 400 Monitor Units verifying the dose rate per minute for an hour, and accumulating the dose received during that period of time.
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Vega C, H.R. [Universidad Autonoma de Zacatecas, Cuerpo Academico de Radiobiologia, A.P. 336, 98000 Zacatecas (Mexico); Barquero, R. [Hospital Universitario Rio Hortega, Valladolid (Spain); Mendez, R.; Iniguez, M.P. [Depto. de Fisica Teorica, Atomica, Molecular y Nuclear, Universidad de Valladolid, 47011 Valladolid (Spain)
2003-07-01
By means of a series of measures and Monte Carlo calculations the dosimetric characteristics of the photoneutrons have been determined that take place in volume to a linear accelerator of radiotherapy of 18 MV, LINAC, mark Siemens Mevatron model. The measures were carried out with thermoluminescent dosemeters TLD 600 and TLD 700 that were naked exposed and confined with cover of Cd and Sn, inside a sphere of paraffin and inside spheres Bonner. (Author)
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Juste, B.; Miro, R.; Verdu, G.; Diez, S.; Campayo, J. M.
2010-07-01
Determining the spectral distribution of the emitted photon medical linear accelerator (linac) used in radiotherapy treatment is extremely important for performing dosimetry calculations as to accurately calculate the therapeutic dose distributions. Since directly measure the spectrum is very complicated, this paper presents an indirect technique to accurately calculate the spectra of Bremsstrahlung photons emitted by linacs.
Jatvia, J M
2002-01-01
"La Universidad de Valencia tiene avanzado el diseno de un acelerador lineal de protones, cuya culminacion depende del compromiso del Consell en sufragar la plantilla que necesitaria el centro para estar operativo" (1 page).
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Juste, B.; Miro, R.; Verdu, G.; Diez, S.; Campayo, J. M.
2012-11-01
A correct dose calculation in patient under radiotherapy treatments requires and accurate description of the radiation source. The main goal of the present work is to study the effects of initial electron beam characteristics on Monte Carlo calculated absorbed dose distribution for a 6 MeV linac photon beam. To that, we propose a methodology to determine the initial electron fluence before hitting the accelerator target for an Elektra Precis a medical linear accelerator. The method used for the electron radiation source description is based on a Software for Uncertainty and Sensitivity Analysis (SUSA) and Monte Carlo simulations using the MCNP5 transport code. This electron spectrum has been validated by means of comparison of its resulting depth dose curve in a water cube with experimental data being the mean difference below the 1%. (Author)
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Corral B, J. R.
2015-07-01
Humans should avoid exposure to radiation, because the consequences are harmful to health. Although there are different emission sources of radiation, generated by medical devices they are usually of great interest, since people who attend hospitals are exposed in one way or another to ionizing radiation. Therefore, is important to conduct studies on radioactive levels that are generated in hospitals, as a result of the use of medical equipment. To determine levels of exposure speed of a radioactive facility there are different methods, including the radiation detector and computational method. This thesis uses the computational method. With the program MCNP5 was determined the speed of the radiation exposure in the radiotherapy room of Cancer Center of ABC Hospital in Mexico City. In the application of computational method, first the thicknesses of the shields were calculated, using variables as: 1) distance from the shield to the source; 2) desired weekly equivalent dose; 3) weekly total dose equivalent emitted by the equipment; 4) occupation and use factors. Once obtained thicknesses, we proceeded to model the bunker using the mentioned program. The program uses the Monte Carlo code to probabilistic ally determine the phenomena of interaction of radiation with the shield, which will be held during the X-ray emission from the linear accelerator. The results of computational analysis were compared with those obtained experimentally with the detection method, for which was required the use of a Geiger-Muller counter and the linear accelerator was programmed with an energy of 19 MV with 500 units monitor positioning the detector in the corresponding boundary. (Author)
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Apaza V, D.; Cardena R, R.; Cayllahua Q, F.; Vega R, J. [Universidad Nacional de San Agustin de Arequipa, Av. Independencia s/n, Hexagonos de Fisica, Arequipa (Peru); Urquizo B, R., E-mail: dgav02@gmail.com [Hospital Nacional Carlos Alberto Seguin Escobedo, Esquina de Peral y Filtro s/n, Arequipa (Peru)
2015-10-15
In systems of radiotherapy treatment for cancer, always looking to maximize the radiation dose on the target (tumor) and minimize to the organs at risk or healthy, so they resort to using electron beams that have properties and characteristics of higher dose deposition at fixed depths, directing and focusing the higher dose in the tumor, without harming healthy tissues to which seeks to radiate in the least possible. Simulating the interaction of electron beams with different equivalent tissues to the human body leads to a better dosimetric evaluation, improving the quality of treatment planning. The aim of this study is the comparison from the characterization of several equivalent tissues to the human body such as soft tissue, bone and lung. Based on the simulation of a calibration beam in water phantom with Penelope code and compared with the results of the calibration curves of beams in water vat by a linear accelerator Elekta Synergy of Hospital Nacional Carlos Alberto Seguin Escobedo EsSalud of Arequipa (Peru). From this to evaluate the behavior of electron beams in a homogeneous medium and then further evaluation in the human body homogeneities, for better evaluation and specific treatment planning. (Author)
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Caballero G, C. A. [Southwest Oncology Centers, North Civic Center Plaza No. 2926, Scottsdale, Arizona (United States); Plascencia, J. C. [Centro Oncologico Louis and Lucille Grado, Republica del Peru No. 102-5, Col. Americas, Aguascalientes (Mexico); Vargas V, M. X.; Toledo J, P., E-mail: cabshm@msn.co [Centro Oncologico de Chihuahua, Hacienda de la Esperanza No. 6304, Fracc. Cima Comercial, Chihuahua (Mexico)
2010-09-15
The helicoid tomo therapy is an external radiotherapy system of modulated intensity, guided by image, in which the radiation is imparted to the patient using a narrow radiation beam in helicoid form, in a similar way to the scanning process with a computerized tomography. The tomo therapy equipment (Tomo Therapy Hi-Art) consists in an electrons linear accelerator with acceleration voltages of 6 MV for treatment and 3.5 MV for image, coupled to a ring that turn around the patient as this is transferred through this ring in perpendicular sense to the radiation beam. The radiation beam is narrow because has the maximum size of 5 x 40 cm{sup 2} in the isocenter. The intensity modulation of the beam is carried out with a binary dynamic collimator of 64 crisscross sheets, and the guide by image though a system of megavoltage computerized tomography. Opposed to the radiation beam, also coupled to the rotational ring, a group of lead plates exists with a total thickness of 13 cm that acts as barrier of the primary radiation beam. The special configuration of the tomography equipment makes to have the following characteristics: 1) the presence of the lead barrier of the equipment reduces the intensity of the primary beam that reaches the bunker walls in considerable way, 2) the disperse and leakage radiations are increased with regard to a conventional accelerator due to the increase in the necessary irradiation time to produce modulated intensity fields by means of the narrow radiation beam. These special characteristics of the tomo therapy equipment make that particularities exist in the application of the formulations for structural shielding calculations that appears in the NCRP reports 49, NCRP 151 and IAEA-SRS-47. For this reason, several researches have development analytic models based on geometric considerations of continuous rotation of the equipment ring to determine the shielding requirements for the primary beam, the dispersed and leakage radiation in tomo
El gran acelerador de hadrones (LHC) y la búsqueda de la partícula divina
Sánchez León, José Guillermo
2008-01-01
El acelerador más grande nunca construido, el LHC, está realizando sus últimas pruebas. Sólo el acelerador requiere un potencia de 120 MW (800000 MWh/año) que serán suministrados desde las centrales nucleares francesas. ¿Qué tiene de especial el LHC que no tengan otros superaceleradores? ¿Qué son los hadrones? ¿Qué es el bosón de Higgs? ¿Qué aprenderemos? ¿Merece la pena gastar miles de millones de euros en instalaciones como ésta? Este artículo intentará dar respuesta a estas preguntas....
Accelerator-based research activities at 'Centro Nacional de Aceleradores', Seville (Spain)
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Respaldiza, M.A. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Departmento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Sevilla (Spain)], E-mail: respaldiza@us.es; Ager, F.J. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Departmento de Fisica Aplicada I, Universidad de Sevilla, Sevilla (Spain); Carmona, A. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Laboratoire de Chimie Nucleaire Analytique et Bioenvironnementale, Universite de Bordeaux (France); Ferrer, J. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Garcia-Leon, M.; Garcia-Lopez, J. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Departmento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Sevilla (Spain); Garcia-Orellana, I. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Gomez-Tubio, B. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Departmento de Fisica Aplicada III, Universidad de Sevilla, Sevilla (Spain); Morilla, Y. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Ontalba, M.A. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Departmento de Fisica, Universidad de Extremadura, Caceres (Spain); Ortega-Feliu, I. [Centro Nacional de Aceleradores, Avd. Thomas A. Edison 7, E-41092 Sevilla (Spain); Departmento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Sevilla (Spain)
2008-05-15
In February 1998, almost 10 years ago, the set-up of the first IBA (ion beam analysis) facility in Spain took place with the arrival of a 3 MV tandem accelerator [J. Garcia-Lopez, F.J. Ager, M. Barbadillo-Rank, F.J. Madrigal, M.A. Ontalba, M.A. Respaldiza, M.D. Ynsa, Nucl. Instr. and Meth. B 161-163 (2000) 1137]. Since then, an intensive research program using IBA techniques has been carried out. Subsequently, a cyclotron for 18 MeV protons has been also installed at the 'Centro Nacional de Aceleradores' (CNA), devoted mainly to isotope production for PET (positron emission tomography) techniques, but possibly applied to material analysis and damage studies on a dedicated beam line. Moreover, a 1 MV tandem has been recently installed for AMS (accelerator mass spectrometry) {sup 14}C dating and environmental research with other isotopes. In the present paper we describe the new facilities and the developments of the 3 MV tandem beam lines occurred during the past years, as well as some examples of the most recent research activities in our Center in the fields of Material Science, Archaeometry, Biomedicine and Environment.
Fuente de Alimentación para los Imanes Superconductores del Acelerador de Partículas Europeo XFEL
García, O.; Francés, A.; J.M. Fernández; Varela, Pablo; Catalanotto, Giuseppe; Alou Cervera, Pedro; Oliver Ramírez, Jesús Angel; Asensi Orosa, Rafael; Prieto López, Roberto; Uceda Antolín, Javier; Cobos Márquez, José Antonio
2013-01-01
En este artículo se presenta la fuente de alimentación que se está diseñando para alimentar los imanes superconductores del acelerador de partículas europeo XFEL que se está construyendo en Hamburgo, cuyas características le hacen el más avanzado del mundo. Un imán superconductor es una carga muy inductiva que debe ser controlada en corriente y que presenta una caída de tensión muy baja cuando está en modo superconductor. La fuente debe ser capaz de alimentar esta carga con una alta fiabilida...
Directory of Open Access Journals (Sweden)
Jackson A. Barbosa
2005-08-01
Full Text Available A utilização de pneu radial em tratores agrícolas na década de 1950 resultou em redução das perdas de potência oriundas da resistência ao rolamento e patinagem, com conseqüente melhoria no desenvolvimento da tração. Este trabalho teve como objetivo comparar o desempenho operacional de um trator agrícola equipado alternadamente com pneus radiais e diagonais. A avaliação foi realizada a partir de análises de parâmetros indicadores do desempenho dos referidos pneus sob condições específicas de trabalho. O uso de pneus radiais proporcionou incrementos nos valores de capacidade de tração e potência na barra, diminuição nos valores de consumo específico de combustível e não causou variações no consumo horário de combustível.The use of radial tire in agricultural tractors in the decade of 1950 resulted in the reduction of the potency losses originated from the rolling resistance and slippage, with consequent improvement in the traction development. This work had as objective to compare the operational performance of an agricultural tractor, equipped alternately with radial and diagonal tires. The evaluation was accomplished, starting from analyses of indicative parameters of the performance of the referred tires under specific conditions of work. The use of radial tires provided increments in the values of traction capacity and drawbar pull, decrease in values of specific consumption of fuel, and didn't cause variations in the hourly consumption of fuel.
Measurement of {sup 236}U on the 1 MV AMS system at the Centro Nacional de Aceleradores (CNA)
Energy Technology Data Exchange (ETDEWEB)
Chamizo, E. [Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092 Seville (Spain); Christl, M. [Laboratory of Ion Beam Physics, ETH Zurich, Otto Stern Weg 5, CH-8093 Zurich (Switzerland); Fifield, L.K. [Department of Nuclear Physics, Research School of Physics and Engineering, The Australian National University, ACT 2601 (Australia)
2015-09-01
In this paper we present the first comprehensive analysis of the 1 MV AMS system at the Centro Nacional de Aceleradores (CNA, Seville, Spain) for {sup 236}U studies in environmental samples. In the last years, this radionuclide has become key in the AMS community, due to the very demanding {sup 236}U/{sup 238}U abundance sensitivities required for general applications. As we demonstrate, the AMS system at the CNA is able to achieve sensitivity for the {sup 236}U/{sup 238}U ratio of about 3 × 10{sup −11} despite its compact design. The use of “{sup 239}Pu”/{sup 238}U ratio as a proxy for “{sup 236}U”/{sup 235}U background correction is proposed and tested with natural samples that were also studied on the 600 kV Tandy AMS system at the ETH Zürich. This correction is significant in the CNA case, due to the low mass resolving power of the low-energy spectrometer and to the lack of a third filter on the high-energy side. With the measurement of reference solutions supplied by the Institute for Reference Materials and Methods (IRMM-075), and reference natural matrixes provided by the International Atomic Energy Agency (IAEA-Soil-6, IAEA-375; 384; 386 and IAEA-RGU), we show that the 1 MV AMS system at the CNA can be routinely used for determinations of anthropogenic {sup 236}U at environmental levels.
El impacto de la política monetaria y la política fiscal en un modelo de acelerador financiero
Botero García, Jesús
2010-01-01
El presente artículo presenta un modelo sencillo de acelerador financiero, en el que a partir de la solución del problema de optimización intertemporal del flujo de renta del empresario en condiciones de competencia monopolística, es posible evaluar el impacto de dichos descuentos, así como también el impacto de la política monetaria, sobre el stock deseado de capital y la inversión deseada. El modelo es un modelo de equilibrio parcial, pero ilustra adecuadamente la forma como la política mon...
Energy Technology Data Exchange (ETDEWEB)
Salgado, Ana Paula; Pereira, Walsan Wagner; Patrao, Karla C. de Souza; Fonseca, Evaldo S. da, E-mail: asalgado@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Batista, Delano V.S. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil)
2009-07-01
This work demonstrates the complexity and the necessary cares for the realization of measurements of neutron fields in rooms for radiotherapy treatment containing clinical accelerators. The acquaintance of the technical characteristics of the monitors and the periodic calibration are actions and fundamental procedures to guarantee traceability and the reliability of measurements
Leonardo A. Monteiro; Kléber P. Lanças; Saulo P. S. Guerra
2011-01-01
A utilização correta de pneus em tratores, tanto em relação ao seu tipo quanto à calibração de sua pressão interna, e a lastragem ideal para cada condição de carga são fatores que influem significativamente no desempenho do trator. Esta pesquisa teve como objetivo comparar o desempenho de um trator equipado com pneus radiais e com pneus diagonais, para três condições de lastragem líquida (0%, 40% e 75% de água), em três condições superficiais de um Nitossolo Vermelho distrófico (superfície fi...
Energy Technology Data Exchange (ETDEWEB)
Juste, B.; Miro, R.; Verdu, G.; Diez, S.; Campayo, J. M.
2014-07-01
In radiotherapy beams of high energy photons produced lower doses in the skin and a lower dose dispersed into surrounding healthy tissue. However, when operating above 10 MV, Linacs have some drawbacks such as the generation of photo-neutrons and activation of some components of the accelerator. The launch and capture of neutrons produce radioactive nuclei that can radiate even when the accelerator is not working. These reactions occur mainly in the heavier materials of the head accelerator. This work has studied the activation generated isotopes resulting, concluding that these derived doses are not negligible. (Author)
Energy Technology Data Exchange (ETDEWEB)
Juste, B.; Miro, R.; Verdu, G.; Diez, S.; Campayo, J. M.
2015-07-01
Monte Carlo estimation of the giant-dipole-resonance (GRN) photoneutrons insider the Elekta Precise Linac head (emitting a 15 MV photon beam) were performed using the MCNP6 code. Each component of Linac head geometry and materials were modelled in detail using the given manufacturer information. Primary photons generate photoneutrons and its transport across the treatment head was simulated, including the (n, γ) reactions which undergo activation products. The MCNP6 was used to develop a method for quantifying the activation of accelerator components. The approach described in this paper is useful in quantifying the origin and the amount of nuclear activation. (Author)
Energy Technology Data Exchange (ETDEWEB)
Gomez Extremera, M.; Gonzalez Infantes, W.; Lallena rojo, A. M.; Anguiano Millan, M.
2013-07-01
Monte Carlo simulation is currently considered the most accurate method for calculations of doses due to electrons. The objective of the work is the characterization of the primary source of electrons from an accelerator of clinical use with Monte Carlo simulation, in order to build a model of sources involving a substantial saving of time of calculation in the simulation of treatment. (Author)
Energy Technology Data Exchange (ETDEWEB)
Planes Meseguer, D.; Dorado Rodriguez, M. P.; Esposito, R. D.
2011-07-01
In this paper we present our solution for the realization of the monthly periodic quality control (CP) geometry - mechanical and multi leaf collimator (MLC), using the electronic system for portal imaging (EPI). We have developed specific programs created with free software. The monitoring results are automatically stored on our web server, along with other information generated in our service.
Directory of Open Access Journals (Sweden)
Leonardo F. V. dos Santos
2011-01-01
Full Text Available O ZNIBU, acelerador de caráter lento foi avaliado neste trabalho em composições de polibutadieno. Este acelerador foi sintetizado com o objetivo de substituir, ou reduzir, o uso de alguns aceleradores comerciais muito utilizados em composições elastoméricas mas que, por serem formadores de nitrosaminas, podem ser prejudiciais à saúde. A fim de corrigir o caráter de acelerador lento do ZNIBU, este composto foi utilizado em conjunto com o acelerador comercial CBS (N-ciclohexil-2-benzotiazol-2-sulfenamida. Foi observado que pequenas quantidades dos dois aceleradores não são efetivas na aceleração da vulcanização nas composições do tipo goma pura. No entanto a presença de negro de fumo exerce um efeito positivo sobre a velocidade. As propriedades mecânicas estudadas mostram que o ZNIBU aumenta a resistência à tração da goma pura (35%, em comparação com a composição similar vulcanizada com CBS e, na presença do negro de fumo, este aumento é ainda mais expressivo (175%. Quanto à resistência ao rasgamento, a vulcanização com o ZNIBU forneceu o mais baixo valor da propriedade para a goma pura, enquanto que a composição com negro de fumo apresentou o mais alto valor.ZNIBU, a slow accelerator, was evaluated in polybutadiene compositions. This accelerator was synthesized intending to replace or reduce the use of some very used commercial accelerators in rubber compositions which, due to their nitrosamine-forming potential, can be harmful to health. In order to correct for the slow accelerating character ZNIBU was used in combination with the commercial accelerator CBS (N-cyclohexyl-2-benzothiazole-2-sulfenamide. It was observed that small amounts of the accelerators are not effective in the vulcanization accelerating process of gum type compositions. Nevertheless, the presence of carbon black exerts a positive effect on the reaction rate. The investigated mechanical properties show that ZNIBU improves stress strength of
Directory of Open Access Journals (Sweden)
Leonardo de A. Monteiro
2011-06-01
Full Text Available A utilização correta de pneus em tratores, tanto em relação ao seu tipo quanto à calibração de sua pressão interna, e a lastragem ideal para cada condição de carga são fatores que influem significativamente no desempenho do trator. Esta pesquisa teve como objetivo comparar o desempenho de um trator equipado com pneus radiais e com pneus diagonais, para três condições de lastragem líquida (0%, 40% e 75% de água, em três condições superficiais de um Nitossolo Vermelho distrófico (superfície firme, preparada e com cobertura vegetal de resto de milho e em três velocidades teóricas de deslocamento (4 km h-1, 5 km h-1 e 7 km h-1, informadas no painel do trator, correspondendo às marchas B1, B2 e C1. O melhor desempenho do trator, equipado com pneu diagonal, ocorreu na condição de 75% de água nos pneus, apresentando maior velocidade de deslocamento, menor patinhagem do trator, menor consumo horário de combustível e gerando maior potência na barra de tração. Com pneus radiais, o melhor desempenho do trator ocorreu na condição de 40% de água nos pneus, proporcionando maiores velocidades de deslocamento do trator, menores patinhagens, menores consumos, horário e específico de combustível, e maiores potência e rendimento na barra de tração.The correct use of tires, as for its construction type as for internal pressure calibration and the optimal weighting for each load condition are factors that impact significantly on their performance. This study aimed to compare the performance of a tractor equipped with radial tires and bias ply tires in three conditions of liquid ballast (0%, 40% and 75% water, three surface conditions of a Dystrophic Red Alfisol (firm surface, tillage surface and surface with corn residues coverage and three theoretical traveling speeds (4 km h-1, 5 km h-1 and 7 km h-1, as indicated at the tractor display, related to the gear boxes B1, B2 and C1. The best tractor's performance, equipped with
Shilov, Georgi E
1977-01-01
Covers determinants, linear spaces, systems of linear equations, linear functions of a vector argument, coordinate transformations, the canonical form of the matrix of a linear operator, bilinear and quadratic forms, Euclidean spaces, unitary spaces, quadratic forms in Euclidean and unitary spaces, finite-dimensional space. Problems with hints and answers.
Vretenar, M
2014-01-01
The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics.
International Nuclear Information System (INIS)
The Neutrons and Reactors Laboratory (NYR) of CAB (Centro Atomico Bariloche) is equipped with a linear electron accelerator (LINAC) Linear particle accelerator). This LINAC is used as a neutron source from which two beams are extracted to perform neutron transmission and dispersion experiments. Through these experiments, structural and dynamic properties of materials can be studied. The neutron transmission experiments consist in a collimated neutron beam which interacts with a sample and a detector behind the sample. Important information about the microstructural characteristics of the material can be obtained from the comparison between neutron spectra before and after the interaction with the sample. This experimental technique has been extensively used to determine cross sections, lattice parameters of a crystalline solid, vibration frequencies of atoms or the strain field of a material. In the NYR Laboratory, cylindrical samples of one inch of diameter have been traditionally studied. Nonetheless, there is a great motivation for doing systematic research on smaller and with different geometries samples; particularly sheets and samples for tensile tests. In such cases, a reduction of the spot size of the beam and an increase of its intensity would have a direct impact on minimizing measurement times. Hence, in the NYR Laboratory it has been considered the possibility of incorporating a neutron guide into the existent transmission line. According to all mentioned above, the main objective of this work consisted in the optimization of the flight transmission tube optics of neutrons. This optimization not only improved the existent line but also contributed to an election criterion for the neutron guide acquisition. The optimization was directed towards maximize the neutron flux on samples of mentioned geometries and to form the divergence of the incident beam upon them. It was then necessary to study the instrument neutron optics, i.e. the characteristics of the
Energy Technology Data Exchange (ETDEWEB)
Salgado, Ana Paula; Pereira, Walsan Wagner; Patrao, Karla C. de Souza; Fonseca, Evaldo S. da, E-mail: asalgado@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Batista, Delano V.S. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil)
2009-07-01
The Neutron Laboratory of the Radioprotection and Dosimetry Institute - IRD/CNEN, Rio de Janeiro, Brazil, initiated studies on the process of calibration of neutron area monitors and the results of the measurements performed at radiotherapy treatment rooms, containing clinical accelerators
International Nuclear Information System (INIS)
From November 28 to December 9, the Stanford Linear Accelerator Center hosted an International Workshop on Next Generation Linear Colliders. The attendance, including delegations from CERN, Frascati (Italy), KEK (Japan), Livermore (US), Novosibirsk (USSR), Drsay (France) and SLAC itself reflected the international interest in this new approach to higher energies
Stoll, R R
1968-01-01
Linear Algebra is intended to be used as a text for a one-semester course in linear algebra at the undergraduate level. The treatment of the subject will be both useful to students of mathematics and those interested primarily in applications of the theory. The major prerequisite for mastering the material is the readiness of the student to reason abstractly. Specifically, this calls for an understanding of the fact that axioms are assumptions and that theorems are logical consequences of one or more axioms. Familiarity with calculus and linear differential equations is required for understand
Liesen, Jörg
2015-01-01
This self-contained textbook takes a matrix-oriented approach to linear algebra and presents a complete theory, including all details and proofs, culminating in the Jordan canonical form and its proof. Throughout the development, the applicability of the results is highlighted. Additionally, the book presents special topics from applied linear algebra including matrix functions, the singular value decomposition, the Kronecker product and linear matrix equations. The matrix-oriented approach to linear algebra leads to a better intuition and a deeper understanding of the abstract concepts, and therefore simplifies their use in real world applications. Some of these applications are presented in detailed examples. In several ‘MATLAB-Minutes’ students can comprehend the concepts and results using computational experiments. Necessary basics for the use of MATLAB are presented in a short introduction. Students can also actively work with the material and practice their mathematical skills in more than 300 exerc...
Sahai, Vivek
2013-01-01
Beginning with the basic concepts of vector spaces such as linear independence, basis and dimension, quotient space, linear transformation and duality with an exposition of the theory of linear operators on a finite dimensional vector space, this book includes the concept of eigenvalues and eigenvectors, diagonalization, triangulation and Jordan and rational canonical forms. Inner product spaces which cover finite dimensional spectral theory and an elementary theory of bilinear forms are also discussed. This new edition of the book incorporates the rich feedback of its readers. We have added new subject matter in the text to make the book more comprehensive. Many new examples have been discussed to illustrate the text. More exercises have been included. We have taken care to arrange the exercises in increasing order of difficulty. There is now a new section of hints for almost all exercises, except those which are straightforward, to enhance their importance for individual study and for classroom use.
Edwards, Harold M
1995-01-01
In his new undergraduate textbook, Harold M Edwards proposes a radically new and thoroughly algorithmic approach to linear algebra Originally inspired by the constructive philosophy of mathematics championed in the 19th century by Leopold Kronecker, the approach is well suited to students in the computer-dominated late 20th century Each proof is an algorithm described in English that can be translated into the computer language the class is using and put to work solving problems and generating new examples, making the study of linear algebra a truly interactive experience Designed for a one-semester course, this text adopts an algorithmic approach to linear algebra giving the student many examples to work through and copious exercises to test their skills and extend their knowledge of the subject Students at all levels will find much interactive instruction in this text while teachers will find stimulating examples and methods of approach to the subject
Allenby, Reg
1995-01-01
As the basis of equations (and therefore problem-solving), linear algebra is the most widely taught sub-division of pure mathematics. Dr Allenby has used his experience of teaching linear algebra to write a lively book on the subject that includes historical information about the founders of the subject as well as giving a basic introduction to the mathematics undergraduate. The whole text has been written in a connected way with ideas introduced as they occur naturally. As with the other books in the series, there are many worked examples.Solutions to the exercises are available onlin
Inauguran nuevo tunel de acelerador
Macedo, C
2003-01-01
"Contendra el Gran Colisionador de Hadrones del CERN. Ayer fue inaugurado el tunel subterraneo que acogera al experimento ATLAS, uno de los cuatro xperimentos que integraran el Gran Colisionador de Hadrones (LHC), que es construido en el Centro Europeo para la Investigacion Nuclear (CERN), en Ginebra" (1/3 page).
Karloff, Howard
1991-01-01
To this reviewer’s knowledge, this is the first book accessible to the upper division undergraduate or beginning graduate student that surveys linear programming from the Simplex Method…via the Ellipsoid algorithm to Karmarkar’s algorithm. Moreover, its point of view is algorithmic and thus it provides both a history and a case history of work in complexity theory. The presentation is admirable; Karloff's style is informal (even humorous at times) without sacrificing anything necessary for understanding. Diagrams (including horizontal brackets that group terms) aid in providing clarity. The end-of-chapter notes are helpful...Recommended highly for acquisition, since it is not only a textbook, but can also be used for independent reading and study. —Choice Reviews The reader will be well served by reading the monograph from cover to cover. The author succeeds in providing a concise, readable, understandable introduction to modern linear programming. —Mathematics of Computing This is a textbook intend...
Bourlès, Henri
2013-01-01
Linear systems have all the necessary elements (modeling, identification, analysis and control), from an educational point of view, to help us understand the discipline of automation and apply it efficiently. This book is progressive and organized in such a way that different levels of readership are possible. It is addressed both to beginners and those with a good understanding of automation wishing to enhance their knowledge on the subject. The theory is rigorously developed and illustrated by numerous examples which can be reproduced with the help of appropriate computation software. 60 exe
Reduction of Linear Programming to Linear Approximation
Vaserstein, Leonid N.
2006-01-01
It is well known that every Chebyshev linear approximation problem can be reduced to a linear program. In this paper we show that conversely every linear program can be reduced to a Chebyshev linear approximation problem.
LINEAR SYSTEMS AND LINEAR INTERPOLATION I
Institute of Scientific and Technical Information of China (English)
丁立峰
2001-01-01
he linear interpolation of linear system on a family of linear systems is introduced and discussed. Some results and examples on singly generated systems on a finite dimensional vector space are given.
Energy Technology Data Exchange (ETDEWEB)
Fax, X.; Piro, N.; Sanchez, N.; Toribio, I.; Hermida, M.; Seioane, A.; Saez, J.; Beltran, M.
2011-07-01
We have studied the feasibility of Varian portal vision system AS500-II, dosimetry calibration mode, as a substitute for radiochromic plates in quality control tests that required the use of such film. Over a period of two months have been analyzed both the dosimetric characteristics of the system and the mechanical positioning. In addition there has been a financial estimate of annual savings that would result from replacing the radiochromic film by the portal system in a multi-energy accelerator.
Energy Technology Data Exchange (ETDEWEB)
Torres Pozas, S.; Monja Rey, P. de la; Sanchez Carrasca, M.; Yanez Lopez, D.; Macias Verde, D.; Martin Oliva, R.
2011-07-01
In recent years, the progress experienced in cancer treatment with ionizing radiation can deliver higher doses to smaller volumes and better shaped, making it necessary to take into account new aspects in the calculation of structural barriers. Furthermore, given that forecasts suggest that in the near future will install a large number of accelerators, or existing ones modified, we believe a useful tool to estimate the thickness of the structural barriers of treatment rooms. The shielding calculation methods are based on standard DIN 6847-2 and the recommendations given by the NCRP 151. In our experience we found only estimates originated from the DIN. Therefore, we considered interesting to develop an application that incorporates the formulation suggested by the NCRP, together with previous work based on the rules DIN allow us to establish a comparison between the results of both methods. (Author)
Energy Technology Data Exchange (ETDEWEB)
Velazquez Miranda, S.; Jimenez Domingiuez, M.; Mateos Perez, J. C.; Herrador Cordoba, M.
2011-07-01
The new design of carbon treatment tables for rotational IMRT application is being submitted in multiple publications, all dosimetric test to determine their influence on treatment. In most publications can be concluded that their influence is not negligible, especially in near-horizontal angles. In the case of IMRT its influence becomes non-intuitive and therefore difficult to estimate. These publications can not consider all the possibilities of clinical practice, so that its applicability is limited. We propose, therefore, a role-table with the exact geometry of the treatment and density adjusted to the experimental data, to resolve the estimation of their influence in each clinical case.
Energy Technology Data Exchange (ETDEWEB)
Sierra Diaz, F.; Gonzalez Ruiz, C.; Garcia Marcos, R.; Gallego Franco, P.; Rodriguez Checa, M.; Gomez Calvar, R.; Lopez Bote, M. A.
2013-07-01
The objective is to show how the working procedures, have been defined unambiguously to ensure together with the structure of the installation, and optimally located elements of radiation protection, compliance with the classification of areas, occupation factors and rates expected according to them. (Author)
Linear Algebra and Smarandache Linear Algebra
Vasantha, Kandasamy
2003-01-01
The present book, on Smarandache linear algebra, not only studies the Smarandache analogues of linear algebra and its applications, it also aims to bridge the need for new research topics pertaining to linear algebra, purely in the algebraic sense. We have introduced Smarandache semilinear algebra, Smarandache bilinear algebra and Smarandache anti-linear algebra and their fuzzy equivalents. Moreover, in this book, we have brought out the study of linear algebra and ve...
... News Physician Resources Professions Site Index A-Z Linear Accelerator A linear accelerator (LINAC) customizes high energy x-rays to ... ensured? What is this equipment used for? A linear accelerator (LINAC) is the device most commonly used ...
Linearly constrained minimax optimization
DEFF Research Database (Denmark)
Madsen, Kaj; Schjær-Jacobsen, Hans
1978-01-01
We present an algorithm for nonlinear minimax optimization subject to linear equality and inequality constraints which requires first order partial derivatives. The algorithm is based on successive linear approximations to the functions defining the problem. The resulting linear subproblems are...
Foundations of linear and generalized linear models
Agresti, Alan
2015-01-01
A valuable overview of the most important ideas and results in statistical analysis Written by a highly-experienced author, Foundations of Linear and Generalized Linear Models is a clear and comprehensive guide to the key concepts and results of linear statistical models. The book presents a broad, in-depth overview of the most commonly used statistical models by discussing the theory underlying the models, R software applications, and examples with crafted models to elucidate key ideas and promote practical model building. The book begins by illustrating the fundamentals of linear models,
Energy Technology Data Exchange (ETDEWEB)
Santana, Emico Ferreira; Milian, Felix Mas; Paixao, Paulo Oliveira; Costa, Raranna Alves da; Velasco, Fermin Garcia, E-mail: efsantana@uesc.br, E-mail: f.mas.milian@gmail.com, E-mail: popaixao@uesc.br, E-mail: racosta@uesc.br, E-mail: fermingv@gmail.com [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil)
2015-07-01
In this paper is used a computational code of radiation transport simulation based on Monte Carlo technique, in order to model a linear accelerator of treatment by Radiotherapy. This work is the initial step of future proposals which aim to study several treatment of patient by Radiotherapy, employing computational modeling in cooperation with the institutions UESC, IPEN, UFRJ e COI. The Chosen simulation code is GATE/Geant4. The average accelerator is TrueBeam of Varian Company. The geometric modeling was based in technical manuals, and radiation sources on the phase space for photons, provided by manufacturer in the IAEA (International Atomic Energy Agency) format. The simulations were carried out in equal conditions to experimental measurements. Were studied photons beams of 6MV, with 10 per 10 cm of field, focusing on a water phantom. For validation were compared dose curves in depth, lateral profiles in different depths of the simulated results and experimental data. The final modeling of this accelerator will be used in future works involving treatments and real patients. (author)
Energy Technology Data Exchange (ETDEWEB)
Gaona, E.; Azorin N, J.; Perez, M.A.; Picon, C.; Castellanos, E.; Plazas, M.C.; Murcia, G.; Archundia, L. [Depto. El Hombre y su Ambiente. Universidad Autonoma Metropolitana, Calz. Del Hueso 1100, 04960 Mexico D.F. (Mexico)
1998-12-31
In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at
Energy Technology Data Exchange (ETDEWEB)
Moreno, S. [Universidade da Beira Interior (UBI), Covilha (Portugal); Chaves, A.; Lopes, M.C. [Instituto Portugues de Oncologia Doutor Francisco Gentil (IPO), Coimbra (Portugal); Peralta, L. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas (LIP), Lisboa (Portugal)]|[Universidade de Lisboa (Portugal). Faculdade de Ciencias
2004-07-01
The advent of linear accelerators (linac) with computer-controlled dynamic collimation systems and functional and anatomical imaging techniques allowed a more exact delimitation and localisation of the target volume. These advanced treatment techniques inevitably increase the complexity level of dose calculation because of the introduction of the temporal variable. On account of this, it is mandatory the usage of more accurate modelling techniques of the collimator components, as it is the case of Monte Carlo (MC) simulation, which has created an enormous interest in research and clinical practice. Because the patients bodies are not homogenous nor are their body surfaces plane and regular, the dose distribution may differ significantly from the standard distribution from the linac calibration. It is in the treatment planning systems, which include algorithms that are usually measured in homogeneous water phantoms specific for each correction that the dose distributions from each case are obtained. In a real treatment, exception made to superficial lesions, two or more radiation fields are used in order to obtain the recommended dose distributions. The simplest arrangement is made from two parallel and opposed fields that originate a homogeneous dose distribution in almost all the irradiated volume. The available resources are, for example, different types of energies and of radiation, the application of bolus, the protection of healthy structures, the usage of wedged filters and the application of dynamic wedges. A virtual or dynamic wedge, modelled through the movement of one of the jaws, when compared with a set of physical wedges offers an alternative calculation method of an arbitrary number of wedged fields, instead of the four traditional fields of 15 deg, 30 deg, 45 deg and 60 deg angle and obtained with physical wedges. The goal of this work consists in the study of the application of dynamic wedges in tailoring the radiation field by the Varian Clinac 600
Energy Technology Data Exchange (ETDEWEB)
Paredes G, L.C. [Instituto Nacional de Investigaciones Nucleares, Direccion de Innovacion Tecnologica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)
2001-07-01
An investigation was made on the theoretical fundamentals for the determination of the neutron fluence in a linear electron accelerator for radiotherapy applications and the limit values of leakage neutron radiation established by guidelines and standards in radiation protection for these type of accelerators. This investigation includes the following parts: a) Exhaustive bibliographical review on the topics mentioned above, in order to combine and to update the necessary basic information to facilitate the understanding of this subject; b) Analysis of the accelerator operation and identification of its main components, specially in the accelerator head; c) Study of different types of targets and its materials for the Bremsstrahlung production which is based on the electron initial energy, the thickness of the target, and its angular distribution and energy, which influences in the neutron generation by means of the photonuclear and electro disintegration reactions; d) Analysis of the neutron yield based on the target type and its thickness, the energy of electrons and photons; e) Analysis of the neutron energy spectra generated in the accelerator head, inside and outside the treatment room; f) Study of the dosimetry fundamentals for neutron and photon mixed fields, the dosimeter selection criteria and standards applied for these applications, specially the Panasonic U D-809 thermoluminescent dosemeter and C R-39 nuclear track dosimeter; g) Theoretical calculation of the neutron yield using a simplified geometric model for the accelerator head with spherical cell, which considers the target, primary collimator, flattener filter, movable collimators and the head shielding as the main components for radiation production. The cases with W and Pb shielding for closed movable collimators and an irradiation field of 20 x 20 cm{sup 2} were analyzed and, h) Experimental evaluation of the leakage neutron radiation from the patient and head planes, observing that the
Switched linear encoding with rectified linear autoencoders
Johnson, Leif; Corcoran, Craig
2013-01-01
Several recent results in machine learning have established formal connections between autoencoders---artificial neural network models that attempt to reproduce their inputs---and other coding models like sparse coding and K-means. This paper explores in depth an autoencoder model that is constructed using rectified linear activations on its hidden units. Our analysis builds on recent results to further unify the world of sparse linear coding models. We provide an intuitive interpretation of ...
Directory of Open Access Journals (Sweden)
J. R. Garcia
2007-03-01
Full Text Available Um dos aspectos principais para o desenvolvimento de concretos refratários está no aprimoramento dos conhecimentos sobre o cimento de alta alumina ou cimento de aluminato de cálcio (CAC, já que esse ligante é o mais utilizado nesta classe de produtos. O objetivo desse trabalho foi o de analisar as informações disponíveis na literatura para se obter um conhecimento mais aprofundado dos mecanismos de ação dos aditivos retardadores e aceleradores da pega deste cimento. Da análise dos dados compilados pode-se concluir que os aditivos retardadores agem geralmente de duas maneiras: 1 dificultando o processo de dissolução do cimento, por meio da formação de barreiras insolúveis ao redor das suas partículas e 2 favorecendo a formação de hidratos mais solúveis, o que aumenta o tempo necessário para que se inicie a precipitação. Por outro lado, os aditivos aceleradores de pega podem atuar favorecendo a formação de hidratos menos solúveis, diminuindo assim o tempo necessário para a precipitação ou ainda pela formação de núcleos iniciadores do processo de crescimento dos cristais dos hidratos. A análise destas informações leva a constatação de que a ação de alguns aditivos retardadores e aceleradores ocorre em estágios distintos no processo de hidratação do CAC. Portanto, pode-se imaginar uma situação onde a combinação desses dois aditivos poderia conferir um tempo de trabalhabilidade adequado e seguro, aliado a um curto tempo de desmoldagem.One of the main aspects for the development of refractories castables is to master the knowledge regarding calcium aluminate cement (CAC, as this binder is the most applied in these products. The objective of this work was to analyze the available information in the literature in order to explain the understanding regarding the actions of retarder and accelerator additives in the setting mechanisms of CACs. The analysis of the compiled information pointed out that the
Institute of Scientific and Technical Information of China (English)
T. (A)LVAREZ
2012-01-01
For a closed linear relation in a Banach space the concept of regularity is introduced and studied.It is shown that many of the results of Mbekhta and other authors for operators remain valid in the context of multivalued linear operators.We also extend the punctured neighbourhood theorem for operators to linear relations and as an application we obtain a characterization of semiFredholm linear relations which are regular.
Classifying Linear Canonical Relations
Lorand, Jonathan
2015-01-01
In this Master's thesis, we consider the problem of classifying, up to conjugation by linear symplectomorphisms, linear canonical relations (lagrangian correspondences) from a finite-dimensional symplectic vector space to itself. We give an elementary introduction to the theory of linear canonical relations and present partial results toward the classification problem. This exposition should be accessible to undergraduate students with a basic familiarity with linear algebra.
Lawson, C. L.; Krogh, F. T.; Gold, S. S.; Kincaid, D. R.; Sullivan, J.; Williams, E.; Hanson, R. J.; Haskell, K.; Dongarra, J.; Moler, C. B.
1982-01-01
The Basic Linear Algebra Subprograms (BLAS) library is a collection of 38 FORTRAN-callable routines for performing basic operations of numerical linear algebra. BLAS library is portable and efficient source of basic operations for designers of programs involving linear algebriac computations. BLAS library is supplied in portable FORTRAN and Assembler code versions for IBM 370, UNIVAC 1100 and CDC 6000 series computers.
Cooperstein, Bruce
2010-01-01
Vector SpacesFieldsThe Space FnVector Spaces over an Arbitrary Field Subspaces of Vector SpacesSpan and IndependenceBases and Finite Dimensional Vector SpacesBases and Infinite Dimensional Vector SpacesCoordinate VectorsLinear TransformationsIntroduction to Linear TransformationsThe Range and Kernel of a Linear TransformationThe Correspondence and Isomorphism TheoremsMatrix of a Linear TransformationThe Algebra of L(V, W) and Mmn(F)Invertible Transformations and MatricesPolynomialsThe Algebra of PolynomialsRoots of PolynomialsTheory of a Single Linear OperatorInvariant Subspaces of an Operator
Non linear system become linear system
Directory of Open Access Journals (Sweden)
Petre Bucur
2007-01-01
Full Text Available The present paper refers to the theory and the practice of the systems regarding non-linear systems and their applications. We aimed the integration of these systems to elaborate their response as well as to highlight some outstanding features.
Blyth, T S
2002-01-01
Basic Linear Algebra is a text for first year students leading from concrete examples to abstract theorems, via tutorial-type exercises. More exercises (of the kind a student may expect in examination papers) are grouped at the end of each section. The book covers the most important basics of any first course on linear algebra, explaining the algebra of matrices with applications to analytic geometry, systems of linear equations, difference equations and complex numbers. Linear equations are treated via Hermite normal forms which provides a successful and concrete explanation of the notion of linear independence. Another important highlight is the connection between linear mappings and matrices leading to the change of basis theorem which opens the door to the notion of similarity. This new and revised edition features additional exercises and coverage of Cramer's rule (omitted from the first edition). However, it is the new, extra chapter on computer assistance that will be of particular interest to readers:...
Linearity in Process Languages
DEFF Research Database (Denmark)
Nygaard, Mikkel; Winskel, Glynn
2002-01-01
The meaning and mathematical consequences of linearity (managing without a presumed ability to copy) are studied for a path-based model of processes which is also a model of affine-linear logic. This connection yields an affine-linear language for processes, automatically respecting open-map bisi......-map bisimulation, in which a range of process operations can be expressed. An operational semantics is provided for the tensor fragment of the language. Different ways to make assemblies of processes lead to different choices of exponential, some of which respect bisimulation.......The meaning and mathematical consequences of linearity (managing without a presumed ability to copy) are studied for a path-based model of processes which is also a model of affine-linear logic. This connection yields an affine-linear language for processes, automatically respecting open...
Shelah, Saharon
2011-01-01
We address the following question: Can we expand an NIP theory by adding a linear order such that the expansion is still NIP? Easily, if acl(A)=A for all A, then this is true. Otherwise, we give counterexamples. More precisely, there is a totally categorical theory for which every expansion by a linear order has IP. There is also an \\omega-stable NDOP theory for which every expansion by a linear order interprets bounded arithmetic.
Carr, Joseph
1996-01-01
The linear IC market is large and growing, as is the demand for well trained technicians and engineers who understand how these devices work and how to apply them. Linear Integrated Circuits provides in-depth coverage of the devices and their operation, but not at the expense of practical applications in which linear devices figure prominently. This book is written for a wide readership from FE and first degree students, to hobbyists and professionals.Chapter 1 offers a general introduction that will provide students with the foundations of linear IC technology. From chapter 2 onwa
Faraway, Julian J
2014-01-01
A Hands-On Way to Learning Data AnalysisPart of the core of statistics, linear models are used to make predictions and explain the relationship between the response and the predictors. Understanding linear models is crucial to a broader competence in the practice of statistics. Linear Models with R, Second Edition explains how to use linear models in physical science, engineering, social science, and business applications. The book incorporates several improvements that reflect how the world of R has greatly expanded since the publication of the first edition.New to the Second EditionReorganiz
Alemania planea un nuevo gran acelerador
Rivera, Alicia
2001-01-01
A tunnel of about 33 km will cross Alemania from Hamburg, if the project is agreed, to make a new particle accelarator, TESLA. In this tunnel, electrons and positrons will be accelerated to collide and to allow physicists to find the mysteries of the cosmos. TESLA will complement CERN (1 page)
International Nuclear Information System (INIS)
An improved recirculating electron beam linear accelerator of the racetrack type is described. The system comprises a beam path of four straight legs with four Pretzel bending magnets at the end of each leg to direct the beam into the next leg of the beam path. At least one of the beam path legs includes a linear accelerator. (UK)
Linear Logical Voting Protocols
DEFF Research Database (Denmark)
DeYoung, Henry; Schürmann, Carsten
2012-01-01
. In response, we promote linear logic as a high-level language for both specifying and implementing voting protocols. Our linear logical specifications of the single-winner first-past-the-post (SW- FPTP) and single transferable vote (STV) protocols demonstrate that this approach leads to concise...
Linear Equations: Equivalence = Success
Baratta, Wendy
2011-01-01
The ability to solve linear equations sets students up for success in many areas of mathematics and other disciplines requiring formula manipulations. There are many reasons why solving linear equations is a challenging skill for students to master. One major barrier for students is the inability to interpret the equals sign as anything other than…
Handbook on linear motor application
International Nuclear Information System (INIS)
This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.
Efficient Non Linear Loudspeakers
DEFF Research Database (Denmark)
Petersen, Bo R.; Agerkvist, Finn T.
2006-01-01
Loudspeakers have traditionally been designed to be as linear as possible. However, as techniques for compensating non linearities are emerging, it becomes possible to use other design criteria. This paper present and examines a new idea for improving the efficiency of loudspeakers at high levels...... by changing the voice coil layout. This deliberate non-linear design has the benefit that a smaller amplifier can be used, which has the benefit of reducing system cost as well as reducing power consumption.......Loudspeakers have traditionally been designed to be as linear as possible. However, as techniques for compensating non linearities are emerging, it becomes possible to use other design criteria. This paper present and examines a new idea for improving the efficiency of loudspeakers at high levels...
Axler, Sheldon
2015-01-01
This best-selling textbook for a second course in linear algebra is aimed at undergrad math majors and graduate students. The novel approach taken here banishes determinants to the end of the book. The text focuses on the central goal of linear algebra: understanding the structure of linear operators on finite-dimensional vector spaces. The author has taken unusual care to motivate concepts and to simplify proofs. A variety of interesting exercises in each chapter helps students understand and manipulate the objects of linear algebra. The third edition contains major improvements and revisions throughout the book. More than 300 new exercises have been added since the previous edition. Many new examples have been added to illustrate the key ideas of linear algebra. New topics covered in the book include product spaces, quotient spaces, and dual spaces. Beautiful new formatting creates pages with an unusually pleasant appearance in both print and electronic versions. No prerequisites are assumed other than the ...
Semidefinite linear complementarity problems
International Nuclear Information System (INIS)
Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.)
Kandasamy, W B Vasantha
2008-01-01
In this book, the authors introduce the notion of Super linear algebra and super vector spaces using the definition of super matrices defined by Horst (1963). This book expects the readers to be well-versed in linear algebra. Many theorems on super linear algebra and its properties are proved. Some theorems are left as exercises for the reader. These new class of super linear algebras which can be thought of as a set of linear algebras, following a stipulated condition, will find applications in several fields using computers. The authors feel that such a paradigm shift is essential in this computerized world. Some other structures ought to replace linear algebras which are over a century old. Super linear algebras that use super matrices can store data not only in a block but in multiple blocks so it is certainly more powerful than the usual matrices. This book has 3 chapters. Chapter one introduces the notion of super vector spaces and enumerates a number of properties. Chapter two defines the notion of sup...
Weisberg, Sanford
2005-01-01
Master linear regression techniques with a new edition of a classic text Reviews of the Second Edition: ""I found it enjoyable reading and so full of interesting material that even the well-informed reader will probably find something new . . . a necessity for all of those who do linear regression."" -Technometrics, February 1987 ""Overall, I feel that the book is a valuable addition to the now considerable list of texts on applied linear regression. It should be a strong contender as the leading text for a first serious course in regression analysis."" -American Scientist, May-June 1987
Weisberg, Sanford
2013-01-01
Praise for the Third Edition ""...this is an excellent book which could easily be used as a course text...""-International Statistical Institute The Fourth Edition of Applied Linear Regression provides a thorough update of the basic theory and methodology of linear regression modeling. Demonstrating the practical applications of linear regression analysis techniques, the Fourth Edition uses interesting, real-world exercises and examples. Stressing central concepts such as model building, understanding parameters, assessing fit and reliability, and drawing conclusions, the new edition illus
Amir-Moez, A R; Sneddon, I N
1962-01-01
Elements of Linear Space is a detailed treatment of the elements of linear spaces, including real spaces with no more than three dimensions and complex n-dimensional spaces. The geometry of conic sections and quadric surfaces is considered, along with algebraic structures, especially vector spaces and transformations. Problems drawn from various branches of geometry are given.Comprised of 12 chapters, this volume begins with an introduction to real Euclidean space, followed by a discussion on linear transformations and matrices. The addition and multiplication of transformations and matrices a
Schneider, Hans
1989-01-01
Linear algebra is one of the central disciplines in mathematics. A student of pure mathematics must know linear algebra if he is to continue with modern algebra or functional analysis. Much of the mathematics now taught to engineers and physicists requires it.This well-known and highly regarded text makes the subject accessible to undergraduates with little mathematical experience. Written mainly for students in physics, engineering, economics, and other fields outside mathematics, the book gives the theory of matrices and applications to systems of linear equations, as well as many related t
Linear Network Fractional Routing
Directory of Open Access Journals (Sweden)
S.ASOKAN,
2011-07-01
Full Text Available A Network is a finite directed acyclic graph with source messages from a fixed alphabet and message demands at sink nodes. Linear Programming is an algorithm design method. It can be used whenthe solution to a problem can be viewed as the result of a sequence of decisions. The Linear Programming model for the network problem where in every variable has a value one or zero. The problem is todetermine a method of transmitting the messages through the network such that all sink demands are satisfied. We will prove fractional routing capacity for some solvable network using Linear Programmingmodel.
Isolated linear blaschkoid psoriasis.
Nasimi, M; Abedini, R; Azizpour, A; Nikoo, A
2016-10-01
Linear psoriasis (LPs) is considered a rare clinical presentation of psoriasis, which is characterized by linear erythematous and scaly lesions along the lines of Blaschko. We report the case of a 20-year-old man who presented with asymptomatic linear and S-shaped erythematous, scaly plaques on right side of his trunk. The plaques were arranged along the lines of Blaschko with a sharp demarcation at the midline. Histological examination of a skin biopsy confirmed the diagnosis of psoriasis. Topical calcipotriol and betamethasone dipropionate ointments were prescribed for 2 months. A good clinical improvement was achieved, with reduction in lesion thickness and scaling. In patients with linear erythematous and scaly plaques along the lines of Blaschko, the diagnosis of LPs should be kept in mind, especially in patients with asymptomatic lesions of late onset. PMID:27663156
Unsupervised Linear Discriminant Analysis
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
An algorithm for unsupervised linear discriminant analysis was presented. Optimal unsupervised discriminant vectors are obtained through maximizing covariance of all samples and minimizing covariance of local k-nearest neighbor samples. The experimental results show our algorithm is effective.
Shetty, Shricharith; Rao, Raghavendra; Kudva, R Ranjini; Subramanian, Kumudhini
2016-01-01
Alopecia areata (AA) over scalp is known to present in various shapes and extents of hair loss. Typically it presents as circumscribed patches of alopecia with underlying skin remaining normal. We describe a rare variant of AA presenting in linear band-like form. Only four cases of linear alopecia have been reported in medical literature till today, all four being diagnosed as lupus erythematosus profundus. PMID:27625568
Andrilli, Stephen
2010-01-01
Elementary Linear Algebra develops and explains in careful detail the computational techniques and fundamental theoretical results central to a first course in linear algebra. This highly acclaimed text focuses on developing the abstract thinking essential for further mathematical study. The authors give early, intensive attention to the skills necessary to make students comfortable with mathematical proofs. The text builds a gradual and smooth transition from computational results to general theory of abstract vector spaces. It also provides flexbile coverage of practical applications, expl
Linear Integer Arithmetic Revisited
Bromberger, M.; Sturm, T.; Weidenbach, C.
2015-01-01
We consider feasibility of linear integer programs in the context of verification systems such as SMT solvers or theorem provers. Although satisfiability of linear integer programs is decidable, many state-of-the-art solvers neglect termination in favor of efficiency. It is challenging to design a solver that is both terminating and practically efficient. Recent work by Jovanovic and de Moura constitutes an important step into this direction. Their algorithm CUTSAT is sound, but does not term...
Shetty, Shricharith; Rao, Raghavendra; Kudva, R Ranjini; Subramanian, Kumudhini
2016-01-01
Alopecia areata (AA) over scalp is known to present in various shapes and extents of hair loss. Typically it presents as circumscribed patches of alopecia with underlying skin remaining normal. We describe a rare variant of AA presenting in linear band-like form. Only four cases of linear alopecia have been reported in medical literature till today, all four being diagnosed as lupus erythematosus profundus. PMID:27625568
Energy Technology Data Exchange (ETDEWEB)
Santos, Maira R.; Silveira, Thiago B.; Garcia, Paulo L.; Trindade, Cassia; Martins, Lais P.; Batista, Delano V.S., E-mail: mairafisica@gmail.com [Instituto Nacional do Cancer (INCA), Rio de Janeiro, RJ (Brazil)
2013-08-15
Given the new methodology introduced in the shielding calculation due to recent modulated techniques in radiotherapy treatment, it became necessary to evaluate the impact of changes in the accelerator routine using such techniques. Based on a group of 30 patients from the National Cancer Institute (INCA) the workload multiplier factors for intensity modulated radiotherapy (IMRT factor) and for RapidArc™ (RA factor) were established. Four different routines in a 6 MV generic accelerator were proposed to estimate the impact of these modified workloads in the building cost of the secondary barriers. The results indicate that if 50% of patients are treating with IMRT, the secondary barrier becomes 14,1% more expensive than the barrier calculated for conformal treatments exclusive. While RA, in the same proportion, leads to a barrier only 3,7% more expensive. Showing that RA can, while reducing treatment time, increase the proportion of patients treated with modulation technique, without increasing the cost of the barrier, when compared with IMRT. (author)
Directory of Open Access Journals (Sweden)
Sinan AYDIN
2009-04-01
Full Text Available Linear algebra is a basic course followed in mathematics, science, and engineering university departments.Generally, this course is taken in either the first or second year but there have been difficulties in teachingand learning. This type of active algebra has resulted in an increase in research by mathematics educationresearchers. But there is insufficient information on this subject in Turkish and therefore it has not beengiven any educational status. This paper aims to give a general overview of this subject in teaching andlearning. These education studies can be considered quadruple: a the history of linear algebra, b formalismobstacles of linear algebra and cognitive flexibility to improve teaching and learning, c the relation betweenlinear algebra and geometry, d using technology in the teaching and learning linear algebra.Mathematicseducation researchers cannot provide an absolute solution to overcome the teaching and learning difficultiesof linear algebra. Epistemological analyses and experimental teaching have shown the learning difficulties.Given these results, further advice and assistance can be offered locally.
Blyth, T S
2002-01-01
Most of the introductory courses on linear algebra develop the basic theory of finite dimensional vector spaces, and in so doing relate the notion of a linear mapping to that of a matrix. Generally speaking, such courses culminate in the diagonalisation of certain matrices and the application of this process to various situations. Such is the case, for example, in our previous SUMS volume Basic Linear Algebra. The present text is a continuation of that volume, and has the objective of introducing the reader to more advanced properties of vector spaces and linear mappings, and consequently of matrices. For readers who are not familiar with the contents of Basic Linear Algebra we provide an introductory chapter that consists of a compact summary of the prerequisites for the present volume. In order to consolidate the student's understanding we have included a large num ber of illustrative and worked examples, as well as many exercises that are strategi cally placed throughout the text. Solutions to the ex...
DEFF Research Database (Denmark)
Høskuldsson, Agnar
1996-01-01
Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four of these cri......Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....
Banach, S
1987-01-01
This classic work by the late Stefan Banach has been translated into English so as to reach a yet wider audience. It contains the basics of the algebra of operators, concentrating on the study of linear operators, which corresponds to that of the linear forms a1x1 + a2x2 + ... + anxn of algebra.The book gathers results concerning linear operators defined in general spaces of a certain kind, principally in Banach spaces, examples of which are: the space of continuous functions, that of the pth-power-summable functions, Hilbert space, etc. The general theorems are interpreted in various mathematical areas, such as group theory, differential equations, integral equations, equations with infinitely many unknowns, functions of a real variable, summation methods and orthogonal series.A new fifty-page section (``Some Aspects of the Present Theory of Banach Spaces'''') complements this important monograph.
Classifications of Linear Controlled Systems
Li, Jing
2008-01-01
This paper is devoted to a study of linear, differential and topological classifications for linear controlled systems governed by ordinary differential equations. The necessary and sufficient conditions for the linear and topological equivalence are given. It is also shown that the differential equivalence is the same as the linear equivalence for the linear controlled systems.
Hogben, Leslie
2013-01-01
With a substantial amount of new material, the Handbook of Linear Algebra, Second Edition provides comprehensive coverage of linear algebra concepts, applications, and computational software packages in an easy-to-use format. It guides you from the very elementary aspects of the subject to the frontiers of current research. Along with revisions and updates throughout, the second edition of this bestseller includes 20 new chapters.New to the Second EditionSeparate chapters on Schur complements, additional types of canonical forms, tensors, matrix polynomials, matrix equations, special types of
Cooperstein, Bruce
2015-01-01
Advanced Linear Algebra, Second Edition takes a gentle approach that starts with familiar concepts and then gradually builds to deeper results. Each section begins with an outline of previously introduced concepts and results necessary for mastering the new material. By reviewing what students need to know before moving forward, the text builds a solid foundation upon which to progress. The new edition of this successful text focuses on vector spaces and the maps between them that preserve their structure (linear transformations). Designed for advanced undergraduate and beginning graduate stud
Green, Ben; Tao, Terence
2006-01-01
Consider a system \\Psi of non-constant affine-linear forms \\psi_1,...,\\psi_t: Z^d -> Z, no two of which are linearly dependent. Let N be a large integer, and let K be a convex subset of [-N,N]^d. A famous and difficult open conjecture of Hardy and Littlewood predicts an asymptotic, as N -> \\infty, for the number of integer points n in K for which the integers \\psi_1(n),...,\\psi_t(n) are simultaneously prime. This implies many other well-known conjectures, such as the Hardy-Littlewood prime tu...
Structured Stochastic Linear Bandits
Johnson, Nicholas; Sivakumar, Vidyashankar; Banerjee, Arindam
2016-01-01
The stochastic linear bandit problem proceeds in rounds where at each round the algorithm selects a vector from a decision set after which it receives a noisy linear loss parameterized by an unknown vector. The goal in such a problem is to minimize the (pseudo) regret which is the difference between the total expected loss of the algorithm and the total expected loss of the best fixed vector in hindsight. In this paper, we consider settings where the unknown parameter has structure, e.g., spa...
Non linear viscoelastic models
DEFF Research Database (Denmark)
Agerkvist, Finn T.
2011-01-01
Viscoelastic eects are often present in loudspeaker suspensions, this can be seen in the displacement transfer function which often shows a frequency dependent value below the resonance frequency. In this paper nonlinear versions of the standard linear solid model (SLS) are investigated. The...
Dobbs, David E.
2013-01-01
A direct method is given for solving first-order linear recurrences with constant coefficients. The limiting value of that solution is studied as "n to infinity." This classroom note could serve as enrichment material for the typical introductory course on discrete mathematics that follows a calculus course.
Duck, F
2010-01-01
The propagation of acoustic waves is a fundamentally non-linear process, and only waves with infinitesimally small amplitudes may be described by linear expressions. In practice, all ultrasound propagation is associated with a progressive distortion in the acoustic waveform and the generation of frequency harmonics. At the frequencies and amplitudes used for medical diagnostic scanning, the waveform distortion can result in the formation of acoustic shocks, excess deposition of energy, and acoustic saturation. These effects occur most strongly when ultrasound propagates within liquids with comparatively low acoustic attenuation, such as water, amniotic fluid, or urine. Attenuation by soft tissues limits but does not extinguish these non-linear effects. Harmonics may be used to create tissue harmonic images. These offer improvements over conventional B-mode images in spatial resolution and, more significantly, in the suppression of acoustic clutter and side-lobe artefacts. The quantity B/A has promise as a parameter for tissue characterization, but methods for imaging B/A have shown only limited success. Standard methods for the prediction of tissue in-situ exposure from acoustic measurements in water, whether for regulatory purposes, for safety assessment, or for planning therapeutic regimes, may be in error because of unaccounted non-linear losses. Biological effects mechanisms are altered by finite-amplitude effects. PMID:20349813
Finite-dimensional linear algebra
Gockenbach, Mark S
2010-01-01
Some Problems Posed on Vector SpacesLinear equationsBest approximationDiagonalizationSummaryFields and Vector SpacesFields Vector spaces Subspaces Linear combinations and spanning sets Linear independence Basis and dimension Properties of bases Polynomial interpolation and the Lagrange basis Continuous piecewise polynomial functionsLinear OperatorsLinear operatorsMore properties of linear operatorsIsomorphic vector spaces Linear operator equations Existence and uniqueness of solutions The fundamental theorem; inverse operatorsGaussian elimination Newton's method Linear ordinary differential eq
Linear Complete Differential Resultants and the Implicitization of Linear DPPEs
Rueda, Sonia L.; Sendra, J. Rafael
2007-01-01
The linear complete differential resultant of a finite set of linear ordinary differential polynomials is defined. We study the computation by linear complete differential resultants of the implicit equation of a system of $n$ linear differential polynomial parametric equations in $n-1$ differential parameters. We give necessary conditions to ensure properness of the system of differential polynomial parametric equations.
Extended linear chain compounds
Linear chain substances span a large cross section of contemporary chemistry ranging from covalent polymers, to organic charge transfer com plexes to nonstoichiometric transition metal coordination complexes. Their commonality, which coalesced intense interest in the theoretical and exper imental solid state physics/chemistry communities, was based on the obser vation that these inorganic and organic polymeric substrates exhibit striking metal-like electrical and optical properties. Exploitation and extension of these systems has led to the systematic study of both the chemistry and physics of highly and poorly conducting linear chain substances. To gain a salient understanding of these complex materials rich in anomalous aniso tropic electrical, optical, magnetic, and mechanical properties, the conver gence of diverse skills and talents was required. The constructive blending of traditionally segregated disciplines such as synthetic and physical organic, inorganic, and polymer chemistry, crystallog...
Birx, Daniel
1992-03-01
Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typicallymarriage of liner accelerator technology and nonlinear magnetic compressors has produced some unique capabilities. It now appears possible to produce electron beams with average currents measured in amperes, peak currents in kiloamperes and gradients exceeding 1 MeV/meter, with power efficiencies approaching 50%. The nonlinear magnetic compression technology has replaced the spark gap drivers used on earlier accelerators with state-of-the-art all-solid-state SCR commutated compression chains. The reliability of these machines is now approaching 1010 shot MTBF. In the following paper we will briefly review the historical development of induction linear accelerators and then discuss the design considerations.
Schmidt, Bruno E; Ernotte, Guilmot; Clerici, Matteo; Morandotti, Roberto; Ibrahim, Heide; Legare, Francois
2016-01-01
In the framework of linear optics, light fields do not interact with each other in a medium. Yet, when their field amplitude becomes comparable to the electron binding energies of matter, the nonlinear motion of these electrons emits new dipole radiation whose amplitude, frequency and phase differ from the incoming fields. Such high fields are typically achieved with ultra-short, femtosecond (1fs = 10-15 sec.) laser pulses containing very broad frequency spectra. Here, the matter not only couples incoming and outgoing fields but also causes different spectral components to interact and mix through a convolution process. In this contribution, we describe how frequency domain nonlinear optics overcomes the shortcomings arising from this convolution in conventional time domain nonlinear optics1. We generate light fields with previously inaccessible properties because the uncontrolled coupling of amplitudes and phases is turned off. For example, arbitrary phase functions are transferred linearly to the second har...
General linear chirplet transform
Yu, Gang; Zhou, Yiqi
2016-03-01
Time-frequency (TF) analysis (TFA) method is an effective tool to characterize the time-varying feature of a signal, which has drawn many attentions in a fairly long period. With the development of TFA, many advanced methods are proposed, which can provide more precise TF results. However, some restrictions are introduced inevitably. In this paper, we introduce a novel TFA method, termed as general linear chirplet transform (GLCT), which can overcome some limitations existed in current TFA methods. In numerical and experimental validations, by comparing with current TFA methods, some advantages of GLCT are demonstrated, which consist of well-characterizing the signal of multi-component with distinct non-linear features, being independent to the mathematical model and initial TFA method, allowing for the reconstruction of the interested component, and being non-sensitivity to noise.
Linearly Refined Session Types
Directory of Open Access Journals (Sweden)
Pedro Baltazar
2012-11-01
Full Text Available Session types capture precise protocol structure in concurrent programming, but do not specify properties of the exchanged values beyond their basic type. Refinement types are a form of dependent types that can address this limitation, combining types with logical formulae that may refer to program values and can constrain types using arbitrary predicates. We present a pi calculus with assume and assert operations, typed using a session discipline that incorporates refinement formulae written in a fragment of Multiplicative Linear Logic. Our original combination of session and refinement types, together with the well established benefits of linearity, allows very fine-grained specifications of communication protocols in which refinement formulae are treated as logical resources rather than persistent truths.
Relativistic Linear Restoring Force
Clark, D.; Franklin, J.; Mann, N.
2012-01-01
We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…
Combustion powered linear actuator
Fischer, Gary J.
2007-09-04
The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.
Redesigning linear algebra algorithms
Energy Technology Data Exchange (ETDEWEB)
Dongarra, J.J.
1983-01-01
Many of the standard algorithms in linear algebra as implemented in FORTRAN do not achieve maximum performance on today's large-scale vector computers. The author examines the problem and constructs alternative formulations of algorithms that do not lose the clarity of the original algorithm or sacrifice the FORTRAN portable environment, but do gain the performance attainable on these supercomputers. The resulting implementation not only performs well on vector computers but also increases performance on conventional sequential computers. 13 references.
Redesigning linear algebra algorithms
Energy Technology Data Exchange (ETDEWEB)
Dongarra, J.J.
1983-01-01
Many of the standard algorithms in linear algebra as implemented in FORTRAN do not achieve maximum performance on today's large-scale vector computers. In this paper we examine the problem and construct alternative formulations of algorithms that do not lose the clarity of the original algorithm or sacrifice the Fortran portable environment, but do gain the performance attainable on these supercomputers. The resulting implementation not only performs well on vector computers but also increases performance on conventional sequential computers.
Fundamentals of linear algebra
Dash, Rajani Ballav
2008-01-01
FUNDAMENTALS OF LINEAR ALGEBRA is a comprehensive Text Book, which can be used by students and teachers of All Indian Universities. The Text has easy, understandable form and covers all topics of UGC Curriculum. There are lots of worked out examples which helps the students in solving the problems without anybody's help. The Problem sets have been designed keeping in view of the questions asked in different examinations.
Sander, K F
1964-01-01
Linear Network Theory covers the significant algebraic aspect of network theory, with minimal reference to practical circuits. The book begins the presentation of network analysis with the exposition of networks containing resistances only, and follows it up with a discussion of networks involving inductance and capacity by way of the differential equations. Classification and description of certain networks, equivalent networks, filter circuits, and network functions are also covered. Electrical engineers, technicians, electronics engineers, electricians, and students learning the intricacies
Uhlmann, Armin
2016-03-01
This is an introduction to antilinear operators. In following Wigner the terminus antilinear is used as it is standard in Physics. Mathematicians prefer to say conjugate linear. By restricting to finite-dimensional complex-linear spaces, the exposition becomes elementary in the functional analytic sense. Nevertheless it shows the amazing differences to the linear case. Basics of antilinearity is explained in sects. 2, 3, 4, 7 and in sect. 1.2: Spectrum, canonical Hermitian form, antilinear rank one and two operators, the Hermitian adjoint, classification of antilinear normal operators, (skew) conjugations, involutions, and acq-lines, the antilinear counterparts of 1-parameter operator groups. Applications include the representation of the Lagrangian Grassmannian by conjugations, its covering by acq-lines. As well as results on equivalence relations. After remembering elementary Tomita-Takesaki theory, antilinear maps, associated to a vector of a two-partite quantum system, are defined. By allowing to write modular objects as twisted products of pairs of them, they open some new ways to express EPR and teleportation tasks. The appendix presents a look onto the rich structure of antilinear operator spaces.
Springer, T A
1998-01-01
"[The first] ten chapters...are an efficient, accessible, and self-contained introduction to affine algebraic groups over an algebraically closed field. The author includes exercises and the book is certainly usable by graduate students as a text or for self-study...the author [has a] student-friendly style… [The following] seven chapters... would also be a good introduction to rationality issues for algebraic groups. A number of results from the literature…appear for the first time in a text." –Mathematical Reviews (Review of the Second Edition) "This book is a completely new version of the first edition. The aim of the old book was to present the theory of linear algebraic groups over an algebraically closed field. Reading that book, many people entered the research field of linear algebraic groups. The present book has a wider scope. Its aim is to treat the theory of linear algebraic groups over arbitrary fields. Again, the author keeps the treatment of prerequisites self-contained. The material of t...
Linearized Kernel Dictionary Learning
Golts, Alona; Elad, Michael
2016-06-01
In this paper we present a new approach of incorporating kernels into dictionary learning. The kernel K-SVD algorithm (KKSVD), which has been introduced recently, shows an improvement in classification performance, with relation to its linear counterpart K-SVD. However, this algorithm requires the storage and handling of a very large kernel matrix, which leads to high computational cost, while also limiting its use to setups with small number of training examples. We address these problems by combining two ideas: first we approximate the kernel matrix using a cleverly sampled subset of its columns using the Nystr\\"{o}m method; secondly, as we wish to avoid using this matrix altogether, we decompose it by SVD to form new "virtual samples," on which any linear dictionary learning can be employed. Our method, termed "Linearized Kernel Dictionary Learning" (LKDL) can be seamlessly applied as a pre-processing stage on top of any efficient off-the-shelf dictionary learning scheme, effectively "kernelizing" it. We demonstrate the effectiveness of our method on several tasks of both supervised and unsupervised classification and show the efficiency of the proposed scheme, its easy integration and performance boosting properties.
Linear capacity storage devices
International Nuclear Information System (INIS)
The linearity of information storage in capacitor storage circuits is discussed. The paper describes two storage circuits whose operation is linear over a wide range of output-signal amplitudes. In one of the circuits the error signal is measured by a differential amplifier and, thanks to the high amplification factor of the amplifier, good linearity is obtained. The second circuit was designed for work in the nanosecond pulse-width range. Input pulses of standard width cut off a pentode, in the anode of which there is a memory capacitor. Since the capacitor is charged from the anode supply through a current generator, the charging current remains almost constant during measurement of the capacitor voltage. The pentode has a large internal resistance so that after the end of the input pulse the magnitude of the current through the pentode is almost equal to its initial value, and the charge stored by the capacitor is remembered. The width of the information memory is limited by the output resistance of the current generator and the internal resistance (Ri) of the pentode. To increase the memory width, a diode may be inserted before the capacitor. (author)
Differential Equations with Linear Algebra
Boelkins, Matthew R; Potter, Merle C
2009-01-01
Linearity plays a critical role in the study of elementary differential equations; linear differential equations, especially systems thereof, demonstrate a fundamental application of linear algebra. In Differential Equations with Linear Algebra, we explore this interplay between linear algebra and differential equations and examine introductory and important ideas in each, usually through the lens of important problems that involve differential equations. Written at a sophomore level, the text is accessible to students who have completed multivariable calculus. With a systems-first approach, t
Fermionic Linear Optics and Matchgates
Knill, E.
2001-01-01
Fermionic linear optics is efficiently classically simulatable. Here it is shown that the set of states achievable with fermionic linear optics and particle measurements is the closure of a low dimensional Lie group. The weakness of fermionic linear optics and measurements can therefore be explained and contrasted with the strength of bosonic linear optics with particle measurements. An analysis of fermionic linear optics is used to show that the two-qubit matchgates and the simulatable match...
Conceição, Ana; PEREIRA, José; Silva, Cátia; Simão, Cristina
2012-01-01
The article (see http://hdl.handle.net/10400.1/1105) was first presented in the 1st National Conference on Symbolic Computation in Education and Research, IST Portugal 2012, where distinguished with the Timberlake Award for Best Article by a Young Researcher. On how to work with the CDF format please see http://www.wolfram.com/cdf-player/. F-Linear is a F-Tool (see http://hdl.handle.net/10400.1/1105), that is, a visual, dynamic, and interactive teaching tool that allow to explore in an inn...
Energy Technology Data Exchange (ETDEWEB)
Casasent, D.; Ghosh, A.
1983-01-01
Many of the linear algebra operations and algorithms possible on optical matrix-vector processors are reviewed. Emphasis is given to the use of direct solutions and their realization on systolic optical processors. As an example, implicit and explicit solutions to partial differential equations are considered. The matrix-decomposition required is found to be the major operation recommended for optical realization. The pipelining and flow of data and operations are noted to be key issues in the realization of any algorithm on an optical systolic array processor. A realization of the direct solution by householder qr decomposition is provided as a specific case study. 19 references.
Lopez, Cesar
2014-01-01
MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Linear Algebra introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. In addition to giving an introduction to
Linear Probability Forecasting
Zhdanov, Fedor
2010-01-01
Multi-class classification is one of the most important tasks in machine learning. In this paper we consider two online multi-class classification problems: classification by a linear model and by a kernelized model. The quality of predictions is measured by the Brier loss function. We suggest two computationally efficient algorithms to work with these problems and prove theoretical guarantees on their losses. We kernelize one of the algorithms and prove theoretical guarantees on its loss. We perform experiments and compare our algorithms with logistic regression.
International Nuclear Information System (INIS)
The purpose of the linear wind-power generator described in this article is to decrease the following disadvantages of the common wind-powered turbine: 1) large bending and twisting moments to the blades and the shaft, especially when strong winds and turbulence exist; 2) significant values of the natural oscillation period of the construction result in the possibility of occurrence of destroying resonance oscillations; 3) high velocity of the peripheral parts of the rotor creating a danger for birds; 4) difficulties, connected with the installation and the operation on the mountain ridges and passages where the wind energy potential is the largest. The working surfaces of the generator in questions driven by the wind are not connected with a joint shaft but each moves along a railway track with few oscillations. So the sizes of each component are small and their number can be rather large. The mechanical trajectory is not a circle but a closed outline in a vertical plain, which consists of two rectilinear sectors, one above the other, connected in their ends by semi-circumferences. The mechanical energy of each component turns into electrical on the principle of the linear electrical generator. A regulation is provided when the direction of the wind is perpendicular to the route. A possibility of effectiveness is shown through aiming of additional quantities of air to the movable components by static barriers
El-Orany, Faisal A A
2009-01-01
In this paper, we develop the notion of the linear atomic quantum coupler. This device consists of two modes propagating into two waveguides, each of them includes a localized and/or a trapped atom. These waveguides are placed close enough to allow exchanging energy between them via evanescent waves. Each mode interacts with the atom in the same waveguide in the standard way, i.e. as the Jaynes-Cummings model (JCM), and with the atom-mode in the second waveguide via evanescent wave. We present the Hamiltonian for the system and deduce the exact form for the wavefunction. We investigate the atomic inversions and the second-order correlation function. In contrast to the conventional linear coupler, the atomic quantum coupler is able to generate nonclassical effects. The atomic inversions can exhibit long revival-collapse phenomenon as well as subsidiary revivals based on the competition among the switching mechanisms in the system. Finally, under certain conditions, the system can yield the results of the two-m...
On the linear programming bound for linear Lee codes.
Astola, Helena; Tabus, Ioan
2016-01-01
Based on an invariance-type property of the Lee-compositions of a linear Lee code, additional equality constraints can be introduced to the linear programming problem of linear Lee codes. In this paper, we formulate this property in terms of an action of the multiplicative group of the field [Formula: see text] on the set of Lee-compositions. We show some useful properties of certain sums of Lee-numbers, which are the eigenvalues of the Lee association scheme, appearing in the linear programming problem of linear Lee codes. Using the additional equality constraints, we formulate the linear programming problem of linear Lee codes in a very compact form, leading to a fast execution, which allows to efficiently compute the bounds for large parameter values of the linear codes.
Energy Technology Data Exchange (ETDEWEB)
Ramirez-Ros, J.; Garcia-Marcos, R.; Huertas Martinez, M. c.; Hurtado Sanchez, A.
2015-07-01
We discuss the field factors obtained for a linear accelerator electron multi energetic with irradiation standard modes and flatter unfiltered. We compared the values obtained with several diodes, two chambers of ionization and film radiochromic We obtain correction factors for diodes and. Finally, we evaluate the Daisy-Chain method, depending on the detector and the field of step. (Author)
Linear algebra, geometry and transformation
Solomon, Bruce
2014-01-01
Vectors, Mappings and Linearity Numeric Vectors Functions Mappings and Transformations Linearity The Matrix of a Linear Transformation Solving Linear Systems The Linear SystemThe Augmented Matrix and RRE Form Homogeneous Systems in RRE Form Inhomogeneous Systems in RRE Form The Gauss-Jordan Algorithm Two Mapping Answers Linear Geometry Geometric Vectors Geometric/Numeric Duality Dot-Product Geometry Lines, Planes, and Hyperplanes System Geometry and Row/Column Duality The Algebra of Matrices Matrix Operations Special Matrices Matrix Inversion A Logical Digression The Logic of the Inversion Alg
Introduction to linear elasticity
Gould, Phillip L
2013-01-01
Introduction to Linear Elasticity, 3rd Edition, provides an applications-oriented grounding in the tensor-based theory of elasticity for students in mechanical, civil, aeronautical, and biomedical engineering, as well as materials and earth science. The book is distinct from the traditional text aimed at graduate students in solid mechanics by introducing the subject at a level appropriate for advanced undergraduate and beginning graduate students. The author's presentation allows students to apply the basic notions of stress analysis and move on to advanced work in continuum mechanics, plasticity, plate and shell theory, composite materials, viscoelasticity and finite method analysis. This book also: Emphasizes tensor-based approach while still distilling down to explicit notation Provides introduction to theory of plates, theory of shells, wave propagation, viscoelasticity and plasticity accessible to advanced undergraduate students Appropriate for courses following emerging trend of teaching solid mechan...
Standing wave linear accelerator
International Nuclear Information System (INIS)
Consideration is being given to standing wave linear accelerator containing generator, phase shifter, two accelerating resonator sections, charged particle injector and waveguide bridge. Its first arm is oined up with generator via the phase shifter, the second and the third ones-with accelerating sections and the fourth one - with HF-power absorber. HF-power absorber represents a section of circular diaphragmatic wavequide with transformer with input wave and intrawaveguide output load located between injector and the first accelerating section. The section possesses holes in side walls lying on accelerator axis. The distances between centers of the last cell of the fast accelerating section and the first cell of the second accelerating sectiOn equal (2n+3)lambda/4, where n=1, 2, 3..., lambda - wave length of generator. The suggested system enables to improve by one order spectral characteristics of accelerators as compared to the prototype in which magnetrons are used as generator
International Nuclear Information System (INIS)
This paper examines a new layout for the injector and accelerating sectins of a linear induction accelerator. The sections are combined in a single housing: an induction system with a current-pulse generator based on double strip shaping lines laid over ferromagnetic cores; a multichannel spark discharger with forced current division among channels; and a system for core demagnetization and electron-beam formation and transport. The results of formation of an electron beam in the injector system and its acceleration in the first accelerating section of the accelerator for injection of beams with energies of 0.2-0.4 MeV, currents of 1-2 kA, and pulse durations of 60 nsec are given
Computer Program For Linear Algebra
Krogh, F. T.; Hanson, R. J.
1987-01-01
Collection of routines provided for basic vector operations. Basic Linear Algebra Subprogram (BLAS) library is collection from FORTRAN-callable routines for employing standard techniques to perform basic operations of numerical linear algebra.
Linear Versus Non-linear Supersymmetry, in General
Ferrara, Sergio; Van Proeyen, Antoine; Wrase, Timm
2016-01-01
We study superconformal and supergravity models with constrained superfields. The underlying version of such models with all unconstrained superfields and linearly realized supersymmetry is presented here, in addition to the physical multiplets there are Lagrange multiplier (LM) superfields. Once the equations of motion for the LM superfields are solved, some of the physical superfields become constrained. The linear supersymmetry of the original models becomes non-linearly realized, its exact form can be deduced from the original linear supersymmetry. Known examples of constrained superfields are shown to require the following LM's: chiral superfields, linear superfields, general complex superfields, some of them are multiplets with a spin.
Monahan, John F
2008-01-01
Preface Examples of the General Linear Model Introduction One-Sample Problem Simple Linear Regression Multiple Regression One-Way ANOVA First Discussion The Two-Way Nested Model Two-Way Crossed Model Analysis of Covariance Autoregression Discussion The Linear Least Squares Problem The Normal Equations The Geometry of Least Squares Reparameterization Gram-Schmidt Orthonormalization Estimability and Least Squares Estimators Assumptions for the Linear Mean Model Confounding, Identifiability, and Estimability Estimability and Least Squares Estimators F
Templates for Linear Algebra Problems
Bai, Z.; Day, D.; Demmel, J.; Dongarra, J.; Gu, M.; Ruhe, A.; Vorst, H.A. van der
2001-01-01
The increasing availability of advanced-architecture computers is having a very signicant eect on all spheres of scientic computation, including algorithm research and software development in numerical linear algebra. Linear algebra {in particular, the solution of linear systems of equations and eig
DEFF Research Database (Denmark)
Engberg, Uffe Henrik; Winskel, Glynn
This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...
On constructing disjoint linear codes
Institute of Scientific and Technical Information of China (English)
ZHANG Weiguo; CAI Mian; XIAO Guozhen
2007-01-01
To produce a highly nonlinear resilient function,the disjoint linear codes were originally proposed by Johansson and Pasalic in IEEE Trans.Inform.Theory,2003,49(2):494-501.In this paper,an effective method for finding a set of such disjoint linear codes is presented.When n≥2k,we can find a set of[n,k] disjoint linear codes with joint linear codes exists with cardinality at least 2.We also describe a result on constructing a set of [n,k] disjoint linear codes with minimum distance at least some fixed positive integer.
Generalized Linear Covariance Analysis
Carpenter, James R.; Markley, F. Landis
2014-01-01
This talk presents a comprehensive approach to filter modeling for generalized covariance analysis of both batch least-squares and sequential estimators. We review and extend in two directions the results of prior work that allowed for partitioning of the state space into solve-for'' and consider'' parameters, accounted for differences between the formal values and the true values of the measurement noise, process noise, and textita priori solve-for and consider covariances, and explicitly partitioned the errors into subspaces containing only the influence of the measurement noise, process noise, and solve-for and consider covariances. In this work, we explicitly add sensitivity analysis to this prior work, and relax an implicit assumption that the batch estimator's epoch time occurs prior to the definitive span. We also apply the method to an integrated orbit and attitude problem, in which gyro and accelerometer errors, though not estimated, influence the orbit determination performance. We illustrate our results using two graphical presentations, which we call the variance sandpile'' and the sensitivity mosaic,'' and we compare the linear covariance results to confidence intervals associated with ensemble statistics from a Monte Carlo analysis.
Berkeley Proton Linear Accelerator
Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.
1953-10-13
A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.
Energy Technology Data Exchange (ETDEWEB)
Adaimi Hernandez, P.; Ramirez Ros, J. C.; Casa de Julian, M. A. de la; Clemente Gutierrez, F.; Cabello Murillo, E.; Diaz Fuente, R.; Ferrando Sanchez, A.
2011-07-01
A revised procedure for daily control of the electron beams to make measurements more meaningful physically, having a better reproducibility and more in line with the recommendations of the Spanish Protocol for Quality Control in Electron Linear Accelerators Clinical Use. The daily quality control beams of high energy electrons that had been done so far was the finding that the record of a series of measures (symmetry, uniformity, stability, energy, beam central dose) were within tolerance values established. The amendment is to check the beam quality by directly measuring changes in absorption depth at which the dose is reduced to half its maximum value, R50.
Energy Technology Data Exchange (ETDEWEB)
Salgado, Ana Paula
2011-07-01
The clinical importance and usage of linear accelerators in cancer treatment increased significantly in the last years. Coupled with this growth came the concern about the use of accelerators with energies over to 10 MeV which produce therapeutic beam contaminated with neutrons generated when high-energy photons interact with high-atomic-number materials such as tungsten and lead present in the accelerator itself. At these facilities, measurements of the ambient dose equivalent for neutrons present difficulties owing to the existence of a mixed radiation field and possible electromagnetic interference near the accelerator. The Neutron Laboratory of the IRD - Brazilian Institute for Radioprotection and Dosimetry, aiming to evaluate the survey meters performance at these facilities, initiated studies of instrumentation response in the presence of different neutron spectra. Neutrons sources with average energies ranging from 0.55 to 4.2 MeV, four different survey meters and one ionization chamber to obtain the ratio between the dose due to neutrons and gamma radiation were used in this work. The evaluation of these measurements, performed in a 15 MV linear accelerator room is presented. This work presents results that demonstrate the complexity and care needed to make neutrons measurements in radiotherapy treatment rooms containing high energy clinical accelerators. (author)
Sparse Linear Identifiable Multivariate Modeling
DEFF Research Database (Denmark)
Henao, Ricardo; Winther, Ole
2011-01-01
In this paper we consider sparse and identifiable linear latent variable (factor) and linear Bayesian network models for parsimonious analysis of multivariate data. We propose a computationally efficient method for joint parameter and model inference, and model comparison. It consists of a fully...... Bayesian hierarchy for sparse models using slab and spike priors (two-component δ-function and continuous mixtures), non-Gaussian latent factors and a stochastic search over the ordering of the variables. The framework, which we call SLIM (Sparse Linear Identifiable Multivariate modeling), is validated...... computational complexity. We attribute this mainly to the stochastic search strategy used, and to parsimony (sparsity and identifiability), which is an explicit part of the model. We propose two extensions to the basic i.i.d. linear framework: non-linear dependence on observed variables, called SNIM (Sparse Non-linear...
Linearization of CIF Through SOS
Agut, Damian Nadales; 10.4204/EPTCS.64.6
2011-01-01
Linearization is the procedure of rewriting a process term into a linear form, which consist only of basic operators of the process language. This procedure is interesting both from a theoretical and a practical point of view. In particular, a linearization algorithm is needed for the Compositional Interchange Format (CIF), an automaton based modeling language. The problem of devising efficient linearization algorithms is not trivial, and has been already addressed in literature. However, the linearization algorithms obtained are the result of an inventive process, and the proof of correctness comes as an afterthought. Furthermore, the semantic specification of the language does not play an important role on the design of the algorithm. In this work we present a method for obtaining an efficient linearization algorithm, through a step-wise refinement of the SOS rules of CIF. As a result, we show how the semantic specification of the language can guide the implementation of such a procedure, yielding a simple ...
Feature-Weighted Linear Stacking
Sill, Joseph; Mackey, Lester; Lin, David
2009-01-01
Ensemble methods, such as stacking, are designed to boost predictive accuracy by blending the predictions of multiple machine learning models. Recent work has shown that the use of meta-features, additional inputs describing each example in a dataset, can boost the performance of ensemble methods, but the greatest reported gains have come from nonlinear procedures requiring significant tuning and training time. Here, we present a linear technique, Feature-Weighted Linear Stacking (FWLS), that incorporates meta-features for improved accuracy while retaining the well-known virtues of linear regression regarding speed, stability, and interpretability. FWLS combines model predictions linearly using coefficients that are themselves linear functions of meta-features. This technique was a key facet of the solution of the second place team in the recently concluded Netflix Prize competition. Significant increases in accuracy over standard linear stacking is demonstrated on the Netflix Prize collaborative filtering da...
Linear algebra and projective geometry
Baer, Reinhold
2005-01-01
Geared toward upper-level undergraduates and graduate students, this text establishes that projective geometry and linear algebra are essentially identical. The supporting evidence consists of theorems offering an algebraic demonstration of certain geometric concepts. These focus on the representation of projective geometries by linear manifolds, of projectivities by semilinear transformations, of collineations by linear transformations, and of dualities by semilinear forms. These theorems lead to a reconstruction of the geometry that constituted the discussion's starting point, within algebra
Linear Programming and Network Flows
Bazaraa, Mokhtar S; Sherali, Hanif D
2011-01-01
The authoritative guide to modeling and solving complex problems with linear programming-extensively revised, expanded, and updated The only book to treat both linear programming techniques and network flows under one cover, Linear Programming and Network Flows, Fourth Edition has been completely updated with the latest developments on the topic. This new edition continues to successfully emphasize modeling concepts, the design and analysis of algorithms, and implementation strategies for problems in a variety of fields, including industrial engineering, management science, operations research
LINEAR2007, Linear-Linear Interpolation of ENDF Format Cross-Sections
International Nuclear Information System (INIS)
1 - Description of program or function: LINEAR converts evaluated cross sections in the ENDF/B format into a tabular form that is subject to linear-linear interpolation in energy and cross section. The code also thins tables of cross sections already in that form. Codes used subsequently need thus to consider only linear-linear data. IAEA1311/15: This version include the updates up to January 30, 2007. Changes in ENDF/B-VII Format and procedures, as well as the evaluations themselves, make it impossible for versions of the ENDF/B pre-processing codes earlier than PREPRO 2007 (2007 Version) to accurately process current ENDF/B-VII evaluations. The present code can handle all existing ENDF/B-VI evaluations through release 8, which will be the last release of ENDF/B-VI. Modifications from previous versions: - Linear VERS. 2007-1 (JAN. 2007): checked against all ENDF/B-VII; increased page size from 60,000 to 600,000 points 2 - Method of solution: Each section of data is considered separately. Each section of File 3, 23, and 27 data consists of a table of cross section versus energy with any of five interpolation laws. LINEAR will replace each section with a new table of energy versus cross section data in which the interpolation law is always linear in energy and cross section. The histogram (constant cross section between two energies) interpolation law is converted to linear-linear by substituting two points for each initial point. The linear-linear is not altered. For the log-linear, linear-log and log- log laws, the cross section data are converted to linear by an interval halving algorithm. Each interval is divided in half until the value at the middle of the interval can be approximated by linear-linear interpolation to within a given accuracy. The LINEAR program uses a multipoint fractional error thinning algorithm to minimize the size of each cross section table
Hood, John Linsley
2013-01-01
The Art of Linear Electronics presents the principal aspects of linear electronics and techniques in linear electronic circuit design. The book provides a wide range of information on the elucidation of the methods and techniques in the design of linear electronic circuits. The text discusses such topics as electronic component symbols and circuit drawing; passive and active semiconductor components; DC and low frequency amplifiers; and the basic effects of feedback. Subjects on frequency response modifying circuits and filters; audio amplifiers; low frequency oscillators and waveform generato
Improvement of Hartman's linearization theorem
Institute of Scientific and Technical Information of China (English)
SHI; Jinlin(史金麟)
2003-01-01
Hartman's linearization theorem tells us that if matrix A has no zero real part and f(x) isbounded and satisfies Lipchitz condition with small Lipchitzian constant, then there exists a homeomorphismof Rn sending the solutions of nonlinear system x' = Ax + f(x) onto the solutions of linear system x' = Ax.In this paper, some components of the nonlinear item f(x) are permitted to be unbounded and we provethe result of global topological linearization without any special limitation and adding any condition. Thus,Hartman's linearization theorem is improved essentially.
Elementary linear programming with applications
Kolman, Bernard
1995-01-01
Linear programming finds the least expensive way to meet given needs with available resources. Its results are used in every area of engineering and commerce: agriculture, oil refining, banking, and air transport. Authors Kolman and Beck present the basic notions of linear programming and illustrate how they are used to solve important common problems. The software on the included disk leads students step-by-step through the calculations. The Second Edition is completely revised and provides additional review material on linear algebra as well as complete coverage of elementary linear program
Linear operator inequalities for strongly stable weakly regular linear systems
Curtain, RF
2001-01-01
We consider the question of the existence of solutions to certain linear operator inequalities (Lur'e equations) for strongly stable, weakly regular linear systems with generating operators A, B, C, 0. These operator inequalities are related to the spectral factorization of an associated Popov funct
Linear and non-linear optics of condensed matter
International Nuclear Information System (INIS)
Part I - Linear optics: 1. General introduction. 2. Frequency dependence of epsilon(ω, k vector). 3. Wave-vector dependence of epsilon(ω, k vector). 4. Tensor character of epsilon(ω, k vector). Part II - Non-linear optics: 5. Introduction. 6. A classical theory of non-linear response in one dimension. 7. The generalization to three dimensions. 8. General properties of the polarizability tensors. 9. The phase-matching condition. 10. Propagation in a non-linear dielectric. 11. Second harmonic generation. 12. Coupling of three waves. 13. Materials and their non-linearities. 14. Processes involving energy exchange with the medium. 15. Two-photon absorption. 16. Stimulated Raman effect. 17. Electro-optic effects. 18. Limitations of the approach presented here. (author)
Spatial Processes in Linear Ordering
von Hecker, Ulrich; Klauer, Karl Christoph; Wolf, Lukas; Fazilat-Pour, Masoud
2016-01-01
Memory performance in linear order reasoning tasks (A > B, B > C, C > D, etc.) shows quicker, and more accurate responses to queries on wider (AD) than narrower (AB) pairs on a hypothetical linear mental model (A -- B -- C -- D). While indicative of an analogue representation, research so far did not provide positive evidence for spatial…
Linear contextual modal type theory
DEFF Research Database (Denmark)
Schack-Nielsen, Anders; Schürmann, Carsten
Abstract. When one implements a logical framework based on linear type theory, for example the Celf system [?], one is immediately con- fronted with questions about their equational theory and how to deal with logic variables. In this paper, we propose linear contextual modal type theory that gives...
Linear Algebra and Image Processing
Allali, Mohamed
2010-01-01
We use the computing technology digital image processing (DIP) to enhance the teaching of linear algebra so as to make the course more visual and interesting. Certainly, this visual approach by using technology to link linear algebra to DIP is interesting and unexpected to both students as well as many faculty. (Contains 2 tables and 11 figures.)
DEFF Research Database (Denmark)
Andersen, Steffen; Harrison, Glenn W.; Hole, Arne Risa;
2012-01-01
We develop an extension of the familiar linear mixed logit model to allow for the direct estimation of parametric non-linear functions defined over structural parameters. Classic applications include the estimation of coefficients of utility functions to characterize risk attitudes and discountin...
Linear Patterns and Their Equations
Institute of Scientific and Technical Information of China (English)
2008-01-01
<正>A linear pattern,the points plotted all lie on the same straight line.In this section we will be looking further into such linear patterns. In this figure,by plotting the points B to F and joining them,
Fuzzy linear regression forecasting models
Institute of Scientific and Technical Information of China (English)
吴冲; 惠晓峰; 朱洪文
2002-01-01
The fuzzy linear regression forecasting model is deduced from the symmetric triangular fuzzy number.With the help of the degree of fitting and the measure of fuzziness, the determination of symmetric triangularfuzzy numbers is changed into a problem of solving linear programming.
Campagnoli, Patrizia; Petris, Giovanni
2009-01-01
State space models have gained tremendous popularity in as disparate fields as engineering, economics, genetics and ecology. Introducing general state space models, this book focuses on dynamic linear models, emphasizing their Bayesian analysis. It illustrates the fundamental steps needed to use dynamic linear models in practice, using R package.
Energy Technology Data Exchange (ETDEWEB)
Cardena R, A. R.; Vega R, J. L.; Apaza V, D. G., E-mail: cardroj@yahoo.es [Universidad Nacional de San Agustin, Av. Independencia s/n, Arequipa (Peru)
2015-10-15
The progress in cancer treatment systems in heterogeneities of human body has had obstacles by the lack of a suitable experimental model test. The only option is to develop simulated theoretical models that have the same properties in interfaces similar to human tissues, to know the radiation behavior in the interaction with these materials. In this paper we used the Monte Carlo method by Penelope code based solely on studies for the cancer treatment as well as for the calibration of beams and their various interactions in mannequins. This paper also aims the construction, simulation and characterization of an equivalent object to the tissues of the human body with various heterogeneities, we will later use to control and plan experientially doses supplied in treating tumors in radiotherapy. To fulfill the objective we study the ionizing radiation and the various processes occurring in the interaction with matter; understanding that to calculate the dose deposited in tissues interfaces (percentage depth dose) must be taken into consideration aspects such as the deposited energy, irradiation fields, density, thickness, tissue sensitivity and other items. (Author)
Energy Technology Data Exchange (ETDEWEB)
Vega R, J. L.; Cayllahua, F.; Apaza, D. G.; Javier, H., E-mail: josevegaramirez@yahoo.es [Universidad Nacional de San Agustin, Departamento de Fisica, Av. Independencia s/n, Arequipa (Peru)
2015-10-15
Percentage depth dose curves were obtained with TLD-100 dosimeters, EDR2 films and Penelope simulation at the interfaces in an inhomogeneous mannequin, composed by equivalent materials to the human body built for this study, consisting of cylindrical plates of solid water-bone-lung-bone-solid water of 15 cm in diameter and 1 cm in height; plates were placed in descending way (4-2-8-2-4). Irradiated with Co-60 source (Theratron Equinox-100) for small radiation fields 3 x 3 cm{sup 2} and 1 x 1 cm{sup 2} at a surface source distance of 100 cm from mannequin. The TLD-100 dosimeters were placed in the center of each plate of mannequin irradiated at 10 Gy. The results were compared between these measurement techniques, giving good agreement in interfaces better than 97%. This study was compared with the same characteristics of another study realized with other equivalent materials to human body not homogeneous acrylic-bone-cork-bone-acrylic. The percentage depth dose curves were obtained with mini-dosimeters L-alanine of 1 mm in diameter and 3 mm in height and 3.5 to 4.0 mg of mass with spectrometer band K (EPR). The mini-dosimeters were irradiated with a lineal accelerator PRIMUS Siemens 6 MV. The results of percentage depth dose of L-alanine mini-dosimeters show a good agreement with the percentage depth dose curves of Penelope code, better than 97.7% in interfaces of tissues. (Author)
Directory of Open Access Journals (Sweden)
Cleber Nogueira de Souza
2001-04-01
Full Text Available Os parâmetros dosimétricos de um feixe de raios X de pequeno diâmetro para um sistema de radiocirurgia comercial foram medidos em água com um detector de diodo de Si do tipo p. As razões tecido-máximo, o fator de espalhamento total e os perfis dos feixes a profundidades de 5 e 10 cm foram medidos para 17 feixes de diâmetros circulares de 5 mm a 50 mm, em incrementos de 2,5 mm. Os fatores de espalhamento totais caíram lentamente, de 0,947 para 0,888 entre os cones de 50 mm e 12,5 mm de diâmetro (variação de 7%; para os cones entre 10 mm e 5 mm de diâmetro, esta queda foi bem maior, de 0,854 para 0,666 (variação de 28%. Os valores obtidos para a relação tecido-máximo são consistentes com dados publicados. Os perfis dos feixes foram medidos nas direções x e y, e estão dentro de 0,2 mm para todos os cones entre as duas direções. A medida da largura à meia-altura se encontra dentro de 1 mm com o diâmetro nominal dos cones.The dosimetric parameters of small diameter photon beams of a commercially available radiosurgery system were measured in a water phantom using a p-type Si photon diode. Tissue maximum ratios, total scattering factor and beam profiles at 5 and 10 cm depth were measured for 17 circular beams ranging from 5 mm to 50 mm in diameter, in 1.5 mm steps. The total scattering factor decreased slowly from 0.947 to 0.888 for the cones with diameter between 50 mm and 12.5 mm (7% variation whereas for cones with diameter between 10 mm and 5 mm the factor decreased more steeply, from 0.854 to 0.666 (28% variation. These tissue maximum ratio data are consistent with the data published by other authors. The beam profiles measured in the x and y directions were aproximately 0.2 mm between the two directions for all cone sizes. The full widths at half maximum were within 1 mm of the nominal cone sizes.
Energy Technology Data Exchange (ETDEWEB)
Vazquez Galinanes, A.; Sanz Freire, C. J.; Diaz Pascual, V.; Collado Chamorro, P.; Gomez Amez, J.; Tomey Montesinos, A.; Ossola Lentati, G. A.
2011-07-01
The technological development affects not only the equipment used to perform radiation therapy treatments, but also to teams that are at our disposal to verify the proper administration of the same. One of these new teams is the 'device for verification of IMRT Deliveries advanced' (DAVID). The DAVID chamber is a multi-wire transmission is placed in a linear accelerator head are firmly anchored to it. The design is intended to be one of the wires passing through the center of each pair of collimator blades along its entire length. This forces each has a design for multi leaf collimator system. In addition, each team has a set of screws that allow fine tuning of both the source-wire distance and the center of the transmission chamber in the radiation field of the accelerator. The work aims make a recommendation, based on our experience, a set of measures to be taken to verify the correct placement of DAVID in the field of treatment, or alternatively, help to make the necessary adjustment. (Author)
The linear-non-linear frontier for the Goldstone Higgs
Gavela, M B; Machado, P A N; Saa, S
2016-01-01
The minimal $SO(5)/SO(4)$ sigma model is used as a template for the ultraviolet completion of scenarios in which the Higgs particle is a low-energy remnant of some high-energy dynamics, enjoying a (pseudo) Nambu-Goldstone boson ancestry. Varying the $\\sigma$ mass allows to sweep from the perturbative regime to the customary non-linear implementations. The low-energy benchmark effective non-linear Lagrangian for bosons and fermions is obtained, determining as well the operator coefficients including linear corrections. At first order in the latter, three effective bosonic operators emerge which are independent of the explicit soft breaking assumed. The Higgs couplings to vector bosons and fermions turn out to be quite universal: the linear corrections are proportional to the explicit symmetry breaking parameters. Furthermore, we define an effective Yukawa operator which allows a simple parametrization and comparison of different heavy fermion ultraviolet completions. In addition, one particular fermionic compl...
Efficient Searching with Linear Constraints
DEFF Research Database (Denmark)
Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff;
2000-01-01
We show how to preprocess a set S of points in d into an external memory data structure that efficiently supports linear-constraint queries. Each query is in the form of a linear constraint xd a0+∑d−1i=1 aixi; the data structure must report all the points of S that satisfy the constraint....... This problem is called halfspace range searching in the computational geometry literature. Our goal is to minimize the number of disk blocks required to store the data structure and the number of disk accesses (I/Os) required to answer a query. For d=2, we present the first data structure that uses linear...... space and answers linear-constraint queries using an optimal number of I/Os in the worst case. For d=3, we present a near-linear-size data structure that answers queries using an optimal number of I/Os on the average. We present linear-size data structures that can answer d-dimensional linear...
Linear and non-linear bias: predictions vs. measurements
Hoffmann, Kai; Bel, Julien; Gaztanaga, Enrique
2016-01-01
We study the linear and non-linear bias parameters which determine the mapping between the distributions of galaxies and the full matter density fields, comparing different measurements and predictions. Accociating galaxies with dark matter haloes in the MICE Grand Challenge N-body simulation we directly measure the bias parameters by comparing the smoothed density fluctuations of halos and matter in the same region at different positions as a function of smoothing scale. Alternatively we mea...
Linear and non-linear calculation of resistive magnetohydrodynamic instabilities
International Nuclear Information System (INIS)
The time-dependent, linear and non-linear, resistive magnetohydrodynamic, numerical models that have been developed at MFECC are reviewed. The purpose of these codes is to compute growth rates, mode structure and saturation of tearing, rippling, and interchange modes in fusion experiments. Cartesian, cylindrical, helical, and toroidal geometries are used in the applications. The numerical methods are described and applications to reversed field configurations are presented
Primordial black holes in linear and non-linear regimes
Allahyari, Alireza; Abolhasani, Ali Akbar
2016-01-01
Using the concept of apparent horizon for dynamical black holes, we revisit the formation of primordial black holes (PBH) in the early universe for both linear and non-linear regimes. First, we develop the perturbation theory for spherically symmetric spacetimes to study the formation of spherical PBHs in linear regime and we fix two gauges. We also introduce a well defined gauge invariant quantity for the expansion. Using this quantity, we argue that PBHs do not form in the linear regime. Finally, we study the non-linear regime. We adopt the spherical collapse picture by taking a closed FRW model in the radiation dominated era to investigate PBH formation. Taking the initial condition of the spherical collapse from the linear theory of perturbations, we allow for both density and velocity perturbations. Our model gives a constraint on the velocity perturbation. This model also predicts that the apparent horizon of PBHs forms when $\\delta > 3$. Applying the sound horizon constraint, we have shown the threshol...
Optimal control linear quadratic methods
Anderson, Brian D O
2007-01-01
This augmented edition of a respected text teaches the reader how to use linear quadratic Gaussian methods effectively for the design of control systems. It explores linear optimal control theory from an engineering viewpoint, with step-by-step explanations that show clearly how to make practical use of the material.The three-part treatment begins with the basic theory of the linear regulator/tracker for time-invariant and time-varying systems. The Hamilton-Jacobi equation is introduced using the Principle of Optimality, and the infinite-time problem is considered. The second part outlines the
The Theory of Linear Prediction
Vaidyanathan, PP
2007-01-01
Linear prediction theory has had a profound impact in the field of digital signal processing. Although the theory dates back to the early 1940s, its influence can still be seen in applications today. The theory is based on very elegant mathematics and leads to many beautiful insights into statistical signal processing. Although prediction is only a part of the more general topics of linear estimation, filtering, and smoothing, this book focuses on linear prediction. This has enabled detailed discussion of a number of issues that are normally not found in texts. For example, the theory of vecto
Practical approach to linear algebra
Choudhary, Prabhat
2009-01-01
""Linear Algebra is the heart of applied science but there are divergent views concerning its meaning. The field of Linear Algebra is more beautiful and more fundamental than its rather dull name may suggest. More beautiful because it is full of powerful ideas that are quite unlike those normally emphasized in a linear algebra course in a mathematics department. Throughout the book the author follows the practice of first presenting required background material, which is then used to develop the results. The book is divided in ten chapters. Relevant material is included in each chapter from ot
International Nuclear Information System (INIS)
This book consists of control linear motor with DSP, which is composed of two parts. The title of the first part is control Algorithm and software with introduction and tracking controller, drive profile on decision of motion time, floating point DSP and quantization effect, motion override Algorithm and drive profile summary, design of digital controller on design for controller structure and analysis of PID control Loop and Motor turning, design for IIR digital filter and protocol structure for communication wit host. The second part describes control hardware, which mentions Linear motor and Amplifier, motor and power supply, DSP board and interface, control of Micro Linear Stepping Motor and conclusion.
Cellular Automata Rules and Linear Numbers
Nayak, Birendra Kumar; Sahoo, Sudhakar; Biswal, Sagarika
2012-01-01
In this paper, linear Cellular Automta (CA) rules are recursively generated using a binary tree rooted at "0". Some mathematical results on linear as well as non-linear CA rules are derived. Integers associated with linear CA rules are defined as linear numbers and the properties of these linear numbers are studied.
Linear Scleroderma and Neurological Complications
Directory of Open Access Journals (Sweden)
J Gordon Millichap
2006-01-01
Full Text Available Three patients with linear scleroderma en coup de sabre who presented with neurologic abnormalities before or concurrent with the dermatologic diagnosis are reported from the Medical College of Wisconsin, Milwaukee, WI.
1988 linear accelerator conference proceedings
International Nuclear Information System (INIS)
This report contains papers presented at the 1988 Linear Accelerator Conference. A few topics covered are beam dynamics; beam transport; superconducting components; free electron lasers; ion sources; and klystron research
Linearity Testing of Photovoltaic Cells
Energy Technology Data Exchange (ETDEWEB)
Pinegar, S.; Nalley, D.; Emery, K.
2006-01-01
Photovoltaic devices are rated in terms of their power output or efficiency with respect to a specific spectrum, total irradiance, and temperature. In order to rate photovoltaic devices, a reference detector whose response is linear with total irradiance is needed. This procedure documents a procedure to determine if a detector is linear over the irradiance range of interest. Testing the short circuit current versus the total irradiance is done by illuminating a reference cell candidate with two lamps that are fitted with programmable filter wheels. The purpose is to reject nonlinear samples as determined by national and international standards from being used as primary reference cells. A calibrated linear reference cell tested by the two lamp method yields a linear result.
CERN balances linear collider studies
ILC Newsline
2011-01-01
The forces behind the two most mature proposals for a next-generation collider, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) study, have been steadily coming together, with scientists from both communities sharing ideas and information across the technology divide. In a support of cooperation between the two, CERN in Switzerland, where most CLIC research takes place, recently converted the project-specific position of CLIC Study Leader to the concept-based Linear Collider Study Leader. The scientist who now holds this position, Steinar Stapnes, is charged with making the linear collider a viable option for CERN’s future, one that could include either CLIC or the ILC. The transition to more involve the ILC must be gradual, he said, and the redefinition of his post is a good start. Though not very much involved with superconducting radiofrequency (SRF) technology, where ILC researchers have made significant advances, CERN participates in many aspect...
Linear And Whorled Nevoid Hypermelanosis
Directory of Open Access Journals (Sweden)
Uppal Monica
2003-01-01
Full Text Available A case of linear and whorled nevoid hypermelanosis in a 7 month old infant is reported. In addition to the cutaneous findings he also had dextrocardia, mental retardation, high arched palate, simian crease, undescended testis and craniostenosis.
Overdetermined Systems of Linear Equations.
Williams, Gareth
1990-01-01
Explored is an overdetermined system of linear equations to find an appropriate least squares solution. A geometrical interpretation of this solution is given. Included is a least squares point discussion. (KR)
Klumpp, A. R.; Lawson, C. L.
1988-01-01
Routines provided for common scalar, vector, matrix, and quaternion operations. Computer program extends Ada programming language to include linear-algebra capabilities similar to HAS/S programming language. Designed for such avionics applications as software for Space Station.
Gyrokinetic linearized Landau collision operator
DEFF Research Database (Denmark)
Madsen, Jens
2013-01-01
The full gyrokinetic electrostatic linearized Landau collision operator is calculated including the equilibrium operator, which represents the effect of collisions between gyrokinetic Maxwellian particles. First, the equilibrium operator describes energy exchange between different plasma species...
DEFF Research Database (Denmark)
Du, Yigang
without iteration steps. The ASA is implemented in combination with Field II and extended to simulate the pulsed ultrasound fields. The simulated results from a linear array transducer are made by the ASA based on Field II, and by a released non-linear simulation program- Abersim, respectively....... The calculation speed of the ASA is increased approximately by a factor of 140. For the second harmonic point spread function the error of the full width is 1.5% at -6 dB and 6.4% at -12 dB compared to Abersim. To further investigate the linear and non-linear ultrasound fields, hydrophone measurements.......3% relative to the measurement from a 1 inch diameter transducer. A preliminary study for harmonic imaging using synthetic aperture sequential beamforming (SASB) has been demonstrated. A wire phantom underwater measurement is made by an experimental synthetic aperture real-time ultrasound scanner (SARUS...
[New technology for linear colliders
International Nuclear Information System (INIS)
This report discusses the following topics on research of microwave amplifiers for linear colliders: Context in current microwave technology development; gated field emission for microwave cathodes; cathode fabrication and tests; microwave cathode design using field emitters; and microwave localization
Linear isometries of Hardy spaces
Institute of Scientific and Technical Information of China (English)
Edoardo VESENTINI
2008-01-01
According to results established by DeLeeuw-Rudin-Wermer and by Forelli,all linear isometries of any Hardy space Hp (p ≥ 1,p ≠ 2) on the open unit disc △ of C are represented by weighted composition operators defined by inner functions on △.After reviewing (and completing when p = ∞) some of those results,the present report deals with a characterization of periodic and almost periodic semigroups of linear isometries of Hp.
BILINEAR FORMS AND LINEAR CODES
Institute of Scientific and Technical Information of China (English)
高莹
2004-01-01
Abraham Lempel et al[1] made a connection between linear codes and systems of bilinear forms over finite fields. In this correspondence, a new simple proof of a theorem in [1] is presented; in addition, the encoding process and the decoding procedure of RS codes are simplified via circulant matrices. Finally, the results show that the correspondence between bilinear forms and linear codes is not unique.
Functional linear regression with derivatives
Mas, André; Pumo, Besnik
2006-01-01
International audience We introduce a new model of linear regression for random functional inputs taking into account the first order derivative of the data. We propose an estimation method which comes down to solving a special linear inverse problem. Our procedure tackles the problem through a double and synchronized penalization. An asymptotic expansion of the mean square prevision error is given. The model and the method are applied to a benchmark dataset of spectrometric curves and com...
LINEAR AND NONLINEAR SEMIDEFINITE PROGRAMMING
Directory of Open Access Journals (Sweden)
Walter Gómez Bofill
2014-12-01
Full Text Available This paper provides a short introduction to optimization problems with semidefinite constraints. Basic duality and optimality conditions are presented. For linear semidefinite programming some advances by dealing with degeneracy and the semidefinite facial reduction are discussed. Two relatively recent areas of application are presented. Finally a short overview of relevant literature on algorithmic approaches for efficiently solving linear and nonlinear semidefinite programming is provided.
Chaotic synchronization via linear controller
Institute of Scientific and Technical Information of China (English)
Chen Feng-Xiang; Zhang Wei-Dong
2007-01-01
A technical framework of constructing a linear controller for chaotic synchronization by utilizing the stability theory of cascade-connected system is presented. Based on the method developed in the paper, two simple and linear feedback controllers, as examples, are derived for the synchronization of Liu chaotic system and Duffing oscillator, respectively.This method is quite flexible in constructing a control law. Its effectiveness is also illustrated by the simulation results.
Polarized Electrons for Linear Colliders
Clendenin, J E; Garwin, E L; Kirby, R E; Luh, D A; Maruyama, T; Prescott, C Y; Sheppard, J C; Turner, J; Prepost, R
2005-01-01
Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a dc-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%.
Explorative methods in linear models
DEFF Research Database (Denmark)
Høskuldsson, Agnar
2004-01-01
The author has developed the H-method of mathematical modeling that builds up the model by parts, where each part is optimized with respect to prediction. Besides providing with better predictions than traditional methods, these methods provide with graphic procedures for analyzing different feat...... features in data. These graphic methods extend the well-known methods and results of Principal Component Analysis to any linear model. Here the graphic procedures are applied to linear regression and Ridge Regression....
International Nuclear Information System (INIS)
Several letters discuss the short-comings of the use of the linear quadratic model in fractionated radiotherapy and the validity of the prediction of hyperfractionation as the operational strategy for most human tumours. Particular points discussed are the absence of a time factor in the linear quadratic model, corrections in regard to OER and the clinical implications of isoeffect relationships for normal tissue damage. (U.K.)
Linear and non-linear bias: predictions vs. measurements
Hoffmann, Kai; Gaztanaga, Enrique
2016-01-01
We study the linear and non-linear bias parameters which determine the mapping between the distributions of galaxies and the full matter density fields, comparing different measurements and predictions. Accociating galaxies with dark matter haloes in the MICE Grand Challenge N-body simulation we directly measure the bias parameters by comparing the smoothed density fluctuations of halos and matter in the same region at different positions as a function of smoothing scale. Alternatively we measure the bias parameters by matching the probablility distributions of halo and matter density fluctuations, which can be applied to observations. These direct bias measurements are compared to corresponding measurements from two-point and different third-order correlations, as well as predictions from the peak-background model, which we presented in previous articles using the same data. We find an overall variation of the linear bias measurements and predictions of $\\sim 5 \\%$ with respect to results from two-point corr...
Transformation matrices between non-linear and linear differential equations
Sartain, R. L.
1983-01-01
In the linearization of systems of non-linear differential equations, those systems which can be exactly transformed into the second order linear differential equation Y"-AY'-BY=0 where Y, Y', and Y" are n x 1 vectors and A and B are constant n x n matrices of real numbers were considered. The 2n x 2n matrix was used to transform the above matrix equation into the first order matrix equation X' = MX. Specially the matrix M and the conditions which will diagonalize or triangularize M were studied. Transformation matrices P and P sub -1 were used to accomplish this diagonalization or triangularization to return to the solution of the second order matrix differential equation system from the first order system.
Boundedness and closedness of linear relations
Shi, Yuming; Xu, Guixin; Ren, Guojing
2016-01-01
This paper studies boundedness and closedness of linear relations, which include both single-valued and multi-valued linear operators. A new (single-valued) linear operator induced by a linear relation is introduced, and its relationships with other two important induced linear operators are established. Several characterizations for closedness, closability, bundedness, relative boundedness, and boundedness from below (above) of linear relations are given in terms of their induced linear oper...
Linear Programming建模研讨%Modeling of Linear Programming
Institute of Scientific and Technical Information of China (English)
宋占奎; 於全收; 范光; 燕嬿; 胡杰军
2007-01-01
研究用图解法、simplexmethod和匈牙利法建立Linear Programming的数学模型并求得了最优解.结果表明:对仅有两个变量的Linear Programming,既可通过图解法求得最优解;也可用单纯形表简便地求得最优解;而对任务和人数不等的assignment problem,则用匈牙利法求最优解.
From Linear to Non-linear Supersymmetry via Functional Integration
Kallosh, Renata; Murli, Divyanshu
2016-01-01
We derive a complete pure de Sitter supergravity action with non-linearly realized supersymmetry and its rigid limit, the Volkov-Akulov action, from the corresponding models with linear supersymmetry, by computing the path integral in the limit of infinite sgoldstino mass. In this, we use a non-Gaussian functional integration formula that was recently discovered in a derivation of de Sitter supergravity from the superconformal theory. We also present explicit examples of pure dS supergravity and the case with one matter multiplet. These two simple examples serve as a test and a demo of the universal action formula valid for de Sitter supergravities with general matter coupling.
A nanoscale linear-to-linear motion converter of graphene.
Dai, Chunchun; Guo, Zhengrong; Zhang, Hongwei; Chang, Tienchong
2016-08-14
Motion conversion plays an irreplaceable role in a variety of machinery. Although many macroscopic motion converters have been widely used, it remains a challenge to convert motion at the nanoscale. Here we propose a nanoscale linear-to-linear motion converter, made of a flake-substrate system of graphene, which can convert the out-of-plane motion of the substrate into the in-plane motion of the flake. The curvature gradient induced van der Waals potential gradient between the flake and the substrate provides the driving force to achieve motion conversion. The proposed motion converter may have general implications for the design of nanomachinery and nanosensors.
Linear Minimum variance estimation fusion
Institute of Scientific and Technical Information of China (English)
ZHU Yunmin; LI Xianrong; ZHAO Juan
2004-01-01
This paper shows that a general mulitisensor unbiased linearly weighted estimation fusion essentially is the linear minimum variance (LMV) estimation with linear equality constraint, and the general estimation fusion formula is developed by extending the Gauss-Markov estimation to the random paramem of distributed estimation fusion in the LMV setting.In this setting ,the fused estimator is a weighted sum of local estimatess with a matrix quadratic optimization problem subject to a convex linear equality constraint. Second, we present a unique solution to the above optimization problem, which depends only on the covariance matrixCK. Third, if a priori information, the expectation and covariance, of the estimated quantity is unknown, a necessary and sufficient condition for the above LMV fusion becoming the best unbiased LMV estimation with dnown prior information as the above is presented. We also discuss the generality and usefulness of the LMV fusion formulas developed. Finally, we provied and off-line recursion of Ck for a class of multisensor linear systems with coupled measurement noises.
International Nuclear Information System (INIS)
Processing of nuclear medicine images is generally performed by essentially linear methods with the non-negativity condition being applied as the only non-linear process. The various methods used: matrix methods in signal space and Fourier or Hadamard transforms in frequency or sequency space are essentially equivalent. Further improvement in images can be obtained by the use of inherently non-linear methods. The recent development of an approximation to a least-difference method (as opposed to a least-square method) has led to an appreciation of the effects of data bounding and to the development of a more powerful process. Data bounding (modification of statistically improbable data values) is an inherently non-linear method with considerable promise. Strong bounding depending on two-dimensional least-squares fitting yields a reduction of mottling (buttermilk effect) not attainable with linear processes. A pre-bounding process removing very bad points is used to protect the strong bounding process from incorrectly modifying data points due to the weight of an extreme but yet unbounded point as the fitting area approaches it
Quantization via Linear homotopy types
Schreiber, Urs
2014-01-01
In the foundational logical framework of homotopy-type theory we discuss a natural formalization of secondary integral transforms in stable geometric homotopy theory. We observe that this yields a process of non-perturbative cohomological quantization of local pre-quantum field theory; and show that quantum anomaly cancellation amounts to realizing this as the boundary of a field theory that is given by genuine (primary) integral transforms, hence by linear polynomial functors. Recalling that traditional linear logic has semantics in symmetric monoidal categories and serves to formalize quantum mechanics, what we consider is its refinement to linear homotopy-type theory with semantics in stable infinity-categories of bundles of stable homotopy types (generalized cohomology theories) formalizing Lagrangian quantum field theory, following Nuiten and closely related to recent work by Haugseng and Hopkins-Lurie. For the reader interested in technical problems of quantization we provide non-perturbative quantizati...
Topics in quaternion linear algebra
Rodman, Leiba
2014-01-01
Quaternions are a number system that has become increasingly useful for representing the rotations of objects in three-dimensional space and has important applications in theoretical and applied mathematics, physics, computer science, and engineering. This is the first book to provide a systematic, accessible, and self-contained exposition of quaternion linear algebra. It features previously unpublished research results with complete proofs and many open problems at various levels, as well as more than 200 exercises to facilitate use by students and instructors. Applications presented in the book include numerical ranges, invariant semidefinite subspaces, differential equations with symmetries, and matrix equations. Designed for researchers and students across a variety of disciplines, the book can be read by anyone with a background in linear algebra, rudimentary complex analysis, and some multivariable calculus. Instructors will find it useful as a complementary text for undergraduate linear algebra courses...
Window observers for linear systems
Directory of Open Access Journals (Sweden)
Utkin Vadim
2000-01-01
Full Text Available Given a linear system x ˙ = A x + B u with output y = C x and a window function ω ( t , i.e., ∀ t , ω ( t ∈ {0,1 }, and assuming that the window function is Lebesgue measurable, we refer to the following observer, x ˆ = A x + B u + ω ( t L C ( x − x ˆ as a window observer. The stability issue is treated in this paper. It is proven that for linear time-invariant systems, the window observer can be stabilized by an appropriate design under a very mild condition on the window functions, albeit for linear time-varying system, some regularity of the window functions is required to achieve observer designs with the asymptotic stability. The corresponding design methods are developed. An example is included to illustrate the possible applications
Uniqueness theorems in linear elasticity
Knops, Robin John
1971-01-01
The classical result for uniqueness in elasticity theory is due to Kirchhoff. It states that the standard mixed boundary value problem for a homogeneous isotropic linear elastic material in equilibrium and occupying a bounded three-dimensional region of space possesses at most one solution in the classical sense, provided the Lame and shear moduli, A and J1 respectively, obey the inequalities (3 A + 2 J1) > 0 and J1>O. In linear elastodynamics the analogous result, due to Neumann, is that the initial-mixed boundary value problem possesses at most one solution provided the elastic moduli satisfy the same set of inequalities as in Kirchhoffs theorem. Most standard textbooks on the linear theory of elasticity mention only these two classical criteria for uniqueness and neglect altogether the abundant literature which has appeared since the original publications of Kirchhoff. To remedy this deficiency it seems appropriate to attempt a coherent description ofthe various contributions made to the study of uniquenes...
Scalar-tensor linear inflation
Artymowski, Michal
2016-01-01
We investigate two approaches to non minimally coupled gravity theories which present linear inflation as attractor solution: a) the scalar-tensor theory approach, where we look for a scalar-tensor theory that would restore results of linear inflation in the strong coupling limit for any form of the non-minimal coupling to gravity of the form of $f(\\varphi)R/2$; b) the particle physics approach, where we motivate the form of the Jordan frame potential by the loop corrections to the inflaton field. In both cases the Jordan frame potentials are modifications of the induced inflation, but instead of the Starobinsky attractor they lead to the linear inflation in the strong coupling limit.
The linear multiplet and ectoplasm
Butter, Daniel; Novak, Joseph
2012-01-01
In the framework of the superconformal tensor calculus for 4D N=2 supergravity, locally supersymmetric actions are often constructed using the linear multiplet. We provide a superform formulation for the linear multiplet and derive the corresponding action functional using the ectoplasm method (also known as the superform approach to the construction of supersymmetric invariants). We propose a new locally supersymmetric action which makes use of a deformed linear multiplet. The novel feature of this multiplet is that it corresponds to the case of a gauged central charge using a one-form potential not annihilated by the central charge (unlike the standard N=2 vector multiplet). Such a gauge one-form can be chosen to describe a variant nonlinear vector-tensor multiplet. As a byproduct of our construction, we also find a variant realization of the tensor multiplet in supergravity where one of the auxiliaries is replaced by the field strength of a gauge three-form.
Linearization: Geometric, Complex, and Conditional
Directory of Open Access Journals (Sweden)
Asghar Qadir
2012-01-01
Full Text Available Lie symmetry analysis provides a systematic method of obtaining exact solutions of nonlinear (systems of differential equations, whether partial or ordinary. Of special interest is the procedure that Lie developed to transform scalar nonlinear second-order ordinary differential equations to linear form. Not much work was done in this direction to start with, but recently there have been various developments. Here, first the original work of Lie (and the early developments on it, and then more recent developments based on geometry and complex analysis, apart from Lie’s own method of algebra (namely, Lie group theory, are reviewed. It is relevant to mention that much of the work is not linearization but uses the base of linearization.
Linear programming foundations and extensions
Vanderbei, Robert J
2001-01-01
Linear Programming: Foundations and Extensions is an introduction to the field of optimization. The book emphasizes constrained optimization, beginning with a substantial treatment of linear programming, and proceeding to convex analysis, network flows, integer programming, quadratic programming, and convex optimization. The book is carefully written. Specific examples and concrete algorithms precede more abstract topics. Topics are clearly developed with a large number of numerical examples worked out in detail. Moreover, Linear Programming: Foundations and Extensions underscores the purpose of optimization: to solve practical problems on a computer. Accordingly, the book is coordinated with free efficient C programs that implement the major algorithms studied: -The two-phase simplex method; -The primal-dual simplex method; -The path-following interior-point method; -The homogeneous self-dual methods. In addition, there are online JAVA applets that illustrate various pivot rules and variants of the simplex m...
Bayes linear statistics, theory & methods
Goldstein, Michael
2007-01-01
Bayesian methods combine information available from data with any prior information available from expert knowledge. The Bayes linear approach follows this path, offering a quantitative structure for expressing beliefs, and systematic methods for adjusting these beliefs, given observational data. The methodology differs from the full Bayesian methodology in that it establishes simpler approaches to belief specification and analysis based around expectation judgements. Bayes Linear Statistics presents an authoritative account of this approach, explaining the foundations, theory, methodology, and practicalities of this important field. The text provides a thorough coverage of Bayes linear analysis, from the development of the basic language to the collection of algebraic results needed for efficient implementation, with detailed practical examples. The book covers:The importance of partial prior specifications for complex problems where it is difficult to supply a meaningful full prior probability specification...
The linear multiplet and ectoplasm
Butter, Daniel; Kuzenko, Sergei M.; Novak, Joseph
2012-09-01
In the framework of the superconformal tensor calculus for 4D {N} = {2} super-gravity, locally supersymmetric actions are often constructed using the linear multiplet. We provide a superform formulation for the linear multiplet and derive the corresponding action functional using the ectoplasm method (also known as the superform approach to the construction of supersymmetric invariants). We propose a new locally supersymmetric action which makes use of a deformed linear multiplet. The novel feature of this multiplet is that it corresponds to the case of a gauged central charge using a one-form potential not annihilated by the central charge (unlike the standard {N} = {2} vector multiplet). Such a gauge one-form can be chosen to describe a variant nonlinear vector-tensor multiplet. As a byproduct of our construction, we also find a variant realization of the tensor multiplet in supergravity where one of the auxiliaries is replaced by the field strength of a gauge three-form.
Penyajian Integral dari Operator Non Linear
Budiman, Herdi; Sunusi, Nurtiti
2004-01-01
Fungsional linear kontinu pada suatu ruang fungsi dapat disajikan dengan suatu integral dan biasanya linear. Pada papaer ini akan diberikan penyajian integral dari suatu operator non linear, dengan cara mengkonstruksi integral non linear Henstock Kurzweil, fungsi f:[0,1] ---------> X, dengan X merupakan ruang Banach, dilanjutkan dengan penyajian integral dari operator non linear pada ruang C=C([0,1],X).
Why quantum dynamics is linear
International Nuclear Information System (INIS)
A seed George planted 45 years ago is still producing fruit now. In 1961, George set out the fundamental proposition that quantum dynamics is described most generally by linear maps of density matrices. Since the first sprout from George's seed appeared in 1962, we have known that George's fundamental proposition can be used to derive the linear Schrodinger equation in cases where it can be expected to apply. Now we have a proof of George's proposition that density matrices are mapped linearly to density matrices, that there can be no nonlinear generalization of this. That completes the derivation of the linear Schrodinger equation. The proof of George's proposition replaces Wigner's theorem that a symmetry transformation is represented by a linear or antilinear operator. The assumption needed to prove George's proposition is just that the dynamics does not depend on anything outside the system but must allow the system to be described as part of a larger system. This replaces the physically less compelling assumption of Wigner's theorem that absolute values of inner products are preserved. The history of this question is reviewed. Nonlinear generalizations of quantum mechanics have been proposed. They predict small but clear nonlinear effects, which very accurate experiments have not seen. This begs the question. Is there a reason in principle why nonlinearity is not found? Is it impossible? Does quantum dynamics have to be linear? Attempts to prove this have not been decisive, because either their assumptions are not compelling or their arguments are not conclusive. The question has been left unsettled. The simple answer, based on a simple assumption, was found in two steps separated by 44 years.
Vanilla technicolor at linear colliders
Frandsen, Mads T.; Järvinen, Matti; Sannino, Francesco
2011-08-01
We analyze the reach of linear colliders for models of dynamical electroweak symmetry breaking. We show that linear colliders can efficiently test the compositeness scale, identified with the mass of the new spin-one resonances, until the maximum energy in the center of mass of the colliding leptons. In particular we analyze the Drell-Yan processes involving spin-one intermediate heavy bosons decaying either leptonically or into two standard model gauge bosons. We also analyze the light Higgs production in association with a standard model gauge boson stemming also from an intermediate spin-one heavy vector.
Correct Linearization of Einstein's Equations
Directory of Open Access Journals (Sweden)
Rabounski D.
2006-06-01
Full Text Available Regularly Einstein's equations can be reduced to a wave form (linearly dependent from the second derivatives of the space metric in the absence of gravitation, the space rotation and Christoffel's symbols. As shown here, the origin of the problem is that one uses the general covariant theory of measurement. Here the wave form of Einstein's equations is obtained in the terms of Zelmanov's chronometric invariants (physically observable projections on the observer's time line and spatial section. The obtained equations depend on solely the second derivatives even if gravitation, the space rotation and Christoffel's symbols. The correct linearization proves: the Einstein equations are completely compatible with weak waves of the metric.
Matrix methods applied linear algebra
Bronson, Richard
2008-01-01
Matrix Methods: Applied Linear Algebra, 3e, as a textbook, provides a unique and comprehensive balance between the theory and computation of matrices. The application of matrices is not just for mathematicians. The use by other disciplines has grown dramatically over the years in response to the rapid changes in technology. Matrix methods is the essence of linear algebra and is what is used to help physical scientists; chemists, physicists, engineers, statisticians, and economists solve real world problems.* Applications like Markov chains, graph theory and Leontief Models are placed i
Generalized, Linear, and Mixed Models
McCulloch, Charles E; Neuhaus, John M
2011-01-01
An accessible and self-contained introduction to statistical models-now in a modernized new editionGeneralized, Linear, and Mixed Models, Second Edition provides an up-to-date treatment of the essential techniques for developing and applying a wide variety of statistical models. The book presents thorough and unified coverage of the theory behind generalized, linear, and mixed models and highlights their similarities and differences in various construction, application, and computational aspects.A clear introduction to the basic ideas of fixed effects models, random effects models, and mixed m
Basic linear partial differential equations
Treves, Francois
2006-01-01
Focusing on the archetypes of linear partial differential equations, this text for upper-level undergraduates and graduate students features most of the basic classical results. The methods, however, are decidedly nontraditional: in practically every instance, they tend toward a high level of abstraction. This approach recalls classical material to contemporary analysts in a language they can understand, as well as exploiting the field's wealth of examples as an introduction to modern theories.The four-part treatment covers the basic examples of linear partial differential equations and their
Introduction to computational linear algebra
Nassif, Nabil; Erhel, Jocelyne
2015-01-01
Introduction to Computational Linear Algebra introduces the reader with a background in basic mathematics and computer programming to the fundamentals of dense and sparse matrix computations with illustrating examples. The textbook is a synthesis of conceptual and practical topics in ""Matrix Computations."" The book's learning outcomes are twofold: to understand state-of-the-art computational tools to solve matrix computations problems (BLAS primitives, MATLAB® programming) as well as essential mathematical concepts needed to master the topics of numerical linear algebra. It is suitable for s
Linear feedback controls the essentials
Haidekker, Mark A
2013-01-01
The design of control systems is at the very core of engineering. Feedback controls are ubiquitous, ranging from simple room thermostats to airplane engine control. Helping to make sense of this wide-ranging field, this book provides a new approach by keeping a tight focus on the essentials with a limited, yet consistent set of examples. Analysis and design methods are explained in terms of theory and practice. The book covers classical, linear feedback controls, and linear approximations are used when needed. In parallel, the book covers time-discrete (digital) control systems and juxtapos
Linear isometries of Hardy spaces
Institute of Scientific and Technical Information of China (English)
Edoardo; VESENTINI
2008-01-01
According to results established by DeLeeuw-Rudin-Wermer and by Forelli,all linear isometries of any Hardy space H~p(p≥1,p≠2)on the open unit discΔof C are represented by weighted composition operators defined by inner functions onΔ.After reviewing(and completing when p=∞)some of those results,the present report deals with a characterization of periodic and almost periodic semigroups of linear isometries of H~p.
Quantized, piecewise linear filter network
DEFF Research Database (Denmark)
Sørensen, John Aasted
1993-01-01
A quantization based piecewise linear filter network is defined. A method for the training of this network based on local approximation in the input space is devised. The training is carried out by repeatedly alternating between vector quantization of the training set into quantization classes...... and equalization of the quantization classes linear filter mean square training errors. The equalization of the mean square training errors is carried out by adapting the boundaries between neighbor quantization classes such that the differences in mean square training errors are reduced...
High dimensional linear inverse modelling
Cooper, Fenwick C
2015-01-01
We introduce and demonstrate two linear inverse modelling methods for systems of stochastic ODE's with accuracy that is independent of the dimensionality (number of elements) of the state vector representing the system in question. Truncation of the state space is not required. Instead we rely on the principle that perturbations decay with distance or the fact that for many systems, the state of each data point is only determined at an instant by itself and its neighbours. We further show that all necessary calculations, as well as numerical integration of the resulting linear stochastic system, require computational time and memory proportional to the dimensionality of the state vector.
Linearization of Conservative Nonlinear Oscillators
Belendez, A.; Alvarez, M. L.; Fernandez, E.; Pascual, I.
2009-01-01
A linearization method of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force which allows us to obtain a frequency-amplitude relation which is valid not only for small but also for large amplitudes and, sometimes, for…
Linear electric field mass spectrometry
McComas, David J.; Nordholt, Jane E.
1992-01-01
A mass spectrometer and methods for mass spectrometry. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field.
Vanilla Technicolor at Linear Colliders
DEFF Research Database (Denmark)
T. Frandsen, Mads; Jarvinen, Matti; Sannino, Francesco
2011-01-01
We analyze the reach of Linear Colliders (LC)s for models of dynamical electroweak symmetry breaking. We show that LCs can efficiently test the compositeness scale, identified with the mass of the new spin-one resonances, till the maximum energy in the center-of-mass of the colliding leptons. In ...
Parameterized Linear Longitudinal Airship Model
Kulczycki, Eric; Elfes, Alberto; Bayard, David; Quadrelli, Marco; Johnson, Joseph
2010-01-01
A parameterized linear mathematical model of the longitudinal dynamics of an airship is undergoing development. This model is intended to be used in designing control systems for future airships that would operate in the atmospheres of Earth and remote planets. Heretofore, the development of linearized models of the longitudinal dynamics of airships has been costly in that it has been necessary to perform extensive flight testing and to use system-identification techniques to construct models that fit the flight-test data. The present model is a generic one that can be relatively easily specialized to approximate the dynamics of specific airships at specific operating points, without need for further system identification, and with significantly less flight testing. The approach taken in the present development is to merge the linearized dynamical equations of an airship with techniques for estimation of aircraft stability derivatives, and to thereby make it possible to construct a linearized dynamical model of the longitudinal dynamics of a specific airship from geometric and aerodynamic data pertaining to that airship. (It is also planned to develop a model of the lateral dynamics by use of the same methods.) All of the aerodynamic data needed to construct the model of a specific airship can be obtained from wind-tunnel testing and computational fluid dynamics
Modelling Loudspeaker Non-Linearities
DEFF Research Database (Denmark)
Agerkvist, Finn T.
2007-01-01
This paper investigates different techniques for modelling the non-linear parameters of the electrodynamic loudspeaker. The methods are tested not only for their accuracy within the range of original data, but also for the ability to work reasonable outside that range, and it is demonstrated that...
Directivity of basic linear arrays
DEFF Research Database (Denmark)
Bach, Henning
1970-01-01
For a linear uniform array ofnelements, an expression is derived for the directivity as a function of the spacing and the phase constants. The cases of isotropic elements, collinear short dipoles, and parallel short dipoles are included. The formula obtained is discussed in some detail and contour...
Decomposable log-linear models
DEFF Research Database (Denmark)
Eriksen, Poul Svante
can be characterized by a structured set of conditional independencies between some variables given some other variables. We term the new model class decomposable log-linear models, which is illustrated to be a much richer class than decomposable graphical models.It covers a wide range of non...
Quantum Computing: Linear Optics Implementations
Sundsøy, Pål
2016-01-01
One of the main problems that optical quantum computing has to overcome is the efficient construction of two-photon gates. Theoretically these gates can be realized using Kerr-nonlinearities, but the techniques involved are experimentally very difficult. We therefore employ linear optics with projective measurements to generate these non-linearities. The downside is that the measurement-induced nonlinearities achieved with linear optics are less versatile and the success rate can be quite low. This project is mainly the result of a literature study but also a theoretical work on the physics behind quantum optical multiports which is essential for realizing two-photon gates. By applying different postcorrection techniques we increase the probability of success in a modifed non-linear sign shift gate which is foundational for the two photon controlled-NOT gate. We prove that it's not possible to correct the states by only using a single beam splitter. We show that it might be possible to increase the probabilit...
Linear Systems on Tropical Curves
Haase, Christian; Yu, Josephine
2009-01-01
A tropical curve \\Gamma is a metric graph with possibly unbounded edges, and tropical rational functions are continuous piecewise linear functions with integer slopes. We define the complete linear system |D| of a divisor D on a tropical curve \\Gamma analogously to the classical counterpart. We investigate the structure of |D| as a cell complex and show that linear systems are quotients of tropical modules, finitely generated by vertices of the cell complex. Using a finite set of generators, |D| defines a map from \\Gamma to a tropical projective space, and the image can be extended to a tropical curve of degree equal to \\deg(D). The tropical convex hull of the image realizes the linear system |D| as a polyhedral complex. We show that curves for which the canonical divisor is not very ample are hyperelliptic. We also show that the Picard group of a \\Q-tropical curve is a direct limit of critical groups of finite graphs converging to the curve.
Linear or Exponential Number Lines
Stafford, Pat
2011-01-01
Having decided to spend some time looking at one's understanding of numbers, the author was inspired by "Alex's Adventures in Numberland," by Alex Bellos to look at one's innate appreciation of number. Bellos quotes research studies suggesting that an individual's natural appreciation of numbers is more likely to be exponential rather than linear,…
Diversity of MIMO Linear Precoding
Mehana, Ahmed Hesham
2012-01-01
Linear precoding is a relatively simple method of MIMO signaling that can also be optimal in certain special cases. This paper is dedicated to high-SNR analysis of MIMO linear precoding. The Diversity-Multiplexing Tradeoff (DMT) of a number of linear precoders is analyzed. Furthermore, since the diversity at finite rate (also known as the fixed-rate regime, corresponding to multiplexing gain of zero) does not always follow from the DMT, linear precoders are also analyzed for their diversity at fixed rates. In several cases, the diversity at multiplexing gain of zero is found not to be unique, but rather to depend on spectral efficiency. The analysis includes the zero-forcing (ZF), regularized ZF, matched filtering and Wiener filtering precoders. We calculate the DMT of ZF precoding under two common design approaches, namely maximizing the throughput and minimizing the transmit power. It is shown that regularized ZF (RZF) or Matched filter (MF) suffer from error floors for all positive multiplexing gains. Howe...
Linear electric field mass spectrometry
Energy Technology Data Exchange (ETDEWEB)
McComas, D.J.; Nordholt, J.E.
1991-03-29
A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.
Linear evolution of sandwave packets
Roos, P.C.; Blondeaux, P.; Hulscher, S.J.M.H.; Vittori, G.
2005-01-01
We investigate how a local topographic disturbance of a flat seabed may become morphodynamically active, according to the linear instability mechanism which gives rise to sandwave formation. The seabed evolution follows from a Fourier integral, which can generally not be evaluated in closed form. As
Linear modeling of glacier fluctuations
Oerlemans, J.
2012-01-01
In this contribution a linear first-order differential equation is used to model glacier length fluctuations. This equation has two parameters describing the physical characteristics of a glacier: the climate sensitivity, expressing how the equilibrium glacier length depends on the climatic state, a
Linearized theory of peridynamic states.
Energy Technology Data Exchange (ETDEWEB)
Silling, Stewart Andrew
2009-04-01
A state-based peridynamic material model describes internal forces acting on a point in terms of the collective deformation of all the material within a neighborhood of the point. In this paper, the response of a state-based peridynamic material is investigated for a small deformation superposed on a large deformation. The appropriate notion of a small deformation restricts the relative displacement between points, but it does not involve the deformation gradient (which would be undefined on a crack). The material properties that govern the linearized material response are expressed in terms of a new quantity called the modulus state. This determines the force in each bond resulting from an incremental deformation of itself or of other bonds. Conditions are derived for a linearized material model to be elastic, objective, and to satisfy balance of angular momentum. If the material is elastic, then the modulus state is obtainable from the second Frechet derivative of the strain energy density function. The equation of equilibrium with a linearized material model is a linear Fredholm integral equation of the second kind. An analogue of Poincare's theorem is proved that applies to the infinite dimensional space of all peridynamic vector states, providing a condition similar to irrotationality in vector calculus.
New directions in linear accelerators
International Nuclear Information System (INIS)
Current work on linear particle accelerators is placed in historical and physics contexts, and applications driving the state of the art are discussed. Future needs and the ways they may force development are outlined in terms of exciting R and D challenges presented to today's accelerator designers. 23 references, 7 figures
DEFF Research Database (Denmark)
Andersen, O. Krogh
1975-01-01
Two approximate methods for solving the band-structure problem in an efficient and physically transparent way are presented and discussed in detail. The variational principle for the one-electron Hamiltonian is used in both schemes, and the trial functions are linear combinations of energy-indepe...
Measures of Linear Correlation for Multiple Variables
Wang, Jianji; Zheng, Nanning
2014-01-01
Multivariate linear correlation analysis plays an important role in various fields such as statistics, economics, and big data analytics. However, there was no compact formulation to define and measure multivariate linear correlation. In this paper, we propose a pair of coupling coefficients, the multivariate linear correlation coefficient (LCC) and linear incorrelation coefficient (LIC), to measure the strength of multivariate linear correlation and linear irrelevance. Pearson's correlation ...
Spaces of Piecewise Linear Manifolds
DEFF Research Database (Denmark)
Gomez Lopez, Mauricio Esteban
Abstract In this thesis we introduce Δ-set ψPLd(RN) which we regard as the piecewise linear analogue of the space ψd(RN) of smooth d-dimensional submanifoldsin RN introduced by Galatius in [4]. Using ψPLd(RN) we define a bi-Δ-set Cd(RN)•,• ( whose geometric realization BCPLd(RN) = llCd(RN)•,•ll ......Abstract In this thesis we introduce Δ-set ψPLd(RN) which we regard as the piecewise linear analogue of the space ψd(RN) of smooth d-dimensional submanifoldsin RN introduced by Galatius in [4]. Using ψPLd(RN) we define a bi-Δ-set Cd(RN)•,• ( whose geometric realization BCPLd(RN) = ll...... BCPLd (RN) ≅ ΩN–1lψPLd (RN)•l when N — d ≥ 3. The proof of the main theorem relies on properties of ψPLd (RN) • which arise from the fact that this Δ-set can be obtained from a more general contravariant functor PL op → Sets defined on the category of finite dimensional polyhedraand piecewise linear...... maps, and on a fiberwise transversality result for piecewise linear submersions whose fibers are contained in R × (-1,1)N-1 ⊆ RN . For the proof of this transversality result we use a theorem of Hudson on extensions of piecewise linear isotopies which is why we need to include the condition N — d ≥ 3...
Linear groups over a locally linear division ring
Hai, Bui Xuan; Deo, Trinh Thanh
2010-01-01
In this paper, in the first we give definitions of some classes of division rings which strictly contain the class of centrally finite division rings. One of our main purpose is to construct non-trivial examples of rings of new defined classes. Further, we study linear groups over division rings of these classes. Our new obtained results generalize precedent results for centrally finite division rings.
Linear inflation from quartic potential
Kannike, Kristjan; Racioppi, Antonio; Raidal, Martti
2016-01-01
We show that if the inflaton has a non-minimal coupling to gravity and the Planck scale is dynamically generated, the results of Coleman-Weinberg inflation are confined in between two attractor solutions: quadratic inflation, which is ruled out by the recent measurements, and linear inflation which, instead, is in the experimental allowed region. The minimal scenario has only one free parameter — the inflaton's non-minimal coupling to gravity — that determines all physical parameters such as the tensor-to-scalar ratio and the reheating temperature of the Universe. Should the more precise future measurements of inflationary parameters point towards linear inflation, further interest in scale-invariant scenarios would be motivated.
Challenges in future linear colliders
Chattopadhyay, S
2002-01-01
For decades, electron-positron colliders have been complementing proton-proton colliders. But the circular LEP, the largest e/sup -/e /sup +/ collider, represented an energy limit beyond which energy losses to synchrotron radiation necessitate moving to e/sup -/e/sup + / linear colliders (LCs), thereby raising new challenges for accelerator builders. Japanese-American, German, and European collaborations have presented options for the "Future Linear Collider " (FLC). Key accelerator issues for any FLC option are the achievement of high enough energy and luminosity. Damping rings, taking advantage of the phenomenon of synchrotron radiation, have been developed as the means for decreasing beam size, which is crucial for ensuring a sufficiently high rate of particle-particle collisions. Related challenges are alignment and stability in an environment where even minute ground motion can disrupt performance, and the ability to monitor beam size. The technical challenges exist within a wider context of socioeconomi...
Cosmological Evolution of Linear Bias
Basilakos, S; Basilakos, Spyros; Plionis, Manolis
2000-01-01
Using linear perturbation theory and the Friedmann-Lemaitre solutions of the cosmological field equations, we derive analytically a second-order differential equation for the evolution of the linear bias factor, b(z), between the background matter and a mass-tracer fluctuation field. We find b(z) to be a strongly dependent function of redshift in all cosmological models. Comparing our analytical solution with the semi-analytic model of Mo & White, which utilises the Press-Schechter formalism and the gravitationally induced evolution of clustering, we find an extremely good agreement even at large redshifts, once we normalize to the same bias value at two different epochs, one of which is the present. Furthermore, our analytic b(z) function agrees well with the outcome of N-body simulations even up to large redshifts.
Linear accelerator for radioisotope production
Energy Technology Data Exchange (ETDEWEB)
Hansborough, L.D.; Hamm, R.W.; Stovall, J.E.
1982-02-01
A 200- to 500-..mu..A source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear accelerator technology; it would be 27.3 m long and cost approx. $6 million. By operating the radio-frequency (rf) power system at a level necessary to produce a 500-..mu..A beam current, the cost of power deposited in the radioisotope-production target is comparable with existing cyclotrons. If the rf-power system is operated at full power, the same accelerator is capable of producing an 1140-..mu..A beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons.
Bayes linear covariance matrix adjustment
Wilkinson, Darren J
1995-01-01
In this thesis, a Bayes linear methodology for the adjustment of covariance matrices is presented and discussed. A geometric framework for quantifying uncertainties about covariance matrices is set up, and an inner-product for spaces of random matrices is motivated and constructed. The inner-product on this space captures aspects of our beliefs about the relationship between covariance matrices of interest to us, providing a structure rich enough for us to adjust beliefs about unknown matrices in the light of data such as sample covariance matrices, exploiting second-order exchangeability and related specifications to obtain representations allowing analysis. Adjustment is associated with orthogonal projection, and illustrated with examples of adjustments for some common problems. The problem of adjusting the covariance matrices underlying exchangeable random vectors is tackled and discussed. Learning about the covariance matrices associated with multivariate time series dynamic linear models is shown to be a...
Correct Linearization of Einstein's Equations
Directory of Open Access Journals (Sweden)
Rabounski D.
2006-04-01
Full Text Available Routinely, Einstein’s equations are be reduced to a wave form (linearly independent of the second derivatives of the space metric in the absence of gravitation, the space rotation and Christoffel’s symbols. As shown herein, the origin of the problem is the use of the general covariant theory of measurement. Herein the wave form of Einstein’s equations is obtained in terms of Zelmanov’s chronometric invariants (physically observable projections on the observer’s time line and spatial section. The equations so obtained depend solely upon the second derivatives, even for gravitation, the space rotation and Christoffel’s symbols. The correct linearization proves that the Einstein equations are completely compatible with weak waves of the metric.
Computational linear and commutative algebra
Kreuzer, Martin
2016-01-01
This book combines, in a novel and general way, an extensive development of the theory of families of commuting matrices with applications to zero-dimensional commutative rings, primary decompositions and polynomial system solving. It integrates the Linear Algebra of the Third Millennium, developed exclusively here, with classical algorithmic and algebraic techniques. Even the experienced reader will be pleasantly surprised to discover new and unexpected aspects in a variety of subjects including eigenvalues and eigenspaces of linear maps, joint eigenspaces of commuting families of endomorphisms, multiplication maps of zero-dimensional affine algebras, computation of primary decompositions and maximal ideals, and solution of polynomial systems. This book completes a trilogy initiated by the uncharacteristically witty books Computational Commutative Algebra 1 and 2 by the same authors. The material treated here is not available in book form, and much of it is not available at all. The authors continue to prese...
Adaptive Local Linear Quantile Regression
Institute of Scientific and Technical Information of China (English)
Yu-nan Su; Mao-zai Tian
2011-01-01
In this paper we propose a new method of local linear adaptive smoothing for nonparametric conditional quantile regression. Some theoretical properties of the procedure are investigated. Then we demonstrate the performance of the method on a simulated example and compare it with other methods. The simulation results demonstrate a reasonable performance of our method proposed especially in situations when the underlying image is piecewise linear or can be approximated by such images. Generally speaking, our method outperforms most other existing methods in the sense of the mean square estimation (MSE) and mean absolute estimation (MAE) criteria. The procedure is very stable with respect to increasing noise level and the algorithm can be easily applied to higher dimensional situations.
Signal processing and linear systems
Lathi, B P
1998-01-01
This text presents a comprehensive treatment of signal processing and linear systems suitable for juniors and seniors in electrical engineering. Based on B. P. Lathi's widely used book, Linear Systems and Signals, it features additional applications to communications, controls, and filtering as well as new chapters on analog and digital filters and digital signal processing. Lathi emphasizes the physical appreciation of concepts rather than the mere mathematical manipulation of symbols. Avoiding the tendency to treat engineering as a branch of applied mathematics, he uses mathematics to enhance physical and intuitive understanding of concepts, instead of employing it only to prove axiomatic theory. Theoretical results are supported by carefully chosen examples and analogies, allowing students to intuitively discover meaning for themselves.
Positive fractional linear electrical circuits
Kaczorek, Tadeusz
2013-10-01
The positive fractional linear systems and electrical circuits are addressed. New classes of fractional asymptotically stable and unstable electrical circuits are introduced. The Caputo and Riemann-Liouville definitions of fractional derivatives are used to analysis of the positive electrical circuits composed of resistors, capacitors, coils and voltage (current) sources. The positive fractional electrical and specially unstable different types electrical circuits are analyzed. Some open problems are formulated.
Linearized supergravity from Matrix theory
Kabat, D; Kabat, Daniel; Taylor, Washington
1998-01-01
We show that the linearized supergravity potential between two objects arising from the exchange of quanta with zero longitudinal momentum is reproduced to all orders in 1/r by terms in the one-loop Matrix theory potential. The essential ingredient in the proof is the identification of the Matrix theory quantities corresponding to moments of the stress tensor and membrane current. We also point out that finite-N Matrix theory violates the Equivalence Principle.
Logistic systems with linear feedback
Son, Leonid; Shulgin, Dmitry; Ogluzdina, Olga
2016-08-01
A wide variety of systems may be described by specific dependence, which is known as logistic curve, or S-curve, between the internal characteristic and the external parameter. Linear feedback between these two values may be suggested for a wide set of systems also. In present paper, we suggest a bifurcation behavior for systems with both features, and discuss it for two cases, which are the Ising magnet in external field, and the development of manufacturing enterprise.
Squares of Random Linear Codes
DEFF Research Database (Denmark)
Cascudo Pueyo, Ignacio; Cramer, Ronald; Mirandola, Diego;
2015-01-01
a positive answer, for codes of dimension $k$ and length roughly $\\frac{1}{2}k^2$ or smaller. Moreover, the convergence speed is exponential if the difference $k(k+1)/2-n$ is at least linear in $k$. The proof uses random coding and combinatorial arguments, together with algebraic tools involving the precise...... computation of the number of quadratic forms of a given rank, and the number of their zeros....
Linear Processes for Functional Data
Mas, André; Pumo, Besnik
2009-01-01
International audience Linear processes on functional spaces were born about fifteen years ago. And this original topic went through the same fast development as the other areas of functional data modeling such as PCA or regression. They aim at generalizing to random curves the classical ARMA models widely known in time series analysis. They offer a wide spectrum of models suited to the statistical inference on continuous time stochastic processes within the paradigm of functional data. Es...
Interpretability in Linear Brain Decoding
Kia, Seyed Mostafa; Passerini, Andrea
2016-01-01
Improving the interpretability of brain decoding approaches is of primary interest in many neuroimaging studies. Despite extensive studies of this type, at present, there is no formal definition for interpretability of brain decoding models. As a consequence, there is no quantitative measure for evaluating the interpretability of different brain decoding methods. In this paper, we present a simple definition for interpretability of linear brain decoding models. Then, we propose to combine the...
Linearization of conservative nonlinear oscillators
Energy Technology Data Exchange (ETDEWEB)
Belendez, A; Alvarez, M L [Departamento de Fisica, IngenierIa de Sistemas y TeorIa de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain); Fernandez, E; Pascual, I [Departamento de Optica, FarmacologIa y AnatomIa, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)], E-mail: a.belendez@ua.es
2009-03-11
A linearization method of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force which allows us to obtain a frequency-amplitude relation which is valid not only for small but also for large amplitudes and, sometimes, for the complete range of oscillation amplitudes. Some conservative nonlinear oscillators are analysed to illustrate the usefulness and effectiveness of the technique.
Supersymmetry at the Linear Collider
Choi, S. Y.
2004-01-01
If supersymmetry (SUSY) is realized at the electroweak scale, its underlying structure and breaking mechanism may be explored with great precision by a future linear $e^+ e^-$ collider (LC) with a clean environment, tunable collision energy, high luminosity polarized beams, and additional $e^-e^-$, $e\\gamma$ and $\\gamma\\gamma$ modes. In this report we summarize four papers submitted to the ICHEP04 conference about the precise measurements of the top squark parameters and $\\tan\\beta$, the impa...
Test accelerator for linear collider
International Nuclear Information System (INIS)
KEK has proposed to build Test Accelerator Facility (TAF) capable of producing a 2.5 GeV electron beam for the purpose of stimulating R ampersand D for linear collider in TeV region. The TAF consists of a 1.5 GeV S-band linear accelerator, 1.5 GeV damping ring and 1.0 GeV X-band linear accelerator. The TAF project will be carried forward in three phases. Through Phase-I and Phase-II, the S-band and X-band linacs will be constructed, and in Phase-III, the damping ring will be completed. The construction of TAF Phase-I has started, and the 0.2 GeV S-band injector linac has been almost completed. The Phase-I linac is composed of a 240 keV electron gun, subharmonic bunchers, prebunchers and traveling buncher followed by high-gradient accelerating structures. The SLAC 5045 klystrons are driven at 450 kV in order to obtain the rf-power of 100 MW in a 1 μs pulse duration. The rf-power from a pair of klystrons are combined into an accelerating structure. The accelerating gradient up to 100 MeV/m will be obtained in a 0.6 m long structure. 5 refs., 3 figs., 2 tabs
BLAS- BASIC LINEAR ALGEBRA SUBPROGRAMS
Krogh, F. T.
1994-01-01
The Basic Linear Algebra Subprogram (BLAS) library is a collection of FORTRAN callable routines for employing standard techniques in performing the basic operations of numerical linear algebra. The BLAS library was developed to provide a portable and efficient source of basic operations for designers of programs involving linear algebraic computations. The subprograms available in the library cover the operations of dot product, multiplication of a scalar and a vector, vector plus a scalar times a vector, Givens transformation, modified Givens transformation, copy, swap, Euclidean norm, sum of magnitudes, and location of the largest magnitude element. Since these subprograms are to be used in an ANSI FORTRAN context, the cases of single precision, double precision, and complex data are provided for. All of the subprograms have been thoroughly tested and produce consistent results even when transported from machine to machine. BLAS contains Assembler versions and FORTRAN test code for any of the following compilers: Lahey F77L, Microsoft FORTRAN, or IBM Professional FORTRAN. It requires the Microsoft Macro Assembler and a math co-processor. The PC implementation allows individual arrays of over 64K. The BLAS library was developed in 1979. The PC version was made available in 1986 and updated in 1988.
High concentration linear Fresnel reflectors
International Nuclear Information System (INIS)
Highlights: • Linear Fresnel reflectors (LFRs) have great potential for cost reductions. • Concentration in the receiver central strip as high as in trough collectors. • Daily constant flux map in the receiver if the filling factor is adequately designed. • High concentration variation between summer and winter for N–S configurations. - Abstract: The late exponential development of Concentrating Solar Power (CSP) technology has driven to a very high power installed worldwide, but with no time for global optimization of the technology. High feed-in-tariffs have concentrated investments on trough collectors and central towers, previously studied during the 1980s. Linear Fresnel reflectors (LFRs) are regarded as a low efficiency technology, which is mainly due to very little previous research. However, the use of slightly bent mirrors drives to high concentration ratios, with obvious cost advantages over other CSP technologies. This paper studies the radiation flux obtained in a flat receiver using different mirror shapes, and analyzes its variation along the year. Linear Fresnel reflector design variables are reviewed, and a Ray Tracing model of the Fresdemo prototype is carried out. Results show higher performances than expected
IFIC expone grandes piezas del acelerador particulas de Ginebra
2005-01-01
The Institute for corpuscular physics of Valencia University exhibits from today great pieces coming from the particle accelerator of CERN in Geneva, an underground laboratory of high technologic level producing small atomic particles which it makes collide at very high energies to study the fundamental components of the matter and its interactions (1 page)
Linear and integer programming theory and practice
Sierksma, Gerard
2001-01-01
Linear optimisation; basic concepts; Dantzig's simplex method; duality and optimality; sensitivity analysis; karmarkar's interior path method; integer linear optimisation; linear network models; computational complexity issues; model building, case studies, and advanced techniques; solutions to selected exercises. Appendices: linear algebra; convexity; graph theory; optimisation theory; computer package INTPM.
Bayes linear covariance matrix adjustment for multivariate dynamic linear models
Wilkinson, Darren J
2008-01-01
A methodology is developed for the adjustment of the covariance matrices underlying a multivariate constant time series dynamic linear model. The covariance matrices are embedded in a distribution-free inner-product space of matrix objects which facilitates such adjustment. This approach helps to make the analysis simple, tractable and robust. To illustrate the methods, a simple model is developed for a time series representing sales of certain brands of a product from a cash-and-carry depot. The covariance structure underlying the model is revised, and the benefits of this revision on first order inferences are then examined.
Powers of lexsegment ideals with linear resolution
Ene, Viviana; Olteanu, Anda
2012-01-01
All powers of lexsegment ideals with linear resolution (equivalently, with linear quotients) have linear quotients with respect to suitable orders of the minimal monomial generators. For a large subclass of the lexsegment ideals the corresponding Rees algebra has a quadratic Gr\\"obner basis, thus it is Koszul. We also find other classes of monomial ideals with linear quotients whose powers have linear quotients too.
Matrix algebra for linear models
Gruber, Marvin H J
2013-01-01
Matrix methods have evolved from a tool for expressing statistical problems to an indispensable part of the development, understanding, and use of various types of complex statistical analyses. This evolution has made matrix methods a vital part of statistical education. Traditionally, matrix methods are taught in courses on everything from regression analysis to stochastic processes, thus creating a fractured view of the topic. Matrix Algebra for Linear Models offers readers a unique, unified view of matrix analysis theory (where and when necessary), methods, and their applications. Written f
Vanilla Technicolor at Linear Colliders
Frandsen, Mads T; Sannino, Francesco
2011-01-01
We analyze the reach of Linear Colliders (LC)s for models of dynamical electroweak symmetry breaking. We show that LCs can efficiently test the compositeness scale, identified with the mass of the new spin-one resonances, till the maximum energy in the center-of-mass of the colliding leptons. In particular we analyze the Drell-Yan processes involving spin-one intermediate heavy bosons decaying either leptonically or into two Standard Model (SM) gauge bosons. We also analyze the light Higgs production in association with a SM gauge boson stemming also from an intermediate spin-one heavy vector.
A linear Fick's law calorimeter
Alpert, Seymour S.; Bryant, Pat D.; Woodside, William F.
1982-10-01
A small animal calorimeter is described that is based on the direct application of Fick's law. Heat flow is channeled through a circular disk of magnesium and the temperature difference between the inside and outside surface of the disk is detected by means of solid-state temperature transducers. The device is calibrated using a light-weight electrical resistive source and is shown to be linear in its response and to have an e-folding time of 4.8 min. A rat was introduced into the calorimeter and its heat energy expenditure rate was observed in both the sedated and unsedated states.
ALPS - A LINEAR PROGRAM SOLVER
Viterna, L. A.
1994-01-01
Linear programming is a widely-used engineering and management tool. Scheduling, resource allocation, and production planning are all well-known applications of linear programs (LP's). Most LP's are too large to be solved by hand, so over the decades many computer codes for solving LP's have been developed. ALPS, A Linear Program Solver, is a full-featured LP analysis program. ALPS can solve plain linear programs as well as more complicated mixed integer and pure integer programs. ALPS also contains an efficient solution technique for pure binary (0-1 integer) programs. One of the many weaknesses of LP solvers is the lack of interaction with the user. ALPS is a menu-driven program with no special commands or keywords to learn. In addition, ALPS contains a full-screen editor to enter and maintain the LP formulation. These formulations can be written to and read from plain ASCII files for portability. For those less experienced in LP formulation, ALPS contains a problem "parser" which checks the formulation for errors. ALPS creates fully formatted, readable reports that can be sent to a printer or output file. ALPS is written entirely in IBM's APL2/PC product, Version 1.01. The APL2 workspace containing all the ALPS code can be run on any APL2/PC system (AT or 386). On a 32-bit system, this configuration can take advantage of all extended memory. The user can also examine and modify the ALPS code. The APL2 workspace has also been "packed" to be run on any DOS system (without APL2) as a stand-alone "EXE" file, but has limited memory capacity on a 640K system. A numeric coprocessor (80X87) is optional but recommended. The standard distribution medium for ALPS is a 5.25 inch 360K MS-DOS format diskette. IBM, IBM PC and IBM APL2 are registered trademarks of International Business Machines Corporation. MS-DOS is a registered trademark of Microsoft Corporation.
Wave propagation in linear electrodynamics
Obukhov, Yu N; Rubilar, G F; Obukhov, Yuri N.; Fukui, Tetsuo; Rubilar, Guillermo
2000-01-01
The Fresnel equation governing the propagation of electromagnetic waves for the most general linear constitutive law is derived. The wave normals are found to lie, in general, on a fourth order surface. When the constitutive coefficients satisfy the so-called reciprocity or closure relation, one can define a duality operator on the space of the two-forms. We prove that the closure relation is a sufficient condition for the reduction of the fourth order surface to the familiar second order light cone structure. We finally study whether this condition is also necessary.
Seismic response of linear accelerators
Collette, Christophe; Artoos, Kurt; Guinchard, Michael; Hauviller, Claude
2010-01-01
This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is valid...
Linear readout of object manifolds
Chung, SueYeon; Lee, Daniel D.; Sompolinsky, Haim
2016-06-01
Objects are represented in sensory systems by continuous manifolds due to sensitivity of neuronal responses to changes in physical features such as location, orientation, and intensity. What makes certain sensory representations better suited for invariant decoding of objects by downstream networks? We present a theory that characterizes the ability of a linear readout network, the perceptron, to classify objects from variable neural responses. We show how the readout perceptron capacity depends on the dimensionality, size, and shape of the object manifolds in its input neural representation.
Linearized Bekenstein Varying Alpha Models
Pina-Avelino, P; Oliveira, J C
2004-01-01
We study the simplest class of Bekenstein-type, varying $\\alpha$ models, in which the two available free functions (potential and gauge kinetic function) are Taylor-expanded up to linear order. Any realistic model of this type reduces to a model in this class for a certain time interval around the present day. Nevertheless, we show that no such model is consistent with all existing observational results. We discuss possible implications of these findings, and in particular clarify the ambiguous statement (often found in the literature) that ``the Webb results are inconsistent with Oklo''.
Linearized Bekenstein varying α models
Avelino, P. P.; Martins, C. J.; Oliveira, J. C.
2004-10-01
We study the simplest class of Bekenstein-type, varying α models, in which the two available free functions (potential and gauge kinetic function) are Taylor-expanded up to linear order. Any realistic model of this type reduces to a model in this class for a certain time interval around the present day. Nevertheless, we show that no such model is consistent with all existing observational results. We discuss possible implications of these findings, and, in particular, clarify the ambiguous statement (often found in the literature) that “the Webb results are inconsistent with Oklo.”
Linear collider research and development
Energy Technology Data Exchange (ETDEWEB)
Siemann, R.H.
1994-08-01
This paper presents a review of work being done on the design of linear colliders with center of mass energies near 0.5 TeV. These include TESLA, SBLC, NLC, JLC, VLEPP, and CLIC. Here the author touches on recent advances made on these designs. Items discussed include advances in the study of beam focusing and spot sizes in setups such as the Final Focus Test Beam, bunching concepts, development of high power RF systems, design of high gradient accelerator structures, and work on emittance features.
Topics in computational linear optimization
DEFF Research Database (Denmark)
Hultberg, Tim Helge
2000-01-01
. The method is based on a matrix modification approach applied to a spiked triangular permutation of the system. The factorization consists of 3 steps. 1) a reordering of the matrix, such that only a small number, 's', of spike columns reach above the diagonal is determined. 2) a block LU factorization...... arithmetic and conditional exceptions. Besides the articles the thesis features six introductory chapters, including a description of two real-world applications of linear optimization, in which I have been involved during my Ph.D. study....
Nonferromagnetic linear variable differential transformer
Ellis, James F.; Walstrom, Peter L.
1977-06-14
A nonferromagnetic linear variable differential transformer for accurately measuring mechanical displacements in the presence of high magnetic fields is provided. The device utilizes a movable primary coil inside a fixed secondary coil that consists of two series-opposed windings. Operation is such that the secondary output voltage is maintained in phase (depending on polarity) with the primary voltage. The transducer is well-suited to long cable runs and is useful for measuring small displacements in the presence of high or alternating magnetic fields.
Lower bounds for adaptive linearity tests
Lovett, Shachar
2008-01-01
Linearity tests are randomized algorithms which have oracle access to the truth table of some function f, and are supposed to distinguish between linear functions and functions which are far from linear. Linearity tests were first introduced by (Blum, Luby and Rubenfeld, 1993), and were later used in the PCP theorem, among other applications. The quality of a linearity test is described by its correctness c - the probability it accepts linear functions, its soundness s - the probability it accepts functions far from linear, and its query complexity q - the number of queries it makes. Linearity tests were studied in order to decrease the soundness of linearity tests, while keeping the query complexity small (for one reason, to improve PCP constructions). Samorodnitsky and Trevisan (Samorodnitsky and Trevisan 2000) constructed the Complete Graph Test, and prove that no Hyper Graph Test can perform better than the Complete Graph Test. Later in (Samorodnitsky and Trevisan 2006) they prove, among other results, th...
Undithering using linear filtering and non-linear diffusion techniques
Asha, V
2011-01-01
Data compression is a method of improving the efficiency of transmission and storage of images. Dithering, as a method of data compression, can be used to convert an 8-bit gray level image into a 1-bit / binary image. Undithering is the process of reconstruction of gray image from binary image obtained from dithering of gray image. In the present paper, I propose a method of undithering using linear filtering followed by anisotropic diffusion which brings the advantage of smoothing and edge enhancement. First-order statistical parameters, second-order statistical parameters, mean-squared error (MSE) between reconstructed image and the original image before dithering, and peak signal to noise ratio (PSNR) are evaluated at each step of diffusion. Results of the experiments show that the reconstructed image is not as sharp as the image before dithering but a large number of gray values are reproduced with reference to those of the original image prior to dithering.
Repair of overheating linear accelerator
Energy Technology Data Exchange (ETDEWEB)
Barkley, Walter; Baldwin, William; Bennett, Gloria; Bitteker, Leo; Borden, Michael; Casados, Jeff; Fitzgerald, Daniel; Gorman, Fred; Johnson, Kenneth; Kurennoy, Sergey; Martinez, Alberto; O’Hara, James; Perez, Edward; Roller, Brandon; Rybarcyk, Lawrence; Stark, Peter; Stockton, Jerry
2004-01-01
Los Alamos Neutron Science Center (LANSCE) is a proton accelerator that produces high energy particle beams for experiments. These beams include neutrons and protons for diverse uses including radiography, isotope production, small feature study, lattice vibrations and material science. The Drift Tube Linear Accelerator (DTL) is the first portion of a half mile long linear section of accelerator that raises the beam energy from 750 keV to 100 MeV. In its 31st year of operation (2003), the DTL experienced serious issues. The first problem was the inability to maintain resonant frequency at full power. The second problem was increased occurrences of over-temperature failure of cooling hoses. These shortcomings led to an investigation during the 2003 yearly preventative maintenance shutdown that showed evidence of excessive heating: discolored interior tank walls and coper oxide deposition in the cooling circuits. Since overheating was suspected to be caused by compromised heat transfer, improving that was the focus of the repair effort. Investigations revealed copper oxide flow inhibition and iron oxide scale build up. Acid cleaning was implemented with careful attention to protection of the base metal, selection of components to clean and minimization of exposure times. The effort has been very successful in bringing the accelerator through a complete eight month run cycle allowing an incredible array of scientific experiments to be completed this year (2003-2004). This paper will describe the systems, investigation analysis, repair, return to production and conclusion.
Linearity of Holographic Entanglement Entropy
Almheiri, Ahmed; Swingle, Brian
2016-01-01
We consider the question of whether the leading contribution to the entanglement entropy in holographic CFTs is truly given by the expectation value of a linear operator as is suggested by the Ryu-Takayanagi formula. We investigate this property by computing the entanglement entropy, via the replica trick, in states dual to superpositions of macroscopically distinct geometries and find it consistent with evaluating the expectation value of the area operator within such states. However, we find that this fails once the number of semi-classical states in the superposition grows exponentially in the central charge of the CFT. Moreover, in certain such scenarios we find that the choice of surface on which to evaluate the area operator depends on the density matrix of the entire CFT. This nonlinearity is enforced in the bulk via the homology prescription of Ryu-Takayanagi. We thus conclude that the homology constraint is not a linear property in the CFT. We also discuss the existence of entropy operators in genera...
Piecewise linear loop quantum gravity
Energy Technology Data Exchange (ETDEWEB)
Engle, Jonathan [MPI fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, D-14476 Potsdam (Germany)
2010-02-07
We define a modification of loop quantum gravity (LQG) in which graphs are required to consist of piecewise linear edges, which we call piecewise linear LQG (plLQG). At the diffeomorphism-invariant level, we prove that plLQG is equivalent to standard LQG, as long as one chooses the class of diffeomorphisms appropriately. That is, we exhibit a unitary map between the diffeomorphism-invariant Hilbert spaces that maps physically equivalent operators into each other. In addition, using the same ideas as in standard LQG, one can define a Hamiltonian and master constraint in plLQG, and the unitary map between plLQG and LQG then provides an exact isomorphism of dynamics in the two frameworks. Furthermore, loop quantum cosmology (LQC) can be exactly embedded into plLQG. This allows a prior program of the author to embed LQC into LQG at the dynamical level to proceed. In particular, this allows a formal expression for a physically motivated embedding of LQC into LQG at the diffeomorphism-invariant level to be given.
OPTIMIZATION WITH LINEAR COMPLEMENTARITY CONSTRAINTS
Directory of Open Access Journals (Sweden)
Joaquim Júdice
2014-12-01
Full Text Available A Mathematical Program with Linear Complementarity Constraints (MPLCC is an optimization problem where a continuously differentiable function is minimized on a set defined by linear constraints and complementarity conditions on pairs of complementary variables. This problem finds many applications in several areas of science, engineering and economics and is also an important tool for the solution of some NP-hard structured and nonconvex optimization problems, such as bilevel, bilinear and nonconvex quadratic programs and the eigenvalue complementarity problem. In this paper some of the most relevant applications of the MPLCC and formulations of nonconvex optimization problems as MPLCCs are first presented. Algorithms for computing a feasible solution, a stationary point and a global minimum for the MPLCC are next discussed. The most important nonlinear programming methods, complementarity algorithms, enumerative techniques and 0 - 1 integer programming approaches for the MPLCC are reviewed. Some comments about the computational performance of these algorithms and a few topics for future research are also included in this survey.
Multicollinearity in hierarchical linear models.
Yu, Han; Jiang, Shanhe; Land, Kenneth C
2015-09-01
This study investigates an ill-posed problem (multicollinearity) in Hierarchical Linear Models from both the data and the model perspectives. We propose an intuitive, effective approach to diagnosing the presence of multicollinearity and its remedies in this class of models. A simulation study demonstrates the impacts of multicollinearity on coefficient estimates, associated standard errors, and variance components at various levels of multicollinearity for finite sample sizes typical in social science studies. We further investigate the role multicollinearity plays at each level for estimation of coefficient parameters in terms of shrinkage. Based on these analyses, we recommend a top-down method for assessing multicollinearity in HLMs that first examines the contextual predictors (Level-2 in a two-level model) and then the individual predictors (Level-1) and uses the results for data collection, research problem redefinition, model re-specification, variable selection and estimation of a final model.
Blind reconstruction of linear scrambler
Institute of Scientific and Technical Information of China (English)
Hui Xie; Fenghua Wang; Zhitao Huang
2014-01-01
An algorithm based on eigenanalysis technique and Walsh-Hadamard transform (WHT) is proposed. The algorithm contains two steps. Firstly, the received sequence is divided into temporal windows, and a covariance matrix is computed. The li-near feedback shift register (LFSR) sequence is reconstructed from the first eigenvector of this matrix. Secondly, equations ac-cording to the recovered LFSR sequence are constructed, and the Walsh spectrum corresponding to the equations is computed. The feedback polynomial of LFSR is estimated from the Walsh spec-trum. The validity of the algorithm is verified by the simulation result. Final y, case studies are presented to il ustrate the perfor-mance of the blind reconstruction method.
Highlights of the LINEAR survey
Palaversa, Lovro
2015-01-01
Lincoln Near-Earth Asteroid Research asteroid survey (LINEAR) observed approximately 10,000 deg$^2$ of the northern sky in the period roughly from 1998 to 2013. Long baseline of observations combined with good cadence and depth ($14.5 < r_{SDSS}< 17.5$) provides excellent basis for investigation of variable and transient objects in this relatively faint and underexplored part of the sky. Details covering the repurposing of this survey for use in time domain astronomy, creation of a highly reliable catalogue of approximately 7,200 periodically variable stars (RR Lyrae, eclipsing binaries, SX Phe stars and LPVs) as well as search for optical signatures of exotic transient events (such as tidal disruption event candidates), are presented.
An Ordering Linear Unification Algorithm
Institute of Scientific and Technical Information of China (English)
胡运发
1989-01-01
In this paper,we present an ordering linear unification algorithm(OLU).A new idea on substituteion of the binding terms is introduced to the algorithm,which is able to overcome some drawbacks of other algorithms,e.g.,MM algorithm[1],RG1 and RG2 algorithms[2],Particularly,if we use the directed eyclie graphs,the algoritm needs not check the binding order,then the OLU algorithm can also be aplied to the infinite tree data struceture,and a higher efficiency can be expected.The paper focuses upon the discussion of OLU algorithm and a partial order structure with respect to the unification algorithm.This algorithm has been implemented in the GKD-PROLOG/VAX 780 interpreting system.Experimental results have shown that the algorithm is very simple and efficient.
PC Basic Linear Algebra Subroutines
Energy Technology Data Exchange (ETDEWEB)
1992-03-09
PC-BLAS is a highly optimized version of the Basic Linear Algebra Subprograms (BLAS), a standardized set of thirty-eight routines that perform low-level operations on vectors of numbers in single and double-precision real and complex arithmetic. Routines are included to find the index of the largest component of a vector, apply a Givens or modified Givens rotation, multiply a vector by a constant, determine the Euclidean length, perform a dot product, swap and copy vectors, and find the norm of a vector. The BLAS have been carefully written to minimize numerical problems such as loss of precision and underflow and are designed so that the computation is independent of the interface with the calling program. This independence is achieved through judicious use of Assembly language macros. Interfaces are provided for Lahey Fortran 77, Microsoft Fortran 77, and Ryan-McFarland IBM Professional Fortran.
Computational aspects of linear control
2002-01-01
Many devices (we say dynamical systems or simply systems) behave like black boxes: they receive an input, this input is transformed following some laws (usually a differential equation) and an output is observed. The problem is to regulate the input in order to control the output, that is for obtaining a desired output. Such a mechanism, where the input is modified according to the output measured, is called feedback. The study and design of such automatic processes is called control theory. As we will see, the term system embraces any device and control theory has a wide variety of applications in the real world. Control theory is an interdisci plinary domain at the junction of differential and difference equations, system theory and statistics. Moreover, the solution of a control problem involves many topics of numerical analysis and leads to many interesting computational problems: linear algebra (QR, SVD, projections, Schur complement, structured matrices, localization of eigenvalues, computation of the...
Hunting Radions at Linear Colliders
Datta, A; Datta, Anindya; Huitu, Katri
2004-01-01
We investigate the possibility to disentangle the radions in the Randall-Sundrum scenario from higgs boson at the next generation high energy $e^+ e^-$ linear colliders. Due to trace anomaly, the radion coupling (and in turn the branching ratio) to gluons is enhanced over the same for the Standard Model (SM) higgs. We study the radion production at electron-positron colliders, via the fusion of W-bosons in association with neutrinos, and propose to investigate radion decay to a pair of gluons. At 500 GeV center of mass energy, our signal is not very promising. We find our results are encouraging for finding radion and differentiating it from higgs for center of mass energies of 1 TeV and above.
Perfusion Linearity and Its Applications
Pianykh, Oleg
2010-01-01
Perfusion analysis computes blood flow parameters (blood volume, blood flow, mean transit time) from the observed flow of contrast agent, passing through the patient's vascular system. Perfusion deconvolution has been widely accepted as the principal numerical tool for perfusion analysis, and is used routinely in clinical applications. This extensive use of perfusion in clinical decision-making makes numerical stability and robustness of perfusion computations vital for accurate diagnostics and patient safety. The main goal of this paper is to propose a novel approach for validating numerical properties of perfusion algorithms. The approach is based on Perfusion Linearity Property (PLP), which we find in perfusion deconvolution, as well as in many other perfusion techniques. PLP allows one to study perfusion values as weighted averages of the original imaging data. This, in turn, uncovers hidden problems with the existing deconvolution techniques, and may be used to suggest more reliable computational approac...
drift tube for linear accelerator
A drift tube from the Linac 1. This was the first tank of the linear accelerator Linac1, the injection system for the Proton Synchrotron, It ran for 34 years (1958 - 1992). Protons entered at the far end and were accelerated between the copper drift tubes by an oscillating electromagnetic field. The field flipped 200 million times a second (200 MHz) so the protons spent 5 nanoseconds crossing a drift tube and a gap. Moving down the tank, the tubes and gaps had to get longer as the protons gained speed. The tank accelerated protons from 500 KeV to 10 MeV. Linac1 was also used to accelerate deutrons and alpha particles for the Intersecting Storage Rings and oxygen and sulpher ions for the Super Proton Synchrotron heavy ion programme.
THE LABYRINTH CONTRADICTS THE LINEAR
Directory of Open Access Journals (Sweden)
Claudio Alexandre de Barros Teixeira
2009-07-01
Full Text Available Labyrinth as opposed to the linear aims to investigate the relationship between the visual texts of Portuguese Baroque poetry and modernist works such as Mallarmé´s Le Livre, James Joyce´s Finnegans Wake, and Ana Hatherly´s O escritor, starting from the concept of labyrinth as a structure or network that offers different ways of reading or of interpretation , an idea close to the concept of work in progress, formulated by Haroldo de Campos and Umberto Eco. The article discusses historical aspects related to the architecture of labyrinths, their transposition to the literary form, still in ancient times, their development during the baroque period and possible parallels with avant-garde works from the second half of the 20thcentury and the beginning of the 21st century that demand different manners of participation from the reader, in a “reinvention” of reading
Sobolev Extension By Linear Operators
Fefferman, Charles L; Luli, Garving K
2012-01-01
Let $L^{m,p}(\\R^n)$ be the Sobolev space of functions with $m^{th}$ derivatives lying in $L^p(\\R^n)$. Assume that $n< p < \\infty$. For $E \\subset \\R^n$, let $L^{m,p}(E)$ denote the space of restrictions to $E$ of functions in $L^{m,p}(\\R^n)$. We show that there exists a bounded linear map $T : L^{m,p}(E) \\rightarrow L^{m,p}(\\R^n)$ such that, for any $f \\in L^{m,p}(E)$, we have $Tf = f$ on $E$. We also give a formula for the order of magnitude of $\\|f\\|_{L^{m,p}(E)}$ for a given $f : E \\rightarrow \\R$ when $E$ is finite.
Linear induction accelerator parameter options
International Nuclear Information System (INIS)
The principal undertaking of the Beam Research Program over the past decade has been the investigation of propagating intense self-focused beams. Recently, the major activity of the program has shifted toward the investigation of converting high quality electron beams directly to laser radiation. During the early years of the program, accelerator development was directed toward the generation of very high current (>10 kA), high energy beams (>50 MeV). In its new mission, the program has shifted the emphasis toward the production of lower current beams (>3 kA) with high brightness (>106 A/(rad-cm)2) at very high average power levels. In efforts to produce these intense beams, the state of the art of linear induction accelerators (LIA) has been advanced to the point of satisfying not only the current requirements but also future national needs
Crab Cavities for Linear Colliders
Energy Technology Data Exchange (ETDEWEB)
Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Beard, C.; Dykes, M.; Goudket, P.; Kalinin, A.; Ma, L.; McIntosh, P.; /Daresbury; Shulte, D.; /CERN; Jones, Roger M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Bellantoni, L.; Chase, B.; Church, M.; Khabouline, T.; Latina, A.; /Fermilab; Adolphsen, C.; Li, Z.; Seryi, Andrei; /SLAC
2011-11-08
Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.
Crab cavities for linear colliders
Burt, G; Carter, R; Dexter, A; Tahir, I; Beard, C; Dykes, M; Goudket, P; Kalinin, A; Ma, L; McIntosh, P; Shulte, D; Jones, Roger M; Bellantoni, L; Chase, B; Church, M; Khabouline, T; Latina, A; Adolphsen, C; Li, Z; Seryi, Andrei; Xiao, L
2008-01-01
Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.
Piecewise Linear Identification of Nonlinear Systems
Billings, S A; Voon, W.S.F.
1986-01-01
Methods of identifying a series of piecewise linear models which approximate to a nonlinear system over some operating range are investigated. Both spatial linear models and models with signal dependent parameters are considered.
Introduction to linear algebra and differential equations
Dettman, John W
1986-01-01
Excellent introductory text focuses on complex numbers, determinants, orthonormal bases, symmetric and hermitian matrices, first order non-linear equations, linear differential equations, Laplace transforms, Bessel functions, more. Includes 48 black-and-white illustrations. Exercises with solutions. Index.
Linear connections on the quantum plane
Dubois-Violette, Michel; Madore, John; Masson, Thierry; Mourad, Jihad
1994-01-01
A general definition has been proposed recently of a linear connection and a metric in noncommutative geometry. It is shown that to within normalization there is a unique linear connection on the quantum plane and there is no metric.
Groupoids with Only Linear Term Functions
Institute of Scientific and Technical Information of China (English)
Jung R. Cho; Józef Dudek
2001-01-01
When one deals with terms over algebras, it is quite natural to look for the simplest terms which represent all the terms, and it will be very convenient for many reasons if every term can be represented by a linear term, as in the cases of modules, semilattices, Boolean groups, affine spaces, and so on. On the other hand, the linearity of terms imposes much restraint on the structure and properties of the algebra. We call an algebra term-linear if every term is equal to some linear term or constant function and every linear term is essential in the sense that it depends on each variable it involves. In this paper, we study some properties and identities of term-linear groupoids, and characterize term-linear semigroups and term-linear commutative idempotent groupoids.
Non-linear constitutive equations for gravitoelectromagnetism
Duplij, Steven; Di Grezia, Elisabetta; Esposito, Giampiero; Kotvytskiy, Albert
2013-01-01
This paper studies non-linear constitutive equations for gravitoelectromagnetism. Eventually, the problem is solved of finding, for a given particular solution of the gravity-Maxwell equations, the exact form of the corresponding non-linear constitutive equations.
Linear superposition solutions to nonlinear wave equations
Institute of Scientific and Technical Information of China (English)
Liu Yu
2012-01-01
The solutions to a linear wave equation can satisfy the principle of superposition,i.e.,the linear superposition of two or more known solutions is still a solution of the linear wave equation.We show in this article that many nonlinear wave equations possess exact traveling wave solutions involving hyperbolic,triangle,and exponential functions,and the suitable linear combinations of these known solutions can also constitute linear superposition solutions to some nonlinear wave equations with special structural characteristics.The linear superposition solutions to the generalized KdV equation K(2,2,1),the Oliver water wave equation,and the k(n,n) equation are given.The structure characteristic of the nonlinear wave equations having linear superposition solutions is analyzed,and the reason why the solutions with the forms of hyperbolic,triangle,and exponential functions can form the linear superposition solutions is also discussed.
Strings and superstrings. Electron linear colliders
International Nuclear Information System (INIS)
Basic string theory; strings in interaction; construction of strings and superstrings in arbitrary space-time dimensions; compactification and phenomenology; linear e+e- colliders; and the Stanford linear collider were discussed
On Bayes linear unbiased estimation of estimable functions for the singular linear model
Institute of Scientific and Technical Information of China (English)
ZHANG Weiping; WEI Laisheng
2005-01-01
The unique Bayes linear unbiased estimator (Bayes LUE) of estimable functions is derived for the singular linear model. The superiority of Bayes LUE over ordinary best linear unbiased estimator is investigated under mean square error matrix (MSEM)criterion.
Linear Design Approach to a Fuzzy Controller
DEFF Research Database (Denmark)
Jantzen, Jan
1999-01-01
A ball-balancer, basically an inverted pendulum problem, is stabilised by a linear controller. With certain design choices, a fuzzy controller is equivalent to a summation; thus it can replace the linear controller. It can be claimed, that the fuzzy controller performs at least as well...... as the linear controller, since the linear controller is contained in the fuzzy controller. The approach makes it somewhat easier to design a fuzzy controller....
Monotonicity of the quantum linear programming bound
Eric M. Rains
1998-01-01
The most powerful technique known at present for bounding the size of quantum codes of prescribed minimum distance is the quantum linear programming bound. Unlike the classical linear programming bound, it is not immediately obvious that if the quantum linear programming constraints are satisfiable for dimension K, that the constraints can be satisfied for all lower dimensions. We show that the quantum linear programming bound is indeed monotonic in this sense, and give an explicitly monotoni...
Bayes linear variance adjustment for time series
Wilkinson, Darren J
2008-01-01
This paper exhibits quadratic products of linear combinations of observables which identify the covariance structure underlying the univariate locally linear time series dynamic linear model. The first- and second-order moments for the joint distribution over these observables are given, allowing Bayes linear learning for the underlying covariance structure for the time series model. An example is given which illustrates the methodology and highlights the practical implications of the theory.
Linear theory of lower hybrid heating
International Nuclear Information System (INIS)
The linear theory of wave propagation in the lower hybrid range of frequencies is presented. The topics of accessibility, linear and quasi-linear theories of electron Landau damping, and the linear theory of ion Landau damping are covered. The theory of wave propagation is extended to include the effect of toroidal geometry. A simulation model incorporating these theories is described and numerical results obtained with the model are given
Experimental study of a linear/non-linear flux rope
Energy Technology Data Exchange (ETDEWEB)
DeHaas, Timothy; Gekelman, Walter; Van Compernolle, Bart [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States)
2015-08-15
Flux ropes are magnetic structures of helical field lines, accompanied by spiraling currents. Commonly observed on the solar surface extending into the solar atmosphere, flux ropes are naturally occurring and have been observed by satellites in the near earth and in laboratory environments. In this experiment, a single flux rope (r = 2.5 cm, L = 1100 cm) was formed in the cylindrical, magnetized plasma of the Large Plasma Device (LaPD, L = 2200 cm, r{sub plasma} = 30 cm, n{sub o} = 10{sup 12 }cm{sup −3}, T{sub e} = 4 eV, He). The flux rope was generated by a DC discharge between an electron emitting cathode and anode. This fixes the rope at its source while allowing it to freely move about the anode. At large currents (I > πr{sup 2}B{sub 0}c/2 L), the flux rope becomes helical in structure and oscillates about a central axis. Under varying Alfven speeds and injection current, the transition of the flux rope from stable to kink-unstable was examined. As it becomes non-linear, oscillations in the magnetic signals shift from sinusoidal to Sawtooth-like, associated with elliptical motion of the flux rope; or the signal becomes intermittent as its current density increases.
Linear and Nonlinear Systems Analysis of the Visual System: Why does it seem so linear?
Shapley, Robert
2009-01-01
Linear and nonlinear systems analysis are tools that can be used to study communication systems like the visual system. The first step of systems analysis often is to test whether or not the system is linear. Retinal pathways are surprisingly linear, and some neurons in the visual cortex also emulate linear sensory transducers. We conclude that the retinal linearity depends on specialized ribbon synapses while cortical linearity is the result of balanced excitatory and inhibitory synaptic interactions. PMID:18940193
Miniversal Deformations of Bimodal Picewise Linear Systems
Ferrer Llop, Josep; Magret Planas, Maria dels Dolors; Pacha Andújar, Juan Ramón; Peña Carrera, Marta
2010-01-01
Keywords: Bimodal piecewise linear system, miniversal deformations, reduced forms. Bimodal linear systems are those consisting of two linear systems on each side of a given hyperplane, having continuous dynamics along that hyperplane. In this work, we focus on the derivation of (orthogonal) miniversal deformations, by using reduced forms.
Stability of Linear Equations--Algebraic Approach
Cherif, Chokri; Goldstein, Avraham; Prado, Lucio M. G.
2012-01-01
This article could be of interest to teachers of applied mathematics as well as to people who are interested in applications of linear algebra. We give a comprehensive study of linear systems from an application point of view. Specifically, we give an overview of linear systems and problems that can occur with the computed solution when the…
Linearization of Systems of Nonlinear Diffusion Equations
Institute of Scientific and Technical Information of China (English)
KANG Jing; QU Chang-Zheng
2007-01-01
We investigate the linearization of systems of n-component nonlinear diffusion equations; such systems have physical applications in soil science, mathematical biology and invariant curve flows. Equivalence transformations of their auxiliary systems are used to identify the systems that can be linearized. We also provide several examples of systems with two-component equations, and show how to linearize them by nonlocal mappings.
Difference Galois theory of linear differential equations
Di Vizio, Lucia; Hardouin, Charlotte; Wibmer, Michael
2013-01-01
We develop a Galois theory for linear differential equations equipped with the action of an endomorphism. This theory is aimed at studying the difference algebraic relations among the solutions of a linear differential equation. The Galois groups here are linear difference algebraic groups, i.e., matrix groups defined by algebraic difference equations.
On Systems of Linear Quaternion Functions
Ell, Todd A.
2007-01-01
A method of reducing general quaternion functions of first degree, i.e., linear quaternion functions, to quaternary canonical form is given. Linear quaternion functions, once reduced to canonical form, can be maintained in this form under functional composition. furthermore, the composition operation is symbolically identical to quaternion multiplication, making manipulation and reduction of systems of linear quaternion functions straight forward.
An Application of Linear Algebra over Lattices
Directory of Open Access Journals (Sweden)
M. Hosseinyazdi
2008-03-01
Full Text Available In this paper, first we consider L n as a semimodule over a complete bounded distributive lattice L. Then we define the basic concepts of module theory for L n. After that, we proved many similar theorems in linear algebra for the space L n. An application of linear algebra over lattices for solving linear systems, was given
First integrals of ordinary linear differential systems
Gorbuzov, V. N.; Pranevich, A. F.
2012-01-01
The spectral method for building first integrals of ordinary linear differential systems is elaborated. Using this method, we obtain bases of first integrals for linear differential systems with constant coefficients, for linear nonautonomous differential systems integrable in closed form (algebraic reducible systems, triangular systems, the Lappo-Danilevskii systems), and for reducible ordinary differential systems with respect to various transformation groups.
Principles of linear algebra with Mathematica
Shiskowski, Kenneth M
2013-01-01
A hands-on introduction to the theoretical and computational aspects of linear algebra using Mathematica® Many topics in linear algebra are simple, yet computationally intensive, and computer algebra systems such as Mathematica® are essential not only for learning to apply the concepts to computationally challenging problems, but also for visualizing many of the geometric aspects within this field of study. Principles of Linear Algebra with Mathematica uniquely bridges the gap between beginning linear algebra and computational linear algebra that is often encountered in applied settings,
Simulation of non-linear ultrasound fields
DEFF Research Database (Denmark)
Jensen, Jørgen Arendt; Fox, Paul D.; Wilhjelm, Jens E.;
2002-01-01
An approach for simulating non-linear ultrasound imaging using Field II has been implemented using the operator splitting approach, where diffraction, attenuation, and non-linear propagation can be handled individually. The method uses the Earnshaw/Poisson solution to Burgcrs' equation for the non......-linear ultrasound imaging in 3D using filters or pulse inversion for any kind of transducer, focusing, apodization, pulse emission and scattering phantom. This is done by first simulating the non-linear emitted field and assuming that the scattered field is weak and linear. The received signal is then the spatial...
Linearly arranged polytypic CZTSSe nanocrystals
Fan, Feng-Jia; Wu, Liang; Gong, Ming; Chen, Shi You; Liu, Guang Yao; Yao, Hong-Bin; Liang, Hai-Wei; Wang, Yi-Xiu; Yu, Shu-Hong
2012-01-01
Even colloidal polytypic nanostructures show promising future in band-gap tuning and alignment, researches on them have been much less reported than the standard nano-heterostructures because of the difficulties involved in synthesis. Up to now, controlled synthesis of colloidal polytypic nanocrsytals has been only realized in II-VI tetrapod and octopod nanocrystals with branched configurations. Herein, we report a colloidal approach for synthesizing non-branched but linearly arranged polytypic I2-II-IV-VI4 nanocrystals, with a focus on polytypic non-stoichiometric Cu2ZnSnSxSe4−x nanocrystals. Each synthesized polytypic non-stoichiometric Cu2ZnSnSxSe4−x nanocrystal is consisted of two zinc blende-derived ends and one wurtzite-derived center part. The formation mechanism has been studied and the phase composition can be tuned through adjusting the reaction temperature, which brings a new band-gap tuning approach to Cu2ZnSnSxSe4-x nanocrystals. PMID:23233871
Linear Motor Free Piston Compressor
Bloomfield, David P.
1995-02-01
A Linear Motor Free Piston Compressor (LMFPC), a free piston pressure recovery system for fuel cell powerplants was developed. The LMFPC consists of a reciprocating compressor and a reciprocating expander which are separated by a piston. In the past energy efficient turbochargers have been used for pressure large (over 50 kW) fuel cell powerplants by recovering pressure energy from the powerplant exhaust. A free piston compressor allows pressurizing 3 - 5 kW sized fuel cell powerplants. The motivation for pressurizing PEM fuel cell powerplants is to improve fuel cell performance. Pressurization of direct methanol fuel cells will be required if PEM membranes are to be used Direct methanol oxidation anode catalysts require high temperatures to operate at reasonable power densities. The elevated temperatures above 80 C will cause high water loss from conventional PEM membranes unless pressurization is employed. Because pressurization is an energy intensive process, recovery of the pressure energy is required to permit high efficiency in fuel cell powerplants. A complete LMFPC which can pressurize a 3 kW fuel cell stack was built. This unit is one of several that were constructed during the course of the program.
A linear atomic quantum coupler
Energy Technology Data Exchange (ETDEWEB)
El-Orany, Faisal A A [Department of Mathematics and computer Science, Faculty of Science, Suez Canal University 41522, Ismailia (Egypt); Wahiddin, M R B, E-mail: el_orany@hotmail.co, E-mail: faisal.orany@mimos.m, E-mail: mridza@mimos.m [Cyberspace Security Laboratory, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur (Malaysia)
2010-04-28
In this paper we develop the notion of the linear atomic quantum coupler. This device consists of two modes propagating into two waveguides, each of which includes a localized atom. These waveguides are placed close enough to allow exchange of energy between them via evanescent waves. Each mode interacts with the atom in the same waveguide in the standard way as the Jaynes-Cummings model (JCM) and with the atom-mode system in the second waveguide via the evanescent wave. We present the Hamiltonian for this system and deduce its wavefunction. We investigate the atomic inversions and the second-order correlation function. In contrast to the conventional coupler the atomic quantum coupler is able to generate nonclassical effects. The atomic inversions can exhibit a long revival-collapse phenomenon as well as subsidiary revivals based on the competition among the switching mechanisms in the system. Finally, under certain conditions the system can yield the results of the two-mode JCM.
Carrington, M. E.; Hansson, T. H.; Yamagishi, H.; Zahed, I.
1989-03-01
We reexamine the various schemes for calculating the linear response (the retarded Green's function) of a hot gluon plasma. The problems related to gauge invariance are discussed in detail, and results in different gauges are compared. We also point out some issues related to the very definition of a thermal ensemble in the presence of unphysical degrees of freedom. By culculating the retarded Green's function directly in real time, we explicitly study the effects of unphysical degrees of freedom in different gauges. Although there appears to be no unique way to define the response function, we find that several schemes can be questioned on formal grounds and that use of the background-field gauge (BFG) is the most satisfactory in this respect. We discuss two proposals to fix the gauge parameter (α) dependence in the BFG response function, the Vilkovisky-DeWitt effective action corresponding to the choice α = 0 (background Landau gauge), and the "gauge-invariant propagator" of Cornwall et al. corresponding to α = 1 (background Feynman gauge).
Linear programming algorithms and applications
Vajda, S
1981-01-01
This text is based on a course of about 16 hours lectures to students of mathematics, statistics, and/or operational research. It is intended to introduce readers to the very wide range of applicability of linear programming, covering problems of manage ment, administration, transportation and a number of other uses which are mentioned in their context. The emphasis is on numerical algorithms, which are illustrated by examples of such modest size that the solutions can be obtained using pen and paper. It is clear that these methods, if applied to larger problems, can also be carried out on automatic (electronic) computers. Commercially available computer packages are, in fact, mainly based on algorithms explained in this book. The author is convinced that the user of these algorithms ought to be knowledgeable about the underlying theory. Therefore this volume is not merely addressed to the practitioner, but also to the mathematician who is interested in relatively new developments in algebraic theory and in...
An Improved Linear Tetrahedral Element for Plasticity
Energy Technology Data Exchange (ETDEWEB)
Puso, M
2005-04-25
A stabilized, nodally integrated linear tetrahedral is formulated and analyzed. It is well known that linear tetrahedral elements perform poorly in problems with plasticity, nearly incompressible materials, and acute bending. For a variety of reasons, linear tetrahedral elements are preferable to quadratic tetrahedral elements in most nonlinear problems. Whereas, mixed methods work well for linear hexahedral elements, they don't for linear tetrahedrals. On the other hand, automatic mesh generation is typically not feasible for building many 3D hexahedral meshes. A stabilized, nodally integrated linear tetrahedral is developed and shown to perform very well in problems with plasticity, nearly incompressible materials and acute bending. Furthermore, the formulation is analytically and numerically shown to be stable and optimally convergent. The element is demonstrated to perform well in several standard linear and nonlinear benchmarks.
Processing Approach of Non-linear Adjustment Models in the Space of Non-linear Models
Institute of Scientific and Technical Information of China (English)
LI Chaokui; ZHU Qing; SONG Chengfang
2003-01-01
This paper investigates the mathematic features of non-linear models and discusses the processing way of non-linear factors which contributes to the non-linearity of a nonlinear model. On the basis of the error definition, this paper puts forward a new adjustment criterion, SGPE.Last, this paper investigates the solution of a non-linear regression model in the non-linear model space and makes the comparison between the estimated values in non-linear model space and those in linear model space.
JET VELOCITY OF LINEAR SHAPED CHARGES
Directory of Open Access Journals (Sweden)
Vječislav Bohanek
2012-12-01
Full Text Available Shaped explosive charges with one dimension significantly larger than the other are called linear shaped charges. Linear shaped charges are used in various industries and are applied within specific technologies for metal cutting, such as demolition of steel structures, separating spent rocket fuel tanks, demining, cutting holes in the barriers for fire service, etc. According to existing theories and models efficiency of linear shaped charges depends on the kinetic energy of the jet which is proportional to square of jet velocity. The original method for measuring velocity of linear shaped charge jet is applied in the aforementioned research. Measurements were carried out for two different linear materials, and the results are graphically presented, analysed and compared. Measurement results show a discrepancy in the measured velocity of the jet for different materials with the same ratio between linear and explosive mass (M/C per unit of surface, which is not described by presented models (the paper is published in Croatian.
Non-linear models: applications in economics
Albu, Lucian-Liviu
2006-01-01
The study concentrated on demonstrating how non-linear modelling can be useful to investigate the behavioural of dynamic economic systems. Using some adequate non-linear models could be a good way to find more refined solutions to actually unsolved problems or ambiguities in economics. Beginning with a short presentation of the simplest non-linear models, then we are demonstrating how the dynamics of complex systems, as the economic system is, could be explained on the base of some more advan...
Linear multi-secret sharing schemes
Institute of Scientific and Technical Information of China (English)
XIAO Liangliang; LIU Mulan
2005-01-01
In this paper the linear multi-secret sharing schemes are studied by using monotone span programs. A relation between computing monotone Boolean functions by using monotone span programs and realizing multi-access structures by using linear multisecret sharing schemes is shown. Furthermore, the concept of optimal linear multi-secret sharing scheme is presented and the several schemes are proved to be optimal.
LINEARIZATION AND CORRECTION METHOD FOR NONLINEAR PROBLEMS
Institute of Scientific and Technical Information of China (English)
何吉欢
2002-01-01
A new perturbation-like technique called linearization and correction method is proposed. Contrary to the traditional perturbation techniques, the present theory does not assume that the solution is expressed in the form of a power series of small parameter. To obtain an asymptotic solution of nonlinear system, the technique first searched for a solution for the linearized system, then a correction was added to the linearized solution. So the obtained results are uniformly valid for both weakly and strongly nonlinear equations.
Advanced linear algebra for engineers with Matlab
Dianat, Sohail A
2009-01-01
Matrices, Matrix Algebra, and Elementary Matrix OperationsBasic Concepts and NotationMatrix AlgebraElementary Row OperationsSolution of System of Linear EquationsMatrix PartitionsBlock MultiplicationInner, Outer, and Kronecker ProductsDeterminants, Matrix Inversion and Solutions to Systems of Linear EquationsDeterminant of a MatrixMatrix InversionSolution of Simultaneous Linear EquationsApplications: Circuit AnalysisHomogeneous Coordinates SystemRank, Nu
LRGS: Linear Regression by Gibbs Sampling
Mantz, Adam B.
2016-02-01
LRGS (Linear Regression by Gibbs Sampling) implements a Gibbs sampler to solve the problem of multivariate linear regression with uncertainties in all measured quantities and intrinsic scatter. LRGS extends an algorithm by Kelly (2007) that used Gibbs sampling for performing linear regression in fairly general cases in two ways: generalizing the procedure for multiple response variables, and modeling the prior distribution of covariates using a Dirichlet process.
Enriching an effect calculus with linear types
DEFF Research Database (Denmark)
Egger, Jeff; Møgelberg, Rasmus Ejlers; Simpson, Alex
2009-01-01
We define an ``enriched effect calculus'' by conservatively extending a type theory for computational effects with primitives from linear logic. By doing so, we obtain a generalisation of linear type theory, intended as a formalism for expressing linear aspects of effects. As a worked example, w....... In particular, the involution property amounts to the self-duality of the free (syntactic) model....
S-Duality for Linearized Gravity
Nieto, J.A.
1999-01-01
We develope the analogue of S-duality for linearized gravity in (3+1)-dimensions. Our basic idea is to consider the self-dual (anti-self-dual) curvature tensor for linearized gravity in the context of the Macdowell-Mansouri formalism. We find that the strong-weak coupling duality for linearized gravity is an exact symmetry and implies small-large duality for the cosmological constant.
A Tractable Extension of Linear Indexed Grammars
Keller, B
1995-01-01
It has been shown that Linear Indexed Grammars can be processed in polynomial time by exploiting constraints which make possible the extensive use of structure-sharing. This paper describes a formalism that is more powerful than Linear Indexed Grammar, but which can also be processed in polynomial time using similar techniques. The formalism, which we refer to as Partially Linear PATR manipulates feature structures rather than stacks.
Linear Maps Preserving Idempotence on Nest Algebras
Institute of Scientific and Technical Information of China (English)
Jian Lian CUI; Jin Chuan HOU
2004-01-01
In this paper, we discuss the rank-1-preserving linear maps on nest algebras of Hilbertspace operators. We obtain several characterizations of such linear maps and apply them to show that a weakly continuous linear bijection on an atomic nest algebra is idempotent preserving if and only if it is a Jordan homomorphism, and in turn, if and only if it is an automorphism or an anti-automorphism.
Network coding for computing: Linear codes
Appuswamy, Rathinakumar; Karamchandani, Nikhil; Zeger, Kenneth
2011-01-01
In network coding it is known that linear codes are sufficient to achieve the coding capacity in multicast networks and that they are not sufficient in general to achieve the coding capacity in non-multicast networks. In network computing, Rai, Dey, and Shenvi have recently shown that linear codes are not sufficient in general for solvability of multi-receiver networks with scalar linear target functions. We study single receiver networks where the receiver node demands a target function of the source messages. We show that linear codes may provide a computing capacity advantage over routing only when the receiver demands a `linearly-reducible' target function. % Many known target functions including the arithmetic sum, minimum, and maximum are not linearly-reducible. Thus, the use of non-linear codes is essential in order to obtain a computing capacity advantage over routing if the receiver demands a target function that is not linearly-reducible. We also show that if a target function is linearly-reducible,...
COMPARISON OF LINEAR CONTROLLERS FOR A
DEFF Research Database (Denmark)
Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik C.;
2005-01-01
In many hydraulic control applications, classic linear controllers are still employed, although there exist a number of number of nonlinear control methods, which may be better suited for handling the intrensic non-linearities often found in hydraulic systems. The focus of this paper is therefore...... on comparing different linear controllers, based on both simulation and experimental results, to determine what is obtainable when applying standard linear controllers to a hydraulic SISO servo system. The paper furthermore addresses how the performance may be improved by using internal pressure control...
Linear algebra a first course with applications
Knop, Larry E
2008-01-01
Linear Algebra: A First Course with Applications explores the fundamental ideas of linear algebra, including vector spaces, subspaces, basis, span, linear independence, linear transformation, eigenvalues, and eigenvectors, as well as a variety of applications, from inventories to graphics to Google's PageRank. Unlike other texts on the subject, this classroom-tested book gives students enough time to absorb the material by focusing on vector spaces early on and using computational sections as numerical interludes. It offers introductions to Maple™, MATLAB®, and TI-83 Plus for calculating matri
Automating linear accelerator quality assurance
Energy Technology Data Exchange (ETDEWEB)
Eckhause, Tobias; Thorwarth, Ryan; Moran, Jean M., E-mail: jmmoran@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109-5010 (United States); Al-Hallaq, Hania; Farrey, Karl [Department of Radiation Oncology and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States); Ritter, Timothy [Ann Arbor VA Medical Center, Ann Arbor, Michigan 48109 (United States); DeMarco, John [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California, 90048 (United States); Pawlicki, Todd; Kim, Gwe-Ya [UCSD Medical Center, La Jolla, California 92093 (United States); Popple, Richard [Department of Radiation Oncology, University of Alabama Birmingham, Birmingham, Alabama 35249 (United States); Sharma, Vijeshwar; Park, SungYong [Karmanos Cancer Institute, McLaren-Flint, Flint, Michigan 48532 (United States); Perez, Mario; Booth, Jeremy T. [Royal North Shore Hospital, Sydney, NSW 2065 (Australia)
2015-10-15
Purpose: The purpose of this study was 2-fold. One purpose was to develop an automated, streamlined quality assurance (QA) program for use by multiple centers. The second purpose was to evaluate machine performance over time for multiple centers using linear accelerator (Linac) log files and electronic portal images. The authors sought to evaluate variations in Linac performance to establish as a reference for other centers. Methods: The authors developed analytical software tools for a QA program using both log files and electronic portal imaging device (EPID) measurements. The first tool is a general analysis tool which can read and visually represent data in the log file. This tool, which can be used to automatically analyze patient treatment or QA log files, examines the files for Linac deviations which exceed thresholds. The second set of tools consists of a test suite of QA fields, a standard phantom, and software to collect information from the log files on deviations from the expected values. The test suite was designed to focus on the mechanical tests of the Linac to include jaw, MLC, and collimator positions during static, IMRT, and volumetric modulated arc therapy delivery. A consortium of eight institutions delivered the test suite at monthly or weekly intervals on each Linac using a standard phantom. The behavior of various components was analyzed for eight TrueBeam Linacs. Results: For the EPID and trajectory log file analysis, all observed deviations which exceeded established thresholds for Linac behavior resulted in a beam hold off. In the absence of an interlock-triggering event, the maximum observed log file deviations between the expected and actual component positions (such as MLC leaves) varied from less than 1% to 26% of published tolerance thresholds. The maximum and standard deviations of the variations due to gantry sag, collimator angle, jaw position, and MLC positions are presented. Gantry sag among Linacs was 0.336 ± 0.072 mm. The
Automating linear accelerator quality assurance
International Nuclear Information System (INIS)
Purpose: The purpose of this study was 2-fold. One purpose was to develop an automated, streamlined quality assurance (QA) program for use by multiple centers. The second purpose was to evaluate machine performance over time for multiple centers using linear accelerator (Linac) log files and electronic portal images. The authors sought to evaluate variations in Linac performance to establish as a reference for other centers. Methods: The authors developed analytical software tools for a QA program using both log files and electronic portal imaging device (EPID) measurements. The first tool is a general analysis tool which can read and visually represent data in the log file. This tool, which can be used to automatically analyze patient treatment or QA log files, examines the files for Linac deviations which exceed thresholds. The second set of tools consists of a test suite of QA fields, a standard phantom, and software to collect information from the log files on deviations from the expected values. The test suite was designed to focus on the mechanical tests of the Linac to include jaw, MLC, and collimator positions during static, IMRT, and volumetric modulated arc therapy delivery. A consortium of eight institutions delivered the test suite at monthly or weekly intervals on each Linac using a standard phantom. The behavior of various components was analyzed for eight TrueBeam Linacs. Results: For the EPID and trajectory log file analysis, all observed deviations which exceeded established thresholds for Linac behavior resulted in a beam hold off. In the absence of an interlock-triggering event, the maximum observed log file deviations between the expected and actual component positions (such as MLC leaves) varied from less than 1% to 26% of published tolerance thresholds. The maximum and standard deviations of the variations due to gantry sag, collimator angle, jaw position, and MLC positions are presented. Gantry sag among Linacs was 0.336 ± 0.072 mm. The
Non-Linear Rheological Properties and Neutron Scattering Investigation on Dilute Ring-Linear Blends
DEFF Research Database (Denmark)
Pyckhout-Hintzen, W.; Bras, A.R.; Wischnewski, A.;
Linear and non-linear Rheology on dilute blends of polystyrene ring polymers in linear matrix is combined with Small Angle Neutron Scattering (SANS) investigations. In this way 2 different entanglement interactions become clear. After stretching the samples to different hencky strains up to 2...... with interpenetrating linear chains. At the same time the non-linear rheological and mechanical data fit to a non-affine slip-tube model as for moderately crosslinked networks and to interchain pressure models or a modified non-linear Doi-Edwards description for the observed strain hardening during the extensional...
Solving non-linear Horn clauses using a linear Horn clause solver
DEFF Research Database (Denmark)
Kafle, Bishoksan; Gallagher, John Patrick; Ganty, Pierre
2016-01-01
In this paper we show that checking satisfiability of a set of non-linear Horn clauses (also called a non-linear Horn clause program) can be achieved using a solver for linear Horn clauses. We achieve this by interleaving a program transformation with a satisfiability checker for linear Horn...... clauses (also called a solver for linear Horn clauses). The program transformation is based on the notion of tree dimension, which we apply to a set of non-linear clauses, yielding a set whose derivation trees have bounded dimension. Such a set of clauses can be linearised. The main algorithm...
Neural Network for Combining Linear and Non-Linear Modelling of Dynamic Systems
DEFF Research Database (Denmark)
Madsen, Per Printz
1994-01-01
The purpose of this paper is to develop a method to combine linear models with MLP networks. In other words to find a method to make a non-linear and multivariable model that performs at least as good as a linear model, when the training data lacks information.......The purpose of this paper is to develop a method to combine linear models with MLP networks. In other words to find a method to make a non-linear and multivariable model that performs at least as good as a linear model, when the training data lacks information....
Utilizing Probabilistic Linear Equations in Cube Attacks
Institute of Scientific and Technical Information of China (English)
Yuan Yao; Bin Zhang; Wen-Ling Wu
2016-01-01
Cube attacks, proposed by Dinur and Shamir at EUROCRYPT 2009, have shown huge power against stream ciphers. In the original cube attacks, a linear system of secret key bits is exploited for key recovery attacks. However, we find a number of equations claimed linear in previous literature actually nonlinear and not fit into the theoretical framework of cube attacks. Moreover, cube attacks are hard to apply if linear equations are rare. Therefore, it is of significance to make use of probabilistic linear equations, namely nonlinear superpolys that can be approximated by linear expressions effectively. In this paper, we suggest a way to test out and utilize these probabilistic linear equations, thus extending cube attacks to a wider scope. Concretely, we employ the standard parameter estimation approach and the sequential probability ratio test (SPRT) for linearity test in the preprocessing phase, and use maximum likelihood decoding (MLD) for solving the probabilistic linear equations in the online phase. As an application, we exhibit our new attack against 672 rounds of Trivium and reduce the number of key bits to search by 7.
Composite Linear Models | Division of Cancer Prevention
By Stuart G. Baker The composite linear models software is a matrix approach to compute maximum likelihood estimates and asymptotic standard errors for models for incomplete multinomial data. It implements the method described in Baker SG. Composite linear models for incomplete multinomial data. Statistics in Medicine 1994;13:609-622. The software includes a library of thirty examples from the literature. |
Controllability of Continuous Bimodal Linear Systems
Josep Ferrer; Juan R. Pacha; Marta Peña
2013-01-01
We consider bimodal linear systems consisting of two linear dynamics acting on each side of a given hyperplane, assuming continuity along the separating hyperplane. We prove that the study of controllability can be reduced to the unobservable case, and for these ones we obtain a simple explicit characterization of controllability for dimensions 2 and 3, as well as some partial criteria for higher dimensions.
Linear Unlearning for Cross-Validation
DEFF Research Database (Denmark)
Hansen, Lars Kai; Larsen, Jan
1996-01-01
The leave-one-out cross-validation scheme for generalization assessment of neural network models is computationally expensive due to replicated training sessions. In this paper we suggest linear unlearning of examples as an approach to approximative cross-validation. Further, we discuss the...... time series prediction benchmark demonstrate the potential of the linear unlearning technique...
Hamilton-Jacobi formalism for linearized gravity
Energy Technology Data Exchange (ETDEWEB)
Bertin, M C [CMCC, Universidade Federal do ABC, Rua Santa Adalia, 166, Santo Andre, SP (Brazil); Pimentel, B M; Valcarcel, C E [Instituto de Fisica Teorica, UNESP, Sao Paulo State University, PO Box 70532-2, 01156-970, Sao Paulo, SP (Brazil); Zambrano, G E R, E-mail: mario.bertin@ufabc.edu.br, E-mail: pimentel@ift.unesp.br, E-mail: valcarcel@ift.unesp.br, E-mail: gramos@udenar.edu.co [Departamento de Fisica, Universidad de Narino, Calle 18 Carrera 50, San Juan de Pasto, Narino (Colombia)
2011-09-07
In this work, we study the theory of linearized gravity via the Hamilton-Jacobi formalism. We make a brief review of this theory and its Lagrangian description, as well as a review of the Hamilton-Jacobi approach for singular systems. Then, we apply this formalism to analyze the constraint structure of the linearized gravity in instant- and front-form dynamics.
Actuarial statistics with generalized linear mixed models
K. Antonio; J. Beirlant
2007-01-01
Over the last decade the use of generalized linear models (GLMs) in actuarial statistics has received a lot of attention, starting from the actuarial illustrations in the standard text by McCullagh and Nelder [McCullagh, P., Nelder, J.A., 1989. Generalized linear models. In: Monographs on Statistics
Linear systems and operators in Hilbert space
Fuhrmann, Paul A
2014-01-01
A treatment of system theory within the context of finite dimensional spaces, this text is appropriate for students with no previous experience of operator theory. The three-part approach, with notes and references for each section, covers linear algebra and finite dimensional systems, operators in Hilbert space, and linear systems in Hilbert space. 1981 edition.
Analysis of latent structures in linear systems
DEFF Research Database (Denmark)
Høskuldsson, Agnar
2004-01-01
the latent structure of a linear model. Here the ‘atomic’ parts of the algorithms that generate the latent structure for linear models are analyzed. It is shown how the PLS algorithm fits within this way of presenting the numerical procedures. The second part is concerning graphic illustrations...
Lie algebras and linear differential equations.
Brockett, R. W.; Rahimi, A.
1972-01-01
Certain symmetry properties possessed by the solutions of linear differential equations are examined. For this purpose, some basic ideas from the theory of finite dimensional linear systems are used together with the work of Wei and Norman on the use of Lie algebraic methods in differential equation theory.
An Inquiry-Based Linear Algebra Class
Wang, Haohao; Posey, Lisa
2011-01-01
Linear algebra is a standard undergraduate mathematics course. This paper presents an overview of the design and implementation of an inquiry-based teaching material for the linear algebra course which emphasizes discovery learning, analytical thinking and individual creativity. The inquiry-based teaching material is designed to fit the needs of a…
Numerical Linear Algebra On The CEDAR Multiprocessor
Meier, Ulrike; Sameh, Ahmed
1988-01-01
In this paper we describe in some detail the architectural features of the CEDAR. multiprocessor. We also discuss strategies for implementation of dense matrix computations, and present performance results on one cluster for a variety of linear system solvers, eigenvalue problem solvers, as well as algorithms for solving linear least squares problems.
Colored Range Searching in Linear Space
DEFF Research Database (Denmark)
Grossi, Roberto; Vind, Søren Juhl
2014-01-01
answer to the colored range reporting problem must report the distinct colors in the query range. We give the first linear space data structure for both problems in two dimensions (d = 2) with o(n) worst case query time. We also give the first data structure obtaining almost-linear space usage and o...
Linear Classification of Dairy Cattle. Slide Script.
Sipiorski, James; Spike, Peter
This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with principles of the linear classification of dairy cattle. Included in the guide are narrations for use with 63 slides, which illustrate the following areas that are considered in the linear classification system: stature, strength,…
Soft materials for linear electromechanical energy conversion
Jakli, Antal; Eber, Nandor
2014-01-01
We briefly review the literature of linear electromechanical effects of soft materials, especially in synthetic and biological polymers and liquid crystals (LCs). First we describe results on direct and converse piezoelectricity, and then we discuss a linear coupling between bending and electric polarization, which maybe called bending piezoelectricity, or flexoelectricity.
CANONICAL EXTENSIONS OF SYMMETRIC LINEAR RELATIONS
Sandovici, Adrian; Davidson, KR; Gaspar, D; Stratila, S; Timotin, D; Vasilescu, FH
2006-01-01
The concept of canonical extension of Hermitian operators has been recently introduced by A. Kuzhel. This paper deals with a generalization of this notion to the case of symmetric linear relations. Namely, canonical regular extensions of symmetric linear relations in Hilbert spaces are studied. The
Non-linear finite element modeling
DEFF Research Database (Denmark)
Mikkelsen, Lars Pilgaard
The note is written for courses in "Non-linear finite element method". The note has been used by the author teaching non-linear finite element modeling at Civil Engineering at Aalborg University, Computational Mechanics at Aalborg University Esbjerg, Structural Engineering at the University...
Microwave Radiometer Linearity Measured by Simple Means
DEFF Research Database (Denmark)
Skou, Niels
2002-01-01
Modern spaceborne radiometer systems feature an almost perfect on-board calibration, hence the primary calibration task to be carried out before launch is a check of radiometer linearity. This paper describes two ways of measuring linearity of microwave radiometers only requiring relatively simple...
Hamiltonian and Variational Linear Distributed Systems
Rapisarda, P.; Trentelman, H.L.
2002-01-01
We use the formalism of bilinear- and quadratic differential forms in order to study Hamiltonian and variational linear distributed systems. It was shown that a system described by ordinary linear constant-coefficient differential equations is Hamiltonian if and only if it is variational. In this pa
Construction and minimality of coordinated linear systems
Kempker, P.L.; Ran, A.C.M.; Schuppen, J.H. van
2014-01-01
Coordinated linear systems are a particular class of hierarchical systems with a top-to-bottom information structure, consisting of a coordinator system and two or more subsystems. This paper deals with the construction and minimality of coordinated linear systems. Construction procedures are given
Linear feature detection based on ridgelet
Institute of Scientific and Technical Information of China (English)
HOU; Biao; (侯彪); LIU; Fang; (刘芳); JIAO; Licheng; (焦李成)
2003-01-01
Linear feature detection is very important in image processing. The detection efficiency will directly affect the perfomance of pattern recognition and pattern classification. Based on the idea of ridgelet, this paper presents a new discrete localized ridgelet transform and a new method for detecting linear feature in anisotropic images. Experimental results prove the efficiency of the proposed method.
Linear pose estimation from points or lines
Ansar, A.; Daniilidis, K.
2002-01-01
We present a general framework which allows for a novel set of linear solutions to the pose estimation problem for both n points and n lines. We present a number of simulations which compare our results to two other recent linear algorithm as well as to iterative approaches.
Linearization of resistance thermometers and other transducers
DEFF Research Database (Denmark)
Diamond, Joseph M.
1970-01-01
Given a resistive transducer which responds directly or indirectly to a physical quantity x, it is shown that the relationship may be linearized by linear methods if and only if both the resistance and conductance of the transducer are concave upward as functions of x. This result applies to eith...
Systems of Linear Equations on a Spreadsheet.
Bosch, William W.; Strickland, Jeff
1998-01-01
The Optimizer in Quattro Pro and the Solver in Excel software programs make solving linear and nonlinear optimization problems feasible for business mathematics students. Proposes ways in which the Optimizer or Solver can be coaxed into solving systems of linear equations. (ASK)
Simplified Linear Equation Solvers users manual
Energy Technology Data Exchange (ETDEWEB)
Gropp, W. (Argonne National Lab., IL (United States)); Smith, B. (California Univ., Los Angeles, CA (United States))
1993-02-01
The solution of large sparse systems of linear equations is at the heart of many algorithms in scientific computing. The SLES package is a set of easy-to-use yet powerful and extensible routines for solving large sparse linear systems. The design of the package allows new techniques to be used in existing applications without any source code changes in the applications.
Regularly Controlled Bidirectional Linear Basic Grammars
Hogendorp, Jan Anne
1990-01-01
We investigate the bidirectional application of grammar productions -- i.e., using the productions in the reversed direction too -- to linear basic grammars. As in the case of regularly controlled bidirectional context-free grammars (or RCB grammars), we provide bidirectional linear basic grammars w
Neural Networks for Non-linear Control
DEFF Research Database (Denmark)
Sørensen, O.
1994-01-01
This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process.......This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process....
Linearized Riccati Technique and (Non-Oscillation Criteria for Half-Linear Difference Equations
Directory of Open Access Journals (Sweden)
Fišnarová Simona
2008-01-01
Full Text Available We consider the half-linear second-order difference equation , , , where , are real-valued sequences. We associate with the above-mentioned equation a linear second-order difference equation and we show that oscillatory properties of the above-mentioned one can be investigated using properties of this associated linear equation. The main tool we use is a linearization technique applied to a certain Riccati-type difference equation corresponding to the above-mentioned one.
Institute of Scientific and Technical Information of China (English)
Ming-xiang Cao; Fan-chao Kong
2009-01-01
By using the vector-method of matrix,we study Growth Curve Model with respect to linear constraint.Under matrix loss function and vector loss function,we obtain necessary and sufficient conditions for admissibility of linear estimators of parameters in the inhomogeneous linear class.
Investigating Students' Modes of Thinking in Linear Algebra: The Case of Linear Independence
Çelik, Derya
2015-01-01
Linear algebra is one of the most challenging topics to learn and teach in many countries. To facilitate the teaching and learning of linear algebra, priority should be given to epistemologically analyze the concepts that the undergraduate students have difficulty in conceptualizing and to define their ways of reasoning in linear algebra. After…
Third SIAM conference on applied linear algebra and short course on linear algebra in statistics
Energy Technology Data Exchange (ETDEWEB)
1988-01-01
This report contains abstracts on the following themes: Large Scale Computing and Numerical Methods; Inverse Eigenvalue Problems; Qualitative and Combinatorial Analysis of Matrices; Linear Systems and Control; Parallel Matrix Computations; Signal Processing; Optimization; Multivariate Statistics; Core Linear Algebra; and Iterative Methods for Solving Linear Systems. (LSP)
Piecewise linear regression splines with hyperbolic covariates
International Nuclear Information System (INIS)
Consider the problem of fitting a curve to data that exhibit a multiphase linear response with smooth transitions between phases. We propose substituting hyperbolas as covariates in piecewise linear regression splines to obtain curves that are smoothly joined. The method provides an intuitive and easy way to extend the two-phase linear hyperbolic response model of Griffiths and Miller and Watts and Bacon to accommodate more than two linear segments. The resulting regression spline with hyperbolic covariates may be fit by nonlinear regression methods to estimate the degree of curvature between adjoining linear segments. The added complexity of fitting nonlinear, as opposed to linear, regression models is not great. The extra effort is particularly worthwhile when investigators are unwilling to assume that the slope of the response changes abruptly at the join points. We can also estimate the join points (the values of the abscissas where the linear segments would intersect if extrapolated) if their number and approximate locations may be presumed known. An example using data on changing age at menarche in a cohort of Japanese women illustrates the use of the method for exploratory data analysis. (author)
Linearization Technologies for Broadband Radio-Over-Fiber Transmission Systems
Xiupu Zhang; Ran Zhu; Dongyan Shen; Taijun Liu
2014-01-01
Linearization technologies that can be used for linearizing RoF transmission are reviewed. Three main linearization methods, i.e. electrical analog linearization, optical linearization, and electrical digital linearization are presented and compared. Analog linearization can be achieved using analog predistortion circuits, and can be used for suppression of odd order nonlinear distortion components, such as third and fifth order. Optical linearization includes mixed-polarization, dual-wavelen...
Linear and Nonlinear Optical Properties of Quasicrystals
Institute of Scientific and Technical Information of China (English)
周详; 胡承正; 龚平; 朱家昆
2004-01-01
An investigation is carried out on the linear and nonlinear optical properties of quasicrystals. The linear and nonlinear susceptibilities are determined for two- and three-dimensional quasicrystals. The results show that for optical linearity, two-dimensional quasicrystals are uniaxial, while icosahedral quasicrystals are optically isotropic.Meanwhile all quasicrystals, except those with 5, 5m, N, Nmm (N = 8, 10, 12) symmetries, have no the firstorder optical nonlinearity. The tensor scheme of the first order nonlinear susceptibility is the same for these eight exceptional kinds of quasicrystals.
Numerical linear algebra with applications using Matlab
Ford, William
2014-01-01
Designed for those who want to gain a practical knowledge of modern computational techniques for the numerical solution of linear algebra problems, Numerical Linear Algebra with Applications contains all the material necessary for a first year graduate or advanced undergraduate course on numerical linear algebra with numerous applications to engineering and science. With a unified presentation of computation, basic algorithm analysis, and numerical methods to compute solutions, this book is ideal for solving real-world problems. It provides necessary mathematical background information for
Linear algebra problems with APL2
Beltrame, Renzo
1997-01-01
We present a performance comparison of three IBM systems, main-frame, SP1, and SP2. Some data are added, which refer to enhanced nodes of SP2, and to two different nodes type and configuration. We choose for the comparison three linear algebra problems : the matrix product, the solution of a system of linear equations, and the calculation of eigenvalues and eigenvectors of a square matrix. The comparison was made by using the APL2 functions and operators that are implemented to solve linear a...
Linear Upconversion of Orbit Angular Momentum
Ding, Dong-Sheng; Shi, Bao-Sen; Zou, Xu-Bo; Guo, Guang-Can
2012-01-01
We experimentally demonstrate that an infrared light imprinted the orbit angular momentum is linearly converted into a visible light using Four-wave mixing (FWM) via a Ladder-type configuration in Rb85 atoms. Simultaneously, we theoretically simulate this linear conversion process, and theoretical analysis is in reasonable agreement with the experimental result. A large single-photon detuning is used to reduce the absorption of the atoms to the up-converted light and to avoid the pattern formation in FWM process. The multi-mode image linear conversion is important for applications in image communications, astrophysics and quantum information so on.
A linear rotary magnetorheological damper for vehicles
Institute of Scientific and Technical Information of China (English)
JIANG Jiandong; LIANG Xichang; ZHANG Bo; XIAO Junli
2004-01-01
A new type of linear rotary magnetorheological damper (MRD) is proposed, which consists of a cylinder-type MRD and a screw mechanism to transform a linear motion into revolving motion. It is found that the structure parameters of MRD have complex relationship with the force of the damper, especially the lead angle, width and radius of the inner rotor. The analyses and simulation calculation of the static magnetic field give some usable data, and experiments of the damping component indicate that the proposed methods is feasible for developing linear rotary MRD.
Ultrasonic Linear Motor with Anisotropic Composite
Institute of Scientific and Technical Information of China (English)
曾周末; 王新辉; 赵伯雷
2004-01-01
An idea to make up the vibrating body of ultrasonic motor with anisotropic composite is proposed and a linear piezoelectric motor is developed in this paper. Relative problems such as actuating mechanism, resonant frequency are discussed theoretically. According to the feature that impulse exists between the elastic body of composite ultrasonic linear motor and the base, an impulse analysis is presented to calculate the motor′s friction driving force and frictional conversion efficiency. The impulse analysis essentially explains the reason why the ultrasonic motor has great driving force, and can be applied to analyze the non-linear ultrasonic motor.
A modern introduction to linear algebra
Ricardo, Henry
2009-01-01
Useful Concepts and Results at the Heart of Linear AlgebraA one- or two-semester course for a wide variety of students at the sophomore/junior undergraduate levelA Modern Introduction to Linear Algebra provides a rigorous yet accessible matrix-oriented introduction to the essential concepts of linear algebra. Concrete, easy-to-understand examples motivate the theory.The book first discusses vectors, Gaussian elimination, and reduced row echelon forms. It then offers a thorough introduction to matrix algebra, including defining the determinant naturally from the PA=LU factorization of a matrix.
Linear algebra and matrix analysis for statistics
Banerjee, Sudipto
2014-01-01
Matrices, Vectors, and Their OperationsBasic definitions and notations Matrix addition and scalar-matrix multiplication Matrix multiplication Partitioned matricesThe ""trace"" of a square matrix Some special matricesSystems of Linear EquationsIntroduction Gaussian elimination Gauss-Jordan elimination Elementary matrices Homogeneous linear systems The inverse of a matrixMore on Linear EquationsThe LU decompositionCrout's Algorithm LU decomposition with row interchanges The LDU and Cholesky factorizations Inverse of partitioned matrices The LDU decomposition for partitioned matricesThe Sherman-W
Matrix Tricks for Linear Statistical Models
Puntanen, Simo; Styan, George PH
2011-01-01
In teaching linear statistical models to first-year graduate students or to final-year undergraduate students there is no way to proceed smoothly without matrices and related concepts of linear algebra; their use is really essential. Our experience is that making some particular matrix tricks very familiar to students can substantially increase their insight into linear statistical models (and also multivariate statistical analysis). In matrix algebra, there are handy, sometimes even very simple "tricks" which simplify and clarify the treatment of a problem - both for the student and
Are Bilinear Quadrilaterals Better Than Linear Triangles?
Energy Technology Data Exchange (ETDEWEB)
D' Azevedo, E.F.
1993-01-01
This paper compares the theoretical effectiveness of bilinear approximation over quadrilaterals with linear approximation over triangles. Anisotropic mesh transformation is used to generate asymptotically optimally efficient meshes for piecewise linear interpolation over triangles and bilinear interpolation over quadrilaterals. For approximating a convex function, although bilinear quadrilaterals are more efficient, linear triangles are more accurate and may be preferred in finite element computations; whereas for saddle-shaped functions, quadrilaterals may offer a higher order approximation on a well-designed mesh. A surprising finding is different grid orientations may yield an order of magnitude improvement in approximation accuracy.
Dyck tilings, linear extensions, descents, and inversions
Kim, Jang Soo; Panova, Greta; Wilson, David B
2012-01-01
Dyck tilings were introduced by Kenyon and Wilson in their study of double-dimer pairings. They are certain kinds of tilings of skew Young diagrams with ribbon tiles shaped like Dyck paths. We give two bijections between "cover-inclusive" Dyck tilings and linear extensions of tree posets. The first bijection maps the statistic (area + tiles)/2 to inversions of the linear extension, and the second bijection maps the "discrepancy" between the upper and lower boundary of the tiling to descents of the linear extension.
Comparing linear probability model coefficients across groups
DEFF Research Database (Denmark)
Holm, Anders; Ejrnæs, Mette; Karlson, Kristian Bernt
2015-01-01
This article offers a formal identification analysis of the problem in comparing coefficients from linear probability models between groups. We show that differences in coefficients from these models can result not only from genuine differences in effects, but also from differences in one or more...... of the following three components: outcome truncation, scale parameters and distributional shape of the predictor variable. These results point to limitations in using linear probability model coefficients for group comparisons. We also provide Monte Carlo simulations and real examples to illustrate...... these limitations, and we suggest a restricted approach to using linear probability model coefficients in group comparisons....
Secondary instabilities of linearly heated falling films
Institute of Scientific and Technical Information of China (English)
HU Jun; SUN Dejun; HU Guohui; YIN Xieyuan
2005-01-01
Secondary instabilities of linearly heated failing films are studied through three steps. Firstly, the analysis of the primary linear instability on Miladinova's long wave equation of the linearly heated film is performed. Secondly, the similar Landau equation is derived through weak nonlinear theory, and a two-dimensional nonlinear saturation solution of primary instability is obtained within the weak nonlinear domain. Thirdly, the secondary (three-dimensional) instability of the two-dimensional wave is studied by the Floquet theorem.Our secondary instability analysis shows that the Marangoni number has destabilization effect on the secondary instability.
Linear programming an introduction with applications
Sultan, A
2014-01-01
Includes one IBM/PC floppy disk. System Requirements: Monochrome monitors, IBM-compatible machines, minimum: 286 IBM, DOS 2.0 or higher. This book gives a complete, concise introduction to the theory and applications of linear programming. It emphasizes the practical applications of mathematics, and makes the subject more accessible to individuals with varying mathematical abilities. It is one of the first rigorous linear programming texts that does not require linear algebra as a prerequisite. In addition, this text contains a floppy disk containing the program SIMPLEX, designed to help stude
All linear optical devices are mode converters
Miller, David A. B.
2012-01-01
We show that every linear optical component can be completely described as a device that converts one set of orthogonal input modes, one by one, to a matching set of orthogonal output modes. This result holds for any linear optical structure with any specific variation in space and/or time of its structure. There are therefore preferred orthogonal "mode converter" basis sets of input and output functions for describing any linear optical device, in terms of which the device can be described b...
The k-Error Linear Complexity and the Linear Complexity for pqn-Periodic Binary Sequences
Institute of Scientific and Technical Information of China (English)
ZHU Fengxiang; QI Wenfeng
2006-01-01
The k-error linear complexity and the linear complexity of the keystream of a stream cipher are two important standards to scale the randomness of the key stream. For a pqn-periodic binary sequences where p, q are two odd primes satisfying that 2 is a primitive root module p and q2 and gcd(p-1 , q-1)=2, we analyze the relationship between the linear complexity and the minimum value k for which the k-error linear complexity is strictly less than the linear complexity.
Fractional linear systems and electrical circuits
Kaczorek, Tadeusz
2015-01-01
This monograph covers some selected problems of positive and fractional electrical circuits composed of resistors, coils, capacitors and voltage (current) sources. The book consists of 8 chapters, 4 appendices and a list of references. Chapter 1 is devoted to fractional standard and positive continuous-time and discrete-time linear systems without and with delays. In chapter 2 the standard and positive fractional electrical circuits are considered and the fractional electrical circuits in transient states are analyzed. Descriptor linear electrical circuits and their properties are investigated in chapter 3, while chapter 4 is devoted to the stability of fractional standard and positive linear electrical circuits. The reachability, observability and reconstructability of fractional positive electrical circuits and their decoupling zeros are analyzed in chapter 5. The fractional linear electrical circuits with feedbacks are considered in chapter 6. In chapter 7 solutions of minimum energy control for standa...
Linear systems control deterministic and stochastic methods
Hendricks, Elbert; Sørensen, Paul Haase
2008-01-01
Linear Systems Control provides a very readable graduate text giving a good foundation for reading more rigorous texts. There are multiple examples, problems and solutions. This unique book successfully combines stochastic and deterministic methods.
Parallel computations in linear algebra. II
Energy Technology Data Exchange (ETDEWEB)
Faddeeva, V.N.; Faddeev, D.K.
1982-05-01
For pt.I, see Kibernetika, vol.13, no.6, p.28 (1977). Considerable effort was devoted in the surveyed period to automatic decomposition of sequential algorithms, or rather of procedures or subprograms written in the algorithmic languages ALGOL or FORTRAN. The authors do not consider this body of research, they only note that, on the one hand, the available linear algebra subprograms included in Eispack provide convenient objects for testing various approaches to automatic construction of parallel programs and, on the other, an important state in this activity is the development of methods for fast and efficient solution of linear recurrences, which reduce to solving systems of linear equations with band-triangular matrix (in particular, of sufficiently small width). This article reflects the penetration of the parallelism ideas into the computational methods of linear algebra in recent years. 74 references.
Macroscopic and non-linear quantum games
International Nuclear Information System (INIS)
Full text: We consider two models of quantum games. The first one is Marinatto and Weber's 'restricted' quantum game in which only the identity and the spin-flip operators are used. We show that this quantum game allows macroscopic mechanistic realization with the use of a version of the 'macroscopic quantum machine' described by Aerts already in 1980s. In the second model we use non-linear quantum state transformations which operate on points of spin-1/2 on the Bloch sphere and which can be used to distinguish optimally between two non-orthogonal states. We show that efficiency of these non-linear strategies out-perform any linear ones. Some hints on the possible theory of non-linear quantum games are given. (author)
Simultaneous Independent Linear Equations and Goldbach Conjecture
Linggen, Song
2007-01-01
It was verified that if Goldbach conjecture was a fault, the number of simultaneous independent linear equations educed from this assumption would be unreasonably at least one more than the number of unknowns involved in these equations.
A Reduced-Complexity Mixer Linearization Scheme
Directory of Open Access Journals (Sweden)
Paul A. Warr
2009-01-01
Full Text Available Measurement results of the signals emanating from both IF and LO ports of a double balanced mixer are presented, and, thus, it is shown that the linearization of the output in a down-converting mixer by the summation of the IF signal and the signal emanating from the LO or RF port is feasible. Feedforward-based architectures for the linearization of down-conversion mixers are introduced that exploit this phenomenon, and linearity performance results of the frequency translation of both two-tone and TETRA-modulated signals are presented. This technique employs only a single mixer and hence overcomes the complexity of other mixer linearization schemes. The overall processing gain of the system is limited by the level of wanted signal present in the error signal.
Balanced truncation for linear switched systems
DEFF Research Database (Denmark)
Petreczky, Mihaly; Wisniewski, Rafal; Leth, John-Josef
2013-01-01
in this paper, we provide a bound on the approximation error in the L2L2 norm for continuous-time and the l2l2 norm for discrete-time linear switched systems. We provide a system theoretic interpretation of grammians and their singular values. Furthermore, we show that the performance of balanced truncation......In this paper, we present a theoretical analysis of the model reduction algorithm for linear switched systems from Shaker and Wisniewski (2011, 2009) and . This algorithm is a reminiscence of the balanced truncation method for linear parameter varying systems (Wood et al., 1996) [3]. Specifically...... depends only on the input–output map and not on the choice of the state-space representation. For a class of stable discrete-time linear switched systems (so called strongly stable systems), we define nice controllability and nice observability grammians, which are genuinely related to reachability...
Radiation Hardened Bolometer Linear Array Project
National Aeronautics and Space Administration — NASA has developed space-based thermal instrument spectrometers based on thermopile detectors linear arrays that are intrinsically radiation hard. Micro-bolometers...
Linear programming mathematics, theory and algorithms
1996-01-01
Linear Programming provides an in-depth look at simplex based as well as the more recent interior point techniques for solving linear programming problems. Starting with a review of the mathematical underpinnings of these approaches, the text provides details of the primal and dual simplex methods with the primal-dual, composite, and steepest edge simplex algorithms. This then is followed by a discussion of interior point techniques, including projective and affine potential reduction, primal and dual affine scaling, and path following algorithms. Also covered is the theory and solution of the linear complementarity problem using both the complementary pivot algorithm and interior point routines. A feature of the book is its early and extensive development and use of duality theory. Audience: The book is written for students in the areas of mathematics, economics, engineering and management science, and professionals who need a sound foundation in the important and dynamic discipline of linear programming.
The Linearized Design Of Thermocouple Sensor
Institute of Scientific and Technical Information of China (English)
2010-01-01
<正>There are large errors of linear measurement when the thermocouple measure temperature as temperature sensor.In order to improve the measurement precision,the sensor cold junction compensation and nonlinear compensation are usually needed.For the circumstances that the cold junction’s temperature is determinate,there is biggish nonlinear between thermoelectric power and temperature signals of the thermocouple sensor’s output.In order to solve the problem,this paper proposed a practical method of linear compensation,introduced the principle of linear compensation and gave the corresponding compensation circuit and circuit analysis.This circuit has the characteristic of simpleness,high reliability,small linear error and so on.
Correlations and Non-Linear Probability Models
DEFF Research Database (Denmark)
Breen, Richard; Holm, Anders; Karlson, Kristian Bernt
2014-01-01
the dependent variable of the latent variable model and its predictor variables. We show how this correlation can be derived from the parameters of non-linear probability models, develop tests for the statistical significance of the derived correlation, and illustrate its usefulness in two applications. Under......Although the parameters of logit and probit and other non-linear probability models are often explained and interpreted in relation to the regression coefficients of an underlying linear latent variable model, we argue that they may also be usefully interpreted in terms of the correlations between...... certain circumstances, which we explain, the derived correlation provides a way of overcoming the problems inherent in cross-sample comparisons of the parameters of non-linear probability models....
Non-linearity in Johnson noise thermometry
White, D. R.
2012-12-01
This paper discusses the effects of non-linearity, some of the mechanisms responsible for non-linearity, and methods for measuring non-linearity in Johnson noise thermometry. Mechanisms considered include quantum tunnelling, bipolar junction transistor and junction field-effect transistor amplifiers, feedback, clipping, output-stage crossover, quantization and dither. It is found that even- and odd-order effects behave differently in correlator-based noise thermometers, with the dominant even-order effects contributing as intermodulation products whereas the dominant odd-order contributions are third-order and at the same frequencies as the parent signals. Possible test methods include the use of discrete tones, changes in spectral shape, and direct measurement using reference noise powers. For correlators operated at constant noise power, direct measurement of non-linearity using reference noise powers enables corrections to be made with negligible additional uncertainty and measurement time.
Linear and integer programming made easy
Hu, T C
2016-01-01
Linear and integer programming are fundamental toolkits for data and information science and technology, particularly in the context of today’s megatrends toward statistical optimization, machine learning, and big data analytics. Drawn from over 30 years of classroom teaching and applied research experience, this textbook provides a crisp and practical introduction to the basics of linear and integer programming. The authors’ approach is accessible to students from all fields of engineering, including operations research, statistics, machine learning, control system design, scheduling, formal verification, and computer vision. Readers will learn to cast hard combinatorial problems as mathematical programming optimizations, understand how to achieve formulations where the objective and constraints are linear, choose appropriate solution methods, and interpret results appropriately. •Provides a concise introduction to linear and integer programming, appropriate for undergraduates, graduates, a short cours...
A Direct Heuristic Algorithm for Linear Programming
Indian Academy of Sciences (India)
S K Sen; A Ramful
2000-02-01
An (3) mathematically non-iterative heuristic procedure that needs no artificial variable is presented for solving linear programming problems. An optimality test is included. Numerical experiments depict the utility/scope of such a procedure.
The mathematics of networks of linear systems
Fuhrmann, Paul A
2015-01-01
This book provides the mathematical foundations of networks of linear control systems, developed from an algebraic systems theory perspective. This includes a thorough treatment of questions of controllability, observability, realization theory, as well as feedback control and observer theory. The potential of networks for linear systems in controlling large-scale networks of interconnected dynamical systems could provide insight into a diversity of scientific and technological disciplines. The scope of the book is quite extensive, ranging from introductory material to advanced topics of current research, making it a suitable reference for graduate students and researchers in the field of networks of linear systems. Part I can be used as the basis for a first course in algebraic system theory, while Part II serves for a second, advanced, course on linear systems. Finally, Part III, which is largely independent of the previous parts, is ideally suited for advanced research seminars aimed at preparing graduate ...
Matrix Superpotential Linear in Variable Parameter
Karadzhov, Yuri
2011-01-01
The paper presents the classification of matrix valued superpotentials corresponding to shape invariant systems of Schr\\"odinger equations. All inequivalent irreducible matrix superpotentials realized by matrices of arbitrary dimension with linear dependence on variable parameter are presented explicitly.
Physics prospects at a linear + - collider
Indian Academy of Sciences (India)
Saurabh D Rindani
2006-10-01
The talk described the prospects of studying standard model parameters as well as scenarios beyond the standard model, like the minimal supersymmetric standard model, theories with extra dimensions and theories with extra neutral gauge bosons, at a future linear + - collider.
Optimal Stopping for Non-linear Expectations
Erhan Bayraktar; Song Yao
2009-01-01
We develop a theory for solving continuous time optimal stopping problems for non-linear expectations. Our motivation is to consider problems in which the stopper uses risk measures to evaluate future rewards.
Accelerating Dense Linear Algebra on the GPU
DEFF Research Database (Denmark)
Sørensen, Hans Henrik Brandenborg
and matrix-vector operations on GPUs. Such operations form the backbone of level 1 and level 2 routines in the Basic Linear Algebra Subroutines (BLAS) library and are therefore of great importance in many scientific applications. The target hardware is the most recent NVIDIA Tesla 20-series (Fermi...... architecture). Most of the techniques I discuss for accelerating dense linear algebra are applicable to memory-bound GPU algorithms in general....
Linear thermal circulator based on Coriolis forces.
Li, Huanan; Kottos, Tsampikos
2015-02-01
We show that the presence of a Coriolis force in a rotating linear lattice imposes a nonreciprocal propagation of the phononic heat carriers. Using this effect we propose the concept of Coriolis linear thermal circulator which can control the circulation of a heat current. A simple model of three coupled harmonic masses on a rotating platform permits us to demonstrate giant circulating rectification effects for moderate values of the angular velocities of the platform.
Linear causal modeling with structural equations
Mulaik, Stanley A
2009-01-01
Emphasizing causation as a functional relationship between variables that describe objects, Linear Causal Modeling with Structural Equations integrates a general philosophical theory of causation with structural equation modeling (SEM) that concerns the special case of linear causal relations. In addition to describing how the functional relation concept may be generalized to treat probabilistic causation, the book reviews historical treatments of causation and explores recent developments in experimental psychology on studies of the perception of causation. It looks at how to perceive causal
Numerical linear algebra in data mining
Eldén, Lars
Ideas and algorithms from numerical linear algebra are important in several areas of data mining. We give an overview of linear algebra methods in text mining (information retrieval), pattern recognition (classification of handwritten digits), and PageRank computations for web search engines. The emphasis is on rank reduction as a method of extracting information from a data matrix, low-rank approximation of matrices using the singular value decomposition and clustering, and on eigenvalue methods for network analysis.
Linear capacitive displacement sensor with frequency readout
Fritsch, Klaus
1987-01-01
A simple, inherently linear technique for measuring changes in the separation of the mirrors of an optical cavity is reported. The capacitor, made up of the reflective metallic coatings, is part of a feedback loop which adjusts the frequency of an oscillator to be proportional to the mirror separation. A linearity of 0.2 percent full scale was achieved for separations up to 0.5 mm with a resolution of 10 nm.
Superconducting linear accelerator system for NSC
Indian Academy of Sciences (India)
P N Prakash; T S Datta; B P Ajith Kumar; J Antony; P Barua; J Chacko; A Choudhury; G K Chadhari; S Ghosh; S Kar; S A Krishnan; Manoj Kumar; Rajesh Kumar; A Mandal; D S Mathuria; R S Meena; R Mehta; K K Mistri; A Pandey; M V Suresh Babu; B K Sahu; A Sarkar; S S K Sonti; A Rai; S Venkatramanan; J Zacharias; R K Bhowmik; A Roy
2002-11-01
This paper reports the construction of a superconducting linear accelerator as a booster to the 15 UD Pelletron accelerator at Nuclear Science Centre, New Delhi. The LINAC will use superconducting niobium quarter wave resonators as the accelerating element. Construction of the linear accelerator has progressed sufﬁciently. Details of the entire accelerator system including the cryogenics facility, RF electronics development, facilities for fabricating niobium resonators indigenously, and present status of the project are presented.
The Stark Effect in Linear Potentials
Robinett, R. W.
2010-01-01
We examine the Stark effect (the second-order shifts in the energy spectrum due to an external constant force) for two one-dimensional model quantum mechanical systems described by linear potentials, the so-called quantum bouncer (defined by V(z) = Fz for z greater than 0 and V(z) = [infinity] for z less than 0) and the symmetric linear potential…
Linear and nonlinear fractional Voigt models
Chidouh, Amar; Guezane-Lakoud, Assia; Bebbouchi, Rachid; Bouaricha, Amor; Torres, Delfim F. M.
2016-01-01
We consider fractional generalizations of the ordinary differential equation that governs the creep phenomenon. Precisely, two Caputo fractional Voigt models are considered: a rheological linear model and a nonlinear one. In the linear case, an explicit Volterra representation of the solution is found, involving the generalized Mittag-Leffler function in the kernel. For the nonlinear fractional Voigt model, an existence result is obtained through a fixed point theorem. A nonlinear example, il...
Linearized warp drive and the energy conditions
Lobo, Francisco S N; Visser, Matt
2004-01-01
''Warp drive'' spacetimes are useful as ''gedanken-experiments'' and as a theoretician's probe of the foundations of general relativity. Applying linearized gravity to the weak-field warp drive, i.e., for non-relativistic warp-bubble velocities, we find that the occurrence of energy condition violations in this class of spacetimes is generic to the form of the geometry under consideration and is not simply a side-effect of the ''superluminal'' properties. Using the linearized construction it ...
Thresholds for Linear Optics Quantum Computation
Knill, E.; Laflamme, R; Milburn, G.
2000-01-01
We previously established that in principle, it is possible to quantum compute using passive linear optics with photo-detectors (quant-ph/0006088). Here we describe techniques based on error detection and correction that greatly improve the resource and device reliability requirements needed for scalability. The resource requirements are analyzed for ideal linear optics quantum computation (LOQC). The coding methods can be integrated both with loss detection and phase error-correction to deal...
Linear Optics Quantum Computation: an Overview
Myers, C R; Laflamme, R
2005-01-01
We give an overview of linear optics quantum computing, focusing on the results from the original KLM paper. First we give a brief summary of the advances made with optics for quantum computation prior to KLM. We next discuss the KLM linear optics scheme, giving detailed examples. Finally we go through quantum error correction for the LOQC theory, showing how to obtain the threshold when dealing with Z-measurement errors.
SLAC linear collider conceptual design report
International Nuclear Information System (INIS)
The linear collider system is described in detail, including the transport system, the collider lattice, final focusing system, positron production, beam damping and compression, high current electron source, instrumentation and control, and the beam luminosity. The experimental facilities and the experimental uses are discussed along with the construction schedule and estimated costs. Appendices include a discussion of space charge effects in the linear accelerator, emittance growth in the collider, the final focus system, beam-beam instabilities and pinch effects, and detector backgrounds
LINEARIZED OSCILLATIONS FOR NEUTRAL DIFFERENTIAL EQUATIONS
Institute of Scientific and Technical Information of China (English)
李建利; 申建华
2004-01-01
Consider the nonlinear neutral delay differential equation d/dt[x(t)-P(t)g(x(t-τ))]+Q(t)h(x(t-σ))=01t≥t0,where P1Q∈C([t01∞),R(τ>01,σ≥0,We obtain a linearized oscillation result by an associate linear equation in the case when liminf P(t)=p0∈[-1,0)。
Homogenization of ordinary and linear transport equations
Peirone, Roberto
1996-01-01
The homogenization of first order ordinary differential equations in $\\mathbb{R}^N$ and associated linear transport equations are studied. We prove the equivalence between $G$-convergence and strong $G$-convergence for the ordinary equations. We give a sufficient condition, which is also necessary in the autonomous case, for the weak homogenization of the linear transport equations. This condition is satisfied when div$_x f=0$.
Linear Basal Cell Carcinoma: A Case Report
Ichinokawa, Yuko; Ohtuki, Akiko; Hattori, Mariko; Sadamasa, Hiroko; Hiruma, Masataro; Matumoto, Toshiharu
2011-01-01
Basal cell carcinoma (BCC) presents with diverse clinical features, and several morphologic and histologic variants of BCC have been reported [Sexton et al.: J Am Acad Dermatol 1990;23:1118-1126]. Linear BCC was first described as a new clinical subtype in 1985 by Lewis [Int J Dematol 1985;24:124-125]. Here, we present a case of linear BCC that we recently encountered in an elderly Japanese patient, and review other cases reported in Japan.
The analysis and design of linear circuits
Thomas, Roland E; Toussaint, Gregory J
2009-01-01
The Analysis and Design of Linear Circuits, 6e gives the reader the opportunity to not only analyze, but also design and evaluate linear circuits as early as possible. The text's abundance of problems, applications, pedagogical tools, and realistic examples helps engineers develop the skills needed to solve problems, design practical alternatives, and choose the best design from several competing solutions. Engineers searching for an accessible introduction to resistance circuits will benefit from this book that emphasizes the early development of engineering judgment.
Photon Linear Collider Gamma-Gamma Summary
Energy Technology Data Exchange (ETDEWEB)
Gronberg, J
2012-02-27
High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.
Measuring service quality by linear indicators
Peña, Daniel
1996-01-01
This paper presents a methodology for building linear indicators of the quality of a service. A regression model is presented in which customers evaluate the overall service quality and a set of dimensions or attributes that determine this service quality. The model assumes that overall service quality is determined by a linear combination of attribute evaluations with some unknown weights. As different customers may have different weights, the estimation of the parameters of the ...
Radiotherapy treatment planning linear-quadratic radiobiology
Chapman, J Donald
2015-01-01
Understand Quantitative Radiobiology from a Radiation Biophysics PerspectiveIn the field of radiobiology, the linear-quadratic (LQ) equation has become the standard for defining radiation-induced cell killing. Radiotherapy Treatment Planning: Linear-Quadratic Radiobiology describes tumor cell inactivation from a radiation physics perspective and offers appropriate LQ parameters for modeling tumor and normal tissue responses.Explore the Latest Cell Killing Numbers for Defining Iso-Effective Cancer TreatmentsThe book compil
Regularly Controlled Bidirectional Linear Basic Grammars
Hogendorp, Jan Anne
1990-01-01
We investigate the bidirectional application of grammar productions -- i.e., using the productions in the reversed direction too -- to linear basic grammars. As in the case of regularly controlled bidirectional context-free grammars (or RCB grammars), we provide bidirectional linear basic grammars with a regular control language over the rules (i.e., productions and their corresponding reductions). Our main result shows that under the so-called RS/B/f-mode of derivation, bidirectionality give...
Linearization of the Relativistic Oscillator Hierarchy
Anderson, Robert L
2016-01-01
This paper is based on MacColl's [1] solution of the equation of motion for a linear (harmonic) oscillator subject to the laws of special relativity in the rest frame of the center of attraction. MacColl's result can be extended to the quartic oscillator in this frame with one extremely simple adjustment of the linearization map given in Anderson [2]. In fact, it can be extended to all the attractive oscillators in this frame.
RELATION BETWEEN FEATURES OF HARMONIC STATISTICAL LINEARIZATION
Savochkin, V.; Shishanov, S.
2007-01-01
The paper presents the basic computations of method of combined linearization of elastic and damping performance of transport machine cushioning system. This method may be realized if the harmonic linearization coefficient of cushioning system are preliminary determined. This method is based on the possibility to present the differentiable random stationary process as a harmonic signal randomly modulated by phase and amplitude; if relational motion of track roller is a differentiable stationa...
Galactic rotation curves and linear potential laws
Carlson, C E; Carlson, Carl E; Lowenstein, Eric J
1996-01-01
We study the possibility that galactic rotation curves can be explained by a gravitational potential that contains a linear term as well as a Newtonian one. This hypothesis, suggested by conformal gravity, does allow good fits to the galactic rotation curves of the galaxies we study, which have a wide range of luminosities. However, the universality one might have expected of the parameter describing the strength of the linear potential does not emerge. Instead, a different regularity is seen.
Schreurs, D; Verspecht, J.; Acciari, G; Colantonio, P.; Giannini, F; Limiti, E.; Leuzzi, G.
2001-01-01
The Non-Linear Scattering Functions have been theoretically defined and experimentally measured for the linear-equivalent design of non-linear circuits in arbitrary large signal conditions. Non-linear measures and simulations have been compared, with good agreement. Linear CAD concepts can therefore be extended to non-linear circuits in a rigorous way.
Direct Heuristic Algorithm for Linear Programming
Directory of Open Access Journals (Sweden)
I. Ramesh Babu
2013-08-01
Full Text Available Many applications in business and economics involve a process called optimization, in which we will be required to find the minimum cost, the maximum profit, or the minimum use of resources, where a decision maker may want to utilize limited available resources in the best possible manner. The limited resources may include material, money, manpower, space and time. Linear Programming provides various methods of solving such problems. The formulation of linear programming problem as a mathematical model is one type of optimization problem called linear programming. There are various methods for solving the linear programming problems. Some of them are approximation algorithm , branch and bound methods, cutting plane method etc. Other than Gomory’s cutting plane method, Branch and bound method LPP along with the DHALP (Direct heuristic algorithm for linear programming algorithm which is more efficient than these existing methods will be used for solving linear programming problems. An optimality test will also be included in this. Numerical experiments will depict the utility/scope of such a procedure.
Introducing linear functions: an alternative statistical approach
Nolan, Caroline; Herbert, Sandra
2015-12-01
The introduction of linear functions is the turning point where many students decide if mathematics is useful or not. This means the role of parameters and variables in linear functions could be considered to be `threshold concepts'. There is recognition that linear functions can be taught in context through the exploration of linear modelling examples, but this has its limitations. Currently, statistical data is easily attainable, and graphics or computer algebra system (CAS) calculators are common in many classrooms. The use of this technology provides ease of access to different representations of linear functions as well as the ability to fit a least-squares line for real-life data. This means these calculators could support a possible alternative approach to the introduction of linear functions. This study compares the results of an end-of-topic test for two classes of Australian middle secondary students at a regional school to determine if such an alternative approach is feasible. In this study, test questions were grouped by concept and subjected to concept by concept analysis of the means of test results of the two classes. This analysis revealed that the students following the alternative approach demonstrated greater competence with non-standard questions.
Linear polarization of rapidly rotating ultracool dwarfs
Miles-Páez, Paulo Alberto; Pallé, Enric; Ramírez, Karla Peña
2013-01-01
Aims. We aim at studying the near infrared linear polarization signal of rapidly rotating ultracool dwarfs with spectral types ranging from M7 through T2 and projected rotational velocities vsini >= 30 km s^{-1}. All these dwarfs are believed to have dusty atmospheres and oblate shapes, an appropriate scenario to produce measurable linear polarization of the continuum light.\\\\ Methods. Linear polarimetric images were collected in the J-band for a sample of 18 fast-rotating ultracool dwarfs, five of which were also observed in the Z-band using the LIRIS spectrograph on the Cassegrain focus of the 4.2-m William Herschel Telescope. The measured median uncertainty in the linear polarization degree is +/-0.13% for our sample, which allowed us to detect polarization signatures above ~0.39% with a confidence of >=3\\sigma.\\\\ Results. About 40+/-15% of the sample is linearly polarized in the Z- and J-bands. All positive detections have linear polarization degrees ranging from 0.4% to 0.8% in both filters independently...
Neighborhood-following algorithms for linear programming
Institute of Scientific and Technical Information of China (English)
无
2004-01-01
［1］Kojima, M., Mizuno, S., Yoshise, A., A polynomial-time algorithm for a class of linear complementarity probems, Mathematical Programming, 1989, 44: 1-26.［2］Megiddo, N., Pathways to the optimal set in linear programming. in Progression Mathematical Programming:Interior Point and Related Methods, New York: Springer-Verlag, 1989, 131-158.［3］Monteiro, R. D. C., Adler, I., Interior path following primal-dual algorithms, Part Ⅰ: linear programming, Mathematical Programming, 1989, 44: 27-41.［4］Monteiro, R. D. C., Adler, I., Interior path following primal-dual algorithms, Part Ⅱ: convex quadratic programming, Mathematical Programming, 1989, 44: 43-46.［5］Wright, S. J., Primal-Dual Interior-Point Methods, Philadephia: SIAM Publications, 1997.［6］Mizuno, S., Todd, M. J., Ye, Y., On adaptive step primal-dual interior-point algorithms for linear programming,Mathematics of Operations Research, 1993, 18:964-981.［7］Gonzaga, C. C., The largest step path following algorithm for monotone linear complementarity problems, Mathematical Programming, 1997, 76: 309-332.［8］Sturm, J. F., Zhang, S., On a wide region of centers primal-dual interior point algorithms for linear programming,Tinbergen Institute Rotterdam, Erasmus University, Rotterdam, The Netherlands, 1995.［9］Hung, P., Ye, Y., An asymptotical O(√nL)-iteration path-following linear programming algorithm that uses wide neighborhoods, SIAM J.Optimization, 1996, 6: 570-586.［10］Ye, Y., Interior Point Algorithms: Theory and Analysis, New York: Wiley-Interscience Publication, 1997.［11］Güler, O., Ye, Y., Convergence behavior of interior-point algorithms. Mathematical Programming, 1993, 60:215-228.［12］Mehrotral, S., On the implementation of a primal-dual interior point mehtod, SIAM J. Optimization, 1992, 2(4):575-601.
SYSTEM IDENTIFICATION METHOD OF LINEAR AND NON—LINEAR LIQUID PREPARATIVE CHROMATOGRAPHIC SEPARATION
Institute of Scientific and Technical Information of China (English)
ShuWenli; LiZhong; 等
1997-01-01
The paper proposes the identification method of linear and non-linear chromatographic system.Isotherms and lumped mass transfer coefficients of chromatography separating isomer sorbitol and mannitol on D80 adsorbent are determined.The analyses of root mean square error of chromatography elution curves are carried out.The results show that the system studied is non-linear and the theoretical elution curves of the non-linear chromatographic model are more accurate than those of the linear chromatographic model,Results of parameter sensitivity analyses show that elution curves of non-linear chromatopraphic separation aremore sensitive to the variation of parameter “ai” in the adsorption isotherms Qi=Ci*/(ai+biCi*) than to the variation of parameter "bi”as well as lumped mass transfer coefficients.
A comparison of equivalent linear and non-linear approaches for site amplification studies
International Nuclear Information System (INIS)
The specification of the seismic design criteria for a nuclear installation requires that the effect of the local soil conditions at the site on seismic motion is assessed. The local soil conditions, in particular the material properties of the different soil strata, will affect both the frequency content and peak ground acceleration of seismic motion at the surface. Two main approaches which are used to account for the non-linear behavior of the soil are the equivalent linear approach and the non-linear incremental approach (Desai, 1976). In this paper the non-linear seismic response of a typical site characterized by shallow weak, horizontal soil layers overlying firm rock is examined using both these approaches. The results are compared and the extent of applicability of the equivalent linear approach is determined. The results are compared also with the results obtained from a linear analysis in order to examine the conservatisms inherent in such an analysis
Institute of Scientific and Technical Information of China (English)
Pascale KULISA; Cédric DANO
2006-01-01
Three linear two-equation turbulence models k- ε, k- ω and k- 1 and a non-linear k- l model are used for aerodynamic and thermal turbine flow prediction. The pressure profile in the wake and the heat transfer coefficient on the blade are compared with experimental data. Good agreement is obtained with the linear k- l model. No significant modifications are observed with the non-linear model. The balance of transport equation terms in the blade wake is also presented. Linear and non-linear k- l models are evaluated to predict the threedimensional vortices characterising the turbine flows. The simulations show that the passage vortex is the main origin of the losses.
Fuzzy Multi-objective Linear Programming Approach
Directory of Open Access Journals (Sweden)
Amna Rehmat
2007-07-01
Full Text Available Traveling salesman problem (TSP is one of the challenging real-life problems, attracting researchers of many fields including Artificial Intelligence, Operations Research, and Algorithm Design and Analysis. The problem has been well studied till now under different headings and has been solved with different approaches including genetic algorithms and linear programming. Conventional linear programming is designed to deal with crisp parameters, but information about real life systems is often available in the form of vague descriptions. Fuzzy methods are designed to handle vague terms, and are most suited to finding optimal solutions to problems with vague parameters. Fuzzy multi-objective linear programming, an amalgamation of fuzzy logic and multi-objective linear programming, deals with flexible aspiration levels or goals and fuzzy constraints with acceptable deviations. In this paper, a methodology, for solving a TSP with imprecise parameters, is deployed using fuzzy multi-objective linear programming. An example of TSP with multiple objectives and vague parameters is discussed.
Linear Riccati Dynamics, Constant Feedback, and Controllability in Linear Quadratic Control Problems
Ronald J. Balvers; Douglas W. Mitchell
2005-01-01
Conditions are derived for linear-quadratic control (LQC) problems to exhibit linear evolution of the Riccati matrix and constancy of the control feedback matrix. One of these conditions involves a matrix upon whose rank a necessary condition and a sufficient condition for controllability are based. Linearity of Riccati evolution allows for rapid iterative calculation, and constancy of the control feedback matrix allows for time-invariant comparative static analysis of policy reactions.
Effect of Linear and Non-linear Resistance Exercise on Anaerobic Performance among Young Women
Homa Esmaeili; Ali Reza Amani; Taher Afsharnezhad
2015-01-01
The main goals of strength training are improving muscle strength, power and muscle endurance. The objective of the current study is to compare two popular linear and nonlinear resistance exercises interventions on the anaerobic power. Previous research has shown differences intervention by the linear and non-linear resistance exercise in performance and strength in male athletes. By the way there are not enough data regarding female subjects. Eighteen young women subjects participated in th...
Non-Linear Rheological Properties and Neutron Scattering Investigation on Dilute Ring-Linear Blends
PYCKHOUT-HINTZEN, W.; Bras, A.R.; Wischnewski, A.; Richter, D; Huang, Qian; Hassager, Ole; Vlassopoulos, D.; Pasquino, R.; Rubinstein, M.
2012-01-01
Linear and non-linear Rheology on dilute blends of polystyrene ring polymers in linear matrix is combined with Small Angle Neutron Scattering (SANS) investigations. In this way 2 different entanglement interactions become clear. After stretching the samples to different hencky strains up to 2 in a filament stretching rheometer, followed by quenching, strong anisotropic scattering patterns were obtained which were described by affinely deformed rings which function as giant, polymeric chemical...
Linear stability of shock profiles for systems of conservation laws with semi-linear relaxation
Godillon, Pauline
2001-01-01
The Evans function theory, which has recently been applied to the study of linear stability of viscous shock profiles, is developed below for semi-linear relaxation. We study the linear stability of shock profiles in the Lax, undercompressive and overcompressive cases. The results we obtain are similar to those found for viscous approximations by Gardner and Zumbrun [Commun. Pure Appl. Math. 51 (7) (1998) 797].
The linear position tracking servo systemusing a linear voice-coil motor
Institute of Scientific and Technical Information of China (English)
褚立新; 林辉
2008-01-01
More and more linear servo systems have been used in servo applications. Direct drive technology can greatly increase the bandwidth and the tracking accuracy. A position servo-system based on linear voice-coil motor was designed for one linear oscillation movement application. Besides the conventional position, speed and current control loops, the speed and acceleration feed-forward control of command position signal were also used. The experimental test proved the correctness of the design, and the system ...
UNDERSTANDING THE APPLICABILITY OF LINEAR & NON-LINEAR MODELS USING A CASE-BASED STUDY
Gaurav Singh Thakur; Anubhav Gupta; Ankur Bhardwaj; Biju R Mohan
2014-01-01
This paper uses a case based study – “product sales estimation” on real-time data to help us understand the applicability of linear and non-linear models in machine learning and data mining. A systematic approach has been used here to address the given problem statement of sales estimation for a particular set of products in multiple categories by applying both linear and non-linear machine learning techniques on a data set of selected features from the original data set. Feature ...
Characterization Of any Non-linear Boolean function Using A Set of Linear Operators
Sahoo, Sudhakar; Choudhury, Pabitra Pal; Chakraborty, Mithun
2008-01-01
Global dynamics of a non-linear Cellular Automata is, in general irregular, asymmetric and unpredictable as opposed to that of a linear CA, which is highly systematic and tractable. In the past efforts have been made to systematize non-linear CA evolutions in the light of Boolean derivatives and Jacobian Matrices. In this paper two different efforts have been made: first we try to systematize non-linear CA evolution in the light of deviant states and non-deviant states. For all the non-devian...
Linearity Limits of Biased 1337 Trap Detectors
Balling, Petr
2015-01-01
The upper power limit of linear response of light trap detectors was recently measured [2,3]. We have completed this measurement with test of traps with bias voltage at several visible wavelengths using silicon photodiodes Hamamatsu S1337 1010 and made a brief test of S5227 1010. Bias extends the linearity limit by factor of more than 10 for very narrow beams and more than 30 for wide beams [5]. No irreversible changes were detected even for the highest irradiance of 33 W/cm2 at 406nm. Here we present measurement of minimal bias voltage necessary for 99%, 99.8% and 99.95% linearity for several beam sizes.
Disc instantons in linear sigma models
Energy Technology Data Exchange (ETDEWEB)
Govindarajan, Suresh E-mail: suresh@chaos.iitm.ernet.in; Jayaraman, T. E-mail: jayaram@imsc.ernet.in; Sarkar, Tapobrata E-mail: tapo@theory.tifr.res.in
2002-12-16
We construct a linear sigma model for open-strings ending on special Lagrangian cycles of a Calabi-Yau manifold. We illustrate the construction for the cases considered by Aganagic and Vafa (AV). This leads naturally to concrete models for the moduli space of open-string instantons. These instanton moduli spaces can be seen to be intimately related to certain auxiliary boundary toric varieties. By considering the relevant Gelfand-Kapranov-Zelevinsky (GKZ) differential equations of the boundary toric variety, we obtain the contributions to the world volume superpotential on the A-branes from open-string instantons. By using an ansatz due to Aganagic, Klemm and Vafa (AKV), we obtain the relevant change of variables from the linear sigma model to the non-linear sigma model variables--the open-string mirror map. Using this mirror map, we obtain results in agreement with those of AV and AKV for the counting of holomorphic disc instantons.
Hypocoercivity for linear kinetic equations conserving mass
Dolbeault, Jean
2015-02-03
We develop a new method for proving hypocoercivity for a large class of linear kinetic equations with only one conservation law. Local mass conservation is assumed at the level of the collision kernel, while transport involves a confining potential, so that the solution relaxes towards a unique equilibrium state. Our goal is to evaluate in an appropriately weighted $ L^2$ norm the exponential rate of convergence to the equilibrium. The method covers various models, ranging from diffusive kinetic equations like Vlasov-Fokker-Planck equations, to scattering models or models with time relaxation collision kernels corresponding to polytropic Gibbs equilibria, including the case of the linear Boltzmann model. In this last case and in the case of Vlasov-Fokker-Planck equations, any linear or superlinear growth of the potential is allowed. - See more at: http://www.ams.org/journals/tran/2015-367-06/S0002-9947-2015-06012-7/#sthash.ChjyK6rc.dpuf
Computing with linear equations and matrices
International Nuclear Information System (INIS)
Systems of linear equations and matrices arise in many disciplines. The equations may accurately represent conditions satisfied by a system or, more likely, provide an approximation to a more complex system of non-linear or differential equations. The system may involve a few or many thousand unknowns and each individual equation may involve few or many of them. Over the past 50 years a vast literature on methods for solving systems of linear equations and the associated problems of finding the inverse or eigenvalues of a matrix has been produced. These lectures cover those methods which have been found to be most useful for dealing with such types of problem. References are given where appropriate and attention is drawn to the possibility of improved methods for use on vector and parallel processors. (orig.)
Linear ultrasonic motor using quadrate plate transducer
Institute of Scientific and Technical Information of China (English)
Jiamei JIN; Chunsheng ZHAO
2009-01-01
A linear ultrasonic motor using a quadrate plate transducer was developed for precision positioning. This motor consists of two pairs of Pb(Zr, Ti)O3 piezo-electric ceramic elements, which are piezoelectrically excited into the second-bending mode of the motor stator's neutral surface in two orthogonal directions, on which the tops of four projections move along an elliptical trajectory, which in turn drives a contacted slider into linear motion via frictional forces. The coincident frequency of the stator is easily obtained for its coincident characteristic dimen-sion in two orthogonal directions. The performance characteristics achieved by the motor are: 1) a maximum linear speed of more than 60 mm/s; 2) a stroke of more than 150 mm; 3) a driving force of more than 5.0 N; and 4) a response time of about 2 ms.
Linear mixed models for longitudinal data
Molenberghs, Geert
2000-01-01
This paperback edition is a reprint of the 2000 edition. This book provides a comprehensive treatment of linear mixed models for continuous longitudinal data. Next to model formulation, this edition puts major emphasis on exploratory data analysis for all aspects of the model, such as the marginal model, subject-specific profiles, and residual covariance structure. Further, model diagnostics and missing data receive extensive treatment. Sensitivity analysis for incomplete data is given a prominent place. Several variations to the conventional linear mixed model are discussed (a heterogeity model, conditional linear mixed models). This book will be of interest to applied statisticians and biomedical researchers in industry, public health organizations, contract research organizations, and academia. The book is explanatory rather than mathematically rigorous. Most analyses were done with the MIXED procedure of the SAS software package, and many of its features are clearly elucidated. However, some other commerc...
Dynamical systems generated by linear maps
Dolićanin, Ćemal B
2014-01-01
The book deals with dynamical systems, generated by linear mappings of finite dimensional spaces and their applications. These systems have a relatively simple structure from the point of view of the modern dynamical systems theory. However, for the dynamical systems of this sort, it is possible to obtain explicit answers to specific questions being useful in applications. The considered problems are natural and look rather simple, but in reality in the course of investigation, they confront users with plenty of subtle questions, and their detailed analysis needs a substantial effort. The problems arising are related to linear algebra and dynamical systems theory, and therefore, the book can be considered as a natural amplification, refinement and supplement to linear algebra and dynamical systems theory textbooks.
Generalized Cross-Gramian for Linear Systems
DEFF Research Database (Denmark)
Shaker, Hamid Reza
2012-01-01
The cross-gramian is a well-known matrix with embedded controllability and observability information. The cross-gramian is related to the Hankel operator and the Hankel singular values of a linear square system and it has several interesting properties. These properties make the cross...... square symmetric systems, the ordinary cross-gramian does not exist. To cope with this problem, a new generalized cross-gramian is introduced in this paper. In contrast to the ordinary cross-gramian, the generalized cross-gramian can be easily obtained for general linear systems and therefore can be used......-gramian popular in several applications including model reduction, control configuration selection and sensitivity analysis. The ordinary cross-gramian which has been defined in the literature is the solution of a Sylvester equation. This Sylvester equation is not always solvable and therefore for some linear...
Linear systems a measurement based approach
Bhattacharyya, S P; Mohsenizadeh, D N
2014-01-01
This brief presents recent results obtained on the analysis, synthesis and design of systems described by linear equations. It is well known that linear equations arise in most branches of science and engineering as well as social, biological and economic systems. The novelty of this approach is that no models of the system are assumed to be available, nor are they required. Instead, a few measurements made on the system can be processed strategically to directly extract design values that meet specifications without constructing a model of the system, implicitly or explicitly. These new concepts are illustrated by applying them to linear DC and AC circuits, mechanical, civil and hydraulic systems, signal flow block diagrams and control systems. These applications are preliminary and suggest many open problems. The results presented in this brief are the latest effort in this direction and the authors hope these will lead to attractive alternatives to model-based design of engineering and other systems.
Sparsity in Linear Predictive Coding of Speech
DEFF Research Database (Denmark)
Giacobello, Daniele
This thesis deals with developing improved techniques for speech coding based on the recent developments in sparse signal representation. In particular, this work is motivated by the need to address some of the limitations of the well- known linear prediction (LP) model currently applied in many...... modern speech coders. In the first part of the thesis, we provide an overview of Sparse Linear Predic- tion, a set of speech processing tools created by introducing sparsity constraints into the LP framework. This approach defines predictors that look for a sparse residual rather than a minimum variance...... of the effectiveness of their application in audio processing. The second part of the thesis deals with introducing sparsity directly in the linear prediction analysis-by-synthesis (LPAS) speech coding paradigm. We first propose a novel near-optimal method to look for a sparse approximate excitation using a compressed...
Seeking Maximum Linearity of Transfer Functions
Silva, Filipi N; Costa, Luciano da F
2016-01-01
Linearity is an important and frequently sought property in electronics and instrumentation. Here, we report a method capable of, given a transfer function, identifying the respective most linear region of operation with a fixed width. This methodology, which is based on least squares regression and systematic consideration of all possible regions, has been illustrated with respect to both an analytical (sigmoid transfer function) and real-world (low-power, one-stage class A transistor amplifier) situations. In the former case, the method was found to identity the theoretically optimal region of operation even in presence of noise. In the latter case, it was possible to identify an amplifier circuit configuration providing a good compromise between linearity, amplification and output resistance. The transistor amplifier application, which was addressed in terms of transfer functions derived from its experimentally obtained characteristic surface, also yielded contributions such as the estimation of local cons...
Controlling attribute effect in linear regression
Calders, Toon
2013-12-01
In data mining we often have to learn from biased data, because, for instance, data comes from different batches or there was a gender or racial bias in the collection of social data. In some applications it may be necessary to explicitly control this bias in the models we learn from the data. This paper is the first to study learning linear regression models under constraints that control the biasing effect of a given attribute such as gender or batch number. We show how propensity modeling can be used for factoring out the part of the bias that can be justified by externally provided explanatory attributes. Then we analytically derive linear models that minimize squared error while controlling the bias by imposing constraints on the mean outcome or residuals of the models. Experiments with discrimination-aware crime prediction and batch effect normalization tasks show that the proposed techniques are successful in controlling attribute effects in linear regression models. © 2013 IEEE.
2009 Linear Collider Workshop of the Americas
Energy Technology Data Exchange (ETDEWEB)
Seidel, Sally [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy
2009-09-29
The 2009 Linear Collider Workshop of the Americas was held on the campus of the University of New Mexico from 29 September to 3 October, 2009. This was a joint meeting of the American Linear Collider Physics Group and the ILC Global Design Effort. Two hundred fifty people attended. The number of scientific contributions was 333. The complete agenda, with links to all of the presentations, is available at physics.unm.edu/LCWA09/. The meeting brought together international experts as well as junior scientists, to discuss the physics potential of the linear collider and advances in detector technology. The validation of detector designs was announced, and the detector design groups planned the next phase of the effort. Detector R&D teams reported on progress on many topics including calorimetry and tracking. Recent accelerator design considerations were discussed in a special session for experimentalists and theorists.
Dirac Equations with Linear Confining Potentials
Noble, J H
2014-01-01
This paper is devoted to a study of relativistic eigenstates of Dirac particles which are simultaneously bound by a static Coulomb potential and added linear confining potentials. It has recently been shown that, despite the addition of radially symmetric, linear confining potentials, some specific bound-state energies surprisingly retain their exact Dirac-Coulomb values (in the sense of an "exact symmetry"). This observation raises pertinent questions as to the generality of the cancellation mechanism. A Foldy-Wouthuysen transformation is used to find the relevant nonrelativistic physical degrees of freedom, which include additional spin-orbit couplings induced by the linear confining potentials. The matrix elements of the effective operators obtained from the scalar, and time-like confining potentials mutually cancel for specific ratios of the prefactors of the effective operators, which must be tailored to the cancellation mechanism. The result of the Foldy-Wouthuysen transformation is used to explicitly s...
Optical systolic solutions of linear algebraic equations
Neuman, C. P.; Casasent, D.
1984-01-01
The philosophy and data encoding possible in systolic array optical processor (SAOP) were reviewed. The multitude of linear algebraic operations achievable on this architecture is examined. These operations include such linear algebraic algorithms as: matrix-decomposition, direct and indirect solutions, implicit and explicit methods for partial differential equations, eigenvalue and eigenvector calculations, and singular value decomposition. This architecture can be utilized to realize general techniques for solving matrix linear and nonlinear algebraic equations, least mean square error solutions, FIR filters, and nested-loop algorithms for control engineering applications. The data flow and pipelining of operations, design of parallel algorithms and flexible architectures, application of these architectures to computationally intensive physical problems, error source modeling of optical processors, and matching of the computational needs of practical engineering problems to the capabilities of optical processors are emphasized.
Linear discriminant analysis for welding fault detection
International Nuclear Information System (INIS)
This work presents a new method for real time welding fault detection in industry based on Linear Discriminant Analysis (LDA). A set of parameters was calculated from one second blocks of electrical data recorded during welding and based on control data from reference welds under good conditions, as well as faulty welds. Optimised linear combinations of the parameters were determined with LDA and tested with independent data. Short arc welds in overlap joints were studied with various power sources, shielding gases, wire diameters, and process geometries. Out-of-position faults were investigated. Application of LDA fault detection to a broad range of welding procedures was investigated using a similarity measure based on Principal Component Analysis. The measure determines which reference data are most similar to a given industrial procedure and the appropriate LDA weights are then employed. Overall, results show that Linear Discriminant Analysis gives an effective and consistent performance in real-time welding fault detection.
Linearly polarized gluon effects in unpolarized collisions
Boer, Daniël
2015-01-01
Linear polarization of gluons inside unpolarized hadrons affects the transverse momentum distribution of produced spin-0 particles, such as of the Higgs or (pseudo-)scalar quarkonium states at LHC. Despite the currently unknown amount of linear gluon polarization, a range of predictions can be obtained, using TMD evolution, which indicates that their effect is on the few percent level in Higgs production, but can be much larger in quarkonium production. Together with asymmetries in open charm or bottom production in electro-production at an Electron-Ion Collider, the size and sign of the linear gluon polarization could be extracted experimentally. These processes also allow to test the behavior expected at small $x$ in and outside the saturation region.
LINEAR REGRESSION WITH R AND HADOOP
Directory of Open Access Journals (Sweden)
Bogdan OANCEA
2015-07-01
Full Text Available In this paper we present a way to solve the linear regression model with R and Hadoop using the Rhadoop library. We show how the linear regression model can be solved even for very large models that require special technologies. For storing the data we used Hadoop and for computation we used R. The interface between R and Hadoop is the open source library RHadoop. We present the main features of the Hadoop and R software systems and the way of interconnecting them. We then show how the least squares solution for the linear regression problem could be expressed in terms of map-reduce programming paradigm and how could be implemented using the Rhadoop library.
Probabilistic analysis of linear elastic cracked structures
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This paper presents a probabilistic methodology for linear fracture mechanics analysis of cracked structures. The main focus is on probabilistic aspect related to the nature of crack in material. The methodology involves finite element analysis; statistical models for uncertainty in material properties, crack size, fracture toughness and loads; and standard reliability methods for evaluating probabilistic characteristics of linear elastic fracture parameter. The uncertainty in the crack size can have a significant effect on the probability of failure, particularly when the crack size has a large coefficient of variation. Numerical example is presented to show that probabilistic methodology based on Monte Carlo simulation provides accurate estimates of failure probability for use in linear elastic fracture mechanics.
Linear transformer driver for pulse generation
Kim, Alexander A; Mazarakis, Michael G; Sinebryukhov, Vadim A; Volkov, Sergey N; Kondratiev, Sergey S; Alexeenko, Vitaly M; Bayol, Frederic; Demol, Gauthier; Stygar, William A
2015-04-07
A linear transformer driver includes at least one ferrite ring positioned to accept a load. The linear transformer driver also includes a first power delivery module that includes a first charge storage devices and a first switch. The first power delivery module sends a first energy in the form of a first pulse to the load. The linear transformer driver also includes a second power delivery module including a second charge storage device and a second switch. The second power delivery module sends a second energy in the form of a second pulse to the load. The second pulse has a frequency that is approximately three times the frequency of the first pulse. The at least one ferrite ring is positioned to force the first pulse and the second pulse to the load by temporarily isolating the first pulse and the second pulse from an electrical ground.
Non-linear flow response and reaction plane correlations
Teaney, Derek; Yan, Li
2012-01-01
We apply the non-linear flow response formalism to the recently measured event plane correlations. We find that as a result of the combined effects of linear and non-linear flow response, the observed event plane correlations can be understood as an effective average of the 'linear limit' and 'non-linear limit'.
Parametrices and exact paralinearization of semi-linear boundary problems
DEFF Research Database (Denmark)
Johnsen, Jon
2008-01-01
The subject is parametrices for semi-linear problems, based on parametrices for linear boundary problems and on non-linearities that decompose into solution-dependent linear operators acting on the solutions. Non-linearities of product type are shown to admit this via exact paralinearization. The...... homogeneous distributions, tensor products and halfspace extensions have been revised. Examples include the von Karman equation....
Parametrices and exact paralinearisation of semi-linear boundary problems
DEFF Research Database (Denmark)
Johnsen, Jon
The subject is parametrices for semi-linear problems, based on parametrices for linear boundary problems and on non-linearities that decompose into solution-dependent linear operators acting on the solutions. Non-linearities of product type are shown to admit this via exact paralinearisation. The...... homogeneous distributions, tensor products and halfspace extensions have been revised. Examples include the von Karman equation....
Logical consecutions in discrete linear temporal logic
Rybakov, V. V.
2005-01-01
We investigate logical consequence in temporal logics in terms of logical consecutions, i.e., inference rules. First, we discuss the question: what does it mean for a logical consecution to be ’correct’ in a propositional logic. We consider both valid and admissible consecutions in linear temporal logics and discuss the distinction between these two notions. The linear temporal logic LDTL, consisting of all formulas valid in the frame 〈 , ≤, ≥ 〉 of all integer numbers, is the prime object of...
Portfolio optimization using fuzzy linear programming
Pandit, Purnima K.
2013-09-01
Portfolio Optimization (PO) is a problem in Finance, in which investor tries to maximize return and minimize risk by carefully choosing different assets. Expected return and risk are the most important parameters with regard to optimal portfolios. In the simple form PO can be modeled as quadratic programming problem which can be put into equivalent linear form. PO problems with the fuzzy parameters can be solved as multi-objective fuzzy linear programming problem. In this paper we give the solution to such problems with an illustrative example.
An R companion to linear statistical models
Hay-Jahans, Christopher
2011-01-01
Focusing on user-developed programming, An R Companion to Linear Statistical Models serves two audiences: those who are familiar with the theory and applications of linear statistical models and wish to learn or enhance their skills in R; and those who are enrolled in an R-based course on regression and analysis of variance. For those who have never used R, the book begins with a self-contained introduction to R that lays the foundation for later chapters.This book includes extensive and carefully explained examples of how to write programs using the R programming language. These examples cove
Observability conditions of switched linear singular systems
Institute of Scientific and Technical Information of China (English)
Bin MENG; Jifeng ZHANG
2007-01-01
The observability problem of switched linear singular(SLS) systems is studied in this paper. Based on the observability definition, the unobservable subspaces of given switching laws are investigated under the condition that all subsystems are regular. A necessary condition and a sufficient condition for observability of SLS systems are given. It is shown that the observability and controllability are dual for some special SLS systems with circulatory switching laws. The method developed here is applicable to the observability analysis of normal switched linear systems.
Introduction to general and generalized linear models
Madsen, Henrik
2010-01-01
IntroductionExamples of types of data Motivating examples A first view on the modelsThe Likelihood PrincipleIntroduction Point estimation theory The likelihood function The score function The information matrix Alternative parameterizations of the likelihood The maximum likelihood estimate (MLE) Distribution of the ML estimator Generalized loss-function and deviance Quadratic approximation of the log-likelihood Likelihood ratio tests Successive testing in hypothesis chains Dealing with nuisance parameters General Linear ModelsIntroduction The multivariate normal distribution General linear mod
Statistical Tests for Mixed Linear Models
Khuri, André I; Sinha, Bimal K
2011-01-01
An advanced discussion of linear models with mixed or random effects. In recent years a breakthrough has occurred in our ability to draw inferences from exact and optimum tests of variance component models, generating much research activity that relies on linear models with mixed and random effects. This volume covers the most important research of the past decade as well as the latest developments in hypothesis testing. It compiles all currently available results in the area of exact and optimum tests for variance component models and offers the only comprehensive treatment for these models a
A linear temperature-to-frequency converter
DEFF Research Database (Denmark)
Løvborg, Leif
1965-01-01
, and that the maximum value of the temperature-frequency coefficient beta in this point is-1/3 alpha, where a is the temperature coefficient of the thermistor at the corresponding temperature. Curves showing the range in which the converter is expected to be linear to within plusmn0.1 degC are given. A laboratory......-built converter having beta = 1.0% degC-1 at 25degC is found to be linear to within plusmn0. 1 degC from 10 to 40degC....
Digitally Controlled Linear Four-Port Network
Directory of Open Access Journals (Sweden)
V. Michalek
1994-09-01
Full Text Available The paper deals with the design of a universal linear multipart. The circuit is based on digitally controlled multiple voltage-controlled voltage sources (MVCVSs. The main advantages of this control are accuracy, invariability, and very small area requirements. The whole system is simply connected to a PC via its parallel port. This multipart can generally be used as a building block for any model of a nonlinear dynamic system, namely for the piecewise-linear (PWL model in both explicit and implicit forms.
LINEAR REGRESSION WITH R AND HADOOP
Oancea, Bogdan
2015-01-01
In this paper we present a way to solve the linear regression model with R and Hadoop using the Rhadoop library. We show how the linear regression model can be solved even for very large models that require special technologies. For storing the data we used Hadoop and for computation we used R. The interface between R and Hadoop is the open source library RHadoop. We present the main features of the Hadoop and R software systems and the way of interconnecting them. We then show how the least ...
Amoebas and coamoebas of linear spaces
Nisse, Mounir
2012-01-01
We give a complete description of the amoebas and coamoebas of $k$-dimensional affine linear spaces in $(\\mathbb{C}^*)^{n}$. We give a lower and an upper bounds of their dimension. and we show that if a $k$-dimensional affine linear space in $(\\mathbb{C}^*)^{n}$ is generic, then the dimension of its (co)amoeba is equal to $\\min \\{2k, n\\}$. We also prove that the volume of its coamoeba is equal $\\pi^{2k}$. Moreover, if the space is real then the volume of its amoeba is equal to $\\frac{\\pi^{2k}}{2^k}$.
Reset stabilisation of positive linear systems
Zhao, Xudong; Yin, Yunfei; Shen, Jun
2016-09-01
In this paper, the problems of reset stabilisation for positive linear systems (PLSs) are investigated. Some properties relating to reset control of PLSs are first revealed. It is shown that these properties are different from the corresponding ones of general linear systems. Second, a class of periodic reset scheme is designed to exponentially stabilise an unstable PLS with a prescribed decay rate. Then, for a given PLS with reset control, some discussions on the upper bound of its decay rate are presented. Meanwhile, the reset stabilisation for PLSs in a special case is probed as well. Finally, two numerical examples are used to demonstrate the correctness and effectiveness of the obtained theoretical results.
Fault tolerant control for switched linear systems
Du, Dongsheng; Shi, Peng
2015-01-01
This book presents up-to-date research and novel methodologies on fault diagnosis and fault tolerant control for switched linear systems. It provides a unified yet neat framework of filtering, fault detection, fault diagnosis and fault tolerant control of switched systems. It can therefore serve as a useful textbook for senior and/or graduate students who are interested in knowing the state-of-the-art of filtering, fault detection, fault diagnosis and fault tolerant control areas, as well as recent advances in switched linear systems.
Linear magnetochiral effect in Weyl semimetals
Cortijo, Alberto
2016-01-01
We suggest the possibility of a linear magnetochiral effect in time reversal breaking Weyl semimetals. Generically the magnetochiral effect consists in a simultaneous linear dependence of the magnetotransport coefficients with the magnetic field and a momentum vector. This simultaneous dependence is allowed by the Onsager reciprocity relations, being the separation vector between the Weyl nodes the vector that plays such role. As a side consequence, we find a non vanishing positive longitudinal magnetoconductivity at Fermi energies above the point where the chirality of the Weyl nodes is globally lost.
Statistics of linear polymers in disordered media
Chakrabarti, Bikas K
2005-01-01
With the mapping of the partition function graphs of the n-vector magnetic model in the n to 0 limit as the self-avoiding walks, the conformational statistics of linear polymers was clearly understood in early seventies. Various models of disordered solids, percolation model in particular, were also established by late seventies. Subsequently, investigations on thestatistics of linear polymers or of self-avoiding walks in, say, porous medium or disordered lattices were started in early eighties. Inspite of the brilliant ideas forwarded and extensive studies made for the next two decades, the
Linear Time Algorithms for Parallel Machine Scheduling
Institute of Scientific and Technical Information of China (English)
Zhi Yi TAN; Yong HE
2007-01-01
This paper addresses linear time algorithms for parallel machine scheduling problems. We introduce a kind of threshold algorithms and discuss their main features. Three linear time threshold algorithm classes DT, PT and DTm are studied thoroughly. For all classes, we study their best possible algorithms among each class. We also present their application to several scheduling problems.The new algorithms are better than classical algorithms in time complexity and/or worst-case ratio.Computer-aided proof technique is used in the proof of main results, which greatly simplifies the proof and decreases case by case analysis.
Snap-Stabilizing Linear Message Forwarding
Lamani, Anissa; Dubois, Swan; Petit, Franck; Villain, Vincent
2010-01-01
In this paper, we present the first snap-stabilizing message forwarding protocol that uses a number of buffers per node being inde- pendent of any global parameter, that is 4 buffers per link. The protocol works on a linear chain of nodes, that is possibly an overlay on a large- scale and dynamic system, e.g., Peer-to-Peer systems, Grids. . . Provided that the topology remains a linear chain and that nodes join and leave "neatly", the protocol tolerates topology changes. We expect that this protocol will be the base to get similar results on more general topologies.