Готові списки джерел за темами / Proportional machines

Зміст

  1. Статті в журналах
  2. Дисертації
  3. Книги
  4. Частини книг
  5. Тези доповідей конференцій
  6. Звіти організацій

Добірка наукової літератури з теми "Proportional machines"

Автор: Grafiati
Опубліковано: 30 травня 2022
Оновлено: 31 травня 2022

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Proportional machines".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Proportional machines"

1

Yin, Na, and Liying Kang. "Minimizing Makespan in Permutation Flow Shop Scheduling with Proportional Deterioration." Asia-Pacific Journal of Operational Research 32, no. 06 (December 2015): 1550050. http://dx.doi.org/10.1142/s0217595915500505.

Повний текст джерела
Анотація:
The [Formula: see text]-job and [Formula: see text]-machine permutation flow shop scheduling problem with a proportional deterioration is considered in which all machines process the jobs in the same order, i.e., a permutation schedule. A proportional deterioration means that the job deterioration as an increasing function that is proportional to a linear function of time. The objective is to minimize the makespan, i.e., the maximum completion time. When some dominant relationships between [Formula: see text] machines can be satisfied, we show that some special cases of the problem can be polynomial solvable. For the general case, we also propose a heuristic algorithm and give the computational experiments.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Arkin, Esther M., and Robin O. Roundy. "Weighted-Tardiness Scheduling on Parallel Machines with Proportional Weights." Operations Research 39, no. 1 (February 1991): 64–81. http://dx.doi.org/10.1287/opre.39.1.64.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Lemmink, Jacques. "‘Op proef doeltreffend gebleken, kunnen we spreken van een bereikt ideaal’." De Moderne Tijd 5, no. 1 (January 1, 2021): 35–59. http://dx.doi.org/10.5117/dmt2021.1.002.lemm.

Повний текст джерела
Анотація:
Abstract ‘Proved effective on trial, we can speak of an achieved ideal’ Abraham Kuyper and the mechanical voting machine, c. 1895-1905 During the latest presidential elections in the United States, unfounded conspiracy theories sprung up concerning alleged ballot box fraud by compromised voting machines. Although different voting machines had been used in the Netherlands since 1966, concerns over their reliability ended this in 2007. This article investigates the forgotten but ultimately failed attempt to introduce mechanical voting machines a century earlier. It focuses on the role played by prominent politician Abraham Kuyper, who personally visited the Standard Voting Machine Company in Rochester in 1898. The article illustrates how Kuyper’s transatlantic political and religious networks facilitated the voting machine’s transfer, rather than scientific connections. Paradoxically, the introduction of proportional representation in 1917 marked the end of tentative attempts to develop a Dutch version of the American mechanical voting machine. The implementation in the voting process turned out be too expensive, too early, and too complicated for the Dutch electoral system at the dawn of the twentieth century.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Kaczmarczyk, Waldemar. "Proportional lot-sizing and scheduling problem with identical parallel machines." International Journal of Production Research 49, no. 9 (May 2011): 2605–23. http://dx.doi.org/10.1080/00207543.2010.532929.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Wan, Yi, Qi Bo Cai, and Huan Wang. "The Research on Intelligent Control Method for EHP System." Advanced Materials Research 580 (October 2012): 12–15. http://dx.doi.org/10.4028/www.scientific.net/amr.580.12.

Повний текст джерела
Анотація:
Optimized machine learning algorithm is applied to control modeling of high-speed electric-hydraulic proportional system of high nonlinear in this paper, a identification model of high-speed electric-hydraulic proportional system is built based on support vector machines, fusion intelligent method of dynamic self-adaptive internal model control and predictive control is realized for high-speed electric-hydraulic proportional control system. Internal model and inverse controller model are online adjusted together. Simulation shows the satisfactory tracking effect by intelligent technology of dynamic self-adaptive internal control and predictive control based on the support vector machine, the dynamic characteristic is greatly improved by the intelligent control strategy for high-speed electric-hydraulic proportional control system, good tracking and control effect is reached in condition of high frequency response. It provides a new intelligent control method for high-speed electric-hydraulic proportional system.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

MATVEEV, Aleksey V. "Testing the Hypothesis about the Dependence of the Mass of Electric Machines on the Power and Speed." Elektrichestvo 7, no. 7 (2021): 4–18. http://dx.doi.org/10.24160//0013-5380-2021-7-4-18.

Повний текст джерела
Анотація:
The hypothesis stating that the mass of any rotating electric machine is proportional to its power capacity taken to a power of 0.75 and is inversely proportional to the square root of its rotation frequency is tested. The testing is carried out on the material of permanent magnet synchronous machines. The infl uence of such factors as voltage, shape of active parts, cooling, effi ciency level, overloads, presence of supporting structures, power supply frequency, and number of poles is studied. The hypothesis is tested by predicting the mass of machines in the widest possible range of power capacities (from 0.03 W to 36 MW) and rotation frequencies (from 2 to 500 000 rpm). The accuracy of the preliminary estimate of the machine mass within about 50% can be considered acceptable, given that the masses of the machines being estimated range from less than a gram to more than 100 t. Based on the study results, the formulation of a new law of electromechanics is proposed, which describes how the machine mass is predetermined in terms of its power capacity and rotation frequency. The ratio of machine power capacity taken to a power of 0.75 to the square root of its rotation frequency is to some extent similar to the “gravity” which the designers try to overcome working on weakening the eff ect of the above-mentioned infl uencing factors.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

MATVEEV, Aleksey V. "Testing the Hypothesis about the Dependence of the Mass of Electric Machines on the Power and Speed." Elektrichestvo, no. 7 (2021): 4–18. http://dx.doi.org/10.24160/0013-5380-2021-7-4-18.

Повний текст джерела
Анотація:
The hypothesis stating that the mass of any rotating electric machine is proportional to its power capacity taken to a power of 0.75 and is inversely proportional to the square root of its rotation frequency is tested. The testing is carried out on the material of permanent magnet synchronous machines. The infl uence of such factors as voltage, shape of active parts, cooling, effi ciency level, overloads, presence of supporting structures, power supply frequency, and number of poles is studied. The hypothesis is tested by predicting the mass of machines in the widest possible range of power capacities (from 0.03 W to 36 MW) and rotation frequencies (from 2 to 500 000 rpm). The accuracy of the preliminary estimate of the machine mass within about 50% can be considered acceptable, given that the masses of the machines being estimated range from less than a gram to more than 100 t. Based on the study results, the formulation of a new law of electromechanics is proposed, which describes how the machine mass is predetermined in terms of its power capacity and rotation frequency. The ratio of machine power capacity taken to a power of 0.75 to the square root of its rotation frequency is to some extent similar to the “gravity” which the designers try to overcome working on weakening the eff ect of the above-mentioned infl uencing factors.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Ambrosimov, Sergey, Victor Meshcheryakov, and Igor Ivshyn. "Provision of High-efficient Milling Methods Using a PMSM Electric Drive with a Controlled Information-Measuring System." E3S Web of Conferences 178 (2020): 01025. http://dx.doi.org/10.1051/e3sconf/202017801025.

Повний текст джерела
Анотація:
The article presents new highly effective methods of milling shaped surfaces, which are implemented on four-and five-coordinate CNC machines. For their implementation, three simultaneously coordinated movements of the machine’s organs are used. To implement the proposed milling methods on CNC machines, an electric drive is proposed, built on the basis of a Permanent Magnet Synchronous Motor (PMSM) with a vector control system with a proportional P-speed controller. For this purpose, an ecstatic control information and measurement system with zero static error is proposed. Comparative results of mathematical modeling of transient processes in electric drives with the standard and proposed control systems are presented.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Gomes, Robert R., Luiz F. Pugliese, Waner W. A. G. Silva, Clodualdo V. Sousa, Guilherme M. Rezende, and Fadul F. Rodor. "Speed Control with Indirect Field Orientation for Low Power Three-Phase Induction Machine with Squirrel Cage Rotor." Machines 9, no. 12 (November 27, 2021): 320. http://dx.doi.org/10.3390/machines9120320.

Повний текст джерела
Анотація:
Induction machines are widely used in the industry due to their many advantages compared to other industrial machines. This article presents the study and implementation of speed control applied to a Three-phase Induction Machine (MIT) of the squirrel cage type. The induction motor was modeled using the rotor flux in the synchronous reference to design Proportional-Integral (PI) type controllers for the current and velocity control loops. It is the objective of the article also to present in detail the development of converter hardware that comprises the stages of power, acquisition, and conditioning of engine signals. The system was simulated using computational tools and validated using a prototype designed, constructed, and commissioned.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Ban, Branko, Stjepan Stipetic, and Tino Jercic. "Minimum Set of Rotor Parameters for Synchronous Reluctance Machine and Improved Optimization Convergence via Forced Rotor Barrier Feasibility." Energies 14, no. 10 (May 11, 2021): 2744. http://dx.doi.org/10.3390/en14102744.

Повний текст джерела
Анотація:
Although rare earth materials are the critical component in high torque density permanent magnet machines, their use has historically been a commercial risk. The alternatives that have been in the recent industry focus are synchronous reluctance machines (SyRM). They have lower torque density but also relatively low material cost and higher overload capability. Multi-layer IPM and SyRM machines have significant geometric complexity, resulting in a high number of parameters. Considering that modern machine design requires the use of optimization algorithms with computational load proportional to the number of parameters, the whole design process can take several days. This paper presents novel SyRM parameterization with reduced number of parameters. Furthermore, the paper introduces the novel forced feasibility concept, applied on rotor barrier parameters, resulting in improved optimization convergence with overall optimization time reduced by 12.3%. Proposed approaches were demonstrated using optimization procedure based on the existing differential evolution algorithm (DE) framework.
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Дисертації з теми "Proportional machines"

1

Zaharia, Mihai Valentin. "Contributions à l’étude des machines à reluctance variable pour application alterno-démarreur automobile." Thesis, Ecole centrale de Lille, 2016. http://www.theses.fr/2016ECLI0022/document.

Повний текст джерела
Анотація:
Ce travail de recherche est réalisé dans le cadre d'une collaboration internationale entre l'Université Technique de Cluj-Napoca en Roumanie et l'Ecole Centrale de Lille en France. Cette thèse a comme premier objectif, de réduire l’ondulation de couple d’une machine triphasée 6/8 à réluctance variable grâce aux paramètres de contrôle dans le mode de fonctionnement moteur et générateur. Par conséquent, un modèle analytique a été développé et mis en œuvre dans un environnement de calcul numérique. Un outil d'optimisation permettant de trouver les meilleurs paramètres de contrôle a été utilisé. Toutefois, le processus d’optimisation est très lent.En conséquence, une stratégie pour réduire le temps du processus d'optimisation sans abaisser la précision des résultats est proposée. Une stratégie de ‘mapping’ est utilisée entre un modèle grossier mais rapide et un modèle fin mais lent. Un travail est mené sur le choix du modèle grossier, dans le cadre d’un modèle fournissant des valeurs en fonction du temps. Deux stratégies de ‘mapping’ ont été utilisées dans cette thèse : l’‘Output Space Mapping Proportional’(OSMP) et le Manifold Mapping (MM). Ces deux stratégies sont utilisées pour déterminer les paramètres de contrôle optimaux. Le problème d’optimisation est ensuite complété en ajoutant des variables géométriques au processus d’optimisation du contrôle. Les outils développés sont ensuite utilisés dans le cadre du dimensionnement par optimisation d’un alterno-démarreur automobile. Finalement, des expériences et des essais sur un prototype de Machine à RV sont menés afin de valider les résultats du processus d'optimisation en mode moteur et générateur
The switched reluctance machine has a simple construction making it cheaper in execution but one of the drawbacks of this machine is the torque ripple. This thesis had as first target, the usage of an optimization tool to calculate the best control parameters to correct this major drawback in motor and generator operation modes. Hence, an analytical model that takes into account the machine geometry and that is able to be simulated in both operation modes by adjusting the commutation angles was provided and implemented in a calculation environment. The second target of this work is to investigate a method to reduce the optimization time without lowering the accuracy of the results. The strategy used in the optimization process is known in literature as the space mapping technique, more precisely for this thesis output space mapping proportional and manifold mapping were studied. After testing them on a mathematical model it was possible to continue the investigation on defining the optimal control parameters of a three-phases 6/8 SR machine prototype, being able that further to use this strategy in a much complicated process, i.e. defining the right geometry and control of a SR machine to be used in automotive integrated starter alternator systems. The final target of the thesis was to conduct experiments and tests on the existing prototype in order to partially validate the results of the optimization process
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Gao, Zhi. "Sensorless Stator Winding Temperature Estimation for Induction Machines." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/13966.

Повний текст джерела
Анотація:
The organic materials used for stator winding insulation are subject to deterioration from thermal, electrical, and mechanical stresses. Stator winding insulation breakdown due to excessive thermal stress is one of the major causes of electric machine failures; therefore, prevention of such a failure is crucial for increasing machine reliability and minimizing financial loss due to motor failure. This work focuses on the development of an efficient and reliable stator winding temperature estimation scheme for small to medium size mains-fed induction machines. The motivation for the stator winding temperature estimation is to develop a sensorless temperature monitoring scheme and provide an accurate temperature estimate that is capable of responding to the changes in the motors cooling capability. A discussion on the two major types of temperature estimation techniques, thermal model-based and parameter-based temperature techniques, reveals that neither method can protect motors without sacrificing the estimation accuracy or motor performance. Based on the evaluation of the advantages and disadvantages of these two types of temperature estimation techniques, a new online stator winding temperature estimation scheme for small to medium size mains-fed induction machines is proposed in this work. The new stator winding temperature estimation scheme is based on a hybrid thermal model. By correlating the rotor temperature with the stator temperature, the hybrid thermal model unifies the thermal model-based and the parameter-based temperature estimation techniques. Experimental results validate the proposed scheme for stator winding temperature monitoring. The entire algorithm is fast, efficient and reliable, making it suitable for implementation in real time stator winding temperature monitoring.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Маленко, Анастасія Олексіївна. "Задача мінімізації сумарного відхилення від спільного директивного строку при виконанні завдань паралельними пристроями". Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/23799.

Повний текст джерела
Анотація:
Магістерська дисертація: 101 с., 26 рис., 22 табл., 1 додаток, 55 джерел. Актуальність. Задачі теорії розкладів широко вивчаються в літературі останні 50 років, їх розгляду приділяється значна увага з боку багатьох вчених і фахівців-практиків по всьому світу. Складні реальні задачі, з якими стикаються різні типи компаній, стали викликом для пошуку шляхів їх розв’язання. Результати отримані дослідженнями різних науковців свідчать про актуальність проблеми та потребу в її подальшому дослідженні. Таким чином, можна з упевненістю сказати, що питання теорії розкладів є одним з найбільш поширених питань в галузі дослідження операцій і наук управління. Проблематика теорії розкладів охоплює дослідження обчислювальної складності задач, розробку точних, наближених та евристичних алгоритмів їх розв’язання. При цьому більшість праць присвячено розвитку комбінаторних підходів. Однак, як показує практика, можливості комбінаторних алгоритмів суттєво обмежені розмірністю розв’язуваних задач. У зв’язку з цим актуальною є розробка програмного продукту для складання розкладу виконання завдань паралельними пристроями, який допоможе мінімізувати сумарне відхилення від директивних строків. Зв'язок роботи з науковими програмами, планами, темами. Робота виконувалась на кафедрі автоматизованих систем обробки інформації та управління Національного технічного університету України «Київський політехнічний інститут ім. Ігоря Сікорського» в рамках теми «Ефективні методи розв’язання задач теорії розкладів» (№ 0117U000919). Мета і завдання дослідження – підвищення якості розв’язку задач календарного планування за рахунок побудови оптимального чи близького до оптимального розкладу, що дозволяє мінімізувати середній час відхилення від директивних строків. 4 Для досягнення мети необхідно виконати наступні завдання:  виконати аналітичний огляд відомих результатів, з розв’язання поставленої в рамках роботи задачі;  розробити алгоритм створення календарного плану виконання завдань паралельними пристроями, що мінімізує сумарне відхилення моментів завершення завдань від директивних строків;  розробити програмну реалізацію розробленого алгоритму;  виконати аналіз отриманих результатів. Об’єкт дослідження – оперативно-календарне планування дрібносерійного виробництва. Предмет дослідження – моделі та методи розв’язання задач календарного планування з метою мінімізації сумарного відхилення виконання завдань від директивних строків паралельними пристроями. Методи дослідження, застосовані в роботі, базуються на методах та алгоритмах теорії розкладів та дослідження операцій. Наукова новизна отриманих результатів. Розроблено евристичний алгоритм розв‘язання задачі мінімізації сумарного відхилення від спільного директивного строку при виконанні завдань паралельними пристроями. Публікації. Матеріали роботи опубліковано у Міжнародному науковому журналі «Науковий огляд» – №9(14). – с. 14–32 у 2017 році [1], також матеріали опубліковано в тезах 20-ї Міжнародної науково-технічної конференції SAIT 2018 [2], наукової конференції студентів, магістрантів та аспірантів «Інформатика та обчислювальна техніка» – ІОТ-2018 [3].
Master’s thesis: 101 pages, 26 figures, 22 tables, 1 appendix, 55 references. Relevance. Scheduling problems have been widely studying in the literature for 50 years, considerable attention from many scholars and practitioners around the world is given to their consideration. The complex real problems faced by different types of companies have become a challenge to find ways to solve them. The results obtained by researches of various scholars indicate the urgency of the problem and the need for its further research. Thus, one can confidently say that the question of the scheduling problems is one of the most common issues in the field of operations research and management sciences. The question of scheduling problems covers the studying the complexity of problems, the development of accurate, approximate and heuristic algorithms for their solution. At the same time, most works are devoted to the development of combinatorial approaches. However, as practice shows, the possibilities of combinatorial algorithms are essentially limited by the dimensionality of solvable problems. In this regard, it is relevant to develop a software product to scheduling tasks by parallel machines, which will help minimize the total deviation from a common due date. Relationship of work with scientific programs, plans, themes. The work was carried out at National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute» the department of Computer-Aided Management and Data Processing Systems within the theme “Effective methods for solving the problems of the theory of schedules” (state registration number 0117U000919). Purpose and objectives of the study. Improving the quality of solving problem scheduling tasks at the expense of construction an optimal or close to optimal schedule, which minimizes the average deviation time from due dates. The following tasks:  performing the known scheduling results analytical review;  developing an algorithm for minimizing the total deviation for common due date by parallel machine scheduling; 6  developing a software implementation of the algorithm in a form that can be used for schedule optimizing;  performing an analysis of the results. The object of study is operational planning of small-scale production. Subject of research: models and methods for solving scheduling problems in order to minimize the total deviation of completion times from a common due date by parallel machines. Scientific novelty of the research. A heuristic algorithm for solving the problem of minimizing the total deviation from the common policy term when performing tasks with parallel devices is developed. Publications. Materials of the work are published in the International Scientific Journal "Scientific Review" - № 9 (14). - p. 14-32 in 2017 [1], materials are also published in the theses of the 20th International Scientific and Technical Conference SAIT 2018 [2] and in the scientific conference of students, graduate students and postgraduates "Informatics and Computing" 2018 [3].
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Ouriagli, Mohammed. "Contribution à la synthèse de commandes robustes pour machines synchrones à aimants permanents." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL136N.

Повний текст джерела
Анотація:
Le travail de mémoire porte sur la synthèse de commandes robustes pour machines synchrones à aimants permanents en tenant compte des amortisseurs et de variations de paramètres de la machine. Dans un premier temps, une commande basée sur le contrôle vectoriel et sur l'utilisation de correcteurs classiques de type proportionnel intégral a été élaborée. Le dimensionnement de ces correcteurs a été facilité par l'introduction d'un algorithme de découplage des courants statoriques direct et en quadrature. Dans un deuxième temps, nous nous sommes intéressé à la synthèse de commandes robustes et particulièrement, au contrôle H infini et à la commande par mode de glissement. Elles permettent la prise en compte des différentes perturbations et assurent en outre, un bon compromis robustesse/performances
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Kontz, Matthew Edward. "Haptic Control of Hydraulic Machinery Using Proportional Valves." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19876.

Повний текст джерела
Анотація:
Supplying haptic or force feedback to operators using hydraulic machinery such as excavators has the potential to increase operator capabilities. Haptic, robotic, human-machine interfaces enable several enhancing features including coordinated motion control and programmable haptic feedback. Coordinated or resolved motion control supplies a more intuitive means of specifying the equipment's motion. Haptic feedback is used to relay meaningful information back to the user in the form of force signals about digging force acting on the bucket, programmable virtual constraints and system limitations imposed by the mechanism, maximum pressure or maximum flow. In order to make this technology economically viable, the benefits must offset the additional cost associated with implementation. One way to minimize this cost is to not use high-end hydraulic components. For smaller backhoes and mini-excavators this means that the hydraulic systems are comprised of a constant displacement pump and proportional direction control valves. Hydraulic and haptic control techniques suitable for backhoes/excavators are developed and tested on a small backhoe test-bed. A virtual backhoe simulator is created for controller design and human evaluation. Not only is the virtual simulator modeled after the test-bed, but the control algorithm used in the simulator is the same as the actual backhoe test-bed. Data from human subject tests are presented that evaluate the control strategies on both the real and virtual backhoe. The end goal of this project is to incorporate coordinated haptic control algorithms that work with low-cost systems and maximize the enhancement of operator capabilities.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Hug, Nicolas. "Contributions to the use of analogical proportions for machine learning : theoretical properties and application to recommendation." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30117/document.

Повний текст джерела
Анотація:
Le raisonnement par analogie est reconnu comme une des principales caractéristiques de l'intelligence humaine. En tant que tel, il a pendant longtemps été étudié par les philosophes et les psychologues, mais de récents travaux s'intéressent aussi à sa modélisation d'un point de vue formel à l'aide de proportions analogiques, permettant l'implémentation de programmes informatiques. Nous nous intéressons ici à l'utilisation des proportions analogiques à des fins prédictives, dans un contexte d'apprentissage artificiel. Dans de récents travaux, les classifieurs analogiques ont montré qu'ils sont capables d'obtenir d'excellentes performances sur certains problèmes artificiels, là où d'autres techniques traditionnelles d'apprentissage se montrent beaucoup moins efficaces. Partant de cette observation empirique, cette thèse s'intéresse à deux axes principaux de recherche. Le premier sera de confronter le raisonnement par proportion analogique à des applications pratiques, afin d'étudier la viabilité de l'approche analogique sur des problèmes concrets. Le second axe de recherche sera d'étudier les classifieurs analogiques d'un point de vue théorique, car jusqu'à présent ceux-ci n'étaient connus que grâce à leurs définitions algorithmiques. Les propriétés théoriques qui découleront nous permettront de comprendre plus précisément leurs forces, ainsi que leurs faiblesses. Comme domaine d'application, nous avons choisi celui des systèmes de recommandation. On reproche souvent à ces derniers de manquer de nouveauté ou de surprise dans les recommandations qui sont adressées aux utilisateurs. Le raisonnement par analogie, capable de mettre en relation des objets en apparence différents, nous est apparu comme un outil potentiel pour répondre à ce problème. Nos expériences montreront que les systèmes analogiques ont tendance à produire des recommandations d'une qualité comparable à celle des méthodes existantes, mais que leur complexité algorithmique cubique les pénalise trop fortement pour prétendre à des applications pratiques où le temps de calcul est une des contraintes principales. Du côté théorique, une contribution majeure de cette thèse est de proposer une définition fonctionnelle des classifieurs analogiques, qui a la particularité d'unifier les approches préexistantes. Cette définition fonctionnelle nous permettra de clairement identifier les liens sous-jacents entre l'approche analogique et l'approche par k plus-proches-voisins, tant au plan algorithmique de haut niveau qu'au plan des propriétés théoriques (taux d'erreur notamment). De plus, nous avons pu identifier un critère qui rend l'application de notre principe d'inférence analogique parfaitement certaine (c'est-à-dire sans erreur), exhibant ainsi les propriétés linéaires du raisonnement par analogie
Analogical reasoning is recognized as a core component of human intelligence. It has been extensively studied from philosophical and psychological viewpoints, but recent works also address the modeling of analogical reasoning for computational purposes, particularly focused on analogical proportions. We are interested here in the use of analogical proportions for making predictions, in a machine learning context. In recent works, analogy-based classifiers have achieved noteworthy performances, in particular by performing well on some artificial problems where other traditional methods tend to fail. Starting from this empirical observation, the goal of this thesis is twofold. The first topic of research is to assess the relevance of analogical learners on real-world, practical application problems. The second topic is to exhibit meaningful theoretical properties of analogical classifiers, which were yet only empirically studied. The field of application that was chosen for assessing the suitability of analogical classifiers in real-world setting is the topic of recommender systems. A common reproach addressed towards recommender systems is that they often lack of novelty and diversity in their recommendations. As a way of establishing links between seemingly unrelated objects, analogy was thought as a way to overcome this issue. Experiments here show that while offering sometimes similar accuracy performances to those of basic classical approaches, analogical classifiers still suffer from their algorithmic complexity. On the theoretical side, a key contribution of this thesis is to provide a functional definition of analogical classifiers, that unifies the various pre-existing approaches. So far, only algorithmic definitions were known, making it difficult to lead a thorough theoretical study. From this functional definition, we clearly identified the links between our approach and that of the nearest neighbors classifiers, in terms of process and in terms of accuracy. We were also able to identify a criterion that ensures a safe application of our analogical inference principle, which allows us to characterize analogical reasoning as some sort of linear process
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Arenas, Joshua A. "Evaluation of a Novel Myoelectric Training Device." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/4050.

Повний текст джерела
Анотація:
Recent technological developments have implemented the use of proportional control in prosthetic hands, giving rise to the importance of appropriate myoelectric control. EMG models in the past have assumed a linear proportionality to simplify the EMG-force relationships. However, it has been shown that a non-linear EMG-force relationship may be a more effective model. This study focused on evaluating three different control algorithms for a novel myoelectric training device, consisting of a toy car controlled by EMG signals from the distal muscles in the arm. Sixteen healthy adult subjects (5 male and 11 female) with an average age of 23.6 years (SD = 2.7) were asked to drive the car through a slalom course. Completion times as well as number of errors (wall hits, cone hits, and reversals) were recorded to evaluate performance. The NASA TLX was administered to evaluate psychometrics such as mental demand, physical demand, frustration, and overall workload. The average total errors per trial on the final day of testing using the linear proportional algorithm was found to be statistically significantly (p < 0.05) lower than digital and non-linear proportional. The average course completion time per trial and overall workload using the non-linear proportional algorithm was found to be statistically significantly (p < 0.05) lower than digital and linear proportional. These results suggest that a non-linear algorithm would be most appropriate for myoelectric control in prosthetic hands.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Nel, Wynand. "Impact of pole shape and proportions on flux leakage in switched-flux generators." abstract and full text PDF (free order & download UNR users only), 2005. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1433347.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Santos, Pereira Guilherme. "Stabilité des systèmes électriques comportant une forte proportion de sources interfacées par électronique de puissance." Thesis, Centrale Lille Institut, 2020. http://www.theses.fr/2020CLIL0018.

Повний текст джерела
Анотація:
L’insertion massive de sources interfacées par Électronique de Puissance (EP) dans le réseau va induire de grands défis techniques à surmonter pour garantir la stabilité du système électrique. L’une des principales préoccupations tient aux caractéristiques de ces sources, qui sont différentes de celles des Machines Synchrones (MS). Ce travail apporte un éclairage supplémentaire sur l’effet de l’insertion massive des sources interfacées par EP dans le système électrique, plus spécifiquement sur l’évolution du comportement de la fréquence de ces systèmes. Pour y répondre, un ensemble d’outils et de méthodes s’inspirant des fondamentaux des systèmes basés sur la production d’électricité avec les MSs a été développé. Des modèles d’ordre réduit des sources interfacées par EP se comportant comme sources de tension ou de courant sont proposés. Comme ces représentations partagent la même approche théorique que les modèles de MSs, il est ensuite possible de les fusionner en vue de l’analyse des systèmes électriques quelconques, indépendamment leur complexité. Les systèmes d’ordre réduit peuvent soit être modélisés en représentant chaque source ou bien en utilisant le concept des zones synchrones, ce qui offre une grande flexibilité d’analyse. Avec une approche progressive, le comportement de la fréquence des systèmes académiques relevé avec la méthodologie proposée est analysé en profondeur et comparé avec celui obtenu avec des modèles détaillés. L’approche développée dans ce travail peut être utilisée pour déterminer l’impact du ratio de pénétration des sources interfacées par EP sur le comportement global de la fréquence, mais aussi pour évaluer les oscillations intra et interzones des différents systèmes électriques
The massive insertion of Power Electronics (PE)-based sources into the grid is creating some technical challenges which must be overcome in order to guarantee the stability of the power system. One of the main concerns is due to the characteristics of these sources, which are different to those of Synchronous Machines (SMs). This research intends to provide a supplementary insight into the massive insertion of PE-based sources into the power system, more specifically the evolution of the frequency behaviour of these systems. For this purpose, a set of methods and tools already used on classical SM-based systems is proposed. Reduced order models of PE-based sources behaving as voltage or current sources are proposed, and, since the obtained representations share the same theoretical approach as that employed for SMs, they can be employed together to analyse any power system, regardless its complexity. The reduced order model of the systems can either be designed by representing each source of the original system or using the concept of synchronous areas, providing flexibility in the analysis. Using a step-by-step approach, the frequency behaviours observed with academic systems are deeply analysed with the proposed methodology, and validated with those obtained with detailed EMT models. The proposed approach developed in this work can be used to determine the impact of the penetration rate of PE-based sources on the overall frequency behaviour, and on the intra- and inter-area oscillations of different power systems
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Santos, Pereira Guilherme. "Stabilité des systèmes électriques comportant une forte proportion de sources interfacées par électronique de puissance." Thesis, Ecole centrale de Lille, 2020. http://www.theses.fr/2020ECLI0018.

Повний текст джерела
Анотація:
L’insertion massive de sources interfacées par Électronique de Puissance (EP) dans le réseau va induire de grands défis techniques à surmonter pour garantir la stabilité du système électrique. L’une des principales préoccupations tient aux caractéristiques de ces sources, qui sont différentes de celles des Machines Synchrones (MS). Ce travail apporte un éclairage supplémentaire sur l’effet de l’insertion massive des sources interfacées par EP dans le système électrique, plus spécifiquement sur l’évolution du comportement de la fréquence de ces systèmes. Pour y répondre, un ensemble d’outils et de méthodes s’inspirant des fondamentaux des systèmes basés sur la production d’électricité avec les MSs a été développé. Des modèles d’ordre réduit des sources interfacées par EP se comportant comme sources de tension ou de courant sont proposés. Comme ces représentations partagent la même approche théorique que les modèles de MSs, il est ensuite possible de les fusionner en vue de l’analyse des systèmes électriques quelconques, indépendamment leur complexité. Les systèmes d’ordre réduit peuvent soit être modélisés en représentant chaque source ou bien en utilisant le concept des zones synchrones, ce qui offre une grande flexibilité d’analyse. Avec une approche progressive, le comportement de la fréquence des systèmes académiques relevé avec la méthodologie proposée est analysé en profondeur et comparé avec celui obtenu avec des modèles détaillés. L’approche développée dans ce travail peut être utilisée pour déterminer l’impact du ratio de pénétration des sources interfacées par EP sur le comportement global de la fréquence, mais aussi pour évaluer les oscillations intra et interzones des différents systèmes électriques
The massive insertion of Power Electronics (PE)-based sources into the grid is creating some technical challenges which must be overcome in order to guarantee the stability of the power system. One of the main concerns is due to the characteristics of these sources, which are different to those of Synchronous Machines (SMs). This research intends to provide a supplementary insight into the massive insertion of PE-based sources into the power system, more specifically the evolution of the frequency behaviour of these systems. For this purpose, a set of methods and tools already used on classical SM-based systems is proposed. Reduced order models of PE-based sources behaving as voltage or current sources are proposed, and, since the obtained representations share the same theoretical approach as that employed for SMs, they can be employed together to analyse any power system, regardless its complexity. The reduced order model of the systems can either be designed by representing each source of the original system or using the concept of synchronous areas, providing flexibility in the analysis. Using a step-by-step approach, the frequency behaviours observed with academic systems are deeply analysed with the proposed methodology, and validated with those obtained with detailed EMT models. The proposed approach developed in this work can be used to determine the impact of the penetration rate of PE-based sources on the overall frequency behaviour, and on the intra- and inter-area oscillations of different power systems
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Книги з теми "Proportional machines"

1

MacCurdy, Edward, ed. The Notebooks of Leonardo Da Vinci: Arranged, Rendered into English, and Introduced by Edward MacCurdy. Old Saybrook, CT,: Konecky & Konecky, 2003.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Leonardo. Leonardo: Un hombre universal en los límites extremos de la mente y del arte. Madrid: Electa, 1999.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

1950-, Desmond Michael, Pedretti Carlo, Leonardo da Vinci 1452-1519, and Powerhouse Museum, eds. Leonardo da Vinci: The Codex Leicester--notebook of a genius. Sydney, N.S.W: Powerhouse, 2000.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Carlo, Pedretti, Melani Margherita, and Basilique nationale du Sacré-Coeur (Belgium), eds. Leonardo da Vinci: The European genius : paintings and drawings : exhibition in the Basilica of Koekelberg, Brussels, in celebration of the 50th anniversary of the Treaty of Rome for the constitution of the European Community (1957-2007). Foligno (PG) [i.e. Perugia, Italy]: Cartei & Bianchi, 2007.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Leonardo. Leonardo da Vinci: I manoscritti dell'Istituto di Francia. Edited by Govi Gilberto 1826-1889, Poli Capri Paola, and Istituto di Francia. Roma: H. van der Poel, 2000.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Leonardo. Leonardo da Vinci: Attualità e mito = Leonardo da Vinci : aktualitás és mítosz. [S.l.]: Museo Ideale, 1991.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

K, Kustodieva T., Strinati Claudio M, Palazzo ducale (Venice Italy), Palazzo del Quirinale (Rome, Italy), and Gosudarstvennyĭ Ėrmitazh (Russia), eds. Leonardo: La Madonna Litta dall'Ermitage di San Pietroburgo. Roma: De Luca, 2003.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Leonardo. Leonardo da Vinci: Engineer and architect. [Montreal]: Montreal Museum of Fine Arts, 1987.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

C, Marani Pietro, Fiorio Maria Teresa, and Castello sforzesco, eds. Leonardo: Dagli studi di proporzioni al Trattato della pittura. Milano: Electa, 2007.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Leonardo. Leonardo da Vinci: Künstler, Erfinder, Wissenschaftler. Speyer: Historisches Museum der Pfalz, 1995.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Частини книг з теми "Proportional machines"

1

Cleophas, Ton J., and Aeilko H. Zwinderman. "Confidence Intervals for Proportions and Differences in Proportions." In Machine Learning in Medicine - Cookbook Three, 117–20. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-12163-5_19.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Poyiadzi, Rafael, Raúl Santos-Rodríguez, and Tijl De Bie. "Ordinal Label Proportions." In Machine Learning and Knowledge Discovery in Databases, 306–21. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-10925-7_19.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Yang, Ying, and Geoffrey I. Webb. "Proportional k-Interval Discretization for Naive-Bayes Classifiers." In Machine Learning: ECML 2001, 564–75. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/3-540-44795-4_48.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Famitafreshi, Golshan, and Cristina Cano. "Achieving Proportional Fairness in WiFi Networks via Bandit Convex Optimization." In Machine Learning for Networking, 85–98. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45778-5_7.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Cleophas, Ton J., and Aeilko H. Zwinderman. "Confidence Intervals for Proportions and Differences in Proportions (100 and 75 Patients)." In Machine Learning in Medicine – A Complete Overview, 633–37. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-33970-8_82.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Cleophas, Ton J., and Aeilko H. Zwinderman. "Confidence Intervals for Proportions and Differences in Proportions (100 and 75 Patients)." In Machine Learning in Medicine - a Complete Overview, 481–84. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-15195-3_77.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Hertrich, Christoph. "Scheduling a Proportionate Flow Shop of Batching Machines." In Operations Research Proceedings, 27–33. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-48439-2_4.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Vargas, Víctor Manuel, Pedro Antonio Gutiérrez, and César Hervás. "Deep Ordinal Classification Based on the Proportional Odds Model." In From Bioinspired Systems and Biomedical Applications to Machine Learning, 441–51. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-19651-6_43.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Luo, Zhipeng, and Milos Hauskrecht. "Hierarchical Active Learning with Proportion Feedback on Regions." In Machine Learning and Knowledge Discovery in Databases, 464–80. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-10928-8_28.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Beltrán-Carbajal, F., E. Chavez-Conde, S. Villanueva, Z. Damián, E. Montes, P. Puerta, R. Pérez, and G. Alvarez. "Robust Proportional-Derivative Control of a Three-Axis Milling Machine Tool." In Intelligent Robotics and Applications, 622–31. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-33509-9_62.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Proportional machines"

1

Toudji, R., M. O. Mahmoudi, H. Zeroug, and H. Sahraoui. "Performance Evaluation Into the Fault-Tolerant operation of SRM with Proportional-Integral and Integral-Proportional Speed controllers." In 8th IET International Conference on Power Electronics, Machines and Drives (PEMD 2016). Institution of Engineering and Technology, 2016. http://dx.doi.org/10.1049/cp.2016.0319.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Zu, Ran, Anjun Xia, Hongguo Li, and Fengxiang Wang. "A Fast Speed Control of PMSMs without Proportional Integral Controller." In 2018 IEEE Student Conference on Electric Machines and Systems. IEEE, 2018. http://dx.doi.org/10.1109/scems.2018.8624736.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Lee, Jihyun, and Chinedum Okwudire. "Effects of Non-Proportional Damping on the Residual Vibrations of Mode-Coupled Ultra-Precision Manufacturing Machines." In ASME 2014 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/dscc2014-6120.

Повний текст джерела
Анотація:
Ultra-precision manufacturing (UPM) machines are used to fabricate and measure complex parts having micrometer-level features and nanometer-level tolerances/surface finishes. Therefore, low-frequency residual vibrations that occur during the motion of the machines’ axes must be minimized. Recent work by the authors has revealed that coupling vibration modes of passively-isolated UPM machines can provide conditions for drastic reduction of residual vibrations vis-a-vis the recommended practice of modal decoupling. This paper presents an investigation into the effects of non-proportional (NP) damping on the conclusions reached in the authors’ prior work. With NP damping added, the conditions under which mode coupling is beneficial relative to decoupling are seen to remain largely the same. However, NP damping is shown to significantly influence the conditions under which the system’s response is most sensitive to mode coupling. Design guidelines for maximally exploiting the benefits of mode coupling are presented and demonstrated experimentally on a UPM machine.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Liu, Xinbo, and Yaohan Zou. "The Proportional Current Control Strategy for Equalization Circuits of Series Battery Packs." In 2018 21st International Conference on Electrical Machines and Systems (ICEMS). IEEE, 2018. http://dx.doi.org/10.23919/icems.2018.8549119.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Zhang, Xuxuan, Zhe Chen, Chunqiang Liu, Abd Alrahman Dawara, and Guangzhao Luo. "Robust Speed Controller Design of PMSM Drives by a Proportional Resonant-Based ADRC." In 2021 24th International Conference on Electrical Machines and Systems (ICEMS). IEEE, 2021. http://dx.doi.org/10.23919/icems52562.2021.9634568.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Niestroj, Roman, Tadeusz Bialon, Marian Pasko, and Jaroslaw Michalak. "Study of adaptive proportional observer of state variables of induction motor taking into consideration the generation mode." In 2017 International Symposium on Electrical Machines (SME). IEEE, 2017. http://dx.doi.org/10.1109/isem.2017.7993561.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Ebad, Mehdi, and Byeong-Mun Song. "Improved design and control of proportional resonant controller for three-phase voltage source inverter." In 2012 IEEE Power Electronics and Machines in Wind Applications (PEMWA). IEEE, 2012. http://dx.doi.org/10.1109/pemwa.2012.6316383.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Minghe, Tian, Wang Bo, Yu Yong, Ma Xing, Dong Qinghua, and Xu Dianguo. "Proportional Resonant-Based Active Disturbance Rejection Control for Speed Fluctuation Suppression of PMSM Drives." In 2019 22nd International Conference on Electrical Machines and Systems (ICEMS). IEEE, 2019. http://dx.doi.org/10.1109/icems.2019.8922243.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Zhao, Tianyi, Yijia Zhang, Hongda Xu, Xianguo Gui, and Dianguo Xu. "DTP-PMSM Drive with Proportional Resonant Regulator and Dual Zero Injection PWM Control Method." In 2018 21st International Conference on Electrical Machines and Systems (ICEMS). IEEE, 2018. http://dx.doi.org/10.23919/icems.2018.8549513.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

McNeill, N., B. Jin, and X. Yuan. "Proportional regenerative base driver circuit with negative offstate voltage for sic bipolar junction transistors." In 8th IET International Conference on Power Electronics, Machines and Drives (PEMD 2016). Institution of Engineering and Technology, 2016. http://dx.doi.org/10.1049/cp.2016.0240.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "Proportional machines"

1

Puttanapong, Nattapong, Arturo M. Martinez Jr, Mildred Addawe, Joseph Bulan, Ron Lester Durante, and Marymell Martillan. Predicting Poverty Using Geospatial Data in Thailand. Asian Development Bank, December 2020. http://dx.doi.org/10.22617/wps200434-2.

Повний текст джерела
Анотація:
This study examines an alternative approach in estimating poverty by investigating whether readily available geospatial data can accurately predict the spatial distribution of poverty in Thailand. It also compares the predictive performance of various econometric and machine learning methods such as generalized least squares, neural network, random forest, and support vector regression. Results suggest that intensity of night lights and other variables that approximate population density are highly associated with the proportion of population living in poverty. The random forest technique yielded the highest level of prediction accuracy among the methods considered, perhaps due to its capability to fit complex association structures even with small and medium-sized datasets.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Gates, Allison, Michelle Gates, Shannon Sim, Sarah A. Elliott, Jennifer Pillay, and Lisa Hartling. Creating Efficiencies in the Extraction of Data From Randomized Trials: A Prospective Evaluation of a Machine Learning and Text Mining Tool. Agency for Healthcare Research and Quality (AHRQ), August 2021. http://dx.doi.org/10.23970/ahrqepcmethodscreatingefficiencies.

Повний текст джерела
Анотація:
Background. Machine learning tools that semi-automate data extraction may create efficiencies in systematic review production. We prospectively evaluated an online machine learning and text mining tool’s ability to (a) automatically extract data elements from randomized trials, and (b) save time compared with manual extraction and verification. Methods. For 75 randomized trials published in 2017, we manually extracted and verified data for 21 unique data elements. We uploaded the randomized trials to ExaCT, an online machine learning and text mining tool, and quantified performance by evaluating the tool’s ability to identify the reporting of data elements (reported or not reported), and the relevance of the extracted sentences, fragments, and overall solutions. For each randomized trial, we measured the time to complete manual extraction and verification, and to review and amend the data extracted by ExaCT (simulating semi-automated data extraction). We summarized the relevance of the extractions for each data element using counts and proportions, and calculated the median and interquartile range (IQR) across data elements. We calculated the median (IQR) time for manual and semiautomated data extraction, and overall time savings. Results. The tool identified the reporting (reported or not reported) of data elements with median (IQR) 91 percent (75% to 99%) accuracy. Performance was perfect for four data elements: eligibility criteria, enrolment end date, control arm, and primary outcome(s). Among the top five sentences for each data element at least one sentence was relevant in a median (IQR) 88 percent (83% to 99%) of cases. Performance was perfect for four data elements: funding number, registration number, enrolment start date, and route of administration. Among a median (IQR) 90 percent (86% to 96%) of relevant sentences, pertinent fragments had been highlighted by the system; exact matches were unreliable (median (IQR) 52 percent [32% to 73%]). A median 48 percent of solutions were fully correct, but performance varied greatly across data elements (IQR 21% to 71%). Using ExaCT to assist the first reviewer resulted in a modest time savings compared with manual extraction by a single reviewer (17.9 vs. 21.6 hours total extraction time across 75 randomized trials). Conclusions. Using ExaCT to assist with data extraction resulted in modest gains in efficiency compared with manual extraction. The tool was reliable for identifying the reporting of most data elements. The tool’s ability to identify at least one relevant sentence and highlight pertinent fragments was generally good, but changes to sentence selection and/or highlighting were often required.
Стилі APA, Harvard, Vancouver, ISO та ін.
Також вас можуть зацікавити розширені добірки на тему "Proportional machines" для конкретних типів джерел:
Статті в журналах Дисертації Книги
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії