1 |
Johnson's system of distributions and microarray data analysisGeorge, Florence 01 June 2007 (has links)
Microarray technology permit us to study the expression levels of thousands of genes simultaneously. The technique has a wide range of applications including identification of genes that change their expression in cells due to disease or drug stimuli. The dissertation is addressing statistical methods for the selection of differentially expressed genes in two experimental conditions. We propose two different methods for the selection of differentially expressed genes. The first method is a classical approach, where we consider a common distribution for the summary measure of equally expressed genes. To estimate this common distribution, the Johnson system of distribution is used. The advantage of using Johnson system is that, there is no need of a parametric assumption for gene expression data. In contrast to other classical methods, in the proposed method, there is a sharing of information across the genes by the assumption of a common distribution for the summary measure of equally expressed genes. The second method is the gene selection using a mixture model approach and Baye's theorem. This approach also uses the Johnson System of distribution for the estimation of distribution of summary measure. Johnson system of distribution has the flexibility of covering a wide variety of distributional shapes. This system provides a unique distribution corresponding to each pair of mathematically possible values of skewness and kurtosis. The significant flexibility of Johnson system is very useful in characterizing the complicated data set like microarray data. In this dissertation we propose a novel algorithm for the estimation of the four parameters of the Johnson system.
|
2 |
BAYESIAN OPTIMIZATION FOR DESIGN PARAMETERS OF AUTOINJECTORS.pdfHeliben Naimeshkum Parikh (15340111) 24 April 2023 (has links)
<p>The document describes the computational framework to optimize spring-driven Autoinjectors. It involves Bayesian Optimization for efficient and cost-effective design of Autoinjectors.</p>
|
3 |
Estrutura ANFIS modificada para identifica??o e controle de plantas com ampla faixa de opera??o e n?o linearidade acentuadaFonseca, Carlos Andr? Guerra 21 December 2012 (has links)
Made available in DSpace on 2014-12-17T14:55:11Z (GMT). No. of bitstreams: 1
CarlosAGF_TESE.pdf: 1739972 bytes, checksum: 7401db4e68ede642dc9d65e00bd935e6 (MD5)
Previous issue date: 2012-12-21 / In this work a modification on ANFIS (Adaptive Network Based Fuzzy Inference System) structure is proposed to find a systematic method for nonlinear plants, with large operational range, identification and control, using linear local systems: models and controllers. This method is based on multiple model approach. This way, linear local models are obtained and then those models are combined by the proposed neurofuzzy structure. A metric that allows a satisfactory combination of those models is obtained after the structure training. It results on plant s global identification.
A controller is projected for each local model. The global control is obtained by mixing local controllers signals. This is done by the modified ANFIS. The modification on ANFIS architecture allows the two neurofuzzy structures knowledge sharing. So the same metric obtained to combine models can be used to combine controllers.
Two cases study are used to validate the new ANFIS structure. The knowledge sharing is evaluated in the second case study. It shows that just one modified ANFIS structure is necessary to combine linear models to identify, a nonlinear plant, and combine linear controllers to control this plant.
The proposed method allows the usage of any identification and control techniques for local models and local controllers obtaining. It also reduces the complexity of ANFIS usage for identification and control. This work has prioritized simpler techniques for the identification and control systems to simplify the use of the method / Neste trabalho prop?e-se uma modifica??o na estrutura neurofuzzy ANFIS (Adaptive Network Based Fuzzy Inference System) para a obten??o de um m?todo sistem?tico para identifica??o e controle de plantas com ampla faixa de opera??o e n?o linearidade acentuada, a partir de t?cnicas lineares de identifica??o e controle. Este m?todo se baseia na metodologia de m?ltiplos modelos. Dessa forma, obt?m-se modelos lineares locais e esses s?o combinados pela estrutura neurofuzzy proposta. Uma m?trica que permite combinar adequadamente esses modelos ? obtida ap?s o treinamento dessa estrutura, resultando na identifica??o global da planta.
Para cada um desses modelos ? projetado um controlador. O controle global ? obtido a partir da combina??o dos sinais dos controladores locais. Essa mistura ? feita pelo ANFIS modificado. A modifica??o na arquitetura do ANFIS permite o compartilhamento do conhecimento adquirido pelo treinamento da estrutura empregada na combina??o de modelos locais. Assim n?o se faz necess?rio o treinamento da estrutura empregada na mistura de controladores.
Avaliaram-se as estruturas modificadas atrav?s de dois estudos de caso. Verificou-se que ? poss?vel treinar apenas um ANFIS, para a obten??o de uma m?trica que permita a combina??o adequada dos modelos lineares, v?lidos localmente, e essa estrutura, j? ajustada, pode ser aplicada na combina??o de controladores lineares, projetados para cada um dos modelos, resultando em um sistema de controle que satisfaz as especifica??es de desempenho previamente estabelecidas.
O m?todo proposto possibilita a utiliza??o de quaisquer t?cnicas de identifica??o e controle para a obten??o dos modelos e controladores locais, e a redu??o da complexidade de utiliza??o do ANFIS para identifica??o e controle. Neste trabalho priorizaram-se as t?cnicas mais simples de identifica??o e controle de sistemas de forma a simplificar a utiliza??o do m?todo
|
4 |
Modelagem de perdas com ações trabalhistas em instituições financeirasRachman, Luciano 07 August 2013 (has links)
Submitted by Luciano Rachman (lucianora@uol.com.br) on 2013-09-03T14:15:04Z
No. of bitstreams: 1
Dissertacao_Luciano_Rachman.pdf: 1167975 bytes, checksum: da1c59096eda72630b44358c1d1e0b0f (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2013-09-03T14:52:47Z (GMT) No. of bitstreams: 1
Dissertacao_Luciano_Rachman.pdf: 1167975 bytes, checksum: da1c59096eda72630b44358c1d1e0b0f (MD5) / Made available in DSpace on 2013-09-03T15:05:37Z (GMT). No. of bitstreams: 1
Dissertacao_Luciano_Rachman.pdf: 1167975 bytes, checksum: da1c59096eda72630b44358c1d1e0b0f (MD5)
Previous issue date: 2013-08-07 / As perdas trabalhistas nas Instituições Financeiras representam um valor considerável que devem ser consideradas no modelo de capital regulatório para risco operacional, segundo Basileia. A presente dissertação demonstra uma forma de mensurar o risco às quais as Instituições Financeiras estão expostas nesse tipo de perdas. Diversos tipos de distribuições são analisados conforme sua aderência tanto na frequência como na severidade das perdas. Para os valores de frequência, foi obtida uma amostra de dados real, enquanto para a severidade foram utilizados valores obtidos de relatórios de instituto de pesquisa que serviram de insumo para os cálculos de ações trabalhistas conforme legislação brasileira vigente na CLT (Consolidação das Leis do Trabalho). / According to Basel, the labor losses in Financial Institutions represent a substantial value that should be regarded in the model of regulatory capital for operational risk. This dissertation demonstrates a way to measure the risk to which Financial Institutions are exposed to in this type of loss. Several types of distributions are analyzed according to their adherence both in frequency and severity of losses. For frequency values, it was obtained a sample of actual data, whilst for the severity were used values given from reports of research institute which served as an input for the calculations of labor actions according to the present Brazilian legislation in CLT (Consolidation of Labor Laws).
|
5 |
Hydrogen systems : what contribution to the energy system? Findings from multiple modelling approaches / Systèmes à hydrogène : quelle contribution au système énergétique? Résultats de plusieurs approches de modélisationTlili, Olfa 07 November 2019 (has links)
L'hydrogène… Cet élément simple et très abondant pourrait être un contributeur clé à la transition énergétique, mais dans quelles conditions technico-économiques et politiques ? Cette thèse propose une contribution à l'évaluation de la faisabilité de pénétration de l'hydrogène dans le système énergétique, en mettant en oeuvre différents modèles qui permettent des éclairages complémentaires. Elle se concentre sur l’hydrogène bas carbone, obtenu par électrolyse de l’eau.Notre analyse multirégionale qui porte sur le contexte énergétique européen, américain, chinois et japonais (régions qui présentent des défis énergétiques contrastés) montre que les politiques énergétiques actuelles ne facilitent qu’une faible pénétration de l'hydrogène dans le système énergétique, lui permettant de réaliser environ 3% de l’effort à fournir par les quatre régions afin de limiter l’augmentation de la température à 2°C par rapport aux niveaux préindustriels. Nous soulignons dans cette thèse que l’injection d’hydrogène dans les réseaux de gaz naturel qui permet dans une certaine mesure d’éviter des fuites de méthane à fort pouvoir de réchauffement, pourrait jouer un rôle significatif dans la réalisation des objectifs de réduction des émissions de gaz à effet de serre.L'analyse des marchés de l'hydrogène a été menée en deux étapes. Tout d'abord, chaque marché (industriel ou énergétique) a été abordé individuellement afin d’établir des coûts d'entrée sur ce marché (pour les différents contextes énergétiques considérés). Ensuite, les différentes applications de l’hydrogène ont été resituées en interaction avec l’ensemble du système énergétique à travers le modèle TIMES-PT et un cas d’étude portant sur le Portugal, permettant ainsi d’examiner le potentiel de couplage entre les secteurs énergétiques rendu possible par l’hydrogène. Ces travaux ont permis de qualifier l'attractivité des différents marchés, celui de la mobilité apparaissant comme le plus favorable.Nous nous sommes ensuite intéressés aux coûts requis sur l'ensemble de la chaîne d'approvisionnement en hydrogène afin de pénétrer le marché de la mobilité.Pour ce faire, nous avons utilisé des modèles avec une maille géographique et temporelle fine (GLAES, EuroPower et InfraGis), en commençant par l’étape de production. Nous avons étudié le rôle potentiel de l'hydrogène pour la fourniture de flexibilité au système électrique dans un contexte de forte pénétration des énergies renouvelables intermittentes en France. Nos résultats montrent que l’hydrogène pourrait permettre non seulement d’éviter d’écrêter la production d’énergies renouvelables (entre 1,4 et 7,9 TWh en fonction du scénario de capacité d’interconnexion), mais pourrait aussi mettre à profit l’énergie nucléaire disponible (bas carbone donc), évitant par-là d’imposer de fortes rampes de puissances aux centrales. Cependant, une attention particulière doit être accordée au taux d'utilisation de l'électrolyseur afin de maintenir les coûts de production d'hydrogène suffisamment bas.Enfin, nous nous sommes concentrés sur l’approvisionnement de l’hydrogène, depuis les sites de production jusqu’à l’utilisation pour la mobilité, la question de l’infrastructure étant un problème majeur entravant les investissements dans l’hydrogène. Cinq filières d’approvisionnement (transport et distribution) ont été développées à la maille régionale et comparées sur le plan économique pour le cas français. Nos résultats montrent que, lors des toutes premières phases de pénétration du marché (scénario 1%), il est plus intéressant de privilégier la production décentralisée. / Hydrogen… This simple, very abundant element holds great promise to contribute to the transition towards a cleaner future energy system, but under which techno-economic and political conditions? This thesis is a contribution to the assessment of the hydrogen penetration feasibility into the energy system, using a multi-model approach. The focus is put on low-carbon hydrogen, obtained by electrolysis.Our multi-regional analysis on the European, American, Chinese and Japanese energy context (presenting contrasted energy challenges) show that, with the current energy policies implemented which result in a modest penetration of hydrogen into the energy system, hydrogen may achieve approximately 3% of the effort that needs to be done by the four regions, in order to limit the increase of the temperature to 2°C, compared to preindustrial levels. We highlight in this thesis that blending hydrogen with natural gas, and thereby avoiding methane leakages to a certain extent, may represent a significant contribution in achieving the carbon mitigation goals.The hydrogen market analysis has been carried out following two steps. First, each market (industrial and energy-related) was tackled aside in order to propose market entry costs considering the four energy contexts and investigate the timeframe of the market penetration potential. Then, the different hydrogen applications were examined within the overall energy system through the TIMES-PT model (for a Portugal case study), allowing to investigate the hydrogen potential for energy sector coupling. Based on this work, the markets attractiveness was evaluated: mobility (using fuel cell vehicles) appears to be the most favourable.Then, we tackled the required costs over the whole hydrogen supply chain in order to enter the mobility market.To do so, we used temporally and spatially resolved models (GLAES, EuroPower and InfraGis) starting with the production side where we studied the hydrogen potential role in providing the electricity system with flexibility and the impact of such electrolysis operation on the hydrogen generation costs in the context of high shares of renewable energies in France. Our results show that hydrogen can contribute to improve the flexibility of the electric system by allowing avoiding renewable curtailment (between 1.4 and 7.9 TWh depending on the interconnection capacity scenario) but also by taking advantage of nuclear plant available energy (thereby avoiding nuclear ramping), the latter ensuring a low carbon and low cost electricity provision. However, a special attention needs to be dedicated to the utilisation rate of the electrolyser, to keep the hydrogen production costs low enough.Last but not least, we focused on how to link the hydrogen production sites and its final use for mobility applications, the delivery infrastructure being a major issue hampering the hydrogen investments. Five transport and delivery pathways were geographically designed and economically assessed, for the French case. According to our findings, during the very first market penetration phases (1% scenario), it is more interesting to start with decentralised production that proved to be less expensive for the whole pathway at this stage.
|
6 |
Разработка модельного подхода к оптимальному управлению развитием стартапа в условиях цифровой трансформации экономики : магистерская диссертация / Development of a model approach to optimal management of startup development in the context of digital transformation of the economyПавленко, В. С., Pavlenko, V. S. January 2023 (has links)
Цель исследования – опираясь на теоретические и практические основы управления стартапами, разработать модельный подход для повышения эффективности управления стартапами за счет разработки и внедрения информационных систем распределения внутренних инвестиционных потоков в компаниях. Объектом исследования является архитектура малого инновационного предприятия на ранних стадиях жизненного цикла (стартап). Предметом исследования дипломной работы являются методы, инструменты и информационные системы стратегического управления развитием малых инновационных предприятий (стартапов). Научная новизна исследования состоит в разработке метода оптимального управления развитием стартапа для эффективного вливания средств к его развитию. Практическая значимость исследования заключается в применении авторских предложений по совершенствованию процесса управления развитием стартапа в условиях трансформации экономики. Эффективность рекомендаций – предложенный автором подход по эффективному управлению развитием стартапа позволит отражать состояние проектов на каждом этапе развития, находящихся в акселераторе, в тех сочетаниях, которые способны привести к возникновению синергетического эффекта между реализуемыми проектами и привести жизненные циклы акселерации и реализуемых им проектов к состоянию резонанса. / The purpose of the study is, based on the theoretical and practical foundations of start-up management, to develop a model approach to improve the efficiency of start-up management through the development and implementation of information systems for the distribution of internal investment flows in companies. The object of the study is the architecture of a small innovative enterprise in the early stages of its life cycle (startup). The subject of the thesis research is methods, tools and information systems for strategic management of the development of small innovative enterprises (startups). The scientific novelty of the research lies in the development of a method for optimal management of the development of a startup for the effective injection of funds for its development. The practical significance of the study lies in the application of the author’s proposals for improving the process of managing the development of a startup in the context of economic transformation. The effectiveness of recommendations - the approach proposed by the author for effectively managing the development of a startup will allow reflecting the state of projects at each stage of development in the accelerator, in those combinations that can lead to a synergistic effect between the projects being implemented and bringing the life cycles of acceleration and the projects it implements to a state of resonance.
|
7 |
Méthodes de rééchantillonnage en méthodologie d'enquêteMashreghi, Zeinab 10 1900 (has links)
Le sujet principal de cette thèse porte sur l'étude de l'estimation de la variance d'une statistique basée sur des données d'enquête imputées via le bootstrap (ou la méthode de Cyrano). L'application d'une méthode bootstrap conçue pour des données d'enquête complètes (en absence de non-réponse) en présence de valeurs imputées et faire comme si celles-ci étaient de vraies observations peut conduire à une sous-estimation de la variance. Dans ce contexte, Shao et Sitter (1996) ont introduit une procédure bootstrap dans laquelle la variable étudiée et l'indicateur de réponse sont rééchantillonnés ensemble et les non-répondants bootstrap sont imputés de la même manière qu'est traité l'échantillon original. L'estimation bootstrap de la variance obtenue est valide lorsque la fraction de sondage est faible.
Dans le chapitre 1, nous commençons par faire une revue des méthodes bootstrap existantes pour les données d'enquête (complètes et imputées) et les présentons dans un cadre unifié pour la première fois dans la littérature.
Dans le chapitre 2, nous introduisons une nouvelle procédure bootstrap pour estimer la variance sous l'approche du modèle de non-réponse lorsque le mécanisme de non-réponse uniforme est présumé.
En utilisant seulement les informations sur le taux de réponse, contrairement à Shao et Sitter (1996) qui nécessite l'indicateur de réponse individuelle, l'indicateur de réponse bootstrap est généré pour chaque échantillon bootstrap menant à un estimateur bootstrap de la variance valide même pour les fractions de sondage non-négligeables.
Dans le chapitre 3, nous étudions les approches bootstrap par pseudo-population et nous considérons une classe plus générale de mécanismes de non-réponse.
Nous développons deux procédures bootstrap par pseudo-population pour estimer la variance d'un estimateur imputé par rapport à l'approche du modèle de non-réponse et à celle du modèle d'imputation. Ces procédures sont également valides même pour des fractions de sondage non-négligeables. / The aim of this thesis is to study the bootstrap variance estimators of a statistic based on imputed survey data. Applying a bootstrap method designed for complete survey data (full response) in the presence of imputed values and treating them as true observations may lead to underestimation of the variance.
In this context, Shao and Sitter (1996) introduced a bootstrap procedure in which the variable under study and the response status are bootstrapped together and bootstrap non-respondents are imputed using the imputation method applied on the original sample.
The resulting bootstrap variance estimator is valid when the sampling fraction is small.
In Chapter 1, we begin by doing a survey of the existing bootstrap methods for (complete and imputed) survey data and, for the first time in the literature, present them in a unified framework.
In Chapter 2, we introduce a new bootstrap procedure to estimate the variance under the non-response model approach when the uniform non-response mechanism is assumed.
Using only information about the response rate, unlike Shao and Sitter (1996) which requires the individual response status, the bootstrap response status is generated for each selected bootstrap sample leading to a valid bootstrap variance estimator even for non-negligible sampling fractions.
In Chapter 3, we investigate pseudo-population bootstrap approaches and we consider a more general class of non-response mechanisms. We develop two pseudo-population bootstrap procedures to estimate the variance of an imputed estimator with respect to the non-response model and the imputation model approaches. These procedures are also valid even for non-negligible sampling fractions.
|
8 |
Inférence doublement robuste en présence de données imputées dans les enquêtesPicard, Frédéric 02 1900 (has links)
L'imputation est souvent utilisée dans les enquêtes pour traiter la non-réponse partielle. Il est bien connu que traiter les
valeurs imputées comme des valeurs observées entraîne une
sous-estimation importante de la variance des estimateurs
ponctuels. Pour remédier à ce problème, plusieurs méthodes
d'estimation de la variance ont été proposées dans la littérature,
dont des méthodes adaptées de rééchantillonnage telles que le
Bootstrap et le Jackknife. Nous définissons le concept de
double-robustesse pour l'estimation ponctuelle et de variance
sous l'approche par modèle de non-réponse et l'approche par modèle
d'imputation. Nous mettons l'emphase sur l'estimation de la
variance à l'aide du Jackknife qui est souvent utilisé dans la
pratique. Nous étudions les propriétés de différents estimateurs
de la variance à l'aide du Jackknife pour l'imputation par la
régression déterministe ainsi qu'aléatoire. Nous nous penchons
d'abord sur le cas de l'échantillon aléatoire simple. Les cas de
l'échantillonnage stratifié et à probabilités inégales seront
aussi étudiés. Une étude de simulation compare plusieurs méthodes
d'estimation de variance à l'aide du Jackknife en terme de biais
et de stabilité relative quand la fraction de sondage n'est pas
négligeable. Finalement, nous établissons la normalité
asymptotique des estimateurs imputés pour l'imputation par
régression déterministe et aléatoire. / Imputation is often used in surveys to treat item nonresponse. It
is well known that treating the imputed values as observed values
may lead to substantial underestimation of the variance of the
point estimators. To overcome the problem, a number of variance
estimation methods have been proposed in the literature, including
appropriate versions of resampling methods such as the jackknife
and the bootstrap. We define the concept of doubly robust point
and variance estimation under the so-called nonresponse and
imputation model approaches. We focus on jackknife variance
estimation, which is widely used in practice. We study the
properties of several jackknife variance estimators under both
deterministic and random regression imputation. We first consider
the case of simple random sampling without replacement. The case
of stratified simple random sampling and unequal probability
sampling is also considered. A limited simulation study compares
various jackknife variance estimators in terms of bias and
relative stability when the sampling fraction is not negligible.
Finally, the asymptotic normality of imputed estimator is
established under both deterministic and random regression
imputation.
|
9 |
Inférence doublement robuste en présence de données imputées dans les enquêtesPicard, Frédéric 02 1900 (has links)
L'imputation est souvent utilisée dans les enquêtes pour traiter la non-réponse partielle. Il est bien connu que traiter les
valeurs imputées comme des valeurs observées entraîne une
sous-estimation importante de la variance des estimateurs
ponctuels. Pour remédier à ce problème, plusieurs méthodes
d'estimation de la variance ont été proposées dans la littérature,
dont des méthodes adaptées de rééchantillonnage telles que le
Bootstrap et le Jackknife. Nous définissons le concept de
double-robustesse pour l'estimation ponctuelle et de variance
sous l'approche par modèle de non-réponse et l'approche par modèle
d'imputation. Nous mettons l'emphase sur l'estimation de la
variance à l'aide du Jackknife qui est souvent utilisé dans la
pratique. Nous étudions les propriétés de différents estimateurs
de la variance à l'aide du Jackknife pour l'imputation par la
régression déterministe ainsi qu'aléatoire. Nous nous penchons
d'abord sur le cas de l'échantillon aléatoire simple. Les cas de
l'échantillonnage stratifié et à probabilités inégales seront
aussi étudiés. Une étude de simulation compare plusieurs méthodes
d'estimation de variance à l'aide du Jackknife en terme de biais
et de stabilité relative quand la fraction de sondage n'est pas
négligeable. Finalement, nous établissons la normalité
asymptotique des estimateurs imputés pour l'imputation par
régression déterministe et aléatoire. / Imputation is often used in surveys to treat item nonresponse. It
is well known that treating the imputed values as observed values
may lead to substantial underestimation of the variance of the
point estimators. To overcome the problem, a number of variance
estimation methods have been proposed in the literature, including
appropriate versions of resampling methods such as the jackknife
and the bootstrap. We define the concept of doubly robust point
and variance estimation under the so-called nonresponse and
imputation model approaches. We focus on jackknife variance
estimation, which is widely used in practice. We study the
properties of several jackknife variance estimators under both
deterministic and random regression imputation. We first consider
the case of simple random sampling without replacement. The case
of stratified simple random sampling and unequal probability
sampling is also considered. A limited simulation study compares
various jackknife variance estimators in terms of bias and
relative stability when the sampling fraction is not negligible.
Finally, the asymptotic normality of imputed estimator is
established under both deterministic and random regression
imputation.
|
10 |
Some aspects of human performance in a Human Adaptive Mechatronics (HAM) systemParthornratt, Tussanai January 2011 (has links)
An interest in developing the intelligent machine system that works in conjunction with human has been growing rapidly in recent years. A number of studies were conducted to shed light on how to design an interactive, adaptive and assistive machine system to serve a wide range of purposes including commonly seen ones like training, manufacturing and rehabilitation. In the year 2003, Human Adaptive Mechatronics (HAM) was proposed to resolve these issues. According to past research, the focus is predominantly on evaluation of human skill rather than human performance and that is the reason why intensive training and selection of suitable human subjects for those experiments were required. As a result, the pattern and state of control motion are of critical concern for these works. In this research, a focus on human skill is shifted to human performance instead due to its proneness to negligence and lack of reflection on actual work quality. Human performance or Human Performance Index (HPI) is defined to consist of speed and accuracy characteristics according to a well-renowned speed-accuracy trade-off or Fitts' Law. Speed and accuracy characteristics are collectively referred to as speed and accuracy criteria with corresponding contributors referred to as speed and accuracy variables respectively. This research aims at proving a validity of the HPI concept for the systems with different architecture or the one with and without hardware elements. A direct use of system output logged from the operating field is considered the main method of HPI computation, which is referred to as a non-model approach in this thesis. To ensure the validity of these results, they are compared against a model-based approach based on System Identification theory. Its name is due to being involved with a derivation of mathematical equation for human operator and extraction of performance variables. Certain steps are required to match the processing outlined in that of non-model approach. Some human operators with complicated output patterns are inaccurately derived and explained by the ARX models.
|
Page generated in 0.062 seconds