Miracle-dz/UniFAR-FTUs huggingface dataset:
Control of a statcom with supercapacitor energy storage

STATCOM (STATic COMpensator) has been used in electrical power systems as a shunt-connected compensator for voltage support and to improve power quality. Compared with the conventional compensators such as the synchronous condenser and the SVC (Static Var Compensator), the STATCOM has a faster speed of response to deal with dynamic and transient impacts. Although the STATCOM is capable of reactive power support to improve power quality, the ability to support real power is limited due to the insufficient energy storage capability of the conventional DC-link capacitor. Therefore, the application of the STATCOM to improving power system stability has been limited. This thesis proposes a solution to enhance the performance of the STATCOM by adding supercapacitor energy storage to the DC-link of the conventional STATCOM. With the fast charge/discharge characteristics of the supercapacitors, the enhanced STATCOM can absorb and inject real power to the ac power grid virtually instantaneously. The control design of the STATCOM based on a vector control strategy is presented, including the design of an instantaneous reactive power controller based on a small-signal model of the ac power system. The control design of the supercapacitor energy storage system (SCESS) based on small-signal models of the de-to-de converter is documented. The STATCOM and the SCESS are controlled together using a feed-forward control technique. In addition, this thesis also proposes that the enhanced STATCOM can be applied to reduce instability and tripping due to the rate of change of frequency (ROCOF) protection devices caused by large load impacts. The amount of the energy required for the enhanced STATCOM to maintain the stability of the system is also discussed.
Recovery of a high pulse rate spark gap switch

A study of purged spark-gap recovery at high pulse rates is reported. This work was part of an evaluation of an innovative approach for configuring the flow channel of a high-pulse-rate spark gap to control unsteady flow processes so that recovery can be near 100% and very repeatable. The switch and purge-flow-channel geometry are configured to utilize the unsteady flows and pressure disturbances in order to augment recovery. Tuned unsteady flow is used to provide purging of the hot gas residue at an adequate distance from the spark gap while simultaneously restoring the gas density between the electrodes to the initial values at the time of subsequent pulses. It is found that the unsteady fluid dynamic model provides a very good description of the recovery process for a high-pulse-rate spark gap. The model predictions show very good agreement with data from high-voltage recovery tests. The modeling and tests were used to evaluate the tuned gap concept, specify a test switch design, and characterize operation at high repetition frequencies. The tuned unsteady-flow configuration operated as expected, with full recovery of the test spark gap demonstrated at pulse rates to approximately 2500 Hz. <<ETX>>
Continuous Performance Testing in Virtual Time

We introduce the notion of performance unit testing which allows developers to explore performance characteristics and detect potential performance problems continuously throughout the development of a software system. Our ideas are embodied in PerfMock, which extends a well-established object mocking framework so that each mock object can be configured with a performance model for predicting the time taken to process each message it receives. PerfMock executes tests in virtual time. This allows performance to be evaluated much more quickly than running a full system performance test, making it possible to test performance continuously, as part of a unit test suite. We demonstrate the core features of PerfMock and show how it can be used to support a process of iterative refinement, whereby models can be improved when more about the actual performance of the objects being mocked becomes known, e.g. by building models from production data. We show that even very simple performance models used early on in the development process can provide useful information for estimating both absolute execution times and the effects of changes in functionality and/or design. The iterative approach we support has the pleasing property that as the system evolves, more decisions are made and more data is collected meaning that we can refine our models, and predicted and actual performance gradually converge.
MINERÍA DE USO DE WEB PARA PREDICCIÓN DE USUARIOS EN LA UNIVERSIDAD

This work presents the techniques, tools and strategies of web mining. Focus in analysis, processing and prediction of human and organizations behavior, based in access and use of web, in order to do some operation. The web mining is a process of identification, extraction of automatic information from web. In this work we use the technique of rules association from web using mining. As result, we present the algorithm Apriori using the rules association to determine the behavior of users and professors form this university when they access and extract and kind of information.
İŞ YÜKÜ, İŞ KONTROLÜ VE TÜKENMİŞLİK İLİŞKİSİ

Bu calismanin amaci, is yukunun, is kontrolunun ve bu iki degisken arasindaki iliskinin tukenmislik uzerindeki etkilerini incelemektir. Bu amacla, Antalya Manavgat’ta faaliyet gosteren bes yildizli bir otelden anketler araciligiyla veriler toplanmistir. 137 anket analizlerde kullanilmistir. Calismanin sonuclari, is yukunun, is kontrolunun ve bu iki degisken arasindaki iliskinin, tukenmislik uzerinde etkili oldugunu gostermistir. Ayrica, farkli is yuku ve is kontrolu oranlarina sahip gruplar arasinda tukenmislik acisindan anlamli farkliliklarin oldugu belirlenmistir. Calismanin iki onemli kisiti bulunmaktadir. Ilki, arastirmanin sadece bir otel isletmesinde yapilmasindan dolayi calisma sonuclarinin genellenememesidir. Ikinci olarak, arastirmada veriler “kendi kendini degerlendirme” yontemi kullanilarak toplanmistir. Bu nedenle diger bir sinirlilik, ortak yontem varyansidir.
Self-excited aerodynamic unsteadiness associated with passenger cars

Passenger cars are bluff bodies and are prone to unsteady phenomena with scales comparable to the scale of the vehicle itself. This type of large-scale, self-excited unsteadiness is the subject of the present work. Aerodynamic unsteadiness can be important for two reasons. It can cause unsteady pressures and forces on the car and it can impact the time-averaged flow through the generation of Reynolds stresses. A range of parametric two-dimensional bodies have been used in the development of novel experimental techniques and analyses and for CFD validation. Detailed investigations have been undertaken on the Ahmed model and on models of a Rover 200 passenger car in wind tunnels at Durham and at MIRA at scales of up to 40%. A method was developed which makes it possible to visualise periodic flow structures from measurements made sequentially in the wake or on the model surface. Unsteady flows for fastback passenger cars were found to be much less periodic than for two-dimensional vortex shedding cases. Pressure fluctuations were significantly lower on the model surface than in the wake resulting in limited unsteady forces. Unsteady flow structures, Strouhal numbers and levels of unsteadiness were similar for the Rover 200 model with and without a backlight spoiler and for the Ahmed model, indicating that sharp corners do not have a dominant effect on unsteadiness. Two principal unsteady structures were observed in the wake of the fastback shapes. A structure was observed at Strouhal numbers around 0.1 involving the alternate strengthening of the two c-pillar vortices in an antisymmetric mode. At Strouhal numbers in the range 0.3 to 0.6 an unsteady structure was observed consisting of the oscillation of the strength of the two c-pillar vortices in a symmetric mode. At the same time the location of the vortices oscillates in the vertical direction.
Multiple antenna systems : channel capacity and low-density parity-check codes.

The demand for high data rate wireless communication systems is evident today as indicated by the rapid growth in wireless subscribers and services. High data rate systems are bandwidth intensive but bandwidth is an expensive and scarce commodity. The ability of future wireless systems to efficiently utilise the available bandwidth is therefore integral to their progress and development. The wireless communications channel is a harsh environment where time varying multipath fading, noise and interference from other users and systems all contribute to the corruption of the received signal. It is difficult to overcome these problems and achieve the high data rates required using single antenna technology. Multiple-input-multipleoutput (MIMO) systems have recently emerged as a promising technique for achieving very large bandwidth efficiencies in wireless channels. Such a system employs multiple antennas at both the transmitter and the receiver. These systems exploit the spatial dimension of the wireless channel to achieve significant gains in terms of capacity and reliability over single antenna systems and consequently achieve high data rates. MIMO systems are currently being considered for 3rd generations cellular systems. The performance of MIMO systems is heavily dependent on the environment in which the system is utilised. For this reason a realistic channel model is essential for understanding the performance of these systems. Recent studies on the capacity of MIMO channels have focused on the effect of spatial correlation but the joint effect of spatial and temporal correlation has not been well studied. The first part of this thesis proposes a new spatially and temporally correlated MIMO channel model which considers motion of the receiver and nonisotropic scattering at both ends of the radio link. The
SACHa: Self-Attestation of Configurable Hardware

Device attestation is a procedure to verify whether an embedded device is running the intended application code. This way, protection against both physical attacks and remote attacks on the embedded software is aimed for. With the wide adoption of Field-Programmable Gate Arrays or FPGAs, hardware also became configurable, and hence susceptible to attacks (just like software). In addition, an upcoming trend for hardware-based attestation is the use of configurable FPGA hardware. Therefore, in order to attest a whole system that makes use of FPGAs, the status of both the software and the hardware needs to be verified, without the availability of a tamper-resistant hardware module.In this paper, we propose a solution in which a prover core on the FPGA performs an attestation of the entire FPGA, including a self-attestation. This way, the FPGA can be used as a tamper-resistant hardware module to perform hardware-based attestation of a processor, resulting in a protection of the entire hardware/software system against malicious code updates.
Building Personal Learning Networks through Event- Based Social Media: a Case Study of the SMiLE Project

In this paper we report on early findings of our SMiLE project which is evaluating how effective various online social networking channels can be in supporting how people network and learn from a major ‘live’ conference. The event took place at the University of Southampton in March 2012. We consider the dynamics of the relation- ship between ‘real’ and ‘virtual’ communities in the development of personal learning networks, for example how social networking impacts upon participants’ interaction and engagement before, during and after the event as the community of practice de- velops. Assessing the impact of social networking activity on ‘real world’ outcomes has historically been a difficult task, but we argue that recent developments in social network visualisation and analysis now enable valuable insights to be generated for the benefit of both event organisers and attendees seeking to build their subject knowledge and extend their networks. We begin with a brief review of networking theory and the emerging role of the online backchannel at ‘live’ events, before describing the approach we took to the col- lection and analysis of social media data from the CAA Conference. We then discuss the implications of our findings for people looking to build learning networks through the increasingly blurred boundaries of ‘real’ and ‘virtual’ networks. We conclude by highlighting some lessons learned and possible directions for future research. Our findings also have relevance to the PLE conference itself – which this year has the added dynamic of two face to face locations for the conference operating at the same time to pose new multi-channel communication and learning challenges for partici- pants.
Short-Term Price Forecasting by Using ANN Algorithms

With deregulation much attention is given to electricity price forecasting. Some of the factors which affect forecast are day of the week, weather, season, hour of the day, year, and special days. In general, the main factor which drives the electricity price is power demand. Here, ANN algorithms i.e. Bayesian Regularization, Levenberg Marquardt back propagation & Scaled Conjugate Gradient algorithms has been applied in short-term price forecasting that is, the one hour-ahead forecast of the electricity price using MATLAB R14a. The simulation results have shown accurate one hour ahead forecasts.
Repairing learned knowledge using experience

Explanation-based learning occurs when something useful is retained from an explanation, usually an account of how some particular problem can be solved given a sound theory. Many real-world explanations are not based on sound theory, however, and wrong things may be learned accidentally, as subsequent failures will likely demonstrate. In this paper, we describe ways to isolate the facts that cause failures, ways to explain why those facts cause problems, and ways to repair learning mistakes. In particular, our program learns to distinguish pails from cups after making a few mistakes.
The Surface Warfare community's 360-degree feedback pilot program : a preliminary analysis and evaluation plan

Abstract : The system known as 360-degree feedback, also called multi-source or multi-rater feedback, is a development program that provides a recipient with feedback from supervisors, peers, and subordinates. There is currently no institutionalized, Navywide 360-degree feedback program for leadership development. Due to widespread civilian acceptance and to the success of the 360-degree program for the Navy s flag officers, the 2004 Surface Warfare Commanders Conference recommended a pilot program for 360-degree feedback be tested on a portion of the Surface Warfare Officer community. Results of the pilot program will be used to inform decisions on implementation of a Navy-wide 360-degree feedback program. The objectives of this thesis were to review the research evidence in the literature on the effectiveness and best practices of 360-degree programs and to identify general program evaluation techniques. The thesis then presents a conceptual analysis of the Navy pilot program and makes recommendations for modifications to the program based on comparisons with empirical research evidence and identified best practices of 360-degree programs. The thesis concludes by developing some guidelines and recommendations for a program evaluation plan that can be used to assess or revise the pilot program during and after its implementation.
Modelling and testing object-oriented communication services with temporal logic

These Ecole polytechnique federale de Lausanne EPFL, n° 2141 (2000)Faculte informatique et communicationsInstitut de systemes de communicationLaboratoire pour les communications informatiques et leurs applications 1Jury: Pierre-Alain Etique, Thierry Labbe, Andre Schiper, Alain Wegmann Public defense: 2000-3-24 Reference doi:10.5075/epfl-thesis-2141Print copy in library catalog Record created on 2005-03-16, modified on 2017-05-12
Drone-Assisted Aerial Surveys of Large Animals in Siberian Winter Forests

There are two main reasons for monitoring the population of forest animals. First of all, regular surveys reveal the real state of biodiversity. Second, they guarantee a prompt response to any negative environmental factor that affects the animal population and make it possible to eliminate the threat before any permanent damage has been done. The research objective was to study the potential of drone planes equipped with thermal infrared imaging cameras. Drone planes proved effective in covering large areas, while thermal infrared cameras provided accurate statistics in the harsh winter conditions of Siberia. The research featured the population of the European elk (Alces alces), which is gradually deteriorating due to poaching and deforestation. The surveyed territory included the Salair State Nature Reserve in the Kemerovo Region, or Kuzbass (Russia). The authors developed an effective methodology for processing the data obtained from drone-mounted thermal infrared cameras. The research provided reliable results concerning the changes in the elk population on the territory in question. The use of drone planes proved an effective means of ungulate animal survey on large areas of Siberian winter forests.
Tribological behavior of dual and triple particle size SiC reinforced Al‐MMCs: a comparative study

Purpose – The aim is to study the tribological behavior of dual particle size (DPS) and triple particle size (TPS) SiC reinforced aluminum alloy‐based metal matrix composites – MMCs (Al/SiCp MMC). Design/methodology/approach – Al‐MMCs with DPS and TPS of SiC were prepared using 20 wt% SiC and developed using stir‐casting process. The TPS composite consist of three different sizes of SiC and DPS composite consist of two different sizes of SiC. The tribological test was carried out using a pin‐on‐disc type tribo‐test machine under dry sliding condition.Findings – The TPS composite exhibited better wear resistance properties compared to DPS composite. It is anticipated that when a composite is integrated with small, intermediate and large SiC particle sizes (which is known as TPS) within the same composite could be an effective method of optimizing the wear resistance properties of the developed material.Practical implications – This study provides a way to enhance the tribological behavior of automotive trib.
Research on Interaction Tracking between Community Discovery and theme Evolution Based on DBLP Scientific Research Cooperation Network

To address the shortcomings of the evolution of the fragmentation theme and the evolution of the network structure itself in the cooperation network, this paper introduces the ideas and techniques of complex network research. It firstly discovers the whole time-slice network, and then introduces BLPA (Balanced Label Propagation Algorithm) to extract the mobile author nodes and the corresponding community theme and the mobile author node theme based on community discovery. A research method combining vertical theme distribution and horizontal theme evolution is designed to analyze the interaction evolution mechanism or law between theme evolution and community evolution. The experiment found that there are theme differences between different communities in the same time-slice, the mobility of co-workers tends to be dispersed, the mobile author nodes guide the theme change, and the theme evolution driven by community evolution is in line with the overall theme evolution trend. This method makes use of complex network related technologies to explore the intrinsic dynamic mechanism of community evolution, community theme evolution and evolution on DBLP datasets, which is realistically feasible.
SISTEMA DE ADQUISICIÓN DE IMÁGENES DE RANGO CON BASE EN ESTÉREO-ACTIVO A RANGE IMAGE ACQUISITION SYSTEM BASE ON ACTIVE-STEREO

In the present work, we describe a low cost active system to acquire range images implemented on MATLAB®. The system combines parameter estimation techniques when two views are provided (uncalibrated methods are considered as well as calibrated methods). We start by defining an uncalibrated system where camera orientations and positions are mainly unknown. After capturing a calibration rig by two uncalibrated cameras, we can estimate the fundamental matrix F and the two camera matrices P1 and P2. This matrices combined establish the spatial configuration of the setup and other relevant parameters. To acquire real objects, we constrain the search area for finding correspondences in two views by simply projecting a line onto the object. Since two views of the object are available, no considerations about calibration and position estimation of the structured light source are necessary. Nevertheless, considerations about noisy estimation of correspondences are necessary to assess the system's accuracy.
Performance Evaluations of a Novel Prototype of High Frequency Non-Contact Power Transformer

In this paper, a practical implementation to reduce leakage flux of a high-frequency inverter based non-contact type power transformer composed of EE-shape ferrite cores is presented for key technology of the next generation medical use X-ray CT scanner system Design consideration for the unique structure of the non-contact power transformer with 900mm in diameter is also introduced The complete non-contact transformer is actually arranged by several blocks of the magnetic circuit assembled by using 10 small EE shape cores with 120mm in length It is experimentally and analytically discussed from a reduced leakage flux viewpoint related to its inductively coupling coefficient A practical method to lower the leakage flux is described based on effective Copper-Sheet-Treatment placed on EE shape ferrite cores of magnetic Circuit.
Análisis de densidad de energía en placas usando métodos aproximados

En este trabajo se presentan tres soluciones aproximadas de la distribucion de la densidad de energia en placas sujetas a excitaciones armonicas. Las soluciones son obtenidas considerando una aproximacion de onda plana en la ecuacion del fl ujo de energia en placas. Los metodos de Galerkin, minimos cuadrados y Ritz son usados para resolver esta ecuacion. La distribucion de la densidad de energia es analizada en placas cuadradas de aluminio simplemente apoyadas con 1 m de longitud y 1 mm de espesor. Se consideraron dos diferentes frecuencias de excitacion (239 Hz y 487 Hz) y cuatro magnitudes del factor de perdida (0.01, 0.05, 0.10 y 0.20) en las placas. Los resultados obtenidos usando las soluciones aproximadas concuerdan aceptablemente con las soluciones exactas reportadas en la literatura con un error relativo menor del 10%. Ademas, las soluciones propuestas son sencillas y faciles para usar en la prediccion aproximada de la distribucion de la densidad en energia en placas
Dual-Band Defected Ground Structure Resonators Wireless Power Transfer System Connected to Voltage-Doubler Circuit

Recently, research on multiband wireless power transfer (WPT) systems has drawn attention high efficiency in the air with a small package of WPT size for the possible bio-related application. However, the WPT system itself is not complete without complementary circuit to convert the received RF power to DC. Thus, this paper presents a design method of integrating a predesigned dual-band WPT system to a voltage-doubler (VD) without external circuit configuration. The method proved to be working as experiment RF-DC conversion efficiency recorded to be 35.2% and 37.9% in both bands, respectively with 20 mm working distance through skin, −1.27% and −1.6% dropped from air condition.