3,637 research outputs found
Barrier island erosion and overwash study -- effect of seawalls. Volume 2
This is the second of a pair of reports documenting the effects of storms on beach systems
including the presence of seawalls. With the aim of simulating the effects of overwash on
barrier islands with seawalls and characterizing their response, a series of eight experiments
was conducted at the Coastal Engineering Laboratory of the University of Florida. The barrier
island was simulated by a 400 feet wide horizontal crest and an initially uniform mildly-sloped
(1:19) beach. The effects of positioning the seawall at two different locations as well as the effects
of various storm surge levels and accompanying overtopping were investigated. Experiments
were conducted with both regular and irregular storm waves. With the seawall located at the
slope break between the crest and the sloping beach of the barrier island, and the crest of the
seawall just submerged in sand, the effects on the sediment transport process were found to be
minimal. For the same position of the seawall but with the crest of the seawall raised above the
surrounding ground level, overtopping caused washover of sand indicating substantial transport
in suspension. Increased levels of overtopping tended to accentuate bed profile changes but
supress bar formation (as did irregular waves). Positioning the seawall at the Mean Sea Level
shoreline caused significant scour both immediately landward as well as immediately seaward
of the seawall. A prominent scour trough developed further seaward. The longshore bar was
highly three-dimensional. It appears that seawalls need to be located adequately landward of the
shoreline to discharge their function effectively without adverse effect to the beach. In addition,
concerns for safety warrant the presence of an adequate buffer-zone between the seawall and
the upland property. (61 pp.
Non-local quantum correlations and detection processes in QFT
Quantum detection processes in QFT must play a key role in the description of
quantum field correlations, such as the appearance of entanglement, and of
causal effects. We consider the detection in the case of a simple QFT model
with a suitable interaction to exact treatment, consisting of a quantum scalar
field coupled linearly to a classical scalar source. We then evaluate the
response function to the field quanta of two-level point-like quantum model
detectors, and analyze the effects of the approximation adopted in standard
detection theory. We show that the use of the RWA, that characterizes the
Glauber detection model, leads in the detector response to non-local terms
corresponding to an instantaneously spreading of source effects over the whole
space. Other detector models, obtained with non-standard or the no-application
of RWA, give instead local responses to field quanta, apart from source
independent vacuum contribution linked to preexisting correlations of
zero-point field.Comment: 23 page
Total harmonic distortion analysis of inverter fed induction motor drive using neuro fuzzy type-1 and neuro fuzzy type-2 controllers
Introduction. When the working point of the indirect vector control is constant, the conventional speed and current controllers operate effectively. The operating point, however, is always shifting. In a closed-system situation, the inverter measured reference voltages show higher harmonics. As a result, the provided pulse is uneven and contains more harmonics, which enables the inverter to create an output voltage that is higher. Aim. A space vector modulation (SVM) technique is presented in this paper for type-2 neuro fuzzy systems. The inverter’s performance is compared to that of a neuro fuzzy type-1 system, a neuro fuzzy type-2 system, and classical SVM using MATLAB simulation and experimental validation. Methodology. It trains the input-output data pattern using a hybrid-learning algorithm that combines back-propagation and least squares techniques. Input and output data for the proposed technique include information on the rotation angle and change of rotation angle as input and output of produced duty ratios. A neuro fuzzy-controlled induction motor drive’s dynamic and steady-state performance is compared to that of the conventional SVM when using neuro fuzzy type-2 SVM the induction motor, performance metrics for current, torque, and speed are compared to those of neuro fuzzy type-1 and conventional SVM. Practical value. The performance of an induction motor created by simulation results are examined using the experimental validation of a dSPACE DS-1104. For various switching frequencies, the total harmonic distortion of line-line voltage using neuro fuzzy type-2, neuro fuzzy type-1, and conventional based SVMs are provided. The 3 hp induction motor in the lab is taken into consideration in the experimental validations.Вступ. Коли робоча точка непрямого векторного управління стала, традиційні регулятори швидкості та струму працюють ефективно. Проте робоча точка постійно змінюється. У ситуації закритої системи виміряна інвертором опорна напруга показує вищі гармоніки. В результаті імпульс, що подається, нерівномірний і містить більше гармонік, що дозволяє інвертору створювати більш високу вихідну напругу. Мета. У цій статті представлена методика просторової векторної модуляції (SVM) для нейронечітких систем типу 2. Продуктивність інвертора порівнюється з продуктивністю нейронечіткої системи типу 1, нейронечіткої системи типу 2 та класичної SVM з використанням моделювання MATLAB та експериментальної перевірки. Методологія. Навчається шаблон даних введення-виводу, використовуючи алгоритм гібридного навчання, який поєднує у собі методи зворотного поширення помилки та методу найменших квадратів. Вхідні та вихідні дані для запропонованої методики включають інформацію про кут повороту і зміну кута повороту як отримані вхідні і вихідні коефіцієнти заповнення. Динамічні характеристики приводу асинхронного двигуна з нейронечітким управлінням порівнюються з характеристиками звичайного SVM. При використанні нейронечіткого SVM типу 2 асинхронний двигун, показники продуктивності по струму обертаючого моменту і швидкості порівнюються з показниками приводу асинхронного двигуна з нейронечітким управлінням типу 1 та традиційного SVM. Практична цінність. Продуктивність асинхронного двигуна, створеного за результатами моделювання, досліджується з використанням експериментальної перевірки dSPACE DS-1104. Для різних частот перемикання розраховуються загальні гармонічні спотворення лінійної напруги з використанням нейронечіткого управління типу 2, нейронечіткого управління типу 1 і традиційного SVM. Асинхронний двигун потужністю 3 л.с. у лабораторії враховується під час експериментальних перевірок
Barrier island erosion and overwash study - volume 1
This is the first of a pair of reports documenting the effects of storms on barrier island systems.
The present report (Volume 1) investigates storm effects on natural island conditions whereas
Volume 2 addresses the effects of seawalls. With the aim of simulating the effects of overwash
on barrier islands and characterizing their response, a series of nine experiments was conducted
at the Coastal Engineering Laboratory of the University of Florida. The barrier island was
simulated by a 400 feet wide (prototype units) horizontal crest and an initially planar (1:19)
beach. The effects of various storm surge levels and accompanying overtopping were investigated.
Experiments were conducted with both regular and irregular storm waves. Regular
waves without overtopping caused the formation of a substantial berm in the swash zone and a
prominent longshore bar offshore. Increasing degrees of overtopping resulted in substantial loss
of sand from the barrier island system. The longshore bar was considerably more subtle for the
highest water level tested (11.5 ft. above mean sea level). Simulation of a storm-surge hydrograph
with rising and falling water levels indicated that the presence of the bar tends to occur
only during a relatively steady or slowly changing water level. The experiments with irregular
waves were conducted with reasonably similar wave heights and carrier periods as those with
regular waves. The major difference was in the characteristics of the longshore bar response. In
comparison with cases with regular waves, the bar was less distinct without overtopping, subtle
with minimal overtopping and absent in cases with substantial overtopping. These experiments
seem to indicate that offshore bars are simply break-point bars which require a fairly steady
break-point and undertow (return of mass transport) for optimal formation. (Document has 84 pages.
ESAHR: Energy Efficient Swarm Adaptive Hybrid Routing Topology for Mobile Ad hoc Networks
Ad hoc networks consist of independent self structured nodes. Nodes use a wireless medium for exchange their message or data, therefore two nodes can converse directly if and only if they are within each other2019;s broadcast range. Swarm intelligence submits to complex behaviors that occur from very effortless individual activities and exchanges, which is frequently experienced in nature, especially amongst social insects such as ants. Although each individual (an ant) has little intelligence and simply follows basic rules using local information gained from the surroundings, for instance ant2019;s pheromone track arranging and following activities, globally optimized activities, such as discovering a shortest route, appear when they work together as a group. In this regard in our earlier work we proposed a biologically inspired metaphor based routing in mobile ad hoc networks that referred as Swarm Adaptive Hybrid Routing (SAHR). . With the motivation gained from SAHR, here in this paper we propose a energy efficient swarm adaptive hybrid routing topology (ESAHR). The goal is to improve transmission performance along with energy conservation that used for packet transmission In this paper we use our earlier proposed algorithm that inspired from Swarm Intelligence to obtain these characteristics. In an extensive set of simulation tests, we evaluate our routing algorithm with state-of-the-art algorithm, and demonstrate that it gets better performance over a wide range of diverse scenarios and for a number of different assessment measures. In particular, we show that it scales better in energy conservation with the number of nodes in the network
An Improvised Methodology to Unbar Android Mobile Phone for Forensic Examination
At the end of 2015, there were 4.7 billion noteworthy mobile subscribers globally, equivalent to 63% of the world’s population. Mobile phones had all the essential components or characteristics neatly fitted into a small space and designed to achieve high speeds, massive storage, and increased functionalities. Smart phones used to carry out imparting or exchanging of information such as calling, texting, Internet browsing, e-mail, photos, videos, and etc. Criminals can use smart phones for a number of activities. Namely, committing a fraud over e-mail, harassment via text messages, drug trafficking, child pornography, etc. In this research paper, We demonstrate, if a mobile phone is identified in a criminal activity and if it is locked by any one of the locking mechanisms such as pattern lock, PIN lock and password lock, then how to unlock the mobile device without data loss for forensic examination. It is a great challenge for forensic experts to extract data from a mobile phone for forensic purpose that can be used as evidence in the court of law. The experimental results show that our approach can break all kinds of pattern locks
Objective structured practical examination as a formative assessment tool for IInd MBBS microbiology students
Background: Assessment drives learning. It is well known that conventional or Traditional Practical Examination (TPE) has several limitations, especially in terms of subjectivity. In OSPE the procedures are standardized, so objectivity is ensured and also reliability maximized. Objectives of the study were to compare TPE & OSPE examination in formative assessment for IInd MBBS microbiology students on the topic culture media and to obtain feedback from students attending OSPE, and faculty.Methods: 76 students were taught about culture media and simultaneously were sensitized about OSPE and TPE, which followed the next week. Informed consent was taken. All students were randomly divided into 2 batches (TPE and OSPE) based on roll call. 71 students were tested, 33 for OSPE and 38 for TPE. Eight OSPE stations were set up with 8 culture media, plus a rest station after station 4. TPE students went for viva-voce to one examiner for same eight culture media. Both OSPE and TPE students were evaluated for a score of 20. OSPE students and the faculty were given a pre-validated questionnaire for feedback.Results: Mean scores, standard deviation (SD) and “p” values were calculated using the T-test from the scores obtained. The mean scores for OSPE and TPE were found to be statistically significant- p-value <0.01. Feedback from OSPE students & faculty was also evaluated.Conclusions: OSPE is more structured and eliminates examiner bias better, and should be practiced in formative assessments and also be introduced in summative assessments
Spin-Orbit Coupling in LaAlO/SrTiO interfaces: Magnetism and Orbital Ordering
The combination of Rashba spin-orbit coupling and electron correlations can
induce unusual phenomena in the metallic interface between SrTiO and
LaAlO. We consider effects of Rashba spin-orbit coupling at this interface
in the context of the recent observation of anisotropic magnetism. Firstly, we
show how Rashba spin-orbit coupling in a system near a band-edge can account
for the observed magnetic anisotropy. Secondly, we investigate the coupling
between in-plane magnetic-moment anisotropy and nematicity in the form of an
orbital imbalance between d / d orbitals. We estimate this
coupling to be substantial in the low electron density regime. Such an orbital
ordering can affect magneto transport
Analysis of Legacy System in Software Application Development: A Comparative Survey
Software evolution is one of the challenging issues in today’s business environment. It is necessary for the organizations, which make use of Information, and Communication Technologies will have to align their business processes to compete with global business. The existing large software systems (“legacy” systems) have never been built to cope with the current business requirement for their poor coding, design structures, logic and documentation. Moreover, Legacy applications have various problems such as lack of up to-date documentation, skilled man power, resources of the Legacy applications, and high maintenance costs. Even though the Legacy system is obsolete, it contains detailed business rules and in continuous use, because it satisfies the users' needs and forms the backbone of the information flow of organization. One of the possible solutions is to refactor or modernize those systems into a new platform. It is necessary to analyse the existing legacy system for better understanding the business logic and its functionalities. This paper analyses various techniques proposed for understanding Legacy systems in existence
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