Miracle-dz/UniFAR-FTUs huggingface dataset:
The Current Status and Direction in Knowledge Management Architecture

This paper investigates knowledge management architecture which is related to the efficient storage, search, and retrieval of knowledge. It is important considerations that should be taken account in any knowledge management system. This study reviews literature and practices of the theory of current status of knowledge management architecture (KMA). Based on the review of the current practice, the characteristics and emphasis of the KMA applications are identified. It tries to suggest how the KMA should facilitate for effective and desirable directions of the KMA.
LVSEP Analysis of Phosphopeptides in Dynamically PVP-Coated Capillaries and Microchannels

To achieve highly sensitive analyses of phosphopeptides with simple experimental procedures in capillary electrophoresis (CE) and microchip electrophoresis (MCE), large-volume sample stacking with an electroosmotic flow pump (LVSEP) was performed in dynamically poly(vinyl pyrrolidone) (PVP)-coated capillaries to suppress the electroosmotic flow. In the analysis of monophosphopeptide (MPP) from bovine β -casein, good enrichments were attained with the sensitive enhancement factor (SEF) of 260 and 400 in CE and MCE, respectively, by using 0.2% PVP in 20 mM HEPES buffer (pH 9.0) in LVSEP.
Ćuk-Buck Converter for Standalone Photovoltaic System

This paper presents MPPT converter for battery charger. The converter combines both ćuk and buck converters to extract the maximum power from the sun while supplying a controlled constant current/voltage to the battery. The topology uses two control signals instead of one control signal; one for tracking the maximum power point, another for charging the battery providing constant current/voltage to the battery. The advantage of this converter is to exploit the maximum power of the PV array avoiding battery damage caused by variable MPPT voltage. The effectiveness of the proposed converter was tested in simulation in various operating conditions.
Quantifying Early-Age Stress Development and Cracking in Low Water-to-Cement Concrete: Restrained-Ring Test with Acoustic Emission

Early-age cracking has been found to occur in some concrete bridge decks, slabs, and pavements when the volumetric changes associated with drying, hydration, and temperature reduction are prevented. While free-shrinkage tests can quantify length change, they may not always be sufficient for detecting materials that are prone to cracking, since the potential for cracking is influenced by complex interactions of strength gain, stiffness development, creep, shrinkage, the degree of restraint, and toughness. The simplicity of the ring test enables it to be used as a comparative test to screen potential mixture designs. From the use of this test, AASHTO developed a provisional standard ring test that establishes specimen geometry; however, the provisional standard does not provide an approach for quantifying stress development or indicating how close a specimen may be to failure. Described is a simple stress solution for quantifying the results of the ring test. Issues related to ring and free-shrinkage specimen geometries are discussed to improve the fundamental understanding of the information provided by the ring test. Also described is how elastic stress and actual stress can be compared to measure the stress relaxation in a material. To better illustrate the microcracking and visible-crack development process, acoustic-emission testing was performed. These experiments indicated that specimens with a higher level of restraint exhibited more microcracking as a part of the stress relaxation process.
Development of a body force model for centrifugal compressors

This project is focused on modeling the internal flow in centrifugal compressors for the purpose of assessing the onset of rotating stall and surge. The current methods to determine centrifugal compressor stability limits are based on empirical data and often, experiments. Unsteady full wheel simulations have become feasible due to the increase in computation power but the prediction of the stability limit still remains a challenge. The presented methodology is based on the idea of body forces and a blade passage model suitable for centrifugal compressors is derived. Previous work has shown that blade passage models are capable of capturing the response to inlet flow distortions and the onset of instability in axial compressors. In this thesis, a blade passage model is developed for centrifugal compressors with the goal of capturing the three-dimensional through-flow computed by steady RANS simulations. The model consists of three main elements, a normal force model, a viscous parallel force model, and a blade metal blockage model. The work demonstrates the model’s capabilities on a radial impeller with prismatic blades where the total-to-static pressure rise coefficient and stage loading coefficient are in agreement with RANS calculations within 6.75% and 5%, respectively. While the model definition is shown to be consistent with other blade passage models for axial compressors, its application to a transonic axial compressor rotor and a high-speed centrifugal compressor stage revealed numerical convergence problems. It is thought that the model derivation and definition are sound and that these issues are due to implementation errors. The methodology and related modeling process are investigated step by step for three-dimensional blade geometries and, where applicable, verified with direct numerical calculation. The model limitations and potential implementation error are discussed at length so as to guide future work required to complete the demonstration of this blade passage model for axial and centrifugal compressors with three-dimensional blade shapes. Thesis Supervisor: Zoltán S. Spakovszky Title: Professor of Aeronautics and Astronautics
Methodology for Preconcentration and Determination of Silver in Aqueous Samples using Cloud Point Extraction

For the selective extraction of silver, a cloud point extraction (CPE) procedure was developed. After synthesizing the solvation species through the reaction of silver ions with 2, 4-dimethyl pentane-3-one (2,4 DMP), the salting-out agent (0.4 mol L-1 NaNO3) was added at 35 °C and, after 10 min, Triton X-114 was used to separate silver ions from aqueous solution. The type and quantity of salting-out agent, silver ion, temperature, heating time, and surfactant volume were all examined as important factors determining the CPE. The analytical curve in the 0.1-100 μg L-1 Ag range was straight at optimal conditions. The detection limit (LOD), quantification limit (LOQ), and enrichment factor (E) were 0.05 µg L-1, 0.15 µg L-1, and 200, respectively. The relative standard deviation (RSD) was estimated as 0.2-3.9% (n = 5) in relation to 1, 40, and 80 μg L-1 Ag. Flame atomic absorption spectrometry and spectrophotometry exploiting dithizone were used to assess the CPE accuracy. The proposed approach was then applied to river water, rain water and sand samples.
Cylindrical phased array with adaptive nulling using eigen‐correlation technique

In this research work, eigen‐correlation matrix based technique is developed for cylindrical antenna array to generate main beam and nulls simultaneously. The array complex weights (amplitude and phase) computed using the developed technique are used for single‐beamforming, multi‐beamforming, and beamforming with nulls steering simultaneously. The limitations of null steering range are investigated for different surface deformations of the cylindrical antenna array. The effects of surface deformations for different cylindrical radii on peak gain of main beam, half‐power beamwidth, first‐null beamwidth, and sidelobe level is also investigated. It is concluded that the developed eigen‐correlation matrix based technique for cylindrical antenna array can be used for desired main beam generation and nulls steering simultaneously. The MATLAB, CST, and measurement validation of eight elements microstrip cylindrical phased array for single/multi‐beams steering and adaptive nulling capability is demonstrated. This in turn makes the cylindrical phased array with adaptive nulling, a potential candidate suitable for use on fuselage portion of aircraft, airport surveillance radars, and mobile communication applications.
Small‐size WWAN tablet computer antenna with distributed and lumped parallel resonant circuits

The technique of embedding a distributed parallel resonant circuit (PRC) and a lumped PRC, respectively, to enhance the bandwidths of the lower and upper bands of a small‐size tablet computer antenna to cover the WWAN operation in the 824–960 and 1710–2170 MHz bands is presented. With the proposed technique, the antenna occupies a small volume of 40 × 10 × 3.8 mm3 only and can mainly be disposed on a thin FR4 substrate of 40 × 10 mm2. The antenna comprises a feeding portion, a long shorted strip, and an antenna ground. The shorted strip is short‐circuited to the antenna ground, which is then connected to the display ground in the tablet computer. A lumped PRC and a distributed PRC are added at the front and open ends of the feeding portion, respectively. The two PRCs, respectively, generate a parallel resonance at the high‐frequency tails of the first two resonant modes at about 900 and 1800 MHz contributed by the shorted strip to result in additional resonances occurred near the two resonant modes, thereby resulting in additional resonant modes excited in the desired antenna's lower and upper bands. This behavior greatly increases the operating bandwidths of the antenna's lower and upper bands, without additional resonant elements needed. Hence, small size for the proposed WWAN antenna is obtained. Details of the proposed antenna and the bandwidth enhancement techniques applied therein are presented. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1348–1353, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26811
Prevalence and Concentration of Escherichia coli O157:H7 in Cattle, Products, and the Environment in the United States of America: A Meta-Analysis Study

Shiga toxin-producing Escherichia coli O157:H7 are bacterial pathogens that cause foodborne infections in humans. The objectives of this study were to find the pooled prevalence and concentration of Escherichia coli O157:H7 in cattle, hides, carcass, and the environment in the United States of America using meta-analysis. The PRISMA and MOOSE research protocols were employed in the methodology. Weighted effect size was calculated using MetaXL software. A total of 1737 publications were screened, out of which 53 were selected for the final analysis. The pooled prevalence in feedlot cattle was 10.96% (95% CI: 4.2-18.8%). In dairy cattle a pooled prevalence of 1.5% (95% CI: 0.11-3.5%) was observed. The prevalence between feedlot and dairy cattle was significantly different (p<0.05). The herd prevalence in combined feedlot and dairy cattle was 31.7% (95% CI: 10.2-55.5%). Hide and carcass samples’ pooled prevalences were 54.7% (95% CI: 41.7-67.5%) and 21.3% (95% CI: 9.7-34.2%), respectively. Prevalence of environmental samples was 8.1% for produce (95% CI: 0-29.6%), 4.6% for watershed and sediment samples (95% CI: 0-12.2%), and 2.4% for water taken from troughs (95% CI: 0.39-5.1%). Significant difference was observed in individual, herd, and environment prevalence between regions (χ2 =903.14, p=0.0000; χ2 =11.06, p=0.0039; χ2 =13.59, p=0.0004, respectively). E. coli O157:H7 concentrations were highest in feces (900- 300,000 cfu/g), followed by hides (5-9,800 cfu/100 square cm), and carcass (1-189 cfu/100 square cm). At least one supershedder exists in a herd. The findings in this study showed that Escherichia coli O157:H7 serotype is widespread in feedlots, herds, hides, and carcass in the United States of America necessitating appropriate measures to prevent human illnesses. Improving management programs in cattle herds, reduction of environmental contamination, and hygienic slaughter practices are targets of intervention.
Modeling and Simulation of Swarm Intelligence Algorithms for Parameters Tuning of PID Controller in Industrial Couple Tank System

Industrial tank system is widely used in consumer liquid processing and chemical processing industry. In liquid-based product manufacturing system, one of the main components consists of an industrial tank. This paper explores the applications of two swarm intelligence algorithms in optimizing the PID controller parameters. These swarm intelligence algorithms are Particle Swarm Optimization (PSO) and Firefly Algorithm (FA). Each agent of the swarm intelligence will represent a possible solution of the problem where each dimension corresponds to the PID controllers parameters. Result obtained shows that there are potential in improving these algorithms to replace the conventional way of obtaining PID controllers parameters
Flux and Speed Estimation Based on the Extended State Observer for Speed Sensorless Control of Indirect Field Oriented Induction Motor Drives

A flux observer based on the extended state observer (ESO) is proposed for rotor flux estimation and speed identification of indirect field oriented induction motor drives system. The uncertain component including rotor resistance and speed in the stator current equation is extended to a new state, the ESO is then constructed. By the current estimate error, the uncertain component convergences to its actual value and the accurate rotor flux, speed and the rotor time constant are obtained. The accuracy of the ESO independent the rotor resistance and load torque variations, simulations under high and low speed show that the proposed method achieves prefect robust, and the validity and practicability is verified by simulation results.
A hybrid algorithm for fast detection and classification of voltage disturbances in electric power systems

To minimize the adverse impacts of power quality disturbances on the electric power supply as well as on the customer equipment, there is clearly a need for detection and classification of such problems. In this paper, a fast detection algorithm for power quality disturbances is presented. The proposed method is a hybrid of two algorithms, abc–0dq transformation and 908 phase shift algorithms. The proposed algorithm is fast and reliable in detecting most voltage disturbances in power systems such as voltage sags, voltage swells, interrupts, flicker, harmonics, etc. In the proposed approach, the three-phase utility voltages are sensed separately by each of the algorithms. These algorithms are combined to explore their individual strengths for a better performance. When a disturbance occurs, both algorithms work together to recognize this distortion and send trip signals to static transfer switches. This control method can be used for critical loads protection in case of utility voltage distortion. Simulation and analysis results obtained in this study illustrate high performance of the strategy in different single-phase and three-phase voltage distortions.
Dijkstra’s Algorithm without the distributivity axiom: a proof of correctness in Agda

Dijkstra’s Algorithm is typically presented as operating on graphs with numeric arc weights, but a more general form of the algorithm exists that operates on graphs where arc weights are drawn from a large class of semirings. In this setting, standard correctness proofs rely on the distributivity property of semirings to establish that the algorithm computes globally optimal path weights over every path from a single source node to all potential destinations, a process which can be interpreted as ﬁnding a ﬁxed point for a certain matrix equation. We present a mechan-ised proof that Dijkstra’s Algorithm can solve these matrix equations even after weakening the semiring axioms so that distributivity does not hold. Fixed points to matrix equations for non-distributive algebras can be interpreted as representing ‘locally optimal’ path weights. We use Agda for our implementation and proof, making use of dependent types and some of Agda’s more cutting edge features—such as induction-recursion—to structure our algorithm and correctness proof.
Enclave-Based Secure Programming with JE

Over the past few years, major hardware vendors have started offering processors that support Trusted Execution Environments (TEEs) allowing confidential computations over sensitive data on untrusted hosts. Unfortunately, developing applications that use TEEs remains challenging. Current solutions require using low-level languages (e.g., C/C++) to handle the TEE management process manually – a complex and error-prone task. Worse, the separation of the application into components that run inside and outside the TEE may lead to information leaks. In summary, TEEs are a powerful means to design secure applications, but there is still a long way to building secure software with TEEs alone.In this work, we present J E, a programming model for developing TEE-enabled applications where developers only need to annotate Java programs to define application-level security policies and run them securely inside enclaves.
SHREC 2019: Matching Humans with Different Connectivity

Objects Matching is a ubiquitous problem in computer science with particular relevance for many applications; property transfer between 3D models and statistical study for learning are just some remarkable examples. The research community spent a lot of effort to address this problem, and a large and increased set of innovative methods has been proposed for its solution. In order to provide a fair comparison among these methods, different benchmarks have been proposed. However, all these benchmarks are domain speciﬁc, e.g., real scans coming from the same acquisition pipeline, or synthetic watertight meshes with the same triangulation. To the best of our knowledge, no cross-dataset comparisons have been proposed to date. This track provides the ﬁrst matching evaluation in terms of large connectivity changes between models that come from totally different modeling methods. We provide a dataset of 44 shapes with dense correspondence as obtained by a highly accurate shape registration method (FARM). Our evaluation proves that connectivity changes lead to Objects Matching difﬁculties and we hope this will promote further research in matching shapes with wildly different connectivity.
Fault isolation in distributed generation connected distribution networks

Protection of a distribution network in the presence of distributed generators (DGs) using overcurrent relays is a challenging task due to the changes in fault current levels and reverse power flow. Specifically, in the presence of current limited converter interfaced DGs, overcurrent relays may fail to isolate the faulted section either in grid connected or islanded mode of operation. In this paper, a new inverse type relay is presented to protect a distribution network, which may have several DG connections. The new relay characteristic is designed based on the measured admittance of the protected line. The relay is capable of detecting faults under changing fault current levels. The relay performance is evaluated using PSCAD simulation and laboratory experiments.
Oil Price and Real Exchange Rate Appreciation: Is there Dutch Disease in Nigeria?

Nigeria has witnessed oil windfalls for decades, however, it was presumed that revenues from oil would assist Nigeria to mark its transition from underdevelopment to industrial development. Regrettably, the high dependence on oil sector has led to deindustrialization and exchange rate appreciation. This paper studies the dynamic relationship between oil price and real exchange rate for Nigeria using annual time series data over the sample period 1970 to 2018. Our analysis is based on Autoregressive distributed lag bound testing to cointegration approach. Following the integration and cointegration tests, the results indicate that all the variables attained long run cointegrating relationship. The results also indicate that oil price, government expenditure and inflation contributes to real exchange rate appreciation, thus, confirming the existence of Dutch disease. Essentially, this is a clear evidence that Dutch disease weakens the competitiveness of the lagging sectors in Nigeria. Also, the paper identifies unidirectional causality from oil price to real exchange rate, and bidirectional causality between oil price and government expenditure, real exchange rate and inflation. This means that the oil price and inflation encourages real exchange rate appreciation. Consequently, the policy implication is to diversify the lagging sectors by investing in human resource development, basic infrastructure and tax concessions will raise the competitiveness level of the lagging sectors.
Noncontacting excitation and measurement of light structures

This paper demonstrates a new method of conducting a noncontacting vibration measurement on light structures. Although laser vibrometry provides a routine method of acquiring response data, the method of achieving noncontacting point excitation of structures remains problematic. This is the primary concern of the paper. There is understandable motivation to develop a viable noncontacting excitation method as exciting methods involve contact thereby altering the structure's in-situ properties. The method demonstrated in the paper explores the use of focused acoustic excitation. An ellipsoid cavity has been constructed which is designed to emit focused plane wave excitation over an area of 1 in. diameter, thus approximating to point excitation. The paper outlines the design and construction of the ellipsoid shell and discusses the design parameters in relation to the frequency response and footprint of the excitation. The results presented compare measurements acquired via this new method and the corresponding Frequency Response Functions obtained by the electrodynamic excitation. Significant differences are observable, largely arising from the mass loading effects associated with the standard modal testing procedures.
Getting Back to Basics: Challenging Complexity and Accountability in the Boardroom

This paper investigates the dynamics of complexity and expertise in the context of compensation committees (ccs). Drawing on semi-structured interviews, mostly with cc members and consultants, we bring to light two axes of subordination that impact the mindset of corporate governance participants, and may ultimately undermine directors’ degree of accountability to shareholders. The first axis involves cc members’ subordination to consultant expertise, which tends to be considered as an indispensable ally in dealing appropriately with the webs of complexity that allegedly characterize executive compensation. Nourished partially by the first axis, the second implies subservience to these webs of complexity, which are widely presumed and naturalized by cc members and the consulting experts they employ. One of our main contributory statements is to question the ascendancy of complexity in the boardroom, casting doubt on one of the key assumptions upon which practices and expertise in contemporary corporate governance institutions are built and promoted. We also question the extent of epistemic dependency in many compensation committees, where much of the knowledge necessary to properly operate the repertoire of practices (deemed necessary to address the problem of executive compensation determination) is not primarily in the hands of cc members, but rather in those of consultants.