Miracle-dz/UniFAR-FTUs huggingface dataset:
Neural Approximation for the Optimal Control of a Hydroplant with Random Inflows and Concave Revenues

We present a method for computing an approximately optimal policy for the control of a hydroelectric reservoir with random inflows and concave, piecewise linear revenues from electricity sales. Our approach uses neurodynamic programming to approximate the future value function by a neural network. Our approximation architecture, based on the feedforward network, gives very smooth approximate functions, allowing the use of a coarse discretization of the state and inflow variables in the training step of the neural functions. Our model takes into account the head variations on the turbine efficiency and assumes the water flows at a steady rate during each period of the planning horizon, while related models in the literature have made less realistic assumptions of constant head or that the natural inflows were unusable until the next period. Moreover, we extend previous results on the concavity of the expected future rewards as a function of the potential energy in the reservoir and on the structure of optimal decision rules.
Digital controller design for switchmode power converters

A thorough and systematic evaluation of different digital control design approaches is presented. The performance of the approaches is compared in terms of both the bandwidth and the phase margin of the control loop, as well as the output transient response subject to line and load step change. Furthermore, the difference of these design approaches under a lower sampling rate is studied. Best digital design approach for power converter applications is identified based on the comparison results.
THE EFFECT OF THE APPLICATION OF INFORMATION TECHNOLOGY AND STRATEGIC PARTNERSHIP ON THE FIRM PERFORMANCE OF LOGISTICS SERVICE PROVIDERS

ABSTRACT There have been conflicting results regarding the effect of the application of information technology (IT) on firm performance reported in the literature. In this study we explore the relationships between IT application, strategic partnership and firm performance for a logistic service provider (LSP). The research model developed based on the literature results and the special characteristics of the LSP and validated using the structural equation modeling method. The data for model validation are collected by questionnaire survey from LSPs operating in Taiwan. Empirical analysis of the stratified sample results show that the application of IT has a positive influence on both strategic partnerships and firm performance. The mediating effect of strategic partnership on the relationship between IT application and firm performance is positive and partially supported. The reciprocal causal hypothesis, where only strategic partnership exerts a positive influence on firm performance, is partially supported. Finally, theoretical and practical implications are also discussed.
High-stake Test Preparation Courses: Washback in Accountability Contexts

Giventhe increasing public demands for preparation courses, the purpose of this study was to discover how high-stakes testing influenced preparation courses. To achieve this end, concepts from Structuration Theory and Washback Hypothesis were employed. The study was conducted with four instructors teaching at the preparation courses for TOEFL and IELTS in Iran. An interpretive ethnographic case study was conducted through observation and field notes to gather data about how high-stakes testing affected teachers' curriculum and methodology. In order to keep observation focused and directed, University of Cambridge Observation Scheme (UCOS) was also used. The scheme was utilized to solely focus on the extent to which the course was test-oriented. The results indicated that teachers were constantly encountered with challenging questions which led to variations in their responses to tests' pressures.
Impact of Radiation on the Wall Heat Load at a Test Bench Gas Turbine Combustion Chamber: Measurements and CFD Simulation

Experimental and numerical work has been carried out to determine the wall heat load at the liner structure of a model gas turbine combustion chamber. Measured cross-sectional profiles of the velocity and temperature field inside the chamber could be used to validate various CFD calculations of the combustion flow. It turned out that only a special treatment of the thermal boundary conditions at all liner walls would actually lead to appropriate values of the wall heat flux. Radiation modeling included two radiative properties models (SG single gray gas and WSSG weighted sum of gray gases) and three radiation transport models (P1, DT discrete transfer, MC Monte Carlo). The performance of the WSGG model has been assessed with charts and the impact of the radiation on the liner wall temperature distribution has been studied. The experimental values are matched within 3% deviation with the best combination of transport and radiation property models. The radiation contributes to 20-30% of the total wall heat flux. The present approach enables Siemens PG to access the thermal design of combustors more precisely.Copyright © 2007 by ASME
Influence of static injection timing on combustion, emission and performance characteristics of DI diesel engine fuelled with honne oil methyl ester

This study is aimed to investigate experimentally the combustion, exhaust emissions and performance characteristics of a direct injection (DI) diesel engine, typically used in the agricultural sector, when fuelled with neat diesel (ND), and abundantly available but untapped honne oil methyl ester (HOME) is used in diesel engines. The static injection timing (SIT) is varied from 23 crank angle (CA) (manufacturer's specified value) to 28 CA. The combustion parameters of HOME improved as SIT increased. The brake thermal efficiency (BTE) of HOME (SIT 27–28 CA before top dead centre (bTDC)) is the highest; however, still it is less than ND. The emissions (smoke opacity (SO), CO, HC and NO x ) of HOME (SIT 23–28 CA bTDC), through out the entire load range, are dropped compared to ND. The reductions in exhaust emissions (SIT 27–28 CA bTDC) together with increase in BTE made the HOME (SIT 27–28 CA bTDC) a suitable alternative fuel for diesel fuel and thus could help in controlling air pollution.
Bubble Burst Control Using Smart Structure Sensor Actuators for Stall Suppression

Based on our previous experimental work conducted pertinent to the flow separation bubble burst control using a thin plate (hereafter burst control plate) attached to the leading-edge of laminar airfoils, the burst control plate in the current study is incorporated in the smart structure sensor actuators system on a NACA 631-012 airfoil for stall suppression, lift enhancement and drag reduction. The smart structure sensor actuators system uses a pressure transducer, a displacement sensor and a feedback controller to operate and to monitor the actuators in an autonomous mode. Note that the height of the burst control plate depends on the angular movement of the actuators located on either end of the airfoil section. Experimental studies were conducted at two different Reynolds numbers of 1.3 x 10 5 and 1.9 x 10 5 based on the airfoil chord length. The wind tunnel experiments demonstrated the effectiveness of the smart structure sensor actuators system and the burst control plate located at 6% chord-wise position (defined at the trailing-edge of the plate) of the airfoil, in that the drag is reduced, stall angle is delayed, and a significant improvement in the lift-to-drag ratio is achieved over a wide range of angles-of-attack. The feedback control approach provides a means to strengthen the vortical structures inside the separated shear layer with the overall drag of the airfoil is kept minimal. The experimental results demonstrated the application of the smart structure sensor actuators system and the burst control plate on the NACA 631-012 airfoil can be effective means of bubble burst control and airfoil stall suppression in low speed air vehicle applications.
Green Coffee Beans Classification Using Attention-Based Features and Knowledge Transfer

In recent years, people’s need for coffee beans has skyrocketed, which results in automatic coffee beans quality recognition being highlighted by researchers. In this study, a Convolutional Neural Networks-based method which has the advantage of having high local feature extraction performance was presented. The experimental results show that the proposed method could be effectively utilized to perform green coffee beans recognition it achieved an F1-score of about 97%.
Weeds Detection Networks

Non-chemical weeds control is a crucial aspect of sustainable organic agriculture. This paper explored the state-of-the-art deep learning networks applicability for weed detection and proposed a novel, simple deep learning model. The proposed network, CovWNET, is the second smallest network among the implementations compared in this study. It has roughly 1/3 times more parameters; however, it achieves 1.8% higher accuracy than the smallest network, MobileNetV2. Correspondingly, CovWNET has approximately five times fewer parameters and 2 % less accuracy than the best achieving model of DenseNet201.
A study on acoustic noise and flow rate from two tandem tubeaxial fans

Stacking two tubeaxial fans in series can simultaneously achieve fan redundancy, high airflow delivery and high packaging density. However, the impact of packing two fans together on overall noise emissions is far from well defined and much less well understood as compared to noise emission from isolated fans. This study demonstrates that spacing between two series fans has a significant impact on overall acoustic noise emissions. Using sound power measured for two tightly bolted 120 mm Nidec fans as a reference, a noise reduction of 5 dB can be achieved by separating two fans 40 mm apart when the air channel between two fans is enclosed. The overall sound power can further be reduced by nearly 3 dB when the channel between two series fans is open to ambient. The impact of open/closed channel and spacing on overall volumetric airflow is also investigated for normal operation and various fan failure scenarios. Flow degradation becomes obvious only in certain fan failure scenarios with the biggest impact observed for downstream fan failure with its fan blades locked at the maximum spacing.
On the role of LTCs in emergency and preventive voltage stability control

This paper discusses the effect of load tap changers (LTCs) on the voltage stability of a power system and in particular under emergency conditions. This discussion covers LTCs both on the bulk power delivery transformers, which are normally controlled automatically, and the transformers between higher voltage levels, typically EHV/HV autotransformers, that in many cases are controlled manually. An algorithm to determine taps for the latter that will maximize loadability is presented.
Fast power cycling test of IGBT modules in traction application

The numerous advantages of insulated gate bipolar transistor (IGBT) power modules and their ongoing development for higher voltage and current ratings make them interesting for traction applications. These applications imply high reliability requirements. One important requirement is the ability to withstand power cycles. Power cycles cause temperature changes which lead to a mechanical stress that can result in a failure. Lifting of bond wires is thereby the predominant failure mechanism. A fast power cycling test method activating the main failure mechanism has been developed which allows reproduction of millions of temperature changes in a short time. The applicability of fast testing is supported by a mechanical analysis. Test results show the number of cycles to failure as a function of temperature changes for an IGBT single switch. A descriptive model is deduced from the results.
Power transformer monitoring using UHF sensors: installation and testing

External UHF couplers have been fitted to a 1000 MVA autotransformer as part of a project aimed at developing new transformer monitoring techniques. The couplers will supply valuable raw data from a transformer operating under normal service conditions. UHF signals were recorded while the transformer was re-energized and returned to load. Initially, some large discharges appeared, but these were short-lived. Background signal levels were low, indicating no significant interference problems. A small intermittent discharge signal was recorded and its characteristics are described. The possibilities for UHF monitoring of transformers are discussed, together with some of the remaining challenges.
Theoretical Investigation of Superradiant Lasing in 2- or 3- Level Atoms in an Optical Lattice

Active optical atomic clocks operating on narrow linewidth clock transitions based on a superradiant lasing are predicted to achieve precision orders of magnitude higher than any currently existing optical atomic clocks. We introduce a general theory of superradiant lasing and implement it for the examples of Ca and Sr atoms. Our simulations coincide well with the experimental results and explain some features of it. The presented model is valid for any two- and three-level system in an optical lattice.
Agile Teams’ Perception in Privacy Requirements Elicitation: LGPD’s compliance in Brazil

Context: The implementation of the Brazilian General Data Protection Law (LGPD) may impact activities carried out by the software development teams. It is necessary for developers to know the existing techniques and tools to carry out privacy requirements elicitation. Objectives: In this research, we investigated the perception of agile software development team members from different organizations, regarding the impact that LGPD will have on the activities of the software development process. Methods: We conducted an online survey and a systematic literature review to identify the techniques, methodologies and tools used in the literature to perform privacy requirements elicitation in the context of Agile Software Development (ASD). In addition, we also investigated the perception of an agile team from a Federal Public Administration organization regarding the impacts of the obligation to develop software in accordance with the LGPD. Results: Our findings reveal that agile teams know the concepts related to data privacy legislation, but they do not use the techniques proposed in the literature to perform privacy requirements elicitation. In addition, agile teams face problems with outdated software requirements specifications and stakeholders’ lack of knowledge regarding data privacy. Conclusions: Agile teams need to improve their knowledge on privacy requirements.
CrowdRE in a Governmental Setting: Lessons from Two Case Studies

Crowd-based Requirements Engineering, or CrowdRE, is a recent paradigm that promotes the active participation of a large number of stakeholders in RE. In CrowdRE, requirements elicitation can be crowdsourced by creating an online platform that allows stakeholders to formulate ideas regarding the specific product. Although some case studies on crowd-based elicitation exist, no conclusive evidence can be derived on the effectiveness of such techniques. In this paper, we study crowd-based elicitation within a large governmental organization. We conduct two case studies of CrowdRE within the Royal Netherlands Marechaussee. For this, we construct the KMar-Crowd method, which adapts CrowdRE ideas to the needs of governmental organizations. While one case compares the crowd-generated ideas with requirements elicited via interviews and similar techniques, the other measures the usefulness of the gathered ideas for a product for which no prior elicitation was conducted. The results of the case studies, which attracted larger crowds than in previous studies, indicate that CrowdRE can be successfully applied to engage the users of a software product in requirements elicitation. Contradicting earlier studies, the inclusion of gamification elements in the CrowdRE method did not increase the motivation to participate, possibly due to the nature of governmental organizations.
Long term observations on Sabella spallanzanii (Annelida, Sabellidae) in the Mar Grande of Taranto (Ionian Sea). The influence of alien species

We report 30-year observations on the abundance of the Mediterranean fan worm Sabella spallanzanii (Gmelin, 1791), and the influence on its density from the introduction of two other sabellid termophilic species, belonging to the Branchiomma genus, in the area of the Mar Grande of Taranto (Mediterranean Sea). After an initial decreasing of abundance of the autochthonous species, at present, it seems that the three species have reached an equilibrium with the dominance of S. spallanzanii
High-Speed NTT-based Polynomial Multiplication Accelerator for Post-Quantum Cryptography

This paper demonstrates an architecture for accelerating the polynomial multiplication using number theoretic transform (NTT). Kyber is one of the finalists in the third round of the NIST post-quantum cryptography standardization process. Simultaneously, the performance of NTT execution is its main challenge, requiring large memory and complex memory access pattern. In this paper, an efficient NTT architecture is presented to improve the respective computation time. We propose several optimization strategies for efficiency improvement targeting different performance requirements for various applications. Our NTT architecture, including four butterfly cores, occupies only 798 LUTs and 715 FFs on a small Artix-7 FPGA, showing more than 44% improvement compared to the best previous work. We also implement a coprocessor architecture for Kyber KEM benefiting from our high-speed NTT core to accomplish three phases of the key exchange in 9, 12, and $\mathbf{19}\mu \mathbf{s}$, respectively, operating at 200 MHz.
Evaluating DNA metabarcoding to analyze diet composition of wild long-snouted seahorse Hippocampus guttulatus

Seahorses are small sedentary fish considered flagship species of the conservation efforts. During the last decades, worldwide decline of local populations led to the inclusion of all seahorse species on the IUCN Red List and Appendix II of CITES. Due to the threatening status, improving knowledge of their dietary composition, while using a noninvasive approach, might be of great importance as it could help to understand the way the environment is exploited. In the present study, we used an amplicon-based HTS (High Throughput Sequencing) approach to investigate the diet of wild long-snouted seahorse Hippocampus guttulatus. The results indicated that the applied approach is adequate for the characterization of diet in wild specimens. Indeed, the applied approach permitted identification of Amphipoda, Decapoda, Isopoda and Calanoida, present in most of the seahorse samples, while less common prey taxa were Gastropoda and Polyplacophora. As only a small amount of starting faecal material is needed and the sampling procedure is neither invasive nor lethal, DNA metabarcoding could be useful in the investigation of threatened seahorse diet in the wild and could help inform management and conservation actions.
On the Feasibility of Cellular-Connected Drones in Existing 4G/5G Networks: Field Trials

Recently, the integration of drone users into our current cellular networks has aroused great interest. This, in turn, requires that wireless network providers to certainly explore the feasibility of using existing infrastructure for a variety of drone applications, as the use of terrestrial networks for aerial communication faces some challenges such as changing coverage and increasing altitude. Hence, in this work, we present comprehensive field trail measurements that were carried out in a sub-urban area where the drone flies at different altitudes and bands. The results presented here reveal the potential and challenges of using real-life industrial 4G/5G networks for drone operation. This is because drones flying at high altitudes are likely to have a LoS propagation condition and since this interferes with neighbouring base stations, it can also negatively affect the performance of the existing terrestrial users. Therefore, to clarify whether a satisfactory coexistence of aerial and terrestrial users is plausible, we also evaluate the impact of drones on the performance of the terrestrial user.
Tolerância do maxixeiro, cultivado em vasos, à salinidade da água de irrigação

Gherkin (Cucumis anguria) is an important crop in the North and Northeast regions of Brazil, and its production is predominantly from spontaneously growing plants. For this reason, little research is done on the crop, especially regarding the effect of salinity. This study was conducted at the Federal Rural University of the Semiarid (UFERSA) in Mossoro, RN, to evaluate the effect of different salinity levels of irrigation water on the development and yield of gherkin. The experiment was arranged in a completely randomized design, with four treatments (salinity levels of irrigation water: S1-0.5, S2-2.0, S3-3.5 and S4-5.0 dS m-1). There were five harvests of fruits and at the end of the experiment the plants were collected and analyzed for major development parameters and yield. We evaluated the following variables: length of the main branch, stem diameter, number of leaves, leaf area, dry mass of leaves, stems, fruits and total fruit number, average fruit weight and yield. The results showed that gherkin is sensitive to salinity. Significant responses were found for all variables that reduced with increasing salinity.
Quantification and characterization of cricket bowling technique for the development of the parameters required for a novel training system for cricket

Cricket bowling has traditionally been referenced using ball release speed, and existing classifications consider the four major bowling types as fast, fast—medium, medium, and spin. A research project based at Loughborough University has recognized the need for an extended bowling classification that not only considers the ball speed, but also its initial flight characteristics, including any spin imparted at release. The purpose of this paper has been the development of an extended bowling classification, which has been used in the development of a requirements specification for an advanced ball delivery system for cricket, to ensure the accurate recreation of technically correct bowling deliveries. Data collected during training and match play have been used to define bowling quantitatively. The initial ball flight characteristics of 30 elite-level bowlers have been filmed in training using a Photron FASTCAM ultima APX high-speed video camera. These videos have been used to determine the speed, the rate of spin, and the initial flight trajectory of the ball at release. Additionally, Hawk-Eye ball-tracking software has been used to investigate the full flight characteristics of seven elite bowlers during a five Test match series.
Microwave Frequency Transfer via 11 km Fiber Link With Fiber-Loop Optical-Microwave Phase Detectors

We demonstrate a microwave frequency transfer experiment with a femtosecond pulse train via 11 km fiber link. The whole system is similar with the previous work conducted by researchers in KAIST, South Korea, but the fiber path length is nearly four times longer than the previous work. The fractional frequency instability between local and remote 7.5 GHz microwave oscillators in terms of Allan deviation reaches 2.3×10-14 at 1 s averaging time and goes down as τ-1.