Miracle-dz/UniFAR-FTUs huggingface dataset:
Logistic Regression Based Classification of Spam and Non-Spam Emails

An email client receives emails from different websites, portals and domains, which can be an advertisement. Receiving a bulk amount of emails can cause serious damages like suspension of a particular email id. Mostly an email client gets exposed to the number of malicious receipts by registering an email account to a web portal, which in turn sends a bulk amount of emails. One of the solutions to escape from spam emails is to develop a decision based system which can classify the spam and non-spam emails. This can be achieved using different machine learning and deep learning and deep learning algorithms to classify the spam and non-spam emails by accessing the received emails of an email client. The machine learning approaches and mechanisms like SVM, naive Bayesian classifier, artificial neural networks and random forests can be of important help to determine spam emails. After classifying a spam email source a user can navigate, block and report the source of the spam email generator like spam-bots.
Application of Geo-spatial Technology in Characterization of African Honeybee (Apis mellifera) Apiaries into Ecosystem Zones for Productivity and Pollination Service

Seven major ecological zones of Nigeria with modern functional apiaries were mapped and sampled in the rainy season between April 2016 and October 2018 for estimating the bee foraging flight range and floral species diversity; collating satellite imagery data for geospatial zone mapping using GPS (Garmin Etrex 20) to capture the coordinates of apiaries locations and their attributes, climatic and topographic data and generating ecological zones: the wetland vegetation, savanna grassland, savanna woodland (disturbed), shrubby forest, lowland dense forest, and Highland rain forest. Honeybee flight ranges between 1 and 5 kilometer radius from where bees at the apiaries can forage for pollen and nectar. Igbeti/Malete/Buari bees forages at similar ecosystems within this range while those at Saki and Abuja apiaries have potentials to forage at different ecological zones ranging from woodland savanna to lowland and high forests. Abuja (woodland savanna and shrubby forest zones) apiaries produces average of 32 liters of honey per hive and Kwara (savanna grassland and wood land Savanna) produces average of 24 liters of honey per hive. There is also structural variation in the floral species diversity and richness as richness marginally differed at the locations. Highest index was observed in Orozo (H=2.62; Margalef = 3.05) and Agbungburu (H=2.54; Margalef = 3.06). Low index was attained at Buari (H= 2.10; Margalef= 2.32) and Igbeti (H= 2.11; Margalef= 2.62). Apiary managers and farmers acquiring relevant knowledge on apiculture and prevailing A. mellifera apiaries would assist management activities; contribute to better production and pollination for food security.
An Improved PPO for Multiple Unmanned Aerial Vehicles

In recent years, multi-agent reinforcement learning (MARL) has been applied widely, especially in large multi-role games such as StarCraft and unmanned aerial vehicles (UAVs) combat simulations. However, MARL is faced with challenges regarding fast convergence and efficient cooperation. In a multi-agent scenario, on the one hand, when a fully centralized network model is adopted, it is difficult for the model to converge due to the huge action space; on the other hand, it is difficult for a decentralized model to cooperate and achieve global optimization. To jointly control multiple agents, we propose an improved PPO algorithm by combining a centralized network and decentralized networks. Our method not only reduces the action space and accelerates the convergence, but also introduces more diversity for agents’ decision-making.
Shannon unicity distance, ε-secrecy criterion and Holevo information in quantum cryptography

In this paper, we consider the relationship between C Shannon’s unicity distance, which is determined by the number of symbols of the encrypted message required to uniquely find the encryption key of the cryptosystem in information-theoretical sense, ε-secrecy criterion in quantum cryptography and Holevo information. A lower bound for the unicity distance for ε-secret keys in quantum cryptography is obtained. The relationship between unicity distance, ε-secrecy criterion in quantum cryptography and Holevo information is demonstrated.
The Effect of Manager Forecast of Future Sales on Company Risk during Sales Decline Using the Fama-French Five-Factor Model

A sales decline period disrupts the time series of earnings and, consequently, reduces their predictability. Such a situation can lead to inappropriate decisions by investors. Therefore, managers need to respond appropriately to negative news resulting from sales decline. Manager response is related to forecasting future sales situations, which could affect risk to the firm. In this study, the ratio of the operating profit margin was used to compare companies with optimistic and pessimistic managers. To investigate the research hypotheses, the Fama-French five-factor model has been used depicting a period of 11 years, from 2007 to 2017, for the companies that are accepted in the Tehran Stock Exchange. It should be noted that market beta of the Fama-French five-factor model is distinguished by upside potential and downside risk factors making it possible to study them individually. The findings imply that in companies with optimistic managers, the upside potential is more than the downside risk, but in companies with pessimistic managers, there is no significant difference between the two. In companies with optimistic managers, upside potential changes are incremental in the period after the decline in sales compared to the period before sales decline.
Insights into the Influence of Solvent Polarity on the Crystallization of Poly(ethylene oxide) Spin-Coated Thin Films via in Situ Grazing Incidence Wide-Angle X-ray Scattering

Controlling polymer thin-film morphology and crystallinity is crucial for a wide range of applications, particularly in thin-film organic electronic devices. In this work, the crystallization behavior of a model polymer, poly(ethylene oxide) (PEO), during spin-coating is studied. PEO films were spun-cast from solvents possessing different polarities (chloroform, THF, and methanol) and probed via in situ grazing incidence wide-angle X-ray scattering. The crystallization behavior was found to follow the solvent polarity order (where chloroform chloroform > methanol). When spun-cast from nonpolar chloroform, crystallization largely followed Avrami kinetics, resulting in the formation of morphologies comprising large spherulites. PEO solutions cast from more polar solvents (THF and methanol) do not form well-defined highly crystalline morphologies and are largely amorphous with the presence of small crystalline regions. The difference in morphological development of PEO spun-cast from polar solvents is attributed to clustering phenomena that inhibit polymer crystallization. This work highlights the importance of considering individual components of polymer solubility, rather than simple total solubility, when designing processing routes for the generation of morphologies with optimum crystallinities or morphologies.
Tuning Energy Levels without Negatively Affecting Morphology: A Promising Approach to Achieving Optimal Energetic Match and Efficient Nonfullerene Polymer Solar Cells

One advantage of nonfullerene polymer solar cells (PSCs) is that they can yield high open‐circuit voltage (VOC) despite their relatively low optical bandgaps. To maximize the VOC of PSCs, it is important to fine‐tune the energy level offset between the donor and acceptor materials, but in a way not negatively affecting the morphology of the donor:acceptor (D:A) blends. Here, an effective material design rationale based on a family of D–A1–D–A2 terthiophene (T3) donor polymers is reported, which allows for the effective tuning of energy levels but without any negative impacts on the morphology of the blend. Based on a T3 donor unit combined with difluorobenzothiadiazole (ffBT) and difluorobenzoxadiazole (ffBX) acceptor units, three donor polymers are developed with highly similar morphological properties. This is particularly surprising considering that the corresponding quaterthiophene polymers based on ffBT and ffBX exhibit dramatic differences in their solubility and morphological properties. With the fine‐tuning of energy levels, the T3 polymers yield nonfullerene PSCs with a high efficiency of 9.0% for one case and with a remarkably low energy loss (0.53 V) for another polymer. This work will facilitate the development of efficient nonfullerene PSCs with optimal energy levels and favorable morphology properties.
A 1.3–4-GHz Quadrature-Phase Digital DLL Using Sequential Delay Control and Reconfigurable Delay Line

A 1.3–4-GHz quadrature-phase digital delay-locked loop (DDLL) with sequential delay control and a reconfigurable delay line is designed using a 28 nm CMOS process. The time resolution of the DDLL is reduced by updating the delay code sequentially. A bidirectional shift register enables this operation with low power, resulting in bang-bang jitter that is three times smaller than that of a conventional DDLL. Conventional delay control is replaced with sequential delay control after a DDLL lock to reduce the locking time. A DDLL with a wide operation range is achieved with a reconfigurable delay line. Unlike the conventional DDLL, the minimum delay difference is adjustable in the proposed structure. To achieve a wide frequency range, the minimum delay difference of the quadrature clock is increased or decreased in three operation modes. To compensate for local variations in the CMOS process, a skew calibration circuit is implemented with the DDLL. The hardware cost of skew calibration is minimized with the proposed DDLL because it shares the subblocks for sequential delay control. The average phase difference from the quadrature clocks becomes the reference for the 90° phase for skew correction. A duty-cycle corrector (DCC) is implemented by collecting the positive edges of the quadrature-phase clocks. The DDLL consumes 6.5 mW at the maximum clock frequency of 4 GHz. The peak-to-peak jitter is improved from 15.6 to 12.5 ps with sequential delay control.
Localization in mobile wireless sensor networks using drones

Localization is one of the most important aspects of wireless sensor networks. Most of the localization algorithms proposed in the literature, work for static networks. However, the performance of these protocols in the mobile environment still needs to be investigated. Localization in a mobile environment may pose challenges of accuracy and computational complexity due to mobility of the nodes. In this article, we have proposed an algorithm for localization in mobile wireless sensor networks using drones (LMWSND). A drone‐based algorithm is proposed to simulate the moving trajectory of the drones. The proposed drone‐based algorithm uses the technique of received signal strength between the drone and unknown sensor nodes to find the distance between them. The distance thus obtained is used for localization of the unknown nodes. A new method is used to solve the system of distance equations to restrict the propagation of error. Furthermore, the mathematical analysis of the propagation error in LMWSND proves the superiority of our proposed algorithm in comparison to other algorithms. The results obtained through simulations further strengthen our conclusion that the proposed algorithm reduces the propagation of error. We have also proposed another algorithm to choose the nearby beacon points for better utilization of the network resources and to reduce the computational efforts.
Evidence of nonlinear Walker circulation feedbacks on extreme El Niño Pacific diversity: Observations and CMIP5 models

The Walker circulation (WC) is essential for the formation and diversity of El Niño events. However, the nonlinear WC feedback during extreme Central and Eastern El Niño episodes (C and E episodes, respectively) has received little attention. This study used observational datasets and the Atmospheric Model Intercomparison Project (AMIP) and historical simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Eight out of 21 historical models that simulate the El Niño‐Southern Oscillation (ENSO) nonlinearity also simulate the nonlinear Bjerknes feedback in C and E episodes. The opposite does not necessarily occur. However, the underestimation of E might limit the empirical determination. Moreover, few historical models simulate the shallow conditional instability of the second kind (CISK) mechanism. Positive C episodes feature an eastward shift in the ascending branch of the Pacific Walker cell (PWC), while shallow convection prevails over the far‐eastern Pacific (FEP). Positive E events feature two anomalous ascending branches located over the central‐western Pacific (170°W) and FEP (80°W). Positive anomalies in sea surface temperature over the FEP induce the second ascending branch. The positive stratification anomaly in the central Pacific Ocean, which is associated with overestimated Ekman feedback, limits the eastward displacement of the first ascending branch of the PWC. The net surface heat flux determines the duration of growth of the two ascending branches of the PWC during C and E events. Because of their coarse resolution, the historical models underestimate the positive stratification anomaly in the FEP, causing the quick demise of the second ascending branch.
CSI7: Novel Three-Phase Current-Source Inverter With Improved Reliability

Unlike voltage-source inverters (VSI), the power decoupling element in current-source inverters (CSI) is inductor. Inductor has a long lifetime and makes the CSI more reliable. However, the traditional CSIs suffer from open-circuit problem and dangerous voltage spikes are generated if the input inductor current is intermitted. Therefore, to avoid the voltage spikes, overlap-time should be inserted in the gate signals. But these intervals distort the output currents and reduce the current source utilization. To address these issues, a novel three-phase CSI is proposed in this article. The proposed inverter is originated from the conventional seven-switch CSI named CSI7 by adding only two small film capacitors. The film capacitors along with the pre-existing diodes of the CSI7 ensure that there is always a path for the inductor current, and thus the open-circuit issue is resolved. The elimination of open-circuit issue enhances the reliability and allows to minimize the overlap-time. This will improve the quality of output currents as well. Moreover, simulation and experimental results are provided at the output power of 950 W to verify the effectiveness of the proposed inverter.
“Gazing” and “performing”: Travel photography and online self-presentation

This article illustrates the self-presentations young people foreground when they visually communicate international volunteer experiences to social media audiences. Through a “categorical-content” analysis of repeated semi-structured interviews and photographic content posted to Facebook, and with theoretical support from Urry’s “tourist gaze” and Goffman’s “presentation of self,” I describe three impressions “given” and “given off” within participants’ profiles. The findings reveal some familiar touristic scenes (necessitating tribute to the well-established “family” and “romantic” gazes) and also inspire a new gazing form (incorporating “gutsy” bodily experiences). However, these holiday-like portrayals were selectively disclosed and complicated by the sentiments participants expressed during face-to-face interviews. As different self-presentations were idealized in different settings, this article helps to elucidate the situational role of the audience and offers unique analytical insights that may not have emerged had I utilized one method in isolation. Its contribution is located within its intersections: blending gazing and performing frameworks, employing verbal and visual approaches, leading to etic and emic understandings.
Discrete-time Sensorless Control Using new BS_SM Controller structure and VM_ SC MRAS Adaptive Speed Observer for The propulsion system of Ship

In this paper, a (BS_SM) new Backstepping_ Sliding mode controll structure combined with a (VM_SC_ MRAS) improved stator current MRAS based on adaptive speed observer using neuron network and sliding mode are proposed to sensorless vector control for The propulsion system of Ship. The design of the controller is based on new BS and SM sructure to improve its performance and robustness. VM_SC_ MRAS improved adaptive speed observer is proposed to estimate the speed of propeller. The combination of BS-SM controller with VM_SC_MRAS adaptive speed observer can compensate for the uncertainties caused by the machine parameter variations, measurement errors, and load disturbances, improving dynamic performance and enhancing the robustness of the SPIM drive system, perfect tuning of the speed reference values, fast response of the motor current and torque, high accuracy of speed regulation. The simulation results lead to the conclusion that the proposed system for the propulsion system of ship is feasible. The simulation results on a test ship propelled showed that the proposed control approach operates satisfactorily
Augmented Reality assisted by GeoGebra 3-D for geometry learning

Geometry becomes a difficult subject for students. The abstract object was one of the factors. Therefore, more concrete learning media are needed. One of them was augmented reality assisted by GeoGebra. The purpose of this study was to determine the ability to understand the geometrical concepts of high school students through augmented reality learning assisted by GeoGebra. Treatment was given to students through learning using GeoGebra-assisted augmented reality. This was a quasi-experimental study with a pre-test post-test control group design. This research instrument was a test of the ability to understand the concept of geometry. The test was used to measure students’ initial abilities, and this was referred to as a covariate. Also, to measure the ability to understand concepts after students follow augmented reality learning assisted by GeoGebra. Data were analyzed by covariate analysis (ANCOVA). The results of this study were F = Fo (A) = 9,150 with p-value = 0,000 <0,005. That means, there are differences in the ability to understand the concept of geometry between those taught with augmented reality which is assisted by GeoGebra and conventional learning. Other results show that t = 6.723 with p-value = 0.000 <0.05. This shows that the ability to understand the geometry concepts of students taught with augmented reality assisted by GeoGebra was higher than students who were taught conventionally after controlling for covariates. The conclusion was that the ability to understand the concepts of geometry through GeoGebra-assisted augmented reality learning was better than students taught with ordinary learning.
Simulation of the Worst Failure Probability of Sharing Platform under Unknown Demand Distribution

The sharing economy integrates the idle resources to match the fragmented market demand via the Internet platform. Different from the supply side, the demand is highly uncertain, in which, significant spikes and valleys exist. Therefore, it is assumed that only the statistical characteristics, instead of precise distributions, are known. The matching efficiency of supply and demand in sharing platform is studied. Firstly, a linear programming model under the moment constraints is proposed to describe the worst failure possibility in demand satisfaction. Then, the equivalent semi-infinite program is developed by Lagrange duality, and the analytical expression of the worst failure probability can be given. Finally, simulation study is implemented. This work not only riches the studies of moment-based bound, but also provides the managerial insights to the demand management of the sharing platform in the uncertain setting.
Humour as a Professionally Significant Competence of a Teacher

The article examines the issue of humour development as a professionally significant competence of a teacher. Conducted theoretical and empirical studies among students of secondary schools, tertiary education students, teachers and university professors have shown that students of secondary schools and university students, in comparison with school and university teachers, used humour more often in complicated situations. There were also differences in the choice of types of jokes by the respondents. The results of the study of humour reflects the ambiguous attitude towards humour that still exists in the teaching environment. The researchers have recorded the insufficient use of the possibilities of humour by teachers as an effective tool of pedagogical activity. The reason might be found in the current educational paradigm. A teacher is perceived as serious and even authoritarian. The development of this professionally significant quality is not given much attention in the process of training of future teachers. The use of humour as a pedagogical tool will help create conditions for the development of an individual style of professional activity, contribute to an increase in professional competence, pedagogical skills and will become one of the conditions for the effectiveness of solving various professional problems.
The Role of the Traditional Crafts as Intangible Heritage on the Global Tourist Market

Research background: The results of the researches in the word show that traditional crafts play very important role in presenting the culture and traditions of any country and provide opportunities for employment with low capital investments. Dubrovnik traditional crafts have not been touristic valorized as well. That is why is relevant to analyse the role and development possibilites of Dubrovnik traditional crafts from international poin of view. Purpose of the article: The aim of the paper was to analyse importance and types of traditional crafts as much as to explore the attitudes of local residents in the area of Dubrovnik towards the possibilities of developing new tourism products forms based on the traditional crafts. Methods: For the purpose of the paper the secondary and primary data have been used. The empirical research has been conducted using the structured interview method. The sample has consisted of 48 employees. The respondents were residents, employed by companies in Dubrovnik. The results of primary and secondary researches have been considered together regarding the elements of cultural motivation. Findings & Value added: The local residents consider that traditional crafts could be important factor of sustainable development of tourist destinations Dubrovnik. There is an interest in “reviving” them and valorizing for tourism purposes, especially Konavle, Mljet and Coastal embroidery, Knitting, Stonemasonry and Sericulture. All traditional crafts had been currently positioned in the area of mediocre level of tourist valorization.