Miracle-dz/UniFAR-FTUs huggingface dataset:
Antenna Arrays for Tactical Communication Systems: A Comparative Study

In this paper, we give a comparative study of several planar antenna concepts for reliable long range links in a tactical environment. The antenna elements are studied in terms of their electrical properties (bandwidth, reflection coefficient and radiation characteristics) and construction (robustness and material consumption). First, we model single antenna elements to investigate if they meet the requirements. Second, we arrange the elements with the best features into 22 arrays. Computer simulations of the arrays are verified by measurements. Finally, we formulate recommendations for large array (88 or 1616 elements) synthesis to achieve the required properties.
TEMPERATURE ANALYSIS OF LNA WITH IMPROVED LINEARITY FOR RF RECEIVER

In this paper we are fully integrated 5.5 GHz high-linearity low noise amplifier (LNA) is designing using post-linearization technique, in sub-120nm & sub-70nm technology. It developed using cascode amplifier with inductors. RC linearization circuit is designed to improve the linearity of the design. Cascode LNA circuit is designed for linearity improvement. In this work Temperature analysis is carried out for LNA circuit performance improvement fully integrated 5.5 GHz high-linearity low noise amplifier (LNA) is designing using post-linearization technique, in sub-120nm & sub-70nm technology. Temperature stability of the circuit is analysed for different temperature ranges our results prove that the proposed LNA design achieve high gain with good linearity. Although power dissipation of the circuit is high, good temperature stability is achieved. Temperature stability of the circuit is analysed for different temperature ranges our results prove that the proposed LNA design achieve high gain with good linearity. Although power dissipation of the circuit is high, we are able to achieve good temperature stability. The Low Noise Amplifier is a special type of electronic amplifier used in communication systems which amplifies very weak signals captured by an antenna.
Spatial Econometric Analysis of China's Sports Capital Market

The capital market provides important capital factor guarantee and supply-side support for the high-quality development of the sports industry, and the healthy development of the sports capital market, which is composed of securities market, loan market, trading derivative market, and physical market, plays a vital role in ensuring the smooth and efficient operation of the sports market economy mechanism. At the present stage, how to play the role of resource allocation in China’s sports capital market and how to improve the quality and efficiency of the sports industry by the capital market have become the core issue of research and discussion. Taking A-share listed companies as the typical micro-market subjects, this paper analyzes the financing needs and behaviors of sports listed companies and the support degree of different types of capital markets; on the basis of traditional measurement methods, spatial econometric analysis is used to explore the effectiveness of capital market on the development of the sports industry.
Effect of instrumental response time in exponential-decay-based cavity ring-down techniques for high reflectivity measurement

Exponential-decay based cavity ring-down (CRD) techniques, such as the pulsed-CRD and continuous-wave (cw) CRD employing a fast switch to shut down the laser beam, are widely used for high reflectivity measurement. In this paper the influence of the response time of the experimental apparatus on the high reflectivity measurement is investigated theoretically and experimentally. Theoretical expressions taking into account the instrumental response time are given for both pulsed- and cw-CRD techniques, respectively. By establishing a simple cw-CRD setup employing detectors with different response time, the influence of the instrumental response time on the high reflectivity measurement is experimentally investigated. By applying a multi-parameter estimation technique to determine simultaneously the cavity decay time and the overall response time of the experimental apparatus via fitting the experimental CRD signal to the corresponding theoretical model, the influence of a long instrumental response time on the reflectivity determination is eliminated. The reflectivities of the cavity mirror measured with detectors with different rise time are in excellent agreement. On the other hand, the error of high reflectivity measurement increases with the increasing rise/fall time of the apparatus in cases that the CRD signals obtained by detectors with relatively slow rise time are simply treated with a single exponential decay fitting procedure.
Forcing level effects of internal acoustic excitation on the improvement of airfoil performance

The effects of internal acoustic excitation on the leading-edge, separated boundary layers and the aerodynamic performance of NACA 633-018 cross section airfoil are examined as a function of forcing level and forcing frequency of the introduced acoustics. Tests are separately conducted in two suction, open-typed wind tunnels at the Reynolds number of 3.0 x 10 s for the measurements and 1.0 x 10 4 for the visualization. Results indicate that the flow separation is delayed at the angles of attack higher than the stalled angle of small level excitation with the forcing frequency fe near the shear layer instability frequency ft. As the forcing level is increased to some extent, the velocity fluctuations around the slot exit are demonstrated to be the primary governing parameter for modifying the separated boundary layers. Data also show that the effective forcing frequency (and the Strouhal number, 50 extends over wider range as compared to the lower level excitation. Meanwhile, the pressure distributions on the airfoil surface exhibit recovery behaviors with different forcing frequencies. The corresponding boundary layers are visualized to be reattached to the surface to form a recirculation region when the airfoil is around at the stalled angles.
DYNAMICS AND SECURITY OF COMPLEX CLUSTERED NETWORK SYSTEMS

Networks with a community (or cluster) structure underlie many social and biological phenomena. In such a network, individuals tend to form sparsely linked local communities, each having dense internal connections. This dissertation explores the different dynamics of complex clustered networks, revealing a new set of rules that show how the dynamic properties are affected by the clustered structures. The dynamics of information propagation on clustered networks is studied by using a three-state epidemic model with a unit spreading rate. A resonance-like phenomenon is uncovered: the information lifetime on the network can be maximized by the number of clusters. Synchronization in complex, clustered random networks is found to be determined by the interplay between inter-cluster and intra-cluster links. The network is most synchronizable when the numbers of the two types of links are approximately equal. In the presence of a mismatch, increasing the number of intra-cluster links, while making the network distance smaller, can suppress or even destroy the synchronization. For clustered networks with regular subnetworks, as the density of intra-cluster links is increased, the network exhibits strong and weak synchronizability in an alternating manner. A theory based on analyzing the eigenvalues and eigenvectors of the coupling matrix is provided to explain this phenomenon. For gradient clustered networks, the synchronizability can be optimized by the strength of the gradient field. A remarkable finding is that, if the gradient field is sufficiently strong, synchronizability of the network is mainly determined by the properties of the subnetworks in the two largest clusters. A model of cascading in complex clustered networks based on physical analysis and numerical computations is developed for the key ingredients of traffic dynamics in typical clustered networks. An effective strategy is proposed for preventing cascading breakdown. By focusing on network synchronizability, it is found that globally coupled networks and random networks are scalable, but locally coupled regular networks are not. Scale-free networks are scalable for certain types of node dynamics. For a typical clustered network, as its size is increased, the synchronizability can be maintained or even enhanced but at the expense of deterioration of the clustered characteristics.
Design for testability, reliability and maintainability

To meet the objective of high yield and high reliability the author proposes the combined use of the following techniques: design for functionality, design to cost, design for manufacture, design for testability, design for reliability, design for maintainability, statistical process control, failure reporting and corrective analysis system, failure mode effect and criticality analysis, and concurrent engineering.
IMPROVING VOLTAGE PROFILE USING PR CONTROLLER BASED FACTS DEVICE IN DISTRIBUTED POWER GENERATION SYSTEMS

Wide usage of renewable energy sources reduce greenhouse gas emissions and perfect replacement of fossil fuels. The integration of wind energy will become an important factor for the electric grid in the case of stability. Due to the necessity, the 'smart' grid must able to operate under any disturbances and provide high quality electric energy to consumers. FACTS (Flexible AC Transmission System) devices are helpful to make the smart grid stable as good enough, which are also called as custom power devices. These devices are tuned by some controllers named, P (Proportional) controller, PI (Proportional Integral) controller, PID (Proportional Integral and Derivative)controller, PR (Proportional Resonant) controller, Fuzzy controller, Nuero FUZZY controller, ANFIS controllers etc.,. In this paper, the response of PI and PR controller has been studied with the help of SSSC. The SSSC is used in transmission line to improve the voltage level, reduce the harmonics and make the system is balanced. In this paper, SSSC operates with the help of PI and PR controller. Both PI and PR controller will be connected to SSSC with the help of alternative switch and analyse its performances. The PI controller has steady state errors and limited disturbance rejection capability. Compared to PI Proportional Resonant (PR) current controller provides gains at a certain frequency (resonant frequency) and eliminates steady state errors.
A Hollow-Core Photonic-Crystal Fiber-Optic Gyroscope Based on a Parallel Double-Ring Resonator

A novel system structure of resonant fiber optical gyroscope using a parallel double hollow-core photonic crystal fiber ring resonator is proposed, which employs the double closed loop and reciprocal modulation–demodulation technique to solve the problem of the length mismatch between rings. This structure can suppress the residual amplitude modulation noise and laser frequency noise, essentially eliminating the influence of the Rayleigh backscattering noise and dramatically reduce the Kerr-effect-induced drift by three orders of magnitude. Thanks to its excellent noise suppression effect, the sensitivity of this novel system can approach the shot-noise-limited theoretical value of 8.94 × 10−7 rad/s assuming the length of the fiber ring resonator is 10 m.
Methodological issues in the study of human factors in teleinformatic systems

Abstract The rapid technological developments in teleinformatics and their many implications for their users means that a human-factors contribution to both research and application is very pressing. This paper reviews the methodological problems confronting human-factors specialists in making this contribution. It examines methodological issues in research and design at the levels of (i) the man-computer interface and (ii) the organizational implications. The paper ends by presenting an idealized, integrated strategy which emphasizes action research to give priority to multidisciplinary teams of information technologists and human and social scientists working together to construct and evaluate telelinformatic systems.
Minimizing Polarization and Disagreement in Social Networks via Link Recommendation

Individual’s opinions are fundamentally shaped and evolved by their interactions with other people, and social phenomena such as disagreement and polarization are now tightly woven into daily life. The quantiﬁcation and optimization of these concepts have been the subject of much recent research behind a wealth of high-impact data mining applications. In particular, researchers have addressed the question of how such concepts can be optimized by inﬂuencing the opinion of a small number of individuals or by designing the network from scratch. Here, rather than a “design-from-scratch” approach or altering the initial opinion, we study the optimization problem of recommending k new links to minimize the sum of polarization and disagreement in a social network with n nodes and m edges. We show that our objective function of this combinatorial optimization problem is not submodular, although it is monotone. We propose a simple greedy algorithm with a constant-factor approximation that solves the problem in cubic running time, and we provide theoretical analysis of the approximation guarantee for the algorithm. To overcome the computation challenge for large networks, we also provide a fast algorithm with computation complexity (cid:101) O ( mk(cid:15) − 2 ) for any (cid:15) > 0 , where the (cid:101) O ( · ) notation suppresses the poly(log n ) factors. Extensive experiments on real datasets demonstrate both the efﬁciency and effectiveness of our algorithms.
ESTIMATING POST HARVEST LOSS: A CHALLENGE OF DEVELOPING NATIONS

This paper has highlighted the importance of reducing postharvest food losses as a necessary step in ensuring future global food security in a sustainable manner. Given the postharvest challenges posed by lack of understanding of postharvest losses, food safety and the non-controlling of aflatoxin cannot be achieved merely through increases in agricultural productivity. There have been very few past studies conducted to estimate food losses. The existing studies have been mostly one-off and do not adopt any consistent methodologies. Methodology assessment identified include-specific food loss assessment consideration-rapid laboratory based procedure, rapid judgement based procedure guesstimate, traditional local estimate, vissloss estimate and on-site expert judgements. Other loss measurement techniques include weight comparisons, separation of damaged kernels and percentage determination. While the African Postharvest Losses Information System has recently made an effort to provide a framework to calculate food losses using a common methodology for south and east Africa, the input used in this process is based on work which may be outdated or not directly relevant. Therefore, it is critical that a more broader and updated effort be implemented to improve the ability to estimate postharvest food losses. The paper outlines a framework which can be adopted for consistent estimation of postharvest losses.
RAAE 1/2022, Regular Article, Obeten et al

Research background: Poor pest management decisions in crop production highly pronounced in most developing countries including Nigeria, result in huge crop losses, human health challenges and environmental degradation, detrimental to sustainable agriculture, food sufficiency and security. Identifying the factors influencing pest management decisions among maize farming households and providing effective solutions by relevant stakeholders can reduce crop losses and reduce the harmful effect to human health and the environment due to harmful pest management practices. Purpose of the article: The research was carried out to determine the factors influencing pest management decisions among maize farming households in the Federal Capital Territory, Nigeria, in order to provide effective and appropriate solutions capable of enhancing pest management decisions and invariably reducing crop losses due to pests, as well as reduce the harmful effect to human health and the environment caused by harmful pest management and control practices. Methods: Multistage sampling technique was the sampling method used, where 324 maize farmers were correctly sampled as respondents for this study. Primary data were collected from the respondents using a well-structured questionnaire. The data were analysed using descriptive statistics and multinomial probit model. The multinomial probit model was used to identify factors that influence pest management decisions. Findings, value added & novelty: The study revealed the use of chemical pesticides as the most used pest management practice among maize farming households in the Federal Capital Territory, Nigeria, while the use of integrated pest management practices was about the least used. Also, result from multinomial probit analysis of the study showed that gender, access to extension services, age and level of education were significant factors that influenced pest management decisions. The study, therefore, recommends the need for relevant non-governmental organisations and government ministries/agencies to engage in the provision of educational facilities and incentives to crop farmers, more robust agricultural extension programmes, input subsidies and farmer field schools, targeted at enhancing pest management decisions in crop production, which can be vital to sustainable and maximized agricultural production, human health and the environment.
The exercise dependence at the time of COVID-19 pandemic: The role of psychological stress among adolescents

The outbreak of COVID-19 disease caused not only unprecedented concerns about public health but also critic stress-related disorders, especially in the younger population. Several studies have found a close connection between psychological stress and exercise dependence, resulting from coping strategies such as excessive perfectionism in controlling external factors, performance, controlling food intake, weight, and body image. Moderate amounts of exercise have been demonstrated to reduce psychological distress. Thus, the aim of the present study has been to analyse the relationship between psychological stress and exercise dependence symptoms in adolescent, concerning the COVID-19 period. Participants were 50 adolescents (aged 15-17) who trained twice a week for 90 minutes per session. They were randomly assigned to participate in either a highly controlled and supervised recreational physical activity program associated with theoretical lessons that were intended to provide information regarding nutritional education (EG;n = 25) or a waitlist control group (CG;n = 25). The physical activity program involved: joint mobility exercises, low-to-moderate intensity aerobic exercise, team-building activities, exercise stations, cardio workout. At baseline and after intervention programs we administered the Exercise Dependence Scale-21, a 21-items scale designed to assess exercise dependence symptoms, and the Perceived Stress Scale that measures the level at which situations in life are perceived as stressful (p < .01). The findings have suggested that after a 12-week recreational physical activity and food re-education, adolescents felt a greater sensation of psycho-physical well-being and that this phenomenon was closely linked to an improvement of the symptoms of exercise dependence.
EVOLVING OPTIMIZED BRACED STEEL FRAMEWORKS FOR TALL BUILDINGS USING MODIFIED PATTERN SEARCH

Direct search methods offer potential for rapid exploration of a design space, enabling novel and optimized designs to be generated. We present the use of modified pattern search for optimizing the topological design of the bracing system for a free -form building of approximately 250m in height, carried out as part of a live building project, with the goal of generating alternative randomized patterns that meet structural performance. The methods developed successfully evolved efficient bracing configurations, in a procedure involving successive bracing element removal, with substantially less computational effor t than a basic automation method. The diversity of solutions introduced by adding a stochastic element to the search procedure and stochastic variation of the initial design proved beneficial for the structural design team. The project successfully applies an established search method, tailored for this scenario, to a complex, large -scale design task and provides a valuable case -study in applying structural topology optimization on live building projects.
A Study on Anonymous Communication

: While the popularity of computer technology has brought great convenience, it has also brought great security risks. People pay more and more attention to the security of information transmission, and anonymous communication has also made great progress. Anonymous communication refers to taking certain measures to conceal the communication relationship in the communication stream, making it difficult for eavesdroppers to obtain or infer the relationship and content of both parties in the communication. The purpose of anonymous communication is to conceal the identities or communication relationships between the two communicating parties and protect the personal communication privacy of network users. This paper studies the current anonymous communication technology, summarizes the working principle of anonymous communication systems, compares the advantages and disadvantages of existing anonymous communication systems, and proposes an anonymous communication mechanism based on P2P network and DNS hidden tunnels.
Index Fund and ETF Ownership and the Market for Corporate Control

If a bidder launches a takeover offer for a listed company being part of a stock market index, then index funds and exchange traded funds (ETF) as shareholders of this company cannot easily tender their shares without losing track of the index. This paper analyzes the impact of index fund and ETF ownership on the outcome of takeover offers in Germany. Based on a sample of 323 takeover offers of publicly listed German companies between 2006 and 2018, we document a significant negative impact of index fund and ETF ownership on the percentage of shares gained by a bidder during a takeover attempt. The fraction of outstanding shares eventually being tendered is decreasing with an increase in the stake of index funds and ETF: a one standard deviation increase in pre-offer index fund and ETF ownership reduces the fraction of outstanding shares gained by the bidder by 4.2 percentage points. For control-taking takeover bids with a bidder’s toehold below 30%, this value increases to 9.5 percentage points. Thus, our results suggest the increasing importance of index funds and ETF to weaken the German market for corporate control. This version: December 15, 2020