207 research outputs found

    The Relationship Between Teachers’ Demographic Profiles And Teachers’ Perception Towards The Internal Quality Assurance Assessment At Program Level In Two Secondary High Schools In Laiza And Mai Ja Yang Townships, Kachin State, Myanmar.

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    The purpose of this study was to determine the teachers’ perception towards Internal Quality Assurance (IQA) Assessment at program level and relationship with the teachers’ demographic factors: age, educational qualification, years of service in school, and academic rank in two Secondary High Schools in Laiza and Mai Ja Yang Townships, Kachin State, Myanmar, and to compare teachers’ perception towards internal quality assurance system according to teachers’ gender. Two set of questionnaires were used to conduct this study: Questionnaires for teachers’ demographic profile and Questionnaires for Internal Quality Assurance (IQA) Assessment at Program Level. 95% of the questionnaires were returned valid and data were analyzed by frequency, percentage, mean, standard deviation, and Pearson’s Product Moment Correlation Coefficient (r). The findings of objectives were that the teachers’ perception towards total internal quality assurance system based on fifteen components was at low level. Therefore, there was no significant difference between male teachers and female teachers’ perception towards internal quality assurance system according to teachers’ gender. There was no significant relationship between internal quality assurance system at program level and other teachers’ demographic factors. Since all the significant values were bigger than .05 at the significant level. The study recommended that school’s principals and board committee members should pay more attention to focus on IQA strategic planning and implementation process in order for promoting schools’ quality

    A Study of the Relationship Between Teachers’ Perceptions of Their Leadership Capacity and Organizational Culture at the Basic Education High Schools in Thanbyuzayat Township, Mon State, Myanmar

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    The aim of this study was to determine the relationship between teachers’ perceptions of their leadership capacity and organizational culture at the Basic Education High Schools in Thanbyuzayat Township, Mon State, Myanmar. The participants were 113 full-time teachers from Basic Education High Schools (No.1&2) during the academic year of 2019-2020. The researcher adopted the survey-High Leadership Capacity School Survey by Lambert (2003) and the survey-Organizational Culture (OCS) by Saravanan (2013). The collected data from each survey was analyzed by Descriptive Statistics, Frequency and Percentage, Mean and Standard Deviation, and Pearson Product Moment Correlation Coefficient. The study results indicated that the level of teachers’ perceptions of their leadership capacity was Moderate, and organizational culture was Positive. Consequently, it was determined that the relationship between the two variables was found to be Significant, however it was interpreted that the relationship between the two was weak due to the correlation (r) value of .388**. The findings suggested that teachers needed to create more opportunities and time for personal reflection for they would help them grow in their profession. In addition, to build collaborative and participative culture which could increase a healthy workplace was also recommended and the school organizations should also upgrade the quality of materials provided to teachers in teaching and learning process as well as innovative technologies should also be realized in order to keep abreast with the 21st century education

    Interference Analysis of Medium Voltage Air Line 20 KV Feeder Using Failure Mode and Effects Analysis Method

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    This article discusses the interference analysis of medium voltage air line 20 kv feeder using failure mode and effects analysis method. The distribution network consists of two parts, the first the distribution network consists of two parts, the first is the medium / primary voltage (JTM) network, which supplies electrical power from the sub-transmission substation to the distribution substation, the primary distribution network uses three wires or four wires for three phases. the impact of the reliability index from the calculation of the impact of the reliability index based on the number of disturbances (SAIFI), it shows that in January 2019 it has the highest index value, namely SAIFI, 1,695 disturbances/ subscribers. From the results of the calculation of the impact of the reliability index based on the number of blackouts (SAIDI), it shows that in January 2019 the SAIDI index value was 3,883 hours/customer

    Min-max Decoding Error Probability Optimization in RIS-Aided Hybrid TDMA-NOMA Networks

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    One of the primary objectives for future wireless communication networks is to facilitate the provision of ultra-reliable and low-latency communication services while simultaneously ensuring the capability for vast connection. In order to achieve this objective, we examine a hybrid multi-access scheme inside the finite blocklength (FBL) regime. This system combines the benefits of non-orthogonal multiple access (NOMA) and time-division multiple access (TDMA) schemes with the aim of fulfilling the objectives of future wireless communication networks. In addition, a reconfigurable intelligent surface (RIS) is utilized to facilitate the establishment of the uplink transmission between the base station and mobile devices in situations when impediments impede their direct communication linkages. This paper aims to minimize the worst-case decoding-error probability for all mobile users by jointly optimizing power allocation, receiving beamforming, blocklength, RIS reflection, and user pairing. To deal with the coupled variables in the formulated mixed-integer non-convex optimization problem, we decompose it into three sub-problems, namely, 1) decoding order determination problem, 2) joint power allocation, receiving beamforming, RIS reflection, and blocklength optimization problem, and 3) optimal user pairing problem. Then, we provide the sequential convex approximation (SCA) and semidefinite relaxation (SDR)-based algorithms as potential solutions for iteratively addressing the deconstructed first two sub-problems at a fixed random user pairing. In addition, the Hungarian matching approach is employed to address the challenge of optimizing user pairing. In conclusion, we undertake a comprehensive simulation, which reveals the advantageous qualities of the proposed algorithm and its superior performance compared to existing benchmark methods.Comment: 11 pages, 7 figure

    Joint User Pairing and Beamforming Design of Multi-STAR-RISs-Aided NOMA in the Indoor Environment via Multi-Agent Reinforcement Learning

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    The development of 6G/B5G wireless networks, which have requirements that go beyond current 5G networks, is gaining interest from academia and industry. However, to increase 6G/B5G network quality, conventional cellular networks that rely on terrestrial base stations are constrained geographically and economically. Meanwhile, NOMA allows multiple users to share the same resources, which improves the spectral efficiency of the system and has the advantage of supporting a larger number of users. Additionally, by intelligently manipulating the phase and amplitude of both the reflected and transmitted signals, STAR-RISs can achieve improved coverage, increased spectral efficiency, and enhanced communication reliability. However, STAR-RISs must simultaneously optimize the amplitude and phase shift corresponding to reflection and transmission, which makes the existing terrestrial networks more complicated and is considered a major challenging issue. Motivated by the above, we study the joint user pairing for NOMA and beamforming design of Multi-STAR-RISs in an indoor environment. Then, we formulate the optimization problem with the objective of maximizing the total throughput of MUs by jointly optimizing the decoding order, user pairing, active beamforming, and passive beamforming. However, the formulated problem is a MINLP. To address this challenge, we first introduce the decoding order for NOMA networks. Next, we decompose the original problem into two subproblems, namely: 1) MU pairing and 2) Beamforming optimization under the optimal decoding order. For the first subproblem, we employ correlation-based K-means clustering to solve the user pairing problem. Then, to jointly deal with beamforming vector optimizations, we propose MAPPO, which can make quick decisions in the given environment owing to its low complexity.Comment: 8 pages, 9 figures, IEEE/IFIP Network Operations and Management Symposium (NOMS) 2024 submitte

    Trajectory Optimization and Phase-Shift Design in IRS Assisted UAV Network for High Speed Trains

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    The recent trend towards the high-speed transportation system has spurred the development of high-speed trains (HSTs). However, enabling HST users with seamless wireless connectivity using the roadside units (RSUs) is extremely challenging, mostly due to the lack of line of sight link. To address this issue, we propose a novel framework that uses intelligent reflecting surfaces (IRS)-enabled unmanned aerial vehicles (UAVs) to provide line of sight communication to HST users. First, we formulate the optimization problem where the objective is to maximize the minimum achievable rate of HSTs by jointly optimizing the trajectory of UAV and the phase-shift of IRS. Due to the non-convex nature of the formulated problem, it is decomposed into two subproblems: IRS phase-shift problem and UAV trajectory optimization problem. Next, a Binary Integer Linear Programming (BILP) and a Soft Actor-Critic (SAC) are constructed in order to solve our decomposed problems. Finally, comprehensive numerical results are provided in order to show the effectiveness of our proposed framework.Comment: This paper has been submitted to IEEE Wireless Communications Letter

    Evaluating Stability of Aqueous Multiwalled Carbon Nanotube Nanofluids by Using Different Stabilizers

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    The 0.5 wt.% multiwalled carbon nanotubes/water nanofluids (MWNFs) were produced by using a two-step synthetic method with different types and concentrations of stabilizers. The static position method, centrifugal sedimentation method, zeta potential measurements, and rheological experiments were used to assess the stability of the MWNFs and to determine the optimal type and fixed MWCNTs-stabilizer concentration of stabilizer. Finally, MWNFs with different concentrations of MWCNTs were produced using the optimal type and fixed concentration ratio of stabilizer, and their stability, thermal conductivity, and pH were measured to assess the feasibility of using them in heat transfer applications. MWNFs containing SDS and SDBS with MWCNTs-stabilizer concentration ratio were 5 : 2 and 5 : 4, respectively, showed excellent stability when they were evaluated by static position, centrifugal sedimentation, zeta potential, and rheological experiments at the same time. The thermal conductivity of the MWNFs indicated that the most suitable dispersing MWNF contained SDBS. MWNFs with MWCNTs concentrations of 0.25, 0.5, and 1.0 wt.% were fabricated using an aqueous SDBS solution. In addition, the thermal conductivity of the MWNFs was found to have increased, and the thermal conductivity values were greater than that of water at 25°C by 3.20%, 8.46%, and 12.49%

    Swin Transformer-Based Dynamic Semantic Communication for Multi-User with Different Computing Capacity

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    Semantic communication has gained significant attention from researchers as a promising technique to replace conventional communication in the next generation of communication systems, primarily due to its ability to reduce communication costs. However, little literature has studied its effectiveness in multi-user scenarios, particularly when there are variations in the model architectures used by users and their computing capacities. To address this issue, we explore a semantic communication system that caters to multiple users with different model architectures by using a multi-purpose transmitter at the base station (BS). Specifically, the BS in the proposed framework employs semantic and channel encoders to encode the image for transmission, while the receiver utilizes its local channel and semantic decoder to reconstruct the original image. Our joint source-channel encoder at the BS can effectively extract and compress semantic features for specific users by considering the signal-to-noise ratio (SNR) and computing capacity of the user. Based on the network status, the joint source-channel encoder at the BS can adaptively adjust the length of the transmitted signal. A longer signal ensures more information for high-quality image reconstruction for the user, while a shorter signal helps avoid network congestion. In addition, we propose a hybrid loss function for training, which enhances the perceptual details of reconstructed images. Finally, we conduct a series of extensive evaluations and ablation studies to validate the effectiveness of the proposed system.Comment: 14 pages, 10 figure

    Field Application of a High-Power Density Electromagnetic Energy Harvester to Power Wireless Sensors in Transportation Infrastructures

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    Finding an efficient source of energy has always been a big challenge for humans on Earth. Fossil fuels, such as coal and oil, have traditionally been considered as major sources of energy. These energy sources are not only nonrenewable but are also harmful to our health and environment. A large portion of this energy is consumed by vehicles moving daily in big cities, causing significant pollution of the environment. However, the motion of vehicles through the transportation infrastructures can also be a significant source of kinetic energy, which can be harvested to power transportation system components, such as sensors, street lights, signals,etc., thereby reducing some dependence on fossil fuel-derived energy
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