27 research outputs found

    A User Scheduling Scheme for Reducing Electromagnetic (EM) Emission in the Uplink of Mobile Communication Systems

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    The ubiquity and convergence of wireless communication services have contributed to an unprecedented popularity of mobile communications. Given that wireless communication systems operate on radiofrequency waves, the electromagnetic (EM) radiation exposure they generate is also unprecedented and, hence, this could have adverse health effects on both humans and animals according to the World Health Organization. In this paper, we propose a user scheduling/power allocation scheme to minimize the EM exposure of users subject to transmitting a target number of bits. Our user scheduling method is based on assigning priority levels to each user and the user with the lowest priority level is scheduled for transmission. Power allocation, on the other hand, is based on the water-filling approach over time by using the past channel gains of a user to compute its water level. Simulation results show that our proposed scheme performs much better than a spectral efficiency based scheme but has a higher EM emission in comparison with a non-practical ideal scheme

    Electromagnetic emission-aware schedulers for the uplink of OFDM wireless communication systems

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    The popularity and convergence of wireless communications have resulted in continuous network upgrades in order to support the increasing demand for bandwidth. However, given that wireless communication systems operate on radiofrequency waves, the health effects of electromagnetic emission from these systems are increasingly becoming a concern due to the ubiquity of mobile communication devices. In order to address these concerns, we propose two schemes (offline and online) for minimizing the EM emission of users in the uplink of OFDM systems, while maintaining an acceptable quality of service. We formulate our offline EM reduction scheme as a convex optimization problem and solve it through water-filling. This is based on the assumption that the long-term channel state information of all the users is known. Given that, in practice, long-term channel state information of all the users cannot always be available, we propose our online EM emission reduction scheme, which is based on minimizing the instantaneous transmit energy per bit of each user. Simulation results show that both our proposed schemes significantly minimize the EM emission when compared to the benchmark classic greedy spectral efficiency based scheme and an energy efficiency based scheme. Furthermore, our offline scheme proves to be very robust against channel prediction errors

    Spectral Efficiency Improvements in HetNets by Exploiting Device-to-Device Communications

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    Next generation cellular networks require huge capacity, ubiquitous coverage and maximum energy efficiency. In order to meet these targets, Device-to-device (D2D) communication is being considered for future heterogeneous networks (HetNets). In this paper, we consider a three tier hierarchical HetNet by exploiting D2D communication in traditional HetNet. D2D communication is deployed within the HetNet where closely located mobile users are engaged in direct communication without routing the traffic through cellular access network. The proposed configuration mandates to reduce the interference offered by the resultant HetNet by reducing the transmitter-receiver distance and ensuring that the mobile users are transmitting with adaptive power subject to maintaining their desired link quality. In this context, we analyzed and compared the spectral efficiency improvements in hierarchical HetNet against traditional HetNet. Simulation results show that D2D communication offers much higher spectral efficiency as compared to traditional HetNet

    Effect of Auditor Ethics, Knowledge and Dysfunctional Behavior Audit Office of the Quality of Public Accountants in Makassar

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    Cases of violation of the Public Accountants Professional Standards at Drs. Mitrawinata and colleagues, due to unfavorable auditor ethics where Drs. Peter Partner Winatadari as Public Accountant (AP) violated the Public Accountants Professional Standards (SPAP) relating to the audit that the general audit assignment restrictions on financial statements Muzatek Jaya. Associated with good audit quality, there are several things that affect them auditor ethics, knowledge and dysfunctional behavior. This study aims to determine the effect of auditor ethics, knowledge and dysfunctional behavior on audit quality either simultaneously or partially on public accounting firm in Makassar. The sampling technique using saturated sampling technique, in order to obtain a sample of 37 respondents. Methods of data analysis using multiple linear regression techniques, test F and test t. These results indicate that the auditor ethics, knowledge and dysfunctional behavior simultaneously significant positive effect on audit quality in the public accounting firm in Makassar. Partially ethics of auditors and knowledge of significant positive effect on audit quality, but not for the dysfunctional behavior that significant negative effect on audit quality. The level of contribution influence auditor ethics, knowledge and dysfunctional behavior on audit quality is high. This is caused by some respondents to variable auditor ethics, knowledge and quality of the audit is still no answer neutral and do not agree, while the dysfunctional behavior variables still exist some respondents who answered disagree and strongly disagree

    Drone Trajectory Optimization using Genetic Algorithm with Prioritized Base Stations

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    Drones have been widely applied to perform emergent tasks in the post-disaster scenario, due to their unique characteristics such as mobility, flexibility, and adaptivity to altitude. However, drones have limited energy capacity, which presents a major drawback in flight time and affects their performance in such scenarios. Hence, trajectory optimization has become a critical research problem for such applications of drones. In this paper, we present an optimal trajectory design for a single drone to ferry data from temporary Base Stations (BSs) deployed within a disaster zone to a fixed gateway node that is the point of origin and final destination for the drone flight. We have used a Genetic Algorithm (GA)-based approach that takes into account the shortest distance traveled and least time spent by the drone during flight. We also examine the case where some BSs have delay requirements that are unknown to the drone in advance. Simulation results show that the performance of our proposed GA-based approach matches that of the benchmark exhaustive search algorithm and the difference in computational time between the 2 algorithms increases with the number of BSs. Accordingly, our proposed algorithm has 96.4% lower computational time complexity compared to the benchmark exhaustive search algorithm when there are 12 BSs in the disaster area

    Motion Sensor-based Small Cell Sleep Scheduling for 5G Networks

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    5G-enabled education 4.0: enabling technologies, challenges, and solutions

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    New technologies such as mobile phones, social media and artificial intelligence, have significant impacts on every aspect of education, where digital connectivity is the foundation to support the way people learn. Current Internet and pre-5G cellular communication networks can deliver visual and auditory data, which enable distance/virtual learning. However, remote physical interaction between students and learning facilities, which is an essential part of a new education paradigm i.e., Education 4.0, is still missing. The 5G cellular network with excellent latency and reliability performance would be a game changer by enabling students to feel the physical objects and control them remotely. In this paper, we identify and discuss the unique opportunities the 5G networks can bring to Education 4.0, their technical challenges and potential solutions. We also showcase our Education 4.0 prototype of remote lab

    Intelligent resource management for eMBB and URLLC in 5G and beyond wireless networks

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    In the era of 5G and beyond wireless networks, the simultaneous support of enhanced Mobile Broadband (eMBB) and Ultra-Reliable Low Latency Communications (URLLC) poses significant challenges in managing radio resources efficiently. By leveraging the puncturing technique, we propose an intelligent resource management framework for meeting the strict latency and reliability requirement of URLLC services and the high data rate for eMBB services. In particular, a semi-supervised learning and deep reinforcement learning (DRL) based architecture is proposed to manage the resources intelligently. We decompose the optimization problem into two subproblems: 1) resource block allocation (RBA) strategy for eMBB slice, and 2) URLLC scheduling. Through extensive simulations and performance evaluations, we demonstrate the effectiveness of the proposed technique in optimizing resource utilization, minimizing latency for URLLC users, and maximizing the throughput for eMBB services. Simulation findings demonstrate that the proposed methodology can ensure the URLLC reliability requirements while maintaining higher average sum rate for eMBB and higher convergence rate. The proposed framework paves the way for the efficient coexistence of diverse services, enabling wireless network operators to optimize resource allocation, improve user experience, and meet the specific requirements of eMBB and URLLC applications

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Energy-Efficient Interference-Aware Precoding for the Downlink of Multi-Cell Multi-User MIMO Systems

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    Energy efficiency (EE) is fast becoming a key performance indicator for designing future wireless communication systems. Equally, precoding/power allocation has proved to be very effective for improving the spectral efficiency (SE) of multi-user (MU) multi-input multi-output (MIMO) communication systems. In a multi-cell environment, other-cell interference (OCI) degrades both the SE and EE performances of the system. We design here an energy efficient OCI-aware precoding/power allocation algorithm for the downlink of MU-MIMO systems by relying on regularized channel inversion and considering a realistic multi-antenna power consumption model. The performance of our proposed scheme is assessed both in presence and absence of OCI and results demonstrate the effectiveness of our approach for mitigating OCI. In addition, results show that our approach improves the EE of the system by saving transmit power in comparison with a traditional SE-based precoding/power allocation approach
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