A Scalable Four-Channel Frequency-Division Multiplexing MIMO Radar Utilizing Single-Sideband Delta-Sigma Modulation

A scalable four-channel multiple-input multiple-output (MIMO) radar that features a modular system architecture and a novel frequency-division multiplexing approach is presented in this article. It includes a single 30-GHz voltage-controlled oscillator (VCO) for the local oscillator signal generation, four cascaded 120-GHz transceivers with a frequency quadrupler, and on-board differential series-fed patch antennas. The utilized uniform antenna configuration results in 16 virtual array elements and enables an angular resolution of 6.2°. The vector modulators in the transmit (TX) paths allow the application of complex bit streams of second-order delta-sigma modulators easily generated on a field-programmable gate array (FPGA) to implement single-sideband (SSB) modulation on the TX signals resulting in orthogonal waveforms for the MIMO operation. Only one phase-locked loop and no digital-To-Analog converter is required. The waveform diversity also allows the simultaneous transmission of the TX signals to reduce the measurement time. The application of the SSB modulation on the frequency-modulated continuous-wave MIMO radar requires only half of the intermediate frequency bandwidth compared with the double-sideband modulation. The issue of the phase and amplitude mismatches at the virtual array elements due to the scalable radar architecture is addressed and a calibration solution is introduced in this article. Radar measurements using different numbers of virtual array elements were compared and the digital-beamforming method was applied to the results to create 2-D images. © 1963-2012 IEEE

City Government in Bangladesh: An Alternative Approach to Bring Efficiency & Effectiveness in Urban Governance

Democracy and development are interelated. Bangladesh is facing a number of difficulties to ensure development through democray in every aspect of its life. City government is an approach to improve and accelerate the process of democracy through governance, where development is major concern, in urban areas of Bangladesh. The conflict between mayors and local MPs (Member of Parliament) is a common phenomenon that is account for failure the development programs in city corporations. The present study aims to clarify the present condition of urban local government and possibility of City Government in Bangladesh. The study found ruling party interfere in local election, which must be avoid, financial independence is crucial issue for city government which will be managed locally if city government established. Awareness of the people, literacy and motivation can increase people's participation for effective governance in cities.  Public Accountability and maintaining hierarchy was also marked as an important for effective city government. Delegation of authority and autonomy of city (local) government were found the precondition to establish of city government in Bangladesh where party politics must be keeping away from

Efficient Regeneration System for the Improvement of Kinnow mandarin (Citrus reticulata Blanco)

Kinnow mandarin (Citrus reticulata Blanco.) is a highly adaptable variety among citrus cultivars. An efficient system for in vitro regeneration by organogenesis starting from seed of (C. reticulata Blanco) was developed. Seeds were treated by Murashige and Skoog (MS) media supplemented with 2, 4-Dichlorophenoxyacetic acid (2, 4-D) to initiate callus induction. The best result (96%) were obtained when seeds were treated with MS basal media + 2,4-D (16.0) μM. The regeneration system tested allowed the attainment of highest shoots (90 %) with BA 13.0 μM. An average of 7.8 well-differentiated shoots per explant was obtained. Highest rooting (85%) was achieved in culture medium with 10.0 μM IBA. The well-developed plantlets were transferred to potting mixture. Of the rooted plant, 95% adapted well to soil conditions. Keywords: C. reticulata Blanco, In vitro, Callus induction, Shoot formation, Explant, Rooting. Abbreviations: μM = Micromolar, BA = Benzyl adenine, IBA = Indole-3-butyric acid, TSS = Total soluble solids, NAA

Nitrogen management in boro rice using chlorophyll meter (SPAD) under sub-tropical condition

Nitrogen deficiency in rice has so far received limited attention in Bangladesh. Balanced fertilization is a pre-requisite for better rice production and it is necessary to determine optimum combination of fertilizer dose and varieties. The field experiment was carried out during the period from November 2020 to May 2021 at the Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh to study the SPAD value and yield performance of boro rice varieties at different nitrogen levels. The experiment comprised of four boro rice varieties viz., BRRI dhan28, BRRI dhan58, BRRI dhan74, BRRI dhan81 and four level of nitrogenous fertilizers viz. 50 kg N ha-1, 100 kg N ha-1, 150 kg N ha-1 and 200kg N ha-1. The experiment was laid out in a randomized complete block design with three replications. SPAD value ranged from 34.01 to 42.12 for variety and 37.81 to 42.15 for nitrogen application, while leaf nitrogen ranged from 2.98 to 3.67 % for variety and 2.94 to 3.48%.  The yield contributing parameter varied significantly with variety and nitrogen rate. The highest grain yield (6.13 t ha-1) was found in BRRI dhan58 and the lowest (3.89 t ha-1) was observed in BRRI dhan28. In terms of fertilizer management, the highest grain yield (5.35 t ha-1) was obtained due to the application of 150 kg N ha-1 and the lowest grain yield (4.72 t ha-1) was recorded from50 kg N ha-1. The interactive effect of variety and fertilizer application exerted that the yield of BRRI dhan58 with 150 kg N ha-1 was the highest (6.59 tha-1) and the lowest performance (3.42 tha-1) in grain yield was found in BRRI dhan28 with 50 kg N ha-1. Thus, the variety BRRI dhan58 with 150 kg N ha-1 was superior for attaining the highest yield

ATM Shield: Analysis of Multitier Security Issues of ATM in the Context of Bangladesh

Over the last decade, consumers have been largely dependent on and trust the Automatic Teller Machine (ATM) to conveniently meet their banking needs. However, despite the numerous advantages of ATM system, ATM fraud has recently become more widespread. In this paper, we provide an overview of the possible fraudulent activities that may be perpetrated against ATMs and investigates recommended approaches to prevent these types of frauds. In particular, we develop a prototype model for the utilization of three tier security equipped ATM to provide security solutions against must of the well-known breaches. In this research article, the tools and techniques of ATM fraud are contemplated. A secure three layer electronic transaction mechanism of ATM is developed to prevent ATM frauds. In this three layer authentication systems the users can improve ATM security against frauds and crimes

Introduction of Bond Market: Would it be a possible Solution for Bangladesh?

This study aims at investigating the prospects of a bond market in Bangladesh. Most of the developed and developing economies have an active and successful bond market. But Bangladesh despite being one of the fastest-growing economies, does not have an active bond market. Hence, this study was designed to investigate the impact of a bond market on the economic growth of Asian countries and what are the prospects and challenges in Bangladesh. To investigate the benefits of a bond market in Bangladesh, this study examined the relationship between bond market return and economic growth of 4 Asian economies which included, India, Indonesia, Hong Kong, and Japan. The average annual yield of 10-year bonds was used as the independent variable and the annual GDP growth rate of these countries was used as the dependent variable in the econometric model. Data for the last 20 years from 2000 to 2019 were used for all the variables. The Unit Root Test showed that 3 variables were stationary at first difference and the other five variables were stationary at level. The Johansen Co-integration test identified the long-run association among the variables indicating the long-run relationship between bond market return and economic growth. Granger Causality revealed a bi-directional relationship for India; unidirectional relationship for Indonesia (Bond→GDP growth) and Japan (GDP Growth→Bond); and no unidirectional or bidirectional relationship among the bond market return and economic growth of Hong Kong. The various new projects, the overextension of the banking sector, and perhaps the overall good condition of the economy has created the perfect situation to develop a bond market in Bangladesh. As there are conditions that provide advantages in bond market creation, there are also various challenges that the government must overcome. Some of the most important challenges to clear up are the underdeveloped tax system, the illiquid or absent secondary market, the alternative source of debt, and the overall lack of investors. Considering the various developed bond markets these policy implications could seriously aid the development process

Smart detection and prevention procedure for DoS attack in MANET

A self-organized wireless communication short-lived network containing collection of mobile nodes is mobile ad hoc network (MANET). The mobile nodes communicate with each other by wireless radio links without the use of any pre-established fixed communication network infrastructure or centralized administration, such as base stations or access points, and with no human intervention. In addition, this network has potential applications in conference, disaster relief, and battlefield scenario, and have received important attention in current years. There is some security concern that increases fear of attacks on the mobile ad-hoc network. The mobility of the NODE in a MANET poses many security problems and vulnerable to different types of security attacks than conventional wired and wireless networks. The causes of these issues are due to their open medium, dynamic network topology, absence of central administration, distributed cooperation, constrained capability, and lack of clear line of defense. Without proper security, mobile hosts are easily captured, compromised, and attacked by malicious nodes. Malicious nodes behavior may deliberately disrupt the network so that the whole network will be suffering from packet losses. One of the major concerns in mobile ad-hoc networks is a traffic DoS attack in which the traffic is choked by the malicious node which denied network services for the user. Mobile ad-hoc networks must have a safe path for transmission and correspondence which is a serious testing and indispensable issue. So as to provide secure communication and transmission, the scientist worked explicitly on the security issues in versatile impromptu organizations and many secure directing conventions and security measures within the networks were proposed. The goal of the work is to study DoS attacks and how it can be detected in the network. Existing methodologies for finding a malicious node that causes traffic jamming is based on node’s retains value. The proposed approach finds a malicious node using reliability value determined by the broadcast reliability packet (RL Packet). In this approach at the initial level, every node has zero reliability value, specific time slice, and transmission starts with a packet termed as reliability packet, node who responded properly in specific time, increases its reliability value and those nodes who do not respond in a specific time decreases their reliability value and if it goes to less than zero then announced that it’s a malicious node. Reliability approach makes service availability and retransmission time