nurul islam - Academia.edu (original) (raw)

Papers by nurul islam

Abstract: This study presents the spatial and temporal dynamics of alluvial char using the LANDSA... more Abstract: This study presents the spatial and temporal dynamics of alluvial char using the LANDSAT TM Satellite image of the Brahmaputra-Jamuna River in Bangladesh. The Explanatory Data Analysis and Geo-statistical techniques have used to analyze, interprete and visualize the data. The results show that every year the charland shifts due to multi-channel river flow and braided characteristics of the Brahmaputra-Jamuna River. The highest charlands accumulation area is measured 20.683 sqkm including sandy char, settlements, agriculture and vegetation cover in 2004, and lowest 13.463 sqkm in 1983. The total area of sandy chars have been increasing science 1973 which occupies 43.478 sqkm and settlements, agriculture and vegetation cover and also takingtotal area 38.47 sqkm in 2014; while water bodies decrease 36.478 sqkm. due to the sedimentaccumulation in Brahmaputra river. Every year charlands are shifting respectively. The local topography, flood, erosion, and sedimentation into the river bed are main causes of charlands shifting. Charland shifting is important phenomenon for braided river and development of the charlands people livelihood. The charlands shifting in the Brahmaputra River causes a severe damage to the agriculture, settlement and vegetation cover on stable chars. Charlands people play important role in our national life and our national progress is not possible without advancement of the charlands. It requires a long term strategy, with a view to the monitoring the charland shifting for the better development of the charlands people livelihood in Bangladesh. It has been argued that further in depth numerical model based study need to carry out for wider implication of Charland shifting phenomenon.

Conference on Lasers and Electro-Optics, 2018

We realize a time-bin qudit-based quantum key distribution system that uses two-photon interferen... more We realize a time-bin qudit-based quantum key distribution system that uses two-photon interference for measuring the phase-basis states, allowing us to generate a secret key at a megabits-per-second rate.

The Pakistan Development Review, 1968

Pakistan has experienced in the last decade a significant rate of growth of exports, especially o... more Pakistan has experienced in the last decade a significant rate of growth of exports, especially of the manufactured exports. The manufactured exports have grown at an annual compound rate of 15 per cent during the period 1960-67. This significant rate of growth of exports has been associated with a large number of export-promotion measures which have ranged from a wide variety of fiscal concessions to such export-incentive schemes as the export bonus and export performance licensing as well as the fixation of compulsory export quotas for the individual manufactured exports. The question has been raised from time to time as to the efficacy of the export-promotion measures in terms of the net foreign-exchange earnings, denned as the actual increase in export earnings from a unit of export minus the direct and indirect requirements of imports necessary for the production of the unit of export. Since one of the important criteria for the determination of the investment priorities in the...

Physical Review A, 2018

Quantum key distribution (QKD) allows two remote users to establish a secret key in the presence ... more Quantum key distribution (QKD) allows two remote users to establish a secret key in the presence of an eavesdropper. The users share quantum states prepared in two mutually-unbiased bases: one to generate the key while the other monitors the presence of the eavesdropper. Here, we show that a general d-dimension QKD system can be secured by transmitting only a subset of the monitoring states. In particular, we find that there is no loss in the secure key rate when dropping one of the monitoring states. Furthermore, it is possible to use only a single monitoring state if the quantum bit error rates are low enough. We apply our formalism to an experimental d = 4 timephase QKD system, where only one monitoring state is transmitted, and obtain a secret key rate of 17.4 ± 2.8 Mbits/s at a 4 dB channel loss and with a quantum bit error rate of 0.045 ± 0.001 and 0.037 ± 0.001 in time and phase bases, respectively, which is 58.4% of the secret key rate that can be achieved with the full setup. This ratio can be increased, potentially up to 100%, if the error rates in time and phase basis are reduced. Our results demonstrate that it is possible to substantially simplify the design of high-dimensional QKD systems, including those that use the spatial or temporal degrees-of-freedom of the photon, and still outperform qubit-based (d = 2) protocols.

Science advances, 2017

The security of conventional cryptography systems is threatened in the forthcoming era of quantum... more The security of conventional cryptography systems is threatened in the forthcoming era of quantum computers. Quantum key distribution (QKD) features fundamentally proven security and offers a promising option for quantum-proof cryptography solution. Although prototype QKD systems over optical fiber have been demonstrated over the years, the key generation rates remain several orders of magnitude lower than current classical communication systems. In an effort toward a commercially viable QKD system with improved key generation rates, we developed a discrete-variable QKD system based on time-bin quantum photonic states that can generate provably secure cryptographic keys at megabit-per-second rates over metropolitan distances. We use high-dimensional quantum states that transmit more than one secret bit per received photon, alleviating detector saturation effects in the superconducting nanowire single-photon detectors used in our system that feature very high detection efficiency (of...

Physical Review Applied, 2017

We experimentally investigate a cascade of temperature-compensated unequal-path interferometers t... more We experimentally investigate a cascade of temperature-compensated unequal-path interferometers that can be used to measure frequency states in a high-dimensional quantum distribution system. In particular, we demonstrate that commercially-available interferometers have sufficient environmental isolation so that they maintain an interference visibility greater than 98.5% at a wavelength of 1550 nm over extended periods with only moderate passive control of the interferometer temperature (< ±0.50 • C). Specifically, we characterize two interferometers that have matched delays: one with a free-spectral range of 2.5 GHz, and the other with 1.25 GHz. We find that the relative path of these interferometers drifts less than 3 nm over a period of one hour during which the temperature fluctuates by < ±0.10 • C. When we purposely heat the interferometers over a temperature range of 20-50 • C, we measure a path-length shift of 26 ± 9 nm/ • C for the 2.5 GHz interferometer. For the 1.25 GHz interferometer, the path-length shift is nonlinear and is locally equal to zero at a temperature of 37.1 • C and is 50 ± 17 nm/ • C at 22 • C. With these devices, we realize a proof-of-concept quantum key distribution experiment and achieve quantum bit error rates of 1.94% and 3.69% in time and frequency basis, respectively, at a quantum channel loss of 14 dB.

Quantum Information Science and Technology II, 2016

High-dimensional (dimension d > 2) quantum key distribution (QKD) protocols that encode informati... more High-dimensional (dimension d > 2) quantum key distribution (QKD) protocols that encode information in the temporal degree of freedom promise to overcome some of the challenges of qubit-based (d = 2) QKD systems. In particular, the long recovery time of single-photon detectors and large channel noise at long distance both limit the rate at which a final secure key can be generated in a low-dimension QKD system. We propose and demonstrate a practical discrete-variable time-frequency protocol with d = 4 at a wavelength of 1550 nm, where the temporal states are secured by transmitting and detecting their dual states under Fourier transformation, known as the frequency-basis states, augmented by a decoy-state protocol. We show that the discrete temporal and frequency states can be generated and detected using commercially-available equipment with high timing and spectral efficiency. In our initial experiments, we only have access to detectors that have low efficiency (1%) at 1550 nm. Together with other component losses, our system is equivalent to a QKD system with ideal components and a 50-km-long optical-fiber quantum channel. We find that our system maintains a spectral visibility of over 99.0% with a quantum bit error rate of 2.3%, which is largely due to the finite extinction ratio of the intensity modulators used in the transmitter. The estimated secure key rate of this system is 7.7×10 4 KHz, which should improve drastically when we use detectors optimized for 1550 nm.

Quarterly Journal of International Agriculture, 1990

PRIFPRI

IFAC Proceedings Volumes, 2011

For a typical biologically inspired multi-segmental mechanical system, the system's locomotion be... more For a typical biologically inspired multi-segmental mechanical system, the system's locomotion behavior is rectified from the segments' rhythmic oscillation. A central pattern generator (CPG) based controller has been developed to achieve the locomotion with a certain sense of natural oscillation. We designed and manufactured a prototype mechanical rectifier (PMR) system which captures the essential mechanism of multi-segmental systems. Experiments were conducted on the PMR system to reveal the effectiveness of the natural oscillation entrainment controller.

Aid and Influence, 1981

It was a major task to draw together all the differing interests and capabilities of donor countr... more It was a major task to draw together all the differing interests and capabilities of donor countries and agencies and weld them into a coherent, balanced and effective development programme. Also within Bangladesh, several groups with different interests were involved and exercised pressure and influence. A wide range of conflicting interests had to be reconciled in the process. Aid had to be found to support the import programme, projects had to be assigned to donors and agreed with them, and ministries and development agencies had to be convinced that they could not always be allowed to arrange things exactly as they wished.

Bangladesh Journal of Plant Taxonomy

IEEE Transactions on Robotics, 2014

Typical animal locomotion is achieved by the rhythmical undulation of its body segments while int... more Typical animal locomotion is achieved by the rhythmical undulation of its body segments while interacting with its environment. It inspires the mechanical design of multilink locomotors. With different postures, a multilink system may present different locomotion gaits. Recently, a so-called natural oscillation gait was studied for multilink systems, and a class of biologically inspired controllers was designed for the achievement of the gait. In this paper, the theoretical design is experimentally applied on a mechanical multilink testbed of two posture configurations in rayfish-like flapping-wing motion and snake-like serpentine motion. The effectiveness of the design is cross examined by theoretical analysis, numerical simulation, and experiments.

2013 American Control Conference, 2013

Frontiers in Optics 2014, 2014

We experimentally demonstrate a quantum cryptography system based on photonic orbital angular mom... more We experimentally demonstrate a quantum cryptography system based on photonic orbital angular momentum. The system achieves a channel capacity of 2.1 bits per sifted photon through the use of a 7-dimensional alphabet for encoding information.

Journal of Life and Earth Science, 2014

The insecticidal activity, insect repellency and brine shrimp lethality tests of three solvent ex... more The insecticidal activity, insect repellency and brine shrimp lethality tests of three solvent extracts of Synedrella nodiflora L. were assessed against the adults of Tribolium castaneum (Herbst) under laboratory conditions. The methanol extract found most effective (LD50 1.229, 0.823 and 0.569mg cm-2 for 24, 36 and 48h of exposure respectively) followed by the chloroform extract (LD50 3.042, 2.773, 2.456 and 2.233mg cm-2 for 12, 24, 36 and 48h of exposure respectively) and petroleum ether extract (LD50 8.416, 4.764, 3.677, 3.392 and 3.177mg cm-2 for 12, 24, 36, 48 and 60h exposure respectively). The CHCl3 and MeOH extracts showed repellent activity against T. castaneum adults at P<0.05 and P<0.01 levels of significance, while the Pet. E. extract did not show any repellency. The similar extracts responded through brine shrimp lethality assay and the Pet. E. extract found most effective (LC50 321.182, 248.151, 182.196 and 140.866ppm) followed by the MeOH extract (LC50 428.356, ...

2004 International Symposium on Electromagnetic Compatibility (IEEE Cat. No.04CH37559)

... Phurnin Kirawanich, Nakka S. Kranthi, and N. E. Islam Electrical and Computer Engineering Dep... more ... Phurnin Kirawanich, Nakka S. Kranthi, and N. E. Islam Electrical and Computer Engineering Department University of Missouri Columbia, MO 6521 I ... of the incident fields on the cable incorporated in the code can be implemented through the Taylor and Agrawal's formulations [ ...

Indian journal of fibre & …, 2001

Journal of the Textile Institute, 2001

Jute fibre is, by nature, hard and coarse. Treated with a sulphite of sodium in its neutral solut... more Jute fibre is, by nature, hard and coarse. Treated with a sulphite of sodium in its neutral solution at about 165° C some of its properties were found to improve as lignin undergoes sulphonation reaction. Incrustation due to lignin is loosened, dislocated and partially ...

IEEE Transactions on Control Systems Technology, 2012

Abstract For a typical biologically inspired multi-segmental mechanical system, the system&#x... more Abstract For a typical biologically inspired multi-segmental mechanical system, the system's locomotion behavior is rectified from the segments' rhythmic oscillation. A central pattern generator (CPG)-based controller was developed to achieve the locomotion with a certain ...