scholarly journals PROPOSING A NEW METHOD FOR ENCRYPTING SATELLITE IMAGES BASED ON HASH FUNCTION AND CHAOS PARAMETERS

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 949-953
Author(s):  
M. Sedighi ◽  
S. K. Mahmoudi ◽  
A. S. Amini
Keyword(s):  
Hash Function ◽  
Satellite Images ◽  
High Sensitivity ◽  
New Method ◽  
Cryptographic Algorithm ◽  
Mapping Parameters ◽  
Dynamic Encryption ◽  
Primary Key ◽  
And Performance ◽  
Hash Key

Abstract. Due to the importance of providing security in satellite imagery and their transmission, in this paper, a new method for encrypting satellite images based on Hash key-based symmetric cryptographic algorithm is proposed which is developed by combining the generated key and chaos mapping parameters. The benefits of this algorithm are high security, high sensitivity and using dynamic encryption blocks. The proposed algorithm consists of three main parts: in the first section, the encryption key is created using the SHA-512 Hash function. In the second section, the initial values and the parameters of the mapping Chaos are determined by the algebraic functions that are related to the primary key. In the third section, with the help of the encryption block, the encrypted image is finally obtained. The purpose of this article is to increase the security of encrypting satellite images by creating an unspecified encryption block to deal with a variety of attacks. In this regard, both aspects of security and performance of the proposed algorithm have been analysed and the results are evaluated.

scholarly journals Biological nanoscale fluorescent probes: From structure and performance to bioimaging

2020 ◽  
Vol 39 (1) ◽  
pp. 209-221
Author(s):  
Jiafeng Wan ◽  
Xiaoyuan Zhang ◽  
Kai Zhang ◽  
Zhiqiang Su
Keyword(s):  
Fluorescent Probes ◽  
Organic Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
High Sensitivity ◽  
Biological Imaging ◽  
Fluorescent Materials ◽  
And Performance

Abstract In recent years, nanomaterials have attracted lots of attention from researchers due to their unique properties. Nanometer fluorescent materials, such as organic dyes, semiconductor quantum dots (QDs), metal nano-clusters (MNCs), carbon dots (CDs), etc., are widely used in biological imaging due to their high sensitivity, short response time, and excellent accuracy. Nanometer fluorescent probes can not only perform in vitro imaging of organisms but also achieve in vivo imaging. This provides medical staff with great convenience in cancer treatment. Combined with contemporary medical methods, faster and more effective treatment of cancer is achievable. This article explains the response mechanism of three-nanometer fluorescent probes: the principle of induced electron transfer (PET), the principle of fluorescence resonance energy transfer (FRET), and the principle of intramolecular charge transfer (ICT), showing the semiconductor QDs, precious MNCs, and CDs. The excellent performance of the three kinds of nano fluorescent materials in biological imaging is highlighted, and the application of these three kinds of nano fluorescent probes in targeted biological imaging is also introduced. Nanometer fluorescent materials will show their significance in the field of biomedicine.

A New Method of 6-DOF Serial Robot’s Trajectory Planning under Multi-Constraints

2014 ◽  
Vol 602-605 ◽  
pp. 1352-1357 ◽  
Author(s):  
Yong Ting Zhao ◽  
Bin Zheng ◽  
Hong Lin Ma
Keyword(s):  
Coordinate System ◽  
Trajectory Planning ◽  
Angular Displacement ◽  
Joint Space ◽  
New Method ◽  
Position Information ◽  
Physical Constraints ◽  
Dynamic Constraints ◽  
Quaternion Interpolation ◽  
And Performance

This paper proposes a new method of 6-DOF serial robot’s trajectory planning. Ensuring to satisfy the physical constraints of space conditions, the robot’s trajectory is interpolated in the Cartesian coordinate system, and using quaternion interpolation to solve the multiple solution problem in RPY interpolation. Meanwhile, the interpolated position information is transformed into the angular displacement information of the joint coordinate system, and the joint space trajectory planning is achieved using the genetic algorithms integrated velocity, acceleration, jerk and torque and other important kinematic and dynamic constraints. In robot safety and stability, the method is better than the general approach, and it has both the ideal trajectory parameters of the global search ability and performance planning.

Quantification of Tire-Tread Particles Using Extractable Organic Zinc as Tracer

1999 ◽  
Vol 72 (5) ◽  
pp. 969-977 ◽  
Author(s):  
Patrik Fauser ◽  
Jens Christian Tjell ◽  
Hans Mosbaek ◽  
Kim Pilegaard
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Environmental Samples ◽  
High Sensitivity ◽  
Absorption Spectrometry ◽  
Soil Samples ◽  
New Method ◽  
Organic Zinc

Abstract A method for identifying and quantifying tire-tread particles in the environment has been developed. It is based on the measurement of extractable organic zinc. The high sensitivity of atomic absorption spectrometry (AAS) with a heated graphite atomizer (HGA) permits assessment of submilligram amounts of tire debris in environmental samples. The analysis is performed on aerosol and soil samples. This new method is more accurate and faster than the previously reported IR method.

scholarly journals Simulation and performance analysis of Multiple PCS sensors system

2017 ◽  
Vol 20 (2) ◽  
pp. 85
Author(s):  
Pawan Whig ◽  
Syed Naseem Ahmad ◽  
Surinder Kumar
Keyword(s):  
Low Cost ◽  
Reference Electrode ◽  
Oxygen Demand ◽  
High Sensitivity ◽  
Readout Circuit ◽  
Active Components ◽  
Multiple Sensors ◽  
Quality Of Water ◽  
Voltage Signal ◽  
And Performance

In this paper, a novel circuit is presented which overcome a serious limitation found in case of multiple sensors system. In this novel system design only one reference electrode and few active components used that makes the implementation of a low-cost system for the supervision of water quality. Photo Catalytic Sensor (PCS) estimates the parameter BOD (Biological Oxygen Demand) which is generally used to estimate quality of water. The system proposed in this paper involves a balanced bridge approach using few electronic components that provides a correlation in the input-output signals of low-cost sensors. The main reason of employing a readout circuit to PCS circuitry, is the fact that the fluctuation of O2 influences the threshold voltage, which is internal parameter of the FET and can manifest itself as a voltage signal at output but as a function of the trans conductance gain. The trans-conductance is a passive parameter and in order to derive voltage or current signal from its fluctuations the sensor has to be attached to readout circuit. This circuit provides high sensitivity to the changes in percentage of O2 in the solution.

NEW METHOD OF IMPULSIVE ELECTROMAGNETIC LOGGING SOUNDING: MAPPING OF THE BAZHENOVSKAYA FORMATION FROM JURASSIC RESERVOIRS PENETRATED BY INCLINED-HORIZONTAL WELLS

2021 ◽  
pp. 31-39
Author(s):  
M. I. Epov ◽  
◽  
V. N. Glinskikh ◽  
M. N. Nikitenko ◽  
K. V. Sukhorukova ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Modeling ◽  
Middle Jurassic ◽  
High Sensitivity ◽  
Horizontal Wells ◽  
New Method ◽  
Electromagnetic Sounding ◽  
Bazhenov Formation ◽  
Spatial Locations

The work is devoted to the substantiation of new geophysical technology for mapping the Bazhenovskaya Formation based on an impulsive electromagnetic sounding from wells. Theoretically shown the possibility of its application to study the formation from highly inclined and subhorizontal wells drilled in the Upper and Middle Jurassic formations. Numerical modeling of the signals in realistic geoelectric models of the Bazhenov Formation with real well trajectories is carried out on the example of the East Surgut field. The calculations have established that the determination of spatial locations of the top and bottom of the beds is possible when using different-length sondes. Zones of high sensitivity of the full magnetic field matrix to the boundaries with a sufficient signal level at considerable distance, even with a small sonde length, are determined. It is theoretically established that pulsed sounding of the Bazhenov Formation from the Upper and Middle Jurassic reservoirs is feasible for both mapping the boundaries of the formation and tracing its lateral variability.

Image Encryption Algorithm Based on a Novel 4D Chaotic System

2021 ◽  
Vol 15 (4) ◽  
pp. 118-131
Author(s):  
Sadiq A. Mehdi
Keyword(s):  
Chaotic System ◽  
Initial Conditions ◽  
High Sensitivity ◽  
Encryption Algorithm ◽  
Pseudorandom Sequence ◽  
Key Space ◽  
Xor Operation ◽  
Change Intensity ◽  
And Performance ◽  
Image Cryptosystem

In this paper, a novel four-dimensional chaotic system has been created, which has characteristics such as high sensitivity to the initial conditions and parameters. It also has two a positive Lyapunov exponents. This means the system is hyper chaotic. In addition, a new algorithm was suggested based on which they constructed an image cryptosystem. In the permutation stage, the pixel positions are scrambled via a chaotic sequence sorting. In the substitution stage, pixel values are mixed with a pseudorandom sequence generated from the 4D chaotic system using XOR operation. A simulation has been conducted to evaluate the algorithm, using the standardized tests such as information entropy, histogram, number of pixel change rate, unified average change intensity, and key space. Experimental results and performance analyses demonstrate that the proposed encryption algorithm achieves high security and efficiency.

Easy-to-Fabricate K2Pd(SO3)2-Dyed Polyester Fabric with Highly Selective and Fast Response to Carbon Monoxide

2021 ◽  
Vol 21 (8) ◽  
pp. 4400-4405
Author(s):  
Junyeop Lee ◽  
Nam Gon Do ◽  
Dong Hyuk Jeong ◽  
Sae-Wan Kim ◽  
Maeum Han ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Color Change ◽  
High Sensitivity ◽  
Cost Effective ◽  
Fast Response ◽  
Polyester Fabric ◽  
High Porosity ◽  
Sensing Material ◽  
Sensitivity And Selectivity ◽  
And Performance

Carbon monoxide (CO) is an odorless, colorless, tasteless, extremely flammable, and highly toxic gas. It is produced when there is insufficient oxygen supply during the combustion of carbon to produce carbon dioxide (CO2). CO is produced from operating engines, stoves, or furnaces. CO poisoning occurs when CO accumulates in the bloodstream and can result in severe tissue damage or even death. Many types of CO sensors have been reported, including electrochemical, semiconductor metal-oxide, catalytic combustion, thermal conductivity, and infrared absorption-type for the detection of CO. However, despite their excellent selectivity and sensitivity, issues such as complexity, power consumption, and calibration limit their applications. In this study, a fabricbased colorimetric CO sensor is proposed to address these issues. Potassium disulfitopalladate (II) (K2Pd(SO3)2) is dyed on a polyester fabric as a sensing material for selective CO detection. The sensing characteristics and performance are investigated using optical instruments such as RGB sensor and spectrometer. The sensor shows immediate color change when exposed to CO at a concentration that is even lower than 20 ppm before 2 min. The fast response time of the sensor is attributed to its high porosity to react with CO. This easy-to-fabricate and cost-effective sensor can detect and prevent the leakage of CO simultaneously with high sensitivity and selectivity toward CO.

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