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( Khan Muhammad ),( Jamil Ahmad ),( Haleem Farman ),( Zahoor Jan ),( Muhammad Sajjad ),( Sung Wook Baik ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.5
Security of information during transmission is a major issue in this modern era. All of the communicating bodies want confidentiality, integrity, and authenticity of their secret information. Researchers have presented various schemes to cope with these Internet security issues. In this context, both steganography and cryptography can be used effectively. However, major limitation in the existing steganographic methods is the low-quality output stego images, which consequently results in the lack of security. To cope with these issues, we present an efficient method for RGB images based on gray level modification (GLM) and multi-level encryption (MLE). The secret key and secret data is encrypted using MLE algorithm before mapping it to the grey-levels of the cover image. Then, a transposition function is applied on cover image prior to data hiding. The usage of transpose, secret key, MLE, and GLM adds four different levels of security to the proposed algorithm, making it very difficult for a malicious user to extract the original secret information. The proposed method is evaluated both quantitatively and qualitatively. The experimental results, compared with several state-of-the-art algorithms, show that the proposed algorithm not only enhances the quality of stego images but also provides multiple levels of security, which can significantly misguide image steganalysis and makes the attack on this algorithm more challenging.
Asif Sajjad,Shafqat SAEED,Mudssar ALI,Fawad Zafar Ahmad KHAN,권용정,Mariano DEVOTO 한국곤충학회 2017 Entomological Research Vol.47 No.6
Seasonal turnover in plant and floral visitor communities changes the structure of the network of interactions they are involved in. Despite the dynamic nature of plant–visitor networks, a usual procedure is to pool year‐round interaction data into a single network which may result in a biased depiction of the real structure of the interaction network. The annual temporal dynamics and the effect of merging monthly data have previously been described for qualitative data (i.e. describing the occurrence of interactions) alone, while its quantitative aspect (i.e. the actual frequency with which interactions occur) remain little explored. For this, we built a set of 12 monthly networks describing year‐round plant–floral visitor interactions in a 30‐hectare planted forest and its adjacent agricultural landscape at Bahauddin Zakariya University Multan, Pakistan. A total of 80 plant and 162 insect species, which engaged in 1573 unique interactions, were recorded. Most network properties (particularly the number of plants, visitors and unique interactions) varied markedly during the year. Data aggregation showed that while animal species, plant species, unique interaction, weighted nestedness, interaction diversity and robustness increased, connectance and specialization decreased. The only metric which seemed relatively unaffected by data pooling was interaction evenness. In general, quantitative metrics were relatively less affected by temporal data aggregation than qualitative ones. Avoiding data aggregation not only gives a more realistic depiction of the dynamic nature of plant–visitor community networks, but also avoids biasing network metrics and, consequently, their expected response to disturbances such as the loss of species.
The electrical, dielectric and magnetic effect of MgFe2O4–polypyrrole and its composites
Alburaih H. A.,Khan Sajjad Ahmad,Khosa Rabia Yasmin,Ejaz Syeda Rabia,Khan Abdul Rauf,Muhammad Ghulam,Waheed Muhammad Suleman,Chughtai Adeel Hussain,Manzoor Sumaira,Aman Salma 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.2
In the modern world of health and life sciences, the utilization of nanoscale materials, particularly magnetic nanoparticles, is a hot topic. Here in the present study, MgFe2O4 is synthesized via the chemical co-precipitation technique, and the polypyrrole (PPy) is fabricated via in situ polymerization technique to form the MgFe2O4/PPy nanocomposite by varying its content in the ferrite material. The electrical, magnetic, and dielectric properties of the fabricated materials were studied to investigate their applications in electronic devices. The magnetization saturation Ms, remanence Mr and coercivity Hc increase with the addition of ferrite material. The activation of the fabricated material increases from 0.11 to 0.34 eV, indicating the increase in electrical resistivity. The other important parameters such as squareness ratio and drift mobility were also calculated. The increment in DC electrical resistivity, saturation magnetic magnetization and remanence as well as reduction in dielectric constant values with the ferrite material addition in the polypyrrole suggest that the materials can be beneficial for recording media as well as high-frequency devices.
Siyal Sajid Hussain,Javed Muhammad Sufyan,Ahmad Awais,Sajjad Muhammad,Batool Saima,Khan Abdul Jabbar,Akram Shakeel,Alothman Asma A.,Alshgari Razan A.,Najam Tayyaba 한국물리학회 2021 Current Applied Physics Vol.31 No.-
The development of smart structured cathode materials for supercapacitors (SCs) has sparked tremendous interest. However, the appropriate design to achieve high capacitance and energy density-based cathode materials remains a major problem for energy storage systems. This article describes the effective synthesis of selfsupported 3D micro-flowers composed of ultrathin nanowires array of Co3O4 on Ni foam (NF) using hydrothermal conditions (Co3O4@NF). The mesoporous Co3O4@NF with a high surface area, providing a rich active state for the Faraday redox reaction and increasing the diffusion rate of the electrolyte ions. The optimized Co3O4@NF-16h electrode exhibited supreme electrochemical performance by delivering a high specific capacitance of 1878, (1127) and 1200 (720 C g 1) F g 1 at 1.0 and 20 A g 1, respectively. The Co3O4@NF electrode retained good capacitance stability of 91% over 10000 cycles at 20 A g 1 with excellent rate-performance of 67% at 20 folded high current values. The obtained results for the Co3O4@NF electrode are presented the enhanced pseudocapacitive performance, indicating the substantial potential for high-performance supercapacitor applications.