Encryption is used to secure sensitive computer data which may be at rest or in motion. There are several standard encryption algorithms that have been used to encrypt and protect blocks of sensitive data to ensure co...Encryption is used to secure sensitive computer data which may be at rest or in motion. There are several standard encryption algorithms that have been used to encrypt and protect blocks of sensitive data to ensure confidentiality. The most popular standard block encryption schemes are the Advanced Encryption Standard (AES), Triple Data Encryption Standard (3DES), and the first standardized encryption scheme, which is no longer the standard scheme now, namely the Data Encryption Standard (DES). AES is the current standard for block encryption used worldwide and is implemented on many processors. In this work, we compare the hardware performance of these three encryption schemes. First, we identified the underlying computational components for these three encryption schemes, and then we analyzed to what extent these computational components were being used in these block encryption schemes to encrypt and decrypt a given message. In this paper, we compared the contribution of these computational components to evaluate the overall encryption efficiency in terms of speed and computational delays for encrypting a given block of data for a given hardware platform. AES was found to be the faster scheme in terms of hardware computation speed in accomplishing the same encryption task compared to the other two block encryption schemes, namely, the DES and 3DES schemes.展开更多
Land use and land cover are essential for maintaining and managing the natural resources on the earth surface. A complex set of economic, demographic, social, cultural, technological, and environmental processes usual...Land use and land cover are essential for maintaining and managing the natural resources on the earth surface. A complex set of economic, demographic, social, cultural, technological, and environmental processes usually result in the change in the land use/land cover change (LULC). Pokhara Metropolitan is influenced mainly by the combination of various driving forces: geographical location, high rate of population growth, economic opportunity, globalization, tourism activities, and political activities. In addition to this, geographically steep slope, rugged terrain, and fragile geomorphic conditions and the frequency of earthquakes, floods, and landslides make the Pokhara Metropolitan region a disaster-prone area. The increment of the population along with infrastructure development of a given territory leads towards the urbanization. It has been rapidly changing due to urbanization, industrialization and internal migration since the 1970s. The landscapes and ground patterns are frequently changing on time and prone to disaster. Here a study has been carried to study on LULC for the last 18 years (2000-2018). The supervised classification on Landsat Imagery was performed and verified the classification through computing the error matrix. Besides, the water bodies and vegetation area were extracted through the Normalized Difference Water Index (NDWI) and Normalized Difference Vegetation Index (NDWI) respectively. This research shows that during the last 18 years the agricultural areas diminishing by 15.66% while urban area is increasing by 13.2%. This research is beneficial for preparing the plan and policy in the sustainable development of Pokhara Metropolitan.展开更多
Microsoft server Operating Systems are considered to have in-built, host based security features that should provide some protection against Distributed Denial of Service (DDoS) attacks. In this paper, we presented re...Microsoft server Operating Systems are considered to have in-built, host based security features that should provide some protection against Distributed Denial of Service (DDoS) attacks. In this paper, we presented results of experiments that were conducted to test the security capability of the latest server Operating System from Microsoft Inc., namely Windows Server 2012 R2. Experiments were designed to evaluate its in-built security features in defending against a common Distributed Denial of Service (DDoS) attack, namely the TCP-SYN based DDoS attack. Surprisingly, it was found that the Windows Server 2012 R2 OS lacked sufficient host-based protection and was found to be unable to defend against even a medium intensity3.1 Gbps-magnitude of TCP-SYN attack traffic. The server was found to crash within minutes after displaying a Blue Screen of Death (BSoD) under such security attacks.展开更多
A novel content based image retrieval （CBIR） algorithmusing relevant feedback is presented. The proposed frameworkhas three major contributions： a novel feature descriptor calledcolor spectral histogram （CSH） to ...A novel content based image retrieval （CBIR） algorithmusing relevant feedback is presented. The proposed frameworkhas three major contributions： a novel feature descriptor calledcolor spectral histogram （CSH） to measure the similarity betweenimages; two-dimensional matrix based indexing approach proposedfor short-term learning （STL）; and long-term learning （LTL）.In general, image similarities are measured from feature representationwhich includes color quantization, texture, color, shapeand edges. However, CSH can describe the image feature onlywith the histogram. Typically the image retrieval process starts byfinding the similarity between the query image and the imagesin the database; the major computation involved here is that theselection of top ranking images requires a sorting algorithm to beemployed at least with the lower bound of O（n log n）. A 2D matrixbased indexing of images can enormously reduce the searchtime in STL. The same structure is used for LTL with an aim toreduce the amount of log to be maintained. The performance ofthe proposed framework is analyzed and compared with the existingapproaches, the quantified results indicates that the proposedfeature descriptor is more effectual than the existing feature descriptorsthat were originally developed for CBIR. In terms of STL,the proposed 2D matrix based indexing minimizes the computationeffort for retrieving similar images and for LTL, the proposed algorithmtakes minimum log information than the existing approaches.展开更多
文摘Encryption is used to secure sensitive computer data which may be at rest or in motion. There are several standard encryption algorithms that have been used to encrypt and protect blocks of sensitive data to ensure confidentiality. The most popular standard block encryption schemes are the Advanced Encryption Standard (AES), Triple Data Encryption Standard (3DES), and the first standardized encryption scheme, which is no longer the standard scheme now, namely the Data Encryption Standard (DES). AES is the current standard for block encryption used worldwide and is implemented on many processors. In this work, we compare the hardware performance of these three encryption schemes. First, we identified the underlying computational components for these three encryption schemes, and then we analyzed to what extent these computational components were being used in these block encryption schemes to encrypt and decrypt a given message. In this paper, we compared the contribution of these computational components to evaluate the overall encryption efficiency in terms of speed and computational delays for encrypting a given block of data for a given hardware platform. AES was found to be the faster scheme in terms of hardware computation speed in accomplishing the same encryption task compared to the other two block encryption schemes, namely, the DES and 3DES schemes.
文摘Land use and land cover are essential for maintaining and managing the natural resources on the earth surface. A complex set of economic, demographic, social, cultural, technological, and environmental processes usually result in the change in the land use/land cover change (LULC). Pokhara Metropolitan is influenced mainly by the combination of various driving forces: geographical location, high rate of population growth, economic opportunity, globalization, tourism activities, and political activities. In addition to this, geographically steep slope, rugged terrain, and fragile geomorphic conditions and the frequency of earthquakes, floods, and landslides make the Pokhara Metropolitan region a disaster-prone area. The increment of the population along with infrastructure development of a given territory leads towards the urbanization. It has been rapidly changing due to urbanization, industrialization and internal migration since the 1970s. The landscapes and ground patterns are frequently changing on time and prone to disaster. Here a study has been carried to study on LULC for the last 18 years (2000-2018). The supervised classification on Landsat Imagery was performed and verified the classification through computing the error matrix. Besides, the water bodies and vegetation area were extracted through the Normalized Difference Water Index (NDWI) and Normalized Difference Vegetation Index (NDWI) respectively. This research shows that during the last 18 years the agricultural areas diminishing by 15.66% while urban area is increasing by 13.2%. This research is beneficial for preparing the plan and policy in the sustainable development of Pokhara Metropolitan.
文摘Microsoft server Operating Systems are considered to have in-built, host based security features that should provide some protection against Distributed Denial of Service (DDoS) attacks. In this paper, we presented results of experiments that were conducted to test the security capability of the latest server Operating System from Microsoft Inc., namely Windows Server 2012 R2. Experiments were designed to evaluate its in-built security features in defending against a common Distributed Denial of Service (DDoS) attack, namely the TCP-SYN based DDoS attack. Surprisingly, it was found that the Windows Server 2012 R2 OS lacked sufficient host-based protection and was found to be unable to defend against even a medium intensity3.1 Gbps-magnitude of TCP-SYN attack traffic. The server was found to crash within minutes after displaying a Blue Screen of Death (BSoD) under such security attacks.
文摘A novel content based image retrieval （CBIR） algorithmusing relevant feedback is presented. The proposed frameworkhas three major contributions： a novel feature descriptor calledcolor spectral histogram （CSH） to measure the similarity betweenimages; two-dimensional matrix based indexing approach proposedfor short-term learning （STL）; and long-term learning （LTL）.In general, image similarities are measured from feature representationwhich includes color quantization, texture, color, shapeand edges. However, CSH can describe the image feature onlywith the histogram. Typically the image retrieval process starts byfinding the similarity between the query image and the imagesin the database; the major computation involved here is that theselection of top ranking images requires a sorting algorithm to beemployed at least with the lower bound of O（n log n）. A 2D matrixbased indexing of images can enormously reduce the searchtime in STL. The same structure is used for LTL with an aim toreduce the amount of log to be maintained. The performance ofthe proposed framework is analyzed and compared with the existingapproaches, the quantified results indicates that the proposedfeature descriptor is more effectual than the existing feature descriptorsthat were originally developed for CBIR. In terms of STL,the proposed 2D matrix based indexing minimizes the computationeffort for retrieving similar images and for LTL, the proposed algorithmtakes minimum log information than the existing approaches.
