In order to meet the needs of higher operation speed and lower energy consumption an optimized SHA-1 algorithm is proposed.It combines two methods loop-unfolding and pre-processing.In the process intermediate variable...In order to meet the needs of higher operation speed and lower energy consumption an optimized SHA-1 algorithm is proposed.It combines two methods loop-unfolding and pre-processing.In the process intermediate variables are introduced in the iterations and pre-calculated so that the original single-threading operation can perform in a multi-threading way.This optimized algorithm exploits parallelism to shorten the critical path for hash operations.And the cycles of the original algorithm are reduced from 80 to 41 which greatly improves the operation speed.Therefore the shortened iterations of the optimized design require a smaller amount of hardware resource thus achieving a lower energy consumption. The optimized algorithm is implemented on FPGA field programmable gate array .It can achieve a throughput rate of 1.2 Gbit /s with the maximum clock frequency of 91 MHz reaching a fair balance between operation speed and throughput rate.The simulation results show that compared with other optimized SHA-1 algorithms this algorithm obtains higher operation speed and throughput rate without compromising the security of the original SHA-1 algorithm.展开更多
This brief conceptual paper contributes a sustainability theoretic perspective of an urbanization paradigm known as Compact City. Compact City is an urban planning and development concept which promotes relatively hig...This brief conceptual paper contributes a sustainability theoretic perspective of an urbanization paradigm known as Compact City. Compact City is an urban planning and development concept which promotes relatively high population density associated with an integrated and mixed-use land district. It is enabled by transit-oriented development and results in low transport-related energy consumption and reduced the GHG （Greenhouse Gases） pollution. Compact City conserves the natural capital of land mass and subscribes to the strong sustainability ethics. ICT （Information and Communications Technology） could be deployed to optimize the Compact City operations by first tackling some of the development problems associated with Compact City and also unleashing new urban innovations and functionalities to achieve sustainable urbanization. The paper suggests and elucidates several general systemic synergies archetypes such as co-benefits, cascading, ICT infrastructure reuse, etc., which could be leveraged to facilitate the emergence of compact green smart and resilient city. These archetypes are solutions to the Compact City paradigm thus conductive to the development ofa Sustainability Science of Compact City.展开更多
This article is devoted to the study of high order accuracy difference methods tor the Cahn-rnmara equation. A three level linearized compact difference scheme is derived. The u^ique solvability and uaconditional conv...This article is devoted to the study of high order accuracy difference methods tor the Cahn-rnmara equation. A three level linearized compact difference scheme is derived. The u^ique solvability and uaconditional convergence of the difference solution are proved. The convergence order is O（T2＋h4） in the maximum norm. The mass conservation and the non-increase of the total energy are also verified. Some numerical examples are given to demonstrate the theoretical results.展开更多
In this paper,we solve the optimal constant problem in the setting of Ohsawa’s generalized L2extension theorem.As applications,we prove a conjecture of Ohsawa and the extended Suita conjecture,we also establish some ...In this paper,we solve the optimal constant problem in the setting of Ohsawa’s generalized L2extension theorem.As applications,we prove a conjecture of Ohsawa and the extended Suita conjecture,we also establish some relations between Bergman kernel and logarithmic capacity on compact and open Riemann surfaces.展开更多
基金The Project of Wireless Intelligence Terminal Inspection Services(No.6704000084)the Special Program of the NationalDevelopment and Reform Committee
文摘In order to meet the needs of higher operation speed and lower energy consumption an optimized SHA-1 algorithm is proposed.It combines two methods loop-unfolding and pre-processing.In the process intermediate variables are introduced in the iterations and pre-calculated so that the original single-threading operation can perform in a multi-threading way.This optimized algorithm exploits parallelism to shorten the critical path for hash operations.And the cycles of the original algorithm are reduced from 80 to 41 which greatly improves the operation speed.Therefore the shortened iterations of the optimized design require a smaller amount of hardware resource thus achieving a lower energy consumption. The optimized algorithm is implemented on FPGA field programmable gate array .It can achieve a throughput rate of 1.2 Gbit /s with the maximum clock frequency of 91 MHz reaching a fair balance between operation speed and throughput rate.The simulation results show that compared with other optimized SHA-1 algorithms this algorithm obtains higher operation speed and throughput rate without compromising the security of the original SHA-1 algorithm.
文摘This brief conceptual paper contributes a sustainability theoretic perspective of an urbanization paradigm known as Compact City. Compact City is an urban planning and development concept which promotes relatively high population density associated with an integrated and mixed-use land district. It is enabled by transit-oriented development and results in low transport-related energy consumption and reduced the GHG （Greenhouse Gases） pollution. Compact City conserves the natural capital of land mass and subscribes to the strong sustainability ethics. ICT （Information and Communications Technology） could be deployed to optimize the Compact City operations by first tackling some of the development problems associated with Compact City and also unleashing new urban innovations and functionalities to achieve sustainable urbanization. The paper suggests and elucidates several general systemic synergies archetypes such as co-benefits, cascading, ICT infrastructure reuse, etc., which could be leveraged to facilitate the emergence of compact green smart and resilient city. These archetypes are solutions to the Compact City paradigm thus conductive to the development ofa Sustainability Science of Compact City.
基金supported by Natural Science Foundation of China (Grant No. 10871044)
文摘This article is devoted to the study of high order accuracy difference methods tor the Cahn-rnmara equation. A three level linearized compact difference scheme is derived. The u^ique solvability and uaconditional convergence of the difference solution are proved. The convergence order is O（T2＋h4） in the maximum norm. The mass conservation and the non-increase of the total energy are also verified. Some numerical examples are given to demonstrate the theoretical results.
基金supported by National Natural Science Foundation of China (Grant No. 11031008)
文摘In this paper,we solve the optimal constant problem in the setting of Ohsawa’s generalized L2extension theorem.As applications,we prove a conjecture of Ohsawa and the extended Suita conjecture,we also establish some relations between Bergman kernel and logarithmic capacity on compact and open Riemann surfaces.
