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A quantum secure direct communication protocol based on a five-particle cluster state and classical XOR operation

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Chinese Physics C 2012年第1期36卷 31-36页

作者：李剑宋丹劼郭晓静景博 School of computer Beijing University of Posts and Telecommunications department of computer science Beijing Institute of Applied Meteorology

In order to transmit secure messages,a quantum secure direct communication protocol based on a five-particle cluster state and classical XOR operation is *** five-particle cluster state is used to detect eavesdroppers,and the classical XOR operation serving as a one-time-pad is used to ensure the security of the *** the security analysis,the entropy theory method is introduced,and three detection strategies are compared quantitatively by using the constraint between the information that the eavesdroppers can obtain and the interference *** the eavesdroppers intend to obtain all the information,the detection rate of the original ping-pong protocol is 50%;the second protocol,using two particles of the Einstein-Podolsky-Rosen pair as detection particles,is also 50%;while the presented protocol is 89%.Finally,the security of the proposed protocol is discussed,and the analysis results indicate that the protocol in this paper is more secure than the other two.

关键词： QSDC XOR operation five-particle cluster state eavesdropping detection protocol security

Early warning and disaster management:the importance of geographic information(Part B)

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International Journal of Digital Earth 2010年第3期3卷 313-315页

作者： Guest Editors Milan Konecny Wolfgang Reinhardt Laboratory on geoinformatics and Cartography Institute of Geography Faculty of Science Masaryk UniversityKotlarska 261137 BRNOCzech Republic AGIS geoinformatics Lab Institute of Applied Computer Science(INF4)University of the BundeswehrMu¨nchenGermany

This special issue is part of a double special issue(Part A was published in the previous issue of this journal)dealing with the role of Geographic Information(GI)for Early Warning(EW)and Disaster Management(DM).In the editorial of Part A we gave an introduction to the topic focussing on initiatives from the EU and China and we have highlighted the importance of Digital Earth for EWand *** have also reflected on the outcome of some events organized by the guest editors which were important for the topic and for this special issue.

关键词： journal disaster Early

Quantum Cosine Transform Based Watermarking Scheme for Quantum Images

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Chinese Journal of Electronics 2015年第2期24卷 321-325页

作者： WANG Shen SONG Xianhua NIU Xiamu School of computer science and Technology Harbin Institute of Technology department of applied Mathematics Harbin University of Science and Technology

A novel watermarking scheme for quantum image is proposed based on Quantum cosine transform(QCT). The cosine coefficients are extracted by executing QCT on quantum image. A dynamic vector for controlling embedding strength instead of a fixed parameter for embedding process in other scheme is utilized to process quantum watermark. The adder operation and the inverse QCT are implemented which offset the QCT and guarantee the embedding process having smaller impact on the quantum carrier image. Simulation results and analysis show that the proposed dynamic watermarking scheme has better visual quality under a higher embedding capacity.

关键词： Quantum computation Quantum image Quantum cosine transform Quantum watermarking

Context-aware reinforcement learning for cooling operation of data centers with an Aquifer Thermal Energy Storage

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Energy and AI

Energy and AI 2024年第3期17卷 233-246页

作者： Lukas Leindals Peter Grønning Dominik Franjo Dominković Rune Grønborg Junker department of applied Mathematics and computer science Technical University of DenmarkDenmark

Data centers are often equipped with multiple cooling units. Here, an aquifer thermal energy storage (ATES) system has shown to be efficient. However, the usage of hot and cold-water wells in the ATES must be balanced for legal and environmental reasons. Reinforcement Learning has been proven to be a useful tool for optimizing the cooling operation at data centers. Nonetheless, since cooling demand changes continuously, balancing the ATES usage on a yearly basis imposes an additional challenge in the form of a delayed reward. To overcome this, we formulate a return decomposition, Cool-RUDDER, which relies on simple domain knowledge and needs no training. We trained a proximal policy optimization agent to keep server temperatures steady while minimizing operational costs. Comparing the Cool-RUDDER reward signal to other ATES-associated rewards, all models kept the server temperatures steady at around 30 °C. An optimal ATES balance was defined to be 0% and a yearly imbalance of −4.9% with a confidence interval of [−6.2, −3.8]% was achieved for the Cool 2.0 reward. This outperformed a baseline ATES-associated reward of 0 at −16.3% with a confidence interval of [−17.1, −15.4]% and all other ATES-associated rewards. However, the improved ATES balance comes with a higher energy consumption cost of 12.5% when comparing the relative cost of the Cool 2.0 reward to the zero reward, resulting in a trade-off. Moreover, the method comes with limited requirements and is applicable to any long-term problem satisfying a linear state-transition system.

关键词： Data centers ATES Smart energy systems Reinforcement learning Delayed rewards

Improved meet-in-the-middle attacks on reduced-round Piccolo

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science China(Information sciences) 2018年第3期61卷 95-107页

作者： Ya LIU Liang CHENG Zhiqiang LIU Wei LI Qingju WANG Dawu GU department of computer science and Engineering University of Shanghai for Science and Technology State Key Laboratory of Cryptology department of computer science and Engineering Shanghai Jiao Tong University School of computer science and Technology Donghua University Shanghai Key Laboratory of Integrated Administration Technologies for Information Security department of applied Mathematics and computer science Technical University of Denmark

Piccolo is a lightweight block cipher that adopts a generalized Feistel network structure with4 branches, each of which is 16 bit long. The key length is 80 or 128 bit, denoted by Piccolo-80 and Piccolo-128, respectively. In this paper, we mounted meet-in-the-middle attacks on 14-round Piccolo-80 without preand post-whitening keys and 18-round Piccolo-128 with post-whitening keys by exploiting the properties of the key schedule and Maximum Distance Separable（MDS） matrix. For Piccolo-80, we first constructed a 5-round distinguisher. Then 4 rounds and 5 rounds were appended at the beginning and at the end,respectively. Based on this structure, we mounted an attack on 14-round Piccolo-80 from the 5 th round to the 18 th round. The data, time, and memory complexities were 2;chosen plaintexts, 2;encryptions, and 2;blocks, respectively. For Piccolo-128, we built a 7-round distinguisher to attack 18-round Piccolo-128 from the 4 th round to the 21st round. The data, time, and memory complexities were 2;chosen plaintexts,2;encryptions, and 2;blocks, respectively. If not considering results on biclique cryptanalysis,these are currently the best public results on this reduced version of the Piccolo block cipher.

关键词： block cipher lightweight Piccolo meet-in-the-middle attack distinguisher

Deep bed filtration model for cake filtration and erosion

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applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 355-372页

作者： L.I.KUZMINA Y.V.OSIPOV A.R.PESTEREV department of applied Mathematics HSE UniversityMoscow 101000Russia department of computer science and applied Mathematics Moscow State University of Civil EngineeringMoscow 129337Russia

Many phenomena in nature and technology are associated with the filtration of suspensions and colloids in porous media. Two main types of particle deposition,namely, cake filtration at the inlet and deep bed filtration throughout the entire porous medium, are studied by different models. A unified approach for the transport and deposition of particles based on the deep bed filtration model is proposed. A variable suspension flow rate, proportional to the number of free pores at the inlet of the porous medium, is considered. To model cake filtration, this flow rate is introduced into the mass balance equation of deep bed filtration. For the cake filtration without deposit erosion,the suspension flow rate decreases to zero, and the suspension does not penetrate deep into the porous medium. In the case of the cake filtration with erosion, the suspension flow rate is nonzero, and the deposit is distributed throughout the entire porous medium. An exact solution is obtained for a constant filtration function. The method of characteristics is used to construct the asymptotics of the concentration front of suspended and retained particles for a filtration function in a general form. Explicit formulae are obtained for a linear filtration function. The properties of these solutions are studied in detail.

关键词： deep bed filtration cake filtration porous medium particle deposition and erosion analytical solution concentration front

A robust WENO scheme for nonlinear waves in a moving reference frame

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Journal of Hydrodynamics 2016年第3期28卷 482-488页

作者： Stavros KONTOS Harry B.BINGHAM Ole LINDBERG Allan P.ENGSIG-KARUP department of Mechanical Engineering Technical University of DenmarkDenmark department of applied Mathematics and computer science Technical University of DenmarkDenmark

For robust nonlinear wave simulation in a moving reference frame, we recast the free surface problem in Hamilton-Jacobi form and propose a Weighted Essentially Non-Oscillatory （WENO） scheme to automatically handle the upwinding of the convective term. A new automatic procedure for deriving the linear WENO weights based on a Taylor series expansion is introduced. A simplified smoothness indicator is proposed and is shown to perform well. The scheme is combined with high-order explicit Runge-Kutta time integration and a dissipative Lax-Friedrichs-type flux to solve for nonlinear wave propagation in a moving frame of reference. The WENO scheme is robust and less dissipative than the equivalent order upwind-biased finite difference scheme for all ratios of frame of reference to wave propagation speed tested. This provides the basis for solving general nonlinear wave-structure interaction problems at forward speed.

关键词： nonlinear waves Weighted Essentially Non-Oscillatory (WENO) finite difference

Comprehensive Approach for Porous Materials Analysis Using a Dedicated Preprocessing Tool for Mass and Heat Transfer Modeling

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Journal of Thermal science 2018年第5期27卷 479-486页

作者： MADEJSKI Pawel KRAKOWSKA Paulina HABRAT Magdalena PUSKARCZYK Edyta JEDRYCHOWSKI Mariusz department of Power Systems and Environmental Protection Facilities Faculty of Mechanical Engineering and Ro-botics AGH University of Science and TechnologyKraków 30-059 Poland department of Geophysics Faculty of Geology Geophysics and Environmental Protection AGH University of Sci-ence and Technology Kraków 30-059 Poland department of geoinformatics and applied computer science Faculty of Geology Geophysics and Environmental Protection AGH University of Science and TechnologyKraków 30-059 Poland department of Condensed Matter Physics Faculty of Physics and Applied Computer Science AGH University of Science and TechnologyKraków 30-059 Poland

The paper presents a comprehensive, newly developed software – poROSE(poROus materials examination SoftwarE) for the qualitative and quantitative assessment of porous materials and analysis methodologies developed by the authors as a solution for emerging challenges. A low porosity rock sample was analyzed and thanks to the developed and implemented methodologies in poROSE software, the main geometrical properties were calculated. A tool was also used in preprocessing part of the computational analysis to prepare a geometrical representation of the porous material. The basic functions as elimination of blind pores in the geometrical model were completed and the geometrical model was exported for CFD software. As a result, it was possible to carry out calculations of the basic properties of the analyzed porous material sample. The developed tool allows to carry out quantitative and qualitative analysis to determine the most important properties characterized porous materials. In presented tool the input data can be images from X-ray computed tomography(CT), scanning electron microscope(SEM) or focused ion beam with scanning electron microscope(FIB-SEM) in grey level. A geometric model developed in the proper format can be used as an input to modeling mass, momentum and heat transfer, as well as, in strength or thermo-strength analysis of any porous materials. In this example, thermal analysis was carried out on the skeleton of rock sample. Moreover, thermal conductivity was estimated using empirical equations.

关键词： porous materials rock software thermal properties preprocessing

Quantum Scars in Microwave Dielec trie Photonic Graphene Billiards

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Chinese Physics Letters 2020年第1期37卷 10-13页

作者： Xiao Wang Guo-Dong Wei department of computer science and Technology Taiyuan University of Science and TechnologyTaiyuan 030024 School of applied science Taiyuan University of Science and TechnologyTaiyuan 030024

Brillouin *** closed graphene system has proven to be the ideal model to investigate relativistic quantum chaos *** electromagnetic material photonic graphene(PG)and electronic graphene not only have the same structural symmetry,but also have the similar band ***,we consider a stadium shaped resonant cavity filled with PG to demonstrate the relativistic quantum chaos phenomenon by numerical *** is interesting that the relativistic quantum scars not only are identified in the PG cavities,but also appear and disappear *** wave vector difference between repetitive scars on the same orbit is analyzed and confirmed to follow the quantization *** exploration will not only demonstrate a visual simulation of relativistic quantum scars but also propose a physical system for observing valley-dependent relativistic quantum scars,which is helpful for further understanding of quantum chaos.

关键词： structure. relativistic quantum