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Sample records for random key pre-distribution

  1. DNA based random key generation and management for OTP encryption.

    Science.gov (United States)

    Zhang, Yunpeng; Liu, Xin; Sun, Manhui

    2017-09-01

    One-time pad (OTP) is a principle of key generation applied to the stream ciphering method which offers total privacy. The OTP encryption scheme has proved to be unbreakable in theory, but difficult to realize in practical applications. Because OTP encryption specially requires the absolute randomness of the key, its development has suffered from dense constraints. DNA cryptography is a new and promising technology in the field of information security. DNA chromosomes storing capabilities can be used as one-time pad structures with pseudo-random number generation and indexing in order to encrypt the plaintext messages. In this paper, we present a feasible solution to the OTP symmetric key generation and transmission problem with DNA at the molecular level. Through recombinant DNA technology, by using only sender-receiver known restriction enzymes to combine the secure key represented by DNA sequence and the T vector, we generate the DNA bio-hiding secure key and then place the recombinant plasmid in implanted bacteria for secure key transmission. The designed bio experiments and simulation results show that the security of the transmission of the key is further improved and the environmental requirements of key transmission are reduced. Analysis has demonstrated that the proposed DNA-based random key generation and management solutions are marked by high security and usability. Published by Elsevier B.V.

  2. Security enhanced optical encryption system by random phase key and permutation key.

    Science.gov (United States)

    He, Mingzhao; Tan, Qiaofeng; Cao, Liangcai; He, Qingsheng; Jin, Guofan

    2009-12-07

    Conventional double random phase encoding (DRPE) encrypts plaintext to white noise-like ciphertext which may attract attention of eavesdroppers, and recent research reported that DRPE is vulnerable to various attacks. Here we propose a security enhanced optical encryption system that can hide the existence of secret information by watermarking. The plaintext is encrypted using iterative fractional Fourier transform with random phase key, and ciphertext is randomly permuted with permutation key before watermarking. Cryptanalysis shows that linearity of the security system has been broken and the permutation key prevent the attacker from accessing the ciphertext in various attacks. A series of simulations have shown the effectiveness of this system and the security strength is enhanced for invisibility, nonlinearity and resistance against attacks.

  3. Analysis of Secret Key Randomness Exploiting the Radio Channel Variability

    Directory of Open Access Journals (Sweden)

    Taghrid Mazloum

    2015-01-01

    Full Text Available A few years ago, physical layer based techniques have started to be considered as a way to improve security in wireless communications. A well known problem is the management of ciphering keys, both regarding the generation and distribution of these keys. A way to alleviate such difficulties is to use a common source of randomness for the legitimate terminals, not accessible to an eavesdropper. This is the case of the fading propagation channel, when exact or approximate reciprocity applies. Although this principle has been known for long, not so many works have evaluated the effect of radio channel properties in practical environments on the degree of randomness of the generated keys. To this end, we here investigate indoor radio channel measurements in different environments and settings at either 2.4625 GHz or 5.4 GHz band, of particular interest for WIFI related standards. Key bits are extracted by quantizing the complex channel coefficients and their randomness is evaluated using the NIST test suite. We then look at the impact of the carrier frequency, the channel variability in the space, time, and frequency degrees of freedom used to construct a long secret key, in relation to the nature of the radio environment such as the LOS/NLOS character.

  4. A Robust on-Demand Path-Key Establishment Framework via Random Key Predistribution for Wireless Sensor Networks

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    Wu Weili

    2006-01-01

    Full Text Available Secure communication is a necessity for some wireless sensor network (WSN applications. However, the resource constraints of a sensor render existing cryptographic systems for traditional network systems impractical for a WSN. Random key predistribution scheme has been proposed to overcome these limits. In this scheme, a ring of keys is randomly drawn from a large key pool and assigned to a sensor. Nodes sharing common keys can communicate securely using a shared key, while a path-key is established for those nodes that do not share any common keys. This scheme requires moderate memory and processing power, thus it is considered suitable for WSN applications. However, since the shared key is not exclusively owned by the two end entities, the established path-key may be revealed to other nodes just by eavesdropping. Based on the random-key predistribution scheme, we present a framework that utilizes multiple proxies to secure the path-key establishment. Our scheme is resilient against node capture, collusive attack, and random dropping, while only incurring a small amount of overhead. Furthermore, the scheme ensures that, with high probability, all path-keys are exclusively known by the two end nodes involved in the communication along the path.

  5. Random-Resistor-Random-Temperature Kirchhoff-Law-Johnson-Noise (RRRT-KLJN Key Exchange

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    Kish Laszlo B.

    2016-03-01

    Full Text Available We introduce two new Kirchhoff-law-Johnson-noise (KLJN secure key distribution schemes which are generalizations of the original KLJN scheme. The first of these, the Random-Resistor (RR- KLJN scheme, uses random resistors with values chosen from a quasi-continuum set. It is well-known since the creation of the KLJN concept that such a system could work in cryptography, because Alice and Bob can calculate the unknown resistance value from measurements, but the RR-KLJN system has not been addressed in prior publications since it was considered impractical. The reason for discussing it now is the second scheme, the Random Resistor Random Temperature (RRRT- KLJN key exchange, inspired by a recent paper of Vadai, Mingesz and Gingl, wherein security was shown to be maintained at non-zero power flow. In the RRRT-KLJN secure key exchange scheme, both the resistances and their temperatures are continuum random variables. We prove that the security of the RRRT-KLJN scheme can prevail at a non-zero power flow, and thus the physical law guaranteeing security is not the Second Law of Thermodynamics but the Fluctuation-Dissipation Theorem. Alice and Bob know their own resistances and temperatures and can calculate the resistance and temperature values at the other end of the communication channel from measured voltage, current and power-flow data in the wire. However, Eve cannot determine these values because, for her, there are four unknown quantities while she can set up only three equations. The RRRT-KLJN scheme has several advantages and makes all former attacks on the KLJN scheme invalid or incomplete.

  6. Quantum cryptography using coherent states: Randomized encryption and key generation

    Science.gov (United States)

    Corndorf, Eric

    With the advent of the global optical-telecommunications infrastructure, an increasing number of individuals, companies, and agencies communicate information with one another over public networks or physically-insecure private networks. While the majority of the traffic flowing through these networks requires little or no assurance of secrecy, the same cannot be said for certain communications between banks, between government agencies, within the military, and between corporations. In these arenas, the need to specify some level of secrecy in communications is a high priority. While the current approaches to securing sensitive information (namely the public-key-cryptography infrastructure and deterministic private-key ciphers like AES and 3DES) seem to be cryptographically strong based on empirical evidence, there exist no mathematical proofs of secrecy for any widely deployed cryptosystem. As an example, the ubiquitous public-key cryptosystems infer all of their secrecy from the assumption that factoring of the product of two large primes is necessarily time consuming---something which has not, and perhaps cannot, be proven. Since the 1980s, the possibility of using quantum-mechanical features of light as a physical mechanism for satisfying particular cryptographic objectives has been explored. This research has been fueled by the hopes that cryptosystems based on quantum systems may provide provable levels of secrecy which are at least as valid as quantum mechanics itself. Unfortunately, the most widely considered quantum-cryptographic protocols (BB84 and the Ekert protocol) have serious implementation problems. Specifically, they require quantum-mechanical states which are not readily available, and they rely on unproven relations between intrusion-level detection and the information available to an attacker. As a result, the secrecy level provided by these experimental implementations is entirely unspecified. In an effort to provably satisfy the cryptographic

  7. Lightweight PUF-based Key and Random Number Generation

    OpenAIRE

    Van Herrewege, Anthony

    2015-01-01

    As embedded electronics continue to be integrated into our daily lives at such a pace that there are nowadays more cellphones than people on the planet, security is becoming ever more crucial. Unfortunately, this is all too often realized as an afterthought and thus the security implementations in many embedded devices offer little to no practical protection. Security does not require only cryptographic algorithms; two other critical modules in a secure system are a key generation module and ...

  8. Random multiple key streams for encryption with added CBC mode of operation

    Directory of Open Access Journals (Sweden)

    P. Penchalaiah

    2016-09-01

    For the first time, in this paper, we present a construction method to generate multiple random keys from a core-key with highest possible immunity to crack. We are with a particular emphasis on novel technique to secure user data, we have designed a secure and cost effective new cryptosystem called Rbits (Random bits cypher. In different directions we identify that Rbits having highest immunity to crack and presenting various analysis tests in support from this viewpoint and the analyzed results are reported.

  9. Hacking on decoy-state quantum key distribution system with partial phase randomization

    Science.gov (United States)

    Sun, Shi-Hai; Jiang, Mu-Sheng; Ma, Xiang-Chun; Li, Chun-Yan; Liang, Lin-Mei

    2014-04-01

    Quantum key distribution (QKD) provides means for unconditional secure key transmission between two distant parties. However, in practical implementations, it suffers from quantum hacking due to device imperfections. Here we propose a hybrid measurement attack, with only linear optics, homodyne detection, and single photon detection, to the widely used vacuum + weak decoy state QKD system when the phase of source is partially randomized. Our analysis shows that, in some parameter regimes, the proposed attack would result in an entanglement breaking channel but still be able to trick the legitimate users to believe they have transmitted secure keys. That is, the eavesdropper is able to steal all the key information without discovered by the users. Thus, our proposal reveals that partial phase randomization is not sufficient to guarantee the security of phase-encoding QKD systems with weak coherent states.

  10. Biased Random Key Genetic Algorithm with Hybrid Decoding for Multi-objective Optimization

    OpenAIRE

    Tangpattanakul, Panwadee; Jozefowiez, Nicolas; Lopez, Pierre

    2013-01-01

    International audience; A biased random key genetic algorithm (BRKGA) is an efficient method for solving combinatorial optimization problems. It can be applied to solve both single-objective and multi-objective optimization problems. The BRKGA operates on a chromosome encoded as a key vector of real values between [0,1]. Generally, the chromosome has to be decoded by using a single decoding method in order to obtain a feasible solution. This paper presents a hybrid decoding, which combines th...

  11. Biometrics based key management of double random phase encoding scheme using error control codes

    Science.gov (United States)

    Saini, Nirmala; Sinha, Aloka

    2013-08-01

    In this paper, an optical security system has been proposed in which key of the double random phase encoding technique is linked to the biometrics of the user to make it user specific. The error in recognition due to the biometric variation is corrected by encoding the key using the BCH code. A user specific shuffling key is used to increase the separation between genuine and impostor Hamming distance distribution. This shuffling key is then further secured using the RSA public key encryption to enhance the security of the system. XOR operation is performed between the encoded key and the feature vector obtained from the biometrics. The RSA encoded shuffling key and the data obtained from the XOR operation are stored into a token. The main advantage of the present technique is that the key retrieval is possible only in the simultaneous presence of the token and the biometrics of the user which not only authenticates the presence of the original input but also secures the key of the system. Computational experiments showed the effectiveness of the proposed technique for key retrieval in the decryption process by using the live biometrics of the user.

  12. Information hiding based on double random-phase encoding and public-key cryptography.

    Science.gov (United States)

    Sheng, Yuan; Xin, Zhou; Alam, Mohammed S; Xi, Lu; Xiao-Feng, Li

    2009-03-02

    A novel information hiding method based on double random-phase encoding (DRPE) and Rivest-Shamir-Adleman (RSA) public-key cryptosystem is proposed. In the proposed technique, the inherent diffusion property of DRPE is cleverly utilized to make up the diffusion insufficiency of RSA public-key cryptography, while the RSA cryptosystem is utilized for simultaneous transmission of the cipher text and the two phase-masks, which is not possible under the DRPE technique. This technique combines the complementary advantages of the DPRE and RSA encryption techniques and brings security and convenience for efficient information transmission. Extensive numerical simulation results are presented to verify the performance of the proposed technique.

  13. An Authenticated Key Agreement Scheme Based on Cyclic Automorphism Subgroups of Random Orders

    Directory of Open Access Journals (Sweden)

    Yang Jun

    2017-01-01

    Full Text Available Group-based cryptography is viewed as a modern cryptographic candidate solution to blocking quantum computer attacks, and key exchange protocols on the Internet are one of the primitives to ensure the security of communication. In 2016 Habeeb et al proposed a “textbook” key exchange protocol based on the semidirect product of two groups, which is insecure for use in real-world applications. In this paper, after discarding the unnecessary disguising notion of semidirect product in the protocol, we establish a simplified yet enhanced authenticated key agreement scheme based on cyclic automorphism subgroups of random orders by making hybrid use of certificates and symmetric-key encryption as challenge-and-responses in the public-key setting. Its passive security is formally analyzed, which is relative to the cryptographic hardness assumption of a computational number-theoretic problem. Cryptanalysis of this scheme shows that it is secure against the intruder-in-the-middle attack even in the worst case of compromising the signatures, and provides explicit key confirmation to both parties.

  14. An eCK-Secure Authenticated Key Exchange Protocol without Random Oracles

    Science.gov (United States)

    Moriyama, Daisuke; Okamoto, Tatsuaki

    This paper presents a (PKI-based) two-pass authenticated key exchange (AKE) protocol that is secure in the extended Canetti-Krawczyk (eCK) security model. The security of the proposed protocol is proven without random oracles (under three assumptions), and relies on no implementation techniques such as a trick by LaMacchia, Lauter and Mityagin (so-called the NAXOS trick). Since an AKE protocol that is eCK-secure under a NAXOS-like implementation trick will be no more eCK-secure if some realistic information leakage occurs through side-channel attacks, it has been an important open problem how to realize an eCK-secure AKE protocol without using the NAXOS tricks (and without random oracles).

  15. Randomized dynamical decoupling strategies and improved one-way key rates for quantum cryptography

    Energy Technology Data Exchange (ETDEWEB)

    Kern, Oliver

    2009-05-25

    The present thesis deals with various methods of quantum error correction. It is divided into two parts. In the first part, dynamical decoupling methods are considered which have the task of suppressing the influence of residual imperfections in a quantum memory. Such imperfections might be given by couplings between the finite dimensional quantum systems (qudits) constituting the quantum memory, for instance. The suppression is achieved by altering the dynamics of an imperfect quantum memory with the help of a sequence of local unitary operations applied to the qudits. Whereas up to now the operations of such decoupling sequences have been constructed in a deterministic fashion, strategies are developed in this thesis which construct the operations by random selection from a suitable set. Formulas are derived which estimate the average performance of such strategies. As it turns out, randomized decoupling strategies offer advantages and disadvantages over deterministic ones. It is possible to benefit from the advantages of both kind of strategies by designing combined strategies. Furthermore, it is investigated if and how the discussed decoupling strategies can be employed to protect a quantum computation running on the quantum memory. It is shown that a purely randomized decoupling strategy may be used by applying the decoupling operations and adjusted gates of the quantum algorithm in an alternating fashion. Again this method can be enhanced by the means of deterministic methods in order to obtain a combined decoupling method for quantum computations analogously to the combining strategies for quantum memories. The second part of the thesis deals with quantum error-correcting codes and protocols for quantum key distribution. The focus is on the BB84 and the 6-state protocol making use of only one-way communication during the error correction and privacy amplification steps. It is shown that by adding additional errors to the preliminary key (a process called

  16. Biased Random-Key Genetic Algorithms for the Winner Determination Problem in Combinatorial Auctions.

    Science.gov (United States)

    de Andrade, Carlos Eduardo; Toso, Rodrigo Franco; Resende, Mauricio G C; Miyazawa, Flávio Keidi

    2015-01-01

    In this paper we address the problem of picking a subset of bids in a general combinatorial auction so as to maximize the overall profit using the first-price model. This winner determination problem assumes that a single bidding round is held to determine both the winners and prices to be paid. We introduce six variants of biased random-key genetic algorithms for this problem. Three of them use a novel initialization technique that makes use of solutions of intermediate linear programming relaxations of an exact mixed integer linear programming model as initial chromosomes of the population. An experimental evaluation compares the effectiveness of the proposed algorithms with the standard mixed linear integer programming formulation, a specialized exact algorithm, and the best-performing heuristics proposed for this problem. The proposed algorithms are competitive and offer strong results, mainly for large-scale auctions.

  17. The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography.

    Science.gov (United States)

    Lee, Jeffrey S; Cleaver, Gerald B

    2017-10-01

    In this note, the Cosmic Microwave Background (CMB) Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n) random key matrix for a Vernam cipher is established.

  18. A nuclear reload optimization approach using a real coded genetic algorithm with random keys

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Alan M.M. de; Schirru, Roberto; Medeiros, Jose A.C.C., E-mail: alan@lmp.ufrj.b, E-mail: schirru@lmp.ufrj.b, E-mail: canedo@lmp.ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear

    2009-07-01

    The fuel reload of a Pressurized Water Reactor is made whenever the burn up of the fuel assemblies in the nucleus of the reactor reaches a certain value such that it is not more possible to maintain a critical reactor producing energy at nominal power. The problem of fuel reload optimization consists on determining the positioning of the fuel assemblies within the nucleus of the reactor in an optimized way to minimize the cost benefit relationship of fuel assemblies cost per maximum burn up, and also satisfying symmetry and safety restrictions. The fuel reload optimization problem difficulty grows exponentially with the number of fuel assemblies in the nucleus of the reactor. During decades the fuel reload optimization problem was solved manually by experts that used their knowledge and experience to build configurations of the reactor nucleus, and testing them to verify if safety restrictions of the plant are satisfied. To reduce this burden, several optimization techniques have been used, included the binary code genetic algorithm. In this work we show the use of a real valued coded approach of the genetic algorithm, with different recombination methods, together with a transformation mechanism called random keys, to transform the real values of the genes of each chromosome in a combination of discrete fuel assemblies for evaluation of the reload optimization. Four different recombination methods were tested: discrete recombination, intermediate recombination, linear recombination and extended linear recombination. For each of the 4 recombination methods 10 different tests using different seeds for the random number generator were conducted 10 generating, totaling 40 tests. The results of the application of the genetic algorithm are shown with formulation of real numbers for the problem of the nuclear reload of the plant Angra 1 type PWR. Since the best results in the literature for this problem were found by the parallel PSO we will it use for comparison

  19. Particle swarm optimization with random keys applied to the nuclear reactor reload problem

    Energy Technology Data Exchange (ETDEWEB)

    Meneses, Anderson Alvarenga de Moura [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear; Fundacao Educacional de Macae (FUNEMAC), RJ (Brazil). Faculdade Professor Miguel Angelo da Silva Santos; Machado, Marcelo Dornellas; Medeiros, Jose Antonio Carlos Canedo; Schirru, Roberto [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mails: ameneses@con.ufrj.br; marcelo@lmp.ufrj.br; canedo@lmp.ufrj.br; schirru@lmp.ufrj.br

    2007-07-01

    In 1995, Kennedy and Eberhart presented the Particle Swarm Optimization (PSO), an Artificial Intelligence metaheuristic technique to optimize non-linear continuous functions. The concept of Swarm Intelligence is based on the socials aspects of intelligence, it means, the ability of individuals to learn with their own experience in a group as well as to take advantage of the performance of other individuals. Some PSO models for discrete search spaces have been developed for combinatorial optimization, although none of them presented satisfactory results to optimize a combinatorial problem as the nuclear reactor fuel reloading problem (NRFRP). In this sense, we developed the Particle Swarm Optimization with Random Keys (PSORK) in previous research to solve Combinatorial Problems. Experiences demonstrated that PSORK performed comparable to or better than other techniques. Thus, PSORK metaheuristic is being applied in optimization studies of the NRFRP for Angra 1 Nuclear Power Plant. Results will be compared with Genetic Algorithms and the manual method provided by a specialist. In this experience, the problem is being modeled for an eight-core symmetry and three-dimensional geometry, aiming at the minimization of the Nuclear Enthalpy Power Peaking Factor as well as the maximization of the cycle length. (author)

  20. Penyelesaian CCVRPTW Menggunakan Biased Random Key Genetic Algorithm-Populasi Degradasi

    Directory of Open Access Journals (Sweden)

    Listy Avri Christiana

    2017-07-01

    Full Text Available The article presents the Biased Random Key Genetic Algorithm-Population Degradation (BRKGA-PD design for completing Capacitated Closed Vehicle Routing Problem with Time Windows (CCVRPTW on soft drink distributions that have been studied by Sembiring (2008. The goal is to determine some closed routes in meeting consumer demand with time limits and limit the capacity of vehicles used, so the total cost of distribution is minimal. The proposed algorithm adopts the extinction of population size. BRKGA-PD is coded using Matlab programming with the best parameter setting. The resulting solution is a subrute with a minimum of distribution fee. This algorithm is compared with two other methods, namely BRKGA general and heuristic methods. The results of this study can be concluded that the BRKGA-PD method is able to improve the general BRKGA because with a time difference that is not significant can provide cost savings of Rp. 6.857,- and BRKGA-PD is better than heuristic method because it can save more cost Rp. 87.000,-.

  1. The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Lee

    2017-10-01

    Full Text Available In this note, the Cosmic Microwave Background (CMB Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n random key matrix for a Vernam cipher is established. Keywords: Particle physics, Computer science, Mathematics, Astrophysics

  2. Optical key distribution system using atmospheric turbulence as the randomness generating function: classical optical protocol for information assurance

    Science.gov (United States)

    Drake, Marvin D.; Bas, Christophe F.; Gervais, David; Renda, Priscilla F.; Townsend, Daniel; Rushanan, Joseph J.; Francoeur, Joe; Donnangelo, Nick; Stenner, Michael D.

    2013-05-01

    We describe an experimental laboratory system that generates and distributes random binary sequence bit streams between two optical terminals (labeled Alice and Bob). The random binary sequence is generated through probing the optical channel of a turbulent atmosphere between the two terminals with coincident laser beams. The two laser beams experience differential phase delays while propagating through the atmospheric optical channel. The differential phase delays are detected and sampled at each terminal to yield raw random bit streams. The random bit streams are processed to remove bit errors and, through privacy amplification, to yield a bit stream known only to Alice and Bob. The same chaotic physical mechanism that provides randomness also provides confidentiality. The laboratory system yielded secret key bit rates of a few bits/second. For external optical channels over longer channel lengths with atmospheric turbulence levels, secret bit rates of 10 s of bits/second are predicted.

  3. Double random phase spread spectrum spread space technique for secure parallel optical multiplexing with individual encryption key

    Science.gov (United States)

    Hennelly, B. M.; Javidi, B.; Sheridan, J. T.

    2005-09-01

    A number of methods have been recently proposed in the literature for the encryption of 2-D information using linear optical systems. In particular the double random phase encoding system has received widespread attention. This system uses two Random Phase Keys (RPK) positioned in the input spatial domain and the spatial frequency domain and if these random phases are described by statistically independent white noises then the encrypted image can be shown to be a white noise. Decryption only requires knowledge of the RPK in the frequency domain. The RPK may be implemented using a Spatial Light Modulators (SLM). In this paper we propose and investigate the use of SLMs for secure optical multiplexing. We show that in this case it is possible to encrypt multiple images in parallel and multiplex them for transmission or storage. The signal energy is effectively spread in the spatial frequency domain. As expected the number of images that can be multiplexed together and recovered without loss is proportional to the ratio of the input image and the SLM resolution. Many more images may be multiplexed with some loss in recovery. Furthermore each individual encryption is more robust than traditional double random phase encoding since decryption requires knowledge of both RPK and a lowpass filter in order to despread the spectrum and decrypt the image. Numerical simulations are presented and discussed.

  4. Randomization in laboratory procedure is key to obtaining reproducible microarray results.

    Directory of Open Access Journals (Sweden)

    Hyuna Yang

    Full Text Available The quality of gene expression microarray data has improved dramatically since the first arrays were introduced in the late 1990s. However, the reproducibility of data generated at multiple laboratory sites remains a matter of concern, especially for scientists who are attempting to combine and analyze data from public repositories. We have carried out a study in which a common set of RNA samples was assayed five times in four different laboratories using Affymetrix GeneChip arrays. We observed dramatic differences in the results across laboratories and identified batch effects in array processing as one of the primary causes for these differences. When batch processing of samples is confounded with experimental factors of interest it is not possible to separate their effects, and lists of differentially expressed genes may include many artifacts. This study demonstrates the substantial impact of sample processing on microarray analysis results and underscores the need for randomization in the laboratory as a means to avoid confounding of biological factors with procedural effects.

  5. A Parallel Biased Random-Key Genetic Algorithm with Multiple Populations Applied to Irregular Strip Packing Problems

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    Bonfim Amaro Júnior

    2017-01-01

    Full Text Available The irregular strip packing problem (ISPP is a class of cutting and packing problem (C&P in which a set of items with arbitrary formats must be placed in a container with a variable length. The aim of this work is to minimize the area needed to accommodate the given demand. ISPP is present in various types of industries from manufacturers to exporters (e.g., shipbuilding, clothes, and glass. In this paper, we propose a parallel Biased Random-Key Genetic Algorithm (µ-BRKGA with multiple populations for the ISPP by applying a collision-free region (CFR concept as the positioning method, in order to obtain an efficient and fast layout solution. The layout problem for the proposed algorithm is represented by the placement order into the container and the corresponding orientation. In order to evaluate the proposed (µ-BRKGA algorithm, computational tests using benchmark problems were applied, analyzed, and compared with different approaches.

  6. Biased random key genetic algorithm with insertion and gender selection for capacitated vehicle routing problem with time windows

    Science.gov (United States)

    Rochman, Auliya Noor; Prasetyo, Hari; Nugroho, Munajat Tri

    2017-06-01

    Vehicle Routing Problem (VRP) often occurs when the manufacturers need to distribute their product to some customers/outlets. The distribution process is typically restricted by the capacity of the vehicle and the working hours at the distributor. This type of VRP is also known as Capacitated Vehicle Routing Problem with Time Windows (CVRPTW). A Biased Random Key Genetic Algorithm (BRKGA) was designed and coded in MATLAB to solve the CVRPTW case of soft drink distribution. The standard BRKGA was then modified by applying chromosome insertion into the initial population and defining chromosome gender for parent undergoing crossover operation. The performance of the established algorithms was then compared to a heuristic procedure for solving a soft drink distribution. Some findings are revealed (1) the total distribution cost of BRKGA with insertion (BRKGA-I) results in a cost saving of 39% compared to the total cost of heuristic method, (2) BRKGA with the gender selection (BRKGA-GS) could further improve the performance of the heuristic method. However, the BRKGA-GS tends to yield worse results compared to that obtained from the standard BRKGA.

  7. An evaluation framework for pre-distribution strategies of certificates in VANETs

    NARCIS (Netherlands)

    Feiri, Michael; Petit, Jonathan; Kargl, Frank

    Security and privacy in vehicular communication are expected to be ensured by the pervasive use of pseudonymous certificates and signed messages. The design and establishment of necessary public key infrastructure and hierarchies of cer- tificate authorities is ongoing in industry consortia, such as

  8. Critical side channel effects in random bit generation with multiple semiconductor lasers in a polarization-based quantum key distribution system.

    Science.gov (United States)

    Ko, Heasin; Choi, Byung-Seok; Choe, Joong-Seon; Kim, Kap-Joong; Kim, Jong-Hoi; Youn, Chun Ju

    2017-08-21

    Most polarization-based BB84 quantum key distribution (QKD) systems utilize multiple lasers to generate one of four polarization quantum states randomly. However, random bit generation with multiple lasers can potentially open critical side channels that significantly endangers the security of QKD systems. In this paper, we show unnoticed side channels of temporal disparity and intensity fluctuation, which possibly exist in the operation of multiple semiconductor laser diodes. Experimental results show that the side channels can enormously degrade security performance of QKD systems. An important system issue for the improvement of quantum bit error rate (QBER) related with laser driving condition is further addressed with experimental results.

  9. Barriers to participation in surgical randomized controlled trials in pediatric urology: A qualitative study of key stakeholder perspectives.

    Science.gov (United States)

    Vemulakonda, Vijaya M; Jones, Jacqueline

    2016-06-01

    Randomized controlled trials (RCTs) are considered the gold standard for assessing treatment efficacy. However, pediatric surgical RCTs have been limited in their ability to recruit patients. The purpose of this study was to identify barriers and motivators to pediatric participation in surgical RCTs. We conducted a series of two focus groups with parents and one focus group with urology providers for children aged ethical research by both parents and providers. While some parents are open to participation in surgical RCTs, providers and parents of children with hydronephrosis feel discomfort with the element of chance in surgical randomized trials. Parents and providers are more likely to participate in observational studies where treatment decisions may be made jointly by the physician and the parent. These findings suggest that pragmatic trial strategies with the option for participation in an observational cohort may improve recruitment of pediatric patients into surgical clinical trials. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  10. Random walk in genome space: A key ingredient of intermittent dynamics of community assembly on evolutionary time scales

    KAUST Repository

    Murase, Yohsuke

    2010-06-01

    Community assembly is studied using individual-based multispecies models. The models have stochastic population dynamics with mutation, migration, and extinction of species. Mutants appear as a result of mutation of the resident species, while migrants have no correlation with the resident species. It is found that the dynamics of community assembly with mutations are quite different from the case with migrations. In contrast to mutation models, which show intermittent dynamics of quasi-steady states interrupted by sudden reorganizations of the community, migration models show smooth and gradual renewal of the community. As a consequence, instead of the 1/f diversity fluctuations found for the mutation models, 1/f2, random-walk like fluctuations are observed for the migration models. In addition, a characteristic species-lifetime distribution is found: a power law that is cut off by a "skewed" distribution in the long-lifetime regime. The latter has a longer tail than a simple exponential function, which indicates an age-dependent species-mortality function. Since this characteristic profile has been observed, both in fossil data and in several other mathematical models, we conclude that it is a universal feature of macroevolution. © 2010 Elsevier Ltd.

  11. Constraint-Induced Aphasia Therapy in the Acute Stage: What Is the Key Factor for Efficacy? A Randomized Controlled Study.

    Science.gov (United States)

    Woldag, Hartwig; Voigt, Nancy; Bley, Maria; Hummelsheim, Horst

    2017-01-01

    Constraint-induced aphasia therapy (CIAT) has proven effective in patients with subacute and chronic forms of aphasia. It has remained unclear, however, whether intensity of therapy or constraint is the relevant factor. Data about intensive speech and language therapy (SLT) are conflicting. To identify the effective component of CIAT and assess the feasibility of SLT in the acute stage after stroke. A total of 60 patients with aphasia (68.2 ± 11.7 years) were enrolled 18.9 days after first-ever stroke. They were randomly distributed into 3 groups: (1) CIAT group receiving therapy for 3 hours per day (10 workdays, total 30 hours); (2) conventional communication treatment group, with same intensity without constraints; and (3) control group receiving individual therapy twice a day as well as group therapy (total 14 hours). Patients were assessed pretreatment and posttreatment using the Aachener Aphasia Test (primary end point: token test) and the Communicative Activity Log (CAL). Pretreatment, there were no between-group differences. Posttreatment, all groups showed significant improvements without between-group differences. It was found that 14 hours of aphasia therapy administered within 2 weeks as individual therapy, focusing on individual deficits, combined with group sessions has proven to be most efficient. This approach yielded the same outcome as 30 hours of group therapy, either in the form of CIAT or group therapy without constraints. SLT in an intensive treatment schedule is feasible and was well tolerated in the acute stage after stroke. © The Author(s) 2016.

  12. An Efficient Genetic Agorithm for Solving the Multi-Mode Resource-Constrained Project Scheduling Problem Based on Random Key Representation

    Directory of Open Access Journals (Sweden)

    Mohammad Hassan Sebt

    2015-11-01

    Full Text Available In this paper, a new genetic algorithm (GA is presented for solving the multi-mode resource-constrained project scheduling problem (MRCPSP with minimization of project makespan as the objective subject to resource and precedence constraints. A random key and the related mode list (ML representation scheme are used as encoding schemes and the multi-mode serial schedule generation scheme (MSSGS is considered as the decoding procedure. In this paper, a simple, efficient fitness function is proposed which has better performance compared to the other fitness functions in the literature. Defining a new mutation operator for ML is the other contribution of the current study. Comparing the results of the proposed GA with other approaches using the well-known benchmark sets in PSPLIB validates the effectiveness of the proposed algorithm to solve the MRCPSP.

  13. [Efficacy on hemiplegic spasticity treated with plum blossom needle tapping therapy at the key points and Bobath therapy: a randomized controlled trial].

    Science.gov (United States)

    Wang, Fei; Zhang, Lijuan; Wang, Jianhua; Shi, Yan; Zheng, Liya

    2015-08-01

    To evaluate the efficacy on hemiplegic spasticity after cerebral infarction treated with plum blossom needle tapping therapy at the key points and Bobath therapy. Eighty patients were collected, in compliance with the inclusive criteria of hemiplegic spasticity after cerebral infarction, and randomized into an observation group and a control group, 40 cases in each one. In the control group, Bobath manipulation therapy was adopted to relieve spasticity and the treatment of 8 weeks was required. In the observation group, on the basis of the treatment as the control group, the tapping therapy with plum blossom needle was applied to the key points, named Jianyu (LI 15), Jianliao (LI 14), Jianzhen (SI 9), Hegu (LI 4), Chengfu (BL 36), Zusanli (ST 36), Xiyangguan (GB 33), etc. The treatment was given for 15 min each time, once a day. Before treatment, after 4 and 8 weeks of treatment, the Fugl-Meyer assessment (FMA) and Barthel index (BI) were adopted to evaluate the motor function of the extremity and the activity of daily life in the patients of the two groups separately. The modified Ashworth scale was used to evaluate the effect of anti-spasticity. In 4 and 8 weeks of treatment, FMA: scores and BI scores were all significantly increased as compared with those before treatment in the two groups: (both PBobath therapy effectively relieves hemiplegic spasticity in the patients of cerebral infarction and improves the motor function of extremity and the activity of daily life.

  14. A Web-Based Data Collection Platform for Multisite Randomized Behavioral Intervention Trials: Development, Key Software Features, and Results of a User Survey.

    Science.gov (United States)

    Modi, Riddhi A; Mugavero, Michael J; Amico, Rivet K; Keruly, Jeanne; Quinlivan, Evelyn Byrd; Crane, Heidi M; Guzman, Alfredo; Zinski, Anne; Montue, Solange; Roytburd, Katya; Church, Anna; Willig, James H

    2017-06-16

    Meticulous tracking of study data must begin early in the study recruitment phase and must account for regulatory compliance, minimize missing data, and provide high information integrity and/or reduction of errors. In behavioral intervention trials, participants typically complete several study procedures at different time points. Among HIV-infected patients, behavioral interventions can favorably affect health outcomes. In order to empower newly diagnosed HIV positive individuals to learn skills to enhance retention in HIV care, we developed the behavioral health intervention Integrating ENGagement and Adherence Goals upon Entry (iENGAGE) funded by the National Institute of Allergy and Infectious Diseases (NIAID), where we deployed an in-clinic behavioral health intervention in 4 urban HIV outpatient clinics in the United States. To scale our intervention strategy homogenously across sites, we developed software that would function as a behavioral sciences research platform. This manuscript aimed to: (1) describe the design and implementation of a Web-based software application to facilitate deployment of a multisite behavioral science intervention; and (2) report on results of a survey to capture end-user perspectives of the impact of this platform on the conduct of a behavioral intervention trial. In order to support the implementation of the NIAID-funded trial iENGAGE, we developed software to deploy a 4-site behavioral intervention for new clinic patients with HIV/AIDS. We integrated the study coordinator into the informatics team to participate in the software development process. Here, we report the key software features and the results of the 25-item survey to evaluate user perspectives on research and intervention activities specific to the iENGAGE trial (N=13). The key features addressed are study enrollment, participant randomization, real-time data collection, facilitation of longitudinal workflow, reporting, and reusability. We found 100% user

  15. CheckMate 025 Randomized Phase 3 Study: Outcomes by Key Baseline Factors and Prior Therapy for Nivolumab Versus Everolimus in Advanced Renal Cell Carcinoma

    DEFF Research Database (Denmark)

    Escudier, Bernard; Sharma, Padmanee; McDermott, David F

    2017-01-01

    BACKGROUND: The randomized, phase 3 CheckMate 025 study of nivolumab (n=410) versus everolimus (n=411) in previously treated adults (75% male; 88% white) with advanced renal cell carcinoma (aRCC) demonstrated significantly improved overall survival (OS) and objective response rate (ORR). OBJECTIV...

  16. A cluster randomized trial of a primary palliative care intervention (CONNECT) for patients with advanced cancer: Protocol and key design considerations.

    Science.gov (United States)

    Becker, Claire L; Arnold, Robert M; Park, Seo Young; Rosenzweig, Margaret; Smith, Thomas J; White, Douglas B; Smith, Kenneth J; Schenker, Yael

    2017-03-01

    The addition of specialty palliative care to standard oncology care improves outcomes for patients with advanced cancer and their caregivers, but many lack access to specialty care services. Primary palliative care-meaning basic palliative care services provided by clinicians who are not palliative care specialists-is an alternative approach that has not been rigorously evaluated. A cluster randomized, controlled trial of the CONNECT (Care management by Oncology Nurses to address supportive care needs) intervention, an oncology nurse-led care management approach to providing primary palliative care for patients with advanced cancer and their family caregivers, is currently underway at 16 oncology practices in Western Pennsylvania. Existing oncology nurses are trained to provide symptom management and emotional support, engage patients and families in advance care planning, and coordinate appropriate care using evidence-based care management strategies. The trial will assess the impact of CONNECT versus standard oncology care on patient quality of life (primary outcome), symptom burden, and mood; caregiver burden and mood; and healthcare resource use. This trial addresses the need for more accessible models of palliative care by evaluating an intervention led by oncology nurses that can be widely disseminated in community oncology settings. The design confronts potential biases in palliative care research by randomizing at the practice level to avoid contamination, enrolling patients prior to informing them of group allocation, and conducting blinded outcome assessments. By collecting patient, caregiver, and healthcare utilization outcomes, the trial will enable understanding of the full range of a primary palliative care intervention's impact. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Key Nutrients.

    Science.gov (United States)

    Federal Extension Service (USDA), Washington, DC.

    Lessons written to help trainer agents prepare aides for work with families in the Food and Nutrition Program are presented in this booklet. The key nutrients discussed in the 10 lessons are protein, carbohydrates, fat, calcium, iron, iodine, and Vitamins A, B, C, and D. the format of each lesson is as follows: Purpose, Presentation, Application…

  18. What are the key ingredients for effective public involvement in health care improvement and policy decisions? A randomized trial process evaluation.

    Science.gov (United States)

    Boivin, Antoine; Lehoux, Pascale; Burgers, Jako; Grol, Richard

    2014-06-01

    In the past 50 years, individual patient involvement at the clinical consultation level has received considerable attention. More recently, patients and the public have increasingly been involved in collective decisions concerning the improvement of health care and policymaking. However, rigorous evaluation guiding the development and implementation of effective public involvement interventions is lacking. This article describes those key ingredients likely to affect public members' ability to deliberate productively with professionals and influence collective health care choices. We conducted a trial process evaluation of public involvement in setting priorities for health care improvement. In all, 172 participants (including 83 patients and public members and 89 professionals) from 6 Health and Social Services Centers in Canada participated in the trial. We video-recorded 14 one-day meetings, and 2 nonparticipant observers took structured notes. Using qualitative analysis, we show how public members influenced health care improvement priorities. Legitimacy, credibility, and power explain the variations in the public members' influence. Their credibility was supported by their personal experience as patients and caregivers, the provision of a structured preparation meeting, and access to population-based data from their community. Legitimacy was fostered by the recruitment of a balanced group of participants and by the public members' opportunities to draw from one another's experience. The combination of small-group deliberations, wider public consultation, and a moderation style focused on effective group process helped level out the power differences between professionals and the public. The engagement of key stakeholders in the intervention design and implementation helped build policy support for public involvement. A number of interacting active ingredients structure and foster the public's legitimacy, credibility, and power. By paying greater attention to

  19. Attitudes and Learning through Practice Are Key to Delivering Brief Interventions for Heavy Drinking in Primary Health Care: Analyses from the ODHIN Five Country Cluster Randomized Factorial Trial

    Directory of Open Access Journals (Sweden)

    Peter Anderson

    2017-01-01

    Full Text Available In this paper, we test path models that study the interrelations between primary health care provider attitudes towards working with drinkers, their screening and brief advice activity, and their receipt of training and support and financial reimbursement. Study participants were 756 primary health care providers from 120 primary health care units (PHCUs in different locations throughout Catalonia, England, The Netherlands, Poland, and Sweden. Our interventions were training and support and financial reimbursement to providers. Our design was a randomized factorial trial with baseline measurement period, 12-week implementation period, and 9-month follow-up measurement period. Our outcome measures were: attitudes of individual providers in working with drinkers as measured by the Short Alcohol and Alcohol Problems Perception Questionnaire; and the proportion of consulting adult patients (age 18+ years who screened positive and were given advice to reduce their alcohol consumption (intervention activity. We found that more positive attitudes were associated with higher intervention activity, and higher intervention activity was then associated with more positive attitudes. Training and support was associated with both positive changes in attitudes and higher intervention activity. Financial reimbursement was associated with more positive attitudes through its impact on higher intervention activity. We conclude that improving primary health care providers’ screening and brief advice activity for heavy drinking requires a combination of training and support and on-the-job experience of actually delivering screening and brief advice activity.

  20. Attitudes and Learning through Practice Are Key to Delivering Brief Interventions for Heavy Drinking in Primary Health Care: Analyses from the ODHIN Five Country Cluster Randomized Factorial Trial.

    Science.gov (United States)

    Anderson, Peter; Kaner, Eileen; Keurhorst, Myrna; Bendtsen, Preben; Steenkiste, Ben van; Reynolds, Jillian; Segura, Lidia; Wojnar, Marcin; Kłoda, Karolina; Parkinson, Kathryn; Drummond, Colin; Okulicz-Kozaryn, Katarzyna; Mierzecki, Artur; Laurant, Miranda; Newbury-Birch, Dorothy; Gual, Antoni

    2017-01-26

    In this paper, we test path models that study the interrelations between primary health care provider attitudes towards working with drinkers, their screening and brief advice activity, and their receipt of training and support and financial reimbursement. Study participants were 756 primary health care providers from 120 primary health care units (PHCUs) in different locations throughout Catalonia, England, The Netherlands, Poland, and Sweden. Our interventions were training and support and financial reimbursement to providers. Our design was a randomized factorial trial with baseline measurement period, 12-week implementation period, and 9-month follow-up measurement period. Our outcome measures were: attitudes of individual providers in working with drinkers as measured by the Short Alcohol and Alcohol Problems Perception Questionnaire; and the proportion of consulting adult patients (age 18+ years) who screened positive and were given advice to reduce their alcohol consumption (intervention activity). We found that more positive attitudes were associated with higher intervention activity, and higher intervention activity was then associated with more positive attitudes. Training and support was associated with both positive changes in attitudes and higher intervention activity. Financial reimbursement was associated with more positive attitudes through its impact on higher intervention activity. We conclude that improving primary health care providers' screening and brief advice activity for heavy drinking requires a combination of training and support and on-the-job experience of actually delivering screening and brief advice activity.

  1. Mapping randomized controlled trials of treatments for eczema - The GREAT database (The Global Resource of Eczema Trials: a collection of key data on randomized controlled trials of treatments for eczema from 2000 to 2010

    Directory of Open Access Journals (Sweden)

    Williams Hywel C

    2011-05-01

    Full Text Available Abstract Background Massive duplication of effort occurs when researchers all over the world undertake extensive searches for randomized controlled trials when preparing systematic reviews, when developing evidence-based guidelines and when applying for research funding for eczema treatments. Such duplication wastes valuable resources. Searching for randomized controlled trials of eczema is a laborious task involving scrutiny of thousands of individual references from diverse electronic databases in order to obtain a few papers of interest. Clinicians and patients who wish to find out more about a particular treatment are at risk of missing the relevant evidence if they are not trained in electronic bibliographic searching. Systematic reviews cannot be relied upon to comprehensively inform current optimal eczema treatments due to incomplete coverage and because many may be out of date. An international, publically available and comprehensive resource which brings together all randomized controlled trials on eczema treatment using a highly sensitive search has the potential to release more filtered knowledge about patient care to those who need it most and to significantly shorten the duration and costs of many clinical eczema research and guideline projects. Description The Global Resource of EczemA Trials brings together information on all randomized controlled trials of eczema treatments published from the beginning of 2000 up to the end of 2010 and will be updated every month. We searched the Cochrane Central Register of Controlled Trials in The Cochrane Library and the Cochrane Skin Group Specialised Register, MEDLINE, EMBASE, LILACS, AMED and CINHAL databases. We included 268 RCTs (24th March 2011 covering over 70 different treatment interventions. The structure of the Global Resource of Eczema Trials allows the user as much, or as little, specificity when retrieving information on trials as they wish, in an easy to use format. For each

  2. Effectiveness of three treatment strategies on occupational limitations and quality of life for patients with non-specific chronic low back pain: Is a multidisciplinary approach the key feature to success: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Petit, Audrey; Roche-Leboucher, Ghislaine; Bontoux, Luc; Dubus, Valérie; Ronzi, Yohann; Roquelaure, Yves; Richard, Isabelle

    2014-04-16

    Chronic low back pain (cLBP) is a significant public health problem, being the primary cause of work absenteeism, as well as affecting sufferers' quality of life, in industrialized society. International guidelines recommend intensive multidisciplinary approaches for patients with cLBP. However, these costly and time-consuming programs can only be offered to a minority of the most heavily affected patients and therefore do not seem likely to respond to public health requirements. Lighter programs may be an alternative to full time hospital-based programs with valuable results in terms of disability and occupational activity for cLBP patients. It is therefore important to define both what the determining components of management to improve activity restriction are and how to treat a larger number of patients more effectively at a lower cost. The aim of this study is to compare three programs with various levels of intensity and multidisciplinary. This paper describes the protocol for a prospective, randomized, controlled, clinical trial in working aged patients with cLBP. Three treatment strategies are compared: (1) intensive and multidisciplinary program conducted in a rehabilitation center; (2) less intensive outpatient program conducted by a private physiotherapist; (3) mixed strategy combining the same out program with a multidisciplinary intervention. The primary outcome of the trial is the impact of the mixed strategy on being able to work compared to hospital centered-program and out program. The secondary outcome is the impact of the mixed strategy on quality of life and social ability compared to the two others programs. The intervention part of the trial programs will take 5 weeks and observational follow-up will take 12 months. The sample size will be 180 participants (60 for each arm). The project has been approved by the Ethical Committee of Angers Hospital, France. On the hypothesis that a multidisciplinary approach is the key feature to programs

  3. Secure key distribution applications of chaotic lasers

    Science.gov (United States)

    Jiang, Ning; Xue, Chenpeng; Lv, Yunxin; Qiu, Kun

    2016-11-01

    Chaotic semiconductor laser is a good candidate for secure communication and high-speed true random bit generator, for its characteristics of broad bandwidth and prominent unpredictability. Based on the synchronization property and true random bit generation characteristic of chaotic semiconductor lasers, physical secure key distribution is available. In this work, we majorly show three key distribution schemes stemming from synchronized chaotic semiconductor lasers or chaos-based key exchange protocol. The numerical results demonstrate that the security of the chaos-synchronization-based key distribution scheme can be physically enhanced by adopting dynamic synchronization scheme or encrypted key generation, and that of key distribution with chaos-based key exchange protocol is dependent on the security of the exchange protocol and finally determined by the difficulty of regeneration the chaos system accurately.

  4. An Empirical Analysis of the Cascade Secret Key Reconciliation Protocol for Quantum Key Distribution

    Science.gov (United States)

    2011-09-01

    sifted key generation, the simulation utilizes the pseudo-random number generator Mersenne Twister developed by Matsumoto and Nishimura (Matsumoto...Mersenne Twister pseudo-random number generator. A cryptographically secure pseudo-random number generator may be a better choice for future... twister : a 623-dimensionally equidistributed uniform pseudo-random number generator. ACM Trans. Model. Comput. Simul. , 8 (1), 3-30. Maurer, U. M

  5. Quantum key management

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth

    2016-11-29

    Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.

  6. Group key management

    Energy Technology Data Exchange (ETDEWEB)

    Dunigan, T.; Cao, C.

    1997-08-01

    This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.

  7. Public Key Cryptography.

    Science.gov (United States)

    Tapson, Frank

    1996-01-01

    Describes public key cryptography, also known as RSA, which is a system using two keys, one used to put a message into cipher and another used to decipher the message. Presents examples using small prime numbers. (MKR)

  8. Key Management Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides a secure environment to research and develop advanced electronic key management and networked key distribution technologies for the Navy and DoD....

  9. Financial Key Ratios

    OpenAIRE

    Tănase Alin-Eliodor

    2014-01-01

    This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

  10. Key predictive factors for efficacy of axitinib in first-line metastatic renal cell carcinoma: subgroup analysis in Japanese patients from a randomized, double-blind phase II study

    Science.gov (United States)

    Tomita, Yoshihiko; Fukasawa, Satoshi; Oya, Mototsugu; Uemura, Hirotsugu; Shinohara, Nobuo; Habuchi, Tomonori; Rini, Brian I.; Chen, Ying; Bair, Angel H.; Ozono, Seiichiro; Naito, Seiji; Akaza, Hideyuki

    2016-01-01

    Objectives To conduct Japanese subgroup analyses of a randomized, global Phase II study of axitinib with and without dose titration in first-line metastatic renal cell carcinoma and to explore predictive factors for axitinib efficacy in first-line metastatic renal cell carcinoma. Methods The data included 44 Japanese and 169 non-Japanese treatment-naïve patients with metastatic renal cell carcinoma. Patients received twice-daily axitinib 5 mg during a 4-week lead-in period. Patients who met the pre-defined randomization criteria were stratified by Eastern Cooperative Oncology Group performance status and randomly assigned (1:1) to axitinib or placebo titration. The primary endpoint was objective response rate; secondary endpoints included progression-free survival and safety. Predictive factors were analyzed using data from all patients. Results The objective response rate (95% confidence interval) was 66% (50–80%) vs. 44% (36–52%) in Japanese and non-Japanese patients, respectively. At the primary analysis, median progression-free survival could not be estimated for Japanese patients, and was 27.6 months (95% confidence interval: 16.6–33.2) in an updated analysis. Hypertension, diarrhea, hand–foot syndrome, dysphonia, hypothyroidism and proteinuria were common adverse events in Japanese patients. Due to a small number of randomized patients, effects of axitinib dose titration could not sufficiently be confirmed among Japanese patients. The multivariate analysis identified time from histopathological diagnosis to treatment and sum of the longest diameter for target lesion at baseline as independent predictive factors for progression-free survival. Conclusions Axitinib is effective and well tolerated as first-line metastatic renal cell carcinoma therapy in Japanese patients. Predictive factors for axitinib efficacy endpoints identified in this setting warrant further investigation. PMID:27572087

  11. LOCKS AND KEYS SERVICE

    CERN Multimedia

    Locks and Keys Service

    2002-01-01

    The Locks and Keys service (ST/FM) will move from building 55 to building 570 from the 2nd August to the 9th August 2002 included. During this period the service will be closed. Only in case of extreme urgency please call the 164550. Starting from Monday, 12th August, the Locks and Keys Service will continue to follow the activities related to office keys (keys and locks) and will provide the keys for furniture. The service is open from 8h30 to 12h00 and from 13h00 to 17h30. We remind you that your divisional correspondents can help you in the execution of the procedures. We thank you for your comprehension and we remain at your service to help you in solving all the matters related to keys for offices and furniture. Locks and Keys Service - ST Division - FM Group

  12. Hashing, Randomness and Dictionaries

    DEFF Research Database (Denmark)

    Pagh, Rasmus

    time and memory space. To some extent we also consider lower bounds, i.e., we attempt to show limitations on how efficient algorithms are possible. A central theme in the thesis is randomness. Randomized algorithms play an important role, in particular through the key technique of hashing. Additionally...

  13. Cryptographic key generation using handwritten signature

    Science.gov (United States)

    Freire-Santos, M.; Fierrez-Aguilar, J.; Ortega-Garcia, J.

    2006-04-01

    Based on recent works showing the feasibility of key generation using biometrics, we study the application of handwritten signature to cryptography. Our signature-based key generation scheme implements the cryptographic construction named fuzzy vault. The use of distinctive signature features suited for the fuzzy vault is discussed and evaluated. Experimental results are reported, including error rates to unlock the secret data by using both random and skilled forgeries from the MCYT database.

  14. The compact key

    NARCIS (Netherlands)

    NN,

    1966-01-01

    Here is given a sample of a new sort of identification key, recently developed by Dr. P. W. Leenhouts of the Rijksherbarium. Having to sort many specimens of Sapindaceae into genera, he became dissatisfied with the common dichotomous key, which too often does not work when the material is not

  15. Web/Internet-based telemonitoring of a randomized controlled trial evaluating the time-integrated effects of a 24-week multicomponent intervention on key health outcomes in patients with fibromyalgia.

    Science.gov (United States)

    Salaffi, Fausto; Ciapetti, Alessandro; Gasparini, Stefania; Atzeni, Fabiola; Sarzi-Puttini, Piercarlo; Baroni, Marinella

    2015-01-01

    The aims of the study were to assess the efficacy of a multicomponent intervention and evaluate the feasibility and user acceptance of an internet-based home telemedical surveillance system for the evaluation of pain and other key health outcomes in patients with fibromyalgia (FM). The study involved 76 FM patients who were randomised to usual care or the multicomponent exercise programme, which consisted of 24 twice-weekly sessions of combined aerobic, muscle strength training exercises and education. All the patients completed the revised version of the Fibromyalgia Impact Questionnaire (FIQR) and the self-administered Fibromyalgia Activity Score (FAS). A predefined website allowed authorised users to enter data via a personal computer (PC) and Internet browser. The differences between the groups were assessed using the Mann-Whitney U-test and Fisher's exact test, and the correlations were analysed using Spearman's rank correlation test. The multicomponent intervention led to a clinically relevant difference in improvement in comparison with the standard approach. It markedly improved the FIQR symptom subscale score, significantly increased the time-integrated area under the curve (AUC) of the FAS scores, and led to a greater benefit in terms of fatigue and the quality of sleep. The mean change in the AUC of the total FIQR score closely correlated with the changes in the AUC of the total FAS score. The multicomponent approach to FM was effective in treating the key symptoms and maintaining the improvements in the short term, and telemonitoring proved to be an easyto-use solution for patient-centred data acquisition.

  16. Evaluating the effectiveness of selected community-level interventions on key maternal, child health, and prevention of mother-to-child transmission of HIV outcomes in three countries (the ACCLAIM Project): a study protocol for a randomized controlled trial.

    Science.gov (United States)

    Woelk, Godfrey B; Kieffer, Mary Pat; Walker, Damilola; Mpofu, Daphne; Machekano, Rhoderick

    2016-02-16

    Efforts to scale up and improve programs for prevention of mother-to-child transmission of HIV (PMTCT) have focused primarily at the health facility level, and limited attention has been paid to defining an effective set of community interventions to improve demand and uptake of services and retention. Many barriers to PMTCT are also barriers to pregnancy, childbirth, and postnatal care faced by mothers regardless of HIV status. Demand for maternal and child health (MCH) and PMTCT services can be limited by critical social, cultural, and structural barriers. Yet, rigorous evaluation has shown limited evidence of effectiveness of multilevel community-wide interventions aimed at improving MCH and HIV outcomes for pregnant women living with HIV. We propose to assess the effect of a package of multilevel community interventions: a social learning and action component, community dialogues, and peer-led discussion groups, on the demand for, uptake of, and retention of HIV positive pregnant/postpartum women in MCH/PMTCT services. This study will undertake a three-arm randomized trial in Swaziland, Uganda, and Zimbabwe. Districts/regions (n = 9) with 45 PMTCT-implementing health facilities and their catchment areas (populations 7,300-27,500) will be randomly allocated to three intervention arms: 1) community leader engagement, 2) community leader engagement with community days, or 3) community leader engagement with community days and male and female community peer groups. The primary study outcome is HIV exposed infants (HEIs) returning to the health facility within 2 months for early infant diagnosis (EID) of HIV. Secondary study outcomes include gestational age of women attending for first antenatal care, male partners tested for HIV, and HEIs receiving nevirapine prophylaxis at birth. Changes in community knowledge, attitudes, practices, and beliefs on MCH/PMTCT will be assessed through household surveys. Implementation of the protocol necessitated changes in the

  17. Keys to the City

    DEFF Research Database (Denmark)

    Monsson, Christian Kjær

    2014-01-01

    Review of: Keys to the City: How Economics, Institutions, Social Interaction, and Politics Shape Development / Michael Storper Princeton University Press, Princeton, NJ, 2013, 288 pp., $39.95/£27.95 (cloth), ISBN 9780691143118......Review of: Keys to the City: How Economics, Institutions, Social Interaction, and Politics Shape Development / Michael Storper Princeton University Press, Princeton, NJ, 2013, 288 pp., $39.95/£27.95 (cloth), ISBN 9780691143118...

  18. Quantum cryptography beyond quantum key distribution

    NARCIS (Netherlands)

    Broadbent, A.; Schaffner, C.

    2016-01-01

    Quantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness generation,

  19. Quantum cryptography beyond quantum key distribution

    NARCIS (Netherlands)

    A. Broadbent (Anne); C. Schaffner (Christian)

    2016-01-01

    textabstractQuantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness

  20. Random tensors

    CERN Document Server

    Gurau, Razvan

    2017-01-01

    Written by the creator of the modern theory of random tensors, this book is the first self-contained introductory text to this rapidly developing theory. Starting from notions familiar to the average researcher or PhD student in mathematical or theoretical physics, the book presents in detail the theory and its applications to physics. The recent detections of the Higgs boson at the LHC and gravitational waves at LIGO mark new milestones in Physics confirming long standing predictions of Quantum Field Theory and General Relativity. These two experimental results only reinforce today the need to find an underlying common framework of the two: the elusive theory of Quantum Gravity. Over the past thirty years, several alternatives have been proposed as theories of Quantum Gravity, chief among them String Theory. While these theories are yet to be tested experimentally, key lessons have already been learned. Whatever the theory of Quantum Gravity may be, it must incorporate random geometry in one form or another....

  1. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

    Statistical Tests That Do Not Require Random Sampling Randomization Tests Numerical Examples Randomization Tests and Nonrandom Samples The Prevalence of Nonrandom Samples in Experiments The Irrelevance of Random Samples for the Typical Experiment Generalizing from Nonrandom Samples Intelligibility Respect for the Validity of Randomization Tests Versatility Practicality Precursors of Randomization Tests Other Applications of Permutation Tests Questions and Exercises Notes References Randomized Experiments Unique Benefits of Experiments Experimentation without Mani

  2. Keys through ARQ

    CERN Document Server

    Latif, Mohamed Abdel; Gamal, Hesham El

    2009-01-01

    This paper develops a novel framework for sharing secret keys using the well-known Automatic Repeat reQuest (ARQ) protocol. The proposed key sharing protocol does not assume any prior knowledge about the channel state information (CSI), but, harnesses the available opportunistic secrecy gains using only the one bit feedback, in the form of ACK/NACK. The distribution of key bits among multiple ARQ epochs, in our approach, allows for mitigating the secrecy outage phenomenon observed in earlier works. We characterize the information theoretic limits of the proposed scheme, under different assumptions on the channel spatial and temporal correlation function, and develop low complexity explicit implementations. Our analysis reveals a novel role of "dumb antennas" in overcoming the negative impact of spatial correlation, between the legitimate and eavesdropper channels, on the achievable secrecy rates. We further develop an adaptive rate allocation policy which achieves higher secrecy rates by exploiting the channe...

  3. Key World Energy Statistics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The IEA produced its first handy, pocket-sized summary of key energy data in 1997. This new edition responds to the enormously positive reaction to the book since then. Key World Energy Statistics produced by the IEA contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts. It exists in different formats to suit our readers' requirements.

  4. Keyed shear joints

    DEFF Research Database (Denmark)

    Hansen, Klaus

    This report gives a summary of the present information on the behaviour of vertical keyed shear joints in large panel structures. An attemp is made to outline the implications which this information might have on the analysis and design of a complete wall. The publications also gives a short...

  5. Cryptographic Key Management System

    Energy Technology Data Exchange (ETDEWEB)

    No, author

    2014-02-21

    This report summarizes the outcome of U.S. Department of Energy (DOE) contract DE-OE0000543, requesting the design of a Cryptographic Key Management System (CKMS) for the secure management of cryptographic keys for the energy sector infrastructure. Prime contractor Sypris Electronics, in collaboration with Oak Ridge National Laboratories (ORNL), Electric Power Research Institute (EPRI), Valicore Technologies, and Purdue University's Center for Education and Research in Information Assurance and Security (CERIAS) and Smart Meter Integration Laboratory (SMIL), has designed, developed and evaluated the CKMS solution. We provide an overview of the project in Section 3, review the core contributions of all contractors in Section 4, and discuss bene ts to the DOE in Section 5. In Section 6 we describe the technical construction of the CKMS solution, and review its key contributions in Section 6.9. Section 7 describes the evaluation and demonstration of the CKMS solution in different environments. We summarize the key project objectives in Section 8, list publications resulting from the project in Section 9, and conclude with a discussion on commercialization in Section 10 and future work in Section 11.

  6. Locks and Keys Service

    CERN Multimedia

    Claude Ducastel

    The GS-LS-SEM section is pleased to inform you that as from Monday 30 November 2009, the opening hours of the Locks and Keys service will be the following: 08h30 - 12h30 / 13h30 - 16:30, Mondays to Fridays. GS-SEM-LS 73333

  7. Key performance indicators

    NARCIS (Netherlands)

    Zwetsloot, G.I.J.M.

    2014-01-01

    This paper addresses how organisations can use OSH performance indicators. This is an important way to mainstream OSH into business management. Key performance indicators (KPIs) should provide objective data on the OSH situation. It is often said that ‘what gets measured gets managed’. Without

  8. Physician Appraisals: Key Challenges

    Directory of Open Access Journals (Sweden)

    Klich Jacek

    2017-06-01

    Full Text Available The main purpose of the article is to identify key criteria being used for physician appraisals and to find how communication skills of physicians are valued in those appraisals. ScienceDirect and EBSCOhost databases were used for this search. The results show that a physician appraisal is underestimated both theoretically and empirically. The particular gap exists with respect to the communication skills of physicians, which are rarely present in medical training syllabi and physician assessments. The article contributes to the theoretical discourse on physician appraisals and points out at the inconsistency between the high status of physicians as a key hospital resource on the one hand and, on the other hand, at inadequate and poorly researched assessment of their performance with a special emphasis on communication skills. The article may inspire health managers to develop and implement up-to-date assessment forms for physicians and good managerial practices in this respect in hospitals and other health care units.

  9. Ancel Keys: a tribute

    Directory of Open Access Journals (Sweden)

    VanItallie Theodore B

    2005-02-01

    Full Text Available Abstract Ancel Keys, Ph.D., who died in November, 2004, at the age of 100, was among the first scientists to recognize that human atherosclerosis is not an inevitable consequence of aging, and that a high-fat diet can be a major risk factor for coronary heart disease. During World War II, he and a group of talented co-workers at the University of Minnesota conducted a large-scale study of experimentally-induced human starvation. The data generated by this study – which was immediately recognized to be a classic – continue to be of inestimable value to nutrition scientists. In his later years, Keys spent more time at his home in Naples, Italy, where he had the opportunity to continue his personal study of the beneficial effects on health and longevity of a Mediterranean diet.

  10. Chapter 06: Identification key

    Science.gov (United States)

    Alex Wiedenhoeft

    2011-01-01

    The key is written to guide you through the identification process in the most efficient and accurate way possible. It presents you with a numbered series of questions and asks you to answer them. The answers you provide will be based on your interpretations of the anatomical characters in your unknown specimen and will lead you to a new set of questions. Each time you...

  11. Electromagnetic scattering from random media

    CERN Document Server

    Field, Timothy R

    2009-01-01

    - ;The book develops the dynamical theory of scattering from random media from first principles. Its key findings are to characterize the time evolution of the scattered field in terms of stochastic differential equations, and to illustrate this framework

  12. Quantum Cryptography Beyond Quantum Key Distribution

    OpenAIRE

    Broadbent, A.; Schaffner, C

    2015-01-01

    textabstractQuantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness generation, secure two- and multi-party computation and delegated quantum computation. Quantum cryptography also studies the limitations and challenges resulting from quantum adversaries—including the ...

  13. Physical key-protected one-time pad

    NARCIS (Netherlands)

    Horstmeyer, Roarke; Judkewitz, Benjamin; Vellekoop, Ivo M.; Assawaworrarit, Sid; Yang, Changhuei

    2013-01-01

    We describe an encrypted communication principle that forms a secure link between two parties without electronically saving either of their keys. Instead, random cryptographic bits are kept safe within the unique mesoscopic randomness of two volumetric scattering materials. We demonstrate how a

  14. Password Authenticated Key Exchange and Protected Password Change Protocols

    Directory of Open Access Journals (Sweden)

    Ting-Yi Chang

    2017-07-01

    Full Text Available In this paper, we propose new password authenticated key exchange (PAKE and protected password change (PPC protocols without any symmetric or public-key cryptosystems. The security of the proposed protocols is based on the computational Diffie-Hellman assumption in the random oracle model. The proposed scheme can resist both forgery server and denial of service attacks.

  15. Finite-key analysis for quantum key distribution with weak coherent pulses based on Bernoulli sampling

    Science.gov (United States)

    Kawakami, Shun; Sasaki, Toshihiko; Koashi, Masato

    2017-07-01

    An essential step in quantum key distribution is the estimation of parameters related to the leaked amount of information, which is usually done by sampling of the communication data. When the data size is finite, the final key rate depends on how the estimation process handles statistical fluctuations. Many of the present security analyses are based on the method with simple random sampling, where hypergeometric distribution or its known bounds are used for the estimation. Here we propose a concise method based on Bernoulli sampling, which is related to binomial distribution. Our method is suitable for the Bennett-Brassard 1984 (BB84) protocol with weak coherent pulses [C. H. Bennett and G. Brassard, Proceedings of the IEEE Conference on Computers, Systems and Signal Processing (IEEE, New York, 1984), Vol. 175], reducing the number of estimated parameters to achieve a higher key generation rate compared to the method with simple random sampling. We also apply the method to prove the security of the differential-quadrature-phase-shift (DQPS) protocol in the finite-key regime. The result indicates that the advantage of the DQPS protocol over the phase-encoding BB84 protocol in terms of the key rate, which was previously confirmed in the asymptotic regime, persists in the finite-key regime.

  16. Autonomous Byte Stream Randomizer

    Science.gov (United States)

    Paloulian, George K.; Woo, Simon S.; Chow, Edward T.

    2013-01-01

    Net-centric networking environments are often faced with limited resources and must utilize bandwidth as efficiently as possible. In networking environments that span wide areas, the data transmission has to be efficient without any redundant or exuberant metadata. The Autonomous Byte Stream Randomizer software provides an extra level of security on top of existing data encryption methods. Randomizing the data s byte stream adds an extra layer to existing data protection methods, thus making it harder for an attacker to decrypt protected data. Based on a generated crypto-graphically secure random seed, a random sequence of numbers is used to intelligently and efficiently swap the organization of bytes in data using the unbiased and memory-efficient in-place Fisher-Yates shuffle method. Swapping bytes and reorganizing the crucial structure of the byte data renders the data file unreadable and leaves the data in a deconstructed state. This deconstruction adds an extra level of security requiring the byte stream to be reconstructed with the random seed in order to be readable. Once the data byte stream has been randomized, the software enables the data to be distributed to N nodes in an environment. Each piece of the data in randomized and distributed form is a separate entity unreadable on its own right, but when combined with all N pieces, is able to be reconstructed back to one. Reconstruction requires possession of the key used for randomizing the bytes, leading to the generation of the same cryptographically secure random sequence of numbers used to randomize the data. This software is a cornerstone capability possessing the ability to generate the same cryptographically secure sequence on different machines and time intervals, thus allowing this software to be used more heavily in net-centric environments where data transfer bandwidth is limited.

  17. Physical key-protected one-time pad.

    Science.gov (United States)

    Horstmeyer, Roarke; Judkewitz, Benjamin; Vellekoop, Ivo M; Assawaworrarit, Sid; Yang, Changhuei

    2013-12-18

    We describe an encrypted communication principle that forms a secure link between two parties without electronically saving either of their keys. Instead, random cryptographic bits are kept safe within the unique mesoscopic randomness of two volumetric scattering materials. We demonstrate how a shared set of patterned optical probes can generate 10 gigabits of statistically verified randomness between a pair of unique 2 mm(3) scattering objects. This shared randomness is used to facilitate information-theoretically secure communication following a modified one-time pad protocol. Benefits of volumetric physical storage over electronic memory include the inability to probe, duplicate or selectively reset any bits without fundamentally altering the entire key space. Our ability to securely couple the randomness contained within two unique physical objects can extend to strengthen hardware required by a variety of cryptographic protocols, which is currently a critically weak link in the security pipeline of our increasingly mobile communication culture.

  18. Sets, Subsets, and Dichotomous Keys

    Science.gov (United States)

    Cole, E. James

    1973-01-01

    Discusses the procedures that should be observed in constructing a dichotomous key. The keying exercise described was used as a laboratory activity in a biology course for elementary education majors, however it could be used in other courses. (JR)

  19. Key Concepts in Informatics: Algorithm

    Science.gov (United States)

    Szlávi, Péter; Zsakó, László

    2014-01-01

    "The system of key concepts contains the most important key concepts related to the development tasks of knowledge areas and their vertical hierarchy as well as the links of basic key concepts of different knowledge areas." (Vass 2011) One of the most important of these concepts is the algorithm. In everyday life, when learning or…

  20. Secret-key certificates (continued)

    NARCIS (Netherlands)

    S.A. Brands (Stefan)

    1995-01-01

    textabstractA new construction is described for designing secret-key certificate schemes based on signature schemes other than of the Fiat-Shamir type. Also described are practical secret-key certificate issuing protocols that enable the Certification Authority to certify public keys, without being

  1. Certificateless Key-Insulated Generalized Signcryption Scheme without Bilinear Pairings

    Directory of Open Access Journals (Sweden)

    Caixue Zhou

    2017-01-01

    Full Text Available Generalized signcryption (GSC can be applied as an encryption scheme, a signature scheme, or a signcryption scheme with only one algorithm and one key pair. A key-insulated mechanism can resolve the private key exposure problem. To ensure the security of cloud storage, we introduce the key-insulated mechanism into GSC and propose a concrete scheme without bilinear pairings in the certificateless cryptosystem setting. We provide a formal definition and a security model of certificateless key-insulated GSC. Then, we prove that our scheme is confidential under the computational Diffie-Hellman (CDH assumption and unforgeable under the elliptic curve discrete logarithm (EC-DL assumption. Our scheme also supports both random-access key update and secure key update. Finally, we evaluate the efficiency of our scheme and demonstrate that it is highly efficient. Thus, our scheme is more suitable for users who communicate with the cloud using mobile devices.

  2. Secure key storage and distribution

    Science.gov (United States)

    Agrawal, Punit

    2015-06-02

    This disclosure describes a distributed, fault-tolerant security system that enables the secure storage and distribution of private keys. In one implementation, the security system includes a plurality of computing resources that independently store private keys provided by publishers and encrypted using a single security system public key. To protect against malicious activity, the security system private key necessary to decrypt the publication private keys is not stored at any of the computing resources. Rather portions, or shares of the security system private key are stored at each of the computing resources within the security system and multiple security systems must communicate and share partial decryptions in order to decrypt the stored private key.

  3. Dynamic randomization and a randomization model for clinical trials data.

    Science.gov (United States)

    Kaiser, Lee D

    2012-12-20

    Randomization models are useful in supporting the validity of linear model analyses applied to data from a clinical trial that employed randomization via permuted blocks. Here, a randomization model for clinical trials data with arbitrary randomization methodology is developed, with treatment effect estimators and standard error estimators valid from a randomization perspective. A central limit theorem for the treatment effect estimator is also derived. As with permuted-blocks randomization, a typical linear model analysis provides results similar to the randomization model results when, roughly, unit effects display no pattern over time. A key requirement for the randomization inference is that the unconditional probability that any patient receives active treatment is constant across patients; when this probability condition is violated, the treatment effect estimator is biased from a randomization perspective. Most randomization methods for balanced, 1 to 1, treatment allocation satisfy this condition. However, many dynamic randomization methods for planned unbalanced treatment allocation, like 2 to 1, do not satisfy this constant probability condition, and these methods should be avoided. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Small Private Key PKS on an Embedded Microprocessor

    Science.gov (United States)

    Seo, Hwajeong; Kim, Jihyun; Choi, Jongseok; Park, Taehwan; Liu, Zhe; Kim, Howon

    2014-01-01

    Multivariate quadratic ( ) cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011), a small public key scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES) accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012. PMID:24651722

  5. Small private key MQPKS on an embedded microprocessor.

    Science.gov (United States)

    Seo, Hwajeong; Kim, Jihyun; Choi, Jongseok; Park, Taehwan; Liu, Zhe; Kim, Howon

    2014-03-19

    Multivariate quadratic (MQ) cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to MQ cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011), a small public key MQ scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key MQ scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing MQ on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key MQ scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES) accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012.

  6. Small Private Key MQPKS on an Embedded Microprocessor

    Directory of Open Access Journals (Sweden)

    Hwajeong Seo

    2014-03-01

    Full Text Available Multivariate quadratic (MQ cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to MQ cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011, a small public key MQ scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key MQ scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing MQ on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key MQ scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012.

  7. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    This paper presents fundamental outcomes from an experimental study on the hydrodynamic performance near inlet key of Piano Key Weir (PKW). Hydrodynamic performance was tested in a circulated open channel that comprised of PKW and sand bed (d50 = 0.25 mm). Instantaneous velocities were measured at 20 cross ...

  8. Key to good fit: body measurement problems specific to key ...

    African Journals Online (AJOL)

    In this manner, key dimensions were identified and defined. The results revealed that, although international descriptions are available for 100% of the key measurements, major problems seem to be experienced with landmarking, and with consensus about the measuring method and about landmarking. If one assumes ...

  9. Analysis of android random number generator

    OpenAIRE

    Sarıtaş, Serkan

    2013-01-01

    Ankara : The Department of Computer Engineering and the Graduate School of Engineering and Science of Bilkent University, 2013. Thesis (Master's) -- Bilkent University, 2013. Includes bibliographical references leaves 61-65. Randomness is a crucial resource for cryptography, and random number generators are critical building blocks of almost all cryptographic systems. Therefore, random number generation is one of the key parts of secure communication. Random number generatio...

  10. Enhanced Usage of Keys Obtained by Physical, Unconditionally Secure Distributions

    Science.gov (United States)

    Kish, Laszlo B.; Granqvist, Claes-Göran

    2015-04-01

    Unconditionally secure physical key distribution schemes are very slow, and it is practically impossible to use a one-time-pad based cipher to guarantee unconditional security for the encryption of data because using the key bits more than once gives out statistical information, for example via the known-plain-text-attack or by utilizing known components of the protocol and language statistics. Here, we outline a protocol that reduces this speed problem and allows almost-one-time-pad based communication with an unconditionally secure physical key of finite length. The physical, unconditionally secure key is not used for data encryption but is employed in order to generate and share a new software-based key without any known-plain-text component. The software-only-based key distribution is then changed from computationally secure to unconditionally secure, because the communicated key-exchange data (algorithm parameters, one-way functions of random numbers, etc.) are encrypted in an unconditionally secure way with a one-time-pad. For practical applications, this combined physical/software key distribution based communication looks favorable compared to the software-only and physical-only key distribution based communication whenever the speed of the physical key distribution is much lower than that of the software-based key distribution. A mathematical security proof of this new scheme remains an open problem.

  11. Random thoughts

    Science.gov (United States)

    ajansen; kwhitefoot; panteltje1; edprochak; sudhakar, the

    2014-07-01

    In reply to the physicsworld.com news story “How to make a quantum random-number generator from a mobile phone” (16 May, http://ow.ly/xFiYc, see also p5), which describes a way of delivering random numbers by counting the number of photons that impinge on each of the individual pixels in the camera of a Nokia N9 smartphone.

  12. DECOY STATE QUANTUM KEY DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Sellami Ali

    2010-03-01

    Full Text Available Experimental weak + vacuum protocol has been demonstrated using commercial QKD system based on a standard bi-directional ‘Plug & Play’ set-up. By making simple modifications to a commercial quantum key distribution system, decoy state QKD allows us to achieve much better performance than QKD system without decoy state in terms of key generation rate and distance. We demonstrate an unconditionally secure key rate of 6.2931 x 10-4per pulse for a 25 km fiber length.

  13. Universal randomness

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, Viktor S [Landau Institute for Theoretical Physics, Russian Academy of Sciences, Moscow (Russian Federation)

    2011-03-31

    In the last two decades, it has been established that a single universal probability distribution function, known as the Tracy-Widom (TW) distribution, in many cases provides a macroscopic-level description of the statistical properties of microscopically different systems, including both purely mathematical ones, such as increasing subsequences in random permutations, and quite physical ones, such as directed polymers in random media or polynuclear crystal growth. In the first part of this review, we use a number of models to examine this phenomenon at a simple qualitative level and then consider the exact solution for one-dimensional directed polymers in a random environment, showing that free energy fluctuations in such a system are described by the universal TW distribution. The second part provides detailed appendix material containing the necessary mathematical background for the first part. (reviews of topical problems)

  14. Key Injury and Violence Data

    Science.gov (United States)

    ... Traumatic Brain Injury Violence Prevention Key Injury and Violence Data Recommend on Facebook Tweet Share Compartir Injuries ... of death among persons 1-44. Injury- and violence-related deaths are only part of the problem ...

  15. Key economic sectors and services

    NARCIS (Netherlands)

    Arent, Douglas J.; Tol, Richard S.J.; Faust, Eberhard; Hella, Joseph P.; Kumar, Surender; Strzepek, Kenneth M.; Tóth, Ferenc L.; Yan, Denghua; Abdulla, Amjad; Kheshgi, Haroon; Xu, He; Ngeh, Julius

    2015-01-01

    Introduction and Context This chapter discusses the implications of climate change on key economic sectors and services, for example, economic activity. Other chapters discuss impacts from a physical, chemical, biological, or social perspective. Economic impacts cannot be isolated; therefore, there

  16. Algorithms for Lightweight Key Exchange.

    Science.gov (United States)

    Alvarez, Rafael; Caballero-Gil, Cándido; Santonja, Juan; Zamora, Antonio

    2017-06-27

    Public-key cryptography is too slow for general purpose encryption, with most applications limiting its use as much as possible. Some secure protocols, especially those that enable forward secrecy, make a much heavier use of public-key cryptography, increasing the demand for lightweight cryptosystems that can be implemented in low powered or mobile devices. This performance requirements are even more significant in critical infrastructure and emergency scenarios where peer-to-peer networks are deployed for increased availability and resiliency. We benchmark several public-key key-exchange algorithms, determining those that are better for the requirements of critical infrastructure and emergency applications and propose a security framework based on these algorithms and study its application to decentralized node or sensor networks.

  17. An entrepreneurial key competencies’ model

    National Research Council Canada - National Science Library

    Arafeh, Labib

    2016-01-01

    ... worldwide.Furthermore, the paper proposes a softcomputing-based entrepreneurial key competencies’ model (SKECM). This tool is capable of predicting/judging the overall quality of entrepreneurial competencies...

  18. Random triangles

    OpenAIRE

    Matula, Dominik

    2013-01-01

    The author summarizes some previous results concerning random triangles. He describes the Gaussian triangle and random triangles whose vertices lie in a unit n-dimensional ball, in a rectangle or in a general bounded convex set. In the second part, the author deals with an inscribed triangle in a triangle - let ABC be an equilateral triangle and let M, N, O be three points, each laying on one side of the ABC. We call MNO inscribed triangle (in an equi- laterral triangle). The median triangle ...

  19. Random matrices

    CERN Document Server

    Mehta, Madan Lal

    1990-01-01

    Since the publication of Random Matrices (Academic Press, 1967) so many new results have emerged both in theory and in applications, that this edition is almost completely revised to reflect the developments. For example, the theory of matrices with quaternion elements was developed to compute certain multiple integrals, and the inverse scattering theory was used to derive asymptotic results. The discovery of Selberg's 1944 paper on a multiple integral also gave rise to hundreds of recent publications. This book presents a coherent and detailed analytical treatment of random matrices, leading

  20. Server-Controlled Identity-Based Authenticated Key Exchange

    Science.gov (United States)

    Guo, Hua; Mu, Yi; Zhang, Xiyong; Li, Zhoujun

    We present a threshold identity-based authenticated key exchange protocol that can be applied to an authenticated server-controlled gateway-user key exchange. The objective is to allow a user and a gateway to establish a shared session key with the permission of the back-end servers, while the back-end servers cannot obtain any information about the established session key. Our protocol has potential applications in strong access control of confidential resources. In particular, our protocol possesses the semantic security and demonstrates several highly-desirable security properties such as key privacy and transparency. We prove the security of the protocol based on the Bilinear Diffie-Hellman assumption in the random oracle model.

  1. An Improved Genetic Algorithm for Developing Deterministic OTP Key Generator

    Directory of Open Access Journals (Sweden)

    Ashish Jain

    2017-01-01

    Full Text Available Recently, a genetic-based random key generator (GRKG for the one-time pad (OTP cryptosystem has been proposed in the literature which has certain limitations. In this paper, two main characteristics (speed and randomness of the GRKG method are significantly improved by presenting the IGRKG method (improved genetic-based random key generator method. The proposed IGRKG method generates an initial pad by using linear congruential generator (LCG and improves the randomness of the initial pad using genetic algorithm. There are three reasons behind the use of LCG: it is easy to implement, it can run efficiently on computer hardware, and it has good statistical properties. The experimental results show the superiority of the IGRKG over GRKG in terms of speed and randomness. Hereby we would like to mention that no prior experimental work has been presented in the literature which is directly related to the OTP key generation using evolutionary algorithms. Therefore, this work can be considered as a guideline for future research.

  2. Side Channel Passive Quantum Key Distribution with One Uninformative State

    Science.gov (United States)

    Kang, Guo-Dong; Zhou, Qing-Ping; Fang, Mao-Fa

    2017-03-01

    In most of quantum key distribution schemes, real random number generators are required on both sides for preparation and measurement bases choice. In this paper, via entangled photon pairs, we present a side channel passive quantum key distribution scheme, in which random number generator is unneeded on the receiver side. On the sender Alice side, along with massive of signal photons, small amount of uninformative photons are randomly sent to her partner Bob for eavesdropper-presence testing and error estimation. While on the other side channel, without using random number generator Bob do not actively measure the income signals randomly in two non-orthogonal bases. Instead, he just passively register photon click events, in two settled symmetric (i.e. X) bases, and the raw key(click events) is the probable outcomes of a special quantum measurement module constructed by Alice and Bob. Further, security analysis and formulas of security bounds for this scheme is also investigated under reasonable assumptions. Our work shows that the uninformative state employed in this paper is powerful to fight against eavesdropper Eve.

  3. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    time fluctuating nature of flows is clearly understood with the help of advanced instrumentation and computing .... validate numerical models concerned with the design and construction of PKW. Acknowledgements ... Erpicum S, Nagel V and Laugier F 2011 Piano Key Weir design study at Raviege dam. Labyrinth and.

  4. Source-Independent Quantum Random Number Generation

    Science.gov (United States)

    Cao, Zhu; Zhou, Hongyi; Yuan, Xiao; Ma, Xiongfeng

    2016-01-01

    Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts—a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over 5 ×103 bit /s .

  5. Remote Key Establishment by Mode Mixing in Multimode Fibres and Optical Reciprocity

    CERN Document Server

    Bromberg, Yaron; Popoff, Sebastien M; Cao, Hui

    2015-01-01

    Disorder and scattering in photonic systems have long been considered a nuisance that should be circumvented. Recently, disorder has been harnessed for a rapidly growing number of applications, including imaging, sensing and spectroscopy. The chaotic dynamics and extreme sensitivity to external perturbations make random media particularly well-suited for optical cryptography. However, using random media for distribution of secret keys between remote users still remains challenging, since it requires the users have access to the same scattering system. Here we utilize random mode mixing in multimode fibres to generate and distribute keys simultaneously. Fast fluctuations in the fibre mode mixing provide the source of randomness for the key generation, and optical reciprocity guarantees that the keys at the two ends of the fibre are identical. We experimentally demonstrate the scheme using classical light and off-the-shelf components, opening the door for cost effective key establishment at the physical-layer o...

  6. Key World Energy Statistics 2013

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-01

    The IEA produced its first handy, pocket-sized summary of key energy data in 1997 and every year since then it has been more and more successful. Key World Energy Statistics contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts.

  7. Key China Energy Statistics 2011

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-01-15

    The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). In 2008 the Group published the Seventh Edition of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.

  8. Key China Energy Statistics 2012

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). The Group has published seven editions to date of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.

  9. Random queues and risk averse users

    DEFF Research Database (Denmark)

    de Palma, André; Fosgerau, Mogens

    2013-01-01

    We analyze Nash equilibrium in time of use of a congested facility. Users are risk averse with general concave utility. Queues are subject to varying degrees of random sorting, ranging from strict queue priority to a completely random queue. We define the key “no residual queue” property, which...

  10. Individual Differences Methods for Randomized Experiments

    Science.gov (United States)

    Tucker-Drob, Elliot M.

    2011-01-01

    Experiments allow researchers to randomly vary the key manipulation, the instruments of measurement, and the sequences of the measurements and manipulations across participants. To date, however, the advantages of randomized experiments to manipulate both the aspects of interest and the aspects that threaten internal validity have been primarily…

  11. Right collaborations is the key

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Right collaborations is the key. Large-scale production and analysis of stress tolerant transgenics needs active collaborations between plant physiologists, biochemists and geneticists. Collaboration between molecular biologists and biochemists is seen. Active collaboration ...

  12. Key World Energy Statistics 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Key World Energy Statistics contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts.

  13. Ten Keys to the Portal

    Science.gov (United States)

    Schaffhauser, Dian

    2011-01-01

    Successful web portals help users stay informed, in touch, and up to speed. They are also a telling window into the efficiency of one's institution. To develop a cutting-edge portal takes planning, communication, and research. In this article, the author presents and discusses 10 keys to portal success: (1) make critical info visible; (2) make the…

  14. School Leadership: Some Key Ideas.

    Science.gov (United States)

    Fidler, Brian

    1997-01-01

    Highlights some key ideas and several perspectives on leadership, including: situational leadership; a leadership framework suggested by T.E. Deal and L.G. Bolman; leadership of the chief executive/leading professional; moral leadership; and curricular leadership. Identifies leadership by its contribution to outcomes and its influence on…

  15. Focusing on key development challenges

    International Development Research Centre (IDRC) Digital Library (Canada)

    Strategic Framework to guide our work during 2010–2015. This framework builds on the Centre's strengths ... Focusing on key development challenges. Building on strengths. Meeting tomorrow's ... durable peace, and the inclusion of marginalized groups, particularly women and girls. • Globalization, Growth and Poverty.

  16. Symmetric Key Authentication Services Revisited

    NARCIS (Netherlands)

    Crispo, B.; Popescu, B.C.; Tanenbaum, A.S.

    2004-01-01

    Most of the symmetric key authentication schemes deployed today are based on principles introduced by Needham and Schroeder [15] more than twenty years ago. However, since then, the computing environment has evolved from a LAN-based client-server world to include new paradigms, including wide area

  17. Continuous variable quantum key distribution

    Science.gov (United States)

    Li, Yong-Min; Wang, Xu-Yang; Bai, Zeng-Liang; Liu, Wen-Yuan; Yang, Shen-Shen; Peng, Kun-Chi

    2017-04-01

    Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 61378010 and 11504219), the Key Project of the Ministry of Science and Technology of China (Grant No. 2016YFA0301403), the Natural Science Foundation of Shanxi Province, China (Grant No. 2014011007-1), and the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province, China.

  18. Random walks in a random environment

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. Random walks as well as diffusions in random media are considered. Methods are developed that allow one to establish large deviation results for both the 'quenched' and the 'averaged' case. Keywords. Large deviations; random walks in a random environment. 1. Introduction. A random walk on Zd is a stochastic ...

  19. Multi-partite entanglement can speed up quantum key distribution in networks

    Science.gov (United States)

    Epping, Michael; Kampermann, Hermann; macchiavello, Chiara; Bruß, Dagmar

    2017-09-01

    The laws of quantum mechanics allow for the distribution of a secret random key between two parties. Here we analyse the security of a protocol for establishing a common secret key between N parties (i.e. a conference key), using resource states with genuine N-partite entanglement. We compare this protocol to conference key distribution via bipartite entanglement, regarding the required resources, achievable secret key rates and threshold qubit error rates. Furthermore we discuss quantum networks with bottlenecks for which our multipartite entanglement-based protocol can benefit from network coding, while the bipartite protocol cannot. It is shown how this advantage leads to a higher secret key rate.

  20. Key drivers of airline loyalty.

    Science.gov (United States)

    Dolnicar, Sara; Grabler, Klaus; Grün, Bettina; Kulnig, Anna

    2011-10-01

    This study investigates drivers of airline loyalty. It contributes to the body of knowledge in the area by investigating loyalty for a number of a priori market segments identified by airline management and by using a method which accounts for the multi-step nature of the airline choice process. The study is based on responses from 687 passengers. Results indicate that, at aggregate level, frequent flyer membership, price, the status of being a national carrier and the reputation of the airline as perceived by friends are the variables which best discriminate between travellers loyal to the airline and those who are not. Differences in drivers of airline loyalty for a number of segments were identified. For example, loyalty programs play a key role for business travellers whereas airline loyalty of leisure travellers is difficult to trace back to single factors. For none of the calculated models satisfaction emerged as a key driver of airline loyalty.

  1. KEY TOPICS IN SPORTS MEDICINE

    OpenAIRE

    Amir Ali Narvani; Panagiotis Thomas; Burce Lynn

    2006-01-01

    Key Topics in Sports Medicine is a single quick reference source for sports and exercise medicine. It presents the essential information from across relevant topic areas, and includes both the core and emerging issues in this rapidly developing field. It covers: 1) Sports injuries, rehabilitation and injury prevention, 2) Exercise physiology, fitness testing and training, 3) Drugs in sport, 4) Exercise and health promotion, 5) Sport and exercise for special and clinical populations, 6) The ps...

  2. Human Resources Key Performance Indicators

    Directory of Open Access Journals (Sweden)

    Gabčanová Iveta

    2012-03-01

    Full Text Available The article brings out a proposed strategy map and respective key performance indicators (KPIs in human resources (HR. The article provides an overview of how HR activities are supported in order to reach the partial goals of HR as defined in the strategic map. Overall the aim of the paper is to show the possibilities of using the modern Balanced Scorecard method in human capital.

  3. The Body: The Key Concepts

    OpenAIRE

    Blackman, Lisa

    2008-01-01

    Questions around 'the body' are central to social theory. Our changing understanding of the body now challenges the ways we conceive power, ideology, subjectivity and social and cultural process. The Body: the key concepts highlights and analyses the debates which make the body central to current sociological, psychological, cultural and feminist thinking. Today, questions around the body are intrinsic to a wide range of debates - from technological developments in media and communications, t...

  4. Disarming the Key Leader Engagement

    Science.gov (United States)

    2010-09-01

    niques and the managed expectation of key leader engagement effects. Effects are not immediate, and we must build them with candor, genuine concern...security agreement for U.S. forces? The agree- ment was understood in theory , but its application generated a litany of ques- tions. However, one...thing was clear: the way ahead would require systematic engagements with Iraqi leaders to leverage their powers of public persuasion. Military

  5. Low carbon development. Key issues

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Frauke; Nordensvaard, Johan (eds.)

    2013-03-07

    This comprehensive textbook addresses the interface between international development and climate change in a carbon constrained world. It discusses the key conceptual, empirical and policy-related issues of low carbon development and takes an international and interdisciplinary approach to the subject by drawing on insights from across the natural sciences and social sciences whilst embedding the discussion in a global context. The first part explores the concept of low carbon development and explains the need for low carbon development in a carbon constrained world. The book then discusses the key issues of socio-economic, political and technological nature for low carbon development, exploring topics such as the political economy, social justice, financing and carbon markets, and technologies and innovation for low carbon development. This is followed by key issues for low carbon development in policy and practice, which is presented based on cross-cutting issues such as low carbon energy, forestry, agriculture and transportation. Afterwards, practical case studies are discussed from low carbon development in low income countries in Africa, middle income countries in Asia and Latin America and high income countries in Europe and North America.

  6. Detector decoy quantum key distribution

    Energy Technology Data Exchange (ETDEWEB)

    Moroder, Tobias; Luetkenhaus, Norbert [Quantum Information Theory Group, Institute of Theoretical Physics I, University Erlangen-Nuremberg, Staudtstrasse 7/B2, 91058 Erlangen (Germany); Curty, Marcos [ETSI Telecomunicacion, Department of Signal Theory and Communications, University of Vigo, Campus Universitario, E-36310 Vigo (Spain)], E-mail: tmoroder@iqc.ca

    2009-04-15

    Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum key distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum key distribution protocols.

  7. Random functions and turbulence

    CERN Document Server

    Panchev, S

    1971-01-01

    International Series of Monographs in Natural Philosophy, Volume 32: Random Functions and Turbulence focuses on the use of random functions as mathematical methods. The manuscript first offers information on the elements of the theory of random functions. Topics include determination of statistical moments by characteristic functions; functional transformations of random variables; multidimensional random variables with spherical symmetry; and random variables and distribution functions. The book then discusses random processes and random fields, including stationarity and ergodicity of random

  8. Key Concepts in Microbial Oceanography

    Science.gov (United States)

    Bruno, B. C.; Achilles, K.; Walker, G.; Weersing, K.; Team, A

    2008-12-01

    The Center for Microbial Oceanography: Research and Education (C-MORE) is a multi-institution Science and Technology Center, established by the National Science Foundation in 2006. C-MORE's research mission is to facilitate a more comprehensive understanding of the diverse assemblages of microorganisms in the sea, ranging from the genetic basis of marine microbial biogeochemistry including the metabolic regulation and environmental controls of gene expression, to the processes that underpin the fluxes of carbon, related bioelements, and energy in the marine environment. The C-MORE education and outreach program is focused on increasing scientific literacy in microbial oceanography among students, educators, and the general public. A first step toward this goal is defining the key concepts that constitute microbial oceanography. After lengthy discussions with scientists and educators, both within and outside C-MORE, we have arrived at six key concepts: 1) Marine microbes are very small and have been around for a long time; 2) Life on Earth could not exist without microbes; 3) Most marine microbes are beneficial; 4) Microbes are everywhere: they are extremely abundant and diverse; 5) Microbes significantly impact our global climate; and 6) There are new discoveries every day in the field of microbial oceanography. A C-MORE-produced brochure on these six key concepts will be distributed at the meeting. Advanced copies may be requested by email or downloaded from the C-MORE web site(http://cmore.soest.hawaii.edu/downloads/MO_key_concepts_hi-res.pdf). This brochure also includes information on career pathways in microbial oceanography, with the aim of broadening participation in the field. C-MORE is eager to work in partnership to incorporate these key concepts into other science literacy publications, particularly those involving ocean and climate literacy. We thank the following contributors and reviewers: P Chisholm, A Dolberry, and A Thompson (MIT); N Lawrence

  9. KeyPathwayMinerWeb

    DEFF Research Database (Denmark)

    List, Markus; Alcaraz, Nicolas; Dissing-Hansen, Martin

    2016-01-01

    such as data integration, input of background knowledge, batch runs for parameter optimization and visualization of extracted pathways. In addition to an intuitive web interface, we also implemented a RESTful API that now enables other online developers to integrate network enrichment as a web service......We present KeyPathwayMinerWeb, the first online platform for de novo pathway enrichment analysis directly in the browser. Given a biological interaction network (e.g. protein-protein interactions) and a series of molecular profiles derived from one or multiple OMICS studies (gene expression...

  10. Key Obama officials leave administration

    Science.gov (United States)

    Showstack, Randy

    2013-01-01

    Secretary of the Interior Ken Salazar is one of the latest members of the Obama administration to announce that he is leaving his position near the start of President Obama's second term in office. Salazar, who has served as interior secretary since January 2009, intends to leave the department by the end of March, the department noted on 16 January. Salazar joins a number of other key officials who are planning to leave the administration. They include Environmental Protection Agency administrator Lisa Jackson, National Oceanic and Atmospheric Administration administrator Jane Lubchenco, and U.S. Geological Survey director Marcia McNutt.

  11. Nephrology key information for internists.

    Science.gov (United States)

    Salim, Sohail Abdul; Medaura, Juan A; Malhotra, Bharat; Garla, Vishnu; Ahuja, Shradha; Lawson, Nicki; Pamarthy, Amaleswari; Sonani, Hardik; Kovvuru, Karthik; Palabindala, Venkataraman

    2017-03-01

    Hospitalists and primary care physicians encounter renal disease daily. Although most cases of acute kidney injury (AKI) are secondary to dehydration and resolve by giving fluids, many cases of AKI are due to not uncommon but unfamiliar causes needing nephrology evaluation. Common indications to consult a nephrologist on an emergency basis include hyperkalemia or volume overload in end stage renal disease patients (ESRD). Other causes of immediate consultation are cresenteric glomerulonephritis / rapidly progressive glomerulonephritis in which renal prognosis of the patient depends on timely intervention. The following evidence-based key information could improve patient care and outcomes. Abbreviations: AKI: Acute kidney injury ESRD: End stage renal disease patients.

  12. Key Note: Living with droughts?

    OpenAIRE

    Erdbrink, C. D.; van Beek, Eelco; van Os, A.G.

    2008-01-01

    The Netherlands Center for River Research (NCR) in its first 10 years of existence has focused its activities on flooding. Climate change might cause that droughts will become as important as or even more important than floods. The dry year 2003 in Europe has shown the huge socio-economic impacts of droughts. New concepts are emerging on how to deal with droughts. This key-note addresses the issues of droughts and scarcity and makes a plea to include more drought research in NCR.

  13. Fibre Optic Communication Key Devices

    CERN Document Server

    Grote, Norbert

    2012-01-01

    The book gives an in-depth description of the key devices of current and next generation fibre optic communication networks. In particular, the book covers devices such as semiconductor lasers, optical amplifiers, modulators, wavelength filters, and detectors but the relevant properties of optical fibres as well. The presentations include the physical principles underlying the various devices, the technologies used for the realization of the different devices, typical performance characteristics and limitations, and development trends towards more advanced components are also illustrated. Thus the scope of the book spans relevant principles, state-of-the-art implementations, the status of current research and expected future components.

  14. Key instrumentation in BWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Laendner, Alexander; Stellwag, Bernhard; Fandrich, Joerg [AREVA NP GmbH, Erlangen (Germany)

    2011-01-15

    This paper describes water chemistry surveillance practices at boiling water reactor (BWR) power plants. The key instrumentation in BWR plants consists of on-line as well as off-line instrumentation. The chemistry monitoring and control parameters are predominantly based on two guidelines, namely the VGB Water Chemistry Guidelines and the EPRI Water Chemistry Guidelines. Control parameters and action levels specified in the VGB guideline are described. Typical sampling locations in BWR plants, chemistry analysis methods and water chemistry data of European BWR plants are summarized. Measurement data confirm the high quality of reactor water of the BWRs in Europe. (orig.)

  15. Key paediatric messages from Amsterdam

    Directory of Open Access Journals (Sweden)

    Jonathan Grigg

    2016-04-01

    Full Text Available The Paediatric Assembly of the European Respiratory Society (ERS maintained its high profile at the 2015 ERS International Congress in Amsterdam. There were symposia on preschool wheeze, respiratory sounds and cystic fibrosis; an educational skills workshop on paediatric respiratory resuscitation; a hot topic session on risk factors and early origins of respiratory diseases; a meet the expert session on paediatric lung function test reference values; and the annual paediatric grand round. In this report the Chairs of the Paediatric Assembly's Groups highlight the key messages from the abstracts presented at the Congress.

  16. Key paediatric messages from Amsterdam

    Science.gov (United States)

    Barben, Jürg; Bohlin, Kajsa; Everard, Mark L.; Hall, Graham; Pijnenburg, Mariëlle; Priftis, Kostas N.; Rusconi, Franca; Midulla, Fabio

    2016-01-01

    The Paediatric Assembly of the European Respiratory Society (ERS) maintained its high profile at the 2015 ERS International Congress in Amsterdam. There were symposia on preschool wheeze, respiratory sounds and cystic fibrosis; an educational skills workshop on paediatric respiratory resuscitation; a hot topic session on risk factors and early origins of respiratory diseases; a meet the expert session on paediatric lung function test reference values; and the annual paediatric grand round. In this report the Chairs of the Paediatric Assembly's Groups highlight the key messages from the abstracts presented at the Congress. PMID:27730186

  17. Enhancing superconducting critical current by randomness

    Science.gov (United States)

    Wang, Y. L.; Thoutam, L. R.; Xiao, Z. L.; Shen, B.; Pearson, J. E.; Divan, R.; Ocola, L. E.; Crabtree, G. W.; Kwok, W. K.

    2016-01-01

    The key ingredient of high critical currents in a type-II superconductor is defect sites that pin vortices. Contrary to earlier understanding on nanopatterned artificial pinning, here we show unequivocally the advantages of a random pinscape over an ordered array in a wide magnetic field range. We reveal that the better performance of a random pinscape is due to the variation of its local density of pinning sites (LDOPS), which mitigates the motion of vortices. This is confirmed by achieving even higher enhancement of the critical current through a conformally mapped random pinscape, where the distribution of the LDOPS is further enlarged. The demonstrated key role of LDOPS in enhancing superconducting critical currents gets at the heart of random versus commensurate pinning. Our findings highlight the importance of random pinscapes in enhancing the superconducting critical currents of applied superconductors.

  18. Public/private key certification authority and key distribution. Draft

    Energy Technology Data Exchange (ETDEWEB)

    Long, J.P.; Christensen, M.J.; Sturtevant, A.P.; Johnston, W.E.

    1995-09-25

    Traditional encryption, which protects messages from prying eyes, has been used for many decades. The present concepts of encryption are built from that heritage. Utilization of modern software-based encryption techniques implies much more than simply converting files to an unreadable form. Ubiquitous use of computers and advances in encryption technology coupled with the use of wide-area networking completely changed the reasons for utilizing encryption technology. The technology demands a new and extensive infrastructure to support these functions. Full understanding of these functions, their utility and value, and the need for an infrastructure, takes extensive exposure to the new paradigm. This paper addresses issues surrounding the establishment and operation of a key management system (i.e., certification authority) that is essential to the successful implementation and wide-spread use of encryption.

  19. Random fixed points and random differential inclusions

    Directory of Open Access Journals (Sweden)

    Nikolaos S. Papageorgiou

    1988-01-01

    Full Text Available In this paper, first, we study random best approximations to random sets, using fixed point techniques, obtaining this way stochastic analogues of earlier deterministic results by Browder-Petryshyn, KyFan and Reich. Then we prove two fixed point theorems for random multifunctions with stochastic domain that satisfy certain tangential conditions. Finally we consider a random differential inclusion with upper semicontinuous orientor field and establish the existence of random solutions.

  20. The random projection method

    CERN Document Server

    Vempala, Santosh S

    2005-01-01

    Random projection is a simple geometric technique for reducing the dimensionality of a set of points in Euclidean space while preserving pairwise distances approximately. The technique plays a key role in several breakthrough developments in the field of algorithms. In other cases, it provides elegant alternative proofs. The book begins with an elementary description of the technique and its basic properties. Then it develops the method in the context of applications, which are divided into three groups. The first group consists of combinatorial optimization problems such as maxcut, graph coloring, minimum multicut, graph bandwidth and VLSI layout. Presented in this context is the theory of Euclidean embeddings of graphs. The next group is machine learning problems, specifically, learning intersections of halfspaces and learning large margin hypotheses. The projection method is further refined for the latter application. The last set consists of problems inspired by information retrieval, namely, nearest neig...

  1. Key Aspects of Wave Energy

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Nørgaard, Jørgen Harck

    2012-01-01

    Diversification of renewable energy sources is fundamental to ensure sustainability. In this contest, wave energy can provide a substantial contribution as soon as the sector breaks into the market. In order to accelerate shift from a technology to a market focus and reduce technical and non...... be used as a breakwater therefore providing a solid structure for harbor protection; the Wave Star can be used as a base for offshore wind and photovoltaic installation in the middle of the sea, realizing an hybrid renewable energy platform. It is the authors´ believe that taking wave energy devices......-technical risks, it is critical to provide comprehensive and reliable information on the technologies without neglecting attractive advantages. It is possible to underline a different key of lecture of wave energy performance by considering efficiency and power production as well as device versatility...

  2. Fibre optic communication key devices

    CERN Document Server

    Grote, Norbert

    2017-01-01

    The book gives an in-depth description of key devices of current and next generation fibre optic communication networks. Devices treated include semiconductor lasers, optical amplifiers, modulators, wavelength filters and other passives, detectors, all-optical switches, but relevant properties of optical fibres and network aspects are included as well. The presentations include the physical principles underlying the various devices, technologies used for their realization, typical performance characteristics and limitations, but development trends towards more advanced components are also illustrated. This new edition of a successful book was expanded and updated extensively. The new edition covers among others lasers for optical communication, optical switches, hybrid integration, monolithic integration and silicon photonics. The main focus is on Indium phosphide-based structures but silicon photonics is included as well. The book covers relevant principles, state-of-the-art implementations, status of curren...

  3. Applied public-key steganography

    Science.gov (United States)

    Guillon, Pierre; Furon, Teddy; Duhamel, Pierre

    2002-04-01

    We consider the problem of hiding information in a steganographic framework, i.e. embedding a binary message within an apparently innocuous content, in order to establish a suspicion-free digital communication channel. The adversary is passive as no intentional attack is foreseen. The only threat is that she discovers the presence of a hidden communication. The main goal of this article is to find if the Scalar Costa Scheme, a recently published embedding method exploiting side information at the encoder, is suitable for that framework. We justify its use assessing its security level with respect to the Cachin's criterion. We derive a public-key stego-system following the ideas of R. Anderson and P. Petitcolas. This technique is eventually applied to PCM audio contents. Experimental performances are detailed in terms of bit-rate and Kullback-Leibler distance.

  4. Key energy technologies for Europe

    Energy Technology Data Exchange (ETDEWEB)

    Holst Joergensen, Birte

    2005-09-01

    The report is part of the work undertaken by the High-Level Expert Group to prepare a report on emerging science and technology trends and the implications for EU and Member State research policies. The outline of the report is: 1) In the introductory section, energy technologies are defined and for analytical reasons further narrowed down; 2) The description of the socio-economic challenges facing Europe in the energy field is based on the analysis made by the International Energy Agency going back to 1970 and with forecasts to 2030. Both the world situation and the European situation are described. This section also contains an overview of the main EU policy responses to energy. Both EU energy R and D as well as Member State energy R and D resources are described in view of international efforts; 3) The description of the science and technology base is made for selected energy technologies, including energy efficiency, biomass, hydrogen, and fuel cells, photovoltaics, clean fossil fuel technologies and CO{sub 2} capture and storage, nuclear fission and fusion. When possible, a SWOT is made for each technology and finally summarised; 4) The forward look highlights some of the key problems and uncertainties related to the future energy situation. Examples of recent energy foresights are given, including national energy foresights in Sweden and the UK as well as links to a number of regional and national foresights and roadmaps; 5) Appendix 1 contains a short description of key international organisations dealing with energy technologies and energy research. (ln)

  5. Dual Key Speech Encryption Algorithm Based Underdetermined BSS

    Directory of Open Access Journals (Sweden)

    Huan Zhao

    2014-01-01

    Full Text Available When the number of the mixed signals is less than that of the source signals, the underdetermined blind source separation (BSS is a significant difficult problem. Due to the fact that the great amount data of speech communications and real-time communication has been required, we utilize the intractability of the underdetermined BSS problem to present a dual key speech encryption method. The original speech is mixed with dual key signals which consist of random key signals (one-time pad generated by secret seed and chaotic signals generated from chaotic system. In the decryption process, approximate calculation is used to recover the original speech signals. The proposed algorithm for speech signals encryption can resist traditional attacks against the encryption system, and owing to approximate calculation, decryption becomes faster and more accurate. It is demonstrated that the proposed method has high level of security and can recover the original signals quickly and efficiently yet maintaining excellent audio quality.

  6. Distributed public key schemes secure against continual leakage

    DEFF Research Database (Denmark)

    Akavia, Adi; Goldwasser, Shafi; Hazay, Carmit

    2012-01-01

    In this work we study distributed public key schemes secure against continual memory leakage. The secret key will be shared among two computing devices communicating over a public channel, and the decryption operation will be computed by a simple 2-party protocol between the devices. Similarly...... the value of the respective function on the internal state of the respective device (namely, on its secret share, internal randomness, and results of intermediate computations). We present distributed public key encryption (DPKE) and distributed identity based encryption (DIBE) schemes that are secure......-secure against continual memory leakage. Our DPKE scheme also implies a secure storage system on leaky devices, where a value s can be secretely stored on devices that continually leak information about their internal state to an external attacker. The devices go through a periodic refresh protocol...

  7. The key stakeholders’ opinions regarding university counseling centers: An experience from Iran

    OpenAIRE

    Niloofar Peykari; Fahimeh Ramezani Tehrani; Hossein Malek Afzali; Monir Baradaran Eftekhari; Shirin Djalalinia

    2011-01-01

    Background: Student counseling centers are responsible for physical, mental and social health of university students. Therefore, this study was conducted to assess the key stakeholders′ opinions on different aspects of the activities performed in these centers. Methods: This qualitative study used focus group discussion. Key stakeholders including university students and key informants from nine randomly selected medical universities participated in the study. After data saturation, thema...

  8. Key aspects of coronal heating

    Science.gov (United States)

    Klimchuk, James A.

    2015-01-01

    We highlight 10 key aspects of coronal heating that must be understood before we can consider the problem to be solved. (1) All coronal heating is impulsive. (2) The details of coronal heating matter. (3) The corona is filled with elemental magnetic stands. (4) The corona is densely populated with current sheets. (5) The strands must reconnect to prevent an infinite build-up of stress. (6) Nanoflares repeat with different frequencies. (7) What is the characteristic magnitude of energy release? (8) What causes the collective behaviour responsible for loops? (9) What are the onset conditions for energy release? (10) Chromospheric nanoflares are not a primary source of coronal plasma. Significant progress in solving the coronal heating problem will require coordination of approaches: observational studies, field-aligned hydrodynamic simulations, large-scale and localized three-dimensional magnetohydrodynamic simulations, and possibly also kinetic simulations. There is a unique value to each of these approaches, and the community must strive to coordinate better. PMID:25897094

  9. VICKEY: Mining Conditional Keys on Knowledge Bases

    DEFF Research Database (Denmark)

    Symeonidou, Danai; Prado, Luis Antonio Galarraga Del; Pernelle, Nathalie

    2017-01-01

    A conditional key is a key constraint that is valid in only a part of the data. In this paper, we show how such keys can be mined automatically on large knowledge bases (KBs). For this, we combine techniques from key mining with techniques from rule mining. We show that our method can scale to KBs...... of millions of facts. We also show that the conditional keys we mine can improve the quality of entity linking by up to 47% points....

  10. Chaos-based encryption keys and neural key-store for cloud-hosted data confidentiality

    CSIR Research Space (South Africa)

    Mosola, NN

    2017-09-01

    Full Text Available no significance if the key management is flawed. To address the inherent key management problem, the solution uses a neural network to learn patterns of an encryption key. Once learnt, the key is then discard to thwart possible key attacks. The key...

  11. KEY TOPICS IN SPORTS MEDICINE

    Directory of Open Access Journals (Sweden)

    Amir Ali Narvani

    2006-12-01

    Full Text Available Key Topics in Sports Medicine is a single quick reference source for sports and exercise medicine. It presents the essential information from across relevant topic areas, and includes both the core and emerging issues in this rapidly developing field. It covers: 1 Sports injuries, rehabilitation and injury prevention, 2 Exercise physiology, fitness testing and training, 3 Drugs in sport, 4 Exercise and health promotion, 5 Sport and exercise for special and clinical populations, 6 The psychology of performance and injury. PURPOSE The Key Topics format provides extensive, concise information in an accessible, easy-to-follow manner. AUDIENCE The book is targeted the students and specialists in sports medicine and rehabilitation, athletic training, physiotherapy and orthopaedic surgery. The editors are authorities in their respective fields and this handbook depends on their extensive experience and knowledge accumulated over the years. FEATURES The book contains the information for clinical guidance, rapid access to concise details and facts. It is composed of 99 topics which present the information in an order that is considered logical and progressive as in most texts. Chapter headings are: 1. Functional Anatomy, 2. Training Principles / Development of Strength and Power, 3. Biomechanical Principles, 4. Biomechanical Analysis, 5. Physiology of Training, 6. Monitoring of Training Progress, 7. Nutrition, 8. Hot and Cold Climates, 9. Altitude, 10. Sport and Travelling, 11. Principles of Sport Injury Diagnosis, 12. Principles of Sport and Soft Tissue Management, 13. Principles of Physical Therapy and Rehabilitation, 14. Principles of Sport Injury Prevention, 15. Sports Psychology, 16. Team Sports, 17. Psychological Aspects of Injury in Sport, 18. Injury Repair Process, 19. Basic Biomechanics of Tissue Injury, 20. Plain Film Radiography in Sport, 21. Nuclear Medicine, 22. Diagnostic Ultrasound, 23. MRI Scan, 24. Other Imaging, 5. Head Injury, 26. Eye

  12. Key issues in transplant tourism.

    Science.gov (United States)

    Akoh, Jacob A

    2012-02-24

    Access to organ transplantation depends on national circumstances, and is partly determined by the cost of health care, availability of transplant services, the level of technical capacity and the availability of organs. Commercial transplantation is estimated to account for 5%-10% (3500-7000) of kidney transplants performed annually throughout the world. This review is to determine the state and outcome of renal transplantation associated with transplant tourism (TT) and the key challenges with such transplantation. The stakeholders of commercial transplantation include: patients on the waiting lists in developed countries or not on any list in developing countries; dialysis funding bodies; middlemen, hosting transplant centres; organ-exporting countries; and organ vendors. TT and commercial kidney transplants are associated with a high incidence of surgical complications, acute rejection and invasive infection which cause major morbidity and mortality. There are ethical and medical concerns regarding the management of recipients of organs from vendors. The growing demand for transplantation, the perceived failure of altruistic donation in providing enough organs has led to calls for a legalised market in organ procurement or regulated trial in incentives for donation. Developing transplant services worldwide has many benefits - improving results of transplantation as they would be performed legally, increasing the donor pool and making TT unnecessary. Meanwhile there is a need to re-examine intrinsic attitudes to TT bearing in mind the cultural and economic realities of globalisation. Perhaps the World Health Organization in conjunction with The Transplantation Society would set up a working party of stakeholders to study this matter in greater detail and make recommendations.

  13. Cognitive processing in new and practiced discrete keying sequences

    Directory of Open Access Journals (Sweden)

    Willem B Verwey

    2010-07-01

    Full Text Available This study addresses the role of cognitive control in the initiation and execution of familiar and unfamiliar movement sequences. To become familiar with two movement sequences participants first practiced two discrete key press sequences by responding to two fixed series of 6 key specific stimuli. In the ensuing test phase they executed these two familiar and also two unfamiliar keying sequences while there was a two-third chance a tone was presented together with one randomly selected key specific stimulus in each sequence. In the counting condition of the test phase participants counted the low pitched (i.e., target tones. By and large the results support the dual processor model in which the prime role of the cognitive processor shifts from executing to initiating sequences while the gradual development of motor chunks allows a motor processor to execute the sequences. Yet, the results extend this simple model by suggesting that with little practice sequence execution is based also on some non-cognitive (perhaps associative learning mechanism and, for some participants, on the use of explicit sequence knowledge. Also, after extensive practice the cognitive processor appears to still contribute to slower responses. The occurrence of long interkey intervals was replicated suggesting that fixed 6-key sequences include several motor chunks. Yet, no indication was found that the cognitive processor is responsible for concatenating these chunks.

  14. High-capacity quantum Fibonacci coding for key distribution

    Science.gov (United States)

    Simon, David S.; Lawrence, Nate; Trevino, Jacob; Dal Negro, Luca; Sergienko, Alexander V.

    2013-03-01

    Quantum cryptography and quantum key distribution (QKD) have been the most successful applications of quantum information processing, highlighting the unique capability of quantum mechanics, through the no-cloning theorem, to securely share encryption keys between two parties. Here, we present an approach to high-capacity, high-efficiency QKD by exploiting cross-disciplinary ideas from quantum information theory and the theory of light scattering of aperiodic photonic media. We propose a unique type of entangled-photon source, as well as a physical mechanism for efficiently sharing keys. The key-sharing protocol combines entanglement with the mathematical properties of a recursive sequence to allow a realization of the physical conditions necessary for implementation of the no-cloning principle for QKD, while the source produces entangled photons whose orbital angular momenta (OAM) are in a superposition of Fibonacci numbers. The source is used to implement a particular physical realization of the protocol by randomly encoding the Fibonacci sequence onto entangled OAM states, allowing secure generation of long keys from few photons. Unlike in polarization-based protocols, reference frame alignment is unnecessary, while the required experimental setup is simpler than other OAM-based protocols capable of achieving the same capacity and its complexity grows less rapidly with increasing range of OAM used.

  15. Astronomical random numbers for quantum foundations experiments

    OpenAIRE

    Leung, Calvin; Brown, Amy; Nguyen, Hien; Friedman, Andrew S.; Kaiser, David I.; Gallicchio, Jason

    2017-01-01

    Photons from distant astronomical sources can be used as a classical source of randomness to improve fundamental tests of quantum nonlocality, wave-particle duality, and local realism through Bell's inequality and delayed-choice quantum eraser tests inspired by Wheeler's cosmic-scale Mach-Zehnder interferometer gedankenexperiment. Such sources of random numbers may also be useful for information-theoretic applications such as key distribution for quantum cryptography. Building on the design o...

  16. Symmetric Key Services Markup Language (SKSML)

    Science.gov (United States)

    Noor, Arshad

    Symmetric Key Services Markup Language (SKSML) is the eXtensible Markup Language (XML) being standardized by the OASIS Enterprise Key Management Infrastructure Technical Committee for requesting and receiving symmetric encryption cryptographic keys within a Symmetric Key Management System (SKMS). This protocol is designed to be used between clients and servers within an Enterprise Key Management Infrastructure (EKMI) to secure data, independent of the application and platform. Building on many security standards such as XML Signature, XML Encryption, Web Services Security and PKI, SKSML provides standards-based capability to allow any application to use symmetric encryption keys, while maintaining centralized control. This article describes the SKSML protocol and its capabilities.

  17. Oral Health in the US: Key Facts

    Science.gov (United States)

    ... Policy Oral Health in the U.S.: Key Facts Oral Health in the U.S.: Key Facts Published: Jun 01, ... Email Print This fact sheet provides data on oral health care coverage and access for children, nonelderly adults ...

  18. Quantum key distribution network for multiple applications

    Science.gov (United States)

    Tajima, A.; Kondoh, T.; Ochi, T.; Fujiwara, M.; Yoshino, K.; Iizuka, H.; Sakamoto, T.; Tomita, A.; Shimamura, E.; Asami, S.; Sasaki, M.

    2017-09-01

    The fundamental architecture and functions of secure key management in a quantum key distribution (QKD) network with enhanced universal interfaces for smooth key sharing between arbitrary two nodes and enabling multiple secure communication applications are proposed. The proposed architecture consists of three layers: a quantum layer, key management layer and key supply layer. We explain the functions of each layer, the key formats in each layer and the key lifecycle for enabling a practical QKD network. A quantum key distribution-advanced encryption standard (QKD-AES) hybrid system and an encrypted smartphone system were developed as secure communication applications on our QKD network. The validity and usefulness of these systems were demonstrated on the Tokyo QKD Network testbed.

  19. Electronic Nicotine Delivery Systems Key Facts Infographic

    Data.gov (United States)

    U.S. Department of Health & Human Services — Explore the Electronic Nicotine Delivery Systems Key Facts Infographic which outlines key facts related to electronic nicotine delivery systems (ENDS), including...

  20. VLSI IMPLEMENTATION OF NOVEL ROUND KEYS GENERATION SCHEME FOR CRYPTOGRAPHY APPLICATIONS BY ERROR CONTROL ALGORITHM

    Directory of Open Access Journals (Sweden)

    B. SENTHILKUMAR

    2015-05-01

    Full Text Available A novel implementation of code based cryptography (Cryptocoding technique for multi-layer key distribution scheme is presented. VLSI chip is designed for storing information on generation of round keys. New algorithm is developed for reduced key size with optimal performance. Error Control Algorithm is employed for both generation of round keys and diffusion of non-linearity among them. Two new functions for bit inversion and its reversal are developed for cryptocoding. Probability of retrieving original key from any other round keys is reduced by diffusing nonlinear selective bit inversions on round keys. Randomized selective bit inversions are done on equal length of key bits by Round Constant Feedback Shift Register within the error correction limits of chosen code. Complexity of retrieving the original key from any other round keys is increased by optimal hardware usage. Proposed design is simulated and synthesized using VHDL coding for Spartan3E FPGA and results are shown. Comparative analysis is done between 128 bit Advanced Encryption Standard round keys and proposed round keys for showing security strength of proposed algorithm. This paper concludes that chip based multi-layer key distribution of proposed algorithm is an enhanced solution to the existing threats on cryptography algorithms.

  1. SUPPLY CHAIN MANAGEMENT – KEY FACTORS

    OpenAIRE

    Magdalena Daniela DINU

    2014-01-01

    This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of bot...

  2. Failure of Kak quantum key distribution protocol

    Indian Academy of Sciences (India)

    Keywords. Quantum cryptography; quantum key distribution. Abstract. Kak's quantum key distribution (QKD) protocol provides not only the distribution but also the integrity of secret key simultaneously in quantum channel. Consequently the additional exchange of information, used to check whether an eavesdropper exists, ...

  3. "Key Concepts in ELT": Taking Stock

    Science.gov (United States)

    Hall, Graham

    2012-01-01

    This article identifies patterns and trends within "Key Concepts in ELT", both since the inception of the feature in ELT Journal in 1993 and during the 17 years of the current editorship. After outlining the aims of the series, the article identifies key themes that have emerged over time, exploring the links between "Key Concepts" pieces and the…

  4. Optimizing Key Updates in Sensor Networks

    DEFF Research Database (Denmark)

    Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming

    2011-01-01

    restrict the amount of data that may be exposed when a key is compromised. In this paper, we propose novel key update methods, and benefiting from stochastic model checking we propose a novel method for determining optimal key update strategies for custom network scenarios. We also present a case study...... where an application in commercial building automation is considered....

  5. Harry Potter and the Dichotomous Key

    Science.gov (United States)

    Crowther, David T.

    2003-01-01

    In this lesson, students use Bertie Bott's Every Flavor Beans--a "wild" candy written about in the Harry Potter books and now available in stores--to learn about classification and dichotomous keys. In these activities, students sort jelly beans according to a key and then construct a key for a "new" flavor of beans. Students then build on their…

  6. The generation of shared cryptographic keys through channel impulse response estimation at 60 GHz.

    Energy Technology Data Exchange (ETDEWEB)

    Young, Derek P.; Forman, Michael A.; Dowdle, Donald Ryan

    2010-09-01

    Methods to generate private keys based on wireless channel characteristics have been proposed as an alternative to standard key-management schemes. In this work, we discuss past work in the field and offer a generalized scheme for the generation of private keys using uncorrelated channels in multiple domains. Proposed cognitive enhancements measure channel characteristics, to dynamically change transmission and reception parameters as well as estimate private key randomness and expiration times. Finally, results are presented on the implementation of a system for the generation of private keys for cryptographic communications using channel impulse-response estimation at 60 GHz. The testbed is composed of commercial millimeter-wave VubIQ transceivers, laboratory equipment, and software implemented in MATLAB. Novel cognitive enhancements are demonstrated, using channel estimation to dynamically change system parameters and estimate cryptographic key strength. We show for a complex channel that secret key generation can be accomplished on the order of 100 kb/s.

  7. Randomly interacting bosons on two spin levels

    Science.gov (United States)

    Mulhall, D.

    2017-12-01

    The problem of random interactions leading to regular spectra in shell model type simulations is described. The key results are reviewed alnog with a selection of the explanations. A model system of N particles on 2 spin levels having random 2-body collisions that conserve angular momentum is examined. Preliminary results are described, including the ground state spin distributions peaked at extreme values of angular momentum, signatures of rotational bands, and smooth parabolic yrast lines. A simple random matrix theory analysis shows signatures of quantum chaos in the level spacing distribution and the Δ3 statistic.

  8. Random Number Generators in Secure Disk Drives

    Directory of Open Access Journals (Sweden)

    Hars Laszlo

    2009-01-01

    Full Text Available Abstract Cryptographic random number generators seeded by physical entropy sources are employed in many embedded security systems, including self-encrypting disk drives, being manufactured by the millions every year. Random numbers are used for generating encryption keys and for facilitating secure communication, and they are also provided to users for their applications. We discuss common randomness requirements, techniques for estimating the entropy of physical sources, investigate specific nonrandom physical properties, estimate the autocorrelation, then mix reduce the data until all common randomness tests pass. This method is applied to a randomness source in disk drives: the always changing coefficients of an adaptive filter for the read channel equalization. These coefficients, affected by many kinds of physical noise, are used in the reseeding process of a cryptographic pseudorandom number generator in a family of self encrypting disk drives currently in the market.

  9. High-Quality Random Number Generation Software for High-Performance Computing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Random number (RN) generation is the key software component that permits random sampling. Software for parallel RN generation (RNG) should be based on RNGs that are...

  10. Efficient Secret Key Delivery Using Heartbeats

    Directory of Open Access Journals (Sweden)

    Cho Kwantae

    2017-01-01

    Full Text Available Recently many researchers have employed physiological signals like heartbeats as a source of the key seed used in key establishment protocols. The physiological signals make it easy to establish a secret key between implantable (or attachable medical devices which can sense physiological signals. A key establishment protocol is a fundamental requirement to support the security of the healthcare and medical services such as diagnosis, treatment, prevention, and follow-up services. However, existing key establishment protocols demand high computational and communication costs or need long key establishment time. In this paper, we propose an efficient IPI-based key establishment protocol that requires relatively short time while keeping the strength of security close.

  11. Quantum Key Distribution with High Loss: Toward Global Secure Communication

    Science.gov (United States)

    Hwang, Won-Young

    2003-08-01

    We propose a decoy-pulse method to overcome the photon-number-splitting attack for Bennett-Brassard 1984 quantum key distribution protocol in the presence of high loss: A legitimate user intentionally and randomly replaces signal pulses by multiphoton pulses (decoy pulses). Then they check the loss of the decoy pulses. If the loss of the decoy pulses is abnormally less than that of signal pulses, the whole protocol is aborted. Otherwise, to continue the protocol, they estimate the loss of signal multiphoton pulses based on that of decoy pulses. This estimation can be done with an assumption that the two losses have similar values. We justify that assumption.

  12. Quantum-key-distribution protocol with pseudorandom bases

    Science.gov (United States)

    Trushechkin, A. S.; Tregubov, P. A.; Kiktenko, E. O.; Kurochkin, Y. V.; Fedorov, A. K.

    2018-01-01

    Quantum key distribution (QKD) offers a way for establishing information-theoretical secure communications. An important part of QKD technology is a high-quality random number generator for the quantum-state preparation and for post-processing procedures. In this work, we consider a class of prepare-and-measure QKD protocols, utilizing additional pseudorandomness in the preparation of quantum states. We study one of such protocols and analyze its security against the intercept-resend attack. We demonstrate that, for single-photon sources, the considered protocol gives better secret key rates than the BB84 and the asymmetric BB84 protocols. However, the protocol strongly requires single-photon sources.

  13. Dynamic Group Diffie-Hellman Key Exchange under standard assumptions

    Energy Technology Data Exchange (ETDEWEB)

    Bresson, Emmanuel; Chevassut, Olivier; Pointcheval, David

    2002-02-14

    Authenticated Diffie-Hellman key exchange allows two principals communicating over a public network, and each holding public-private keys, to agree on a shared secret value. In this paper we study the natural extension of this cryptographic problem to a group of principals. We begin from existing formal security models and refine them to incorporate major missing details (e.g., strong-corruption and concurrent sessions). Within this model we define the execution of a protocol for authenticated dynamic group Diffie-Hellman and show that it is provably secure under the decisional Diffie-Hellman assumption. Our security result holds in the standard model and thus provides better security guarantees than previously published results in the random oracle model.

  14. Random broadcast on random geometric graphs

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Elsasser, Robert [UNIV OF PADERBORN; Friedrich, Tobias [ICSI/BERKELEY; Sauerwald, Tomas [ICSI/BERKELEY

    2009-01-01

    In this work, we consider the random broadcast time on random geometric graphs (RGGs). The classic random broadcast model, also known as push algorithm, is defined as: starting with one informed node, in each succeeding round every informed node chooses one of its neighbors uniformly at random and informs it. We consider the random broadcast time on RGGs, when with high probability: (i) RGG is connected, (ii) when there exists the giant component in RGG. We show that the random broadcast time is bounded by {Omicron}({radical} n + diam(component)), where diam(component) is a diameter of the entire graph, or the giant component, for the regimes (i), or (ii), respectively. In other words, for both regimes, we derive the broadcast time to be {Theta}(diam(G)), which is asymptotically optimal.

  15. Ergodicity of Random Walks on Random DFA

    OpenAIRE

    Balle, Borja

    2013-01-01

    Given a DFA we consider the random walk that starts at the initial state and at each time step moves to a new state by taking a random transition from the current state. This paper shows that for typical DFA this random walk induces an ergodic Markov chain. The notion of typical DFA is formalized by showing that ergodicity holds with high probability when a DFA is sampled uniformly at random from the set of all automata with a fixed number of states. We also show the same result applies to DF...

  16. Random fractional Fourier transform.

    Science.gov (United States)

    Liu, Zhengjun; Liu, Shutian

    2007-08-01

    We propose a novel random fractional Fourier transform by randomizing the transform kernel function of the conventional fractional Fourier transform. The random fractional Fourier transform inherits the excellent mathematical properties from the fractional Fourier transform and can be easily implemented in optics. As a primary application the random fractional Fourier transform can be directly used in optical image encryption and decryption. The double phase encoding image encryption schemes can thus be modeled with cascaded random fractional Fourier transformers.

  17. Integration of random amplification of polymorphic DNA-polymerase ...

    African Journals Online (AJOL)

    adjusted reaction conditions strain-distinctive PCR-restriction fragment lenght polymorphism (RFLP) can be designed. Key words: Echinococcus granulosus, strain-specificity, random amplification of polymorphic DNA-polymerase chain reaction ...

  18. Random amplified polymorphic DNA (RAPD) marker associated ...

    African Journals Online (AJOL)

    Jane

    2011-06-29

    Jun 29, 2011 ... between the studied provenances were less than 39%. Key words: Acacia Senegal, provenance variation, random amplified polymorphic DNA (RAPD) marker, salt tolerance, seed germination, seedling growth. INTRODUCTION. Salinity is the major factor limiting plants growth, widely spread and has more ...

  19. Random amplified polymorphic DNA (RAPD) marker associated ...

    African Journals Online (AJOL)

    Jane

    2011-06-29

    Jun 29, 2011 ... bands detected were polymorphic for the provenances of A. senegal and the dissimilarity indices between the studied provenances were less than 39%. Key words: Acacia Senegal, provenance variation, random amplified polymorphic DNA (RAPD) marker, salt tolerance, seed germination, seedling growth ...

  20. Random walks in a random environment

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 114; Issue 4. Random Walks in a Random Environment. S R S Varadhan. Invited Articles Volume 114 Issue ... Author Affiliations. S R S Varadhan1. Department of Mathematics, Courant Institute of Mathematical Sciences, New York University, NY 10012, USA ...

  1. Optimization of Quantum Key Distribution Protocols

    OpenAIRE

    Tannous, C.; Langlois, J.

    2017-01-01

    Quantum Key Distribution is a practically implementable information-theoretic secure method for transmitting keys to remote partners performing quantum communication. After examining various protocols from the simplest such as QC and BB84 we move on to describe BBM92, DPSK, SARG04 and finally MDI from the largest possible communication distance and highest secret key bitrate. We discuss how any protocol can be optimized by reviewing the various steps and underlying assumptions proper to every...

  2. FPGA BASED HARDWARE KEY FOR TEMPORAL ENCRYPTION

    Directory of Open Access Journals (Sweden)

    B. Lakshmi

    2010-09-01

    Full Text Available In this paper, a novel encryption scheme with time based key technique on an FPGA is presented. Time based key technique ensures right key to be entered at right time and hence, vulnerability of encryption through brute force attack is eliminated. Presently available encryption systems, suffer from Brute force attack and in such a case, the time taken for breaking a code depends on the system used for cryptanalysis. The proposed scheme provides an effective method in which the time is taken as the second dimension of the key so that the same system can defend against brute force attack more vigorously. In the proposed scheme, the key is rotated continuously and four bits are drawn from the key with their concatenated value representing the delay the system has to wait. This forms the time based key concept. Also the key based function selection from a pool of functions enhances the confusion and diffusion to defend against linear and differential attacks while the time factor inclusion makes the brute force attack nearly impossible. In the proposed scheme, the key scheduler is implemented on FPGA that generates the right key at right time intervals which is then connected to a NIOS – II processor (a virtual microcontroller which is brought out from Altera FPGA that communicates with the keys to the personal computer through JTAG (Joint Test Action Group communication and the computer is used to perform encryption (or decryption. In this case the FPGA serves as hardware key (dongle for data encryption (or decryption.

  3. Random walks on random Koch curves

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, S; Hoffmann, K H [Institut fuer Physik, Technische Universitaet, D-09107 Chemnitz (Germany); Essex, C [Department of Applied Mathematics, University of Western Ontario, London, ON N6A 5B7 (Canada)

    2009-06-05

    Diffusion processes in porous materials are often modeled as random walks on fractals. In order to capture the randomness of the materials random fractals are employed, which no longer show the deterministic self-similarity of regular fractals. Finding a continuum differential equation describing the diffusion on such fractals has been a long-standing goal, and we address the question of whether the concepts developed for regular fractals are still applicable. We use the random Koch curve as a convenient example as it provides certain technical advantages by its separation of time and space features. While some of the concepts developed for regular fractals can be used unaltered, others have to be modified. Based on the concept of fibers, we introduce ensemble-averaged density functions which produce a differentiable estimate of probability explicitly and compare it to random walk data.

  4. Key innovations and the ecology of macroevolution.

    Science.gov (United States)

    Hunter, J P

    1998-01-01

    The origin or evolutionary `success' of taxa is often attributed to key innovations-aspects of organismal phenotype that promote diversification. Different ways of delimiting taxa and measuring `success' (i.e. number or longevity of species, morphological variety or differential control of energy) give rise to different ideas of how key innovations might operate. Key innovations may enhance competitive ability, relax adaptive trade-offs or permit exploitation of a new productive resource base. Recent key innovation studies comparing species richness in extant sister clades may miss important observations possible only with consideration of the fossil record, traditional higher taxa and phenotypic diversity.

  5. 33 CFR 110.189a - Key West Harbor, Key West, Fla., naval explosives anchorage area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Key West Harbor, Key West, Fla..., Key West, Fla., naval explosives anchorage area. (a) The anchorage ground. A circular area with its... this section shall be enforced by the Commander, U.S. Naval Base, Key West, Fla., and any other...

  6. Analysis of selected methods for the recovery of encrypted WEP key

    Science.gov (United States)

    Wójtowicz, Sebastian; Belka, Radosław

    2014-11-01

    This paper deals with some of the WEP (Wired Equivalent Privacy) key decryption methods based on aircrack-ng software, which was embedded in Backtrack operating system (Linux distribution). The 64-bit (40-bit) and 128-bit (104- bit) key encrypted with RC4 cipher weakness was shown. Research methods were made in different network environments. In this work we compared different types of keys to check how strong the RC4 stream cipher can be. The 40-bit and 104-bit WEP key has been tested on IEEE 802.11 based wireless LAN using laptop with live-CD Linux operating system. A short analysis of key creation methods was performed to compare the amount of time necessary to decrypt random and nonrandom WEP keys.

  7. Key-value store with internal key-value storage interface

    Energy Technology Data Exchange (ETDEWEB)

    Bent, John M.; Faibish, Sorin; Ting, Dennis P. J.; Tzelnic, Percy; Gupta, Uday; Grider, Gary; Bonnie, David J.

    2018-01-16

    A key-value store is provided having one or more key-value storage interfaces. A key-value store on at least one compute node comprises a memory for storing a plurality of key-value pairs; and an abstract storage interface comprising a software interface module that communicates with at least one persistent storage device providing a key-value interface for persistent storage of one or more of the plurality of key-value pairs, wherein the software interface module provides the one or more key-value pairs to the at least one persistent storage device in a key-value format. The abstract storage interface optionally processes one or more batch operations on the plurality of key-value pairs. A distributed embodiment for a partitioned key-value store is also provided.

  8. Public-Key Cryptography (Dagstuhl Seminar 16371)

    OpenAIRE

    Fischlin, Marc; May, Alexander; Pointcheval, David; Rabin, Tal

    2017-01-01

    This report documents the program and results of Dagstuhl seminar 16731 “Public-Key Cryptography” which took place September 11th -16th, 2016. The goal of the seminar was to bring together different sub areas from public-key cryptography and to promote research among these areas.

  9. Bioenergy has a key role to play!

    DEFF Research Database (Denmark)

    Holm-Nielsen, Jens Bo

    2010-01-01

    Key note speach - Opening seremony of the 6.th International Bioenergy Conference organized by NASU - Kiev, Ukraine; www.biomass.kiev.ua;......Key note speach - Opening seremony of the 6.th International Bioenergy Conference organized by NASU - Kiev, Ukraine; www.biomass.kiev.ua;...

  10. Locks & keys service moves to building 55

    CERN Multimedia

    2012-01-01

    Please note that as of July 12 Locks & keys service will be at building 55 second floor. The opening hours are as follows: 08:30 am to 12:30 pm - 1:30 pm to 5:30 pm. The procedures and rules relating to applications for key and cylinder have not changed. GI-IS Group

  11. Failure of Kak quantum key distribution protocol

    Indian Academy of Sciences (India)

    Abstract. Kak's quantum key distribution (QKD) protocol provides not only the dis- tribution but also the integrity of secret key simultaneously in quantum channel. Conse- quently the additional exchange of information, used to check whether an eavesdropper exists, is unnecessary. In this comment, we will point out the ...

  12. Strategy Keys as Tools for Problem Solving

    Science.gov (United States)

    Herold-Blasius, Raja

    2017-01-01

    Problem solving is one of the main competences we seek to teach students at school for use in their future lives. However, when dealing with mathematical problems, teachers encounter a wide variety of difficulties. To foster students' problem-solving skills, the authors developed "strategy keys." Strategy keys can serve as material to…

  13. The LOFAR Transients Key Science Project

    NARCIS (Netherlands)

    Stappers, B.; Fender, R.; Wijers, R.

    2009-01-01

    The Transients Key Science Project (TKP) is one of six Key Science Projects of the next generation radio telescope LOFAR. Its aim is the study of transient and variable low-frequency radio sources with an extremely broad science case ranging from relativistic jet sources to pulsars, exoplanets,

  14. Key Stakeholders' Perceptions of Effective School Leadership

    Science.gov (United States)

    Odhiambo, George; Hii, Amy

    2012-01-01

    There has been limited research on how teachers, parents and students perceive effective school leadership in practice. The purpose of this article is to present some of the findings derived from a study of key stakeholders' perceptions of effective school leadership. Key stakeholders were identified as teachers, students and parents. Data were…

  15. SUPPLY CHAIN MANAGEMENT – KEY FACTORS

    Directory of Open Access Journals (Sweden)

    Magdalena Daniela DINU

    2014-06-01

    Full Text Available This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of both Supply Chain’ s components, procedures, workflow, processes and the importance of Supply Chain Management into maximizing company's value. SCORE model able to provide solid information about measuring performance and identifying priorities within Supply Chain Management will help us to understand the key factors by analyzing its elements: Plan, Source, Make, Deliver,Return, Enable. These elements covers all the challenging areas from first to third tier of Supply Chain Management.

  16. Musical key perception in relation to color.

    Science.gov (United States)

    Firth, Ian C

    2014-12-01

    A link between musical keys and colors is common among musicians, although there has never been any agreement about which color matches which key. This study tested two alternative key-color associations: E is red and Eb is green, or vice versa. 21 participants (10 men, 11 women; M age = 20 yr., SD = 3.3) with absolute pitch listened to melodies beginning with an anacrusis and a perfect cadence which were played through in C major. Then the melodies began in another key, while four or two colored squares were displayed (in Experiments 1 and 2, respectively). Participants were asked to chose the color which best matched the quality of the new key. The results showed strong support for the E red / Eb green linkage.

  17. New weak keys in simplified IDEA

    Science.gov (United States)

    Hafman, Sari Agustini; Muhafidzah, Arini

    2016-02-01

    Simplified IDEA (S-IDEA) is simplified version of International Data Encryption Algorithm (IDEA) and useful teaching tool to help students to understand IDEA. In 2012, Muryanto and Hafman have found a weak key class in the S-IDEA by used differential characteristics in one-round (0, ν, 0, ν) → (0,0, ν, ν) on the first round to produce input difference (0,0, ν, ν) on the fifth round. Because Muryanto and Hafman only use three differential characteristics in one-round, we conducted a research to find new differential characteristics in one-round and used it to produce new weak key classes of S-IDEA. To find new differential characteristics in one-round of S-IDEA, we applied a multiplication mod 216+1 on input difference and combination of active sub key Z1, Z4, Z5, Z6. New classes of weak keys are obtained by combining all of these characteristics and use them to construct two new differential characteristics in full-round of S-IDEA with or without the 4th round sub key. In this research, we found six new differential characteristics in one round and combined them to construct two new differential characteristics in full-round of S-IDEA. When two new differential characteristics in full-round of S-IDEA are used and the 4th round sub key required, we obtain 2 new classes of weak keys, 213 and 28. When two new differential characteristics in full-round of S-IDEA are used, yet the 4th round sub key is not required, the weak key class of 213 will be 221 and 28 will be 210. Membership test can not be applied to recover the key bits in those weak key classes. The recovery of those unknown key bits can only be done by using brute force attack. The simulation result indicates that the bit of the key can be recovered by the longest computation time of 0,031 ms.

  18. KEY FACTORS INFLUENCING PURCHASE INTENTIONS TOWARDS AUTOMOBILES IN PAKISTAN

    Directory of Open Access Journals (Sweden)

    SYED NAVEED ALTAF

    2016-04-01

    Full Text Available In this paper the authors identify and investigate the key factors which influence intentions to purchase passenger cars among consumers in Pakistan. A questionnaire was developed to check the significance of these key variables identified from previous studies, especially those conducted in the context of automobile purchasing in Asian countries. Faculty members from universities of two major cities in Pakistan were selected at random as respondents for this study. The findings of the study will be useful to both managers in the auto industry as well as policy makers. It will help managers in the auto industry to gain a better understanding of consumer intentions and identify the factors which influence them. Policy makers in Pakistan’s auto sector would benefit from the insights of this study when developing the long overdue Auto Policy. Analysis of the data collected has revealed that the three key factors identified from studies in other Asian countries are also relevant for Pakistani auto consumers.

  19. Random matrices, random processes and integrable systems

    CERN Document Server

    2011-01-01

    This book explores the remarkable connections between two domains that, a priori, seem unrelated: Random matrices (together with associated random processes) and integrable systems. The relations between random matrix models and the theory of classical integrable systems have long been studied. These appear mainly in the deformation theory, when parameters characterizing the measures or the domain of localization of the eigenvalues are varied. The resulting differential equations determining the partition function and correlation functions are, remarkably, of the same type as certain equations appearing in the theory of integrable systems. They may be analyzed effectively through methods based upon the Riemann-Hilbert problem of analytic function theory and by related approaches to the study of nonlinear asymptotics in the large N limit. Associated with studies of matrix models are certain stochastic processes, the "Dyson processes", and their continuum diffusion limits, which govern the spectrum in random ma...

  20. Long distance free-space quantum key distribution

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt-Manderbach, T.

    2007-10-16

    The aim of the presented experiment was to investigate the feasibility of satellite-based global quantum key distribution. In this context, a free-space quantum key distribution experiment over a real distance of 144 km was performed. The transmitter and the receiver were situated in 2500 m altitude on the Canary Islands of La Palma and Tenerife, respectively. The small and compact transmitter unit generated attenuated laser pulses, that were sent to the receiver via a 15-cm optical telescope. The receiver unit for polarisation analysis and detection of the sent pulses was integrated into an existing mirror telescope designed for classical optical satellite communications. To ensure the required stability and efficiency of the optical link in the presence of atmospheric turbulence, the two telescopes were equipped with a bi-directional automatic tracking system. Still, due to stray light and high optical attenuation, secure key exchange would not be possible using attenuated pulses in connection with the standard BB84 protocol. The photon number statistics of attenuated pulses follows a Poissonian distribution. Hence, by removing a photon from all pulses containing two or more photons, an eavesdropper could measure its polarisation without disturbing the polarisation state of the remaining pulse. In this way, he can gain information about the key without introducing detectable errors. To protect against such attacks, the presented experiment employed the recently developed method of using additional 'decoy' states, i.e., the the intensity of the pulses created by the transmitter were varied in a random manner. By analysing the detection probabilities of the different pulses individually, a photon-number-splitting attack can be detected. Thanks to the decoy-state analysis, the secrecy of the resulting quantum key could be ensured despite the Poissonian nature of the emitted pulses. For a channel attenuation as high as 35 dB, a secret key rate of up to 250

  1. Manyfield inflation in random potentials

    Science.gov (United States)

    Bjorkmo, Theodor; Marsh, M. C. David

    2018-02-01

    We construct models of inflation with many randomly interacting fields and use these to study the generation of cosmological observables. We model the potentials as multi-dimensional Gaussian random fields (GRFs) and identify powerful algebraic simplifications that, for the first time, make it possible to access the manyfield limit of inflation in GRF potentials. Focussing on small-field, slow-roll, approximate saddle-point inflation in potentials with structure on sub-Planckian scales, we construct explicit examples involving up to 100 fields and generate statistical ensembles comprising of 164,000 models involving 5 to 50 fields. For the subset of these that support at least sixty e-folds of inflation, we use the 'transport method' and δ N formalism to determine the predictions for cosmological observables at the end of inflation, including the power spectrum and the local non-Gaussianities of the primordial perturbations. We find three key results: i) Planck compatibility is not rare, but future experiments may rule out this class of models; ii) In the manyfield limit, the predictions from these models agree well with, but are sharper than, previous results derived using potentials constructed through non-equilibrium Random Matrix Theory; iii) Despite substantial multifield effects, non-Gaussianities are typically very small: fNLloc ll 1. We conclude that many of the 'generic predictions' of single-field inflation can be emergent features of complex inflation models.

  2. New Design of Crypto-Based Pseudo random number generator (CBPRNG) using BLOW FISH cipher

    OpenAIRE

    T.Chalama Reddy; Dr.R.Seshadri

    2013-01-01

    Random Number Generators (RNGs) are an important building block for algorithms and protocols in cryptography. Random number generation is used in a wide variety of cryptographic operations, such as key generation and challenge/response protocols. A random number generator outputs a sequence of 0s and 1s such that at any position, the next bit cannot be expected on the previous bits. However, true random number produces non- deterministic output since if the same random generator is run twice,...

  3. Misuse of randomization

    DEFF Research Database (Denmark)

    Liu, Jianping; Kjaergard, Lise Lotte; Gluud, Christian

    2002-01-01

    The quality of randomization of Chinese randomized trials on herbal medicines for hepatitis B was assessed. Search strategy and inclusion criteria were based on the published protocol. One hundred and seventy-six randomized clinical trials (RCTs) involving 20,452 patients with chronic hepatitis B....../150) of the studies were imbalanced at the 0.05 level of probability for the two treatments and 13.3% (20/150) imbalanced at the 0.01 level in the randomization. It is suggested that there may exist misunderstanding of the concept and the misuse of randomization based on the review....

  4. Cryptanalysis of a chaotic block cipher with external key and its improved version

    Energy Technology Data Exchange (ETDEWEB)

    Li Chengqing [Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong (China)], E-mail: cqli@ee.cityu.edu.hk; Li Shujun [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Alvarez, Gonzalo [Instituto de Fisica Aplicada, Consejo Superior de Investigaciones Cientificas, Serrano 144, 28006 Madrid (Spain); Chen Guanrong [Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Lo, K.-T. [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2008-07-15

    Recently, Pareek et al. proposed a symmetric key block cipher using multiple one-dimensional chaotic maps. This paper reports some new findings on the security problems of this kind of chaotic cipher: (1) a number of weak keys exist; (2) some important intermediate data of the cipher are not sufficiently random; (3) the whole secret key can be broken by a known-plaintext attack with only 120 consecutive known plain-bytes in one known plaintext. In addition, it is pointed out that an improved version of the chaotic cipher proposed by Wei et al. still suffers from all the same security defects.

  5. Monocular Road Detection Using Structured Random Forest

    Directory of Open Access Journals (Sweden)

    Liang Xiao

    2016-05-01

    Full Text Available Road detection is a key task for autonomous land vehicles. Monocular vision-based road-detection algorithms are mostly based on machine learning approaches and are usually cast as classification problems. However, the pixel-wise classifiers are faced with the ambiguity caused by changes in road appearance, illumination and weather. An effective way to reduce the ambiguity is to model the contextual information with structured learning and prediction. Currently, the widely used structured prediction model in road detection is the Markov random field or conditional random field. However, the random field-based methods require additional complex optimization after pixel-wise classification, making them unsuitable for real-time applications. In this paper, we present a structured random forest-based road-detection algorithm which is capable of modelling the contextual information efficiently. By mapping the structured label space to a discrete label space, the test function of each split node can be trained in a similar way to that of the classical random forests. Structured random forests make use of the contextual information of image patches as well as the structural information of the labels to get more consistent results. Besides this benefit, by predicting a batch of pixels in a single classification, the structured random forest-based road detection can be much more efficient than the conventional pixel-wise random forest. Experimental results tested on the KITTI-ROAD dataset and data collected in typical unstructured environments show that structured random forest-based road detection outperforms the classical pixel-wise random forest both in accuracy and efficiency.

  6. Proposing New Wilderness Areas: Okefenokee, Pelican Islands, Island Bay, Cedar Keys, Passage Key, and Wichita Mountains

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — President Transmittal on the proposal of wilderness additions that include Okefenokee, Pelican Islands, Island Bay, Cedar Keys, Passage Key, and Wichita Mountains.

  7. Brain potentials index executive functions during random number generation.

    Science.gov (United States)

    Joppich, Gregor; Däuper, Jan; Dengler, Reinhard; Johannes, Sönke; Rodriguez-Fornells, Antoni; Münte, Thomas F

    2004-06-01

    The generation of random sequences is considered to tax different executive functions. To explore the involvement of these functions further, brain potentials were recorded in 16 healthy young adults while either engaging in random number generation (RNG) by pressing the number keys on a computer keyboard in a random sequence or in ordered number generation (ONG) necessitating key presses in the canonical order. Key presses were paced by an external auditory stimulus to yield either fast (1 press/800 ms) or slow (1 press/1300 ms) sequences in separate runs. Attentional demands of random and ordered tasks were assessed by the introduction of a secondary task (key-press to a target tone). The P3 amplitude to the target tone of this secondary task was reduced during RNG, reflecting the greater consumption of attentional resources during RNG. Moreover, RNG led to a left frontal negativity peaking 140 ms after the onset of the pacing stimulus, whenever the subjects produced a true random response. This negativity could be attributed to the left dorsolateral prefrontal cortex and was absent when numbers were repeated. This negativity was interpreted as an index for the inhibition of habitual responses. Finally, in response locked ERPs a negative component was apparent peaking about 50 ms after the key-press that was more prominent during RNG. Source localization suggested a medial frontal source. This effect was tentatively interpreted as a reflection of the greater monitoring demands during random sequence generation.

  8. New Cholesterol Fighting Meds Target Key Gene

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_165942.html New Cholesterol Fighting Meds Target Key Gene Two trials show ... New gene-based therapies appear to significantly decrease cholesterol levels in people, and could even cut down ...

  9. PDS4 Training: Key Concepts and Vocabulary

    Science.gov (United States)

    Gordon, M. K.; Guinness, E. A.; Neakrase, L. D. V.; Padams, J.; Raugh, A. C.

    2017-06-01

    Those planning to attend the PDS4 training session are strongly encouraged to review this poster prior to the training session. This poster briefly describes new vocabulary and a number of key concepts introduced with PDS4.

  10. Exercise Is Key to Healthy Aging

    Science.gov (United States)

    ... on. NIH Research Exercise Is Key to Healthy Aging Past Issues / Winter 2015 Table of Contents Dr. Hodes, Director of the National Institute on Aging, does regular strength training and aerobic exercise. Photo ...

  11. Defending Critical Infrastructure as Cyber Key Terrain

    Science.gov (United States)

    2016-08-01

    AU/ACSC/2016 AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY Defending Critical Infrastructure as Cyber Key Terrain by Derek Molle, Civ, USAF...20 Converged Enterprise Network...23 Logically Isolated Enterprise

  12. Finite key analysis in quantum cryptography

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, T.

    2007-10-31

    In view of experimental realization of quantum key distribution schemes, the study of their efficiency becomes as important as the proof of their security. The latter is the subject of most of the theoretical work about quantum key distribution, and many important results such as the proof of unconditional security have been obtained. The efficiency and also the robustness of quantum key distribution protocols against noise can be measured by figures of merit such as the secret key rate (the fraction of input signals that make it into the key) and the threshold quantum bit error rate (the maximal error rate such that one can still create a secret key). It is important to determine these quantities because they tell us whether a certain quantum key distribution scheme can be used at all in a given situation and if so, how many secret key bits it can generate in a given time. However, these figures of merit are usually derived under the ''infinite key limit'' assumption, that is, one assumes that an infinite number of quantum states are send and that all sub-protocols of the scheme (in particular privacy amplification) are carried out on these infinitely large blocks. Such an assumption usually eases the analysis, but also leads to (potentially) too optimistic values for the quantities in question. In this thesis, we are explicitly avoiding the infinite key limit for the analysis of the privacy amplification step, which plays the most important role in a quantum key distribution scheme. We still assume that an optimal error correction code is applied and we do not take into account any statistical errors that might occur in the parameter estimation step. Renner and coworkers derived an explicit formula for the obtainable key rate in terms of Renyi entropies of the quantum states describing Alice's, Bob's, and Eve's systems. This results serves as a starting point for our analysis, and we derive an algorithm that efficiently computes

  13. Key Facts about Seasonal Flu Vaccine

    Science.gov (United States)

    ... Variant Pandemic Other Key Facts About Seasonal Flu Vaccine Language: English (US) Español Recommend on Facebook Tweet ... can spread through that community. How do flu vaccines work? Flu vaccines cause antibodies to develop in ...

  14. Key Data Elements in Myeloid Leukemia

    NARCIS (Netherlands)

    Varghese, J.; Holz, C.; Neuhaus, P.; Bernardi, M.; Boehm, A.; Ganser, A.; Gore, S.; Heaney, M.; Hochhaus, A.; Hofmann, W.K.; Krug, U.; Muller-Tidow, C.; Smith, A.; Weltermann, A.; Witte, T.J.M. de; Hehlmann, R.; Dugas, M.

    2016-01-01

    Data standards consisting of key data elements for clinical routine and trial documentation harmonize documentation within and across different health care institutions making documentation more efficient and improving scientific data analysis. This work focusses on the field of myeloid leukemia

  15. A Key to the Art of Letters

    DEFF Research Database (Denmark)

    Jensen-Rix, Robert William

    2008-01-01

    The article examines A. Lane's grammar A Key to the Art of Letters and its contexts. Symbolically published at the threshold to the eighteenth century, Lane presents an unusually bold plan to make English a world language. Although Lane's book holds a key position in the development of English gr...... that Lane is the first to use English as the basis for writing universal grammar, as part of his strategy to promote English as a universal code for learning and science......The article examines A. Lane's grammar A Key to the Art of Letters and its contexts. Symbolically published at the threshold to the eighteenth century, Lane presents an unusually bold plan to make English a world language. Although Lane's book holds a key position in the development of English...

  16. Benthic Habitats of the Florida Keys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The benthic habitats of the Florida Keys were mapped from a series of 450 aerial photographs. Ecologists outlined the boundaries of specific habitat types by...

  17. KEY FACTORS IN MARKETING FOCUSED SERVICES BUSINESSES

    National Research Council Canada - National Science Library

    Doris Yohanna Martínez Castrillón

    2016-01-01

    This article aims to identify the key success factors in the marketing area and describe them as managerial allies for companies that wish to position themselves in the market under a good sustainable...

  18. Key Communicators--An Authorized Grapevine

    Science.gov (United States)

    Bagin, Don

    1975-01-01

    Key communicators--community members who come in contact with many people and who are informal information sources--can be used by the schools as sources of feedback from the community and as information disseminators. (DS)

  19. Interactive simulations for quantum key distribution

    CERN Document Server

    Kohnle, Antje

    2016-01-01

    Secure communication protocols are becoming increasingly important, e.g. for internet-based communication. Quantum key distribution allows two parties, commonly called Alice and Bob, to generate a secret sequence of 0s and 1s called a key that is only known to themselves. Classically, Alice and Bob could never be certain that their communication was not compromised by a malicious eavesdropper. Quantum mechanics however makes secure communication possible. The fundamental principle of quantum mechanics that taking a measurement perturbs the system (unless the measurement is compatible with the quantum state) also applies to an eavesdropper. Using appropriate protocols to create the key, Alice and Bob can detect the presence of an eavesdropper by errors in their measurements. As part of the QuVis Quantum Mechanics Visualization Project, we have developed a suite of four interactive simulations that demonstrate the basic principles of three different quantum key distribution protocols. The simulations use either...

  20. High Efficient Secret Key Distillation for Long Distance Continuous Variable Quantum Key Distribution

    OpenAIRE

    Zhao, Yi-bo; Han, Zheng-fu; Chen, Jin-jian; Gui, You-zhen; Guo, Guang-can

    2006-01-01

    The continuous variable quantum key distribution is expected to provide high secret key rate without single photon source and detector, but the lack of the secure and effective key distillation method makes it unpractical. Here, we present a secure single-bit-reverse-reconciliation protocol combined with secret information concentration and post-selection, which can distill the secret key with high efficiency and low computational complexity. The simulation results show that this protocol can...

  1. Mathematical Background of Public Key Cryptography

    DEFF Research Database (Denmark)

    Frey, Gerhard; Lange, Tanja

    2005-01-01

    The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material.......The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material....

  2. The Digital Thread as the Key Enabler

    Science.gov (United States)

    2016-11-01

    life cycle by providing the capability to access, integrate and transform disparate data into actionable information. The digital thread is the...17 Defense AT&L: November-December 2016 The Digital Thread as the Key Enabler Col. Keith Bearden, USAF Bearden is the deputy director of...enabling you to do your job better, faster and cheaper. There is one initiative, the key enabler, to accomplish this goal—the digital thread. But let’s

  3. SAXICOLE BRYOPHYTES FROM VÂLSAN KEYS

    Directory of Open Access Journals (Sweden)

    Codruţa Mihaela Dobrescu

    2015-07-01

    Full Text Available The paper presents a review of the saxicole species in the Vâlsan Keys and considerations regarding the bryophytic saxicole cenoses from the protected area. To analyze the diversity of the saxicole bryophytes, we considered the number of species, as well as the phytogeografical element, the growth form and the “life strategy” of each species. From the systematic perspective, Vâlsan Keys are featured by a high specific diversity of the saxicole bryophytes.

  4. 78 FR 79061 - Noise Exposure Map Notice; Key West International Airport, Key West, FL

    Science.gov (United States)

    2013-12-27

    ... Federal Aviation Administration Noise Exposure Map Notice; Key West International Airport, Key West, FL... Administration (FAA) announces its determination that the Noise Exposure Maps submitted by Monroe County for the...: This notice announces that the FAA finds that the Noise Exposure Maps submitted for the Key West...

  5. Is the Green Key standard the golden key for sustainability measurement in the hospitality sector?

    NARCIS (Netherlands)

    Rietbergen, M.G.|info:eu-repo/dai/nl/14111634X; Van Rheede, A.

    2014-01-01

    The Green Key is an eco-rating program that aims at promoting sustainable business practices in the hospitality sector. The Green Key assesses amongst others the sustainable management of energy, water and waste within hotels and other hospitality firms. The Green Key standard awards points if

  6. Key-Phenomenon and Religious Meaning

    Directory of Open Access Journals (Sweden)

    Lomuscio Vincenzo

    2017-09-01

    Full Text Available In this paper I develop a phenomenology of religious experience through the notion of keyphenomenon. My analysis moves from a general phenomenology of situation, in which we have to relate different phenomena according to a sense. What does “according to a sense” mean? My suggestion is that we should look for a relationship among these data when we find a key-phenomenon (among a series of phenomena that would enlighten all the others. This key-phenomenon would show a non-phenomenal meaning which would make all the others understandable. Each other datum, therefore, becomes the witness of invisible meaning through a key-witness. The key-phenomenon we choose determines the role (i.e., the truth of each datum within its situation. This phenomenological relationship belongs to both the sense of day-life situations, and that one of possible religious situations. If the religious interpretation of a situation depends on our choice of key-phenomenon, or key-witness, we have to define what kind of keyphenomenon constitutes a religious intuition.

  7. A General Construction of IND-CCA2 Secure Public Key Encryption

    DEFF Research Database (Denmark)

    Kiltz, Eike; Malone-Lee, John

    2003-01-01

    We propose a general construction for public key encryption schemes that are IND-CCA2 secure in the random oracle model. We show that the scheme proposed in [1, 2] fits our general framework and moreover that our method of analysis leads to a more efficient security reduction....

  8. Random Linear Network Coding is Key to Data Survival in Highly Dynamic Distributed Storage

    DEFF Research Database (Denmark)

    Sipos, Marton A.; Fitzek, Frank; Roetter, Daniel Enrique Lucani

    2015-01-01

    and Reed-Solomon mechanisms. Our results use traces from a BitTorrent client for Android devices to show that RLNC outperforms the next best scheme (fully centralized Reed-Solomon) not only by having a much lower probability of data loss, but by reducing storage requirements by up to 50% and reconstruction...

  9. Random Linear Network Coding is Key to Data Survival in Highly Dynamic Distributed Storage

    DEFF Research Database (Denmark)

    Sipos, Marton; H. P. Fitzek, Frank; Lucani Rötter, Daniel Enrique

    2015-01-01

    and control the repair process. Given the large costs for maintaining and cooling large data centers, our work proposes and studies the feasibility of a fully decentralized systems that can store data even on unreliable and, sometimes, unavailable mobile devices. This imposes new challenges on the design...

  10. Does Prescribed Randomness Hold the Key to Interface Synthetic and Natural Systems?

    Science.gov (United States)

    Xu, Ting

    The bottlenecks to engineering biomimetic functional materials are not only to duplicate hierarchical structures, but also to manipulate the system dynamics. Bio-inspired responsive materials have been investigated extensively within the past few decades with much success. Yet, the level of control of these complex systems is still rather simplistic. More importantly, we have yet to uncover the design rules to synergize natural and synthetic building blocks that allows us to go beyond just a few specific families of natural building blocks. I am going to discuss our recent studies that demonstrated the feasibility to develop synthetic protein-like polymers that can interface with natural proteins and biomachinaries. Rational design of these protein-like polymers thus opens a viable approach toward functional materials based on natural components. The work is supported by DOD-ARO W911NF-16-1-0405.

  11. Enhancing superconducting critical current by randomness

    OpenAIRE

    Wang, Y. L.; Thoutam, L. R.; Xiao, Z. L.; Shen, B.; Pearson, J. E.; Divan, R.; Ocola, L. E.; Crabtree, G. W.; Kwok, W. K.

    2015-01-01

    The key ingredient of high critical currents in a type-II superconductor is defect sites that 'pin' vortices. Contrary to earlier understanding on nano-patterned artificial pinning, here we show unequivocally the advantages of a random pinscape over an ordered array in a wide magnetic field range. We reveal that the better performance of a random pinscape is due to the variation of its local-density-of-pinning-sites (LDOPS), which mitigates the motion of vortices. This is confirmed by achievi...

  12. Blocked Randomization with Randomly Selected Block Sizes

    Directory of Open Access Journals (Sweden)

    Jimmy Efird

    2010-12-01

    Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  13. Blocked randomization with randomly selected block sizes.

    Science.gov (United States)

    Efird, Jimmy

    2011-01-01

    When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  14. Random walks, random fields, and disordered systems

    CERN Document Server

    Černý, Jiří; Kotecký, Roman

    2015-01-01

    Focusing on the mathematics that lies at the intersection of probability theory, statistical physics, combinatorics and computer science, this volume collects together lecture notes on recent developments in the area. The common ground of these subjects is perhaps best described by the three terms in the title: Random Walks, Random Fields and Disordered Systems. The specific topics covered include a study of Branching Brownian Motion from the perspective of disordered (spin-glass) systems, a detailed analysis of weakly self-avoiding random walks in four spatial dimensions via methods of field theory and the renormalization group, a study of phase transitions in disordered discrete structures using a rigorous version of the cavity method, a survey of recent work on interacting polymers in the ballisticity regime and, finally, a treatise on two-dimensional loop-soup models and their connection to conformally invariant systems and the Gaussian Free Field. The notes are aimed at early graduate students with a mod...

  15. Quantum random number generators

    Science.gov (United States)

    Herrero-Collantes, Miguel; Garcia-Escartin, Juan Carlos

    2017-01-01

    Random numbers are a fundamental resource in science and engineering with important applications in simulation and cryptography. The inherent randomness at the core of quantum mechanics makes quantum systems a perfect source of entropy. Quantum random number generation is one of the most mature quantum technologies with many alternative generation methods. This review discusses the different technologies in quantum random number generation from the early devices based on radioactive decay to the multiple ways to use the quantum states of light to gather entropy from a quantum origin. Randomness extraction and amplification and the notable possibility of generating trusted random numbers even with untrusted hardware using device-independent generation protocols are also discussed.

  16. Automated secured cost effective key refreshing technique to enhance WiMAX privacy key management

    Science.gov (United States)

    Sridevi, B.; Sivaranjani, S.; Rajaram, S.

    2013-01-01

    In all walks of life the way of communication is transformed by the rapid growth of wireless communication and its pervasive use. A wireless network which is fixed and richer in bandwidth is specified as IEEE 802.16, promoted and launched by an industrial forum is termed as Worldwide Interoperability for Microwave Access (WiMAX). This technology enables seamless delivery of wireless broadband service for fixed and/or mobile users. The obscurity is the long delay which occurs during the handoff management in every network. Mobile WiMAX employs an authenticated key management protocol as a part of handoff management in which the Base Station (BS) controls the distribution of keying material to the Mobile Station (MS). The protocol employed is Privacy Key Management Version 2- Extensible Authentication Protocol (PKMV2-EAP) which is responsible for the normal and periodical authorization of MSs, reauthorization as well as key refreshing. Authorization key (AK) and Traffic Encryption key (TEK) plays a vital role in key exchange. When the lifetime of key expires, MS has to request for a new key to BS which in turn leads to repetition of authorization, authentication as well as key exchange. To avoid service interruption during reauthorization , two active keys are transmitted at the same time by BS to MS. The consequences of existing work are hefty amount of bandwidth utilization, time consumption and large storage. It is also endured by Man in the Middle attack and Impersonation due to lack of security in key exchange. This paper designs an automatic mutual refreshing of keys to minimize bandwidth utilization, key storage and time consumption by proposing Previous key and Iteration based Key Refreshing Function (PKIBKRF). By integrating PKIBKRF in key generation, the simulation results indicate that 21.8% of the bandwidth and storage of keys are reduced and PKMV2 mutual authentication time is reduced by 66.67%. The proposed work is simulated with Qualnet model and

  17. Probability sampling of stony coral populations in the Florida Keys.

    Science.gov (United States)

    Smith, Steven G; Swanson, Dione W; Chiappone, Mark; Miller, Steven L; Ault, Jerald S

    2011-12-01

    Principles of probability survey design were applied to guide large-scale sampling of populations of stony corals and associated benthic taxa in the Florida Keys coral reef ecosystem. The survey employed a two-stage stratified random sampling design that partitioned the 251-km(2) domain by reef habitat types, geographic regions, and management zones. Estimates of the coefficient of variation (ratio of standard error to the mean) for stony coral population density and abundance ranged from 7% to 12% for four of six principal species. These levels of survey precision are among the highest reported for comparable surveys of marine species. Relatively precise estimates were also obtained for octocoral density, sponge frequency of occurrence, and benthic cover of algae and invertebrates. Probabilistic survey design techniques provided a robust framework for estimating population-level metrics and optimizing sampling efficiency.

  18. Random Differential Privacy

    OpenAIRE

    Hall, Rob; Rinaldo, Alessandro; Wasserman, Larry

    2011-01-01

    We propose a relaxed privacy definition called {\\em random differential privacy} (RDP). Differential privacy requires that adding any new observation to a database will have small effect on the output of the data-release procedure. Random differential privacy requires that adding a {\\em randomly drawn new observation} to a database will have small effect on the output. We show an analog of the composition property of differentially private procedures which applies to our new definition. We sh...

  19. Synchronization in Quantum Key Distribution Systems

    Directory of Open Access Journals (Sweden)

    Anton Pljonkin

    2017-10-01

    Full Text Available In the description of quantum key distribution systems, much attention is paid to the operation of quantum cryptography protocols. The main problem is the insufficient study of the synchronization process of quantum key distribution systems. This paper contains a general description of quantum cryptography principles. A two-line fiber-optic quantum key distribution system with phase coding of photon states in transceiver and coding station synchronization mode was examined. A quantum key distribution system was built on the basis of the scheme with automatic compensation of polarization mode distortions. Single-photon avalanche diodes were used as optical radiation detecting devices. It was estimated how the parameters used in quantum key distribution systems of optical detectors affect the detection of the time frame with attenuated optical pulse in synchronization mode with respect to its probabilistic and time-domain characteristics. A design method was given for the process that detects the time frame that includes an optical pulse during synchronization. This paper describes the main quantum communication channel attack methods by removing a portion of optical emission. This paper describes the developed synchronization algorithm that takes into account the time required to restore the photodetector’s operation state after the photon has been registered during synchronization. The computer simulation results of the developed synchronization algorithm were analyzed. The efficiency of the developed algorithm with respect to synchronization process protection from unauthorized gathering of optical emission is demonstrated herein.

  20. Evaluation of Key Dependent S-Box Based Data Security Algorithm using Hamming Distance and Balanced Output

    Directory of Open Access Journals (Sweden)

    Balajee Maram K.

    2016-02-01

    Full Text Available Data security is a major issue because of rapid evolution of data communication over unsecured internetwork. Here the proposed system is concerned with the problem of randomly generated S-box. The generation of S-box depends on Pseudo-Random-Number-Generators and shared-secret-key. The process of Pseudo-Random-Number-Generator depends on large prime numbers. All Pseudo-Random-Numbers are scrambled according to shared-secret-key. After scrambling, the S-box is generated. In this research, large prime numbers are the inputs to the Pseudo-Random-Number-Generator. The proposed S-box will reduce the complexity of S-box generation. Based on S-box parameters, it experimentally investigates the quality and robustness of the proposed algorithm which was tested. It yields better results with the S-box parameters like Hamming Distance, Balanced Output and Avalanche Effect and can be embedded to popular cryptography algorithms

  1. A Novel Method for Generating Encryption Keys

    Directory of Open Access Journals (Sweden)

    Dascalescu Ana Cristina

    2009-12-01

    Full Text Available The development of the informational society, which has led to an impressive growth of the information volume circulating in the computer networks, has accelerated the evolution and especially the use of modern cryptography instruments. Today, the commercial products use standard cryptographic libraries that implement certified and tested cryptographic algorithms. Instead, the fragility ofencryption algorithms is given by compositional operations like key handling or key generation. In this sense, the article proposes an innovative method to generate pseudorandom numbers which can be used for the construction of secure stream encryption keys. The proposed method is based on the mathematical complements based on the algebra of the finite fields and uses a particularized structure of the linear feedback shift registers.

  2. Anonymity-Preserving Public-Key Encryption

    DEFF Research Database (Denmark)

    Kohlweiss, Markulf; Maurer, Ueli; Onete, Cristina

    2013-01-01

    A receiver-anonymous channel allows a sender to send a message to a receiver without an adversary learning for whom the message is intended. Wireless broadcast channels naturally provide receiver anonymity, as does multi-casting one message to a receiver population containing the intended receiver....... While anonymity and confidentiality appear to be orthogonal properties, making anonymous communication confidential is more involved than one might expect, since the ciphertext might reveal which public key has been used to encrypt. To address this problem, public-key cryptosystems with enhanced...... security properties have been proposed. We investigate constructions as well as limitations for preserving receiver anonymity when using public-key encryption (PKE). We use the constructive cryptography approach by Maurer and Renner and interpret cryptographic schemes as constructions of a certain ideal...

  3. A Short History of Randomized Experiments in Criminology: A Meager Feast.

    Science.gov (United States)

    Farrington, David P.

    2003-01-01

    Discusses advantages of randomized experiments and key issues raised in this special issue. Focuses on growth and decrease in the use of randomized experiments by the California Youth Authority, the U.S. National Institute of Justice, and the British Home Office. Calls for increased recognition of the importance of randomized experiments. (SLD)

  4. Extending key sharing: how to generate a key tightly coupled to a network security policy

    Science.gov (United States)

    Kazantzidis, Matheos

    2006-04-01

    Current state of the art security policy technologies, besides the small scale limitation and largely manual nature of accompanied management methods, are lacking a) in real-timeliness of policy implementation and b) vulnerabilities and inflexibility stemming from the centralized policy decision making; even if, for example, a policy description or access control database is distributed, the actual decision is often a centralized action and forms a system single point of failure. In this paper we are presenting a new fundamental concept that allows implement a security policy by a systematic and efficient key distribution procedure. Specifically, we extend the polynomial Shamir key splitting. According to this, a global key is split into n parts, any k of which can re-construct the original key. In this paper we present a method that instead of having "any k parts" be able to re-construct the original key, the latter can only be reconstructed if keys are combined as any access control policy describes. This leads into an easily deployable key generation procedure that results a single key per entity that "knows" its role in the specific access control policy from which it was derived. The system is considered efficient as it may be used to avoid expensive PKI operations or pairwise key distributions as well as provides superior security due to its distributed nature, the fact that the key is tightly coupled to the policy, and that policy change may be implemented easier and faster.

  5. Public key infrastructure for DOE security research

    Energy Technology Data Exchange (ETDEWEB)

    Aiken, R.; Foster, I.; Johnston, W.E. [and others

    1997-06-01

    This document summarizes the Department of Energy`s Second Joint Energy Research/Defence Programs Security Research Workshop. The workshop, built on the results of the first Joint Workshop which reviewed security requirements represented in a range of mission-critical ER and DP applications, discussed commonalties and differences in ER/DP requirements and approaches, and identified an integrated common set of security research priorities. One significant conclusion of the first workshop was that progress in a broad spectrum of DOE-relevant security problems and applications could best be addressed through public-key cryptography based systems, and therefore depended upon the existence of a robust, broadly deployed public-key infrastructure. Hence, public-key infrastructure ({open_quotes}PKI{close_quotes}) was adopted as a primary focus for the second workshop. The Second Joint Workshop covered a range of DOE security research and deployment efforts, as well as summaries of the state of the art in various areas relating to public-key technologies. Key findings were that a broad range of DOE applications can benefit from security architectures and technologies built on a robust, flexible, widely deployed public-key infrastructure; that there exists a collection of specific requirements for missing or undeveloped PKI functionality, together with a preliminary assessment of how these requirements can be met; that, while commercial developments can be expected to provide many relevant security technologies, there are important capabilities that commercial developments will not address, due to the unique scale, performance, diversity, distributed nature, and sensitivity of DOE applications; that DOE should encourage and support research activities intended to increase understanding of security technology requirements, and to develop critical components not forthcoming from other sources in a timely manner.

  6. Several Key Features of Marriage in Kosovo

    OpenAIRE

    Dr.Sc. Hamdi Podvorica

    2014-01-01

    In this paper titled “Several key features of marriage in Kosovo”, I have made efforts to address the matrimony, as an important societal and legal concept, in the light of positive law in Kosovo. In short terms, I have addressed the historical development of marriage in general, from the period of promiscuity until today, and I have emphasized key features of marriage in various time periods, only to comprehend better the ways of development of marriage in time and space. A special empha...

  7. Quantum attacks on public-key cryptosystems

    CERN Document Server

    Yan, Song Y

    2013-01-01

    The cryptosystems based on the Integer Factorization Problem (IFP), the Discrete Logarithm Problem (DLP) and the Elliptic Curve Discrete Logarithm Problem (ECDLP) are essentially the only three types of practical public-key cryptosystems in use. The security of these cryptosystems relies heavily on these three infeasible problems, as no polynomial-time algorithms exist for them so far. However, polynomial-time quantum algorithms for IFP, DLP and ECDLP do exist, provided that a practical quantum computer exists.Quantum Attacks on Public-Key Cryptosystems presemts almost all?known quantum comput

  8. Key nuclear reaction experiments discoveries and consequences

    CERN Document Server

    Paetz gen. Schieck, Hans

    2015-01-01

    In this book the author charts the developments in nuclear physics since its inception around a century ago by reviewing the key experiments that helped drive and shape our understanding of the field, especially in the context of the wider developments in physics in the early 20th Century. In addition to providing a path through the field and the crucial events it looks at how these experiments not only answered key questions at the time but presented new challenges to the contemporary perception of the nuclear and sub-atomic worlds and how they helped develop our present understanding of nuclear physics.

  9. Partially Key Distribution with Public Key Cryptosystem Based on Error Control Codes

    Science.gov (United States)

    Tavallaei, Saeed Ebadi; Falahati, Abolfazl

    Due to the low level of security in public key cryptosystems based on number theory, fundamental difficulties such as "key escrow" in Public Key Infrastructure (PKI) and a secure channel in ID-based cryptography, a new key distribution cryptosystem based on Error Control Codes (ECC) is proposed . This idea is done by some modification on McEliece cryptosystem. The security of ECC cryptosystem obtains from the NP-Completeness of block codes decoding. The capability of generating public keys with variable lengths which is suitable for different applications will be provided by using ECC. It seems that usage of these cryptosystems because of decreasing in the security of cryptosystems based on number theory and increasing the lengths of their keys would be unavoidable in future.

  10. Passive Decoy-State Quantum Key Distribution with Coherent Light

    Directory of Open Access Journals (Sweden)

    Marcos Curty

    2015-06-01

    Full Text Available Signal state preparation in quantum key distribution schemes can be realized using either an active or a passive source. Passive sources might be valuable in some scenarios; for instance, in those experimental setups operating at high transmission rates, since no externally driven element is required. Typical passive transmitters involve parametric down-conversion. More recently, it has been shown that phase-randomized coherent pulses also allow passive generation of decoy states and Bennett–Brassard 1984 (BB84 polarization signals, though the combination of both setups in a single passive source is cumbersome. In this paper, we present a complete passive transmitter that prepares decoy-state BB84 signals using coherent light. Our method employs sum-frequency generation together with linear optical components and classical photodetectors. In the asymptotic limit of an infinite long experiment, the resulting secret key rate (per pulse is comparable to the one delivered by an active decoy-state BB84 setup with an infinite number of decoy settings.

  11. Architecture for the Secret-Key BC3 Cryptography Algorithm

    Directory of Open Access Journals (Sweden)

    Arif Sasongko

    2011-08-01

    Full Text Available Cryptography is a very important aspect in data security. The focus of research in this field is shifting from merely security aspect to consider as well the implementation aspect. This paper aims to introduce BC3 algorithm with focus on its hardware implementation. It proposes architecture for the hardware implementation for this algorithm. BC3 algorithm is a secret-key cryptography algorithm developed with two considerations: robustness and implementation efficiency. This algorithm has been implemented on software and has good performance compared to AES algorithm. BC3 is improvement of BC2 and AE cryptographic algorithm and it is expected to have the same level of robustness and to gain competitive advantages in the implementation aspect. The development of the architecture gives much attention on (1 resource sharing and (2 having single clock for each round. It exploits regularity of the algorithm. This architecture is then implemented on an FPGA. This implementation is three times smaller area than AES, but about five times faster. Furthermore, this BC3 hardware implementation has better performance compared to BC3 software both in key expansion stage and randomizing stage. For the future, the security of this implementation must be reviewed especially against side channel attack.

  12. Random errors revisited

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    2000-01-01

    the random errors of estimates of the sound intensity in, say, one-third octave bands from the power and cross power spectra of the signals from an intensity probe determined with a dual channel FFT analyser. This is not very practical, though. In this paper it is demonstrated that one can predict the random...

  13. a randomized controlled trial.

    African Journals Online (AJOL)

    milk, only an estimated one -fourth of neonates in India were breastfed within ... standard of care in India and mothers are informed about. 6 months of ... weeks postpartum. A random number sequence was generated using a com- puter program. Block randomization was used with a fixed block size of four. Concealment of ...

  14. Social patterns revealed through random matrix theory

    Science.gov (United States)

    Sarkar, Camellia; Jalan, Sarika

    2014-11-01

    Despite the tremendous advancements in the field of network theory, very few studies have taken weights in the interactions into consideration that emerge naturally in all real-world systems. Using random matrix analysis of a weighted social network, we demonstrate the profound impact of weights in interactions on emerging structural properties. The analysis reveals that randomness existing in particular time frame affects the decisions of individuals rendering them more freedom of choice in situations of financial security. While the structural organization of networks remains the same throughout all datasets, random matrix theory provides insight into the interaction pattern of individuals of the society in situations of crisis. It has also been contemplated that individual accountability in terms of weighted interactions remains as a key to success unless segregation of tasks comes into play.

  15. Teaching Tools for Diagnostics: The Behavior Key.

    Science.gov (United States)

    Ellsworth, J'Anne D.

    This paper presents a set of charts that may help a teacher develop a theory about what is working well in the classroom and where problems exist. Each chart is divided into two categories repeatedly. In effect, the chart serves as a dichotomous key. At each point where two choices diverge, the teacher should move to the more likely answer. The…

  16. Radiology Aide. Instructor Key [and] Student Manual.

    Science.gov (United States)

    Hartwein, Jon; Dunham, John

    This manual can be used independently by students in secondary health occupations programs or by persons receiving on-the-job training in a radiology department. The manual includes an instructor's key that provides answers to the activity sheets and unit evaluations. The manual consists of the following five units: (1) orientation to radiology;…

  17. Expectations as a key element in trusting

    DEFF Research Database (Denmark)

    Rasmussen, Mette Apollo; Hansen, Uffe Kjærgaard; Conradsen, Maria Bosse

    Considering the need for a tangible focus for qualitative research on trusting, we propose that expectations to the behavior of others can provide that. By focusing on expectations, researchers can produce narrative descriptions that explains how trusting develops and changes. Then the key theore...

  18. Quantum Cryptography: Key Distribution and Beyond

    OpenAIRE

    Akshata Shenoy-Hejamadi; Anirban Pathak; Srikanth Radhakrishna

    2017-01-01

    Uniquely among the sciences, quantum cryptography has driven both foundational research as well as practical real-life applications. We review the progress of quantum cryptography in the last decade, covering quantum key distribution and other applications. Quanta 2017; 6: 1–47.

  19. Student Engagement: Key to Personalized Learning

    Science.gov (United States)

    Ferlazzo, Larry

    2017-01-01

    Personalized learning has the potential to greatly improve student achievement--but realistic teachers know that any instructional strategy will only be effective if students are willing to do the work. That is why Larry Ferlazzo emphasizes the importance of weaving intrinsic motivation into every personalized learning classroom. Four key elements…

  20. Key variables of organisation design in servitization

    DEFF Research Database (Denmark)

    Kreye, Melanie; Jensen, Per Langaa

    2014-01-01

    to external environment to ensure performance. We present a case in the European renewable energy sector. The findings show three key variables: (i) processes need to enable information flow between business departments; (ii) servitization strategy needs to be translated into service-centred activities...

  1. Key requirements for future control room functionality

    DEFF Research Database (Denmark)

    Tornelli, Carlo; Zuelli, Roberto; Marinelli, Mattia

    2016-01-01

    This internal report provides the key requirements for the future control centres. R8.1 represents the starting point of WP8 activities and wants to achieve a double objective. On the one hand it collects general requirements on future control centres emerging from the general trends in power...

  2. Number Theory and Public-Key Cryptography.

    Science.gov (United States)

    Lefton, Phyllis

    1991-01-01

    Described are activities in the study of techniques used to conceal the meanings of messages and data. Some background information and two BASIC programs that illustrate the algorithms used in a new cryptographic system called "public-key cryptography" are included. (CW)

  3. Public key cryptography from weaker assumptions

    DEFF Research Database (Denmark)

    Zottarel, Angela

    This dissertation is focused on the construction of public key cryptographic primitives and on the relative security analysis in a meaningful theoretic model. This work takes two orthogonal directions. In the first part, we study cryptographic constructions preserving their security properties al...

  4. Crystallization: Key thermodynamic, kinetic and hydrodynamic aspects

    Indian Academy of Sciences (India)

    the knowledge gaps therein that pose challenges to research as well as industrial requirements. The section is organized as follows: first, crystallization practice in industry is briefly reviewed and key issues are .... by which these clusters form is either not very well understood or scantly available in the lit- erature. Primary ...

  5. Tajikistan : Key Priorities for Climate Change Adaptation

    OpenAIRE

    Barbone, Luca; Reva, Anna; Zaidi, Salman

    2010-01-01

    How should Tajikistan adapt to ongoing and future climate change, in particular given the many pressing development challenges it currently faces? The paper argues that for developing countries like Tajikistan, faster economic and social development is the best possible defense against climate change. It presents some key findings from a recent nationally representative household survey to...

  6. Key characteristics of different management styles

    OpenAIRE

    AGADZHANYAN A.S.

    2015-01-01

    The article reveals main management styles practiсed by managers all over the world. The author considers key characteristics of management styles, conditions of their using. The paper analyzes cultural differences in management styles in the West and in the East.

  7. Five Keys for Teaching Mental Math

    Science.gov (United States)

    Olsen, James R.

    2015-01-01

    After studying the Common Core State Standards for Mathematics (CCSSM) and brain-based learning research, James Olsen believes mental math instruction in secondary school mathematics (grades 7-12) and in teacher education programs needs increased attention. The purpose of this article is to share some keys for teaching mental math. Olsen also…

  8. Scientific independence: A key to credibility

    Science.gov (United States)

    Leonard F. Ruggiero

    2007-01-01

    Independence and objectivity are key ingredients of scientific credibility, especially in research organizations that are part of a natural resource management agency like the Forest Service. Credibility, in turn, is essential to the utility of scientific information in socio-political processes. In order to develop this thesis further, a basic understanding of Forest...

  9. Key Competences in vocational education and training

    DEFF Research Database (Denmark)

    Andersen, Ole Dibbern; Kruse, Katrine

    This article presents and discusses how key competences in the school based learning are embedded in the VET curricula during the last five years. It gives an overview of how their role has developed in light of the comprehensive Danish VET reform agreed in 2014 and implemented since August 2015....

  10. Memory for melody and key in childhood.

    Directory of Open Access Journals (Sweden)

    E Glenn Schellenberg

    Full Text Available After only two exposures to previously unfamiliar melodies, adults remember the tunes for over a week and the key for over a day. Here, we examined the development of long-term memory for melody and key. Listeners in three age groups (7- to 8-year-olds, 9- to 11-year-olds, and adults heard two presentations of each of 12 unfamiliar melodies. After a 10-min delay, they heard the same 12 old melodies intermixed with 12 new melodies. Half of the old melodies were transposed up or down by six semitones from initial exposure. Listeners rated how well they recognized the melodies from the exposure phase. Recognition was better for old than for new melodies, for adults compared to children, and for older compared to younger children. Recognition ratings were also higher for old melodies presented in the same key at test as exposure, and the detrimental effect of the transposition affected all age groups similarly. Although memory for melody improves with age and exposure to music, implicit memory for key appears to be adult-like by 7 years of age.

  11. Environmental conflicts: Key issues and management implications ...

    African Journals Online (AJOL)

    Environmental conflicts have emerged as key issues challenging local, regional, national and global security. Environmental crises and problems throughout the world are widespread and increasing rapidly. In relation to these concerns, the article discusses the following aspects: people and the environment, environmental ...

  12. Quantum key distribution using three basis states

    Indian Academy of Sciences (India)

    This note presents a method of public key distribution using quantum communication of photons that simultaneously provides a high probability that the bits have not been tampered. It is a variant of the quantum method of Bennett and Brassard (BB84) where the transmission states have been decreased from 4 to 3 and ...

  13. Quantum Cryptography: Key Distribution and Beyond

    Directory of Open Access Journals (Sweden)

    Akshata Shenoy-Hejamadi

    2017-06-01

    Full Text Available Uniquely among the sciences, quantum cryptography has driven both foundational research as well as practical real-life applications. We review the progress of quantum cryptography in the last decade, covering quantum key distribution and other applications. Quanta 2017; 6: 1–47.

  14. Soil fauna: key to new carbon models

    NARCIS (Netherlands)

    Filser, Juliane; Faber, J.H.; Tiunov, Alexei V.; Brussaard, L.; Frouz, J.; Deyn, de G.B.; Uvarov, Alexei V.; Berg, Matty P.; Lavelle, Patrick; Loreau, M.; Wall, D.H.; Querner, Pascal; Eijsackers, Herman; Jimenez, Juan Jose

    2016-01-01

    Soil organic matter (SOM) is key to maintaining soil fertility, mitigating climate change, combatting land degradation, and conserving above- and below-ground biodiversity and associated soil processes and ecosystem services. In order to derive management options for maintaining these essential

  15. Key Management in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ismail Mansour

    2015-09-01

    Full Text Available Wireless sensor networks are a challenging field of research when it comes to security issues. Using low cost sensor nodes with limited resources makes it difficult for cryptographic algorithms to function without impacting energy consumption and latency. In this paper, we focus on key management issues in multi-hop wireless sensor networks. These networks are easy to attack due to the open nature of the wireless medium. Intruders could try to penetrate the network, capture nodes or take control over particular nodes. In this context, it is important to revoke and renew keys that might be learned by malicious nodes. We propose several secure protocols for key revocation and key renewal based on symmetric encryption and elliptic curve cryptography. All protocols are secure, but have different security levels. Each proposed protocol is formally proven and analyzed using Scyther, an automatic verification tool for cryptographic protocols. For efficiency comparison sake, we implemented all protocols on real testbeds using TelosB motes and discussed their performances.

  16. Authenticity, Autonomy and Altruism: Keys for Transformation

    Science.gov (United States)

    Clarken, Rodney

    2011-01-01

    The value of authentic knowing, autonomous behavior and altruistic motivation is presented. Authenticity, autonomy and altruism are primary human capacities and keys for individual and collective transformation. Realizing the full development of these three basic potentialities can serve as goals and standards for well-being. Authenticity,…

  17. Key performance indicators: Global product development

    DEFF Research Database (Denmark)

    Taylor, Thomas Paul; Ahmed-Kristensen, Saeema

    2014-01-01

    investigates the use of key performance indicators as an approach for measuring the success of global product development projects. With the conclusions from a survey and workshop together with observations during a global development project, the need for an alternative approach to measurement than...

  18. Escherichia Coli--Key to Modern Genetics.

    Science.gov (United States)

    Bregegere, Francois

    1982-01-01

    Mid-nineteenth century work by Mendel on plant hybrids and by Pasteur on fermentation gave birth by way of bacterial genetics to modern-day molecular biology. The bacterium Escherichia Coli has occupied a key position in genetic studies leading from early gene identification with DNA to current genetic engineering using recombinant DNA technology.…

  19. Memory for melody and key in childhood.

    Science.gov (United States)

    Schellenberg, E Glenn; Poon, Jaimie; Weiss, Michael W

    2017-01-01

    After only two exposures to previously unfamiliar melodies, adults remember the tunes for over a week and the key for over a day. Here, we examined the development of long-term memory for melody and key. Listeners in three age groups (7- to 8-year-olds, 9- to 11-year-olds, and adults) heard two presentations of each of 12 unfamiliar melodies. After a 10-min delay, they heard the same 12 old melodies intermixed with 12 new melodies. Half of the old melodies were transposed up or down by six semitones from initial exposure. Listeners rated how well they recognized the melodies from the exposure phase. Recognition was better for old than for new melodies, for adults compared to children, and for older compared to younger children. Recognition ratings were also higher for old melodies presented in the same key at test as exposure, and the detrimental effect of the transposition affected all age groups similarly. Although memory for melody improves with age and exposure to music, implicit memory for key appears to be adult-like by 7 years of age.

  20. Key Data on Education in Europe 2012

    Science.gov (United States)

    Ranguelov, Stanislav; De Coster, Isabelle; Norani, Sogol; Paolini, Giulia

    2012-01-01

    Key Data on Education in Europe 2012 is a Eurydice flagship publication tracing the main developments of European education systems over the last decade. The report combines statistical data with qualitative information to describe the organisation, management and functioning of 37 European education systems from pre-primary to higher education.…

  1. Key Data on Education in Europe 2009

    Science.gov (United States)

    Ranguelov, Stanislav; de Coster, Isabelle; Forsthuber, Bernadette; Noorani, Sogol; Ruffio, Philippe

    2009-01-01

    This seventh edition of "Key Data on Education in Europe" retains its main special feature which is the combination of statistical data and qualitative information to describe the organisation and functioning of education systems in Europe. The present 2009 edition maintains the subject-based structure defined by the previous one but…

  2. TRANSITIONAL JUSTICE AND DEMOCRATIC CHANGE: KEY CONCEPTS

    Directory of Open Access Journals (Sweden)

    ELENA ANDREEVSKA

    2013-05-01

    Full Text Available This Article proposes a genealogy of transitional justice and focuses on transitional justice as one of the key steps in peace building that needs to be taken to secure a stable democratic futureTransitional justice is a response to systematic or widespread violations of human rights. It seeks recognition for victims and promotion of possibilities for peace, reconciliation and democracy. The paper focuses on key concepts of transitional justice before addressing its traditional components: justice, reparation, truth and institutional reform. This Article meeting point on the transitional process in a society which has experienced a violent conflict and needs adequate mechanisms to deal with the legacies of the past in order to prevent future violence and cover the way for reconciliation and democratic consolidation. It provides key stakeholders with an overview of transitional justice and its different components, while examining key challenges faced by those working in this area. The present paper concludes with some remarks that challenge the traditional concept of transitional justice and its processes in order to initiate important debate on where future work in this field is needed.

  3. The Kotter Key Is Not the Answer.

    Science.gov (United States)

    Johnson, Simon O.

    1980-01-01

    The author, responding to an article in the April 1980 "Educational Leadership" states that he has not found any indication that the Kotter syndrome (from the television series "Welcome Back, Kotter") is a key to educating disadvantaged students. (Author/MLF)

  4. Random Walks and Trees

    Directory of Open Access Journals (Sweden)

    Shi Zhan

    2011-03-01

    Full Text Available These notes provide an elementary and self-contained introduction to branching random walks. Section 1 gives a brief overview of Galton–Watson trees, whereas Section 2 presents the classical law of large numbers for branching random walks. These two short sections are not exactly indispensable, but they introduce the idea of using size-biased trees, thus giving motivations and an avant-goût to the main part, Section 3, where branching random walks are studied from a deeper point of view, and are connected to the model of directed polymers on a tree. Tree-related random processes form a rich and exciting research subject. These notes cover only special topics. For a general account, we refer to the St-Flour lecture notes of Peres [47] and to the forthcoming book of Lyons and Peres [42], as well as to Duquesne and Le Gall [23] and Le Gall [37] for continuous random trees.

  5. Two-Dimensional Key Table-Based Group Key Distribution in Advanced Metering Infrastructure

    Directory of Open Access Journals (Sweden)

    Woong Go

    2014-01-01

    Full Text Available A smart grid provides two-way communication by using the information and communication technology. In order to establish two-way communication, the advanced metering infrastructure (AMI is used in the smart grid as the core infrastructure. This infrastructure consists of smart meters, data collection units, maintenance data management systems, and so on. However, potential security problems of the AMI increase owing to the application of the public network. This is because the transmitted information is electricity consumption data for charging. Thus, in order to establish a secure connection to transmit electricity consumption data, encryption is necessary, for which key distribution is required. Further, a group key is more efficient than a pairwise key in the hierarchical structure of the AMI. Therefore, we propose a group key distribution scheme using a two-dimensional key table through the analysis result of the sensor network group key distribution scheme. The proposed scheme has three phases: group key predistribution, selection of group key generation element, and generation of group key.

  6. Identifying key hospital service quality factors in online health communities.

    Science.gov (United States)

    Jung, Yuchul; Hur, Cinyoung; Jung, Dain; Kim, Minki

    2015-04-07

    The volume of health-related user-created content, especially hospital-related questions and answers in online health communities, has rapidly increased. Patients and caregivers participate in online community activities to share their experiences, exchange information, and ask about recommended or discredited hospitals. However, there is little research on how to identify hospital service quality automatically from the online communities. In the past, in-depth analysis of hospitals has used random sampling surveys. However, such surveys are becoming impractical owing to the rapidly increasing volume of online data and the diverse analysis requirements of related stakeholders. As a solution for utilizing large-scale health-related information, we propose a novel approach to identify hospital service quality factors and overtime trends automatically from online health communities, especially hospital-related questions and answers. We defined social media-based key quality factors for hospitals. In addition, we developed text mining techniques to detect such factors that frequently occur in online health communities. After detecting these factors that represent qualitative aspects of hospitals, we applied a sentiment analysis to recognize the types of recommendations in messages posted within online health communities. Korea's two biggest online portals were used to test the effectiveness of detection of social media-based key quality factors for hospitals. To evaluate the proposed text mining techniques, we performed manual evaluations on the extraction and classification results, such as hospital name, service quality factors, and recommendation types using a random sample of messages (ie, 5.44% (9450/173,748) of the total messages). Service quality factor detection and hospital name extraction achieved average F1 scores of 91% and 78%, respectively. In terms of recommendation classification, performance (ie, precision) is 78% on average. Extraction and

  7. Key Generation Using External Source Excitation: Capacity, Reliability, and Secrecy Exponent

    CERN Document Server

    Chou, Tzu-Han; Sayeed, Akbar M

    2011-01-01

    We study the fundamental limits to secret key generation from an excited distributed source (EDS). In an EDS a pair of terminals observe dependent sources of randomness excited by a pre-arranged signal. We first determine the secret key capacity for such systems with one-way public messaging. We then characterize a tradeoff between the secret key rate and exponential bounds on the probability of key agreement failure and on the secrecy of the key generated. We find that there is a fundamental tradeoff between reliability and secrecy. We then explore this framework within the context of reciprocal wireless channels. In this setting, the users transmit pre-arranged excitation signals to each other. When the fading is Rayleigh, the observations of the users are jointly Gaussian sources. We show that an on-off excitation signal with an SNR-dependent duty cycle achieves the secret key capacity of this system. Furthermore, we characterize a fundamental metric -- minimum energy per key bit for reliable key generatio...

  8. Identification of the Key Fields and Their Key Technical Points of Oncology by Patent Analysis.

    Directory of Open Access Journals (Sweden)

    Ting Zhang

    Full Text Available This paper aims to identify the key fields and their key technical points of oncology by patent analysis.Patents of oncology applied from 2006 to 2012 were searched in the Thomson Innovation database. The key fields and their key technical points were determined by analyzing the Derwent Classification (DC and the International Patent Classification (IPC, respectively. Patent applications in the top ten DC occupied 80% of all the patent applications of oncology, which were the ten fields of oncology to be analyzed. The number of patent applications in these ten fields of oncology was standardized based on patent applications of oncology from 2006 to 2012. For each field, standardization was conducted separately for each of the seven years (2006-2012 and the mean of the seven standardized values was calculated to reflect the relative amount of patent applications in that field; meanwhile, regression analysis using time (year and the standardized values of patent applications in seven years (2006-2012 was conducted so as to evaluate the trend of patent applications in each field. Two-dimensional quadrant analysis, together with the professional knowledge of oncology, was taken into consideration in determining the key fields of oncology. The fields located in the quadrant with high relative amount or increasing trend of patent applications are identified as key ones. By using the same method, the key technical points in each key field were identified. Altogether 116,820 patents of oncology applied from 2006 to 2012 were retrieved, and four key fields with twenty-nine key technical points were identified, including "natural products and polymers" with nine key technical points, "fermentation industry" with twelve ones, "electrical medical equipment" with four ones, and "diagnosis, surgery" with four ones.The results of this study could provide guidance on the development direction of oncology, and also help researchers broaden innovative ideas and

  9. Identification of the Key Fields and Their Key Technical Points of Oncology by Patent Analysis.

    Science.gov (United States)

    Zhang, Ting; Chen, Juan; Jia, Xiaofeng

    2015-01-01

    This paper aims to identify the key fields and their key technical points of oncology by patent analysis. Patents of oncology applied from 2006 to 2012 were searched in the Thomson Innovation database. The key fields and their key technical points were determined by analyzing the Derwent Classification (DC) and the International Patent Classification (IPC), respectively. Patent applications in the top ten DC occupied 80% of all the patent applications of oncology, which were the ten fields of oncology to be analyzed. The number of patent applications in these ten fields of oncology was standardized based on patent applications of oncology from 2006 to 2012. For each field, standardization was conducted separately for each of the seven years (2006-2012) and the mean of the seven standardized values was calculated to reflect the relative amount of patent applications in that field; meanwhile, regression analysis using time (year) and the standardized values of patent applications in seven years (2006-2012) was conducted so as to evaluate the trend of patent applications in each field. Two-dimensional quadrant analysis, together with the professional knowledge of oncology, was taken into consideration in determining the key fields of oncology. The fields located in the quadrant with high relative amount or increasing trend of patent applications are identified as key ones. By using the same method, the key technical points in each key field were identified. Altogether 116,820 patents of oncology applied from 2006 to 2012 were retrieved, and four key fields with twenty-nine key technical points were identified, including "natural products and polymers" with nine key technical points, "fermentation industry" with twelve ones, "electrical medical equipment" with four ones, and "diagnosis, surgery" with four ones. The results of this study could provide guidance on the development direction of oncology, and also help researchers broaden innovative ideas and discover new

  10. Secure detection in quantum key distribution by real-time calibration of receiver

    Science.gov (United States)

    Marøy, Øystein; Makarov, Vadim; Skaar, Johannes

    2017-12-01

    The single-photon detectionefficiency of the detector unit is crucial for the security of common quantum key distribution protocols like Bennett-Brassard 1984 (BB84). A low value for the efficiency indicates a possible eavesdropping attack that exploits the photon receiver’s imperfections. We present a method for estimating the detection efficiency, and calculate the corresponding secure key generation rate. The estimation is done by testing gated detectors using a randomly activated photon source inside the receiver unit. This estimate gives a secure rate for any detector with non-unity single-photon detection efficiency, both inherit or due to blinding. By adding extra optical components to the receiver, we make sure that the key is extracted from photon states for which our estimate is valid. The result is a quantum key distribution scheme that is secure against any attack that exploits detector imperfections.

  11. Nonmarket economic user values of the Florida Keys/Key West

    Science.gov (United States)

    Vernon R. Leeworthy; J. Michael Bowker

    1997-01-01

    This report provides estimates of the nonmarket economic user values for recreating visitors to the Florida Keys/Key West that participated in natural resource-based activities. Results from estimated travel cost models are presented, including visitor’s responses to prices and estimated per person-trip user values. Annual user values are also calculated and presented...

  12. Public-key quantum digital signature scheme with one-time pad private-key

    Science.gov (United States)

    Chen, Feng-Lin; Liu, Wan-Fang; Chen, Su-Gen; Wang, Zhi-Hua

    2018-01-01

    A quantum digital signature scheme is firstly proposed based on public-key quantum cryptosystem. In the scheme, the verification public-key is derived from the signer's identity information (such as e-mail) on the foundation of identity-based encryption, and the signature private-key is generated by one-time pad (OTP) protocol. The public-key and private-key pair belongs to classical bits, but the signature cipher belongs to quantum qubits. After the signer announces the public-key and generates the final quantum signature, each verifier can verify publicly whether the signature is valid or not with the public-key and quantum digital digest. Analysis results show that the proposed scheme satisfies non-repudiation and unforgeability. Information-theoretic security of the scheme is ensured by quantum indistinguishability mechanics and OTP protocol. Based on the public-key cryptosystem, the proposed scheme is easier to be realized compared with other quantum signature schemes under current technical conditions.

  13. On the Wrong Key Randomisation and Key Equivalence Hypotheses in Matsui’s Algorithm 2

    DEFF Research Database (Denmark)

    Bogdanov, Andrey; Tischhauser, Elmar

    2014-01-01

    can therefore result in a more powerful attack. A second assumption usually made in linear cryptanalysis is the key equivalence hypothesis, even though due to the linear hull effect, the bias can heavily depend on the key. As a further contribution of this paper, we propose a practical technique...

  14. Adding-Listing Machines (Ten-Key and Full-Key), Business Education: 7718.07.

    Science.gov (United States)

    McKinney, Lottie N.

    This pamphlet describes a course designed to give students mastery over the 10-key and full-key adding-listing machines in solving special business problems. With course guidelines, performance objectives, course content, learning activities, evaluative instruments, student and teacher resources, the course content seeks to develop occupational…

  15. Fundamental finite key limits for one-way information reconciliation in quantum key distribution

    Science.gov (United States)

    Tomamichel, Marco; Martinez-Mateo, Jesus; Pacher, Christoph; Elkouss, David

    2017-11-01

    The security of quantum key distribution protocols is guaranteed by the laws of quantum mechanics. However, a precise analysis of the security properties requires tools from both classical cryptography and information theory. Here, we employ recent results in non-asymptotic classical information theory to show that one-way information reconciliation imposes fundamental limitations on the amount of secret key that can be extracted in the finite key regime. In particular, we find that an often used approximation for the information leakage during information reconciliation is not generally valid. We propose an improved approximation that takes into account finite key effects and numerically test it against codes for two probability distributions, that we call binary-binary and binary-Gaussian, that typically appear in quantum key distribution protocols.

  16. PERBANDINGAN APLIKASI MENGGUNAKAN METODE CAMELLIA 128 BIT KEY DAN 256 BIT KEY

    Directory of Open Access Journals (Sweden)

    Lanny Sutanto

    2014-01-01

    Full Text Available The rapid development of the Internet today to easily exchange data. This leads to high levels of risk in the data piracy. One of the ways to secure data is using cryptography camellia. Camellia is known as a method that has the encryption and decryption time is fast. Camellia method has three kinds of scale key is 128 bit, 192 bit, and 256 bit.This application is created using the C++ programming language and using visual studio 2010 GUI. This research compare the smallest and largest key size used on the file extension .Txt, .Doc, .Docx, .Jpg, .Mp4, .Mkv and .Flv. This application is made to comparing time and level of security in the use of 128-bit key and 256 bits. The comparison is done by comparing the results of the security value of avalanche effect 128 bit key and 256 bit key.

  17. Short Review on Quantum Key Distribution Protocols.

    Science.gov (United States)

    Giampouris, Dimitris

    2017-01-01

    Cryptographic protocols and mechanisms are widely investigated under the notion of quantum computing. Quantum cryptography offers particular advantages over classical ones, whereas in some cases established protocols have to be revisited in order to maintain their functionality. The purpose of this paper is to provide the basic definitions and review the most important theoretical advancements concerning the BB84 and E91 protocols. It also aims to offer a summary on some key developments on the field of quantum key distribution, closely related with the two aforementioned protocols. The main goal of this study is to provide the necessary background information along with a thorough review on the theoretical aspects of QKD, concentrating on specific protocols. The BB84 and E91 protocols have been chosen because most other protocols are similar to these, a fact that makes them important for the general understanding of how the QKD mechanism functions.

  18. Progress in satellite quantum key distribution

    Science.gov (United States)

    Bedington, Robert; Arrazola, Juan Miguel; Ling, Alexander

    2017-08-01

    Quantum key distribution (QKD) is a family of protocols for growing a private encryption key between two parties. Despite much progress, all ground-based QKD approaches have a distance limit due to atmospheric losses or in-fibre attenuation. These limitations make purely ground-based systems impractical for a global distribution network. However, the range of communication may be extended by employing satellites equipped with high-quality optical links. This manuscript summarizes research and development which is beginning to enable QKD with satellites. It includes a discussion of protocols, infrastructure, and the technical challenges involved with implementing such systems, as well as a top level summary of on-going satellite QKD initiatives around the world.

  19. Key Design Properties for Shipping Information Pipeline

    DEFF Research Database (Denmark)

    Jensen, Thomas; Tan, Yao-Hua

    2015-01-01

    . The contribution of the paper is to expand previous research with complementary key design properties. The paper starts with a review of existing literature on previous proposed solutions for increased collaboration in the supply chain for international trade, Inter-Organization Systems and Information......This paper reports on the use of key design properties for development of a new approach towards a solution for sharing shipping information in the supply chain for international trade. Information exchange in international supply chain is extremely inefficient, rather uncoordinated, based largely...... on paper, e-mail, phone and text message, and far too costly. This paper explores the design properties for a shared information infrastructure to exchange information between all parties in the supply chain, commercial parties as well as authorities, which is called a Shipping Information Pipeline...

  20. Identification of Key Barriers in Workforce Development

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-03-31

    This report documents the identification of key barriers in the development of an adequate national security workforce as part of the National Security Preparedness Project, being performed under a Department of Energy/National Nuclear Security Administration grant. Many barriers exist that prevent the development of an adequate number of propertly trained national security personnel. Some barriers can be eliminated in a short-term manner, whereas others will involve a long-term strategy that takes into account public policy.

  1. George's secret key to the universe

    CERN Document Server

    Hawking, Lucy; Galfard, Christophe; Parsons, Gary

    2007-01-01

    In their bestselling book for young readers, noted physicist Stephen Hawking and his daughter, Lucy, provide a grand and funny adventure that explains fascinating information about our universe, including Dr. Hawking's latest ideas about black holes. It's the story of George, who's taken through the vastness of space by a scientist, his daughter, and their super-computer named Cosmos. George's Secret Key to the Universe was a New York Times bestseller and a selection of Al's Book Club on the Today show.

  2. Quantum key distribution over multicore fiber.

    Science.gov (United States)

    Dynes, J F; Kindness, S J; Tam, S W-B; Plews, A; Sharpe, A W; Lucamarini, M; Fröhlich, B; Yuan, Z L; Penty, R V; Shields, A J

    2016-04-18

    We present the first quantum key distribution (QKD) experiment over multicore fiber. With space division multiplexing, we demonstrate that weak QKD signals can coexist with classical data signals launched at full power in a 53 km 7-core fiber, while showing negligible degradation in performance. Based on a characterization of intercore crosstalk, we perform additional simulations highlighting that classical data bandwidths beyond 1Tb/s can be supported with high speed QKD on the same fiber.

  3. Quantum key distribution over multicore fiber

    OpenAIRE

    Dynes, JF; Kindness, Stephen; Tam, SW-B; Plews, A.; Sharpe, AW; Lucamarini, M.; Fröhlich, B.; Yuan, ZL; Penty, Richard Vincent; Shields, AJ

    2016-01-01

    We present the first quantum key distribution (QKD) experiment over multicore fiber. With space division multiplexing, we demonstrate that weak QKD signals can coexist with classical data signals launched at full power in a 53 km 7-core fiber, while showing negligible degradation in performance. Based on a characterization of intercore crosstalk, we perform additional simulations highlighting that classical data bandwidths beyond 1Tb/s can be supported with high speed QKD on the same fiber.

  4. Key factors of teenagers' mobile advertising acceptance

    OpenAIRE

    Martí Parreño, José; Sanz Blas, Silvia; Ruiz Mafé, Carla; Aldás Manzano, Joaquín

    2013-01-01

    Purpose – The purpose of this paper is to analyse key drivers of teenagers’ attitude toward mobile advertising and its effects on teenagers’ mobile advertising acceptance. Design/methodology/approach – A proposed model of affective (irritation and entertainment) and cognitive (perceived usefulness) antecedents of attitude toward mobile advertising and its effects on mobile advertising acceptance is analysed. The sample consisted of 355 Spanish teenagers. The model was tested us...

  5. Key Physical Mechanisms in Nanostructured Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Dr Stephan Bremner

    2010-07-21

    The objective of the project was to study both theoretically and experimentally the excitation, recombination and transport properties required for nanostructured solar cells to deliver energy conversion efficiencies well in excess of conventional limits. These objectives were met by concentrating on three key areas, namely, investigation of physical mechanisms present in nanostructured solar cells, characterization of loss mechanisms in nanostructured solar cells and determining the properties required of nanostructured solar cells in order to achieve high efficiency and the design implications.

  6. Triple symmetric key cryptosystem for data security

    Science.gov (United States)

    Fuzail, C. Md; Norman, Jasmine; Mangayarkarasi, R.

    2017-11-01

    As the technology is getting spreads in the macro seconds of speed and in which the trend changing era from human to robotics the security issue is also getting increased. By means of using machine attacks it is very easy to break the cryptosystems in very less amount of time. Cryptosystem is a process which provides the security in all sorts of processes, communications and transactions to be done securely with the help of electronical mechanisms. Data is one such thing with the expanded implication and possible scraps over the collection of data to secure predominance and achievement, Information Security is the process where the information is protected from invalid and unverified accessibilities and data from mishandling. So the idea of Information Security has risen. Symmetric key which is also known as private key.Whereas the private key is mostly used to attain the confidentiality of data. It is a dynamic topic which can be implemented over different applications like android, wireless censor networks, etc. In this paper, a new mathematical manipulation algorithm along with Tea cryptosystem has been implemented and it can be used for the purpose of cryptography. The algorithm which we proposed is straightforward and more powerful and it will authenticate in harder way and also it will be very difficult to break by someone without knowing in depth about its internal mechanisms.

  7. Interactive simulations for quantum key distribution

    Science.gov (United States)

    Kohnle, Antje; Rizzoli, Aluna

    2017-05-01

    Secure communication protocols are becoming increasingly important, e.g. for internet-based communication. Quantum key distribution (QKD) allows two parties, commonly called Alice and Bob, to generate a secret sequence of 0s and 1s called a key that is only known to themselves. Classically, Alice and Bob could never be certain that their communication was not compromised by a malicious eavesdropper. Quantum mechanics however makes secure communication possible. The fundamental principle of quantum mechanics that taking a measurement perturbs the system (unless the measurement is compatible with the quantum state) also applies to an eavesdropper. Using appropriate protocols to create the key, Alice and Bob can detect the presence of an eavesdropper by errors in their measurements. As part of the QuVis Quantum Mechanics Visualisation Project, we have developed a suite of four interactive simulations that demonstrate the basic principles of three different QKD protocols. The simulations use either polarised photons or spin 1/2 particles as physical realisations. The simulations and accompanying activities are freely available for use online or download, and run on a wide range of devices including tablets and PCs. Evaluation with students over three years was used to refine the simulations and activities. Preliminary studies show that the refined simulations and activities help students learn the basic principles of QKD at both the introductory and advanced undergraduate levels.

  8. Species Identification Key of Korean Mammal Hair

    Science.gov (United States)

    LEE, Eunok; CHOI, Tae-Young; WOO, Donggul; MIN, Mi-Sook; SUGITA, Shoei; LEE, Hang

    2014-01-01

    ABSTRACT The hair microstructures of Korean terrestrial mammals from 23 species (22 wild and one domestic) were analyzed using light and scanning electron microscopy (SEM) to construct a hair identification key. The hairs were examined using the medulla structures and cuticular scales of guard hairs from the dorsal regions of mature adult animals. All cuticular scale structures in the hair of Rodentia, Lagomorpha, Carnivora and Insectivora showed the petal pattern, and those of Artiodactyla and Chiroptera showed the wave pattern and coronal pattern, respectively. Rodentia, Lagomorpha and Carnivora showed multicellular, and Insectivora and Artiodactyla showed unicellular regular, mesh or columnar in the medulla structures, respectively. Chiroptera did not show the medulla structures in their hair. We found that it is possible to distinguish between species and order based on general appearance, medulla structures and cuticular scales. Thus, we constructed a hair identification key with morphological characteristics from each species. This study suggests that hair identification keys could be useful in fields, such as forensic science, food safety and foraging ecology. PMID:24451929

  9. Satellite-to-ground quantum key distribution

    Science.gov (United States)

    Liao, Sheng-Kai; Cai, Wen-Qi; Liu, Wei-Yue; Zhang, Liang; Li, Yang; Ren, Ji-Gang; Yin, Juan; Shen, Qi; Cao, Yuan; Li, Zheng-Ping; Li, Feng-Zhi; Chen, Xia-Wei; Sun, Li-Hua; Jia, Jian-Jun; Wu, Jin-Cai; Jiang, Xiao-Jun; Wang, Jian-Feng; Huang, Yong-Mei; Wang, Qiang; Zhou, Yi-Lin; Deng, Lei; Xi, Tao; Ma, Lu; Hu, Tai; Zhang, Qiang; Chen, Yu-Ao; Liu, Nai-Le; Wang, Xiang-Bin; Zhu, Zhen-Cai; Lu, Chao-Yang; Shu, Rong; Peng, Cheng-Zhi; Wang, Jian-Yu; Pan, Jian-Wei

    2017-09-01

    Quantum key distribution (QKD) uses individual light quanta in quantum superposition states to guarantee unconditional communication security between distant parties. However, the distance over which QKD is achievable has been limited to a few hundred kilometres, owing to the channel loss that occurs when using optical fibres or terrestrial free space that exponentially reduces the photon transmission rate. Satellite-based QKD has the potential to help to establish a global-scale quantum network, owing to the negligible photon loss and decoherence experienced in empty space. Here we report the development and launch of a low-Earth-orbit satellite for implementing decoy-state QKD—a form of QKD that uses weak coherent pulses at high channel loss and is secure because photon-number-splitting eavesdropping can be detected. We achieve a kilohertz key rate from the satellite to the ground over a distance of up to 1,200 kilometres. This key rate is around 20 orders of magnitudes greater than that expected using an optical fibre of the same length. The establishment of a reliable and efficient space-to-ground link for quantum-state transmission paves the way to global-scale quantum networks.

  10. Practical Cryptanalysis of a Public-key Encryption Scheme Based on New Multivariate Quadratic Assumptions

    DEFF Research Database (Denmark)

    Albrecht, Martin Roland; Faugére, Jean-Charles; Fitzpatrick, Robert

    2014-01-01

    In this paper, we investigate the security of a public-key encryption scheme introduced by Huang, Liu and Yang (HLY) at PKC’12. This new scheme can be provably reduced to the hardness of solving a set of quadratic equations whose coefficients of highest degree are chosen according to a discrete...... Gaussian distributions. The other terms being chosen uniformly at random. Such a problem is a variant of the classical problem of solving a system of non-linear equations (PoSSo), which is known to be hard for random systems. The main hypothesis of Huang, Liu and Yang is that their variant is not easier...

  11. RSA-Based Password-Authenticated Key Exchange, Revisited

    Science.gov (United States)

    Shin, Seonghan; Kobara, Kazukuni; Imai, Hideki

    The RSA-based Password-Authenticated Key Exchange (PAKE) protocols have been proposed to realize both mutual authentication and generation of secure session keys where a client is sharing his/her password only with a server and the latter should generate its RSA public/private key pair (e, n), (d, n) every time due to the lack of PKI (Public-Key Infrastructures). One of the ways to avoid a special kind of off-line (so called e-residue) attacks in the RSA-based PAKE protocols is to deploy a challenge/response method by which a client verifies the relative primality of e and φ(n) interactively with a server. However, this kind of RSA-based PAKE protocols did not give any proof of the underlying challenge/response method and therefore could not specify the exact complexity of their protocols since there exists another security parameter, needed in the challenge/response method. In this paper, we first present an RSA-based PAKE (RSA-PAKE) protocol that can deploy two different challenge/response methods (denoted by Challenge/Response Method1 and Challenge/Response Method2). The main contributions of this work include: (1) Based on the number theory, we prove that the Challenge/Response Method1 and the Challenge/Response Method2 are secure against e-residue attacks for any odd prime e (2) With the security parameter for the on-line attacks, we show that the RSA-PAKE protocol is provably secure in the random oracle model where all of the off-line attacks are not more efficient than on-line dictionary attacks; and (3) By considering the Hamming weight of e and its complexity in the. RSA-PAKE protocol, we search for primes to be recommended for a practical use. We also compare the RSA-PAKE protocol with the previous ones mainly in terms of computation and communication complexities.

  12. Random maintenance policies

    CERN Document Server

    Nakagawa, Toshio

    2014-01-01

    Exploring random maintenance models, this book provides an introduction to the implementation of random maintenance, and it is one of the first books to be written on this subject.  It aims to help readers learn new techniques for applying random policies to actual reliability models, and it provides new theoretical analyses of various models including classical replacement, preventive maintenance and inspection policies. These policies are applied to scheduling problems, backup policies of database systems, maintenance policies of cumulative damage models, and reliability of random redundant systems. Reliability theory is a major concern for engineers and managers, and in light of Japan’s recent earthquake, the reliability of large-scale systems has increased in importance. This also highlights the need for a new notion of maintenance and reliability theory, and how this can practically be applied to systems. Providing an essential guide for engineers and managers specializing in reliability maintenance a...

  13. Drawing a random number

    DEFF Research Database (Denmark)

    Wanscher, Jørgen Bundgaard; Sørensen, Majken Vildrik

    2006-01-01

    highly uniform multidimensional draws, which are highly relevant for todays traffic models. This paper shows among others combined shuffling and scrambling seems needless, that scrambling gives the lowest correlation and that there are detectable differences between random numbers, dependent...

  14. Theory of random sets

    CERN Document Server

    Molchanov, Ilya

    2017-01-01

    This monograph, now in a thoroughly revised second edition, offers the latest research on random sets. It has been extended to include substantial developments achieved since 2005, some of them motivated by applications of random sets to econometrics and finance. The present volume builds on the foundations laid by Matheron and others, including the vast advances in stochastic geometry, probability theory, set-valued analysis, and statistical inference. It shows the various interdisciplinary relationships of random set theory within other parts of mathematics, and at the same time fixes terminology and notation that often vary in the literature, establishing it as a natural part of modern probability theory and providing a platform for future development. It is completely self-contained, systematic and exhaustive, with the full proofs that are necessary to gain insight. Aimed at research level, Theory of Random Sets will be an invaluable reference for probabilists; mathematicians working in convex and integ...

  15. Exploring complex networks through random walks.

    Science.gov (United States)

    Costa, Luciano da Fontoura; Travieso, Gonzalo

    2007-01-01

    Most real complex networks--such as protein interactions, social contacts, and the Internet--are only partially known and available to us. While the process of exploring such networks in many cases resembles a random walk, it becomes a key issue to investigate and characterize how effectively the nodes and edges of such networks can be covered by different strategies. At the same time, it is critically important to infer how well can topological measurements such as the average node degree and average clustering coefficient be estimated during such network explorations. The present article addresses these problems by considering random, Barabási-Albert (BA), and geographical network models with varying connectivity explored by three types of random walks: traditional, preferential to untracked edges, and preferential to unvisited nodes. A series of relevant results are obtained, including the fact that networks of the three studied models with the same size and average node degree allow similar node and edge coverage efficiency, the identification of linear scaling with the size of the network of the random walk step at which a given percentage of the nodes/edges is covered, and the critical result that the estimation of the averaged node degree and clustering coefficient by random walks on BA networks often leads to heavily biased results. Many are the theoretical and practical implications of such results.

  16. Image encryption based on interference that uses fractional Fourier domain asymmetric keys.

    Science.gov (United States)

    Rajput, Sudheesh K; Nishchal, Naveen K

    2012-04-01

    We propose an image encryption technique based on the interference principle and phase-truncation approach in the fractional Fourier domain. The proposed scheme offers multiple levels of security with asymmetric keys and is free from the silhouette problem. Multiple input images bonded with random phase masks are independently fractional Fourier transformed. Amplitude truncation of obtained spectrum helps generate individual and universal keys while phase truncation generates two phase-only masks analytically. For decryption, these two phase-only masks optically interfere, and this results in the phase-truncated function in the output. After using the correct random phase mask, universal key, individual key, and fractional orders, the original image is retrieved successfully. Computer simulation results with four gray-scale images validate the proposed method. To measure the effectiveness of the proposed method, we calculated the mean square error between the original and the decrypted images. In this scheme, the encryption process and decryption keys formation are complicated and should be realized digitally. For decryption, an optoelectronic scheme has been suggested.

  17. Quasiclassical Random Matrix Theory

    OpenAIRE

    Prange, R. E.

    1996-01-01

    We directly combine ideas of the quasiclassical approximation with random matrix theory and apply them to the study of the spectrum, in particular to the two-level correlator. Bogomolny's transfer operator T, quasiclassically an NxN unitary matrix, is considered to be a random matrix. Rather than rejecting all knowledge of the system, except for its symmetry, [as with Dyson's circular unitary ensemble], we choose an ensemble which incorporates the knowledge of the shortest periodic orbits, th...

  18. Quantum randomness and unpredictability

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Gregg [Quantum Communication and Measurement Laboratory, Department of Electrical and Computer Engineering and Division of Natural Science and Mathematics, Boston University, Boston, MA (United States)

    2017-06-15

    Quantum mechanics is a physical theory supplying probabilities corresponding to expectation values for measurement outcomes. Indeed, its formalism can be constructed with measurement as a fundamental process, as was done by Schwinger, provided that individual measurements outcomes occur in a random way. The randomness appearing in quantum mechanics, as with other forms of randomness, has often been considered equivalent to a form of indeterminism. Here, it is argued that quantum randomness should instead be understood as a form of unpredictability because, amongst other things, indeterminism is not a necessary condition for randomness. For concreteness, an explication of the randomness of quantum mechanics as the unpredictability of quantum measurement outcomes is provided. Finally, it is shown how this view can be combined with the recently introduced view that the very appearance of individual quantum measurement outcomes can be grounded in the Plenitude principle of Leibniz, a principle variants of which have been utilized in physics by Dirac and Gell-Mann in relation to the fundamental processes. This move provides further support to Schwinger's ''symbolic'' derivation of quantum mechanics from measurement. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Proposal for an index to evaluate dichotomous keys.

    Science.gov (United States)

    Sinh, Nguyen Van; Wiemers, Martin; Settele, Josef

    2017-01-01

    Dichotomous keys are the most popular type of identification keys. Studies have been conducted to evaluate dichotomous keys in many aspects. In this paper we propose an index for quantitative evaluation of dichotomous keys (Edicho). The index is based on the evenness and allows comparing identification keys of different sizes.

  20. Soil fauna: key to new carbon models

    Science.gov (United States)

    Filser, Juliane; Faber, Jack H.; Tiunov, Alexei V.; Brussaard, Lijbert; Frouz, Jan; De Deyn, Gerlinde; Uvarov, Alexei V.; Berg, Matty P.; Lavelle, Patrick; Loreau, Michel; Wall, Diana H.; Querner, Pascal; Eijsackers, Herman; José Jiménez, Juan

    2016-11-01

    Soil organic matter (SOM) is key to maintaining soil fertility, mitigating climate change, combatting land degradation, and conserving above- and below-ground biodiversity and associated soil processes and ecosystem services. In order to derive management options for maintaining these essential services provided by soils, policy makers depend on robust, predictive models identifying key drivers of SOM dynamics. Existing SOM models and suggested guidelines for future SOM modelling are defined mostly in terms of plant residue quality and input and microbial decomposition, overlooking the significant regulation provided by soil fauna. The fauna controls almost any aspect of organic matter turnover, foremost by regulating the activity and functional composition of soil microorganisms and their physical-chemical connectivity with soil organic matter. We demonstrate a very strong impact of soil animals on carbon turnover, increasing or decreasing it by several dozen percent, sometimes even turning C sinks into C sources or vice versa. This is demonstrated not only for earthworms and other larger invertebrates but also for smaller fauna such as Collembola. We suggest that inclusion of soil animal activities (plant residue consumption and bioturbation altering the formation, depth, hydraulic properties and physical heterogeneity of soils) can fundamentally affect the predictive outcome of SOM models. Understanding direct and indirect impacts of soil fauna on nutrient availability, carbon sequestration, greenhouse gas emissions and plant growth is key to the understanding of SOM dynamics in the context of global carbon cycling models. We argue that explicit consideration of soil fauna is essential to make realistic modelling predictions on SOM dynamics and to detect expected non-linear responses of SOM dynamics to global change. We present a decision framework, to be further developed through the activities of KEYSOM, a European COST Action, for when mechanistic SOM models

  1. Key Impact Factors on Dam Break Fatalities

    Science.gov (United States)

    Huang, D.; Yu, Z.; Song, Y.; Han, D.; Li, Y.

    2016-12-01

    Dam failures can lead to catastrophes on human society. However, there is a lack of research about dam break fatalities, especially on the key factors that affect fatalities. Based on the analysis of historical dam break cases, most studies have used the regression analysis to explore the correlation between those factors and fatalities, but without implementing optimization to find the dominating factors. In order to understand and reduce the risk of fatalities, this study has proposed a new method to select the impact factors on the fatality. It employs an improved ANN (Artificial Neural Network) combined with LOOCV (Leave-one-out cross-validation) and SFS (Stepwise Forward Selection) approach to explore the nonlinear relationship between impact factors and life losses. It not only considers the factors that have been widely used in the literature but also introduces new factors closely involved with fatalities. Dam break cases occurred in China from 1954 to 2013 are summarized, within which twenty-five cases are selected with a comprehensive coverage of geographic position and temporal variation. Twelve impact factors are taken into account as the inputs, i.e., severity of dam break flood (SF), population at risk (PR), public understanding of dam break (UB), warning time (TW), evacuation condition (EC), weather condition during dam break (WB), dam break mode (MB), water storage (SW), building vulnerability (VB), dam break time (TB), average distance from the affected area to the dam (DD) and preventive measures by government (PG).From those, three key factors of SF, MB and TB are chosen. The proposed method is able to extract the key factors, and the derived fatality model performs well in various types of dam break conditions.

  2. Cryptographic Key Management and Critical Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Abercrombie, Robert K [ORNL

    2014-05-01

    The Department of Energy Office of Electricity Delivery and Energy Reliability (DOE-OE) CyberSecurity for Energy Delivery Systems (CSEDS) industry led program (DE-FOA-0000359) entitled "Innovation for Increasing CyberSecurity for Energy Delivery Systems (12CSEDS)," awarded a contract to Sypris Electronics LLC to develop a Cryptographic Key Management System for the smart grid (Scalable Key Management Solutions for Critical Infrastructure Protection). Oak Ridge National Laboratory (ORNL) and Sypris Electronics, LLC as a result of that award entered into a CRADA (NFE-11-03562) between ORNL and Sypris Electronics, LLC. ORNL provided its Cyber Security Econometrics System (CSES) as a tool to be modified and used as a metric to address risks and vulnerabilities in the management of cryptographic keys within the Advanced Metering Infrastructure (AMI) domain of the electric sector. ORNL concentrated our analysis on the AMI domain of which the National Electric Sector Cyber security Organization Resource (NESCOR) Working Group 1 (WG1) has documented 29 failure scenarios. The computational infrastructure of this metric involves system stakeholders, security requirements, system components and security threats. To compute this metric, we estimated the stakes that each stakeholder associates with each security requirement, as well as stochastic matrices that represent the probability of a threat to cause a component failure and the probability of a component failure to cause a security requirement violation. We applied this model to estimate the security of the AMI, by leveraging the recently established National Institute of Standards and Technology Interagency Report (NISTIR) 7628 guidelines for smart grid security and the International Electrotechnical Commission (IEC) 63351, Part 9 to identify the life cycle for cryptographic key management, resulting in a vector that assigned to each stakeholder an estimate of their average loss in terms of dollars per day of system

  3. Noiseless Steganography The Key to Covert Communications

    CERN Document Server

    Desoky, Abdelrahman

    2012-01-01

    Among the features that make Noiseless Steganography: The Key to Covert Communications a first of its kind: The first to comprehensively cover Linguistic Steganography The first to comprehensively cover Graph Steganography The first to comprehensively cover Game Steganography Although the goal of steganography is to prevent adversaries from suspecting the existence of covert communications, most books on the subject present outdated steganography approaches that are detectable by human and/or machine examinations. These approaches often fail because they camouflage data as a detectable noise b

  4. Stahlschüssel key to steel

    CERN Document Server

    Wegst, W S

    2016-01-01

    The Key to Steel (Stahlschlüssel/Stahlschluessel) cross reference book will help you to decode / decipher steel designations and find equivalent materials worldwide. The 2016 edition includes more than 70,000 standard designations and trade names from approximately 300 steelmakers and suppliers. Presentation is trilingual: English, French, and German. Materials covered include structural steels, tool steels, valve steels, high temperature steels and alloys, stainless and heat-resisting steels, and more. Standards and designations from 25 countries are cross-referenced.

  5. Data key to quest for quality.

    Science.gov (United States)

    Chang, Florence S; Nielsen, Jon; Macias, Charles

    2013-11-01

    Late-binding data warehousing reduces the time it takes to obtain data needed to make crucial decisions. Late binding refers to when and how tightly data from the source applications are bound to the rules and vocabularies that make it useful. In some cases, data can be seen in real time. In historically paper-driven environments where data-driven decisions may be a new concept, buy-in from clinicians, physicians, and hospital leaders is key to success in using data to improve outcomes.

  6. 5 keys to business analytics program success

    CERN Document Server

    Boyer, John; Green, Brian; Harris, Tracy; Van De Vanter, Kay

    2012-01-01

    With business analytics is becoming increasingly strategic to all types of organizations and with many companies struggling to create a meaningful impact with this emerging technology, this work-based on the combined experience of 10 organizations that display excellence and expertise on the subject-shares the best practices, discusses the management aspects and sociology that drives success, and uncovers the five key aspects behind the success of some of the top business analytics programs in the industry. Readers will learn about numerous topics, including how to create and manage a changing

  7. On the security of a simple three-party key exchange protocol without server's public keys.

    Science.gov (United States)

    Nam, Junghyun; Choo, Kim-Kwang Raymond; Park, Minkyu; Paik, Juryon; Won, Dongho

    2014-01-01

    Authenticated key exchange protocols are of fundamental importance in securing communications and are now extensively deployed for use in various real-world network applications. In this work, we reveal major previously unpublished security vulnerabilities in the password-based authenticated three-party key exchange protocol according to Lee and Hwang (2010): (1) the Lee-Hwang protocol is susceptible to a man-in-the-middle attack and thus fails to achieve implicit key authentication; (2) the protocol cannot protect clients' passwords against an offline dictionary attack; and (3) the indistinguishability-based security of the protocol can be easily broken even in the presence of a passive adversary. We also propose an improved password-based authenticated three-party key exchange protocol that addresses the security vulnerabilities identified in the Lee-Hwang protocol.

  8. User-Centric Key Entropy: Study of Biometric Key Derivation Subject to Spoofing Attacks

    Directory of Open Access Journals (Sweden)

    Lavinia Mihaela Dinca

    2017-02-01

    Full Text Available Biometric data can be used as input for PKI key pair generation. The concept of not saving the private key is very appealing, but the implementation of such a system shouldn’t be rushed because it might prove less secure then current PKI infrastructure. One biometric characteristic can be easily spoofed, so it was believed that multi-modal biometrics would offer more security, because spoofing two or more biometrics would be very hard. This notion, of increased security of multi-modal biometric systems, was disproved for authentication and matching, studies showing that not only multi-modal biometric systems are not more secure, but they introduce additional vulnerabilities. This paper is a study on the implications of spoofing biometric data for retrieving the derived key. We demonstrate that spoofed biometrics can yield the same key, which in turn will lead an attacker to obtain the private key. A practical implementation is proposed using fingerprint and iris as biometrics and the fuzzy extractor for biometric key extraction. Our experiments show what happens when the biometric data is spoofed for both uni-modal systems and multi-modal. In case of multi-modal system tests were performed when spoofing one biometric or both. We provide detailed analysis of every scenario in regard to successful tests and overall key entropy. Our paper defines a biometric PKI scenario and an in depth security analysis for it. The analysis can be viewed as a blueprint for implementations of future similar systems, because it highlights the main security vulnerabilities for bioPKI. The analysis is not constrained to the biometric part of the system, but covers CA security, sensor security, communication interception, RSA encryption vulnerabilities regarding key entropy, and much more.

  9. Key Questions in Marine Megafauna Movement Ecology

    KAUST Repository

    Hays, Graeme C.

    2016-03-12

    It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology. Technical advances make this an exciting time for animal movement studies, with a range of small, reliable data-loggers and transmitters that can record horizontal and vertical movements as well as aspects of physiology and reproductive biology.Forty experts identified key questions in the field of movement ecology.Questions have broad applicability across species, habitats, and spatial scales, and apply to animals in both marine and terrestrial habitats as well as both vertebrates and invertebrates, including birds, mammals, reptiles, fish, insects, and plankton. © 2016 Elsevier Ltd.

  10. SARS: Key factors in crisis management.

    Science.gov (United States)

    Tseng, Hsin-Chao; Chen, Thai-Form; Chou, Shieu-Ming

    2005-03-01

    This study was conducted at a single hospital selected in Taipei during the SARS (Severe Acute Respiratory Syndrome) outbreak from March to July, 2003 in Taiwan. During this period of time, 104 SARS patients were admitted to the hospital. There were no negative reports related to the selected hospital despite its being located right in the center of an area struck by the epidemic. The purpose of this study was to identify the key factors enabling the hospital to survive SARS unscathed. Data were collected from in-depth interviews with the nursing directors and nursing managers of the SARS units, along with a review of relevant hospital documents. The five key elements identified as survival factors during this SARS crisis are as follows: 1. good control of timing for crisis management, 2. careful decision-making, 3. thorough implementation, 4. effective communication, and 5. trust between management and employees. The results of this study reconfirmed the selected hospital as a model for good crisis management during the SARS epidemic.

  11. KEY FACTORS IN MARKETING FOCUSED SERVICES BUSINESSES

    Directory of Open Access Journals (Sweden)

    Doris Yohanna Martínez Castrillón

    2016-07-01

    Full Text Available This article aims to identify the key success factors in the marketing area and describe them as managerial allies for companies that wish to position themselves in the market under a good sustainable performance , for it has been consulted theoretical references of Marketing as a management partner with collection and integration of data. Methodologically, it is located within the type of descriptive research field, with a design of transactional non-experimental, with an intentional non-probabilistic stratified sample of four reporting units. The findings established fifteen (15 points of influence called "key success factors (FCE in the area of marketing, and managerial allies of service companies in the security, surveillance and protection sector in industrial, commercial and residential sectors. Finally, it is intended that the actions of marketing service companies should focus to the welfare of both the organization, such as users, both in the environment, and economic, social and technological, characterized by ethics, sustainable development and transparency to respond appropriately.

  12. Network topology reveals key cardiovascular disease genes.

    Directory of Open Access Journals (Sweden)

    Anida Sarajlić

    Full Text Available The structure of protein-protein interaction (PPI networks has already been successfully used as a source of new biological information. Even though cardiovascular diseases (CVDs are a major global cause of death, many CVD genes still await discovery. We explore ways to utilize the structure of the human PPI network to find important genes for CVDs that should be targeted by drugs. The hope is to use the properties of such important genes to predict new ones, which would in turn improve a choice of therapy. We propose a methodology that examines the PPI network wiring around genes involved in CVDs. We use the methodology to identify a subset of CVD-related genes that are statistically significantly enriched in drug targets and "driver genes." We seek such genes, since driver genes have been proposed to drive onset and progression of a disease. Our identified subset of CVD genes has a large overlap with the Core Diseasome, which has been postulated to be the key to disease formation and hence should be the primary object of therapeutic intervention. This indicates that our methodology identifies "key" genes responsible for CVDs. Thus, we use it to predict new CVD genes and we validate over 70% of our predictions in the literature. Finally, we show that our predicted genes are functionally similar to currently known CVD drug targets, which confirms a potential utility of our methodology towards improving therapy for CVDs.

  13. Fully device-independent quantum key distribution.

    Science.gov (United States)

    Vazirani, Umesh; Vidick, Thomas

    2014-10-03

    Quantum cryptography promises levels of security that are impossible to replicate in a classical world. Can this security be guaranteed even when the quantum devices on which the protocol relies are untrusted? This central question dates back to the early 1990s when the challenge of achieving device-independent quantum key distribution was first formulated. We answer this challenge by rigorously proving the device-independent security of a slight variant of Ekert's original entanglement-based protocol against the most general (coherent) attacks. The resulting protocol is robust: While assuming only that the devices can be modeled by the laws of quantum mechanics and are spatially isolated from each other and from any adversary's laboratory, it achieves a linear key rate and tolerates a constant noise rate in the devices. In particular, the devices may have quantum memory and share arbitrary quantum correlations with the eavesdropper. The proof of security is based on a new quantitative understanding of the monogamous nature of quantum correlations in the context of a multiparty protocol.

  14. Key attributes of expert NRL referees.

    Science.gov (United States)

    Morris, Gavin; O'Connor, Donna

    2017-05-01

    Experiential knowledge of elite National Rugby League (NRL) referees was investigated to determine the key attributes contributing to expert officiating performance. Fourteen current first-grade NRL referees were asked to identify the key attributes they believed contributed to their expert refereeing performance. The modified Delphi method involved a 3-round process of an initial semi-structured interview followed by 2 questionnaires to reach consensus of opinion. The data revealed 25 attributes that were rated as most important that underpin expert NRL refereeing performance. Results illustrate the significance of the cognitive category, with the top 6 ranked attributes all cognitive skills. Of these, the referees ranked decision-making accuracy as the most important attribute, followed by reading the game, communication, game understanding, game management and knowledge of the rules. Player rapport, positioning and teamwork were the top ranked game skill attributes underpinning performance excellence. Expert referees also highlighted a number of psychological attributes (e.g., concentration, composure and mental toughness) that were significant to performance. There were only 2 physiological attributes (fitness, aerobic endurance) that were identified as significant to elite officiating performance. In summary, expert consensus was attained which successfully provided a hierarchy of the most significant attributes of expert NRL refereeing performance.

  15. Key business restart drivers in Slovakia

    Directory of Open Access Journals (Sweden)

    Anna Pilková

    2013-01-01

    Full Text Available The phenomenon of business restart, also referred to as second chance, proved to be an integral part of entrepreneurial dynamics. Considering the high level of individual entrepreneurial activity (14.2% in 2011, 10.2% in 2012 accompanied with high discontinuance rate in Slovakia (7.0% in 2011, 4.7% in 20121, it is important to further investigate key factors which influence business restart in our country. These findings could unveil what helps to preserve the current entrepreneurial activity, which is besides producing more new entrepreneurs another option to secure self-employment and job creation through individual business activities, with positive impact on economic growth in the country.The main aim of our paper is to analyze the issue of business restart in Slovakia through dynamics measured on individual level and to identify the key drivers of restart activity. These findings represent a good information basis for policy makers helping them better understand the characteristics of business restart phenomenon and develop relevant entrepreneurship policies, as well as for further entrepreneurship research.Our research is primarily based on Slovak Global entrepreneurship Monitor (GEM 2011 and 2012 individual level data. We applied binominal logistic regression to analyze relationships between business restart and its potential drivers.

  16. The locks and keys to industrial biotechnology.

    Science.gov (United States)

    Wohlgemuth, Roland

    2009-04-01

    The sustainable use of resources by Nature to synthesize the required products at the right place, when they are needed, continues to be the role model for total synthesis and production in general. The combination of molecular and engineering science and technology in the biotechnological approach needs no protecting groups at all and has therefore been established for numerous large-scale routes to both natural and synthetic products in industry. The use of biobased raw materials for chemical synthesis, and the economy of molecular transformations like atom economy and step economy are of growing importance. As safety, health and environmental issues are key drivers for process improvements in the chemical industry, the development of biocatalytic reactions or pathways replacing hazardous reagents is a major focus. The integration of the biocatalytic reaction and downstream processing with product isolation has led to a variety of in situ product recovery techniques and has found numerous successful applications. With the growing collection of biocatalytic reactions, the retrosynthetic thinking can be applied to biocatalysis as well. The introduction of biocatalytic reactions is uniquely suited to cost reductions and higher quality products, as well as to more sustainable processes. The transfer of Nature's simple and robust sensing and control principles as well as its reaction and separation organization into useful technical systems can be applied to different fermentations, biotransformations and downstream processes. Biocatalyst and pathway discovery and development is the key towards new synthetic transformations in industrial biotechnology.

  17. Stakeholders' perception of key performance indicators (KPIs) of public-private partnership (PPP) projects

    OpenAIRE

    Olabode Emmanuel Ogunsanmi

    2013-01-01

    The study investigates key performance indicators (KPIs) that could improve performance of public-private partnership (PPP) projects in Nigeria. The study objectives include a comparison of stakeholders’ perception on KPIs and to investigate if significant difference exists between stakeholders’ perceptions on most KPIs. A structured questionnaire was used to collect information from various respondents who were recently involved in PPP projects. Random sampling technique was used to select f...

  18. Analysis of Random Segment Errors on Coronagraph Performance

    Science.gov (United States)

    Stahl, Mark T.; Stahl, H. Philip; Shaklan, Stuart B.; N'Diaye, Mamadou

    2016-01-01

    At 2015 SPIE O&P we presented "Preliminary Analysis of Random Segment Errors on Coronagraph Performance" Key Findings: Contrast Leakage for 4thorder Sinc2(X) coronagraph is 10X more sensitive to random segment piston than random tip/tilt, Fewer segments (i.e. 1 ring) or very many segments (> 16 rings) has less contrast leakage as a function of piston or tip/tilt than an aperture with 2 to 4 rings of segments. Revised Findings: Piston is only 2.5X more sensitive than Tip/Tilt

  19. Quantum Random Number Generation on a Mobile Phone

    Directory of Open Access Journals (Sweden)

    Bruno Sanguinetti

    2014-09-01

    Full Text Available Quantum random number generators (QRNGs can significantly improve the security of cryptographic protocols by ensuring that generated keys cannot be predicted. However, the cost, size, and power requirements of current Quantum random number generators have prevented them from becoming widespread. In the meantime, the quality of the cameras integrated in mobile telephones has improved significantly so that now they are sensitive to light at the few-photon level. We demonstrate how these can be used to generate random numbers of a quantum origin.

  20. Key Account Management Practices in Home Appliance Industry of Pakistan

    OpenAIRE

    Razzaq, Abdul

    2007-01-01

    Abstract Key account management (KAM) is considered as an important marketing trend since last few years. The purpose of this thesis orients to the discussion about key account management practices from selling company’s perspectives in home appliance market of Pakistan. The study is carried through with four steps: elements of key accounts management, identification and analysis of key accounts, strategies for key accounts, and operational level capabilities used in key account management fo...

  1. Key determinants of students’ mobile phone choice

    Directory of Open Access Journals (Sweden)

    Michael Dzigbordi Dzandu

    2014-08-01

    Full Text Available As there is still only limited research on students brand choice of mobile phones, the focus of this study was to ascertain drivers of tertiary students’ mobile phone brand choice in Ghana. Using a structured questionnaire, data was collected from a random sample of 840 students from three tertiary institutions in Ghana. The study revealed that the most significant determinant of the students brand choice of mobile phones was perceived quality (p0.05. The study concludes that in spite of their economic handicaps, students brand choice was driven most by perceived quality and not price. Recommendations on how information technology manufacturers’ particularly mobile phone companies and marketers can exploit these drivers to sustain and improve their brand equity among students have been made.

  2. Coded Random Access

    DEFF Research Database (Denmark)

    Paolini, Enrico; Stefanovic, Cedomir; Liva, Gianluigi

    2015-01-01

    , in which the structure of the access protocol can be mapped to a structure of an erasure-correcting code defined on graph. This opens the possibility to use coding theory and tools for designing efficient random access protocols, offering markedly better performance than ALOHA. Several instances of coded......The rise of machine-to-machine communications has rekindled the interest in random access protocols as a support for a massive number of uncoordinatedly transmitting devices. The legacy ALOHA approach is developed under a collision model, where slots containing collided packets are considered...... as waste. However, if the common receiver (e.g., base station) is capable to store the collision slots and use them in a transmission recovery process based on successive interference cancellation, the design space for access protocols is radically expanded. We present the paradigm of coded random access...

  3. Effective trapping of random walkers in complex networks.

    Science.gov (United States)

    Hwang, S; Lee, D-S; Kahng, B

    2012-04-01

    Exploring the World Wide Web has become one of the key issues in information science, specifically in view of its application to the PageRank-like algorithms used in search engines. The random walk approach has been employed to study such a problem. The probability of return to the origin (RTO) of random walks is inversely related to how information can be accessed during random surfing. We find analytically that the RTO probability for a given starting node shows a crossover from a slow to a fast decay behavior with time and the crossover time increases with the degree of the starting node. We remark that the RTO probability becomes almost constant in the early-time regime as the degree exponent approaches two. This result indicates that a random surfer can be effectively trapped at the hub and supports the necessity of the random jump strategy empirically used in the Google's search engine.

  4. Key Developments in Ionic Liquid Crystals

    Directory of Open Access Journals (Sweden)

    Alexandra Alvarez Fernandez

    2016-05-01

    Full Text Available Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?

  5. Secure Key Management in the Cloud

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Jakobsen, Thomas Pelle; Nielsen, Jesper Buus

    2013-01-01

    information such as cryptographic keys. Applications like this include many cases where secure multiparty computation is outsourced to the cloud, and in particular a number of online auctions and benchmark computations with confidential inputs. We consider fully autonomous servers that switch between online......We consider applications involving a number of servers in the cloud that go through a sequence of online periods where the servers communicate, separated by offline periods where the servers are idle. During the offline periods, we assume that the servers need to securely store sensitive...... and offline periods without communicating with anyone from outside the cloud, and semi-autonomous servers that need a limited kind of assistance from outside the cloud when doing the transition. We study the levels of security one can – and cannot – obtain in this model, propose light-weight protocols...

  6. Low-Power Public Key Cryptography

    Energy Technology Data Exchange (ETDEWEB)

    BEAVER,CHERYL L.; DRAELOS,TIMOTHY J.; HAMILTON,VICTORIA A.; SCHROEPPEL,RICHARD C.; GONZALES,RITA A.; MILLER,RUSSELL D.; THOMAS,EDWARD V.

    2000-11-01

    This report presents research on public key, digital signature algorithms for cryptographic authentication in low-powered, low-computation environments. We assessed algorithms for suitability based on their signature size, and computation and storage requirements. We evaluated a variety of general purpose and special purpose computing platforms to address issues such as memory, voltage requirements, and special functionality for low-powered applications. In addition, we examined custom design platforms. We found that a custom design offers the most flexibility and can be optimized for specific algorithms. Furthermore, the entire platform can exist on a single Application Specific Integrated Circuit (ASIC) or can be integrated with commercially available components to produce the desired computing platform.

  7. Key Questions in Marine Megafauna Movement Ecology.

    Science.gov (United States)

    Hays, Graeme C; Ferreira, Luciana C; Sequeira, Ana M M; Meekan, Mark G; Duarte, Carlos M; Bailey, Helen; Bailleul, Fred; Bowen, W Don; Caley, M Julian; Costa, Daniel P; Eguíluz, Victor M; Fossette, Sabrina; Friedlaender, Ari S; Gales, Nick; Gleiss, Adrian C; Gunn, John; Harcourt, Rob; Hazen, Elliott L; Heithaus, Michael R; Heupel, Michelle; Holland, Kim; Horning, Markus; Jonsen, Ian; Kooyman, Gerald L; Lowe, Christopher G; Madsen, Peter T; Marsh, Helene; Phillips, Richard A; Righton, David; Ropert-Coudert, Yan; Sato, Katsufumi; Shaffer, Scott A; Simpfendorfer, Colin A; Sims, David W; Skomal, Gregory; Takahashi, Akinori; Trathan, Philip N; Wikelski, Martin; Womble, Jamie N; Thums, Michele

    2016-06-01

    It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Keys through ARQ: Theory and Practice

    CERN Document Server

    Abdallah, Yara; Youssef, Moustafa; Sultan, Ahmed; Gamal, Hesham El

    2010-01-01

    This paper develops a novel framework for sharing secret keys using the Automatic Repeat reQuest (ARQ) protocol. We first characterize the underlying information theoretic limits, under different assumptions on the channel spatial and temporal correlation function. Our analysis reveals a novel role of "dumb antennas" in overcoming the negative impact of spatial correlation on the achievable secrecy rates. We further develop an adaptive rate allocation policy, which achieves higher secrecy rates in temporally correlated channels, and explicit constructions for ARQ secrecy coding that enjoy low implementation complexity. Building on this theoretical foundation, we propose a unified framework for ARQ-based secrecy in Wi-Fi networks. By exploiting the existing ARQ mechanism in the IEEE 802.11 standard, we develop security overlays that offer strong security guarantees at the expense of only minor modifications in the medium access layer. Our numerical results establish the achievability of non-zero secrecy rates ...

  9. Partially Turboelectric Aircraft Drive Key Performance Parameters

    Science.gov (United States)

    Jansen, Ralph H.; Duffy, Kirsten P.; Brown, Gerald V.

    2017-01-01

    The purpose of this paper is to propose electric drive specific power, electric drive efficiency, and electrical propulsion fraction as the key performance parameters for a partially turboelectric aircraft power system and to investigate their impact on the overall aircraft performance. Breguet range equations for a base conventional turbofan aircraft and a partially turboelectric aircraft are found. The benefits and costs that may result from the partially turboelectric system are enumerated. A break even analysis is conducted to find the minimum allowable electric drive specific power and efficiency, for a given electrical propulsion fraction, that can preserve the range, fuel weight, operating empty weight, and payload weight of the conventional aircraft. Current and future power system performance is compared to the required performance to determine the potential benefit.

  10. Key indicators for organizational performance measurement

    Directory of Open Access Journals (Sweden)

    Firoozeh Haddadi

    2014-09-01

    Full Text Available Each organization for assessing the amount of utility and desirability of their activities, especially in complex and dynamic environments, requires determining and ranking the vital performance indicators. Indicators provide essential links among strategy, execution and ultimate value creation. The aim of this paper is to develop a framework, which identifies and prioritizes Key Performance Indicators (KPIs that a company should focus on them to define and measure progress towards organizational objectives. For this purpose, an applied research was conducted in 2013 in an Iranian telecommunication company. We first determined the objectives of the company with respect to four perspectives of BSC (Balanced Scorecard framework. Next, performance indicators were listed and paired wise comparisons were accomplished by company's high-ranked employees through standard Analytic Hierarchy Process (AHP questionnaires. This helped us establish the weight of each indicator and to rank them, accordingly.

  11. Altruity: Key to the Fight Against Poverty

    Directory of Open Access Journals (Sweden)

    Philippe Kourilsky

    2012-06-01

    Full Text Available This paper presents the concept of altruity and illustrates its philosophical and practical importance in the fight against poverty. Altruity –a highly specific form of rational altruism– is the duty that comes with freedom. The individual duty of altruity is the necessary counterpart of the right to individual freedoms. It is, by its very nature, distinct from (though complementary to generosity, and devoid of any expectation of reciprocity (while not excluding it. The idea of altruity is the cornerstone of a theory of individual responsibility, and of a theory of justice, which provide a conceptual framework for the struggle against poverty. And because it is only meaningful if implemented with a pre-defined method, it also provides a framework for action, as the FACTS Initiative has shown. Altruity thus emerges as one of the keys to the fight against poverty.

  12. Key issues in space nuclear power

    Science.gov (United States)

    Brandhorst, Henry W.

    1991-01-01

    The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. Key to the success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience has been made. These needs fall into three broad categories: survival, self sufficiency, and industrialization. The cost of delivering payloads to orbital locations from LEO to Mars has been determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options has been made. These goals are largely dependent upon orbital location and energy storage needs. Finally the cost of present space power systems has been determined and projections made for future systems.

  13. Biocatalysis--key to sustainable industrial chemistry.

    Science.gov (United States)

    Wohlgemuth, Roland

    2010-12-01

    The ongoing trends to process improvements, cost reductions and increasing quality, safety, health and environment requirements of industrial chemical transformations have strengthened the translation of global biocatalysis research work into industrial applications. One focus has been on biocatalytic single-step reactions with one or two substrates, the identification of bottlenecks and molecular as well as engineering approaches to overcome these bottlenecks. Robust industrial procedures have been established along classes of biocatalytic single-step reactions. Multi-step reactions and multi-component reactions (MCRs) enable a bottom-up approach with biocatalytic reactions working together in one compartment and recations hindering each other within different compartments or steps. The understanding of the catalytic functions of known and new enzymes is key for the development of new sustainable chemical transformations. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Chip-based quantum key distribution

    Science.gov (United States)

    Sibson, P.; Erven, C.; Godfrey, M.; Miki, S.; Yamashita, T.; Fujiwara, M.; Sasaki, M.; Terai, H.; Tanner, M. G.; Natarajan, C. M.; Hadfield, R. H.; O'Brien, J. L.; Thompson, M. G.

    2017-01-01

    Improvement in secure transmission of information is an urgent need for governments, corporations and individuals. Quantum key distribution (QKD) promises security based on the laws of physics and has rapidly grown from proof-of-concept to robust demonstrations and deployment of commercial systems. Despite these advances, QKD has not been widely adopted, and large-scale deployment will likely require chip-based devices for improved performance, miniaturization and enhanced functionality. Here we report low error rate, GHz clocked QKD operation of an indium phosphide transmitter chip and a silicon oxynitride receiver chip—monolithically integrated devices using components and manufacturing processes from the telecommunications industry. We use the reconfigurability of these devices to demonstrate three prominent QKD protocols—BB84, Coherent One Way and Differential Phase Shift—with performance comparable to state-of-the-art. These devices, when combined with integrated single photon detectors, pave the way for successfully integrating QKD into future telecommunications networks. PMID:28181489

  15. Athena Wide Field Imager key science drivers

    Science.gov (United States)

    Rau, Arne; Nandra, Kirpal; Aird, James; Comastri, Andrea; Dauser, Thomas; Merloni, Andrea; Pratt, Gabriel W.; Reiprich, Thomas H.; Fabian, Andy C.; Georgakakis, Antonis; Güdel, Manuel; RóŻańska, Agata; Sanders, Jeremy S.; Sasaki, Manami; Vaughan, Simon; Wilms, Jörn; Meidinger, Norbert

    2016-07-01

    The Wide Field Imager (WFI) is one of two instruments for the Advanced Telescope for High-ENergy Astrophysics (Athena). In this paper we summarise three of the many key science objectives for the WFI { the formation and growth of supermassive black holes, non-gravitational heating in clusters of galaxies, and spin measurements of stellar mass black holes { and describe their translation into the science requirements and ultimately instrument requirements. The WFI will be designed to provide excellent point source sensitivity and grasp for performing wide area surveys, surface brightness sensitivity, survey power, and absolute temperature and density calibration for in-depth studies of the outskirts of nearby clusters of galaxies and very good high-count rate capability, throughput, and low pile-up, paired with very good spectral resolution, for detailed explorations of bright Galactic compact objects.

  16. Inherited thrombophilia: key points for genetic counseling.

    Science.gov (United States)

    Varga, Elizabeth

    2007-06-01

    With the evolution of medical genetics to focus on highly prevalent, multifactorial conditions, it is inevitable that genetic counselors will be called upon to participate in the evaluation and counseling of individuals with inherited thrombophilia. The purpose of this review is to educate the genetic counselor on key issues related to risk assessment and genetic counseling for hereditary thrombophilia. The information contained in this document is derived from an extensive review of the literature, as well as the author's personal expertise. Upon completion of this review, the genetic counselor will be able to: a) describe inherited and acquired risk factors for thrombosis, b) collect and interpret personal and family histories to assess risk related to hereditary thrombophilia, c) discuss the potential advantages and disadvantages of thrombophilia testing, including psychosocial aspects and implications for medical management, and d) identify educational and support resources for patients and families.

  17. Chip-based quantum key distribution.

    Science.gov (United States)

    Sibson, P; Erven, C; Godfrey, M; Miki, S; Yamashita, T; Fujiwara, M; Sasaki, M; Terai, H; Tanner, M G; Natarajan, C M; Hadfield, R H; O'Brien, J L; Thompson, M G

    2017-02-09

    Improvement in secure transmission of information is an urgent need for governments, corporations and individuals. Quantum key distribution (QKD) promises security based on the laws of physics and has rapidly grown from proof-of-concept to robust demonstrations and deployment of commercial systems. Despite these advances, QKD has not been widely adopted, and large-scale deployment will likely require chip-based devices for improved performance, miniaturization and enhanced functionality. Here we report low error rate, GHz clocked QKD operation of an indium phosphide transmitter chip and a silicon oxynitride receiver chip-monolithically integrated devices using components and manufacturing processes from the telecommunications industry. We use the reconfigurability of these devices to demonstrate three prominent QKD protocols-BB84, Coherent One Way and Differential Phase Shift-with performance comparable to state-of-the-art. These devices, when combined with integrated single photon detectors, pave the way for successfully integrating QKD into future telecommunications networks.

  18. Security of practical quantum key distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Nitin

    2015-02-24

    This thesis deals with practical security aspects of quantum key distribution (QKD) systems. At the heart of the theoretical model of any QKD system lies a quantum-mechanical security proof that guarantees perfect secrecy of messages - based on certain assumptions. However, in practice, deviations between the theoretical model and the physical implementation could be exploited by an attacker to break the security of the system. These deviations may arise from technical limitations and operational imperfections in the physical implementation and/or unrealistic assumptions and insufficient constraints in the theoretical model. In this thesis, we experimentally investigate in depth several such deviations. We demonstrate the resultant vulnerabilities via proof-of-principle attacks on a commercial QKD system from ID Quantique. We also propose countermeasures against the investigated loopholes to secure both existing and future QKD implementations.

  19. BENCHMARKING - PRACTICAL TOOLS IDENTIFY KEY SUCCESS FACTORS

    Directory of Open Access Journals (Sweden)

    Olga Ju. Malinina

    2016-01-01

    Full Text Available The article gives a practical example of the application of benchmarking techniques. The object of study selected fashion store Company «HLB & M Hennes & Mauritz», located in the shopping center «Gallery», Krasnodar. Hennes & Mauritz. The purpose of this article is to identify the best ways to develop a fashionable brand clothing store Hennes & Mauritz on the basis of benchmarking techniques. On the basis of conducted market research is a comparative analysis of the data from different perspectives. The result of the author’s study is a generalization of the ndings, the development of the key success factors that will allow to plan a successful trading activities in the future, based on the best experience of competitors.

  20. Key questions to consider in stalking cases.

    Science.gov (United States)

    Sheridan, Lorraine; Roberts, Karl

    2011-01-01

    Stalkers can inflict severe injury upon and have been known to kill their victims. Based on the detailed responses of 1,565 stalking victims, a set of key questions was produced with the aim of increasing the opportunities of police officers to identify potentially dangerous stalkers. Despite marked methodological differences and the inclusion of a large number of variables, regression analyses for significant correlates for physical assault per se and for severe violence largely reflected the results of earlier works. For severe violence (n=136), the most important correlate was a high level of victim fear, suggesting that victims are adept at assessing their own risk of stalker violence. The set of 11 questions performed well on preliminary tests and is presented here. Copyright © 2011 John Wiley & Sons, Ltd.

  1. Independence day explosion on lovers key.

    Science.gov (United States)

    Harding, Brett A; Wolf, Barbara C

    2007-09-01

    The display of fireworks is a popular holiday celebration in the United States. Because injuries due to recreational fireworks-related explosions among private consumers are relatively common, the sale of fireworks is regulated by the federal government and is also limited by state and local laws. In contrast, because fireworks display companies are under tight safety regulations, explosions in the professional pyrotechnics industry are uncommon occurrences, and the literature contains rare reports of injuries and fatalities resulting from such explosions. We report the 2003 Fourth of July commercial fireworks explosion on Lovers Key in southwest Florida that resulted in five fatalities. Events occurring during the investigation of the scene of this explosion illustrate the unique considerations and hazards for medicolegal death investigators, law enforcement and other investigative agencies. Additionally, this case demonstrates unusual aspects of the postmortem examinations performed on victims of fireworks-related incidents.

  2. Key comparison of liquid density standards

    Science.gov (United States)

    Buchner, Christian; Zelenka, Zoltan; Kajastie, Heikki; Madec, Tanguy; Wolf, Henning; Vámossy, Csilla; Lorefice, Salvatore; Garberg, Torgunn; Lenard, Elżbieta; Spohr, Isabel; Mares, Gabriela; Spurný, Robert; Lumbreras, Angel; Medina, Nieves; Y Akçadağ, Ümit; Perkin, Michael

    2015-01-01

    Hydrostatic density determination for liquids is mainly performed by laboratories to provide means for calibrating liquid density measuring instruments such as oscillation-type density meters. From 2002 to 2005 the CIPM key comparison CCM.D-K2 'comparison of liquid density standards' was carried out piloted by the PTB. The aim was to compare the results of the density determination by the participating laboratories to support entries to the CMC tables in this sub-field. To provide further laboratories the possibility to support their entries to the CMC tables at the meeting of the EUROMET Working Group on Density in 2007 this comparison was agreed on. BEV (Austria) organized the comparison supported by the PTB (Germany). For the comparison samples of pentadecane, water, tetrachloroethylene and of an oil of high viscosity were measured in the temperature range from 5 °C to 60 °C at atmospheric pressure by hydrostatic weighing. The measurements were completed in 2008. The reference values of the first reports based on the draft of the CCM.D-K2. After the official publication of the CCM.D-K2 the reference values were recalculated and the report was finalised in 2015. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  3. Several Key Features of Marriage in Kosovo

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Hamdi Podvorica

    2014-02-01

    Full Text Available In this paper titled “Several key features of marriage in Kosovo”, I have made efforts to address the matrimony, as an important societal and legal concept, in the light of positive law in Kosovo. In short terms, I have addressed the historical development of marriage in general, from the period of promiscuity until today, and I have emphasized key features of marriage in various time periods, only to comprehend better the ways of development of marriage in time and space. A special emphasis is put on the essential (material conditions of marital union. The paper provides sufficient reasons for which the positive law in Kosovo has provided on the free expression of will of spouses; opposite sexes; the age threshold; entry into matrimony before a competent state authority, and under a procedure provided by law, as substantial conditions for entering a valid matrimony. Sufficient room is allowed also for the treatment of consequences and responsibilities of various entities if marriage is developed without obeying substantial conditions as provided by law. Due to the nature of the paper, formal conditions for entering matrimony are not addressed. The right to enter marriage and establish a family under provided legal conditions is guaranteed to every Kosovo citizen, as a substantial right. The marriage is a basic cell of the family, and as such, it is protected by the state and society. Apart from normative and sociological methods, I have also used the historical method in developing this paper. The purpose was to discover several marriage features, which used to exist, and do not anymore, and also underline some new features, which nowadays form the pillars of the marriage.

  4. Coral recruitment patterns in the Florida Keys

    Directory of Open Access Journals (Sweden)

    Alison L Moulding

    2005-05-01

    Full Text Available This study examines scleractinian zooxanthellate coral recruitment patterns in the Florida Keys to determine if differences in density or community composition exist between regions.From July to September 2002,nine patch reefs,three in each of the upper,middle and lower Keys,were surveyed for coral recruits (colonies Se examina los patrones de reclutamiento de corales escleractinios zooxantelados en los Cayos de la Florida para determinar si existen diferencias en densidad o composición de la comunidad en diferentes regiones.Entre julio y setiembre del 2002,se inventariaron los reclutas (colonias de <5 cm de diámetrousando cuadrantes y transectos al azar en nueve "parches "arrecifales:tres en los cayos del norte,tres en los del medio y tres en los del sur.Todos fueron numerados,medidos e identificados a nivel de género.Se observaron catorce géneros:entre cinco y 13 por sitio.Las densidades tuvieron un ámbito de 6.29 ±1.92 (promedio ±DSa 39.08 ±4.53 reclutas m-2, con diferencias estadísticamente significativas entre sitios y entre regiones.La densidad de reclutas en los cayos del norte fue significativamente menor que en los demás.Los cayos del norte tuvieron menor diversidad y diferente distribución de tamaños de reclutas.La mayoría de los reclutas eran de especies de escleractinios no masivas,las cuales contribuyen relativamente poco al proceso de crecimiento del arrecife,algo parecido a lo informado en otros estudios. Se encontraron menos reclutas de especies masivas en los cayos del norte.El patrón de reclutamiento en los arrecifes de los cayos del norte podría inhibir potencialmente la recuperación tras "impactos "y perturbaciones.

  5. Lidars: a key component of urban biodefense.

    Science.gov (United States)

    Mayor, Shane D; Benda, Paul; Murata, Christina E; Danzig, Richard J

    2008-03-01

    A biological aerosol attack in a city could infect tens of thousands of people. In the absence of announcements by the attacker or detection by present point detection systems, victims would be unaware of their exposure prior to developing symptoms. Since infections are most effectively countered before the onset of symptoms, detection technologies that provide early awareness of an attack should be given high priority. Current biological point detection (BPD) systems collect environmental air samples and then analyze them in laboratories so as to permit detection within 12-36 hours of an attack. Improvements in the pipeline may reduce this lag time to as little as a few hours. However, BPD systems have inherent weaknesses when used to detect and respond to an aerosol attack. The likelihood of a limited number of BPD systems intercepting an aerosol plume in a vast attack space may be low. Moreover, BPD systems do not provide critical information needed for response, such as the source location, precise time, and geographic reach of an attack. The missing information would invaluably guide prophylaxis distribution, identification of contaminated areas, and criminal apprehension. This article describes how lidars used for real-time observation of aerosol plumes could complement BPD systems by providing fine-scale spatial and temporal information. A lidar system also could be used to corroborate positive BPD system results, to improve reaction to positive results, and/or to provide an independent basis for low-regret protective steps. Lidar systems can resolve key biodefense challenges, and this article describes three compatible concepts of operations. Leveraging lessons from a lidar system now operating at the Pentagon, a test of an expanded lidar network would provide immediate protection for key Washington, DC, assets, demonstrate the synergy of BPD systems and lidars, and provide a test bed for research to improve lidar's shortcomings.

  6. A discrete fractional random transform

    OpenAIRE

    Liu, Zhengjun; Zhao, Haifa; Liu, Shutian

    2006-01-01

    We propose a discrete fractional random transform based on a generalization of the discrete fractional Fourier transform with an intrinsic randomness. Such discrete fractional random transform inheres excellent mathematical properties of the fractional Fourier transform along with some fantastic features of its own. As a primary application, the discrete fractional random transform has been used for image encryption and decryption.

  7. [Key aspects in interpreting clinical trials in radiology].

    Science.gov (United States)

    Díaz Gómez, L; García Villar, C; Seguro Fernández, Á

    2015-01-01

    A clinical trial is an experimental study to evaluate the efficacy and safety of a treatment or diagnostic technique in human beings. To ensure the methodological quality of a clinical trial and the validity of its results, various checklists have been elaborated to identify biases that could invalidate its conclusions. This article focuses on the points we need to consider in the critical evaluation of a clinical trial. We can usually find this information in the "materials and methods" and "results" sections of articles. Randomization, follow-up (or analysis of losses), blinding, and equivalence between groups (apart from the intervention itself) are some key aspects related to design. In the "results" section, we need to consider what measures of clinical efficacy were used (relative risk, odds ratio, or number needed to treat, among others) and the precision of the results (confidence intervals). Once we have confirmed that the clinical trial fulfills these criteria, we need to determine whether the results can be applied in our environment and whether the benefits obtained justify the risks and costs involved. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  8. Chaotic Image Encryption Based on Running-Key Related to Plaintext

    Directory of Open Access Journals (Sweden)

    Cao Guanghui

    2014-01-01

    Full Text Available In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.

  9. Enhanced smartcard-based password-authenticated key agreement using extended chaotic maps.

    Science.gov (United States)

    Lee, Tian-Fu; Hsiao, Chia-Hung; Hwang, Shi-Han; Lin, Tsung-Hung

    2017-01-01

    A smartcard based password-authenticated key agreement scheme enables a legal user to log in to a remote authentication server and access remote services through public networks using a weak password and a smart card. Lin recently presented an improved chaotic maps-based password-authenticated key agreement scheme that used smartcards to eliminate the weaknesses of the scheme of Guo and Chang, which does not provide strong user anonymity and violates session key security. However, the improved scheme of Lin does not exhibit the freshness property and the validity of messages so it still fails to withstand denial-of-service and privileged-insider attacks. Additionally, a single malicious participant can predetermine the session key such that the improved scheme does not exhibit the contributory property of key agreements. This investigation discusses these weaknesses and proposes an enhanced smartcard-based password-authenticated key agreement scheme that utilizes extended chaotic maps. The session security of this enhanced scheme is based on the extended chaotic map-based Diffie-Hellman problem, and is proven in the real-or-random and the sequence of games models. Moreover, the enhanced scheme ensures the freshness of communicating messages by appending timestamps, and thereby avoids the weaknesses in previous schemes.

  10. Securing Metering Infrastructure of Smart Grid: A Machine Learning and Localization Based Key Management Approach

    Directory of Open Access Journals (Sweden)

    Imtiaz Parvez

    2016-08-01

    Full Text Available In smart cities, advanced metering infrastructure (AMI of the smart grid facilitates automated metering, control and monitoring of power distribution by employing a wireless network. Due to this wireless nature of communication, there exist potential threats to the data privacy in AMI. Decoding the energy consumption reading, injecting false data/command signals and jamming the networks are some hazardous measures against this technology. Since a smart meter possesses limited memory and computational capability, AMI demands a light, but robust security scheme. In this paper, we propose a localization-based key management system for meter data encryption. Data are encrypted by the key associated with the coordinate of the meter and a random key index. The encryption keys are managed and distributed by a trusted third party (TTP. Localization of the meter is proposed by a method based on received signal strength (RSS using the maximum likelihood estimator (MLE. The received packets are decrypted at the control center with the key mapped with the key index and the meter’s coordinates. Additionally, we propose the k-nearest neighbors (kNN algorithm for node/meter authentication, capitalizing further on data transmission security. Finally, we evaluate the security strength of a data packet numerically for our method.

  11. Password-only authenticated three-party key exchange with provable security in the standard model.

    Science.gov (United States)

    Nam, Junghyun; Choo, Kim-Kwang Raymond; Kim, Junghwan; Kang, Hyun-Kyu; Kim, Jinsoo; Paik, Juryon; Won, Dongho

    2014-01-01

    Protocols for password-only authenticated key exchange (PAKE) in the three-party setting allow two clients registered with the same authentication server to derive a common secret key from their individual password shared with the server. Existing three-party PAKE protocols were proven secure under the assumption of the existence of random oracles or in a model that does not consider insider attacks. Therefore, these protocols may turn out to be insecure when the random oracle is instantiated with a particular hash function or an insider attack is mounted against the partner client. The contribution of this paper is to present the first three-party PAKE protocol whose security is proven without any idealized assumptions in a model that captures insider attacks. The proof model we use is a variant of the indistinguishability-based model of Bellare, Pointcheval, and Rogaway (2000), which is one of the most widely accepted models for security analysis of password-based key exchange protocols. We demonstrated that our protocol achieves not only the typical indistinguishability-based security of session keys but also the password security against undetectable online dictionary attacks.

  12. Password-Only Authenticated Three-Party Key Exchange with Provable Security in the Standard Model

    Directory of Open Access Journals (Sweden)

    Junghyun Nam

    2014-01-01

    Full Text Available Protocols for password-only authenticated key exchange (PAKE in the three-party setting allow two clients registered with the same authentication server to derive a common secret key from their individual password shared with the server. Existing three-party PAKE protocols were proven secure under the assumption of the existence of random oracles or in a model that does not consider insider attacks. Therefore, these protocols may turn out to be insecure when the random oracle is instantiated with a particular hash function or an insider attack is mounted against the partner client. The contribution of this paper is to present the first three-party PAKE protocol whose security is proven without any idealized assumptions in a model that captures insider attacks. The proof model we use is a variant of the indistinguishability-based model of Bellare, Pointcheval, and Rogaway (2000, which is one of the most widely accepted models for security analysis of password-based key exchange protocols. We demonstrated that our protocol achieves not only the typical indistinguishability-based security of session keys but also the password security against undetectable online dictionary attacks.

  13. The key stakeholders' opinions regarding university counseling centers: An experience from Iran.

    Science.gov (United States)

    Peykari, Niloofar; Tehrani, Fahimeh Ramezani; Afzali, Hossein Malek; Eftekhari, Monir Baradaran; Djalalinia, Shirin

    2011-09-01

    Student counseling centers are responsible for physical, mental and social health of university students. Therefore, this study was conducted to assess the key stakeholders' opinions on different aspects of the activities performed in these centers. This qualitative study used focus group discussion. Key stakeholders including university students and key informants from nine randomly selected medical universities participated in the study. After data saturation, thematic analysis was conducted. Themes were drawn out through constant comparative method. Based on 243 extracted codes and through comparative analysis, four categories were determined, namely students' need for students counseling centers, successes and limitations of student counseling centers, student counseling services priorities, and suggestions for service promotion. According to stakeholders' opinions, youth participation in needs assessment and priority setting processes in real-based situations leads to better performance of counseling services. Empowering the counselors is another point required for better outcomes. In addition, strategic planning and monitoring, along with evaluation of programs, could promote the provided services.

  14. Practical issues in decoy-state quantum key distribution based on the central limit theorem

    Science.gov (United States)

    Trushechkin, A. S.; Kiktenko, E. O.; Fedorov, A. K.

    2017-08-01

    Decoy-state quantum key distribution (QKD) is a standard tool for long-distance quantum communications. An important issue in this field is processing the decoy-state statistics taking into account statistical fluctuations (or "finite-key effects"). In this work, we propose and analyze an option for decoy statistics processing, which is based on the central limit theorem. We discuss such practical issues as inclusion of the failure probability of the decoy-state statistical estimates in the total failure probability of a QKD protocol and also taking into account the deviations of the binomially distributed random variables used in the estimations from the Gaussian distribution. The results of numerical simulations show that the obtained estimations are quite tight. The proposed technique can be used as a part of post-processing procedures for industrial quantum key distribution systems.

  15. Quantum Key Distribution with High Order Fibonacci-like Orbital Angular Momentum States

    Science.gov (United States)

    Pan, Ziwen; Cai, Jiarui; Wang, Chuan

    2017-08-01

    The coding space in quantum communication could be expanded to high-dimensional space by using orbital angular momentum (OAM) states of photons, as both the capacity of the channel and security are enhanced. Here we present a novel approach to realize high-capacity quantum key distribution (QKD) by exploiting OAM states. The innovation of the proposed approach relies on a unique type of entangled-photon source which produces entangled photons with OAM randomly distributed among high order Fiboncci-like numbers and a new physical mechanism for efficiently sharing keys. This combination of entanglement with mathematical properties of high order Fibonacci sequences provides the QKD protocol immunity to photon-number-splitting attacks and allows secure generation of long keys from few photons. Unlike other protocols, reference frame alignment and active modulation of production and detection bases are unnecessary.

  16. Quantum hacking of a continuous-variable quantum-key-distribution system using a wavelength attack

    Science.gov (United States)

    Huang, Jing-Zheng; Weedbrook, Christian; Yin, Zhen-Qiang; Wang, Shuang; Li, Hong-Wei; Chen, Wei; Guo, Guang-Can; Han, Zheng-Fu

    2013-06-01

    The security proofs of continuous-variable quantum key distribution are based on the assumptions that the eavesdropper can neither act on the local oscillator nor control Bob's beam splitter. These assumptions may be invalid in practice due to potential imperfections in the implementations of such protocols. In this paper, we consider the problem of transmitting the local oscillator in a public channel and propose a wavelength attack which allows the eavesdropper to control the intensity transmission of Bob's beam splitter by switching the wavelength of the input light. Specifically we target continuous-variable quantum key distribution systems that use the heterodyne detection protocol using either direct or reverse reconciliation. Our attack is proved to be feasible and renders all of the final keys shared between the legitimate parties insecure, even if they have monitored the intensity of the local oscillator. To prevent our attack on commercial systems, a simple wavelength filter should be randomly added before performing monitoring detection.

  17. Experimental polarization encoded quantum key distribution over optical fibres with real-time continuous birefringence compensation

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, G B; Vilela de Faria, G; Temporao, G P; Von der Weid, J P [Centre for Telecommunication Studies, Pontifical Catholic University of Rio de Janeiro-R Marques de Sao Vicente 225 Gavea, Rio de Janeiro (Brazil); Walenta, N; Gisin, N; Zbinden, H [GAP-Optique, University of Geneva, rue de l' Ecole-de-Medecine 20, CH-1211 Geneva 4 (Switzerland)], E-mail: guix@opto.cetuc.puc-rio.br

    2009-04-15

    In this paper we demonstrate an active polarization drift compensation scheme for optical fibres employed in a quantum key distribution experiment with polarization encoded qubits. The quantum signals are wavelength multiplexed in one fibre along with two classical optical side channels that provide the control information for the polarization compensation scheme. This set-up allows us to continuously track any polarization change without the need to interrupt the key exchange. The results obtained show that fast polarization rotations of the order of 40{pi} rad s{sup -1} are effectively compensated for. We demonstrate that our set-up allows continuous quantum key distribution even in a fibre stressed by random polarization fluctuations. Our results pave the way for Bell-state measurements using only linear optics with parties separated by long-distance optical fibres.

  18. Randomized Clinical Trials With Biomarkers: Design Issues

    Science.gov (United States)

    McShane, Lisa M.; Korn, Edward L.

    2010-01-01

    Clinical biomarker tests that aid in making treatment decisions will play an important role in achieving personalized medicine for cancer patients. Definitive evaluation of the clinical utility of these biomarkers requires conducting large randomized clinical trials (RCTs). Efficient RCT design is therefore crucial for timely introduction of these medical advances into clinical practice, and a variety of designs have been proposed for this purpose. To guide design and interpretation of RCTs evaluating biomarkers, we present an in-depth comparison of advantages and disadvantages of the commonly used designs. Key aspects of the discussion include efficiency comparisons and special interim monitoring issues that arise because of the complexity of these RCTs. Important ongoing and completed trials are used as examples. We conclude that, in most settings, randomized biomarker-stratified designs (ie, designs that use the biomarker to guide analysis but not treatment assignment) should be used to obtain a rigorous assessment of biomarker clinical utility. PMID:20075367

  19. Aspects of randomness in neural graph structures

    CERN Document Server

    Rudolph-Lilith, Michelle

    2013-01-01

    In the past two decades, significant advances have been made in understanding the structural and functional properties of biological networks, via graph-theoretic analysis. In general, most graph-theoretic studies are conducted in the presence of serious uncertainties, such as major undersampling of the experimental data. In the specific case of neural systems, however, a few moderately robust experimental reconstructions do exist, and these have long served as fundamental prototypes for studying connectivity patterns in the nervous system. In this paper, we provide a comparative analysis of these "historical" graphs, both in (unmodified) directed and (often symmetrized) undirected forms, and focus on simple structural characterizations of their connectivity. We find that in most measures the networks studied are captured by simple random graph models; in a few key measures, however, we observe a marked departure from the random graph prediction. Our results suggest that the mechanism of graph formation in th...

  20. Species selection and random drift in macroevolution.

    Science.gov (United States)

    Chevin, Luis-Miguel

    2016-03-01

    Species selection resulting from trait-dependent speciation and extinction is increasingly recognized as an important mechanism of phenotypic macroevolution. However, the recent bloom in statistical methods quantifying this process faces a scarcity of dynamical theory for their interpretation, notably regarding the relative contributions of deterministic versus stochastic evolutionary forces. I use simple diffusion approximations of birth-death processes to investigate how the expected and random components of macroevolutionary change depend on phenotype-dependent speciation and extinction rates, as can be estimated empirically. I show that the species selection coefficient for a binary trait, and selection differential for a quantitative trait, depend not only on differences in net diversification rates (speciation minus extinction), but also on differences in species turnover rates (speciation plus extinction), especially in small clades. The randomness in speciation and extinction events also produces a species-level equivalent to random genetic drift, which is stronger for higher turnover rates. I then show how microevolutionary processes including mutation, organismic selection, and random genetic drift cause state transitions at the species level, allowing comparison of evolutionary forces across levels. A key parameter that would be needed to apply this theory is the distribution and rate of origination of new optimum phenotypes along a phylogeny. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  1. Random regression models

    African Journals Online (AJOL)

    zlukovi

    modelled as a quadratic regression, nested within parity. The previous lactation length was ... This proportion was mainly covered by linear and quadratic coefficients. Results suggest that RRM could .... The multiple trait models in scalar notation are presented by equations (1, 2), while equation. (3) represents the random ...

  2. Randomized response methods

    NARCIS (Netherlands)

    van der Heijden, P.G.M.; Cruyff, Maarten; Bockenholt, U.

    2014-01-01

    In survey research it is often problematic to ask people sensitive questions because they may refuse to answer or they may provide a socially desirable answer that does not reveal their true status on the sensitive question. To solve this problem Warner (1965) proposed randomized response (RR). Here

  3. Random eigenvalue problems revisited

    Indian Academy of Sciences (India)

    The description of real-life engineering structural systems is associated with some amount of uncertainty in specifying material properties, geometric parameters, boundary conditions and applied loads. In the context of structural dynamics it is necessary to consider random eigenvalue problems in order to account for these ...

  4. absolutely regular random sequences

    Directory of Open Access Journals (Sweden)

    Michel Harel

    1996-01-01

    Full Text Available In this paper, the central limit theorems for the density estimator and for the integrated square error are proved for the case when the underlying sequence of random variables is nonstationary. Applications to Markov processes and ARMA processes are provided.

  5. A random matrix analysis

    Indian Academy of Sciences (India)

    chaos to galaxies. We demonstrate the applicability of random matrix theory for networks by pro- viding a new dimension to complex systems research. We show that in spite of huge differences ... as mentioned earlier, different types of networks can be constructed based on the nature of connections. For example,.

  6. Random eigenvalue problems revisited

    Indian Academy of Sciences (India)

    Several studies have been conducted on this topic since the mid-sixties. The. A list of .... Random eigenvalue problems revisited. 297 and various elements of Hij ,i ≤ j are statistically independent and Gaussian. The pdf of H can be expressed as, ...... Generality of this result however remains to be verified in future studies.

  7. On Randomness and Probability

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. On Randomness and Probability How to Mathematically Model Uncertain Events ... Author Affiliations. Rajeeva L Karandikar1. Statistics and Mathematics Unit, Indian Statistical Institute, 7 S J S Sansanwal Marg, New Delhi 110 016, India.

  8. Alzheimer random walk

    Science.gov (United States)

    Odagaki, Takashi; Kasuya, Keisuke

    2017-09-01

    Using the Monte Carlo simulation, we investigate a memory-impaired self-avoiding walk on a square lattice in which a random walker marks each of sites visited with a given probability p and makes a random walk avoiding the marked sites. Namely, p = 0 and p = 1 correspond to the simple random walk and the self-avoiding walk, respectively. When p> 0, there is a finite probability that the walker is trapped. We show that the trap time distribution can well be fitted by Stacy's Weibull distribution b(a/b){a+1}/{b}[Γ({a+1}/{b})]-1x^a\\exp(-a/bx^b)} where a and b are fitting parameters depending on p. We also find that the mean trap time diverges at p = 0 as p- α with α = 1.89. In order to produce sufficient number of long walks, we exploit the pivot algorithm and obtain the mean square displacement and its Flory exponent ν(p) as functions of p. We find that the exponent determined for 1000 step walks interpolates both limits ν(0) for the simple random walk and ν(1) for the self-avoiding walk as [ ν(p) - ν(0) ] / [ ν(1) - ν(0) ] = pβ with β = 0.388 when p ≪ 0.1 and β = 0.0822 when p ≫ 0.1. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  9. Key aspects about education for refugee children

    Directory of Open Access Journals (Sweden)

    Mª Jesús Vega Pascual

    2003-01-01

    Full Text Available This presentation entitled «Key Aspects about Education for Refugee Children:Refugee Camp Situation», is based on the 2003 UNHCR Guidelines on Education and highlights the relevance of the education even in situations of emergency and crisis, interms of protection and psychosocial well-being of children. It also mentions key issues to consider when working with refugees, internally displaced people, asylum-seekers,stateless and other populations of concen to UNHCR. Aspects such as refugee children’s rights, UNHCR policy commitments to education, participation of refugees and their communities in the design, establishement and implementation of education programmes, specially in emergencies, will be dealt with in this presentation. It will alsomentions topics such as the school drop out, education for vulnerable groups and the need for promoting a gender sentitive approach, bearing in mind that the hard experience of exile, the changes of family structure, the ethnic, cultural, religious and legal differences are key when working with this populationEsta presentación titulada "Consideraciones esenciales sobre la educación de los niños refugiados: la situación en los campos de refugiados", está basada en las Directrices del ACNUR sobre Eduación de 2003, y pretende resaltar la importancia de la educación en las situaciones de refugiados, incluso en situaciones de emergencia o crisis, y cómo ésta juega en favor de la protección y del bienestar psicosocial de los niños. Se mencionan las peculiaridades más relevantes que deben tenerse en cuenta cuando se trabaja con refugiados, desplazados internos, solicitantes de asilo, apátridas y otras poblaciones de las que se ocupa el ACNUR. Se verán aspectos como los derechos de los niños refugiados, los compromisos del Alto Comisionado en materia de Educación, la participación de los refugiados y sus comunidades para diseñar, establecer e impartir programas de educación especialmente

  10. Applications of random process excursion analysis

    CERN Document Server

    Brainina, Irina S

    2013-01-01

    This book addresses one of the key problems in signal processing, the problem of identifying statistical properties of excursions in a random process in order to simplify the theoretical analysis and make it suitable for engineering applications. Precise and approximate formulas are explained, which are relatively simple and can be used for engineering applications such as the design of devices which can overcome the high initial uncertainty of the self-training period. The information presented in the monograph can be used to implement adaptive signal processing devices capable of d

  11. 29 CFR 825.219 - Rights of a key employee.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Rights of a key employee. 825.219 Section 825.219 Labor....219 Rights of a key employee. (a) An employer who believes that reinstatement may be denied to a key... recover its cost of health benefit premiums. A key employee's rights under FMLA continue unless and until...

  12. Secure SCADA communication by using a modified key management scheme.

    Science.gov (United States)

    Rezai, Abdalhossein; Keshavarzi, Parviz; Moravej, Zahra

    2013-07-01

    This paper presents and evaluates a new cryptographic key management scheme which increases the efficiency and security of the Supervisory Control And Data Acquisition (SCADA) communication. In the proposed key management scheme, two key update phases are used: session key update and master key update. In the session key update phase, session keys are generated in the master station. In the master key update phase, the Elliptic Curve Diffie-Hellman (ECDH) protocol is used. The Poisson process is also used to model the Security Index (SI) and Quality of Service (QoS). Our analysis shows that the proposed key management not only supports the required speed in the MODBUS implementation but also has several advantages compared to other key management schemes for secure communication in SCADA networks. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Research on Key Technologies of Cloud Computing

    Science.gov (United States)

    Zhang, Shufen; Yan, Hongcan; Chen, Xuebin

    With the development of multi-core processors, virtualization, distributed storage, broadband Internet and automatic management, a new type of computing mode named cloud computing is produced. It distributes computation task on the resource pool which consists of massive computers, so the application systems can obtain the computing power, the storage space and software service according to its demand. It can concentrate all the computing resources and manage them automatically by the software without intervene. This makes application offers not to annoy for tedious details and more absorbed in his business. It will be advantageous to innovation and reduce cost. It's the ultimate goal of cloud computing to provide calculation, services and applications as a public facility for the public, So that people can use the computer resources just like using water, electricity, gas and telephone. Currently, the understanding of cloud computing is developing and changing constantly, cloud computing still has no unanimous definition. This paper describes three main service forms of cloud computing: SAAS, PAAS, IAAS, compared the definition of cloud computing which is given by Google, Amazon, IBM and other companies, summarized the basic characteristics of cloud computing, and emphasized on the key technologies such as data storage, data management, virtualization and programming model.

  14. The Herschel DUNES Open Time Key Programme

    Science.gov (United States)

    Danchi, William C.

    2009-01-01

    We will use the unique photometric capabilities provided by Herschel to perform a deep and systematic survey for faint, cold debris disks around nearby stars. Our sensitivity-limited Open Time Key Programme (OTKP) aims at finding and characterizing faint extrasolar analogues to the Edgeworth-Kuiper Belt (EKB) in an unbiased, statistically significant sample of nearby FGK main-sequence stars. Our target set spans a broad range of stellar ages (from 0.1 to 10 Gyr) and is volume-limited (distances 5. The observations in the other Herschel bands will allow us to characterize, model, and constrain the disks. As a result, it will be possible for us to reach fractional dust luminosities of a few times 10-7, close to the EKB level in the Solar System. This will provide an unprecedented lower limit to the fractional abundance of planetesimal systems and allow us to assess the presence of giant planets, which would play dynamical roles similar to those played by Jupiter and Neptune in the Solar System. The proposed observations will provide new and unique evidence for the presence of mature planetary systems in the solar neighbourhood and, in turn, will address the universality of planet/planetary system formation in disks around young stars.

  15. KEY COMPETENCES OF SLOVENIAN SPORT MANAGERS

    Directory of Open Access Journals (Sweden)

    Iztok Retar

    2013-06-01

    Full Text Available The paper presents the results of research that examined the key competences in the management field in Slovenian sports. The success rate of sport organisations and sportsmen is based on the creative, innovative and quality expert work of employees or/and volunteers. Their work is planned, organised, managed and supervised by a sport manager who possesses knowledge as well as managerial, technical, social, creative and other competences. The purpose of the presented research, which involved successful Slovenian sport managers, was to establish which competences are the most important for successful work in the field of sport management. The paper also presents the technical framework for the selected determination of sport management terminology and competences as well as a competence structure model, prepared by the authors. We have found that the human resources management competence most significantly contributes to the success of Slovenian sport managers in the field of general competences. Respondents evaluated the competence of developing a positive working environment as the most important specific competence that supplements general competences.

  16. Microalgae for Bioenergy: Key Technology Nodes

    Science.gov (United States)

    Kastanek, Frantisek; Rouskova, Milena; Matejkova, Martina; Kastanek, Petr

    2015-01-01

    Microalgae have increasingly gained research interest as a source of lipids for biodiesel production. The wet way processing of harvested microalgae was suggested and evaluated with respect to the possible environmental impacts and production costs. This study is focused on the three key steps of the suggested process: flocculation, water recycling, and extraction of lipids. Microalgae strains with high content of lipids were chosen for cultivation and subsequent treatment process. Ammonium hydroxide was tested as the flocculation agent and its efficiency was compared with chitosan. Determined optimal flocculation conditions for ammonium hydroxide enable the water recycling for the recurring microalgae growth, which was verified for the use of 30, 50, and 80% recycled water. For extraction of the wet microalgae hexane, hexane/ethanol and comparative chloroform/methanol systems were applied. The efficiency of hexane/ethanol extraction system was found as comparable with chloroform/methanol system and it seems to be promising owing to its low volatility and toxicity and mainly the low cost. PMID:26000336

  17. Microalgae for Bioenergy: Key Technology Nodes

    Directory of Open Access Journals (Sweden)

    Ywetta Maleterova

    2015-01-01

    Full Text Available Microalgae have increasingly gained research interest as a source of lipids for biodiesel production. The wet way processing of harvested microalgae was suggested and evaluated with respect to the possible environmental impacts and production costs. This study is focused on the three key steps of the suggested process: flocculation, water recycling, and extraction of lipids. Microalgae strains with high content of lipids were chosen for cultivation and subsequent treatment process. Ammonium hydroxide was tested as the flocculation agent and its efficiency was compared with chitosan. Determined optimal flocculation conditions for ammonium hydroxide enable the water recycling for the recurring microalgae growth, which was verified for the use of 30, 50, and 80% recycled water. For extraction of the wet microalgae hexane, hexane/ethanol and comparative chloroform/methanol systems were applied. The efficiency of hexane/ethanol extraction system was found as comparable with chloroform/methanol system and it seems to be promising owing to its low volatility and toxicity and mainly the low cost.

  18. Personality, a key factor in personalized medicine?

    Science.gov (United States)

    Boersma, Gretha J; Benthem, Lambertus; van Beek, Andre P; van Dijk, Gertjan; Scheurink, Anton J W

    2011-09-30

    The incidence of health problems resulting from obesity is growing and obesity and its related diseases has become one of the main causes in death in industrialized societies. Environmental influences are crucial for the interactions between genetic, neurohormonal and metabolic factors that may be important in understanding individual differences in the development of obesity and metabolic diseases like type 2 diabetes. In particular the interactions between the personality of an individual and the environment play a key role in predicting the chance for successful treatment. Our experimental data clearly point out that the success of interventions designed to prevent or treat metabolic diseases could be considerably improved by adjusting the intervention to the personality of the individual. Furthermore, certain physiological and neuroendocrine characteristics of a personality are strong indicators for pathology development, both in experimental animals and humans. Future research should focus on the identification of easily measurable physiological and neuroendocrine markers indicative of the coping style or personality in humans. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Key personality traits of sales managers.

    Science.gov (United States)

    Lounsbury, John W; Foster, Nancy A; Levy, Jacob J; Gibson, Lucy W

    2014-01-01

    Sales managers are crucial for producing positive sales outcomes for companies. However, there has been a relative dearth of scholarly investigations into the personal attributes of sales managers. Such information could prove important in the recruitment, selection, training needs identification, career planning, counseling, and development of sales managers. Drawing on Holland's vocational theory, we sought to identify key personality traits that distinguish sales managers from other occupations and are related to their career satisfaction. The main sample was comprised of a total of 978 sales managers employed in a large number of companies across the United States (along with a comparison sample drawn from 79,512 individuals from other professional occupations). Participants completed an online version of Resource Associates' Personal Style Inventory as well a measure of career satisfaction. Our sample of 978 sales managers had higher levels of Assertiveness, Customer Service Orientation, Extraversion, Image Management, Optimism, and Visionary Style; and lower levels of Conscientiousness, Agreeableness, Intrinsic Motivation, Openness, and Tough-Mindedness than a sample of 79,512 individuals in a variety of other occupations. Nine of these traits were significantly correlated with sales managers' career satisfaction. Based on the results, a psychological profile of sales managers was presented as were implications for their recruitment, selection, training, development, and mentoring.

  20. Key considerations in designing a somatosensory neuroprosthesis.

    Science.gov (United States)

    Delhaye, Benoit P; Saal, Hannes P; Bensmaia, Sliman J

    2016-11-01

    In recent years, a consensus has emerged that somatosensory feedback needs to be provided for upper limb neuroprostheses to be useful. An increasingly promising approach to sensory restoration is to electrically stimulate neurons along the somatosensory neuraxis to convey information about the state of the prosthetic limb and about contact with objects. To date, efforts toward artificial sensory feedback have consisted mainly of demonstrating that some sensory information could be conveyed using a small number of stimulation patterns, generally delivered through single electrodes. However impressive these achievements are, results from different studies are hard to compare, as each research team implements different stimulation patterns and tests the elicited sensations differently. A critical question is whether different stimulation strategies will generalize from contrived laboratory settings to activities of daily living. Here, we lay out some key specifications that an artificial somatosensory channel should meet, discuss how different approaches should be evaluated, and caution about looming challenges that the field of sensory restoration will face. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. KEY PERFORMING FACTORS OF LEADING ROMANIAN COMPANIES

    Directory of Open Access Journals (Sweden)

    BURJA CAMELIA

    2014-08-01

    Full Text Available The analysis of financial economic ratios provides managers and external partners feedback on the results obtained from operational activities and the associated performance and risks. This paper studies the functional dependence of the companies’ success (on performance over internal financial management elements. The research was carried out for the most traded non-financial securities Bucharest listed companies and covers the period 2011- 2013. To carry out its purpose it analyzed the interdependence between the key financial ratios, studying the impact of liquidity ratios, solvency and efficiency on profitability. The study provides empirical evidences to identify factors that have ensured the performance of companies and their ranking in the segment of the most traded companies in Romania. Results suggest the view that the source of company success on the capital market lies in the positive signals sent to investors regarding profitability and the low risk of solvency. This study gives additional information for managerial decision-making in order to create more value and a better positioning of the companies in the market

  2. An improved quantum key distribution protocol

    Science.gov (United States)

    Wu, Ting-wan; Wu, Guo-hua

    2008-08-01

    This paper presented an improved quantum key distribution protocol of the quantum cryptology. Using the same measure polarizer as BB84 protocol, the improved protocol we designed with not any classical channel, but a new looped quantum channel instead, so the job of sending and receiving can be finished only by one same person. It brings several good points: the utilization ratio of photons 100% in perfect condition, at least twice over other protocols, or even higher; the public channel easy to be attacked is avoided. Further, the improved protocol authenticates the legal communicators with pre-share information, so that no attacker can jump over the progress of authentication. Be alien from the protocol of BB84, the improved protocol uses message summary to detect whether messages intercepted by attacker. Because the message summary is encrypted by one-time-pad method using pre-share information, attacker could not alter the message summary and that not to be discovered. Moreover, some theoretical analysis to the improved protocol given with information theory: we used the measure channel concept for quantum detection, and calculated the information quantity obtained by attacker in the quantum secrecy communication. The analysis results provide the theory criterion for the legal communicators and the attackers.

  3. Human Connectivity: The Key to Progress

    Directory of Open Access Journals (Sweden)

    Janani Harish

    2016-10-01

    Full Text Available Progress results from human interaction. Advances in knowledge, transportation, communication, technology and industry have aided in social development only to the extent that they have brought greater numbers of people closer. It is only human ingenuity that has achieved. Historically, every event that marks a step forward in social evolution coincides with a discovery, invention or organizational innovation that brings people closer in contact. When two people meet, the knowledge, resourcefulness and capacity that they bring together grow not cumulatively but exponentially. Thus every additional connection made to the human network adds to its depth and richness. When this is done at a larger scale, between entire cultures and civilizations, the result is an explosion of creativity. Urbanization and advances in technology have accelerated this interchange between people and cultures. Unlike all other resources, human capital is inexhaustible, self-replenishing and has the potential to meet and overcome every challenge the world faces today. The logistics of bringing human minds together effectively holds the key to consciously accelerating human progress.

  4. A Novel Key Distribution Solution for Combined Public/Secret Key ...

    African Journals Online (AJOL)

    Moreover, an implementation over the new IPv6 Internet protocol is presented such that the system can be ported to both wired and wireless networking environments. Keywords: cryptography, key distribution, security server. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

  5. The Efficacy of Key Performance Indicators in Ontario Universities as Perceived by Key Informants

    Science.gov (United States)

    Chan, Vivian

    2015-01-01

    The Ontario Ministry of Education and Training's Task Force on University Accountability first proposed key performance indicators (KPIs) for colleges and universities in Ontario in the early 1990s. The three main KPIs for Ontario universities are the rates of (1) graduation, (2) employment, and (3) Ontario Student Assistance Program loan default.…

  6. Economic contribution of recreating visitors to the Florida Keys/Key West

    Science.gov (United States)

    Donald B.K. English; Warren Kriesel; Vernon R Leeworthy; Peter C. Wiley

    1996-01-01

    This report provides estimates of the economic impact that visitors to the Florida Keys have on both the Monroe County and larger South Florida regional economies. Estimates are made for output/sales, income, and employment and include both direct and secondary economic impacts. This report provides the basis for demonstrating the income-producing asset value of the...

  7. Random vibrations theory and practice

    CERN Document Server

    Wirsching, Paul H; Ortiz, Keith

    1995-01-01

    Random Vibrations: Theory and Practice covers the theory and analysis of mechanical and structural systems undergoing random oscillations due to any number of phenomena— from engine noise, turbulent flow, and acoustic noise to wind, ocean waves, earthquakes, and rough pavement. For systems operating in such environments, a random vibration analysis is essential to the safety and reliability of the system. By far the most comprehensive text available on random vibrations, Random Vibrations: Theory and Practice is designed for readers who are new to the subject as well as those who are familiar with the fundamentals and wish to study a particular topic or use the text as an authoritative reference. It is divided into three major sections: fundamental background, random vibration development and applications to design, and random signal analysis. Introductory chapters cover topics in probability, statistics, and random processes that prepare the reader for the development of the theory of random vibrations a...

  8. Random Raman lasing

    CERN Document Server

    Hokr, Brett H; Mason, John D; Beier, Hope T; Rockwll, Benjamin A; Thomas, Robert J; Noojin, Gary D; Petrov, Georgi I; Golovan, Leonid A; Yakovlev, Vladislav V

    2013-01-01

    Propagation of light in a highly scattering medium is among the most fascinating optical effect that everyone experiences on an everyday basis and possesses a number of fundamental problems which have yet to be solved. Conventional wisdom suggests that non-linear effects do not play a significant role because the diffusive nature of scattering acts to spread the intensity, dramatically weakening these effects. We demonstrate the first experimental evidence of lasing on a Raman transition in a bulk three-dimensional random media. From a practical standpoint, Raman transitions allow for spectroscopic analysis of the chemical makeup of the sample. A random Raman laser could serve as a bright Raman source allowing for remote, chemically specific, identification of powders and aerosols. Fundamentally, the first demonstration of this new light source opens up an entire new field of study into non-linear light propagation in turbid media, with the most notable application related to non-invasive biomedical imaging.

  9. On fairness and randomness

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2009-01-01

    We investigate the relation between the behavior of non-deterministic systems under fairness constraints, and the behavior of probabilistic systems. To this end, first a framework based on computable stopping strategies is developed that provides a common foundation for describing both fair...... and probabilistic behavior. On the basis of stopping strategies it is then shown that fair behavior corresponds in a precise sense to random behavior in the sense of Martin-Löf's definition of randomness. We view probabilistic systems as concrete implementations of more abstract non-deterministic systems. Under...... this perspective the question is investigated what probabilistic properties are needed in such an implementation to guarantee (with probability one) certain required fairness properties in the behavior of the probabilistic system. Generalizing earlier concepts of ε -bounded transition probabilities, we introduce...

  10. Free random variables

    CERN Document Server

    Voiculescu, Dan; Nica, Alexandru

    1992-01-01

    This book presents the first comprehensive introduction to free probability theory, a highly noncommutative probability theory with independence based on free products instead of tensor products. Basic examples of this kind of theory are provided by convolution operators on free groups and by the asymptotic behavior of large Gaussian random matrices. The probabilistic approach to free products has led to a recent surge of new results on the von Neumann algebras of free groups. The book is ideally suited as a textbook for an advanced graduate course and could also provide material for a seminar. In addition to researchers and graduate students in mathematics, this book will be of interest to physicists and others who use random matrices.

  11. Intravaginal stimulation randomized trial.

    Science.gov (United States)

    Smith, J J

    1996-01-01

    The effectiveness of intravaginal electrical stimulation was compared to standard therapy in the treatment of genuine stress urinary incontinence and detrusor instability. A total of 57 women with urinary incontinence was evaluated with video urodynamics and voiding diaries before and after treatment. Of the women 18 with stress urinary incontinence were randomized to electrical stimulation or Kegel exercise and 38 with detrusor instability were randomized to anticholinergic therapy or electrical stimulation. Of patients using electrical stimulation in the stress urinary incontinence group 66% improved and 72% of the patients with detrusor instability treated with electrical stimulation improved. These rates were not statistically significant when compared to traditional therapy. Electrical stimulation is safe and at least as effective as properly performed Kegel and anticholinergic therapy in the treatment of stress urinary incontinence and detrusor instability.

  12. Certified randomness in quantum physics.

    Science.gov (United States)

    Acín, Antonio; Masanes, Lluis

    2016-12-07

    The concept of randomness plays an important part in many disciplines. On the one hand, the question of whether random processes exist is fundamental for our understanding of nature. On the other, randomness is a resource for cryptography, algorithms and simulations. Standard methods for generating randomness rely on assumptions about the devices that are often not valid in practice. However, quantum technologies enable new methods for generating certified randomness, based on the violation of Bell inequalities. These methods are referred to as device-independent because they do not rely on any modelling of the devices. Here we review efforts to design device-independent randomness generators and the associated challenges.

  13. Certified randomness in quantum physics

    Science.gov (United States)

    Acín, Antonio; Masanes, Lluis

    2016-12-01

    The concept of randomness plays an important part in many disciplines. On the one hand, the question of whether random processes exist is fundamental for our understanding of nature. On the other, randomness is a resource for cryptography, algorithms and simulations. Standard methods for generating randomness rely on assumptions about the devices that are often not valid in practice. However, quantum technologies enable new methods for generating certified randomness, based on the violation of Bell inequalities. These methods are referred to as device-independent because they do not rely on any modelling of the devices. Here we review efforts to design device-independent randomness generators and the associated challenges.

  14. Cluster randomized trials for pharmacy practice research.

    Science.gov (United States)

    Gums, Tyler; Carter, Barry; Foster, Eric

    2016-06-01

    Introduction Cluster randomized trials (CRTs) are now the gold standard in health services research, including pharmacy-based interventions. Studies of behaviour, epidemiology, lifestyle modifications, educational programs, and health care models are utilizing the strengths of cluster randomized analyses. Methodology The key property of CRTs is the unit of randomization (clusters), which may be different from the unit of analysis (individual). Subject sample size and, ideally, the number of clusters is determined by the relationship of between-cluster and within-cluster variability. The correlation among participants recruited from the same cluster is known as the intraclass correlation coefficient (ICC). Generally, having more clusters with smaller ICC values will lead to smaller sample sizes. When selecting clusters, stratification before randomization may be useful in decreasing imbalances between study arms. Participant recruitment methods can differ from other types of randomized trials, as blinding a behavioural intervention cannot always be done. When to use CRTs can yield results that are relevant for making "real world" decisions. CRTs are often used in non-therapeutic intervention studies (e.g. change in practice guidelines). The advantages of CRT design in pharmacy research have been avoiding contamination and the generalizability of the results. A large CRT that studied physician-pharmacist collaborative management of hypertension is used in this manuscript as a CRT example. The trial, entitled Collaboration Among Pharmacists and physicians To Improve Outcomes Now (CAPTION), was implemented in primary care offices in the United States for hypertensive patients. Limitations CRT design limitations include the need for a large number of clusters, high costs, increased training, increased monitoring, and statistical complexity.

  15. Key conclusions from AVOID Work Stream One

    Science.gov (United States)

    Warren, Rachel

    2010-05-01

    AVOID work stream (WS1)one has produced emission scenarios that simulate potential future global emission pathways for greenhouse gases during the 21st century. The study explored the influence of three key features of such pathways: (1) the year in which emissions peak globally, (2) the rate of emission reduction, and (3) the minimum level to which emissions are eventually reduced. It examined the resultant climate change, climate change impacts and economic implications using computer simulations. Avoided impacts, carbon taxes and GDP change increase throughout the 21st century in the models. AVOID-WS1 showed that in the absence of climate policy it is very likely that global mean temperatures would exceed 3 degrees and there are evens chances that the temperature would rise by 4 degrees relative to pre-industrial times. Scenarios that peak emissions in 2016 were more effective at constraining temperatures to below 3 degrees than those that peaked in 2030: one ‘2016' scenario achieved a probability of 45% of avoiding breaching of a 2 degree threshold. Scenarios peaking in 2030 were inconsistent with constraining temperatures to below 2 degrees. Correspondingly, scenarios that peak in 2030 are more effective at avoiding climate impacts than scenarios that peak in 2016, for all sectors that we studied. Hence the date at which emissions peak is more important than the rate of subsequent emissions reduction in determining the avoided impacts. Avoided impacts increase with time, being negligible in the 2030s, significant by the 2050s and large by the 2080s. Finally, the choice of GCM influences the magnitude of the avoided impacts strongly, so that the uncertainties in our estimates of avoided impacts for each scenario are larger than the difference between the scenarios. Our economic analysis is based on models which differ greatly in the assumptions that they make, but generally show that the date at which emissions peak is a stronger driver of induced GDP changes

  16. Iteration and superposition encryption scheme for image sequences based on multi-dimensional keys

    Science.gov (United States)

    Han, Chao; Shen, Yuzhen; Ma, Wenlin

    2017-12-01

    An iteration and superposition encryption scheme for image sequences based on multi-dimensional keys is proposed for high security, big capacity and low noise information transmission. Multiple images to be encrypted are transformed into phase-only images with the iterative algorithm and then are encrypted by different random phase, respectively. The encrypted phase-only images are performed by inverse Fourier transform, respectively, thus new object functions are generated. The new functions are located in different blocks and padded zero for a sparse distribution, then they propagate to a specific region at different distances by angular spectrum diffraction, respectively and are superposed in order to form a single image. The single image is multiplied with a random phase in the frequency domain and then the phase part of the frequency spectrums is truncated and the amplitude information is reserved. The random phase, propagation distances, truncated phase information in frequency domain are employed as multiple dimensional keys. The iteration processing and sparse distribution greatly reduce the crosstalk among the multiple encryption images. The superposition of image sequences greatly improves the capacity of encrypted information. Several numerical experiments based on a designed optical system demonstrate that the proposed scheme can enhance encrypted information capacity and make image transmission at a highly desired security level.

  17. Random recursive trees and the elephant random walk

    Science.gov (United States)

    Kürsten, Rüdiger

    2016-03-01

    One class of random walks with infinite memory, so-called elephant random walks, are simple models describing anomalous diffusion. We present a surprising connection between these models and bond percolation on random recursive trees. We use a coupling between the two models to translate results from elephant random walks to the percolation process. We calculate, besides other quantities, exact expressions for the first and the second moment of the root cluster size and of the number of nodes in child clusters of the first generation. We further introduce another model, the skew elephant random walk, and calculate the first and second moment of this process.

  18. Shaping the spectrum of random-phase radar waveforms

    Science.gov (United States)

    Doerry, Armin W.; Marquette, Brandeis

    2017-05-09

    The various technologies presented herein relate to generation of a desired waveform profile in the form of a spectrum of apparently random noise (e.g., white noise or colored noise), but with precise spectral characteristics. Hence, a waveform profile that could be readily determined (e.g., by a spoofing system) is effectively obscured. Obscuration is achieved by dividing the waveform into a series of chips, each with an assigned frequency, wherein the sequence of chips are subsequently randomized. Randomization can be a function of the application of a key to the chip sequence. During processing of the echo pulse, a copy of the randomized transmitted pulse is recovered or regenerated against which the received echo is correlated. Hence, with the echo energy range-compressed in this manner, it is possible to generate a radar image with precise impulse response.

  19. A Randomization Approach for Stochastic Workflow Scheduling in Clouds

    Directory of Open Access Journals (Sweden)

    Wei Zheng

    2016-01-01

    Full Text Available In cloud systems consisting of heterogeneous distributed resources, scheduling plays a key role to obtain good performance when complex applications are run. However, there is unavoidable error in predicting individual task execution times and data transmission times. When this error is being not negligible, deterministic scheduling approaches (i.e., scheduling based on accurate time prediction may suffer. In this paper, we assume the error in time predictions is modelled in stochastic manner, and a novel randomization approach making use of the properties of random variables is proposed to improve deterministic scheduling. The randomization approach is applied to a classic deterministic scheduling heuristic, but its applicability is not limited to this one heuristic. Evaluation results obtained from extensive simulation show that the randomized scheduling approach can significantly outperform its static counterpart and the extra overhead introduced is not only controllable but also acceptable.

  20. Implementing traceability using particle randomness-based textile printed tags

    Science.gov (United States)

    Agrawal, T. K.; Koehl, L.; Campagne, C.

    2017-10-01

    This article introduces a random particle-based traceability tag for textiles. The proposed tag not only act as a unique signature for the corresponding textile product but also possess the features such as easy to manufacture and hard to copy. It seeks applications in brand authentication and traceability in textile and clothing (T&C) supply chain. A prototype has been developed by screen printing process, in which micron-scale particles were mixed with the printing paste and printed on cotton fabrics to attain required randomness. To encode the randomness, the image of the developed tag was taken and analyzed using image processing. The randomness of the particles acts as a product key or unique signature which is required to decode the tag. Finally, washing and abrasion resistance tests were conducted to check the durability of the printed tag.

  1. Review of Random Phase Encoding in Volume Holographic Storage

    Directory of Open Access Journals (Sweden)

    Wei-Chia Su

    2012-09-01

    Full Text Available Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holographic storage. We then review an image encryption system based on random phase encoding. The alignment of phase key for decryption of the encoded image stored in holographic memory is analyzed and discussed. In the latter part of the review, an all-optical sensing system implemented by random phase encoding and holographic interconnection is presented.

  2. Learning a keying sequence you never executed: evidence for independent associative and motor chunk learning.

    Science.gov (United States)

    Verwey, Willem B; Wright, David L

    2014-09-01

    A substantial amount of research has addressed how people learn and control movement sequences. Recent results suggested that practice with discrete key pressing sequences results in two types of sequence learning: associative learning and motor chunk development (Verwey & Abrahamse, 2012). In the present study, we addressed whether in keying sequences of limited length associative learning develops also when the use of the chunking mode is prevented by introducing during practice random deviants. In line with the notion of two different learning mechanisms, the present results indicate that associative sequence learning develops when motor chunks cannot be developed during practice. This confirms the notion that motor chunks do not rely on these associations. In addition, experience with a particular execution mode during the practice phase seems to benefit subsequent use of that mode with unfamiliar and random sequences. Also, participants with substantial video-gaming experience were faster in executing discrete keying sequences in the chunking mode. These last two results may point to the development of a general ability to produce movement sequences in the chunking mode. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Strong Decomposition of Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jørgensen, Jørgen; Kagan, Abram M.; Pitt, Loren D.

    2007-01-01

    A random variable X is stongly decomposable if X=Y+Z where Y=Φ(X) and Z=X-Φ(X) are independent non-degenerated random variables (called the components). It is shown that at least one of the components is singular, and we derive a necessary and sufficient condition for strong decomposability...... of a discrete random variable....

  4. Random Numbers and Quantum Computers

    Science.gov (United States)

    McCartney, Mark; Glass, David

    2002-01-01

    The topic of random numbers is investigated in such a way as to illustrate links between mathematics, physics and computer science. First, the generation of random numbers by a classical computer using the linear congruential generator and logistic map is considered. It is noted that these procedures yield only pseudo-random numbers since…

  5. Investigating the Randomness of Numbers

    Science.gov (United States)

    Pendleton, Kenn L.

    2009-01-01

    The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…

  6. Aerosol typing - key information from aerosol studies

    Science.gov (United States)

    Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

    2016-04-01

    Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

  7. Random Projection Trees Revisited

    OpenAIRE

    Dhesi, Aman; Kar, Purushottam

    2010-01-01

    The Random Projection Tree structures proposed in [Freund-Dasgupta STOC08] are space partitioning data structures that automatically adapt to various notions of intrinsic dimensionality of data. We prove new results for both the RPTreeMax and the RPTreeMean data structures. Our result for RPTreeMax gives a near-optimal bound on the number of levels required by this data structure to reduce the size of its cells by a factor $s \\geq 2$. We also prove a packing lemma for this data structure. Our...

  8. Random matrix theory

    CERN Document Server

    Deift, Percy

    2009-01-01

    This book features a unified derivation of the mathematical theory of the three classical types of invariant random matrix ensembles-orthogonal, unitary, and symplectic. The authors follow the approach of Tracy and Widom, but the exposition here contains a substantial amount of additional material, in particular, facts from functional analysis and the theory of Pfaffians. The main result in the book is a proof of universality for orthogonal and symplectic ensembles corresponding to generalized Gaussian type weights following the authors' prior work. New, quantitative error estimates are derive

  9. Random Cell Identifiers Assignment

    Directory of Open Access Journals (Sweden)

    Robert Bestak

    2012-01-01

    Full Text Available Despite integration of advanced functions that enable Femto Access Points (FAPs to be deployed in a plug-and-play manner, the femtocell concept still cause several opened issues to be resolved. One of them represents an assignment of Physical Cell Identifiers (PCIs to FAPs. This paper analyses a random based assignment algorithm in LTE systems operating in diverse femtocell scenarios. The performance of the algorithm is evaluated by comparing the number of confusions for various femtocell densities, PCI ranges and knowledge of vicinity. Simulation results show that better knowledge of vicinity can significantly reduce the number of confusions events.

  10. Random Constraint Satisfaction Problems

    Directory of Open Access Journals (Sweden)

    Amin Coja-Oghlan

    2009-11-01

    Full Text Available Random instances of constraint satisfaction problems such as k-SAT provide challenging benchmarks. If there are m constraints over n variables there is typically a large range of densities r=m/n where solutions are known to exist with probability close to one due to non-constructive arguments. However, no algorithms are known to find solutions efficiently with a non-vanishing probability at even much lower densities. This fact appears to be related to a phase transition in the set of all solutions. The goal of this extended abstract is to provide a perspective on this phenomenon, and on the computational challenge that it poses.

  11. Authentication and key distribution for wired and wireless systems

    OpenAIRE

    Komninos, N.; Samarakoon, M. I.; Honary, B.

    2000-01-01

    With the emergence of E-Commerce communication security has become a very important issue. Two main considerations of secure communication systems are authentication, and key distribution. Authentication and key distribution may differ from one system to another due to the system parameters such as bandwidth, and available processing power at the end terminals. This paper focuses on end-to-end authentication and key management strategies in wireless and wired systems. Public and secret key en...

  12. Computational Complexity of Continuous Variable Quantum Key Distribution

    OpenAIRE

    Zhao, Yi-Bo; Gui, You-Zhen; Chen, Jin-Jian; Han, Zheng-Fu; Guo, Guang-Can

    2006-01-01

    The continuous variable quantum key distribution has been considered to have the potential to provide high secret key rate. However, in present experimental demonstrations, the secret key can be distilled only under very small loss rates. Here, by calculating explicitly the computational complexity with the channel transmission, we show that under high loss rate it is hard to distill the secret key in present continuous variable scheme and one of its advantages, the potential of providing hig...

  13. A short history of randomized experiments in criminology. A meager feast.

    Science.gov (United States)

    Farrington, David P

    2003-06-01

    This article discusses advantages of randomized experiments and key issues raised in the following articles. The main concern is the growth and decrease in the use of randomized experiments by the California Youth Authority, the U.S. National Institute of Justice, and the British Home Office, although other experiments are also discussed. It is concluded that feast and famine periods are influenced by key individuals. It is recommended that policy makers, practitioners, funders, the mass media, and the general public need better education in research quality so that they can tell the difference between good and poor evaluation studies. They might then demand better evaluations using randomized experiments.

  14. Quantum Encryption Minimising Key Leakage under Known Plaintext Attacks

    DEFF Research Database (Denmark)

    Pedersen, Thomas Brochmann

    2006-01-01

    In this dissertation we show how, by using a quantum channel, we can get more unconditionally secret communication with a symmetric key under known plaintext attacks. In unconditionally secret encryption schemes the key is necessarily an expensive resource since it cannot safely be reused for mor....... In this encryption scheme the entire key can be safely recycled when no eavesdropping is detected....

  15. Public Key Infrastructure Increment 2 (PKI Inc 2)

    Science.gov (United States)

    2016-03-01

    2016 Major Automated Information System Annual Report Public Key Infrastructure Increment 2 (PKI Inc 2) Defense Acquisition Management...6615 DSN Phone: 244-4900 DSN Fax: Date Assigned: July 1, 2015 Program Information Program Name Public Key Infrastructure Increment 2 (PKI Inc 2... Public Key Infrastructure (PKI) is a critical enabling technology for Information Assurance (IA) services to support seamless secure information flows

  16. Space division multiplexing chip-to-chip quantum key distribution

    DEFF Research Database (Denmark)

    Bacco, Davide; Ding, Yunhong; Dalgaard, Kjeld

    2017-01-01

    nodes of the quantum keys to their respective destinations. In this paper we present an experimental demonstration of a photonic integrated silicon chip quantum key distribution protocols based on space division multiplexing (SDM), through multicore fiber technology. Parallel and independent quantum...... keys are obtained, which are useful in crypto-systems and future quantum network....

  17. Anonymity for key-trees with adaptive adversaries

    NARCIS (Netherlands)

    Beye, M.; Veugen, P.J.M.

    2012-01-01

    Hash-lock authentication protocols for Radio Frequency IDentification (RFID) tags incur heavy search on the server. Key-trees have been proposed as a way to reduce search times, but because partial keys in such trees are shared, key compromise affects several tags. Buttyán [4] and Beye and Veugen

  18. Privacy for Key-Trees with Adaptive Adversaries

    NARCIS (Netherlands)

    Beye, M.; Veugen, P.J.M.

    2011-01-01

    Hash-lock authentication protocols for Radio Frequency IDentification (RFID) tags incur heavy search on the server. Key-trees have been proposed as a way to reduce search times, but because partial keys in such trees are shared, key compromise affects several tags. Butty´an [3] and Beye and Veugen

  19. The identification of key competencies of university graduates

    Directory of Open Access Journals (Sweden)

    Eremina Anastasia Vitalievna

    2015-12-01

    Full Text Available The article focuses on problems of key competences identification of university graduates in the view of existing approaches to definitions of “competence” and “key competence”. The authors consider the results of self-identification of key competences by university graduates and found out the more important groups of competences

  20. Quincke random walkers

    Science.gov (United States)

    Pradillo, Gerardo; Heintz, Aneesh; Vlahovska, Petia

    2017-11-01

    The spontaneous rotation of a sphere in an applied uniform DC electric field (Quincke effect) has been utilized to engineer self-propelled particles: if the sphere is initially resting on a surface, it rolls. The Quincke rollers have been widely used as a model system to study collective behavior in ``active'' suspensions. If the applied field is DC, an isolated Quincke roller follows a straight line trajectory. In this talk, we discuss the design of a Quincke roller that executes a random-walk-like behavior. We utilize AC field - upon reversal of the field direction a fluctuation in the axis of rotation (which is degenerate in the plane perpendicular to the field and parallel to the surface) introduces randomness in the direction of motion. The MSD of an isolated Quincke walker depends on frequency, amplitude, and waveform of the electric field. Experiment and theory are compared. We also investigate the collective behavior of Quincke walkers,the transport of inert particles in a bath of Quincke walkers, and the spontaneous motion of a drop containing Quincke active particle. supported by NSF Grant CBET 1437545.

  1. Lectures on random interfaces

    CERN Document Server

    Funaki, Tadahisa

    2016-01-01

    Interfaces are created to separate two distinct phases in a situation in which phase coexistence occurs. This book discusses randomly fluctuating interfaces in several different settings and from several points of view: discrete/continuum, microscopic/macroscopic, and static/dynamic theories. The following four topics in particular are dealt with in the book. Assuming that the interface is represented as a height function measured from a fixed-reference discretized hyperplane, the system is governed by the Hamiltonian of gradient of the height functions. This is a kind of effective interface model called ∇φ-interface model. The scaling limits are studied for Gaussian (or non-Gaussian) random fields with a pinning effect under a situation in which the rate functional of the corresponding large deviation principle has non-unique minimizers. Young diagrams determine decreasing interfaces, and their dynamics are introduced. The large-scale behavior of such dynamics is studied from the points of view of the hyd...

  2. Random-walk enzymes

    Science.gov (United States)

    Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

    2015-09-01

    Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C →U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics.

  3. Single-random-phase holographic encryption of images

    Science.gov (United States)

    Tsang, P. W. M.

    2017-02-01

    In this paper, a method is proposed for encrypting an optical image onto a phase-only hologram, utilizing a single random phase mask as the private encryption key. The encryption process can be divided into 3 stages. First the source image to be encrypted is scaled in size, and pasted onto an arbitrary position in a larger global image. The remaining areas of the global image that are not occupied by the source image could be filled with randomly generated contents. As such, the global image as a whole is very different from the source image, but at the same time the visual quality of the source image is preserved. Second, a digital Fresnel hologram is generated from the new image, and converted into a phase-only hologram based on bi-directional error diffusion. In the final stage, a fixed random phase mask is added to the phase-only hologram as the private encryption key. In the decryption process, the global image together with the source image it contained, can be reconstructed from the phase-only hologram if it is overlaid with the correct decryption key. The proposed method is highly resistant to different forms of Plain-Text-Attacks, which are commonly used to deduce the encryption key in existing holographic encryption process. In addition, both the encryption and the decryption processes are simple and easy to implement.

  4. Key scientific problems from Cosmic Ray History

    Science.gov (United States)

    Lev, Dorman

    2016-07-01

    Recently was published the monograph "Cosmic Ray History" by Lev Dorman and Irina Dorman (Nova Publishers, New York). What learn us and what key scientific problems formulated the Cosmic Ray History? 1. As many great discoveries, the phenomenon of cosmic rays was discovered accidentally, during investigations that sought to answer another question: what are sources of air ionization? This problem became interesting for science about 230 years ago in the end of the 18th century, when physics met with a problem of leakage of electrical charge from very good isolated bodies. 2. At the beginning of the 20th century, in connection with the discovery of natural radioactivity, it became apparent that this problem is mainly solved: it was widely accepted that the main source of the air ionization were α, b, and γ - radiations from radioactive substances in the ground (γ-radiation was considered as the most important cause because α- and b-radiations are rapidly absorbed in the air). 3. The general accepted wrong opinion on the ground radioactivity as main source of air ionization, stopped German meteorologist Franz Linke to made correct conclusion on the basis of correct measurements. In fact, he made 12 balloon flights in 1900-1903 during his PhD studies at Berlin University, carrying an electroscope to a height of 5500 m. The PhD Thesis was not published, but in Thesis he concludes: "Were one to compare the presented values with those on ground, one must say that at 1000 m altitude the ionization is smaller than on the ground, between 1 and 3 km the same amount, and above it is larger with values increasing up to a factor of 4 (at 5500 m). The uncertainties in the observations only allow the conclusion that the reason for the ionization has to be found first in the Earth." Nobody later quoted Franz Linke and although he had made the right measurements, he had reached the wrong conclusions, and the discovery of CR became only later on about 10 years. 4. Victor Hess, a

  5. KEY COMPARISON: Key comparison CCQM-K60: Total selenium and selenomethionine in selenised wheat flour

    Science.gov (United States)

    Goenaga Infante, Heidi; Sargent, Mike

    2010-01-01

    Key comparison CCQM-K60 was performed to assess the analytical capabilities of national metrology institutes (NMIs) to accurately quantitate the mass fraction of selenomethionine (SeMet) and total selenium (at low mg kg-1 levels) in selenised wheat flour. It was organized by the Inorganic Analysis Working Group (IAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) as a follow-up key comparison to the previous pilot study CCQM-P86 on selenised yeast tablets. LGC Limited (Teddington, UK) and the Institute for National Measurement Standards, National Research Council Canada (NRCC, Ottawa, Canada) acted as the coordinating laboratories. CCQM-K60 was organized in parallel with a pilot study (CCQM-P86.1) involving not only NMIs but also expert laboratories worldwide, thus enabling them to assess their capabilities, discover problems and learn how to modify analytical procedures accordingly. Nine results for total Se and four results for SeMet were reported by the participant NMIs. Methods used for sample preparation were microwave assisted acid digestion for total Se and multiple-step enzymatic hydrolysis and hydrolysis with methanesulfonic acid for SeMet. For total Se, detection techniques included inductively coupled plasma mass spectrometry (ICP-MS) with external calibration, standard additions or isotope dilution analysis (IDMS); instrumental neutron activation analysis (INAA); and graphite furnace atomic absorption spectrometry (GFAAS) with external calibration. For determination of SeMet in the wheat flour sample, the four NMIs relied upon measurements using species-specific IDMS (using 76Se-enriched SeMet) with HPLC-ICP-MS. Eight of the nine participating NMIs reported results for total Se within 3.5% deviation from the key comparison reference value (KCRV). For SeMet, the four participating NMIs reported results within 3.2% deviation from the KCRV. This shows that the performance of the majority of the CCQM-K60 participants was very good

  6. Solid-State Random Lasers

    CERN Document Server

    Noginov, Mikhail A

    2005-01-01

    Random lasers are the simplest sources of stimulated emission without cavity, with the feedback provided by scattering in a gain medium. First proposed in the late 60’s, random lasers have grown to a large research field. This book reviews the history and the state of the art of random lasers, provides an outline of the basic models describing their behavior, and describes the recent advances in the field. The major focus of the book is on solid-state random lasers. However, it also briefly describes random lasers based on liquid dyes with scatterers. The chapters of the book are almost independent of each other. So, the scientists or engineers interested in any particular aspect of random lasers can read directly the relevant section. Researchers entering the field of random lasers will find in the book an overview of the field of study. Scientists working in the field can use the book as a reference source.

  7. Space division multiplexing chip-to-chip quantum key distribution.

    Science.gov (United States)

    Bacco, Davide; Ding, Yunhong; Dalgaard, Kjeld; Rottwitt, Karsten; Oxenløwe, Leif Katsuo

    2017-09-29

    Quantum cryptography is set to become a key technology for future secure communications. However, to get maximum benefit in communication networks, transmission links will need to be shared among several quantum keys for several independent users. Such links will enable switching in quantum network nodes of the quantum keys to their respective destinations. In this paper we present an experimental demonstration of a photonic integrated silicon chip quantum key distribution protocols based on space division multiplexing (SDM), through multicore fiber technology. Parallel and independent quantum keys are obtained, which are useful in crypto-systems and future quantum network.

  8. A Comparison of the Effectiveness of a Dichotomous Key and a Multi-Access Key to Woodlice

    OpenAIRE

    Morse, David R.; Tardival, G.M.; Spicer, J.

    1996-01-01

    The efficiency, accuracy and usability of a multiaccess key, a paper based dichotomous key and a computer based version of the same were compared. All three identification aids covered the same group of woodlice, using comparable information. The keys were evaluated by first year Biology undergraduates at Sheffield University. Students using a computer based method were slower to reach an identification than those using the paper key. The number of correct identifications was similar for the ...

  9. Quantum Public Key Cryptosystem Based on Bell States

    Science.gov (United States)

    Wu, WanQing; Cai, QingYu; Zhang, HuanGuo; Liang, XiaoYan

    2017-11-01

    Classical public key cryptosystems ( P K C), such as R S A, E I G a m a l, E C C, are no longer secure in quantum algorithms, and quantum cryptography has become a novel research topic. In this paper we present a quantum asymmetrical cryptosystem i.e. quantum public key cryptosystem ( Q P K C) based on the Bell states. In particular, in the proposed QPKC the public key are given by the first n particles of Bell states and generalized Pauli operations. The corresponding secret key are the last n particles of Bell states and the inverse of generalized Pauli operations. The proposed QPKC encrypts the message using a public key and decrypts the ciphertext using a private key. By H o l e v o ' s theorem, we proved the security of the secret key and messages during the QPKC.

  10. Public Key Encryption with Keyword Search from Lattices in Multiuser Environments

    Directory of Open Access Journals (Sweden)

    Daini Wu

    2016-01-01

    Full Text Available A public key encryption scheme with keyword search capabilities is proposed using lattices for applications in multiuser environments. The proposed scheme enables a cloud server to check if any given encrypted data contains certain keywords specified by multiple users, but the server would not have knowledge of the keywords specified by the users or the contents of the encrypted data, which provides data privacy as well as privacy for user queries in multiuser environments. It can be proven secure under the standard learning with errors assumption in the random oracle model.

  11. Information analysis of iris biometrics for the needs of cryptology key extraction

    Directory of Open Access Journals (Sweden)

    Adamović Saša

    2013-01-01

    Full Text Available The paper presents a rigorous analysis of iris biometric information for the synthesis of an optimized system for the extraction of a high quality cryptology key. Estimations of local entropy and mutual information were identified as segments of the iris most suitable for this purpose. In order to optimize parameters, corresponding wavelets were transformed, in order to obtain the highest possible entropy and mutual information lower in the transformation domain, which set frameworks for the synthesis of systems for the extraction of truly random sequences of iris biometrics, without compromising authentication properties. [Projekat Ministarstva nauke Republike Srbije, br. TR32054 i br. III44006

  12. A New Quantum Key Distribution Scheme based on Frequency and Time Coding

    OpenAIRE

    Zhu, Chang-hua; Pei, Chang-xing; Quan, Dong-xiao; Chen, Nan; Yi, Yun-hui

    2010-01-01

    A new scheme of quantum key distribution (QKD) using frequency and time coding is proposed, in which the security is based on the frequency-time uncertainty relation. In this scheme, the binary information sequence is encoded randomly on either the central frequency or the time delay at the sender. The central frequency of the single photon pulse is set as omega1 for bit "0" and set as omega2 for bit "1" when frequency coding is selected. While, the single photon pulse is not delayed for bit ...

  13. Integration of quantum key distribution and private classical communication through continuous variable

    Science.gov (United States)

    Wang, Tianyi; Gong, Feng; Lu, Anjiang; Zhang, Damin; Zhang, Zhengping

    2017-12-01

    In this paper, we propose a scheme that integrates quantum key distribution and private classical communication via continuous variables. The integrated scheme employs both quadratures of a weak coherent state, with encrypted bits encoded on the signs and Gaussian random numbers encoded on the values of the quadratures. The integration enables quantum and classical data to share the same physical and logical channel. Simulation results based on practical system parameters demonstrate that both classical communication and quantum communication can be implemented over distance of tens of kilometers, thus providing a potential solution for simultaneous transmission of quantum communication and classical communication.

  14. Efficient Certificate-Based Signcryption Secure against Public Key Replacement Attacks and Insider Attacks

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2014-01-01

    Full Text Available Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner. As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously. In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security. We show that an existing certificate-based signcryption scheme is insecure in our model. We also propose a new certificate-based signcryption scheme that achieves security against both public key replacement attacks and insider attacks. We prove in the random oracle model that the proposed scheme is chosen-ciphertext secure and existentially unforgeable. Performance analysis shows that the proposed scheme outperforms all the previous certificate-based signcryption schemes in the literature.

  15. Common-signal-induced synchronization in photonic integrated circuits and its application to secure key distribution.

    Science.gov (United States)

    Sasaki, Takuma; Kakesu, Izumi; Mitsui, Yusuke; Rontani, Damien; Uchida, Atsushi; Sunada, Satoshi; Yoshimura, Kazuyuki; Inubushi, Masanobu

    2017-10-16

    We experimentally achieve common-signal-induced synchronization in two photonic integrated circuits with short external cavities driven by a constant-amplitude random-phase light. The degree of synchronization can be controlled by changing the optical feedback phase of the two photonic integrated circuits. The change in the optical feedback phase leads to a significant redistribution of the spectral energy of optical and RF spectra, which is a unique characteristic of PICs with the short external cavity. The matching of the RF and optical spectra is necessary to achieve synchronization between the two PICs, and stable synchronization can be obtained over an hour in the presence of optical feedback. We succeed in generating information-theoretic secure keys and achieving the final key generation rate of 184 kb/s using the PICs.

  16. Multi-party Semi-quantum Key Agreement with Delegating Quantum Computation

    Science.gov (United States)

    Liu, Wen-Jie; Chen, Zhen-Yu; Ji, Sai; Wang, Hai-Bin; Zhang, Jun

    2017-10-01

    A multi-party semi-quantum key agreement (SQKA) protocol based on delegating quantum computation (DQC) model is proposed by taking Bell states as quantum resources. In the proposed protocol, the participants only need the ability of accessing quantum channel and preparing single photons {|0〉, |1〉, |+〉, |-〉}, while the complicated quantum operations, such as the unitary operations and Bell measurement, will be delegated to the remote quantum center. Compared with previous quantum key agreement protocols, this client-server model is more feasible in the early days of the emergence of quantum computers. In order to prevent the attacks from outside eavesdroppers, inner participants and quantum center, two single photon sequences are randomly inserted into Bell states: the first sequence is used to perform the quantum channel detection, while the second is applied to disorder the positions of message qubits, which guarantees the security of the protocol.

  17. AUDIO CRYPTANALYSIS- AN APPLICATION OF SYMMETRIC KEY CRYPTOGRAPHY AND AUDIO STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    Smita Paira

    2016-09-01

    Full Text Available In the recent trend of network and technology, “Cryptography” and “Steganography” have emerged out as the essential elements of providing network security. Although Cryptography plays a major role in the fabrication and modification of the secret message into an encrypted version yet it has certain drawbacks. Steganography is the art that meets one of the basic limitations of Cryptography. In this paper, a new algorithm has been proposed based on both Symmetric Key Cryptography and Audio Steganography. The combination of a randomly generated Symmetric Key along with LSB technique of Audio Steganography sends a secret message unrecognizable through an insecure medium. The Stego File generated is almost lossless giving a 100 percent recovery of the original message. This paper also presents a detailed experimental analysis of the algorithm with a brief comparison with other existing algorithms and a future scope. The experimental verification and security issues are promising.

  18. Automated information extraction of key trial design elements from clinical trial publications.

    Science.gov (United States)

    de Bruijn, Berry; Carini, Simona; Kiritchenko, Svetlana; Martin, Joel; Sim, Ida

    2008-11-06

    Clinical trials are one of the most valuable sources of scientific evidence for improving the practice of medicine. The Trial Bank project aims to improve structured access to trial findings by including formalized trial information into a knowledge base. Manually extracting trial information from published articles is costly, but automated information extraction techniques can assist. The current study highlights a single architecture to extract a wide array of information elements from full-text publications of randomized clinical trials (RCTs). This architecture combines a text classifier with a weak regular expression matcher. We tested this two-stage architecture on 88 RCT reports from 5 leading medical journals, extracting 23 elements of key trial information such as eligibility rules, sample size, intervention, and outcome names. Results prove this to be a promising avenue to help critical appraisers, systematic reviewers, and curators quickly identify key information elements in published RCT articles.

  19. Quantum Entanglement Growth under Random Unitary Dynamics

    Directory of Open Access Journals (Sweden)

    Adam Nahum

    2017-07-01

    Full Text Available Characterizing how entanglement grows with time in a many-body system, for example, after a quantum quench, is a key problem in nonequilibrium quantum physics. We study this problem for the case of random unitary dynamics, representing either Hamiltonian evolution with time-dependent noise or evolution by a random quantum circuit. Our results reveal a universal structure behind noisy entanglement growth, and also provide simple new heuristics for the “entanglement tsunami” in Hamiltonian systems without noise. In 1D, we show that noise causes the entanglement entropy across a cut to grow according to the celebrated Kardar-Parisi-Zhang (KPZ equation. The mean entanglement grows linearly in time, while fluctuations grow like (time^{1/3} and are spatially correlated over a distance ∝(time^{2/3}. We derive KPZ universal behavior in three complementary ways, by mapping random entanglement growth to (i a stochastic model of a growing surface, (ii a “minimal cut” picture, reminiscent of the Ryu-Takayanagi formula in holography, and (iii a hydrodynamic problem involving the dynamical spreading of operators. We demonstrate KPZ universality in 1D numerically using simulations of random unitary circuits. Importantly, the leading-order time dependence of the entropy is deterministic even in the presence of noise, allowing us to propose a simple coarse grained minimal cut picture for the entanglement growth of generic Hamiltonians, even without noise, in arbitrary dimensionality. We clarify the meaning of the “velocity” of entanglement growth in the 1D entanglement tsunami. We show that in higher dimensions, noisy entanglement evolution maps to the well-studied problem of pinning of a membrane or domain wall by disorder.

  20. Gossip in Random Networks

    Science.gov (United States)

    Malarz, K.; Szvetelszky, Z.; Szekf, B.; Kulakowski, K.

    2006-11-01

    We consider the average probability X of being informed on a gossip in a given social network. The network is modeled within the random graph theory of Erd{õ}s and Rényi. In this theory, a network is characterized by two parameters: the size N and the link probability p. Our experimental data suggest three levels of social inclusion of friendship. The critical value pc, for which half of agents are informed, scales with the system size as N-gamma with gamma approx 0.68. Computer simulations show that the probability X varies with p as a sigmoidal curve. Influence of the correlations between neighbors is also evaluated: with increasing clustering coefficient C, X decreases.

  1. Investments in random environments

    Science.gov (United States)

    Navarro-Barrientos, Jesús Emeterio; Cantero-Álvarez, Rubén; Matias Rodrigues, João F.; Schweitzer, Frank

    2008-03-01

    We present analytical investigations of a multiplicative stochastic process that models a simple investor dynamics in a random environment. The dynamics of the investor's budget, x(t) , depends on the stochasticity of the return on investment, r(t) , for which different model assumptions are discussed. The fat-tail distribution of the budget is investigated and compared with theoretical predictions. We are mainly interested in the most probable value xmp of the budget that reaches a constant value over time. Based on an analytical investigation of the dynamics, we are able to predict xmpstat . We find a scaling law that relates the most probable value to the characteristic parameters describing the stochastic process. Our analytical results are confirmed by stochastic computer simulations that show a very good agreement with the predictions.

  2. Tailored Random Graph Ensembles

    Science.gov (United States)

    Roberts, E. S.; Annibale, A.; Coolen, A. C. C.

    2013-02-01

    Tailored graph ensembles are a developing bridge between biological networks and statistical mechanics. The aim is to use this concept to generate a suite of rigorous tools that can be used to quantify and compare the topology of cellular signalling networks, such as protein-protein interaction networks and gene regulation networks. We calculate exact and explicit formulae for the leading orders in the system size of the Shannon entropies of random graph ensembles constrained with degree distribution and degree-degree correlation. We also construct an ergodic detailed balance Markov chain with non-trivial acceptance probabilities which converges to a strictly uniform measure and is based on edge swaps that conserve all degrees. The acceptance probabilities can be generalized to define Markov chains that target any alternative desired measure on the space of directed or undirected graphs, in order to generate graphs with more sophisticated topological features.

  3. Random discrete Schroedinger operators from random matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, Jonathan [Institute of Mathematics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Forrester, Peter J [Department of Mathematics and Statistics, University of Melbourne, Parkville, Vic 3010 (Australia); Smilansky, Uzy [Department of Physics of Complex Systems, Weizmann Institute, Rehovot 76100 (Israel)

    2007-02-02

    We investigate random, discrete Schroedinger operators which arise naturally in the theory of random matrices, and depend parametrically on Dyson's Coulomb gas inverse temperature {beta}. They are similar to the class of 'critical' random Schroedinger operators with random potentials which diminish as vertical bar x vertical bar{sup -1/2}. We show that as a function of {beta} they undergo a transition from a regime of (power-law) localized eigenstates with a pure point spectrum for {beta} < 2 to a regime of extended states with a singular continuous spectrum for {beta} {>=} 2. (fast track communication)

  4. Energy-Efficient Implementation of ECDH Key Exchange for Wireless Sensor Networks

    Science.gov (United States)

    Lederer, Christian; Mader, Roland; Koschuch, Manuel; Großschädl, Johann; Szekely, Alexander; Tillich, Stefan

    Wireless Sensor Networks (WSNs) are playing a vital role in an ever-growing number of applications ranging from environmental surveillance over medical monitoring to home automation. Since WSNs are often deployed in unattended or even hostile environments, they can be subject to various malicious attacks, including the manipulation and capture of nodes. The establishment of a shared secret key between two or more individual nodes is one of the most important security services needed to guarantee the proper functioning of a sensor network. Despite some recent advances in this field, the efficient implementation of cryptographic key establishment for WSNs remains a challenge due to the resource constraints of small sensor nodes such as the MICAz mote. In this paper we present a lightweight implementation of the elliptic curve Diffie-Hellman (ECDH) key exchange for ZigBee-compliant sensor nodes equipped with an ATmega128 processor running the TinyOS operating system. Our implementation uses a 192-bit prime field specified by the NIST as underlying algebraic structure and requires only 5.20 ·106 clock cycles to compute a scalar multiplication if the base point is fixed and known a priori. A scalar multiplication using a random base point takes about 12.33 ·106 cycles. Our results show that a full ECDH key exchange between two MICAz motes consumes an energy of 57.33 mJ (including radio communication), which is significantly better than most previously reported ECDH implementations on comparable platforms.

  5. The distinction between key ideas in teaching school physics and key ideas in the discipline of physics

    Science.gov (United States)

    Deng, Zongyi

    2001-05-01

    The distinction between key ideas in teaching a high school science and key ideas in the corresponding discipline of science has been largely ignored in scholarly discourse about what science teachers should teach and about what they should know. This article clarifies this distinction through exploring how and why key ideas in teaching high school physics differ from key ideas in the discipline of physics. Its theoretical underpinnings include Dewey's (1902/1990) distinction between the psychological and the logical and Harré's (1986) epistemology of science. It analyzes how and why the key ideas in teaching color, the speed of light, and light interference at the high school level differ from the key ideas at the disciplinary level. The thesis is that key ideas in teaching high school physics can differ from key ideas in the discipline in some significant ways, and that the differences manifest Dewey's distinction. As a result, the article challenges the assumption of equating key ideas in teaching a high school science with key ideas in the corresponding discipline of science, and the assumption that having a college degree in science is sufficient to teach high school science. Furthermore, the article expands the concept of pedagogical content knowledge by arguing that key ideas in teaching high school physics constitute an essential component.

  6. Security analysis of quantum key distribution on passive optical networks.

    Science.gov (United States)

    Lim, Kyongchun; Ko, Heasin; Suh, Changho; Rhee, June-Koo Kevin

    2017-05-15

    Needs for providing security to end users have brought installation of quantum key distribution (QKD) in one-to-many access networks such as passive optical networks. In the networks, a presence of optical power splitters makes issues for secure key rate more important. However, researches for QKD in access networks have mainly focused on implementation issues rather than protocol development for key rate enhancement. Since secure key rate is theoretically limited by a protocol, researches without protocol development cannot overcome the limit of secure key rate given by a protocol. This brings need of researches for protocol development. In this paper, we provide a new approach which provides secure key rate enhancement over the conventional protocol. Specifically, we propose the secure key rate formula in a passive optical network by extending the secure key rate formula based on the decoy-state BB84 protocol. For a passive optical network, we provide a way that incorporates cooperation across end users. Then, we show that the way can mitigate a photon number splitting (PNS) attack which is crucial in an well known decoy BB84 protocol. Especially, the proposed scheme enables multi-photon states to serve as secure keys unlike the conventional decoy BB84 protocol. Numerical simulations demonstrate that our proposed scheme outperforms the decoy BB84 protocol in secure key rate.

  7. Characterization of Available Light for Seagrass and Patch Reef Productivity in Sugarloaf Key, Lower Florida Keys

    Directory of Open Access Journals (Sweden)

    Gerardo Toro-Farmer

    2016-01-01

    Full Text Available Light availability is an important factor driving primary productivity in benthic ecosystems, but in situ and remote sensing measurements of light quality are limited for coral reefs and seagrass beds. We evaluated the productivity responses of a patch reef and a seagrass site in the Lower Florida Keys to ambient light availability and spectral quality. In situ optical properties were characterized utilizing moored and water column bio-optical and hydrographic measurements. Net ecosystem productivity (NEP was also estimated for these study sites using benthic productivity chambers. Our results show higher spectral light attenuation and absorption, and lower irradiance during low tide in the patch reef, tracking the influx of materials from shallower coastal areas. In contrast, the intrusion of clearer surface Atlantic Ocean water caused lower values of spectral attenuation and absorption, and higher irradiance in the patch reef during high tide. Storms during the studied period, with winds >10 m·s−1, caused higher spectral attenuation values. A spatial gradient of NEP was observed, from high productivity in the shallow seagrass area, to lower productivity in deeper patch reefs. The highest daytime NEP was observed in the seagrass, with values of almost 0.4 g·O2·m−2·h−1. Productivity at the patch reef area was lower in May than during October 2012 (mean = 0.137 and 0.177 g·O2·m−2·h−1, respectively. Higher photosynthetic active radiation (PAR levels measured above water and lower light attenuation in the red region of the visible spectrum (~666 to ~699 nm had a positive correlation with NEP. Our results indicate that changes in light availability and quality by suspended or resuspended particles limit benthic productivity in the Florida Keys.

  8. When are cellular automata random?

    Science.gov (United States)

    Coe, J. B.; Ahnert, S. E.; Fink, T. M. A.

    2008-12-01

    A random cellular automaton is one in which a cell's behaviour is independent of its previous states. We derive analytical conditions which must be satisfied by random cellular automata and find deterministic and probabilistic cellular automata that satisfy these conditions. Many random cellular automata are seen to have a flow as they are updated through time. We define a correlation current that describes this flow and develop an analytical expression for its size. We compare results from this analytical expression with those from simulation. The randomness in a cell comes from randomness in adjacent cells or from the stochastic nature of update rules. We give an expression for how much randomness comes from each of these two sources.

  9. Methods and analysis of realizing randomized grouping.

    Science.gov (United States)

    Hu, Liang-Ping; Bao, Xiao-Lei; Wang, Qi

    2011-07-01

    Randomization is one of the four basic principles of research design. The meaning of randomization includes two aspects: one is to randomly select samples from the population, which is known as random sampling; the other is to randomly group all the samples, which is called randomized grouping. Randomized grouping can be subdivided into three categories: completely, stratified and dynamically randomized grouping. This article mainly introduces the steps of complete randomization, the definition of dynamic randomization and the realization of random sampling and grouping by SAS software.

  10. [Controlled randomized clinical trials].

    Science.gov (United States)

    Jaillon, Patrice

    2007-01-01

    It is generally agreed that the first comparative clinical trial in history was done by James Lind in 1747, in the treatment of scurvy. The general bases of modern experimental medicine were published by Claude Bernard in 1865. However, it is the development of new drugs and the evolution of methodological concepts that led to the first randomized controlled clinical trial, in 1948, which showed that the effects of streptomycin on pulmonary tuberculosis were significantly different from those of a placebo. Today, "evidence-based" medicine aims to rationalize the medical decision-making process by taking into account, first and foremost, the results of controlled randomized clinical trials, which provide the highest level of evidence. In the second half of the 20th century it became clear that different kinds of clinical trials might not provide the same level of evidence. Practitioners' intimate convictions must be challenged by the results of controlled clinical trials. Take the CAST trial for example, which, in 1989, tested antiarrhythmic drugs versus placebo in patients with myocardial infarction. It was well known that ventricular arrhythmias were a factor of poor prognosis in coronary heart disease, and it was therefore considered self-evident that drug suppression of these ventricular arrhythmias would reduce the mortality rate. In the event, the CAST trial showed the exact opposite, with an almost 3-fold increase in total mortality among patients with coronary heart disease who were treated with antiarrhythmic drugs. These results had a profound impact on the use of antiarrythmic drugs, which became contraindicated after myocardial infarction. A clinical trial has to fulfill certain methodological standards to be accepted as evidence-based medicine. First, a working hypothesis has to be formulated, and then the primary outcome measure must be chosen before beginning the study. An appropriate major endpoint for efficacy must be selected, in keeping with the

  11. Fractional random walk lattice dynamics

    Science.gov (United States)

    Michelitsch, T. M.; Collet, B. A.; Riascos, A. P.; Nowakowski, A. F.; Nicolleau, F. C. G. A.

    2017-02-01

    We analyze time-discrete and time-continuous ‘fractional’ random walks on undirected regular networks with special focus on cubic periodic lattices in n  =  1, 2, 3,.. dimensions. The fractional random walk dynamics is governed by a master equation involving fractional powers of Laplacian matrices {{L}\\fracα{2}}} where α =2 recovers the normal walk. First we demonstrate that the interval 0<α ≤slant 2 is admissible for the fractional random walk. We derive analytical expressions for the transition matrix of the fractional random walk and closely related the average return probabilities. We further obtain the fundamental matrix {{Z}(α )} , and the mean relaxation time (Kemeny constant) for the fractional random walk. The representation for the fundamental matrix {{Z}(α )} relates fractional random walks with normal random walks. We show that the matrix elements of the transition matrix of the fractional random walk exihibit for large cubic n-dimensional lattices a power law decay of an n-dimensional infinite space Riesz fractional derivative type indicating emergence of Lévy flights. As a further footprint of Lévy flights in the n-dimensional space, the transition matrix and return probabilities of the fractional random walk are dominated for large times t by slowly relaxing long-wave modes leading to a characteristic {{t}-\\frac{n{α}} -decay. It can be concluded that, due to long range moves of fractional random walk, a small world property is emerging increasing the efficiency to explore the lattice when instead of a normal random walk a fractional random walk is chosen.

  12. Octonions in random matrix theory

    OpenAIRE

    Forrester, Peter J.

    2016-01-01

    The octonions are one of the four normed division algebras, together with the real, complex and quaternion number systems. The latter three hold a primary place in random matrix theory, where in applications to quantum physics they are determined as the entries of ensembles of Hermitian random by symmetry considerations. Only for $N=2$ is there an existing analytic theory of Hermitian random matrices with octonion entries. We use a Jordan algebra viewpoint to provide an analytic theory for $N...

  13. Random Numbers from Astronomical Imaging

    OpenAIRE

    Pimbblet, Kevin A.; Bulmer, Michael

    2004-01-01

    This article describes a method to turn astronomical imaging into a random number generator by using the positions of incident cosmic rays and hot pixels to generate bit streams. We subject the resultant bit streams to a battery of standard benchmark statistical tests for randomness and show that these bit streams are statistically the same as a perfect random bit stream. Strategies for improving and building upon this method are outlined.

  14. Efficient Raman generation in a waveguide: A route to ultrafast quantum random number generation

    Energy Technology Data Exchange (ETDEWEB)

    England, D. G.; Bustard, P. J.; Moffatt, D. J.; Nunn, J.; Lausten, R.; Sussman, B. J., E-mail: ben.sussman@nrc.ca [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada)

    2014-02-03

    The inherent uncertainty in quantum mechanics offers a source of true randomness which can be used to produce unbreakable cryptographic keys. We discuss the development of a high-speed random number generator based on the quantum phase fluctuations in spontaneously initiated stimulated Raman scattering (SISRS). We utilize the tight confinement and long interaction length available in a Potassium Titanyl Phosphate waveguide to generate highly efficient SISRS using nanojoule pulse energies, reducing the high pump power requirements of the previous approaches. We measure the random phase of the Stokes output using a simple interferometric setup to yield quantum random numbers at 145 Mbps.

  15. Password-based authenticated key exchange scheme using smart card

    Science.gov (United States)

    Liu, Hui; Zhong, Shaojun

    2013-03-01

    A protocol that allows any two entities to negotiate a shared session key is commonly called a key exchange protocol. If the protocol provides a function to authenticate each other, we call the protocol authenticated key exchange protocol (AKE). Password authentication key exchange (PAKE) is the AKE protocol in which the two entities share a humanmemorable password. Most of current PAKE relies on the existence of a public key infrastructure, which sometime is impossible for a certain environments such as low computational device due to the computation overhead. In this paper, we propose password-based authenticated key exchange using smart card. Compared to previous PAKE, our protocol is more efficient because our protocol is based on ECC. Thereby, the proposed protocol can be well applied to low computation device.

  16. A key management concept for the CTBT International Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Herrington, P.; Draelos, T.; Craft, R. [Sandia National Labs., Albuquerque, NM (United States); Brickell, E.; Frankel, Y.; Silvestri, M. [CertCo (United States)

    1997-08-01

    Cryptographic authentication (commonly referred to as ``technical authentication`` in Working Group B) is an enabling technology which ensures the integrity of sensor data and security of digital networks under various data security compromise scenarios. The use of cryptographic authentication,however, implies the development of a key management infrastructure for establishing trust in the generation and distribution of cryptographic keys. This paper proposes security and operational requirements for a CTBT (Comprehensive Test Ban Treaty) key management system and, furthermore, presents a public key based solution satisfying the requirements. The key management system is instantiated with trust distribution technologies similar to those currently implemented in industrial public key infrastructures. A complete system solution is developed.

  17. Importance of randomness in biological networks: A random matrix ...

    Indian Academy of Sciences (India)

    2015-01-29

    Jan 29, 2015 ... We show that in spite of huge differences these interaction networks, representing real-world systems, posses from random matrix models, the spectral properties of the underlying matrices of these networks follow random matrix theory bringing them into the same universality class. We further demonstrate ...

  18. Architectural Building A Public Key Infrastructure Integrated Information Space

    Directory of Open Access Journals (Sweden)

    Vadim Ivanovich Korolev

    2015-10-01

    Full Text Available The article keeps under consideration the mattersto apply the cryptographic system having a public key to provide information security and to implya digital signature. It performs the analysis of trust models at the formation of certificates and their use. The article describes the relationships between the trust model and the architecture public key infrastructure. It contains conclusions in respect of the options for building the public key infrastructure for integrated informationspace.

  19. Key working for families with young disabled children.

    Science.gov (United States)

    Carter, Bernie; Thomas, Megan

    2011-01-01

    For families with a disabled child, the usual challenges of family life can be further complicated by the need to access a wide range of services provided by a plethora of professionals and agencies. Key working aims to support children and their families in navigating these complexities ensuring easy access to relevant, high quality, and coordinated care. The aim of this paper is to explore the key worker role in relation to "being a key worker" and "having a key worker". The data within this paper draw on a larger evaluation study of the Blackpool Early Support Pilot Programme. The qualitative study used an appreciative and narrative approach and utilised mixed methods (interviews, surveys and a nominal group workshop). Data were collected from 43 participants (parents, key workers, and other stakeholders). All stakeholders who had been involved with the service were invited to participate. In the paper we present and discuss the ways in which key working made a difference to the lives of children and their families. We also consider how key working transformed the perspectives of the key workers creating a deeper and richer understanding of family lives and the ways in which other disciplines and agencies worked. Key working contributed to the shift to a much more family-centred approach, and enhanced communication and information sharing between professionals and agencies improved. This resulted in families feeling more informed. Key workers acted in an entrepreneurial fashion, forging new relationships with families and between families and other stakeholders. Parents of young disabled children and their service providers benefited from key working. Much of the benefit accrued came from strong, relational, and social-professional networking which facilitated the embedding of new ways of working into everyday practice. Using an appreciative inquiry approach provided an effective and relevant way of engaging with parents, professionals, and other stakeholders to

  20. EFFECTIVE MYANMAR KEY LAYOUT DESIGN ANALYZING FOR ANDROID SOFT KEYBOARD

    OpenAIRE

    NANDAR PWINT OO; NI LAR THEIN

    2012-01-01

    In mobile phone soft keyboard layout, some Myanmar characters are behind the keyboard layout scene and it is needed to switch with some control key. For mobile phone text entry system, optimizing the fit between technology and the user is critical for realizing the potential benefits of assistive technology. It is a necessarytask to try out the effective key layout design that can enhance the text entry speed. Moreover, there is also weak in analyzing of key layout design for Myanmar Language...

  1. Key Working for Families with Young Disabled Children

    Directory of Open Access Journals (Sweden)

    Bernie Carter

    2011-01-01

    Full Text Available For families with a disabled child, the usual challenges of family life can be further complicated by the need to access a wide range of services provided by a plethora of professionals and agencies. Key working aims to support children and their families in navigating these complexities ensuring easy access to relevant, high quality, and coordinated care. The aim of this paper is to explore the key worker role in relation to “being a key worker” and “having a key worker”. The data within this paper draw on a larger evaluation study of the Blackpool Early Support Pilot Programme. The qualitative study used an appreciative and narrative approach and utilised mixed methods (interviews, surveys and a nominal group workshop. Data were collected from 43 participants (parents, key workers, and other stakeholders. All stakeholders who had been involved with the service were invited to participate. In the paper we present and discuss the ways in which key working made a difference to the lives of children and their families. We also consider how key working transformed the perspectives of the key workers creating a deeper and richer understanding of family lives and the ways in which other disciplines and agencies worked. Key working contributed to the shift to a much more family-centred approach, and enhanced communication and information sharing between professionals and agencies improved. This resulted in families feeling more informed. Key workers acted in an entrepreneurial fashion, forging new relationships with families and between families and other stakeholders. Parents of young disabled children and their service providers benefited from key working. Much of the benefit accrued came from strong, relational, and social-professional networking which facilitated the embedding of new ways of working into everyday practice. Using an appreciative inquiry approach provided an effective and relevant way of engaging with parents, professionals

  2. Pseudo-random number generator based on asymptotic deterministic randomness

    Energy Technology Data Exchange (ETDEWEB)

    Wang Kai [Department of Radio Engineering, Southeast University, Nanjing (China)], E-mail: kaiwang@seu.edu.cn; Pei Wenjiang; Xia Haishan [Department of Radio Engineering, Southeast University, Nanjing (China); Cheung Yiuming [Department of Computer Science, Hong Kong Baptist University, Hong Kong (China)

    2008-06-09

    A novel approach to generate the pseudorandom-bit sequence from the asymptotic deterministic randomness system is proposed in this Letter. We study the characteristic of multi-value correspondence of the asymptotic deterministic randomness constructed by the piecewise linear map and the noninvertible nonlinearity transform, and then give the discretized systems in the finite digitized state space. The statistic characteristics of the asymptotic deterministic randomness are investigated numerically, such as stationary probability density function and random-like behavior. Furthermore, we analyze the dynamics of the symbolic sequence. Both theoretical and experimental results show that the symbolic sequence of the asymptotic deterministic randomness possesses very good cryptographic properties, which improve the security of chaos based PRBGs and increase the resistance against entropy attacks and symbolic dynamics attacks.

  3. Evaluating viral marketing: isolating the key criteria in insurance industry

    National Research Council Canada - National Science Library

    Maria Gooyandeh Hagh

    2015-01-01

    This paper presents an empirical investigation to determine the key criteria that viral marketing practitioners believe should be implemented to measure about the success of viral marketing campaigns...

  4. Key agreement in peer-to-peer wireless networks

    DEFF Research Database (Denmark)

    Cagalj, Mario; Capkun, Srdjan; Hubaux, Jean-Pierre

    2006-01-01

    We present a set of simple techniques for key establishment over a radio link in peer-to-peer networks. Our approach is based on the Diffie-Hellman key agreement protocol, which is known to be vulnerable to the “man-in-the-middle” attack if the two users involved in the protocol do not share any...... authenticated information about each other (e.g., public keys, certificates, passwords, shared keys, etc.) prior to the protocol execution. In this paper, we solve the problem by leveraging on the natural ability of users to authenticate each other by visual and verbal contact.We propose three techniques...

  5. Key events in the history of sustainable development

    OpenAIRE

    Sustainable Development Commission

    2005-01-01

    This document is a table which summaries the key events in the history of sustainable development, adapted from International Institute for Sustainable Development's sustainable development timeline. Publisher PDF

  6. Public key infrastructure building trusted applications and web services

    CERN Document Server

    Vacca, John R

    2004-01-01

    OVERVIEW OF PKI TECHNOLOGYPublic Key Infrastructures (PKIs): What Are They?Type of Certificate Authorities (CAS) ServicesPKI StandardsTypes of Vendor and Third-Party CA SystemsProtecting Private KeysCA System AttacksStolen Private Keys: What Can Be Done?Certificate Practice StatementsPKI ReadinessANALYZING AND DESIGNING PUBLIC KEY INFRASTRUCTURESPKI Design IssuesCost Justification and ConsiderationPKI Standards Design IssuesPKI Architectural Design ConsiderationsIMPLEMENTING PKIRequirementsImplementation ScheduleImplementation CostsPKI PerformanceMANAGING PKIRequesting a CertificateObtaining a

  7. Asymmetric evolving random networks

    Science.gov (United States)

    Coulomb, S.; Bauer, M.

    2003-10-01

    We generalize the Poissonian evolving random graph model of M. Bauer and D. Bernard (2003), to deal with arbitrary degree distributions. The motivation comes from biological networks, which are well-known to exhibit non Poissonian degree distributions. A node is added at each time step and is connected to the rest of the graph by oriented edges emerging from older nodes. This leads to a statistical asymmetry between incoming and outgoing edges. The law for the number of new edges at each time step is fixed but arbitrary. Thermodynamical behavior is expected when this law has a large time limit. Although (by construction) the incoming degree distributions depend on this law, this is not the case for most qualitative features concerning the size distribution of connected components, as long as the law has a finite variance. As the variance grows above 1/4, the average being < 1/2, a giant component emerges, which connects a finite fraction of the vertices. Below this threshold, the distribution of component sizes decreases algebraically with a continuously varying exponent. The transition is of infinite order, in sharp contrast with the case of static graphs. The local-in-time profiles for the components of finite size allow to give a refined description of the system.

  8. Recoverable Random Numbers in an Internet of Things Operating System

    Directory of Open Access Journals (Sweden)

    Taeill Yoo

    2017-03-01

    Full Text Available Over the past decade, several security issues with Linux Random Number Generator (LRNG on PCs and Androids have emerged. The main problem involves the process of entropy harvesting, particularly at boot time. An entropy source in the input pool of LRNG is not transferred into the non-blocking output pool if the entropy counter of the input pool is less than 192 bits out of 4098 bits. Because the entropy estimation of LRNG is highly conservative, the process may require more than one minute for starting the transfer. Furthermore, the design principle of the estimation algorithm is not only heuristic but also unclear. Recently, Google released an Internet of Things (IoT operating system called Brillo based on the Linux kernel. We analyze the behavior of the random number generator in Brillo, which inherits that of LRNG. In the results, we identify two features that enable recovery of random numbers. With these features, we demonstrate that random numbers of 700 bytes at boot time can be recovered with the success probability of 90% by using time complexity for 5.20 × 2 40 trials. Therefore, the entropy of random numbers of 700 bytes is merely about 43 bits. Since the initial random numbers are supposed to be used for sensitive security parameters, such as stack canary and key derivation, our observation can be applied to practical attacks against cryptosystem.

  9. Random Number Generation and Executive Functions in Parkinson's Disease: An Event-Related Brain Potential Study.

    Science.gov (United States)

    Münte, Thomas F; Joppich, Gregor; Däuper, Jan; Schrader, Christoph; Dengler, Reinhard; Heldmann, Marcus

    2015-01-01

    The generation of random sequences is considered to tax executive functions and has been reported to be impaired in Parkinson's disease (PD) previously. To assess the neurophysiological markers of random number generation in PD. Event-related potentials (ERP) were recorded in 12 PD patients and 12 age-matched normal controls (NC) while either engaging in random number generation (RNG) by pressing the number keys on a computer keyboard in a random sequence or in ordered number generation (ONG) necessitating key presses in the canonical order. Key presses were paced by an external auditory stimulus at a rate of 1 tone every 1800 ms. As a secondary task subjects had to monitor the tone-sequence for a particular target tone to which the number "0" key had to be pressed. This target tone occurred randomly and infrequently, thus creating a secondary oddball task. Behaviorally, PD patients showed an increased tendency to count in steps of one as well as a tendency towards repetition avoidance. Electrophysiologically, the amplitude of the P3 component of the ERP to the target tone of the secondary task was reduced during RNG in PD but not in NC. The behavioral findings indicate less random behavior in PD while the ERP findings suggest that this impairment comes about, because attentional resources are depleted in PD.

  10. Random selection of Borel sets

    Directory of Open Access Journals (Sweden)

    Bernd Günther

    2010-10-01

    Full Text Available A theory of random Borel sets is presented, based on dyadic resolutions of compact metric spaces. The conditional expectation of the intersection of two independent random Borel sets is investigated. An example based on an embedding of Sierpinski’s universal curve into the space of Borel sets is given.

  11. Students' Misconceptions about Random Variables

    Science.gov (United States)

    Kachapova, Farida; Kachapov, Ilias

    2012-01-01

    This article describes some misconceptions about random variables and related counter-examples, and makes suggestions about teaching initial topics on random variables in general form instead of doing it separately for discrete and continuous cases. The focus is on post-calculus probability courses. (Contains 2 figures.)

  12. Forecasting Using Random Subspace Methods

    NARCIS (Netherlands)

    T. Boot (Tom); D. Nibbering (Didier)

    2016-01-01

    textabstractRandom subspace methods are a novel approach to obtain accurate forecasts in high-dimensional regression settings. We provide a theoretical justification of the use of random subspace methods and show their usefulness when forecasting monthly macroeconomic variables. We focus on two

  13. Developments in Random Matrix Theory

    OpenAIRE

    Snaith, N. C.; Forrester, P. J.; Verbaarschot, J. J. M.

    2003-01-01

    In this preface to the Journal of Physics A, Special Edition on Random Matrix Theory, we give a review of the main historical developments of random matrix theory. A short summary of the papers that appear in this special edition is also given.

  14. QCD and random matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, A.D. [Niels Bohr Inst., Copenhagen (Denmark)

    1998-08-10

    Chiral random matrix theory has recently been shown to provide a tool useful for both modeling chiral symmetry restoration in QCD and for providing analytic descriptions of the microscopic spectral content of lattice gauge simulations. The basic ideas of chiral random matrix theory and some recent results are discussed. (orig.) 24 refs.

  15. First direct landscape-scale measurement of tropical rain forest Leaf Area Index, a key driver of global primary productivity

    Science.gov (United States)

    David B. Clark; Paulo C. Olivas; Steven F. Oberbauer; Deborah A. Clark; Michael G. Ryan

    2008-01-01

    Leaf Area Index (leaf area per unit ground area, LAI) is a key driver of forest productivity but has never previously been measured directly at the landscape scale in tropical rain forest (TRF). We used a modular tower and stratified random sampling to harvest all foliage from forest floor to canopy top in 55 vertical transects (4.6 m2) across 500 ha of old growth in...

  16. a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    MS Yıldırım

    2016-02-01

    Full Text Available The aim of this study was to compare the effects of static stretching, proprioceptive neuromuscular facilitation (PNF stretching and Mulligan technique on hip flexion range of motion (ROM in subjects with bilateral hamstring tightness. A total of 40 students (mean age: 21.5±1.3 years, mean body height: 172.8±8.2 cm, mean body mass index: 21.9±3.0 kg • m-2 with bilateral hamstring tightness were enrolled in this randomized trial, of whom 26 completed the study. Subjects were divided into 4 groups performing (I typical static stretching, (II PNF stretching, (III Mulligan traction straight leg raise (TSLR technique, (IV no intervention. Hip flexion ROM was measured using a digital goniometer with the passive straight leg raise test before and after 4 weeks by two physiotherapists blinded to the groups. 52 extremities of 26 subjects were analyzed. Hip flexion ROM increased in all three intervention groups (p<0.05 but not in the no-intervention group after 4 weeks. A statistically significant change in initial–final assessment differences of hip flexion ROM was found between groups (p<0.001 in favour of PNF stretching and Mulligan TSLR technique in comparison to typical static stretching (p=0.016 and p=0.02, respectively. No significant difference was found between Mulligan TSLR technique and PNF stretching (p=0.920. The initial–final assessment difference of hip flexion ROM was similar in typical static stretching and no intervention (p=0.491. A 4-week stretching intervention is beneficial for increasing hip flexion ROM in bilateral hamstring tightness. However, PNF stretching and Mulligan TSLR technique are superior to typical static stretching. These two interventions can be alternatively used for stretching in hamstring tightness.

  17. An Efficient Method to Audio Steganography based on Modification of Least Significant Bit Technique using Random Keys

    National Research Council Canada - National Science Library

    Ali M Meligy; Mohammed M Nasef; Fatma T Eid

    2015-01-01

      Steganography is the art of amalgamating the secret message into another public message which may be text, audio or video file in a way that no one can know or imperceptible the existence of message...

  18. A Wiki-based Key to Garden and Village Birds

    OpenAIRE

    Trilar, Tomi

    2010-01-01

    A Wiki-based Key to Garden and Village Birds is available in two versions: a dichotomous, hyperlinked and printable version, and as step-bystep identification version. It is supported by jKey Player in English, Slovenian, Spanish, Romanian and German.

  19. Classification and the Dichotomous Key: Tools for Teaching Identification

    Science.gov (United States)

    Watson, Sandy; Miller, Ted

    2009-01-01

    Classification is a vital science-process skill for all students to master. Understanding dichotomous keys as a means of classification enables students to better comprehend large amounts of information and understand how to organize, compare and contrast, and analyze that information. To biology students, mastering the dichotomous key provides an…

  20. Perceptions of food risk management among key stakeholders

    DEFF Research Database (Denmark)

    van Kleef, Ellen; Frewer, Lynn J.; Chryssochoidis, George M.

    2006-01-01

    In designing and implementing appropriate food risk management strategies, it is important to examine how key stakeholders perceive both the practice and effectiveness of food risk management.......In designing and implementing appropriate food risk management strategies, it is important to examine how key stakeholders perceive both the practice and effectiveness of food risk management....