WorldWideScience

Sample records for adaptive subcarrier psk

  1. Reconfigurable digital receiver for 8PSK subcarrier multiplexed and 16QAM single carrier phase‐modulated radio over fiber links

    Guerrero Gonzalez, Neil; Zibar, Darko; Yu, Xianbin;

    2011-01-01

    A reconfigurable digital receiver based on the k‐means algorithm is proposed for phase‐modulated subcarrier multiplexed (SCM) and quadrature amplitude‐modulated single carrier, phase‐modulated radio‐over‐fiber links. We report successful demodulation after 40 km single mode fiber transmission wit...... three 50 Mbaud 8PSK SCM signals and a 312.5 Mbaud 16QAM single carrier. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1015–1018, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25905...

  2. Optical phase-modulated radio-over-fiber links with k-means algorithm for digital demodulation of 8PSK subcarrier multiplexed signals

    Guerrero Gonzalez, Neil; Zibar, Darko; Yu, Xianbin;

    2010-01-01

    A k-means algorithm for phase recovery of three, 50 Mbaud, 8PSK subcarrier multiplexed signals at 5 GHz for optical phase-modulated radio-over-fiber is proposed and experimentally demonstrated after 40 km of single mode fiber transmission......A k-means algorithm for phase recovery of three, 50 Mbaud, 8PSK subcarrier multiplexed signals at 5 GHz for optical phase-modulated radio-over-fiber is proposed and experimentally demonstrated after 40 km of single mode fiber transmission...

  3. Adaptive Subcarrier and Bit Allocation for Downlink OFDMA System with Proportional Fairness

    Sudhir B. Lande

    2011-11-01

    Full Text Available This paper investigates the adaptive subcarrier and bit allocation algorithm for OFDMA systems. To minimize overall transmitted power, we propose a novel adaptive subcarrier and bit allocation algorithm based on channel state information (CSI and quality state information (QSI. A suboptimal approach that separately performs subcarrier allocation and bit loading is proposed. It is shown that a near optimal solution is obtained by the proposed algorithm which has low complexity compared to that of other conventional algorithm. We will study the problem of finding an optimal sub-carrier and power allocation strategy for downlink communication to multiple users in an OFDMA based wireless system.Assuming knowledge of the instantaneous channel gains for all users, we propose a multiuser OFDMA subcarrier, and bit allocation algorithm to minimize the total transmit power. This is done by assigning each user a set of subcarriers and by determining the number of bits and the transmit power level for each subcarrier. The objective is to minimize the total transmitted power over the entire network to satisfy the application layer and physical layer. We formulate this problem as a constrained optimization problem and present centralized algorithms. The simulation results will show that our approach results in an efficient assignment of subcarriers and transmitter power levels in terms of the energy required for transmitting each bit of information, to address this need, we also present a bit loading algorithm for allocating subcarriers and bits in order to satisfy the rate requirements of the links.

  4. Efficient MAC Protocol for Subcarrier-Wise Rate Adaptation over WLAN

    Sung Won Kim

    2010-01-01

    Full Text Available While bit-loading algorithms over wireless systems have been extensively studied, the development of a protocol which implements bit-loading-based rate adaptation over wireless systems has not been highlighted. The design of such a protocol is not a trivial problem, due to the overhead associated with the feedback information. In this paper, a novel protocol is proposed to provide an efficient way to implement subcarrier-wise rate adaptation in OFDM-based wireless systems. When receiving a Ready-To-Send (RTS packet, the receiver determines the number of bits to be allocated on each subcarrier through channel estimation. This decision is delivered to the sender using an additional OFDM symbol in the Clear-To-Send (CTS packet. That is, bit-allocation over subcarriers is achieved using only one additional OFDM symbol. The protocol enhances the channel efficiency in spite of the overhead of one additional OFDM symbol.

  5. Blind Adaptive Subcarrier Combining Technique for MC-CDMA Receiver in Mobile Rayleigh Channel

    Shakya, Indu; Stipidis, Elias

    2011-01-01

    A new subcarrier combining technique is proposed for MC -CDMA receiver in mobile Rayleigh fading channel. It exploits the structure formed by repeating spreading sequences of users on different subcarriers to simultaneously suppress multiple access interference (MAI) and provide implicit channel tracking without any knowledge of the channel amplitudes or training sequences. This is achieved by adaptively weighting each subcarrier in each symbol period by employing a simple gradient descent algorithm to meet the constant modulus (CM) criterion with judicious selection of step-size. Improved BER and user capacity performance are shown with similar complexity in order of O(N) compared with conventional maximum ratio combining and equal gain combining techniques even under high channel Doppler rates.

  6. Efficient MAC Protocol for Subcarrier-Wise Rate Adaptation over WLAN

    Kim Byung-Seo; Hong SungBack; Kim SungWon

    2010-01-01

    While bit-loading algorithms over wireless systems have been extensively studied, the development of a protocol which implements bit-loading-based rate adaptation over wireless systems has not been highlighted. The design of such a protocol is not a trivial problem, due to the overhead associated with the feedback information. In this paper, a novel protocol is proposed to provide an efficient way to implement subcarrier-wise rate adaptation in OFDM-based wireless systems. When receiving a R...

  7. Multiuser subcarriers and bit allocation combining adaptive mapping for SC-FDMA system

    ZHANG Yu-mei; XIN Yu; YANG Da-cheng

    2008-01-01

    In this article, a multiuser single carrier frequency division multiple access (SC-FDMA) system is considered, based on which an adaptive subcarrier and bit allocation algorithm is investigated. The algorithm has been used to achieve a subcarrier mapping mode in this system, which combines the advantages of single- and multi-carrier transmissions, such as, low peak to average power ratio, orthogonality of signals of different users, and low complexity. Simulation results show that it has a similar performance as that of the adaptive allocation algorithm in the orthogonal frequency division multiple (OFDM) system and the proposed mapping mode has a performance gain over the two existing mapping modes at the link level.

  8. Joint sub-carrier pairing and resource allocation for cognitive networks with adaptive relaying

    Soury, H.

    2013-11-09

    Relayed transmission in a cognitive radio (CR) environment could be used to increase the coverage and capacity of communication system that benefits already from the efficient management of the spectrum developed by CR. Furthermore, there are many types of cooperative communications, including decode-and-forward (DAF) and amplify-and-forward (AAF). In this paper, these techniques are combined in an adaptive mode to benefit from its forwarding advantages; this mode is called adaptive relaying protocol (ARP). Moreover, this work focuses on the joint power allocation in a cognitive radio system in a cooperative mode that operates ARP in multi-carrier mode. The multi-carrier scenario is used in an orthogonal frequency division multiplexing (OFDM) mode, and the problem is formulated to maximize the end-to-end rate by searching the best power allocation at the transmitters. This work includes, besides the ARP model, a sub-carrier pairing strategy that allows the relays to switch to the best sub-carrier pairs to increase the throughput. The optimization problem is formulated and solved under the interference and power budget constraints using the sub-gradient algorithm. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques. The results show also the consequence of the choice of the pairing strategy. 2013 Stolojescu-Crisan and Isar; licensee Springer.

  9. Adaptive subcarrier allocation for MIMO-OFDMA wireless systems using Hungarian method

    GUAN Zhang-jun; LI Hao; XU Chang-qing; ZHOU Xi-lang; ZHANG Wei-jiong

    2009-01-01

    MIMO-OFDMA is a promising technique for future broadband wireless communication systems. In this paper, the problem of allocating subcarriers among different users to maximize the total capacity is addressed. The optimal solution can be obtained by Hungarian method is proved, using two utility matrices, i.e. the Frobenius-norm matrix and the determinant matrix. Simulation results show that the proposed algorithm can achieve higher capacity than the existing algorithms, and it is globally optimal and easy to be implemented.

  10. Receiving Pseudorandom PSK

    Janson, Thomas; Schindelhauer, Christian

    2015-01-01

    Pseudorandom PSK [1] enables parallel communication on the same carrier frequency and at the same time. We propose different signal processing methods to receive data modulated with pseudorandom PSK. This includes correlation with the carrier frequency which can be applied to signals in the kHz to MHz range and signal processing in the intermediate frequency where the correlation with the carrier frequency is performed analogous in the RF front end. We analyze the computation complexity for s...

  11. Joint Subcarrier Pairing and Resource Allocation for Cognitive Network and Adaptive Relaying Strategy

    Soury, Hamza

    2012-05-01

    Recent measurements show that the spectrum is under-utilized by licensed users in wireless communication. Cognitive radio (CR) has been proposed as a suitable solution to manage the inefficient usage of the spectrum and increase coverage area of wireless networks. The concept is based on allowing a group of secondary users (SUs) to share the unused radio spectrum originally owned by the primary user (PUs). The operation of CR should not cause harmful interference to the PUs. In the other hand, relayed transmission increases the coverage and achievable capacity of communication systems and in particular in CR systems. In fact there are many types of cooperative communications, however the two main ones are decode-and-forward (DAF) and amplify-and-forward (AAF). Adaptive relaying scheme is a relaying technique by which the benefits of the amplifying or decode and forward techniques can be achieved by switching the forwarding technique according to the quality of the signal. In this dissertation, we investigate the power allocation for an adaptive relaying protocol (ARP) scheme in cognitive system by maximizing the end-to-end rate and searching the best carriers pairing distribution. The optimization problem is under the interference and power budget constraints. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques, and the consequence of the choice of the pairing strategy.

  12. RESILIENSI BERBASIS RELIGI BAGI MANTAN PSK DAN MUCIKARI PASCAPENUTUPAN LOKALISASI GANDUL TUBAN

    Mujib Ridlwan

    2015-01-01

    This article attempts to explain resilience (ability to adapt and to remain tough in critical and difficult situation) of prostitute women (Pekerja Seks Komersial or PSK) and procurers after the prostitution site of Gandul in Pakah, Gesing Village in Tuban Regency has been closed. The study aims to reveal not only the resilience of the ex-prostitute women (PSK) and procurers in dealing with difficult situation but it also tries expose the role of religion to help these people in dealing with ...

  13. BER of subcarrier MPSK and MDPSK systems in atmospheric turbulence

    Song, Xuegui

    2015-01-01

    Bit-error rate (BER) performance of subcarrier $M$-ary phase-shift keying (MPSK) and $M$-ary differential PSK (MDPSK) is analyzed for optical wireless communications over Gamma-Gamma and lognormal turbulence channels. We study the relation between the exact BER and the approximate BER, which is obtained by dividing the symbol-error rate by the number of bits per symbol, for subcarrier MPSK and MDPSK modulations. The asymptotic BER performance gap between the exact and the approximate BERs is quantified analytically through our asymptotic analyses. The accuracy of the approximate BER of both MPSK and MDPSK depends on the channel conditions. Under weak turbulence conditions, the approximate BER expression can be used to predict the system performance with high accuracy, while under strong turbulence conditions the approximate BER becomes inaccurate and can only serve as a loose lower bound of the exact BER. The asymptotic BER performance loss of MDPSK with respect to MPSK is also quantified analytically.

  14. BER of subcarrier MPSK/MDPSK modulated OWC systems in Gamma-Gamma turbulence

    Song, Xuegui

    2013-12-01

    Bit-error rate (BER) performance of subcarrier Mary phase-shift keying (MPSK) and M-ary differential PSK (MDPSK) is analyzed for optical wireless communications in Gamma-Gamma turbulence. We study the relation between the exact BER and the approximate BER, which is obtained by dividing the symbol error rate by the number of bits per symbol, for subcarrier MPSK and MDPSK modulations. The asymptotic performance gap between the exact and the approximate BERs is quantified analytically through our asymptotic analyses. The accuracy of the approximate BER of both MPSK and MDPSK depends on the channel conditions. Under weak turbulence conditions, the approximate BER expression can be used to predict the system performance with high accuracy, while under strong turbulence conditions the approximate BER becomes inaccurate and can only serve as a loose lower bound of the exact BER. The asymptotic BER performance loss of MDPSK with respect to MPSK is also quantified analytically. © 2013 IEEE.

  15. MIMO Free-Space Optical Communication Employing Subcarrier Intensity Modulation in Atmospheric Turbulence Channels

    Ghassemlooy, Zabih; Popoola, Wasiu O.; Ahmadi, Vahid; Leitgeb, Erich

    In this paper, we analyse the error performance of transmitter/receiver array free-space optical (FSO) communication system employing binary phase shift keying (BPSK) subcarrier intensity modulation (SIM) in clear but turbulent atmospheric channel. Subcarrier modulation is employed to eliminate the need for adaptive threshold detector. Direct detection is employed at the receiver and each subcarrier is subsequently demodulated coherently. The effect of irradiance fading is mitigated with an array of lasers and photodetectors. The received signals are linearly combined using the optimal maximum ratio combining (MRC), the equal gain combining (EGC) and the selection combining (SelC). The bit error rate (BER) equations are derived considering additive white Gaussian noise and log normal intensity fluctuations. This work is part of the EU COST actions and EU projects.

  16. On the diversity enhancement and power balancing of per-subcarrier antenna selection in OFDM systems

    Park, Kihong

    2010-09-01

    In this paper, we consider multi-carrier systems with multiple transmit antennas under a power balancing constraint. Applying transmit antenna selection and discrete rate adaptive modulation using M-ary quadrature amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal antenna selection scheme in terms of maximum spectral efficiency where all the possible grouping to send the same information bearing signals in a group of subcarriers are searched and the groups of subcarriers to provide the frequency diversity gain are formed. In addition, we propose a suboptimal method to reduce the computational complexity of the optimal method. The suboptimal scheme consider only the subcarriers under outage and those are combined sequentially until it meets a required SNR. Numerical results show that the proposed suboptimal method with diversity combining outperforms the optimal antenna selection without diversity combining introduced in [1], especially for low SNR region and offers the spectral efficiency close to that of the optimal method with diversity combining, while maintaining lower complexity. ©2010 IEEE.

  17. CARRIER SYNCHRONIZATION IN SOFTWARE DEFINED RADIO FOR 8PSK

    R.MUTHAIAH

    2013-02-01

    Full Text Available The main aim behind the growth of software defined radio is the skill to reconfigure radios, thereby increasing the efficiency in the usage of radio resources. In wireless communication the multipath effectproduce interference and also changes in the phase of the signal. In order to correctly recover the transmitted data with minimum error, carrier synchronization is essential. One of the challenging tasks in a communication system is synchronization of the carrier signal. In this paper 8PSK modulation scheme is used for data transmission. Since 8PSK achieves high data rate, the probability of actual signal recovery is quite difficult. Here the carrier recovery for 8PSK modulation has been performed.

  18. On the diversity enhancement and power balancing of per-subcarrier transmit antenna selection in OFDM systems

    Park, Kihong

    2011-01-01

    In this paper, we consider multicarrier systems with multiple transmit antennas under a power-balancing constraint. Applying transmit antenna selection and discrete rate-adaptive modulation using M-ary quadrature-amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal transmit antenna selection scheme in terms of the maximum spectral efficiency, where all the possible groupings for sending the same information-bearing signals in a group of subcarriers are searched, and the groups of subcarriers for providing the frequency diversity gain are formed. In addition, we propose a suboptimal method for reducing the computational complexity of the optimal method. The suboptimal scheme considers only the subcarriers under outage, and these subcarriers are sequentially combined until the required signal-to-noise ratio (SNR) is met. Numerical results show that the proposed suboptimal method with diversity combining outperforms the optimal antenna selection without diversity combining, as introduced in the work of Sandell and Coon, particularly for low-SNR regions, and offers the spectral efficiency close to the optimal method with diversity combining while maintaining lower complexity. © 2011 IEEE.

  19. Subcarrier Resource Optimization for Cooperated Multipoint Transmission

    Hui Zhang; Xiaodong Xu; Jingya Li; Xiaofeng Tao

    2010-01-01

    The concept of Cooperated Multipoint (CoMP) transmission is proposed for LTE-Advanced, which is in a form of distributed networks. In this background, a novel CoMP architecture is proposed in this paper, based on Group Cell concept in China FuTURE 4G TDD systems. Moreover, four actual scenarios are also concluded in CoMP, which, respectively, are single user in intracell, multiple users in intracell, single user in intercell and slide handover in intercell. In addition, a joint subcarrier opt...

  20. RESILIENSI BERBASIS RELIGI BAGI MANTAN PSK DAN MUCIKARI PASCAPENUTUPAN LOKALISASI GANDUL TUBAN

    Mujib Ridlwan

    2015-09-01

    Full Text Available This article attempts to explain resilience (ability to adapt and to remain tough in critical and difficult situation of prostitute women (Pekerja Seks Komersial or PSK and procurers after the prostitution site of Gandul in Pakah, Gesing Village in Tuban Regency has been closed. The study aims to reveal not only the resilience of the ex-prostitute women (PSK and procurers in dealing with difficult situation but it also tries expose the role of religion to help these people in dealing with resilience. To know whether the religion is able to play role in such situation, the writer along with a number of prominent figures of Gandul Village as well as the ex-prostitute women and procurers have initiated a set of religious activities. The religious activities provide these people a valuable matters and information about Islamic teachings such as prayer (salat, fasting, and charity. In addition, the activities also deal with social aspects. These activities aim to help the participants perform Islamic teachings correctly and live better.

  1. Effective DSP Methods of PSK Feedback Timing Synchronization

    M. Kasal; J. Sebesta

    2005-01-01

    This paper deals with simplification and improvement of data timing synchronization algorithms. Timing error synchronizers are usually the most complicated subsystems in the demodulator, and limit the DSP technique used for the high-rate application. This article is focused on feedback timing estimators for PSK modulation schemes, and shows modifications of widely used algorithms, that are suitable for the DSP implementation, as well as reach better parameters of the detection process. The me...

  2. Study the Performance of SLM for Different Number of Subcarriers

    Mohammad Alamgir Hossain

    2012-08-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM is an attractive modulation technique for transmitting large amounts of digital data over radio waves. One major disadvantage of OFDM is that the time domain OFDM signal which is a sum of several sinusoids leads to high peak to average power ratio (PAPR which leads to power inefficiency in RF section of the transmitter and increased complexity in the analog to digital and digital to analog Converter. Selected mapping (SLM is a well-known method for reducing the PAPR in OFDM. In this paper, we have studied the performance of SLM for Different Number of Subcarriers. Simulation result shows that the PAPR is reduced significantly when the number of phase sequences is increased and PAPR is increased when the number of subcarriers is increased. It also shows that data speed increases when subcarriers increase where N-point IFFT/FFT circuit depends on N-subcarriers.

  3. Polysaccharide-K (PSK) in cancer--old story, new possibilities?

    Sun, C; Rosendahl, A H; Wang, X D; Wu, D Q; Andersson, R

    2012-01-01

    Polysaccharide-K (PSK, Krestin) is one of the most commonly used medicinal mushroom extracts with a long history as an additive in cancer therapy in Asia, especially in Japan. PSK has a documented anti-tumor activity both in vitro and in vitro, in various types of cancers, including colorectal, gastric, breast, liver, pancreatic, and lung cancer. Despite PSK having been studied for about 40 years as an immune modulator and biological response modifier, the mechanisms of action by PSK have not yet been clearly and completely elucidated. This review aims to provide an up-to-date account for the effects of PSK in cancer with the hope of thereby providing an increased understanding of the molecular mechanisms of PSK and also its potential as an additive in modern cancer therapy. PMID:22204346

  4. The radiation sensitizing effect of PSK in the treatment for the cervical cancer patients

    PSK is the protein-bound polysaccharide isolated from Coriolus versicolor (strain CM-101) belonging to Basidiomycetes. It has been widely used as antitumor agent by oral route in Japan for cancer of digestive organs, lung cancer, breast cancer and so on. In this paper, clinical data for the radiation sensitizing effect of PSK in the treatment for the cervical cancer patients is reported. The action mechanism of PSK is still unclear. (Auth.)

  5. Subcarrier and power allocation algorithm based on inter-cell interference mitigation for OFDMA system

    ZOU Ting; DENG Gang; WANG Ying; ZHANG Ping

    2007-01-01

    This article proposes a dynamic subcarrier and power allocation algorithm for multicell orthogonal frequency division multiple access (OFDMA) downlink system, based on inter-cell interference (ICI) mitigation. Different from other ICI mitigation schemes, which pay little attention to power allocation in the system, the proposed algorithm assigns channels to each user, based on proportional-fair (PF) scheduling and ICI coordination, whereas allocating power is based on link gain distribution and the loading bit based on adaptive modulation and coding (AMC) in base transceiver station (BTS). Simulation results show that the algorithm yields better performance for data services under fast fading.

  6. Face recognition using 4-PSK joint transform correlation

    Moniruzzaman, Md.; Alam, Mohammad S.

    2016-04-01

    This paper presents an efficient phase-encoded and 4-phase shift keying (PSK)-based fringe-adjusted joint transform correlation (FJTC) technique for face recognition applications. The proposed technique uses phase encoding and a 4- channel phase shifting method on the reference image which can be pre-calculated without affecting the system processing speed. The 4-channel PSK step eliminates the unwanted zero-order term, autocorrelation among multiple similar input scene objects while yield enhanced cross-correlation output. For each channel, discrete wavelet decomposition preprocessing has been used to accommodate the impact of various 3D facial expressions, effects of noise, and illumination variations. The performance of the proposed technique has been tested using various image datasets such as Yale, and extended Yale B under different environments such as illumination variation and 3D changes in facial expressions. The test results show that the proposed technique yields significantly better performance when compared to existing JTC-based face recognition techniques.

  7. Subcarrier Group Assignment for MC-CDMA Wireless Networks

    Tho Le-Ngoc

    2007-12-01

    Full Text Available Two interference-based subcarrier group assignment strategies in dynamic resource allocation are proposed for MC-CDMA wireless systems to achieve high throughput in a multicell environment. Least interfered group assignment (LIGA selects for each session the subcarrier group on which the user receives the minimum interference, while best channel ratio group assignment (BCRGA chooses the subcarrier group with the largest channel response-to-interference ratio. Both analytical framework and simulation model are developed for evaluation of throughput distribution of the proposed schemes. An iterative approach is devised to handle the complex interdependency between multicell interference profiles in the throughput analysis. Illustrative results show significant throughput improvement offered by the interference-based assignment schemes for MC-CDMA multicell wireless systems. In particular, under low loading conditions, LIGA renders the best performance. However, as the load increases BCRGA tends to offer superior performance.

  8. Anticancer effects and mechanisms of polysaccharide-K (PSK): implications of cancer immunotherapy.

    Fisher, Monte; Yang, Li-Xi

    2002-01-01

    Polysaccharide-K (polysaccharide-Kureha; PSK), also known as krestin, is a unique protein-bound polysaccharide, which has been used as a chemoimmunotherapy agent in the treatment of cancer in Asia for over 30 years. PSK and Polysaccharopeptide (PSP) are both protein-bound polysaccharides which are derived from the CM-101 and COV-1 strains of the fungus Coriolus versicolor by Japanese and Chinese researchers, respectively. Both polysaccharide preparations have documented anticancer activity in vitro, in vivo and in human clinical trials, though PSK has been researched longer and has therefore undergone more thorough laboratory, animal and clinical testing. Several randomized clinical trials have demonstrated that PSK has great potential as an adjuvant cancer therapy agent, with positive results seen in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunotherapy or biological response modifier (BRM). BRMs potentially have the ability to improve the "host versus tumor response," thereby increasing the ability of the host to defend itself from tumor progression. The mechanisms of biological response modification by PSK have yet to be clearly and completely elucidated. Some studies suggest that PSK may act to increase leukocyte activation and response through up-regulation of key cytokines. Indeed, natural killer (NK) and lymphocyte-activated killer (LAK) cell activation has been demonstrated in vivo and in vitro, and recent genetic studies reveal increased expression of key immune cytokines in response to treatment with PSK. An antimetastatic action of PSK has also been demonstrated and is perhaps attributed to its potential to inhibit metalloproteinases and other enzymes involved in metastatic activity. PSK has also been shown to cause differentiation of leukemic cells in vitro, and this effect has been attributed to induction of differentiation cytokines. PSK has further been

  9. A POLAR-BASED DEMAPPER OF 8PSK DEMODULATION FOR DVB-S2 SYSTEMS

    Barré, Anthony; Boutillon, Emmanuel; Blas, Neysser; Diaz, Daniel

    2013-01-01

    In this paper, we propose a polar-based 8-PSK demapper for DVB-S2 receivers. This demapper computes the Log- Likelihood Ratio (LLR) of the transmitted bit using the polar coordinate of the received 8-PSK symbol. Thanks to interpolation and approximation, the resulting demapper outperforms the classical LLR receiver based on Cartesian coordinates. Simulation shows almost no degradation compared to the optimal LLR generation for a 5-bit input precision of the LDPC decoder.

  10. Subcarrier intensity modulated free-space optical communication systems

    Popoola, Wasiu Oyewole

    2009-01-01

    This thesis investigates and analyses the performance of terrestrial free-space optical communication (FSO) system based on the phase shift keying pre-modulated subcarrier intensity modulation (SIM). The results are theoretically and experimentally compared with the classical On-Off keying (OOK) modulated FSO system in the presence of atmospheric turbulence. The performance analysis is based on the bit error rate (BER) and outage probability metrics. Optical signal traversing the atmospheric ...

  11. Analysis and comparison of the 4-PSK and 8-PSK STTC over Rayleigh fading Channels for determining Performance

    Pragya Gupta

    2012-09-01

    Full Text Available Demands for capacity in wireless communications, driven by cellular mobile, Internet and multimedia services have been rapidly increasing worldwide. On the other hand, the available radio spectrum is limited and the communication capacity needs cannot be met without a significant increase in communication spectral efficiency. Coding techniques designed for multiple antenna transmission are called space-time coding. Space-time coding can achieve transmit diversity and coding gain over spatially uncoded systems without sacrificing the bandwidth. Space-time trellis code (STTC has been widely applied to coded multiple-input multiple-output (MIMO systems because of its gains in coding and diversity. Diversity techniques are used to reduce the effect of fading. Space-time trellis code is a bandwidth and power efficient method of communication over Rayleigh fading that realizes the benefits of multiple transmit and receive antennas. In this paper we present analytical performance results for space–time trellis codes over spatially correlated Rayleigh fading channels. In this paper we analyze and compare the 8-PSK STTC over Rayleigh fading Channels for determining Performance.

  12. All-optical subcarrier labeling based on the carrier suppression of the payload

    Chi, Nan; Zhang, Jianfeng; Jeppesen, Palle

    2003-01-01

    We report on a new approach to all-optical subcarrier labeling based on sideband generation through carrier-suppression of the payload. The experimental transmission over 50-km standard fiber of a 10-Gb/s payload data multiplexed with a synchronized 1.25-Gb/s subcarrier label is carried out with...

  13. 47 CFR 73.4246 - Stereophonic pilot subcarrier use during monophonic programming.

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Stereophonic pilot subcarrier use during monophonic programming. 73.4246 Section 73.4246 Telecommunication FEDERAL COMMUNICATIONS COMMISSION....4246 Stereophonic pilot subcarrier use during monophonic programming. See Report and Order,...

  14. Performance of chirped-fsk and chirped-psk in the presence of partial-band interference

    Dutta, Ramen; Kokkeler, André B.J.; Zee, van der Ronan; Bentum, Mark J.

    2011-01-01

    To improve interference robustness of wireless communication, spread spectrum techniques are often used. We use the chirp spreading technique along with FSK and PSK binary modulation schemes to obtain interference robust radio communication. The performance of chirped-FSK and chirped- PSK modulation

  15. 16-level differential phase shift keying (D16PSK) in direct detection optical communication systems

    Sambaraju, R.; Tokle, Torger; Jensen, J.B.;

    2006-01-01

    Optical 16-level differential phase shift keying (D16PSK) carrying four bits for every symbol is proposed for direct detection optical communication systems. Transmitter and receiver schematics are presented, and the receiver sensitivity is discussed. We numerically investigate the impact of...

  16. Optimally Joint Subcarrier Matching and Power Allocation in OFDM Multihop System

    Wang Wenyi

    2008-01-01

    Full Text Available Orthogonal frequency division multiplexing (OFDM multihop system is a promising way to increase capacity and coverage. In this paper, we propose an optimally joint subcarrier matching and power allocation scheme to further maximize the total channel capacity with the constrained total system power. First, the problem is formulated as a mixed binary integer programming problem, which is prohibitive to find the global optimum in terms of complexity. Second, by making use of the equivalent channel power gain for any matched subcarrier pair, a low complexity scheme is proposed. The optimal subcarrier matching is to match subcarriers by the order of the channel power gains. The optimal power allocation among the matched subcarrier pairs is water-filling. An analytical argument is given to prove that the two steps achieve the optimally joint subcarrier matching and power allocation. The simulation results show that the proposed scheme achieves the largest total channel capacity as compared to the other schemes, where there is no subcarrier matching or no power allocation.

  17. Optimally Joint Subcarrier Matching and Power Allocation in OFDM Multihop System

    Shuyuan Yang

    2008-04-01

    Full Text Available Orthogonal frequency division multiplexing (OFDM multihop system is a promising way to increase capacity and coverage. In this paper, we propose an optimally joint subcarrier matching and power allocation scheme to further maximize the total channel capacity with the constrained total system power. First, the problem is formulated as a mixed binary integer programming problem, which is prohibitive to find the global optimum in terms of complexity. Second, by making use of the equivalent channel power gain for any matched subcarrier pair, a low complexity scheme is proposed. The optimal subcarrier matching is to match subcarriers by the order of the channel power gains. The optimal power allocation among the matched subcarrier pairs is water-filling. An analytical argument is given to prove that the two steps achieve the optimally joint subcarrier matching and power allocation. The simulation results show that the proposed scheme achieves the largest total channel capacity as compared to the other schemes, where there is no subcarrier matching or no power allocation.

  18. Enhancement of Antitumor Effect of Tegafur/Uracil (UFT) plus Leucovorin by Combined Treatment with Protein-Bound Polysaccharide, PSK, in Mouse Models

    Ryoji Katoh; Mitsuru Ooshiro

    2007-01-01

    We evaluated the antitumor effect of combined therapy with tegafur/uracil (UFT) plus leucovorin (LV) (UFT/LV)and protein-bound polysaccharide, PSK, in three mouse models of transplantable tumors. UFT/LV showed antitumor effect against Meth A sarcoma, and the antitumor effect was enhanced when PSK given concomitantly.UFT/LV showed antitumor effect to Lewis lung carcinoma and PSK alone also showed antitumor effect at high dose, but a combination of UFT/LV and PSK resulted in no enhanced antitumor effect. Colon 26 carcinoma was weakly responsive to UFT/LV, and no enhancement of antitumor effect was found even PSK was used in combination. In conclusion, while the effect of PSK varies depending on tumor, combined use of UFT/LV and PSK may be expected to augment the antitumor effect.

  19. Subcarrier and power allocation for the downlink of multiuser OFDM transmission

    El Baamrani, Khalid; Ait Ouahman, Abdellah; Gil-Jiménez, Víctor P.; García-Armada, Ana; Allaki, Said

    2006-01-01

    In this paper, a new algorithm for subcarrier and power allocation for the downlink of multiuser OFDM transmission is presented. The proposed algorithm is more stable and it offers a lower complexity and better performance than previous existing algorithms.

  20. A Novel Broadband MIMO/OFDM System Using Adaptive Modulation and Adaptive Diversity

    PANYahan; KhaledBenLetaief; CAOZhigang; QIUYonghong

    2005-01-01

    OFDM (Orthogonal frequency division multiplexing) has been widely regarded as an effective modulation technique for mitigating the effects of ISI in a frequency selective fading channel and for providing reliable high-data transmission over wireless links. Adaptive modulation combined with adaptive transmit and receive diversity can achieve further increases in system's capacity and bandwidth efficiency, as well as in QoS improvement in conventional OFDM systems. In this paper, we propose a novel broadband MIMO/OFDM system using adaptive modulation and adaptive transmit and receive diversity. By applying an EVD on each sub-carrier channel matrix, joint optimal transmit and receive antenna weights as well as maximal SNR on each sub-carrier are obtained. Then, by employing adaptive modulation on each sub-carrier, the maximal SNR on each sub-carrier obtained by adaptive transmit and receive diversity is further maximized through adaptive bit assignment and power assignment on each sub-carrier under the constraint of power and overall bit rate. Simulation results show that the proposed system can achieve better performance than an adaptive antenna array based OFDM system without adaptive modulation over multipath fading channels.

  1. Max-utility subcarrier allocation for heterogeneous services in wireless OFDM system

    CHEN Zi-xiong; SUN Kai; YUAN Jun; WANG Ying

    2009-01-01

    In future wireless network, one user will require multiple homogeneous or heterogeneous services simultaneously. Then, the scheduling algorithm is not only responsible for assigning a resource block to different users but also sharing the assigned resource block among multiple services for one user. Most of the traditional scheduling algorithms are designed to serve one service per user, and cannot be applied directly to this scenario because of the fairness criterion. This article focuses on adaptive resource allocation for multiple services per user at the downlink of orthogonal frequency division multiplexing (OFDM) based system. This article addresses this integrative resource scheduling problem based on utility function. First, the optimal algorithm for dynamic subcarrier allocation and share is deduced for homogeneous best-effort service system. Then the algorithm is extended to heterogeneous services system by classifying the delay sensitive service according to the head-of-line packet delay. The design goal is to maximize aggregate utility function to exploit multiuser diversity gain to the greatest extent even as guaranteeing quality of service (QoS) for delay sensitive service.

  2. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    Garrido Federico; Collado Antonia; Algarra Ignacio; Romero Irene; Berruguilla Enrique; Jiménez-Medina Eva; Garcia-Lora Angel

    2008-01-01

    Abstract Background Protein-bound polysaccharide (PSK) is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an imm...

  3. Low complexity digital backpropagation for high baud subcarrier-multiplexing systems.

    Zhang, Fangyuan; Zhuge, Qunbi; Qiu, Meng; Plant, David V

    2016-07-25

    In this paper, we propose two modifications to reduce the complexity of the subcarrier-multiplexing (SCM) based digital backpropagation (DBP) for high symbol rate SCM systems. The first one is to reduce the number of interfering subcarriers (RS-SCM-DBP) when evaluating the cross-subcarrier nonlinearity (CSN). The second one is to replace the original frequency domain CSN filters with the infinite impulse response (IIR) filters (IIR-RS-SCM-DBP) in the CSN compensation. The performance of the proposed schemes are numerically evaluated in three-channel dual-polarization (DP) 16QAM wavelength-division multiplexing (WDM) transmissions. The aggregate symbol rate for each channel is 120 GBaud and the transmission distance is 1600 km. For the SCM system with 16 subcarriers, the IIR-RS-SCM-DBP with only 4 interfering subcarriers and 2 steps can achieve a 0.3 dB Q-factor improvement in the WDM transmission. Compared to the original SCM-DBP, the proposed IIR-RS-SCM-DBP reduces the complexity by 48% at a performance loss of only 0.07 dB. PMID:27464154

  4. Mitigation of phase noise in all-optical OFDM systems based on minimizing interaction time between subcarriers

    Hmood, Jassim K.; Noordin, Kamarul A.; Harun, Sulaiman W.; Shalaby, Hossam M. H.

    2015-11-01

    A new approach to mitigate the phase noise in all-optical OFDM systems is analytically modeled and numerically demonstrated. The interaction time between subcarriers is minimized by shaping the envelopes of QAM subcarriers and making a delay time between even and odd subcarriers. Return-to-zero (RZ) coding is adopted for shaping the envelopes of subcarriers. In addition, the subcarriers are alternately delayed (AD) by optical time delayers. The performance of an all-optical OFDM system, that implements the proposed technique, is analyzed and simulated. This system has 29 subcarriers with symbol rate of 25 Gsymbol/s and is composed of coupler-based inverse fast Fourier transform (IFFT)/fast Fourier transform (FFT) schemes. Each subcarrier is modulated with QAM format before shaping with RZ coding. Due to RZ being more affected by dispersion; a full periodic dispersion map is adopted to keep the total accumulated dispersion low. The results reveal that the nonlinear phase noise (NPN) due to fiber nonlinearity is significantly mitigated when the time delay between the odd and even subcarriers is equal to half the symbol period. The total phase noise variance is reduced from 9.3×10-3 to 6.1×10-3 rad2 when employing AD RZ-QAM for a transmission distance of 550 km. Furthermore, both the transmission distance and optical signal to noise ratio (OSNR) are improved when compared to all-optical OFDM systems that adopt traditional QAM modulation formats.

  5. On the induction of protective responses in Salmonella typhimurium strain TA1535/pSK1002 by UVA (365 nm)

    Exposure to UVA (365 nm) led to growth delay, loss of viability and inhibition of 3H-thymidine incorporation into the cells of Salmonella typhimurium strain TA1535 containing multiple copies of a plasmid pSK1002 carrying a umuC'-'lacZ fusion gene. Ultraviolet-A induced umu gene expression, as monitored by the estimation of β-galactosidase, in a linear fluence-dependent manner. The induction of umu gene expression increased with the increase of postirradiation incubation period of the cells in the LB-ampicillin (LBA) medium at 37oC and leveled off from 2 h onward. The induction of gene expression depended on concomitant protein synthesis and represented the induction of the SOS response in the particular S. typhimurium cells used. The exposure to low fluences (sublethal) of UVA also led to the induction of an adaptive response in the same bacterial cells, which made them resistant to subsequent challenge by a much higher fluence of the same radiation. The adaptive response, as monitored by the assays of viability and β-galactosidase units, increased with the period of exposure to sublethal fluences of UVA, attained a maximum at the UVA exposure of 4.5 kJ/m2 (15 min) and thereafter gradually decreased with further increase of UVA exposure period. Modulation studies involving D2O, LBA growth medium, different scavengers of free radicals and quenchers of activated oxygen species indicated the involvement of both hydroxyl free radicals and singlet oxygen in the UVA-induced umu gene expression. (author)

  6. Power and Subcarrier Allocation for Physical-Layer Security in OFDMA-based Broadband Wireless Networks

    Wang, Xiaowei; Mo, Jianhua; Xu, Youyun

    2011-01-01

    Providing physical-layer security for mobile users in future broadband wireless networks is of both theoretical and practical importance. In this paper, we formulate an analytical framework for resource allocation in a downlink OFDMA-based broadband network with coexistence of secure users (SU) and normal users (NU). The SU's require secure data transmission at the physical layer while the NU's are served with conventional best-effort data traffic. The problem is formulated as joint power and subcarrier allocation with the objective of maximizing average aggregate information rate of all NU's while maintaining an average secrecy rate for each individual SU under a total transmit power constraint for the base station. We solve this problem in an asymptotically optimal manner using dual decomposition. Our analysis shows that an SU becomes a candidate competing for a subcarrier only if its channel gain on this subcarrier is the largest among all and exceeds the second largest by a certain threshold. Furthermore,...

  7. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    Protein-bound polysaccharide (PSK) is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G0/G1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells

  8. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    Garrido Federico

    2008-03-01

    Full Text Available Abstract Background Protein-bound polysaccharide (PSK is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. Methods The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. Results PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G0/G1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. Conclusion These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells.

  9. Indoor RF signal distribution using a coherence multiplexed/subcarrier multiplexed optical transmission system

    Taniman, Robert; Meijerink, Arjan; Etten, van Wim; Haartsen, Jaap

    2003-01-01

    A Radio over Fiber (RoF) distribution network based on single-mode fiber (SMF) and a combination of coherence multiplexing (CM) and subcarrier multiplexing (SCM) is proposed. CM is a relatively unknown and potentially inexpensive form of photonic code-division multiplexing, and is used here as a mea

  10. Phase noise and sub-carrier spacing effects on the performance of an OFDM communication system

    García-Armada, Ana; CALVO-RAMÓN, Miguel

    1998-01-01

    This letter analyzes the phase noise effects on an orthogonal frequency division multiplexing (OFDM) signal and its dependence with the sub-carrier spacing. Pilot-based channel estimation, which has been suggested as a means of combating the channel effects, can also correct the phase noise effects under some circumstances, which are investigated

  11. A Non-Cooperative Approach to the Joint Subcarrier and Power Allocation Problem in Multi-Service SCFDMA Networks

    E. E. Tsiropoulou

    2016-06-01

    Full Text Available In this paper a joint resource allocation problem is studied in a multi-service Single Carrier FDMA (SC-FDMA wireless network. Mobile users request various services with different Quality of Service (QoS characteristics and they determine in a distributed and non-cooperative manner a joint subcarrier and power allocation towards fulfilling their QoS prerequisites. Initially, a well-designed utility function is formulated to appropriately represent users’ diverse QoS prerequisites with respect to their requested service. The subcarriers allocation problem is solved based on a multilateral bargaining model, where users are able to select different discount factors to enter the bargaining game, thus better expressing their different needs in system resources with respect to their requested service. The subcarriers mapping is realized based either on the localized SC-FDMA method where the subcarriers are sequentially allocated to the users or the distributed SC-FDMA via considering the maximum channel gain policy, where each subcarrier is allocated to the user with the maximum channel gain. Given the subcarriers assignment, an optimization problem with respect to users’ uplink transmission power is formulated and solved, in order to determine the optimal power allocation per subcarrier assigned to each user. Finally, the performance of the proposed framework is evaluated via modeling and simulation and extensive numerical results are presented.

  12. Space-Time Trellis Coded 8PSK Schemes for Rapid Rayleigh Fading Channels

    Salam A. Zummo

    2002-05-01

    Full Text Available This paper presents the design of 8PSK space-time (ST trellis codes suitable for rapid fading channels. The proposed codes utilize the design criteria of ST codes over rapid fading channels. Two different approaches have been used. The first approach maximizes the symbol-wise Hamming distance (HD between signals leaving from or entering to the same encoder′s state. In the second approach, set partitioning based on maximizing the sum of squared Euclidean distances (SSED between the ST signals is performed; then, the branch-wise HD is maximized. The proposed codes were simulated over independent and correlated Rayleigh fading channels. Coding gains up to 4 dB have been observed over other ST trellis codes of the same complexity.

  13. PAPR Reduction in OFDM Systems with Large Number of Sub-Carriers by Carrier Interferometry Approaches

    HE Jian-hui; QUAN Zi-yi; MEN Ai-dong

    2004-01-01

    High Peak-to-Average Power Ratio (PAPR) is one of the major drawbacks of Orthogonal Frequency Division Multiplexing ( OFDM) systems. This paper presents the structures of the particular bit sequences leading to the maximum PAPR (PAPRmax) in Carrier-Interferometry OFDM (CI/OFDM) and Pseudo Orthogonal Carrier-Interferometry OFDM (PO-CI/OFDM) systems for Binary Phase Shift Keying (BPSK) modulation. Furthermore, the simulation and analysis of PAPRmax and PAPR cumulative distribution in CI/OFDM and PO-CI/OFDM systems with 2048 sub-carriers are presented in this paper. The results show that the PAPR of OFDM system with large number of sub-carriers reduced evidently via CI approaches.

  14. Implementation of multiplexing in a subcarrier-wave quantum cryptography system

    Quantum cryptography allows distributing secure keys in a way that any eavesdropping in the channel is inevitably detected. This work is dedicated to introducing wavelength division multiplexing in a subcarrier-wave quantum cryptography system. Compared to other existing schemes, the resulting device is able to achieve higher bitrates (up to 2.26 Mbit/s at 20 km), is robust against external conditions and compatible with standard telecommunication fibres in multi-user environment

  15. Power allocation, bit loading and sub-carrier bandwidth sizing for OFDM-based cognitive radio

    Desai Uday

    2011-01-01

    Full Text Available Abstract The function of the Radio Resource Management module of a Cognitive Radio (CR system is to evaluate the available resources and assign them to meet the Quality of Service (QoS objectives of the Secondary User (SU, within some constraints on factors which limit the performance of the Primary User (PU. While interference mitigation to the PU spectral band from the SU's transmission has received a lot of attention in recent literature; the novelty of our work is in considering a more realistic and effective approach of dividing the PU into sub-bands, and ensuring that the interference to each of them is below a specified threshold. With this objective, and within a power budget, we execute the tasks of power allocation, bit loading and sizing the sub-carrier bandwidth for an orthogonal frequency division multiplexing (OFDM-based SU. After extensively analyzing the solution form of the optimization problems posed for the resource allocation, we suggest iterative algorithms to meet the aforementioned objectives. The algorithm for sub-carrier bandwidth sizing is novel, and not previously presented in literature. A multiple SU scenario is also considered, which entails assigning sub-carriers to the users, besides the resource allocation. Simulation results are provided, for both single and multi-user cases, which indicate the effectiveness of the proposed algorithms in a CR environment.

  16. Subcarrier phase recovery performance in bent-pipe mode of Shuttle data transmission. [on Tracking and Data Relay Satellite System Ku-band return link

    Mckenzie, T. M.; Braun, W. R.

    1978-01-01

    The subcarrier phase recovery is analyzed for the bent-pipe mode of Space Shuttle detached-payload data transmission on the Tracking and Data Relay Satellite System (TDRSS) Ku-band return link. The high-power component of the subcarrier modulation is unrestored payload data, either at baseband or modulating another subcarrier. At the receiver a Costas loop recovers the subcarrier phase. To analyze its performance in the baseband case, we obtain the loop S-curve, the power spectral density of the equivalent noise process, and the loop phase error variance.

  17. The phytosulfokine (PSK) receptor is capable of guanylate cyclase activity and enabling cyclic GMP-dependent signaling in plants

    Kwezi, Lusisizwe

    2011-04-19

    Phytosulfokines (PSKs) are sulfated pentapeptides that stimulate plant growth and differentiation mediated by the PSK receptor (PSKR1), which is a leucine-rich repeat receptor-like kinase. We identified a putative guanylate cyclase (GC) catalytic center in PSKR1 that is embedded within the kinase domain and hypothesized that the GC works in conjunction with the kinase in downstream PSK signaling. We expressed the recombinant complete kinase (cytoplasmic) domain of AtPSKR1 and show that it has serine/threonine kinase activity using the Ser/Thr peptide 1 as a substrate with an approximate Km of 7.5 μM and Vmax of 1800 nmol min-1 mg-1 of protein. This same recombinant protein also has GC activity in vitro that is dependent on the presence of either Mg2+ or Mn2+. Overexpression of the full-length AtPSKR1 receptor in Arabidopsis leaf protoplasts raised the endogenous basal cGMP levels over 20-fold, indicating that the receptor has GC activity in vivo. In addition, PSK-α itself, but not the non-sulfated backbone, induces rapid increases in cGMP levels in protoplasts. Together these results indicate that the PSKR1 contains dual GC and kinase catalytic activities that operate in vivo and that this receptor constitutes a novel class of enzymes with overlapping catalytic domains. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Rate 8/9 coded 8-PSK system for downlink applications

    Fang, Russell; Kappes, Mark; Miller, Susan

    1992-02-01

    An advanced Coded Trellis Modulation (CTM) System which achieves a 2 bits/s/Hz bandwidth efficiency at an information rate of 200 Mbit/s while minimizing satellite power requirements, was developed for downlink earth station applications. The CTM system employs a high-speed rate 8/9 convolutional code with Viterbi decoding and an 8-Phase Shift Keying (PSK) modem. The minimum Euclidean distance between the modulated waveforms corresponding to the information sequences are maximized in order to maximize the noise immunity of the system. Nyquist filters with a square-root of 40 percent roll-off are used at the transmit and receive sides of the modem in order to minimize intersymbol interference, adjacent channel interference, and distortion at the nonlinear satellite power amplifier. The use of a coded system here also minimizes the effects of co-channel interference. The developed performance of the hardware system was measured to achieve within 1.5 dB from theory at a bit error rate of 5 x 10(exp -7) over an additive white Gaussian noise channel.

  19. Performance analyses of subcarrier BPSK modulation over M turbulence channels with pointing errors

    Ma, Shuang; Li, Ya-tian; Wu, Jia-bin; Geng, Tian-wen; Wu, Zhiyong

    2016-05-01

    An aggregated channel model is achieved by fitting the Weibull distribution, which includes the effects of atmospheric attenuation, M distributed atmospheric turbulence and nonzero boresight pointing errors. With this approximate channel model, the bit error rate ( BER) and the ergodic capacity of free-space optical (FSO) communication systems utilizing subcarrier binary phase-shift keying (BPSK) modulation are analyzed, respectively. A closed-form expression of BER is derived by using the generalized Gauss-Lagueree quadrature rule, and the bounds of ergodic capacity are discussed. Monte Carlo simulation is provided to confirm the validity of the BER expressions and the bounds of ergodic capacity.

  20. Subcarrier MPSK/MDPSK modulated optical wireless communications in lognormal turbulence

    Song, Xuegui

    2015-03-01

    Bit-error rate (BER) performance of subcarrier Mary phase-shift keying (MPSK) and M-ary differential phase-shift keying (MDPSK) is analyzed for optical wireless communications over the lognormal turbulence channels. Both exact BER and approximate BER expressions are presented. We demonstrate that the approximate BER, which is obtained by dividing the symbol error rate by the number of bits per symbol, can be used to estimate the BER performance with acceptable accuracy. Through our asymptotic analysis, we derive closed-form asymptotic BER performance loss expression for MDPSK with respect to MPSK in the lognormal turbulence channels. © 2015 IEEE.

  1. Subcarrier Wave Quantum Key Distribution in Telecommunication Network with Bitrate 800 kbit/s

    Gleim, A. V.; Nazarov, Yu. V.; Egorov, V. I.; Smirnov, S. V.; Bannik, O. I.; Chistyakov, V. V.; Kynev, S. M.; Anisimov, A. A.; Kozlov, S. A.; Vasiliev, V. N.

    2015-09-01

    In the course of work on creating the first quantum communication network in Russia we demonstrated quantum key distribution in metropolitan optical network infrastructure. A single-pass subcarrier wave quantum cryptography scheme was used in the experiments. BB84 protocol with strong reference was chosen for performing key distribution. The registered sifted key rate in an optical cable with 1.5 dB loss was 800 Kbit/s. Signal visibility exceeded 98%, and quantum bit error rate value was 1%. The achieved result is a record for this type of systems.

  2. Subcarrier Wave Quantum Key Distribution in Telecommunication Network with Bitrate 800 kbit/s

    Gleim A.V.

    2015-01-01

    Full Text Available In the course of work on creating the first quantum communication network in Russia we demonstrated quantum key distribution in metropolitan optical network infrastructure. A single-pass subcarrier wave quantum cryptography scheme was used in the experiments. BB84 protocol with strong reference was chosen for performing key distribution. The registered sifted key rate in an optical cable with 1.5 dB loss was 800 Kbit/s. Signal visibility exceeded 98%, and quantum bit error rate value was 1%. The achieved result is a record for this type of systems.

  3. Performance of Orthogonal Frequency Division Multiplexing System Based on Mobile Velocity and Subcarrier

    Zulkeflee B. Khalidin

    2010-01-01

    Full Text Available Problem statement: Nowadays, the mobile telecommunications industry faces the problem of providing the technology that be able to support a wide variety of services ranging from voice communication with a bit rate of a few kbps to wireless multimedia in which bit rate up to 2 Mbps. Approach: This study introduced a new performance study to enhance the Orthogonal Frequency Division Multiplexing (OFDM system based on both efficient iterative number of subcarrier estimation techniques and a tracking algorithm was proposed. Result: The performance of system degrades with increase of the mobile velocity or increase of the number of channel fingers. The noiseless received signal at the weakest subcarrier is estimated based on all the detected data symbols using a hard or soft decision. Due to the flexibility of the transform design, the analysis conducted is applicable for other common systems as well. Conclusion: Simulation results showed the proposed algorithm can track the velocity variation very well and perform channel estimation using the most efficient tracking mode.

  4. Design and Cost Performance of Decoding Technique for Hybrid Subcarrier Spectral Amplitude Coding-Optical Code Division Multiple Access System

    R. K.Z. Sahbudin

    2011-01-01

    Full Text Available Problem statement: A hybrid technique combining subcarrier multiplexed and Spectral Amplitude Coding-Optical Code Division Multiple Access (SAC-OCDMA deploying the Khazani-Syed code was proposed. It was proposed as a mean of increasing the maximum number of simultaneous active users by increasing the subcarrier and/or the SAC-OCDMA code word. Multiple Access Interference (MAI is the most dominant cause of performance degradation in SACOCDMA systems. Approach: A decoding technique which was simple and easy to build named Spectral Direct Decoding (SDD technique was proposed for the hybrid system of subcarrier SACOCDMA. Results: The comparison between the complementary subtraction and proposed SDD techniques for hybrid subcarrier SAC-OCDMA system in terms of cost performance was presented here. Results showed that the cost performance of the SDD technique offers a significant improvement over the complementary subtraction detection technique. Conclusion: It is shown that the cost performance of the hybrid system using SDD technique is significantly better than using the Complementary subtraction technique.

  5. Generalized Tensor Analysis Model for Multi-Subcarrier Analog Optical Systems

    Zhao, Ying; Yu, Xianbin; Zheng, Xiaoping;

    2011-01-01

    We propose and develop a general tensor analysis framework for a subcarrier multiplex analog optical fiber link for applications in microwave photonics. The goal of this work is to construct an uniform method to address nonlinear distortions of a discrete frequency transmission system. We employ...... addition, it is demonstrated that each corresponding tensor is formally determined by device structures, which allows for a synthesized study of device combinations more systematically. For implementing numerical methods, the practical significance of the tensor model is it simplifies the derivation...... details compared with series-based approaches by hiding the underlying multi-fold summation and index operation. The integrity of the proposed methodology is validated by investigating the classical intensity modulated system. Furthermore, to give an application model of the tensor formalism, we make a...

  6. BLOCK CODING SCHEME FOR REDUCING PAPR IN OFDM SYSTEMS WITH LARGE NUMBER OF SUBCARRIERS

    Jiang Tao; Zhu Guangxi; Zheng Jianbin

    2004-01-01

    The major drawback in Orthogonal Frequency Division Multiplexing (OFDM) system is due to the high Peak-to-Average Power Ratio (PAPR), so the performance of the system is significantly degraded by the nonlinearity of a High Power Amplifier (HPA) in the transmitter.In order to mitigate distortion, a block coding scheme for reducing PAPR in OFDM systems with large number of subcarriers based on complementary sequences and predistortion is proposed,which is capable of both error correction and PAPR reduction. Computer simulation results show that the proposed scheme significantly improves Bit Error Rate(BER) performance as compared to an uncoded system when an HPA is employed or a coded system without predistortion.

  7. Preamble and pilot symbol design for channel estimation in OFDM systems with null subcarriers

    Ohno Shuichi

    2011-01-01

    Full Text Available Abstract In this article, design of preamble for channel estimation and pilot symbols for pilot-assisted channel estimation in orthogonal frequency division multiplexing system with null subcarriers is studied. Both the preambles and pilot symbols are designed to minimize the l 2 or the l ∞ norm of the channel estimate mean-squared errors (MSE in frequency-selective environments. We use convex optimization technique to find optimal power distribution to the preamble by casting the MSE minimization problem into a semidefinite programming problem. Then, using the designed optimal preamble as an initial value, we iteratively select the placement and optimally distribute power to the selected pilot symbols. Design examples consistent with IEEE 802.11a as well as IEEE 802.16e are provided to illustrate the superior performance of our proposed method over the equi-spaced equi-powered pilot symbols and the partially equi-spaced pilot symbols.

  8. Securing OFDM over Wireless Time-Varying Channels Using Subcarrier Overloading with Joint Signal Constellations

    Gill R. Tsouri

    2009-01-01

    Full Text Available A method of overloading subcarriers by multiple transmitters to secure OFDM in wireless time-varying channels is proposed and analyzed. The method is based on reverse piloting, superposition modulation, and joint decoding. It makes use of channel randomness, reciprocity, and fast decorrelation in space to secure OFDM with low overheads on encryption, decryption, and key distribution. These properties make it a good alternative to traditional software-based information security algorithms in systems where the costs associated with such algorithms are an implementation obstacle. A necessary and sufficient condition for achieving information theoretic security in accordance with channel and system parameters is derived. Security by complexity is assessed for cases where the condition for information theoretic security is not satisfied. In addition, practical means for implementing the method are derived including generating robust joint constellations, decoding data with low complexity, and mitigating the effects of imperfections due to mobility, power control errors, and synchronization errors.

  9. AN EFFICIENT RADIO RESOURCE MANAGEMENT STRATEGY FOR ADAPTIVE OFDM CELLULAR SYSTEMS

    Yu Guanding; Zhang Zhaoyang; Qiu Peiliang

    2006-01-01

    This paper presents an efficient Radio Resource Management (RRM) strategy for adaptive Orthogonal Frequency Division Multiplexing (OFDM) cellular systems. In the proposed strategy, only those users who have the same distance from their base stations can reuse a same subcarrier. This can guarantee the received Carrier-to-Interference ratio (C/I) of each subcarrier to be acceptable as required by system planning. Then by employing different modulation scheme on each subcarrier according to its received C/I, system spectral efficiency can be gracefully increased. Analytical and simulation results show that the spectral efficiency is improved by 40% without sacrificing the Bit Error Rate (BER) performance and call blocking probability and system capacity of the proposed strategy is better than conventional systems.

  10. Adapt

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  11. A novel orthogonal modulation format of D8PSK/ASK with differential bi-phase encoding and its application in a label switching optical network

    ZHANG Xing; ZHANG Xiao-lei; WANG Yong-jun; XIN Xiang-jun; YIN Xiao-li; LI Ling; ZHAO Ji-jun

    2012-01-01

    The principle of a novel orthogonal modulation format of differential 8-level phase-shift keying amplitude-shift keying (D8PSK/ASK) with differential bi-phase encoding (DBC) is introduced.Based on it,an optical labeling scheme,in which the payload is 100 Gbit/s D8PSK signal and the label is 10 Gbit/s DBC-ASK signal,is proposed and simulated.The results are compared with other current schemes,and the effects of transmission range,modulation extinction ratio (ER) and received power on system performance are analyzed,respectively.The results show that the spectrum efficiency and bit error rate (BER) are improved greatly,and when the modulation ER is increased to 11 dB,the balanced performance between the payload and label is achieved.

  12. Energy-Efficiency Analysis of Per-Subcarrier Antenna Selection with Peak-Power Reduction in MIMO-OFDM Wireless Systems

    Ngoc Phuc Le

    2014-01-01

    Full Text Available The use of per-subcarrier antenna subset selection in OFDM wireless systems offers higher system capacity and/or improved link reliability. However, the implementation of the conventional per-subcarrier selection scheme may result in significant fluctuations of the average power and peak power across antennas, which affects the potential benefits of the system. In this paper, power efficiency of high-power amplifiers and energy efficiency in per-subcarrier antenna selection MIMO-OFDM systems are investigated. To deliver the maximum overall power efficiency, we propose a two-step strategy for data-subcarrier allocation. This strategy consists of an equal allocation of data subcarriers based on linear optimization and peak-power reduction via cross-antenna permutations. For analysis, we derive the CCDF (complementary cumulative distribution function of the power efficiency as well as the analytical expressions of the average power efficiency. It is proved from the power-efficiency perspective that the proposed allocation scheme outperforms the conventional scheme. We also show that the improvement in the power efficiency translates into an improved capacity and, in turn, increases energy efficiency of the proposed system. Simulation results are provided to validate our analyses.

  13. A novel adaptive classification scheme for digital modulations in satellite communication

    Wu Dan; Gu Xuemai; Guo Qing

    2007-01-01

    To make the modulation classification system more suitable for signals in a wide range of signal to noise ratios (SNRs) , a novel adaptive modulation classification scheme is presented in this paper. Different from traditional schemes, the proposed scheme employs a new SNR estimation algorithm for small samples before modulation classification, which makes the modulation classifier work adaptively according to estimated SNRs. Furthermore, it uses three efficient features and support vector machines (SVM) in modulation classification. Computer simulation shows that the scheme can adaptively classify ten digital modulation types (i.e. 2ASK, 4ASK, 2FSK, 4FSK, 2PSK, 4PSK, 16QAM, TFM, π/4QPSK and OQPSK) at SNRS ranging from OdB to 25 dB and success rates are over 95% when SNR is not lower than 3dB. Accuracy, efficiency and simplicity of the proposed scheme are obviously improved, which make it more adaptive to engineering applications.

  14. Adaptive antenna system for OFDMA WiMAX radio-over-fiber links using a directly modulated R-SOA and optical filtering

    Presi, Marco; Prince, Kamau; Chiuchiarelli, Andrea;

    2009-01-01

    We implement an adaptive beam steering system based on a directly-modulated unseeded reflective SOA. this system allows the distribution of 2.4 GHz 64-QAM OFDMA signals with 2048-subcarriers (72 Mb/s) satisfying the IEEE 802.16e specifications......We implement an adaptive beam steering system based on a directly-modulated unseeded reflective SOA. this system allows the distribution of 2.4 GHz 64-QAM OFDMA signals with 2048-subcarriers (72 Mb/s) satisfying the IEEE 802.16e specifications...

  15. Blind Adaptive Successive Interference Cancellation for Multicarrier DS-CDMA

    Shakya, Indu; Stipidis, Elias

    2011-01-01

    A new adaptive receiver design for the Multicarrier (MC) DS-CDMA is proposed employing successive interference cancellation (SIC) architecture. One of the main problems limiting the performance of SIC in MC DS-CDMA is the imperfect estimation of multiple access interference (MAI), and hence, the limited frequency diversity gain achieved in multipath fading channels. In this paper, we design a blind adaptive SIC with new multiple access interference suppression capability implemented within despreading process to improve both detection and cancellation processes. Furthermore, dynamic scaling factors derived from the despreader weights are used for interference cancellation process. This method applied on each subcarrier is followed by maximum ratio or equal gain combining to fully exploit the frequency diversity inherent in the multicarrier CDMA systems. It is shown that this way of MAI estimation on individual subcarrier provides significantly improved performance for a MC DS-CDMA system compared to that with...

  16. Comparative Study in Performance for Subcarrier Mapping in Uplink 4G-LTE under Different Channel Cases

    Raad Farhood Chisab

    2014-01-01

    Full Text Available in recent years, wireless communication has experienced a rapid growth and it promises to become a globally important infrastructure. One common design approach in fourth generation 4G systems is Single Carrier Frequency Division Multiple Access (SC-FDMA. It is a single carrier communication technique on the air interface. It has become broadly accepted mainly because of its high resistance to frequency selective fading channels. The third Generation Partnership Project-Long Term Evolution (3GPP-LTE uses this technique in uplink direction because of its lower peak to average power ratio PAPR as compared to Orthogonal Frequency Division Multiple Access (OFDMA that is used for downlink direction. In this paper the LTE in general and SCFDMA will be discuss in details and its performance will be study under two types of subcarrier mapping which are localized and distributed mode also within different channel cases. The results show that the localized subcarrier mapping give lower bit error rate BER than the distributed mode and give different activity under miscellaneous channel cases.

  17. Practical Approaches to Adaptive Resource Allocation in OFDM Systems

    N. Y. Ermolova

    2007-11-01

    Full Text Available Whenever a communication system operates in a time-frequency dispersive radio channel, the link adaptation provides a benefit in terms of any system performance metric by employing time, frequency, and, in case of multiple users, multiuser diversities. With respect to an orthogonal frequency division multiplexing (OFDM system, link adaptation includes bit, power, and subcarrier allocations. While the well-known water-filling principle provides the optimal solution for both margin-maximization and rate-maximization problems, implementation complexity often makes difficult its application in practical systems. This paper presents a few suboptimal (low-complexity adaptive loading algorithms for both single- and multiuser OFDM systems. We show that the single-user system performance can be improved by suitable power loading and an algorithm based on the incomplete channel state information is derived. At the same time, the power loading in a multiuser system only slightly affects performance while the initial subcarrier allocation has a rather big impact. A number of subcarrier allocation algorithms are discussed and the best one is derived on the basis of the order statistics theory.

  18. Practical Approaches to Adaptive Resource Allocation in OFDM Systems

    Ermolova NY

    2008-01-01

    Full Text Available Abstract Whenever a communication system operates in a time-frequency dispersive radio channel, the link adaptation provides a benefit in terms of any system performance metric by employing time, frequency, and, in case of multiple users, multiuser diversities. With respect to an orthogonal frequency division multiplexing (OFDM system, link adaptation includes bit, power, and subcarrier allocations. While the well-known water-filling principle provides the optimal solution for both margin-maximization and rate-maximization problems, implementation complexity often makes difficult its application in practical systems. This paper presents a few suboptimal (low-complexity adaptive loading algorithms for both single- and multiuser OFDM systems. We show that the single-user system performance can be improved by suitable power loading and an algorithm based on the incomplete channel state information is derived. At the same time, the power loading in a multiuser system only slightly affects performance while the initial subcarrier allocation has a rather big impact. A number of subcarrier allocation algorithms are discussed and the best one is derived on the basis of the order statistics theory.

  19. Adaptive antenna system for OFDMA WiMAX radio-over-fiber links using a directly modulated R-SOA and optical filtering

    Presi, Marco; Prince, Kamau; Chiuchiarelli, Andrea; Cerutti, Isabella; Constabile, Giampiero; Tafur Monroy, Idelfonso; Ciaramella, Ernesto

    We implement an adaptive beam steering system based on a directly-modulated unseeded reflective SOA. this system allows the distribution of 2.4 GHz 64-QAM OFDMA signals with 2048-subcarriers (72 Mb/s) satisfying the IEEE 802.16e specifications...

  20. Modified EESM Based Link Adaptation Algorithm for Multimedia Transmission in Multicarrier Systems

    Sandanalakshmi, R; Manivannan, K

    2010-01-01

    The previous link adaptation algorithms on ofdm based systems use equal modulation order for all sub carrier index within a block. For multimedia transmission using ofdm as the modulation technique, unequal constellation is used within one ofdm subcarrier block, a set of subcarriers for audio and another set for video transmissions. A generic model has been shown for such a transmission and link adaptation algorithm has been proposed using EESM (Effective Exponential SNR mapping) method as basic method. Mathematical model has been derived for the channel based on bivariate Gaussian distribution in which the amplitude varies two dimensionally in the same envelope. From the Moment generating function of bivariate distribution, Probability of error has been theoretically derived. Results have been shown for BER performance of an ofdm system using unequal constellation. BER performances have been shown for different values of correlation parameter and fading figure.

  1. Modified PTS with FECs for PAPR Reduction in MIMO-OFDM System with Different Subblocks and Subcarriers

    Mukunthan Pandurangan

    2011-07-01

    Full Text Available Multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM systems have been proposed in the recent past for providing high data-rate services over wireless channels. When combined with space time coding it provides the advantages of space-time coding and OFDM, resulting in a spectrally efficient wideband communication system. However, MIMO OFDM systems suffer with the problem of inherent high peak-to-average power ratio (PAPR due to the intersymbol interference between the subcarriers. In order to obtain optimal PAPR reduction using the partial transmitted sequence (PTS, the total search for the number of subblocks and the rotation factors must be accomplished. As the number of subblocks and rotation factors increases, PAPR reduction improves. The number of calculation increases as the number of subblocks increases, such that complexity increases exponentially and the process delay occurs simultaneously. In this paper, a generalised framework for PAPR reduction for MIMO OFDM systems based on modified PTS using forward error-correcting codes (FECs such as Turbo codes and Golay codes are employed. PAPR reduction is jointly optimised in both the real and imaginary part by use of fast Fourier transform (FFT algorithm in the modified PTS which can be utilized for finding the optimum phase weighting factors, and can achieve the lower PAPR and computational complexity of MIMO OFDM systems. The simulation results show that the combined FEC with modified PTS technique significantly provides better PAPR reduction with reduced computational complexity compared to original PTS technique in the MIMOOFDM systems.

  2. SDR implementation of the receiver of adaptive communication system

    Skarzynski, Jacek; Darmetko, Marcin; Kozlowski, Sebastian; Kurek, Krzysztof

    2016-04-01

    The paper presents software implementation of a receiver forming a part of an adaptive communication system. The system is intended for communication with a satellite placed in a low Earth orbit (LEO). The ability of adaptation is believed to increase the total amount of data transmitted from the satellite to the ground station. Depending on the signal-to-noise ratio (SNR) of the received signal, adaptive transmission is realized using different transmission modes, i.e., different modulation schemes (BPSK, QPSK, 8-PSK, and 16-APSK) and different convolutional code rates (1/2, 2/3, 3/4, 5/6, and 7/8). The receiver consists of a software-defined radio (SDR) module (National Instruments USRP-2920) and a multithread reception software running on Windows operating system. In order to increase the speed of signal processing, the software takes advantage of single instruction multiple data instructions supported by x86 processor architecture.

  3. Complete sequences of four plasmids of Lactococcus lactis subsp. cremoris SK11 reveal extensive adaptation to the dairy environment.

    Siezen, Roland J; Renckens, Bernadet; van Swam, Iris; Peters, Sander; van Kranenburg, Richard; Kleerebezem, Michiel; de Vos, Willem M

    2005-12-01

    Lactococcus lactis strains are known to carry plasmids encoding industrially important traits. L. lactis subsp. cremoris SK11 is widely used by the dairy industry in cheese making. Its complete plasmid complement was sequenced and found to contain the plasmids pSK11A (10,372 bp), pSK11B (13,332 bp), pSK11L (47,165 bp), and pSK11P (75,814 bp). Six highly homologous repB-containing replicons were found, all belonging to the family of lactococcal theta-type replicons. Twenty-three complete insertion sequence elements segment the plasmids into numerous modules, many of which can be identified as functional units or containing functionally related genes. Plasmid-encoded functions previously known to reside on L. lactis SK11 plasmids were now mapped in detail, e.g., lactose utilization (lacR-lacABCDFEGX), the proteolytic system (prtM-prtP, pepO, pepF), and the oligopeptide permease system (oppDFBCA). Newly identified plasmid-encoded functions could facilitate the uptake of various cations, while the pabA and pabB genes could be essential for folate biosynthesis. A competitive advantage could be obtained by using the putative flavin adenine dinucleotide-dependent d-lactate dehydrogenase and oxalate:formate antiporter for enhanced ATP synthesis, while the activity of the predicted alpha-acetolactate decarboxylase may contribute to the formation of an additional electron sink. Various stress response proteins are plasmid encoded, which could enhance strain robustness. A substantial number of these "adaptation" genes have not been described before on L. lactis plasmids. Moreover, several genes were identified for the first time in L. lactis, possibly reflecting horizontal gene transfer. PMID:16332824

  4. Performance Bounds on Micro-Doppler Estimation and Adaptive Waveform Design Using OFDM Signals

    Sen, Satyabrata [ORNL; Barhen, Jacob [ORNL; Glover, Charles Wayne [ORNL

    2014-01-01

    We analyze the performance of a wideband orthogonal frequency division multiplexing (OFDM) signal in estimating the micro-Doppler frequency of a target having multiple rotating scatterers (e.g., rotor blades of a helicopter, propellers of a submarine). The presence of rotating scatterers introduces Doppler frequency modulation in the received signal by generating sidebands about the transmitted frequencies. This is called the micro-Doppler effects. The use of a frequency-diverse OFDM signal in this context enables us to independently analyze the micro-Doppler characteristics with respect to a set of orthogonal subcarrier frequencies. Therefore, to characterize the accuracy of micro-Doppler frequency estimation, we compute the Cram er-Rao Bound (CRB) on the angular-velocity estimate of the target while considering the scatterer responses as deterministic but unknown nuisance parameters. Additionally, to improve the accuracy of the estimation procedure, we formulate and solve an optimization problem by minimizing the CRB on the angular-velocity estimate with respect to the transmitting OFDM spectral coefficients. We present several numerical examples to demonstrate the CRB variations at different values of the signal-to-noise ratio (SNR) and the number of OFDM subcarriers. The CRB values not only decrease with the increase in the SNR values, but also reduce as we increase the number of subcarriers implying the significance of frequency-diverse OFDM waveforms. The improvement in estimation accuracy due to the adaptive waveform design is also numerically analyzed. Interestingly, we find that the relative decrease in the CRBs on the angular-velocity estimate is more pronounced for larger number of OFDM subcarriers.

  5. Performance bounds on micro-Doppler estimation and adaptive waveform design using OFDM signals

    Sen, Satyabrata; Barhen, Jacob; Glover, Charles W.

    2014-05-01

    We analyze the performance of a wideband orthogonal frequency division multiplexing (OFDM) signal in estimating the micro-Doppler frequency of a target having multiple rotating scatterers (e.g., rotor blades of a helicopter, propellers of a submarine). The presence of rotating scatterers introduces Doppler frequency modulation in the received signal by generating sidebands about the transmitted frequencies. This is called the micro-Doppler effects. The use of a frequency-diverse OFDM signal in this context enables us to independently analyze the micro-Doppler characteristics with respect to a set of orthogonal subcarrier frequencies. Therefore, to characterize the accuracy of micro-Doppler frequency estimation, we compute the Craḿer-Rao Bound (CRB) on the angular-velocity estimate of the target while considering the scatterer responses as deterministic but unknown nuisance parameters. Additionally, to improve the accuracy of the estimation procedure, we formulate and solve an optimization problem by minimizing the CRB on the angular-velocity estimate with respect to the transmitting OFDM spectral coefficients. We present several numerical examples to demonstrate the CRB variations at different values of the signal-to-noise ratio (SNR) and the number of OFDM subcarriers. The CRB values not only decrease with the increase in the SNR values, but also reduce as we increase the number of subcarriers implying the significance of frequency-diverse OFDM waveforms. The improvement in estimation accuracy due to the adaptive waveform design is also numerically analyzed. Interestingly, we find that the relative decrease in the CRBs on the angular-velocity estimate is more pronounced for larger number of OFDM subcarriers.

  6. Ergodic capacity comparison of optical wireless communications using adaptive transmissions.

    Hassan, Md Zoheb; Hossain, Md Jahangir; Cheng, Julian

    2013-08-26

    Ergodic capacity is investigated for the optical wireless communications employing subcarrier intensity modulation with direct detection, and coherent systems with and without polarization multiplexing over the Gamma-Gamma turbulence channels. We consider three different adaptive transmission schemes: (i) variable-power, variable-rate adaptive transmission, (ii) complete channel inversion with fixed rate, and (iii) truncated channel inversion with fixed rate. For the considered systems, highly accurate series expressions for ergodic capacity are derived using a series expansion of the modified Bessel function and the Mellin transformation of the Gamma-Gamma random variable. Our asymptotic analysis reveals that the high SNR ergodic capacities of coherent, subcarrier intensity modulated, and polarization multiplexing systems gain 0.33 bits/s/Hz, 0.66 bits/s/Hz, and 0.66 bits/s/Hz respectively with 1 dB increase of average transmitted optical power. Numerical results indicate that a polarization control error less than 10° has little influence on the capacity performance of polarization multiplexing systems. PMID:24105580

  7. Coded Adaptive Linear Precoded Discrete Multitone Over PLC Channel

    Muhammad, Fahad Syed; Hélard, Jean-François; Crussière, Matthieu

    2008-01-01

    Discrete multitone modulation (DMT) systems exploit the capabilities of orthogonal subcarriers to cope efficiently with narrowband interference, high frequency attenuations and multipath fadings with the help of simple equalization filters. Adaptive linear precoded discrete multitone (LP-DMT) system is based on classical DMT, combined with a linear precoding component. In this paper, we investigate the bit and energy allocation algorithm of an adaptive LP-DMT system taking into account the channel coding scheme. A coded adaptive LPDMT system is presented in the power line communication (PLC) context with a loading algorithm which accommodates the channel coding gains in bit and energy calculations. The performance of a concatenated channel coding scheme, consisting of an inner Wei's 4-dimensional 16-states trellis code and an outer Reed-Solomon code, in combination with the proposed algorithm is analyzed. Theoretical coding gains are derived and simulation results are presented for a fixed target bit error ra...

  8. Performance of Adaptive Subchannel Assignment-Based MIMO/OFDM Systems over Multipath Fading Channels

    2006-01-01

    Adaptive antenna arrays at both the base and mobile stations can further increase system capacity and improve the quality of service of conventional orthogonal frequency division multiplexing (OFDM) systems. Conventional adaptive antenna array-based multiple-input multiple-output (MIMO)/OFDM systems use the sub-carriers characterized by the largest eigenvalue to transmit the OFDM symbols. This paper describes the performance of adaptive subchannel assignment-based MIMO/OFDM systems over multipath fading channels. The system adaptively selects the eigenvectors associated with the relatively large subchannel eigenvalues to generate the antenna array weights at the base and mobile stations and then adaptively assigns the corresponding best subchannels to transmit the OFDM symbols. Simulation results show that the proposed system can achieve better performance than the conventional adaptive antenna array-based MIMO/OFDM system over multipath fading channels.

  9. Novel Link Adaptation Schemes for OFDM System

    LEI Ming; CAI Peng; XU Yue-shan; ZHANG Ping

    2003-01-01

    Orthogonal Frequency Division Multiplexing (OFDM) is the most promising technique supporting the high data rate transmission. The combination of the link adaptation and OFDM can further increase the spectral efficiency. In this paper, we put forward two link adaptation schemes for OFDM system which have the advantages of both flexibility and practicability. Both of the two novel link adaptation schemes are based on the iterative mechanism to allocate the bit and power to subcarriers according to their channel gains and noisy levels which are assumed to be already known at the transmitter. The candidate modulation modes are determined freely before the link adaptation schemes are performed. The distinction between the two novel link adaptation schemes is that in the novel scheme A, the modulation mode is upgraded to the neighboring higher-order mode, while in the novel scheme B the modulation is upgraded to the genuine optimal mode. Therefore, the novel scheme A has the advantage of lower complexity and the novel scheme B has the advantage of higher spectral efficiency.

  10. Suboptimal Rate Adaptive Resource Allocation for Downlink OFDMA Systems

    Sanam Sadr

    2009-01-01

    Full Text Available This paper aims to study the performance of low complexity adaptive resource allocation in the downlink of OFDMA systems with fixed or variable rate requirements (with fairness consideration. Two suboptimal resource allocation algorithms are proposed using the simplifying assumption of transmit power over the entire bandwidth. The objective of the first algorithm is to maximize the total throughput while maintaining rate proportionality among the users. The proposed suboptimal algorithm prioritizes the user with the highest sensitivity to the subcarrier allocation, and the variance over the subchannel gains is used to define the sensitivity of each user. The second algorithm concerns rate adaptive resource allocation in multiuser systems with fixed rate constraints. We propose a suboptimal joint subchannel and power allocation algorithm which prioritizes the users with the highest required data rates. The main feature of this algorithm is its low complexity while achieving the rate requirements.

  11. ADAPTIVE CHANNEL EQUALIZATION FOR FBMC BASED ON VARIABLE LENGTH STEP SIZE AND MEAN-SQUARED ERROR

    Mashhoor AlTarayrah

    2014-03-01

    Full Text Available Recently, increasing data transmission rates and the demand of more bandwidth at the same time have been a challenge. The trend now is to support high data rates in wireless communications. Multicarrier systems have overcome many challenges of high bandwidth efficiency and at the same time provided also high spectral efficiency. Filter bank multicarrier systems (FBMC provide some advantages more than the traditional orthogonal frequency division multiplexing (OFDM with cyclic prefix (CP. FBMC systems provide a much better spectral shaping of the subcarriers than orthogonal frequency division multiplexing (OFDM. Therefore, the most obvious difference between the two techniques is in frequency selectivity. In this paper, we will present a least-meansquare (LMS algorithm which is based on well-known cost functions, which is the mean-squared error (MSE adapted for FBMC system with offset QAM modulation (OQAM. This leads to a per-subchannel adaptive equalizer solution with low complexity. The proposed simulations have used practical channel information based on the International Telecommunications Union (ITU Standards. Moreover, we will discuss how the proposed algorithm will optimize and evaluate the convergence characteristic curves of LMS equalization algorithm per-subcarrier.

  12. Investigation of Frequency-Domain Link Adaptation for a 5-MHz OFDMA/HSDPA system

    Pokhariyal, Akhilesh; Kolding, Troels E.; Frederiksen, Frank;

    2005-01-01

    In this paper, we investigate frequency domain link adaptation (FDLA), e.g. utilizing the frequency selectivity of the channel in an OFDMA system. To make the study specific and based on realistic parameters, we re-use the specifications from a recent 3GPP 5-MHz OFDMA study item. The link...... adaptation and the frequency domain link adaptation are developed in a way compliant with the basic HSDPA specifications. With FDLA we show up to 75% cell throughput gain over the OFDMA reference system at the cost of increased uplink channel quality signaling overhead for frequency selective channels. We...... find that optimum waterfilling power distribution only provides a marginal gain over a simpler on/off equal power distribution algorithm per sub-carrier pool when signaling imperfections are taken into account....

  13. Optical Millimeter-Wave Sub-Carrier Generation Based on Optical Parametric Loop Mirror%基于光纤参量环形镜的光毫米波副载波产生

    李恒文; 江阳; 徐静; 周竹雅; 王顺艳

    2012-01-01

    Based on a fiber optical parametric loop mirror (OPLM) and a fiber Bragg grating (FBG),a scheme of 60 GHz optical millimeter-wave sub-carrier generation is analyzed and demonstrated. The conclusion indicates that OPLM can be used to achieve high-order harmonic and pump filter of photonic microwave signals at the same time,then optical millimeter-wave subcarrier can be obtained by leaving only the high harmonics. In the experimental demonstration,utilizing 5 GHz baseband signal,high-order harmonic generation and separation of the pump can be achieved by modulating the nonlinear and four-wave mixing and filtering in OPLM. Eventually,the required 60 GHz optical millimeter-wave sub-carrier signals can be realized successfully. Which shows good performance.%提出并验证了一种基于光纤参量环形镜(OPLM)和光纤光栅(FBG)的60 GHz光毫米波副载波产生方案.理论上分析了OPLM的原理特性,发现可以利用OPLM同时完成光子微波信号的高次谐波产生和抽运滤波,直接获得光毫米波副载波信号.在实验验证中,从5 GHz的基频信号出发,通过调制非线性和OPLM中的四波混频和滤波过程,完成高次谐波产生和抽运分离,成功得到60 GHz的光毫米波副载波信号,表现出良好的性能.

  14. ADAPTIVE GUARD INTERVAL AND POWER ALLOCATION FOR OFDM-BASED COGNITIVE RADIO

    Taskeen Nadkar

    2011-06-01

    Full Text Available The function of the Radio Resource Management module of a CR system is to evaluate the available resources and assign them to meet the Quality of Service (QoS objectives of the Secondary User (SU, within some constraints on factors which limit the performance of the Primary User (PU. While interference mitigation to the PU spectral band from the SU’s transmission, has received a lot of attention in recent literature, the novelty of our work is in considering a more realistic and effective approach of dividing the PU into sub-bands, and ensuring that the interference to each of them is below a specified threshold. The objective of this paper is joint determination of the channel adaptive guard interval, along with sub-carrier power allocation for an orthogonal frequency division multiplexing (OFDM-based SU, to maximize the SU’s throughput, within a power budget and with the aforementioned PU interference constraint. A multiple SU scenario is also considered, which entails assigning sub-carriers to users, besides determining the guard interval and power allocation. Simulation results are provided, which indicate the effectiveness of the proposed algorithms in a CR environment.

  15. Adaptive Lighting

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive LightingAdaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled i...

  16. Dinamika Personal Adjustment Pada Mantan PSK

    Ginting, Reza Yoga Pratama

    2014-01-01

    The research uses qualitative approach and aims to find the personal adjustment dynamic of former sexual worker. This research uses two respondents living in Medan and Pematang Siantar. The procedure of selecting the respondent was snowball method. The data were obtain by conducting interview. Theory that has been used in this research is personal adjustment theory by Weiten & Lyoid (2006) that consist of three aspects: stress and coping stress, interpersonal realm, and developmental transiti...

  17. 一种基于子载波侦听的宽带无线网络接入控制策略%A Subcarrier-Sensing-Based Medium Access Control Scheme in Wireless Broadband Networks

    尹杰晨; 毛玉明; 冷鹏

    2014-01-01

    In the orthogonal frequency division multiple access (OFDMA)wireless broadband networks ,the efficiency of ran-dom access can be improved by distributing contention onto multiple channels .However ,due to the multichannel property ,the tradi-tional systems based on request-to-send (RTS )control frame have to encounter the idleness of subchannel ,the extension of RTS transmission time and the complex synchronization of uplink communication .To solve these problems ,in our scheme ,the users send signals on random subcarrier to request transmission opportunity .The access point senses these request signals ,and determines which user is permitted to access channel according to the busy state of the subcarriers .The theoretical analysis and simulation results both show that our scheme outperforms the traditional RTS-based schemes in term of the throughput .%在基于正交频分多址技术的宽带网络中,通过把竞争分散到多个子信道能有效改善随机接入的性能。然而多信道特性也会使传统基于Request-To-Send (RTS )控制帧的随机接入协议面临子信道空闲、RTS传输时间延长、上行复杂的问题。针对这些问题,在本文所提出的接入方法中,用户在没有被分配到资源时通过在随机子载波上发送信号来请求传输机会,与此同时,接入点对这些信号侦听,并根据子载波忙闲状态确定哪些用户可以接入。理论分析及仿真结果表明,相比传统依靠RTS的接入方法,采用子载波侦听,系统将获得更高的吞吐量。

  18. Adaptive skills

    Staša Stropnik; Jana Kodrič

    2013-01-01

    Adaptive skills are defined as a collection of conceptual, social and practical skills that are learned by people in order to function in their everyday lives. They include an individual's ability to adapt to and manage her or his surroundings to effectively function and meet social or community expectations. Good adaptive skills promote individual's independence in different environments, whereas poorly developed adaptive skills are connected to individual's dependency and with g...

  19. Adaptive Lighting

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... distributed differently into an architectural body. We also examine what might occur when light is dynamic and able to change colour, intensity and direction, and when it is adaptive and can be brought into interaction with its surroundings. In short, what happens to an architectural space when artificial...

  20. Adaptive Lighting

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... the investigations of lighting scenarios carried out in two test installations: White Cube and White Box. The test installations are discussed as large-scale experiential instruments. In these test installations we examine what could potentially occur when light using LED technology is integrated and...

  1. Adaptive skills

    Staša Stropnik

    2013-02-01

    Full Text Available Adaptive skills are defined as a collection of conceptual, social and practical skills that are learned by people in order to function in their everyday lives. They include an individual's ability to adapt to and manage her or his surroundings to effectively function and meet social or community expectations. Good adaptive skills promote individual's independence in different environments, whereas poorly developed adaptive skills are connected to individual's dependency and with greater need for control and help with everyday tasks. Assessment of adaptive skills is often connected to assessment of intellectual disability, due to the reason that the diagnosis of intellectual disability includes lower levels of achievements on standardized tests of intellectual abilities as well as important deficits in adaptive skills. Assessment of adaptive behavior is a part of standard assessment battery with children and adults with different problems, disorders or disabilities that affect their everyday functioning. This contribution also presents psychometric tools most regularly used for assessment of adaptive skills and characteristics of adaptive skills with individual clinical groups.

  2. ADAPT Dataset

    National Aeronautics and Space Administration — Advanced Diagnostics and Prognostics Testbed (ADAPT) Project Lead: Scott Poll Subject Fault diagnosis in electrical power systems Description The Advanced...

  3. New Adaptive Data Transmission Scheme Over HF Radio

    Adil H. Ahmad

    2008-01-01

    Full Text Available Acceptable Bit Error rate can be maintained by adapting some of the design parameters such as modulation, symbol rate, constellation size, and transmit power according to the channel state.An estimate of HF propagation effects can be used to design an adaptive data transmission system over HF link. The proposed system combines the well known Automatic Link Establishment (ALE together with variable rate transmission system. The standard ALE is modified to suite the required goal of selecting the best carrier frequency (channel for a given transmission. This is based on measuring SINAD (Signal plus Noise plus Distortion to Noise plus Distortion, RSL (Received Signal Level, multipath phase distortion and BER (Bit Error Rate for each channel in the frequency list. Channel condition evaluation is done by two arrangements. In the first an FFT analysis is used where a pilot signal is transmitted over the channel, while the data itself is used in the second arrangement. Passive channel assessment is used to avoid bad channels hence limiting the frequency pool size to be used in the point to point communication and the time required for scanning and linking. An exchange of channel information between the transmitting and receiving stations is considered to select the modulation scheme for transmission. Mainly MPSK and MFSK are considered with different levels giving different data rate according to the channel condition. The results of the computer simulation have shown that when transmitting at a fixed channel symbol rate of 1200 symbol/sec, the information rate ranges from 2400 bps using 4FSK up to 3600 bps using 8PSK for SNR ranges from 11dB up to 26dB.

  4. Ambiguous Adaptation

    Møller Larsen, Marcus; Lyngsie, Jacob

    We investigate why some exchange relationships terminate prematurely. We argue that investments in informal governance structures induce premature termination in relationships already governed by formal contracts. The formalized adaptive behavior of formal governance structures and the flexible and...... reciprocal adaptation of informal governance structure create ambiguity in situations of contingencies, which, subsequently, increases the likelihood of premature relationship termination. Using a large sample of exchange relationships in the global service provider industry, we find support for a hypothesis...

  5. Strategic Adaptation

    Andersen, Torben Juul

    2015-01-01

    This article provides an overview of theoretical contributions that have influenced the discourse around strategic adaptation including contingency perspectives, strategic fit reasoning, decision structure, information processing, corporate entrepreneurship, and strategy process. The related...... concepts of strategic renewal, dynamic managerial capabilities, dynamic capabilities, and strategic response capabilities are discussed and contextualized against strategic responsiveness. The insights derived from this article are used to outline the contours of a dynamic process of strategic adaptation...

  6. Is adaptation. Truly an adaptation? Is adaptation. Truly an adaptation?

    Thais Flores Nogueira Diniz

    2008-04-01

    Full Text Available The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition, joined with the study of recycling, remaking, and every form of retelling. The film deals with the attempt by the scriptwriter Charles Kaufman, cast by Nicholas Cage, to adapt/translate a non-fictional book to the cinema, but ends up with a kind of film which is by no means what it intended to be: a film of action in the model of Hollywood productions. During the process of creation, Charles and his twin brother, Donald, undergo a series of adventures involving some real persons from the world of film, the author and the protagonist of the book, all of them turning into fictional characters in the film. In the film, adaptation then signifies something different from itstraditional meaning. The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition

  7. Adaptive test

    Kjeldsen, Lars Peter; Eriksen, Mette Rose

    2010-01-01

    Artikelen er en evaluering af de adaptive tests, som blev indført i folkeskolen. Artiklen sætter særligt fokus på evaluering i folkeskolen, herunder bidrager den med vejledning til evaluering, evalueringsværktøjer og fagspecifkt evalueringsmateriale.......Artikelen er en evaluering af de adaptive tests, som blev indført i folkeskolen. Artiklen sætter særligt fokus på evaluering i folkeskolen, herunder bidrager den med vejledning til evaluering, evalueringsværktøjer og fagspecifkt evalueringsmateriale....

  8. CSI Feedback-based CS for Underwater Acoustic Adaptive Modulation OFDM System with Channel Prediction

    蒯小燕; 孙海信; 齐洁; 程恩; 许小卡; 郭瑜辉; 陈友淦

    2014-01-01

    In this paper, we investigate the performance of adaptive modulation (AM) orthogonal frequency division multiplexing (OFDM) system in underwater acoustic (UWA) communications. The aim is to solve the problem of large feedback overhead for channel state information (CSI) in every subcarrier. A novel CSI feedback scheme is proposed based on the theory of compressed sensing (CS). We propose a feedback from the receiver that only feedback the sparse channel parameters. Additionally, prediction of the channel state is proposed every several symbols to realize the AM in practice. We describe a linear channel prediction algorithm which is used in adaptive transmission. This system has been tested in the real underwater acoustic channel. The linear channel prediction makes the AM transmission techniques more feasible for acoustic channel communications. The simulation and experiment show that significant improvements can be obtained both in bit error rate (BER) and throughput in the AM scheme compared with the fixed Quadrature Phase Shift Keying (QPSK) modulation scheme. Moreover, the performance with standard CS outperforms the Discrete Cosine Transform (DCT) method.

  9. Adaptation Laboratory

    Huq, Saleemul

    2011-11-15

    Efforts to help the world's poor will face crises in coming decades as climate change radically alters conditions. Action Research for Community Adapation in Bangladesh (ARCAB) is an action-research programme on responding to climate change impacts through community-based adaptation. Set in Bangladesh at 20 sites that are vulnerable to floods, droughts, cyclones and sea level rise, ARCAB will follow impacts and adaptation as they evolve over half a century or more. National and international 'research partners', collaborating with ten NGO 'action partners' with global reach, seek knowledge and solutions applicable worldwide. After a year setting up ARCAB, we share lessons on the programme's design and move into our first research cycle.

  10. Hedonic "adaptation"

    Paul Rozin

    2008-02-01

    Full Text Available People live in a world in which they are surrounded by potential disgust elicitors such as ``used'' chairs, air, silverware, and money as well as excretory activities. People function in this world by ignoring most of these, by active avoidance, reframing, or adaptation. The issue is particularly striking for professions, such as morticians, surgeons, or sanitation workers, in which there is frequent contact with major disgust elicitors. In this study, we study the ``adaptation'' process to dead bodies as disgust elicitors, by measuring specific types of disgust sensitivity in medical students before and after they have spent a few months dissecting a cadaver. Using the Disgust Scale, we find a significant reduction in disgust responses to death and body envelope violation elicitors, but no significant change in any other specific type of disgust. There is a clear reduction in discomfort at touching a cold dead body, but not in touching a human body which is still warm after death.

  11. Adaptive ethnography

    Berth, Mette

    2005-01-01

    This paper focuses on the use of an adaptive ethnography when studying such phenomena as young people's use of mobile media in a learning perspective. Mobile media such as PDAs and mobile phones have a number of affordances which make them potential tools for learning. However, before we begin to...... design and develop educational materials for mobile media platforms we must first understand everyday use and behaviour with a medium such as a mobile phone. The paper outlines the research design for a PhD project on mobile learning which focuses on mobile phones as a way to bridge the gap between...... formal and informal learning contexts. The paper also proposes several adaptive methodological techniques for studying young people's interaction with mobiles....

  12. Adaptable positioner

    This paper describes the circuits and programs in assembly language, developed to control the two DC motors that give mobility to a mechanical arm with two degrees of freedom. As a whole, the system is based in a adaptable regulator designed around a 8 bit microprocessor that, starting from a mode of regulation based in the successive approximation method, evolve to another mode through which, only one approximation is sufficient to get the right position of each motor. (Author) 22 fig. 6 ref

  13. Adaptive positioner

    This paper describes the circuits and programs in assembly language, developed to control the two DC motors that give mobility to a mechanical arm with two degrees of freedom. As a whole, the system is based in a adaptable regulator designed around a 8 bit microprocessor that, starting from a mode of regulation based in the successive approximation method, evolve to another mode through which, only one approximation is sufficient to get the right position of each motor. (Author) 6 refs

  14. Adaptive noise

    Viney, Mark; Reece, Sarah E.

    2013-01-01

    In biology, noise implies error and disorder and is therefore something which organisms may seek to minimize and mitigate against. We argue that such noise can be adaptive. Recent studies have shown that gene expression can be noisy, noise can be genetically controlled, genes and gene networks vary in how noisy they are and noise generates phenotypic differences among genetically identical cells. Such phenotypic differences can have fitness benefits, suggesting that evolution can shape noise ...

  15. Adaptive management

    Rist, Lucy; Campbell, Bruce Morgan; Frost, Peter

    2013-01-01

    in scientific articles, policy documents and management plans, but both understanding and application of the concept is mixed. This paper reviews recent literature from conservation and natural resource management journals to assess diversity in how the term is used, highlight ambiguities and consider how......Adaptive management (AM) emerged in the literature in the mid-1970s in response both to a realization of the extent of uncertainty involved in management, and a frustration with attempts to use modelling to integrate knowledge and make predictions. The term has since become increasingly widely used...... the concept might be further assessed. AM is currently being used to describe many different management contexts, scales and locations. Few authors define the term explicitly or describe how it offers a means to improve management outcomes in their specific management context. Many do not adhere to the idea...

  16. Resource Allocation with Adaptive Spread Spectrum OFDM Using 2D Spreading for Power Line Communications

    Baudais Jean-Yves

    2007-01-01

    Full Text Available Bit-loading techniques based on orthogonal frequency division mutiplexing (OFDM are frequently used over wireline channels. In the power line context, channel state information can reasonably be obtained at both transmitter and receiver sides, and adaptive loading can advantageously be carried out. In this paper, we propose to apply loading principles to an spread spectrum OFDM (SS-OFDM waveform which is a multicarrier system using 2D spreading in the time and frequency domains. The presented algorithm handles the subcarriers, spreading codes, bits and energies assignment in order to maximize the data rate and the range of the communication system. The optimization is realized at a target symbol error rate and under spectral mask constraint as usually imposed. The analytical study shows that the merging principle realized by the spreading code improves the rate and the range of the discrete multitone (DMT system in single and multiuser contexts. Simulations have been run over measured power line communication (PLC channel responses and highlight that the proposed system is all the more interesting than the received signal-to-noise ratio (SNR is low.

  17. Rate Adaptive Resource Allocation and Utility-Based Packet Scheduling in Multicarrier Systems

    Fernando Casadevall

    2011-03-01

    Full Text Available There are several approaches for Radio Resource Management (RRM in multicarrier cellular systems. This work analyzes and compares two of them: rate-adaptive resource allocation (sub-carriers and power based on instantaneous data rates, and utility-based packet scheduling based on average data rates. A fundamental RRM problem in wireless cellular networks was chosen as a background to evaluate the aforementioned approaches: the trade-off between system spectral efficiency and fairness among the users when opportunistic allocation is used. Extensive system-level simulations were performed and important network metrics such as total cell throughput, mean user throughput, system fairness index and user satisfaction were assessed. It was concluded from the simulation results that it is possible to achieve an efficient trade-off between resource efficiency and fairness using any of the two RRM approaches. However, utility-based packet scheduling algorithms based on average data rates have the advantage of presenting higher user satisfaction with less computational complexity.

  18. Use Case Design for AdaptIVe

    Wolter, Stefan; Kelsch, Johann

    2014-01-01

    AdaptIVe is a large scale European project on vehicle automation and the pertaining human-machine interaction. The use case design process is a crucial part of the system design process and a part of the human-vehicle integration subproject. This paper explains the methodology for describing use cases in AdaptIVe. They are primarily based on sequence diagrams with main and alternative flows.

  19. Adaptively robust filtering with classified adaptive factors

    CUI Xianqiang; YANG Yuanxi

    2006-01-01

    The key problems in applying the adaptively robust filtering to navigation are to establish an equivalent weight matrix for the measurements and a suitable adaptive factor for balancing the contributions of the measurements and the predicted state information to the state parameter estimates. In this paper, an adaptively robust filtering with classified adaptive factors was proposed, based on the principles of the adaptively robust filtering and bi-factor robust estimation for correlated observations. According to the constant velocity model of Kalman filtering, the state parameter vector was divided into two groups, namely position and velocity. The estimator of the adaptively robust filtering with classified adaptive factors was derived, and the calculation expressions of the classified adaptive factors were presented. Test results show that the adaptively robust filtering with classified adaptive factors is not only robust in controlling the measurement outliers and the kinematic state disturbing but also reasonable in balancing the contributions of the predicted position and velocity, respectively, and its filtering accuracy is superior to the adaptively robust filter with single adaptive factor based on the discrepancy of the predicted position or the predicted velocity.

  20. Adaptive Image Denoising by Mixture Adaptation.

    Luo, Enming; Chan, Stanley H; Nguyen, Truong Q

    2016-10-01

    We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the expectation-maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper. First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. The experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms. PMID:27416593

  1. Adaptive Modular Playware

    Lund, Henrik Hautop; Þorsteinsson, Arnar Tumi

    2011-01-01

    In this paper, we describe the concept of adaptive modular playware, where the playware adapts to the interaction of the individual user. We hypothesize that there are individual differences in user interaction capabilities and styles, and that adaptive playware may adapt to the individual user’s...

  2. Adaptive Sticky Generalized Metropolis

    Fabrizio Leisen; Roberto Casarin; David Luengo; Luca Martino

    2013-01-01

    We introduce a new class of adaptive Metropolis algorithms called adaptive sticky algorithms for efficient general-purpose simulation from a target probability distribution. The transition of the Metropolis chain is based on a multiple-try scheme and the different proposals are generated by adaptive nonparametric distributions. Our adaptation strategy uses the interpolation of support points from the past history of the chain as in the adaptive rejection Metropolis. The algorithm efficiency i...

  3. Expressing Adaptation Strategies Using Adaptation Patterns

    Zemirline, N.; Bourda, Y.; Reynaud, C.

    2012-01-01

    Today, there is a real challenge to enable personalized access to information. Several systems have been proposed to address this challenge including Adaptive Hypermedia Systems (AHSs). However, the specification of adaptation strategies remains a difficult task for creators of such systems. In this paper, we consider the problem of the definition…

  4. Uncertainty in adaptive capacity

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. (authors)

  5. Adaptive Rationality, Adaptive Behavior and Institutions

    Volchik Vyacheslav, V.

    2015-12-01

    Full Text Available The economic literature focused on understanding decision-making and choice processes reveals a vast collection of approaches to human rationality. Theorists’ attention has moved from absolutely rational, utility-maximizing individuals to boundedly rational and adaptive ones. A number of economists have criticized the concepts of adaptive rationality and adaptive behavior. One of the recent trends in the economic literature is to consider humans irrational. This paper offers an approach which examines adaptive behavior in the context of existing institutions and constantly changing institutional environment. It is assumed that adaptive behavior is a process of evolutionary adjustment to fundamental uncertainty. We emphasize the importance of actors’ engagement in trial and error learning, since if they are involved in this process, they obtain experience and are able to adapt to existing and new institutions. The paper aims at identifying relevant institutions, adaptive mechanisms, informal working rules and practices that influence actors’ behavior in the field of Higher Education in Russia (Rostov Region education services market has been taken as an example. The paper emphasizes the application of qualitative interpretative methods (interviews and discourse analysis in examining actors’ behavior.

  6. Adaptive Coordinate Descent

    Loshchilov, Ilya; Schoenauer, Marc; Sebag, Michèle

    2011-01-01

    Independence from the coordinate system is one source of efficiency and robustness for the Covariance Matrix Adaptation Evolution Strategy (CMA-ES). The recently proposed Adaptive Encoding (AE) procedure generalizes CMA-ES adaptive mechanism, and can be used together with any optimization algorithm. Adaptive Encoding gradually builds a transformation of the coordinate system such that the new coordinates are as decorrelated as possible with respect to the objective function. But any optimizat...

  7. Analysis and comparison of the 4-PSK and 8-PSK STTC over Rayleigh fading Channels for determining Performance

    Pragya Gupta

    2012-09-01

    Full Text Available Demands for capacity in wireless communications, drivenby cellular mobile, Internet and multimedia services havebeen rapidly increasing worldwide. On the other hand, theavailable radio spectrum is limited and the communicationcapacity needs cannot be met without a significantincrease in communication spectral efficiency. Codingtechniques designed for multiple antenna transmission arecalled space-time coding. Space-time coding can achievetransmit diversity and coding gain over spatially uncodedsystems without sacrificing the bandwidth. Space-timetrellis code (STTC has been widely applied to codedmultiple-input multiple-output (MIMO systems because ofits gains in coding and diversity. Diversity techniques areused to reduce the effect of fading. Space-time trellis codeis a bandwidth and power efficient method ofcommunication over Rayleigh fading that realizes thebenefits of multiple transmit and receive antennas. In thispaper we present analytical performance results for space–time trellis codes over spatially correlated Rayleigh fadingchannels. In this paper we analyze and compare the 8-PSKSTTC over Rayleigh fading Channels for determiningPerformance.

  8. Adaptation to climate change

    J. Carmin; K. Tierney; E. Chu; L.M. Hunter; J.T. Roberts; L. Shi

    2015-01-01

    Climate change adaptation involves major global and societal challenges such as finding adequate and equitable adaptation funding and integrating adaptation and development programs. Current funding is insufficient. Debates between the Global North and South center on how best to allocate the financ

  9. Origins of adaptive immunity.

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity. PMID:21395512

  10. Technology transfer for adaptation

    Biagini, Bonizella; Kuhl, Laura; Gallagher, Kelly Sims; Ortiz, Claudia

    2014-09-01

    Technology alone will not be able to solve adaptation challenges, but it is likely to play an important role. As a result of the role of technology in adaptation and the importance of international collaboration for climate change, technology transfer for adaptation is a critical but understudied issue. Through an analysis of Global Environment Facility-managed adaptation projects, we find there is significantly more technology transfer occurring in adaptation projects than might be expected given the pessimistic rhetoric surrounding technology transfer for adaptation. Most projects focused on demonstration and early deployment/niche formation for existing technologies rather than earlier stages of innovation, which is understandable considering the pilot nature of the projects. Key challenges for the transfer process, including technology selection and appropriateness under climate change, markets and access to technology, and diffusion strategies are discussed in more detail.

  11. Diffusion Adaptation over Networks

    Sayed, Ali H

    2012-01-01

    Adaptive networks are well-suited to perform decentralized information processing and optimization tasks and to model various types of self organized and complex behavior encountered in nature. Adaptive networks consist of a collection of agents with processing and learning abilities. The agents are linked together through a connection topology, and they cooperate with each other through local interactions to solve distributed inference problems in real-time. The continuous diffusion of information across the network enables agents to adapt their performance in relation to changing data and network conditions; it also results in improved adaptation and learning performance relative to non-cooperative networks. This article provides an overview of diffusion strategies for adaptation and learning over networks. The article is divided into several sections: 1. Motivation; 2. Mean-Square-Error Estimation; 3. Distributed Optimization via Diffusion Strategies; 4. Adaptive Diffusion Strategies; 5. Performance of Ste...

  12. Consciousness And Adaptive Behavior

    Sieb, Richard/A.

    2005-01-01

    Consciousness has resisted scientific explanation for centuries. The main problem in explaining consciousness is its subjectivity. Subjective systems may be adaptive. Humans can produce voluntary new or novel intentional (adaptive) action and such action is always accompanied by consciousness. Action normally arises from perception. Perception must be rerepresented in order to produce new or novel adaptive action. The internal explicit states produced by a widespread nonlinear emergen...

  13. Human Adaptations: Free divers

    Tournat, Troy Z.

    2014-01-01

    Freediving has been around for thousands of years and was only way to dive until the inventionof oxygen tanks in the 19th century. Around the world, people dove for goods such as pearls, andtoday people freedive for sport. Divers stretch the limit of their body and mind’s capabilitiesthrough psychological adaptations from thermal, respiratory, and cardiovascular responses.Findings conclude that thermal adaptations are a similar process to cold adaptive response. Withthe implementation of wets...

  14. Adaptive Multimedia Retrieval: Semantics, Context, and Adaptation

    This book constitutes the thoroughly refereed post-conference proceedings of the 10th International Conference on Adaptive Multimedia Retrieval, AMR 2012, held in Copenhagen, Denmark, in October 2012. The 17 revised full papers presented were carefully reviewed and selected from numerous submissi......This book constitutes the thoroughly refereed post-conference proceedings of the 10th International Conference on Adaptive Multimedia Retrieval, AMR 2012, held in Copenhagen, Denmark, in October 2012. The 17 revised full papers presented were carefully reviewed and selected from numerous...

  15. Decentralized adaptive control

    Oh, B. J.; Jamshidi, M.; Seraji, H.

    1988-01-01

    A decentralized adaptive control is proposed to stabilize and track the nonlinear, interconnected subsystems with unknown parameters. The adaptation of the controller gain is derived by using model reference adaptive control theory based on Lyapunov's direct method. The adaptive gains consist of sigma, proportional, and integral combination of the measured and reference values of the corresponding subsystem. The proposed control is applied to the joint control of a two-link robot manipulator, and the performance in computer simulation corresponds with what is expected in theoretical development.

  16. Adaptive Wireless Transceiver Project

    National Aeronautics and Space Administration — Wireless technologies are an increasingly attractive means for spatial data, input, manipulation, and distribution. Mobitrum is proposing an innovative Adaptive...

  17. Behavioral Adaptation and Acceptance

    Martens, M.H.; Jenssen, G.D.

    2012-01-01

    One purpose of Intelligent Vehicles is to improve road safety, throughput, and emissions. However, the predicted effects are not always as large as aimed for. Part of this is due to indirect behavioral changes of drivers, also called behavioral adaptation. Behavioral adaptation (BA) refers to uninte

  18. Behavioural adaptation and acceptance

    Martens, M.H.; Jenssen, G.D.; Eskandarian, A.

    2012-01-01

    One purpose of Intelligent Vehicles is to improve road safety, throughput, and emissions. However, the predicted effects are not always as large as aimed for. Part of this is due to indirect behavioral changes of drivers, also called behavioral adaptation. Behavioral adaptation (BA) refers to uninte

  19. Adaptive Capacity and Traps

    William A. Brock

    2008-12-01

    Full Text Available Adaptive capacity is the ability of a living system, such as a social–ecological system, to adjust responses to changing internal demands and external drivers. Although adaptive capacity is a frequent topic of study in the resilience literature, there are few formal models. This paper introduces such a model and uses it to explore adaptive capacity by contrast with the opposite condition, or traps. In a social–ecological rigidity trap, strong self-reinforcing controls prevent the flexibility needed for adaptation. In the model, too much control erodes adaptive capacity and thereby increases the risk of catastrophic breakdown. In a social–ecological poverty trap, loose connections prevent the mobilization of ideas and resources to solve problems. In the model, too little control impedes the focus needed for adaptation. Fluctuations of internal demand or external shocks generate pulses of adaptive capacity, which may gain traction and pull the system out of the poverty trap. The model suggests some general properties of traps in social–ecological systems. It is general and flexible, so it can be used as a building block in more specific and detailed models of adaptive capacity for a particular region.

  20. Adapt or Become Extinct!

    Goumas, Georgios; McKee, Sally A.; Själander, Magnus;

    2011-01-01

    boundaries (walls) for applications which limit software development (parallel programming wall), performance (memory wall, communication wall) and viability (power wall). The only way to survive in such a demanding environment is by adaptation. In this paper we discuss how dynamic information collected...... during the execution of an application can be utilized to adapt the execution context and may lead to performance gains beyond those provided by static information and compile-time adaptation. We consider specialization based on dynamic information like user input, architectural characteristics such as...... from static analysis (either during ahead-of-time or just-in-time) compilation. We extend the notion of information-driven adaptation and outline the architecture of an infrastructure designed to enable information ow and adaptation throughout the life-cycle of an application....

  1. Appraising Adaptive Management

    Kai N. Lee

    1999-12-01

    Full Text Available Adaptive management is appraised as a policy implementation approach by examining its conceptual, technical, equity, and practical strengths and limitations. Three conclusions are drawn: (1 Adaptive management has been more influential, so far, as an idea than as a practical means of gaining insight into the behavior of ecosystems utilized and inhabited by humans. (2 Adaptive management should be used only after disputing parties have agreed to an agenda of questions to be answered using the adaptive approach; this is not how the approach has been used. (3 Efficient, effective social learning, of the kind facilitated by adaptive management, is likely to be of strategic importance in governing ecosystems as humanity searches for a sustainable economy.

  2. Adaptive noise cancellation

    In this report we describe the concept of adaptive noise canceling, an alternative method of estimating signals corrupted by additive noise of interference. The method uses 'primary' input containing the corrupted signal and a 'reference' input containing noise correlated in some unknown way with the primary noise, the reference input is adaptively filtered and subtracted from the primary input to obtain the signal estimate. Adaptive filtering before subtraction allows the treatment of inputs that are deterministic or stochastic, stationary or time variable. When the reference input is free of signal and certain other conditions are met then noise in the primary input can be essentially eliminated without signal distortion. It is further shown that the adaptive filter also acts as notch filter. Simulated results illustrate the usefulness of the adaptive noise canceling technique. (author)

  3. Adaptive signal processor

    An experimental, general purpose adaptive signal processor system has been developed, utilizing a quantized (clipped) version of the Widrow-Hoff least-mean-square adaptive algorithm developed by Moschner. The system accommodates 64 adaptive weight channels with 8-bit resolution for each weight. Internal weight update arithmetic is performed with 16-bit resolution, and the system error signal is measured with 12-bit resolution. An adapt cycle of adjusting all 64 weight channels is accomplished in 8 μsec. Hardware of the signal processor utilizes primarily Schottky-TTL type integrated circuits. A prototype system with 24 weight channels has been constructed and tested. This report presents details of the system design and describes basic experiments performed with the prototype signal processor. Finally some system configurations and applications for this adaptive signal processor are discussed

  4. The process of organisational adaptation through innovations, and organisational adaptability

    Tikka, Tommi

    2010-01-01

    This study is about the process of organisational adaptation and organisational adaptability. The study generates a theoretical framework about organisational adaptation behaviour and conditions that have influence on success of organisational adaptation. The research questions of the study are: How does an organisation adapt through innovations, and which conditions enhance or impede organisational adaptation through innovations? The data were gathered from five case organisations withi...

  5. Adaptive network countermeasures.

    McClelland-Bane, Randy; Van Randwyk, Jamie A.; Carathimas, Anthony G.; Thomas, Eric D.

    2003-10-01

    This report describes the results of a two-year LDRD funded by the Differentiating Technologies investment area. The project investigated the use of countermeasures in protecting computer networks as well as how current countermeasures could be changed in order to adapt with both evolving networks and evolving attackers. The work involved collaboration between Sandia employees and students in the Sandia - California Center for Cyber Defenders (CCD) program. We include an explanation of the need for adaptive countermeasures, a description of the architecture we designed to provide adaptive countermeasures, and evaluations of the system.

  6. Introduction to adaptive arrays

    Monzingo, Bob; Haupt, Randy

    2011-01-01

    This second edition is an extensive modernization of the bestselling introduction to the subject of adaptive array sensor systems. With the number of applications of adaptive array sensor systems growing each year, this look at the principles and fundamental techniques that are critical to these systems is more important than ever before. Introduction to Adaptive Arrays, 2nd Edition is organized as a tutorial, taking the reader by the hand and leading them through the maze of jargon that often surrounds this highly technical subject. It is easy to read and easy to follow as fundamental concept

  7. [Adaptive optics for ophthalmology].

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy. PMID:27019970

  8. Theory of adaptive adjustment

    Weihong Huang

    2000-01-01

    Full Text Available Conventional adaptive expectation as a mechanism of stabilizing an unstable economic process is reexamined through a generalization to an adaptive adjustment framework. The generic structures of equilibria that can be stabilized through an adaptive adjustment mechanism are identified. The generalization can be applied to a broad class of discrete economic processes where the variables interested can be adjusted or controlled directly by economic agents such as in cobweb dynamics, Cournot games, Oligopoly markets, tatonnement price adjustment, tariff games, population control through immigration etc.

  9. Symmetry Adapted Basis Sets

    Avery, John Scales; Rettrup, Sten; Avery, James Emil

    In theoretical physics, theoretical chemistry and engineering, one often wishes to solve partial differential equations subject to a set of boundary conditions. This gives rise to eigenvalue problems of which some solutions may be very difficult to find. For example, the problem of finding...... such problems can be much reduced by making use of symmetry-adapted basis functions. The conventional method for generating symmetry-adapted basis sets is through the application of group theory, but this can be difficult. This book describes an easier method for generating symmetry-adapted basis sets...

  10. Asimovian Adaptive Agents

    Gordon, D F

    2011-01-01

    The goal of this research is to develop agents that are adaptive and predictable and timely. At first blush, these three requirements seem contradictory. For example, adaptation risks introducing undesirable side effects, thereby making agents' behavior less predictable. Furthermore, although formal verification can assist in ensuring behavioral predictability, it is known to be time-consuming. Our solution to the challenge of satisfying all three requirements is the following. Agents have finite-state automaton plans, which are adapted online via evolutionary learning (perturbation) operators. To ensure that critical behavioral constraints are always satisfied, agents' plans are first formally verified. They are then reverified after every adaptation. If reverification concludes that constraints are violated, the plans are repaired. The main objective of this paper is to improve the efficiency of reverification after learning, so that agents have a sufficiently rapid response time. We present two solutions: ...

  11. Limits to adaptation

    Dow, Kirstin; Berkhout, Frans; Preston, Benjamin L.; Klein, Richard J. T.; Midgley, Guy; Shaw, M. Rebecca

    2013-04-01

    An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society's responses to climate change.

  12. The genomics of adaptation.

    Radwan, Jacek; Babik, Wiesław

    2012-12-22

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far are beginning to challenge some widespread views of the way in which natural selection operates at the genomic level. Papers in this Special Feature of Proceedings of the Royal Society B illustrate various aspects of the broad field of adaptation genomics. This introductory article sets up a context and, on the basis of a few selected examples, discusses how genomic data can advance our understanding of the process of adaptation. PMID:23097510

  13. Adaptive shared control system

    Sanders, David

    2009-01-01

    A control system to aid mobility is presented that is intended to assist living independently and that provides physical guidance. The system has two levels: a human machine interface and an adaptive shared controller.

  14. Adaptations, exaptations, and spandrels.

    Buss, D M; Haselton, M G; Shackelford, T K; Bleske, A L; Wakefield, J C

    1998-05-01

    Adaptation and natural selection are central concepts in the emerging science of evolutionary psychology. Natural selection is the only known causal process capable of producing complex functional organic mechanisms. These adaptations, along with their incidental by-products and a residue of noise, comprise all forms of life. Recently, S. J. Gould (1991) proposed that exaptations and spandrels may be more important than adaptations for evolutionary psychology. These refer to features that did not originally arise for their current use but rather were co-opted for new purposes. He suggested that many important phenomena--such as art, language, commerce, and war--although evolutionary in origin, are incidental spandrels of the large human brain. The authors outline the conceptual and evidentiary standards that apply to adaptations, exaptations, and spandrels and discuss the relative utility of these concepts for psychological science. PMID:9612136

  15. Adapt or Die

    Brody, Joshua Eric; Larsen, Kasper Green

    2015-01-01

    In this paper, we study the role non-adaptivity plays in maintaining dynamic data structures. Roughly speaking, a data structure is non-adaptive if the memory locations it reads and/or writes when processing a query or update depend only on the query or update and not on the contents of previously...... read cells. We study such non-adaptive data structures in the cell probe model. This model is one of the least restrictive lower bound models and in particular, cell probe lower bounds apply to data structures developed in the popular word-RAM model. Unfortunately, this generality comes at a high cost......: the highest lower bound proved for any data structure problem is only polylogarithmic. Our main result is to demonstrate that one can in fact obtain polynomial cell probe lower bounds for non-adaptive data structures. To shed more light on the seemingly inherent polylogarithmic lower bound barrier, we...

  16. Adaptive Space Structures

    Wada, B.

    1993-01-01

    The term adaptive structures refers to a structural control approach in which sensors, actuators, electronics, materials, structures, structural concepts, and system-performance-validation strategies are integrated to achieve specific objectives.

  17. Adaptive Spectral Doppler Estimation

    Gran, Fredrik; Jakobsson, Andreas; Jensen, Jørgen Arendt

    2009-01-01

    In this paper, 2 adaptive spectral estimation techniques are analyzed for spectral Doppler ultrasound. The purpose is to minimize the observation window needed to estimate the spectrogram to provide a better temporal resolution and gain more flexibility when designing the data acquisition sequence....... The methods can also provide better quality of the estimated power spectral density (PSD) of the blood signal. Adaptive spectral estimation techniques are known to pro- vide good spectral resolution and contrast even when the ob- servation window is very short. The 2 adaptive techniques are tested and...... compared with the averaged periodogram (Welch’s method). The blood power spectral capon (BPC) method is based on a standard minimum variance technique adapted to account for both averaging over slow-time and depth. The blood amplitude and phase estimation technique (BAPES) is based on finding a set of...

  18. Adaptive multiresolution methods

    Schneider Kai

    2011-12-01

    Full Text Available These lecture notes present adaptive multiresolution schemes for evolutionary PDEs in Cartesian geometries. The discretization schemes are based either on finite volume or finite difference schemes. The concept of multiresolution analyses, including Harten’s approach for point and cell averages, is described in some detail. Then the sparse point representation method is discussed. Different strategies for adaptive time-stepping, like local scale dependent time stepping and time step control, are presented. Numerous numerical examples in one, two and three space dimensions validate the adaptive schemes and illustrate the accuracy and the gain in computational efficiency in terms of CPU time and memory requirements. Another aspect, modeling of turbulent flows using multiresolution decompositions, the so-called Coherent Vortex Simulation approach is also described and examples are given for computations of three-dimensional weakly compressible mixing layers. Most of the material concerning applications to PDEs is assembled and adapted from previous publications [27, 31, 32, 34, 67, 69].

  19. Adaptive Heat Engine

    Allahverdyan, A. E.; Babajanyan, S. G.; Martirosyan, N. H.; Melkikh, A. V.

    2016-07-01

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where—due to feedback from the functional part—the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment.

  20. Adaptive Architectural Envelope

    Foged, Isak Worre; Kirkegaard, Poul Henning

    2010-01-01

    Recent years have seen an increasing variety of applications of adaptive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability....... The general scopes of this paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or...... two different shape alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock- up...

  1. Statistical Physics of Adaptation

    Perunov, Nikolai; England, Jeremy

    2014-01-01

    All living things exhibit adaptations that enable them to survive and reproduce in the natural environment that they inhabit. From a biological standpoint, it has long been understood that adaptation comes from natural selection, whereby maladapted individuals do not pass their traits effectively to future generations. However, we may also consider the phenomenon of adaptation from the standpoint of physics, and ask whether it is possible to delineate what the difference is in terms of physical properties between something that is well-adapted to its surrounding environment, and something that is not. In this work, we undertake to address this question from a theoretical standpoint. Building on past fundamental results in far-from-equilibrium statistical mechanics, we demonstrate a generalization of the Helmholtz free energy for the finite-time stochastic evolution of driven Newtonian matter. By analyzing this expression term by term, we are able to argue for a general tendency in driven many-particle systems...

  2. Adaptive trial designs.

    Lai, Tze Leung; Lavori, Philip William; Shih, Mei-Chiung

    2012-01-01

    We review adaptive designs for clinical trials, giving special attention to the control of the Type I error in late-phase confirmatory trials, when the trial planner wishes to adjust the final sample size of the study in response to an unblinded analysis of interim estimates of treatment effects. We point out that there is considerable inefficiency in using the adaptive designs that employ conditional power calculations to reestimate the sample size and that maintain the Type I error by using certain weighted test statistics. Although these adaptive designs have little advantage over familiar group-sequential designs, our review also describes recent developments in adaptive designs that are both flexible and efficient. We also discuss the use of Bayesian designs, when the context of use demands control over operating characteristics (Type I and II errors) and correction of the bias of estimated treatment effects. PMID:21838549

  3. Leak test adapter for containers

    Hallett, Brian H.; Hartley, Michael S.

    1996-01-01

    An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

  4. Frustratingly Easy Domain Adaptation

    Daumé, Hal

    2009-01-01

    We describe an approach to domain adaptation that is appropriate exactly in the case when one has enough ``target'' data to do slightly better than just using only ``source'' data. Our approach is incredibly simple, easy to implement as a preprocessing step (10 lines of Perl!) and outperforms state-of-the-art approaches on a range of datasets. Moreover, it is trivially extended to a multi-domain adaptation problem, where one has data from a variety of different domains.

  5. Adaptive quantum teleportation

    Modlawska, Joanna; Grudka, Andrzej

    2008-01-01

    We consider multiple teleportation in the Knill-Laflamme-Milburn (KLM) scheme. We introduce adaptive teleportation, i.e., such that the choice of entangled state used in the next teleportation depends on the results of the measurements performed during the previous teleportations. We show that adaptive teleportation enables an increase in the probability of faithful multiple teleportation in the KLM scheme. In particular if a qubit is to be teleported more than once then it is better to use n...

  6. The Adaptive Automation Design

    Calefato, Caterina; Montanari, Roberto; TESAURI, Francesco

    2008-01-01

    After considering the positive effects of adaptive automation implementation, this chapter focuses on two partly overlapping phenomena: on the one hand, the role of trust in automation is considered, particularly as to the effects of overtrust and mistrust in automation's reliability; on the other hand, long-term lack of exercise on specific operation may lead users to skill deterioration. As a future work, it will be interesting and challenging to explore the conjunction of adaptive automati...

  7. The genomics of adaptation

    Radwan, Jacek; Babik, Wiesław

    2012-01-01

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far ...

  8. Facilitation of CRISPR adaptation

    Abedon, Stephen T.

    2011-01-01

    CRISPR systems, as bacterial defenses against phages, logically must display in their functioning a sequence of at least three major steps. These, in order of occurrence, are “facilitation,” adaptation and interference, where the facilitation step is the main issue considered in this commentary. Interference is the blocking of phage infections as mediated in part by CRISPR spacer sequences. Adaptation, at least as narrowly defined, is the acquisition of these spacer sequences by CRISPR loci. ...

  9. Robust Adaptive Control

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  10. Climate Adaptation in Europe

    At the Conference of Parties in Copenhagen, Denmark, December 7-18, 2009 Change Magazine will present a special issue on 'Climate Adaptation in Europe'. The magazine contains articles on climate policy strategies in European countries and cross-border studies on climate change, articles on climate adaptation in the Alps, on water quality as a bottleneck for the agricultural sector, and drought in the mediterranean countries. How will member countries in the European Union tackle the climate crisis?.

  11. Network and adaptive sampling

    Chaudhuri, Arijit

    2014-01-01

    Combining the two statistical techniques of network sampling and adaptive sampling, this book illustrates the advantages of using them in tandem to effectively capture sparsely located elements in unknown pockets. It shows how network sampling is a reliable guide in capturing inaccessible entities through linked auxiliaries. The text also explores how adaptive sampling is strengthened in information content through subsidiary sampling with devices to mitigate unmanageable expanding sample sizes. Empirical data illustrates the applicability of both methods.

  12. Opportunistic Adaptation Knowledge Discovery

    Badra, Fadi; Cordier, Amélie; Lieber, Jean

    2009-01-01

    The original publication is available at www.springerlink.com International audience Adaptation has long been considered as the Achilles' heel of case-based reasoning since it requires some domain-specific knowledge that is difficult to acquire. In this paper, two strategies are combined in order to reduce the knowledge engineering cost induced by the adaptation knowledge (CA) acquisition task: CA is learned from the case base by the means of knowledge discovery techniques, and the CA a...

  13. Learning to Adapt. Organisational Adaptation to Climate Change Impacts

    Analysis of human adaptation to climate change should be based on realistic models of adaptive behaviour at the level of organisations and individuals. The paper sets out a framework for analysing adaptation to the direct and indirect impacts of climate change in business organisations with new evidence presented from empirical research into adaptation in nine case-study companies. It argues that adaptation to climate change has many similarities with processes of organisational learning. The paper suggests that business organisations face a number of obstacles in learning how to adapt to climate change impacts, especially in relation to the weakness and ambiguity of signals about climate change and the uncertainty about benefits flowing from adaptation measures. Organisations rarely adapt 'autonomously', since their adaptive behaviour is influenced by policy and market conditions, and draws on resources external to the organisation. The paper identifies four adaptation strategies that pattern organisational adaptive behaviour

  14. Adaptation and perceptual norms

    Webster, Michael A.; Yasuda, Maiko; Haber, Sara; Leonard, Deanne; Ballardini, Nicole

    2007-02-01

    We used adaptation to examine the relationship between perceptual norms--the stimuli observers describe as psychologically neutral, and response norms--the stimulus levels that leave visual sensitivity in a neutral or balanced state. Adapting to stimuli on opposite sides of a neutral point (e.g. redder or greener than white) biases appearance in opposite ways. Thus the adapting stimulus can be titrated to find the unique adapting level that does not bias appearance. We compared these response norms to subjectively defined neutral points both within the same observer (at different retinal eccentricities) and between observers. These comparisons were made for visual judgments of color, image focus, and human faces, stimuli that are very different and may depend on very different levels of processing, yet which share the property that for each there is a well defined and perceptually salient norm. In each case the adaptation aftereffects were consistent with an underlying sensitivity basis for the perceptual norm. Specifically, response norms were similar to and thus covaried with the perceptual norm, and under common adaptation differences between subjectively defined norms were reduced. These results are consistent with models of norm-based codes and suggest that these codes underlie an important link between visual coding and visual experience.

  15. On Adaptive vs. Non-adaptive Security of Multiparty Protocols

    Canetti, Ran; Damgård, Ivan Bjerre; Dziembowski, Stefan; Ishai, Yuval; Malkin, Tal

    course of the computation. We study the relations between adaptive security (i.e., security in the adaptive setting) and non-adaptive security, according to two definitions and in several models of computation. While affirming some prevailing beliefs, we also obtain some unexpected results. Some...... definition of Canetti, for honest-but-curious adversaries, adaptive security is equivalent to non-adaptive security when the number of parties is logarithmic, and is strictly stronger than non-adaptive security when the number of parties is super-logarithmic. For Byzantine adversaries, adaptive security is...

  16. Solar Adaptive Optics

    Thomas R. Rimmele

    2011-06-01

    Full Text Available Adaptive optics (AO has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO and Ground-Layer AO (GLAO will be given.

  17. Adaptation and risk management

    Preston, Benjamin L [ORNL

    2011-01-01

    Adaptation assessment methods are compatible with the international risk management standard ISO:31000. Risk management approaches are increasingly being recommended for adaptation assessments at both national and local levels. Two orientations to assessments can commonly be identified: top-down and bottom-up, and prescriptive and diagnostic. Combinations of these orientations favor different types of assessments. The choice of orientation can be related to uncertainties in prediction and taking action, in the type of adaptation and in the degree of system stress. Adopting multiple viewpoints is to be encouraged, especially in complex situations. The bulk of current guidance material is consistent with top-down and predictive approaches, thus is most suitable for risk scoping and identification. Abroad range ofmaterial fromwithin and beyond the climate change literature can be used to select methods to be used in assessing and implementing adaptation. The framing of risk, correct formulation of the questions being investigated and assessment methodology are critical aspects of the scoping phase. Only when these issues have been addressed should be issue of specific methods and tools be addressed. The reorientation of adaptation from an assessment focused solely on anthropogenic climate change to broader issues of vulnerability/resilience, sustainable development and disaster risk, especially through a risk management framework, can draw from existing policy and management understanding in communities, professions and agencies, incorporating existing agendas, knowledge, risks, and issues they already face.

  18. Decoupled Adapt-then-Combine diffusion networks with adaptive combiners

    Fernandez-Bes, Jesus; Arenas-García, Jerónimo; Silva, Magno T. M.; Azpicueta-Ruiz, Luis A.

    2015-01-01

    In this paper we analyze a novel diffusion strategy for adaptive networks called Decoupled Adapt-then-Combine, which keeps a fully local estimate of the solution for the adaptation step. Our strategy, which is specially convenient for heterogeneous networks, is compared with the standard Adapt-then-Combine scheme and theoretically analyzed using energy conservation arguments. Such comparison shows the need of implementing adaptive combiners for both schemes to obtain a good performance in cas...

  19. Evolution of adaptation mechanisms: Adaptation energy, stress, and oscillating death.

    Gorban, Alexander N; Tyukina, Tatiana A; Smirnova, Elena V; Pokidysheva, Lyudmila I

    2016-09-21

    In 1938, Selye proposed the notion of adaptation energy and published 'Experimental evidence supporting the conception of adaptation energy.' Adaptation of an animal to different factors appears as the spending of one resource. Adaptation energy is a hypothetical extensive quantity spent for adaptation. This term causes much debate when one takes it literally, as a physical quantity, i.e. a sort of energy. The controversial points of view impede the systematic use of the notion of adaptation energy despite experimental evidence. Nevertheless, the response to many harmful factors often has general non-specific form and we suggest that the mechanisms of physiological adaptation admit a very general and nonspecific description. We aim to demonstrate that Selye׳s adaptation energy is the cornerstone of the top-down approach to modelling of non-specific adaptation processes. We analyze Selye׳s axioms of adaptation energy together with Goldstone׳s modifications and propose a series of models for interpretation of these axioms. Adaptation energy is considered as an internal coordinate on the 'dominant path' in the model of adaptation. The phenomena of 'oscillating death' and 'oscillating remission' are predicted on the base of the dynamical models of adaptation. Natural selection plays a key role in the evolution of mechanisms of physiological adaptation. We use the fitness optimization approach to study of the distribution of resources for neutralization of harmful factors, during adaptation to a multifactor environment, and analyze the optimal strategies for different systems of factors. PMID:26801872

  20. Adaptive cancellation techniques

    1983-11-01

    An adaptive signal canceller has been evaluated for the enhancement of pulse signal reception during the transmission of a high power ECM jamming signal. The canceller design is based on the use of DRFM(Digital RF Memory) technology as part of an adaptive multiple tapped delay line. The study includes analysis of relationship of tap spacing and waveform bandwidth, survey of related documents in areas of sidelobe cancellers, transversal equalizers, and adaptive filters, and derivation of control equations and corresponding control processes. The simulation of overall processes included geometric analysis of the multibeam transmitting antenna, multiple reflection sources and the receiving antenna; waveforms, tap spacings and bandwidths; and alternate control algorithms. Conclusions are provided regarding practical system control algorithms, design characteristics and limitations.

  1. Adaptable Embedded Systems

    Lisbôa, Carlos; Carro, Luigi

    2013-01-01

    As embedded systems become more complex, designers face a number of challenges at different levels: they need to boost performance, while keeping energy consumption as low as possible, they need to reuse existent software code, and at the same time they need to take advantage of the extra logic available in the chip, represented by multiple processors working together.  This book describes several strategies to achieve such different and interrelated goals, by the use of adaptability. Coverage includes reconfigurable systems, dynamic optimization techniques such as binary translation and trace reuse, new memory architectures including homogeneous and heterogeneous multiprocessor systems, communication issues and NOCs, fault tolerance against fabrication defects and soft errors, and finally, how one can combine several of these techniques together to achieve higher levels of performance and adaptability.  The discussion also includes how to employ specialized software to improve this new adaptive system, and...

  2. Engineering Adaptive Web Applications

    Dolog, Peter

    2007-01-01

    Information and services on the web are accessible for everyone. Users of the web differ in their background, culture, political and social environment, interests and so on. Ambient intelligence was envisioned as a concept for systems which are able to adapt to user actions and needs....... With the growing amount of information and services, the web applications become natural candidates to adopt the concepts of ambient intelligence. Such applications can deal with divers user intentions and actions based on the user profile and can suggest the combination of information content and services which...... suit the user profile the most. This paper summarizes the domain engineering framework for such adaptive web applications. The framework provides guidelines to develop adaptive web applications as members of a family. It suggests how to utilize the design artifacts as knowledge which can be used...

  3. Adaptive Metric Kernel Regression

    Goutte, Cyril; Larsen, Jan

    1998-01-01

    Kernel smoothing is a widely used nonparametric pattern recognition technique. By nature, it suffers from the curse of dimensionality and is usually difficult to apply to high input dimensions. In this paper, we propose an algorithm that adapts the input metric used in multivariate regression by...... minimising a cross-validation estimate of the generalisation error. This allows one to automatically adjust the importance of different dimensions. The improvement in terms of modelling performance is illustrated on a variable selection task where the adaptive metric kernel clearly outperforms the standard...

  4. STUDYING COMPLEX ADAPTIVE SYSTEMS

    John H. Holland

    2006-01-01

    Complex adaptive systems (cas) - systems that involve many components that adapt or learn as they interact - are at the heart of important contemporary problems. The study of cas poses unique challenges: Some of our most powerful mathematical tools, particularly methods involving fixed points, attractors, and the like, are of limited help in understanding the development of cas. This paper suggests ways to modify research methods and tools, with an emphasis on the role of computer-based models, to increase our understanding of cas.

  5. Adaptive metric kernel regression

    Goutte, Cyril; Larsen, Jan

    2000-01-01

    Kernel smoothing is a widely used non-parametric pattern recognition technique. By nature, it suffers from the curse of dimensionality and is usually difficult to apply to high input dimensions. In this contribution, we propose an algorithm that adapts the input metric used in multivariate...... regression by minimising a cross-validation estimate of the generalisation error. This allows to automatically adjust the importance of different dimensions. The improvement in terms of modelling performance is illustrated on a variable selection task where the adaptive metric kernel clearly outperforms the...

  6. Adaptive radar resource management

    Moo, Peter

    2015-01-01

    Radar Resource Management (RRM) is vital for optimizing the performance of modern phased array radars, which are the primary sensor for aircraft, ships, and land platforms. Adaptive Radar Resource Management gives an introduction to radar resource management (RRM), presenting a clear overview of different approaches and techniques, making it very suitable for radar practitioners and researchers in industry and universities. Coverage includes: RRM's role in optimizing the performance of modern phased array radars The advantages of adaptivity in implementing RRMThe role that modelling and

  7. The Adaptability of Teams

    Jørgensen, Frances; Boer, Harry

    2006-01-01

    In this paper, data from a longitudinal case study in an organization attempting to adapt its internal work processes to changes in its external context are presented, analyzed and discussed. Specifically, functionally structured work teams in one department of a Danish production facility were...... proper alignment between the structuring of the work processes and characteristics of the external context (Lawrence & Lorsch, 1967) – it provides a unique opportunity to explore the adaptation process in practice. The paper contributes to the development of contingency theory by lending support to the...

  8. Adaptive heat engine

    Allahverdyan, A.E.; Babajanyan, S. G.; Martirosyan, N. H.; Melkikh, A. V.

    2016-01-01

    A major limitations for many heat engines is that their functioning demands on-line control, and/or an external fitting between environmental parameters (e.g. temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where---due to feedback from the functional part---the engine's structure adapts to given thermal baths. Hence no on-line control and no external fitting are needed. The engine can employ unknown resources, it can also ada...

  9. Intestinal mucosal adaptation

    Laurie Drozdowski; Alan BR Thomson

    2006-01-01

    Intestinal failure is a condition characterized by malnutrition and/or dehydration as a result of the inadequate digestion and absorption of nutrients. The most common cause of intestinal failure is short bowel syndrome, which occurs when the functional gut mass is reduced below the level necessary for adequate nutrient and water absorption. This condition may be congenital, or may be acquired as a result of a massive resection of the small bowel. Following resection, the intestine is capable of adaptation in response to enteral nutrients as well as other trophic stimuli. Identifying factors that may enhance the process of intestinal adaptation is an exciting area of research with important potential clinical applications.

  10. How harmful are adaptation restrictions

    Bruin, de, B.; Dellink, R.B.

    2009-01-01

    The dominant assumption in economic models of climate policy remains that adaptation will be implemented in an optimal manner. There are, however, several reasons why optimal levels of adaptation may not be attainable. This paper investigates the effects of suboptimal levels of adaptation, i.e. adaptation restrictions, on the composition and level of climate change costs and on welfare. Several adaptation restrictions are identified and then simulated in a revised DICE model, extended with ad...

  11. Robust Optimal Adaptive Control Method with Large Adaptive Gain

    Nguyen, Nhan T.

    2009-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

  12. Magnetic adaptive testing

    Tomáš, Ivan; Vértesy, G.

    Rijeka : INTECHWEB.ORG, 2012 - (Omar, M.), s. 145-184 ISBN 978-953-51-0108-6 R&D Projects: GA ČR GA101/09/1323 Institutional research plan: CEZ:AV0Z10100520 Keywords : ferromagnetic materials * nondestructive testing * steel * cast iron * industrial degradation * Magnetic Adaptive Testing Subject RIV: BM - Solid Matter Physics ; Magnetism

  13. Prism Adaptation in Schizophrenia

    Bigelow, Nirav O.; Turner, Beth M.; Andreasen, Nancy C.; Paulsen, Jane S.; O'Leary, Daniel S.; Ho, Beng-Choon

    2006-01-01

    The prism adaptation test examines procedural learning (PL) in which performance facilitation occurs with practice on tasks without the need for conscious awareness. Dynamic interactions between frontostriatal cortices, basal ganglia, and the cerebellum have been shown to play key roles in PL. Disruptions within these neural networks have also…

  14. Generalization of Prism Adaptation

    Redding, Gordon M.; Wallace, Benjamin

    2006-01-01

    Prism exposure produces 2 kinds of adaptive response. Recalibration is ordinary strategic remapping of spatially coded movement commands to rapidly reduce performance error. Realignment is the extraordinary process of transforming spatial maps to bring the origins of coordinate systems into correspondence. Realignment occurs when spatial…

  15. Adaptive municipal electronic forms

    Kuiper, Pieter; Dijk, van Betsy; Bondarouk, Tanya; Ruël, Huub; Guiderdoni-Jourdain, Karine; Oiry, Ewan

    2009-01-01

    Adaptation of electronic forms (e-forms) seems to be a step forward to reduce the burden for people who fill in forms. Municipalities more and more offer e-forms online that can be used by citizens to request a municipal product or service or by municipal employees to place a request on behalf of a

  16. Adaptive Computerized Instruction.

    Ray, Roger D.; And Others

    1995-01-01

    Describes an artificially intelligent multimedia computerized instruction system capable of developing a conceptual image of what a student is learning while the student is learning it. It focuses on principles of learning and adaptive behavioral control systems theory upon which the system is designed and demonstrates multiple user modes.…

  17. Robust Adaptive Structural Control

    Yang, Chi-Ming; Beck, James L.

    1995-01-01

    A new robust adaptive structural control design methodology is developed and presented which treats modeling uncertainties and limitations of control devices. Furthermore, no restriction is imposed on the structural models and the nature of the control devices so that the proposed method is very general. A simple linear single degree-of-freedom numerical example is presented to illustrate this approach.

  18. Adenosine in exercise adaptation.

    Simpson, R E; Phillis, J. W.

    1992-01-01

    By influencing the regulation of the mechanisms of angiogenesis, erythropoietin production, blood flow, myocardial glucose uptake, glycogenolysis, systolic blood pressure, respiration, plasma norepinephrine and epinephrine levels, adenosine may exert a significant effect on the body's adaptation response to exercise. However, adenosine's possible influence over the vasodilatory response to exercise in skeletal muscle is controversial and more research is required to resolve this issue. Variou...

  19. Adapting to Environmental Jolts.

    Meyer, Alan D.

    1982-01-01

    Examines the reactions of three San Francisco (California) hospitals to the 1975 doctors' strike. Analyzes the anticipatory, responsive, and readjustment phases of the hospitals' adaptations in terms of each hospital's previous market strategy, organizational structure and ideology, and deployment of slack resources, including financial, human,…

  20. ADAM: ADaptive Autonomous Machine

    Oosten, van Daan C.; Nijenhuis, Lucas F.J.; Bakkers, André W.P.; Vervoort, Wiek A.

    1996-01-01

    This paper describes a part of the development of an adaptive autonomous machine that is able to move in an unknown world extract knowledge out of the perceived data, has the possibility to reason, and finally has the capability to exchange experiences and knowledge with other agents. The agent is n

  1. Adaptation investments and homeownership

    Hansen, Jørgen Drud; Skak, Morten

    2008-01-01

    This article develops a model where ownership improves efficiency of the housing market as it enhances the utility of housing consumption for some consumers. The model is based on an extended Hotelling-Lancaster utility approach in which the ideal variant of housing is obtainable only by adapting...

  2. Unbiased Adaptive Expectation Schemes

    Antonio Palestrini; Mauro Gallegati

    2015-01-01

    There are situations in which the old-fashioned adaptive expectation process seems to provide a good description of agents' behavior (Chow, 2011). Unfortunately, this expectation scheme may not satisfy the necessary rationality condition (unconditional mean-zero error). This paper shows how to simply fix the problem introducing a bias correction term.

  3. Exploring Adaptive Program Behavior

    Bonnichsen, Lars Frydendal; Probst, Christian W.

    . Both solutions come at a cost; adaptivity issues a runtime overhead and requires more design effort, while dynamic recompilation takes time to perform. In this project, we plan to investigate the possibilities, limitations, and benefits of these techniques. This abstract covers our thoughts on how...

  4. Aging and dark adaptation.

    Jackson, G R; Owsley, C; McGwin, G

    1999-11-01

    Older adults have serious difficulty seeing under low illumination and at night, even in the absence of ocular disease. Optical changes in the aged eye, such as pupillary miosis and increased lens density, cannot account for the severity of this problem, and little is known about its neural basis. Dark adaptation functions were measured on 94 adults ranging in age from the 20s to the 80s to assess the rate of rod-mediated sensitivity recovery after exposure to a 98% bleach. Fundus photography and a grading scale were used to characterize macular health in subjects over age 49 in order to control for macular disease. Thresholds for each subject were corrected for lens density based on individual estimates, and pupil diameter was controlled. Results indicated that during human aging there is a dramatic slowing in rod-mediated dark adaptation that can be attributed to delayed rhodopsin regeneration. During the second component of the rod-mediated phase of dark adaptation, the rate of sensitivity recovery decreased 0.02 log unit/min per decade, and the time constant of rhodopsin regeneration increased 8.4 s/decade. The amount of time to reach within 0.3 log units of baseline scotopic sensitivity increased 2.76 min/decade. These aging-related changes in rod-mediated dark adaptation may contribute to night vision problems commonly experienced by the elderly. PMID:10748929

  5. Adaptive acoustooptic filter

    Psaltis, Demetri; Hong, John

    1984-01-01

    A new adaptive filter utilizing acoustooptic devices in a space integrating architecture is described. Two configurations are presented; one of them, suitable for signal estimation, is shown to approximate the Wiener filter, while the other, suitable for detection, is shown to approximate the matched filter.

  6. Experimental demonstration of subcarrier multiplexed quantum key distribution system

    Mora Almerich, José; Ruiz Alba Gaya, Antonio; Amaya Ocampo, Waldimar Alexander; Martínez García, Alfonso; García Muñoz, Víctor; Calvo Díaz-Aldagalán, David; Capmany Francoy, José

    2012-01-01

    This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.37.002031. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law

  7. Transformational adaptation when incremental adaptations to climate change are insufficient.

    Kates, Robert W; Travis, William R; Wilbanks, Thomas J

    2012-05-01

    All human-environment systems adapt to climate and its natural variation. Adaptation to human-induced change in climate has largely been envisioned as increments of these adaptations intended to avoid disruptions of systems at their current locations. In some places, for some systems, however, vulnerabilities and risks may be so sizeable that they require transformational rather than incremental adaptations. Three classes of transformational adaptations are those that are adopted at a much larger scale, that are truly new to a particular region or resource system, and that transform places and shift locations. We illustrate these with examples drawn from Africa, Europe, and North America. Two conditions set the stage for transformational adaptation to climate change: large vulnerability in certain regions, populations, or resource systems; and severe climate change that overwhelms even robust human use systems. However, anticipatory transformational adaptation may be difficult to implement because of uncertainties about climate change risks and adaptation benefits, the high costs of transformational actions, and institutional and behavioral actions that tend to maintain existing resource systems and policies. Implementing transformational adaptation requires effort to initiate it and then to sustain the effort over time. In initiating transformational adaptation focusing events and multiple stresses are important, combined with local leadership. In sustaining transformational adaptation, it seems likely that supportive social contexts and the availability of acceptable options and resources for actions are key enabling factors. Early steps would include incorporating transformation adaptation into risk management and initiating research to expand the menu of innovative transformational adaptations. PMID:22509036

  8. Adaptation: Needs, Financing and Institutions

    Klein, Richard J.T.; Kartha, Sivan; Persson, Aasa; Watkiss, Paul; Ackerman, Frank; Downing, Thomas E.; Kjellen, Bo; Schipper, Lisa (Stockholm Environment Institute, Stockholm (SE))

    2008-07-01

    Regardless of the efforts put into mitigation, some impacts of climate change are already unavoidable. Adaptation to climate change has therefore become a key component of domestic climate policy, along with mitigation. Adaptation has also become key to the success of global climate policy. Without an agreement on supporting adaptation in developing countries, there will be no agreement on mitigation. Strong mitigation efforts make it more likely that adaptation will be effective and affordable. The world cannot rely on adaptation alone: it would eventually lead to a level of climate change to which adaptation is no longer feasible. Government action is needed to create an enabling environment for adaptation. This includes removing existing financial, legal, institutional and knowledge barriers to adaptation, and strengthening the capacity of people and organisations to adapt. The success of adaptation relies on the success of development, and vice versa. Poverty reduction, good governance, education, environmental protection, health and gender equality all contribute to adaptive capacity. Substantially more money is needed to support adaptation in developing countries. Current levels of funding will soon have to be scaled up by two orders of magnitude (from US$ hundreds of million to US$ tens of billion per year). An agreement on adaptation in Copenhagen in 2009 will need to include concrete steps towards a strengthened knowledge base for adaptation, substantially more funding for developing countries, and enhanced adaptation planning and implementation at the national level. Recommendations: Developed countries should accept a transparent, principle-based allocation of responsibility for adaptation funding, resulting in adequate, new and additional money to support adaptation programmes in developing countries. Levies on carbon market transactions and auctioning emission permits are two existing mechanisms of generating new and additional funds consistent with

  9. Performance Comparison of Adaptive Algorithms for Adaptive line Enhancer

    Sanjeev Kumar Dhull; Sandeep K. Arya; O. P. Sahu

    2011-01-01

    We have designed and simulated an adaptive line enhancer system for conferencing. This system is based upon a least-mean-square (LMS) and recursive adaptive algorithm (RLS) Performance of ALE is compared for LMSandRLS algorithms.

  10. Adaptive versus non-adaptive strategies for quantum channel discrimination

    Harrow, Aram W.; Hassidim, Avinatan; Leung, Debbie W.; Watrous, John

    2009-01-01

    We provide a simple example that illustrates the advantage of adaptive over non-adaptive strategies for quantum channel discrimination. In particular, we give a pair of entanglement-breaking channels that can be perfectly discriminated by means of an adaptive strategy that requires just two channel evaluations, but for which no non-adaptive strategy can give a perfect discrimination using any finite number of channel evaluations.

  11. AdaptME toolkit : adaptation monitoring and evaluation

    Pringle, Patrick

    2011-01-01

    Organisations that have undertaken adaptation activities now face the challenge of evaluating what worked, what didn’t, how and why. This toolkit responds to a growing demand for practical support in evaluating adaptation progress and performance. AdaptME will help you to think through some of the factors that can make an evaluation of adaptation activities inherently challenging, and equip you to design a robust evaluation. You will be able to ‘tweak’ a single part of your evaluation des...

  12. SpotADAPT

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach;

    2015-01-01

    Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... Processing Tasks) which is designed to help users by first, estimating the workload execution time on different AWS instance types, and, second, proposing the deployment (i.e., specific availability zone, instance type, pricing model) aligned with user-provided optimization goals (fastest or cheapest...... execution within boundaries). Moreover, during the execution of the workload, SpotADAPT suggests a redeployment if the current spot instance gets terminated by Amazon or a better deployment becomes possible due to fluctuations of the spot prices. The approach is evaluated using the actual execution times of...

  13. Unconsciously triggered conflict adaptation.

    Simon van Gaal

    Full Text Available In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked or unconsciously (strongly masked primes. We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition.

  14. NEEDS - Information Adaptive System

    Kelly, W. L.; Benz, H. F.; Meredith, B. D.

    1980-01-01

    The Information Adaptive System (IAS) is an element of the NASA End-to-End Data System (NEEDS) Phase II and is focused toward onboard image processing. The IAS is a data preprocessing system which is closely coupled to the sensor system. Some of the functions planned for the IAS include sensor response nonuniformity correction, geometric correction, data set selection, data formatting, packetization, and adaptive system control. The inclusion of these sensor data preprocessing functions onboard the spacecraft will significantly improve the extraction of information from the sensor data in a timely and cost effective manner, and provide the opportunity to design sensor systems which can be reconfigured in near real-time for optimum performance. The purpose of this paper is to present the preliminary design of the IAS and the plans for its development.

  15. Adaptive manifold learning.

    Zhang, Zhenyue; Wang, Jing; Zha, Hongyuan

    2012-02-01

    Manifold learning algorithms seek to find a low-dimensional parameterization of high-dimensional data. They heavily rely on the notion of what can be considered as local, how accurately the manifold can be approximated locally, and, last but not least, how the local structures can be patched together to produce the global parameterization. In this paper, we develop algorithms that address two key issues in manifold learning: 1) the adaptive selection of the local neighborhood sizes when imposing a connectivity structure on the given set of high-dimensional data points and 2) the adaptive bias reduction in the local low-dimensional embedding by accounting for the variations in the curvature of the manifold as well as its interplay with the sampling density of the data set. We demonstrate the effectiveness of our methods for improving the performance of manifold learning algorithms using both synthetic and real-world data sets. PMID:21670485

  16. Adaptive Large Neighbourhood Search

    Røpke, Stefan

    Large neighborhood search is a metaheuristic that has gained popularity in recent years. The heuristic repeatedly moves from solution to solution by first partially destroying the solution and then repairing it. The best solution observed during this search is presented as the final solution. This...... tutorial introduces the large neighborhood search metaheuristic and the variant adaptive large neighborhood search that dynamically tunes parameters of the heuristic while it is running. Both heuristics belong to a broader class of heuristics that are searching a solution space using very large...... neighborhoods. The tutorial also present applications of the adaptive large neighborhood search, mostly related to vehicle routing problems for which the heuristic has been extremely successful. We discuss how the heuristic can be parallelized and thereby take advantage of modern desktop computers that...

  17. Adaptive semantics visualization

    Nazemi, Kawa

    2016-01-01

    This book introduces a novel approach for intelligent visualizations that adapts the different visual variables and data processing to human’s behavior and given tasks. Thereby a number of new algorithms and methods are introduced to satisfy the human need of information and knowledge and enable a usable and attractive way of information acquisition. Each method and algorithm is illustrated in a replicable way to enable the reproduction of the entire “SemaVis” system or parts of it. The introduced evaluation is scientifically well-designed and performed with more than enough participants to validate the benefits of the methods. Beside the introduced new approaches and algorithms, readers may find a sophisticated literature review in Information Visualization and Visual Analytics, Semantics and information extraction, and intelligent and adaptive systems. This book is based on an awarded and distinguished doctoral thesis in computer science.

  18. Adaptive Inflow Control System

    Volkov, Vasily Y; Zhuravlev, Oleg N; Nukhaev, Marat T; Shchelushkin, Roman V

    2014-01-01

    This article presents the idea and realization for the unique Adaptive Inflow Control System being a part of well completion, able to adjust to the changing in time production conditions. This system allows to limit the flow rate from each interval at a certain level, which solves the problem of water and gas breakthroughs. We present the results of laboratory tests and numerical calculations obtaining the characteristics of the experimental setup with dual-in-position valves as parts of adaptive inflow control system, depending on the operating conditions. The flow distribution in the system was also studied with the help of three-dimensional computer model. The control ranges dependences are determined, an influence of the individual elements on the entire system is revealed.

  19. Adaptive sensor fusion

    Kadar, Ivan

    1995-07-01

    A perceptual reasoning system adaptively extracting, associating, and fusing information from multiple sources, at various levels of abstraction, is considered as the building block for the next generation of surveillance systems. A system architecture is presented which makes use of both centralized and distributed predetection fusion combined with intelligent monitor and control coupling both on-platform and off-board track and decision level fusion results. The goal of this system is to create a `gestalt fused sensor system' whose information product is greater than the sum of the information products from the individual sensors and has performance superior to either individual or a sub-group of combined sensors. The application of this architectural concept to the law enforcement arena (e.g. drug interdiction) utilizing multiple spatially and temporally diverse surveillance platforms and/or information sources, is used to illustrate the benefits of the adaptive perceptual reasoning system concept.

  20. Adapting Mathematical Domain Reasoners

    Heeren, Bastiaan

    2010-01-01

    Mathematical learning environments help students in mastering mathematical knowledge. Mature environments typically offer thousands of interactive exercises. Providing feedback to students solving interactive exercises requires domain reasoners for doing the exercise-specific calculations. Since a domain reasoner has to solve an exercise in the same way a student should solve it, the structure of domain reasoners should follow the layered structure of the mathematical domains. Furthermore, learners, teachers, and environment builders have different requirements for adapting domain reasoners, such as providing more details, disallowing or enforcing certain solutions, and combining multiple mathematical domains in a new domain. In previous work we have shown how domain reasoners for solving interactive exercises can be expressed in terms of rewrite strategies, rewrite rules, and views. This paper shows how users can adapt and configure such domain reasoners to their own needs. This is achieved by enabling users...

  1. Engineering Adaptive Applications

    Dolog, Peter

    Applications on the Web are accessible for users with different background, technical environment used, political, social environment where they reside, interests, goals and so on. The different user types have slightly different requirements for features which such Web applications should have....... The different requirements might be satisfied by different variants of features maintained and provided by Web applications. An adaptive Web application can be seen as a family of Web applications where application instances are those generated for particular user based on his characteristics relevant...... for a domain.In this book, we propose a new domain engineering framework which extends a development process of Web applications with techniques required when designing such adaptive customizable Web applications. The framework is provided with design abstractions which deal separately with...

  2. An Adaptive Robot Game

    Hansen, Søren Tranberg; Svenstrup, Mikael; Dalgaard, Lars

    2010-01-01

    The goal of this paper is to describe an adaptive robot game, which motivates elderly people to do a regular amount of physical exercise while playing. One of the advantages of robot based games is that the initiative to play can be taken autonomously by the robot. In this case, the goal is to...... improve the mental and physical state of the user by playing a physical game with the robot. Ideally, a robot game should be simple to learn but difficult to master, providing an appropriate degree of challenge for players with different skills. In order to achieve that, the robot should be able to adapt...... to the behavior of the interacting person. This paper presents a simple ball game between a single player and a mobile robot platform. The algorithm has been validated using simulation and real world experiments....

  3. Designing Adaptive Web Applications

    Dolog, Peter

    2008-01-01

    The unique characteristic of web applications is that they are supposed to be used by much bigger and diverse set of users and stakeholders. An example application area is e-Learning or business to business interaction. In eLearning environment, various users with different background use the e......Learning system to study a discipline. In business to business interaction, different requirements and parameters of exchanged business requests might be served by different services from third parties. Such applications require certain intelligence and a slightly different approach to design. Adpative web...... adaptation to the changed parameters of environments, user or context. Adaptation can be seen as an orthogonal concern or viewpoint in a design process. In this paper I will discuss design abstractions which are employed in current design methods for web applications. I will exemplify the use...

  4. Adaptive method of lines

    Saucez, Ph

    2001-01-01

    The general Method of Lines (MOL) procedure provides a flexible format for the solution of all the major classes of partial differential equations (PDEs) and is particularly well suited to evolutionary, nonlinear wave PDEs. Despite its utility, however, there are relatively few texts that explore it at a more advanced level and reflect the method''s current state of development.Written by distinguished researchers in the field, Adaptive Method of Lines reflects the diversity of techniques and applications related to the MOL. Most of its chapters focus on a particular application but also provide a discussion of underlying philosophy and technique. Particular attention is paid to the concept of both temporal and spatial adaptivity in solving time-dependent PDEs. Many important ideas and methods are introduced, including moving grids and grid refinement, static and dynamic gridding, the equidistribution principle and the concept of a monitor function, the minimization of a functional, and the moving finite elem...

  5. Semantische Adaption von Komponenten

    Söldner, Guido

    2012-01-01

    Im Bereich der Informationstechnik ist die Adaption von Software an veränderte Gegebenheiten und Umgebungen ein wichtiges Thema. Dabei bestimmen vor allem die konkret verwendete Software-Programmiersprache, die benutzten Entwurfsmuster und die der Applikation zugrundeliegende Software-Architektur, mit welchem Aufwand eine Anwendung auf neue Anforderungen eingehen kann. Darüber hinaus war und ist es interessant, Mechanismen zu entwickeln, mit denen Applikationen selbst auf spontane Änderungen ...

  6. Traffic-Adaptive Routing

    Kammenhuber, Nils

    2011-01-01

    Despite the bursty and highly volatile traffic, routing in the Internet today is optimised only on coarse time scales, as load-adaptive routing is known to induce performance deterioration by causing massive oscillations. We describe ReplEx, an universally applicable distributed algorithm for dynamic routing/traffic engineering, which is based on game theory. We show through extensive realistic simulations that ReplEx does not oscillate, and that it achieves performance gains comparable to tr...

  7. Invited article: Adaptability

    Olivia Parr Rud

    2011-01-01

    Full Text Available For the last several decades, organizations have dealt with economic shifts using change management. Based on the new science, there are two major flaws with this approach. First, the word change implies an event with an ending. Second, it implies that change can be managed. In a world of economic volatility, this approach is no longer viable. The continuous climate of uncertainty and volatility demands another view, one that supports adaptability and resilience.

  8. Adaptive positioner; Posicionador adaptativo

    Labrador Pavon, I.

    1993-07-01

    This paper describes the circuits and programs in assembly language, developed to control the two DC motors that give mobility to a mechanical arm with two degrees of freedom. As a whole, the system is based in a adaptable regulator designed around a 8 bit microprocessor that, starting from a mode of regulation based in the successive approximation method, evolve to another mode through which, only one approximation is sufficient to get the right position of each motor. (Author) 6 refs.

  9. Homeowiscous adaptation in fish

    Flipiak, Anna; Gondko, Roman; Gabryelak, Teresa

    1997-01-01

    Homeowiscous adaptation is a common phenomenon observed in poikilotherms which remain active at different temperatures. It is usually caused by changes in fatty acids pool in cellular membranes, what enable to maintain the physical structure of their membranes within tolerable limits. The increased unsaturaition of membrane lipids has as its basis some changes in activity of the appropriate enzymes. Fluctuations in fluidity of membrame lipids activate transcription of the genes...

  10. Adaptive modulations of martensites

    Kaufmann, S.; Roßler, U.K.; Heczko, Oleg; Wuttig, M.; Buschbeck, J.; Schultz, L.; Fähler, S.

    2010-01-01

    Roč. 104, č. 14 (2010), 145702/1-145702/4. ISSN 0031-9007 Institutional research plan: CEZ:AV0Z10100520 Keywords : adaptive concept of modulated martensite * martensitic Ni-Mn-Ga films * austenite * 14M martensite Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.621, year: 2010 http://link.aps.org/doi/10.1103/PhysRevLett.104.145702

  11. Reconfigurable environmentally adaptive computing

    Coxe, Robin L. (Inventor); Galica, Gary E. (Inventor)

    2008-01-01

    Described are methods and apparatus, including computer program products, for reconfigurable environmentally adaptive computing technology. An environmental signal representative of an external environmental condition is received. A processing configuration is automatically selected, based on the environmental signal, from a plurality of processing configurations. A reconfigurable processing element is reconfigured to operate according to the selected processing configuration. In some examples, the environmental condition is detected and the environmental signal is generated based on the detected condition.

  12. Improved Adaptive Fingerprint Binarization

    Bartunek, Josef Ström; Nilsson, Mikael; Nordberg, Jörgen; Claesson, Ingvar

    2008-01-01

    In this paper improvements to a previous work are presented. Removing the redundant artifacts in the fingerprint mask is introduced enhancing the final result. The proposed method is entirely adaptive process adjusting to each fingerprint without any further supervision of the user. Hence, the algorithm is insensitive to the characteristics of the fingerprint sensor and the various physical appearances of the fingerprints. Further, a detailed description of fingerprint mask generation not ful...

  13. Adaptive Mobile Work Processes

    Hauso, Frode; Røed, Øivind

    2005-01-01

    Systems that efficiently provide support for adaptive work processes in a mobile environment do not exist according to our knowledge. Such systems would increase efficiency and safety in environments where work is inherently mobile, ad-hoc, and requires input from a set of heterogeneous sources. Traditional work support systems are normally not capable of dynamic change and plans must be made before work is started. This conflicts with most work processes, which are dynamic and where plans ca...

  14. Adaptive structures flight experiments

    Martin, Maurice

    The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

  15. Adaptive Consumption Behavior

    Peter Howitt; Ömer Özak

    2009-01-01

    This paper proposes and studies a theory of adaptive consumption behavior under income uncertainty and liquidity constraints. We assume that consumption is governed by a linear function of wealth, whose coefficients are revised each period by a procedure, which, although sophisticated, places few informational or computational demands on the consumer. We show that under a variety of settings, our procedure converges quickly to a set of coefficients with low welfare cost relative to a fully op...

  16. Adaptive Brain Interfaces

    Millán, José del R.

    2003-01-01

    Severely disabled people are largely excluded from the benefits information and communication technologies have brought to our industries, economies, appliances, and general quality of life. But what if that technology would allow them to communicate their wishes or control electronic devices directly through their thoughts alone? This is the goal and promise of the Adaptive Brain Interfaces (ABI) project, which aims to augment natural human capabilities by enabling people to interact with co...

  17. Adaptive optical processors.

    Ghosh, A

    1989-06-15

    There are two different approaches for improving the accuracy of analog optical associative processors: postprocessing with a bimodal system and preprocessing with a preconditioner. These two approaches can be combined to develop an adaptive optical multiprocessor that can adjust the computational steps depending on the data and produce solutions of linear algebra problems with a specified accuracy in a given amount of time. PMID:19752909

  18. Creative Adaptation through Learning

    Cully, Antoine

    2015-01-01

    Robots have transformed many industries, most notably manufacturing, and have the power to deliver tremendous benefits to society, for example in search and rescue, disaster response, health care, and transportation. They are also invaluable tools for scientific exploration of distant planets or deep oceans. A major obstacle to their widespread adoption in more complex environments and outside of factories is their fragility. While animals can quickly adapt to injuries, current robots cannot ...

  19. Adaptive Dynamic Bayesian Networks

    Ng, B M

    2007-10-26

    A discrete-time Markov process can be compactly modeled as a dynamic Bayesian network (DBN)--a graphical model with nodes representing random variables and directed edges indicating causality between variables. Each node has a probability distribution, conditional on the variables represented by the parent nodes. A DBN's graphical structure encodes fixed conditional dependencies between variables. But in real-world systems, conditional dependencies between variables may be unknown a priori or may vary over time. Model errors can result if the DBN fails to capture all possible interactions between variables. Thus, we explore the representational framework of adaptive DBNs, whose structure and parameters can change from one time step to the next: a distribution's parameters and its set of conditional variables are dynamic. This work builds on recent work in nonparametric Bayesian modeling, such as hierarchical Dirichlet processes, infinite-state hidden Markov networks and structured priors for Bayes net learning. In this paper, we will explain the motivation for our interest in adaptive DBNs, show how popular nonparametric methods are combined to formulate the foundations for adaptive DBNs, and present preliminary results.

  20. Vestibulospinal adaptation to microgravity

    Paloski, W. H.

    1998-01-01

    Human balance control is known to be transiently disrupted after spaceflight; however, the mechanisms responsible for postflight postural ataxia are still under investigation. In this report, we propose a conceptual model of vestibulospinal adaptation based on theoretical adaptive control concepts and supported by the results from a comprehensive study of balance control recovery after spaceflight. The conceptual model predicts that immediately after spaceflight the balance control system of a returning astronaut does not expect to receive gravity-induced afferent inputs and that descending vestibulospinal control of balance is disrupted until the central nervous system is able to cope with the newly available vestibular otolith information. Predictions of the model are tested using data from a study of the neurosensory control of balance in astronauts immediately after landing. In that study, the mechanisms of sensorimotor balance control were assessed under normal, reduced, and/or altered (sway-referenced) visual and somatosensory input conditions. We conclude that the adaptive control model accurately describes the neurobehavioral responses to spaceflight and that similar models of altered sensory, motor, or environmental constraints are needed clinically to predict responses that patients with sensorimotor pathologies may have to various visual-vestibular or changing stimulus environments.

  1. Adaptation to High Altitude

    H. S. Nayar

    1984-10-01

    Full Text Available Hypoxia is inconsequential for physiologically fit persons below an effective altitude of 2640 metres. At higher altitudes, the adaptation is brought about by four main factors, viz., hyperventilation, increased diffusion of oxygen across alveolar membrane, erythrocythemia and maintenance of body hydration. Carbon dioxide sensitivity is markedly elevated at high altitude, both in sojourners and acclimatized low-landers. The greater pulmonary diffusing capacity observed in high altitude natives is well documented. RBC count, haemoglobin and haematocrit increase whereas arterial oxyhaemoglobin saturation percentage decreases at high altitude. Diuretics (Furosemide have no role in adaptation to high altitude and adequate body hydration must be maintained.The ultimate adaptive mechanisms occur at tissue level which facilitate the diffusion of oxygen from blood to tissue and its utilization. The work capacity decreases at high altitude and a relationship between load carried and speed of marching has been determined at various altitudes. Although altitude has an adverse effect on process of cold acclimatization, yet it is possible to induce cold acclimatization by exposing subjects to a temperature of 0° to -5°C for a period of three hours daily for three weeks. The caloric requirements increase at high altitudes and are 4,286 K Cal and 4,380 K Cal at 13000 feet (3950 m and 17000 feet (5170 m, respectively.

  2. Adaptive building skin structures

    The concept of adaptive and morphing structures has gained considerable attention in the recent years in many fields of engineering. In civil engineering very few practical applications are reported to date however. Non-conventional structural concepts like deployable, inflatable and morphing structures may indeed provide innovative solutions to some of the problems that the construction industry is being called to face. To give some examples, searches for low-energy consumption or even energy-harvesting green buildings are amongst such problems. This paper first presents a review of the above problems and technologies, which shows how the solution to these problems requires a multidisciplinary approach, involving the integration of architectural and engineering disciplines. The discussion continues with the presentation of a possible application of two adaptive and dynamically morphing structures which are proposed for the realization of an acoustic envelope. The core of the two applications is the use of a novel optimization process which leads the search for optimal solutions by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope is ensured by the virtual force density method

  3. Radio-adaptive response

    An adaptive response to radiation stress was found as a suppressed induction of chromosomal damage including micronuclei and sister chromatid exchanges in cultured Chinese hamster V79 cells pre-exposed to very low doses of ionizing radiations. The mechanism underlying this novel chromosomal response, called 'radio-adaptive response (RAR)' has been studied progressively. The following results were obtained in recent experiments. 1. Low doses of β-rays from tritiated water (HTO) as well as tritium-thymidine can cause RAR. 2. Thermal neutrons, a high LET radiation, can not act as tritium β-rays or γ-rays. 3. The RAR expression is suppressed not only by the treatment with an inhibitor of protein synthesis but also by RNA synthesis inhibition. 4. Several proteins are newly synthesized concurrently with the RAR expression after the adapting doses, viewed by two-dimensional electrophoresis of cellular proteins. These results suggests that the RAR might be a cellular stress response to a signal produced preferentially by very low doses of low LET radiation under restricted conditions, accompany the inducible specific gene expression. (author)

  4. AdapterRemoval v2

    Schubert, Mikkel; Lindgreen, Stinus; Orlando, Ludovic Antoine Alexandre

    2016-01-01

    BACKGROUND: As high-throughput sequencing platforms produce longer and longer reads, sequences generated from short inserts, such as those obtained from fossil and degraded material, are increasingly expected to contain adapter sequences. Efficient adapter trimming algorithms are also needed to...... process the growing amount of data generated per sequencing run. FINDINGS: We introduce AdapterRemoval v2, a major revision of AdapterRemoval v1, which introduces (i) striking improvements in throughput, through the use of single instruction, multiple data (SIMD; SSE1 and SSE2) instructions and multi......-threading support, (ii) the ability to handle datasets containing reads or read-pairs with different adapters or adapter pairs, (iii) simultaneous demultiplexing and adapter trimming, (iv) the ability to reconstruct adapter sequences from paired-end reads for poorly documented data sets, and (v) native gzip and...

  5. Adaptive Structural Mode Control Project

    National Aeronautics and Space Administration — M4 Engineering proposes the development of an adaptive structural mode control system. The adaptive control system will begin from a "baseline" dynamic model of the...

  6. Feature-Level Domain Adaptation

    Kouw, Wouter M.; Krijthe, Jesse H.; Loog, Marco; van der Maaten, Laurens J. P.

    2015-01-01

    Domain adaptation is the supervised learning setting in which the training and test data originate from different domains: the so-called source and target domains. In this paper, we propose and study a domain adaption approach, called feature-level domain adaptation (flda), that models the dependence between two domains by means of a feature-level transfer distribution. The domain adapted classifier is trained by minimizing the expected loss under this transfer distribution. Our empirical eva...

  7. Strategy for Climate Change Adaptation

    Rasmussen, Torben Valdbjørn

    The absence of a global agreement on the reduction of greenhouse gas emissions calls for adaptation to climate change. The associated paper explains the need for climate change adaptation of the building stock and suggests a pattern for a strategic approach to how to reach the climate change...... adaptation needed. Issues that must be addressed in case a strategic approach is not developed, as the building sector is continuously investing in measures to adapt to climate change as impacts emerge are described....

  8. Attention modulates visual size adaptation.

    Kreutzer, Sylvia; Fink, G R; R. Weidner

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance ...

  9. Chapter 17 - Economics of adaptation

    Chambwera, M.; Heal, G.; Dubeux, C.; Hallegatte, S.; Leclerc, L.; Markandya, A.; McCarl, B.A.; Mechler, R; Neumann, J.E.

    2014-01-01

    This chapter assesses the literature on the economics of climate change adaptation, building on the Fourth Assessment Report (AR4) and the increasing role that economic considerations are playing in adaptation decisionmaking and policy. AR4 provided a limited assessment of the costs and benefits of adaptation, based on narrow and fragmented sectoral and regional literature (Adger et al, 2007). Substantial advances have been made in the economics of climate change adaptation after AR4.

  10. How Harmful are Adaptation Restrictions

    Bruin, de K.C.; Dellink, R.B.

    2009-01-01

    The dominant assumption in economic models of climate policy remains that adaptation will be implemented in an optimal manner. There are, however, several reasons why optimal levels of adaptation may not be attainable. This paper investigates the effects of suboptimal levels of adaptation, i.e. adap

  11. Evolving concepts of sensory adaptation

    Webster, Michael A.

    2012-01-01

    Sensory systems constantly adapt their responses to match the current environment. These adjustments occur at many levels of the system and increasingly appear to calibrate even for highly abstract perceptual representations of the stimulus. The similar effects of adaptation across very different stimulus domains point to common design principles but also continue to raise questions about the purpose of adaptation.

  12. Theory of psychological adaptive modes.

    Lehti, Juha

    2016-05-01

    When an individual is facing a stressor and normal stress-response mechanism cannot guarantee sufficient adaptation, special emotional states, adaptive modes, are activated (for example a depressive reaction). Adaptive modes are involuntary states of mind, they are of comprehensive nature, they interfere with normal functioning, and they cannot be repressed or controlled the same way as many emotions. Their transformational nature differentiates them from other emotional states. The object of the adaptive mode is to optimize the problem-solving abilities according to the situation that has provoked the mode. Cognitions and emotions during the adaptive mode are different than in a normal mental state. These altered cognitions and emotional reactions guide the individual to use the correct coping skills in order to deal with the stressor. Successful adaptation will cause the adaptive mode to fade off since the adaptive mode is no longer necessary, and the process as a whole will lead to raised well-being. However, if the adaptation process is inadequate, then the transformation period is prolonged, and the adaptive mode will turn into a dysfunctional state. Many psychiatric disorders are such maladaptive processes. The maladaptive processes can be turned into functional ones by using adaptive skills that are used in functional adaptive processes. PMID:27063089

  13. Adaptation : A Partially Automated Approach

    Manjing, Tham; Bukhsh, F.A.; Weigand, H.

    2014-01-01

    This paper showcases the possibility of creating an adaptive auditing system. Adaptation in an audit environment need human intervention at some point. Based on a case study this paper focuses on automation of adaptation process. It is divided into solution design and validation parts. The artifact

  14. Adaptive filtering prediction and control

    Goodwin, Graham C

    2009-01-01

    Preface1. Introduction to Adaptive TechniquesPart 1. Deterministic Systems2. Models for Deterministic Dynamical Systems3. Parameter Estimation for Deterministic Systems4. Deterministic Adaptive Prediction5. Control of Linear Deterministic Systems6. Adaptive Control of Linear Deterministic SystemsPart 2. Stochastic Systems7. Optimal Filtering and Prediction8. Parameter Estimation for Stochastic Dynamic Systems9. Adaptive Filtering and Prediction10. Control of Stochastic Systems11. Adaptive Control of Stochastic SystemsAppendicesA. A Brief Review of Some Results from Systems TheoryB. A Summary o

  15. Adaptability Responding Effectively to Change

    (CCL), Center for Creative Leadership; Calarco, Allan

    2011-01-01

    In today's business world, the complexity and pace of change can be daunting. Adaptability has become recognized as a necessary skill for leaders to develop to be effective in this environment. Even so, leaders rarely know what they can do to become more adaptable and foster adaptability in others. This guidebook contributes to a greater understanding of adaptability and the cognitive, emotional, and dispositional flexibility it requires. Leaders will learn how to develop their adaptability and to become more effective for themselves, the people they lead, and their organizations.

  16. Adaptive antennas and receivers

    Weiner, Melvin M

    2005-01-01

    In our modern age of remote sensing, wireless communication, and the nearly endless list of other antenna-based applications, complex problems require increasingly sophisticated solutions. Conventional antenna systems are no longer suited to high-noise or low-signal applications such as intrusion detection. Detailing highly effective approaches to non-Gaussian weak signal detection, Adaptive Antennas and Receivers provides an authoritative introduction to state-of-the-art research on the modeling, testing, and application of these technologies.Edited by innovative researcher and eminent expert

  17. Adaptive Noise Reduction System

    Ivana Ropuš

    2013-01-01

    Full Text Available Noise is an all-present environment pollutant, considered to be one of the greatest contemporary pollutants. World-wide, co-ordinated actions are conducted in order to develop systems which minimise the noise influence onto society.In this article we argue that novel approach to suppression of influence of noise is useful. Furthermore, we argue that the efficient approach is formulation of the efficient, broadly applicable, ubiquituous, adaptive noise-protection system. The approach combines the natural noise-protection form based on plants with the artificially formed coatings.Elements of the system are discussed, its formation and maintenance analysed and perspectives conjectured.

  18. The Adaptation Finance Gap Report

    UNEP’s Adaptation Gap Report series focuses on Finance, Technology and Knowledge gaps in climate change adaptation. It compliments the Emissions Gap Report series, and explores the implications of failing to close the emissions gap. The report builds on a 2014 assessment by the United Nations...... Environment Programme (UNEP), which laid out the concept of ‘adaptation gaps’ and outlined three such gaps: technology, finance and knowledge. The 2016 Adaptation Gap Report assesses the difference between the financial costs of adapting to climate change in developing countries and the amount of money...... actually available to meet these costs – a difference known as the “adaptation finance gap”. Like the 2014 report, the 2016 report focuses on developing countries, where adaptation capacity is often the lowest and needs the highest, and concentrates on the period up to 2050. The report identifies trends...

  19. AdapterRemoval v2

    Schubert, Mikkel; Lindgreen, Stinus; Orlando, Ludovic

    2016-01-01

    process the growing amount of data generated per sequencing run. FINDINGS: We introduce AdapterRemoval v2, a major revision of AdapterRemoval v1, which introduces (i) striking improvements in throughput, through the use of single instruction, multiple data (SIMD; SSE1 and SSE2) instructions and multi......-threading support, (ii) the ability to handle datasets containing reads or read-pairs with different adapters or adapter pairs, (iii) simultaneous demultiplexing and adapter trimming, (iv) the ability to reconstruct adapter sequences from paired-end reads for poorly documented data sets, and (v) native gzip and...... bzip2 support. CONCLUSIONS: We show that AdapterRemoval v2 compares favorably with existing tools, while offering superior throughput to most alternatives examined here, both for single and multi-threaded operations....

  20. Science of adaptation to climate change and science for adaptation

    RobSwart

    2014-07-01

    Full Text Available Adaptation to climate change has gained a prominent place next to mitigation on global, national and local policy agendas. However, while an abundance of adaptation strategies, plans and programmes have been developed, progress in turning these into action has been slow. The development of a sound knowledge basis to support adaptation globally is suggested to accelerate progress, but has lagged behind. The emphasis in both current and newly proposed programmes is very much on practice-oriented research with strong stakeholder participation. This paper supports such practice-oriented research, but argues that this is insufficient to support adaptation policy and practice in a productive manner. We argue that there is not only a need for science for adaptation, but also a science of adaptation. The paper argues that participatory, practice-oriented research is indeed essential, but has to be complemented by and connected to more fundamental inquiry and concept development, which takes into account knowledge that has been developed in disciplinary sciences and on issues other than climate change adaptation. At the same time, the level and method of participation in science for adaptation should be determined on the basis of the specific project context and goals. More emphasis on science of adaptation can lead to improved understanding of the conditions for successful science for adaptation.

  1. Classifying climate change adaptation frameworks

    Armstrong, Jennifer

    2014-05-01

    Complex socio-ecological demographics are factors that must be considered when addressing adaptation to the potential effects of climate change. As such, a suite of deployable climate change adaptation frameworks is necessary. Multiple frameworks that are required to communicate the risks of climate change and facilitate adaptation. Three principal adaptation frameworks have emerged from the literature; Scenario - Led (SL), Vulnerability - Led (VL) and Decision - Centric (DC). This study aims to identify to what extent these adaptation frameworks; either, planned or deployed are used in a neighbourhood vulnerable to climate change. This work presents a criterion that may be used as a tool for identifying the hallmarks of adaptation frameworks and thus enabling categorisation of projects. The study focussed on the coastal zone surrounding the Sizewell nuclear power plant in Suffolk in the UK. An online survey was conducted identifying climate change adaptation projects operating in the study area. This inventory was analysed to identify the hallmarks of each adaptation project; Levels of dependency on climate model information, Metrics/units of analysis utilised, Level of demographic knowledge, Level of stakeholder engagement, Adaptation implementation strategies and Scale of adaptation implementation. The study found that climate change adaptation projects could be categorised, based on the hallmarks identified, in accordance with the published literature. As such, the criterion may be used to establish the matrix of adaptation frameworks present in a given area. A comprehensive summary of the nature of adaptation frameworks in operation in a locality provides a platform for further comparative analysis. Such analysis, enabled by the criterion, may aid the selection of appropriate frameworks enhancing the efficacy of climate change adaptation.

  2. Analysis and Optimization of Error Performance of a WiMAX Transceiver using Novel Adaptive Cyclic Prefix Strategy under AWGN and Rayleigh Fading Scenario

    Budhaditya Bhattacharyya

    2012-12-01

    Full Text Available In order to increase channel capacity at lowchannel SNR selection of higher order modulation and coderates are crucial. However, poor channel condition causessevere ISI resulting in asynchronous phase error betweenthe subcarriers hindering the selection of higher ordermodulation schemes at low channel SNR condition. In thispaper, a complete novel and unique selection strategy forAdaptive Cyclic Prefix (ACP is proposed for IEEE 802.16e-WiMAX Physical Layer (PHY using a Simulink-VSA basedsimulation model. ACP selects higher order modulation andcode rates for low channel SNR condition by dynamicselection of Cyclic Prefix (CP. Better Quality of Service(QoS is guaranteed in the form of lowest average error(0.034 dB for low channel SNR condition, compared to theexisting Fixed Cyclic Prefix (FCP scenario (3dB inWiMAX. In addition to implementing ACP algorithm forAWGN scenario, a Modified ACP (MACP algorithm is alsoproposed for a Rayleigh multipath fading scenario.Simulation results reflect the efficiency of both ACP andMACP for low channel SNR condition in the selection ofhigher order modulation and coding schemes in a WiMAXbased system. Moreover, an elaborate performance study onthe effect of EVM and RCE on Symbol Error Probability(SEP for all possible modulations has been addressed inthis paper. Results confirm that effective reduction in EVMand RCE, reduces SEP significantly and thus selection ofhigher order modulation and code rates is possible even inlow channel SNR condition (0dB -20dB.

  3. Bayesian Adaptive Exploration

    Loredo, Thomas J.

    2004-04-01

    I describe a framework for adaptive scientific exploration based on iterating an Observation-Inference-Design cycle that allows adjustment of hypotheses and observing protocols in response to the results of observation on-the-fly, as data are gathered. The framework uses a unified Bayesian methodology for the inference and design stages: Bayesian inference to quantify what we have learned from the available data and predict future data, and Bayesian decision theory to identify which new observations would teach us the most. When the goal of the experiment is simply to make inferences, the framework identifies a computationally efficient iterative ``maximum entropy sampling'' strategy as the optimal strategy in settings where the noise statistics are independent of signal properties. Results of applying the method to two ``toy'' problems with simulated data-measuring the orbit of an extrasolar planet, and locating a hidden one-dimensional object-show the approach can significantly improve observational efficiency in settings that have well-defined nonlinear models. I conclude with a list of open issues that must be addressed to make Bayesian adaptive exploration a practical and reliable tool for optimizing scientific exploration.

  4. Europe adapts to climate change: Comparing National Adaptation Strategies

    Biesbroek, G. Robbert; Swart, Rob J.; Carter, Timothy R.;

    2010-01-01

    Adaptation Strategies in the wider governance of adaptation differs between countries but clearly benchmarks a new political commitment to adaptation at national policy levels. However, we also find that in most cases approaches for implementing and evaluating the strategies are yet to be defined. The paper......For the last two decades, European climate policy has focused almost exclusively on mitigation of climate change. It was only well after the turn of the century, with impacts of climate change increasingly being observed, that adaptation was added to the policy agenda and EU Member States started...... to develop National Adaptation Strategies (NASs). This paper reviews seven National Adaptation Strategies that were either formally adopted or under development by Member States at the end of 2008. The strategies are analysed under the following six themes. Firstly, the factors motivating and...

  5. Adaptive Playware in Physical Games

    Lund, Henrik Hautop; Thorsteinsson, Arnar Tumi

    2011-01-01

    We describe how playware and games may adapt to the interaction of the individual user. We hypothesize that in physical games there are individual differences in user interaction capabilities and styles, and that adaptive playware may adapt to the individual user’s capabilities, so that the...... activity automatically will match the capability of the individual user. With small test groups, we investigate how different age groups and gender groups physically interact with some playware games, and find indications of differences between the groups. Despite the small test set, the results are a...... proof of existence of differences and of the need for adaptation, and therefore we investigate adaptation as an important issue for playware. With simple playware games, we show that the adaptation will speed the physical game up and down to find the appropriate level that matches the reaction speed of...

  6. Adaptive challenges in medical practices.

    Daiker, Barbara L

    2013-01-01

    The purpose of this qualitative grounded theory study was to describe the theoretical structures of the strategies used by medical practices to navigate adaptive challenges. The process of responding to adaptive challenges in five medical practices was studied using a grounded theory approach, collecting data from interviews with the organizations' leaders and managers. The leadership of these medical practices had successfully navigated adaptive challenges within two years of the study. The analysis revealed a model that describes the key elements in finding solutions to adaptive challenges. The model was named the Adaptation Solution Dynamic, which explains the elements of Rational Tools, Relationship Commitment, and Achievement Drive. The findings from the results of this study provide a theoretical basis for studying how leaders support identifying solutions to adaptive challenges. PMID:23866647

  7. Adapting to climate change

    Arndt, Channing; Strzepek, Kenneth; Tarp, Finn;

    2011-01-01

    Mozambique, like many African countries, is already highly susceptible to climate variability and extreme weather events. Climate change threatens to heighten this vulnerability. In order to evaluate potential impacts and adaptation options for Mozambique, we develop an integrated modeling...... framework that translates atmospheric changes from general circulation model projections into biophysical outcomes via detailed hydrologic, crop, hydropower and infrastructure models. These sector models simulate a historical baseline and four extreme climate change scenarios. Sector results are then passed...... down to a dynamic computable general equilibrium model, which is used to estimate economy-wide impacts on national welfare, as well as the total cost of damages caused by climate change. Potential damages without changes in policy are significant; our discounted estimates range from US2.3 to US2.3toUS7...

  8. Mobile, Flexible, and Adaptable

    Agergaard, Jytte; Thao, Thi Vu

    2011-01-01

    Industrialisation and urban growth are constitutive aspects of Vietnam's new economy and are important driving forces behind increasing rural-to-urban migration. Growth in informal sector employment is a significant aspect of this development, which has provided for both male and female migrants...... networking, and remittance practices. The paper is organised around why and how migrants have entered the informal labour market in Hanoi and how they make their livings there while also maintaining ties with their rural homes. In conclusion, we discuss how the migration networks and remittance practices of...... the female porters demonstrate a particular way of adapting to the migration process. Also, it is emphasised how women's flexible practices are facilitated by women's own village-based networks. It is suggested that ‘in-betweenness’, which stands for the simultaneous and overlapping presence of urban...

  9. SAR based adaptive GMTI

    Vu, Duc; Guo, Bin; Xu, Luzhou; Li, Jian

    2010-04-01

    We consider ground moving target indication (GMTI) and target velocity estimation based on multi-channel synthetic aperture radar (SAR) images. Via forming velocity versus cross-range images, we show that small moving targets can be detected even in the presence of strong stationary ground clutter. Moreover, the velocities of the moving targets can be estimated, and the misplaced moving targets can be placed back to their original locations based on the estimated velocities. Adaptive beamforming techniques, including Capon and generalizedlikelihood ratio test (GLRT), are used to form velocity versus cross-range images for each range bin of interest. The velocity estimation ambiguities caused by the multi-channel array geometry are analyzed. We also demonstrate the effectiveness of our approaches using the Air Force Research Laboratory (AFRL) publicly-released Gotcha SAR based GMTI data set.

  10. Adaptively Compressed Exchange Operator

    Lin, Lin

    2016-01-01

    The Fock exchange operator plays a central role in modern quantum chemistry. The large computational cost associated with the Fock exchange operator hinders Hartree-Fock calculations and Kohn-Sham density functional theory calculations with hybrid exchange-correlation functionals, even for systems consisting of hundreds of atoms. We develop the adaptively compressed exchange operator (ACE) formulation, which greatly reduces the computational cost associated with the Fock exchange operator without loss of accuracy. The ACE formulation does not depend on the size of the band gap, and thus can be applied to insulating, semiconducting as well as metallic systems. In an iterative framework for solving Hartree-Fock-like systems, the ACE formulation only requires moderate modification of the code, and can be potentially beneficial for all electronic structure software packages involving exchange calculations. Numerical results indicate that the ACE formulation can become advantageous even for small systems with tens...

  11. Bayesian Adaptive Exploration

    Loredo, T J

    2004-01-01

    I describe a framework for adaptive scientific exploration based on iterating an Observation--Inference--Design cycle that allows adjustment of hypotheses and observing protocols in response to the results of observation on-the-fly, as data are gathered. The framework uses a unified Bayesian methodology for the inference and design stages: Bayesian inference to quantify what we have learned from the available data and predict future data, and Bayesian decision theory to identify which new observations would teach us the most. When the goal of the experiment is simply to make inferences, the framework identifies a computationally efficient iterative ``maximum entropy sampling'' strategy as the optimal strategy in settings where the noise statistics are independent of signal properties. Results of applying the method to two ``toy'' problems with simulated data--measuring the orbit of an extrasolar planet, and locating a hidden one-dimensional object--show the approach can significantly improve observational eff...

  12. Adaptive Sentence Boundary Disambiguation

    Palmer, D D; Palmer, David D.; Hearst, Marti A.

    1994-01-01

    Labeling of sentence boundaries is a necessary prerequisite for many natural language processing tasks, including part-of-speech tagging and sentence alignment. End-of-sentence punctuation marks are ambiguous; to disambiguate them most systems use brittle, special-purpose regular expression grammars and exception rules. As an alternative, we have developed an efficient, trainable algorithm that uses a lexicon with part-of-speech probabilities and a feed-forward neural network. After training for less than one minute, the method correctly labels over 98.5\\% of sentence boundaries in a corpus of over 27,000 sentence-boundary marks. We show the method to be efficient and easily adaptable to different text genres, including single-case texts.

  13. Climate Change Adaptation

    Hudecz, Adriána

    The European Union ROADEX Project 1998 – 2012 was a trans-national roads co-operation aimed at developing ways for interactive and innovative management of low traffic volume roads throughout the cold climate regions of the Northern Periphery Area of Europe. Its goals were to facilitate co......-operation and research into the common problems of the Northern Periphery. This report is an output of the ROADEX “Implementing Accessibility” project (2009-2012). It gives a summary of the results of research into adaptation measures to combat climate change effects on low volume roads in the Northern...... Periphery. The research was carried out between January 2000 and March 2012. One of the biggest challenges that mankind has to face is the prospect of climate change resulting from emissions of greenhouse gases. These gases trap energy in the atmosphere and cause global surface temperatures to rise. This...

  14. PCMAT, an adaptive learning platform

    Couto, Paulo; Fernandes, Marta; Martins, Constantino; Faria, Luiz

    2013-01-01

    This paper is about PCMAT, an adaptive learning platform for Mathematics in Basic Education schools. Based on a constructivist approach, PCMAT aims at verifying how techniques from adaptive hypermedia systems can improve e-learning based systems. To achieve this goal, PCMAT includes a Pedagogical Model that contains a set of adaptation rules that influence the student-platform interaction. PCMAT was subject to a preliminary testing with students aged between 12 and 14 years old on th...

  15. Protein Adaptations in Archaeal Extremophiles

    Reed, Christopher J; Hunter Lewis; Eric Trejo; Vern Winston; Caryn Evilia

    2013-01-01

    Extremophiles, especially those in Archaea, have a myriad of adaptations that keep their cellular proteins stable and active under the extreme conditions in which they live. Rather than having one basic set of adaptations that works for all environments, Archaea have evolved separate protein features that are customized for each environment. We categorized the Archaea into three general groups to describe what is known about their protein adaptations: thermophilic, psychrophilic, and halophil...

  16. Adaptive designs for sequential experiments

    林正炎; 张立新

    2003-01-01

    Various adaptive designs have been proposed and applied to clinical trials, bioassay, psychophysics, etc.Adaptive designs are also useful in high cost engineering trials.More and more people have been paying attention to these design methods. This paper introduces several broad families of designs, such as the play-the-winner rule, randomized play-the-winner rule and its generalization to the multi-arm case, doubly biased coin adaptive design, Markov chain model.

  17. Adaptive Mesh Refinement in CTH

    This paper reports progress on implementing a new capability of adaptive mesh refinement into the Eulerian multimaterial shock- physics code CTH. The adaptivity is block-based with refinement and unrefinement occurring in an isotropic 2:1 manner. The code is designed to run on serial, multiprocessor and massive parallel platforms. An approximate factor of three in memory and performance improvements over comparable resolution non-adaptive calculations has-been demonstrated for a number of problems

  18. Staff Adaptation in Selected Company

    Štolcová, Jana

    2011-01-01

    The work focuses on personnel actions of employee adaptation as, nowadays, it is very important to maintain a good and skilled staff. The main aim of this work is to analyze and evaluate the process of adaptation of new employees at the headquarters of the BILLA, Ltd., which operates more than 200 supermarkets around the Czech Republic,. Another task is to propose partial measures which would improve the process of adaptation in the society. The literature review discusses the importance of ...

  19. Maritime adaptive optics beam control

    Corley, Melissa S.

    2010-01-01

    The Navy is interested in developing systems for horizontal, near ocean surface, high-energy laser propagation through the atmosphere. Laser propagation in the maritime environment requires adaptive optics control of aberrations caused by atmospheric distortion. In this research, a multichannel transverse adaptive filter is formulated in Matlab's Simulink environment and compared to a complex lattice filter that has previously been implemented in large system simulations. The adaptive fil...

  20. Staff Adaptation in Selected Company

    Haňáčková, Ivana

    2014-01-01

    This thesis deals with the management system adaptation workers in the chosen company . Staffing adaptation of workers today is very important because it helps businesses maintain a good and loyal employee. The main goal of this work is to analyze the management system to evaluate the adaptation of workers in terms of a particular company ie company Primagra, a.s. and if identified deficiencies propose appropriate measures. The theoretical part of the paper summarizes the findings of the lite...

  1. Understanding Adaptation in Large Populations

    Talia Karasov; Messer, Philipp W.; Petrov, Dmitri A.

    2010-01-01

    Adaptation in eukaryotes is generally assumed to be mutation-limited because of small effective population sizes. This view is difficult to reconcile, however, with the observation that adaptation to anthropogenic changes, such as the introduction of pesticides, can occur very rapidly. Here we investigate adaptation at a key insecticide resistance locus (Ace) in Drosophila melanogaster and show that multiple simple and complex resistance alleles evolved quickly and repeatedly within individua...

  2. Stored waveform adaptive motor control

    Beall, Jeffery C.

    1986-01-01

    This study investigates an adaptive control scheme designed to maintain accurate motor speed control in spite of high-frequency periodic variations in load torque, load inertia, and motor parameters. The controller adapts, stores and replays a schedule of torques to be delivered at discrete points throughout the periodic load cycle. The controller also adapts to non-periodic changes in load conditions which occur over several load cycles and contains inherent integrator control action to ...

  3. TCP Reno over Adaptive CSMA

    Chen, Wei; Wang, Yue; Chen, Minghua; Liew, Soung Chang

    2010-01-01

    An interesting distributed adaptive CSMA MAC protocol, called adaptive CSMA, was proposed recently to schedule any strictly feasible achievable rates inside the capacity region. Of particular interest is the fact that the adaptive CSMA can achieve a system utility arbitrarily close to that is achievable under a central scheduler. However, a specially designed transport-layer rate controller is needed for this result. An outstanding question is whether the widely-installed TCP Reno is compatib...

  4. Content adaptive screen image scaling

    Zhai, Yao; Wang, Qifei; Lu, Yan; Li, Shipeng

    2015-01-01

    This paper proposes an efficient content adaptive screen image scaling scheme for the real-time screen applications like remote desktop and screen sharing. In the proposed screen scaling scheme, a screen content classification step is first introduced to classify the screen image into text and pictorial regions. Afterward, we propose an adaptive shift linear interpolation algorithm to predict the new pixel values with the shift offset adapted to the content type of each pixel. The shift offse...

  5. Covariance-Adaptive Slice Sampling

    Thompson, Madeleine; Neal, Radford M.

    2010-01-01

    We describe two slice sampling methods for taking multivariate steps using the crumb framework. These methods use the gradients at rejected proposals to adapt to the local curvature of the log-density surface, a technique that can produce much better proposals when parameters are highly correlated. We evaluate our methods on four distributions and compare their performance to that of a non-adaptive slice sampling method and a Metropolis method. The adaptive methods perform favorably on low-di...

  6. Adaptive Motion Compensation in Radiotherapy

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  7. Insight into Enabling Adaptive Management

    Lorne A. Greig

    2013-09-01

    Full Text Available The U.S. National Commission on Science for Sustainable Forestry recognized a need for effective adaptive management to support management for biological diversity. However, difficulties in implementing adaptive management in the U.S. Northwest Forest Plan led the Commission to wonder if comparisons across multiple adaptive management trials in the forest sector could provide insight into the factors that serve to enable or inhibit adaptive management. This comparison and the resulting discussions among a group of seasoned practitioners, with adaptive management experience at a variety of scales and levels of complexity, led to insights into a hierarchy of ten factors that can serve to either enable or inhibit implementation. Doing high quality adaptive management is about doing good science to enable learning from management experience. Enabling adaptive management though is about working with people to understand their concerns, to develop a common understanding and an environment of trust that allows adaptive management to proceed. Careful attention to enabling factors is critical to fulfilling the promise of adaptive management.

  8. Adaptive filtering and change detection

    Gustafsson, Fredrik

    2003-01-01

    Adaptive filtering is a classical branch of digital signal processing (DSP). Industrial interest in adaptive filtering grows continuously with the increase in computer performance that allows ever more conplex algorithms to be run in real-time. Change detection is a type of adaptive filtering for non-stationary signals and is also the basic tool in fault detection and diagnosis. Often considered as separate subjects Adaptive Filtering and Change Detection bridges a gap in the literature with a unified treatment of these areas, emphasizing that change detection is a natural extensi

  9. Adaptive Behaviour Assessment System: Indigenous Australian Adaptation Model (ABAS: IAAM)

    du Plessis, Santie

    2015-01-01

    The study objectives were to develop, trial and evaluate a cross-cultural adaptation of the Adaptive Behavior Assessment System-Second Edition Teacher Form (ABAS-II TF) ages 5-21 for use with Indigenous Australian students ages 5-14. This study introduced a multiphase mixed-method design with semi-structured and informal interviews, school…

  10. Computerized adaptive testing item selection in computerized adaptive learning systems

    Eggen, T.J.H.M.; Veldkamp, B.P.

    2012-01-01

    Item selection methods traditionally developed for computerized adaptive testing (CAT) are explored for their usefulness in item-based computerized adaptive learning (CAL) systems. While in CAT Fisher information-based selection is optimal, for recovering learning populations in CAL systems item selection based on Kullback-Leibner information is an alternative

  11. Smartphone adapters for digital photomicrography

    Somak Roy

    2014-01-01

    Full Text Available Background: Photomicrographs in Anatomic Pathology provide a means of quickly sharing information from a glass slide for consultation, education, documentation and publication. While static image acquisition historically involved the use of a permanently mounted camera unit on a microscope, such cameras may be expensive, need to be connected to a computer, and often require proprietary software to acquire and process images. Another novel approach for capturing digital microscopic images is to use smartphones coupled with the eyepiece of a microscope. Recently, several smartphone adapters have emerged that allow users to attach mobile phones to the microscope. The aim of this study was to test the utility of these various smartphone adapters. Materials and Methods: We surveyed the market for adapters to attach smartphones to the ocular lens of a conventional light microscope. Three adapters (Magnifi, Skylight and Snapzoom were tested. We assessed the designs of these adapters and their effectiveness at acquiring static microscopic digital images. Results: All adapters facilitated the acquisition of digital microscopic images with a smartphone. The optimal adapter was dependent on the type of phone used. The Magnifi adapters for iPhone were incompatible when using a protective case. The Snapzoom adapter was easiest to use with iPhones and other smartphones even with protective cases. Conclusions: Smartphone adapters are inexpensive and easy to use for acquiring digital microscopic images. However, they require some adjustment by the user in order to optimize focus and obtain good quality images. Smartphone microscope adapters provide an economically feasible method of acquiring and sharing digital pathology photomicrographs.

  12. Techniques of English Textbooks Adaptation

    张婧雯; 杨竞欧

    2014-01-01

    This essay attempts to aim English teachers to evaluate and adapt the current English textbooks.According to different levels and majors of the students,English teachers can enhance the teaching materials and their teaching skills.This paper would provide several useful techniques for teachers to make evaluations and adaptations of using teaching materials.

  13. Dynamic adaption of vascular morphology

    Okkels, Fridolin; Jacobsen, Jens Christian Brings

    2012-01-01

    The structure of vascular networks adapts continuously to meet changes in demand of the surrounding tissue. Most of the known vascular adaptation mechanisms are based on local reactions to local stimuli such as pressure and flow, which in turn reflects influence from the surrounding tissue. Here ...

  14. Adaptive Assessments Using Open Specifications

    Leon, Hector Barbosa; Garcia-Penalvo, Francisco J.; Rodriguez-Conde, Maria Jose; Morales, Erla M.; de Pablos, Patricia Ordonez

    2012-01-01

    Evaluation is a key element in formal education processes; it must be constructed in a way that the item questions within help students understand by adapting them to the learning style as well. The focus of the present research work specifically in the convenience to adapt an associated multimedia material in each single question besides the…

  15. Interdisciplinarity in Adapted Physical Activity

    Bouffard, Marcel; Spencer-Cavaliere, Nancy

    2016-01-01

    It is commonly accepted that inquiry in adapted physical activity involves the use of different disciplines to address questions. It is often advanced today that complex problems of the kind frequently encountered in adapted physical activity require a combination of disciplines for their solution. At the present time, individual research…

  16. Tracking adaptation and measuring development

    Brooks, Nick; Anderson, Simon; Ayers, Jessica; Burton, Ian; Tellam, Ian

    2011-11-15

    This is the first paper in the new IIED Climate Change Working Paper series. As adaptation to climate change becomes the focus of increasing attention and the target of significant spending, there is a growing need for frameworks and tools that enable organisations to track and assess the outcomes of adaptation interventions. This paper presents a coherent framework for climate change adaptation programming, including potential indicators, or indicator categories/types, for tracking and evaluating the success of adaptation support and adaptation interventions. The paper begins with a discussion of some of the key issues related to the evaluation of adaptation, and outlines some of the main difficulties and constraints with respect to the development of adaptation indicators. Next, an evaluation framework is proposed and indicator categories or 'domains' are identified. Lastly, key conclusions are provided and a theory of change is outlined that shows how development and use of the framework could lead to more effective adaptation investments for climate resilient development.

  17. Adapting playware to multiple players

    Þorsteinsson, Arnar Tumi; Lund, Henrik Hautop; Mastorakis, Nikos;

    2011-01-01

    With the creation of playware as intelligent hardware and software that creates play, it is possible to adapt the play tool to the individual user, and even to multiple users playing at the same time with the play tool. In this paper, we show how it is possible to implement adaptivity in modular...

  18. The adaptation to climate change

    The authors address the issue of adaptation to climate change. They first address the physical aspects related to this issue: scenarios of temperature evolution, main possible impacts. Then, they address the social impacts related to climate risks, and the adaptation strategies which aim at reducing the exposure and vulnerability of human societies, or at increasing their resilience. Some examples of losses of human lives and of economic damages due to recent catastrophes related to climate change are evoked. The authors address the international framework, the emergence of an international regime on climate, the quite recent emergence of adaptation within international negotiations in 2001, the emergence of the idea of a support to developing countries. National and local policies are presented in the next chapter (in the European Union, the Netherlands which are faced with the issue of sea level rise, programs in developing countries) and their limitations are also outlined. The next chapter addresses the adaptation actions performed by private actors (enterprises, households, associations, civil society, and so on) with example of vulnerability, and adaptation opportunities and possibilities in some specific sectors. The last chapter presents a typology of actions of adaptation, indicators of adaptation to climate change, and examples of mistaken adaptation

  19. Statistical Physics of Adaptation

    Perunov, Nikolay; Marsland, Robert A.; England, Jeremy L.

    2016-04-01

    Whether by virtue of being prepared in a slowly relaxing, high-free energy initial condition, or because they are constantly dissipating energy absorbed from a strong external drive, many systems subject to thermal fluctuations are not expected to behave in the way they would at thermal equilibrium. Rather, the probability of finding such a system in a given microscopic arrangement may deviate strongly from the Boltzmann distribution, raising the question of whether thermodynamics still has anything to tell us about which arrangements are the most likely to be observed. In this work, we build on past results governing nonequilibrium thermodynamics and define a generalized Helmholtz free energy that exactly delineates the various factors that quantitatively contribute to the relative probabilities of different outcomes in far-from-equilibrium stochastic dynamics. By applying this expression to the analysis of two examples—namely, a particle hopping in an oscillating energy landscape and a population composed of two types of exponentially growing self-replicators—we illustrate a simple relationship between outcome-likelihood and dissipative history. In closing, we discuss the possible relevance of such a thermodynamic principle for our understanding of self-organization in complex systems, paying particular attention to a possible analogy to the way evolutionary adaptations emerge in living things.

  20. Adapt or die?

    Visser, S S; Nel, A H

    1996-12-01

    The worldwide economic recession and the concomitant limited stock of finances have had an influence on the available money of every household and have also inhibited the improvement of socio-economic conditions and medicine. The Reconstruction and Development Programme (RDP) has the objective of improving the living conditions of the people with regard to housing, education, training and health care. The latter seems to be a major problem which has to be addressed with the emphasis on the preventive and promotional aspects of health care. A comprehensive health care system did not come into being property in the past because of the maldistribution of health care services, personnel and differences in culture and health care beliefs and values. The question that now arises, is how to render a quality health care service within the constraints of inadequate financing and resources. A comprehensive literature study has been done with reference to quality health care and financing followed by a survey of existing health services and finances. Recommendations are made about minimum requirements to be accepted if one were to adapt rather than die in terms of the provision of healthcare: the decentralization and rationalization of the administration of health care, the stress on and realization of effective and efficient primary health care, the acceptance of participative management in health providing organizations, the provision of financial management training for health care managers and the application of management accounting principles for the improvement of the efficiency and effectiveness of management. PMID:9283343

  1. Adapting to an aftereffect.

    Sheth, Bhavin R; Shimojo, Shinsuke

    2008-01-01

    We report a new type of orientation-contingent color aftereffect in which the color aftereffect is opposite to the classical McCollough effect, i.e., the perceived color of the aftereffect is the same as the inducer's color. Interleaved exposure to red, horizontal and achromatic (gray), horizontal gratings led to a long-lasting aftereffect in which achromatic horizontal gratings appeared reddish. The effect, termed the anti-McCollough effect, although weaker than the classical aftereffect, remained stable for a moderate duration of time (24 hours). Unlike the classical aftereffect, which is known to not transfer interocularly, the new after-aftereffect transferred 100%, suggesting that its locus in the brain was downstream of the classical effect. It is likely that neurons in a higher-order area adapted to the classical color aftereffect that was represented in a lower-order area, thus forming an aftereffect of an aftereffect, i.e., an after-aftereffect. Our finding has implications as to how neural activity in lower- and higher-level areas in the brain interacts to yield conscious visual experience. PMID:18484835

  2. Success and adaptation

    2013-01-01

    Yesterday morning, the last colliding proton beams of 2013 were extracted from the LHC, heralding the start of the machine’s first long shutdown (LS1) and crowning its first three glorious years of running. I hardly need to tell the CERN community what a fabulous performance all the people running the machine, the experiments, the computing and all supporting infrastructures put in. Those people are you, and you all know very well what a great job everyone did.   Nevertheless, I would like to express my thanks to all the people who made this first LHC run such a success. Re-measuring the whole Standard Model in such a short period, and then completing it with the discovery of what looks increasingly like the Higgs boson, is no mean feat. What I’d like to focus on today is another aspect of our field: its remarkable ability to adapt. When I started out in research, experiments involved a handful of people and lasted a few years at most. The timescale for the development of ...

  3. Strategy for Climate Change Adaptation

    Rasmussen, Torben Valdbjørn

    2014-01-01

    . This absence of an agreement calls for adaptation to climate change. Emphasis should be put on buildings, as they play a vital economic and social role in society and are vulnerable to climate change. Therefore, the building stock deserves its own policy and implementation plans as well as tools that...... enable adequate and cost-efficient adaptation to climate change. This paper explains the need for climate change adaptation of the building stock and suggests a pattern for a strategic approach to how to reach the climate change adaptation needed. The suggested and presented need of a strategic approach...... is based on three main initiatives consisting of the need to examine the potential impacts of climate change on the building stock, the need to assess and develop a roadmap of current and future adaptation measures that can withstand the effects of climate change, and the need to engage relevant...

  4. Strategy for Climate Change Adaptation

    Rasmussen, Torben Valdbjørn

    2013-01-01

    . This absence of an agreement calls for adaptation to climate change. Emphasis should be put on buildings, as they play a vital economic and social role in society and are vulnerable to climate change. Therefore, the building stock deserves its own policy and implementation plans as well as tools that...... enable adequate and cost-efficient adaptation to climate change. This paper explains the need for climate change adaptation of the building stock and suggests a pattern for a strategic approach to how to reach the climate change adaptation needed. The suggested and presented need of a strategic approach...... is based on three main initiatives consisting of the need to examine the potential impacts of climate change on the building stock, the need to assess and develop a roadmap of current and future adaptation measures that can withstand the effects of climate change, and the need to engage relevant...

  5. Adapting Playware to Rehabilitation Practices

    Nielsen, Camilla Balslev; Lund, Henrik Hautop

    2012-01-01

    We describe how playware and games may become adaptive to the interaction of the individual user and how therapists use this adaptation property to apply modular interactive tiles in rehabilitation practices that demand highly individualized training. Therapists may use the interactive modular ti...... patients modulating exercises and difficulty levels. We also find that in physical games there are individual differences in patient interaction capabilities and styles, and that modularity allows the therapist to adapt exercises to the individual patient’s capabilities.......We describe how playware and games may become adaptive to the interaction of the individual user and how therapists use this adaptation property to apply modular interactive tiles in rehabilitation practices that demand highly individualized training. Therapists may use the interactive modular...

  6. Adapting Playware to Rehabilitation Practices

    Nielsen, Camilla Balslev; Lund, Henrik Hautop

    2011-01-01

    We describe how playware and games may become adaptive to the interaction of the individual user and how therapists use this adaptation property to apply modular interactive tiles in rehabilitation practices that demand highly individualized training. Therapists may use the interactive modular ti...... patients modulating exercises and difficulty levels. We also find that in physical games there are individual differences in patient interaction capabilities and styles, and that modularity allows the therapist to adapt exercises to the individual patient’s capabilities.......We describe how playware and games may become adaptive to the interaction of the individual user and how therapists use this adaptation property to apply modular interactive tiles in rehabilitation practices that demand highly individualized training. Therapists may use the interactive modular...

  7. Parallel Adaptive Mesh Refinement

    Diachin, L; Hornung, R; Plassmann, P; WIssink, A

    2005-03-04

    As large-scale, parallel computers have become more widely available and numerical models and algorithms have advanced, the range of physical phenomena that can be simulated has expanded dramatically. Many important science and engineering problems exhibit solutions with localized behavior where highly-detailed salient features or large gradients appear in certain regions which are separated by much larger regions where the solution is smooth. Examples include chemically-reacting flows with radiative heat transfer, high Reynolds number flows interacting with solid objects, and combustion problems where the flame front is essentially a two-dimensional sheet occupying a small part of a three-dimensional domain. Modeling such problems numerically requires approximating the governing partial differential equations on a discrete domain, or grid. Grid spacing is an important factor in determining the accuracy and cost of a computation. A fine grid may be needed to resolve key local features while a much coarser grid may suffice elsewhere. Employing a fine grid everywhere may be inefficient at best and, at worst, may make an adequately resolved simulation impractical. Moreover, the location and resolution of fine grid required for an accurate solution is a dynamic property of a problem's transient features and may not be known a priori. Adaptive mesh refinement (AMR) is a technique that can be used with both structured and unstructured meshes to adjust local grid spacing dynamically to capture solution features with an appropriate degree of resolution. Thus, computational resources can be focused where and when they are needed most to efficiently achieve an accurate solution without incurring the cost of a globally-fine grid. Figure 1.1 shows two example computations using AMR; on the left is a structured mesh calculation of a impulsively-sheared contact surface and on the right is the fuselage and volume discretization of an RAH-66 Comanche helicopter [35]. Note the

  8. Adaptive designs for sequential experiments

    林正炎; 张立新

    2003-01-01

    Various adaptive designe have been proposed and applied to clinical trials,bioassay,psycho-physics,etc.Adaptive designs are also useful in high cost engineering trials.More and More people have been paying attention to these desing methods.This paper introduces several broad families of designs,such as the play-the-winner rele,randomized play-the-winner rule and its generalization to the multi-arm case,doubly bi-ased coin adaptive design,Markov chain model.

  9. Racism in America through adaptation

    Munk, Jakob; Jakobsen, Sebastian; Chung, Jacinta; Schulze, Anja; Papakonstantinou, Vaitza

    2015-01-01

    This study examines the adaptation of the movie 12 Years a Slave from the memoir of Solomon Northup. In order to analyse the adaptation, several theories will be used as guidelines for our research such as adaptation theories and film techniques. The analysis will lead through the different chapters of the book focusing on atmosphere, characters and religion. The main themes dealt with in the book as well as the movie will be linked with the events which unfolded in Ferguson and Baltimore. In...

  10. Adaptive stochastic cellular automata: Applications

    Qian, S.; Lee, Y. C.; Jones, R. D.; Barnes, C. W.; Flake, G. W.; O'Rourke, M. K.; Lee, K.; Chen, H. H.; Sun, G. Z.; Zhang, Y. Q.; Chen, D.; Giles, C. L.

    1990-09-01

    The stochastic learning cellular automata model has been applied to the problem of controlling unstable systems. Two example unstable systems studied are controlled by an adaptive stochastic cellular automata algorithm with an adaptive critic. The reinforcement learning algorithm and the architecture of the stochastic CA controller are presented. Learning to balance a single pole is discussed in detail. Balancing an inverted double pendulum highlights the power of the stochastic CA approach. The stochastic CA model is compared to conventional adaptive control and artificial neural network approaches.

  11. FDM adaptive optics technology development

    Thibault, Simon; Doucet, Michel; Rioux, Myriam

    2004-10-01

    INO supports research on Ferrofluidic Deformable Mirror (FDM) adaptive optics technologies and, as such, its research activities include the development and characterization of FDM and high resolution (ExAO) adaptive optics systems using such FDMs. Liquid mirrors have long been recognized as a potential low-cost alternative to conventional solid mirrors. Since the trend is towards advanced adaptive optics systems, a need for deformable mirrors with a large number of low-cost actuators exists. This paper presents updated experimental results using a new INO FDM prototype (271 actuators, 50 µm stroke) as well as a theoretical model of surface behaviors.

  12. Resource-adaptive cognitive processes

    Crocker, Matthew W

    2010-01-01

    This book investigates the adaptation of cognitive processes to limited resources. The central topics of this book are heuristics considered as results of the adaptation to resource limitations, through natural evolution in the case of humans, or through artificial construction in the case of computational systems; the construction and analysis of resource control in cognitive processes; and an analysis of resource-adaptivity within the paradigm of concurrent computation. The editors integrated the results of a collaborative 5-year research project that involved over 50 scientists. After a mot

  13. The Vulnerability of Threatened Species: Adaptive Capability and Adaptation Opportunity

    Andrew McVey

    2013-07-01

    Full Text Available Global targets to halt the loss of biodiversity have not been met, and there is now an additional Aichi target for preventing the extinction of known threatened species and improving their conservation status. Climate change increasingly needs to be factored in to these, and thus there is a need to identify the extent to which it could increase species vulnerability. This paper uses the exposure, sensitivity, and adaptive capacity framework to assess the vulnerability of a selection of WWF global priority large mammals and marine species to climate change. However, it divides adaptive capacity into adaptive capability and adaptation opportunity, in order to identify whether adaptation is more constrained by the biology of the species or by its environmental setting. Lack of evidence makes it difficult to apply the framework consistently across the species, but it was found that, particularly for the terrestrial mammals, adaptation opportunities seems to be the greater constraint. This framework and analysis could be used by conservationists and those wishing to enhance the resilience of species to climate change.

  14. Farming System Evolution and Adaptive Capacity: Insights for Adaptation Support

    Jami L. Dixon

    2014-02-01

    Full Text Available Studies of climate impacts on agriculture and adaptation often provide current or future assessments, ignoring the historical contexts farming systems are situated within. We investigate how historical trends have influenced farming system adaptive capacity in Uganda using data from household surveys, semi-structured interviews, focus-group discussions and observations. By comparing two farming systems, we note three major findings: (1 similar trends in farming system evolution have had differential impacts on the diversity of farming systems; (2 trends have contributed to the erosion of informal social and cultural institutions and an increasing dependence on formal institutions; and (3 trade-offs between components of adaptive capacity are made at the farm-scale, thus influencing farming system adaptive capacity. To identify the actual impacts of future climate change and variability, it is important to recognize the dynamic nature of adaptation. In practice, areas identified for further adaptation support include: shift away from one-size-fits-all approach the identification and integration of appropriate modern farming method; a greater focus on building inclusive formal and informal institutions; and a more nuanced understanding regarding the roles and decision-making processes of influential, but external, actors. More research is needed to understand farm-scale trade-offs and the resulting impacts across spatial and temporal scales.

  15. Externalizing Research Through Adaptive Frameworks

    Vedel, Jane Bjørn; Irwin, Alan; Høngaard Andersen, Peter

    2013-01-01

    Adaptive approaches to collaborations between industry and academic research institutions can enable both parties to achieve their goals more effectively. Here, we discuss our experience with such approaches and suggest recommendations for addressing the associated management challenges....

  16. Adaptation : climate change briefing paper

    Acclimatise

    2009-01-01

    Climate change adaptation means recognising what is happening to our climate on a global and local scale, and developing strategies to manage the risks that this presents is crucial to the growth, development and continuing success of any organisation.

  17. Viewer preferences for adaptive playout

    Deshpande, Sachin

    2013-03-01

    Adaptive media playout techniques are used to avoid buffer underflow in a dynamic streaming environment where the available bandwidth may be fluctuating. In this paper we report human perceptions from audio quality studies that we performed on speech and music samples for adaptive audio playout. Test methods based on ITU-R BS. 1534-1 recommendation were used. Studies were conducted for both slow playout and fast playout. Two scales - a coarse scale and a finer scale was used for the slow and fast audio playout factors. Results from our study can be used to determine acceptable slow and fast playout factors for speech and music content. An adaptive media playout algorithm could use knowledge of these upper and lower bounds on playback speeds to decide its adaptive playback schedule.

  18. Genetic Algorithms for Case Adaptation

    Case based reasoning (CBR) paradigm has been widely used to provide computer support for recalling and adapting known cases to novel situations. Case adaptation algorithms generally rely on knowledge based and heuristics in order to change the past solutions to solve new problems. However, case adaptation has always been a difficult process to engineers within (CBR) cycle. Its difficulties can be referred to its domain dependency; and computational cost. In an effort to solve this problem, this research explores a general-purpose method that applying a genetic algorithm (GA) to CBR adaptation. Therefore, it can decrease the computational complexity of the search space in the problems having a great dependency on their domain knowledge. The proposed model can be used to perform a variety of design tasks on a broad set of application domains. However, it has been implemented for the tablet formulation as a domain of application. The proposed system has improved the performance of the CBR design systems

  19. Color Ratios and Chromatic Adaptation

    Finlayson, Graham D.; Süsstrunk, Sabine

    2002-01-01

    In this paper, the performance of chromatic adaptation transforms based on stable color ratios is investigated.It was found that for three different sets of reflectance data, their performance was not statistically different from CMCCAT2000,when applying the chromatic adaptation transforms to Lam’s corresponding color data set and using a perceptual error metric of CIE Delta E94.The sensors with the best color ratio stability are much sharper and more de-correlated than the CMCCAT2000 sensors...

  20. Face Adaptation Without a Face

    Ghuman, Avniel Singh; McDaniel, Jonathan R.; Martin, Alex

    2010-01-01

    Prolonged viewing of a stimulus results in a subsequent perceptual bias [1], [2] and [3]. This perceptual adaptation and the resulting aftereffect reveal important characteristics regarding how perceptual systems are tuned [2], [4], [5] and [6]. These aftereffects occur not only for simple stimulus features but also for high-level stimulus properties [7], [8], [9] and [10]. Here we report a novel cross-category adaptation aftereffect demonstrating that prolonged viewing of a human body withou...

  1. Adaptive oxide electronics: A review

    Ha, Sieu D.; Ramanathan, Shriram

    2011-10-01

    Novel information processing techniques are being actively explored to overcome fundamental limitations associated with CMOS scaling. A new paradigm of adaptive electronic devices is emerging that may reshape the frontiers of electronics and enable new modalities. Creating systems that can learn and adapt to various inputs has generally been a complex algorithm problem in information science, albeit with wide-ranging and powerful applications from medical diagnosis to control systems. Recent work in oxide electronics suggests that it may be plausible to implement such systems at the device level, thereby drastically increasing computational density and power efficiency and expanding the potential for electronics beyond Boolean computation. Intriguing possibilities of adaptive electronics include fabrication of devices that mimic human brain functionality: the strengthening and weakening of synapses emulated by electrically, magnetically, thermally, or optically tunable properties of materials.In this review, we detail materials and device physics studies on functional metal oxides that may be utilized for adaptive electronics. It has been shown that properties, such as resistivity, polarization, and magnetization, of many oxides can be modified electrically in a non-volatile manner, suggesting that these materials respond to electrical stimulus similarly as a neural synapse. We discuss what device characteristics will likely be relevant for integration into adaptive platforms and then survey a variety of oxides with respect to these properties, such as, but not limited to, TaOx, SrTiO3, and Bi4-xLaxTi3O12. The physical mechanisms in each case are detailed and analyzed within the framework of adaptive electronics. We then review theoretically formulated and current experimentally realized adaptive devices with functional oxides, such as self-programmable logic and neuromorphic circuits. Finally, we speculate on what advances in materials physics and engineering may

  2. Algebraic and Adaptive MIMO Radar

    Morency, Matthew

    2015-01-01

    Breaking causality is the main distinction of the multiple-input multiple-output (MIMO) paradigm as used for active sensing/radar. This is because the transmitting side can be optimized in many ways to manipulate the capabilities of the system. Adaptive beamforming is a fundamental problem in array-processing, communications, and radar among other fields which has once again garnered significant research interest in recent years within the MIMO paradigm. In this work, transmit adaptive beamfo...

  3. Adaptive constraints for feature tracking

    K. I. Hodges

    1999-01-01

    In this paper extensions to an existing tracking algorithm are described. These extensions implement adaptive tracking constraints in the form of regional upper-bound displacements and an adaptive track smoothness constraint. Together, these constraints make the tracking algorithm more flexible than the original algorithm (which used fixed tracking parameters) and provide greater confidence in the tracking results. The result of applying the new algorithm to high-resolution ...

  4. The Adaptive Evolution Database (TAED)

    Liberles, David A; Schreiber, David R.; Govindarajan, Sridhar; Chamberlin, Stephen G.; Steven A Benner

    2001-01-01

    Background The Master Catalog is a collection of evolutionary families, including multiple sequence alignments, phylogenetic trees and reconstructed ancestral sequences, for all protein-sequence modules encoded by genes in GenBank. It can therefore support large-scale genomic surveys, of which we present here The Adaptive Evolution Database (TAED). In TAED, potential examples of positive adaptation are identified by high values for the normalized ratio of nonsynonymous to synonymous nucleotid...

  5. Fair adaptation to climate change

    This article identifies social justice dilemmas associated with the necessity to adapt to climate change, examines how they are currently addressed by the climate change regime, and proposes solutions to overcome prevailing gaps and ambiguities. We argue that the key justice dilemmas of adaptation include responsibility for climate change impacts, the level and burden sharing of assistance to vulnerable countries for adaptation, distribution of assistance between recipient countries and adaptation measures, and fair participation in planning and making decisions on adaptation. We demonstrate how the climate change regime largely omits responsibility but makes a general commitment to assistance. However, the regime has so far failed to operationalise assistance and has made only minor progress towards eliminating obstacles for fair participation. We propose the adoption of four principles for fair adaptation in the climate change regime. These include avoiding dangerous climate change, forward-looking responsibility, putting the most vulnerable first and equal participation of all. We argue that a safe maximum standard of 400-500 ppm of CO2 concentrations in the atmosphere and a carbon tax of $20-50 per carbon equivalent ton could provide the initial instruments for operationalising the principles. (author)

  6. Adaptive Liquid Crystal Windows

    Taheri, Bahman; Bodnar, Volodymyr

    2011-12-31

    Energy consumption by private and commercial sectors in the U.S. has steadily grown over the last decade. The uncertainty in future availability of imported oil, on which the energy consumption relies strongly, resulted in a dramatic increase in the cost of energy. About 20% of this consumption are used to heat and cool houses and commercial buildings. To reduce dependence on the foreign oil and cut down emission of greenhouse gases, it is necessary to eliminate losses and reduce total energy consumption by buildings. To achieve this goal it is necessary to redefine the role of the conventional windows. At a minimum, windows should stop being a source for energy loss. Ideally, windows should become a source of energy, providing net gain to reduce energy used to heat and cool homes. It is possible to have a net energy gain from a window if its light transmission can be dynamically altered, ideally electronically without the need of operator assistance, providing optimal control of the solar gain that varies with season and climate in the U.S. In addition, the window must not require power from the building for operation. Resolution of this problem is a societal challenge and of national interest and will have a broad global impact. For this purpose, the year-round, allclimate window solution to provide an electronically variable solar heat gain coefficient (SHGC) with a wide dynamic range is needed. AlphaMicron, Inc. (AMI) developed and manufactured 1ft × 1ft prototype panels for the world’s first auto-adjusting Adaptive Liquid Crystal Windows (ALCWs) that can operate from sunlight without the need for external power source and demonstrate an electronically adjustable SHGC. This novel windows are based on AlphaMicron’s patented e-Tint® technology, a guesthost liquid crystal system implemented on flexible, optically clear plastic films. This technology is suitable both for OEM and aftermarket (retro-fitting) lamination to new and existing windows. Low level of

  7. How seabirds adapt to ocean processes

    Powers, K.D.

    A general review is presented of the adaptations made by seabirds to their environments. Included in the discussion are behavioral, morphological and physiological adaptation to the ocean environment.

  8. Low dose effects. Adaptive response

    The purpose of this work was to evaluate if there are disturbancies in adaptive response when lymphocytes of people living on the polluted with radionuclides area after Chernobyl disaster and liquidators suffered from accident have been investigated. The level of lymphocytes with micronuclei have been scored in Moscow donors and people living in Bryansk region with the degree of contamination 15 - 40 Ci/km. The doses that liquidators have been obtained were not higher then 25 cGy. The mean spontaneous level of MN in control people and people from Chernobyl zones does't differ significantly but the individual variability in the mean value between two populations does not differ significantly too. And in this case it seems that persons of exposed areas. Then another important fact in lymphocytes of people living on polluted areas the chronic low dose irradiation does not induce the adaptive response. In Moscow people in most cases (≅ 59 %) the adaptive response is observed and in some cases the demonstration of adaptive response is not significant (≅1%). In Chernobyl population exposed to chronic low level, low dose rate irradiation there are fewer people here with distinct adaptive response (≅38%). And there appear beings with increased radiosensitivity after conditioned dose. Such population with enhanced radiosensitivity have not observed in Moscow. In liquidators the same types of effects have been registered. These results have been obtained on adults. Adaptive response in children 8 - 14 old population living in Moscow and in Chernobyl zone have been investigated too. In this case the spontaneous level of MN is higher in children living in polluted areas, after the 1.0 Gy irradiation the individual variability is very large. Only 5 % of children have distinct is very large. Only 5 % of children have distinct adaptive response, the enhancement of radiosensitivity after conditioned dose is observed. (authors)

  9. Adaptive Multilevel Monte Carlo Simulation

    Hoel, H

    2011-08-23

    This work generalizes a multilevel forward Euler Monte Carlo method introduced in Michael B. Giles. (Michael Giles. Oper. Res. 56(3):607–617, 2008.) for the approximation of expected values depending on the solution to an Itô stochastic differential equation. The work (Michael Giles. Oper. Res. 56(3):607– 617, 2008.) proposed and analyzed a forward Euler multilevelMonte Carlo method based on a hierarchy of uniform time discretizations and control variates to reduce the computational effort required by a standard, single level, Forward Euler Monte Carlo method. This work introduces an adaptive hierarchy of non uniform time discretizations, generated by an adaptive algorithmintroduced in (AnnaDzougoutov et al. Raùl Tempone. Adaptive Monte Carlo algorithms for stopped diffusion. In Multiscale methods in science and engineering, volume 44 of Lect. Notes Comput. Sci. Eng., pages 59–88. Springer, Berlin, 2005; Kyoung-Sook Moon et al. Stoch. Anal. Appl. 23(3):511–558, 2005; Kyoung-Sook Moon et al. An adaptive algorithm for ordinary, stochastic and partial differential equations. In Recent advances in adaptive computation, volume 383 of Contemp. Math., pages 325–343. Amer. Math. Soc., Providence, RI, 2005.). This form of the adaptive algorithm generates stochastic, path dependent, time steps and is based on a posteriori error expansions first developed in (Anders Szepessy et al. Comm. Pure Appl. Math. 54(10):1169– 1214, 2001). Our numerical results for a stopped diffusion problem, exhibit savings in the computational cost to achieve an accuracy of ϑ(TOL),from(TOL−3), from using a single level version of the adaptive algorithm to ϑ(((TOL−1)log(TOL))2).

  10. Evolution or adaptation? What do heritable adaptive changes imply?

    M. Kemal Irmak

    2014-02-01

    Full Text Available Interactions between environmental factors and epigenetic inheritance system produce a great deal of variation from one geographic region to another in human craniofacial morphology, skin color, hair form, stature and body proportions. In this system, while environmental factors produce modifications in the body, they simultaneously induce long-term epigenetic modifications in the germ cells that are inherited to offspring. This kind of heritable changes is called biological adaptation. It was previously reported that biological adaptation is limited to neural crest derivatives such as craniofacial tissues, melanocytes, and structures related to hair form, stature and body proportions. Thus, inheritance of adaptive changes is limited to a number of traits and species-to-species evolution seems unlikely. [J Exp Integr Med 2014; 4(1.000: 13-16

  11. On Adaptation of Loss Functions in Decentralized Adaptive Control

    Šmídl, Václav

    Villeneuve d'Ascq: IFAC, 2010, s. 1-6. [12th LSS symposium, Large Scale Systems: Theory and Applications. Villeneuve d'Ascq (FR), 12.07.2010-14.07.2010] R&D Projects: GA MŠk 1M0572; GA ČR GP102/08/P250 Institutional research plan: CEZ:AV0Z10750506 Keywords : decentralized control * LQG control * fully probabilistic design Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2010/AS/smidl-on adaptation of loss functions in decentralized adaptive control .pdf

  12. Molecular evolution and thermal adaptation

    Chen, Peiqiu

    2011-12-01

    In this thesis, we address problems in molecular evolution, thermal adaptation, and the kinetics of adaptation of bacteria and viruses to elevated environmental temperatures. We use a nearly neutral fitness model where the replication speed of an organism is proportional to the copy number of folded proteins. Our model reproduces the distribution of stabilities of natural proteins in excellent agreement with experiment. We find that species with high mutation rates tend to have less stable proteins compared to species with low mutation rate. We found that a broad distribution of protein stabilities observed in the model and in experiment is the key determinant of thermal response for viruses and bacteria. Our results explain most of the earlier experimental observations: striking asymmetry of thermal response curves, the absence of evolutionary trade-off which was expected but not found in experiments, correlation between denaturation temperature for several protein families and the Optimal Growth Temperature (OGT) of their carrier organisms, and proximity of bacterial or viral OGTs to their evolutionary temperatures. Our theory quantitatively and with high accuracy described thermal response curves for 35 bacterial species. The model also addresses the key to adaptation is in weak-link genes (WLG), which encode least thermodynamically stable essential proteins in the proteome. We observe, as in experiment, a two-stage adaptation process. The first stage is a Luria-Delbruck type of selection, whereby rare WLG alleles, whose proteins are more stable than WLG proteins of the majority of the population (either due to standing genetic variation or due to an early acquired mutation), rapidly rise to fixation. The second stage constitutes subsequent slow accumulation of mutations in an adapted population. As adaptation progresses, selection regime changes from positive to neutral: Selection coefficient of beneficial mutations scales as a negative power of number of

  13. Protein Adaptations in Archaeal Extremophiles

    Christopher J. Reed

    2013-01-01

    Full Text Available Extremophiles, especially those in Archaea, have a myriad of adaptations that keep their cellular proteins stable and active under the extreme conditions in which they live. Rather than having one basic set of adaptations that works for all environments, Archaea have evolved separate protein features that are customized for each environment. We categorized the Archaea into three general groups to describe what is known about their protein adaptations: thermophilic, psychrophilic, and halophilic. Thermophilic proteins tend to have a prominent hydrophobic core and increased electrostatic interactions to maintain activity at high temperatures. Psychrophilic proteins have a reduced hydrophobic core and a less charged protein surface to maintain flexibility and activity under cold temperatures. Halophilic proteins are characterized by increased negative surface charge due to increased acidic amino acid content and peptide insertions, which compensates for the extreme ionic conditions. While acidophiles, alkaliphiles, and piezophiles are their own class of Archaea, their protein adaptations toward pH and pressure are less discernible. By understanding the protein adaptations used by archaeal extremophiles, we hope to be able to engineer and utilize proteins for industrial, environmental, and biotechnological applications where function in extreme conditions is required for activity.

  14. Adaptive evolution in ecological communities.

    Martin M Turcotte

    Full Text Available Understanding how natural selection drives evolution is a key challenge in evolutionary biology. Most studies of adaptation focus on how a single environmental factor, such as increased temperature, affects evolution within a single species. The biological relevance of these experiments is limited because nature is infinitely more complex. Most species are embedded within communities containing many species that interact with one another and the physical environment. To understand the evolutionary significance of such ecological complexity, experiments must test the evolutionary impact of interactions among multiple species during adaptation. Here we highlight an experiment that manipulates species composition and tracks evolutionary responses within each species, while testing for the mechanisms by which species interact and adapt to their environment. We also discuss limitations of previous studies of adaptive evolution and emphasize how an experimental evolution approach can circumvent such shortcomings. Understanding how community composition acts as a selective force will improve our ability to predict how species adapt to natural and human-induced environmental change.

  15. Toward Adaptability: Where to from Here?

    Parsons, Seth A.; Vaughn, Margaret

    2016-01-01

    In this article, the collection of articles in this issue are synthesized to discuss conceptualizations of adaptive teaching as a means to foster spaces for adaptive teaching in today's complex educational system. Themes that exist across this collection of articles include adaptive teachers as constructivists, adaptive teachers as knowledgeable…

  16. Training Adaptive Decision-Making.

    Abbott, Robert G.; Forsythe, James C.

    2014-10-01

    Adaptive Thinking has been defined here as the capacity to recognize when a course of action that may have previously been effective is no longer effective and there is need to adjust strategy. Research was undertaken with human test subjects to identify the factors that contribute to adaptive thinking. It was discovered that those most effective in settings that call for adaptive thinking tend to possess a superior capacity to quickly and effectively generate possible courses of action, as measured using the Category Generation test. Software developed for this research has been applied to develop capabilities enabling analysts to identify crucial factors that are predictive of outcomes in fore-on-force simulation exercises.

  17. Adaptive sampling for noisy problems

    Cantu-Paz, E

    2004-03-26

    The usual approach to deal with noise present in many real-world optimization problems is to take an arbitrary number of samples of the objective function and use the sample average as an estimate of the true objective value. The number of samples is typically chosen arbitrarily and remains constant for the entire optimization process. This paper studies an adaptive sampling technique that varies the number of samples based on the uncertainty of deciding between two individuals. Experiments demonstrate the effect of adaptive sampling on the final solution quality reached by a genetic algorithm and the computational cost required to find the solution. The results suggest that the adaptive technique can effectively eliminate the need to set the sample size a priori, but in many cases it requires high computational costs.

  18. Adaptive Radiation for Lung Cancer

    Daniel R. Gomez

    2011-01-01

    need to spare surrounding critical structures. Evolving radiotherapy technologies, such as four-dimensional (4D image-based motion management, daily on-board imaging and adaptive radiotherapy based on volumetric images over the course of radiotherapy, have enabled us to deliver higher dose to target while minimizing normal tissue toxicities. The image-guided radiotherapy adapted to changes of motion and anatomy has made the radiotherapy more precise and allowed ablative dose delivered to the target using novel treatment approaches such as intensity-modulated radiation therapy, stereotactic body radiation therapy, and proton therapy in lung cancer, techniques used to be considered very sensitive to motion change. Future clinical trials using real time tracking and biological adaptive radiotherapy based on functional images are proposed.

  19. Adaptive dynamics of saturated polymorphisms.

    Kisdi, Éva; Geritz, Stefan A H

    2016-03-01

    We study the joint adaptive dynamics of n scalar-valued strategies in ecosystems where n is the maximum number of coexisting strategies permitted by the (generalized) competitive exclusion principle. The adaptive dynamics of such saturated systems exhibits special characteristics, which we first demonstrate in a simple example of a host-pathogen-predator model. The main part of the paper characterizes the adaptive dynamics of saturated polymorphisms in general. In order to investigate convergence stability, we give a new sufficient condition for absolute stability of an arbitrary (not necessarily saturated) polymorphic singularity and show that saturated evolutionarily stable polymorphisms satisfy it. For the case [Formula: see text], we also introduce a method to construct different pairwise invasibility plots of the monomorphic population without changing the selection gradients of the saturated dimorphism. PMID:26676357

  20. Adaptive Sampling in Hierarchical Simulation

    Knap, J; Barton, N R; Hornung, R D; Arsenlis, A; Becker, R; Jefferson, D R

    2007-07-09

    We propose an adaptive sampling methodology for hierarchical multi-scale simulation. The method utilizes a moving kriging interpolation to significantly reduce the number of evaluations of finer-scale response functions to provide essential constitutive information to a coarser-scale simulation model. The underlying interpolation scheme is unstructured and adaptive to handle the transient nature of a simulation. To handle the dynamic construction and searching of a potentially large set of finer-scale response data, we employ a dynamic metric tree database. We study the performance of our adaptive sampling methodology for a two-level multi-scale model involving a coarse-scale finite element simulation and a finer-scale crystal plasticity based constitutive law.

  1. Time-adaptive quantile regression

    Møller, Jan Kloppenborg; Nielsen, Henrik Aalborg; Madsen, Henrik

    2008-01-01

    An algorithm for time-adaptive quantile regression is presented. The algorithm is based on the simplex algorithm, and the linear optimization formulation of the quantile regression problem is given. The observations have been split to allow a direct use of the simplex algorithm. The simplex method...... and an updating procedure are combined into a new algorithm for time-adaptive quantile regression, which generates new solutions on the basis of the old solution, leading to savings in computation time. The suggested algorithm is tested against a static quantile regression model on a data set with...... wind power production, where the models combine splines and quantile regression. The comparison indicates superior performance for the time-adaptive quantile regression in all the performance parameters considered....

  2. Adaptive filters: stable but divergent

    Rupp, Markus

    2015-12-01

    The pros and cons of a quadratic error measure in the context of various applications have often been discussed. In this tutorial, we argue that it is not only a suboptimal but definitely the wrong choice when describing the stability behavior of adaptive filters. We take a walk through the past and recent history of adaptive filters and present 14 canonical forms of adaptive algorithms and even more variants thereof contrasting their mean-square with their l 2-stability conditions. In particular, in safety critical applications, the convergence in the mean-square sense turns out to provide wrong results, often not leading to stability at all. Only the robustness concept with its l 2-stability conditions ensures the absence of divergence.

  3. Adaptive Optics for Large Telescopes

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments

  4. Adaptive Optics for Large Telescopes

    Olivier, S

    2008-06-27

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  5. An Adaptive Memory Evolution Algorithm

    Caihong Wu

    2013-01-01

    Full Text Available Memory mechanism is applied to the optimization algorithm by more study. In order to improve the algorithm of adaptive ability, introducing memory ability in evolutionary algorithm framework, an Adaptive Memory Evolution Algorithm (AMEA is proposed. The algorithm set matrix to record the exploring experiences and exploring results of the individual parent. The algorithm uses these records to guide the generation of offspring. And thus AMEA can adaptively select the dimension to mutate and exploring radius. In addition, to improve the algorithm accuracy, the algorithm raises the best opportunities by using super-variation operator. In the simulation test, compared with similar algorithms, the results show that AMEA has fast convergence speed and optimum performance of global convergence.

  6. Model reference adaptive control and adaptive stability augmentation

    Henningsen, Arne; Ravn, Ole

    1993-01-01

    A comparison of the standard concepts in MRAC design suggests that a combination of the implicit and the explicit design techniques may lead to an improvement of the overall system performance in the presence of unmodelled dynamics. Using the ideas of adaptive stability augmentation a combined...

  7. Model reference adaptive control and adaptive stability augmentation

    Henningsen, Arne; Ravn, Ole

    A comparison of the standard concepts in MRAC design suggests that a combination of the implicit and the explicit design techniques may lead to an improvement of the overall system performance in the presence of unmodelled dynamics. Using the ideas of adaptive stability augmentation a combined...

  8. ADAPTER: Analysing & Developing Adaptability & Performance in Teams to Enhance Resilience

    Beek, F.A. van der; Schraagen, J.M.C.

    2015-01-01

    In the current study, the concept of team resilience was operationalized by developing a first version of a questionnaire (ADAPTER) driven by the four essential abilities of resilience (Hollnagel, 2011) and expanded with more relation-oriented abilities of leadership and cooperation. The development

  9. Adapting Books: Ready, Set, Read!: EAT: Equipment, Adaptations, and Technology

    Schoonover, Judith; Norton-Darr, Sally

    2016-01-01

    Developing multimodal materials to introduce or extend literacy experiences sets the stage for literacy success. Alternative ways to organize, display and arrange, interact and respond to information produces greater understanding of concepts. Adaptations include making books easier to use (turning pages or holding), and text easier to read…

  10. Application of ANFIS to Phase Estimation for Multiple Phase Shift Keying

    Drake, Jeffrey T.; Prasad, Nadipuram R.

    2000-01-01

    The paper discusses a novel use of Adaptive Neuro-Fuzzy Inference Systems (ANFIS) for estimating phase in Multiple Phase Shift Keying (M-PSK) modulation. A brief overview of communications phase estimation is provided. The modeling of both general open-loop, and closed-loop phase estimation schemes for M-PSK symbols with unknown structure are discussed. Preliminary performance results from simulation of the above schemes are presented.

  11. Adaptation and diversification on islands.

    Losos, Jonathan B; Ricklefs, Robert E

    2009-02-12

    Charles Darwin's travels on HMS Beagle taught him that islands are an important source of evidence for evolution. Because many islands are young and have relatively few species, evolutionary adaptation and species proliferation are obvious and easy to study. In addition, the geographical isolation of many islands has allowed evolution to take its own course, free of influence from other areas, resulting in unusual faunas and floras, often unlike those found anywhere else. For these reasons, island research provides valuable insights into speciation and adaptive radiation, and into the relative importance of contingency and determinism in evolutionary diversification. PMID:19212401

  12. Adapting agriculture with traditional knowledge

    Swiderska, Krystyna; Reid, Hannah [IIED, London (United Kingdom); Song, Yiching; Li, Jingsong [Centre for Chinese Agriculutral Policy (China); Mutta, Doris [Kenya Forestry Research Institute (Kenya)

    2011-10-15

    Over the coming decades, climate change is likely to pose a major challenge to agriculture; temperatures are rising, rainfall is becoming more variable and extreme weather is becoming a more common event. Researchers and policymakers agree that adapting agriculture to these impacts is a priority for ensuring future food security. Strategies to achieve that in practice tend to focus on modern science. But evidence, both old and new, suggests that the traditional knowledge and crop varieties of indigenous peoples and local communities could prove even more important in adapting agriculture to climate change.

  13. Practical Binary Adaptive Block Coder

    Reznik, Yuriy A

    2007-01-01

    This paper describes design of a low-complexity algorithm for adaptive encoding/ decoding of binary sequences produced by memoryless sources. The algorithm implements universal block codes constructed for a set of contexts identified by the numbers of non-zero bits in previous bits in a sequence. We derive a precise formula for asymptotic redundancy of such codes, which refines previous well-known estimate by Krichevsky and Trofimov, and provide experimental verification of this result. In our experimental study we also compare our implementation with existing binary adaptive encoders, such as JBIG's Q-coder, and MPEG AVC (ITU-T H.264)'s CABAC algorithms.

  14. Rapid Adaptation in Digital Transformation

    Hansen, Anne Mette; Kræmmergaard, Pernille; Mathiassen, Lars

    2011-01-01

    In today’s highly dynamic environments, organizational leaders need to quickly adapt existing approaches to digital transformation. However, without a shared mindset between IS and business leaders, it is difficult to adopt new approaches in response to changes in the competitive and technology...... the organization’s digitization approach. We demonstrate in detail how the leaders within these two organizations were engaged and offer recommendations for how other organizations can use the PPM to rapidly adapt their approaches to digital transformation through more effective IS leadership roles....

  15. Brucella evasion of adaptive immunity.

    Martirosyan, Anna; Gorvel, Jean-Pierre

    2013-02-01

    The complex immune system of mammals is the result of evolutionary forces that include battles against pathogens, as sensing and defeating intruders is a prerequisite to host survival. On the other hand, microorganisms have evolved multiple mechanisms to evade both arms of immunity: the innate and the adaptive immune systems. The successful pathogenic intracellular bacterium Brucella is not an exception to the rule: Brucella displays mechanisms that allow evasion of immune surveillance in order to establish persistent infections in mammals. In this review, we highlight some key mechanisms that pathogenic Brucella use to evade the adaptive immune system. PMID:23374122

  16. Micro Evolutionary Processes and Adaptation

    SHADMANOV R K; RUBAN I N; VOROPAEVA N L; SHADMANOVA A R

    2008-01-01

    @@ It would be well to note that in the absence of clear data about the formation of adaptation systems,or mechanisms of their occurrence,all that is recognized is the realization of the micro evolutionary processes.There is no well-defined connection between information exchange and formation of adaptation systems.Obviously,it occurs because mechanisms and systems reacting to any external actions are not considered from the point of view of "coexistence" of dynamic and static processes and structures.

  17. Adaptive critics for dynamic optimization.

    Kulkarni, Raghavendra V; Venayagamoorthy, Ganesh Kumar

    2010-06-01

    A novel action-dependent adaptive critic design (ACD) is developed for dynamic optimization. The proposed combination of a particle swarm optimization-based actor and a neural network critic is demonstrated through dynamic sleep scheduling of wireless sensor motes for wildlife monitoring. The objective of the sleep scheduler is to dynamically adapt the sleep duration to node's battery capacity and movement pattern of animals in its environment in order to obtain snapshots of the animal on its trajectory uniformly. Simulation results show that the sleep time of the node determined by the actor critic yields superior quality of sensory data acquisition and enhanced node longevity. PMID:20223635

  18. Changement climatique : impacts et adaptations

    Ardoin-Bardin, Sandra; Arnaud, N.; Boutin, S.; Chotte, Jean-Luc; Jarne, P.; Kosuth, P.; Lebaron, P.; Servat, Eric

    2015-01-01

    Ce dossier présente les acteurs de la recherche basés dans la région Languedoc-Roussillon, qui se mobilisent pour répondre aux enjeux liés à l'étude des impacts et des adaptations au changement climatique : 46 unités ; 2 "laboratoires d'excellence" et 1 institut ; 5 infrastructures de recherche, d'envergure nationale ou européenne ; 5 partenaires étrangers ou internationaux. L'étendue des travaux scientifiques menés par les acteurs régionaux sur l'impact ou l'adaptation au changement climatiq...

  19. Adaptive approaches to biosecurity governance.

    Cook, David C; Liu, Shuang; Murphy, Brendan; Lonsdale, W Mark

    2010-09-01

    This article discusses institutional changes that may facilitate an adaptive approach to biosecurity risk management where governance is viewed as a multidisciplinary, interactive experiment acknowledging uncertainty. Using the principles of adaptive governance, evolved from institutional theory, we explore how the concepts of lateral information flows, incentive alignment, and policy experimentation might shape Australia's invasive species defense mechanisms. We suggest design principles for biosecurity policies emphasizing overlapping complementary response capabilities and the sharing of invasive species risks via a polycentric system of governance. PMID:20561262

  20. Error signals driving locomotor adaptation

    Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo; Bouyer, Laurent J

    2016-01-01

    perturbations. Forces were applied to the ankle joint during the early swing phase using an electrohydraulic ankle-foot orthosis. Repetitive 80 Hz electrical stimulation was applied to disrupt cutaneous feedback from the superficial peroneal nerve (foot dorsum) and medial plantar nerve (foot sole) during...... anaesthesia (n = 5) instead of repetitive nerve stimulation. Foot anaesthesia reduced ankle adaptation to external force perturbations during walking. Our results suggest that cutaneous input plays a role in force perception, and may contribute to the 'error' signal involved in driving walking adaptation when...

  1. Sleep facilitates long-term face adaptation

    Ditye, T.; A.H Javadi; Carbon, C.C.; Walsh, V

    2013-01-01

    Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted imag...

  2. Rapid, generalized adaptation to asynchronous audiovisual speech

    Van der Burg, Erik; Goodbourn, Patrick T.

    2015-01-01

    The brain is adaptive. The speed of propagation through air, and of low-level sensory processing, differs markedly between auditory and visual stimuli; yet the brain can adapt to compensate for the resulting cross-modal delays. Studies investigating temporal recalibration to audiovisual speech have used prolonged adaptation procedures, suggesting that adaptation is sluggish. Here, we show that adaptation to asynchronous audiovisual speech occurs rapidly. Participants viewed a brief clip of an...

  3. Comparison of Adaptive Information Security Approaches

    Antti Evesti; Eila Ovaska

    2013-01-01

    Dynamically changing environments and threat landscapes require adaptive information security. Adaptive information security makes it possible to change and modify security mechanisms at runtime. Hence, all security decisions are not enforced at design-time. This paper builds a framework to compare security adaptation approaches. The framework contains three viewpoints, that is, adaptation, security, and lifecycle. Furthermore, the paper describes five security adaptation approaches and compa...

  4. Prototyping Adaptive Online Learning Courses

    Geleverya, Tim; Malinovskaya, Olga; Gavrilova, Tatiana; Golenkov, Vladimir

    2007-01-01

    This article describes the process of prototyping adaptive online learning using the authoring tool for developers, which is based on ontologies. The article also gives a brief overview of contemporary situation and describes modern trends of evolution e-learning courses and present standards in this area. It also describes architecture of system VITA II.

  5. Micro Evolutionary Processes and Adaptation

    SHADMANOV; R; K; RUBAN; I; N; VOROPAEVA; N; L; SHADMANOVA; A; R

    2008-01-01

    It would be well to note that in the absence of clear data about the formation of adaptation systems,or mechanisms of their occurrence,all that is recognized is the realization of the micro evolutionary processes.There is no well-defined connection between information exchange and formation of

  6. Reward Modulates Adaptations to Conflict

    Braem, Senne; Verguts, Tom; Roggeman, Chantal; Notebaert, Wim

    2012-01-01

    Both cognitive conflict (e.g. Verguts & Notebaert, 2009) and reward signals (e.g. Waszak & Pholulamdeth, 2009) have been proposed to enhance task-relevant associations. Bringing these two notions together, we predicted that reward modulates conflict-based sequential adaptations in cognitive control. This was tested combining either a single…

  7. Generalized Adaptive Artificial Neural Networks

    Tawel, Raoul

    1993-01-01

    Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

  8. Adaptive Clustering of Hypermedia Documents.

    Johnson, Andrew; Fotouhi, Farshad

    1996-01-01

    Discussion of hypermedia systems focuses on a comparison of two types of adaptive algorithm (genetic algorithm and neural network) in clustering hypermedia documents. These clusters allow the user to index into the nodes to find needed information more quickly, since clustering is "personalized" based on the user's paths rather than representing…

  9. Inducible competitors and adaptive diversification

    Beren W. ROBINSON, David W. PFENNIG

    2013-08-01

    Full Text Available Identifying the causes of diversification is central to evolutionary biology. The ecological theory of adaptive diversification holds that the evolution of phenotypic differences between populations and species––and the formation of new species––stems from divergent natural selection, often arising from competitive interactions. Although increasing evidence suggests that phenotypic plasticity can facilitate this process, it is not generally appreciated that competitively mediated selection often also provides ideal conditions for phenotypic plasticity to evolve in the first place. Here, we discuss how competition plays at least two key roles in adaptive diversification depending on its pattern. First, heterogenous competition initially generates heterogeneity in resource use that favors adaptive plasticity in the form of “inducible competitors”. Second, once such competitively induced plasticity evolves, its capacity to rapidly generate phenotypic variation and expose phenotypes to alternate selective regimes allows populations to respond readily to selection favoring diversification, as may occur when competition generates steady diversifying selection that permanently drives the evolutionary divergence of populations that use different resources. Thus, competition plays two important roles in adaptive diversification––one well-known and the other only now emerging––mediated through its effect on the evolution of phenotypic plasticity [Current Zoology 59 (4: 537–552, 2013].

  10. Adaptive protection algorithm and system

    Hedrick, Paul [Pittsburgh, PA; Toms, Helen L [Irwin, PA; Miller, Roger M [Mars, PA

    2009-04-28

    An adaptive protection algorithm and system for protecting electrical distribution systems traces the flow of power through a distribution system, assigns a value (or rank) to each circuit breaker in the system and then determines the appropriate trip set points based on the assigned rank.

  11. Physiological adaptation in desert birds

    Williams, JB; Tieleman, BI; Williams, Joseph B.

    2005-01-01

    We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement

  12. Livelihood Resilience and Adaptive Capacity

    Thulstrup, Andreas Waaben

    2015-01-01

    This article analyses the implementation and outcomes of national development programs in a mountainous commune in Vietnam. The article traces the history of State intervention and the capacity of households and the community to adapt to change. The assessment reveals unintended consequences of t...

  13. School Adaptation of Roma Children

    Gerganov, Encho; Varbanova, Silvia; Kyuchukov, Hristo

    2005-01-01

    This paper examines the degree of school adaptation among Roma children who were included in a program for the desegregation of Roma schools in Bulgaria. More specifically, the program requires Roma children to attend mixed classes with Bulgarian students and Roma teacher assistants to work with them. The Bulgarian version of the Questionnaire on…

  14. Human whole body cold adaptation.

    Daanen, Hein A M; Van Marken Lichtenbelt, Wouter D

    2016-01-01

    Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold. PMID:27227100

  15. Adaptive Multilinear Tensor Product Wavelets.

    Weiss, Kenneth; Lindstrom, Peter

    2016-01-01

    Many foundational visualization techniques including isosurfacing, direct volume rendering and texture mapping rely on piecewise multilinear interpolation over the cells of a mesh. However, there has not been much focus within the visualization community on techniques that efficiently generate and encode globally continuous functions defined by the union of multilinear cells. Wavelets provide a rich context for analyzing and processing complicated datasets. In this paper, we exploit adaptive regular refinement as a means of representing and evaluating functions described by a subset of their nonzero wavelet coefficients. We analyze the dependencies involved in the wavelet transform and describe how to generate and represent the coarsest adaptive mesh with nodal function values such that the inverse wavelet transform is exactly reproduced via simple interpolation (subdivision) over the mesh elements. This allows for an adaptive, sparse representation of the function with on-demand evaluation at any point in the domain. We focus on the popular wavelets formed by tensor products of linear B-splines, resulting in an adaptive, nonconforming but crack-free quadtree (2D) or octree (3D) mesh that allows reproducing globally continuous functions via multilinear interpolation over its cells. PMID:26529742

  16. Continuous-time adaptive critics.

    Hanselmann, Thomas; Noakes, Lyle; Zaknich, Anthony

    2007-05-01

    A continuous-time formulation of an adaptive critic design (ACD) is investigated. Connections to the discrete case are made, where backpropagation through time (BPTT) and real-time recurrent learning (RTRL) are prevalent. Practical benefits are that this framework fits in well with plant descriptions given by differential equations and that any standard integration routine with adaptive step-size does an adaptive sampling for free. A second-order actor adaptation using Newton's method is established for fast actor convergence for a general plant and critic. Also, a fast critic update for concurrent actor-critic training is introduced to immediately apply necessary adjustments of critic parameters induced by actor updates to keep the Bellman optimality correct to first-order approximation after actor changes. Thus, critic and actor updates may be performed at the same time until some substantial error build up in the Bellman optimality or temporal difference equation, when a traditional critic training needs to be performed and then another interval of concurrent actor-critic training may resume. PMID:17526332

  17. Adaptive optics projects at ESO

    Hubin, Norbert N.; Arsenault, Robin; Bonnet, Henri; Conan, Rodolphe; Delabre, Bernard; Donaldson, Robert; Dupuy, Christophe; Fedrigo, Enrico; Ivanescu, L.; Kasper, Markus E.; Kissler-Patig, Markus; Lizon, Jean-Luis; Le Louarn, Miska; Marchetti, Enrico; Paufique, J.; Stroebele, Stefan; Tordo, Sebastien

    2003-02-01

    Over the past two years ESO has reinforced its efforts in the field of Adaptive Optics. The AO team has currently the challenging objectives to provide 8 Adaptive Optics systems for the VLT in the coming years and has now a world-leading role in that field. This paper will review all AO projects and plans. We will present an overview of the Nasmyth Adaptive Optics System (NAOS) with its infrared imager CONICA installed successfully at the VLT last year. Sodium Laser Guide Star plans will be introduced. The status of the 4 curvature AO systems (MACAO) developed for the VLT interferometer will be discussed. The status of the SINFONI AO module developed to feed the infrared integral field spectrograph (SPIFFI) will be presented. A short description of the Multi-conjugate Adaptive optics Demonstrator MAD and its instrumentation will be introduced. Finally, we will present the plans for the VLT second-generation AO systems and the researches performed in the frame of OWL.

  18. Adaptive controlling of power boiler

    Wojcik, W.; Kalita, M; Smolarz, A.

    2004-01-01

    This paper presents research on adaptive control (AC) of combastion process in in¬dustry. Results were obtained from research conducted in laboratory combustion chamber with usage of Fiber Optical Measurement System (FOMS) with electronic block. Simulation proved that implementing AC and FOMS to burning process improves flue gasses parameters -direct measure of power boiler ecologic and economical quality of work.

  19. The Adaptation of Migrant Children

    Portes, Alejandro; Rivas, Alejandro

    2011-01-01

    Alejandro Portes and Alejandro Rivas examine how young immigrants are adapting to life in the United States. They begin by noting the existence of two distinct pan-ethnic populations: Asian Americans, who tend to be the offspring of high-human-capital migrants, and Hispanics, many of whose parents are manual workers. Vast differences in each, both…

  20. Conceptual Model of User Adaptive Enterprise Application

    Inese Šūpulniece

    2015-07-01

    Full Text Available The user adaptive enterprise application is a software system, which adapts its behavior to an individual user on the basis of nontrivial inferences from information about the user. The objective of this paper is to elaborate a conceptual model of the user adaptive enterprise applications. In order to conceptualize the user adaptive enterprise applications, their main characteristics are analyzed, the meta-model defining the key concepts relevant to these applications is developed, and the user adaptive enterprise application and its components are defined in terms of the meta-model. Modeling of the user adaptive enterprise application incorporates aspects of enterprise modeling, application modeling, and design of adaptive characteristics of the application. The end-user and her expectations are identified as two concepts of major importance not sufficiently explored in the existing research. Understanding these roles improves the adaptation result in the user adaptive applications.

  1. Economics of adaptation to climate change

    This report proposes a general economic framework for the issue of adaptation to climate change in order to help public and private actors to build up efficient adaptation strategies. It proposes a general definition of adaptation, identifies the major stakes for these strategies, and discusses the assessment of global costs of adaptation to climate change. It discusses the role and modalities of public action and gives some examples of possible adaptation measures in some important sectors (building and town planning, energy and transport infrastructures, water and agriculture, ecosystems, insurance). It examines the regional and national dimensions of adaptation and their relationship, and defines steps for implementing an adaptation strategy. It describes and discusses the use of economic tools in the elaboration of an adaptation strategy, i.e. how to take uncertainties into account, which scenarios to choose, how to use economic calculations to assess adaptation policies

  2. Adaptive Controller Effects on Pilot Behavior

    Trujillo, Anna C.; Gregory, Irene M.; Hempley, Lucas E.

    2014-01-01

    Adaptive control provides robustness and resilience for highly uncertain, and potentially unpredictable, flight dynamics characteristic. Some of the recent flight experiences of pilot-in-the-loop with an adaptive controller have exhibited unpredicted interactions. In retrospect, this is not surprising once it is realized that there are now two adaptive controllers interacting, the software adaptive control system and the pilot. An experiment was conducted to categorize these interactions on the pilot with an adaptive controller during control surface failures. One of the objectives of this experiment was to determine how the adaptation time of the controller affects pilots. The pitch and roll errors, and stick input increased for increasing adaptation time and during the segment when the adaptive controller was adapting. Not surprisingly, altitude, cross track and angle deviations, and vertical velocity also increase during the failure and then slowly return to pre-failure levels. Subjects may change their behavior even as an adaptive controller is adapting with additional stick inputs. Therefore, the adaptive controller should adapt as fast as possible to minimize flight track errors. This will minimize undesirable interactions between the pilot and the adaptive controller and maintain maneuvering precision.

  3. Climate change adaptation planning in agriculture: processes, experiences and lessons learned from early adapters

    Bizikova, L.; Crawford, E.; Nijnik, M.; Swart, R.J.

    2014-01-01

    This paper explores the lessons learned by leaders in agricultural adaptation planning in order to assist other jurisdictions to develop adaptation strategies. It seeks to identify effective institutional, participatory and collaborative processes involved in designing agricultural adaptation strate

  4. Kinetics of the early adaptive response and adaptation threshold dose

    The expression kinetics of the adaptive response (RA) in mouse leukocytes in vivo and the minimum dose of gamma radiation that induces it was determined. The mice were exposed 0.005 or 0.02 Gy of 137 Cs like adaptation and 1h later to the challenge dose (1.0 Gy), another group was only exposed at 1.0 Gy and the damage is evaluated in the DNA with the rehearsal it makes. The treatment with 0. 005 Gy didn't induce RA and 0. 02 Gy causes a similar effect to the one obtained with 0.01 Gy. The RA was show from an interval of 0.5 h being obtained the maximum expression with 5.0 h. The threshold dose to induce the RA is 0.01 Gy and in 5.0 h the biggest quantity in molecules is presented presumably that are related with the protection of the DNA. (Author)

  5. Evolution or adaptation? What do heritable adaptive changes imply?

    M. Kemal Irmak

    2014-01-01

    Interactions between environmental factors and epigenetic inheritance system produce a great deal of variation from one geographic region to another in human craniofacial morphology, skin color, hair form, stature and body proportions. In this system, while environmental factors produce modifications in the body, they simultaneously induce long-term epigenetic modifications in the germ cells that are inherited to offspring. This kind of heritable changes is called biological adaptation. It wa...

  6. Adaptive security systems -- Combining expert systems with adaptive technologies

    The Adaptive Multisensor Integrated Security System (AMISS) uses a variety of computational intelligence techniques to reason from raw sensor data through an array of processing layers to arrive at an assessment for alarm/alert conditions based on human behavior within a secure facility. In this paper, the authors give an overview of the system and briefly describe some of the major components of the system. This system is currently under development and testing in a realistic facility setting

  7. Brand Identity, Adaptation, and Media Franchise Culture

    Marazi Katerina

    2014-12-01

    Full Text Available In spite of the noticeable practices within the field of Adaptation, Adaptation theory seems to be lagging behind whilst perpetuating various fallacies. Geoffrey Wagner’s types of Adaptation and Kamilla Elliott’s proposed concepts for examining adaptations have proved useful but due to their general applicability they seem to perpetuate the fallacies existing within the field of Adaptation. This article will propose a context-specific concept pertaining to Media Franchise Culture for the purpose of examining Adaptations and re-assessing long-held debates concerning the Original, the Content/Form debate and Fidelity issues that cater to the twelve fallacies discussed by Thomas Leitch.

  8. The adaptation challenge in the Arctic

    Ford, James D.; McDowell, Graham; Pearce, Tristan

    2015-12-01

    It is commonly asserted that human communities in the Arctic are highly vulnerable to climate change, with the magnitude of projected impacts limiting their ability to adapt. At the same time, an increasing number of field studies demonstrate significant adaptive capacity. Given this paradox, we review climate change adaptation, resilience and vulnerability research to identify and characterize the nature and magnitude of the adaptation challenge facing the Arctic. We find that the challenge of adaptation in the Arctic is formidable, but suggest that drivers of vulnerability and barriers to adaptation can be overcome, avoided or reduced by individual and collective efforts across scales for many, if not all, climate change risks.

  9. Integrating adaptive governance and participatory multicriteria methods: a framework for climate adaptation governance

    Stefania Munaretto; Giuseppina Siciliano; Margherita E. Turvani

    2014-01-01

    Climate adaptation is a dynamic social and institutional process where the governance dimension is receiving growing attention. Adaptive governance is an approach that promises to reduce uncertainty by improving the knowledge base for decision making. As uncertainty is an inherent feature of climate adaptation, adaptive governance seems to be a promising approach for improving climate adaptation governance. However, the adaptive governance literature has so far paid little attention to decisi...

  10. Adaptive Parameter Selection for Strategy Adaptation in Differential Evolution for Continuous Optimization

    Wenyin Gong; Zhihua Cai

    2012-01-01

    In order to automatically select the most suitable strategy for a specific problem without any prior knowledge, in this paper, we present an adaptive parameter selection technique for strategy adaptation in differential evolution (DE). First, a simple strategy adaptation mechanism is employed to implement the adaptive strategy selection in DE. Then, the probability- matching-based adaptive parameter selection method is proposed to select the best parameter of the strategy adaptation mechanism...

  11. A simple angular transmit diversity scheme using a single RF frontend for PSK modulation schemes

    Alrabadi, Osama Nafeth Saleem; Papadias, Constantinos B.; Kalis, Antonis

    A Simple angular transmit diversity scheme based on switching between a pair of weakly-correlated beam patterns at one end of the wireless link (the wireless handheld terminal) in an outdoor macro-cellular radio channel is proposed. The diversity scheme is employed using a simple switched parasitic...... array (SPA) with a single transceiver, and an array area of 0.0625 square wavelengths. The scheme which requires no channel state information (CSI) at the transmitter, provides mainly a diversity gain to combat against multipath fading. The performance/capacity of the proposed diversity scheme is...

  12. Transmission of Waveforms Determined by 7 Eigenvalues with PSK-Modulated Spectral Amplitudes

    Buelow, Henning; Idler, Wilfried

    2016-01-01

    2-ns waveforms with 7 eigenvalues and their QPSK-modulated spectral amplitudes were optimized by taking constraints of link, transmitter, and receiver into account. In experiment these signals were transmitted with a BER of 3.2E-3 over 1440-km of NZ-DSF fiber spans.

  13. Four-dimensionally coded PSK systems for combatting effects of severe ISI and CCI

    Fang, R.; Lee, W.

    A combined forward error correction (FEC) coding and modulation technique is proposed for transmissions over four-dimensional (4-D) channels that are interference and noise limited. Improved error performance is achieved by 4-D channel coding, with the expanded signal set in a manner similar to Ungerboeck's set-partitioning method, which maximizes the free Euclidean distance. Lower bounds on free Euclidean distance at the output of the 4-D modulator are derived for evaluating the asymptotic performance. As an example, a rate 2/3 convolutional encoder combined with a 4-D coded QPSK signal could yield an Eb/No gain of about 3 to 4 dB over an uncoded two-dimensional (2-D) BPSK system. Performance over a linear channel in the presence of thermal noise, intersymbol interference (ISI), and co-channel interference (CCI) is also evaluated.

  14. Convolutional FEC design considerations for data transmission over PSK satellite channels

    Garrison, G. J.; Wong, V. C.

    Simulation results are provided for rate R = 1/2 convolutional error correcting codes suited to data transmission over BPSK, gray coded QPSK, and OQPSK channels. The burst generation mechanism resulting from differential encoding/decoding is analyzed in terms of the impairment to code performance and offsetting internal/external interleaving techniques are described.

  15. A universal encoding scheme for MIMO transmission using a single active element for PSK modulation schemes

    Alrabadi, Osama; Papadias, C.B.; Kalis, A.;

    2009-01-01

    A universal scheme for encoding multiple symbol streams using a single driven element (and consequently a single radio frequency (RF) frontend) surrounded by parasitic elements (PE) loaded with variable reactive loads, is proposed in this paper. The proposed scheme is based on creating a MIMO...

  16. INDIRECT ACCELERATED ADAPTIVE FUZZY CONTROLLER

    ZHU Liye; FANG Yuan; ZHANG Weidong

    2008-01-01

    According to a type of normal nonlinear system, an indirect adaptive fuzzy (IAF) controller has been applied to those systems where no accurate mathematical models of the systems under control are available. To satisfy with system performance, an indirect accelerated adaptive fuzzy (IAAF) controller is proposed, and its general form is presented. The general form IAAF controller ensures necessary control criteria and system's global stability using Lyapunov Theorem. It has been proved that the close-loop system error converges to a small neighborhood of equilibrium point. The optimal IAAF controller is derived to guarantee the process's shortest settling time. Simulation results indicate the IAAF controller make the system more stable, accurate, and fast.

  17. On the Adaptiveness of Quicksort

    Brodal, Gerth Stølting; Fagerberg, Rolf; Moruz, Gabriel

    Quicksort was first introduced in 1961 by Hoare. Many variants have been developed, the best of which are among the fastest generic sorting algorithms available, as testified by the choice of Quicksort as the default sorting algorithm in most programming libraries. Some sorting algorithms are...... new insights on the behavior of the Quicksort algorithm. We also give some empirical results on the adaptive behavior of Heapsort and Mergesort....... adaptive, i.e. they have a complexity analysis which is better for inputs which are nearly sorted, according to some specified measure of presortedness. Quicksort is not among these, as it uses Omega(n log n) comparisons even when the input is already sorted. However, in this paper we demonstrate...

  18. ADAPTABLE DESIGN IN PRODUCT DEVELOPMENT

    WU Qingming; MEI Huafeng

    2006-01-01

    A newly emerging design pattern, named as adaptable design (AD), which aims at developing products that are adaptable from design to post-life cycle, is discussed. AD consists of four main phases: product modeling, design platform, specific design and product redesign. A new process-based design data model (PDDM) is presented which is organized according to the principles of conveniem knowledge extraction, data representation, layout, sharing and reuse. Based on the PDDM, a universal design platform for product family development is established, which has characters of modularity, parameter-driven, variant design, etc. The framework of the platform is also proposed as a conceptual structure and overall logical organization for generating a family of products. AD methodology is successfully applied to develop a family of tunnel boring machine (TBM) for different engineering projects, with the efficiency of our developing team being greatly increased.

  19. Flexible Adaptation in Cognitive Radios

    Li, Shujun

    2013-01-01

    This book provides an introduction to software-defined radio and cognitive radio, along with methodologies for applying knowledge representation, semantic web, logic reasoning and artificial intelligence to cognitive radio, enabling autonomous adaptation and flexible signaling. Readers from the wireless communications and software-defined radio communities will use this book as a reference to extend software-defined radio to cognitive radio, using the semantic technology described. Readers with a background in semantic web and artificial intelligence will find in this book the application of semantic web and artificial intelligence technologies to wireless communications. For readers in networks and network management, this book presents a new approach to enable interoperability, collaborative optimization and flexible adaptation of network components. Provides a comprehensive ontology covering the core concepts of wireless communications using a formal language; Presents the technical realization of using a ...

  20. Plant adaptation to drought stress

    Basu, Supratim; Ramegowda, Venkategowda; Kumar, Anuj; Pereira, Andy

    2016-01-01

    Plants in their natural habitats adapt to drought stress in the environment through a variety of mechanisms, ranging from transient responses to low soil moisture to major survival mechanisms of escape by early flowering in absence of seasonal rainfall. However, crop plants selected by humans to yield products such as grain, vegetable, or fruit in favorable environments with high inputs of water and fertilizer are expected to yield an economic product in response to inputs. Crop plants selected for their economic yield need to survive drought stress through mechanisms that maintain crop yield. Studies on model plants for their survival under stress do not, therefore, always translate to yield of crop plants under stress, and different aspects of drought stress response need to be emphasized. The crop plant model rice ( Oryza sativa) is used here as an example to highlight mechanisms and genes for adaptation of crop plants to drought stress. PMID:27441087

  1. Cardiovascular adaptations to exercise training

    Hellsten, Ylva; Nyberg, Michael

    2016-01-01

    Aerobic exercise training leads to cardiovascular changes that markedly increase aerobic power and lead to improved endurance performance. The functionally most important adaptation is the improvement in maximal cardiac output which is the result of an enlargement in cardiac dimension, improved...... arteries is reduced, a factor contributing to increased arterial compliance. Endurance training may also induce alterations in the vasodilator capacity, although such adaptations are more pronounced in individuals with reduced vascular function. The microvascular net increases in size within the muscle...... allowing for an improved capacity for oxygen extraction by the muscle through a greater area for diffusion, a shorter diffusion distance, and a longer mean transit time for the erythrocyte to pass through the smallest blood vessels. The present article addresses the effect of endurance training on systemic...

  2. Adaptive Behavior for Mobile Robots

    Huntsberger, Terrance

    2009-01-01

    The term "System for Mobility and Access to Rough Terrain" (SMART) denotes a theoretical framework, a control architecture, and an algorithm that implements the framework and architecture, for enabling a land-mobile robot to adapt to changing conditions. SMART is intended to enable the robot to recognize adverse terrain conditions beyond its optimal operational envelope, and, in response, to intelligently reconfigure itself (e.g., adjust suspension heights or baseline distances between suspension points) or adapt its driving techniques (e.g., engage in a crabbing motion as a switchback technique for ascending steep terrain). Conceived for original application aboard Mars rovers and similar autonomous or semi-autonomous mobile robots used in exploration of remote planets, SMART could also be applied to autonomous terrestrial vehicles to be used for search, rescue, and/or exploration on rough terrain.

  3. A simplified adaptive optics system

    Ivanescu, Liviu; Racine, René; Nadeau, Daniel

    2003-02-01

    Affordable adaptive optics on small telescopes allow to introduce the technology to a large community and provide opportunities to train new specialists in the field. We have developed a low order, low cost adaptive optics system for the 1.6m telescope of the Mont Megantic Observatory. The system corrects tip-tilt, focus, astigmatisms and one trefoil term. It explores a number of new approaches. The sensor receives a single out-of-focus image of the reference star. The central obstruction of the telescope can free the focus detection from the effect of seeing and allows a very small defocus. The deformable mirror is profiled so as to preserve a parabolic shape under pressure from actuators located at its edge. A separate piezoelectric platform drives the tilt mirror.

  4. Evolutionary advantages of adaptive rewarding

    Szolnoki, Attila

    2012-01-01

    Our wellbeing depends as much on our personal success, as it does on the success of our society. The realization of this fact makes cooperation a very much needed trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remain elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly reach social dynamics that explains why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding that is due to over-aggression, which in turn hinders optimal utiliz...

  5. Clinical significance of adaptive thermogenesis.

    Major, G C; Doucet, E; Trayhurn, P; Astrup, A; Tremblay, A

    2007-02-01

    The epidemic of obesity is developing faster than the scientific understanding of an efficient way to overcome it, as reflected by the low success rate of short- and long-term weight loss interventions. From a clinical standpoint, this suggests that the body tends to defend a set point of possible genetic origin in the context of a weight-reducing program. As described in this paper, this limited therapeutic success may depend on adaptive thermogenesis, which represents in this case the decrease in energy expenditure (EE) beyond what could be predicted from the changes in fat mass or fat-free mass under conditions of standardized physical activity in response to a decrease in energy intake. This issue has been documented in recent studies that have shown in obese individuals adhering to a weight reduction program a greater than predicted decrease in EE, which in some cases was quantitatively sufficient to overcome the prescribed energy restriction, suggesting a role for adaptive thermogenesis in unsuccessful weight loss interventions and reduced body weight maintenance. As also discussed in this paper, this 'adaptive thermogenesis' can be influenced by environmental factors, which have not been frequently considered up to now. This is potentially the case for plasma organochlorine concentration and oxygen desaturation in obstructive sleep apnea syndrome. It is concluded that health professionals should be aware that in some vulnerable individuals, adaptive thermogenesis can be multi-causal, and has the capacity to compensate, at least partly, for the prescribed energy deficit, possibly going beyond any good compliance of some patients. PMID:17260010

  6. Three sided complex adaptative systems

    D'Hulst, R

    1999-01-01

    We introduce two three sided adaptative systems as toy models to mimic the exchange of commodities between buyers and sellers. These models are simple extensions of the minority game, exhibiting similar behaviour as well as some new features. The main difference between our two models is that in the first the three sides are equivalent while in the second, one choice appears as a compromise between the two other sides. Both models are investigated numerically and compared with the original minority game.

  7. Adaptive Management of Renewable Resources

    Walters, C. J.

    1986-01-01

    The author challenges the traditional approach to dealing with uncertainty in the management of such renewable resources as fish and wildlife. He argues that scientific understanding will come from the experience of management as an ongoing, adaptive, and experimental process, rather than through basic research or the development of ecological theory. The opening chapters review approaches to formulating management objectives as well as models for understanding how policy choices affect ...

  8. Adaptive Bases for Reinforcement Learning

    Di Castro, Dotan

    2010-01-01

    We consider the problem of reinforcement learning using function approximation, where the approximating basis can change dynamically while interacting with the environment. A motivation for such an approach is maximizing the value function fitness to the problem faced. Three errors are considered: approximation square error, Bellman residual, and projected Bellman residual. Algorithms under the actor-critic framework are presented, and shown to converge. The advantage of such an adaptive basis is demonstrated in simulations.

  9. SENSATION SEEKING SCALE: INDIAN ADAPTATION

    Basu, Debasish; Verma, Vijoy K.; Malhotra, Savita; Malhotra, Anil

    1993-01-01

    SUMMARY Sensation seeking refers to a biologically based personality dimension defined as the need for varied, novel and complex sensations and experiences, and the willingness to take physical and social risks for the sake of such experiences. Although researched worldwide for nearly three decades now, there is to date no published Indian study utilizing the concept of sensation seeking. This paper describes adaptation of the Sensation Seeking Scale for the Indian population. After due modif...

  10. Adapting to changing user expectations

    Poland, Jean

    2004-01-01

    Results of user surveys indicate that science and technology library user needs differ from those of humanists and social scientists and are changing rapidly. Science and technology libraries are taking the lead in adapting the public services model accordingly. Science and technology library users are most interested in easy-to-use access tools and library Web sites that enable them to find information on their own as well as easy access to materials from home and office. Their expectations ...

  11. Neural Adaptive Sequential Monte Carlo

    Gu, Shixiang; Ghahramani, Zoubin; Turner, Richard E

    2015-01-01

    Sequential Monte Carlo (SMC), or particle filtering, is a popular class of methods for sampling from an intractable target distribution using a sequence of simpler intermediate distributions. Like other importance sampling-based methods, performance is critically dependent on the proposal distribution: a bad proposal can lead to arbitrarily inaccurate estimates of the target distribution. This paper presents a new method for automatically adapting the proposal using an approximation of the Ku...

  12. Mutualism, Parasitism, and Evolutionary Adaptation

    Watson, Richard A.; Reil, Torsten; Pollack, Jordan B.

    2000-01-01

    Our investigations concern the role of symbiosis as an enabling mechanism in evolutionary adaptation. Previous work has illustrated how the formation of mutualist groups can guide genetic variation so as to enable the evolution of ultimately independent organisms that would otherwise be unobtainable. The new experiments reported here show that this effect applies not just in genetically related organisms but may also occur from symbiosis between distinct species. In addition, a new detail is ...

  13. Parallel adaptive finite state automata

    Rocha, Ricardo L.; Garanhani, César E.C.

    2006-01-01

    The interest on parallelism has grown in many areas of technology. Hardware development has evolved greatly in the last years, leaving to software developers the goal of building better tools and compilers for parallel computation. Also, symbolic computation must take advantage of parallel computation. The proposal contained in this paper is to use functional languages as a tool to implement adaptive automata using the concepts of symbolic computation

  14. Adaptive Missile Guidance Using GPS

    Pallavi Sharad Rupnar; Prof. A. B. Diggikar

    2013-01-01

    The name adaptive means we can guide any missile using GPS in any critical conditions. GPS guided missiles, using the exceptional navigational and surveying abilities of GPS, after being launched, could deliver a warhead to any part of the globe via the interface of the onboard computer in the missile with the GPS satellite system.GPS allows accurate targeting of various military weapons including ICBMs, cruise missiles and precision-guided munitions. Artillery projectiles with embedded GPS r...

  15. Alternative adaptive immunity in invertebrates

    Kurtz, Joachim; Armitage, Sophie Alice Octavia

    2006-01-01

    Vertebrate adaptive immunity is characterized by challenge-specific long-term protection. This specific memory is achieved through the vast diversity of somatically rearranged immunological receptors such as antibodies. Whether or not invertebrates are capable of a comparable phenotypic plasticit...... and memory has long been a matter of debate. A recent study on Anopheles gambiae mosquitoes now establishes Down syndrome cell adhesion molecule (Dscam) as a key immune surveillance factor with characteristics analogous to antibodies....

  16. Adaptive Control of Parabolic PDEs

    Smyshlyaev, Andrey

    2010-01-01

    This book introduces a comprehensive methodology for adaptive control design of parabolic partial differential equations with unknown functional parameters, including reaction-convection-diffusion systems ubiquitous in chemical, thermal, biomedical, aerospace, and energy systems. Andrey Smyshlyaev and Miroslav Krstic develop explicit feedback laws that do not require real-time solution of Riccati or other algebraic operator-valued equations. The book emphasizes stabilization by boundary control and using boundary sensing for unstable PDE systems with an infinite relative degree. The book also

  17. Bayesian Optimization for Adaptive MCMC

    Mahendran, Nimalan; Wang, Ziyu; Hamze, Firas; De Freitas, Nando

    2011-01-01

    This paper proposes a new randomized strategy for adaptive MCMC using Bayesian optimization. This approach applies to non-differentiable objective functions and trades off exploration and exploitation to reduce the number of potentially costly objective function evaluations. We demonstrate the strategy in the complex setting of sampling from constrained, discrete and densely connected probabilistic graphical models where, for each variation of the problem, one needs to adjust the parameters o...

  18. PKM Mechatronic Clamping Adaptive Device

    Alberto Borboni; Francesco Aggogeri; Angelo Merlo; Nicola Pellegrini; Cinzia Amici

    2015-01-01

    This study proposes a novel adaptive fixturing device based on active clamping systems for smart micropositioning of thin-walled precision parts. The modular architecture and the structure flexibility make the system suitable for various industrial applications. The proposed device is realized as a Parallel Kinematic Machine (PKM), opportunely sensorized and controlled, able to perform automatic error-free workpiece clamping procedures, drastically reducing the overall fixturing set-up time. ...

  19. Multiple Regressive Model Adaptive Control

    Garipov, Emil; Stoilkov, Teodor; Kalaykov, Ivan

    2008-01-01

    The essence of the ideas applied to this text consists in the development of the strategy for control of the arbitrary in complexity continuous plant by means of a set of discrete timeinvariant linear controllers. Their number and tuned parameters correspond to the number and parameters of the linear time-invariant regressive models in the model bank, which approximate the complex plant dynamics in different operating points. Described strategy is known as Multiple Regressive Model Adaptive C...

  20. Comparative Aspects of Cardiac Adaptation

    Ošťádal, Bohuslav

    New York : Springer, 2013 - (Ošťádal, B.; Dhalla, N.), s. 3-18 ISBN 978-1-4614-5202-7. - (Advances in Biochemistry in Health and Disease) R&D Projects: GA ČR(CZ) GAP302/11/1308 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : cardiac adaptation * poikilotherms * homeotherms Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  1. Certification Considerations for Adaptive Systems

    Bhattacharyya, Siddhartha; Cofer, Darren; Musliner, David J.; Mueller, Joseph; Engstrom, Eric

    2015-01-01

    Advanced capabilities planned for the next generation of aircraft, including those that will operate within the Next Generation Air Transportation System (NextGen), will necessarily include complex new algorithms and non-traditional software elements. These aircraft will likely incorporate adaptive control algorithms that will provide enhanced safety, autonomy, and robustness during adverse conditions. Unmanned aircraft will operate alongside manned aircraft in the National Airspace (NAS), with intelligent software performing the high-level decision-making functions normally performed by human pilots. Even human-piloted aircraft will necessarily include more autonomy. However, there are serious barriers to the deployment of new capabilities, especially for those based upon software including adaptive control (AC) and artificial intelligence (AI) algorithms. Current civil aviation certification processes are based on the idea that the correct behavior of a system must be completely specified and verified prior to operation. This report by Rockwell Collins and SIFT documents our comprehensive study of the state of the art in intelligent and adaptive algorithms for the civil aviation domain, categorizing the approaches used and identifying gaps and challenges associated with certification of each approach.

  2. Metabolic Adaptation to Muscle Ischemia

    Cabrera, Marco E.; Coon, Jennifer E.; Kalhan, Satish C.; Radhakrishnan, Krishnan; Saidel, Gerald M.; Stanley, William C.

    2000-01-01

    Although all tissues in the body can adapt to varying physiological/pathological conditions, muscle is the most adaptable. To understand the significance of cellular events and their role in controlling metabolic adaptations in complex physiological systems, it is necessary to link cellular and system levels by means of mechanistic computational models. The main objective of this work is to improve understanding of the regulation of energy metabolism during skeletal/cardiac muscle ischemia by combining in vivo experiments and quantitative models of metabolism. Our main focus is to investigate factors affecting lactate metabolism (e.g., NADH/NAD) and the inter-regulation between carbohydrate and fatty acid metabolism during a reduction in regional blood flow. A mechanistic mathematical model of energy metabolism has been developed to link cellular metabolic processes and their control mechanisms to tissue (skeletal muscle) and organ (heart) physiological responses. We applied this model to simulate the relationship between tissue oxygenation, redox state, and lactate metabolism in skeletal muscle. The model was validated using human data from published occlusion studies. Currently, we are investigating the difference in the responses to sudden vs. gradual onset ischemia in swine by combining in vivo experimental studies with computational models of myocardial energy metabolism during normal and ischemic conditions.

  3. Classification algorithms using adaptive partitioning

    Binev, Peter

    2014-12-01

    © 2014 Institute of Mathematical Statistics. Algorithms for binary classification based on adaptive tree partitioning are formulated and analyzed for both their risk performance and their friendliness to numerical implementation. The algorithms can be viewed as generating a set approximation to the Bayes set and thus fall into the general category of set estimators. In contrast with the most studied tree-based algorithms, which utilize piecewise constant approximation on the generated partition [IEEE Trans. Inform. Theory 52 (2006) 1335.1353; Mach. Learn. 66 (2007) 209.242], we consider decorated trees, which allow us to derive higher order methods. Convergence rates for these methods are derived in terms the parameter - of margin conditions and a rate s of best approximation of the Bayes set by decorated adaptive partitions. They can also be expressed in terms of the Besov smoothness β of the regression function that governs its approximability by piecewise polynomials on adaptive partition. The execution of the algorithms does not require knowledge of the smoothness or margin conditions. Besov smoothness conditions are weaker than the commonly used Holder conditions, which govern approximation by nonadaptive partitions, and therefore for a given regression function can result in a higher rate of convergence. This in turn mitigates the compatibility conflict between smoothness and margin parameters.

  4. Adaptation-Based Programming in Haskell

    Tim Bauer

    2011-09-01

    Full Text Available We present an embedded DSL to support adaptation-based programming (ABP in Haskell. ABP is an abstract model for defining adaptive values, called adaptives, which adapt in response to some associated feedback. We show how our design choices in Haskell motivate higher-level combinators and constructs and help us derive more complicated compositional adaptives. We also show an important specialization of ABP is in support of reinforcement learning constructs, which optimize adaptive values based on a programmer-specified objective function. This permits ABP users to easily define adaptive values that express uncertainty anywhere in their programs. Over repeated executions, these adaptive values adjust to more efficient ones and enable the user's programs to self optimize. The design of our DSL depends significantly on the use of type classes. We will illustrate, along with presenting our DSL, how the use of type classes can support the gradual evolution of DSLs.

  5. Limitations of science and adaptive management

    Narasimhan, T. N.

    2001-01-01

    Adaptive management consists in patterning human sustenance within the constraints of Earth and biological systems whose behavior is inherently uncertain and difficult to control. For successful adaptive management, a mind-set recognizing the limitations of science is needed.

  6. Adaptation-Based Programming in Haskell

    Bauer, Tim; Fern, Alan; Pinto, Jervis; 10.4204/EPTCS.66.1

    2011-01-01

    We present an embedded DSL to support adaptation-based programming (ABP) in Haskell. ABP is an abstract model for defining adaptive values, called adaptives, which adapt in response to some associated feedback. We show how our design choices in Haskell motivate higher-level combinators and constructs and help us derive more complicated compositional adaptives. We also show an important specialization of ABP is in support of reinforcement learning constructs, which optimize adaptive values based on a programmer-specified objective function. This permits ABP users to easily define adaptive values that express uncertainty anywhere in their programs. Over repeated executions, these adaptive values adjust to more efficient ones and enable the user's programs to self optimize. The design of our DSL depends significantly on the use of type classes. We will illustrate, along with presenting our DSL, how the use of type classes can support the gradual evolution of DSLs.

  7. Understanding the adaptive approach to thermal comfort

    Humphreys, M.A. [Oxford Univ. (United Kingdom). Centre for the Study of Christianity and Culture; Nicol, J.F. [Oxford Brookes Univ. (United Kingdom). School of Architecture

    1998-10-01

    This paper explains the adaptive approach to thermal comfort, and an adaptive model for thermal comfort is presented. The model is an example of a complex adaptive system (Casti 1996) whose equilibria are determined by the restrictions acting upon it. People`s adaptive actions are generally effective in securing comfort, which occurs at a wide variety of indoor temperatures. These comfort temperatures depend upon the circumstances in which people live, such as the climate and the heating or cooling regime. The temperatures may be estimated from the mean outdoor temperature and the availability of a heating or cooling plant. The evaluation of the parameters of the adaptive model requires cross-sectional surveys to establish current norms and sequential surveys (with and without intervention) to evaluate the rapidity of people`s adaptive actions. Standards for thermal comfort will need revision in the light of the adaptive approach. Implications of the adaptive model for the HVAC industry are noted.

  8. A structure-based approach to evaluation product adaptability in adaptable design

    Adaptable design, as a new design paradigm, involves creating designs and products that can be easily changed to satisfy different requirements. In this paper, two types of product adaptability are proposed as essential adaptability and behavioral adaptability, and through measuring which respectively a model for product adaptability evaluation is developed. The essential adaptability evaluation proceeds with analyzing the independencies of function requirements and function modules firstly based on axiomatic design, and measuring the adaptability of interfaces secondly with three indices. The behavioral adaptability reflected by the performance of adaptable requirements after adaptation is measured based on Kano model. At last, the effectiveness of the proposed method is demonstrated by an illustrative example of the motherboard of a personal computer. The results show that the method can evaluate and reveal the adaptability of a product in essence, and is of directive significance to improving design and innovative design

  9. Adaptations In Buyer-Seller Relationships

    Brennan, R.; Turnbull, P W

    1995-01-01

    The concept of inter-firm adaptations has been an important component of the IMP Interaction Approach since the first IMP study. Researchers working within the IMP tradition have put forward a number of taxonomies of adaptations, but no satisfactory definition of the concept. The management of inter-firm adaptations is a critical component of relationship portfolio management. In order better to understand this concept, and to support the formulation of inter-firm adaptation strategy, progres...

  10. Probing human vision with spatial adaptation

    Mark W. Greenlee; Magnussen, S.

    2014-01-01

    Adaptation to spatial displays has robust effects on the perception of visual stimuli presented after adaptation. Referred to as the ‘psychophysicist’s microelectrode’ (Frisby, 1979), spatial adaptation and aftereffects has proved to be a powerful technique in the investigation of the functional organization of the human visual system. Our 20 years of collaboration on spatial adaptation research in the hospitable atmosphere of Lothar Spillmann’s laboratory at the University of Freiburg has re...

  11. The Political Economy of Mitigation and Adaptation

    Habla, Wolfgang; Roeder, Kerstin

    2016-01-01

    In this paper, we acknowledge that the mitigation of and adaptation to climate change have differential fiscal impacts. Whereas mitigation typically raises fiscal revenues, adaptation is costly to the taxpayer and to a greater extent the more distortionary the tax system is. In an OLG model with majority voting, we analyze how the choices of mitigation and adaptation are distorted under a lump-sum and a distortionary income tax regime. We find that whenever emissions and adaptation exhibit st...

  12. Adaptation to blurred and sharpened video

    Haun, Andrew M.; Peli, Eli

    2013-01-01

    The visual system can distinguish different levels of blur and different levels of excess sharpness. Adaptation alters this capacity so that the adapted blur (or sharp) level looks more like a normal, properly focused image. Here, we describe the more general pattern of aftereffects of blur and sharp adaptation by measuring matching functions, using video clips from a DVD movie as stimuli. Results show that blur and sharp adaptation are selective: The sharpening aftereffects of blur adaptatio...

  13. Imprecision of Adaptation in Escherichia coli Chemotaxis

    Silke Neumann; Nikita Vladimirov; Krembel, Anna K.; Wingreen, Ned S.; Victor Sourjik

    2014-01-01

    Adaptability is an essential property of many sensory systems, enabling maintenance of a sensitive response over a range of background stimulus levels. In bacterial chemotaxis, adaptation to the preset level of pathway activity is achieved through an integral feedback mechanism based on activity-dependent methylation of chemoreceptors. It has been argued that this architecture ensures precise and robust adaptation regardless of the ambient ligand concentration, making perfect adaptation a cel...

  14. Adaptation to interocular differences in blur

    Kompaniez, E.; Sawides, L.; Marcos, S.; Webster, M A

    2013-01-01

    Adaptation to a blurred image causes a physically focused image to appear too sharp, and shifts the point of subjective focus toward the adapting blur, consistent with a renormalization of perceived focus. We examined whether and how this adaptation normalizes to differences in blur between the two eyes, which can routinely arise from differences in refractive errors. Observers adapted to images filtered to simulate optical defocus or different axes of astigmatism, as well as to images that w...

  15. Visuomotor Adaptation: How Forgetting Keeps Us Conservative

    Katinka van der Kooij; Eli Brenner; van Beers, Robert J; Smeets, Jeroen B.J.

    2015-01-01

    Even when provided with feedback after every movement, adaptation levels off before biases are completely removed. Incomplete adaptation has recently been attributed to forgetting: the adaptation is already partially forgotten by the time the next movement is made. Here we test whether this idea is correct. If so, the final level of adaptation is determined by a balance between learning and forgetting. Because we learn from perceived errors, scaling these errors by a magnification factor has ...

  16. ADAPTIVE CAPACITY OF STUDENTS’ CARDIOVASCULAR SYSTEM

    Arabadzhi Liliya Ivanivna

    2012-01-01

    Data about adaptive capacity of cardiovascular system of 106 students were analyzed. Using the method of R.M. Bayevskiy, current adaptive capacity of students’ organisms was estimated. The number of students with stress adaptation mechanisms significantly increased with their age (from 17 to 23 years). In our opinion, this could be explained by negative impact of urbanization, significant learning overload and lack of physical activity among the students. Dependence of the adaptive capacity...

  17. Economics, institutions and adaptation to climate change

    Oberlack, Christoph; Neumärker, Bernhard

    2011-01-01

    Adaptation to the consequences of climate change has attracted increasing interest as a necessary complement to greenhouse gas mitigation. Economic approaches to climate adaptation are rarely articulated and discussed explicitly despite many benefits of such a framework-level discourse. Therefore, this article investigates how climate adaptation is framed and approached in economics and attempts to contribute to the development of economic frameworks of climate adaptation. First, the paper id...

  18. THE ADAPTIVE NATURE OF MANAGING SOFTWARE INNOVATION

    Mihai Liviu Despa

    2013-01-01

    The focus of this article is pointed at adaptive management in the context of innovative software projects. Software development is presented through the filter of innovation. The aspects that differentiate software innovation from any other kind of innovation are highlighted. Adaptive management is addressed from a general point of view. The circumstances that require adaptive management are emphasized. Methods of implementing adaptive management in innovation oriented software projects are ...

  19. A review on biological adaptation: with applications in engineering science

    LiMin Luo; WenJun Zhang

    2014-01-01

    Biological adaptation refers to that organisms change themselves at morphological, physiological, behavioral and molecular level to better survive in a changing environment. It includes phenotype adaptation and molecular adaptation. Biological adaptation is a driving force of evolution. Biological adaptation was described from Darwinian theory of evolution to the theory of molecular evolution in present paper. Adaptive control and adaptive filtering were briefly described also.

  20. Adaptive independent component analysis to analyze electrocardiograms

    Yim, Seong-Bin; Szu, Harold H.

    2001-03-01

    In this work, we apply adaptive version independent component analysis (ADAPTIVE ICA) to the nonlinear measurement of electro-cardio-graphic (ECG) signals for potential detection of abnormal conditions in the heart. In principle, unsupervised ADAPTIVE ICA neural networks can demix the components of measured ECG signals. However, the nonlinear pre-amplification and post measurement processing make the linear ADAPTIVE ICA model no longer valid. This is possible because of a proposed adaptive rectification pre-processing is used to linearize the preamplifier of ECG, and then linear ADAPTIVE ICA is used in iterative manner until the outputs having their own stable Kurtosis. We call such a new approach adaptive ADAPTIVE ICA. Each component may correspond to individual heart function, either normal or abnormal. Adaptive ADAPTIVE ICA neural networks have the potential to make abnormal components more apparent, even when they are masked by normal components in the original measured signals. This is particularly important for diagnosis well in advance of the actual onset of heart attack, in which abnormalities in the original measured ECG signals may be difficult to detect. This is the first known work that applies Adaptive ADAPTIVE ICA to ECG signals beyond noise extraction, to the detection of abnormal heart function.

  1. The Adaptation Gap Report - a Preliminary Assessment

    Alverson, Keith; Olhoff, Anne; Noble, Ian;

    This first Adaptation Gap report provides an equally sobering assessment of the gap between adaptation needs and reality, based on preliminary thinking on how baselines, future goals or targets, and gaps between them might be defined for climate change adaptation. The report focuses on gaps in...... developing countries in three important areas: finance, technology and knowledge....

  2. Adapting Music Instruction for Students with Dyslexia

    Vance, Kate O'Brien

    2004-01-01

    This article discusses how several simple adaptations in the music classroom can greatly enhance dyslexic students' learning. The sections included in this article are: (1) What Is Dyslexia?; (2) Students with Dyslexia; (3) What to Look for; (4) Adapting Instruction; (5) Reading Notation; and (6) Motor Skills. A list of practical adaptations; and…

  3. Visuomotor Adaptation: How Forgetting Keeps Us Conservative

    Kooij, K. van der; Brenner, E.M.; Beers, R.J. van; Smeets, J.B.J.

    2015-01-01

    Even when provided with feedback after every movement, adaptation levels off before biases are completely removed. Incomplete adaptation has recently been attributed to forgetting: the adaptation is already partially forgotten by the time the next movement is made. Here we test whether this idea is

  4. Feedback in Videogame-Based Adaptive Training

    Rivera, Iris Daliz

    2010-01-01

    The field of training has been changing rapidly due to advances in technology such as videogame-based adaptive training. Videogame-based adaptive training has provided flexibility and adaptability for training in cost-effective ways. Although this method of training may have many benefits for the trainee, current research has not kept up to pace…

  5. National-level progress on adaptation

    Lesnikowski, Alexandra; Ford, James; Biesbroek, Robbert; Berrang-Ford, Lea; Heymann, S. Jody

    2016-03-01

    It is increasingly evident that adaptation will figure prominently in the post-2015 United Nations climate change agreement. As adaptation obligations under the United Nations Framework Convention on Climate Change evolve, more rigorous approaches to measuring adaptation progress among parties will be critical. In this Letter we elaborate on an emerging area of research referred to as `adaptation tracking’, which has potential to inform development of a global adaptation monitoring framework. We evaluate this potential by presenting evidence on policy change for 41 high-income countries between 2010 and 2014. We examine whether countries that were in early stages of adaptation planning in 2010 are making progress to close adaptation gaps, and how the landscape of adaptation in these countries has evolved. In total we find an 87% increase in reported adaptation policies and measures, and evidence that implementation of concrete adaptation initiatives is growing. Reflecting on the strengths and challenges of this early methodology, we further discuss how adaptation tracking practices could guide development of a robust framework for monitoring global adaptation progress and inform future research on policy change across countries.

  6. The Worker as Proteus: Understanding Occupational Adaptability.

    Faddis, Constance R.

    The purpose of this paper is to review and synthesize what is known about occupational adaptability and to propose a heuristic model of the process(es) of adaptation in work. Following an introductory chapter, three chapters contain a review of literature that draws from many disciplines and presents an overview of human adaptation in general, as…

  7. Framework of Combined Adaptive and Non-adaptive Attitude Control System for a Helicopter Experimental System

    Akira Inoue; Ming-Cong Deng

    2006-01-01

    This paper presents a framework of a combined adaptive and non-adaptive attitude control system for a helicopter experimental system. The design method is based on a combination of adaptive nonlinear control and non-adaptive nonlinear control. With regard to detailed attitude control system design, two schemes are shown for different application cases.

  8. Adaptive vehicle motion estimation and prediction

    Zhao, Liang; Thorpe, Chuck E.

    1999-01-01

    Accurate motion estimation and reliable maneuver prediction enable an automated car to react quickly and correctly to the rapid maneuvers of the other vehicles, and so allow safe and efficient navigation. In this paper, we present a car tracking system which provides motion estimation, maneuver prediction and detection of the tracked car. The three strategies employed - adaptive motion modeling, adaptive data sampling, and adaptive model switching probabilities - result in an adaptive interacting multiple model algorithm (AIMM). The experimental results on simulated and real data demonstrate that our tracking system is reliable, flexible, and robust. The adaptive tracking makes the system intelligent and useful in various autonomous driving tasks.

  9. Adaptive Fuzzy Control for CVT Vehicle

    2005-01-01

    On the simple continuously variable transmission (CVT) driveline model, the design of adaptive fuzzy control system for CVT vehicle is presented. The adaptive fuzzy control system consists of a scaling factor self-tuning fuzzy-PI throttle controller, and a hybrid fuzzy-PID CVT ratio and brake controller. The presented adaptive fuzzy control strategy is vehicle model independent, which depends only on the instantaneous vehicle states, but does not depend on vehicle parameters. So it has good robustness against uncertain vehicle parameters and exogenous load disturbance. Simulation results show that the proposed adaptive fuzzy strategy has good adaptability and practicality value.

  10. Adaptive Distance Protection for Microgrids

    Lin, Hengwei; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez;

    2015-01-01

    Due to the increasing penetration of distributed generation resources, more and more microgrids can be found in distribution systems. This paper proposes a phasor measurement unit based distance protection strategy for microgrids in distribution system. At the same time, transfer tripping scheme is...... adopted to accelerate the tripping speed of the relays on the weak lines. The protection methodology is tested on a mid-voltage microgrid network in Aalborg, Denmark. The results show that the adaptive distance protection methodology has good selectivity and sensitivity. What is more, this system also has...

  11. The Promise of Domain Adaptation

    Mahabal, Ashish A.; Li, Jingling; Vaijanapurkar, Samarth; Bue, Brian; Miller, Adam; Donalek, Ciro; Djorgovski, Stanislav G.; Drake, Andrew J.; Graham, Matthew; CRTS, iPTF

    2016-01-01

    Most new surveys spend an appreciable time in collecting data on which to train classifiers before they can be used on future observations from the same dataset. The result generating phase can start much earlier if the training could incorporate data accumulated from older surveys enhanced with a small set from the new survey. This is exactly what Domain Adaptation (DA) allows us to do. The main idea behind DAs can be summarized thus: if we have two classes of separable objects in some feature space of a Source survey (S), we can define a hyperplane to separate the two types. In a second Target survey (T), for the same features the hyperplane would be inclined differently. DA methods get the mapping between the two hyperplanes using a small fraction of data from the Target (T) survey and can then be used to predict the classes of the remaining majority of data in T. We discuss the parameters that need to be tuned, the difficulties involved, and ways to improve the results. As we move towards bigger, and deeper surveys, being able to use existing labelled information to conduct classification in future surveys will be more cost-effective and promote time efficiency as well. Starting with the light curve data of 50,000 periodic objects from Catalina Real-Time Transient Survey (CRTS), we have applied domain adaptation techniques such as Geodesic Flow Kernel (GFK) with Random forest classifier and Co-training for domain adaptation (CODA) to the CRTS data which has 35,000 points overlapping with Palomar Transient Factory (PTF), and 12,000 with Lincoln Near-Earth Asteroid Research (LINEAR). The results suggest that domain adaptation is an area worth exploring as the knowledge between these surveys is transferable and the approaches to find the mappings between these surveys can be applied to the remaining data as well as for near future surveys such as CRTS-II, Zwicky Transient Facility (ZTF) and the Large Synoptic Survey Telescope (LSST) to name a few at the optical

  12. Compressive adaptive computational ghost imaging

    Aßmann, Marc; 10.1038/srep01545

    2013-01-01

    Compressive sensing is considered a huge breakthrough in signal acquisition. It allows recording an image consisting of $N^2$ pixels using much fewer than $N^2$ measurements if it can be transformed to a basis where most pixels take on negligibly small values. Standard compressive sensing techniques suffer from the computational overhead needed to reconstruct an image with typical computation times between hours and days and are thus not optimal for applications in physics and spectroscopy. We demonstrate an adaptive compressive sampling technique that performs measurements directly in a sparse basis. It needs much fewer than $N^2$ measurements without any computational overhead, so the result is available instantly.

  13. Time Simulation of Bone Adaptation

    Bagge, Mette

    1998-01-01

    The structural adaptation of a three-dimensional finite element model ofthe proximal femur is considered. Presuming the bone possesses the optimalstructure under the given loads, the bone material distribution is foundby minimizing the strain energy averaged over ten load cases with avolume...... constraint. Theoptimized design is used as a start-configuration for the remodelingsimulation.The parameter characterizing the equilibrium level where no remodeling occurs is estimated from the optimization parameters.The loads vary in magnitude, location and direction simulating timedependent loading. The...

  14. Adaptive, dynamic, and resilient systems

    Suri, Niranjan

    2015-01-01

    As the complexity of today's networked computer systems grows, they become increasingly difficult to understand, predict, and control. Addressing these challenges requires new approaches to building these systems. Adaptive, Dynamic, and Resilient Systems supplies readers with various perspectives of the critical infrastructure that systems of networked computers rely on. It introduces the key issues, describes their interrelationships, and presents new research in support of these areas.The book presents the insights of a different group of international experts in each chapter. Reporting on r

  15. Rapidly Adaptable Instrumentation Tester (RAIT)

    Emerging technologies in the field of ''Test ampersand Measurement'' have recently enabled the development of the Rapidly Adaptable Instrumentation Tester (RAIT). Based on software developed with LabVIEW, the RAIT design enables quick reconfiguration to test and calibrate a wide variety of telemetry systems. The consequences of inadequate testing could be devastating if a telemetry system were to fail during an expensive flight mission. Supporting both open-bench testing as well as automated test sequences, the RAIT has significantly lowered total time required to test and calibrate a system. This has resulted in an overall lower per unit testing cost than has been achievable in the past

  16. Split quaternion nonlinear adaptive filtering.

    Ujang, Bukhari Che; Took, Clive Cheong; Mandic, Danilo P

    2010-04-01

    A split quaternion learning algorithm for the training of nonlinear finite impulse response adaptive filters for the processing of three- and four-dimensional signals is proposed. The derivation takes into account the non-commutativity of the quaternion product, an aspect neglected in the derivation of the existing learning algorithms. It is shown that the additional information taken into account by a rigorous treatment of quaternion algebra provides improved performance on hypercomplex processes. A rigorous analysis of the convergence of the proposed algorithms is also provided. Simulations on both benchmark and real-world signals support the approach. PMID:19926443

  17. Taking steps: mainstreaming national adaptation

    Huq, Saleemul; Ayers, Jessica

    2008-11-15

    Climate change poses a massive threat to development. The poorest populations of poor countries – the Least Developed Countries, Small Island Developing States, and the nations of Africa – face the concentrated challenge of tackling the worst of the impacts with the least capacity to do so. Clearly, adaptation to climate impacts must be seamlessly integrated into any development planning and policy. This fourstep plan for mainstreaming climate change aims to fulfil that need. A 'learning by doing' approach, it focuses first on national capacity to ensure that development in all sectors and at all levels is effectively climate-proofed.

  18. Computerized adaptive testing: implementation issues

    Antal, Margit; Imre, Attila

    2010-01-01

    One of the fastest evolving field among teaching and learning research is students' performance evaluation. Computer based testing systems are increasingly adopted by universities. However, the implementation and maintenance of such a system and its underlying item bank is a challenge for an inexperienced tutor. Therefore, this paper discusses the advantages and disadvantages of Computer Adaptive Test (CAT) systems compared to Computer Based Test systems. Furthermore, a few item selection strategies are compared in order to overcome the item exposure drawback of such systems. The paper also presents our CAT system along its development steps. Besides, an item difficulty estimation technique is presented based on data taken from our self-assessment system.

  19. Robust Adaptable Video Copy Detection

    Assent, Ira; Kremer, Hardy

    2009-01-01

    Video copy detection should be capable of identifying video copies subject to alterations e.g. in video contrast or frame rates. We propose a video copy detection scheme that allows for adaptable detection of videos that are altered temporally (e.g. frame rate change) and/or visually (e.g. change...... in contrast). Our query processing combines filtering and indexing structures for efficient multistep computation of video copies under this model. We show that our model successfully identifies altered video copies and does so more reliably than existing models....

  20. Context Aware Adaptable Applications - A global approach

    Dalmau, Marc; Laplace, Sophie

    2009-01-01

    Actual applications (mostly component based) requirements cannot be expressed without a ubiquitous and mobile part for end-users as well as for M2M applications (Machine to Machine). Such an evolution implies context management in order to evaluate the consequences of the mobility and corresponding mechanisms to adapt or to be adapted to the new environment. Applications are then qualified as context aware applications. This first part of this paper presents an overview of context and its management by application adaptation. This part starts by a definition and proposes a model for the context. It also presents various techniques to adapt applications to the context: from self-adaptation to supervised approached. The second part is an overview of architectures for adaptable applications. It focuses on platforms based solutions and shows information flows between application, platform and context. Finally it makes a synthesis proposition with a platform for adaptable context-aware applications called Kalimuch...

  1. Population extinction and the genetics of adaptation.

    Orr, H Allen; Unckless, Robert L

    2008-08-01

    Theories of adaptation typically ignore the effect of environmental change on population size. But some environmental challenges--challenges to which populations must adapt--may depress absolute fitness below 1, causing populations to decline. Under this scenario, adaptation is a race; beneficial alleles that adapt a population to the new environment must sweep to high frequency before the population becomes extinct. We derive simple, though approximate, solutions to the probability of successful adaptation (population survival) when adaptation involves new mutations, the standing genetic variation, or a mixture of the two. Our results show that adaptation to such environmental challenges can be difficult when relying on new mutations at one or a few loci, and populations will often decline to extinction. PMID:18662122

  2. Adaptation and creativity in cultural context

    Leonora M. Cohen

    2012-06-01

    Full Text Available Adaptation is the fit between the individual and the environment. The dynamic interplay between person, culture, and environment is one of the most important issues in analyzing creativity. Adaptation is defined as the fit or adjustment of the individual to external conditions, but adaptation can also mean moving from one environment to another more suitable, or even forcing the environment to adapt in response to creative efforts. Culture impacts creativity in limiting acceptable boundaries, yet providing the artifacts used in creating. Culture is impacted and changed by creative efforts. Tight conformity to confining environments or cultures can stifle. The creator must be aware of cultural values and not overstep these boundaries for work to be accepted. A developmental continuum of adaptive, creative behaviors suggests a shift from individual adaptation to the environment to adaptation by the world to the individual.

  3. Integrating Adaptive Functionality in a LMS

    Kees van der Sluijs

    2009-12-01

    Full Text Available Learning management systems are becoming more and more important in the learning process in both educational and corporate settings. They can nowadays even be used to server actual courses to the learner. However, one important feature is lacking in learning management systems: personalization. In this paper we look into this issue of personalization that enables courses to be adapted to the knowledge level and learning preferences of the user. We shortly review the state of the art in adaptive systems that allow creating adaptive courses. Then, exemplified in the popular LMS called CLIX we look at the authoring of an adaptive Business English course. We demonstrate how such a static course can be made adaptive by using the GALE adaptive engine. We then show that GALE can be integrated into CLIX, and in other LMSs as well, so that personalization and adaptation can become widely established technology.

  4. Differential adaptation: An operational approach to adaptation for solving numerical problems with CBR

    Fuchs, Béatrice; Lieber, Jean; Mille, Alain; Napoli, Amedeo

    2014-01-01

    Case-based reasoning relies on four main steps: retrieval, adaptation, revision and retention. This article focuses on the adaptation step; we propose differential adaptation as an operational formalization of adaptation for numerical problems. The solution to a target problem is designed on the basis of relations existing between a source case (problem and solution) and a target case. Differential adaptation relies on the metaphor of differential calculus where small variations on variable v...

  5. New Adaptive Optics Technique Demonstrated

    2007-03-01

    First ever Multi-Conjugate Adaptive Optics at the VLT Achieves First Light On the evening of 25 March 2007, the Multi-Conjugate Adaptive Optics Demonstrator (MAD) achieved First Light at the Visitor Focus of Melipal, the third Unit Telescope of the Very Large Telescope (VLT). MAD allowed the scientists to obtain images corrected for the blurring effect of atmospheric turbulence over the full 2x2 arcminute field of view. This world premiere shows the promises of a crucial technology for Extremely Large Telescopes. ESO PR Photo 19a/07 ESO PR Photo 19a/07 The MCAO Demonstrator Telescopes on the ground suffer from the blurring effect induced by atmospheric turbulence. This turbulence causes the stars to twinkle in a way which delights the poets but frustrates the astronomers, since it blurs the fine details of the images. However, with Adaptive Optics (AO) techniques, this major drawback can be overcome so that the telescope produces images that are as sharp as theoretically possible, i.e., approaching space conditions. Adaptive Optics systems work by means of a computer-controlled deformable mirror (DM) that counteracts the image distortion induced by atmospheric turbulence. It is based on real-time optical corrections computed from image data obtained by a 'wavefront sensor' (a special camera) at very high speed, many hundreds of times each second. The concept is not new. Already in 1989, the first Adaptive Optics system ever built for Astronomy (aptly named "COME-ON") was installed on the 3.6-m telescope at the ESO La Silla Observatory, as the early fruit of a highly successful continuing collaboration between ESO and French research institutes (ONERA and Observatoire de Paris). Ten years ago, ESO initiated an Adaptive Optics program to serve the needs for its frontline VLT project. Today, the Paranal Observatory is without any doubt one of the most advanced of its kind with respect to AO with no less than 7 systems currently installed (NACO, SINFONI, CRIRES and

  6. When is emotional contagion adaptive?

    Nakahashi, Wataru; Ohtsuki, Hisashi

    2015-09-01

    Empathy plays an important role in animal social behavior. Since emotional contagion forms one of the bases of empathy, here we study conditions for emotional contagion to be adaptive, compared with other behavioral rules such as behavioral mimicry. We consider the situation where the focal individual (=observer) reacts to a behavior of another individual (=demonstrator). By emotional contagion one spontaneously copies the emotional state of the demonstrator and takes a behavior driven by that emotion. By behavioral mimicry, in contrast, one copies the behavior of the demonstrator itself. Through mathematical models we show that emotional contagion is adaptive when the environmental similarity between the demonstrator and the observer is intermediate. The advantage of adopting emotional contagion over behavioral mimicry increases when observing others' behavior is difficult or cognitively demanding. We show that emotional contagion is often a more flexible strategy than behavioral mimicry in order to cope with the living environment. In other words, emotional contagion often works as a better social learning strategy. These results suggest some ecological conditions that would favor the evolution of emotional contagion, and give a part of the explanations of why emotional contagion is frequently observed in group-living animals. PMID:26113192

  7. AEST: Adaptive Eigenvalue Stability Code

    Zheng, L.-J.; Kotschenreuther, M.; Waelbroeck, F.; van Dam, J. W.; Berk, H.

    2002-11-01

    An adaptive eigenvalue linear stability code is developed. The aim is on one hand to include the non-ideal MHD effects into the global MHD stability calculation for both low and high n modes and on the other hand to resolve the numerical difficulty involving MHD singularity on the rational surfaces at the marginal stability. Our code follows some parts of philosophy of DCON by abandoning relaxation methods based on radial finite element expansion in favor of an efficient shooting procedure with adaptive gridding. The δ W criterion is replaced by the shooting procedure and subsequent matrix eigenvalue problem. Since the technique of expanding a general solution into a summation of the independent solutions employed, the rank of the matrices involved is just a few hundreds. This makes easier to solve the eigenvalue problem with non-ideal MHD effects, such as FLR or even full kinetic effects, as well as plasma rotation effect, taken into account. To include kinetic effects, the approach of solving for the distribution function as a local eigenvalue ω problem as in the GS2 code will be employed in the future. Comparison of the ideal MHD version of the code with DCON, PEST, and GATO will be discussed. The non-ideal MHD version of the code will be employed to study as an application the transport barrier physics in tokamak discharges.

  8. Evolutionary advantages of adaptive rewarding

    Our well-being depends on both our personal success and the success of our society. The realization of this fact makes cooperation an essential trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remains elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly rich social dynamics that explain why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding, coming from over-aggression, which in turn hinders optimal utilization of network reciprocity. This may explain why, despite its success, rewarding is not as firmly embedded into our societal organization as punishment. (paper)

  9. Adaptive feedback active noise control

    Kuo, Sen M.; Vijayan, Dipa

    Feedforward active noise control (ANC) systems use a reference sensor that senses a reference input to the controller. This signal is assumed to be unaffected by the secondary source and is a good measure of the undesired noise to be cancelled by the system. The reference sensor may be acoustic (e.g., microphone) or non-acoustic (e.g., tachometer, optical transducer). An obvious problem when using acoustic sensors is that the reference signal may be corrupted by the canceling signal generated by the secondary source. This problem is known as acoustic feedback. One way of avoiding this is by using a feedback active noise control (FANC) system which dispenses with the reference sensor. The FANC technique originally proposed by Olson and May employs a high gain negative feedback amplifier. This system suffered from the drawback that the error microphone had to be placed very close to the loudspeaker. The operation of the system was restricted to low frequency range and suffered from instability due to the possibility of positive feedback. Feedback systems employing adaptive filtering techniques for active noise control were developed. This paper presents the FANC system modeled as an adaptive prediction scheme.

  10. Perceptually adapted MPEG video encoding

    Bordes, Philippe; Guillotel, Philippe

    2000-06-01

    In picture quality assessment, the amount of distortion perceived by a human observer differs from one region to another according to its particular local content. This subjective perception can be explained/predicted by considering some simple psychovisual properties (masking) of the Human Visual System (HVS). We have implemented a HVS model based on a pyramid decomposition for extracting the spatial frequencies, associated with a multi-resolution motion representation. Then the visibility of the decoded errors is computed by exploiting the Kelly's contrast sensitivity spatio-velocity model. The resulting data is called a 'Quality-map.' Special attention has been paid to temporal/moving effects since, in the case of video sequences, motion strongly influences the subjective quality assessment. The quality of the motion information is thus preponderant. In the second part, two possible uses of these psychovisual properties for improving MPEG video encoding performances are depicted: (1) The pre-processing of the pictures to remove non-visible information using a motion adapted filtering. This process is efficient in term of bits saved and degradation is not significant especially on consumer electronic TV sets. (2) A perceptual quantizer based on a local adaptation scheme in order to obtain Quality-maps as uniform as possible (homogeneous perceived distortion), at constant bit-rate. Further improvements have been considered, especially when the viewer is tracking a moving object in the scene.

  11. Economics of adaptation to climate change; Economie de l'adaptation au changement climatique

    Perthuis, Ch.; Hallegatte, St.; Lecocq, F.

    2010-02-15

    This report proposes a general economic framework for the issue of adaptation to climate change in order to help public and private actors to build up efficient adaptation strategies. It proposes a general definition of adaptation, identifies the major stakes for these strategies, and discusses the assessment of global costs of adaptation to climate change. It discusses the role and modalities of public action and gives some examples of possible adaptation measures in some important sectors (building and town planning, energy and transport infrastructures, water and agriculture, ecosystems, insurance). It examines the regional and national dimensions of adaptation and their relationship, and defines steps for implementing an adaptation strategy. It describes and discusses the use of economic tools in the elaboration of an adaptation strategy, i.e. how to take uncertainties into account, which scenarios to choose, how to use economic calculations to assess adaptation policies

  12. Adaptation to Climate Change in Developing Countries

    Mertz, Ole; Halsnæs, Kirsten; Olesen, Jørgen E.;

    2009-01-01

    Adaptation to climate change is given increasing international attention as the confidence in climate change projections is getting higher. Developing countries have specific needs for adaptation due to high vulnerabilities, and they will in this way carry a great part of the global costs of...... climate change although the rising atmospheric greenhouse gas concentrations are mainly the responsibility of industrialized countries. This article provides a status of climate change adaptation in developing countries. An overview of observed and projected climate change is given, and recent literature...... developing countries. It is concluded that although many useful steps have been taken in the direction of ensuring adequate adaptation in developing countries, much work still remains to fully understand the drivers of past adaptation efforts, the need for future adaptation, and how to mainstream climate...

  13. Adaptive systems research in the NASA

    Montgomery, R.

    1973-01-01

    The past contributions of NASA to adaptive control technology are reviewed. The review places emphasis on aircraft applications although spacecraft and launch vehicle control applications are included. Particular emphasis is given to the adaptive control system used in the X-15 research aircraft. Problem areas that limited the realizable performance of this adaptive system are discussed. Current technological capabilities are used to extrapolate the present-day potential for adaptive flight control. Specifically, the potential created by use of the modern high-speed digital computer in flight control is discussed. Present plans for research in digital adaptive control systems for the NASA F8-C digital fly-by-wire program are presented. These plans are currently envisioned to include research in at least two types of adaptive controls, the system identification/on-line design type, and the model reference type.

  14. Adaptive Filtering Algorithms and Practical Implementation

    Diniz, Paulo S R

    2013-01-01

    In the fourth edition of Adaptive Filtering: Algorithms and Practical Implementation, author Paulo S.R. Diniz presents the basic concepts of adaptive signal processing and adaptive filtering in a concise and straightforward manner. The main classes of adaptive filtering algorithms are presented in a unified framework, using clear notations that facilitate actual implementation. The main algorithms are described in tables, which are detailed enough to allow the reader to verify the covered concepts. Many examples address problems drawn from actual applications. New material to this edition includes: Analytical and simulation examples in Chapters 4, 5, 6 and 10 Appendix E, which summarizes the analysis of set-membership algorithm Updated problems and references Providing a concise background on adaptive filtering, this book covers the family of LMS, affine projection, RLS and data-selective set-membership algorithms as well as nonlinear, sub-band, blind, IIR adaptive filtering, and more. Several problems are...

  15. A holistic strategy for adaptive land management

    Herrick, Jeffrey E.; Duniway, Michael C.; Pyke, David A.; Bestelmeyer, Brandon T.; Wills, Skye A.; Brown, Joel R.; Karl, Jason W.; Havstad, Kris M.

    2012-01-01

    Adaptive management is widely applied to natural resources management (Holling 1973; Walters and Holling 1990). Adaptive management can be generally defined as an iterative decision-making process that incorporates formulation of management objectives, actions designed to address these objectives, monitoring of results, and repeated adaptation of management until desired results are achieved (Brown and MacLeod 1996; Savory and Butterfield 1999). However, adaptive management is often criticized because very few projects ever complete more than one cycle, resulting in little adaptation and little knowledge gain (Lee 1999; Walters 2007). One significant criticism is that adaptive management is often used as a justification for undertaking actions with uncertain outcomes or as a surrogate for the development of specific, measurable indicators and monitoring programs (Lee 1999; Ruhl 2007).

  16. Regional adaptive delaminating algorithm for rapid prototyping

    CAI Daosheng; SHI Yusheng; HUANG Shuhuai

    2005-01-01

    With the development of rapid prototyping (RP) technology, the contradiction between fabricating speed and precision becomes more and more acute. In order to solve the contradiction, a regional effective adaptive delaminating algorithm is proposed in this paper. It is different from the traditional method that the regional adaptive delaminating method divides slicing contours into several regions and adaptively delaminates in respective region only according to the contours information. Namely, this method can not only adaptively delaminate at different height of CAD model but also adaptively delaminate different regions in one slicing layer. Furthermore, because the two-dimensional contour data adopted in this method are necessary for rapid prototyping system, this regional effective adaptive delaminating method is suitable for all RP systems. A comparative study is used to analyze the effectiveness of this method, which can demonstrate that this method can increase the fabricating speed and reduce the running cost under the condition of ensuring fabricating precision.

  17. Downhole tool adapted for telemetry

    Hall, David R.; Fox, Joe

    2010-12-14

    A cycleable downhole tool such as a Jar, a hydraulic hammer, and a shock absorber adapted for telemetry. This invention applies to other tools where the active components of the tool are displaced when the tool is rotationally or translationally cycled. The invention consists of inductive or contact transmission rings that are connected by an extensible conductor. The extensible conductor permits the transmission of the signal before, after, and during the cycling of the tool. The signal may be continuous or intermittent during cycling. The invention also applies to downhole tools that do not cycle, but in operation are under such stress that an extensible conductor is beneficial. The extensible conductor may also consist of an extensible portion and a fixed portion. The extensible conductor also features clamps that maintain the conductor under stresses greater than that seen by the tool, and seals that are capable of protecting against downhole pressure and contamination.

  18. Towards Adaptive Spoken Dialog Systems

    Schmitt, Alexander

    2013-01-01

    In Monitoring Adaptive Spoken Dialog Systems, authors Alexander Schmitt and Wolfgang Minker investigate statistical approaches that allow for recognition of negative dialog patterns in Spoken Dialog Systems (SDS). The presented stochastic methods allow a flexible, portable and  accurate use.  Beginning with the foundations of machine learning and pattern recognition, this monograph examines how frequently users show negative emotions in spoken dialog systems and develop novel approaches to speech-based emotion recognition using hybrid approach to model emotions. The authors make use of statistical methods based on acoustic, linguistic and contextual features to examine the relationship between the interaction flow and the occurrence of emotions using non-acted  recordings several thousand real users from commercial and non-commercial SDS. Additionally, the authors present novel statistical methods that spot problems within a dialog based on interaction patterns. The approaches enable future SDS to offer m...

  19. Fluctuating epidemics on adaptive networks

    Shaw, Leah B

    2008-01-01

    A model for epidemics on an adaptive network is considered. Nodes follow an SIRS (susceptible-infective-recovered-susceptible) pattern. Connections are rewired to break links from non-infected nodes to infected nodes and are reformed to connect to other non-infected nodes, as the nodes that are not infected try to avoid the infection. Monte Carlo simulation and numerical solution of a mean field model are employed. The introduction of rewiring affects both the network structure and the epidemic dynamics. Degree distributions are altered, and the average distance from a node to the nearest infective increases. The rewiring leads to regions of bistability where either an endemic or a disease-free steady state can exist. Fluctuations around the endemic state and the lifetime of the endemic state are considered. The fluctuations are found to exhibit power law behavior.

  20. Towards personalized adaptive user interfaces

    An approach towards standardization of the general rules for synthesis and design of man machine interfaces that include dynamic adaptive behavior is presented. The link between the personality type (Myers-Briggs or Kersey Temperament sorter) and the personal preferences of the users (Kansei) for the purpose of building Graphical User Interface (GU]) was investigated. The rules for a personalized el-notional GUI based on the subjective preferences of the users were defined. The results were tested on a modified TETRIS game that displayed background characters capable of emotional response. When the system responded to a user in a manner that is customized to his or her preferences, the reaction time was smaller and the information transfer was faster. Usability testing methods were used and it was shown that development of pleasant cartoon face GUI based on the users inborn personality tendencies was feasible. (Author)

  1. Adaptive learning and complex dynamics

    In this paper, we explore the dynamic properties of a group of simple deterministic difference equation systems in which the conventional perfect foresight assumption gives place to a mechanism of adaptive learning. These systems have a common feature: under perfect foresight (or rational expectations) they all possess a unique fixed point steady state. This long-term outcome is obtained also under learning if the quality underlying the learning process is high. Otherwise, when the degree of inefficiency of the learning process is relatively strong, nonlinear dynamics (periodic and a-periodic cycles) arise. The specific properties of each one of the proposed systems is explored both in terms of local and global dynamics. One macroeconomic model is used to illustrate how the formation of expectations through learning may eventually lead to awkward long-term outcomes.

  2. Development of environmental adaptable polymer

    Biodegradable polymers were modified by radiation crosslinking techniques to develop environmental adaptable polymer. Poly(ε-caprolactone), OCL, (melting temperature, 60 deg C) by irradiation in the supercooled state led to the highest gel content and this polymer has high heat resistance. Relatively smaller dose such as 15 and 30 kGy were effective to improve process ability of aliphatic polyester by formation of branch structure during irradiation. It was found that sodium carboxymethyl cellulose (CMC-Na) with degree of substitution (DS) from 0.7 to 2.2 and sodium carboxymethyl starch (CMS-Na) with DS 0.15 caused crosslinking at past like condition by irradiation. The condition with higher concentration such as 50-60% was most effective for crosslinking of CMC-Na and CMS-Na. Crosslinked CMC-Na and CMS-Na formed hydrogel. PCL, CMC-Na, and CMS-Na had biodegradability even after crosslinking in irradiation. (author)

  3. Backpressure with Adaptive Redundancy (BWAR)

    Alresaini, Majed; Krishnamachari, Bhaskar; Neely, Michael J

    2011-01-01

    Backpressure scheduling and routing, in which packets are preferentially transmitted over links with high queue differentials, offers the promise of throughput-optimal operation for a wide range of communication networks. However, when the traffic load is low, due to the corresponding low queue occupancy, backpressure scheduling/routing experiences long delays. This is particularly of concern in intermittent encounter-based mobile networks which are already delay-limited due to the sparse and highly dynamic network connectivity. While state of the art mechanisms for such networks have proposed the use of redundant transmissions to improve delay, they do not work well when the traffic load is high. We propose in this paper a novel hybrid approach that we refer to as backpressure with adaptive redundancy (BWAR), which provides the best of both worlds. This approach is highly robust and distributed and does not require any prior knowledge of network load conditions. We evaluate BWAR through both mathematical ana...

  4. Adaptive Processing for Sequence Alignment

    Zidan, Mohammed Affan

    2012-01-26

    Disclosed are various embodiments for adaptive processing for sequence alignment. In one embodiment, among others, a method includes obtaining a query sequence and a plurality of database sequences. A first portion of the plurality of database sequences is distributed to a central processing unit (CPU) and a second portion of the plurality of database sequences is distributed to a graphical processing unit (GPU) based upon a predetermined splitting ratio associated with the plurality of database sequences, where the database sequences of the first portion are shorter than the database sequences of the second portion. A first alignment score for the query sequence is determined with the CPU based upon the first portion of the plurality of database sequences and a second alignment score for the query sequence is determined with the GPU based upon the second portion of the plurality of database sequences.

  5. Adaptive Missile Guidance Using GPS

    Pallavi Sharad Rupnar

    2013-05-01

    Full Text Available The name adaptive means we can guide any missile using GPS in any critical conditions. GPS guided missiles, using the exceptional navigational and surveying abilities of GPS, after being launched, could deliver a warhead to any part of the globe via the interface of the onboard computer in the missile with the GPS satellite system.GPS allows accurate targeting of various military weapons including ICBMs, cruise missiles and precision-guided munitions. Artillery projectiles with embedded GPS receivers able to withstand accelerations of 12,000 G have been developed for use in 155mm.GPS guided weapons, with their technological advances over previous, are the superior weapon of choice in modern days

  6. Adaptive mesh refinement in titanium

    Colella, Phillip; Wen, Tong

    2005-01-21

    In this paper, we evaluate Titanium's usability as a high-level parallel programming language through a case study, where we implement a subset of Chombo's functionality in Titanium. Chombo is a software package applying the Adaptive Mesh Refinement methodology to numerical Partial Differential Equations at the production level. In Chombo, the library approach is used to parallel programming (C++ and Fortran, with MPI), whereas Titanium is a Java dialect designed for high-performance scientific computing. The performance of our implementation is studied and compared with that of Chombo in solving Poisson's equation based on two grid configurations from a real application. Also provided are the counts of lines of code from both sides.

  7. Adaptive Local Linear Quantile Regression

    Yu-nan Su; Mao-zai Tian

    2011-01-01

    In this paper we propose a new method of local linear adaptive smoothing for nonparametric conditional quantile regression. Some theoretical properties of the procedure are investigated. Then we demonstrate the performance of the method on a simulated example and compare it with other methods. The simulation results demonstrate a reasonable performance of our method proposed especially in situations when the underlying image is piecewise linear or can be approximated by such images. Generally speaking, our method outperforms most other existing methods in the sense of the mean square estimation (MSE) and mean absolute estimation (MAE) criteria. The procedure is very stable with respect to increasing noise level and the algorithm can be easily applied to higher dimensional situations.

  8. Local intensity adaptive image coding

    Huck, Friedrich O.

    1989-01-01

    The objective of preprocessing for machine vision is to extract intrinsic target properties. The most important properties ordinarily are structure and reflectance. Illumination in space, however, is a significant problem as the extreme range of light intensity, stretching from deep shadow to highly reflective surfaces in direct sunlight, impairs the effectiveness of standard approaches to machine vision. To overcome this critical constraint, an image coding scheme is being investigated which combines local intensity adaptivity, image enhancement, and data compression. It is very effective under the highly variant illumination that can exist within a single frame or field of view, and it is very robust to noise at low illuminations. Some of the theory and salient features of the coding scheme are reviewed. Its performance is characterized in a simulated space application, the research and development activities are described.

  9. Fundamentals of adaptive signal processing

    Uncini, Aurelio

    2015-01-01

    This book is an accessible guide to adaptive signal processing methods that equips the reader with advanced theoretical and practical tools for the study and development of circuit structures and provides robust algorithms relevant to a wide variety of application scenarios. Examples include multimodal and multimedia communications, the biological and biomedical fields, economic models, environmental sciences, acoustics, telecommunications, remote sensing, monitoring, and, in general, the modeling and prediction of complex physical phenomena. The reader will learn not only how to design and implement the algorithms but also how to evaluate their performance for specific applications utilizing the tools provided. While using a simple mathematical language, the employed approach is very rigorous. The text will be of value both for research purposes and for courses of study.

  10. Adaptive Intrusion Data System (AIDS)

    The adaptive intrusion data system (AIDS) was developed to collect data from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique data system which uses computer controlled data systems, video cameras and recorders, analog-to-digital conversion, environmental sensors, and digital recorders to collect sensor data. The data can be viewed either manually or with a special computerized data-reduction system which adds new data to a data base stored on a magnetic disc recorder. This report provides a synoptic account of the AIDS as it presently exists. Modifications to the purchased subsystems are described, and references are made to publications which describe the Sandia-designed subsystems

  11. Performance Analysis of LMS Adaptive FIR Filter and RLS Adaptive FIR Filter for Noise Cancellation

    Jyotsna Yadav

    2013-06-01

    Full Text Available Interest in adaptive filters continues to grow as they begin to find practical real-time applications in areas such as channel equalization, echo cancellation, noise cancellation and many other adaptive signal processing applications. The key to successful adaptive signal processing understands the fundamental properties of adaptive algorithms such as LMS, RLS etc. Adaptive filter is used for the cancellation of the noise component which is overlap with undesired signal in the same frequency range. This paper presents design, implementation and performance comparison of adaptive FIR filter using LMS and RMS algorithms. MATLAB Simulink environment are used for simulations.

  12. Performance Analysis of LMS Adaptive FIR Filter and RLS Adaptive FIR Filter for Noise Cancellation

    Jyotsna Yadav

    2013-07-01

    Full Text Available Interest in adaptive filters continues to grow as they begin to find practical real-time applications in areassuch as channel equalization, echo cancellation, noise cancellation and many other adaptive signalprocessing applications. The key to successful adaptive signal processing understands the fundamentalproperties of adaptive algorithms such as LMS, RLS etc. Adaptive filter is used for the cancellation of thenoise component which is overlap with undesired signal in the same frequency range. This paper presentsdesign, implementation and performance comparison of adaptive FIR filter using LMS and RMSalgorithms. MATLAB Simulink environment are used for simulations.

  13. Adaptive Endpoint Detection Based on Subband Speech

    张文军; 谢剑英

    2003-01-01

    An adaptive endpoint detection algorithm based on band energy and adaptive smoothing algorithm is described.This algorithm utilizes the capability of adaptive smoothing algorithm that intensifies the discontinuity between local areas. The band energy features are selected because of their usefulness in detecting high energy regions (in the incoming signal) and making the distinction between speech and noise. Heuristic "edge-focusing" is used to endpoint detection to save the time in iteration.

  14. Building muscle : a translation of training adaptation

    Boman, Niklas

    2016-01-01

    Training is preparation for what is expected to come through utilization of the plastic and resistive features of nature, known as adaptation. As such, training in humans may have a number of desired goals. These are typically related to sports performance or education. Whatever the goal, a plan needs to be made for reaching it. One needs to identify or select which activities and environments constitute the event or events to which adaptation is sought. Adaptations occurs by imposing somethi...

  15. Preoperative prism adaptation test in normosensoric strabismus

    Schildwächter-von Langenthal, Annette; Kommerell, Guntram; Klein, Ulrike; Simonsz, Huib

    1989-01-01

    textabstractIn 19 patients with normosensoric esotropia, the squint angles measured with the alternate cover test were compared with those after prolonged prismatic correction of the squint angle and with those after prolonged occlusion of one eye. All patients showed an increase of the squint angle after prism adaptation. The angle was generally smaller after diagnostic occlusion of one eye than after prism adaptation. We assume that the increase in the squint angle after prism adaptation is...

  16. Web-Based Adaptive Testing System

    2006-01-01

    Due to the maturing of Internet technology, the adaptive testing can be utilized in the web-based environment and the examinee can take the test anywhere and any time. The purpose of the research is to apply item response theory (IRT), adaptive testing theory and web-service technique to construct an XML format itembank and a system of web-based adaptive testing (WAT) by the framework of three-tiered client server distance testing.

  17. Finnish expatriates' adaptation to a multicultural environment

    Saarentalo-VuorimÀki, Johanna

    2015-01-01

    Finnish expatriates' adaptation to a multicultural environment This study addresses Finnish expatriates adaptation to a multicultural environment. The study focuses on the role of individual values and empathy in adaptation, using Van Oudenhoven and Van der Zee s (e.g., 2000) work on the multicultural personality as the frame of interpretation. The target group were Finnish expatriates and expatriate spouses (N=52) in Brussels. The method used was conversion mixed data analysis. Adaptat...

  18. Delayed radiation effect on animals: adaptive reply

    The adaptive response by micronuclei test was studied in mole-voles (Ellobius talpinus) from two populations differing in degree of radioactive contamination. It was found the significant adaptive response in animals living the left coast of the Techa River, as compared to the reference one. Some convincing evidences of the adaptive rearrangements and higher radioresistance of animals inhabiting the radiocontaminated zone during a long period and in the course of changing generations was obtained at the example of radiosensitive specie. (authors)

  19. Adaptive cluster synchronization in complex dynamical networks

    Cluster synchronization is investigated in different complex dynamical networks. In this Letter, a novel adaptive strategy is proposed to make a complex dynamical network achieve cluster synchronization, where the adaptive strategy of one edge is adjusted only according to its local information. A sufficient condition about the global stability arbitrarily grouped of cluster synchronization is derived. Several numerical simulations show the effectiveness of the adaptive strategy.

  20. Mitochondrial function adaptations to changed metabolic conditions

    Bakkman, Linda

    2010-01-01

    The skeletal muscle mitochondria play a decisive role for the metabolic capacity of the body. A capability to adapt to changed metabolic conditions and energy demands is crucial for weight control and physical exercise. The aim of this thesis was to describe how the mitochondria adapt its function to different environmental conditions and changed metabolic demands. In study I, the aim was to evaluate mitochondrial adaptations to hypoxic exercise. The effect of one-legged...