Evolving hash functions by means of genetic programming

Proceedings of the 8th annual conference on Genetic and evolutionary computation. Seattle, Washington, USA, July 08-12, 2006The design of hash functions by means of evolutionary computation is a relatively new and unexplored problem. In this work, we use Genetic Programming (GP) to evolve robust and fast hash functions. We use a fitness function based on a non-linearity measure, producing evolved hashes with a good degree of Avalanche Effect. Efficiency is assured by using only very fast operators (both in hardware and software) and by limiting the number of nodes. Using this approach, we have created a new hash function, which we call gp-hash, that is able to outperform a set of five human-generated, widely-used hash functions.This article has been financed by the Spanish founded research MCyT project OP:LINK, Ref:TIN2005-08818-C04-02.Publicad

Finding state-of-the-art non-cryptographic hashes with genetic programming

Proceding of: 9th International Conference, Reykjavik, Iceland, September 9-13, 2006.The design of non-cryptographic hash functions by means of evolutionary computation is a relatively new and unexplored problem. In this paper, we use the Genetic Programming paradigm to evolve collision free and fast hash functions. For achieving robustness against collision we use a fitness function based on a non-linearity concept, producing evolved hashes with a good degree of Avalanche Effect. The other main issue, efficiency, is assured by using only very fast operators (both in hardware and software) and by limiting the number of nodes. Using this approach, we have created a new hash function, which we call gp-hash, that is able to outperform a set of five human-generated, widely-used hash functions.This article has been financed by the Spanish founded research MCyT project OP:LINK, Ref:TIN2005-08818-C04-02

Field experimental study of traffic-induced turbulence on highways

This paper is focused on traffic-induced turbulence (TIT) analysis from a field campaign performed in 2011, using ultrasonic anemometers deployed in the M-12 Highways, Madrid (Spain). The study attempts to improve knowledge about the influence of traffic-related parameters on turbulence. Linear relationships between vehicle speed and turbulent kinetic energy (TKE) values are found with coefficients of determination (R2) of 0.75 and 0.55 for the lorry and van respectively. The vehicle-induced fluctuations in the wind components (u', v' and w') showed the highest values for the longitudinal component (v) because of the wake-passing effect. In the analysis of wake produced by moving vehicles it is indicated how the turbulence dissipates in relation to a distance d and height h. The TKE values were found to be higher at the measuring points closer to the surface during the wake analysis.This work was supported by the OASIS Research Project that was co financed by CDTI (Spanish Science and Innovation Ministry) and developed with the Spanish companies: Iridium, OHL Concesiones, Abertis, Sice, Indra, Dragados, OHL, Geocisa, GMV, Asfaltos Augusta, Hidrofersa, Eipsa, PyG, CPS, AEC and Torre de Comares Arquitectos s.l and 16 research centres

Self-adaptive MOEA feature selection for classification of bankruptcy prediction data

Article ID 314728Bankruptcy prediction is a vast area of finance and accounting whose importance lies in the relevance for creditors and investors in evaluating the likelihood of getting into bankrupt. As companies become complex, they develop sophisticated schemes to hide their real situation. In turn, making an estimation of the credit risks associated with counterparts or predicting bankruptcy becomes harder. Evolutionary algorithms have shown to be an excellent tool to deal with complex problems in finances and economics where a large number of irrelevant features are involved.This paper provides a methodology for feature selection in classification of bankruptcy data sets using an evolutionary multiobjective approach that simultaneously minimise the number of features and maximise the classifier quality measure (e.g., accuracy).The proposed methodology makes use of self-adaptation by applying the feature selection algorithm while simultaneously optimising the parameters of the classifier used. The methodology was applied to four different sets of data. The obtained results showed the utility of using the self-adaptation of the classifier.This work was partially supported by the Portuguese Foundation for Science and Technology under Grant PEst-C/CTM/LA0025/2011 (Strategic Project-LA 25-2011-2012) and by the Spanish Ministerio de Ciencia e Innovacion, under the project "Gestion de movilidad efficiente y sostenible, MOVES" with Grant Reference TIN2011-28336

Sensory function in cluster headache: an observational study comparing the symptomatic and asymptomatic sides

Background: Based on inconsistent sensory alterations demonstrated in cluster headache (CH), the aim of this study was to determine whether patients with CH develop sensory changes in the symptomatic side compared to the asymptomatic side. Methods: Quantitative sensory testing (QST), including pressure pain threshold (PPT), tactile detection threshold (TDT), prick detection threshold (PDT), and two-point detection threshold (2PDT), was evaluated in 16 patients (seven women; age 41.9±6.8 years) with CH. Test sites included the rst, second, and third divisions of the trigeminal nerve, cervical spine, and thenar eminence in the symptomatic and asymptomatic sides. Results: The symptomatic side, compared to the asymptomatic side, presented signi cantly decreased PPT in the rst (P=0.011; 423.81±174.05 kPa vs 480.13±214.99 kPa) and second (P=0.023; 288.88±140.80 kPa vs 326.38±137.33 kPa) divisions of the trigeminal nerve, significantly increased TDT in the first (P=0.002; 2.44±0.40 vs 1.74±0.24) and second (P=0.016; 1.92±0.34 vs 1.67±0.09) divisions, and increased 2PDT in the rst division (P=0.004; 18.13±4.70 mm vs 15.0±4.92 mm) and neck (P=0.007; 45.31±20.65 mm vs 38.44±16.10 mm). Conclusion: These results support the prior evidence suggesting a specific pattern of alteration of sensory function with alterations in the symptomatic side compared to the asymp- tomatic side

Immediate Effects of Upper Cervical Translatoric Mobilization on Cervical Mobility and Pressure Pain Threshold in Patients With Cervicogenic Headache: A Randomized Controlled Trial

Objective The purpose of this study was to evaluate the immediate effects of upper cervical translatoric spinal mobilization (UC-TSM) on cervical mobility and pressure pain threshold in subjects with cervicogenic headache (CEH). Methods Eighty-two volunteers (41.54 ± 15.29 years, 20 male and 62 female) with CEH participated in the study and were randomly divided into the control and treatment groups. The treatment group received UC-TSM and the control group remained in the same position for the same time as the UC-TSM group, but received no treatment. Cervical mobility (active cervical mobility and flexion-rotation test), pressure pain thresholds over upper trapezius muscles, C2-3 zygapophyseal joints and suboccipital muscles, and current headache intensity (visual analog scale) were measured before and immediately after the intervention by 2 blinded investigators. Results After the intervention, UC-TSM group exhibited significant increases in total cervical mobility (P =.002, d = 0.16) and the flexion–rotation test (P .05). Nevertheless, there was a significantly lower intensity of headache in the UC-TSM group (P =.039, d = 0.57). Conclusions Upper cervical translatoric spinal mobilization intervention increased upper, and exhibited a tendency to improve general, cervical range of motion and induce immediate headache relief in subjects with CEH

Ultrasound measurement of the effects of high, medium and low hip long-axis distraction mobilization forces on the joint space width and its correlation with the joint strain

Background: No study has evaluated the mechanical effect of different magnitudes of long axis-distraction mobilization (LADM) force on hip joint space width (JSW) or the association between the separation of joint surfaces and the strain on hip capsular ligaments. Objective: To compare the joint separation when applying three different magnitudes of LADM forces (low, medium and high) and to analyse the correlation between joint separation, strain on the inferior ilio-femoral ligament and magnitude of applied force. Design: Repeated measures controlled laboratory cadaveric study. Methods: Three magnitudes of force were applied to 11 cadaveric hip joints (mean age 73 years). Ultrasound images were used to measure joint separation, and strain gauges recorded inferior ilio-femoral ligament strain during each condition. Results: The magnitude of joint separation was significantly different between low (0.23 ± 0.19 mm), medium (0.72 ± 0.22 mm) and high (2.62 ± 0.43 mm) forces (p 0.723; p < 0.001). Conclusion: Hip joint separation and ligament strain during LADM are associated with the magnitude of the applied force

Effects of a resistance-training programme on endoplasmic reticulum unfolded protein response and mitochondrial functions in PBMCs from elderly subjects

10 p.Aging has been related with a decline in the ability to handle protein folding, which leads to endoplasmic reticulum stress and alterations in unfolded protein response (UPR). Importantly, physical activity could activate the UPR and attenuate or prevent age-induced endoplasmic reticulum (ER) dysfunction. The current study evaluated the effects of a resistance exercise on UPR and mitochondrial functions in peripheral blood mononuclear cells (PBMCs) from elderly subjects. Thirty healthy women and men (age, 72.8, sx− = 2.2 years) were randomized to a training group, which performed an 8-week resistance training programme, or a control group, which followed their daily routines. The phosphorylation of PERK and IRE1, as well as ATF4, and XBP1 protein expression, significantly increased following the training, while expression of BiP, AFT6 and CHOP remain without changes. Additionally, the intervention also induced an increase in PGC-1α and Mfn1 protein levels, while no changes were found in Drp1 expression. Finally, the resistance protocol was not able to activate PINK1/Parkin and Bnip3/Nix pathways. The results obtained seem to indicate that 8-week resistance exercise activates the UPR, stimulates mitochondrial biogenesis, maintains mitochondrial dynamics and prevents mitophagy activation by unfolded proteins in PBMCs from elderly subjects.S