Analysis of 3-line generalized Feistel networks with double SD-functions

Generalized Feistel networks (GFN) are broadly employed in the design of primitives for block ciphers, stream ciphers, and hash functions. Lately, endowing the functions of GFNs with the structure of nonlinear substitution followed by linear diffusion (substitution-diffusion, SD) has received a great deal of attention. In this contribution, we prove tight lower bounds on the number of differentially and linearly active S-boxes for 3-line GFNs with double SD-functions where two SD-structures are applied one after another. We also show 8-round impossible differentials for 3-line GFNs with bijective functions. Moreover, we demonstrate that the proportion of active S-boxes in all S-boxes for such GFNs is by up to 14% higher than that for 4-line GFNs with double SD-functions, when instantiated with MDS matrices. This indicates that, rather surprisingly, the 3-line GFNs can be more efficient in practice than those with 4 lines.     

Productivity of concentrated hyaluronic acid using a Maxblend fermentor

Application of the Maxblend impeller to the fermentative production of hyaluronic acid (HA) was investigated. A 2-m3-scale fermentor fitted with this impeller (MBF) was used and the main fermentation was started with 85% of the nominal volume containing the pre-culture broth and medium. The kinetic characteristics of the MBF were compared with those of a conventional-type fermentor fitted with a turbine blade (TBN). The HA production yield in the MBF was over 20% higher than that in the TBN under the operating conditions of a high aeration rate and low vessel pressure since the broth viscosity increased. The apparent viscosity of the broth at the end of the cultivation rose to about 70 Pa.s. The molecular weight of the HA produced was independent of the agitation speed within the investigated range, and no significant difference was observed between the viscosity-average molecular weights of the HA obtained in the two types of fermentor, each having an estimated value of 4.3 x 10(6) under the same agitation power.     

Neuron-MOS Parallel Search Hardware for Real-Time Signal Processing

Circuit architecture for parallel data processing directly carried out on the hardware have been developed based on a high-functionality transistor, neuron MOSFET (neuMOS or MOS for short). In the MOS data sorting circuit, multiple analog input data are numbered in binary codes according to the order of their magnitudes after a single ramp voltage scan. A MOS motion-vector detector has been developed for on-chip moving image processing based on x- and y-projection data. The circuit can find the movement of an image in two successive frames within a few 100 nsec. The projection-data-based motion detection algorithm has been tested by computer simulation. Test circuits were fabricated by a double-polysilicon CMOS process and basic operation of the circuits has been demonstrated.     

Effect of posture on the heat transfer areas of the human body

The purpose of this paper is to measure the heat transfer areas of the human body and to examine the effect of posture on these values, which is necessary data for calculating heat exchange between the human body and its environment. The total surface area of a subject's body was measured directly. Then, the convective heat transfer area, radiative heat transfer area and conductive heat transfer area were measured for the same subject in 9 postures: standing, chair sitting, seiza sitting, cross-legged sitting, sideways sitting, both-knees-erect sitting, legs-out sitting, lateral position and supine. The ratios of the radiative heat transfer area, convective heat transfer area ratio and conductive heat transfer area to body surface area were as follows: Standing, 0.942, 0.773, 0.013; chair sitting, 0.910, 0.732, 0.008; seiza sitting, 0.853, 0.621, 0.013; cross-legged sitting, 0.843, 0.606, 0.029; sideways sitting, 0.877, 0.634, 0.030; both-knees-erect sitting, 0.865, 0.609, 0.023; legs-out sitting, 0.878, 0.686, 0.038; lateral position, 0.879, 0.712, 0.039; and supine, 0.811, 0.708, 0.100. Posture was shown to have a noticeable effect on the heat transfer areas of the human body.     

Aqueous solution properties of disulfide linked gemini and cleaved monomeric thiol surfactants

Monomeric thiol surfactants, [C(n)H(2n+1)N(CH(3))(2)CH(2)CH(2)SH]Br, were produced by the cleavage of gemini surfactant containing a disulfide bond in the spacer chain, [C(n)H(2n+1)N(CH(3))(2)CH(2)CH(2)SSCH(2)CH(2)N(CH(3))(2)C(n)H(2n+1)]2Br. The disulfide bond was completely reduced by the addition of four times moles of dithiothreitol in water at room temperature. The critical micelle concentrations of monomeric surfactants were significantly increased in comparison with original gemini surfactants. The monomeric thiol surfactants were stable in the presence of dithiothreitol, whereas they returned gradually to their original gemini surfactants within several days due to air oxidation in water without dithiothreitol. The micelle formation induced by the disulfide linkage formation was suggested by the fluorescence intensity ratio of pyrene. The time course of decrease in thiol concentration associated with the recovery of gemini surfactants was confirmed by the absorption spectra utilizing the reactions with 4,4'-dithiopyridine.     

Advanced glycation end products inhibitors from Alpinia zerumbet rhizomes

Advanced glycation end products (AGEs) are major factors responsible for the complication of diabetes. The present study was carried out to investigate the inhibitory activities on fructosamine adduct and α-dicarbonyl formations by hexane extracts of various parts of Alpinia zerumbet. Furthermore, we isolated two previously known compounds, namely 5,6-dehydrokawain (DK) and dihydro-5,6-dehydrokawain (DDK). 8(17),12-Labdadiene-15,16-dial (labdadiene) was isolated for the first time from the rhizome of A. zerumbet. The results showed that labdadiene (IC₅₀ = 51.06 μg/mL) had similar activity to rutin and quercetin against fructosamine adduct. The inhibition of α-dicarbonyl compounds formation by labdadiene was significantly higher than that of DK and DDK. Our results indicate that labdadiene is a potent antiglycation agent which was found to inhibit AGEs formation in three different steps in the pathway. These data indicate that labdadiene could be used to prevent glycation-associated complications in diabetes.     

Regression Models for Dynamic Properties of Highly Organic Soils

Regression models are presented for the dynamic properties of highly organic soils. The models are based on a database of triaxial and resonant-column/torsional-shear cyclic loading tests on thin walled tube samples mainly retrieved from the Sacramento-San Joaquin Delta. The soils in this database range from highly fibrous peat to amorphous organic clays with organic contents (OC) ranging from 14–81%, water contents ranging from 88–495%, total densities (ρ) ranging from 1.056–1.450?Mg/m3, and effective consolidation stresses (σvc′) ranging from 11–135?kPa. The secant shear modulus (G) and equivalent damping ratio (ξ) were modeled as variables dependent on the shear strain amplitude (γc), consolidation stress (σvc′), and OC. The residuals of the regression models were analyzed against other predictor variables including undisturbed density (ρ), loading frequency (f), and number of loading cycles (N). A regression model for ρ was developed, and conditional probabilities were used to improve the estimation of G and ξ when ρ measurements were available. The database of in situ measurements of shear wave velocity (Vs) was used to adjust the regression model for in situ conditions. Variances and correlations in the regression models are presented.     

Generation of a large area thermal induction plasma by applying a 50 kHz magnetic field

Inductively coupled radio frequency plasmas are gradually becoming an important source of high-temperature and high-reactivity plasmas for processing new functional materials or for removal of unwanted substances. Spatially wider plasmas are required for higher rate, more uniform processing in the future. Although low MHz frequencies have been usually used for induction plasmas, an attempt to expand the high temperature plasma fields was made by superimposing lower frequency 50-kHz magnetic fields on the DC plasma discharge to obtain a small source plasma. Because the penetration depth in such a low frequency field is as long as a few hundred mm, a larger radius plasma can be expected. As a first step, we have investigated the operating conditions under which a stable low frequency plasma is generated, based on theoretical calculations that include the time dependent rate equations for heat transfer and fluid flow in conjunction with the Maxwell electro-magnetic equations. Results showed that the minimum necessary power for expanding a small DC plasma to a wider plasma 100 mm in diameter by applying a 50-kHz magnetic field, is about 130 kW at 0. 1-MPa pressure. This power level is recognized to be within the available range in existing high-power oscillator systems. Measurements were carried out of the time variation of the spectral emission from the plasma immediately after superimposing the 50-kHz magnetic field upon a small area plasma generated with DC power of 1.5 kW at a pressure of 0.01 MPa in Ar gas. At a low power level of about 60 kW, the small plasma starts to expand in the radial direction, and finally, converges to a new wider plasma with 100 mm diameter. FFT analysis of the oscillograph showed that during the transient state, a period fluctuation in light emission occurs at a few tens of Hz reflecting the thermal time constant of a few tens of ms, besides the power frequency of 41.7 kHz. The plasma temperature was estimated by using the spectroscopic line intensities from neutral Ar atoms, as between 8,000 and 11,000 K. A uniformly distributed temperature field was successfully produced by applying the 50-kHz magnetic field, as expected. © 1998 Scripta Technica, Electr Eng Jpn, 123 (4): 48–57, 1998     

A hybrid method for real-time animation of trees swaying in wind fields

Trees are one of the most important elements of natural landscapes. Therefore, in computer graphics, there is a great demand for methods to realize the natural representation of trees in virtual landscapes in various fields such as the entertainment industry or environmental assessment in construction. Many studies have been made on techniques in which the shapes of trees are modeled but only a few studies have been reported on methods to incorporate the shapes with motions in a wind field. Most of these studies use physical simulation techniques based on the equations of motion to generate the branch motions and cannot realize the motions of individual leaves. In this paper, we propose a method to create the natural motions of individual leaves and branches swaying in a wind field. The proposed method uses a hybrid approach combining a stochastic method and a simulation method. The stochastic method is based on 1/f noise, which is observed in various natural phenomena, and provides natural motion to leaves and branches. In addition, a simple simulation method based on the spring model is applied to branches to enhance the reality of their motions. This method enables the real-time creation of the leaf and branch motions. Diverse motions according to tree species and shapes and wind conditions can be easily realized by controlling the parameters.