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Showing papers by "Technion – Israel Institute of Technology published in 1976"


Journal ArticleDOI
TL;DR: The quantity R \ast (d) is determined, defined as the infimum ofrates R such that communication is possible in the above setting at an average distortion level not exceeding d + \varepsilon .
Abstract: Let \{(X_{k}, Y_{k}) \}^{ \infty}_{k=1} be a sequence of independent drawings of a pair of dependent random variables X, Y . Let us say that X takes values in the finite set \cal X . It is desired to encode the sequence \{X_{k}\} in blocks of length n into a binary stream of rate R , which can in turn be decoded as a sequence \{ \hat{X}_{k} \} , where \hat{X}_{k} \in \hat{ \cal X} , the reproduction alphabet. The average distortion level is (1/n) \sum^{n}_{k=1} E[D(X_{k},\hat{X}_{k})] , where D(x,\hat{x}) \geq 0, x \in {\cal X}, \hat{x} \in \hat{ \cal X} , is a preassigned distortion measure. The special assumption made here is that the decoder has access to the side information \{Y_{k}\} . In this paper we determine the quantity R \ast (d) , defined as the infimum ofrates R such that (with \varepsilon > 0 arbitrarily small and with suitably large n )communication is possible in the above setting at an average distortion level (as defined above) not exceeding d + \varepsilon . The main result is that R \ast (d) = \inf [I(X;Z) - I(Y;Z)] , where the infimum is with respect to all auxiliary random variables Z (which take values in a finite set \cal Z ) that satisfy: i) Y,Z conditionally independent given X ; ii) there exists a function f: {\cal Y} \times {\cal Z} \rightarrow \hat{ \cal X} , such that E[D(X,f(Y,Z))] \leq d . Let R_{X | Y}(d) be the rate-distortion function which results when the encoder as well as the decoder has access to the side information \{ Y_{k} \} . In nearly all cases it is shown that when d > 0 then R \ast(d) > R_{X|Y} (d) , so that knowledge of the side information at the encoder permits transmission of the \{X_{k}\} at a given distortion level using a smaller transmission rate. This is in contrast to the situation treated by Slepian and Wolf [5] where, for arbitrarily accurate reproduction of \{X_{k}\} , i.e., d = \varepsilon for any \varepsilon >0 , knowledge of the side information at the encoder does not allow a reduction of the transmission rate.

3,288 citations


Journal ArticleDOI
TL;DR: A new approach to the problem of evaluating the complexity ("randomness") of finite sequences is presented, related to the number of steps in a self-delimiting production process by which a given sequence is presumed to be generated.
Abstract: A new approach to the problem of evaluating the complexity ("randomness") of finite sequences is presented. The proposed complexity measure is related to the number of steps in a self-delimiting production process by which a given sequence is presumed to be generated. It is further related to the number of distinct substrings and the rate of their occurrence along the sequence. The derived properties of the proposed measure are discussed and motivated in conjunction with other well-established complexity criteria.

2,473 citations


Journal ArticleDOI
TL;DR: In this article, hot-wire measurements in a plane incompressible jet are reported, where the flow was found to be self-preserving beyond x/d > 40 and measurements were made up to x/D = 120.
Abstract: Results of hot-wire measurements in a plane incompressible jet are reported. The flow was found to be self-preserving beyond x/d > 40 and measurements were made up to x/d = 120. The quantities measured include mean velocities, turbulence intensities and third- and fourth-order terms, as well as two-point correlations and the intermittency factor. Conditional sampling techniques were used to obtain exclusively data within the turbulent zone of the jet. The results are compared with previous investigations.This is the third paper in a sequence providing data on turbulent free shear flows.

515 citations


Journal ArticleDOI
TL;DR: The Berthelot reaction, based on development of a deep blue colour when ammonia reacts with phenol and alkaline hypochlorite, was investigated and modified in this paper, and a convenient and reliable analytical procedure was developed for ammonia and Kjeldahl nitrogen determination.

426 citations


Journal ArticleDOI
TL;DR: The above results suggest that both human and chicken retinol binding proteins behave similar with respect to the binding of the ligands.
Abstract: Fluorimetric titrations were used to determine apparent dissociation constants of the all-trans isomers of retinol, retinoic acid, retinyl acetate and retinyl palmitate to human-retinol binding protein and chicken-retinol binding protein. Enhancement of the fluorescence of retinol and retinyl acetate when bound to the protein was utilized to establish the binding affinity of these compounds. With retinoic acid which is essentially a non-fluorescent compound, quenching of protein fluorescence due to energy transfer to the bound ligand from tryptophanyl residues served to determine the binding affinity. The various ligands display 1:1 molecular complexes with both types of retinol binding proteins. Retinol, retinoic acid and retinyl acetate were found to have similar binding affinities to both species of carrier proteins: For retinol K'd=1.9 X 10(-7) M with human-retinol binding protein and K'd=1.5 X 10(-7) M with chicken-retinol binding protein; for retinoic acid K'd-2.1 X 10(-7) M with human-retinol binding protein; for retinyl acetate and K'd=2.2 X 10(-7) M with chicken-retinol binding protein; for retinyl acetate K'd=2.2 X 10(-7) M with human-retinol binding protein and K'd=1.7 X 10(-7) M with chicken-retinol binding protein. Retinyl palmitate appeared to have weak association with either of the two retinol binding proteins, if at all. The above results suggest that both human and chicken retinol binding proteins behave similar with respect to the binding of the ligands. Non-polar interactions probably play a primary role in the binding and effects of functional groups and charges are of secondary importance.

390 citations


Journal ArticleDOI
TL;DR: This paper provides a linear-time algorithm for computing an st-numbering for any biconnected graph and can be combined with some new results by Booth and Lueker to provide alinear-time implementation of the Lempel-Even-Cederbaum planarity-testing algorithm.

294 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical and experimental study of the aeroelastic instability of a panel with various boundary conditions on its leading and trailing edges, exposed to air flow over its upper surface or on both sides.

276 citations


Journal ArticleDOI
TL;DR: Brief pulses of Laser emitted radiant heat were used to induce cutaneous painful sensations in human volunteers and a late negative-positive component of the EP which correlated in amplitude with the subjective sensation was abserved in four subjects.
Abstract: Brief pulses of Laser emitted radiant heat were used to induce cutaneous painful sensations in human volunteers. Accurate timing of the stimuli permitted recording of scalp averaged evoked potentials. A late negative-positive component of the EP which correlated in amplitude with the subjective sensation was abserved in four subjects. The latency of this component (130–160 msec) correlated with stimulus intensity.

245 citations




Journal ArticleDOI
TL;DR: In this paper, the authors presented 5563 nuclear mass excesses of nuclei beyond the 1 p shell, calculated from the semi-empirical shell-model mass equation of Liran and Zeldes.

Journal ArticleDOI
TL;DR: This is the first demonstration of age-related alterations in a purified form of a non-metabolic enzyme, which can be related to reduced activity, in age-dependent deterioration of cellular functions.
Abstract: Cytoplasmic superoxide dismutase has been purified from livers of young (6 months) and old (27 months) rats The enzyme purified from old animals shows an age-related reduction in the specific activity, accumulation of antigenically cross-reacting material and increased sensitivity to temperature No differences were found in the molecular weight, electrophoretic mobility, antigenicity and Ki between enzymes purified from young and old rats This is the first demonstration of age-related alterations in a purified form of a non-metabolic enzyme, which can be related to reduced activity The possible role of this reduced activity in age-dependent deterioration of cellular functions is discussed

Journal ArticleDOI
TL;DR: Despite the differences in age-related changes in specific activity in homogenates of liver, heart and brain the enzyme shows a considerable decline in catalytic activity per antigenic unit in all three organs in both aging rats and mice.

Journal ArticleDOI
TL;DR: It is shown that determining who wins such a game if each player plays perfectly is very hard; this result suggests that the theory of combinational games is difficult.
Abstract: This paper considers a generalization, called the Shannon switching game on vertices, of a familiar board game called Hex. It is shown that determining who wins such a game if each player plays perfectly is very hard; in fact, if this game problem is solvable in polynomial time, then any problem solvable in polynomial space is solvable in polynomial time. This result suggests that the theory of combinational games is difficult.

Journal ArticleDOI
TL;DR: This paper suggests conducting a logical analysis of programs by using invariants which express what is actually occurring in the program, and provides criteria for using the invariants to check simultaneously for correctness or incorrectness.
Abstract: Most present systems for verification of computer programs are incomplete in that intermediate inductive assertions must be provided manually by the user, termination is not proven, and incorrect programs are not treated. As a unified solution to these problems, this paper suggests conducting a logical analysis of programs by using invariants which express what is actually occurring in the program.The first part of the paper is devoted to techniques for the automatic generation of invariants. The second part provides criteria for using the invariants to check simultaneously for correctness (including termination) or incorrectness. A third part examines the implications of the approach for the automatic diagnosis and correction of logical errors.

Journal ArticleDOI
TL;DR: A lower bound on the minimal mean-square error in estimating nonlinear diffusion processes is derived and the bound holds for causal and noncausal filtering.
Abstract: A lower bound on the minimal mean-square error in estimating nonlinear diffusion processes is derived. The bound holds for causal and noncausal filtering.

Journal ArticleDOI
TL;DR: In this paper, the effect of two calcareous fillers (ground limestone and reagent quality CaCO 3 ) on the compressive strength of Portland cement, was studied and compared with the corresponding effect of pozzolanic fillers and one non-calcareous, non-hydraulic filler (reagent quality caF 2 ).

Journal ArticleDOI
TL;DR: In this article, it was shown that the stability of a dither system is related to that of an equivalent smoothed system, whose nonlinear element is the convolution of the dither distribution and the original nonlinearity.
Abstract: A dither is a high-frequency signal introduced into a nonlinear system with the object of augmenting stability. In this paper,[1] it is shown that the effects of dither depend on its amplitude distribution function. The stability of a dithered system is related to that of an equivalent smoothed system, whose nonlinear element is the convolution of the dither distribution and the original nonlinearity. The ability of dithers to stabilize large classes of nonlinear systems is explained in terms of an effective narrowing of the nonlinear sector. A feature of the approach taken here is that a deterministic (i.e., strong) concept of stability is established under probabilistic (i.e., weak) assumptions on the dither.

Journal ArticleDOI
TL;DR: It was found that right visual field superiority which was independent of scanning direction appeared at the fifth grade, suggesting that hemispheric dominance and its attributes, parallel and sequential pattern recognition processes, is the major factor which determines the field preference for verbal material.

Journal ArticleDOI
TL;DR: In this article, a new theoretical model for calculating bubble formation at an orifice submerged in an inviscid liquid is presented, which is able to determine the instant of detachment as the moment at which the neck of the bubble closes.

Journal ArticleDOI
TL;DR: This paper calculates the expected cost of following a modified BRP for lifetime distributions possessing a special structure and illustrates it for the case of an Erlang distribution and a numerical comparison is made between a modifiedBRP and a standardBRP for the special case of a two stage Erlang distributions.
Abstract: A well known preventive replacement policy is the block replacement policy (BRP). In such a policy the item undergoes a planned replacement at a sequence of equally spaced time points independent of failure history. The main advantage of a BRP is its simplicity, because under this policy it is unnecessary to keep detailed records about times of failures or ages of items. The main drawback of a BRP is that at planned replacement times we may be replacing practically new items. In this paper we study a modified BRP which is free of this drawback. We calculate the expected cost of following a modified BRP for lifetime distributions possessing a special structure and illustrate it for the case of an Erlang distribution. A numerical comparison is made between a modified BRP and a standard BRP for the special case of a two stage Erlang distribution.

Book ChapterDOI
TL;DR: A speculative model reference adaptive scheme for the muscle control system is proposed, and the model is then simulated, using physiological data, to investigate the relative effectiveness and feasibility of parameters and signal adaption.
Abstract: Publisher Summary Using the adaptive system in engineering as a background, a speculative model reference adaptive scheme for the muscle control system is proposed in this chapter. The model is then simulated, using physiological data, to investigate the relative effectiveness and feasibility of parameters and signal adaption. The simulations are followed by experimental results supporting the adaptation concepts in addition to the manifestation of unconscious learning—equivalent to the building of the model reference in the present scheme. The basic results can be summarized as—the parameters of the small signal, linear muscle model are non-linearly and strongly interrelated; the range of variations of the reflex loop parameters is physiologically bound; signal levels in the central nervous system (CNS) have higher bounds than those of the reflex loop; in view of the first two points, it is quite obvious that parameter adaptation schemes developed for engineering purposes are inadequate, and that parameter adaptation is inferior to signal adaptation; and signal adaptation is feasible in cases unaffected by neural delay. Parameter adaptation helps modify the response to external disturbance input, as long as the system is well identified.

Journal ArticleDOI
TL;DR: In this article, the photodissolution rate is proportional to the light intensity absorbed in the As2S3 at the Ag interface, but photoelectrons ejected from the Ag into the As 2S3 also contribute.
Abstract: A new technique, measurement of the electrical resistance change of the Ag layer, is developed to study the kinetics of photodissolution of Ag in amorphous As2S3. It is shown that the photodissolution rate is proportional to the light intensity absorbed in the As2S3 at the As2S3Ag interface, but photoelectrons ejected from the Ag into the As2S3 also contribute. The process is shown to be two-stage. Firstly a critical “radiation damage” dose must be accumulated in the As2S3. Secondly, the Ag atom is photon-assisted across the As2S3Ag interface activation barrier.

Journal ArticleDOI
TL;DR: In this article, the tensile strength of angle ply balanced laminated made of glass fibers and epoxy matrix has been investigated under dynamic loading using an instrumented drop weight apparatus, and a comparison of theoretical and experimental stress-strain curves reveals that good agreement exists for a certain range of fiber orientation.
Abstract: Tensile strength of angle ply balanced laminated made of glass fibers and epoxy matrix has been investigated under dynamic loading using an instrumented drop weight apparatus. A comparison of theoretical and experimental stress-strain curves reveals that good agreement exists for a certain range of fiber orientation. Different failure criteria have to be used for each range. Failure stresses in the dynamic case are found to be con siderably higher than the corresponding static values for the complete range of fiber orientation. Failure strains and initial effective moduli are the same for static and for impact loadings.

Journal ArticleDOI
01 Jan 1976
TL;DR: It is shown that higher gains are attainable without limit cycle oscillations and with improved steady-state error, and a simple pole is added at the origin of the forward transfer function for improved system performance.
Abstract: Limit-cycle oscillations of two models of the triceps surae muscle stretch reflex system are analyzed, using previously derived criteria for single sign integral pulse frequency modulated (SSIPFM) control systems The muscle spindle (MS) is assumed to function as an SSIPFM encoder The system's stability and error correction ability are studied using the SSIPFM model together with published physiological data It is shown that the loop gain, which in the model represents the decerebrate preparation, is close to the instability value, despite its relatively small magnitude This observation and the steady-state error of the model concur with physiological phenomena of decerebrate preparations In accordance with the adaptive control systems model in which the parameters can be modified, a simple pole is added at the origin of the forward transfer function for improved system performance The new model is analyzed, and it is shown that higher gains are attainable without limit cycle oscillations and with improved steady-state error A sensitivity study of the influence of system parameter variation on stability is carried out for both systems

Journal ArticleDOI
TL;DR: The interaction between retinol-binding proteins and prealbumins of human and chicken was studied by fluorescence polarization techniques and suggested that prealbumin possesses four identical binding sites for retinl-binding protein, one for each subunit, but that the binding is of a negative cooperative nature.

Journal ArticleDOI
TL;DR: In this article, the effect of gypsum on strength was analyzed in terms of its influence on the extent of hydration and on the chemical composition of the CSH gel.
Abstract: The paste hydration of C3S containing different amounts of gypsum was studied. Reaction rates and the composition of hydrated products were evaluated. The gypsum influenced the quantity and quality of the hydrated products by accelerating the hydration process and, at the same time, lowering the intrinsic strength of the gel. Variations in intrinsic strength correlated linearly with the C/S ratio of the CSH gel. The effect of gypsum on strength was interpreted in terms of its influence on the extent of hydration and on the chemical composition of the gel.

Journal ArticleDOI
TL;DR: In this paper, a previously developed fatigue failure criterion for laminae in a state of plane stress is used to establish a failure criteria for first fatigue failure of balanced laminates, and an extensive tension-tension fatigue testing program for E-glass/epoxy angle plies with various reinforcement angles has been carried out to test the validity of the theory.
Abstract: A previously developed fatigue failure criterion for laminae in a state of plane stress is used to establish a failure criterion for first fatigue failure of balanced laminates An extensive tension-tension fatigue testing program for E-glass/epoxy angle plies with various reinforcement angles has been carried out in order to test the validity of the theory It has been found that for certain ranges of reinforcement angle there is good agreement between theory and experiment, whereas for other ranges of reinforcement angle this is not the case


Journal ArticleDOI
TL;DR: A literature review on the structure, crystallization and properties of lead glasses is given in this paper, with a focus on the properties of the lead crystal. But this review is limited to lead glasses.
Abstract: A literature review is given on the structure, crystallization and properties of lead glasses.