Showing papers by "University of Electro-Communications published in 1973"
TL;DR: A criterion to measure derivational complexity of formal grammars and languages is proposed and discussed and it is shown that for each nonnegative integer k, there exists a context\3-free language whose rank is k.
Abstract: A criterion to measure derivational complexity of formal grammars and languages is proposed and discussed. That is, the associate language and the L-associate language are defined for a grammar such that the former represents all the valid derivations and the latter represents all the valid leftmost derivations. It is shown that for any phrase\3-structure grammar, the associate language is a contex\3-sensitive language and the L\3-associate language is a context\3-free language. Necessary and sufficient conditions for an associate language to be a regular set and to be a context\3-free language are found. The idea in the above necessary and sufficient conditions is extended to the notion of “rank≓ for a measure of derivational complexity of context\3-free grammars and languages. It is shown that for each nonnegative integer k, there exists a context\3-free language whose rank is k. The paper also includes a few solvable decision problems concerning derivational complexity of grammars.
53 citations
33 citations
TL;DR: In this paper, the triplet and quintet states arising from the low lying terms of the ferrous heme iron atom and those of the oxygen molecule were calculated for all the triplets and quintets.
Abstract: Calculation is carried out for all the triplet and quintet states arising from the low lying terms of the ferrous heme iron atom and those of the oxygen molecule. The charge transfer configurations of ionic structures, Fe 3+ –O 2 - and Fe + –O 2 + , are also taken into account. The results are compared with those for the singlet and septet states calculated previously. If the value of an unknown splitting energy between u and υ orbitals is estimated to be 4,000 cm -1 or more, the singlet state composed mainly of 3 E and 3 Σ g - terms (triplet-triplet binding) becomes the lowest in energy at short distances between the heme and the oxygen molecule. Thus, the diamagnetism of oxyhemoglobin can be explained theoretically on the basis of the electronic structures of the hemes determined by the ligand field theory.
15 citations
Proceedings Article•
20 Aug 1973TL;DR: An artificial tactile sense with multi-elements that not only takes the pressure information without crushing an object in the hand, but also discriminates one pattern from another on the surfaces being in touch therewith is described.
Abstract: This paper describes an artificial tactile sense with multi-elements that not only takes the pressure information without crushing an object in the hand, but also discriminates one pattern from another on the surfaces being in touch therewith.
The eigenvalue of pattern of stress distribution on the surface of the receptor elements is derived from the lielmholtz equation. The element spacing of receptor is designed by using the relative error of the eigenvalue of the sampled pattern as the design specification.
A simple experiment classifying cylinders, trigonal prism and square pillar was performed by the artificial hand with multi-elements. As a result, a high percentage of correct answer is obtained.
12 citations
TL;DR: In this paper, two different processes for photo-carrier excitation in a MOS structure are elucidated: one is an electron-hole pair excitation across the band gap of silicon in the depletion layer of the field-induced junction and another is electron excitation through interface states at the silicon-silicon dioxide interface.
Abstract: Photocurrent of a p-channel MOS-FET was measured as a function of illuminating position, gate voltage, and drain voltage after illumination by a light beam on its gate. Two different processes for photo-carrier excitation in a MOS structure are elucidated: one is an electron-hole pair excitation across the band gap of silicon in the depletion layer of the field-induced junction and another is an electron excitation through interface states at the silicon-silicon dioxide interface. The interface states concerned in the photo-carrier excitation are related to the levels caused by hydroxyl groups frozen at the interface. The levels are situated at 0·16 eV above the valence band of silicon.
10 citations
9 citations
TL;DR: It is shown that each context-free matrix language is a homomorphic image of the intersection of a state language with unconditional transfer and a regular set.
Abstract: The context-free matrix grammar and the state grammar without any restriction in applying productions are considered. It turned out that these grammars are equivalent in the generative power. Another type of state grammar called the state grammar with unconditional transfer is introduced, and it is shown that each context-free matrix language is a homomorphic image of the intersection of a state language with unconditional transfer and a regular set.
9 citations
TL;DR: In this article, the optical spectrum of a hydrogen-like exciton in a static uniform magnetic field is studied theoretically on the basis of the adiabatic approximation as a sequel of our series of study.
Abstract: The optical spectrum of a hydrogen-like exciton in a static uniform magnetic field is studied theoretically on the basis of the adiabatic approximation as a sequel of our series of study. The emphasis of this paper is put on the isotropic excitons rather than anisotropic ones. In §1 and §2 the formulations are given for the hydrogen-like excitons in the magnetic field and the adiabatic approximation, respectively. The results of the calculation are given for the adiabatic potentials, energy levels and optical absorption intensities for m =0 and | m |=1 states for some lower values of n . A way of overcoming the adiabatic approximation will be suggested on the basis of Born's method. It may, however, be difficult to carry out the calculation and the problem is left untouched. Direct comparison with experiment will not be tried in this paper. A qualitative comparison was attempted in another paper.
9 citations
TL;DR: In this article, the contribution of sea spray and materials of continental origin to the atmospheric salt was discussed from the data obtained, and some criticism was made on the way of approach and the methods employed including their check for the future extention of the present investigation.
Abstract: Atmospheric salt samples were collected on meshes over the sea, from which water soluble fractions were separated to determine Cl, Na, K, Mg, Ca and F. The contribution of sea spray and materials of continental origin to the atmospheric salt was discussed from the data obtained. In the light of the initial aim of the present investigation, some criticism was made on the way of approach and the methods employed including their check for the future extention of the present investigation.
7 citations
TL;DR: In this article, a light-scattering experiment with a 45° Y-cut KH2 PO4 crystal was conducted to obtain knowledge of domain structures in ferroelectrics, and it was found that domain walls in KH2PO4 act as reflecting planes, and that many beams generated by the reflection at least partially interfere.
Abstract: In the course of a light-scattering experiment with a 45° Y-cut KH2 PO4 crystal, some new crystal-optics phenomena were observed in the ferroelectric phase when light was incident 45° to the polar axis. (i) A bright oblique line appears in the crystal, (ii) two mutually orthogonally polarized beams, of which images consist of many stripes, emerge from the crystal perpendicular to the incident beams, and (iii) the irradiances of these beams as well as that of the Raman scattering exhibit oscillatory changes with temperature and tend to constant values at Tc − T > 10°–15°. These effects are explained in terms of reflection and interference of light by domains. It is found that domain walls in KH2PO4 act as reflecting planes, that many beams generated by the reflection at least partially interfere, and that the domain structure can drastically change the polarization state of light as it passes through the crystal. This provides a new optical method to obtain knowledge of domain structures in ferroelectrics.
5 citations
TL;DR: In this paper, the Triad approximation method was applied to the anthracene-TCNQ molecular complex and the transition to the second lowest excition state (B u mainly consists the complex are in accord with those observed in solution.
TL;DR: In this paper, a mathematical analysis of molecular integrals of relativistic interactions in molecules is presented based on Gaussian-type orbitals and include those arising from variation of electron mass with velocity.
Abstract: A mathematical analysis is presented of molecular integrals of relativistic interactions in molecules. The integrals are based on Gaussian-type orbitals and include those arising from variation of electron mass with velocity, one-electron Fermi contact interaction, electron spin-same-orbit interaction, electron spin-nuclear spin interaction, electron spin-spin contact interaction, electron spin-other-orbit interaction, electron spin-spin dipolar interaction and electron orbit-orbit interaction. The integrals are expressed in suitable forms for use in computer. It is also pointed out that the integrals are written essentially in terms of the overlap, nuclear attraction, electron repulsion, or field integrals.
TL;DR: In this article, a method to construct SCF intermolecular orbitalS (IMO) is proposed in order to overcome the difficulty that the theoretical excitation energy to a CT exciton configurational state diverges with the increase of crystal size, in the usual configuration interaction method with a one-site excitation model.
TL;DR: In this article, the magnetic properties of polycrystalline films of CrTe 1-x Sb x (0≦ x ≦ 0.4) through ferromagnetic resonance in the temperature range from liquid nitrogen temperature to room temperature were investigated.
Abstract: A study is made of the magnetic properties of polycrystalline films of CrTe 1- x Sb x (0≦ x ≦0.4) through ferromagnetic resonance in the temperature range from liquid nitrogen temperature to room temperature. The observation of spin wave resonance is disturbed because of the broadening of the resonance lines unless x <0.3 or the temperature is far below the Curie temperature T c . The exchange coupling constant A in CrTe film is evaluated to be 0.37×10 -6 erg/cm at 77 K. The value of A decreases gradually as T c is approached or x increases. The dependence of A on temperature is generally consistent with that for Co metal given by Tannenwald and Weber or Cu-Ni alloys by Nose from spin wave resonance. The g -factor is nearly constant at low temperatures but increases rather abruptly as T c is approached. This behavior of g is explained on the basis of two layer-sublattices with a canted spin structure.
TL;DR: In this article, the dependence of the Hall effect of carbons on the electronic band parameters has been analyzed on the basis of Yazawa's band model which takes into account in a simple way the interlayer perturbation.
TL;DR: In this paper, the molecular integrals of variation of electron mass from relativity, spin-orbit interaction, orbit-orbit interation and spin-spin interaction with the overlap, the nuclear attraction and the electron repulsion integrals are derived.
TL;DR: In this paper, a study of the mass spectra of deuterated derivatives of acetanilide, o-, m-and p-chloroacetanilides has confirmed that elimination of ketene from these compounds proceeds via a 4-membered transition state.
Abstract: A study of[M-C2H2O]+, [M-C2H2O-HCN]+, and[M-C2H2O-HCN-H]+ ions in the mass spectra of deuterated derivatives of acetanilide, o-, m-and p-chloroacetanilide has confirmed that elimination of ketene from the molecular ions of these compounds proceeds via a 4-membered transition state.
TL;DR: In this article, a numerical study is made on the ducted-whistler propagation in the magnetosphere by using the phase-integral technique and guidance in the present model takes place along a dipole field-aligned irregularity with a slowly varying, quartic distribution of ionization density.
Abstract: A numerical study is made on the ducted-whistler propagation in the magnetosphere by using the phase-integral technique The guidance in the present model takes place along a dipole field-aligned irregularity with a slowly varying, quartic distribution of ionization density Numerical calculations are made on the track widths, the mode angles, and the travel times of trapped modes for a wide range of irregularity parameters Calculations are carried out for a field line for which the shell parameter L=2, Angerami and Thomas's model of ionization density being employed as a background component of the plasma distribution It is shown that an increase in the transverse size of irregularity may not be responsible for the increase in whistler diffuseness
TL;DR: In this article, the change of molecular size distribution of polymers due to the formation of crosslinks accompanied with scission is studied and the condition for gelation in their case is obtained in a simple form.
Abstract: The change of molecular size distribution of polymers due to the formation of crosslinks accompanied with scission is studied. Fundamental equation of size distribution of polymers of a new type is proposed. The condition for gelation in our case is obtained in a simple form.
TL;DR: In this paper, a navigation system and corresponding equipment components for straight steering of a convoy of snow vehicles traveling on the Antarctic plateau is described. Butler et al. describe a new navigation system consisting of one guide vehicle situated at the end of the convoy and a pilot vehicle at the head of the convoy.
Abstract: A new navigation system and corresponding equipment components for straight steering of a convoy of snow vehicles traveling on the Antarctic plateau is described. On the polar plateau, magnetic compass readings become unreliable, and the surface of snow does not have any distinct target for determination of direction. This new system consists of one guide vehicle situated at the end of the convoy and a pilot vehicle at the head of the convoy. The guide vehicle has two transmission antennas that each transmit alternately. The patterns of these two antennas overlap on the centerline, providing a right-left guidance capability. The pilot vehicle detects this signal and from it determines his correct bearings. The equipment for this system must be protected from the violent vibrations of the snow vehicle. Transistorized equipment designs were therefore selected to meet these requirements.
TL;DR: In this article, the intrinsic viscosity of spherical polymer molecules is calculated on the assumption that the density of segments inside each spherical molecule is represented as an arbitrary function of the distance from its center.
Abstract: Intrinsic viscosity of spherical polymer molecules is calculated on the assumption that the density of segments inside each spherical molecule is represented as an arbitrary function of the distance from its center. The hydrodynamical equations are solved in Stokes' approximation by making use of the spherical harmonics. Both solutions for the inside and outside of the spherical molecule are connected continuously, the energy dissipation is calculated, and the intrinsic viscosity is derived along the similar line with Einstein's work. Debye and Bueche's result for the constant segmental distribution is given as a simple example of our theoretical treatment. Sedimentation of spherical polymer molecules is solved on the same way.