bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Properties of Atoms and Chemical Nature of Bonds in Molecules, Clusters, and Solids as Derived from a Topological Analysis of Theoretical or (and) Experimental Charge Densities
Authors: GATTI C. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The roles of noncatalytic ATP binding and ADP binding in the regulation of dynein motile activity in flagella
Authors: Inoue Yuichi , Shingyoji Chikako 
Published: July 2007

AbstractThe regulation of dynein activity to produce microtubule sliding in flagella has not been well understood. To gain more insight into the roles of ATP and ADP in the regulation, we examined the effects of fluorescent ATP analogues and fluorescent ADP analogues on the ATPase activity and motile activity of dynein. 21S dynein purified from the outer arms of sea urchin sperm flagella hydrolyzed BODIPY® FL ATP (FL‐ATP) at 78% of the rate for ATP hydrolysis. FL‐ATP at 0.1–1 mM, however, induced neither microtubule translocation on a dynein‐coated glass surface nor sliding disintegration of elastase‐treated axonemes. Direct observation of single molecules of the fluorescent analogues showed that both the ATP and ADP analogues were stably bound to dynein over several minutes (dissociation rates = 0.0038–0.0082/s). When microtubule translocation on 21S dynein was induced by ATP, the initial increase of the mean velocity was accelerated by preincubation of the dynein with ADP. Similar increase was also induced by the preincubation with the ADP analogues. Even after preincubation with ADP, FL‐ATP did not induce sliding disintegration of elastase‐treated axonemes. After preincubation with a nonhydrolyzable ATP analogue, AMPPNP (adenosine 5′‐(β:γ‐imido)triphosphate), however, FL‐ATP induced sliding disintegration in ∼10% of the axonemes. These results indicate that both noncatalytic ATP binding and stable ADP binding, in addition to ATP hydrolysis, are involved in the regulation of the chemo‐mechanical transduction in axonemal dynein. © 2007 Wiley‐Liss, Inc.
On the interpolation function for classes of sampling theorems with non‐uniform sampling points
Authors: Kido Takuro 
Published: July 2007

AbstractA time waveform which is absolutely square integrable and whose Fourier spectrum is identically zero above a certain finite frequency is called a band‐limited waveform. This paper discusses a sampling theorem for a band‐limited waveform based on a set of sampling points. The waveform structure is such that a finite number of sampling points are periodically repeated. The following results are obtained. An interpolation formula which is sufficiently general is established for the sampling theorem of the discussed type. The necessary and sufficient condition is derived for the interpolation function in order that the interpolation formula apply to any band‐limited waveform. By this theorem, required interpolation functions can systematically be determined by the Fourier expansion coefficient, with respect to the angular frequency, of a finite number of two‐variable functions of time and angular frequency, called the generating variable. Then a special case of sampling theorem is considered, where the interpolation filter determined in correspondence to the interpolation function is time‐invariant, deriving the necessary and sufficient condition for the Fourier spectrum of the interpolation function (i.e., the frequency characteristics of the interpolation filter). Some detailed expressions are discussed for the interpolation function, which can easily make the Fourier spectrum continuous or smooth.
A construction of single error correcting and multiple unidirectional error detecting codes
Authors: Itoh Hideo , Nakamichi Matsuroh 
Published: July 2007

AbstractThis paper proposes a construction method for a code (SEC‐MUED code) which corrects single errors and detects multiple unidirectional errors. It is a kind of concatenated code which can be obtained by concatenating the check bits of a Hamming single error correcting code, Berger code, parity code and Berger code with natural number weight assigned to logic value 0 with the information bits. Another method of construction of an SEC‐MUED code has already been proposed by Bose et al. This paper first discusses the construction of the proposed code, proof of the code and construction of the encoder and the decoder. Then a quantitative comparison is made of the proposed code and the code by Berger et al. from the viewpoint of the number of check bits, the number of gates in the signal path of the encoder and decoder, and the complexity of hardware from the implementation viewpoint. As a result, it is shown that the proposed code results in fewer check bits than the code by Bose et al., fewer gates in the encoder and the decoder and less hardware complexity. For example, for information bit length of 64, the number of gates is 69% and 58% of the Bose code in encoding and decoding, respectively, and the hardware complexity is 51% of the Bose code. The proposed code is thus shown to be a more efficient SEC‐MUED code.
Adaptive channel equalizer with frequency sampling filter
Authors: Fujii Tetsurou , Harashima Hiroshi , Miyakawa Hiroshi 
Published: July 2007

AbstractThis paper proposes a new method of circuit construction for the adaptive channel equalizer using frequency sampling filter, together with the result of analysis of its characteristics. In the proposed method, the discrete Fourier transform is applied successively to the received signal and, by adjusting the tap coefficients according to the energy in each DFT coefficient, high‐speed convergence is realized. A discrete Fourier transform using a frequency sampling filter is adopted in the proposed system, whereby an adaptive equalizer with arbitrary number of taps can easily be constructed. From the result obtained by using a simulated sequence, it is seen that the proposed system has the same order of convergence speed with approximately half the number of multiplications and divisions required with the lattice‐type adaptive equalizer. A parallel construction is possible for the adaptive channel equalizer with frequency sampling filter and the method is applicable to existing equipment.
Thin film fresnel light modulators
Authors: Takizawa Kuniharu 
Published: July 2007

AbstractThin film Fresnel modulators were analyzed and studied experimentally. These devices, which can electrically control the phase of the diffracted light from a one‐dimensional Fresnel lens, have the following advantages: (1) they can perform simultaneous focusing and optical modulation; (2) the light output is unaffected by temperature variation; (3) no analyzer is required; (4) a high optical input power can be used. The light modulator may be of the amplitude type, using a channel waveguide, or the phaseshift type, using a slab waveguide. The former has a better light extinction ratio and consumes less power, while the latter has a high light output and is easy to fabricate. A LiNbO3 crystal was cut in the Y direction and thermally diffused with Ti,producing one‐dimensional lens 2 mm wide with a total length of 5 mm, having 13 zones. Electrodes were placed on the even‐numbered zones by photolithography. In the amplitudetype, the diameter of the focal spot used 56 μm, the extinction ratio was 18.1 dB, the half‐wave voltage was 28 V and an efficiency of ‐10.1 dB was obtained. In the phase‐shift type, the spot diameter was 53 μm, the extinction ratio was 11.7 dB, the half‐wave voltage was 39 V and an efficiency of ‐10.6 dB was obtained. The focal length of both types was 12.4 cm.
Frequency weighted LPC spectral matching measures
Authors: Sugiyama Masahide , Shikano Kiyohiro 
Published: July 2007

AbstractSpectral matching is a powerful method of calculating the distance between two frames in speech data which is used in speech analysis, speech recognition and the evaluation of speech quality. Since the introduction of LPC [linear prediction coefficient] analysis, several LPC spectral matching measures have been proposed. It is widely known that human hearing has greater sensitivity in the low‐frequency region than in the high‐frequency region. However, it is impossible to assign frequency weighting using conventional LPC spectral matching measures. This paper proposes two types of frequency weighted LPC spectral matching. The first method is applicable only to the peak weighted measure, while the second is applicable to a more general LPC spectral matching measure. The theoretical relation between these two types of frequency weighting methods is discussed and vowel identification experiments are carried out to examine the effectiveness of these methods. It is seen that the first method is effective in assigning the same frequency weighting to all frames and the second method is effective in assigning different frequency weightings to frames with different phonemic reference patterns.
Time‐optimal transmission of time‐variant particle flow streams through time‐invariant networks
Authors: Onaga Kenji 
Published: July 2007

AbstractThis paper deals with the dynamic flow problem in the time‐optimal transmission of time‐variant input particle flow streams through the time‐invariant networks with edge capacity c and edge delay d. The minimum‐cost static flow problem is first solved by the successive assignment method to obtain the routing information i = 1, 2,…, k}, where pi is the i‐th minimum‐cost path, Δi is the maximum flow augmentation is the cost. The routing information is next used to find an algorithm for constructing the maximum flow and preserving time optimality. In the first half of the paper a solution is found for the case in which both time and flow are discrete; in the second half, the result is extended to the case in which time and flow are continuous.
Propagation properties of dielectric waveguides with optically induced plasma layers
Authors: Ogusu Kazuhiko , Itoh Hidetoshi , Tanaka Ikuo 
Published: July 2007

AbstractPropagation of millimeter waves in a semiconductor dielectric waveguide is controlled by illuminating the waveguide by light with a photon energy larger than the forbidden gap because of the generation of plasma. A theoretical and experimental study is made of this and the effects of waveguide size and plasma layer thickness on attenuation and phase shift are analyzed for various illumination intensities. Further, the modulation characteristics are examined in relation to the response of the plasma density. A shorter plasma recombination time is found to be favorable for high speed control, but this requires intense illumination to maintain the required plasma density. A test made with a Si waveguide at 50 GHz substantiates the usefulness of this technique and the validity of the theory.
Design of CMOS masterslice logic LSI
Authors: Asano Michio , Masaki Akira , Itoh Tsuneo , Takechi Makoto , Fujita Minoru , Ikuzaki Kunihiko , Murata Shingo 
Published: July 2007

AbstractThis paper describes the design of a masterslice LSI with two‐input equivalent 6000 gates (three‐input 4000 gates). It uses 2 μm CMOS dual Al interconnect process technology and has application to medium and small computers, terminals and peripheral equipment. It is shown that a three‐input bent‐type gate basic cell effectively realizes high integration because various logic gates can be constructed with small areas. to realize high speed, the chip is designed in several blocks. the intra‐block net uses short interconnects, whereas the inter‐block net is driven by buffers with high load drive capability. Special clock supply circuits for small clock signal skew and a register‐file to accommodate a small capacity RAM into LSI are designed. the number of wiring channels is determined based on the theoretical wiring length, and it has been confirmed that channel utilization agrees with the theoretical value. Since it is important that a masterslice LSI be designed to its specifications within a short time, a method is developed to calculate accurately the circuit delay time during the design. Evaluation of the test LSIs shows that the average gate delay time of 1.81 ns is obtained; this agrees to within 5.4% of the calculated delay time.
Wave digital filters for second and fourth order basic reactance sections
Authors: Suzuki Masatoshi , Wakabayashi Hiroyuki , Miki Nobuhiro , Nagai Nobuo 
Published: July 2007

AbstractOne way to realize a low coefficient sensitivity digital filter is to simulate a resistively terminated LC ladder network. This is called a wave digital filter. However, the transfer functions realized with a resistively terminated LC ladder network are limited. A resistively terminated reactance network realizing an arbitrary transfer function may be synthesized by cascading basic reactance sections. In this paper, we use Brune, Types C, E and D sections with 2‐wire lines as the models for the basic reactance section. These basic sections are represented using modal decomposition by equivalent circuits made of ideal transforming networks (including gyrators for nonreciprocal circuits) and uncoupled lossless lines. Then we derive basic wave digital filters of reciprocal and nonreciprocal second‐order sections and reciprocal fourth‐order sections. the digital filters realized from the basic wave digital filters in the present method do not correspond exactly to the original analog circuit as long as they are constructed with multipliers with finite word length; however, they become low coefficient sensitivity digital filters with as good performance as the wave digital ladder filters.
Power spectral density of multilevel digital signals in nonlinear channels
Authors: Okamoto Eiji 
Published: July 2007

AbstractIn digital microwave communication, a power amplifier is located at the transmitting side. Generally, such a power amplifier has a nonlinear input‐output characteristic. However, the greatest problem with this kind of nonlinear transmission system is the spectrum width of the signals. Until now, a spectrum has been obtained by approximating the input‐output characteristics of a power amplifier by third‐order equations. When third‐order equations are used, however, only one sidelobe appears in the spectrum. to obtain a more detailed spectrum, the input‐output characteristics of the power amplifier must be approximated by equations of higher than third‐order. This paper presents equations for the power spectral density of multilevel digital output signals of a transmission system. the system consists of a power amplifier having an input‐output characteristic which can be approximated by a filter and fifth‐order equations. Consequently, it has become possible to compute a power spectral density, for example, for quadrature amplitude modulation (QAM) having more than 32 levels, which was difficult to obtain by the simulation method. Examples show the results of computations for power spectral densities of 16‐ and 32‐level QAMs.
Effect of axial misalignment and multiple reflection on jones matrix of a four‐crystal light modulator
Authors: Moritani Akihiro , Nakai Junkichi 
Published: July 2007

AbstractThe latest off‐the‐shelf 45 X‐cut (ADP or KDP) four‐crystal light modulators with low driving voltage consist of four crystal units to accomplish temperature compensation and to make possible a low driving voltage. Therefore, axial misalignment is not uncommon. Also, because there are many interfaces between the crystals and the matching dielectric fluid, multiple reflection may cause problems. the effects of these phenomena on the Jones matrix describing the fundamental characteristics of optical phase modulation are examined. First, the dielectric tensor of the crystals with axial misalignment and the characteristic plarizations in the crystal are derived. Then, using Berreman's 4 × 4 matrix formulation, the Jones matrix representation of a four‐crystal light modulator with axial misalignment is derived. It is pointed out that the off‐diagonal terms arise from axial misalignment, which is one cause of temperature variation of the light modulator characteristics. A numerical estimate is made of the effect of multiple reflection. It is pointed out that the effect of multiple reflection on the off‐diagonal elements of the Jones matrix is negligible while the effect of the diagonal elements is substantial. an experimental example with an actual modulator is given to determine the location of the axial misalignment.
Bandpass filters using electrically‐coupled TM010dielectric rod resonators
Authors: Kobayashi Yoshio , Kojima Katsuto , Yoshida Shinichiro 
Published: July 2007

AbstractThe authors previously described the design of shielded TM010dielectric rod resonators (below referred to as “TM010resonators”), a new configuration of small‐size resonators for microwave frequencies. This paper describes the design of bandpass filters using coaxially oriented electrically‐coupled TM010dielectric rod resonators. First, the resonant frequency of electrically‐coupled TM010resonators is analyzed by applying the Ritz‐Galerkin method to the integral equations that express the boundary conditions. This method is shown to be effective in numerical calculation of the coupling coefficients and center frequency of the coupled resonators and the resonant frequencies for inserted TM010resonators which are required for filter design. Next the characteristics of the coupling probe which effectively produces the strong coupling of the axially symmetric TM010mode of resonators and suppresses the excitation of the higher modes are determined experimentally, making it possible to estimate the center frequency for a filter which takes the variation of the resonant frequency produced by the excitation and coupling hole into consideration. Finally, design of 2‐ and 3‐stage filters of various bandwidths at 2.7 GHz demonstrates the suitability of the approach. Relative bandwidths of 1 to 10%, low losses of. 15 to. 6 db, and absence of spurious responses over bands wider than 1 octave are obtained.
Radiation of millimeter waves from a corrugated ferrite‐slab waveguide
Authors: Ohira Takashi , Yuasa Tetsuji , Tsutsumi Makoto , Kumagai Nobuaki 
Published: July 2007

AbstractA theoretical analysis based on the multiple scale method is presented for the behavior of the leaky wave in a corrugated ferrite image guide. the attenuation of the guided mode due to leakage is given analytically as a complex perturbation of the propagation constant. As an application of this structure, a millimeter wave leaky wave antenna has been considered and its radiation efficiency and directivity have been studied. Next, experiments are carried out for a leaky wave antenna using a poly‐crystalline YIG slab. the radiation pattern has been measured in the 40‐GHz band and compared with theoretical values. A change in dc magnetic bias by 1 Wb/m2 shifts the main beam to be scanned by 17.5 degrees. the experimental results agree well with theoretical data.
Low‐loss faraday cell for a laser gyro with brewster‐angle quarter‐wave plates
Authors: Izumi Yoshinori , Uchiyama Taro , Fujioka Tomoo 
Published: July 2007

AbstractA new type of low‐loss Faraday bias cell has been designed to overcome the lock‐in phenomenon, which is the weak point of conventional ring laser gyros. Low loss has been achieved by shaping a quarter‐wave plate into a Brewster‐type plate. Experiments using this cell for internal modulation have confirmed that the cell is sufficiently effective as a bias modulation element in eliminating the lock‐in phenomenon.
Analytical expressions for the electric field constants at cathode of electron gun
Authors: Kajiyama Yoshino 
Published: July 2007

AbstractThe electrical characteristics of the cathode immersion lens in an electron gun can be clearly expressed in terms of four electric field constants. This paper proposes a method for analytical derivation of these constants in contrast to the conventional simulation methods. It is shown that the electric field constants can be determined in practice by a simple procedure of calculating the potential distribution function corresponding to its linear function approximation on the cylindrical surface along the electrode hole. By means of this procedure, dependence of the electric field constants on the electrode dimensions can be clearly understood. an integral equation was derived that connects the potential distributions corresponding to the planar space and the cylindrical space. By computer solution, accurate values of the potential distribution on the cylindrical surface along the electrode hole were determined. Repeating the calculation with these correct boundary values, we can derive accurate electrical field constants. Comparing these results with those obtained by a simplified method, reliability of the latter has been confirmed. It is also possible to analytically calculate the potential distributions in the entire space. Many applications are expected based on unique features of the method enabling a good perspective of the problem.
Anti‐fading polygonal cylinder passive repeater
Authors: Numano Yuji 
Published: July 2007

AbstractFor economical construction of general microwave communication channels passive repeaters are used. Effective improvement in avoiding momentary interruptions cannot be expected unless measures are adopted to prevent fading at passive repeaters and space diversity is employed at the antenna side.The radiation field of an aperture type antenna is represented by the product of the amplitude distribution and the phase distribution of the field at the aperture. Amplitude distribution has been the main area considered in analyses to date. This paper discusses a method for controlling the phase distribution and shows that this method is best suited to prevent fading. the method modifies the shape of a conventional flat reflector excited by plane waves into a polygonal cylinder which inscribes a shallow parabolic cylinder, so that a near‐axis directional beam is formed in even the direction of the first null point of the reflected waves. the level at the first null point of a polygonal cylindrical reflector designed to keep the gain reduction directly on the axis below about 1 dB agrees well with the predicted mean field intensity due to fading at a receiving point. the use of a polygonal cylinder reflector is economical and prevents momentary interruptions due to fading so that the communication channels remain stable and possess high quality with improved reliability.
Statistical time lag of gas discharge in electrostatic recording
Authors: Kimura Masatoshi , Wanou Masahiro , Nakajima Junzo 
Published: July 2007

AbstractElectrostatic recording is applied widely to facsimiles and printers because of its high speed and high resolution. the time lag in gas discharge formation causes dots to be missed, which must be improved for high‐speed, high resolution recording. We tested the latent image formation by using an aluminum drum coated with a dielectric film uniformly charged to positive potential and a pin electrode. the effects of the pin electrode material, the recording pulse repetition period, and the recording voltage on the statistical time lag on initiating discharges have been investigated. the following results were obtained: (1) A phosphor bronze electrode causes the smallest time lag, followed by nickel and tungsten. (2) the logarithm of the mean statistical time lag is proportional to that of the repetition period. (3) the logarithm of the mean statistical time lag is inversely proportional to the air gap electric field. (4) When the recording pulsewidth is larger than 15 μs for a gap field of 55 MV/m and a recording pulse period of 10 s, the dots missing probability becomes less than 1%.