Showing papers by "Aoyama Gakuin University published in 1993"
09 Jul 1993
TL;DR: The extended version of the algorithm of Chow and Liu in that the learning algorithm selects the model in the range where the dependencies among the attributes are represented by some general plural number of trees.
Abstract: This paper addresses learning stochastic rules especially on an inter-attribute relation based on a Minimum Description Length (MDL) principle with a finite number of examples, assuming an application to the design of intelligent relational database systems. The stochastic rule in this paper consists of a model giving the structure like the dependencies of a Bayesian Belief Network (BBN) and. some stochastic parameters each indicating a conditional probability of an attribute value given the state determined by the other attributes' values in the same record, Especially, we propose the extended version of the algorithm of Chow and Liu in that our learning algorithm selects the model in the range where the dependencies among the attributes are represented by some general plural number of trees.
177 citations
TL;DR: An experimental model of a pressure/displacement transducer with a laser distance sensor is introduced, which has been developed for monitoring muscle hardness non-invasively and quantitatively and can be calculated from the slope of the pressure/ displacement line which is recorded with the experimental equipment.
Abstract: THERE IS no objective and quantitative non-invasive method to evaluate hardness of soft tissues, especially that of muscles. In usual clinical practice, hardness is evaluated only by palpation. To date, quantitative evaluation of muscle hardness has been performed on extracted muscles (MAsoN, 1978; HASAN and MASON, 1978). Despite various studies on non-invasive measurement methods to evaluate human muscle hardness, no widely accepted techniques have yet been developed. In the past, SCHADE (1926) and other researchers used such equipment as the elastometer or sclerometer for measuring the elasticity and hardness of skin and organs. However, such equipment could not provide objective and reproducible data. Later, other researchers tried to measure muscle hardness using the changes of resonance frequency associated with the changes of mechanical impedance. This was performed using vibration on the measuring site of the body (KATO et al., 1980). However, there were some problems with this method. For example, influences from the tonic vibration reflex of muscles, which are produced by the given vibration, are unavoidable. Also unavoidable are the errors made by improper contact of the measuring system with the body surface. I n the present study, we introduce an experimental model of a pressure/displacement transducer with a laser distance sensor, which has been developed for monitoring muscle hardness non-invasively and quantitatively. Muscle hardness can be calculated from the slope of the pressure/ displacement line which is recorded with our experimental equipment.
97 citations
TL;DR: In this paper, the authors used a single detector and a unified charge-and-energy determination method to determine the absolute intensities of the heavy primary nuclei over a wide energy range from a few GeV/nucleon up to \ensuremath{\sim}1 TeV/Nucleon.
Abstract: We have exposed a new type of emulsion chamber of area 1.53 ${\mathrm{m}}^{2}$ at an atmospheric depth of 11.7 g/${\mathrm{cm}}^{2}$ for 22.2 h. The chamber makes extensive use of screen-type x-ray films, which have recorded the tracks due to over 100 000 cosmic-ray heavy primary nuclei of Z\ensuremath{\gtrsim}8. With this experiment we have succeeded in determining the absolute intensities of the heavy primaries over a pretty wide energy range from a few GeV/nucleon up to \ensuremath{\sim}1 TeV/nucleon, using a single detector and a unified charge-and-energy determination method. In the present paper we give a report of our results on silicon and heavier components, accompanied by a detailed account on our newly adopted energy determination method and a discussion of its accuracy. Our iron flux is in agreement with that obtained by Spacelab-2, the integral spectral index \ensuremath{\beta} being nearly constant, \ensuremath{\sim}1.5, up to a few TeV/nucleon. Of peculiar interest is our silicon flux, which is again consistent with the Spacelab-2 result. The energy spectrum gets softer beyond 100 GeV/nucleon, \ensuremath{\beta} being as high as \ensuremath{\sim}1.95 there. Current interstellar acceleration and propagation models will meet difficulty in explaining this result. We also report about the abundance ratio of the subiron group to iron, which is strongly sensitive to the escape length of cosmic rays in the Galaxy, and find that it decreases in the form of power laws over the wide energy range from a few GeV/nucleon to a few TeV/nucleon, though a quantitative study in connection with a particular propagation model is reserved to the future.Our all-particle spectrum deviates significantly from that of the proton satellites beyond 50 TeV/particle, while both agree rather well with each other in the lower energy range. When we investigate individual heavy components, we find that all their respective fluxes multiplied by ${\mathit{E}}_{\mathit{P}}^{2.5}$ (${\mathit{E}}_{\mathit{P}}$ is the primary energy per particle) show a decreasing tendency around \ensuremath{\sim}10 TeV/particle and beyond, no indication of recovery being observed as the energy gets even higher. This means that the heavy components, paricularly iron, do not increase so drastically as to cover the excess in the ``knee'' region. Extrapolation of our all-particle spectrum up to ${10}^{15}$--${10}^{16}$ eV/particle indicates a milder ``knee'' shape than that found by the air shower experiments. If the break is as sharp as hitherto reported, then it will suggest either (i) there is a sharp break which might be due to a drastic advent of new components (other than heavy primary nuclei), or a drastic change in nuclear interaction, or (ii) the break just appears to be sharp due to a \ensuremath{\sim}20% (or more) systematic overestimation in converting the air shower sizes into the primary energy values in the ``knee'' region.
85 citations
TL;DR: In this article, the authors present data on polar wind velocities, examined in conjunction with electron properties, as a function of altitude in the ionosphere, and show a vertical component to the polar wind, consistent with model results.
Abstract: The authors report recent results from the Akebono satellite. They present data on polar wind velocities, examined in conjunction with electron properties, as a function of altitude in the ionosphere. This data came from the Suprathermal ion Mass Spectrometer and the Thermal Electron energy Distribution instruments. The measurements show a vertical component to the polar wind, consistent with model results, when measured in terms of H[sup +] ions. There was a definite altitude dependence of the velocity of the hydrogen ions, and there was also a positive correlation of this velocity with the measured electron temperature.
74 citations
TL;DR: In this article, the catalytic effect of iron wires on plasma syntheses of ammonia and hydrazine has been studied in the nitrogen-hydrogen plasma prepared using rf discharge at a pressure of 650 Pa (5 Torr).
Abstract: The catalytic effect of iron wires on plasma syntheses of ammonia and hydrazine has been studied in the nitrogen-hydrogen plasma prepared using rf discharge at a pressure of 650 Pa (5 Torr). The product was mainly ammonia including a small amount of hydrazine. When iron wires were placed in the plasma downstream of the gas flow, the yields of both products increased, about two times in ammonia and two orders of magnitude in hydrazine. The yields increased with increasing number of wires (the surface area of the catalyst). The dissociative adsorption of nitrogen molecules and/or molecular ions on the iron surface and the formation of NHx by the reaction with hydrogen in the plasma followed by the formation of NH3 or N2H4 are considered as a reaction scheme. This is supported by the identification of NH3 with XPS of the surface of iron wires.
52 citations
TL;DR: In this article, an unusual particle track has been recorded in an emulsion chamber exposed to cosmic rays on a ballon at the atmospheric depth 11.7 g/cm2, which is extraordinary with this particle is its arrival zenith angle, 87.4°.
Abstract: One example of an unusual particle track has been recorded in an emulsion chamber exposed to cosmic rays on a ballon at the atmospheric depth 11.7 g/cm2. The particle arrived at the chamber withZ/β=40±2 and β≳0.8. What is extraordinary with this particle is its arrival zenith angle, 87.4°, which amounts to a traversed atmospheric thickness ∼200 g/cm2. The anomalous nature of the present track “ET” (exotic track) is demonstrated through the difficulties in reconciling it with the explanation that it is due to an ordinary ultra-heavy cosmic-ray nucleus.
43 citations
TL;DR: A new copper oxide superconductor containing carbon and boron was synthesized under ambient pressure in this article, and the superconducting transition was observed for the samples with x = 015 and 0.15.
Abstract: A new copper oxide superconductor containing carbon and boron Sr2CuO2(CO3)1−x(BO3)x was synthesized under ambient pressure. The superconducting transition was observed for the samples with x = 015 and 0.2. The highest Tc(≈32K) determined by magnetization measurements was obtained for the sample with x = 0.15. The X-ray Rietveld analysis of this compound can be characterized by the tetragonal symmetry (I 4 ) with a = 0.77881 (15) nm and c = 1.49681 (3) nm (x = 0.15). The crystal structure determination suggests that the crystal structure is basically the same as that of Sr2CuO2(CO3).
43 citations
TL;DR: The Tridimensional Personality Questionnaire appears to have test-retest reliability and content validity among a Japanese student population; it is uninfluenced by psychiatric morbidity or social desirability.
37 citations
TL;DR: The average superstructure periodicity of the present specimen is around 7 a 0, which is relatively shorter than the value of 8 a 0 previously claimed by Goutenoire et al..
Abstract: Superstructures of oxycarbonate superconductor TlSr 4− x Ba x Cu 2 (CO 3 )O y ( x =2; T c =73K) were examined by electron diffraction and HRTEM techniques. Part of the crystals show a commensurate superstructure with a 6 a 0 periodicity due to crystallographic shears by c /2 to form -(C-C-C)-(Tl-Tl-Tl)-(C-C-C-)-(Tl-Tl-Tl)- type of sequences along the (100) direction in the basal planes. Incommensurate superstructures with longer periodicities up to 7.4 a 0 due to mixed intergrowths of -(C-C-C-C)- and -(C-C-C)- sequences were also observed. The average superstructure periodicity of the present specimen is around 7 a 0 , which is relatively shorter than the value of 8 a 0 previously claimed by Goutenoire et al. [Physica C 210 (1993) 359] for a similar superconductor with T c =62 K. This suggests the possibility of a close relationship between the modulation periodicity and the transition temperature in the TlSr 4− x Ba x Cu 2 (CO 3 )O y system with x =1–2.5. Observed structures were compared with an another type of superstructure recently discovered in HgBa 2 Sr 2 Cu 2 (CO 3 )O y by Uehara et al.
27 citations
05 Jan 1993
TL;DR: The author attempts to economize the decision making on the part of a group of experts while maintaining the quality of their decisions, i.e., their forecasting, by introducing a fuzzy Delphi method, which has turned out to be possible to decrease the number of repetitive surveys and/or interviews.
Abstract: From the viewpoint of managing GDS (group decision support), the author attempts to economize the decision making on the part of a group of experts while maintaining the quality of their decisions, i.e., their forecasting, by introducing a fuzzy Delphi method. By doing so, the interaction time and the time for information exchange can also be remarkably saved. The author examines both the developmental objectives and the developmental process of this method, and discusses how to determine the membership functions. Two algorithms are proposed, one via max-min normativism and the other via fuzzy integration, along with the required steps to be taken, by virtue of the fuzzy Delphi method, it has turned out to be possible to decrease the number of repetitive surveys and/or interviews. Moreover, the internal structure to be analyzed can be observed on a multilateral basis and thus the selection procedure of the results has become easier. >
23 citations
TL;DR: In this article, two (Bi,Pb)-oxycarbonate superconductors have been found by resistivity and magnetization measurements, and the crystal structures were analyzed by using the HRTEM and X-ray diffraction techniques.
Abstract: Two (Bi,Pb)-oxycarbonate superconductors have been found by resistivity and magnetization measurements. Transition temperatures are 41 K (54K) for the low- T c phase (high- T c phase). The crystal structures were analyzed by using the HRTEM and X-ray diffraction techniques. The lattice parameters were a 0 =3.821 A , c 0 =39.444 A (a 0 =3.88 A , c 0 =54.52 A ) for low- T c phase (high- T c phase) in the tetragonal unit cell. A crystal structure model is proposed in which the chemical formula for the low- T c phase (high- T c phase) is (Bi,Pb) 2 Sr 4 Cu 2 CO 3 O 8 ((Bi,Pb) 2 Sr 6 Cu 3 (CO 3 ) 2 O 10 ), which can be described as the combination of a single (double) Sr 2 CO 3 block and a single (Bi,Pb) 2 Sr 2 O 4 block.
TL;DR: In this paper, the effects of growth conditions on the superconductivity of Ba1−xKxBiO3 (BGBO) crystals grown electrochemically have been studied.
Abstract: The effects of growth conditions on the superconductivity of Ba1−xKxBiO3 (BGBO) crystals grown electrochemically have been studied. Magnetic and resistive measurements reveal that the superconductivity of BKBO crystals depends strongly on the synthesis temperature, applied voltage and current, and synthesis time. The electron-phonon coupling parameter (λph) estimated from critical field parameters of a single crystal (Tc = 30 K) suggests a phonon-mediated mechanism for superconductivity in BKBO.
TL;DR: In this article, a new family of oxycarbonate compounds (Ln,Ca) (Sr,Ba) 2 (C,Cu)Cu 2 O 7-δ with a so-called "CO 3 -1212" structure was synthesized.
Abstract: We have synthesized a new family of oxycarbonate compounds (Ln,Ca) (Sr,Ba) 2 (C,Cu)Cu 2 O 7-δ (Ln: rare-earth metals) with a so-called “CO 3 -1212” structure. Two kinds of single phase in the general formula Er 0.5 Ca 0.5 Sr 2- x Ba x Cu 3- y C y O 7-δ with ( x , y )=(0.6, 0.5) and (1.3, 0.4) were prepared at different CO 2 partial pressures. The former compound shows a superconducting transition at about 45 K, and the latter has T c up to 80 K. This rise in T c may come from the increase of carrier density because of the decrease of carbon content. We have also studied the Ln-dependence, and it is revealed that most of the compounds Ln 0.5 Ca 0.5 Sr 0.7 Ba 1.3 Cu 2.6 C 0.4 O 7−δ show the same results, except for Ln = Ce and Tb, which did not construct the structure, and also Ln = Pr , which shows suppressed superconductivity with T c of 30 K.
TL;DR: In this article, three kinds of beads with different mean diameters were each packed in a rectangular cell and saturated with NaCl-aqueous solution and used as a porous media.
28 Oct 1993
TL;DR: Electroencephalograms and ECGs are analyzed, the relations between them are observed, and the possibility of ECGs to refine the detection system of fnclining sleep stages is discussed.
Abstract: In order to prevent traffic accidents, developing a system which find out sleepy states of drivers and warning them the dangerous state. W e have found that special EEG8 called grouped a waves appear in sleepy state of drivers, and defined the sleepy states characterized by grouped a waves as ’inclining sleep (low awake) stage‘, And then, we made a subsystem to find out inclining Sleep stages of drivers using grouped a waves. The first kind of error about the subsystem is 2% and tne second kind Of that is 25”35%. In order to improve the reliability of the system, we analyze ECG6 as detail as EEGs during driving. As the results, EEGs is more suitable to sleepy states of drivers and ECGs are also used t o improve the reliability of such a detection-subsystem. 1 . INTRODUCTION It is important to develop a system to prevent traffic accidents caused by drivers‘ dozing off. We have analyzed electroencephalograms (EEGa) during driving a car or other simple works. As the results. we find out the fact that a special EEC8 called as grouped a waves appear in most cases. Then we defined the state which is characterized by the appearance o f grouped a waves as ‘inclining sleep stage’ and made a system which automatically detects inclining sleep stage using grouped a waves‘’. The ratio which the system can not detect inclining sleep is 2% and the ratfo which the system detects non-inclining sleep stage as inclining sleep stage is about 25%-35%. Since it is required not to overlook sleepy stages to such a detection system, the system w e made satisfied such property. But we wish to refine the system more reliable, and then we measure not only EEGs but also electrocardiographs (ECCs) and analyze them. Because i t is reported that ECGs are deeply concerned with fatigue of human beings‘’. in t h e f i led of ergonomics. In this paper, we analyze both of EEGs and ECGs, observe the relations between them, and discuss the possibility of ECGs to refine the detection system of fnclining sleep stages.
TL;DR: In this article, the Hall coefficient of Ba0.62K0.38BiO3 has been measured up to 1.2 GPa and the absolute value of Hall coefficient decreases with pressure by 10% GPa, which is almost the same as that obtained in most CuO-based high-temperature superconductors.
Abstract: The superconducting transition temperature (Tc) of Ba0.62K0.38Bio3 (Tc=30 K) has been measured under high pressure up to 8 GPa. It is observed that Tc increases initially with pressure, as reported by Uwe et al., Shirber et al. and Huang et al., but decreases above 4 GPa. The Hall coefficient of Ba0.62K0.38BiO3 has been measured up to 1.2 GPa. The absolute value of the Hall coefficient decreases with pressure by 10% GPa, the value of which is almost the same as that obtained in most CuO-based high-temperature superconductors.
TL;DR: The relationship between the detection sensitivity for charged particles and the molecular structure of polymers like CR-39 was studied while changing the average chain length of the carbonate linkages crosslinking the polyallyl chains as discussed by the authors.
TL;DR: Empirical tests indicate that a very tight upper bound often causes a degenerate case ensuring zero-variance portfolios, and this result is incompatible with the market efficiency.
Abstract: The purpose of this paper is to discuss the relationship between the number of securities which constitute an efficient portfolio as defined by the standard mean-variance portfolio selection model and the number of periods used to compute the efficient portfolio. It is shown that the number of data gives the upper bound of the number of securities which constitute an efficient portfolio, when each efficient portfolio is unique for a given expected return. Empirical tests based on actual return data show that this upper bound is very tight when the number of data is small. However, when more data are used, the upper bound becomes looser. This result is incompatible with the market efficiency. These empirical tests also indicate that a very tight upper bound often causes a degenerate case ensuring zero-variance portfolios.
TL;DR: In this article, diamond was extracted from CCl4-H2 plasmas using X-ray diffraction and Raman spectroscopy without covering by amorphous components.
TL;DR: In this article, it was shown that cis-enediol is preferentially formed via the lowest excited singlet state of 2,2′-pyridyl in ethereal solutions.
Abstract: In ethers, such as tetrahydrofuran and 1,4-dioxane, 2,2′-pyridyl (di-2-pyridyl diketone) is photochemically reduced to the cis -enediol-type compound ( cis -1,2-di(2-pyridyl)-1,2-ethenediol), in contrast with the previously reported trans -enediol formation in alcohols, etc. This solvent dependence of the photochemical behaviour can be interpreted in terms of the difference in the reactive excited states of 2,2′-pyridyl in the two photochemical reactions. Investigations of the external heavy atom effect, triplet quenching experiments and the initial concentration dependence of the substrate indicate that cis -enediol is preferentially formed via the lowest excited singlet state of 2,2′-pyridyl in ethereal solutions, whereas the lowest excited triplet state participates in trans -enediol formation in alcohols, etc. From the isotope effects observed in deuterated tetrahydrofuran and ethanol, the initial step in the photoreactions, i.e. hydrogen atom abstraction or electron transfer, is briefly discussed.
TL;DR: In this article, the magnetization carried by a phonon is shown to be antiparallel to the bulk magnetization and its magnitude is ∼ 0.1 μ B, which depends upon the temperature and the wave number.
TL;DR: In this paper, a general comparison of alternative pricing schema including collusive, Loschian, and optimal pricing is presented in a table and a general, if not the general, prices-and-welfare comparison is made.
Abstract: . Loschian duopoly under heterogeneous cost conditions is examined to show that it is not equivalent, contra past findings, to spatial collusion. Moreover, within the confines of the assumed demand and cost conditions spatial collusion is shown to be superior to Loschian competition in terms of both (aggregate) consumer surplus and producer surplus, which implies a possible welfare gain from collusion. A general, if not the general, prices-and-welfare comparison of alternative pricing schema including collusive, Loschian, and optimal pricing is summarily presented in a table.
TL;DR: In this paper, a controlled atmosphere on-site spraying system was developed to deposit a high-quality coating with superior resistance to wet corrosion, which was compared with those of coatings deposited by conventional and low-pressure plasma techniques.
Abstract: New controlled atmosphere on-site spraying systems were developed to deposit a high-quality coating with superior resistance to wet corrosion. Characteristics and corrosion resistance of coatings deposited by arc and flame spraying of wire in argon gas were compared with those of coatings deposited by conventional and low-pressure plasma techniques. It was found that the coating deposited by the arc spraying of wire in argon gas is free of oxides and possesses excellent corrosion resistance in chloride and acid solutions. The coating suffers slight pitting and crevice corrosion associated with the isolated pores and electric potential paths. Corrosion resistance was improved by using a modified spraying system.
17 Jan 1993
TL;DR: This paper describes the construction of a universal code for minimizing L.D. Davisson's minimax redundancy in a range where the true model and stochastic parameters are unknown.
Abstract: This paper describes the construction of a universal code for minimizing L.D. Davisson's minimax redundancy in a range where the true model and stochastic parameters are unknown.
TL;DR: In this paper, the smallest gap value was found at ±2 meV for x = 0 with T c = 6.5 K and the obtained gap values almost scale with x and thus T c throughout the superconducting phase.
Abstract: Superconducting energy gaps in Bi 2 Sr 2− x Nd x CuO 6+ y (0⩽ x ⩽0.7) with T c =6.5−20 K have been studied by the electron tunneling technique. The smallest gap value was found at ±2 meV for x =0 with T c =6.5 K. The obtained gap values almost scale with x and thus T c throughout the superconducting phase. The ratio 2 Δ peak / k B T c =7.1 (2 Δ / k B T c =4−5 with Δ from the BCS analysis) for the sample with T c =6.5 K is still larger than the BCS ratio 3.5 of non-copper oxides (BaPb 0.75 Bi 0.25 O 3 and Li 1+ x Ti 2− x O 4 ) with T c =11−12 K, indicating a substantial pairing nature difference between them.
TL;DR: A superconducting phase in single-crystal Nb 1-x Ta x Se 3 with 0.135
Abstract: We have found a superconducting phase in single-crystal Nb 1-x Ta x Se 3 with 0.135
01 Jan 1993
TL;DR: In this article, the authors presented a book dedicated to Mel Greenhut, a leading figure in the development of modern spatial microeconomics, on which this book is focused.
Abstract: The chapters in this book are presented in honour of our esteemed colleague and friend, Mel Greenhut. Professor Greenhut has been a leading figure (see George Norman’s account, Chapter 2 in this volume) in the development of modern spatial microeconomics, on which this book is focused. However, we honour him in this book not only for his leadership in this field of specialization, but also in respect and thanks for his important contributions to the study of economics in general.
TL;DR: In this article, the effects of pressure on the antiferromagnetic long-range ordering in Pr 2 CuO 4- y were studied between 0.25 and 0.75 GPa by neutron diffraction experiments at temperatures down to 12K.
Abstract: The effects of pressure on the antiferromagnetic long-range ordering in Pr 2 CuO 4- y have been studied between 0.25 and 0.75 GPa by neutron diffraction experiments at temperatures down to 12K. Under a pressure of 0.25 GPa, successive magnetic phase transitions are observed at T N ≈ 250 K and T 1 ≈ 170 K, as was reported previously. Upon further cooling in the present experiments another transition has been found at T 2 ≈ 50 K. These magnetic phase transitions can be attributed to spin reorientations induced under high pressure. The temperature T 1 increases at a rate of about 40 K/GPa with pressure; on the other hand, T 2 decreases greatly at - 120 K/Gpa.
28 Oct 1993