Showing papers in "Interdisciplinary Information Sciences in 2001"
TL;DR: In this article, a survey of hamiltonian theorems, problems and conjectures in graph theorical aspect is given, which supplements a well-known survey of Gould.
Abstract: In this article, we give a survey hamiltonian theorems, problems and conjectures in graph theorical aspect which supplements a well-known survey of Gould.
14 citations
TL;DR: A survey of results on quadrangulations on closed surfaces, especially on diagonal transformations and related topics, is given in this paper, where the authors also give a survey of quadrangulation on closed spaces.
Abstract: In this paper, we give a survey of results on quadrangulations on closed surfaces, especially on diagonal transformations and related topics.
14 citations
TL;DR: Based on a thorough survey on digital money, mostly on anonymous digitalMoney, basic components and a history of digital money systems are explained.
Abstract: Digital money, a digital substitute of physical money, has been extensively examined and developed in a past decade. Especially anonymous digital money has received much attention. Based on a thorough survey on digital money, mostly on anonymous digital money, we explain basic components and a history of digital money systems.
10 citations
TL;DR: This paper discusses several classes of restricted traveling salesman tours and polynomial time algorithms to find a shortest tour in those classes and considers the constraints for intervals of edges in a tour.
Abstract: This paper discusses several classes of restricted traveling salesman tours and polynomial time algorithms to find a shortest tour in those classes. Here we consider the constraints for intervals of edges in a tour. Each restricted tour is an extension of a pyramidal tour and the algorithms can be applied for special cases of the traveling salesman problem.
9 citations
TL;DR: In this paper, the authors consider the zeta functions of the line graph and the middle graph of a regular covering of a graph G, and their related topics, and show that the total graph of the graph G with covering transformation group A is a regular cover of M and T of G with the same covering transformation transformation group, respectively.
Abstract: We consider the zeta functions of the line graph and the middle graph of a regular covering of a graph G, and their related topics. Let M (G) be the middle graph of G and T (G) the total graph of G. We show that the middle graph and the total graph of a regular covering of a graph G with covering transformation group A is a regular covering of M (G) and T (G) with the same covering transformation group A, respectively. For a regular graph G, we express the zeta functions of the line graph and the middle graph of a regular covering of G by using the characteristic polynomial of that regular covering.
7 citations
TL;DR: A method of handling the robot’s moment of rotation by the force of the link which come from the assisting robot and it is concluded that it is necessary to change the link position to climb and descend a step safely.
Abstract: This paper describes a new cooperative strategy for two wheelchairs to climb a step. These two wheelchair robots are connected with a simple linkage mechanism between the rear of one wheelchair and the front of another. Two wheelchair robots climb a step one after the other. In this research, we did not use a method by which a robot lifts up and supports its weight using any special actuator but a method of handling the robot’s moment of rotation by the force of the link which come from the assisting robot. This method is especially influenced by the height of the two robot’s link positions. So we study this method from the viewpoint of changing the two-link positions. We perform a numerical calculation to clarify the combination of the two robot’s link positions from the two fixed points which enable them to climb (or descend) a step and is stable at the same time. We conclude from the result of the simulation that it is necessary to change the link position to climb and descend a step safely. We ascertain the effectiveness of this method by means of experiments using the robot system.
6 citations
TL;DR: This paper construct regular knot diagrams of the knots of divides by using half plane models and present a systematic algorithm for making Dowker-Thistlethwaite codes of the Knots of divides.
Abstract: The divide is a new and interesting object which was introduced by N. A'Campo as an extension of complex plane curve singularities. In this paper we construct regular knot diagrams of the knots of divides by using half plane models and present a systematic algorithm for making Dowker-Thistlethwaite codes of the knots from the divides.
5 citations
TL;DR: A survey of studies on topological graph theory developed by Japanese people in the recent two decades is presented in this paper, which presents a big bibliography including almost all papers written by Japanese topology graph theorists.
Abstract: This is a survey of studies on topological graph theory developed by Japanese people in the recent two decades and presents a big bibliography including almost all papers written by Japanese topological graph theorists.
4 citations
TL;DR: In this article, the authors discuss some properties of finite volume infinite graphs defined arithmetically, from a spectral point of view, known as Ramanujan diagrams, which are constructed from principal congruence subgroups over function fields.
Abstract: We discuss some properties of certain finite volume infinite graphs defined arithmetically, from a spectral point of view. These graphs are constructed from principal congruence subgroups over function fields and known to be Ramanujan diagrams.
4 citations
TL;DR: A stereo-matching algorithm to establish reliable correspondence between images by selecting a desirable window size for SAD (Sum of Absolute Differences) computation is presented and a window-parallel and pixel-serial architecture is proposed to achieve 100% utilization of processing elements.
Abstract: This paper presents a stereo-matching algorithm to establish reliable correspondence between images by selecting a desirable window size for SAD (Sum of Absolute Differences) computation. In SAD computation, a degree of parallelism between pixels in a window changes depending on its window size, while a degree of parallelism between windows is predetermined by the input-image size. Based on this consideration, a window-parallel and pixel-serial architecture is proposed to achieve 100% utilization of processing elements. Not only 100% utilization but also a simple interconnection network between memory modules and processing elements makes the VLSI processor much superior to conventional processors.
4 citations
TL;DR: The main object is the graph embedded into the 3-space, called the spatial graph, which is an equivalence relation generated by clasp-pass moves and ambient isotopies and implied by a clasp- pass equivalence.
Abstract: In this paper our main object is the graph embedded into the 3-space, called the spatial graph. We study a clasp-pass equivalence on spatial graphs, which is an equivalence relation generated by clasp-pass moves and ambient isotopies. Our approach is an analogy of the delta equivalence classification on spatial graphs, where a delta equivalence is an equivalence relation generated by delta moves and ambient isotopies and implied by a clasp-pass equivalence. Consequently, clasp-pass classifications on spatial embeddings of several non-planar graphs and a specified planar graph are given. This is a preliminary report on our recent work and details will appear elsewhere.
TL;DR: In this paper, the triviality of bouquets is discussed by using the tangle description, and a necessary and sufficient condition for a bouquet to be trivial is given.
Abstract: In this paper, we discuss the triviality of bouquets by using the tangle description, and give a necessary and sufficient condition for a bouquet to be trivial. We also give a necessary and sufficient condition for a tunnel number one knot to be a 2-bridge knot and prove that if each component of a tunnel number one link is a trivial knot, then the link is 2-bridge.
TL;DR: In this paper, a multidimensional perceptual space derived from the results of psychoacoustical experiments on similarities in the quality of sounds amplitude-modulated by nine triangular waves different in rise-and fall-times was discussed.
Abstract: This paper discusses multidimensional perceptual space derived from the results of psychoacoustical experiments on similarities in the quality of sounds amplitude-modulated by nine triangular waves different in rise- and fall-times. For sinusoidal (1 kHz) and random-noise carriers, three experiments were conducted with different modulation frequencies, namely 8, 16 and 32 Hz. In each experiment, similarities in sound quality for stimuli with modulation depths of 0.4, 0.8 and 1.0, as well as the original carrier wave, were rated. The similarities were analyzed by a multidimensional scaling method (ALSCAL), and three-dimensional configurations were derived. A common configuration correlated with the modulation depth was seen irrespective of carrier wave and modulation frequency. There was a perceptual dimension related to shape of amplitude modulation for all conditions except for noise carrier with 32-Hz modulation. The difference in rise time caused larger differences in sound quality than similar differences in fall time up to a modulation frequency of 16 Hz, irrespective of the kind of carrier wave.