Visualization with hierarchically structured trees for an explanation reasoning system

This work is concerned with an application of drawing hierarchically structured trees. The tree drawing is applied to an explanation reasoning system. The reasoning is based on synthetic abduction (hypothesis) that gets a case from a rule and a result. In other words, the system searches a proper environment to get a desired result. In order that the system may be reliably related to the amount of rules which are used to get the answer, we visualize a process of reasoning to show how rules have concern with the process. Since the process of reasoning in the system makes a hierarchically structured tree, the visualization of reasoning is a drawing of a hierarchically structured tree. We propose a method of visualization that is applicable to the explanation reasoning system.</p

A three-dimensional visualization of communications in distributed program environments

In order to understand the behaviour of distributed program environments, we describe a three-dimensional visualization of communications. Most previous visualizations presented communications by means of the two dimensions of time and process, however, three dimensions are required to represent a message intermediary with visualization functions. We make use of a semantic configuration of messages, which is constructed by the quantities for three parametric factors: (i) time sequence, (ii) identifications of processors, and (iii) message exchanges.</p

Fatigue Strength of Wood Under Pulsating Tension-Torsion Combined Loading

Fatigue strength of wood under cyclic tension-torsion combined loading was investigated experimentally. The material used for the experiments was a rectangular bar of Japanese cypress. Pulsating tension-torsion combined loadings were respectively applied along and around the longitudinal axis of the specimen, which coincided with the longitudinal direction of the wood. The obtained results of fatigue tests were found to be influenced by the combined-stress ratios and the applied stress levels, and were summarized as follows: 1) All data were located in a slightly wide band on the S-N plot in spite of different combined-stress ratios, but the slope of the S-N curves became low when tensile stress was dominant. 2) Failure modes of the test specimen depended on whether tensile or shear stress was dominant in the biaxial stress ratios. 3) Hill's criterion for the static strength was suitable for evaluating the fatigue strength under combined-stress ratios

Visualization for management of electronics product composition

There are some systems called supply chain management system or value chain management system that manages production. It is a powerful tool in normal cases, but in a problem such that some parts are out of stock, it can solve the problem only by simple solutions, like postponing shipping of the product because it does not have enough information about production and functions to use the various information. Our research is concerned with a system to integrate information about production and show a solution to help users to judge which way is better to solve the problem. We implemented a prototype system. It takes inputs of some information that were not integrated in one place in former systems, but distributed among systems, people, or sections. It shows a solution for a problem making use of the information integrated in the system. The solution comes as process of reasoning to help user to judge what is the best to do in the case. We also implemented the user interface to show the process of reasoning.</p

An interactive environment for generating sequential information

We propose an interactive environment in which we can generate sequential information. Sequential information is a sequence of movements which makes changes of situations. The system allows a user to construct an environment for generating sequential information. We provide interactions and visualization for sequential information generation based on theoretical grounds.</p

Bending Fatigue of Wood: Strain Energy-Based Failure Criterion and Fatigue Life Prediction

In this study, bending fatigue behavior of Japanese cedar and Selangan batu was examined. A nonreversible triangular waveform with loading frequencies of 0.5 and 5 Hz was used as load. Applied loads were about 110-70% of the static strength. The fatigue life of Japanese cedar was found to be longer at 5 Hz, especially at low stress level. For Selangan batu, however, loading frequency did not affect fatigue life. When fatigue life exceeded about 40,000 cycles, a crack formed on the compressive sides of the specimens regardless of the loading frequency and species. Cumulative strain energy at failure was found to be the failure criterion regardless of the loading frequency. This criterion could be estimated using the strain energy through the static test. A fatigue life prediction method based on the strain energy of the second loading cycle was proposed. This prediction method provided a good prediction of fatigue life

Fatigue Damage in Wood Under Pulsating Multiaxial-Combined Loading

A fatigue test was performed under axial-torsion combined loading, with the aim of investigating fatigue damage in wood under multiaxial stresses. This research particularly focused on the energy loss captured during fatigue tests and the fatigue limit for wood. Air-dried samples of Japanese cypress were used for the tests. An electrohydraulic servomachine that could apply axial and torsional loads simultaneously was used for the fatigue tests. An axial load was applied in the fiber direction (along L), and torque was applied around the axis in the same direction as L. A pulsating triangular axial load was applied in the longitudinal direction at 1 Hz while each specimen was also simultaneously subjected to a twisting moment at the same phase. On the basis of the experimental results of the fatigue tests, energy loss was obtained from the stress-strain curve at each loading cycle and examined precisely in relation to the number of loading cycles and combined stress states. The energy loss per cycle in the dominant stress was large and increased gradually toward fatigue failure. The stress level was so high that the energy loss per cycle was extremely large. In the relationship between cumulative energy loss and the number of loading cycles, the cumulative energy loss was so large that the fatigue life was extremely long. The cumulative energy loss for shear in the compression group was larger than that in the tension group. The mean energy loss per cycle for the fatigue limit was also presumed from the relationships between mean energy loss per cycle, stress amplitude, and fatigue life, and was estimated to be about 10 kJ/m3/cycle, as determined on the basis of the equivalent stress principle. That is, the fatigue life will be infinite when the energy loss per cycle is below 10 kJ/m3/cycle

Fatigue Behavior in Wood Under Pulsating Compression-Torsion-Combined-Loading

We have experimentally investigated the effects of cyclic compression-torsion-combined loading on the fatigue behavior and stress-strain properties of wood. Pulsating compression and torsion loadings were applied along and around the longitudinal axis of the rectangular bar specimen (Japanese cypress). According to the relationships between stress and strain during fatigue tests, the secant modulus of the stress-strain curve changed with an increase in the number of loading cycles, and the differences between the curves for compression and shear were observed. We found that the experimental results of fatigue tests were influenced by the combined-stress ratios. Compressive stiffness tended to maintain its initial values during almost all loading cycles to failure. Shear stiffness decreased with increasing number of loading cycles, and the final decrease of shear stiffness was larger as compressive stress became dominant. The failure mode was affected by the combined stress states; typical torsion failure was observed in combined stress states with dominant application of shear stress. In contrast, typical compression failure was observed in combined stress states with dominant application of compressive stress. The failure mode under compressive-shear combined stress states was not affected by the stress level, although, as previously demonstrated, it was affected by the stress level under tensile-shear states

THEORETICAL ESTIMATION OF MECHANICAL PROPERTIES OF PLYWOOD-SHEATHED SHEAR WALL WITH COMBINED USE OF ADHESIVE TAPE AND WOOD DOWELS

Shear walls often function as elements that provide resistance to horizontal external forces exerted on wooden frames. Many shear walls with superior strength performance have been developed for this purpose. Amidst this backdrop, we have attempted to develop a shear wall that, in addition to strength performance, decreases the time and labor required for disposal. More specifically, the authors proposed a novel “metalless” shear wall: a shear wall in which industrial double-sided adhesive tape is used to attach plywood to the framework. Also, wood dowels are used as supplementary connectors with the aim of enhancing strength performance. Unlike conventional shear walls that use nails and metal fixtures, separation at the time of disposal is unnecessary, and therefore, disposal time and labor of the wall are anticipated to be significantly decreased. Thus, this study involved demonstrating and verifying a methodof theoretical analysis for the mechanical performance of these kinds of shear walls toward in-plane shear force. Specifically, this study derived a method to estimate the mechanical behavior (load-deformation angle relationship) of plywood-sheathed shear walls based on shear performance obtained from double shear tests of joint specimens with the combined use of adhesive tape and wood dowels. Also, the validity of the method was experimentally verified. The results showed that the method proposed in this study was able to estimate the mechanical behavior and mechanical properties of the newly proposed shear wall, and the validity of the method was confirmed

ENERGETICS APPROACH TO FATIGUE BEHAVIOR OF WOODEN JOINT USING DOUBLE-SIDED ADHESIVE TAPE

The authors have previously studied the possibility of the use of industrial double-sided adhesive tape as a method for jointing wooden panel to wooden framework. The mechanical performance of joints formed by such methods is comparable to that of nailed joint under static load conditions. However, the mechanical performance of such joints has not been evaluated under cyclic load conditions. This study was conducted to investigate this aspect of their performance. Double-shear specimens were prepared by bonding wooden panel to wooden framework using two types of adhesive tape with different substrates. Specimens were also prepared with wooden dowels to strengthen their jointing performance. The joint specimens were subjected to cyclic shear loading testing. The results of the tests were analyzed from an energetics perspective, and the shear deformability of the specimens at failure was estimated. The test results indicate that both the specimens formed using adhesive tape and those formed using wooden dowels had fatigue properties comparable to nailed joint specimens. A tendency for the shear deformability caused by cyclic loading to increase with the stress level was observed. It was possible to estimate the shear deformability by evaluating the energy absorption capacity of the joints from an energetics standpoint