Patterns exist in many contexts and can be considered the useful information for decision making. However, many patterns are not directly visible without careful presentation. Here, we describe an interactive visualization approach for browsing patterns in a history of interacting with a computer system. While a user is carrying out his/her business using computers, activities with respect to time and location are captured to determine the situational interactions. We first integrate the timeline and geographical map to create a structure to visualize spatiotemporal events in the interaction history. The spiral-based interactive visualization technique, presented in this paper, is then used to derive patterns according to the user-specified different spatial viewpoints on the map. In this study, we demonstrate how patterns can be used as visual statements for the analysis of a spatiotemporal data set in the information visualization.

A novel method is proposed to retrieve image sequences with the goal of forecasting complex and time-varying natural patterns. To that end, we introduce a framework called Memory-Based Forecasting; it provides forecast information based on the temporal development of past retrieved sequences. This paper targets the radar echo patterns in weather radar images, and aims to realize an image retrieval method that supports weather forecasters in predicting local precipitation. To characterize the radar echo patterns, an appearance-based representation of the echo pattern, and its velocity field are employed. Temporal texture features are introduced to represent local pattern features including non-rigid complex motion. Furthermore, the temporal development of a sequence is represented as paths in eigenspaces of the image features, and a normalized distance between two sequences in the eigenspace is proposed as a dissimilarity measure that is used in retrieving similar sequences. Several experiments confirm the good performance of the proposed retrieval scheme, and indicate the predictability of the image sequence.

Scheduling directed a-cyclic task graphs (DAGs) onto multiprocessors is known to be an intractable problem. Although there have been several heuristic algorithms for scheduling DAGs onto multiprocessors, few address the mapping onto a given number of completely connected processors with an objective of minimizing the finish time. We present an efficient algorithm called ClusterMerge to statically schedule directed a-cyclic task graphs onto a homogeneous completely connected MIMD system with a given number of processors. The algorithm clusters tasks in a DAG using a longest path heuristic and then iteratively merges these clusters to give a number of clusters identical to the number of available processors. Each of these clusters is then scheduled on a separate processor. Using simulations, we demonstrate that ClusterMerge schedules task graphs yielding the same or lower execution times than those of other researchers, but using fewer processors. We also discuss pitfalls in the various approaches to defining the longest path in a directed a-cyclic task graph.

The call processing capacity of a base station in CDMA cellular network can be changeable due to the additive loads from handoff, paging and location registration as well as call setup/release. In general, the load box test is widely used for measuring the call processing capacity of a exchange in the fixed network. But, it is difficult to estimate the processing capacity accurately because system load includes hand-off, paging in a mobile network. In this paper, we propose a new methodology for the calculation of call processing capacity to investigate the effect of traffic parameters on the system capacity, through the traffic modeling of call flow in base station. This result shows that the traffic load of hand-off limits the system capacity largely and is more severe than has been expected. Regression analysis will be also derived for the investigation of unit load and linear relation between CPU load and traffic load. This analysis using the field data from an operating site indicates that the call processing capacity in the wireless network must be specified with the rates of hand-off, paging and location registration, in contrast with the fixed network.

This article shows a Boolean Multivalued logical model of varying confirmation by observation of events in human inference and, as an introductory example, applies the model to solve Hempel's paradox of the ravens.

Our recent progress in improving the performance of the GaInNAs laser is fully reviewed here. We improved the crystal quality of GaInNAs by optimizing the conditions for its grown by gas-source molecular beam epitaxy (MBE) using N radicals as a N source. We found that the temperature window for obtaining GaInNAs with high crystal quality, good surface morphology, and good photoluminescence (PL) characteristics is smaller than that for obtaining this kind of GaInAs. Like dopant atoms such as Si or Be in GaAs, the N radicals produced by an RF discharge have a high sticking coefficient. Their use is therefore effective when we want to increase and control the N content of GaInNAs. We found that the AsH3-flow-rate mainly affected crystal quality of GaInNAs rather than incorporation of nitrogen atoms. We also investigated the effects of thermal annealing on the optical properties of as-grown GaInNAs layers and found that it greatly increased the PL intensity and produced the large shift in the PL wavelength. The absorption spectra of the GaInNAs bulk layer revealed that the large shift in the PL wavelength is probably caused by a bandgap shift in the GaInNAs well layer, and cathodeluminescence measurements revealed that the increased PL intensity is due to the improved emission being more uniform spatially: uniformity from the entire region; in comparison, nonuniform dot-like regions exist in an as-grown GaInNAs layer. Optimizing the growth conditions and using thermal annealing effect, we made a 1.3-µm GaInNAs/GaAs single-quantum-well laser that has a high characteristic temperature (215 K) under pulsed operation. To our knowledge, this is the highest characteristic temperature reported for a 1.3-µm band-edge emitter suitable for used in optical-fiber communication systems. The use of GaInNAs as an active layer is, therefore, very promising for the fabrication of long-wavelength laser diodes with excellent high-temperature performance.

In this letter, we describe a four thin-film-transistor (TFT) pixel circuit based on hydrogenated amorphous silicon (a-Si:H) technology for the active-matrix organic light-emitting diode (AMOLED) display applications. The circuit uses current-writing mechanism and can automatically adjust the threshold-voltage shifts of both the organic light-emitting diodes (OLEDs) and the TFTs induced by the circuit aging or process variations. Experimental results indicate virtually no variation of the output driving current after long-term bias-temperature-stress (BTS).

This work presents a scalable and high performance prediction protocol for optical networks. In the proposed protocol, we develop a mathematical model to maintain the stability of a network system by prediction based on the traffic temporal locality property. All the critical factors, including transceiver tuning time, propagation delay, and processing time for dealing with control packets, are considered in the proposed prediction protocol. Furthermore, our protocol can resolve the bottlenecks attributed to control signaling and electronics processing. The performance evaluation reveals that the proposed scheme can yield the higher bandwidth efficiency and incur a lower packet delay than those of the TDM and conventional reservation schemes. Also, the proposed protocol can flexibly support any scaled network system such as MANs or LANs.

A software requirements specification (SRS) is a document at the first phase of software development. Since it is difficult to make an accurate SRS at the beginning of software development, we propose a supporting method to detect and interpret the inconsistency of SRS. First, we classify and define the inconsistency of SRS. Next, we describe how to detect and interpret the inconsistency of SRS. We use the Requirements Frame Model to detect the inconsistency of SRS. We apply the Dempster and Shafer's theory to interpret the inconsistency of SRS. We illustrate our method with an example.

This paper presents an object-oriented model to handle the temporal relationship for all of the multimedia objects at the presentation platform. Synchronization of the composite media objects is achieved by ensuring that all objects presented in the upcoming "manageable" period must be ready for execution. To this end, the nature of overlays is first investigated for various types of objects. Critical overlaps which are crucial in synchronization are also defined. The objective of synchronization is to ensure that the media objects can be initiated precisely at the critical point of the corresponding critical overlap. The concept of manageable presentation interval is introduced and the irreducible media group is defined. The resource scheduling of each presentation group for media object pre-fetch time versus buffer occupancy is also examined. Accordingly, a new model called group cascade object composition Petri-net (GCOCPN) is proposed and an algorithm to implement this temporal synchronization scheme is presented.

An epoxy-modified urethane rubber mixed with carbon particles is now chosen as the millimeter-wave absorber material in our study. The absorption characteristics of the absorber is measured under temperature changes. The weatherability of our absorber is also clarified based on absorption characteristics, thickness and hardness of the sample. As a result of the temperature characteristics of the absorber, the difference of the maximum absorption frequency under temperature changes is about 1 GHz, however the absorption of 20 dB or more is obtained between 54 and 58 GHz. The result of accelerated artificial exposure test is that 2.8% of the thickness of our sample is shrunk after 1000 hour exposure, and the hardness of rubber is hardened with increasing test time. It is also confirmed that the deterioration of the absorption ranges from 1 to 3 dB, although the absorption of about 20 dB is kept at the frequency range. As a consequence, it is confirmed that the wave absorber using the epoxy-modified urethane rubber mixed with carbon particles has good weatherability including our desired temperature characteristics, and it is suitable for outdoor use.

We will discuss performance optimization of strain and temperature sensors based on long period fiber gratings (LPFGs) through control of the temperature sensitivity of the resonant peak shifts. Distinction between the effects of strain and temperature is a major concern for applications to communication and sensing. This was achieved in this work by suppressing or enhancing the temperature sensitivity by adjusting the doping concentrations of GeO2 and B2O3 in the core or cladding. The LPFGs were fabricated with a CO2 laser by the mechanical stress relaxation and microbending methods. The optimized temperature sensitivities were 0.002 nm/ for the suppressed case and 0.28 nm/ for the enhanced case, respectively. These LPFGs were used for simultaneous measurement of strain and temperature. The result indicates the rms errors of 23 µstrain for the strain and 1.3 for the temperature.

A correlation-based technique for measuring Brillouin gain spectrum distribution along an optical fiber is proposed, which employs frequency-modulated pump and probe lightwaves. The spatial-resolution of about 40 cm is demonstrated, which cannot be realized by the conventional pulse-based technique.

A short review of distributed and multiplexed sensor technology, based on fibre gratings, is given. This is followed by details of more specific work in this area at the University of Southampton, particularly grating fabrication, distributed and multiplexed addressing and important practical aspects such as temperature and strain discrimination. The paper concludes with a short discussion of the problems that must be avoided in order to construct viable systems for engineering requirements.

A novel temperature sensor device based on a conventional long-period fiber grating but having an improved sensing resolution is presented. By forming a reflector at one cleaved end of the fiber embedding a long-period grating, a fine interference fringe pattern was obtained within the conventional broadband resonant spectrum of the grating. Due to the fine internal structure of the reflection spectrum of the proposed device, the accuracy in reading the temperature-induced resonant wavelength shift was improved. The formation of the self-interference fringe is analyzed and its properties are discussed in detail. The performance of the proposed device is analyzed by measuring the resonant wavelength shift of the device placed in a hot oven under varying temperature. The rate of the fringe shift is measured to be 551 pm/. The rms deviation is 10 pm over a 100 dynamic range, which corresponds to 0.2 in rms temperature deviation. The thermal variation of the differential effective index of the fiber is calculated to be (0.3 0.1)10-6/ by comparing the analytic calculations with the experimental results. The interference fringe shift is revealed to be inversely proportional to the differential effective group index of the fiber, which implies that the shifting rate strongly depends on the type of fibers and also on the order of the involved cladding mode.

The technique used is based on thermal optical activity measurement of temperature combined with electric-field-induced polarization modulation of the input light. Quartz is used as the sensing element. A 1/4 wave plate is placed behind the quartz so that a single sensing head can simultaneously output two signals: one includes the Pockels effect for voltage measurement; the other optical activity for the temperature measurement. The operating principle of the sensor which detects voltage and temperature is presented theoretically and experimentally. The technique for separating voltage and temperature from the signals is analyzed theoretically and experimentally. It was found that the sensitivity of the voltage sensor to temperature depends on the magnitudes of voltage applied to it. To realize temperature compensation over a full range, two key parameters must be obtained: one is the response of the voltage sensor to temperature when the applied voltage is zero; another is the response of the sensing material to temperature when a certain voltage is applied. In the absence of electrogyration the effect of voltage on the temperature sensor may be neglected. The technique was demonstrated using a fiber-optic voltage sensor with temperature compensation. The sensor offered a voltage measurement range of 0-10 kV, and a temperature stability of 0.4% within the temperature range of 20-70.

The interaction between the human eye and electromagnetic (EM) waves in the ISM (industrial, scientific, and medical) frequency bands is investigated with the use of the finite-difference time-domain (FDTD) method. In order to assess possible health hazards, the specific absorption rates (SARs) are calculated and compared with the recommended safety standards. In particular, we calculate temperature rises in the human eye to assess the possibility of microwave-induced cataract formation. The results show that the maximum values of averaged SARs are less than the standard levels. In addition, we observed what is called the 'hot spot' in the region of eye humor at 2.4 GHz but not at 900 MHz and 5.8 GHz. Furthermore, the maximum temperature rise due to the incident EM power density of 5.0 mW/cm2, which is the MPE (maximum permissible exposure) limit for controlled environments, has been found to be at most 0.26 at 5.8 GHz, which is small compared with the threshold temperature rise 3.0 for cataract formation.

An ATMS (Assumption-based Truth Maintenance System) has been widely used for maintaining the truth of an information by detecting and solving the contradictions in rule-based systems. However, the ATMS cannot correctly maintain the truth of the information in case that the generated information is satisfied within a time interval or includes data about temporal relations of events in time varying situations, because it has no mechanism manipulating temporal data. In this paper, we propose the extended ATMS that can maintain the truth of the information in the knowledge-based system using information changing over time or temporal relations of events. To maintain the contexts generated by relations of events, we modify the label representation method, the disjunction and conjunction simplification method in the label-propagation procedure and the nogood handling method of the conventional ATMS.

A 5-pole lumped element bandpass filter (BPF) of center frequency 264.05 MHz and fractional bandwidth (FBW) 0.76% is designed and fabricated using YBa2Cu3O7-d (YBCO) thin films deposited on both sides of a MgO substrate(40 mm 40 mm 0.5 mm). The return loss, minimum insertion loss and ripple were measured to be 20.0 dB, less than 0.1 dB and less than 0.1 dB at 70 K, respectively. These results verify both the compactness and low loss characteristics in the VHF band. The simulated frequency response, where the frequency dependences of inductance (L) and capacitance (C) elements and housing effect are taken into account, is in good agreement with the measured frequency response.

Methods to discover laws are reviewed from among both statistical approach and artificial intelligence approach with more emphasis placed on the latter. Dimensions discussed are variable dependency checking, passive or active data gathering, single or multiple laws discovery, static (equilibrium) or dynamic (transient) behavior, quantitative (numeric) or qualitative or structural law discovery, and use of domain-general knowledge. Some of the representative discovery systems are also briefly discussed in conjunction with the methods used in the above dimensions.