An estimation method for shading and narcissus in forward looking infrared camera (FLIR) is discussed. Shading and narcissus are common optical noises in FLIR formed mainly by infrared emission from warm housing and cold surface. These noises are clearly observed when the background of an image is uniform. The estimation method proposed in this paper produces an uniform background by covering the field of view (FOV) with a black body placed in front of the FLIR. Shading and narcissus are evaluated as the infrared intensity variation at the detector. Assuming that the emission surface is Lambertian, intensity contribution from black body, lenses, warm housing and cold surface in both direct and reflected paths pathis is considered. A simulation program based on ray tracing is developed for calculating the intensity variation at the detector. Examples of both simulation and experimental results are presented.
This paper describes a method for estimating narcissus pattern of 2D-IRCCD based forward looking infrared camera (FLIR). Narcissus is a common optical noise in FUR caused by infrared emission from warm housing and cold surface reaching to the detector after reflected at lens surfaces. Since sharp edges in the narcissus pattern result in poor image quality, smooth narcissus edge is a significant design concept for FLIR. The narcissus pattern estimation method proposed in this paper hypothetically treats the cold surface as a negative infrared light source. Infrared intensity from this negative source creates narcissus at the detector surface. The narcissus pattern is obtained by normalizing the intensity variation of narcissus. A simulation program is developed using ray tracing technique for narcissus pattern calculation. Examples of both simulation and experimental results are presented.
Dependences of laser output energy and excitation power on gap length (14 to 21mm) and ambient pressure (2 to 3atm) are discussed experimentally on an UV-preionized discharge-pumped KrF excimer laser with a charge transfer system for a gas mixture of Kr/F2/He/Ne=2.0/0.25/14.45/83.3%. The specific laser output energy increases with the excitation power, of which relation is expressed in a straight line. It is clarified that the same linear relationship is found in spite of the change of the gap length and ambient pressure. A similarity relationship between the excitation power per unit pressure and the product of gap length and ambient pressure is also clarified. In the case of pressure varied from 2 to 3atm, the increase of excitation power brings larger laser output energy. As the gap length is increased, the increase of the discharge volume also contributes to the laser output energy in addition to the effect of the excitation power. By theoretical discussion with a computer simulation code in the wider range of the gap length and pressure, the existence of an optimum gap length and pressure for obtaining the largest excitation power is clarified. At this case, energy transfer efficiency from a primary capacitor to a secondary capacitor is shown to be about 60 percent.
We consider a problem of routing, that is, a problem of choosing an optimal route for each call in telephone networks. For this problem we present an adaptive routing scheme based on observation of traffic information. A main adaptive routing scheme that has been presented is a scheme using learning automata. Under this scheme, a learning automaton is located at each station. For each call arriving at the station, the automaton makes probabilistic choice of a link from some set of links connecting with the next relay stations. This scheme asymptotically attains equalization of blocking probabilities among the links. This “load equalization” provides a desirable effect to decrease the blocking, but with a possibility that a call takes a quite roundabout route. To avoid such a possibility and to reduce costs of connecting calls, for each call generating at each station our scheme makes deterministic choice of a route from some set of routes leading to the destination, based on observation of a blocking frequency of each route. It is shown that our scheme asymptotically attains equalization of the blocking frequencies among the routes, which is also one kind of load equalization.
This paper concerns a new type joy stick for teaching operation of manipulators. The device is equipped with conic coil springs as force transducers which have non-linear force-deflection characteristics: An operational force applied to the device can be detected with high sensitivity in small range and with wide dynamic range. The device is assembled with lever mechanisms of paired springs to obtain independent 3 degrees of momental freedom. The springs added are designed to have linear characteristics as well for the smaller half of the maximum deflection as a countermeasure to retain the effectiveness of non-linearity. Deflection of each spring is directly detected as change of inductance so it contributes to make the composition of the device simple without any other measures of detecting it. In the study, the force sensing transducers made of conic coils and the 3-axis joy sticks were actually manufactured. And, their detection characteristics were evaluated to obtain satisfactory results.
This paper proposes an improved simulated annealing method based on genetic algorithm and applies it to a floorplan design of VLSI. The proposed method can effectively search wide state space for an optimal solution because of the parallel search starting from many initial points and the genetic selection among its paths. Computational experiments show that this method is more powerful to get a better solution than conventional simulated annealing method.