Pair Of Terminals Research Articles

3D magnetic-field sensor using only a pair of terminals

A lateral magnetotransistor (LMT) with asymmetric topology sensitive to the three directions of the magnetic field and using only a pair of terminals is reported. The experimental results are justified in terms of the Lorentz deflection of carriers. Modelling the device as an LMT and a diode, sensitive to the magnetic field, in parallel with the E–B junction, allows the response of the device to be interpreted through the variation of areas associated with each component. The analysis of the results suggests some design criteria in order to obtain a magnetic-field-vector sensor.

The smallest pair of noncrossing paths in a rectilinear polygon

Smallest rectilinear paths are rectilinear paths with simultaneous minimum numbers of bends and minimum lengths. Given two pairs of terminals within a rectilinear polygon, the authors derive an algorithm to find a pair of noncrossing rectilinear paths within the polygon such that the total number of bends and the total length are both minimized. Although a smallest rectilinear path between two terminals in a rectilinear polygon always exists, they show that such a smallest pair may not exist for some problem instances. In that case, the algorithm presented will find, among all noncrossing paths with a minimum total number of bends, a pair whose total length is the shortest, or find, among all noncrossing paths with a minimum total length, a pair whose total number of bends is minimized. They provide a simple linear time and space algorithm based on the fact that there are only a limited number of configurations of such a solution pair.

An Efficient Link Allocation Algorithm for ATM-Based Personal Communication Networks

The wireless personal communication networks (PCN) will play an important role throughout the 1990s and into the next century. Due to the demand for extending the wireless services to integrated services such as data, voice, images and video, a high-speed backbone network to connect the base stations in the microcells is required. One of the possible solutions is to apply the ATM-based backbone network. In such an ATM-based PCN, the communication path between a pair of mobile terminals might be elongated due to the mobility of terminals. Generally, there are two ways to resolve this problem. The first is to migrate the elongated path to a better one when necessary. The other is to design an appropriate backbone network by considering the mobile environment. Recently, several mechanisms based on the former approach have been proposed. In this paper, the latter approach is considered and the design problem of allocating the backbone links among the ATM switches so that the network performance affected by the terminal mobility is kept as less as possible is investigated. We show that this link allocation problem is NP-hard. A simple and efficient heuristic is also proposed for this problem. Simulation results show that based on the backbone obtained by the heuristic, the average length of each communication path is kept as short as possible even under the mobile environment. As a result, the number of successfully established paths in the network is increased significantly.

LINEAR-TIME ALGORITHMS FOR DISJOINT TWO-FACE PATHS PROBLEMS IN PLANAR GRAPHS

In this paper we present a linear-time algorithm for the vertex-disjoint Two-Face Paths Problem in planar graphs, i.e., the problem of finding k vertex-disjoint paths between pairs of terminals which lie on two face boundaries. The algorithm is based on the idea of finding rightmost paths with a certain property in planar graphs. Using this method, a linear-time algorithm for finding vertex-disjoint paths of a prescribed homotopy is derived. Moreover, the algorithm is modified to solve the more general linkage problem in linear time, as well.

Optimum path packing on wheels: The consecutive case

We show that, given a wheel with nonnegative edge lengths and pairs of terminals located on the wheel's outer cycle such that the terminal pairs are in consecutive order, then a path packing, i.e., a collection of edge disjoint paths connecting the given terminal pairs, of minimum length can be found in strongly polynomial time. Moreover, we exhibit for this case a system of linear inequalities that provides a complete and nonredundant description of the path packing polytope, which is the convex hull of all incidence vectors of path packings and their supersets.

Optimal node disjoint paths on partial 2-trees: A linear algorithm and polyhedral results

We present anO(p · n) algorithm for the problem of finding disjoint simple paths of minimum total length betweenp given pairs of terminals on oriented partial 2-trees withn nodes and positive or negative arc lengths. The algorithm is inO(n) if all terminals are distinct nodes. We characterize the convex hull of the feasible solution set for the casep=2.

5278505 Self-cancelling RF receive coil used to decouple MRI transmit/receive RF coils

In addition to the usual winding of an MRI RF receive coil, a second, opposite sense, winding is connected to the same pair of RF output terminals and linked to at least part of the same space as the first winding. One or more serially connected RF switches in the second winding selectively connect it in circuit only during transmission of NMR RF nutation pulses. Under these conditions, any transmitted RF fields linked to the first winding are also linked to the second winding. Accordingly, any induced RF currents flowing in the receive coil windings produce self-cancelling effects in the tissue being imaged (thereby reducing possible distortion of the desired transmit fields being used for NMR nutation purposes).

Maximum number of disjoint paths connecting specified terminals in a graph

Suppose G is a finite graph and let T ⊆ V ( G ) be a subset of its vertices throughout referred to as terminals . The problem MAXIMUM DISJOINT T -PATHS (MDT-P) is to find a family of maximum pairwise disjoint paths connecting pairs of terminals. MDT-P is a nontrivial extension of the maximum matching problem; the latter being equivalent to the special case T = V . We present a dual problem of minimum odd T-disconnector , an appropriate minimax theorem and an O( n 4 ) algorithm constructing optimal solutions for both primal and dual problems.

Finding k Disjoint Paths in a Directed Planar Graph

It is shown that, for each fixed $k$, the problem of finding $k$ pairwise vertex-disjoint directed paths between given pairs of terminals in a directed planar graph is solvable in polynomial time.

Minimum cost multiflows in undirected networks

LetN = (G, T, c, a) be a network, whereG is an undirected graph,T is a distinguished subset of its vertices (calledterminals), and each edgee ofG has nonnegative integer-valuedcapacity c(e) andcost a(e). Theminimum cost maximum multi(commodity)flow problem (*) studied in this paper is to find ac-admissible multiflowf inG such that: (i)f is allowed to contain partial flows connecting any pairs of terminals, (ii) the total value off is as large as possible, and (iii) the total cost off is as small as possible, subject to (ii). This generalizes, on one hand, the undirected version of the classical minimum cost maximum flow problem (when |T| = 2), and, on the other hand, the problem of finding a maximum fractional packing ofT-paths (whena ≡ 0). Lovasz and Cherkassky independently proved that the latter has a half-integral optimal solution.

Preventive Equipment for Urinary Incontinence: A Device Employing Lower Abdominal Impendance Changes

The object of this work was to develop a monitoring device for measuring the volume of urine in the bladder to signal, in advance, the need to urinate and thus help prevent urinary incontinence. A high-frequency electric current of 50 KHz transmitter was applied to a pair of terminals placed on the surface of a human body. The constant current was 2mA (p-p). A pair of voltage electrodes was placed in the path of the electric current to pick up high-frequency voltage signals. The best position for current electrodes was found to be on the surface of both femoral joints. Positioning the voltage electrode above the bladder on the lower abdomen was most efficient for detecting the volume of urine. New current electrodes sutured onto underpants were fitted on the surface above the femoral joints, which did not shift in the case of movement by the subjects. The reproducibility and stability were remarkably good with this electrode. The alarm level which foretold both maximum storage volume and maximum desire to void was examined. After that, when the alarm level was set within the range of impedance charge, 60% to 70%, the possibility of prediction of urination exists.

Shannon-like games are difficult

We deal with an analogy of the Shannon switching game, called n−pair games, played on a graph with n pairs of terminals (+1, −1), (+2, −2),…, (+n, −n. Here these 2n terminals are not necessarily bounds and relationships distinct and a coincidence of terminals is indicated by =. Each player at his turn labels an edge unlabeled as yet. Short intends to make a path consisting of the edges labeled by him between one of the given n pairs of terminals and Cut intends to obstruct it. The classical strategy theory can be generalized for the so-called double-matroid games, including 2-pair games [cf. Yamasaki (1978, 1989)]. However, certain particular 3-pair games are ‘difficult’ (cf. Yamasaki, to appear).

Technique for measurement of powerline impedances in the frequency range from 500 kHz to 500 MHz

A method for measuring power line impedances using two current probes is examined. This method is characterized by good isolation of the measurement equipment from the power line voltage and by the capability of measuring power line impedances between any pair of power-plug terminals. The use of this two-current probe method with the model described is effective in measuring power line impedances from 0.5 MHz to 100 MHz. Using purely resistive loads for calibration, the error is less than 5% for frequencies below 100 MHz, and less than 20% for frequencies between 100 MHz and 500 MHz. The error in an impedance measurement increases with the magnitude of the load impedance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Interpretation of time constant and electrotonic length estimates in multicylinder or branched neuronal structures.

1. We have investigated the theoretical and practical problems associated with the interpretation of time constants and the estimation of electrotonic length with equivalent cylinder formulas for neurons best represented as multiple cylinders or branched structures. Two analytic methods were used to compute the time constants and coefficients of passive voltage transients (and time constants of current transients under voltage clamp). One method, suitable for simple geometries, involves analytic solutions to boundary value problems. The other, suitable for neurons of any geometric complexity, is an algebraic approach based on compartmental models. Neither of these methods requires the simulation of transients. 2. We computed the time constants and coefficients of voltage transients for several hypothetical neurons and also for a spinal motoneuron whose morphology was characterized from serial reconstructions. These time constants and coefficients were used to generate voltage transients. Then exponential peeling, nonlinear regression, and transform methods were applied to these transients to test how well these procedures estimate the underlying time constants and coefficients. 3. For a serially reconstructed motoneuron with 732 compartments, we found that the theoretical and peeled tau 0 values were nearly equal, but the theoretical tau 1 was much larger than the peeled tau 1. The theoretical tau 1 could not be peeled because it was associated with a coefficient, C1, that had a very small value. In fact, there were 156 time constants between 1.0 and 6.0 ms, most of which had very small coefficients; none had a coefficient larger than 2% of the signal. The peeled value of tau 1 (called tau 1 peel) can be viewed as some sort of a weighted average of the time constants having the largest coefficients. 4. We studied simple hypothetical neurons to determine what interpretation could be applied to the multitude of theoretical time constants. We found that after tau 0, there was a group of time constants associated with eigenfunctions that were odd (or approximately odd) functions with respect to the soma. These time constants could be interpreted as "equalizing" time constants along particular paths between different pairs of dendritic terminals in the neuron. After this group of time constants, there was one that we call tau even because it was associated with an eigen-function that was approximately even with respect to the soma. This tau even could be interpreted as an equalizing time constant for charge equalization between proximal membrane (soma and proximal dendrites) and distal membrane (including all distal dendrites).4=

An Exact Sublinear Algorithm for the Max-Flow, Vertex Disjoint Paths and Communication Problems on Random Graphs

This paper describes a randomized algorithm for solving the maximum-flow maximum-cut problem on connected random graphs. The algorithm is very fast—it does not look up most vertices in the graph. Another feature of this algorithm is that it almost surely provides, along with an optimal solution, a proof of optimality of the solution. In addition, the algorithm's solution is, by construction, a collection of vertex-disjoint paths which is maximum. Under a restriction on the graph's density, an optimal solution to the NP-hard communication problem is provided as well, that is, finding a maximum collection of vertex-disjoint paths between sender-receiver pairs of terminals. The algorithm lends itself to a sublogarithmic parallel and distributed implementation. Its effectiveness is demonstrated via extensive empirical study.

Shannon switching games without terminals III

Shannon switching game has been analyzed by Lehman [3] in matroid theory. Kano [2] has studied games with many terminals where Short intends to connect at least two of them. This result is included in [6] and [7], where the games are described on graphs with group action. These results will be generalized in this paper which deals with games on a finite set with two matroid structures. Our new theory can be applied to the game where Short's purpose is to connect all the given pairs of terminals and to the game where Short's purpose is to connect at least one of given two pairs of terminals. On the other hand, the game is not reversible (see [9]) if Short's purpose is to connect at least one of given three pairs of terminals.

A dual frequency ultrasonic probe for medical application.

A dual frequency probe employing two ceramic layers for medical ultrasonic diagnostic equipment has been developed for simultaneously obtaining both a high-resolution tomogram and a high S/N Doppler mode image. This ceramic vibrator, which has opposite poling directions and different individual thicknesses, has enabled the excitement of a second harmonic in addition to the fundamental resonance. Therefore, only a pair of electrical terminals are enough to excite dual frequencies. Ultrasonic attenuation in a human body is reduced, since the Doppler reference frequency can be set below the tomogram center frequency. Moreover, the two relative resonant levels are widely controllable by changing the thickness ratio of the two layers. An optimum thickness ratio of 1:0.7 has been obtained by computer simulation under Mason’s model. A cofiring multilayer method has been developed to achieve a multilayer ceramic with a large adhesive strength. As a result, the S/N of the Doppler mode has been improved as much as 5 dB over that of a conventional probe at an artery located 5 cm deep from the surface.

The dilated slipped Banyan switching network architecture for use in an all-optical local-area network

A modification of the classical banyan switching network architecture, called the dilated slipped banyan, is described. This architecture is recursive and switching networks of any size perform permutation switching under a simple switching rule. They also exhibit column-control and dilation, properties that are particularly relevant to guided-wave and free-space photonic technologies. A photonic switching network, with this dilated slipped banyan architecture, is proposed as the hub of an all-optical active-star local-area network. The switching assignment at this hub is time-multiplexed on a fixed schedule that is known to all the terminals. This all-optical local-area network provides the equivalent of full-connectivity with high simultaneous data rates between every pair of terminals. A 16-terminal local-area network with 100 Mb/s of contention-free bandwidth between every pair of terminals is described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A difficulty in particular Shannon-like games

We have a simple theory of strategy for generalized Shannon switching games (on edges). This theory naturally gives us an algorithm of polynomial order. On the other hand Reisch states the PSPACE completeness of judging who can win in all the positions of Hex. Our purpose in this paper is to discuss the difficulty not of a class but of each particular game. We shall see that any strategy theory of a certain type cannot be applied either to Hex of 4 2 vertices or to a certain 3-pair game, though it can be applied to all 2-pair games. Here, an n-pair game is a game played on the edge set of a graph where a designated player intends to connect at least one of the given n pairs of terminals.

Reduction of simultaneous-switching noise in large crossbar networks

Delta-I noise (simultaneous switching noise) poses a severe limitation on the size of the individual crosspoint chips that can be used to synthesize a large crossbar network. An architectural solution for reduction of the Delta-I noise in a crossbar network by using a one-sided crosspoint switching circuits is presented. Because of the existence of multiple switching paths between any pair of terminals to be connected, these circuits provide the potential for minimizing the Delta-I noise by placing the active line drivers uniformly among the switching chips. It is shown that when the sequence of connections and disconnections is arbitrary, and with a minimal nonblocking configuration of one-sided switching chips, no algorithm exists for allocation of paths in the network that can prevent the active line drivers from getting concentrated in a few chips. However, it is possible to reduce the maximum number of active line drivers in a chip by using extra columns of chips. Tight upper bounds are achieved for the number of additional columns required for a one-sided nonblocking crossbar network when a Delta-I constraint is imposed. >