This Letter proposes a timer based ordered registration (TBOR) scheme for CDMA private user zone (PUZ) service. The proposed TBOR scheme solves the problem that both the PUZ system loads and the public system loads are increased due to excessive registration. Also the TBOR scheme is quite simple to implement and compatible with the existing public CDMA system.

We propose a method for camera calibration based on image registration. This method registers two images; one is a real image captured by a camera with a calibration object with known shape and texture, and the other is a synthetic image containing the object. The proposed method estimates the parameters of the rotation and translation of the object by using the depth information of the synthetic image. The Gauss-Newton method is used to minimize the residuals of intensities of the two images. The proposed method does not depend on initial values of the minimization, and is applicable to images with much noise. Experimental results using real images demonstrate the robustness against initial state and noise on the image.

In this paper, we examine the basic properties of n-th order linear feedback shift registers and show that n-th order shift registers based discrete logarithm problem is equivalent to discrete logarithm problem. This shows that the algebraic structure of n-th order linear feedback shift registers is useful in constructing cryptographic primitives.

Construction of large-scale virtual environment is gaining more attentions for its applications in virtual mall, virtual sightseeing, tele-presence, etc. This paper presents a framework for building a realistic virtual environment from geometry-based approach. We propose an algorithm to construct a realistic 3-D model from multi-view range data and multi-view texture images. The proposed method tries to adopt the result of region segmentation of range images in some phases of the modeling process. It is shown that the relations obtained from region segmentation are quite effective in improving the result of registration as well as mesh merging.

In this study, we consider movement-based registration (MBR), improved MBR (IMBR) and distance-based registration (DBR). Analytical models based on 2-dimensional random walk in hexagonal cell configuration are considered to analyze the performance of MBR/IMBR and DBR. Especially, we focus on the derivation of the registration cost of DBR scheme by using analytical method and then show that DBR always outperforms not only MBR but also IMBR.

In this paper, we investigate the performance of Mobile IP regional registration and compare it with that of Mobile IP. The performance measures used are registration delay and the CPU processing overheads loaded on the agents to handle mobility of mobile nodes. Through the investigation, the effectiveness of adopting Mobile IP regional registration in the wide-area wireless network in terms of reducing the CPU processing overheads on the home agent and lowering the signaling delay is observed. We also compare the scalability of Mobile IP regional registration schemes when two and three levels of foreign agent hierarchy are considered. Based on the comparison, we propose a network design strategy for achieving optimized performance and cost.

We propose Concatenated Location Management (CLM), utilizing tendency for mobile terminals (MTs) to move as a group. When many MTs are on the same train, for example, they move together and share the same mobility characteristics. Therefore, we propose to concatenate the MTs and link them to the train for more efficient location management. CLM can reduce the number of location management signals because the train sends only one location registration signal on behalf of all of the individual MTs when a location registration area boundary is crossed. We discuss the key functions for CLM including location registration, paging, and location register configuration.

In conventional Web Geographic Information System (GIS), there are serious drawbacks of high waiting time and low accessibility because the subsequent query has to wait until all the spatial data has been completely transmitted. In addressing these problems, this paper proposes a progressive transmission method which can reduce waiting time and increase accessibility. The proposed method has the following steps. First, significant vertices of geographic objects are selected into based on an algorithm, Priority_Order_Estimation (POE). Second, the selected vertices are inserted the data structure, Priority_Order_Queue (POQ). This allows a client to view, to request and occasionally to reject spatial data, rather than waiting for the whole map to arrive. Third, the transmission steps are processed progressively, where significant vertices of POQ are sent from server to client one by one. In the final step, if necessary, the entire spatial data set of SENDOBJSP, which is a transmission structure, is transmitted so that the original map is accurately displayed. The performance of the system proposed here has been evaluated according to the factors such as system response time and client storage space. For the comparisons, the total transmission method, layer transmission method and the proposed four-step transmission method were used. Compared with the conventional Web-based GIS, the system response time is twenty-two percent shorter and client storage space is reduced by about twenty-one percent. As a result, performance improvement, fast response time and less client storage usage, is achieved. Therefore, the proposed method can make a significant contribution in support of Web-based Vector GIS applications such as Environmental Management, Map On Demand Service and Assessment and Planning System.

Tracking mobile users in cellular wireless networks involves two basic functions: location update and paging. Location update refers to the process of tracking the location of mobile users that are not in conversation. Three basic algorithms have been proposed in the literature, namely the distance-based, time-based, and movement-based algorithms. The problem of minimizing the location update and paging costs has been solved in the literature by considering exponentially distributed Cell Residence Times (CRT) and Inter-Call Time (ICT), which is the time interval between two consecutive phone calls. In this paper we select the movement-based scheme since it is effective and easy to implement. Applying the theory of the delayed renewal process, we find the distribution of the number of cell crossings when the ICT is a mixture of exponentially distributed random variables and the CRT comes from any distribution with Laplace transform. In particular, we consider the case in which the first CRT may have a different distribution from the remaining CRT's, which includes the case of circular cells. We aim at the total cost minimization in this case.

A fast, low-power 16-bit adder, 32-word register file and 512-bit cache SRAM have been developed using 0.25-µm GaAs HEMT technology for future multi-GHz processors. The 16-bit adder, which uses a negative logic binary look-ahead carry structure based on NOR gates, operates at the maximum clock frequency of 1.67 GHz and consumes 134.4 mW at a supply voltage of 0.6 V. The active area is 1.6 mm2 and there are about 1,230 FETs. A new DC/DC level converter has been developed for use in high-speed, low-power storage circuits such as SRAMs and register files. The level converter can increase the DC voltage, which is supplied to an active-load circuit on request, or supply a minimal DC voltage to a load circuit in the stand-by mode. The power dissipation (P) of the 32-word register file with on-chip DC/DC level converters is 459 mW, a reduction to 25.2% of that of an equivalent conventional register file, while the operating frequency (fc) was 5.17 GHz that is 74.8% of fc for the conventional register file. P for the 512-bit cache SRAM with the new DC/DC level converters is 34.3 mW, 89.7% of the value for an equivalent conventional cache SRAM, with the read-access time of 455 psec, only 1.1% longer than that of the conventional cache SRAM.

It is shown that the effective secret-key size of TOYOCRYPT-HS1 stream cipher is only 96 bits, although the secret key consists of 128 bits. This characteristic opens a door for developing an algorithm for cryptanalysis based on the time-memory-data trade-off with the overall complexity significantly smaller than the exhaustive search over the effective key space.

This paper deals with a method of registration and superimposition of a coronary arterial tree on a myocardial SPECT (Single Photon Emission Computed Tomography) image. We can grasp the myocardial function more easily in connection with the shape of the coronary arterial tree. The superimposed image is easily obtainable through some manual pointing on coronary angiograms (CAG) followed by an automatic matching method: First, a rough shape model of left ventricle is estimated by using SPECT data. This 3-D left ventricular model is projected on a pair of bi-plane CAG images. We can obtain two 2-D coronary images on bull's eye map by scanning the left ventricular surface projected on CAG. By maximizing a matching degree between two 2-D coronary images, registration between CAG and SPECT is performed. Finally the superimposed image is obtained by integrating two 2-D coronary images and bull's eye image of SPECT. We validated our method by numerical experiments with artificial data set and also applied it to two clinical data sets.

In this paper, we propose a new digital signature scheme based on a third order linear feedback shift register for signing documents. This signature scheme is different from most of the signature schemes that are based on discrete logarithm problem, elliptic curves discrete logarithm problem, RSA or quadratic residues. An efficient algorithm for computing kth term of a sequence is also presented. The advantage of this scheme is that the computation is efficient than Schnorr scheme. We also show that the security of the proposed signature scheme is equivalent to that of Schnorr signature scheme.

Functional magnetic resonance imaging (fMRI) allows to display functional activities of certain brain areas. In combination with a three dimensional anatomical dataset, acquired with a standard magnetic resonance (MR) scanner, it can be used to identify eloquent brain areas, resulting in so-called functional neuronavigation, supporting the neurosurgeon while planning and performing the operation. But during the operation brain shift leads to an increasing inaccuracy of the navigation system. Intraoperative MR imaging is used to update the neuronavigation system with a new anatomical dataset. To preserve the advantages of functional neuronavigation, it is necessary to save the functional information. Since fMRI cannot be repeated intraoperatively with the unconscious patient easily we tried to solve this problem by means of image processing and pattern recognition algorithms. In this paper we present an automatic approach for transfering preoperative markers into an intraoperative 3-D dataset. In the first step the brains are segmented in both image sets which are then registered and aligned. Next, corresponding points are determined. These points are then used to determine the position of the markers by estimating the local influence of brain shift.

It is widely recognized that IP-based mobile network will be a dominant trend. For mobile IP networks, the address starvation problem and scalable mobility management for mobile nodes are important issues. In order to cope with these issues, we propose an approach to realize mobile IP network supporting private addresses for mobile nodes. Our approach introduces regional registration of mobile nodes (Hierarchical Mobile IPv4) and coordinates NAT and DNS functions with the Mobile IP protocol. It enables a mobile node to be assigned a global address temporally in a visited network and to accept a call initiated by a correspondent node connected to the global IP network. This paper describes the detailed design of our approach and the implementation of proposed procedures based on the Mobile IPv4 software developed by the CMU Monarch project.

This letter proposes a hardware/software partitioning algorithm for digital signal processor cores with two register files. Given a compiled assembly code and a timing constraint of execution time, the proposed algorithm generates a processor core configuration with a new assembly code running on the generated processor core. The proposed algorithm considers two register files and determines the number of registers in each of register files. Moreover the algorithm considers two or more types of functional units for each arithmetic or logical operation and assigns functional units with small area to a processor core without causing performance penalty. A generated processor core will have small area compared with processor cores which have a single register file or those which consider only one type of functional units for each operation. The experimental results demonstrate the effectiveness and efficiency of the proposed algorithm.

We propose a method for compensating distortion of image by calibrating intrinsic camera parameters by image registration which does not need point-to-point correspondence. The proposed method divides the registration between a calibration pattern and a distorted image observed by a camera into two steps. The first step is the straightforward registration from the pattern in order to correct the displacement due to projection. The second step is the backward registration from the observed image for compensating the distortion of the image. Both of the steps use Gauss-Newton method, a nonlinear optimization technique, to minimize residuals of intensities so that the pattern and the observed image become the same. Experimental results show the usefulness of the proposed method. Finally we discuss the convergence of the proposed method which consists of the two registration steps.

This letter presents a method which attempts to minimize the number of spill codes to resolve usage conflicts of distributed registers in application specific DSPs. It searches for a set of ordering restrictions among operations which sequentialize the lifetimes of the values residing in the same register as much as possible. Experimental results show that the proposed analysis method reduces the number of register spills into 28%.

A timer-based scheme is proposed to manage information within terminal and service profiles for both incall registration/deregistration of UPT users and incall registration resets of terminal owners. In the timer-based scheme, information related to incall registration for a UPT user in a terminal profile is deleted due to a timer expiration without accessing the terminal profile. The performance of the timer-based scheme is compared with the previously proposed request-based scheme in terms of; 1) total cost and, 2) the number of terminal profile accesses per unit time for a terminal. Even though provision of the timer-based scheme requires the modification of incoming call delivery procedure, the timer-based scheme can reduce both the total cost and the number of terminal profile accesses compared to the previously proposed request-based scheme.

An algorithm for cryptanalysis of certain keystream generators is proposed. The developed algorithm has the following two advantages over other reported ones: it is more powerful, and it can be implemented by a high-speed software or a simple hardware suitable for high parallel architectures. The algorithm is based on error-correction of information bits only (of the corresponding binary block code) with a novel method for construction of the parity-checks, and the employed error-correction procedure is an APP based threshold decoding. Experimental and theoretical analyses of the algorithm performance are presented, and its complexity is evaluated. The proposed algorithm is compared with recently proposed improved fast correlation attacks based on convolutional codes and turbo decoding. The underlying principles, performance and complexity are compared, and the gain obtained with the novel approach is pointed out.