bluuebunny/crossref_metadata_2025 huggingface dataset:
Character recognition in cursive handwriting with the mechanism of selective attention
Authors: Imagawa Taro , Fukushima Kunihiko
Published: July 2007

The recognition of connected characters in cursive handwriting is a difficult task with ordinary pattern‐matching techniques, since the shape of the individual character is affected by its preceding and succeeding characters. One of the authors has proposed a neural network model called the selective attention model, which has the ability to recognize and extract individual patterns from a composite of a number of elementary patterns. However, when a large number of patterns are presented concurrently, this model doe not always work correctly. In this paper, we extend the idea of this model and construct a new system, which has the ability to recognize the connected characters in cursive handwriting. it has been verified by computer simulation that this system can be used to correctly recognize connected characters.
Structure from motion by voting algorithm
Authors: Hamano Teruo , Ishii Kenichiro , Yasuno Takayuki
Published: July 2007

In methods for extracting three‐dimensional structure by conventional spatiotemporal image analysis, camera motion was restricted to constant velocity linear motion in order to use epipolar constraints. In this paper, we are proposing a method for extracting three‐dimensional structure that permits arbitrary camera motion by introducing weighted voting of the lines of sight in the spatiotemporal image analysis and does not track the paths of feature points in the image space. Since there is absolutely no matching among images in this method, it is very robust when gaps occur in the feature point paths as a result of occlusion and noise. Tests were performed using a real image and the effectiveness of this method for a complex image with occlusions was verified.
A system for building interactive visual simulator of digital hardware
Authors: Kojima Taizo , Sugimoto Akira
Published: July 2007

A digital system software simulator can provide high level support for testing and debugging of firmware using graphical user interfaces which perform visualization of the hardware model. Since sufficient knowledge of the target hardware is required for the development of a simulator, a simulator is usually developed by a hardware engineer, even though the hardware engineer may not have enough knowledge for building interactive graphical user interfaces. Therefore, it is not easy for a hardware engineer to develop a visual simulator using graphical user interfaces. In this paper, a new system for building interactive visual simulators and an example of its application are presented. In this system, an object‐oriented simulator kernel is introduced for separation of hardware description and user interface implementation. This kernel is built based on an object‐oriented method, and it provides common functions for hardware modeling and user interfaces, such, as an event driven mechanism. Layered on this kernel, an object‐oriented hardware description language and a user interface description language are implemented. By this approach, both hardware descriptions and user interfaces have a high level software reusability. Therefore, a hardware engineer can develop an interactive visual simulator by describing only the hardware model. Furthermore, by using user interface description language, a hardware engineer can customize a graphical user interface according to the purpose of simulation.
Acquisition of local maps by fixation
Authors: Ishiguro Hirushi , Stelmaszyk Patrick , Tsuji Saburo
Published: July 2007

The vision sensor of a conventional mobile robot is attached to the body of the robot. For more flexible environment recognition, it is necessary to allow the vision sensor to controlling visual attention mechanism of a mobile robot, and examine a method for obtaining a local map. A set of equations which produces the local map from continuous observational data is described. Advantages of the controlling visual attention are presented, based on an error analysis. The advantages are that the environment can be obtained from a coordinate system based on the object under attention, and that errors in the determined position of the object are smaller than with other methods which do not include a controlling visual attention. Experimental results using a Kalman filter for a set of continuous observational data show that an accurate local map is produced.
Use of a linear predictive analysis method to detect gas bubbles generated in the bloodstream during decompression
Authors: Nakai Tokayoshi , Watanabe Masahiro , Suzuki Hisayoshi
Published: July 2007

This paper discusses an algorithm for detecting bubbles in a diver's bloodstream during decompression from submergence. A widely employed method at present for detecting bubbles is the ultrasonic Doppler method, which is based on aural sensation. However, a problem here is that the Doppler signal contains various kinds of noises such as cardiac motion signals. Thus, the observer is required to concentrate to detect the bubble sound from the noise when the number of bubbles are few, and to count the number when there are many. This is not an easy task, even for an expert.

The authors discovered the features of the typical bubble sound with respect to the time waveform and the frequency spectrum, and developed a new bubble‐detection algorithm based on linear predictive signal processing. An experiment for bubble detection is executed, using a material to demonstrate the bubble‐detection Doppler method and data recorded in the simulated 300‐m manned submergence. It is verified that the proposed method has nearly the same performance as that of an expert.

Finally, this paper discusses the phenomenon where the frequency of the bubble decreases with the increase in bubble generation.
A neural algorithm incorporating winner‐take‐all subnets for combinatorial optimization
Authors: Urahama Kiichi
Published: July 2007

Using a neural net composed of subnets with a winner‐take‐all (WTA) mode of operations, the constraint that the variables must form a probability vector or a probability matrix can automatically be satisfied. Taking advantage of this property, this paper proposes a neural algorithm than can derive the approximate solution for a combinatorial optimization problem such as set partitioning. As a simple example, the 3‐partition maximum‐cut problem is considered.

The worst‐case error is evaluated theoretically, and it is shown that the proposed method is one‐third (relative) approximate algorithm. For comparison, the performance of the conventional method also is evaluated theoretically. The performances also are compared by experiment. Both the theoretical and experimental results confirm that the proposed method can achieve better performance than the conventional method.
Invertible affine transformations on integer coordinate system — general theory in n ‐ dimensional space
Authors: Shizawa Masahiko
Published: July 2007

This paper considers a lattice represented by integer coordinates in n‐dimensional space (digital lattice). On the digital lattice, an automorphism is constructed by a newly proposed theory and algorithm, to enable the approximation of the arbitrarily given equivolume affine transformation. The equivolume affine transformation is a general affine transformation that satisfies the condition of volume invariance, and is characterized by the determinant of the representation matrix having an absolute value of 1. An equivolume affine transformation in n‐dimensional space can represent any combination of reflection, rotation, equivolume expansion/contraction and skew deformation. These transformations often are employed as fundamental transformations in the handling of geometrical information in computers.

This paper discusses first the geometrical characters of equivolume affine transformations. It then defines the fundamental reflection, skew and translations. It is shown that the equivolume affine transformation in n‐dimensional space can be decomposed into the product of (n2‐1) fundamental skew transformations, n fundamental translations and a finite number of fundamental reflections.

For the fundamental transformation, one‐to‐one integer approximation is defined, and a systematic method is proposed to evaluate the upper bound of the approximation error. With the proposed error estimation method, an algorithm is proposed to determine the decomposition suppressing the error in the overall system. One advantage of this theory is that it is no longer necessary to preserve the geometrical information before transformation in the computer, which has been commonplace up to now in computer programming.
Load‐sharing algorithms for parallel database processing on shared‐everything multiprocessors
Authors: Hirano Yasuhiro , Satoh Tetsuji , Inoue Ushio , Teranaka Katsumi
Published: July 2007

This paper describes new load‐sharing algorithms for parallel database processing. There is a trade‐off between overhead and load unbalance in ordinary algorithms. The proposed algorithms solve the tradeoff by varying the number of tasks allocated at one time, which is fixed in ordinary algorithms. Performance evaluations show that the proposed algorithms achieve fair load sharing with low overhead, independent of database size, the number of processors and data distribution.
Architecture of highly parallel ap1000 computer
Authors: Ishihata Hiroaki , Shimizu Toshiyuki , Ikesaka Morio , Inano Satoshi , Ikesaka Morio
Published: July 2007

This paper describes the architectural features of the AP1000 message‐passing computer. The architecture is designed to speed up barrier synchronization, data distribution and collection, broadcasting, and message handling. In recent message‐passing computers, the most significant communication overhead is that associated with interrupt processing and message assembly/disassembly, because the adoption of new routing schemes has reduced the network latency.

It is important for a fast message‐passing computer to reduce not only network latency but also message handling latency. Although broadcasting, data distribution and collection, and barrier synchronization are necessary functions in many applications, these functions were slow in prior message‐passing computers because each of these functions were simulated by many one‐to‐one communications. The AP1000 has three independent communication networks and message handling hardwares, fast barrier synchronization capabilities, and data distribution and collection hardware to speed up those functions.
Scene retrieval method using temporal condition changes
Authors: Abe Shinji , Tonomura Yoshinobu
Published: July 2007

This paper proposes a method that retrieves a required scene with such dynamic changes as the motion of the object in the scene as the key from the dynamic images stored as the database. In the traditional database, scenes are retrieved using the keyword for each scene, for example. By contrast, in the proposed system the object of retrieval is an arbitrary interval represented by the dynamic images, and the images are retrieved based on the content represented by the dynamic images. The retrieval request from the user is transformed into the functional format, which describes the time‐course of changes of the object in the image. The retrieval is based on the primitive characteristic data (PCD) as the management data for the video images, and the condition description factor (CDF) obtained by the transformation of the retrieval request from the user.

An experiment is attempted where the two‐dimensional position coordinate of the object on the scene is used as PCD, and the motion of the object in the scene or the relative motion of more than one object is used as the key to retrieve the desired scene. The effectiveness of the method is verified.
Syntactic analysis and letter‐to‐phoneme conversion using neural networks — an application of neural networks to an english text‐to‐speech system
Authors: Yamaguchi Yukiko , Matsumoto Tatsuro
Published: July 2007

This paper presents a speech synthesis system using the neural network. While there have been a large number of speech synthesis systems developed, most of them are rule‐based systems for a restricted range of languages, describing the expert knowledges for the language in the form of rules. Thus problems arise in that a large amount of effort is required in developing the system, and the extension of other languages is not easy.

In the area of natural language processing, on the other hand, there are practical applications of machine translation, and it is desired that speech synthesis systems for various languages be developed in the future. From such a viewpoint, the authors developed the English speech synthesis system, aiming at the easy extension to multiple languages without requiring expert knowledge.

In this paper, the neural networks is applied to the part‐of‐speech detection function, the syntactic boundary detection function and the letter‐to‐phoneme conversion function, all of which have stronger language dependencies among the components of the speech synthesis system.
Evaluation of parallel execution performance by highly parallel computer EM‐4
Authors: Kodama Yuetsu , Sakai Shuichi , Yamaguchi Yoshinori
Published: July 2007

The EM‐4 is a highly parallel computer which achieves high performance in data communication as well as instruction execution. An EM‐4 prototype which consists of 80 processing elements (PEs) has been fully operational since April 1990.

This paper evaluates the basic parallel execution performance of the EM‐4 prototype, considering the performance of instruction execution, network data transfer, and data synchronization. First, an attempt is made to achieve maximum performance by executing artificial programs and comparing them to the theoretical maximum performance. Next, the average performance is evaluated by executing simple programs. The results show that the instruction execution performance is 630 MIPS, the network data transfer is 400 Mpacket/s, and the data synchronization is 35 Msync/s.
Acceleration by prediction for error back‐propagation algorithm of neural network
Authors: Kanda Arihiro , Fujita Satoshi , Ae Tadashi
Published: July 2007

This paper proposes a speed improvement of the error back propagation algorithm, which is employed widely in the multilayered neural network, by introducing the prediction. The idea is to realize a larger acceleration by introducing the differential factor for the moment terms in the error back‐propagation algorithm.
Identification of front‐view facial images based on isodensity maps
Authors: Ueno Kunikazu , Kato Masahiro , Nakamura Osamu , Minami Toshi
Published: July 2007

In this paper, we describe a method for identifying facial images based on isodensity maps. An isodensity map reflects the 3D shape of the face in sets of closed loops that represent the connectivity of pixels with the same gray level and is a useful feature in facial descriptions. Identification begins by extracting the face region from the source image, then is followed by matching. The extraction of the face region is easily implemented using isodensity lines that represent facial contours. Two‐stage matching composed of template matching of isodensity maps (global matching) and local density matching of isodensity lines (fine matching) was adopted. Matching tests were performed on images of faces which included people wearing eyeglasses, women wearing makeup, and unshaven men. A total of 3, 481 pairs (59 pairs of the same person and 3,422 pairs of different people) were used and 3,479 (99.9%, 57 pairs of the same person and 3,422 pairs of different people) were correctly identified. The experimental results demonstrated that this is an extremely effective method for personal identification and is sufficiently robust in practical use.
Extraction of road segments by spatial filters
Authors: Kim Wookhyun , Hirai Yuzo , Furukawa Takashi , Arita Hidenobu
Published: July 2007

This paper proposes a new approach for extracting segments from map data. In general, it is difficult to construct a system that can completely extract all road data noise free. On the other hand, it will be easy to construct a system that can extract all road data although noises are included. Such a system extracts all road information at least, and in this paper is called the sufficient feature extraction network. It will also be easy to construct a system that is noise free, although not all of the road information is extracted. Such a system extracts at least only road data, and is called the necessary feature extraction network.

This paper shows that the road segments on a map can be extracted completely noise‐free by combining those sufficient features and the necessary features. Experiments were conducted for various map areas, and the effectiveness of the proposed method is verified.
Computer design system of compensating filter for radiography treatment
Authors: Tsuruno Reiji , Isobe Yoshihide , Ozaki Shin , Kosako Hideo , Bamba Eiichi
Published: July 2007

The following problem sometimes arises in the radiation treatment of a pathological area in the human body. Due to the nonuniformity of thickness and the difference of density of the tissue passed by the radiation energy, the radiation dose in the target area may not be uniform.

To avoid such a situation, this paper considers a method in which the attenuation configuration of the radiation in passing through the body is estimated in detail. A three‐dimensional block is placed between the radiation source and the target area to realize the radiation treatment with the dose correction.

The design method for the three‐dimensional block, i.e., the compensation filter for the correction, is discussed. First, the CT value for each density voxel obtained by the continuous tomography of X‐ray CT image is converted into the absorption coefficient of the high‐energy X‐ray for treatment. Then the values of the voxels passed from the radiation generator to the pathological area are summed up, and the radiation dose in the target areas is calculated.

The three‐dimensional shape of the compensation filter, which can correct adequately the dose distribution, is determined based on the tissue‐air dose ratio obtained from the actual measurement. The block is constructed based on the shape data. By the experiment using a phantom, the nonuniformity of the dose is reduced approximately from 10 percent to 3 percent. In the simulation for the application to the biological object, the area of high dose distribution fits the target area, indicating the effectiveness of the dose correction.
A still image coding method in which AR model estimation is applied to dct coefficients of edge blocks
Authors: Fukuda Koichi , Mizuguchi Tomohiko , Kawanaka Akira
Published: July 2007

Image coding technology has been developed for various purposes with the progress of large‐scale communication networks and recording technology. Notably, a method using a discrete cosine transform (DCT) and a variable‐length code (VLC) has been popular for still image coding. Although this method is excellent for general purposes, some images such as the edges of letters become blurred unless the code compression rate is sufficiently high.

This paper proposes a method of estimating high‐frequency components from low‐frequency components and auto‐regressive (AR) coefficients by applying an AR model to the DCT coefficient of an image block (or “block edge”) containing sharp edges. The method produces AR coefficients for each block and preserves the AR coefficients, DCT coefficients and the estimated errors of high‐frequency components as data to reconstruct images. The newly introduced AR coefficients are quantized uniformly and added to the head of the components in the standard method. The estimated errors are added to the data instead of the high‐frequency components. Examples of images containing sharp edges such as letters were processed by the proposed method, and the results confirm the usefulness of the method.
Interpretation of SDL specification in LOTOS
Authors: Ando Tsuyoshi , Ohta Masataka , Takahashi Kaoru
Published: July 2007

This paper aims at: 1 improvement of the specification verification capability of SDL without losing its advantages, i.e., transparency and descriptive power; and 2 realization of translation between specifications described by SDL and LOTOS. A method is proposed which gives a LOTOS interpretation of the specification by SDL.

First, the mapping of the object system structure indicated by SDL specification to the LOTOS description is discussed. Then the description of the processing definition of SDL specification is described. Using the method proposed in this paper, a LOTOS interpretation is presented as an example for the SDL specification for the switching service. The result of interpretation is evaluated and the flexibility of the verification process is discussed.
Combinatorial optimization by using a neural network operating in block‐sequential mode
Authors: Shiratani Fumiyuki , Yamamoto Kimiaki
Published: July 2007

In a laterally connected neural network which has continuous output functions and has its state updated in block‐sequential mode at discrete times, a condition inequality is derived for the slope of the output function and the stepwidth of the updating rule which ensures that the network energy decreases monotonically with the state variation. This makes it possible to update in block‐sequential mode, which is more general than synchronous updating or asynchronous updating, application to an arbitrary optimization problem in which the evaluation function is given in a quadratic form. As one example, the method is applied to the traveling salesman problem. The advantages of applying this method as opposed to synchronous and asynchronous updating are discussed, and its effectiveness is confirmed.
Bitonic sort on a network computer with a node failure
Authors: Kobayashi Hiromi , Funaki Hidetake , Yamamaoto Hiroaki , Yamaura Hiroo
Published: July 2007

Massively parallel computers are being realized for aiming at high performance. Bitonic sort is an efficient algorithm for network computers. But generally, it is impossible to use a bitonic sort algorithm on a network computer with a node failure.

This paper presents a fault‐tolerant scheme of bitonic sort algorithm for a network computer that makes it possible to tolerate a node failure without an additional hardware cost. The method does not have hardware redundancy but has software redundancy. The method does not depend on the network topology. However, the method takes about two times as many steps as that of original bitonic sort.

This paper also shows that the method is applicable to a chordal ring connected computer as an example.
Evaluation of parallel ray tracing algorithm using screen space subdivision for image generation system MAGG
Authors: Kawai Toshiyuki , Ohnishi Mitsuhisa , Abeki Junichi , Ohnishi Hironobu
Published: July 2007

To produce a realistic image at a fast speed, a parallel graphic generator MAGG using transputers and a graphic generation software using a parallel ray tracing algorithm have been developed. A screen space subdivision is sued for the parallel processing. To avoid the limitation of a local memory due to the object data, a necessary part of the data alone is transmitted to the local memory.

To avoid the reduction of the effect of the parallel processing due to the increase of the interprocessor communication, the overall object data are stored in the shared memory so that they are transmitted to the local memory at a high speed using a DMA. The load balancing is carried out by dividing the screen into many small sections, which are called subscreens and are sufficiently larger than that of the processors, and by allocating the load dynamically. This method requires an estimation of the appropriate number of subscreens before the execution. To avoid this difficulty, already allocated subscreens are redivided and reallocated.

The control of the reallocation is carried out adaptively by a message exchange. The proposed method makes the distribution of the load uniform even though there are only a few small screens and the method improves both the image generation time and the parallel processing efficiency.
Restoration of shift variant blurred image estimating the parameter distribution of point‐spread function
Authors: Hashimoto Shoichi , Saito Hideo
Published: July 2007

This paper describes a method of restoring a position‐dependent (shift variant) blurred image by estimating the size of the blurred part and by adjusting the restoration proportionally to it. In this method, it is assumed that all blurred images are due to a defocussing of a lens system or accidental camera motion. If the point‐spread function (PSF) of the blurred point is known, the estimation of the PSF can be replaced by the estimation of its parameter distribution (consisting of the diameter of a defocussed circle and the width of the motion caused by the accidental camera motions). Then a blind deconvolution of a shift‐variant blurred image can be realized by locally applying a Wiener filter to the estimated distribution. The method was tested using computer simulated images and actual images taken by a CCD camera, both with blurred parts. The results confirm the effectiveness of the method.
Automatic process design from nonprocedural specification
Authors: Harada Minoru , Nishimurae Junichi , Nakamura Yoshiyuki
Published: July 2007

There are very few systems for automatic process designing despite its importance in the middle software development phase. A theory for designing a process flow depending on the functional dependency between a data item and the structure of the data was postulated and an automatic process design system ECS/P was then developed. EOS/P inputs a nonprocedural specification of business data processing, wherein the relationship between attributes of entities and associations are represented as a set of equations. These attributes are modified here by identifiers of entities and associations. These modifications may be single‐step or multistep by way of associations. The purpose of EOS/P is to generate specifications, each of which can perform the required process without storing the intermediate results in outer files. Therefore, the first EOS/P creates for each multistep modification merged files that include both the modifier entity and the modified entity; then by using these files a series of single‐step modified process specifications equivalent to the given multistep modified specification are generated. Furthermore, in this transformation, appropriate intermediate files are created when order‐clash and structure‐clash are detected in files. The finally generated specifications can be transformed automatically into COBOL programs by our previously proposed automatic module design system EOS/M and automatic programming system SPACE.
A polynomial‐time algorithm for computing characteristic strings under a set of strings
Authors: Ito Minoru , Shimizu Kuniyasu , Nakanishi Michio , Hashimoto Akihiro
Published: July 2007

A substring of a string a1a2…an has the form ai+1ai+2…aj. The difference between two strings is the minimum number of editing steps (insertions, deletions, changes) that transform one string into the other. Let S be a finite set of strings, let T be a subset of S, and let δ be a positive integer. A δ‐characteristic string of T under S is a string that is a common substring of T and that has at least δ‐differences from any substring of any string in S ‐ T.

In this paper, the following result is presented. It can be decided in O(l2 · S) time whether or not there exists a δ‐characteristic string of T under S, where l is the length of a shortest string in T, and S is the size of S. If such a string exists, then all the shortest δ‐characteristic strings of T under S can also be obtained in that time.
Optical model for motion image analysis
Authors: Mukawa Naoki
Published: July 2007

In previous analysis of the motion image, the existence of the light source has not particularly been considered. In this paper, the optical model describing the relations among the light source, the object and the view point is introduced. The optical flow estimation problem is discussed based on the gradient method, using the constructed model. First, the relation between the light source and the object model is described as an optical model, and the constraint inherent in the considered scene is derived. As a result, it is shown that the optical flow can be estimated with a high precision also for the scene containing a light source.

It is shown that the parameter, which has been considered as a correction term for improving the precision of the optical flow, is a physical parameter indicating the geometrical relation between the light source and the object, from the standpoint of the optical model. Then, not only can the optical flow be estimated with a high precision, but also the information concerning the incident direction from the light source and the reflection coefficients of the object can be newly restored. If the scene is of a simple structure, all parameters that describe the scene, i.e., the information concerning the location of the light source, the object and the camera, as well as the information concerning the shape of the object, and the reflection coefficient of the surface of the object can be estimated. The feasibility of the scene reconstruction is investigated using the CG techniques.
Code scheduling on a superscalar processor: SARCH
Authors: Nakanishi Chikako , Ando Hideki , Machida Hirohisa , Nakaya Masao
Published: July 2007

This paper proposes a superscalar architecture SARCH. An efficient mechanism for exploiting instruction‐level parallelism (ILP) is required to achieve high performance on nonnumerical applications. SARCH employs boosting for speculative execution to exploit large ILP, and a branch scheme to reduce branch penalty. Although these mechanisms are realized by simple hardware, code motion beyond basic blocks by compilers is necessary. A code scheduler is developed which performs global scheduling for the boosting and the delayed branch. The performance evaluation shows that the scheduled code achieves 1.52 time performance improvement over the original code, and 1.75x speed‐up over the scalar processor.
Adaptive load balancing with bidirectional piggybacking
Authors: Watanabe Takashi , Ohta Tsuyoshi , Mizuno Tadanori , Nakanishi Hikaru
Published: July 2007

Computer network technology is no longer experimental. Having come of age, this technology is now both practical and necessary. Downsizing of computers and open and high‐speed networks have required multimedia processing as well as traditional data processing on a networked system connected by various types of computers. However, in current network systems, users are responsible for job submission, while simultaneously considering what and where the necessary and available resources are. This will create a heavier burden in the future. A framework of load balancing with distributed dispatchers that uses an analysis of network delay and job characteristics is proposed here. Examining an adaptive load balancing scheme with bidirectional piggybacking permits basic study of this framework. First a bidirectional piggybacking is proposed that uses the results of a job as an information carrier for a remote server and that uses the request of a job as an information carrier for a local server. We also propose a load balancing scheme using bidirectional piggybacking. This scheme is then compared with other schemes on homogeneous and heterogeneous environments with and without communication delay. Finally, the reliability of piggybacked information on the arrival rate of local/remote job, communication delay, etc. are discussed. The effects of this scheme based on bidirectional piggybacking are also discussed.
Extraction of three‐dimensional structure from images of multiple viewpoints by two‐step voting
Authors: Kawato Shinjiro
Published: July 2007

This paper proposes a method to extract 3‐D information from images of multiple viewpoints, avoiding the problem of feature point matching which is common in stereo techniques. A straight line connecting a characteristic point in an image and the lens center (a backprojection line) goes through a real point on the object. Thus, the object space is divided into small voxels. For each backprojection line of all images, give a vote to each voxel which intersects with it and extract voxels with high score. Then they are expected to be common to many images and represent characteristic points of the object in 3‐D space.

However, in actual calculation, it is not so simple. For example, there are problems of: (1) voxel size selection; (2) interference of very near points; and (3) difference of the scores caused by occlusion. (Details are mentioned later.) Problem (1) will be solved by introducing a concept that voxels are supported by images instead of backprojection lines. Problems (2) and (3) will be solved by two‐step voting: the first vote is done uniformly along the backprojection lines, and the second is done selectively based on the result of the first vote. Since the proposed voting method is not affected by the voxel size, it is possible to adopt an algorithm to begin with large voxels and divide only necessary voxels into smaller ones recursively until necessary resolution is gained. Experiments with synthesized images and actual images show validation of the method.
Logic circuit design for testability using orthonormal expansions
Authors: Takahashi Ryuichi , Nanya Takashi
Published: July 2007

For m‐variables logic functions, an orthonormal system of order n is defined as an n‐tuple of m‐vari‐ables logic functions where one and only one of the m‐variables logic function equals 1. Any given logic function can be expressed as a sum of products between these n‐tuple of functions and appropriate coefficients for these functions. This form is known as an orthonormal expansion. This paper deals with the fact that the orthonormal system of order n divides the input space into n disjoint subspaces. We show that this property, along with appropriate restrictions on the expansions, enables us to design four level circuits where all of the single stuck‐at faults are testable. Since the circuits based on the expansions include partial circuits for the orthonormal systems, these can be activated one by one. This is the key property that guarantees the testability of s‐a‐0 faults. On the other hand, when a test for a s‐a‐1 fault should make an element of the orthonormal system equal to 0, this input can make one and only one of the other elements equal to 1. This is key to guaranteeing the testability of s‐a‐1 faults. Expansions are carried out with appropriate restrictions considering these properties. Where there exists a coefficient that is covered by all of the other coefficients, a corresponding element is eliminated. This elimination, which can be regarded as a generalized absorption law for Boolean functions, guarantees the existence of the solution for any given set of logic functions. The number of tests for the circuit is proportional to the number of prime implicants in the expansions. These tests are generated as a byproduct during the expansions.
Generating a hierarchical aspect graph based on multiple range data
Authors: Morita Satoru , Kawashima Toshio
Published: July 2007

This paper proposes a method of producing an aspect graph from multiple range data. Generally, when an object is of complex shape, the search of its shape and posture become more difficult, since the number of aspects necessarily increases. To solve this problem, a hierarchical aspect graph (an expanded idea of the aspect graph) is introduced. After a projection range image has been divided into regions based on its differential geometrical features, the viewpoint space is also divided referring to the difference of topologies on the zero‐crossing surface of a scale space. Hierarchical events by which a viewpoint space is divided are obtained by analyzing changes of the topology of the differential geometrical features caused by a viewpoint and resolution at feature points. A reliable aspect graph is produced by interpolating unobserved events due to the limited data of viewpoints and resolutions. The viewpoint space is divided coarsely in its upper structure, and densely in its lower structure. This makes an efficient search of the shape, position and posture of an object based on the coarse‐to‐fine tactic. Three‐dimensional aspect graphs based on real range‐finder input data were processed. The results show the usefulness of the proposed method for identifying the shapes, positions and postures of objects and analyzing moving images.
Adaptive garbage collection and experiments for implementation
Authors: Tanaka Eiko , Tanaka Yoshio , Nakanishi Masakazu
Published: July 2007

In the list processing language, dynamic memory management is indispensable, and hence various methods have been proposed. In one such method, the object is discriminated according to its life, time and garbage collection (GC) is applied efficiently to the unnecessary object, based on a preset “threshold.” A problem is how the threshold should be set in order to realize the most efficient GC.

This paper points out that the threshold that realizes the highest efficiency depends on the application to be executed, and proposes the technique of adaptive garbage collection (AGC). An experiment toward its implementation is reported. AGC is a kind of GC which adjusts the threshold dynamically according to memory use, so that efficient operation is realized for a variety of applications. Experiments aiming at the realization of AGC show that applications have their own pace in consuming the memory, and the optimal value of the threshold is related to that pace. It is seen also that the memory‐consuming pace of the application is related closely to the data in the interpreter, leading to the definition of the useful parameter for realizing the efficient AGC.
Model‐based object recognition using basic probability assignment
Authors: Yamane Sadaaki , Aoki Keiji , Izumi Masao , Fukunaga Kunio
Published: July 2007

A method of object recognition is proposed based on Dempster‐Shafer theory (DS theory), which can treat the ambiguity of image data. A model based object recognition technique based on an aspect imaging method will also be proposed. The aspect imaging method recognizes a similar aspect object by comparing an input image with an aspect image of the model database.

Our proposed method calculates the degree of similarity based on the DS theory instead of Bayes theory, represents an uncertainty factor of similarity as a basic probability of DS theory, and assigns a basic probability of information to be decided. The experimental results show that the proposed method is both more robust and more reliable.
Use of associative information to continuous speech recognition
Authors: Sekiguchi Yoshihiro , Shigenaga Minoru
Published: July 2007

The continuous speech frequently includes intervals where the utterer is “lazy” and does not exhibit a precise pronunciation. Sometimes the accurate recognition of auxiliaries, which are grammatically important, is prevented. Consequently, to recognize the continuous speech, it is necessary to make use of more intuitive information, i.e., the associative information as the human does, in addition to linguistic information such as syntax and semantics.

First, this paper shows that the continuous speech contains ambiguously uttered intervals, for which the acoustic processing is difficult. Next, the human associations among the words are examined and investigated, aiming at the construction of the associative word dictionary to be utilized in the speech recognition. Using such an associative word dictionary, the association strength between words is determined, and the succeeding word is predicted. The associative information, not only the acoustic information, also is included in the recognition of the phrase.

In the previous speech recognition system by the authors, the phoneme recognition rate of approximately 90 percent is required in order to achieve the sentence recognition rate of 75 percent, if the associative information is not utilized. The phoneme recognition rate of approximately 80 percent is sufficient to achieve the sentence recognition rate of 75 percent by utilizing the associative information. It is seen also in the system constructed by the authors that the acoustic information and the associative information should be utilized by the ratio of approximately 3:1, for scoring the information.
Organization of a file system using class name expressions based on a B‐tree
Authors: Hirade Motoichi , Tanaka Eiichi
Published: July 2007

In the search of data from a database using a key, it is desirable that, even if the input key or the key in the database is in error, and there is no exactly matched key, still the system lists similar keys or retrieve the closest key.

This paper discusses the organization and manipulation of the file, where the keys similar to the input key are listed, or the closest key is retrieved. The basic idea is to combine the high efficiency of the B‐tree for the retrieve/insert/delete of the key, and the ability of the hierarchical file based on the class name expression for the similar key search. By such an elaboration, it is possible to realize the search of similar keys, which cannot be executed by the B‐tree, or insert/delete of the key, which is not considered in the hierarchical file based on the class name expression.

An experiment is made by splitting the characters into two classes, i.e., a to m and n to z, and using 16,561 English words of length 6 to 10. The number of read‐outs from the secondary memory in the retrieve/insert/delete of the key is approximately 3, and the number of write‐ins into the secondary memory in insert/delete is approximately 1. The search for the similar keys requires approximately 7.3 to 8.5 times larger read‐ins compared to the search of the exact key. The retrieval rate is approximately 95 to 99 percent for a single error (substitution/insertion/missing). The efficiency of the use of the memory is approximately 70 percent.
The software on the VPP500 system
Authors: Okada Shin , Sakamoto Yoshinori , Asai Noboru
Published: July 2007

The VPP500 system is a commercial, distributed memory, parallel computer system based on vector parallel architecture. The software of the VPP500 system is described here. The OS is UNIX‐based, enhanced with distributed parallel features. A system that is easy to use and has high performance requires a (1) realized one‐system image; (2) pursued ultrahigh performance; and (3) enhanced operation of the system. To satisfy two fundamental requirements of a language processor system, (1) effective use of the existing program assets and (2) extraction of potential performance of hardware system, we have implemented VPP Fortran (the standard FORTRAN77 enhanced with the features of parallel processing). The various data on VPP Fortran show that the VPP500 system, which consists of hardware, OS and language processor system, has both high performance and high efficiency.
An Experiment on Shape Discrimination and Signal Detection in Octopus
Authors: Muntz W. R. A.
Published: July 2007

Ten octopuses were trained to perform a successive discrimination between the two shapes shown in Figure I (a). After 7 days of training, when performance was significantly above chance, transfer tests were given with other shapes that were either rotations or parts of the original training shapes. At least six theories have been put forward to explain shape discrimination in the octopus, but none of these are capable of explaining the present results. The transfer tests suggest that the discrimination was performed in terms of component parts of the shapes (vertical bars projecting upwards or downwards), and their relationship to the shape as a whole (terminal or central).

During successive discrimination training the general level of attack varies between animals, and fluctuates from day to day. As a result there are often more attacks on both the positive and negative shapes on some occasions than others, making it difficult to compare the levels of discrimination achieved. It is suggested that the concepts of signal detection theory can help overcome this difficulty. Attacks on the positive shape (“hits”) plotted against attacks on the negative shape (“false positives”) constitute an ROC curve from which a value of d′, independant of the general level of attack, can be obtained.
The Recall of Affirmative and Negative Sentences in an Incidental Learning Task
Authors: Cornish Elizabeth R. , Wason P. C.
Published: July 2007

This experiment examined the recall of positive and negative information in an incidental learning task. The two main findings were that a significantly greater number of affirmative than negative clues were correctly recalled and that the majority of errors took the form of conversions from negative to affirmative, independently of meaning. The difficulty associated with the negative clues was explained in terms of their inappropriateness in the situation, namely in the absence of any prior expectations.
Effects of Instructions and Drug Administration on Temporal Resolution of Paired Flashes
Authors: Gruzelier J. H. , Corballis M. C.
Published: July 2007

Sixteen male alcoholics were shown pairs of light flashes separated by intervals ranging from 0 to 100 msec., and judged whether there were one or two flashes. Two-flash fusion theshold (TFT) was raised by administration of promazine hydrochloride, a tranquilizing drug, and was higher for strict than for lenient instructions. Signal detection analysis showed that the drug reduced sensitivity but did not affect criterion, while instructions altered criterion placement without changing sensitivity.
Non-Interaction of Ventromedial and Lateral Hypothalamic Mechanisms in the Regulation of Feeding and Hoarding Behaviour in the Rat
Authors: Herberg L. J. , Blundell J. E.
Published: July 2007

Lesions of the hypothalamic ventromedial nucleus (VMN) led to an immediate increase in food intake but not to any increase in hoarding activity. Later, when subjects were very obese, they failed to hoard even in response to a 16-hr. deprivation schedule, although this schedule did produce hoarding if body weights were held at, or were brought down to, preoperative levels. These results indicate that the lateral hypothalamic mechanism responsible for hoarding and feeding responds to long-term nutritional factors, and that it is not directly affected by the short-term satiety mechanisms in the VMN. These findings support the hypothesis (a) that even “non-physiological” activities (e.g. hoarding, exploration) are motivated by physiological needs, and (b) that the reason these activities do not ordinarily covary with physiological drives is that, unlike the physiological drives, they are not subject to inhibition by the hypothalamic satiety mechanisms.
Associative Factors in Free Recall
Authors: Matthews W. A. , Manasse K.
Published: July 2007

An experiment on the free recall of 18-word lists is reported in which variations were made in associative frequency, word frequency and the number, and therefore size, of the presented groups. Recall efficiency was positively related to increasing associative frequency and larger presented group size. Measures of clustering were obtained along with subjects’ own reports on the associative labels helpful to them in organizing their recall. A two-level storage model is proposed to account for the results.