摘要:

AbstractThe job for which processing is determined only in the course of execution is called the unschedulable job. When an unschedulable job is to be executed in a parallel processing system, it is not predetermined when the communication between processors arises, and synchronization among processors is a serious problem.This paper considers the mathematical theory for the existence of interprocessor communication and the transmission time in the execution of the unschedulable job. The message‐passing scheme is extended, considering the message transmission probability and the indeterminate aspects of the transmission time. Then the advance processing control is considered, which helps the synchronization among processors in the execution of the unschedulable job, and the overhead is theoretically analyzed. The condition for the task assignment to the processors is derived so that the deterioration of the processing speed due to the overhead can be minimize

ISSN:0882-1666    

DOI:10.1002/scj.4690230601

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractWith the advanced use of databases, on‐line and batch transactions are executed concurrently. Then a demand arose for the concurrency control method which can realize the excellent on‐line transaction processing independently of the batch transactions. The multiversion concurrency control is suitable for such a requirement.This paper proposes a new multiversion concurrency control algorithm which has a high concurrency between the partial update transactions, which is a typical on‐line transaction, and the bulk retrieval transactions, which is a typical batch transaction. The algorithm is based on a mixture of an improved two‐version, two‐phase locking and the multiversion time stamp ordering. It is shown as simulation results that the proposed algorithm is better than the traditional ones in terms of the completion ratio of the partial update and the completion ratio of the bulk retrieval, independently of the number of partial updates executed concurrently. It is shown also that the algorithm is better than the traditional ones in such an environment since the data contention between partial update transaction

ISSN:0882-1666    

DOI:10.1002/scj.4690230602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractRedundant network structures allow efficient retrievals. Procedures to design network structures that allow efficient retrievals [9] add redundancies into network structures. However, as redundancies increase, costs of updates increase. When network structures are redundant, costs of updates include costs of updating original data, checking consistencies, and updating derived data.This paper presents the super‐key condition to reduce the costs of checking consistencies in redundant network structures.First, constraints required to keep redundant network structures consistent are shown and then a sequence of processes to delete or insert a record in redundant network structures maintaining the constraints is given. Relationships between functional dependencies and updates are discussed to derive the super‐key condition. The condition classifies network structures regarding costs of the processes to delete or insert a record. Finally, a procedure to design network structures that satisfy the super‐key condition is given. The procedure may increase redundancies of network structures to reduce costs of up

ISSN:0882-1666    

DOI:10.1002/scj.4690230603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe segmentation of continuous speech into phonemes, i.e., labeling, is one of the most important procedures in constructing the speech database. At the present stage, the labeling is executed by the inspection of the time‐series of acoustic parameters by the human expert. Because of this procedure, a large amount of time and effort are required in the construction of the speech database.From such a viewpoint, the authors have developed an automatic speech labeling system aiming at the automatic labeling. In the proposed system, a correspondence is established between the phoneme symbol sequence and the characteristic changes in the time‐course of the acoustic parameters, and the rough position of the phonemes are determined. Then the boundaries between the phonemes are adjusted by the detailed observation of the change of acoustic parameters near the phoneme boundaries. Finally, the change of the acoustic parameters in each phoneme interval is examined to verify the match of the label. The system is evaluated by experiment.Eight sentences uttered by seven adult males, who participated in the development of rules, are used for evaluation; 6.7 percent of the phoneme boundaries are rejected. For the remaining phoneme boundaries, 99.1 percent of the boundaries are set within 30 ms of the position decided previously by the human expert. For 10 sentences uttered by four adult males, who did not participate in the rule development, the foregoing scores turned out to be 8.9 and 95.5 percent, respectively. Those results indicate the usefulness of the proposed sys

ISSN:0882-1666    

DOI:10.1002/scj.4690230604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe authors are attempting to clarify the emphasizing mechanism of phoneme perception in co‐articulation. Psychoacoustic experiments were made on the symmetrical and asymmetrical three‐vowel sequences, and the effect of the preceding or succeeding vowels on the central vowel is examined.Based on the examined effect, a model is proposed wherein the perceptual phoneme boundary lines of the central vowel are set, considering the three‐vowel sequence as a unit. Using this model, the perceptual phoneme boundary line of the central vowel of the three‐vowel sequence can be defined by adjusting the 50 percent phoneme boundary line in the perceptual phoneme distribution of the steady vowel onF1‐F2logarithmic plane, according to the positions of the formant frequencies of the preceding and succeeding vowels.A model is presented here which defines the phoneme boundary lines of the central vowel in the three‐vowel sequence with co‐articulation, by adjusting the 50 percent perceptual phoneme boundary lines of the steady vowel. It is then applied to the real spoken vowels, and its effectiveness is evaluated. Then an automatic recognition system for the three‐vowel sequence is proposed, which is based on the trajectory of the three‐vowel formant frequency and the perceptual phoneme boundary lines set by the flexible model. A recognition experiment is conducted for the three‐vowel sequences using the system, and the usefulness of the sys

ISSN:0882-1666    

DOI:10.1002/scj.4690230605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractIt is desirable to arrive at the scene description at a higher level, by grouping such image features as edges and region boundaries to generalize the scene interpretation or to recognize the object with a structure. Often, however, the feature extraction and the grouping are not unique, conflicting, or contain errors. Here, this problem is called the multiplicity of scene description.The basic framework is presented for constructing a system to solve this problem, which is composed of the following two processes: (1) the image features and the spatial relationships are considered as hypothesis and are managed in ATMS. The conflicting scene descriptions are represented by the multiple context; and (2) the bottom‐up processing is realized by the rule base. The rule base is composed of the hypothetic knowledge permitting contained errors and the constraining knowledge declaring the relations among alternative data. Based on this framework, the following system is realized. The feature extraction and structurization are executed for the stereo color gray‐level images. A subclass of generalized plane composing an orthogonal hexahedron are derived as the three‐dimensional description elements for the scene. Then the scene is interpreted by the matching to the model.In the proposed system, the scene description and interpretation are derived as more than one maximal set composed of the hypothesis together with its derivation, which can account for the largest number of observed edges and region boundaries. Some examples of processing also are

ISSN:0882-1666    

DOI:10.1002/scj.4690230606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper discusses the classification of blood cell images. The image input method using the single CCD color TV camera and the special color compensation filter, as well as the method of region segmentation for the blood cell images, are described. The following elaborations are made in the image input stage to separate the red blood cell and the white blood cell images in a stable way using optical means.(1) The bluish green light near 450 ∼ 500 nm is cut off from the white light.(2) The accompanying light imbalance between the blue light and the green/red light is compensated by the special color compensation filter.In the (region) segmentation of the blood cell images, a logical operation is developed in which the region of the red blood cell is extracted based on the binary images obtained by the threshold processing of the subtracted image. Using those methods, 59 blood cell images are processed and a satisfactory segmentation result is obtaine

ISSN:0882-1666    

DOI:10.1002/scj.4690230607

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractSince human eye movement easily follows one's intention, it is possible to use this to instruct a computer through a display screen, e.g., selection of a menu and control of a cursor. This paper proposes a method to detect a gaze point on a display screen independently of the movement of an operator's head. The method uses an eye tracker based on the limbus boundary method and a three‐dimensional (3‐D) magnetic sensor which determines the position of an operator's head in a fixed coordinate. Experiments show that position‐detection errors are about 1°, and this is enough for this application. To overcome an effect caused by a small involuntary movement of eyes around a target, a mouse is used at the same time. Experimental comparison between the proposed method (with a mouse) and a conventional operation (a mouse alone) shows that the former is faster when a target is relatively separated from the center, i.e., the method is eff

ISSN:0882-1666    

DOI:10.1002/scj.4690230608

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper presents a shell‐oriented Boolean set operations algorithm which is simple and makes the most of the F‐L‐E‐V type B‐reps based on boundary edge loops of a face. The characteristic feature of the algorithm is that it resolves an operation between solids into plural operations between faces, generates intermediate open shells and finally reconstructs a new solid by combining them. The method is quite different from the conventional edge‐oriented algorithm, e.g., that of BUILD, which is suited for the well‐known winged‐edge type B‐reps based on the information with respect to the individual edges.First, the outline of the conventional set operations algorithm is shown, which is suited for the winged‐edge type B‐reps and is used in almost all conventional solid modellers. Afterward, in comparison to it, our algorithm is discussed in detail.An algorithm for the case of a basic intersection, with which the basic algorithms in other set operations, i.e., union and set difference, are also realized, is described first and then some essential expansions are made to meet more complex and

ISSN:0882-1666    

DOI:10.1002/scj.4690230609

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY