This research aims to construct a high-quality Japanese TTS (Text-to-Speech) system that has high flexibility in treating prosody. Many TTS systems have implemented a prosody control system but such systems have been fundamentally designed to output speech with a standard pitch and speech rate. In this study, we employ a unit selection-concatenation method and also introduce an analysis-synthesis process to provide precisely controlled prosody in output speech. Speech quality degrades in proportion to the amount of prosody modification, therefore a target cost for prosody is set to evaluate prosodic difference between target prosody and speech candidates in such a unit selection system. However, the conventional cost ignores the original prosody of speech segments, although it is assumed that the quality deterioration tendency varies in relation to the pitch or speech rate of original speech. In this paper, we propose a novel cost function design based on the prosody of speech segments. First, we recorded nine databases of Japanese speech with different prosodic characteristics. Then with respect to the speech databases, we investigated the relationships between the amount of prosody modification and the perceptual degradation. The results indicate that the tendency of perceptual degradation differs according to the prosodic features of the original speech. On the basis of these results, we propose a new cost function design, which changes a cost function according to the prosody of a speech database. Results of preference testing of synthetic speech show that the proposed cost functions generate speech of higher quality than the conventional method.

A low-band spectrum envelope reconstruction method was tested to see if it could improve the sound quality of F0 modified speech with the PSOLA (Pitch Synchronous OverLap Add) method. In the conventional PSOLA method, the extracted spectrum envelope using a Hanning window with two-pitch-period length had no reliable information in the band of frequencies lower than the original F0. This problem causes sound degradation of the F0 modified speech when the F0 is shifted downward. In the proposed method, the low-band spectrum envelope was properly modified according to the F0 modification rate. The amplitude of the F0 harmonic components in the low-band were reproduced based on the spectral tilt of the spectrum envelope. Subjective listening tests suggest the proposed method yields improved sound quality than the conventional TD-PSOLA method when the downward modification rate exceeds 0.4 octave.

A round-ended wide straight slot cut in the broad wall of a rectangular waveguide is analyzed by the Method of Moments (MoM) using numerical eigenmode basis functions derived by the edge-based finite element method (FEM), referred to as MoM/FEM. The frequency characteristics of the calculated transmission coefficients are compared with the measured ones, and good agreement is observed for a wide variety of antenna parameters. For simpler analysis that does not use MoM/FEM, an equivalent rectangular slot approximation for a round-ended slot is discussed. The resonant frequencies of empirically introduced "equal-area" and "equal-perimeter" slots are compared with those of round-ended slots for a wide variety of parameters such as slot width, wall thickness and dielectric constant inside the waveguide. Based upon MoM/FEM, which can be a reliable reference, it is found that the equal-area slot always gives a better approximation of the order of 1% over that of the equal-perimeter one which is of the order of 5%. For higher accuracy, a new rectangular slot approximation of a round-ended slot is proposed to be a linear combination of equal-area and equal perimeter approximation. The error is around 0.25% for a wide variety of parameters such as slot width-to-length ratio, wall thickness and dielectric constant of the filling material inside the waveguide.

This paper presents a test vector modification method for reducing average power dissipation during test application for a full-scan circuit. The method first identifies a set of don't care (X) inputs of given test vectors, to which either logic value 0 or 1 can be assigned without losing fault coverage. Then, the method reassigns logic values to the X inputs so as to decrease switching activity of the circuit during scan shifting. Experimental results for benchmark circuits show the proposed method could decrease switching activity of a given test set to 45% of the original test sets in average.

In this paper, a new voice personality transformation algorithm which uses the vocal tract characteristics and pitch period as feature parameters is proposed. The vocal tract transfer function is divided into time-invariant and time-varying parts. Conversion rules for the time-varying part are constructed by the classified-linear transformation matrix based on soft-clustering techniques for LPC cepstrum expressed in KL (Karhunen-Loève) coefficients. An excitation signal containing prosodic information is transformed by average pitch ratio. In order to improve the naturalness, transformation on the excitation signal is separately applied to voiced and unvoiced bands to preserve the overall spectral structure. Objective tests show that the distance between the LPC cepstrum of a target speaker and that of the speech synthesized using the proposed method is reduced by about 70% compared with the distance between the target speaker's LPC cepstrum and the source speaker's. Also, subjective listening tests show that 60-70% of listeners identify the transformed speech as the target speaker's.

In this paper, a digital processing method is described for modifying tone contrast that is defined as the greatest difference in frequencies between peaks and valleys of pitch curves in monosyllable utterances. Under quiet and noisy backgrounds, modified Mandarin tone words were presented to hearing-im- paired Chinese listeners with moderate to severe sensorineural hearing loss. The listeners were asked to identify four alternative monosyllable words which were distinguishable by tones 1, 2, 3 and 4 respectively. Employing this method, it was found that modified speech with enhanced tone contrast yielded moderate gains in the percentage of correct identification of the tones when compared to unmodified speech tones with only compression amplification. It was likewise found that reducing tone contrast generally reduced the degree of correct tone identification. These findings therefore offer support to the assertion that a hearing aid with tone modifications is indeed effective for hearing-impaired Chinese.

Semantic ambiguity is a serious problem in information retrieval. Query expansion has been proposed as one method of solving this problem. However, queries tend not to have much information for fitting query vectors to the latent semantics, which are difficult to express in a few query terms given by users. We propose a document vector modification method that modifies document vectors based on the relevance of documents. This method is expected to show better retrieval effectiveness than conventional methods. In this paper, we evaluate our method through retrieval experiments in which the relevance of documents extracted from scientific papers is assessed, and a comparison with tfidf is described.

We have developed an active Q adaptor (AQA) to achieve integration of multiple management protocols and dynamic modification of managed object (MO) definitions. To achieve dynamic modification, we introduce a new MO framework, called dynamic-MO, which has the ability of modifying its own definition. A dynamic-MO is composed of meta-data and some behavior programs. Meta-data lists attributes of a dynamic-MO in a text format and a behavior program describes actions of a dynamic-MO in scripting language such as Java, Tcl, etc. In our AQA architecture, modules which manage individual components of a dynamic-MO communicate among themselves via an object request broker (ORB) in order to achieve system scalability with high performance. To realize the functionality of a dynamic-MO, we propose interfaces among these modules that are independent of dynamic-MO definitions and an update mechanism of behavior programs. We define the interfaces based on the common management information protocol (CMIP) operations to avoid re-defining the interfaces when dynamic-MO definitions are modified. Furthermore, to execute modified behavior programs without any negative influence on the workings of the other behavior programs, we employ a Java class-loader which has its own specific naming-space on a Java virtual machine (Java VM). With all of these features, our AQA is extremely promising for developing programmable network management systems for end-to-end management of heterogeneous telecommunication networks.

Three types of mechanisms were evaluated to determine their applicability to partially modifying an online switching system file and to creating a partial file during the debugging phase. First, the applicability of the basic plug-in mechanism, currently used in commercial switching systems, was evaluated by using data obtained from an initial implementation of PHS and ATM switching systems. It was found to be applicable irrespective of software type (call-processing or OA&M) and service type (PHS or ATM). It was also found to be applicable to both specification changes and service feature additions. Then, an extended plug-in mechanism that is enhanced to be more robust against complicated software behaviour was evaluated by simulation. It was found to cover cases where the basic plug-in mechanism is difficult to apply. Used together, these two mechanisms guarantee stable and effective file management of an online switching system. A plug-in for offline file creation was found to be applicable to almost all types of file modifications, except when the interface definition is significantly changed. These plug-in mechanisms can serve as the basis for managing the files in multimedia communication service systems.

Ion beam irradiation effects on a novolac positive-tone photoresist and its application to micron-size field emitters have been investigated. Irradiation of Ar and P ions was examined. The electrical resistivity of the photoresist film is found to decrease after Ar ion implantation at doses on the order of 1016 cm-2. Baking of the photoresist prior to irradiation at a high temperature is preferred to produce electrical conductivity. P ions show weaker effects than Ar ions. Raman spectroscopy shows that carbon-carbon bonds such as the graphite bond are produced due to ion bombardment. The field emission of electrons is observed from emitters made of the ion-irradiated photoresist. The emission current is shown to be fairly stable when it is compared with an emission characteristic of synthesized diamond. Fabrication of field emitter arrays using a mold technique is demonstrated. The field emitter array shows emission at a current level of about 40 µA.

This paper describes key techniques for automatic program generation of office data handling for all types of switching systems. Our office data scenario tool generates logical-physical office data conversion programs to be installed in switching systems. Also, it generates logical office data generation programs to be installed in a logical office data generation tool that converts office conditions to a logical office data file. We were able to apply this tool to all the office data types for our new switching systems, and automatically generated about 5. 5% of the total program size. This technique reduces not only the software production cost but also the bug ratio because there is no room for human error. Also, switching system programs are much more portable, since no machine-code-dependent parts are involved in office data handling. Thus, we expect that these techniques will be the basis for highly productive, reliable, and portable software platforms for the next-generation multimedia communication systems.

The Non-stop Service-Enhanceable Software (NOSES) platform was developed as part of our overall plan to establish a communications software platform that can be customized for use by various communications systems, such as STM, ATM and IN. The developed NOSES techniques are call-recovery restart, system file update, and on-line partial file modification, so called "Plug-in"; they were achieved by using dynamic program modification. A system-file update inevitably affects calls in service, despite efforts to save in-service calls by copying the call data from the old file to the new one. We therefore developed a different approach: Plug-in modification. This paper evaluates the applicability of the plug-in mechanism of the NOSES platform. Plug-in is a dynamic partial-file modification technique that does not affect calls in service in a communication switching system. In order to apply plug-in program modification widely, the static and dynamic properties of the modified software must be considered. Therefore, an applicability judgement matrix is introduced. The evaluated applicability of plug-in based on case studies and field data was about 60% for service feature additions and modifications. Thus, plug-in is effective for file maintenance of switching systems from the viewpoint of quick provisioning of new service features and bug fixes.

One approach to develop software efficiently is to reuse existing software by modifying a part of it. However, modifying software will often introduce unexpected side effects into other parts of it. As a result, it costs much time and care to modify the software. So, in order to modify software efficiently, we have proposed a functional model to represent information about side effects caused by modification and a model based supporting system for modifying software. So far, however, an expert software developer must describe the entire functional model of the target software through the analysis of practical modifying processes. This will be an unnecessary burden on him. Moreover, the larger target software becomes, the harder the model construction becomes. Therefore, an automatic constructing method of the functional model is needed in order to solve this problem. So, this paper considers a method of acquiring useful interaction information by learning from training examples of modification. However, in our application domain, it seems that it is impossible to make complete domain theory and to prepare a large number or training examples in advance. Therefore, our learning method involves an integration of explanation-based learning (EBL) from positive examples of modification generated by the user and Similarity-based learning (SBL) from positive or negative examples generated by the user and the learning system. As a result, our method can acquire valid knowledge about the interaction from not so many examples under incomplete theory. Then, this paper presents a constructing method, in which our proposed learning method is incorporated, of a functional model. Finally, this paper demonstrates construction of the functional model in the domain of an event-driven queueing simulation program according to our learning method.

This paper describes the design of the reflective concurrent object-oriented specification language RMondel. RMondel is designed for the specification and modeling of distributed systems. It allows the development of executable specifications which may be modified dynamically. Reflection in RMondel is supported by two fundamental features that are: Structural Reflection (SR) and Behavioral Reflection (BR). Reflection is the capability to monitor and modify dynamically the structure and the behavior of the system. We show how the features of the language are enhanced using specific meta-operations and meta-objects, to allow for the dynamic modification of types (classes) and instances using the same language. RMondel specification can be modified by adding or modifying types and instances to get a new adapted specification. Consistency is checked dynamically at the type level as well as at the specification level. At the type level, structural and behavioral constrations are defined to preserve the conformance of types. At the specification level, a transaction mechanism and a locking protocol are defined to ensure the consistency of the whole specification.

This paper describes an advanced rule-embedded neural network (RENN+) that has an extended framework for achieving a very tight integration of learning-based neural networks and rule-bases of existing if-then rules. The RENN+ is effective in pattern recognition with ill-posed conditions. It is basically composed of several component RENNs and an output RENN, which are three-layer back-propagation (BP) networks except for the input layer. Each RENN can be pre-organized by embedding the if-then rules through translation of the rules into logic functions in a disjunctive normal form, and can be trainded to acquire adaptive rules as required. A weight-modification-reduced learning algorithm (WMR) capable of standard regularization is used for the post-training to suppress excessive modification of the weights for the embedded rules. To estimate the effectiveness of the proposed RENN+, it was used for pattern recognition in a radar system for detection of buried pipes. This trial showed that a RENN+ with two component RENNs had good recognition capability, whereas a conventional BP network was ineffective.

Trouble management is a key function in solving the problems and maintaining the high communications capability of a network when communication service network users encounter problems in the quality of services [1]. This paper proposes technologies and architecture for an intelligent management system to achieve advanced service/network trouble management. The system generates operation scenarios to find a cause to solve a reported trouble, executes them, and modifies them according to operation circumstance changes. In the scenario execution process, fault propagation simulation is used to isolate a fault in necessary cases. The evaluation of the system applied to the ISDN services shows that the proposed system can achieve high-speed, precise trouble management by the integrated cooperative work of a human (operator) and a machine (operation system).

It has become more important to shorten development periods of high performance computer systems and their LSIs. During debugging of computer prototypes, logic designers request very frequent LSI refabrication to change logic circuits and to add some functions in spite of their extensive logic simulation by several GFLOPS supercomputers. To meet these demands, an automated on-chip direct wiring modification system has been developed, which enables wire-cut and via-digging by a precise focused ion beam machine, and via-filling and jumper-writing by a laser CVD machine, directly on pre-redesign (original) chips. This modification system was applied to LSI reworks during the development of Hitachi large scale computers M-880 and S-3800, and contributed to shorten system debugging period by four to six months.

Scaling-down of MOSFETs (metal-oxide-semiconductor field effect transistors can be divided to semi-classical and quantum mechanical one. In the regime of semi-classical scaling-down the behavior of electrons and holes can be well described with the effective mass approximation and in the regime of quantum mechanical scaling-down the characteristics of electrons and holes as wave becomes markedly. The minimum size limit of MOSFETs scaled down in semi-classical regime is mainly determined by the subthreshold characteristics and the short channel effect on the threshold voltage and 0.1 µm will be the minimum channel length from practical viewpoints. Scaling down of MOSFETs enhances their operational speed, but the substrates with high resistivity which are often used in SOI (silicon on insulator) substrates result longer dielectric relaxation time. While the dielectric relaxation time becomes longer than the reciprocal of signal frequency, the semiconductors work as lossy dielectrics and may lead to new types of dynamic circuits. Modification of material properties utilizing the wave nature of electrons is an illustration of quantum mechanical way to improve characteristics of MOSFETs. Suppression of optical phonon scattering of two dimensional electrons by introducing two dimensional array of quantum dots into substrates is expected to improve high field characteristics of material. Brillouin zone folding is another way to control the band structure of materials, especially to make the indirect transition band structure to the direct transition band structure. Heat transfer from a chip severely limits the number of devices which can be integrated on the chip. Reduction of signal charge to electronic elementary charge, that is quantum limit, is expected to be useful for realization of nano-power electronics.

A new direct projection patterning technique of aluminum using synchrotron radiation (SR) is proposed. It is based on the thermal reaction control effect of SR excitation. In the case of the Si surface, pure thermal growth is possible at 200, however, this growth is suppressed perfectly by SR irradiation. On the other hand, Al growth on the SiO2 surface is impossible at the same temperature thermally, however, SR has an effect to initiate thermal reaction. Both new effects of SR, suppression and initiation, are clarified to be caused by atomic order level thin layers formed from CVD gases by SR excitation on the surfaces. By using these effects, the direct inverse and normal projection patterning of Al are successfully demonstrated.

The outputs of all gates in a circuit are assumed to be observable unber the highly observable condition, which is mainly based on the use of E-beam testers. When using the E-beam tester, it is desirable that the test set for a circuit is small and the test vectors in the test set can be applied in a successive and repetitive manner. For a combinational circuit, these requirements can be satisfied by modifying the circuit into a k-UCP circuit, which needs only a small number of tests for diagnosis. For a sequential circuit, however, even if the combinational portion has been modified into a k-UCP circuit, it is impossible that the test vectors for the combinational portion can always be applied in a successive and repetitive manner because of the existence of feedback loops. To solve this problem, the concept of k-UCP scan circuits is proposed in this paper. It is shown that the test vectors for the combinational portion in a k-UCP scan circuit can be applied in a successive and repetitive manner through a specially constructed scan-path. An efficient method of modifying a sequential circuit into a k-UCP scan circuit is also presented.