Mitsuteru Nakamura

A performance evaluation of tree-based coherent distributed shared memory

The system is organized based on the tree-based coherent algorithm, in which the coherence is maintained at the network nodes, in a fully distributed and localized manner. The system has an overlapped tree structure, where the processors are located on the leaves. The proposed coherence protocol relies only on one-to-one message passing. Simulation shows that, in a matrix multiplication program, the 32-processor system can execute 21 times faster than the single processor. How the performance of network nodes and block size affect overall system performance is also discussed. As regards performance, only the copy-request and the invalidate message are thought to be insufficient.<<ETX>>

Validity of the Mind Monitoring System as a Mental Health Indicator

We have been developing a method to evaluate the mental health condition of a person by the sound of his or her voice. Now, we have applied this technology as a system to create a smartphone app. Since using voice to measure ones mental health condition is a non-invasive method and as it could be used continually through the smartphone, one carries, unlike a routine checkup, it could be used for monitoring on a daily basis. The purpose of this study is to compare this vitality score and the widely used BDI (Beck Depression Inventory) and evaluate its validity. This experiment was conducted at COI (Center of Innovation) Program of the University of Tokyo with a total of 50 employees of multiple corporations as subjects between early December 2015 and early February 2016. The test subjects were each lent a smartphone with our app recording their voices automatically during calls, and in addition to it, we had them read and record a fixed phrase daily. BDI test was conducted at the beginning of the experiment period. The vitality score was calculated based on the voice data collected during the first two weeks of the experiment and considered it the vitality score of the time BDI was conducted. When these two indicators were compared, we found there was a negative correlation between BDI and the vitality score. Additionally, it was a useful method to identify a test subject with a high BDI score.

Study on Depression Evaluation Indicator in the Elderly using Sensibility Technology.

Depression is important issue with aging of global population. Previously we have proposed a method to evaluate the mental health status of a person by his or her voice and developed a smartphone-based system to monitor mental health from voice during a call. Although the system has excellent continuous monitoring capability, it has not enough specificity for screening. Therefore, in this study we propose an evaluation indicator to assess depression status in the elderly, based on multivariate analysis using the emotional components of the voice data collected in the aforementioned system and the BDI score. The voice emotion data on subjects was divided into two groups according to BDI score, one where doctor’s diagnosis was deemed necessary and the other not so. A significant difference between the two groups was observed in t-test when the mean of the evaluation indicator estimated using data of each group and applying logistic regression prediction equation was compared. Moreover, a performance corresponding to AUC of approximately 0 .75 was achieved in the ROC curve of the derived evaluation indicator. The results suggest that a new method to evaluate depression using voice has likely been developed.

Ultrasound influence on impression evaluation of music

We have investigated whether ultrasound changes our audible impressions when we listen tomusic or not. To solve this question, we verify that there might be a mechanism perceiving ultrasound by a physiological pre-experiment, and review discrepancy in subjective estimations for two kinds of sounds played back with and without ultrasound by a psychological experiment. In this paper, we study whether we can distinguish between the two of those sounds by subjective estimations or not by using discriminant analysis in multivariate analysis technique. As a result, we discriminated those two kinds of sounds with a high rate on drum music. This result suggests that ultrasound affects our audible impressions when we listen to music.

Proposal of contents-oriented cognitive network architecture towards realization of the New Generation Network

This paper proposes a contents-oriented cognitive network architecture as post-Internet. This architecture consists of three layers, that is, physical, semantic and application layers. Fluency function approximation-based unified coding of multimedia is one of key technologies. In semantic layer, both of cognitive function which corresponds to “intuition function”, that is, “pattern recognition” and logical processing are implemented. A contents-overlay, which consists of same kinds of contents based on the criterion of contents-similarity, can be formed. The unified coding of multimedia is effective for not only explosion of information but energy saving. Moreover, contents-overlay is effective for SPAM and for lightening the burden on network administrators