Development of an auditory emotion recognition function using psychoacoustic parameters based on the International Affective Digitized Sounds.

The purpose of this study was to develop an auditory emotion recognition function that could determine the emotion caused by sounds coming from the environment in our daily life. For this purpose, sound stimuli from the International Affective Digitized Sounds (IADS-2), a standardized database of sounds intended to evoke emotion, were selected, and four psychoacoustic parameters (i.e., loudness, sharpness, roughness, and fluctuation strength) were extracted from the sounds. Also, by using an emotion adjective scale, 140 college students were tested to measure three basic emotions (happiness, sadness, and negativity). From this discriminant analysis to predict basic emotions from the psychoacoustic parameters of sound, a discriminant function with overall discriminant accuracy of 88.9% was produced from training data. In order to validate the discriminant function, the same four psychoacoustic parameters were extracted from 46 sound stimuli collected from another database and substituted into the discriminant function. The results showed that an overall discriminant accuracy of 63.04% was confirmed. Our findings provide the possibility that daily-life sounds, beyond voice and music, can be used in a human-machine interface.

Development of SQUID detection technology for a superconducting gravimeter.

In this paper, we present research on the development of SQUID (Superconducting QUantum Interference Device) detection technology for a superconducting gravimeter (SG), aiming to achieve precise real-time measurements of gravity. We provide an introduction to the composition and internal details of the SQUID-based superconducting gravimeter (SSG). The internal components of the SSG are designed based on theoretical calculations to optimize the system and enhance its sensitivity. With the current in the levitation coil set to persistent mode, a unique proof mass is levitated through electromagnetic force. We demonstrate the equilibrium position of the levitated proof mass by assessing the change in the coil inductance. Furthermore, we present preliminary experimental results of earth tidal measurements using the developed SQUID detection technology and compare these outcomes with measurements from an absolute gravimeter (FG5X) and with theoretical calculations. These comparisons confirm the potential of the proposed new gravity measurement technology.

Optimization of an impulse pressure generator based on the drop-weight method.

An optimized impulse dynamic pressure generator based on a drop-weight method was developed as a secondary standard. The impulse pressure generator was characterized in detail using various parameters in order to obtain a proper reference dynamic pressure, to calibrate a dynamic pressure sensor. Both a hardware filter and a software filter were successfully employed to eliminate unavoidable noise when the impulse pressure was generated. Five variables were considered to optimize the system. A larger effective area piston-cylinder assembly should be used to obtain a faster impulse pressure. To control the peak pressure using a variable drop height is easier rather than drop weight because the change is linearly proportional to the impact speed associated with the drop height. An increase in drop weight causes an increase in duration as well as an increase in peak pressure. In addition, the pressure transmission medium is very important for generating the optimized impulse pressure, so an appropriate fluid choice is required. The viscosity and bulk modulus among the fluid properties are considered as design variables. High viscosity fluids with high bulk modulus can achieve high peak pressures without jittering. The drop weight based impulse pressure generator design and implementation method is proposed based on the detailed characterizations in this study.

Frequency analysis of a step dynamic pressure calibrator.

A dynamic high pressure standard is becoming more essential in the fields of mobile engines, space science, and especially the area of defense such as long-range missile development. However, a complication arises when a dynamic high pressure sensor is compared with a reference dynamic pressure gauge calibrated in static mode. Also, it is difficult to determine a reference dynamic pressure signal from the calibrator because a dynamic high pressure calibrator generates unnecessary oscillations in a positive-going pressure step method. A dynamic high pressure calibrator, using a quick-opening ball valve, generates a fast step pressure change within 1 ms; however, the calibrator also generates a big impulse force that can lead to a short life-time of the system and to oscillating characteristics in response to the dynamic sensor to be calibrated. In this paper, unnecessary additional resonant frequencies besides those of the step function are characterized using frequency analysis. Accordingly, the main sources of resonance are described. In order to remove unnecessary frequencies, the post processing results, obtained by a filter, are given; also, a method for the modification of the dynamic calibration system is proposed.

Evaluation of high temperature pressure sensors.

It is becoming more important to measure the pressure in high temperature environments in many industrial fields. However, there is no appropriate evaluation system and compensation method for high temperature pressure sensors since most pressure standards have been established at room temperature. In order to evaluate the high temperature pressure sensors used in harsh environments, such as high temperatures above 250 °C, a specialized system has been constructed and evaluated in this study. The pressure standard established at room temperature is connected to a high temperature pressure sensor through a chiller. The sensor can be evaluated in conditions of changing standard pressures at constant temperatures and of changing temperatures at constant pressures. According to the evaluation conditions, two compensation methods are proposed to eliminate deviation due to sensitivity changes and nonlinear behaviors except thermal hysteresis.

The development of a blood pressure simulator in KRISS.

Blood pressure is defined as the amount of force at unit area which the blood exerts on a wall of a blood vessel. The BP has a clinical importance as the basic index in the medical examination of patients. Especially, the percentage of the hypertensive is more than 15% in an adult population of Korea and hypertension is notorious as 'a silent killer' because it has no prior symptoms. The most important thing in the diagnosis, treatment and prognosis of hypertension is the accurate measurement of the BP. In this study, we developed the blood pressure simulator for the monitoring of oscillometric BP devices and compared this KRISS simulator with commercial simulators. Finally, we tested the commercial oscillometric BP devices (6 models from 5 manufacturers) using the KRISS simulator. The KRISS simulator has the repeatability error below 0.1% for the pressure generation and we expected to develop the BP simulator for Korean by the collection of clinical data from Koreans.