• Safety and Health at Work
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• v.8 no.4
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• pp.386-392
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• 2017

Background: Fire service workers often implement multiple duties in the emergency conditions, with such duties being mostly conducted in various ambient temperatures. Methods: The aim of the current study was to assess the firefighters' physiological responses, information processing, and working memory prior to and following simulated firefighting activities in three different hot environments. Seventeen healthy male firefighters performed simulated firefighting tasks in three separate conditions, namely (1) low heat (LH; $29-31^{\circ}C$, 55-60% relative humidity), (2) moderate heat (MH; $32-34^{\circ}C$, 55-60% relative humidity), and (3) severe heat (SH; $35-37^{\circ}C$, 55-60% relative humidity). It took about 45-50 minutes for each firefighter to finish all defined firefighting activities and the paced auditory serial addition test (PASAT). Results: At the end of all the three experimental conditions, heart rate (HR) and tympanic temperature (TT) increased, while PASAT scores as a measure of information processing performance decreased relative to baseline. HR and TT were significantly higher at the end of the experiment in the SH ($159.41{\pm}4.25beats/min$; $38.22{\pm}0.10^{\circ}C$) compared with the MH ($156.59{\pm}3.77beats/min$; $38.20{\pm}0.10^{\circ}C$) and LH ($154.24{\pm}4.67beats/min$; $38.17{\pm}0.10^{\circ}C$) conditions (p < 0.05). There was no significant difference in PASAT scores between LH and MH (p > 0.05). Nonetheless, there was a measurable difference in PASAT scores between LH and SH (p < 0.05). Conclusion: These consequences demonstrate that ambient temperature is effective in raising the physiological responses following firefighting activities. It is therefore argued that further increase of ambient temperature can impact firefighters' information processing and working memory during firefighting activity.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.59-66
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• 2021

Humans mainly recognize surrounding objects using visual and auditory information among the five senses (sight, hearing, smell, touch, taste). Major research related to the latest object recognition mainly focuses on analysis using image sensor information. In this paper, after emitting various chirp audio signals into the observation space, collecting echoes through a 2-channel receiving sensor, converting them into spectral images, an object recognition experiment in 3D space was conducted using an image learning algorithm based on deep learning. Through this experiment, the experiment was conducted in a situation where there is noise and echo generated in a general indoor environment, not in the ideal condition of an anechoic room, and the object recognition through echo was able to estimate the position of the object with 83% accuracy. In addition, it was possible to obtain visual information through sound through learning of 3D sound by mapping the inference result to the observation space and the 3D sound spatial signal and outputting it as sound. This means that the use of various echo information along with image information is required for object recognition research, and it is thought that this technology can be used for augmented reality through 3D sound.

• Physical Therapy Rehabilitation Science
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• v.6 no.3
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• pp.134-139
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• 2017

Objective: Dual-task interference is defined as decrements in performance observed when people attempt to perform two tasks concurrently, such as a verbal task and walking. The purpose of this study was to investigate the changes of gait ability according to the dual task interference in chronic stroke survivors. Design: Cross-sectional study. Methods: Ten chronic stroke survivors (9 male, 1 female; mean age, 55.30 years; mini mental state examination, 19.60; onset duration, 56.90 months) recruited from the local community participated in this study. Gait ability (velocity, paretic side step, and stride time and length) under the single- and dual-task conditions at a self-selected comfortable walking speed was measured using the motion analysis system. In the dual task conditions, subjects performed three types of cognitive tasks (controlled oral word association test, auditory clock test, and counting backwards) while walking on the track. Results: For velocity, step and stride length, there was a significant decrease in the dual-task walking condition compared to the single walking condition (p<0.05). In particular, higher reduction of walking ability was observed when applying the counting backward task. Conclusions: Our results revealed that the addition of cognitive tasks while walking may lead to decrements of gait ability in stroke survivors. In particular, the difficulty level was the highest for the calculating task. We believe that these results provide basic information for improvements in gait ability and may be useful in gait training to prevent falls after a stroke incident.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.512-515
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• 2009

In this paper, we propose layout based multimodal contents authoring tool for Digilog Book. In authoring step, users create a virtual area using mouse or pen-type device and select property of the area repetitively. After finishing authoring step, system recognizes printed page number and generate page layout including areas and property information. Page layout is represented as a scene graph and stored as XML format. Digilog Book viewer loads stored page layout and analyze properties then augment virtual contents or execute functions based on area. Users can author visual and auditory contents easily by using hybrid interface. In AR environment, system provides area templates in order to help creating area. In addition, proposed authoring tool separates page recognition module from page tracking module. So, it is possible to author many pages using only single marker. As a result of experiment, we showed proposed authoring tool has reasonable performance time in AR environment. We expect that proposed authoring tool would be applicable to many fields such as education and publication.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1424-1430
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• 2017

Human senses have been studied widely. Many studied are being actively conducted to analyze correlations between two or more different senses. Among them, research on tactile visuality where a subject can indirectly experience visual sensation through tactile elements is also progressing in various fields. In this study, we analyzed color information by having subjects perceive sandpapers with different roughness through tactile sense, then having them choose a color that is reminiscent of the tactile sensation. Unlike existing tactile-visuality studies allowing the perception of indirect visual sense by using tactile sense, this study shows that it is possible to analyze with quantitative value by representing visual image perceived by tactile sense as a color. This study will contribute to emotional evaluation research that combines two or more of the senses felt by humans, and especially is considered to be useful as basic data when conducting research about tactile visuality or auditory tactile sense.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.4
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• pp.470-485
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• 2003

The steganography is one of methods that users can hide data. Some steganography softwares use audio data among multimedia data. However, these commercialized audio steganography softwares have disadvantages that the existence of hidden messages can or easily recognized visually and only certain-sized data can be hidden. To solve these problems, this study suggested, designed and implemented Dynamic Message Embedding (DME) algorithm. Also, to improve the security level of the secret message, the file encryption algorithm has been applied. Through these, StegoWaveK system that performs audio steganography was designed and implemented. Then, the suggested system and the commercialized audio steganography system were compared and analyzed on criteria of the Human Visilable System (HVS), Human Auditory System (HAS), Statistical Analysis (SA), and Audio Measurement (AM).

• Archives of design research
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• v.18 no.1 s.59
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• pp.195-204
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• 2005

Due to the of evolution of digital technology, trends are moving toward personalization and customization in design (art), media, science. Existing mass media has been broadcasting to the general public due to technical and economic limitation and art works also communicate one-sidedly with spectators in the gallery or stage. But nowaday, it is possible for spectators to participate directly. We can make different products depending on the tastes of individuals who demand media or art. The essence of technology which makes it possible is 'interactive technology'. A goal of this research is to find out the true nature of the interactive design in multimedia contents and find the course of interactive communication design research. In this paper, we pass through two stages to solve this kind of problem. At first, we studied the concept of multimedia contents from the aspect of information revolution. Next, we decided our research topic to be 'visual reacting with audio' and made audio-visual art work as graphic designers. Through this research we can find the possibility to promote 'communication' in a broad sense, with appropriate interactive design.

• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.495-502
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• 1999

We propose efficient speech signal processing algorithms and a system for cochlear implant in this paper. The outer and the middle car which perform amplifying, lowpass filtering and AGC, are modeled by an analog system, and the inner ear acting as a time-delayed multi filter and the transducer is implemented by the DSP circuit which enables real-time processing. Especially, the basilar membrane characteristic of the inner ear is modeled by a nonlinear filter bank, and then tonotopy and periodicity of the auditory system is satisfied by using a pitch-synchronous multi-spectra(PSMS) method. Moreover, most of the speech processing is performed by S/W so the system can be easily modified. And as our program is written in C-language, it can be easily transplanted to the system using other processors.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.881-886
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• 2007

This study was to develope a vibrotactile display system using windows media player from digital audio signal. WMPlayer10SDK system which was plug-in tool by microsoft windows media player provided its video and audio signal information. The audio signal was tried to be change into vibrotactile display. Audio signal had 4 sections such as 8bit, 16bit, 24bit, and 32bit. Each section was computed its frequency and vibrato scale. And data was transferred to 38400bps network port(COM1) for vibration. Using this system was able to develop the music suit which presented tactile feeling of music beyond sound. Therefore, it may provide cross modal technology for fusion technology of human senses.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.581-587
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• 2010

In this study, we investigated the effect of the simplification for low frequency region in Head-Related Transfer Function(HRTF) on the sound localization. For this purpose, HRTF was measured and analyzed. The result in the standard deviation of HRTF showed that the directional dependence of low frequency was smaller than that of high frequency region, which means the possibility of simplification in the low frequency region. Simplification was performed by flattening of the low frequency amplitude characteristics with the insertion of the high-pass filter, whose cutoff frequency is given by boundary frequency. Auditory experiments were performed to evaluate the simplified HRTF. The result showed that direction perception was not influenced by the simplification of the frequency characteristics of HRTF for the error of sound localization. The rate of confusion for the front and back was not affected by the simplification of the frequency characteristics within 1kHz of HRTF. Finally, we made it clear that the sound localization was not affected by the simplification of frequency characteristics of HRTF within 1kHz. The result is expected to be utilized to reduce the size of speech information with no deterioration of the directional characteristics of the speech signal.