• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.2
• /
• pp.69-76
• /
• 2023

A high-quality audio/voice codec using the MDCT/IMDCT process can perfectly restore the current frame through an overlap-add process with the previous frame. In the overlap-add process, an algorithm delay equal to the frame length occurs. In this paper, we propose a MDCT/IMDCT process that reduces algorithm delay by using a variable phase shift in MDCT/IMDCT process. In this paper, a low-delay audio/speech codec was proposed by applying the low delay MDCT/IMDCT algorithm to the ITU-T standard codec G.729.1 codec. The algorithm delay in the MDCT/IMDCT process can be reduced from 20 ms to 1.25 ms. The performance of the decoded output signal of the audio/speech codec to which low-delay MDCT/IMDCT is applied is evaluated through the PESQ test, which is an objective quality test method. Despite of the reduction in transmission delay, it was confirmed that there is no difference in sound quality from the conventional method.

• Korean Journal of Audiology
• /
• v.23 no.4
• /
• pp.197-203
• /
• 2019

Background and Objectives: Many studies have reported no benefit of sound localization, but improved speech understanding in noise after treating patients with single-sided deafness (SSD). Furthermore, their performances provided a large individual difference. The present study aimed to measure the ability of speech perception and gap detection in noise for the SSD patients to better understand their hearing nature. Subjects and Methods: Nine SSD patients with different onset and period of hearing deprivation and 20 young adults with normal hearing and simulated conductive hearing loss as the control groups conducted speech perception in noise (SPIN) and Gap-In-Noise (GIN) tests. The SPIN test asked how many presented sentences were understood at the +5 and -5 dB signal-to-noise ratio. The GIN test was asked to find the shortest gap in white noise with different lengths in the gap. Results: Compared to the groups with normal hearing and simulated instant hearing loss, the SSD group showed much poor performance in both SPIN and GIN tests while supporting central auditory plasticity of the SSD patients. Rather than a longer period of deafness, the large individual variance indicated that the congenital SSD patients showed better performance than the acquired SSD patients in two measurements. Conclusions: The results suggested that comprehensive assessments should be implemented before any treatment of the SSD patient considering their onset time and etiology, although these findings need to be generalized with a large sample size.

• The Journal of the Acoustical Society of Korea
• /
• v.25 no.6
• /
• pp.298-304
• /
• 2006

This paper proposes a ray-based forward modeling scheme which is suitable for the shallow water acoustic wave propagation simulations. The proposed model comprises of ray tracings for the layered media of which sound speed profiles are interpolated linearly. considerations of plane and spherical wave reflection coefficients. and calculations of the phases and the amplitudes of eigen rays. The main characteristic of the scheme is fast simulation time due to direct calculation of the broad-band time signals in the time-domain, i.e. without transformation of the frequency-domain solutions to the time si 밍 131s. Finally, we applied the model to 4-types of test environments and compared the resulting signals with those of ORCA and Ram in order to validate the proposed model.

• Journal of the Institute of Convergence Signal Processing
• /
• v.14 no.3
• /
• pp.147-153
• /
• 2013

Functional game, which is the combination of play and learning and a futuristic tool, can minimize the dysfunction and maximize the proper functions, and furthermore, has taken root as a new alternative that can change the game industry and game culture. Recently, the focus of game and education markets is shifting to the development of more advanced learning contents, rather than emphasizing the self-control and motivation of users. Along with that, the game market has excluded the socially dysfunctional elements, such as the addiction and learning disabilities, and has witnessed a diversification into the human-friendly entertainment business that emphasizes the mental and physical health and pursues scientific educational effects. In addition, functional games are expanding its reach from the professional sectors - such as medical aide/medical learning, military simulation, health, auxiliary tools, special education and learning tools - to the realm of routine education, mental health, etc., and has seen a steady growth. However, most functional games, which are being currently planned and developed to cope with the special characteristics of the market, have not undergone accurate scientific assessment of their functions and have not proven their effectiveness. An overwhelming proportion of the functional games are being developed based on the intuition and experience of game developers. Moreover, the type of games, which involve the repetition of simple tasks or take the form of simple puzzles, cannot effectively combine the practically interesting factors and the learning effects. Most games incorporate unscientific methods leading to the vague anticipation of improvement in functions, rather than the assessment of human functions. In this paper, a study was conducted to present the measures that could maximize the effects of functional games in relation to the changes in the visual and auditory stimulations in order to maximize the effects of functional games, i,e., the immersion and concentration. To compare the degree of effects arising from the visual stimulation, the functional game contents made in the form of 2D and 3D were utilized. In addition. ultra sound and 3-dimensional functional game contents were utilized to compare the degree of effects resulting from the changes in the auditory stimulation. The brainwave of the users were measured while conducting the experiments related to the response to the changes in visual and auditory stimulations in 3 steps, and the results of the analysis were compared.

• Journal of Intelligence and Information Systems
• /
• v.20 no.3
• /
• pp.45-58
• /
• 2014

The Korean Culture Contents spread out to Worldwide, because the Korean wave is sweeping in the world. The contents stand in the middle of the Korean wave that we are used it. Each country is ongoing to keep their Culture industry improve the national brand and High added value. Performing contents is important factor of arousal in the enterprise industry. To improve high arousal confidence of product and positive attitude by populace is one of important factor by advertiser. Culture contents is the same situation. If culture contents have trusted by everyone, they will give information their around to spread word-of-mouth. So, many researcher study to measure for person's arousal analysis by statistical survey, physiological response, body movement and facial expression. First, Statistical survey has a problem that it is not possible to measure each person's arousal real time and we cannot get good survey result after they watched contents. Second, physiological response should be checked with surround because experimenter sets sensors up their chair or space by each of them. Additionally it is difficult to handle provided amount of information with real time from their sensor. Third, body movement is easy to get their movement from camera but it difficult to set up experimental condition, to measure their body language and to get the meaning. Lastly, many researcher study facial expression. They measures facial expression, eye tracking and face posed. Most of previous studies about arousal and interest are mostly limited to reaction of just one person and they have problems with application multi audiences. They have a particular method, for example they need room light surround, but set limits only one person and special environment condition in the laboratory. Also, we need to measure arousal in the contents, but is difficult to define also it is not easy to collect reaction by audiences immediately. Many audience in the theater watch performance. We suggest the system to measure multi-audience's reaction with real-time during performance. We use difference image analysis method for multi-audience but it weaks a dark field. To overcome dark environment during recoding IR camera can get the photo from dark area. In addition we present Multi-Audience Engagement Index (MAEI) to calculate algorithm which sources from sound, audience' movement and eye tracking value. Algorithm calculates audience arousal from the mobile survey, sound value, audience' reaction and audience eye's tracking. It improves accuracy of Multi-Audience Engagement Index, we compare Multi-Audience Engagement Index with mobile survey. And then it send the result to reporting system and proposal an interested persons. Mobile surveys are easy, fast, and visitors' discomfort can be minimized. Also additional information can be provided mobile advantage. Mobile application to communicate with the database, real-time information on visitors' attitudes focused on the content stored. Database can provide different survey every time based on provided information. The example shown in the survey are as follows: Impressive scene, Satisfied, Touched, Interested, Didn't pay attention and so on. The suggested system is combine as 3 parts. The system consist of three parts, External Device, Server and Internal Device. External Device can record multi-Audience in the dark field with IR camera and sound signal. Also we use survey with mobile application and send the data to ERD Server DB. The Server part's contain contents' data, such as each scene's weights value, group audience weights index, camera control program, algorithm and calculate Multi-Audience Engagement Index. Internal Device presents Multi-Audience Engagement Index with Web UI, print and display field monitor. Our system is test-operated by the Mogencelab in the DMC display exhibition hall which is located in the Sangam Dong, Mapo Gu, Seoul. We have still gotten from visitor daily. If we find this system audience arousal factor with this will be very useful to create contents.

• Proceedings of the KOSOMBE Conference
• /
• v.1992 no.05
• /
• pp.27-47
• /
• 1992

Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

• Journal of the Korean Wood Science and Technology
• /
• v.16 no.3
• /
• pp.48-64
• /
• 1988

This study was carried out to investigate the free vibrational properties of traditional and replaceable species for sounding board, using piezoelectrical accelerometer and signal analyzer. In the study, the frequency equations of free-free beam carrying a concentrated mass in the transverse vibration and of free-mass beam in the longitudinal vibration were used. The results obtained were as follows. 1. Average values of dynamic modulus of rigidity of Korean commercial species measured were as follows. Paulownia tomatosa (Thunb.) Steudel: $5.590\times10^9\;dyne/cm^2$ Tilia amurensis Rupr.: $5.414\times10^9\;dyne/cm^2$ Macckia amurensis Rupr.: $10.044\times10^9\;dyne/cm^2$ Fraxinus mandshurica Rupr.: $8.876\times10^9\;dyne/cm^2$ Ulmus davidiana var.japonica Nakai: $8.677\times10^9\;dyne/cm^2$ Pinus rigida Miller: $6.33\times10^9\;dyne/cm^2$ Fraxinus rhynchophylla Hance: $4.666\times10^9\;dyne/cm^2$ 2. The ratio of dynamic transverse Young's modulus to dynamic modulus of rigidity, $E_T/G_{LT}$, was 24.922 for Fraxinus rhynchophylla Hance, which was the highest, 7.317 for Paulownia tomentosa (Thunb.) Steudel, which was the lowest among Korean commercial species measured. 3. The value of longitudinal dynamic Young's modulus was about 3.7% and 19.8%, respectively, higher than those of transverse dynamic and static Young's modulus. The value of transverse dynamic Young's modulus was about 15.5% higher than that of static Young's modulus. 4. Predicted value of MOR in terms of correlation coefficient by transverse dynamic Young's modulus was slightly higher than that of static Young's modulus, but no significance was found out. 5. Transverse dynamic Youne's modulus was $(2.002\pm0.288)\times10^{11}\;dyne/cm^2$ for Fraxinus mandshurlca Rupr., which was the highest, $(0.601\pm0.100)\times10^{11}\;dyne/cm^2$ for Paulownia tomentosa (Thunb.) Steudel, which was the lowest among Korean commercial species measured. The sound velocity of sitka spruce was 5,685 m/sec, which was the highest. 6. Internal friction of Paulownia tomentosa (Thunb.) Steudel was shown the lowest value among Korean commercial species, $(8.795\pm1.795)\times10^{-3}$, but was higher than that of sitka spruce, $(7.331\pm0.991)\times10^{-3}$. Internal friction was shown negative correlation with density and dynamic Young's modulus, respectively. 7. K value was affected largely by internal friction and was the highest, $2.225\times10^8$ for Paulownia tomentosa (Thunb.) Steudel and was the lowest, $0.550\times10^8$ for Fraxinus rhynchophylla Hance. K value of Paulownia tomentosa (Thunb.) Steudel was higher than that of sitka spruce and K values of melapi and cottonwood, which have been considered to be replaceable species with sitka spruce in the piano industry, were lower than those of Paulownia tomentosa (Thunb.) Steudel and mill amurensis Rupr.

• The Journal of the Acoustical Society of Korea
• /
• v.30 no.1
• /
• pp.33-41
• /
• 2011

To substitute TLS in the hybrid system which is combined with Sagnac interferometer and fiber bragg grating (FBG) it is necessary to investigate how the laser source (TLS and CW) and sensor material variate the response of fiber optic sensor. Two different hollow cylinder type mandrel materials are proposed which are PTFE and PTFE+carbon and 18 m optical fiber is wounded at the mandrel surface. CW laser source experiments had been done in the oil tank which is filled with transformer oil in the 1 kHz~20 kHz frequency range. Also Sagnac interferometer fiber optic sensor is combined with FBG called hybrid system and TLS used as a light source. Based on the experimental results PTFE sensor showed more higher magnitude of detection signal rather than carbon sensor and this result is agreement with the McMahon's theoretical results. Phase variation is inversely proportional to the elastic modulus of the mandrel material. In PTFE fiber sensor, tunable laser source showed more higher performance rather than CW case. Therefore, TLS fiber optic sensor can be applied to the hybrid system which is combined with Sagnac and FBG.

• Geophysics and Geophysical Exploration
• /
• v.14 no.1
• /
• pp.18-24
• /
• 2011

A multi-channel seismic reflection (MCS) survey was conducted in 2009 to explore the deep crustal structure of the Pacific Plate south of Hokkaido. The survey line happened to traverse a 250-km-wide Warm Core Ring (WCR), a current eddy that had been generated by the Kuroshio Extension. We attempted to use these MCS data to delineate the WCR fine structure. The survey line consists of two profiles: one with a shot interval of 200m and the other with a shot interval of 50 m. Records from the denser shot point line show much higher background noise than the records from the sparser shot point line. We identified the origin of this noise as acoustic reverberations between the sea surface, seafloor and subsurface discontinuities, from previous shots. Results showed that a prestack migration technique could enhance the signal buried in this background noise efficiently, if the sound speed information acquired from concurrent temperature measurements is available. The WCR is acoustically an assemblage of concave reflectors dipping inward, with steeper slopes (${\sim}2^{\circ}$) on th ocean side and gentler slopes (${\sim}1^{\circ}$) on the coastal side. Within the WCR, we recognised a 30-km-wide lens-shaped structure with reflectors on the perimeter.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.27 no.5
• /
• pp.426-431
• /
• 2007

When a high-energy ultrasound propagates through a solid body that contains a crack or a delamination, the two faces of the defect do not ordinarily vibrate in unison, and dissipative phenomena such as friction, rubbing and clapping between the faces will convert some of the vibrational energy to heat. By combining this heating effect with infrared imaging, one can detect a subsurface defect in material in real time. In this paper a realtime detection of the brazing defect of thin Inconel plates using the UIR (ultrasonic infrared imaging) technology is described. A low frequency (23 kHz) ultrasonic transducer was used to infuse the welded Inconel plates with a short pulse of sound for 280 ms. The ultrasonic source has a maximum power of 2 kW. The surface temperature of the area under inspection is imaged by an infrared camera that is coupled to a fast frame grabber in a computer. The hot spots, which are a small area around the bound between the two faces of the Inconel plates near the defective brazing point and heated up highly, are observed. And the weak thermal signal is observed at the defect position of brazed plate also. Using the image processing technology such as background subtraction average and image enhancement using histogram equalization, the position of defective brazing regions in the thin Inconel plates can be located certainly.