• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.12
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• pp.92-98
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• 1998

In this paper, we implemented an angularly multiplexed volume holographic memory system using an AOD that is controlled electronically, with rapid access time(10$mutextrm{s}$) and accurate repeatability of the reference beam. First we designed an AOD-based angular multiplexing system without the frequency compensation of the object beam, and magnified the deflection angle of AOD through the combination of lens so that we increased the storage capacity up to six times. Finally fifty-one images were stored experimentally in a photorefractive material of 1㎤ Fe:LiNbO$_3$.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2240-2243
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• 2003

In this paper. we present a new speech recognition system using DSP chip. DSP chip used TMS320c6711 of TI. We designed hardware system including acoustic model, word list and code book in flash memory. The word candidates are recognized based on CV, VCCV, and VC units HMM. This system can be applied to various electric ＆ electronic devices: home automation, robotics etc.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.289-297
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• 2010

In this paper, A method to prevent the external acoustic noise from being misrecognized as the speech recognition object is presented in the speech activity detection process for the speech recognition. Also this paper confirmed besides the acoustic energy to the lip movement image signals. First of all, the successive images are obtained through the image camera for personal computer and the lip movement whether or not is discriminated. The next, the lip movement image signal data is stored in the shared memory and shares with the speech recognition process. In the mean time, the acoustic energy whether or not by the utterance of a speaker is verified by confirming data stored in the shared memory in the speech activity detection process which is the preprocess phase of the speech recognition. Finally, as a experimental result of linking the speech recognition processor and the image processor, it is confirmed to be normal progression to the output of the speech recognition result if face to the image camera and speak. On the other hand, it is confirmed not to the output the result of the speech recognition if does not face to the image camera and speak. Also, the initial feature values under off-line are replaced by them. Similarly, the initial template image captured while off-line is replaced with a template image captured under on-line, so the discrimination of the lip movement image tracking is raised. An image processing test bed was implemented to confirm the lip movement image tracking process visually and to analyze the related parameters on a real-time basis. As a result of linking the speech and image processing system, the interworking rate shows 99.3% in the various illumination environments.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.4
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• pp.189-198
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• 2015

Most IoT-related approaches have tried to establish the relation by connecting the network between things. The proposed research will present how the pervasive interaction of eco-system formed by touching the objects between humans and things can be recognized on purpose. By collecting and sharing the detected patterns among all kinds of things, we can construct the environment which enables individualized interactions of different objects. To perform the aforementioned, we are going to utilize technical procedures such as event-driven signal processing, pattern matching for signal recognition, and hardware in the loop simulation. We will also aim to implement the prototype of sensor processor based on Arduino MCU, which can be integrated with system using Arduino-Matlab/Simulink hybrid-interoperation environment. In the experiment, we use piezo transducer to detect the vibration or vibrates the surface using acoustic wave, which has specific frequency spectrum and individualized signal shape in terms of time axis. The signal distortion in time and frequency domain is recorded into memory tracer within sensor processor to extract the meaningful pattern by comparing the stored with lookup table(LUT). In this paper, we will contribute the initial prototypes for the acoustic touch processor by using off-the-shelf MCU and the integrated framework based on Matlab/Simulink model to provide the individualization of the touch-sensing for the user on purpose.

• Progress in Medical Physics
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• v.21 no.1
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• pp.42-51
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• 2010

Imaging studies using MRI, PET, and/or MEG have been primary evaluation methods to quantitatively assess cognitive function. Recent advances in computational technology and information technology may allow a novel evaluation methodology to quantitate cognitive function more cost-effectively. In this study, we developed a software package composed of a series of tests to evaluate cognitive ability combined with a user-friendly touch screen input device. This cognitive assessment tool can quantitate concentration, numeric memory, associative memory, topological memory, visual and muscular reaction, and acoustic reaction over a relatively short testing time. We performed an empirical study on eighty normal subjects aged 20 and 59 years old using the developed evaluation methods. Age-related cognitive deterioration after 40 years old was confirmed. There was no difference in cognitive ability between male and female in the same age group. This study demonstrates the feasibility of a simple but effective evaluation software tool to quantitatively assess cognitive ability. This methodology may provide improved accessibility and reduced costs to perform cognitive function studies to compare between various subject groups.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1083-1089
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• 2010

Shape memory alloys (SMAs) are smart materials. The unique characteristics of SMAs enable the production of large force and displacement. Hence, SMAs can be used in many applications such as in actuators and active structural acoustic controllers; the SMAs can also be used for dynamic tuning and shape control. A SMA torque tube actuator consisting of SMA tubes and superelastic springs is proposed, and the behaviors of the actuator are investigated. From the results of heat transfer analysis, it is proved that the SMA torque tube actuator with both resistive heating of SMA itself and a separate conventional heating rod in the tube core has good performance. The behavior of an actuator system was analyzed by performing a contact analysis, and the twisting motion was noticed when checking the actuation. 3D SMA nonlinear constitutive equations were formulated numerically and implemented by performing a nonlinear analysis by using Abaqus UMAT.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.5
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• pp.601-614
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• 2012

Since the optimized use of sonar systems available for detection is a very practical problem for a given ocean environment, the measure of mission achievability is needed for operating the sonar system efficiently. In this paper, a theory on Measure Of Effectiveness(MOE) for specific mission such as detection is described as the measure of mission achievability, and a recursive Cumulative Detection Probability(CDP) algorithm is found to be most efficient from comparing three CDP algorithms for discrete glimpses search to reduce computation time and memory for complicated scenarios. The three CDPs which are MOE for sonar-maneuver pattern are calculated as time evolves for comparison, based on three different formula depending on the assumptions as follows; dependent or independent glimpses, unimodal or non-unimodal distribution of Probability of Detection(PD) as a function of observation time interval for detection. The proposed CDP algorithm which is made from unimodal formula is verified and applied to OASPP(Optimal Acoustic Search Path Planning) with complicated scenarios.

• Geophysics and Geophysical Exploration
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• v.3 no.2
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• pp.39-47
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• 2000

A great deal of computing time and a large computer memory are needed to solve wave equation in a large complex subsurface layers using the finite difference method. The computing time and memory can be reduced by decreasing the number of grid points per minimum wave length. However, the decrease of grids may cause numerical dispersion and poor accuracy. In this study we performed the grid dispersion analysis for several rotated finite difference operators, which was commonly used to reduce grids per wavelength with accuracy in order to determine the solution for the acoustic wave equation in frequency domain. The rotated finite difference operators were to be extended to 81, 121 and 169 difference stars and studied whether the minimum grids could be reduced to 2 or not. To obtain accuracy (numerical errors less than $1\%$) the following was required: more than 13 grids for conventional 5 point difference stars, 9 grids for 9 difference stars, 3 grids for 25 difference stars, and 2.7 grids for 49 difference stars. After grid dispersion analysis for the new rotated finite difference operators, more than 2.5 grids for 81 difference stars, 2.3 grids for 121 difference stars and 2.1 grids for 169 difference stars were needed. However, in the 169 difference stars, there was no solution because of oscillation of the dispersion curves in the group velocity curves. This indicated that the grids couldn't be reduced to 2 in the frequency acoustic wave equation. According to grid dispersion analysis for the determination of grid points, the more rotated finite difference operators, the fewer grid points. However, the more rotated finite difference operators that are used, the more complex the difference equation terms.

• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.97-103
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• 2013

Schizophrenia is a severe psychiatric disorder and characterized by positive symptom (i.e., delusions, hallucinations), negative symptom (i.e., lack of emotion, social withdrawal), and cognitive impairment. Previously, we reported that the ethanolic extract of Prunella vulgaris var. lilacina attenuated the MK-801-induced schizophrenia-like behaviors such as prepulse inhibition (PPI) deficits and cognitive impairment in mice. The aim of the present study was to investigate whether danshensu isolated from P. vulgaris var. lilacina attenuates MK-801-induced sensorimotor gating dysfunction (PPI deficits), hyperlocomotion, and memory impairment in mice. Acute administration of danshensu (1, 3, or 10 mg/kg) significantly ameliorated the MK-801-induced PPI deficits in the acoustic startle response test. We also observed that the impaired recognition memory induced by MK-801 was attenuated by danshensu (1 mg/kg) in the novel object recognition test. However, danshensu failed to reverse the MK-801-induced hyperlocomotion in the open-field test. Collectively, the present results indicate danshensu would be an active agent for treating neuropsychiatric disorders such as schizophrenia.

• Phonetics and Speech Sciences
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• v.11 no.4
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• pp.63-70
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• 2019

This study investigated individual variability of L2 learners' categorical judgments of L2 stops by exploring English learners' perceptual processing of two acoustic cues (voice onset time [VOT] and f0) and working memory capacity as sources of variation. As prior research has reported that English speakers' greater use of the redundant cue f0 was responsible for gradient processing of native stops, we examined whether the same processing characteristics would be observed in L2 learners' perception of Korean stops (/t/-/t^h/). 22 English learners of L2 Korean with a range of L2 proficiency participated in a visual analogue scaling task and demonstrated variable manners of judging the L2 Korean stops: Some were more gradient than others in performing the task. Correlation analysis revealed that L2 learners' categorical responses were modestly related to individuals' utilizations of a primary cue for the stop contrast (VOT for L1 English stops and f0 for L2 Korean stops), and were also related to better working memory capacity. Together, the current experimental evidence demonstrates adult L2 learners' top-down processing of stop consonants where linguistic and cognitive resources are devoted to a process of determining abstract phonemic identity.