• Journal of Sensor Science and Technology
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• 제25권6호
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• pp.406-411
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• 2016

The application of visual and auditory senses into virtual reality is easily taken for granted, but the sense of smell has been largely ignored. But many researches have shown that olfactory stimulation in virtual environments can increase the immersion and reality. In practical virtual reality, the use of scents is not always able to increase the immersion and reality. An ill-matched scent can decrease the reality. To solve this problem, we developed scent devices that can adjustable scents and scent intensity in order to display a well-matched scents in virtual reality. And we propose simple and practical way to program specific location to display scents and developed API function to control a developed scent device at virtual reality software.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제24권3호
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• pp.157-163
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• 2013

Objectives : Previous studies reported that attention-deficit hyperactivity disorder (ADHD) resulted from a deficit of selective attention and sustained attention. In this study, we assessed the result of methylphenidate-induced changes of the cerebral frontal executive functions in patients with ADHD. Methods : The subjects in this study consisted of 16 ADHD patients whose age ranged from 7 to 12. We used ADHD Diagnostic System (ADS) for the attention improvement, and the Stroop Test for the executive function response to pharmacotherapy with MPH. Results : After pharmacotherapy with methylphenidate for 12 weeks, the study group showed improvement in the clinical aspects through Clinical Global Impression-Severity, ADHD-rating scale and Inattention/Overactivity With Aggression Conner's Parents Rating Scale. In the ADS test, only in auditory task there was a decrease of both the response time and the standard deviation of the response time significantly. In the Stroop Test, there was a decrease in the word task, color task and color-word task significantly. Conclusion : Our results show that psychostimulant medication improves neuropsychological function, including the cerebral frontal executive function. This study implies that we have to consider the improvement of executive function, as well as attention when evaluating the efficacy of treatment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제19권4호
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• pp.355-362
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• 2009

Sound source localization method based on the time delay of arrival(TDOA) is applied to many research fields such as a robot auditory system, teleconferencing and so on. When multi-microphones are utilized to localize the source in 3 dimensional space, the conventional localization methods based on TDOA decide the actual source position using the TDOAs from all microphone arrays and the detection measure, which represents the errors between the actual source position and the estimated ones. Performance of these methods usually depends on the number of microphones because it determines the resolution of an estimated position. In this paper, we proposed the localization method using spatially mapped GCC functions. The proposed method does not use just TDOA for localization such as previous ones but it uses spatially mapped GCC functions which is the cross correlation function mapped by an appropriate mapping function over the spatial coordinate. A number of the spatially mapped GCC functions are summed to a single function over the global coordinate and then the actual source position is determined based on the summed GCC function. Performance of the proposed method for the noise effect and estimation resolution is verified with the real environmental experiment. The mean value of estimation error of the proposed method is much smaller than the one based on the conventional ones and the percentage of correct estimation is improved by 30% when the error bound is ${\pm}20^{\circ}$.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제18권2호
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• pp.93-103
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• 2019

This study analyzed the impact of smartphone usage on walking speed during walking on two pedestrian walkways in Daejeon Metropolitan City. For the analysis, the video data about the actual use of smartphone was acquired and the walking speed was calculated based on the walking density of the pedestrian Level Of Service(LOS) presented in the Road Capacity Manual. Multiple regression analysis and decision tree using machine learning were used to analyze the impact of smartphone usage on walking speed, and as the explanatory variables, gender, disable smartphone, use of smartphone using auditory function, use of smartphone using visual function, LOS A, LOS B, LOS C were adopted. The result showed that LOS C had the highest impact on walking speed change and the women's group using their visual function was founded to have the slowest walking speed in LOS C. In particular, the author found that walking speed significantly decreased in the case of use of visual function rather than listening to music or the hearing on the phone.

• Journal of Oral Medicine and Pain
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• 제32권4호
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• pp.383-396
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• 2007

The aim of this study was to measure the suprathreshold taste intensity for NaCl, sucrose, citric acid, and quinine HCl in elderly Korean women using a whole-mouth, sip-and-spit procedure, employing the method of magnitude matching. The results were analysed in terms of aging, menopause, and salivary flow rate. 31 elderly women (mean age; $50.8{\pm}5.1$ years) and 30 young women (mean age; $25.1{\pm}1.71$ years) were included for the study. Subjects were instructed to give nonmodulus magnitude estimates to the intensities of five concentrations each of sucrose, NaCl, citric acid, and quinine HCl; distilled water; 6 loudness level of a 1,000-Hz tone, using the same 9-point intensity scale. Each of the 21 taste stimuli and 6 auditory stimuli are presented in random order twice. The auditory function is used to assess the absolute intensity function of the subject's taste system. The results were as follows; 1. Comparing to young women, elderly women showed decreased taste intensities for lower concentration solutions of NaCl and sucrose. However, other solutions didn't show any difference in taste intensities between young and elderly women. 2. There were not significant difference in perceived taste intensities for NaCl, sucrose, citric acid, and quinine HCl between menopause and pre-menopause women in elderly women group. 3. There were not significant difference in perceived taste intensities for NaCl, sucrose, and quinine HCl between low salivation women and high salivation women in elderly women group. 4. The low salivation women in elderly group showed higher taste intensity for low concentration citric acid than high salivation women.

• Journal of Music and Human Behavior
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• 제12권2호
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• pp.19-36
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• 2015

The purpose of this study was to examine the effects of rhythmic auditory stimulation (RAS) on gait parameters, with and without the presence of a melody, for adolescents with traumatic brain injury (TBI). Three adolescents with TBI received a total of ten individual RAS training sessions. At pre and posttest, spatiotemporal parameters including cadence, velocity and kinematic parameters were measured using the VICON 370 Motion Analysis System. The results showed no significant difference in gait velocity between the two conditions, thus the presence of the melody condition did not impact the outcome of RAS gait training. On the other hand, all participants showed improvement in gait function after RAS training. The cadence, velocity, stride length, and symmetry were increased and the stride time was reduced after training. The motion analysis demonstrated that the movement patterns of hip and knee joints improved, as they were more similar to normal gait, which indicates that the walkings tance became more stable. The research findings indicate that rhythm is the primary factor in mediating gait functions via RAS training. This study also supports that RAS training can effectively improve the gait function for adolescents with TBI.

• Journal of Oral Medicine and Pain
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• 제30권2호
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• pp.149-162
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• 2005

The aim of this study was to measure the suprathreshold taste intensity for sucrose, NaCl, citric acid, and quinine HCl in Korean young people using a whole-mouth, sip-and-spit procedure, employing the method of magnitude matching. The results were analysed in terms of sex, taste preference, and smoker or nonsmoker. One hundred twenty three subjects (61 male and 62 female, mean age of 25.2$\pm$2.1 years) were included for the study. Subjects were instructed to give nonmodulus magnitude estimates to the intensities of five concentrations each of sucrose, NaCl, citric acid, and quinine HCl; distilled water; 6 loudness levels of a 1,000-Hz tone, using the same 9-point intensity scale. Each of the 21 taste stimuli and 6 auditory stimuli are presented in random order twice. The auditory function is used to assess the absolute intensity function of the subject's taste system. The results were as follows; 1. The perceived taste intensity for sucrose, NaCl, citric acid, and quinine HCl increased progressively as the concentrations of taste solutions were increased. Most of the subjects are standing within the zone of mean value $\pm$1standard deviation in their total perceived intensity score, and nobody is outside the limit of mean value - 2standard deviation. 2. There were not significant difference in total perceived intensities for sucrose, NaCl, citric acid, and quinine HCl between males and females. 3. There were not significant difference in total perceived intensities for sucrose, NaCl, citric acid, and quinine HCl according to the difference in taste preference. 4. There were not significant difference in total perceived intensities for sucrose, NaCl, citric acid, and quinine HCl between smokers and non-smokers in males.

• Annals of Clinical Neurophysiology
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• 제3권2호
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• pp.136-142
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• 2001

Background : Nervous system dysfunction is a major complication of end stage renal disease. Although severe neurologic symptoms are partially or completely reversed by adequate hemodialysis, even optimally dialyzed patients will usually not return to normal neurocognitive function. To investigate the influence of chronic renal failure and hemodialysis on higher cognitive function electrophysiologically, we studied auditory P300 event-related potentials in 14 hemodialysis patients and 14 age- and sex-matched normal healthy controls. Methods : The subjects consisted of 14 patients(M: 6, F: 8) with chronic renal failure(CRF) for 1 to 10 years and 14 age- and sex-matched healthy controls(M: 5, F: 9). For the reliability of study, patients with diabetes mellitus, abnormal brain CT findings, or low mini-mental state score(below 20) were excluded. Event related potentials(ERPs) for hemodialysis patients were performed at pre- and post-hemodialysis. To obtain ERPs, subjects underwent 2-tone auditory discrimination test(oddball paradigm). Results : Although the age(control: $48.79{\pm}10.31years$, CRF: $51.21{\pm}7.61years$) and mini-mental state score(control: $27.00{\pm}1.71points$, predialysis CRF: $25.07{\pm}3.58points$) were not different in normal control and CRF groups significantly(P>0.05), P300 latencies at Cz(control: $288.11{\pm}17.36msec$, predialysis CRF: $332.35{\pm}42.34msec$) were significantly delayed(P<0.05)and the duration of Trail making test A was significantly prolonged(control: $64.2{\pm}24.2sec$, CRF: $118.9{\pm}101sec$) in CRF group. P300 latencies between pre- and post-hemodialysis CRF patients(predialysis CRF: $332.35{\pm}42.34msec$, postdialysis CRF: $325.82{\pm}38.69msec$) were not significantly different. The P300 latency was not related with the duration of CRF(Spearman's correlation test, r=0.25, P>0.05) and the frequency of hemodialysis(Spearman's correlation test, r=0.28, P>0.05). Conclusions : From these results, we suggest that P300 latency is valuable in evaluating cognitive brain dysfunction in patients with CRF and hemodialysis does not have a significant effect on cognitive brain dysfunction in patients with CRF.

• Journal of Korean Medical Ki-Gong Academy
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• 제23권1호
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• pp.10-29
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• 2024

Objective : The purpose of this study is to determine whether An's breathing meditation qigong therapy (ABMQT) delivers bioenergy to the frontal lobe, prefrontal lobe, the olfactory tract in the mesolimbic pathway, olfactory bulb, CV22, CV21, olfactory area and vocal-related areas in Parkinson's disease (PD) patients to help improve olfactory disorders (anosmia) and vocal functions. Methods : The subjects of this study were 4 patients with idiopathic PD (3 males/1 female, 65.0±NA/68.7±10.2 years old). ABMQT was applied once a week, 120 minutes per session for 12 weeks in a non-invasive and noncontact manner, and the test before and after ABMQT application included olfactory impairment test the Korean version of Sniffin' stick test (KVSS), voice acoustic test, aerodynamic test, vocal handicap index (VHI-30), and auditory perception scale test tools. The results before and after the experiment were analyzed assuming a normal distribution, and a chi-square test was performed using a continuity correction, and the significance level was set to p<0.05. And the medical diagnosis and findings of the examiner (doctor in charge) before and after the experiment were described. Results : KVSS was significant as 0.2±0.5 and 9.0±0.0 before and after the experiment. There was no significant difference between the voice acoustic test FO and Jitter, the vocal aerodynamic test MPT, SP, AE, the vocal disorder index test, and the auditory perception test. However, the medical diagnosis findings of four study subjects showed that olfactory disorders, voice disorders, and laryngeal function were improved before and after the application of ABMQT. Conclusions : The breathing meditation qigong program showed significant effects on improving the olfactory disorders (anosmia) and speech function of each study subject. However, to produce meaningful results, it is thought that experiments involving a larger number of research participants are necessary, and additional blood and FMRI tests are conducted to verify metabolic activities and the olfactory neuron signal transmission system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제24권4호
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• pp.282-288
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• 2014

Three-dimensional multimedia industry such as 3D TV, movie and broadcast has been developed vividly. For generating 3D contents with high quality, virtual auditory display, so called VAD, is being researched to offer more realistic experience to listeners. When people render VAD using headphones or two speakers, head-related transfer function(HRTF) plays a key role. The best solution is measuring all individuals' HRTFs, but it is hard to measure all listeners' HRTFs. To overcome this difficulty, many research groups have tried to construct their own measurement system and to build HRTF databases. However, some of them have not enough subjects or spatial resolution and they are mainly focused on Caucasian. There exists difference between Korean and Caucasian in a view of physical features. In other words, if Koreans hear three-dimensional sound rendered by HRTF database based on Caucasian, performance might be hindered. To verify this possibility and remedy the drawbacks, construction of new HRTF database aimed at Korean is needed. Therefore, our laboratory built HRTF measurement system which can measure HRTF of three-dimensional space with dense spatial resolution. With this system, 55 Korean males and 45 females' HRTFs were measured and Korean HRTF database was built based on these data.