• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.69-73
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• 2003

음향압축에 있어서 인간의 청각신경의 특성을 이용하는 방식이 사용되고 있다. 이러한 방법은 심리음향모델(psychoacustical model)에서 도입되었다. 음향압축에서는 이러한 심리음향모델을 사용하여 인간이 지각할 수 없는 한도 내에서 부호화하지 않는 지각음향부호화(perceptual audio coding)사용한다. 지각음향부호화는 분석필터와 합성필터로 각각 부호화 복호화하는데 이것은 필터뱅크(filter bank)로 구현된 서브밴드코더(subband coder) 이다. 본 논문에서는 분석필터와 합성필터에 사용되는 MDCT(Modified Discrete Cosine Transform)와 IMDCT(Inverse Modified Discrete Cosine Transform)를 FPGA에 구현하였다.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.73-88
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• 2018

The present study examined how processing features of visual information near the hand would affect task switching. Recent studies reported enhanced cognitive control of visual information presented the near hands. To investigate the enhancement of cognitive control based on the relationship between hand proximity and attention, we implemented 2 experiments. In the task switching performance experiment, the hand proximity effect depended on modality of cue and target. The first experiment showed that stimuli near the hand received greater cognitive control than stimuli far from the hand, resulting in smaller switch cost. The result could rule out the feature-binding problem, which identifies reduced switch cost as the cause instead of hand proximity. Our results show that hand proximity actually reduced switch cost. In the second experiment, we examined the effects of hand nearness, modality, and their interaction on switch cost. In task switching, the target was always visual, and the cue was presented either visually or auditorily. In addition, we manipulated the cue-target interval to observe the preparation effect of cue. The results showed that a visual cue near the hand reduced switch cost by shortening task preparation time. Also, modality switching between an auditory cue and visual target was remarkable in a hand-near condition. The results for the visual cue could be interpreted as a benefit of rapid visual attention orienting. On the other hand, the results for the auditory cue could be interpreted as the cost of interference of modality switching by slower attentional disengagement of stimuli near the hands. Finally, modulation of switch cost by attention induced by hand nearness was discussed.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.2
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• pp.1-11
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• 2021

Objective : The purpose of this study was to compare sensory processing ability by smartphone addiction levels in preschool children, and to investigate the correlation between smartphone addiction level and sensory processing ability within smartphone addiction group. Method : The subjects of this study were 324 persons, with 124 persons in the addiction group and 200 in the normal user group. Measurements in this study were a questionnaire about general characteristics of subject, smartphone addiction scale, and short sensory profile. Methods for the data analysis included descriptive statistics, independent t-test, Pearson correlation analysis of SPSS 22.0. Results : There was a significant difference in the total Short Sensory Profile (SSP) score and in all sub-domains between the addiction and normal use groups (p<0.05). In the smartphone addiction group, there was a negative correlation between the SSP total score (r=-.278), auditory filtering (r=-.293), visual/auditory sensitivity (r=-.393) and smartphone addiction level. Conclusion : This study confirmed that there was a difference in smartphone addiction and sensory processing ability between the preschool children addiction and normal use groups. It has been proven that there is an interrelationship between sensory processing ability and smartphone addiction in the addiction group. It is significant in that it provides basic data to prevent smartphone addiction.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.2
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• pp.121-128
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• 2009

일반적으로, 소비자는 담배를 구매하기 전 디자인, 색상, 상표명 등을 평가하고, 피우기 전에는 포장된 필름의 찢김성, 필터부위의 오염여부 등의 외관과 외향을 감지하게 되며, 마지막으로 흡연하면서 담배의 다양한 향과 맛의 관능적 특성을 평가한다. 담배의 본질적인 특징은 물리 화학적인 측정기기를 이용한 이화학적 데이터와 사람의 오감을 이용해 감지한 향미특성을 종합함으로써 분석 할 수 있다. 이들 특성이 소비자 기호 선호도에 미치는 영향요인을 도출하여 소비자가 원하는 제품을 개발(Carter & Riskey, 1990)하는 데 중요한 연결고리를 관능평가를 통해 얻을 수 있다. 미국 Institute of Food Technologists(IFT)에서는 관능평가를 '식품과 물질의 특성이 시각, 후각, 미각, 촉각 및 청각으로 감지되는 반응을 측정, 분석 및 해석하는 과학의 한 분야'로 정의하고 있다(IFT Sensory Evaluation Division, 1981).

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.522-528
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• 2011

Artificial basilar membranes made of PVDF(polyvinylidene fluoride) are manufactured using microfabrication processes. The mechanical behavior of PVDF artificial basilar membrane was measured to evaluate its performance as a mechanical frequency analyzer using scanning LDV(laser Doppler vibrometer). The experimental setup consists of the microfabricated artificial basilar membrane, a loud speaker connected to an amplifier for generating acoustic pressure of specific spectral pattern, and a scanning LDV with controlling unit for measuring the displacement of the membrane on the incoming acoustic stimulation. The microfabricated artificial basilar membrane was attached tightly upon a package containing a chamber which can be filled with silicone oil before placed on the experimental setup stage. The experiment results showed that the microfabricated artificial basilar membrane has a property as a mechanical frequency analyzer.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.516-521
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• 2011

The basilar membrane, an important functional part of the cochlea, is responsible for spectral separation of vibration signals transmitted from the stapes. In current study, scaled-up polymer membranes designed by mimicking the human basilar membrane were used for investigation of the frequency-separation characteristic. Displacement field formed on each polymer membrane was acquired by Laser Doppler scanning vibrometer and post-processed frequency-wise. The locations of the maximum displacement along the centerline were identified and collected for individual frequency range to produce the frequency-position map of individual polymer membrane. The influences of the membrane thickness and material properties on the variation of the frequency separability were discussed.

• Information and Communications Magazine
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• v.24 no.4
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• pp.27-35
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• 2007

음성 통신을 할 때 배경 잡음이 존재하게 되면 일반적으로 음질이 저하된다. 이것은 잡음 자체가 듣기 싫다거나 음성을 더 작게 들리게 만들기 때문이기도 하고 음성 코덱이 잡음이 섞이지 않은 깨끗한 음성에 최적화되어 있어서 잡음이 섞인 음성에 대한 코딩 효율이 떨어지기 때문이기도 하다. 이 논문에서는 잡음에 의한 음성 통신의 품질 저하를 막기 위한 방법으로서 음성 향상(speech enhancement) 기술과 음성 강화(speech reinforcement) 기술에 대해 소개한다. 음성 향상 기술이란 전송부의 마이크에서 녹음된 잡음과 음성이 섞인 입력 음성으로부터 깨끗한 음성을 추정하는 기술을 말한다. 음성 향상 기술은 상당히 오랜 기간 동안 연구되어 온 기술이며, 최근에는 각 파라미터의 분포에 의존하는 방법보다 확률 모델에 기반한 방법이 각광을 받고 있으며 인간의 청각 특성을 고려한 음성 향상 방법도 제안되고 있다. 음성 강화 기술이란 수신단에서 주변 잡음에 따라 전송되어 온 음성을 주파수별로 증폭하여 더 잘 들리도록 만드는 기술이다. 음성 향상이 내 주위의 잡음이 상대방에게 들리는 음성에 미치는 영향 혹은 상대방 주변의 잡음이 나에게 들리는 소리에 미치는 영향을 줄여주는 기술이라면 음성 강화는 내 주위의 잡음이 나에게 들리는 음성에 미치는 영향을 상쇄해 주는 기술이다. 이 경우 주변 잡음은 어떤 전자 시스템도 거치지 않고 귀로 직접 들어오기 때문에 잡음 자체를 줄여 주는 것은 힘들고 전송되어 온 음성을 적절히 증폭 혹은 변형함으로써 귀에 들리는 음질 또는 명료성을 개선하게 된다. 이 논문에서는 통계 모델을 기반으로 한 음성 향상 기법과 인간의 청각 특성을 고려한 음성 향상 기법, 그리고 음성 강화 기법에 대해 설명한다.을 시도한 결과 안정적이고 반복 가능한 급성 심부전 모델을 얻을 수 있었다. bench scale실험결과와 같이 AOC는 배수관망에서의 박테리아 증식과 크게 상관관계를 갖고 있는 것으로 밝혀졌다.)', 'have a headache (2.10±0.79)', 'poor memory (2.09±0.83)', 'no appetite (1.99±0.85)', As for the correlation between iron parameter and clinical symptoms related to anemia, the hematocrit rate was negatively correlated with 'get a cold easily', 'pale face', 'feeling blue', 'difficult digestion' (p<0.05). The level of iron was negatively correlated with 'tired out easily', 'get a cold easily' (p<0.05) and TS (%) were negatively correlated with 'tired out easily (p<0.05)', 'get a cold easily (p<0.01). Our study resulted that the prevalence of a iron deficiency of a middle school girl is very high, therefore the guidelines for iron supplementation and nutritional education to improve their iron status should be provided.한 질소제거를 N-balance로부터

• Journal of Sensor Science and Technology
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• v.6 no.6
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• pp.466-475
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• 1997

In this paper, an implantable middle ear hearing aids using an electromagnetic transducer which consists of a tiny coil and a magnet is designed, and objective design method to implement a vibrator of the electromagnetic type transducer is proposed. Sound characteristic of the electromagnetic type vibrator is excellent but power transfer rate is lower than that of a ceramic type. To improve power transfer efficiency of system, external and inner part of a middle ear system is designed using FM transmission method. We implemented an experimental set of the designed transducer, inner part, and outer part. Then, we measured vibration characteristics of a metal strip and a temporal bone of a dead body. As the results, we confirmed the advantage of FM method and showed that designed transducer could effectively transmit vibration of amplified input sound pressure to ossicle.

• Journal of the Korea Society of Computer and Information
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• v.19 no.5
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• pp.37-42
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• 2014

The objective of this study is the frequency of the noise source 170 dB level of impulsive sound attenuation performance by earplugs to identify, to analyze the frequency characteristics of a shape and pattern. The attenuation performance of the impulsive noise by the frequency levels on the Combat Arm and 3M Form types 1100 Earplugs were evaluated. In order to check the sound attenuation performance of the B&K head and torso simulator and sound attenuation performance of the ear simulator data was verified. Previous studies have most impact, even in the noise source and the impulse noise level is 140 dB, but this study is higher than that of the impulsive noise source features. The results of the impulse noise attenuation effect is frequency-dependent mean 28.58 dB.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.3
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• pp.381-386
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• 2008

Virtual 3D audio methods that create 3D sound effects are researched highly for multimedia devices using 2 speakers or headphone. The most typical method to create 3D effects is a technology through use of head related transfer function (HRTF) which contains the information that sound arrives from a sound source to the ears of the listener. But it can decline some 3D effects by cone of confusion between front and back directions due to the non-individual HRTF depending on each listener. In this paper, we propose a new method to use psychoacoustic theory that creates realistic 3D audio. In order to improve 3D sound, we calculate the excitation energy of each symmetric HRTF and extract the ratio of energy of each bark range. Informal listening tests show that the proposed method improves the front-bach sound localization characteristics much better than the conventional methods.