• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.187-191
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• 2001

Sound quality engineering in automobile noise applications has become more and more important under the current quiet driving condition that the interior noise level is below 65 dBA, because various noise components masked under high noise level can be audible in quieter driving situation. Many researches have been carried out for subjective and objective assessments on automobile sounds and noises. In particular, the interior sound quality has been one of research fields that can give high-quality feature to automobile products. Although many works related to the interior sound quality have been progressed or completed in foreign countries, limited research results are presented in the country. In the study, as a base step necessary to objective assessments on car interior noises, subjective assessments are performed with 20 subjects. For this purpose, perceptual adjectives suitable to the assessment of acceleration noises are selected as assessment scales through questionnaire procedures using 35 subjects. Mean values and standard deviations are calculated for noises created through digital filtering of acceleration noises measured. In addition, the correlation analysis and the factor analysis are carried out to investigate the dependence of the assessment scales selected.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.420-426
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• 2018

데니스 게이버(Dennis Gabor)의 음향 양자(Acoustic Quanta) 이론은 음향 합성법의 하나인 그래뉼러 합성법(Granular Synthesis)의 이론적 토대가 되어 많은 컴퓨터 음악 작곡가들과 사운드 디자이너들에게 영감을 주었다. 음향 양자는 1에서 100 ms의 지속시간을 가진, 시간적으로 더 이상 짧게 분해될 수 없는 소리를 뜻한다. 그래뉼러 합성법은 원음을 매우 짧은 시간 간격으로 분할하여 소리 입자들(Sound Grain)로 만든 다음, 이 소리 입자들을 조합하여 새로운 음악 또는 음색을 구현하는 방법이다. 음향 양자 개념은 그래뉼러 합성법의 소재가 되는 소리 입자의 이론적 근거가 되었다. 기존 음향 합성법과는 전혀 다른 음색의 사운드를 만들어 낼 수 있는 그래뉼러 합성법은 사운드 디자인 분야에서 다양한 용도로 사용 가능하다. 본 논문에서는 게이버의 음향 양자 개념을 소개하고 이를 그래뉼러 합성법에 적용하여 활용 가능한 사운드 디자인 방법, 특히 동기식(Synchronous) 그래뉼러 방식에 의한 신디사이저(Synthesizer) 제작 가능성과 그 응용에 대하여 논하였다. 연구결과 가청주파수를 감안한 음향 양자의 지속시간은 0.239에서 33.367 ms 사이가 되어야하기 때문에 음향 양자의 본래 개념과는 차이가 있었다.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.241-255
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• 2021

The human auricle is the first part to receive sound from the outside. In this part, the frequency range of human recognizable form is divided and organized. In this study, we propose modeling by applying a single sound source to the surface of the human auricle. This means that when the sound pressure of a low frequency (low frequency) sound enters the pinna, the impedance felt at the tip of a part of the non-linear surface of the pinna is mainly due to the tensile force at the end of the part of the non-linear surface of the pinna. By expressing the situation of moving at a very small speed, the characteristic impedance of the pinna was confirmed to be negative infinity, and it was also confirmed that the speed at the tip of a part of the non-linear surface of the pinna was 0 in the anti-resonance state. It was found that the wave propagation phenomenon that determines the characteristics of the filter is determined by how large the wavelength, kL, is compared to the length of the tip of a part of the non-straight surface of the pinna. Humans first receive sounds from outside through their ears. The auricle is non-linear and has a curved shape, and it is known that it analyzes frequencies while receiving external sounds. The human ear has an audible frequency range of 20Hz - 20,000Hz. Through the study, we applied the characteristics of the notch filter to hypothesize that the human audible frequency range is separated from the auricle, and applied filter theory to analyze it, and as a result, meaningful results were obtained. The curved part and the inner part of the auricle function as a trumpet, collecting sounds, and at the same time amplifying the weak sound of a specific band. The point was found and the shape of the envelope detected in the auricle was found. Selectivity for selecting sounds coming from the outside is the formula of the pinna that implements the function of Q. The function of distinguishing human-recognizable sound from the pinna from low to high through frequency analysis is performed in the pinna, and the 2-3kHz area, where human hearing threshold is the most sensitive, is also the acoustic impedance of the most recessed area of the pinna. It can be seen that starting from.

• 수산해양기술연구
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• 제33권4호
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• pp.285-289
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• 1997

제주도 연안에 분포되어 있는 정치망에 어획되는 어류의 음향 유집 효과에 대한 기초자료를 제공할 목적으로, 정치망의 주요 어획 대상 어종인 잿방어의 식이음, 유영음, 어선의 기관소음, 정현파 순음 등을 녹음시켜, 제작한 수중확성기로잿방어를 사육하는 가두리 양식장에 방성하였을 때, 각 음에 대한 어류을 행동 반응을 조사.분석한 결과는 다음과 같다. 1. 제작된 수중확성기의 수중 실험에서는 측정 주파수의 모든 주파수에서 입력파형과 출력파형이 잘 일치하여 주파수 200.600Hz의 수중음을 방성할 수 있었다. 2. 순음 주파수 300Hz및 400Hz를 방성하였을 때 보다 훨씬 민감한 반을을 보였다. 4. 잿방어 어군의 식이음, 유영음 스펙트럼은 주간과 야간에 관계없이 비슷한 음압분포를 나타내었고, 주파수 200~600Hz부근에서 낮은 음압 분포를 나타내었다.

• 만화애니메이션 연구
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• 통권36호
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• pp.469-491
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• 2014

웹툰은 출판만화에서 사운드를 시각적으로 표현했던 방법을 발전시켜왔으며, 웹 기술의 발전을 토대로 직접 소리를 들려주기까지 한다. 직접 들리는 소리는 당연히 사운드 분석의 대상이 된다. 그러나 들리지 않는 사운드도 분석 대상이 될 수 있다. 본 연구는 들리지 않는 소리를 분석할 수 있다는 것의 이론적 토대를 인지심리학의 이중부호 개념에 둔다. 작가는 자신의 청각적 기억을 시각적으로 기호화할 수 있고, 독자는 기억과 인출의 과정을 통해 시각화된 기호를 보고 사운드를 떠올릴 수 있다. 이와 같은 웹툰의 들리지는 않지만 떠올릴 수 있는 사운드와 직접 들리는 사운드 두 경우를 본 연구는 함께 분석대상으로 한다. 구체적 분석을 위해서는 이론적 성과물이 있는 영화 사운드 분석 방법을 활용할 수 있다. 소리를 구성하는 세 요소인 음량, 음조, 음색은 음향학에서는 주파수 등으로 설명되고 직접 들을 때는 느낌으로 알지만, 시각적으로는 사운드를 표현한 글자나 이미지의 선의 굵기와 위치, 음원의 이미지 등으로 알 수 있다. 내화면 사운드와 외화면 사운드의 시각적 표현은 만화의 칸과 관련이 있다. 일반적으로는 칸 외부로 외화면 사운드를 표현하지만 웹툰에서는 듣는 자를 강조하는 방법으로 칸 내부에 외화면 소리를 표현하기도 한다. 그리고 영화의 호러 장르가 장르 효과를 높이기 위해 사운드를 많이 사용하는데 웹툰에서도 호러 장르가 같은 효과를 위해 사운드를 많이 사용한다. 이러한 영화 사운드 분석 방법을 활용해 사운드를 이미지로 표현한 작품들을 분석해볼 때, 초창기 출판만화에서부터 시작한 사운드의 청각적 표현들이 계속 발전해서 웹툰에서 창의적으로 표현되고 있음을 알 수 있다. 특히 세로 이동을 활용한 칸의 배치 및 소리표현의 방식들은 웹툰이 보여준 새로운 방법들이며, 칸 모양도 훨씬 다양해졌다. 직접 들려주는 소리로는 BGM이 가장 먼저 사용되었는데 최근에는 한 회의 분위기에 맞춰 음향효과까지 섞어 맞춤 작곡된 곡들이 사용된다. 그리고 스크롤 이동에 맞춰 소리를 들려주는 프로그램이 개발되면서 특정 순간의 음향효과나 특정 장면에 어울리는 음악들을 들을 수 있게 되었다. 특히 호러 장르에서는 특정한 이미지와 공포를 불러일으키는 사운드를 같이 사용하여 장르적 효과를 배가시킨다. 이렇게 웹툰에서는 다양한 사운드 시각화 방법이 계속 창조되고 있으며 기술과 접목된 새로운 시도들이 이루어지고 있다. 이러한 발전은 웹툰이 하나의 문화콘텐츠로서의 융합의 장이 될 수 있음을 보여준다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.465-472
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• 2001

This paper describes the characteristics of wind induced noise from high-voltage overhead transmission facilities which include transmission lines. insulator strings. and aviation beacon spheres installed on the overhead ground wires. High-voltage overhead transmission lines generate an audible wind noise due to the alternate shedding of wind-induced vortices. The frequency spectrum from the insulator strings reveals its resonance peak. This resonance sound mechanism has been supposed the self-excitation phenomenon of the resonance and the velocity fluctuation. The booming noises from the aviation beacon spheres are detected and analysed.

• 한국소음진동공학회논문집
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• 제21권3호
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• pp.212-219
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• 2011

In this paper, intrusion detection technique based on the sound field variation of audio frequency in the security space is proposed. The sound field formed by sound source can be detected with the microphone when the obstacle or intruder is positioned. The sound field variation due to the intruder is mainly caused by the interference of audio wave. With the help of numerical simulation of sound field formations, the increase or decrease of sound pressure level is analyzed not only by the obstacle, but also by the intruder. Even the microphone is positioned behind the source, sound pressure level can be increased or decreased due to the interference of sound wave. Frequency response test is performed with Gaussian white noise signal to get the whole frequency response from 0 to half of sampling frequency. There are three security cases. Case 1 is the situation of empty space with and without intruder, case 2 is the situation of blocking obstacle with and without intruder, and case 3 is the situation of side blocking obstacle with and without intruder. At each case, the frequency response is obtained first at the security space without intruder, and second with intruder. From the experiment, intruder size of diameter of 50 cm pillar can be successfully detected with the proposed technique. Moreover, the case 2 and case 3 bring about bigger sound field variation. It means that the proposed technique have the potential of more credible security guarantee in real situation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.187-192
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• 2010

In this paper, intrusion detection technique based on the sound field variation of audio frequency in the security space is proposed. The sound field formed by sound source can be detected with the microphone when the obstacle or intruder is positioned. The sound field variation due to the intruder is based on the interference of audio wave. With the help of numerical simulation of sound field formations, the increase or decrease of sound pressure level is analyzed not only the obstacle, but also the intruder. Even the microphone is positioned behind the source, sound pressure level can be increase or decrease due to the interference. Frequency response test is performed with Gaussian white noise signal to get the whole frequency response from 0 to half of sampling frequency. There are three security cases. Case 1 is the situation of empty space with and without intruder, case 2 is the situation of blocking obstacle with and without intruder, and case 3 is the situation of side blocking obstacle with and without intruder. At each case, the frequency response is obtained first at the security space without intruder, and second with intruder. From the experiment, intruder size of $50cm{\times}50cm$ can be successfully detected with the proposed technique. Moreover, the case 2 or case 3 bring about bigger sound field variation. It means that the proposed technique have the potential of more credible security sensing in real situation.

• Journal of Chest Surgery
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• 제11권1호
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• pp.92-96
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• 1978

Congenital diaphragmatic eventration is a rare disease and generally accepted as an abnormally high position of part or all of the diaphragm, usually associated with a marked decrease in muscle fibers and a membranous appearance of the abnormal area. There were 4 cases of the congenital diaphragmatic eventration at the Dept. of Thoracic Surgery, Seoul National University Hospital, from 1957 to 1977. They were two boys and two girls and ranging from 1 day to 3 years of age. They were all repaired by surgical operation and one was expired postoperatively, another one was dead one year later due to complication. The ratio between right and left was 1:3 and their symptoms were cyanosis, dyspnea and frequent respiratory disease. In physical examination there was noted decreased breathing sound on the affected lung field and bowel sound was audible in some cases. Diagnosis was done by Chest X-ray and plication of the affected diaphragm was usually done in operation. There were noted atelectasis and cystic change of the affected side lung. And the liver, colon, spleen and small intestine were found in the dome of the eventrated diaphragm.

• 한국CDE학회논문집
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• 제14권2호
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• pp.87-95
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• 2009

This paper describes the design of the ossicular replacement prosthesis for the people who have problem of hearing because of middle ear disease. Also the simulation results of the designed product for verification by finite element analysis software (ABAQUS) are presented. New model is applied to middle ear FE analysis which was generated in previous study. The full replacements of ossicular prosthesis for ossicles (malleus, incus and stapes) are made of Hydroxyapatite and Titanium. Although other existing prosthesis models consider only sound amplification effect, current type has damper system which is operating on the audible frequencies. High frequency sound transmitted to inner ear can be reduced and the prosthesis and inner ear can be prevented from damage.