차량 내 음향 장치의 음압수준 변화에 따른 사용자의 주관적인 지각 차이에 대한 연구

권상현(Sanghyun Kwon),반상우(Sangwoo Bahn),김제용(Jeyong Kim),강신규(Shinkyu Kang),윤명환(Myung Hwan Yun) 대한인간공학회 2010 대한인간공학회 학술대회논문집 Vol.2010 No.10

When people hear sounds through sound system, perceptive loudness of each sound pressure level varies with each level. This difference causes some confusion in adjusting volume level and designing the volume level of sound systems. According to previous studies, it is known that perceptive sensitivity of variation in sound pressure level depends on the sound pressure level and frequency of sound source. However, quantitative analysis on user’s perceptive sensitivity of sound level which they actually perceive from the change of sound pressure level has not been studied yet. This study aims to understand the perceptive sensitivity of variation in sound pressure level for some specific frequency bands. To this end, 118 sound samples (frequencies: 500 ㎐, 1 ㎑, 2 ㎑, sound pressure levels: from 40㏈ SPL to 100㏈ SPL) were evaluated by 27 participants (male: 17, female: 10) in the condition of driving automobile. Based on the results of subjective ratings of unit change of sound pressure level and 2㏈ SPL, the characteristics of perceptive sensitivity of variation in sound pressure level were identified. Also, through curve fitting analysis of the subjective rating results, perceptive sensitivity curves of each frequency were estimated. According to the results, when frequency is high, the perceptive sensitivity tends to be more sensitive than the case of low frequency and the sensitivity curve was estimated to have cubic relation. These results could be used to adjust the volume level of sound system in automobile to meet customer’s perceptive characteristics and needs.

어린이집 자유놀이시간에 발생하는 교실 내 소음 실태

이영애 한국열린교육학회 2020 열린교육연구 Vol.28 No.1

The present study aimed to investigate the levels of noise during free-play time in nursery schools. The researchers measured the noise levels of 10 classrooms in three nursery schools from November 29 to December 18, 2018. We measured the noise levels with an Integrated Sound Level Meter (TES53S). Considering play centers, classroom size, and children’s pathways, we settled on three places for the measurements and recorded the noise level at each spot three times every 5 minutes for 45 minutes in total. We assessed the average level of noise, maximum level, and minimum standards. The observer observed children's play and recorded field notes as well. The results indicated that the noise levels were high. The overall average sound levels were 73.7~83.1 dB(A)(A), and the value was above the standard for school noise level allowances. The government should support policies that look at environmental and acoustic factors in nursery schools and, where required, should reduce noise levels. Children should not be at risk for hearing loss during play time and neither should school staff and teachers. 본 연구는 어린이집 자유놀이시간 교실 내 전반적인 소음 수준을 살펴보기 위하여 자유놀이시간에 발생하는 교실 자체 내 소음 수준을 지점별로 측정하였다. 어린이집 교실 내 소음 측정은 Integrated Sound Level Meter(TES53S)를 사용하여 어린이집을 직접 방문하여 측정하는 현장측정 방법으로 실시하였다. 어린이집에 등원한 원아들이 일과 활동을 하고 있는 교실을 측정공간으로 하여 각 교실의 크기와 형태, 흥미영역의 구성, 원아들의 이동 경로를 고려하여 세 군데의 중간지점을 설정하고 45분 동안 각 지점별로 5분 간격이 되도록 세 지점을 돌아가며 3회씩 차례대로 등가소음레벨을 측정하였다. 소음측정과 동시에 교실 내 영상 촬영을 통해 소음측정 당시 흥미영역별 유아의 인원수, 놀이 형태 등을 관찰 기록하였다. 각 교실별 등가소음레벨과 최고소음, 최소소음을 살펴본 결과, 교실 내 소음 수준은 전반적으로 상당히 높은 수준임을 알 수 있었다. 전체적인 등가소음레벨의 평균값은 73.7~83.1dB(A)이었는데, 학교소음 허용치인 50dB(A)을 모두 넘는 수준이었다. 소음 수준의 지점별 차이는 없었다. 유아들이 마음껏 몰입하고 놀이할 수 있는 환경과 시간이 확보되어야 함과 동시에 교사와 유아의 건강을 보호하기 위한 교실 내 환경적 소음저감 대책 또한 시급히 논의되어야 할 것이다.

초등학생의 연음규칙 인식수준 비교

이은선,석동일,Lee, Eun-Seon,Seok, Dong-Il 한국음성학회 2005 음성과학 Vol.12 No.2

The purpose of this study was to examine the awareness level of the prolonged sound rules in elementary school students. The participants in this study were 148 elementary school students in grades 1 through 6. Their awareness level of the prolonged sound rules was evaluated on reading tasks composed of 40 words and sentences. An one-way ANOVA followed by Scheffe hoc tests showed the showed the statistically significant difference between the groups for the awareness level of prolonged sound rules. The younger the children, the larger differences in the awareness of prolonged sound rules. The awareness might affect their cognitive development and a systematic instruction may be helpful especially in lower graders. In conclusion, the findings of this study showed significant differences in the awareness level of the prolonged sound rules at both words and sentences level. It was also found that as the age of children increases, the awareness level of the prolonged sound rules tends to increase which appeared to be completed by the 3rd grade.

한국 IT 기업의 주가 수준과 재무적 건전도 그리고 투자성향 간의 연계성 분석

박정미 조선대학교 지식경영연구원 2023 기업과 혁신연구 Vol.46 No.1

This study aims to provide implications by analyzing the effects of the stock price and financial soundness of Korean IT companies, and the interaction between stock prices and financial soundness, on the investment propensity of IT companies. For the purpose of this study, we conduct difference analysis (t-test) and OLS regression analysis using 5,358 company-year data among IT companies listed on the Korea Exchange from 2011 to 2020 as a sample for this study. As a result of the analysis, first, there is a negative (-) relationship between the stock price level and investment propensity of IT companies. This indicates that the stock price level of IT companies is directly related to the company's investment propensity. Second, there is a positive (+) relationship between the financial soundness of IT companies and their propensity to invest. This means that IT companies relatively overinvest when their financial soundness is better. Third, when stock prices are undervalued, IT companies seem to overinvest when financial constraints are high. When stock prices are overvalued, IT companies under-invest when their financial soundness is high. Therefore, it seems that IT companies make different investment decisions depending on their stock level and financial soundness. The contributions of this study to related research fields are as follows. First, unlike previous studies, this study empirically analyzes and provides evidence that the stock price level and financial soundness of IT companies, and the interaction between the stock price level and financial soundness, are related to IT companies' investment propensity. Second, the financial soundness and stock price level of IT companies, and the interaction between their financial soundness and stock price level, are also analyzed by empirical analysis on the investment propensity of IT companies by dividing them by stock price level, and presenting the results. It provides important implications to stakeholders involved in their investment decisions. 본 연구는 한국 IT 기업의 주가와 재무 건전도, 그리고 이들의 상호작용이 IT 기업의 투자성향에 미치는 영향을 분석하여 그 시사점을 제공하려고 한다. 본 연구의 목적을 위하여 한국거래소에 2011년부터 2020년까지 상장된 IT 기업 중 5,358개의 기업-연도 자료를 본 연구의 표본으로 하여 차이분석 및 OLS 회귀분석을 진행한다. 분석 결과, 첫째, IT 기업의 주가 수준과 투자성향 사이에는 음(-)의 관련성이 있다. 이는 IT 기업의 주가 수준이 기업의 투자성향에 직접적으로 관련이 있음을 의미한다. 둘째, IT 기업의 재무적 건전도와 기업의 투자성향 사이에는 양(+)의 관련성이 있다. 이는 재무적 건전도가 좋을수록 상대적으로 과잉투자를 한다는 것을 의미한다. 셋째, IT기업의 주가 수준과 재무적 건전도의 상호작용과 IT 기업의 투자성향 사이의 관계는 주가 수준이 저평가된 경우에는 재무적 건전도가 높을수록 과잉투자성향을 가지고 있는 것으로 나타났으며, 주가 수준이 과대평가된 경우에는 재무적 건전도가 높을수록 과소투자성향을 나타내고 있어서 기업의 주식 수준과 재무적 건전도의 상황에 따라 IT 기업들의 투자성향이 다른 것으로 보인다. 본 연구는 관련 연구 분야에 기여도는 다음과 같다. 첫째 선행연구들과는 달리 주가 수준과 재무적 건전도, 그리고 이들의 상호작용이 기업의 투자성향과 관계가 있다는 것을 실증분석을 통해 그 결과들을 제공함으로써 선행연구들과 차별화한다. 둘째, 주가 수준별 재무적 건전도에 따른 투자성향 간의 관련성에 대해서도 실증 분석하여 그 결과들을 제시함으로써 IT 기업의 투자의사결정에 관련된 이해관계자들에게 중요한 시사점을 제공한다.

경보음 종류에 따른 유발행동 유형에 관한 연구

오소영,함승희,이준 한국도로학회 2024 한국도로학회논문집 Vol.26 No.2

PURPOSES : This study focuses on how quickly emergency alarm facilities recognize a fire, respond to evacuation behavior, and induce appropriate behavior in response to the fire alarm sound by listening to the fire alarm sound from a sound device. METHODS : Prior research on alarm sounds affecting evacuation behavior was identified, and a subjective evaluation of alarm sounds was conducted to study the most appropriate evacuation-inducing behavior for alarm sounds. In the event of a fire, a subjective evaluation of the sound pressure level and frequency analysis of the sound system, which affects the occupants in the building, were conducted to analyze the type of alarm sound and evacuation behavior. RESULTS : As a result of the subjective evaluation of the occupants’ listening risk, there was little cognitive response to the change in sound pressure level according to frequency. It was found that the alarm sound could give a sense of crisis or tension owing to the difference in sound pressure level change according to the change in time difference. CONCLUSIONS : In conclusion, with high sound pressure and large decibel deviation, the evacuation behavior of respondents after education was more active in the wake-up call that made a sound that seemed to be torn.

중국인 한국어 학습자의‘ㅊ’받침과 모음 조사 결합에 의한 발음 실현 연구

황현숙 충남대학교 인문과학연구소 2007 인문학연구 Vol.34 No.3

<Abstract> The Study for Realization of Pronunciation when a Final Consonant /ㅊ/ Meets with the Vowel Particles by Chinese Korean Learners Hwang, Hyeon―Sook This paper aims to analyse the realization of pronunciation that when ‘ㅊ’ as a final consonant meets with the particles as of ‘이, 에(서), 으로/을, 의, 아’ by Chinese Korean learners. Because Chinese Korean learners felt the difficulty when they pronounce the final sounds of Korean words as of ‘ㅊ, ㅌ, ㅋ, ㅍ’. Therefore, the realization of /ㅊ, ㅌ, ㅋ, ㅍ/ pronunciation when they, as a final sounds, meet with the vowel particles as of ‘이, 에(서), 으로/을, 의, 아’ should be analysed in order to facilitate to teach Korean to Chinese Korean learners in Korean education institute. For this research, only ‘ㅊ’ as a final consonant meeting with the particles as of ‘이, 에(서), 으로/을, 의, 아’ is the research objects because /ㅊ/ as a final sound is most difficult for foreigners to pronounce. 20 number of Chinese Korean learners with the level of Beginner and Advanced participated and then recorded their voice for more correct result of the realization of /ㅊ/ sound’s variation. As the result and the cause from this research are as followings. The first, /ㅊ/ as a final sound in Korean words has many dominant causes to be influenced from ‘unified words’ form’ as of ‘/ㅌ/ → /ㅅ/’ than /ㅌ/ sound in final. The second, /ㅊ/ as a final sound in Korean words are to be mostly prolonged sound when its sound meets with the started vowel particles as a major particle. The third, when /ㅊ/ as a final sound meets with the started vowel particles, the portion of advance level Korean learners to pronounce the standard pronunciation is greater than the one of beginners’. The forth, when /ㅊ/ as a final sound meets with the vocative particle ‘아’, it is more likely to be the prolonged sound as a standard pronunciation than with other vowel particles.

중공관 형태별 흡음 효과에 관한 실험적 연구

손철수 啓明大學校 産業技術硏究所 1999 産業技術硏究所 論文報告集 Vol.22 No.2

The purpose of this research is to investigate the performance characteristics of sound absorption at the form of voided circular tube. To do this research, the method for field measurement of floor impact sound level was used following the Korea Standard F2810-1996. Two kinds of voided circular form are used for this research. The results are as follows; 1. The main factor to effect the performance characteristics of sound absorption is sound-absorbing materials at the voided circular tube. 2. The main factor to effect the difference of Sound Pressure Level is the form of circular tube in the concrete slab. 3. The form of circular tubes effects the performance characteristics of sound absorption at the circular tube. More study will be needed about the depth and distance of sound absorption materials, and the characteristics of sound absorption materials.

방음벽에 미치는 바람의 영향에 관한 연구

여운호(Woon-Ho Yeo) 한국환경관리학회 2007 環境管理學會誌 Vol.13 No.4

방음벽에 미치는 바람의 영향을 연구하기 위해 인천국제공항고속도로 및 그 밖의 3개 고속도로에 대하여 조사하였다. 그리고 교통 소음도를 상동 풍림아파트 및 검암동 풍림아파트에서 측정하였다. 방음벽의 높이는 대부분 5m와 10m 사이였다. 상동 풍림아파트 1층과 최상층에서 측정한 교통소음도는 61.0㏈(A) 및 74.6㏈(A)였다. 검암 풍림아파트 1층과 최상층에서 측정한 교통소음도는 64.2㏈(A) 및 69.2㏈(A)였다. 최상층에서 측정한 소음도가 1층에서 측정한 소음도 보다 더 높았는데 그 이유는 방음벽의 높이가 충분히 높지 않기 때문이다. 그리고 최상층에서 측정한 소음도는 환경소음기준값을 초과하였다. 만일 방음벽 높이가 더 높아지면 방음벽은 바람의 영향을 받을 것으로 보이며, 풍압에 의해 붕괴 가능성도 있을 수 있다. In order to study on the effect of wind to sound barrier the Incheon International Airport Expressway and 3 expressways were researched. And traffic noise levels were measured at Sangdong Punglim APT and Geumam Punglim APT. The heights of sound barriers are between 5m and 10m. The traffic noise levels measured at the 1st floor and the highest floor of Sangdong Punglim APT were 61.0㏈(A) and 74.6㏈(A). And the traffic noise levels measured at the 1st floor and the highest floor of Geumam Punglim APT were 64.2㏈(A) and 69.2㏈(A). The noise levels measured at the highest floor were higher than those measured at the 1st floor because the height of sound barrier is low. And the noise levels measured at the highest floor were higher than Standard Environmental Noise Level. If the height of sound barrier is higher sound barrier is pressured by wind. And sound barrier can be broken by wind pressure.

음풍경 적용을 위한 도시천변에서의 연출음 도입 효과에 관한 실험적 연구

이태강(Lee, Tai-gang),송민정(Song, Min-Jeong),장길수(Jang, Gil-soo) 한국소음진동공학회 2005 한국소음진동공학회 논문집 Vol.15 No.8

It is very difficult to reduce ambient noise level in the downtown. The best method is to improve the sound amenity of the districts, considering concept of soundscape. This study aims to survey the effect of introducing sound and masking to reduce the background noise level. We carried out the evaluating test for 18 introducing sounds varied S/N ratio(-5, 0, +5) in the city riverside. In these test, subjects evaluated the sound environment with five bipolar adjective scales. It was evaluated that introducing sounds improved the sound environment, and that S/N +5 dB was very appropriate to mask the background noise. But the hearing level was suggested to be S/N 0 dB or less.

Assessment of traffic-induced low frequency sound radiated from a viaduct by field experiment

Kawatani, M.,Kim, C.W.,Nishitani, K. Techno-Press 2010 Interaction and multiscale mechanics Vol.3 No.4

This study is intended to assess low frequency sound radiated from a viaduct under normal traffic. The bridge comprises steel box girders and wide cantilever decks on which vehicles pass. The low frequency sound and the acceleration response of the bridge under normal traffic are measured to investigate how bridge vibrations affect the low frequency sound observed near the bridge. Observations demonstrate that strong relationships exist between frequency characteristic of bridge's acceleration response and the sound pressure level of low frequency sound. A noteworthy point is that the dynamic feature of the sound pressure level is mostly affected by dynamic feature of the span locating near the observation point.