• 제목/요약/키워드: Sound Quality Analysis

검색결과 333건 처리시간 0.031초

도?주부의 Life Style에 따른 승용차 정보탐색활동에 관한연구 (A Study on Automobile Information Search Activity According to Urban Housewives' Life Style)

  • 양남희
    • 가정과삶의질연구
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    • 제11권2호
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    • pp.13-29
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    • 1993
  • The Purpopse of this study are to classify the lifestyles of urban housewives with automobiles living in Gwangju to see their relationship between lifestyle and demographic social and econo-mic variables and to see the relationship between lifestyle and prepurchase information search activity. For these purpose a survey was conducted using questionaires on 410 The data was collected from March 8 to March 20 1993 and analyzed by factor analysis cluster analysis Duncan test {{{{ chi ^2 }} }}- t e s t a nd ANOVA. The findings are classified into 7 types: enjoyable convenience type (15.6%) conservative sound and thrifty type(17.3%) rationative type (13.2%) thrifty life type (11.0%) passive-inactive type(8.3%) fashion-pursuity type(12.9%) 2) The lifestyles of he respondents showed significant difference according to their age education level employment status. length marriage consumer education and type of housing. 3) The lifestyles of the respondents showed a difference only automobile attitude While showing no significant difference by automobile size information sources of automobile priority of automobile attitude and time spent in searching information The lifestyle of respondents showed a difference by automobile price size quality secuity warranty service and maintenance cost. 4) Among the lifestyle patterns of the respondents the passive-inactive type and rationative typ were positive about all the prepurchase information activity of automobile.

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차량 필러부품 프레스 금형설계를 위한 금형보정이력 정보 데이터베이스 구축 (Construction of information database with tool compensation histories for the tool design of a pillar part)

  • 김세호
    • 한국산업정보학회논문지
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    • 제17권7호
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    • pp.43-50
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    • 2012
  • 본 논문에서는 차량용 센터필러 부품의 성형공정에서 발생하는 스프링백 문제를 해결하기 위한 일환으로 기존 부품의 금형보정이력 정보를 체계적으로 데이터베이스화하였다. 기존 부품의 경우 과도한 스프링백 발생에 의한 형상정밀도 불량을 해결하기 위하여 3차의 금형 보정을 현장기술자의 작업에 의하여 수행하였으나, 보정값이 정량화되어 있지 못한 문제가 있었다. 본 논문에서는 기존 금형 보정과정의 결과를 유한요소해석을 통하여 정량적으로 분석하고 보정이 의도대로 이루어졌는지를 평가하는 데이터베이스를 구축하였다. 구축된 데이터베이스 정보를 활용하여 유사부품의 금형설계에 활용하였으며, 결과적으로 보정횟수를 감소시키고도 제품을 성공적으로 성형할 수 있었다.

Sustainable Earnings and Its Forecast: The Case of Vietnam

  • DO, Nhung Hong;PHAM, Nha Van Tue;TRAN, Dung Manh;LE, Thuy Thu
    • The Journal of Asian Finance, Economics and Business
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    • 제7권3호
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    • pp.73-85
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    • 2020
  • The study aims to provide better understanding of sustainable earnings by a comprehensive analysis of earnings persistence of business firms in Vietnam as an example of developing economies in South-East Asia. Dataset of 1,278 publicly listed firms (excluding banking and financial services firms) on Vietnam Stock Exchange for the period from 2008 to 2017 was collected. By applying fixed effect regression model, the empirical results provided the basis to measure the persistence index (Pers index) and find low level of their earnings persistence. The literature of earnings quality analysis in developed countries suggests earnings persistence as a noteworthy determinant of future earnings forecast and stock valuation. However, research of sustainable earnings in developing countries is still highly underdeveloped. For Vietnamese listed firms, the average Pers index was estimated for the period from 2008 to 2010, indicating low level of earnings persistence. We also incorporated earnings persistence level into future earnings forecast by running the quintile regression model divided the data into four equal levels and conducted each section independently to see the difference in each percentile, thence assessed the factors' influence on the specific model. The findings provide important information on the expected returns of firms, especially helping investors make sound decisions.

환풍기용 외전형 단상 브러시리스 직류전동기 개발 (Development of Single-phase Brushless DC Motor with Outer Rotor for Ventilation Fan)

  • 박용운;정학균;조주희;소지영;정동화;김대경
    • 조명전기설비학회논문지
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    • 제27권8호
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    • pp.36-41
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    • 2013
  • This paper is development of single-phase brushless DC motor with outer rotor for ventilation fan. Cogging torque causes the noise vibration to greatest impact on ventilation fan. Asymmetric notches are applied to tapered-teeth for cogging torque reduction of single-phase brushless DC motor. Initial model is notchless and proposed model is applied 2 asymmetric notches. The proposed method is proved motor characteristic through finite element analysis(FEA). Also, experimental results verify that the proposed model considerably reduces cogging torque and have the good sound quality in ventilation system.

물 환경 건전화를 위한 도시하천의 물 순환 모의 (I) - 안양천 유역 - (Hydrologic Cycle Simulation of Urban river for Rehabilitation of Water Environment (I) - Anyangcheon Basin -)

  • 이정민;이상호;이길성
    • 한국물환경학회지
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    • 제22권2호
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    • pp.349-357
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    • 2006
  • Nowadays, the discharges of urban streams during dry season are depleted because the hydrologic cycle in the watershed has been destroyed due to the expansion of the impermeable area, the excessive groundwater pumping, climate change, and so forth. The streamflow depletion may bring out severe water quality problems. This research are to investigate the hydrologic characteristics and to develop a technology to restore sound hydrologic cycle of Anyangcheon watershed. For the hydrological cycle analysis of the Anyangcheon watershed, continuous simulations of urban runoff were performed for the upstream basin of Gocheok bridge whose basin area covered 4/5 of the whole catchment area. The increase of impervious area by urbanization was analysed and its effect on urban runoff was evaluated. The SWMM 5 (Storm Water Management Model 5) was used for the continuous simulation of urban runoff. The analysis results of urbanization effect on runoff are as follows: the surface runoff in 2000 increases to 65% of the whole precipitation whereas the surface runoff in 1975 amounts to 50% of the precipitation; the groundwater runoff in 2000 amounts to 7% and shows 6% decrease during the period from 1975 to 2000.

IT컨설팅 서비스 품질 측정에 대한 타당성 검증에 관한 연구 (The Validity of IT Consulting SERVQUAL Measurement Tool)

  • 서현석
    • Journal of Information Technology Applications and Management
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    • 제12권3호
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    • pp.111-128
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    • 2005
  • This paper examines the validity of the newly developed IT consulting SERVQUAL measurement tool. In an attempt to measure Ire IS customers' expectations and perceived quality of the services they received, the researchers developed a diagnostic tool of SERVQUAL based on the solid theoretical background, which can specifically be applied to the IT consulting service sector. This on-going research so far, has been applied to six (6) different organizations that have received IT consulting services over the past years. From the preliminary data collected, the correlation and the factor analyses were conducted to understand the underlying concept and refinement of the measurement tool. Although the correlation analysis showed a little tendency of collinearity among some of the variables, all showed sound relationship of the proposed hypotheses. The exploratory factor analytic approach was chosen because it does not set any priori constraints on the estimation of components or the number of components to be extracted. The number of different factor solutions was extracted and tested to see which solution represents better grouping of the variables. The Crombach's Alpha was computed on different combinations of the factor solutions to ensure validity. The results show 8-dimensional IT consulting SERVQUAL measures which they are, assurance, knowledge & skill, customer relationship, support, empathy, process management, expertise, and education, seem more appropriate than the originally proposed 6 dimensions. The study approach was non-experimental cross-sectional research design. The longitudinal design of follow-up studies to periodically revise and refine current measure is strongly recommended for fine tuning of the tool.

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진동 유동해석기법을 이용한 자동차 실내소음 저감 및 음질 개선 (A Study on Improvement of Sound Quality of Vehicle Using the Vibrational Power Flow)

  • 이상권
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.208-214
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    • 2000
  • Reduction of structure-borne noise of the compartment in a car is an important task in automotive engineering. Transfer path analysis using vibroacoustic reciprocity technique or multiple path decomposition method has generally been used for structure-borne noise path analysis. These methods are useful in solving particular problem but do not quantify the effectiveness of vibration isolation of each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow has been used for a simple isolation system or a laboratory based isolation system. It is often difficult to apply the vibrational power flow technique to the complex isolation system like a car. In this paper, a simple equation is derived for calculation of the vibrational power flow of an isolation system with multiple isolators such as a car. It is successfully applied to not only quantifying the relative contributions of eighteen isolators but also reducing structure-borne noise of a passenger car. According to the results, the main contributor of eighteen isolators is the rear roll mount of an engine. The reduced structure-borne noise level is about 5dBA.

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2019 개정 누리과정 놀이실행자료에 기초한 유아교사용 놀이지원 척도 개발 (A Development of the Preschool Teacher Play Support Scale Based on the Play Practice Resources for Teachers of the 2019 Revised Nuri Curriculum)

  • 성안나;김연하;이지선
    • 한국보육지원학회지
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    • 제18권2호
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    • pp.19-38
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    • 2022
  • Objective: The goal of this study is to develop an instrument for measuring the quality of teacher support for children's play (age 3-5) based on the Play Practice Resources for Teachers presented in the 2019 revised Nuri Curriculum. Methods: The subjects of this study were 333 early childhood educators. Exploratory and confirmatory factor analysis, as well as correlation analysis were all performed to confirm construct validity and concurrent validity. The reliability of each factor was verified using Cronbach's alpha. Results: The Preschool Teacher Play Support Scale (PTPSS) was finalized with 25 items, which included the following four sub-factors: interaction, play materials, play space, and play safety. The concurrent validity was also confirmed through significant correlations between the existing measures such as the Teacher Self-Efficacy Scale, the Teaching Efficacy Scale for Play, and the Teacher-Toddler Interaction Scale. The reliability of each factor was also desirable. Conclusion/Implications: The PTPSS was verified as a sound measure quantifying the play support behavior of teachers who respect the autonomy and initiative of young children which is being pursued by the 2019 revised Nuri Curriculum.

선형 탐촉자에서 관심 시각 영역 변화에 따른 화질 분석 (Image Quality Analysis According to the of a Linear Transducer)

  • 박지나;한재복;곽종길;송종남
    • 한국방사선학회논문지
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    • 제16권7호
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    • pp.975-984
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    • 2022
  • 선형 탐촉자는 탐촉자의 길이만큼의 관심 영역을 갖기 때문에 장비에 탑재된 virtual convex 기능을 사용하여 관심 영역을 확장 시킬 수 있다. 하지만 관심 시각 영역의 변화에 따라 초음파 음속 방향의 변화로 인해 화질에 영향을 미칠 것으로 생각되어 이를 객관적으로 확인하고자 하였다. 본 연구를 위해 초음파 정도 관리용 팬텀의 영상 평가와 SNR·CNR을 측정하였다. 그 결과 팬텀 영상 평가에서는 두 영상 모두 기능적 분해능, 회색조 및 동적 범위에서 모두 구조물 식별이 가능했다. 하지만 구조물의 크기와 형태 재현성에는 Standard 영상이 우수한 것을 확인할 수 있었다. SNR·CNR 평가결과, 특정 위치의 구조물을 제외하고는 대부분이 Trapezoidal 영상의 SNR·CNR이 낮았다. 또한, 통계 분석 그래프를 통해 낭성 구조물의 크기가 작아질수록 깊이별 SNR과 CNR이 감소하는 것을 추가로 확인할 수 있었다. 본 연구를 통해 기능사용이 넓은 관심 시각 영역을 제공하는 장점이 있으나 화질에 영향을 준다는 것을 확인할 수 있었으며 Virtual Convex 기능사용 시 검사자는 이를 적절한 상황에 사용하고 질 높은 영상 획득과 장비의 이해도와 숙련도 향상을 위해 다양한 연구를 해야 할 것으로 판단된다.

제7차 초등교육과정에서 지속가능한 발전을 위한 환경교육 실태 연구 (A Study on the Present Situation of Environmental Education for Sustainable Development in the 7th Curriculum Elementary School)

  • 박후서;이규섭;박정희;최석진;안종운
    • 한국환경교육학회지:환경교육
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    • 제20권1호
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    • pp.28-41
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    • 2007
  • Current environmental education at elementary school is demanded to be changed into 'Sustainable Development', Therefore, we should find a new program to reflect appropriateness and diversity of environmental education at elementary school for 'Sustainable Development'. The result of analysing textbooks and the realities in environmental education at elementary school is as follows, First, when we analysed the contents of the textbook in environmental education, the reflecting rate was high in 'natural environment' and 'sound consumption', compared with in 'artificial environment', 'resource and energy' and 'health and environment'. Second, we realized the necessity for 'environmental education' complementary to 'Sustainable Development'. That is because the analysis showed the lack for the activity for approaching and solving environmental problems with 'artificial environment', 'resource and energy' and 'health and environment'. Third, the analysis also showed the deficiency in the reflection of 'environmental education' contents for maintaining healthful environment through improving the quality of life. Current textbook didn't deal with very important elements of 'environmental education' - the Quality of indoor atmosphere, harmful matter, safe things to eat, noise, stench, etc. For those reasons, it is necessary to reconstruct the realm and the contents of 'environmental education' for 'Sustainable Development' appropriate to elementary school. We require a new curriculum and textbook to cover diverse' environmental education' as well.

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