• 제목/요약/키워드: frequency and correlation analysis

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바이올린용 소재의 진동모드 해석에 관한 연구 -제2보. 소재 연륜폭 및 절삭방향이 브릿지의 공진주파수에 미치는 영향 (Studies on the vibrational modal analysis of solid woods for the violin making II, Effect of annual ring width and cutting direction on the resonant frequency of the bridges)

  • 정우양
    • 한국가구학회지
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    • 제16권1호
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    • pp.17-23
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    • 2005
  • European maple is famous for the optimum solid wood for making bridge which is the most important part in violin acoustics. This study was carried out to investigate the variation of main features, i. e. annual ring width and cutting direction of costly imported violin bridge blanks and to examine the effect of these features of the blanks on the vibrational characteristics of bridge blanks. Imported violin bridge blanks had somewhat large variation in major macroscopical and physical properties and there was little relationship between annual ring density and weight of maple blanks. Resonant frequency of violin bridge blanks had some positive correlation with weight, however, damping having negative relationship with frequency was seldom affected by any physical properties of the maple blanks. Deviation from the radial cutting of tail side(ray direction from top toward feet on the edge of bridge blank) lowered the resonant frequency. Consequently, weight and ray direction should be taken for the critical quality decisive factors(QDF) of incoming bridge blanks by not only inspectors also luthiers who tune the bridge by shaping and are responsible for the final timbre quality of this complicate instrument.

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핵심자기평가(CSE)와 일-가족 지원, 직장만족 그리고 이직의도의 관계 연구 (A study on the Relationships of Core-Self Evaluation, Work-Family Facilitation, Job Satisfaction and Turnover Intention)

  • 최현정
    • 한국조리학회지
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    • 제17권4호
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    • pp.219-237
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    • 2011
  • 본 연구의 목적은 국내 외식업계의 비정규직 직원을 대상으로 핵심자기평가, 일-가족 지원, 직장만족 그리고 이직의도의 관계를 분석함으로써 직원의 이직을 줄이기 위한 방안을 모색하고 추후 이와 관련된 연구의 방향을 제시하는 것이다. 본 연구의 가설을 검증하기 위하여 AMOS 4.0과 SPSS 10.0 통계 프로그램을 이용하였으며, 분석 방법은 신뢰도분석(reliability analysis), 빈도분석(frequency analysis), 확인적 요인분석(confirmatory factor analysis), 상관관계 분석(correlation analysis) 그리고 공분산 구조분석(covariance structure analysis)을 실시하였다. 연구 결과, 핵심자기평가는 일-가족 방향 지원과 가족-일 방향 지원 모두에 긍정적인 영향이 있는 것으로 밝혀졌다. 일-가족 지원과 직장만족의 관계에 있어서는 가족-일 방향 지원만이 직장만족에 긍정적인 영향이 있는 것으로 나타났다. 마지막으로 직장만족은 직원의 이직을 줄이는 것에 효과가 있는 것으로 규명되었다.

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텍스트 마이닝을 활용한 캡스톤 디자인에 관한 학생 인식 탐색: 산업경영공학 사례 (A Text Mining Analysis on Students' Perceptions about Capstone Design: Case of Industrial & Management Engineering)

  • 위광호;김윤진;김문수
    • 공학교육연구
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    • 제25권5호
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    • pp.85-93
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    • 2022
  • Capstone Design, a project-based learning technique, is the most important curriculum that clarifying major knowledge and cultivating the ability to apply through the process of solving problems in the industrial field centered on the student project team. Accordingly, various and extensive studies are being conducted for the successful implementation of capstone design courses. Unlike previous studies, this study aimed to quantitatively analyze the opinions that recorded the experiences and feelings of students who performed capstone design, and used text mining methodologies such as frequency analysis, correlation analysis, topic modeling, and sentiment analysis. As a result of examining the overall opinions of the latter period through frequency analysis and correlation analysis, there was a difference between the languages used by the students in the opinions according to gender and project results. Through topic modeling analysis, 'topic selection' and 'the relationship between team members' showed an increase in occupancy or high occupancy, and topics such as 'presentation', 'leadership', and 'feeling what they felt' showed a tendency to decreasing occupancy. Lastly, sentiment analysis has found that female students showed more neutral emotions than male students, and the passed group showed more negative emotions than the non-passed group and less neutral emotions. Based on these findings, students' practical recognition of the curriculum was considered and implications for the improvement of capstone design were presented.

이용자 행태 분석을 통한 병동부 체류 공간에 관한 건축계획 연구 - 근로복지공단병원 병동부 공용공간을 중심으로 (A Study on the Architectural Planning for Space for Stay in the Ward Based on the Analysis of User Behavior - Chronic Patient Ward in Korea Workers' Compensation Hospital)

  • 손지혜;양내원
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제22권3호
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    • pp.35-44
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    • 2016
  • Purpose: This study is focus on investigation of user's spontaneous behavior in the public space of ward where chronic patients are hospitalized. Methods: The notion and necessity of social healing environment is analyzed by literature review. User's location and behaviour are investigated for analyzing behavior by visiting the six wards. Results: The result 1) Stay is main behavior of users. 2) The frequency of stay is high in the place where are planned as the dayroom, the program room and the balcony. 3) In the corridor, the users are staying around court and single side corridor. And the users who are staying in the ward planned middle corridor and double corridor are spreaded all over the corridor. As the result of the analysis of correlation between frequency of user for stay and area of public space, 4) The area of the dayroom, the program room and the balcony is bigger, the frequency of users are higher. 5) There is no correlation between area of corridor and frequency of users. 6) When the density of user is highest in the place for stay, one person occupied $1.96m^2$. Implications: Hereafter the public space, which social healing environment is considered, is planned, this study could suggest the directions of architectural planning about area.

중간관리자와 조리사에 대한 만족도의 관련성에 관한 연구 (A Study on the Management Satisfaction to Cook)

  • 진양호;김숙희
    • 한국조리학회지
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    • 제3권
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    • pp.83-122
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    • 1997
  • The purpose of this study is to inquire management satisfaction factors of cook, and to grope for the correlation of career, number of cook, income, and education. To attain the purpose of this study, questionnaire was developed through pilot test. Questionnaire scale was adopted 5 point. The SPSS package was utilized for the analyses of questionnaire. The method was Frequency analysis and Chi Square analysis. The results obtained from the above data-based analysis are concentrated on management satisfaction to cook, and management recruiting method.

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한국 노인의 본인인지 구강건강상태와 치주질환 관련성 (A study on the correlation between self-perceived oral health status and periodontal diseases in elderly Koreans)

  • 정은서;이경희
    • 한국치위생학회지
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    • 제17권6호
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    • pp.1135-1145
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    • 2017
  • Objectives: The objective of the study was to review the correlation between self-perceived oral health status and periodontal diseases in elderly Koreans, using data from the $6^{th}$ (2nd year) Korea National Health and Nutrition Examination Survey (2014). Methods: The subjects for this study were a total of 1,454 elderly people aged 65 years or older who responded to the health questionnaires of the $6^{th}$ (2nd year) Korea National Health and Nutrition Examination Survey conducted in 2014. Their general characteristics were analyzed using frequency analysis, while a cross-tabulation analysis (${\chi}^2-test$) was performed to understand the correlation with periodontal diseases. To clarify any effect of self-perceived oral health status on periodontal diseases, the selected variables were controlled and subsequently analyzed according to the logistic regression analysis. Results: In terms of the difference between elderly people with periodontal disease and those without periodontal disease, higher prevalence rates of periodontal diseases were found in women, those of younger age, those with lower educational and income levels, those with poorer subjective oral health status, those in the presence of chewing discomfort, those who had a toothbrushing frequency of twice per day, and/or those who had received no oral examination over the previous one year. Regarding the effect of self-perceived oral health status on periodontal diseases, 1.78-fold and 1.74-fold higher prevalence rates of periodontal diseases were shown with poorer subjective oral health status and in the presence of chewing discomfort, respectively. Conclusions: Based upon the results above, it is considered that a better understanding of self-perceived oral health status is necessary for a healthy life of the elderly. Furthermore, constant relevant studies and effective prevention programs intended to moderate the progress of or prevent periodontal diseases in the elderly in communities should be performed and implemented for the sake of better quality of life and oral health.

다주파수 생체임피던스 저항을 이용한 당뇨병 환자의 허증 변증 예측 (Prediction of Deficiency Pattern in Diabetic Patients Using Multi-frequency Bioimpedance Resistance)

  • 김가혜;김슬기;차지윤;유호룡;김재욱
    • 동의생리병리학회지
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    • 제36권3호
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    • pp.94-99
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    • 2022
  • The discovery of biomarkers related to pattern identification (PI), the core diagnostic theory of Korean medicine (KM), is one of the methods that can provide objective and reliable evidence by applying PI to clinical practice. In this study, 40 diabetic patients and 41 healthy control subjects recruited from the Korean medicine clinic were examined to determine the human electrical response related to the deficiency pattern, a representative pattern of diabetes. Qi-Blood-Yin-Yang deficiency pattern scores, which are representative deficiency patterns for diabetes mellitus, were obtained through a questionnaire with verified reliability and validity, and the human electrical response was measured non-invasively using a bioimpedance meter. In ANCOVA analysis using gender as a covariate, the 5 kHz frequency resistance and 5-250 kHz frequency reactance were significantly lower in the diabetic group than in non-diabetic control group. In addition, the multiple regression analysis showed a positive correlation (R2=0.11~0.19) between the Yang deficiency pattern score and resistance value for the diabetic group; the correlation was higher at higher frequencies of 50kHz (R2=0.18) and 250kHz (R2=0.19) compared to 5kHz(R2=0.11). In contrast, there was no such significant association in the control group. It implies that bioimpedance resistance measured at finite frequencies may be useful in predicting Yang deficiency, which is closely related to diabetic complications by reflecting the decrease in body water content and metabolism. In the future, large-scale planned clinical studies will be needed to identify biomarkers associated with different types of PI in diabetes.

Wavelet-based automatic identification method of axle distribution information

  • Wang, Ning-Bo;Ren, Wei-Xin;Chen, Zhi-Wei
    • Structural Engineering and Mechanics
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    • 제63권6호
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    • pp.761-769
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    • 2017
  • Accurately extracting the axle distribution information of a passing vehicle from bridge dynamic responses experiences a key and challenging step in non-pavement bridge weigh-in-motion (BWIM). In this article, the wavelet transformation is adopted and the wavelet coefficient curve is used as a substitute for dynamic response. The driving frequency is introduced and expanded to multi-axle vehicle, and the wavelet coefficient curve on specific scale corresponding to the driving frequency is confirmed to contain obvious axle information. On this basis, an automatic method for axle distribution information identification is proposed. The specific wavelet scale can be obtained through iterative computing, and the false peaks due to bridge vibration can be eliminated through cross-correlation analysis of the wavelet coefficients of two measure points. The integrand function that corresponds to the maximum value of the cross-correlation function is used to identify the peaks caused by axles. A numerical application of the proposed axle information identification method is carried out. Numerical results demonstrate that this method acquires precise axle information from the responses of an axle-insensitive structure (e.g., girder) and decreases the requirement of sensitivity structure of BWIM. Finally, an experimental study on a full-scale simply supported bridge is also conducted to verify the effectiveness of this method.

물류센터 작업질환과 직무만족간 상관성 조사 및 개선방안 (Survey of the correlation between work injuries and job satisfaction in Logistics Center and ways to improve work satisfaction)

  • 김기홍;신승준;안계인;남승돈;강경식
    • 대한안전경영과학회지
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    • 제13권4호
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    • pp.25-33
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    • 2011
  • Workers in logistics centers also are exposed to serious musculoskeletal disorders the same as workers in general manufacturing due to operating forklifts and other labor duties. The frequency of these work related injuries decreases, workers' job satisfaction In addition, it causes many employees questioning a job change, which is regarded as the primary factor which drops the productivity. In this paper, we conducted a survey ti perceive the correlation between work related injuries in the fields of distribution centers and job satisfaction. Furthermore we made statistical analysis with our findings. The results of our analysis showed that the frequency of work related injuries due to workers' repetitive loading and unloading work is the primary factor which lowers job satisfaction. In order to improve aforementioned problem we propose first of all loading and unloading on pallet basis, second of all automation and computerization of logistics systems, and third of all ensurinf sufficient break time.

4채널 환경에서 독립벡터분석 및 주파수대역 빔형성 알고리즘에 의한 혼합잡음제거 (Mixed Noise Cancellation by Independent Vector Analysis and Frequency Band Beamforming Algorithm in 4-channel Environments)

  • 최재승
    • 한국전자통신학회논문지
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    • 제14권5호
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    • pp.811-816
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    • 2019
  • 본 논문에서는 잡음이 포함된 4채널의 음원신호를 주파수 대역의 독립벡터분석 알고리즘에 의하여 깨끗한 음성신호와 혼합잡음신호를 분리하는 기법을 먼저 제안한다. 제안한 독립벡터분석 알고리즘에 의하여 분리된 음원신호를 주파수대역 지연합 빔형성기로부터 출력되는 신호와 독립벡터분석으로부터 분리된 출력신호 간의 상호 상관성을 이용하여 향상된 출력음성신호를 구한다. 본 실험에서는 백색잡음이 포함된 0dB, -5dB의 SNR의 입력 혼합잡음음성에 대하여, 본 논문에서 제안하고 있는 알고리즘이 주파수대역 지연합 빔형성기 알고리즘만을 사용하였을 때 보다 최대 10.90dB의 SNR 및 10.02dB의 Segmental SNR이 개선되었음을 확인하였다. 따라서 본 논문의 알고리즘 기법이 주파수대역 지연합 빔형성기와 비교하여 음성품질이 향상된 것을 실험 및 고찰을 통하여 확인할 수 있었다.