• Title/Summary/Keyword: Frequency Contribution Analysis

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Prediction of Heavy-Weight Floor Impact Sound in Multi-unit House using Finite Element Analysis (유한요소해석을 이용한 공동주택의 중량충격음 예측)

  • Mun, Dae-Ho;Lee, Sang-Hyun;Hwang, Jae-Seung;Baek, Gil-Ok;Park, Hong-Gun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.6
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    • pp.645-657
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    • 2015
  • In this study floor impact noise and structure acceleration response of bare concrete slabs were predicted by using Finite Element Analysis(FEA). Prediction results were compared with experimental results to prove the accuracy of numerical model. Acoustic absorption were addressed by using panel impedance coefficients with frequency characteristics and structural modal damping of numerical model were applied by modal testing results and analysis of prediction and test results. By using frequency response function, the floor acceleration and acoustic pressure responses for various impact sources were calculated at the same time. In the FEA, the natural frequencies and the shapes of vibration and acoustic modes can be estimated through the eigen-value analysis, and it can be visually seen the vibration and sound pressure field and the contribution of major modes.

An Analysis on the Effect of Financial Stabilization Program in the Korean Health Insurance (醫療保險 財政共同事業의 效果分析)

  • 이현실;남길현
    • Health Policy and Management
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    • v.7 no.1
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    • pp.73-99
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    • 1997
  • This study was carried out by using questionnaires with 126 insurance societies from Sept. 30, 1995 to Oct. 18, 1995. The primary data collected bythe survey have been significantly supplemented by secondary data obtained from sources such as health insurance statistical year books and internal data in the Ministry of Health and Wolfare. Major findings were summarized as follows: Two financial coordinating programs have significantly improved financial status of regional health insurance societies: the catastrophic program for high cost medical care that was initiated in 1991 and the program for hospitalization cost of the aged in 1995. Another finding is that there existed ambiguity and inconsistency of equity index that had been used by stabilization programs and its side effects could not be ignored. Regression analyses were made to identify factors that affect financial transfers. Inde pendent variables in the regression include utilization frequency, dependancy ration, insurance contribution per insured and medical expense per insured. All these variables were statistically significant in the equations of applying distribution rate (distribution/contribution) and transfer rate (transfer/contribution) as dependent variables. Policy suggestions for the catastrophic program for high cost medical care are modifying the definition of catastrophic case and setting the maximum amount of subsidies for each society based on distribution rates. To solve the problems of the financial coordinating program for the aged, we could consider reimbursing more than 50% of the copayment incurred by the aged 65 or more and determining the maximum amount of outpatient copayment at 10,000 Won per day or per visit for the elderly. More fundamental improvement could be made by amending the Welfare Benefit Act to establish and expand medical and welfare facilities for the elderly.

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Study on the Acoustic Behaviour Pattern of Fish Shool and Species Identification 1. Shoal Behaviour pattern of anchovy (Engraulis japonicus) in Korean waters and Species Identification Test. (어군의 음향학적 형태 및 분포특성과 어종식별에 관한 연구 1.한국 연근해 멸치어군의 형태 및 분포특성과 종식별 실험)

  • 김장근
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.34 no.1
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    • pp.52-61
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    • 1998
  • We studied behaviour pattern of anchovy (Engraulis japonicus) shoal by a method of shoal echo integration and tested species identification by a method of artificial neural network using the acoustic data collected in the East China Sea in March 1994 and in the southern coastal waters of the East Sea of Korea in March 1995. Between areas, frequency distribution of 10 shoal descriptors was different, which showed characteristics of shoal behaviour in size, bathymetric position and acoustic strength. The range and mean of shoal size distribution in length and height was wider and bigger in the southern coastal waters of the East Sea than in the East China Sea. Relative shoal size of China Sea. Fractal dimension of shoal was almost same in both areas. Mean volume reverbration index of shoal was 3 dB higher in the southern coastal waters of the East Sea than in the East China Sea. The depth layer of shoal distribution was related to bottom depth in the southern coastal waters of the East Sea, while it was between near surface and central layer in the East China Sea. Principal component analysis of shoal descriptors showed the correlation between shoal size and acoustic strength which was higher in the southern coastal waters of the East Sea, than in the East China Sea. Correlation was also found among the bathymetric positions of shoal to some degree higher in the southern coastal waters of the East Sea than in the East China Sea. The anchovy shoal of two areas was identified by artificial neural network. The contribution factor index (Cio) of the shoal descriptors between two areas were almost identical feature. The shoal volume reverberation index (Rv) was showed the highest contribution to the species identification, while shoal length and shoal height showed relatively high negative contribution to the species identification.

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Effect of the Elderly's Change of Life on the Satisfaction of Care Service through the Donation Bank of Social Contribution Activities : Focusing on the Mediating Effect of Social Integration (사회공헌활동 기부은행을 통한 돌봄노인의 생활변화가 돌봄서비스 만족도에 미치는 영향 : 사회통합감의 매개효과를 중심으로)

  • Choi, Mi-Young;Jang, Young-Shin
    • The Journal of the Korea Contents Association
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    • v.20 no.4
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    • pp.254-263
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    • 2020
  • The purpose of this study is to verify whether there is a mediating effect of social integration in the relationship between the elderly's change of life and satisfaction of care service through the 'Donation Bank of Social Contribution Activities'. The ultimate aim is to improve social values and the quality of life of the senior citizens. In order to achieve the purpose of this study, a survey was conducted focusing on senior citizens using care services from 50 institutions performing Care Bank activities and data of 434 people were finally used for analysis. For the analysis method, frequency analysis, descriptive statistics, correlation analysis and hierarchical regression analysis were applied by using SPSS 25 package program. As a result of the analysis, it was found that the life changes of caring elderly had a significant effect on satisfaction of care service. In addition, the social integration had a statistically significant mediating effect on the relationship between the elderly's change of life and satisfaction with care service. Based on these findings, practical and policy alternatives were discussed to improve the quality of life of senior citizens, and to enhance social integration and satisfaction with care services.

Three-dimensional free vibration analysis of functionally graded fiber reinforced cylindrical panels using differential quadrature method

  • Yas, M.H.;Aragh, B. Sobhani;Heshmati, M.
    • Structural Engineering and Mechanics
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    • v.37 no.5
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    • pp.529-542
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    • 2011
  • Three dimensional solutions for free vibrations analysis of functionally graded fiber reinforced cylindrical panel are presented, using differential quadrature method (DQM). The orthotropic panel is simply supported at the edges and is assumed to have an arbitrary variation of reinforcement volume fraction in the radial direction. Suitable displacement functions that identically satisfy the simply supported boundary condition are used to reduce the equilibrium equations to a set of coupled ordinary differential equations with variable coefficients, which can be solved by differential quadrature method to obtain natural frequencies. The main contribution of this work is presenting useful results for continuous grading of fiber reinforcement in the thickness direction of a cylindrical panel and comparison with similar discrete laminate composite ones. Results indicate that significant improvement is found in natural frequency of a functionally graded fiber reinforced composite panel due to the reduction in spatial mismatch of material properties.

A Novel Theory of Support in Social Media Discourse

  • Solomon, Bazil Stanley
    • Asia Pacific Journal of Corpus Research
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    • v.1 no.1
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    • pp.95-125
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    • 2020
  • This paper aims to inform people how to support each other on social media. It alludes to an architecture for social media discourse and proposes a novel theory of support in social media discourse. It makes a methodological contribution. It combines predominately artificial intelligence with corpus linguistics analysis. It is on a large-scale dataset of anonymised diabetes-related user's posts from the Facebook platform. Log-likelihood and precision measures help with validation. A multi-method approach with Discourse Analysis helps in understanding any potential patterns. People living with Diabetes are found to employ sophisticated high-frequency patterns of device-enabled categories of purpose and content. It is with, for example, linguistic forms of Advice with stance-taking and targets such as Diabetes amongst other interactional ways. There can be uncertainty and variation of effect displayed when sharing information for support. The implications of the new theory aim at healthcare communicators, corpus linguists and with preliminary work for AI support-bots. These bots may be programmed to utilise the language patterns to support people who need them automatically.

An Experimental Analysis of the Contributions to the Radiated Noise due to Panel Vibration of a Rotational Machine (회전체 진동으로 인한 판넬 방사소음의 실험적 기여도 분석)

  • 국형석;허승진;고강호
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.2
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    • pp.126-131
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    • 2003
  • This study is concerned with the reduction of noise radiation by an industrial fan unit. First, spectral decomposition method is used to decompose the spectrogram obtained in experiments into source function and noise transfer function, and then major noise generation sources are investigated. Among the noise sources involved in the fan unit. this article is focused on the noise source due to vibration of panels of the unit housing. It is shown here that noise radiation associated with the panel vibration can be as significant in some frequency ranges as that associated with other noise sources such as aeroacoustic fan noise.

The evaluation of vibration contribution about the eccentric rotor system by multiple dimensional spectral analysis (다차원 해석법을 이용한 편심 회전체의 전달 기여도 평가)

  • 조문갑;조용구;김동원;이정윤;오재응
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.298-303
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    • 2003
  • The eccentric rotor system has various problems by vibration of unbalance mass. Specially, it is difficult to analyze vibration problem for the drum washing machine due to correlation of transmission paths. We analyze the mechanical structure by multidimensional spectral density to identify the maximum vibration magnitude at the frequency domain. It estimates the coherence function of the signals to pass the transmission paths. In case of the drum washing machine, because the transmission paths are correlated partially it needs to determinate the priority ranking. And the correlated parts are eliminated using conditioned spectral density function. Finally the shielding effect method confirms the reasonability of the modeling.

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Contribution of the Mode Vibration to Heavy Weight Floor Impact Noise (슬래브 진동모드의 바닥충격음 기여특성에 관한 연구)

  • Hwang, Jae-Seung;Park, Hong-Gun;Moon, Dae-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.159-160
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    • 2014
  • The floor impact noise arising between upper and lower households in residential houses has been known as one of major causes worsening residential environment and still led to serious social troubles in a residential community. It is known that the heavy weight floor impact noise is induced by flexural vibration modes in the relatively lower frequency ranges. In this study, a procedure is examined to evaluate the relations between the vibration modes and the corresponding noise of the slab. In the process, for simplicity of the numerical analysis, it is assumed that the slab is simply supported plate-like structure and the acoustic mode formed in the lower room by acoustic boundary conditions is ignored.

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Analysis and Design of Resonant Inverter for Reactive Gas Generator Considering Characteristics of Plasma Load

  • Ahn, Hyo Min;Sung, Won-Yong;Lee, Byoung Kuk
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.345-351
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    • 2018
  • This paper analyzes a resonant inverter to generate plasma. The resonant inverter consists of a full bridge converter, resonant network and reactor to generate a magnetic field for plasma generation. A plasma load has very distinct characteristics compared to conventional loads. The characteristics of plasma load are analyzed through experimental results. This paper presents the study on the resonant network, which was performed in order to determine how to achieve a constant current gain. Another important contribution of this study is the analysis of drop-out phenomenon observed in plasma loads which is responsible for unpredictable shutdown of the plasma generator that requires stable operation. In addition, the design process for the resonant network of a plasma generator is proposed. The validity of this study is verified through simulations and experimental results.