• Title/Summary/Keyword: Frequency Contribution Analysis

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The Leisure Participation and Leisure Satisfaction of Single Working People (미혼 직장인의 여가활동참여와 여가만족 - 부산시를 중심으로 -)

  • 이정숙
    • Korean Journal of Rural Living Science
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    • v.10 no.1
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    • pp.33-42
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    • 1999
  • The purpose of this study was to empirically verify the influence of variables on leisure participation and leisure satisfaction of single working people and the relative contribution of individual leisure participation and family leisure participation. The subject of this study were 176 single working people in Pusan and interviewed with a questionnaire. The data were analyzed by SPSS/PC+ program for the frequency, mean, standard deviation, Cronbach'$\alpha$, factor analysis and regression. The major results of this study were as follows : 1. The score of family leisure participation were higher than individual leisure participation. The Level of leisure satisfaction was relatively high. 2. Variables that affect the leisure participation were job, degree of information using and perception level of the adequacy of household income. 3. Variables that affect leisure satisfaction were perception level of the adequacy of household income and individual leisure participation.

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Fatigue Assessment of Very Large Container Ships Considering Springing Effect Based on Stochastic Approach

  • Jung, Byoung-Hoon;Ahn, In-Gyu;Seo, Sun-Kee;Kim, Beom-Il
    • Journal of Ocean Engineering and Technology
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    • v.34 no.2
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    • pp.120-127
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    • 2020
  • Evaluation of fatigue strength considering the springing effect of very large container ships is crucial in the design stage. In this study, we established a fatigue strength evaluation method considering a linear springing component in the frequency domain. Based on a three-dimensional global model, a fluid-structure interaction analysis was performed and the modal superposition method was applied to determine the hot spot stress at the hatch corner of very large container ships. Fatigue damage was directly estimated using the stress transfer function with a linear springing response. Furthermore, we proposed a new methodology to apply the springing effect to fatigue damage using hull girder loads. Subsequently, we estimated the fatigue damage contribution due to linear springing components along the ship length. Finally, we discussed the practical application of the proposed methods.

A Study on Life Management Strategy and Variables of Unmarried Men and Women (미혼남녀의 생활관리전략과 관련변인 연구)

  • 이정숙
    • The Korean Journal of Community Living Science
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    • v.14 no.1
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    • pp.37-53
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    • 2003
  • The purpose of this study was to empirically verify influence of objective variables and subjective variables of life management strategy of unmarried man and women and provide a basis for the development of time management. The subject of this study were 355 unmarried men and women and interviewed with a questionnaire. The data were analyzed by SPSS program for the frequency, mean, standard deviation, t-test and regression analysis. The major results of this study were as follows: 1. The score of time management strategy of unmarried man and women was the highest. The score of leisure management strategy of unmarried man and women was the lowest. 2. Variables that affect overall life management strategy were academic career, degree of information using, fate control orientation and perception level of living relative to others. 3. The relative contribution of subjective variables on life management strategy were higher than objective variables.

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Analysis of Underwater Acoustic Radiation of SWATH vessel using Transfer Function Method (전달함수법을 이용한 SWATH선의 수중 음향 방사 해석)

  • 김재호
    • Journal of the Korea Institute of Military Science and Technology
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    • v.6 no.2
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    • pp.20-34
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    • 2003
  • The good sea-keeping capability of the SWATH(Small Waterplane Area Twin Hull) ship has been attractive for research or surveillance vessels. Especially, for the naval ships accomplishing the underwater acoustic missions, it is necessary to access and minimize the underwater radiated noise level generated by the ships. Therefore, acoustic signature management and control are very important topics for these vessels. Underwater radiation pattern in the low frequency range is dominated by the tonals from the vibration of onboard machinery. In this work, the radiated noise level generated by the propulsion machine in the submerged hull is predicted using the transfer function technique and the hull transfer function for the submerged hull is determined by analyzing the longitudinal/circumferential stiffened infinitely long cylindrical shell and considering the empirical database of the previous vessels. It is confirmed that the transfer function technique can give useful information for identifying the noise source and estimating its contribution to the total radiatied noise level.

An Experimental Analysis of the Contributions to the Radiated Noise due to Panel Vibration in a Fan Unit (공조기기 판넬 진동으로 인한 방사소음의 실험적 기여도 분석)

  • Kook, Hyung-Seok;Huh, Seung-Jin;Ko, Kang-Ho;Lee, Jae-Hyung;Hong, Seok-In;Kim, Jin-Yong
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.192-197
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    • 2001
  • This study is concerned with the reduction of noise radiation by an industrial fan unit. 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.

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A Study on Internet Marketing Strategy Through Homepage Comparison Between National-Public General Hospitals and Private General Hospitals (국공립병원과 사립병원의 홈페이지 비교를 통한 인터넷 마케팅전략 연구)

  • Ahn, Sang-Yoon;Kim, Kwang-Hwan
    • Korea Journal of Hospital Management
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    • v.19 no.1
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    • pp.21-31
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    • 2014
  • This study aimed to find marketing strategy through comparison of internet homepage between national-public hospitals and private hospitals in Korea. A total of 51 hospitals' data were used with frequency, chi-square, t-test, multi-regression, correlation analysis. They were verified by SPSS Ver. 15.0 program. According to the result of this research, national-public hospitals operated more contents of public interests such as social contribution, volunteer work than private hospitals. Otherwise private hospitals operated more contents of costumer interests such as customer counselling, statistical data and cafe of customer voices than national-public hospitals. Synthetically we find that private hospitals try to get closer to the consumer than national-public hospitals. Because feedback and interaction between hospitals and consumer are very important, we suggest that national-public hospitals and private hospitals mutually should operate internet homepage in accordance with consumer needs of medical market.

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Effects of Rotational Stiffness of Isolators on Vibration Power Transmission in Vibration Isolation Systems over High Frequency Range (진동 절연계에서 절연요소 회전강성계수가 고주파수 대역 진동파워 전달에 미치는 영향)

  • 김진성;이호정;김광준
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.5
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    • pp.375-383
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    • 2003
  • For a performance analysis of vibration isolation systems, the concept of vibration power flow can be employed preferably when noise radiated from the supporting structure with finite impedances is of interest. The idea is basically simple to understand and formulas for precise estimation of the vibration power are easy to derive. However, It is often required to simplify the process of experimentation under several assumptions due to instrumental limitations. For an example, rotational degree of freedom has not been well treated in bending vibrations of beam or plate-like structures. Yet, several recent studies showed that the moments and rotations play an important role in power transmission and should be taken into consideration carefully as the frequency range of interest goes to audibly high. Therefore, it is readily agreed that reduction of the noise radiation over the high frequency range can be effectively accomplished by adjusting the rotational stiffness of the isolator without changing the vibration isolator efficiency in low frequency range relevant to the translational stiffness of the isolator In this paper, the vibration power flow approach is applied to an AC motor installed on a finite plate in order to illustrate the contribution of the rotational vibration power to the total vibration power transmission. The effects of rotational stiffness of the isolator on the vibration power transmission are investigated by inserting various shapes of Isolators with different rotational stiffness but with $ame translational stiffness between the motor and the plate. The resultant noise radiation from the plate is presented to verify the proposed approach.

Analysis of Phase Noise in Frequency Synthesizer with DDS Driven PLL Architecture (DDS Driven PLL 구조 주파수 합성기의 위상 잡음 분석)

  • Kwon, Kun-Sup;Lee, Sung-Jae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.11
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    • pp.1272-1280
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    • 2008
  • In this paper, we have proposed a phase noise model of fast frequency hopping synthesizer with DDS Driven PLL architecture. To accurately model the phase noise contribution of noise sources in frequency hopping synthesizer, they were investigated using model of digital divider for PLL, DAC for DDS and Leeson's model for reference oscillator and VCO. Especially it was proposed that the noise component of low pass filter was considered together with the phase noise of VCO. Under assuming linear operation of a phase locked loop, the phase noise transfer functions from noise sources to the output of synthesizer was analyzed by superposition theory. The proposed phase noise prediction model was evaluated and its results were compared with measured data.

A Comparison Study of the Daily Food Intake and Its Related Factors of the Elderly Living in Incheon (인천지역 노인들의 식품군별 식품섭취 및 관련인자 비교연구)

  • 우경자;천종희;최은옥;노정옥
    • Journal of the East Asian Society of Dietary Life
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    • v.13 no.5
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    • pp.379-390
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    • 2003
  • The daily food intake and its related factors of the elderly(aged over 60) living in Incheon were compared. Self administered questionnaires were collected from 418 elderly. Statistical data analysis was completed using a SPSS v. 10.0 program. The results are summarized as follows: About 70% of elderly took grains and starch foods relatively high. The daily intakes of them was significantly influenced by ages of elderly, self-perceived health status, degree of drinking, meal regularity and nutritional balance of meals. More than 80% of elderly responded to take the food group of meat, fish and eggs poorly. Among various factors, the residence type and snack intake frequency influenced the daily intake of those foods statistically. A half of elderly took the vegetables and fruits everyday more than average. The daily consumption of vegetables and fruits was significantly influenced by sex, ages, exercise, snack intake frequency and preference of spices. Most elderly consumed fewer servings of milk and dairy products. About 60% of them did not take milk and dairy products daily. The daily contribution of those foods was significantly influenced by residence and exercise. 45.5% of elderly took oils and sugars more than average everyday which was influenced significantly by residence, exercise, snack intake frequency and meal regularity. In conclusion, the important influencing factors on the daily food intakes of elderly might be related to ages, residence, family, smoking, drinking, exercise, snack intake frequency and meal regularity. Therefore, a situation-oriented and practically organized nutrition education and ingestion support programs which consider the elderlies' socioeconomic status may help to improve the daily food intake of elderly in Incheon area.

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A Study on the Structure Improvement of Bracket Housing for Structural Noise and Vibration Reduction in Hydraulic Breaker (유압 브레이커의 구조 소음.진동 저감을 위한 브래킷 하우징의 구조 개선에 관한 연구)

  • Kim, Bong-Suk;Kim, Min-Gi;Byun, Dong-Woo;Lee, Seong-Min;Lee, Soo-Hun
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.11 s.188
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    • pp.108-115
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    • 2006
  • A hydraulic breaker is widely utilized for many civil engineering areas for the purpose of destroying objects such as rocks, concrete, or road. However, since the high-level noise and vibration by a hydraulic breaker is one of the major sources of environmental noise and recently the environmental regulations on construction equipments are also getting more strengthened, in order to solve such problems, it is certainly necessary to design and develop a hydraulic breaker with low noise and low vibration. This research is to understand the noise characteristics through the noise test and acoustic analysis of the bracket housing in a hydraulic breaker and to identify the element part to be modified based on the result of the element contribution analysis. An improved breaker model including X-typed rib shows the result of low-noise level within target frequency band compared with a commercial breaker model.