• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.291-296
• /
• 2007

This study presents the evaluation process for door module. Its objective evades the resonance generated at module plate due to the operation of window regulator motor. For this study, the design improvement process is composed of experimental methods having three steps. First step is modal analysis at door assembly status for acquisition of dynamic characteristics which are modal frequency and damping. Second step is a vibration experiment to get the test mode considered an efficiency of window regulator motor. Last step is a vibration measurement by the form of $6{\times}6$ array on module plate. A vibration measurement of 6x6 array form can be got to three analysis results which are a transfer path of vibration using cross correlation function, a vibration map using OA level and a contribution by frequency band using coherent output power spectrum on module plate. These results are applied to SDM(structural dynamic modification) for design improvement to get around the resonance on module plate by the excitation of window regulator motor.

• 한국소음진동공학회논문집
• /
• 제17권11호
• /
• pp.1093-1101
• /
• 2007

This study presents the design improvement process for door module. Its objective evades the resonance generated at module plate due to the operation of window regulator motor. For this study, the design improvement process is composed of experimental methods having three steps. First step is modal analysis at door assembly status for acquisition of dynamic characteristics which are modal frequency and damping. Second step is a vibration experiment to get the test mode considered an efficiency of window regulator motor. Last step is a vibration measurement by the form of $6{\times}6$ array on module plate. A vibration measurement of $6{\times}6$ array form can be got to three analysis results which are a transfer path of vibration using cross correlation function, a vibration map using OA level and a contribution by frequency band using coherent output power spectrum on module plate. These results are applied to SDM(structural dynamic modification) for design improvement to get around the resonance on module plate by the excitation of window regulator motor.

• 대한음성학회지:말소리
• /
• 제55권
• /
• pp.45-60
• /
• 2005

The purpose of this paper is to represent values of acoustic cues for Korean oral stops in the multi-dimensional space, and to attempt to find possible relationships among acoustic cues through correlation analyses. The acoustic cues used for differentiation of 3 types of Korean stops are closure duration, voice onset time and fundamental frequency of a vowel after a stop. The values of these cues are plotted in the two and three dimensional space to see what the critical cues are for separation of different types of stops. Correlation coefficient analyses show that multi-variate approach to statistical analysis is legitimate, and that there are statistically significant relationships among acoustic cues but Oey are not strong enough to make the conjecture that there is a possible relationship among the articulatory or laryngeal mechanisms employed by the acoustic cues.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집B
• /
• pp.661-666
• /
• 2000

Near-wake flow field of a circular cylinder is studied by means of a cinematic PIV system with high sampling rate and large internal memory block. Experiments are conducted in a closed-cycle water tunnel system and a cross-correlation algorithm in conjunction with FFT (Fast Fourier Transform) analysis and an offset correlation technique is used for vector processing. With the help of very high sampling frequency compared to the shedding frequency, it is possible to obtain phase-averaged information of the three-dimensional wake, even though the shedding is not forced but natural. Phase-locked vortical structures observed simultaneously from the spanwise and cross-stream planes are displayed in the wake-transition regime where fine-scale secondary vortices have a spanwise wavelength or around one diameter. Spatial relations and temporal evolutions of the primary Karman vortex and the secondary vortex are also discussed schematically.

• 사상체질의학회지
• /
• 제10권1호
• /
• pp.65-80
• /
• 1998

Proceeding an objective Study of sasang constitution diagnosis by Sound Analysis which uses Computed Sound lab(CSL), we verified the confidence level of Questionnaire of Sasang Constitution classification II(QSCC II) and the first results of Sound Analysis for verifying correlation between the physical character and Sound character are as follows. 1. The confidence level of QSCC II is 70.8% to Soeumin, 60.8% to Soyangin, 74.5% to Taeumin, and 70.08% in total. But, the actual results of verifying the confidence level after making 100 persons an object of study, are that the confidence level of that is 55.10% to Soeumin, 30.77% to Soyangin, 80.00% to Taeumin, and 55.29% in total. So it doesn't coincide with the confidence lecel of QSCC II 70.8%. 2. The results of verifying the confidence level about other 134 persons after enough explanation before the constitutional diagnosis by QSCC II are that the confidence of that is 71.08 to Soeumin, 54.76% to Soyangin 81.82% to Taeumin, and 69.22% in total. 3. The results of verifying the correlation between B.M.I. and Sasang Costitution are that there are significant differences below P<0.001 between Taeumin and Soeumin, and between Taeumin and Soyangin. 4. Height and Weight influence on a fundamental frequency and formant frequency. 5. There are differences for every constitutions in a amplitude when we nave a Sound analysis. As aboves, it is considered that we can find the differences among the constitutional groups, if we have a Sound analysis of the constitutional Sound characters.

• 한국소음진동공학회논문집
• /
• 제20권11호
• /
• pp.995-1000
• /
• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.

• 한국태양에너지학회 논문집
• /
• 제37권4호
• /
• pp.13-22
• /
• 2017

In this study, long and short-wave radiations were observed in urban and suburban areas during the summer season, and frequency analysis was performed for each radiation intensity by a new analysis method. The following results were obtained. (1) Long-wave radiation values were found to be larger in the afternoon than in the morning, in both urban and suburban areas, unlike short-wave radiation values. (2) Short-wave radiation showed a right-skewed frequency distribution. In the high energy area greater than $900W/m^2$, the frequency was significantly higher in the suburbs than in the urban areas. (3) Long-wave radiation was in the range of $290{\sim}479W/m^2$, its frequency distribution resembled a normal distribution, and the frequency of 410, $420W/m^2$ was the highest.

• 한국추진공학회지
• /
• 제19권4호
• /
• pp.45-51
• /
• 2015

정상초음파의 영향을 받는 메탄-공기 예혼합화염의 주파수-당량비 상관도 분석을 위한 실험적 연구가 수행되었다. 슐리렌가시화기법을 이용하여 예혼합화염의 전파영상을 획득하였으며, 영상 후처리를 통해 화염의 구조변이 및 전파거동을 면밀히 관찰하였다. 정상초음파가 개재할 때, 화염선단과 기연부에서 구조적 변이와 연소반응 촉진으로 인한 화염의 전파속도의 증가를 가져온다는 사실에 더하여, 초음파 구동주파수와 당량비에 대한 화염거동의 종속성을 확인하였다.

• 웰빙융합연구
• /
• 제4권1호
• /
• pp.11-18
• /
• 2021

Purpose: This study aims to explore the correlation between job and hypertension. Hypertension is a major risk factor such as stroke, myocardial infarction, heart failure, and vascular aneurysms. Research design, data and methodology: The data from this study are the 2017 National Health and Nutrition Examination Survey classified into office workers and non-office workers. Frequency analysis was used for general characteristics analysis, and ANOVA test analysis was used for correlation between subjects' basic variables and blood pressure. The post analysis as turey was used to verify the validity of the statistical results. All statistical analyzes were performed using the IBM SPSS 24.0 program. Results: There was a difference in the prevalence of hypertension among office workers and non-office workers.

• 전자공학회논문지D
• /
• 제35D권2호
• /
• pp.93-100
• /
• 1998

In this paper we analyze the effect of nonlinear gain on laser modulation characteristics applying a small-signal analysis to the rate equation which includes a nonlinear gain term. Also we analyze the resonance frequency and the damping factor which determine laser modulation characteristics, define K factor which is the proportionality factor between resonance frequency and damping factor, and conclude that the decrease in K factor is due to increases in differential gain and no correlation between K factor and nonlinear gain is identified.