• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집A
• /
• pp.883-888
• /
• 2001

The theoretical method is developed to investigate the effects of ring stiffeners on free vibration characteristics and transient response for the ring stiffened composite cylindrical shells subjected to the impulse pressure loading. In the theoretical procedure, the Love's thin shell theory combined with the discrete stiffener theory to consider the ring stiffening effect is adopted to formulate the theoretical model. The concentric or eccentric ring stiffeners are laminated with composite and have the uniform rectangular cross section. The modal analysis technique is used to develop the analytical solutions of the transient problem. The analysis is based on an expansion of the loads, displacements in the double Fourier series that satisfy the boundary conditions. The effect of stiffener's eccentricity, number, size, and position on transient response of the shells is examined. The theoretical results are verified by comparison with FEM results.

• 논리연구
• /
• 제21권1호
• /
• pp.39-57
• /
• 2018

이 글에서 우리는 약화 없는 비교환적인 퍼지 논리의 비대수적 크립키형 의미론 즉 집합 이론적 크립키형 의미론을 다룬다. 이를 위하여 먼저 우리는 가-유니놈에 기반한 퍼지 논리 HpsUL의 한 확장 체계인 $CnHpsUL^*$을 소개한다. 다음으로 CnHpsUL*을 위한 집합 이론적 크립키형 의미론을 소개한다.

• KIEAE Journal
• /
• 제13권1호
• /
• pp.3-8
• /
• 2013

Environmental quality(EQ) is one of the most important components of the assessment of "Quality of Life(QOL)". Most EQ related research dealt with overall built environmental quality issues as represented by several clusters of factors related to occupants' satisfaction. This paper aims to identify and understand the theoretical background and the occupants' comparative standards of response to conditions of the built environment related to environmental quality(EQ). Therefore, this paper have reviewed the theoretical framework and empirical research for environmental quality in built environment. the concept of environmental quality if elaborated from diverse perspectives. Different ways of interpreting environmental quality have led to a variety of ways to conduct evaluations. A review of the theories and methods used for the analysis of perceived environmental quality provides a strong foundation for new research frameworks and environmental quality in built environment.

• 한국연초학회지
• /
• 제7권2호
• /
• pp.189-197
• /
• 1985

The purpose of this study is to improve the method and the apparatus for recovering freon-11 used in a process for increasing the filling capacity of tobacco. The first, the theoretical recovery rate of freon-11 was calculated from vapour pressure and thermodynamic properties of freon-11. The second, the usability of theoretical data was evaluated by the comparison between the theoretical data and the experimental data from the pilot plant. The result obtained under the present experiment condition was quite similar to the rate at 15kg/cm2 and 5$^{\circ}C$, but the theoretical data evaluated were 0.1 to 0.3% lower than the experimental data at 20 to 25kg/cm2 and 5$^{\circ}C$. The recovery rate of the cooling and the compression system was about 95% with freon-11 used in this system and that with freon-11 concentrate of waste gas was about 3 to 3.6% at 20 to 25kg/cm2 and 5$^{\circ}C$.

• 정보저장시스템학회:학술대회논문집
• /
• 정보저장시스템학회 2005년도 추계학술대회 논문집
• /
• pp.210-214
• /
• 2005

The purpose of this paper is to study the effects of the flexibility of HDD base plates on spindle vibration via theoretical predictions and experimental measurements. The flexibility of the base plate can significantly affect HDD spindle vibration. This is the most prominent feature in 2.5 inch HDD. Nevertheless, theoretical analysis of the spindle vibration often neglects the flexibility of the non-rotating part including spindle, base plate, and top cover. Our theoretical model developed in University of Washington can include the flexibilities of spindle and base plate. As a result, our theoretical prediction generally agrees well with our experimental measurements in vibration analysis. Moreover, Because of its small form factor, industrial practice is to use flanged disks instead of regular disks in vibration testing of prototypes. Our experimental measurements indicate that flanged disks and regular disks have very different behavior when the frequency is above 1 KHz.

• 한국농공학회지
• /
• 제24권4호
• /
• pp.80-91
• /
• 1982

To precict the suspended sediments which are 80% of total sediments in a flood disch- arge, an equation representing vertical distribution of sediment concentration was derived based upon the diffusion theory and the logalithmic velocity distribution function in the tubulent flow mechanism. The hypothesis that the uniform mass transfer is occurred at upper part along the center line of water depth, was established as a preconition to solve the problem. The theorecal and the observed values were compared. And the theoretical equation was modified to be fit the theoretical values the observed values. Observed results are as follow; 1) Equation 12) is the theoretical equation representing the vertical concentration distri- bution of suspended sedimenta 2) Rous&exonential type vertical concentration distribution equation shows signification errors near the water surface. But the equation 12) shows substation cocentration values near the water surface. 3) Equation 15) is the modified theoretical equation which is possible to predict the vertical concentration distribution of suspended sediments.

• Steel and Composite Structures
• /
• 제2권6호
• /
• pp.461-474
• /
• 2002

This paper presents the experimental and theoretical results of SUS 304 stainless tubes with different diameter-to-thickness ratio (D/t ratio) subjected to pure bending creep. Pure bending creep occurs when a circular tube is bent to a desired moment and held at that moment for a period of time. It was found that the magnitudes of the creep curvature and ovalization of tube cross-section increase faster with a higher hold moment than that with a lower one. Due to continuously increasing curvature, the circular tubes eventually buckle. Finally, a theoretical form was proposed in this study so that it can be used to describe the relationship between the creep curvature and time. Theoretical simulations are compared with the experimental test data, showing that good agreement between the experimental and theoretical results has been achieved.

• 산업기술연구
• /
• 제27권A호
• /
• pp.47-53
• /
• 2007

A theoretical model based on Rayleigh-Ritz method is proposed to predict the resonance frequency of a W/T(Wind Turbine) tower structure supported by guy cables. In order to verify the validity of the theoretical model, a reduced W/T tower system is manufactured and tested. Frequency response and mode data are determined by modal testing and finite element analysis is performed to calculate the natural frequency of the tower model. Numerical and experimental results are compared with those by the theoretical analysis. Parametric study by the theoretical model shows how the cable tension and cable elasticity influence the resonance frequency of the W/T tower structure. Finally, vibration response under various rotating speed is investigated to examine the possibility of severe resonance.

• 대한화학회지
• /
• 제47권2호
• /
• pp.89-95
• /
• 2003

본 논문에서는 몇몇 사슬형 니트로 화합물의, 실험적으로 측정된 생성열과 이론적으로 계산된 생성열과의 개선된 상관관계에 대해 보고하였다. 이 방법은 이전에 보고된 이론적인 방법을 따르고 있으며, 적당한 결합 파라메터를 도입하는 것으로 이전의 방법을 개선하였다. 실험적으로 측정된 값 그리고 이전의 이론값과 비교해본 결과 상당히 만족할 만한 결과를 보였다. 추후 적용 가능한 몇가지 점에 대해 지적하였다.

• 대한가정학회지
• /
• 제26권2호
• /
• pp.69-79
• /
• 1988

This study was to increase the experimental learning effect of textile materials in middle and high school. To this study, three kinds of simply devised apparatus were used for warmth retaining test, air permeability test and static electricity test. Two classes were chosen in a girls' high school comparing learning effect and classified the theoretical learning group and the experimental learning group. In the experimental group, a teaching plan to teach the properties of textile materials was made to use these apparatuses. The results were. 1. In the interest on the unit either the theoretical learning group or the experimental learning group were not different significantly. 2. In the items facilitation of motivation, unsatisfied desires and prevention of failure, effect of transfer and development of inquiry power, both groups were significant. 3. For the purpose of comparing the learning effect, two groups were examined for determining the level of understanding after teaching properties of textile materials. The mean value of the experimental learning group was higher than that of the theoretical learning group. The experimental learning group had more higher markers(over the point of 90) than the theoretical learning group.