• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.963-968
• /
• 2006

The main purpose of this paper is to investigate the stability of water tower with a relatively small footing. The water tower is modeled that the column carrying a container is supported by a rotational spring at the base and is of constant cross-section, with a weight per unit length of column axis. The column model is based on the Bernoulli-Euler beam theory. The Runge-Kutta method and Determinant Search method are used to perform the integration of the governing differential equation and to determine the critical values(critical own weight. and critical buckling load), respectively. The critical buckling loads are calculated over a range of system parameters: the rotational stiffness parameter, the dimensionless radius of container and the own weight parameter of the column. The relation between the rotational stiffness parameter and the critical own weight parameter of the column is analyzed.

• 폴리머
• /
• 제38권6호
• /
• pp.735-743
• /
• 2014

폴리프로필렌의 분자량 및 분자량 분포를 예측하기 위해 레오메터, 고유점도측정기 및 MI(melt index) 기기 등을 이용하여 유변 물성을 측정하였고, 분자구조해석에는 GPC가 사용되었다. 기존에 사용되어온 동적진동측정을 이용한 교차 모듈러스에서 결정된 유변학적 PI(다분산 지표)와 변형된 Carreau 모델을 이용하여 계산된 분포 폭 매개변수(distribution broadness parameter)를 분자량 분포와의 관계를 비교해보았다. 유변학적 PI의 경우 이론적 근거가 부족하고, 압출에 의해 재 생성된 폴리프로필렌 시료에 대해서는 분자량 분포와 잘 일치하지만 반응기에서 중합된 시료 즉, 분자량 분포가 넓거나 다른 경우 잘 일치하지 않는다는 보고가 지배적인데 비해 분포 폭 매개변수는 폴리프로필렌의 전단담화의 정도를 직접적으로 측정하는 것으로 분자량 분포를 잘 예측할 수 있음을 알았다.

• The Journal of Korean Physical Therapy
• /
• 제26권3호
• /
• pp.136-139
• /
• 2014

Purpose: The purpose of this study will demonstrate that relationship between scoliosis and gait factor and foot weight bearing in ambulation. Methods: Subjects were 40 elementary students. A normal control group consisted of a total of 20 children without any known musculoskeletal disorders and an AIS group of 20 children with mild AIS (defined by a Cobb angle between 10 and $25^{\circ}$) were recruited. Measurements were scoliometer screening test, Cobb angle, gait parameter (rate of swing/stance phase, gait velosity), foot weight bearing (entire, fore, hind). Results: Scoliometer screening test (P = 0.000) and X-ray Cobb angle (P = 0.000) significant difference of group which was significantly higher in the AIS group. Gait parameter not showed significant difference. Forefoot weight bearing was significantly higher in the AIS group than more normal group. Conclusion: It seems that the results of weight bearing analysis in ambulation may be used in modifying rehabilitation programs for individual needs of patients with idiopathic scoliosis.

• 전기전자학회논문지
• /
• 제22권1호
• /
• pp.14-20
• /
• 2018

The purpose of training a convolutional neural network (CNN) is to obtain weight factors that give high classification accuracies. The initial values of hyper-parameters affect the training results, and it is important to train a CNN with a suitable hyper-parameter set of a learning rate, a batch size, the initialization of weight factors, and an optimizer. We investigate the effects of a single hyper-parameter while others are fixed in order to obtain a hyper-parameter set that gives higher classification accuracies and requires shorter training time using a proposed VGG-like CNN for training since the VGG is widely used. The CNN is trained for four datasets of CIFAR10, CIFAR100, GTSRB and DSDL-DB. The effects of the normalization and the data transformation for datasets are also investigated, and a training scheme using merged datasets is proposed.

• 한국멀티미디어학회논문지
• /
• 제21권4호
• /
• pp.441-449
• /
• 2018

Deep learning has been used for various processing centered on image recognition. One core algorithms of the deep learning, convolutional neural network is an deep neural network that specialized in image recognition. In this paper, we use a convolutional neural network to classify forest insects and propose an optimization method. Experiments were carried out by combining two weight initialization and six parameter update methods. As a result, the Xavier-SGD method showed the highest performance with an accuracy of 82.53% in the 12 different combinations of experiments. Through this, the latest learning algorithms, which complement the disadvantages of the previous parameter update method, we conclude that it can not lead to higher performance than existing methods in all application environments.

• Journal of Ginseng Research
• /
• 제13권1호
• /
• pp.49-55
• /
• 1989

정상 wistar rat strain의 체중 및 장기무게 변화 그리고 사료, 물 섭취량의 변화 등을 조사함으로써 polyacetylene 화합물들의 투여량에 따른 독성변수(toxicological parameter)의 범위를 추정하고자 하였다. 또한, ICR mouse strain의 Sarcoma-180으로 유도되는 고형암의 억제와 관련해서 polyacetylene 화합물들의 투여량에 따른 독성변수(toxicological parameter)와의 관계를 관찰하고자 하였다. Panaxydol 40$\mumoles/kg b.w.을 3일간 연속 복강 투여했을때 wistar rat의 체중증가율은 대조군보다 약 17% 감소하였으나, polyacetylene 의 투여를 중지하면 약 4일 경과후부터 체중증가율이 정상으로 회복되었다. 이 투여량을 20$\mumoles/kg b.w.로 줄이면 대조군과의 체중증가율의 차이는 약 10% 정도로 완화되며 그 체중감소율은 panaxydol, panaxynol, panaxytriol의 순으로 증가하였다. 이때 장기무게의 관찰 결과는 대조군과 polyacetylene 화합물들 투여군 사이에 의미있는 차이가 없는 것으로 나타났다. 또한 정상 mice의 간세포에 대한 electron micrograph 관찰결과, panaxydol 40$\mumoles/kg b.w./day 투여시에도 대조군에 비하여 별다른 미세조직의 변화가 관찰되지 않았다.

• 품질경영학회지
• /
• 제33권4호
• /
• pp.117-122
• /
• 2005

Variable sampling rate(VSR) scheme varies the sampling rate for the current sample depending on the previous value of the control statistic. In this paper, we propose EWMA control charts with variable parameter(VP) scheme, which allows both the sample rate(the sample size or the sampling interval) and the weight to vary. We investigate the effectiveness of the VP scheme relative to the fixed parameter(FP) scheme and the VSR scheme in EWMA control charts. It is shown that using the VP scheme gives some improvements to the ability in detecting small and moderate shifts in the process normal mean.

• Bulletin of the Korean Chemical Society
• /
• 제22권11호
• /
• pp.1255-1260
• /
• 2001

The expansion of two different kinds of hydrodynamic size of polymethyl methacrylate (PMMA Mw: 1.56- 2.04 ${\times}$ 106 g/mol) has been measured by dynamic light scattering and viscometry above the Flory $\theta$ temperature of the variou s solvents such as n-butyl chloride, 3-heptanone, and 4-heptanone. The expansion of PMMA chains was analyzed in terms of universal temperature parameters and also compared with previous results of polystyrene (PS) system. First it was found that simple $\tau/{\tau}c$ parameter no longer had its universality for the expansion behavior of hydrodynamic size in the chemically different linear polymer chains. However after modifying ${\tau}/{\tau}c$ parameter into $(Mw/Ro2)3}2(\tau/\tauc)$, we observed a much better universality for both PMMA and PS systems. Here Mw, Ro, $\tau[=(T-{\theta}$)/${\theta}$]$, and ${\tau}c[=({\theta}-Tc)/Tc]$ are defined as the weight average molecular weight, the unperturbed end-to-end distance, the reduced temperature and the reduced critical temperature, respectively.

• Journal of the Korean Statistical Society
• /
• 제22권1호
• /
• pp.1-12
• /
• 1993

An approach to make the information bound sharper in median-unbiased estimation, based on an analogue of the Cramer-Rao inequality developed by Sung et al. (1990), is introduced for continuous densities with a nuisance parameter by considering information quantities contained both in the parametric function of interest and in the nuisance parameter in a linear fashion. This approach is comparable to that of improving the information bound in mean-unbiased estimation for the case of two unknown parameters. Computation of an optimal weight corresponding to the nuisance parameter is also considered.

• Journal of applied mathematics & informatics
• /
• 제42권1호
• /
• pp.213-221
• /
• 2024

A family of sixth-order multiple-root solver have been developed and the special case of weight function is investigated. The dynamical analysis of selected iterative schemes with uniparametric polynomial weight function are studied using Möbius conjugacy map applied to the form ((z - A)(z - B))^m and the stability surfaces of the strange fixed points for the conjugacy map are displayed. The numerical results are shown through various parameter spaces.