• International Journal of Reliability and Applications
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• 제2권4호
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• pp.263-268
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• 2001

Shanmugam(1991) generalized the Poisson distribution to capture a restriction on the incidence rate $\theta$ (i.e. $\theta$ ＜ $\beta$, an unknown upper limit), and named it incidence rate restricted Poisson (IRRP) distribution. Using Neyman's C($\alpha$) concept, Shanmugam then devised a hypothesis testing procedure for $\beta$ when $\theta$ remains unknown nuisance parameter. Shanmugam's C ($\alpha$) based .results involve inverse moments which are not easy tools, This article presents an alternate testing procedure based on likelihood ratio concept. It turns out that likelihood ratio test statistic offers more power than the C($\alpha$) test statistic. Numerical examples are included.

• 대한기계학회논문집A
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• 제25권2호
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• pp.214-219
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• 2001

In this paper, the nonlinear behavior of ultrasonic wave in partially degraded material is considered. For this aim, FDM(finite difference method) model for the nonlinear wave equation was developed with the restriction to the 1-D longitudinal wave motion and how the partial degradation in material contributes to the detected nonlinear parameter was analyzed quantitatively. In order to verify the rightness of this simulation method, the relation between the detected nonlinear parameter and the continuous distribution of degradation obtained from simulation was compared with experiment results and the simulation and experiment results showed similar tendency. It can be known from simulation result that the degree of degradation, the range of degradation and the continuous distribution of degradation have strong correlation with the detected nonlinear parameter. As it was possible in these simulations that only special part is assumed as degraded one, the quantitative evaluation of partially degraded material may be obtained by using this method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.369-372
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• 1994

In this paper, the robust stability of characteristic polynomials with respect to real parameter variations is investigated through a new functional approach. Specifically there is no restriction on the interrelationship between coefficients of the polynomials. This allows one to treat the robust stability problems alike without distinction as to continuous or discrete time systems. Necessary condition and sufficient condition for the robust stability are shown and some examples extracted from two-link planar manipulator are provided.

• 응용통계연구
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• 제10권1호
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• pp.105-119
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• 1997

일원배열형태의 가산 자료집합에서 각 군의 평균을 이용하여 처리효과를 비교할 수 있다. Barnwal과 Paul(1988)은 각 군의 산포모수가 같다는 가정 아래에서 처리에 따른 차이를 검정하는 우도검정통계량과 $C(\alpha)$ 통계량을 유도하였는데 본 연구에서는 이러한 가정이 만족되지 않아도 검정할 수 있도록 통계량을 일반화하였다. 또한 음이항분포 대신 Efron(1986)의 이중지수계 포아송 모형을 도입하여 새로운 통계량을 제시하였다. 모의실험을 통해 이중지수계 포아송 모형으로부터 유도된 $C(\alpha)$ 통계량이 어느 경우에나 적합함을 밝혔다.

• Structural Engineering and Mechanics
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• 제31권4호
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• pp.393-405
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• 2009

The Purpose of this paper is to show the applicability of a methodology, developed by the authors, with which to perform the mechanical optimization of space truss structures strongly restricted. This methodology use a parameter call "Volumetric Displacement", as the Objective Function of the optimization process. This parameter considers altogether the structure weight and deformation whose effects are opposed. The Finite Element Method is employed to calculate the stress/strain state and the natural frequency of the structure through a structural linear static and natural frequency analysis. In order to show the potentially of this simple methodology, its application on a large diameter telescope structure (10 m) considering the strongly restriction that became of its use, is presented. This methodology, applied in previous works on continuous structures, such as shell roof and fluid storage vessels, is applied in this case to a space truss structure, with the purpose of generalize its applicability to different structural topology. This technique could be useful in the morphology design of deployable and retractable roof structures, whose use has extensively spread in the last years.

• Journal of the Korean Statistical Society
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• 제19권2호
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• pp.113-121
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• 1990

Let ${X_n : n=1,2,\cdots}$ be iid random variables with distribution $P_{\theta}, \theta \in H$ where $H$ is some abstract parameter space. We consider a sequential confidence interval I for the mean $\mu = \mu(\theta)$ of $P_{\theta}$ satisfying $P_{\theta}(\mu \in I) \geq 1-\alpha$ and $P_{\theta}(\mu-\delta(\mu) \in I) \leq \beta$ for all $\theta \in H$ for any given an imprecision real valued function $\delta(\mu) > 0$ and error probabilities $0 < \alpha, \beta < 1$. A one-sided sequential confidence interval is constructed under some restriction of the family {P_{\theta} : \theta \in H}$ and the imprecision function $\delta$. This is extended to the two-sided cases.

• Smart Structures and Systems
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• 제21권6호
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• pp.741-749
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• 2018

Structural health monitoring (SHM) systems are necessary to achieve smart predictive maintenance and repair planning as well as they lead to a safe operation of mechanical structures. In the context of vibration-based SHM the measured structural responses are employed to draw conclusions about the structural integrity. This usually leads to a mathematically illposed inverse problem which needs regularization. The restriction of the solution set of this inverse problem by using prior information about the damage properties is advisable to obtain meaningful solutions. Compared to the undamaged state typically only a few local stiffness changes occur while the other areas remain unchanged. This change can be described by a sparse damage parameter vector. Such a sparse vector can be identified by employing $L_1$-regularization techniques. This paper presents a novel framework for damage parameter identification by combining sparse solution techniques with an Extended Kalman Filter. In order to ensure sparsity of the damage parameter vector the measurement equation is expanded by an additional nonlinear $L_1$-minimizing observation. This fictive measurement equation accomplishes stability of the Extended Kalman Filter and leads to a sparse estimation. For verification, a proof-of-concept example on a quadratic aluminum plate is presented.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.33-38
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• 1999

컴퓨터 분야에서 얼굴근육 이미지합성은 살아있는 것 같은 모델을 실현하기 위한 가장 실재적인 접근방법 중의 하나이며, 얼굴근육 모델은 얼굴조직 성분과 근육으로 구성된다. 이 모델에서 얼굴 조직 성분에 영향을 주는 힘(force)은 각 근육의 수축강도로써 계산되어지고, 각 근육 파라메터의 결합은 명확한 얼굴표현으로 결정한다. 또한 각 근육 파라메터는 실험과 샘플 사진과 근육편집기로 생성한 명확한 이미지를 비유하여 에러처리과정을 통해 결정된다. 이 논문에서 신경회로망을 사용한 2D(Two-Dimension) 지시점의 움직임으로부터 얼굴근육의 자동인식 방법을 제안하고자 하며, 얼굴모델을 기반으로 한 물리학적 제한하에 캡처된 이미지에서 정보 흐름과 2D 포인트로부터 3D(Three-Dimension) 움직임 인식을 하고자 한다.

• International Journal of Precision Engineering and Manufacturing
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• 제9권1호
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• pp.47-50
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• 2008

This paper presents a new water-lubricated hybrid sliding bearing for a high speed and high accuracy main shaft system, along with the numerical method used for its design. The porous material for the restrictor and the restriction parameter were chosen based on the special requirements of the water-lubricated bearing. Subsequent numerical calculations give the load capacity, stiffness, and friction power of different forms of water-lubricated bearings. The pressure distribution of the water film in a 6-cavity bearing is shown, based on the results of the numerical calculations. A comparison of oil-lubricated and water-lubricated bearings shows that the latter benefits more from improved processing precision and efficiency. An analysis of the stiffness and friction power results shows that 6-cavity bearings are the preferred type, due their greater stiffness and lower friction power. The average elevated temperature was calculated and found to be satisfactory. The relevant parameters of the porous restrictor were determined by calculating the restriction rate. All these results indicate that this design for a water-lubricated bearing meets specifications for high speed and high accuracy.

• Asian-Australasian Journal of Animal Sciences
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• 제24권3호
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• pp.414-420
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• 2011

A study was conducted to investigate the effects of the combined stressor induced by high stocking density with feed restriction on immunological parameters such as leukocyte differential counts and cytokine expression in laying hens. A total of forty White Leghorn laying hens were randomly allotted into the control (12 kg of body weight/$m^2$) and the stress (44 kg of body weight/$m^2$) groups, and then birds of the stress group were given 75% of voluntary intake of the control birds for 12-d on a daily basis. There was a significant decrease in body weight without affecting the relative weights of the liver and spleen after 12-d of the combined stressor. In hematological values, no significant difference in leukocyte differential counts including heterophils (H), lymphocytes (L), monocytes and H:L ratio was observed between the two groups. In cytokines, hepatic lipopolysaccharide-induced tumor necrosis factor-${\alpha}$ (LITNF-${\alpha}$) and inducible nitric oxide synthase (iNOS) expression levels in the stress group were significantly (p<0.05) higher compared with those in the control group. However, the expression levels of interleukin (IL)-4 and IL-6 in the liver were not affected by the combined stressor. Splenic LITNF-${\alpha}$ expression in the combined stressor group was significantly (p<0.05) up-regulated compared with that in the control birds. However, the combined stressor did not affect splenic IL-4, IL-6 and iNOS expression. In conclusion, the combined stressor caused by high stocking density with feed restriction enhanced some pro-inflammatory cytokines including LITNF-${\alpha}$ and iNOS in lymphoid and non-lymphoid organs of birds, suggesting that altered cytokine expression to given stressors can be another parameter that can be used in assessing stress responses of birds.