• Journal of Mechanical Science and Technology
• /
• v.17 no.11
• /
• pp.1659-1664
• /
• 2003

A cracked plate with a patch bonded on one side was treated with a crack-bridging model using weight function: assuming continuous distribution of springs acting between th crack surfaces, the stress intensity factor of the patched crack was numerically obtained. Especially in the case of a patched crack subjected to residual non-uniform stress, the stress intensity factor was easily with the corresponding approximate weight function. This paper presented the stress intensity factors for a crack partially patched within a finite plate or a patched crack initiated from a notch.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.304-310
• /
• 2001

Cracks at mechanical fastener holes usually nucleate as elliptical comer cracks at the faying surface of the mechanical joints and grow as elliptical arc through cracks after penetrating the opposite surface. In this study mode I, II and III stress intensity factors at two surface points of elliptical arc through cracks at mechanical fastener holes are analyzed by applying weight function method. The weight function method for two dimensional mixed-mode problem is extended to three dimensional one and it is verified.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.1
• /
• pp.146-151
• /
• 2009

In this paper, a weight function theory for the calculation of the mode III stress intensity factor in a rectilinear anisotropic body is formulated. This formulation employs Lekhnitskii's formalism for two dimensional anisotropic materials. To illustrate the method used for the weight function theory, we calculated the mode III stress intensity factor in a single edge-notched configuration.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.9 s.180
• /
• pp.2344-2352
• /
• 2000

Mechanical joints such as bolted or riveted joints are widely used in mechanical components. The reliable determination of the stress intensity factors for cracks in bolted joints is needed to evaluate the safety and fatigue life of them. The weight function method is an efficient technique to calculate the stress intensity factors for various loading conditions because only the stress analysis of an uncracked model is required. In this paper the mixed-mode stress intensity factors for cracks in bolted joints are obtained by weight function method, in which the coefficients of weight function are determined by finite element analyses for reference loadings. Critical inclined angle that mode I stress intensity factor becomes maximum is determined and the effects of crack length and the magnitude of clearance on critical inclined angle are investigated.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1338-1341
• /
• 2004

In this paper, we have proposed a new approach of routing and wavelength assignment algorithms, called Possible Available Wavelength (PAW) algorithm. The weight of a link is used as the main factor for routing decision in PAW algorithm. The weight of a link is defined as a function of hop count and available wavelengths. This function includes a determination factor of the number of wavelengths that are being used currently and are supposed to be available after a certain time. The session requests from users will be routed on the links that has the greatest number of link weight by using Dijkstra's shortest path algorithm. This means that the selected lightpath will has the least hop count and the greatest number of possible available wavelengths. The impact of proposed link weight computing function on the blocking probability and link utilization is investigated by means of computer simulation and comparing with the traditional mechanism. The results show that the proposed PAW algorithm can achieve the better performance in terms of the blocking probability and link utilization.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.583-590
• /
• 2002

Point collocation method based on the fast derivatives approximation of meshfree shape function is applied to solid mechanics in this study. Enhanced meshfree approximation with approximated derivative of shape function is reviewed, and formulation of linear elastic solid mechanics by point collocation method is presented. It implies that governing equation of solid mechanics with strong form is directly formulated without no numerical integration cells or grid. The regularity of weight function is not required due to a use of approximated derivative, so we propose the exponential type weight function that is discontinuous in first derivative. The convergence and stability of the proposed method is verified by passing the generalized patch test. Also, the efficiency and applicability of the proposed method in solid mechanics is verified by solving types of solid problems. Numerical results show that not only a use of proposed weight function leads lower error and higher convergence rate than that of the conventional weight functions, but also the improved collocation method with derivative approximation enables to compute the derivatives of shape function very fast and accurately enough to replace the classical direct derivative calculation.

• Kyungpook Mathematical Journal
• /
• v.46 no.1
• /
• pp.19-29
• /
• 2006

In this paper, we obtain some inequalities similar to Hilbert type. Some new inequalities are also given.

• The Journal of Pediatrics of Korean Medicine
• /
• v.19 no.2
• /
• pp.243-253
• /
• 2005

Objective : In this study we aimed to· investigate the parental recognition on Herbal Medication. The result showed that parents concerned about the effect of Herbal Medication on liver function and gaining weight. Therefore, we had a retrospective study on the effect of Herbal Medicaion on liver function and gaining weight. Method : In parent's recognition study, we surveyed 354 parents of children who make a first visit to Department of Oriental Pediatrics in ${\bigcirc}{\bigcirc}$ Medical Center from 3 October to 2 November 2005. In retrospective study, we examined medical record of 22 children who visited to Department of Oriental Pediatrics in Kyunghee Medical Center from 30 September 2005 to 1 January 2005. Height, weight, BMI, body fat mass, body fat ratio, AST and ALT were estimated at two points; before and after Herbal Medicaion treatment. Result: The mean of expectation of parents on the efficacy of Herbal Medication was 75.14 on the VAS scale, which was interpreted as significantly high. The result showed the effect of Herbal Medicaion on liver function(48%) and gaining weight(53%) took the largest portion. When we observe the effect of Herbal Medication on Liver function, after Herbal Medication treatment we have slightly increased AST and slightly decreased ALT, but they were not statistically significant. Also we observe the effect of Herbal Medication on getting obesity after Herbal Medication treatment. The result showed that we have slightly decreased BMI, body fat mass, body fat ratio, but they were not statistical1y significant. Conclusion : Our report shows parents of children have high expectation and stand favorable on the efficacy of the Herbal Medication. We found that parents concerned the most about the effect of Herbal Medicaion on liver function and gaining weight. Our retrospective study showed that Herbal Medicaion treatment on children has relationship with neither liver function nor the degree of obesity.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.22 no.2
• /
• pp.82-89
• /
• 1985

A new non-inferior solution is obtained by investigating method of weight p- norm to explain the conception of MCO (multiple criterion optimization) problem. And then the optimum non-inferior solution is obtained by the weight minimization method applied to objective function of MOSFET NAND rATEAlso this weight minimization method using weight P- norm methods can be applied to non-convex objective function. The result of this minimization method shows the efficiency in comparison with that of Lightner.

• International Journal of Precision Engineering and Manufacturing
• /
• v.8 no.3
• /
• pp.60-63
• /
• 2007

Weight functions in fracture mechanics represent the stress intensity factors as weighted averages of the externally impressed boundary tractions and body forces. We extended the weight function theory for cracked linear elastic materials to calculate the notch stress intensity factor of a notched structure with anti-plane deformation. The well-known method of deriving weight functions by differentiation cannot be used for notched structures. By combining an appropriate singular field with a regular field, we derived weight functions for the notch stress intensity factor. Closed expressions of weight functions for notched cylindrical bodies are given as examples.