• Journal of Mechanical Science and Technology
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• v.16 no.1
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• pp.75-82
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• 2002

A simultaneous optimal design problem of structural and control systems is discussed by taking a 3-D truss structure as an object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider a minimum weight design problem for structural system and disturbance suppression problem for the control system. The structural objective function is the structural weight and the control objective function is $H_{\infty}$ norm from the disturbance input to the controlled output in the closed-loop system. The design variables are cross sectional areas of the truss members. The conditions for the existence of controller are expressed in terms of linear matrix inequalities (LMI) By minimizing the linear sum of the normalized structural objective function and control objective function, it is possible to make optimal design by which the balance of the structural weight and the control performance is taken. We showed in this paper the validity of simultaneous optimal design of structural and control systems.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.604-610
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• 1991

In this paper, the weight functions for the Mode I and Mode II in SEN(single edge notched) specimen are obtained by superposition of the displacement in the singular field of the Buckner type and the displacements by opposite tractions induced by the singular field. The stress intensity factors, $K_{I}$ and $K_{II}$ are calculated by the weight function theory in SEN specimen under the loading equivalent to uniform tension and shear at infinity in Griffith crack. And the results are compared with the exact solutions.s.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.153-159
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• 2004

A control-structure combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider not only minimum weight design problem for structure system, but also suppression problem of the effect of disturbances for control system as the purpose of the design. By minimizing the linear sum of the normalized structural objective function and control objective function, it is possible to make optimal design by which the balance of the structural weight and the control performance is taken.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.777-781
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• 1988

A method for weighing fruits without separating them from stem is proposed. The base of stem is fixed and a fruit or a cluster of fruits is forced to vibrate. The approximated vibration model is constructed by the use of Transfer Matrix Method. The natural frequency (w) in this model can be represented as a function of weight elements, and the length and stiffness of branch elements of stem. With this function, only w is possible to measure. However, several small weights whose weights are known are attached to weight elements in various combinations. From these equations, unknown parameters are determined so that the weight of each fruit can be obtained by a non-destructive method.

• Journal of Korean Public Health Nursing
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• v.28 no.1
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• pp.22-31
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• 2014

Purpose: The purpose of this study was to examine the impact of body mass index (BMI) and waist circumference (WC) for pulmonary function in normal-weight and obese women. Methods: Data from women aged ${\geq}40$ years were obtained from the 2011 Korean National Health and Nutrition Examination Survey. Obesity was measured by BMI and WC and pulmonary function was measured by forced vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$), and a ratio between forced expiratory volume in 1 second ($FEV_1$/FVC). Multiple linear regression analysis was performed for assessment of the association between FVC, $FEV_1$, $FEV_1$/FVC and obesity variables. Results: BMI showed positive association with FVC, $FEV_1$, $FEV_1$/FVC, and WC showed positive association with $FEV_1$ and $FEV_1$/FVC in normal-weight women. BMI and WC showed negative association with FVC, $FEV_1$ in obese women. A 1 unit increase in BMI showed an association with a 25-mL reduction in FVC and a 19-mL reduction in $FEV_1$. A 1-cm increase in WC showed an association with a 6-mL reduction in FVC and a 4-mL reduction in $FEV_1$. Conclusions: BMI and WC showed negative association with pulmonary function in obese adult women. Therefore, obese women with reduced pulmonary function should be encouraged to lose weight for improvement of their pulmonary function.

• Fashion & Textile Research Journal
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• v.22 no.5
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• pp.676-685
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• 2020

This study developed smart vests with heat and massage functions that changed patterns, designs, materials, etc., and evaluated their functions and satisfaction. A knitted fabric with good elasticity and a heating lining were used, and in consideration of this, the final vest pattern fitted to the upper body was completed. A heat pad was attached to the back, and 6 vibration motors were attached to the trapezius muscle. The controller was placed on the left chest for easy operation, and the battery was stored in an inner pocket under the controller. The heating effect of the smart vest, the location of the devices, and the ease of operation were excellent. When the massage function was operated, the thermal comfort was increased compared to when the massage function was not operated, and the high thermal comfort was perceived by the operation of heat and heat+massage function. Due to the battery, the weight, irritating contact of devices and wearing sensation decreased, but there was no reduction in wearing sensation due to heat and vibration devices. The greater the satisfaction with the massage function, thermal comfort, fit, appearance and weight, the greater the product satisfaction.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.3
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• pp.52-57
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• 2000

This study intends to reduce the weight of structure without changing the dynamic characteristics. At first, the Vibration analysis by the Substructure Synthesis Method and FFM using the ANSYS are performed for the engine speed converter to confirm the reliability of the analyzing tools. Weight minimization is performed by the Sensitivity Analysis and the Optimum Structural Modification. To decrease the converter weight ideally, the parts with low sensitivity are to be cut mainly, and the changing quantity of the natural frequency by the cut is to be recovered by the weight modification of the parts with high sensitivity. As the unique mathematical solution for the homogeneous problem(i.e. 0 object function problem) does not exist, the converter is redesigned with much thinner initial thickness. The goal of this study is to recover the dynamic characteristics of redesigned structure to those of the original one. To say in the other words, the modified structure has the same dynamic characteristics and the more lighter weight to compare with the original one.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.551-554
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• 2005

This study uses a characteristic function to explain correlations between the objective function and design variables. Analysis of means and table of orthogonal array were carried out. The change of shape of diaphragm, thickness of diaphragm and voice coil weight based on the table of orthogonal array is made. Therefore this study carried to decide shape of diaphragm, voice coil weight and thickness of diaphragm for minimizing 1st natural frequency and maximizing 2nd natural frequency of diaphragm using design of experiments and characteristic function with constraints. we showed improved design factors that minimized 1st natural frequency and maximized 2nd natural frequency of diaphragm.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1177-1180
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• 1999

This study describes the growth of broiler chickens to the two forms of Gompertz function for application in broiler production models. The first form is based on the estimated mature weight ($W_A$), while the second is based on the estimated hatch weight ($W_O$). Both equations gave identical estimation because they are mathematically identical. To fit the growth curve of commercial broilers that marketed at 35-42 days, it is unnecessary to keep broilers to near maturity (> day 140) to obtain growth data for deriving the Gompertz function. This date does not improve the curve fitting of the early growing period. Additionally, a high mortality and health problem occurred to this type of chicken after day 105.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1377-1382
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• 1990

In Multi-Layer Perceptron (MLP) which realizes continuous mappings, the output errors is directly affected by the weight errors which may be caused by the limited precision of digital or analog hardware in implementations. So, it is important to study the sensitivity due to the perturbation of connection weights between neurons. In this paper, we derive a sensitivity function to the statistical weight perturbations in MLP with differentiable activation functions. This sensitivity function can be regarded as an ensemble average of deterministic sensitivity measures due to the perturbations of weights. Hence, this sensitivity function can be used as the criteria for selecting weights with the minimum sensitivity among possible sets of connection weights in MLP. For the verification of the validity of the proposed sensitivity function, computer simulations have been performed and through the simulations we find good agreement between the theoretical and simulation results.