• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.9
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• pp.2800-2811
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• 1996

The deformation of a structure shall be called homologous, if a given geometrical relation holds, for a given number of structural points, before, during, and after the deformation. Some researchers have utilized the idea on structural design with finite element method. The approaches use the decomposition of the FEM equation or equality of eqality equations to obtain homologous deformation. However, weight reduction and response constraints such as stress, displacement or natural frequency cannot be considered by those theories. An optimization method solving the above problems is suggested to gain homologous deformation. Homology constraints can be considered under multiple loadindg conditions as well as a single loading condition. Homology index is defined for the multiple loading conditions Examples are solved to present the performances of the method.

• Journal of Korean Society for Quality Management
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• v.35 no.4
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• pp.52-60
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• 2007

A multi-attribute robust design methodology is presented. This method can be applied where there are various technical constraints in design variables, multiple potentially conflicting design attributes, and uncontrollable noise variables. Two forms of technical constraints, soft and hard constraints, are considered in robust design settings. Specifically, this work presents procedures for integrating two types of design constraints seamlessly on the multiple design attributes, which is achieved through a development of multi-attribute utility formulation. The effectiveness of the overall procedures is tested with the aid of an I-Beam design problem, and results of sensitivity analysis are discussed.

• International Journal of Human Ecology
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• v.15 no.2
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• pp.81-92
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• 2014

This paper explores factors associated with multiple concurrent care and education arrangements in early childhood in South Korea. It draws on a subsample from the Korean Longitudinal Survey of Women and Families. Results show that about one-fifth of the families utilized multiple arrangements for their first preschool child. The primary non-parental option in multiplicity was nurseries or kindergartens. Home care and education options such as home study materials were found to be most prevalent secondary non-parental option, followed by services at private institution as well as relative care. Children's age, care cost, non-parental care time and time constraints were found to be positively related to the incidence of multiplicity for the first preschool child while family income and cost constraints were negatively associated. As a secondary option in the multiplicity, services at private institutions increased with children's age, care cost and when the grandparents live far from the parents' house. Home care and education utilization was found more among mothers with low degree of time constraints. Utilization of relative support decreased with the children's age and meant lower care cost and increased with mother's employment, fathers' education, family income, cost constraints and when grandparents live nearby. This paper, based on the associated factors, suggests how issues of children enrichment and constraints might be related to the multiplicity.

• Journal of the Korean Data and Information Science Society
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• v.15 no.4
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• pp.1019-1031
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• 2004

This paper describes a new modeling method for the prediction of transmembrane protein topology. The structural regions of the transmembrane protein have been modeled by means of a multiple state hidden Markov model that has provided for the detailed modeling of the heterogeneous amino acid distributions of each structural region. Grammatical constraints have been incorporated to the prediction method in order to capture the biological order of membrane protein topology. The proposed method correctly predicted 76% of all membrane spanning regions and 92% sidedness of the integration when all membrane spanning regions were found correctly.

• Computational Structural Engineering
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• v.9 no.3
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• pp.179-186
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• 1996

A simple nonlinear programming(NLP) formulation for the optimal topology problem of structures is developed and examined. The NLP formulation is general, and can handle arbitrary objective functions and arbitrary stress, displacement constraints under multiple loading conditions. The formulation is based on simultaneous analysis and design approach to avoid stiffness matrix singularity resulting from zero sizing variables. By embedding the equilibrium equations as equality constraints in the nonlinear programming problem, we avoid constructing and factoring a system stiffness matrix, and hence avoid its singularity. The examples demonstrate that the formulation is effective for finding an optimal solution, and shown to be robust under a variety of constraints.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.10
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• pp.930-939
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• 2004

In this paper, both dynamic constraints and kinematic constraints are considered for the analysis of manipulability of robotic systems comprised of multiple cooperating arms. Given bounds on the torques of each Joint actuator for every robot, the purpose of this study is to drive the bounds of task-space acceleration of object carried by the system. Bounds on each joint torque, described as a polytope, is transformed to the task-space acceleration through matrices related with robot dynamics, robot kinematics, object dynamics, grasp conditions, and contact conditions. A series of mathematical manipulations including the procedure calculating minimum infinite-norm solution of linear equation is applied to get the reachable acceleration bounds from given actuator dynamic constrains. Several examples including two robot systems as well as three robot system are shown with the assumptions of complete-constraint contact model(or' very soft contact') and insufficient or proper degree of freedom robot.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.4
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• pp.85-92
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• 1995

A new partitioning algorithm has been developed to implement a large circuit by using multiple field programmable gate array (FPGA) chips. While the conventional partitioning is to minimze the number of nets cut under size constraints, partitioning for multiple FPGAs has several additional constraints so that each partitioned subcircuit can be implemented in a FPGA chip. To obtain satisfactory results under the constraints, the partitioning is performed in two steps whhich are the intial partitioning for global optimization and the iterative partitioning improvements for constraint satisfaction. Experismental results using the MCNC benchmark examples show that our partition method produces better results thatn those of other recent approaches on the average.

• The Journal of the Acoustical Society of Korea
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• v.27 no.3E
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• pp.104-111
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• 2008

Recently, a method for robust time reversal focusing has been introduced to extend the period of stable focusing in time-dependent ocean environments [S. Kim et al., J. Acoust. Soc. Am. 114, 145-157, (2003)]. In this study, concept of focal-size broadening based on waveguide invariant theory in an ocean time reversal acoustics is described. It is achieved by imposing the multiple location constraints. The signal vector used in multiple location constraints are found from the theory on waveguide invariant for frequency band corresponding the extended focal range. The broadening of foci in an ocean waveguide can play an important role in the application of time reversal processing, particularly to the underwater acoustic communication with moving vehicles. The proposed method is demonstrated in the context of the underwater acoustic communication from the transmit/receive array (TRA) to a slowly moving vehicle.

• Language and Information
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• v.6 no.1
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• pp.41-69
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• 2002

This paper addresses the issue of constraints on the conversion of the participle II in German, proposing a constraint-based lexical semantic approach. I argue against the widely accepted syntactic view which is based on the dichotomous distinction of intransitive verbs, which has been advanced by the Unaccusative Hypothesis [Perlmutter (1978)]. Several arguments are also given against the semantic view which is based on some aspectual notions such as 'telicity', 'transformativity' or 'terminativity'. The crucial constraints on the conversion of the participle II in German, it is argued, is instead two lexical semantic entailments, movement with a definite change of location and affectedness. These and other lexical semantic entailments in the sense of Dowty (1991) are encoded into the multiple inheritance type hierarchy of qfpsoa. The proposal made in this paper is based on the multiple inheritance hierarchy which is envisaged in a recent framework of head-driven Phrase Structure Grammar.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.4
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• pp.219-229
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• 2010

The PERT/CPM are considered as the base procedures for the most successful project scheduling programs. Unfortunately, it is not easy to apply these procedures to real-life projects. This is due to the fact that PERT/CPM assume an infinite number of resources for each activity in project networks. Obviously, the completion time under no constraints is less than when constraints are imposed. One way of approaching this problem is to use heuristic solution techniques. In this paper, we present three heuristics; MRU (Maximum Resource Use) rule, STU (Shortest Time Use) rule, MRUP (Max Resource Use and Period) rule for allocating resources to activities of projects under multiple resource constraints. Comparisons of the project durations show that these heuristic rules are superior to AG3 rule that has been widely used in practice (Elsayed and Boucher, 1994).