• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.4
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• pp.251-263
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• 2003

This paper presents matrix inequality conditions for Η$_2$control and Η$_2$controller design method of linear time-invariant descriptor systems with parameter uncertainties in continuous and discrete time cases, respectively. First, the necessary and sufficient condition for Η$_2$control and Η$_2$ controller design method are expressed in terms of LMI(linear matrix inequality) with no equality constraints in continuous time case. Next, the sufficient condition for Hi control and Η$_2$controller design method are proposed by matrix inequality approach in discrete time case. Based on these conditions, we develop the robust Η$_2$controller design method for parameter uncertain descriptor systems and give a numerical example in each case.

• International Journal of Human Ecology
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• v.9 no.1
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• pp.5-16
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• 2008

Development of technology in the $20^{th}$ century has made great contributions to women's lives. With the development of digital convergence, home network, and DMBs (Distance Method Bracings), the ubiquitous technology information era is expected to create a new progressive era for women. The purpose of this study is to investigate the lifestyle that Korean women would like to pursue, especially in regards to the sense of value within the personal and social life of each individual. As a method to suggest how the socio-cultural trends of women's lifestyle will change in the ubiquitous era, qualitative interviews have been conducted over 6 groups with 77 persons between the digital ages of 20s and 30s, living in Seoul. The majority had positive opinions regarding the economic, cultural, emotional, and physical prospects of the ubiquitous information environment. Results show high expectations evolved around freedom from household chores, the equality between the sexes (at home and in society), enhancing the working environment at home, an expansion of human relationships leading to creative knowledge, being able to maintain a single life without economic constraints, and the enjoyment that the internet provides. for suggestions to improve the quality of women's lifestyle through ubiquitous technology, issues such as individual based customization, time management, creating emotional hyperspaces, multi-media communication systems, and women as leaders were studied.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.80-89
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• 2013

This paper presents an efficient approach for solving economic dispatch (ED) problems with nonconvex cost functions using a 'Mean-Variance Optimization (MVO)' algorithm with Kuhn-Tucker condition and swap process. The aim of the ED problem, one of the most important activities in power system operation and planning, is to determine the optimal combination of power outputs of all generating units so as to meet the required load demand at minimum operating cost while satisfying system equality and inequality constraints. This paper applies Kuhn-Tucker condition and swap process to a MVO algorithm to improve a global minimum searching capability. The proposed MVO is applied to three different nonconvex ED problems with valve-point effects, prohibited operating zones, transmission network losses, and multi-fuels with valve-point effects. Additionally, it is applied to the large-scale power system of Korea. The results are compared with those of the state-of-the-art methods as well.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.3 s.258
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• pp.355-364
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• 2007

Multidisciplinary design optimization based on independent subspaces (MDOIS) is a simple and practical method that can be applied to the practical engineering MDO problems. However, the current version of MDOIS does not handle the common design variables. A new version of MDOIS is proposed and named as MDOIS/2006. It is a two-level MDO method while the original MDOIS is a single-level method. At first, system analysis is performed to solve the coupling in the analysis. If the termination criteria are not satisfied, each discipline solves its own design problem. Each discipline in the lower level solves the problem with common design variables while they are constrained by equality constraints. In the upper level, the common design variables of related disciplines are determined by using the optimum sensitivity of the objective function. To validate MDOIS/2006, mathematical problem and NASA test bed problem are solved. The results are compared with those from other MDO methods. Finally, MDOIS/2006 is applied to flow patterner design and shows that it can be successfully applied to the practical engineering MDO problem.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.6
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• pp.951-957
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• 2010

An optimal path generation method considering the safety of UGV(Unmanned Ground Vehicle) is proposed and demonstrated through examples. Among various functions of UGV, real-time obstacle avoidance is a key issue to realize realistic scenario in FCS(Future Combat Systems). A two-dimensional narrow corridor environment is considered as a test field. For each step of UGV movement, two objectives are considered: One is to minimize the distance to the target and the other to maximize the distance to the nearest point of an obstacle. A weighted objective function is used in the optimization problem. Equality and inequality constraints are taken to secure the UGV's dynamics and safety. The weighting factors are controlled by a fuzzy controller which is constructed by a fuzzy rule set and membership functions. Simulations are performed for two cases. First the weighting factors are considered as constant values to understand the characteristics of the corresponding solutions and then as variables that are adjusted by the fuzzy controller. The results are satisfactory for realistic situations considered. The proposed optimal path generation with the fuzzy control is expected to be well applicable to real environment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.12
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• pp.3871-3882
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• 1996

In this paper, a closed-form formulation for inverse kinematics of robot manipulators with kinematic redundancy under the constrained environment has been derived using the Kuhn-Tucker condition, the extended Lagrange multiplier method and the working set method. The proposed algorithm satisfies the necessaryand sufficient conditions for optimization subject to equality and inequality constraints. In addition, computationally efficient kinematic control methods have been proposed using differential kinemetics and gradient projection mehtod. The effectiveness of the proposed methods has been demonstrated with a 4-dof planar robot, and then a 7-dof spatial robot as a practical application to the nozzle dam task in the Nuclear Power Plant.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.475-480
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• 2014

In the fields of researches associated with plant layout optimization, the main goal is to minimize the costs of pipelines for connecting equipment. However, what is the lacking of considerations in previous researches is to handle the multi floor processes considering the safety distances for domino impacts on a complex plant. The mathematical programming formulation can be transformed into MILP (Mixed Integer Linear Programming) problems as considering safety distances, maintenance spaces, and economic benefits for solving the multi-floor plant layout problem. The objective function of this problem is to minimize piping costs connecting facilities in the process. However, it is really hard to solve this problem due to complex unequality or equality constraints such as sufficient spaces for the maintenance and passages, meaning that there are many conditional statements in the objective function. Thus, it is impossible to solve this problem with conventional optimization solvers using the derivatives of objective function. In this study, the PSO (Particle Swarm Optimization) technique, which is one of the representative sampling approaches, is employed to find the optimal solution considering various constraints. The EO (Ethylene Oxide) plant is illustrated to verify the efficacy of the proposed method.

• Journal of KIISE:Software and Applications
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• v.31 no.10
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• pp.1304-1319
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• 2004

We can significantly reduce the cost o# program testing by automating the process of test data generation. Test data generation usually concerns identifying input values on which a selected path is executed. Although lots of research has been done so far, there still remains a lot of issues to be addressed. One of the issues is the shape problem. The shape problem refers to the problem of figuring out a shape of the input data structure required to cause the traversal of a given path. In this paper, we introduce a new method for the shape problem. The method converts the selected path into static single assignment (SSA) form without pointer dereferences. This allows us to consider each statement in the selected path as a constraint involving equality or inequality. We solve the constraints to get a solution which will be represented in terms of the points-to relations for each input variable. Simple, but illustrative examples are given to explain the proposed method.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.366-382
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• 2023

Among the many novels penned by Thomas Hardy, the novel "Tess of the d'Urbervilles" came into print in 1891.In this novel, Hardy portrays Tess who was born and raised in a rural middle-class family but ends up working as a laborer, trapped in a society where she is subjugated by the men's wealth, leading a life marked by loneliness and isolation. The novel presents the status of women, moral struggles, and the challenging fate that they must overcome. It highlights the powerlessness of women living in a structurally unreasonable social environment, forced to depend on the ever-changing twists of destiny. This story delves into the complexities of love between the genders, moral conflicts, and the societal criticism that must be confronted. By utilizing the life of the young woman Tess, it underscores the struggle for existence and elucidates the roles, expectations, and constraints imposed on gender during the Victorian era. This research paper aims to compare the roles of women in the Victorian era in Britain and woman in contemporary Korean society. The Victorian era featured rigid gender norms, confining women to prescribed roles. In contrast, modern Korean society blends tradition and modernity, empowering women to play vital roles and reshape societal norms. Our research explores the interplay of tradition and change, providing a comprehensive understanding of women's evolving roles in both historical and contemporary contexts. We will present our discussions regarding the enduring roles that women have faced in both periods. Furthermore, we aim to highlight the distinctive roles women are called upon to play while dealing with the swift transformations in contemporary Korean society, recognizing them as essential agents in the agents in advancing Korean society.