• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.8
• /
• pp.790-797
• /
• 2007

This paper proposes a new measure of cost function ruggedness in local optimization with DEAS. DEAS is a computational optimization method developed since 2002 and has been applied to various engineering fields with success. Since DEAS is a recent optimization method which is rarely introduced in Korean, this paper first provides a brief overview and description of DEAS. In minimizing cost function with this non-gradient method, information on function shape measured automatically will enhance search capability. Considering the search strategies of DEAS are well designed with binary matrix structures, analysis of search behaviors will produce beneficial shape information. This paper deals with a simple quadratic function contained with various magnitudes of noise, and DEAS finds local minimum yielding ruggedness measure of given cost function. The proposed shape information will be directly used in improving DEAS performance in future work.

• Journal of Korean Society for Quality Management
• /
• v.21 no.1
• /
• pp.199-213
• /
• 1993

The function-cost matrix table is not constant, but can be changed by many factors including equipment capacity, level of production technique, fluctuation of production volume, and the continuous development of products. Such changes would give the VE analysists additional work burden. By using computer. in this study, much of the time and effort of the function evaluation could be saved, and the efficiency of the analysis could also be enhanced. The application of the function evaluation data of R Company, as a case analysis, to the function evaluation computer program developed in this study resulted in the faster management of function-cost matrix table and function evaluation.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.12
• /
• pp.3782-3791
• /
• 1996

A great deal of effert has been invested in upgrading the performance and the efficiency of mechanical structures. Using experimental modal analysis(EMA) or finite element analysis(FEA) data of mechanical structures, this performance and efficiency can be effectively evaluated. In order to analyze complex structures such as automobiles and aircraft, for the sake of computing efficiency, the dynamic substructuring techniques that allow to predict the dynamic behavior of a structure based on that of the composing structures, are widely used. By llinking a modal model obtained from EMA and an analytical model obtained from FEA, the best conditioned structures can be desinged. In this paper, a new algorithm for structural dynamic modification-SRFSM (substructure response function sensitivity method) is proposed by linking frequency responce function synthesis and response function sensitivity. A mehtod to obtain response function sensitivity using direct derivative of mechanical impedance, is also used.

• Journal of the Korean Institute of Rural Architecture
• /
• v.8 no.2
• /
• pp.27-35
• /
• 2006

The park in city, is more than just ecological function, contributes emotional refinement and psychological stability to citizens, and give satisfaction of social and recreational activities to the citizens. And it is the place of leisure and the place to raise up the quality of urban environment. Especially, the neighborhood park among urban parks occupies the most important position as a leisure space for local resident, but it can not perform its purpose and function as a leisure space, due to its too formal and insufficient facilities. This study, approaching from point of physical method, intends to make types through classifying each parks by built-type and installed facilities which affect human-beings, approaching from point of human-beings, intends to make the using-type analysis of park-users, and the questionnaire.By grasping of their requirements regarding to the characters and facilities what they want, willing to present the fundamental data for effective utility-activating method of small-scaled neighborhood park.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.33 no.3
• /
• pp.137-145
• /
• 2010

The objective of this paper is to evaluate the equilibrium price between PSTN and VoIP telephony services in the case of non-linear utility function. Currently there are two types of wired phone services we are known PSTN (Public Switched Telephone Network) and VoIP (Voice over Internet Protocol). The PSTN telephony which provide high quality service and VoIP which provides relatively low quality service form a vertically differentiated oligopoly. Therefore, the evaluation of the equilibrium price between PSTN and VoIP services is very important to wired phone service providers. The equilibrium price depends on the state of the service cost function has been proved different value. This paper was evaluated each equilibrium price for the state of the linear cost function and non-linear cost function. Subsequently, this paper analyzed the demand of both services and the equilibrium profit which can maximize the profit of both service providers.

• The Korean Journal of Applied Statistics
• /
• v.21 no.3
• /
• pp.547-560
• /
• 2008

It is well known that spectral density function determines auto-covariance function of stationary time-series data and smoothed periodogram is a consistent estimator of spectral density function. Recently, Kim and Park (2007) showed that smoothed- periodogram based distances performs very well for the classification. In this paper, we introduce classification methods with smoothed periodogram and apply the approaches to the monthly precipitation measurements obtained from January, 1987 through December, 2007 at 22 locations in South Korea.

• Journal of Digital Contents Society
• /
• v.11 no.1
• /
• pp.9-16
• /
• 2010

Recently, needs and interests that people want to create their digital contents in ubiquitous environment are growing fast. Among the digital contents, people are also interested in the music contents. However, it is hard to find a system which manages and shares music contents easily. The paper proposes a system that provides a composition function for music, a mixing function for music, and a function for ear training. The contributions of the paper are as follows. First, the paper provides a music management system which enables music compositions, listening function of music, searching functionalities. Second, the paper introduces a function of mixing drum sound for managing rhythms. Third, the paper provides game contents which improve senses of music. The proposed system is expected that enables users composite music in ubiquitous environment, provides rich functions for compositions, and improves senses of music.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.3
• /
• pp.39-46
• /
• 2005

In this paper, adaptive higher harmonic control technique using Neural Networks (NN) is proposed. First, linear transfer function is estimated to relate the input harmonics and output harmonics, then NN which has the universal function approximation property is applied to expand application range of the transfer function. Optimal control gain matrix computed from the transfer function is used to train NN weights. Online weight adaptation laws are derived from Lyapunov's direct method to guarantee internal stability. Results of the simulation of 6-input 2-output nonlinear system show that adaptive HHC is applicable to the system with uncertain transfer function.

• The Korean Journal of Physiology and Pharmacology
• /
• v.8 no.5
• /
• pp.253-257
• /
• 2004

Schwann cells play an important role in peripheral nerve regeneration. Upon neuronal injury, activated Schwann cells clean up the myelin debris by phagocytosis, and promote neuronal survival and axon outgrowth by secreting various neurotrophic factors. However, it is unclear how the nerve injury induces Schwann cell activation. Recently, it was reported that certain cytoplasmic molecules, which are secreted by cells undergoing necrotic cell death, induce immune cell activation via the toll-like receptors (TLRs). This suggests that the TLRs expressed on Schwann cells may recognize nerve damage by binding to the endogenous ligands secreted by the damaged nerve, thereby inducing Schwann cell activation. Accordingly, this study was undertaken to examine the expression and the function of the TLRs on primary Schwann cells and iSC, a rat Schwann cell line. The transcripts of TLR2, 3, 4, and 9 were detected on the primary Schwann cells as well as on iSC. The stimulation of iSC with poly (I : C), a synthetic ligand for the TLR3, induced the expression of $TNF-{\alpha}$ and RANTES. In addition, poly (I : C) stimulation induced the iNOS expression and nitric oxide secretion in iSC. These results suggest that the TLRs may be involved in the inflammatory activation of Schwann cells, which is observed during Wallerian degeneration after a peripheral nerve injury.

• Mycobiology
• /
• v.31 no.3
• /
• pp.179-182
• /
• 2003

A total of 187 endophytic fungi were isolated from 11 plant species, which were collected from 11 locations in Korea. Their antifungal activities were screened in vivo by antifungal bioassays after they were cultured in potato dextrose broth and rice solid media. Antifungal activity against plant pathogenic fungi such as Magnaporthe grisea(rice blast), Corticium sasaki(rice sheath blight), Botrytis cinerea(tomato gray mold), Phytophthora infestans(tomato late blight), Puccinia recondita(wheat leaf rust), and Blumeria graminis f. sp. hordei(barley powdery mildew) was determined in vivo by observing the inhibition of plant disease development. Twenty(11.7%) endophytic fungi fermentation broths were able to control, by more than 90%, at least one of the six plant diseases tested. Among 187 liquid broths, the F0010 strain isolated from Abies holophylla had the most potent disease control activity; it showed control values of more than 90% against five plant diseases, except for tomato late blight. On the other hand, fourteen(7.5%) solid culture extracts exhibited potent disease control values of more than 90% against one of six plant diseases. The screening results of this study strongly suggested that metabolites of plant endophytic fungi could be good potential sources for screening programs of bioactive natural products.