• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.8 s.101
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• pp.939-944
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• 2005

In this paper, a sound quality index for the evaluation of the vehicle intake noise was developed through a correlation analysis of the objective measurement and the subjective evaluation. First, intake orifice noise was measured at the wide-open throttle sweep condition. And then, the acoustic transfer function between intake orifice noise and interior noise was measured. Simultaneously, subjective evaluation was carried out with a 10-scale score by 8 special engineers. The correlation analysis between the psychoacoustic parameters derived from the measurement and the subjective evaluation was performed. The most critical factor was determined and the corresponding sound quality index for intake noise was obtained from the multiple factor regression analysis method. Finally, the effectiveness of the proposed index was validated.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.11
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• pp.1003-1012
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• 2000

When a robot hand grasp an object, the number of ways to grasp it stably are infinite and thus an optimal grasp planning is needed to find the optimal grasp points for satisfying the objective of the given task. In this paper, we first define some grasp indices to evaluate the quality of each feasible grasp and then a weighted composite grasp index by combining all of the grasp indices is also defined. Next, we propose a method to find the optimal grasp points of the given object by comparing the defined weighted composite grasp index for each feasible grasp points. By simulation results, we show the effectiveness of the proposed optimal grasp planning method and also discuss the trend of each grasp index as the grasp polygon.

• Journal of Information Technology Services
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• v.7 no.3
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• pp.145-157
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• 2008

The existing XML storage methods which use relational data model, usually store path information for every node type including literal contents in order to keep the structural information of XML documents. Such path information is usually maintained by an inverted index to efficiently process XPath queries for large XML documents. In this study, We propose an improved approach that retrieve information from the large volume of XML documents stored in a relational database, while using a segment-based inverted index for path searches. Our new approach can reduce the number of searching an inverted index for getting target path information. We show the effectiveness of this approach through several experiments that compare XPath query performance with the existing methods.

• Korean Journal of Construction Engineering and Management
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• v.23 no.5
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• pp.98-107
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• 2022

The purpose of this study is to suggest a model for evaluation of a risk based value index for modular design alternatives in plant construction projects. Accordingly, 1) Setting the basic project cost and the scope to apply the module, 2) Evaluating the importance, easiness, and effectiveness index for Engineering, Procurement, Fabrication, transportation, and construction work, 3) Estimating the total project cost by analyzing the risk reserve Step, 4) Comparing the effectiveness index and total project cost for each modular design alternative, it was composed of the steps of deriving RVI. To verify such a model, Plan-A, which applied a module to one process, and Plan-B, which applied a module to three processes, were composed to evaluate RVI.

• Journal of People, Plants, and Environment
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• v.22 no.3
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• pp.269-277
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• 2019

This study aims to see what changes flower arrangement programs bring to the stress index of elderly people with chronic diseases and its correlation with cognition. Furthermore, seniors from a day care center and a nursing home were compared for the purpose of identifying the effectiveness of flower arrangement activities as a supplementary remedy designed to relieve the symptoms and improve the quality of life of patients with chronic diseases. In this study, 24 seniors with chronic diseases were divided into two groups: Group A consists of 15 seniors from a day care center and Group B consists of nine seniors from a nursing home. Both groups participated in simple flower arrangement activities in 10 sessions. In each session, red and green cut flowers that were preferred by the elderly were provided to elicit and develop their thoughts and behaviors. The results showed that the overall average stress index was significantly reduced from 58.0±11.6 before the program to 50.6±17.1 after the program (p = .037). This study examined that the program was more effective for Group A (p = .021) than for Group B (p = .678). Results of the correlation analysis showed that there was no correlation between cognitive function and stress index (p = .569), but that the activity was more effective for Group A. This study shows that arranging flowers effectively lowers the stress index of elderly people with chronic diseases. Also, sharing the outcomes of such activities with others or continuously caring for the flowers even after the activity can maximize the effectiveness of the therapy and rehabilitation. Thus, the study concluded that the program needs to be applied continuously, not in the short-term, in order to relieve or treat the symptoms of elderly patients with chronic diseases.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1449-1466
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• 2014

In this paper, we consider a hedge portfolio based on futures of underlying asset. A classical way to estimate a hedge ratio for a hedge portfolio of a spot and futures is a regression analysis. However, a regression analysis is not capable of reflecting long-run equilibrium between a spot and futures and volatility clustering in the conditional variance of financial time series. In order to overcome such defects, we analyzed KOSPI200 index and futures using VECM-CC-GARCH model and computed a hedge ratio from the estimated conditional covariance-variance matrix. In real data analysis, we compared a regression and VECM-CC-GARCH models in terms of hedge effectiveness based on variance, value at risk and expected shortfall of log-returns of hedge portfolio. The empirical results show that the multivariate GARCH models significantly outperform a regression analysis and improve hedging effectiveness in the period of high volatility.

• (The) Korean Journal of Advertising
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• v.27 no.3
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• pp.113-139
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• 2016

The purpose of this study was to investigate perception of media characteristics inorder to provide a theoretical background for the media mix strategy. Considering the qualitative-vale of each medium, this study conducted a survey consisting of 60 academic and advertising industry experts to examine how they perceive and evaluate the characteristics of TV, radio, newspaper, OOH, Internet, mobile, and digital signage in terms of media effectiveness. The results, first, show that 'media engagement', 'effective reach', and 'behavioral targeting' are three most important indices to assess the media effectiveness. Second, the Internet was best evaluated in its various aspects according to the MAIX model, which gauges the effectiveness of each advertising medium. The study also proved that each advertising medium has unique advantages so that each medium should adopt a strategic positioning to differentiate it from other media. As such, this study provides meaningful evidences to understand the various characteristics and competitive value of advertising media and useful guidelines for media planning.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.440-447
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• 2000

In order to evaluate the cost effectiveness of seismic isolation for bridges in low and moderate seismic region, a method of calculation minimum life-cycle cost of seismic-isolated bridges under specific acceleration level and soil condition is developed. Input ground motion is modeled as spectral density function compatible with response spectrum for combination of acceleration coefficient and site coefficient. Failure probability is calculated by spectrum analysis based on random vibration theories to simplify repetitive calculations in the minimization procedure. Ductility of piers and its effects on cost effectiveness are considered by stochastic linearization method. Cost function and cost effectiveness index are defined by taking into consideration the characteristics of seismic isolated bridges. Limit states for calculation of failure probability are defined on superstructure, isolator and pier, respectively. The results of example design and analysis show that seismic isolation is more cost-effective in low and moderate seismic region than in high seismic region.

• Journal of the Korea Society of Computer and Information
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• v.23 no.8
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• pp.85-93
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• 2018

In this research, it is proposed that a method to hide data by modifying directory index entry information. It consists of two methods: a directory list hiding and a file contents hiding. The directory list hiding method is to avoid the list of files from appearing in the file explorer window or the command prompt window. By modifying the file names of several index entries to make them duplicated, if the duplicated files are deleted, then the only the original file is deleted, but the modified files are retained in the MFT entry intact. So, the fact that these files are hidden is not exposed. The file contents hiding is to allocate data to be hidden on an empty index record page that is not used. If many files are made in the directory, several 4KB index records are allocated. NTFS leaves the empty index records unchanged after deleting the files. By modifying the run-list of the index record with the cluster number of the file-to-hide, the contents of the file-to-hide are hidden in the index record. By applying the proposed method to the case of hiding two files, the file lists are not exposed in the file explorer and the command prompt window, and the contents of the file-to-hide are hidden in the empty index record. It is proved that the proposed method has effectiveness and validity.

• Structural Engineering and Mechanics
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• v.26 no.3
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• pp.315-341
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• 2007

A sudden change of stiffness in a structure, associated with the events such as weld fracture and brace breakage, will cause a discontinuity in acceleration response time histories recorded in the vicinity of damage location at damage time instant. A new damage index is proposed and implemented in this paper to detect the damage time instant, location, and severity of a structure due to a sudden change of structural stiffness. The proposed damage index is suitable for online structural health monitoring applications. It can also be used in conjunction with the empirical mode decomposition (EMD) for damage detection without using the intermittency check. Numerical simulation using a five-story shear building under different types of excitation is executed to assess the effectiveness and reliability of the proposed damage index and damage detection approach for the building at different damage levels. The sensitivity of the damage index to the intensity and frequency range of measurement noise is also examined. The results from this study demonstrate that the damage index and damage detection approach proposed can accurately identify the damage time instant and location in the building due to a sudden loss of stiffness if measurement noise is below a certain level. The relation between the damage severity and the proposed damage index is linear. The wavelet-transform (WT) and the EMD with intermittency check are also applied to the same building for the comparison of detection efficiency between the proposed approach, the WT and the EMD.