• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.11
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• pp.1021-1027
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• 2007

A construction noise is the main reason for people's petition among the pollution. The purpose of this study is to develop the noise prediction program to see the level of the noise on the construction site more accurately. For this purpose, the database of the power level on the various equipments was made. The noise reduction by distance and the noise reduction by diffraction of barrier were mainly considered and calculated. The simple noise prediction program will provide the information about proper height and length of the potable barrier which satisfies noise criteria of the construction sites from a construction planning stage. To investigate the reliability of this program, the predicted data was compared with the measured data. An average of difference between measured data and predicted data is $0.1{\sim}2.8\;dB(A)$ and a coefficient of correlation is about $0.85{\sim}0.95$.

• Korean Journal of Human Ecology
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• v.15 no.3
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• pp.481-490
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• 2006

Adjusting pressure level in the construction of athletes' tight-fitting garments by reducing the elastic knit pattern is a challenging subject, which influences the performance of the wearer directly. Therefore, in this study, relationship between the reduction rates of the basic pattern obtained from 3D human scan data and resultant clothing pressure was explored to improve the fit and pressure exerted by clothing. 3D scan data were obtained using Cyberware and they were transformed into a flat pattern using software based on Runge-Kutta method. Reduction rate was examined by subjective wear test as well as objective pressure measurement. As a result, difference in the length between the original 3D body scan data and the 2D tight-fitting pattern was 0.02$\sim$0.50cm (0.05$\sim$1.06%), which was within the range of tolerable limits in making clothes. Among the five garments, the 3T-pattern was superior in terms of subjective sensation and fit. The pressure of the 3T pattern was 2$\sim$4 gf/cm2 at five locations on the body, which is almost the same or a bit higher than that of Z-pattern. In the case of tight-fitting overall garment, the reduction rate of the pattern in the wale direction is more critical to the subjective sensation than the course direction. It is recommended that the reduction grading rules of course direction should be larger than that of Ziegert for a better fit of tight-fitting garments. In the case of wale direction, however, reduction grading rule should be kept the same as suggested earlier by Ziegert (1988).

• Journal of Korean Society of Water and Wastewater
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• v.35 no.2
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• pp.121-133
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• 2021

This study set up the estimates of leakage management efficiency evaluation and leakage management goal that could be used in local water distribution networks efficiency business and modernization business. The data were analyzed using data envelopment analysis and multiple regression analysis. To this end, with leakage management input indices concerning leakage reduction activities (e.g., aged pipe replacement, water meter replacement, leakage restoration, and leakage detection) and leakage management calculation indices (e.g., the increase of revenue water ratio and the reduction of leakage ratio), the data on 22 K-water consignment local water supply systems were analyzed for the years from 2004 through 2018. Using the results of efficiency analysis by data envelopment analysis, the other DMUs (Decision Making Unit) benchmarked the DMU with the highest efficiency to maximize the leakage management efficiency for all DMUs. Through this, leakage management goal estimates were drawn with the input indices of four leakage reduction activities and calculation indices of the increase of revenue water ratio and the reduction of leakage ratio by multiple regression analysis for each group based on the revenue water ratio and leakage ratio. The correlation coefficients of the leakage management goal estimate for the criteria for the revenue water ratio amounted to 0.553 and 0.771. The correlation coefficients of the leakage management goal estimate for the criteria for leakage ratio were 0.397 and 0.865. Accordingly, we estimated the quantity and priority of four leakage reduction activities for the target leakage ratio and revenue water ratio.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.3
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• pp.383-388
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• 2006

SBR is one of the most general sewage/wastewater treatment processes and, particularly, has an advantage in high concentration wastewater treatment like sewage wastewater. A Kernel PCA based fault diagnosis system for biological reaction in full-scale wastewater treatment plant was proposed using only common bio-chemical sensors such as ORP(Oxidation-Reduction Potential) and DO(Dissolved Oxygen). During the SBR operation, the operation status could be divided into normal status and abnormal status such as controller malfunction, influent disturbance and instrumental trouble. For the classification and diagnosis of these statuses, a series of preprocessing, dimension reduction using PCA, LDA, K-PCA and feature reduction was performed. Also, the diagnosis result using differential data was superior to that of raw data, and the fusion data show better results than other data. Also, the results of combination of K-PCA and LDA were better than those of LDA or (PCA+LDA). Finally, the fault recognition rate in case of using only ORP or DO was around maximum 97.03% and the fusion method showed better result of maximum 98.02%.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.4
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• pp.24-33
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• 2004

Advances in remote sensing technologies are resulting in the rapid increase of the number of spectral channels, and thus, growing data volumes. This creates a need for developing faster techniques for processing such data. One application in which such fast processing is needed is the dimension reduction of the multispectral data. Principal component transformation is perhaps the mostpopular dimension reduction technique for multispectral data. In this paper, we discussed the processing procedures of principal component transformation. And we presented and discussed the results of the principal component transformation of the multispectral data. Moreover principal components image data are classified by the Maximum Likelihood method and Multilayer Perceptron method. In addition, the performances of two classification methods and data reduction effects are evaluated and analyzed based on the experimental results.

• Journal of Information Technology Services
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• v.11 no.2
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• pp.243-258
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• 2012

The G2B system is one of the important information systems in the e-government implementation. It is difficult to measure the cost reduction effect of the system introduction because there are many participants in the complex procurement processes. Previous approaches of the performance evaluation of such processes have been based on conducting some surveys and interviews with statistical methods. Therefore there have been some limitations in the verification of feasibility. Therefore this study tries to suggest a case of performance evaluation about the cost reduction in using of the G2B system by analyzing operational DB data from the G2B system. This study analyzed the procurement processes of G2B system according to 'goods' and 'facilities/services' and classified the procurement processes into 12 sub-processes. By developing an evaluation model for the cost reduction of e-procurement, we derived the whole cost reduction effect was 8,000 billon Won for the use of Korea KONEPS G2B system in 2008. Specially the cost reduction in the private sector was 6,600 billion Won. It was mainly due to the decrease of the offline visits to the related organizations to participate a bidding process. Moreover, the cost reduction of using shopping mall was 1,000 billion Won among the total 1,400 billion Won in the whole public sector. The main contribution of this paper is to show the more objective evaluation result of the use of e-procurement, which verifies the necessity of G2B system.

• The Korean Journal of Franchise Management
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• v.13 no.3
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• pp.45-55
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• 2022

Purpose: Consumers' experience of functional attributes is remembered, and the experience lowers the cost of consumers' input from their point of view and reduces uncertainty. It also plays an important role in consumers' positive emotions and responses. Accordingly, if information search costs are reduced in terms of the costs perceived by consumers about restaurants, a strategy differentiated from other companies can be established. Therefore, this study investigated the effect of functional congruence of restaurant stores on information search cost reduction, positive/negative emotions, and loyalty. Research Design, Data, and Methodology: This study investigated functional congruence, information search cost reduction, and positive/negative emotions. The structural relationship between loyalty was analyzed. To verify this, a research hypothesis was established based on previous studies and a research model was constructed. The questionnaire items were modified and used according to the current study, based on previous studies. The data were collected using the questionnaire method from 187 people who had dining out experience. Frequency analysis was performed to confirm demographic characteristics. Reliability, convergent validity, and discriminant validity of the collected data were verified. The research model was analyzed with a structural equation modeling (SmartPLS 4). Results: The findings show that functional congruence had significant positive effects on information search cost reduction and positive emotion, but no significant effect on negative emotion. Information search cost reduction had significant positive effects on positive emotion/negative emotion but did not significantly affect loyalty. Lastly, both positive and negative emotions had significant positive effects on loyalty. Conclusion: Based on transaction cost theory, this study found how functional congruence and information search cost reduction influence consumers' emotions. The functional attributes of restaurants were perceived by customers as information, thus uncertainty was decreased. Finally, appropriate management strategies and implications of functional congruence and information search cost in the restaurant were suggested.

• Journal of Industrial Convergence
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• v.21 no.2
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• pp.125-131
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• 2023

In this paper, research was conducted to solve the problem of reducing the dimming level and flicker that occurs in the visible light communication system. Visible light communication is a convergence technology that provides both communication and lighting, and must satisfy not only communication performance but also lighting performance. However, since the existing data transmission method transmits without considering the transmission data sequence, it reduces the dimming level and causes a flicker phenomenon. To solve this problem, in this paper, the Dimming Improvement and Flicker Reduction Mapping technique was studied. Existing systems simply transmitted data of '0' and '1', but in this system, original data transmission channels and DIFR (Dimming Improvement and Flicker Reduction) transmission channels are assigned to RGB channels. Original data is allocated to the R channel and original data or inverse original data is allocated to the DIFR-G channel, and the DIFR-B channel maintains the maximum dimming level by transmitting through the logical operation of the R channel and the G channel. At the same time, the flicker phenomenon is prevented by preventing continuous occurrence of 'OFF' patterns. Through this, we proposed an adaptive data allocation algorithm that can faithfully play a role as a light as well as a communication function.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.117-126
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• 2011

RSA-CRT algorithm is widely used to improve the performance of RSA algorithm. However, it is also vulnerable to side channel attacks like as general RSA. One of the power attacks on RSA-CRT, proposed by Boer et al., is a power analysis which utilizes reduction steps of RSA-CRT algorithm with equidistant chosen messages, called as ECMPA(Equidistant Chosen Messages Power Analysis) or MRED(Modular Reduction on Equidistant Data) analysis. This method is to find reduction output value r=xmodp which has the same equidistant patterns as equidistant messages. One can easily compute secret prime p from exposure of r. However, the result of analysis from a reduction step in [5] is remarkably different in our experiment from what Boer expected in [5]. Especially, we found that there are Ghost key patterns depending on the selection of attack bits and selected reduction algorithms. Thus, in this paper we propose several Ghost key patterns unknown to us until now, then we suggest enhanced and detailed analyzing methods.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.172-177
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• 2007

Wavelet transforms provide basis functions for time-frequency analysis and have properties that are particularly useful for the compression of analogue point on wave transient and disturbance power system signals. This paper evaluates the compression properties of the discrete wavelet transform using actual power system data. The results presented in the paper indicate that reduction ratios up to 10:1 with acceptable distortion are achievable. The paper discusses the application of the reduction method for expedient fault analysis and protection assessment.