• Korean Journal of Remote Sensing
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• v.35 no.6_1
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• pp.895-905
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• 2019

Commercial Unmanned Aerial Vehicle (UAV) image processing software products currently used in the industry provides camera calibration information and block bundle adjustment accuracy. However, they provide mapping accuracy achievable out of input UAV images. In this paper, the quality of mapping is calculated by using orientation parameters from UAV image processing software. We apply the orientation parameters to the digital photogrammetric workstation (DPW) for verifying the reliability of the mapping quality calculated. The quality of mapping accuracy was defined as three types of accuracy: Y-parallax, relative model and absolute model accuracy. The Y-parallax is an accuracy capable of determining stereo viewing between stereo pairs. The Relative model accuracy is the relative bundle adjustment accuracy between stereo pairs on the model coordinates system. The absolute model accuracy is the bundle adjustment accuracy on the absolute coordinate system. For the experimental data, we used 723 images of GSD 5 cm obtained from the rotary wing UAV over an urban area and analyzed the accuracy of mapping quality. The quality of the relative model accuracy predicted by the proposed technique and the maximum error observed from the DPW showed precise results with less than 0.11 m. Similarly, the maximum error of the absolute model accuracy predicted by the proposed technique was less than 0.16 m.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.4
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• pp.655-666
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• 2010

Purpose : The examine the reliability and validity of the modified Emory Functional Ambulation Profile(mEFAP) for assessing gait function in chronic stroke patients. Methods : A total of 45 stroke patients, who had a stroke more than 6 months, participated in the study. Reliability was determined by Intra-class Correlation Coefficient($ICC_{3,1}$), including Bland and Altman method (Standard Error of Measurement: SEM, Small Real Differences: SRD). Validity was examined by correlating results to the gait ability(mEFAP, Modified Motor Assessment Scale-Gait(MMAS-G), Scandinavian Stroke Scale-Gait(SSS-G), Functional Ambulation Category(FAC), 10m Waking Test(10m WT)), and Fugl Meyer-Lower/Extremity(FM-L/E), Berg Balance Scale(BBS). Results : Inter-rater reliability for the total mEFAP was High($ICC_{2,1}$=.998), and absolute reliability were excellent (SEM: 1.75, SRD: 4.85). Subjects without assistance factor performed better on all tests than did subjects who had stroke. There were significant correlations between the mEFAP and MMAS-G, SSS-G, FAC(r=-.66~-.79), 10 m WT(r=-.86), and FM-L/E, BBS(r=-.72~-.78), indicating good validity. Increased times on the mEFAP correlated with poor performance on the gait ability, motor function of lower extremity, BBS and slow gait speeds on the 10 m WT in stroke patients. Conclusion : The mEFAP can be administered easily and comprehensively. It is a reliable gait assessment tool for patients with stroke and correlated with known of function, the mEFAP may be a clinically useful measure of ambulation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.04a
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• pp.91-98
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• 2000

Derivation of stage-discharge relationship and characteristics for Yangsan river is presented in this paper. This research has been conducted as the second one after the first trial of 1997. The determination of discharge at a Yangsan river gauging was best made by measuring the flow velocities with a current meter and rod float. The rating curve obtained through 52 stage-discharge measurements on Yangsan river basin in 1999 is represented by Q=15.3540-140.6076H+182.44372$H^2$, which is discovered to be most excellent among other curves in reliability analysis. The capability of the observed stage-discharge data for Yangsan river was tested by HEC-RAS program, and its capability to reproduce discharge was investigated and compared with the computational results. Rating curve stability is determined on the basis of deviations in the stage-discharge relationship, utilization of specific gauge, and absolute differences between sequential stream flow measurements and an analysis residuals. Therefore it seems necessary to research method to obtain rating curve in a rigorous and accurate manner.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.11
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• pp.1066-1074
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• 2004

A vibration isolation system for a large reverberation chamber (1,228 $m^3$ and 1,000 ton) has been installed and verified. The reverberation chamber generates loud noise and induces high level of vibration while performing spacecraft acoustic reliability tests. The isolation system prevents vibration transfer from the chamber to the enclosure buildings. This paper describes design process and commissioning experiments of the system. Design criteria have been derived from rigid body model of the chamber. The stiffness of neoprene pads has been selected by employing finite element analysis of the reverberant chamber and isolation system. A total of 21 neoprene pads have been installed between the chamber and supporting Pedestals. A sand bag of 800kg was dropped on the chamber floor to measure the natural frequency of the isolation system. While 136.9 dB noise is generated in the chamber, absolute transmissibility of the isolation system has been measured. The measured natural frequency of the chamber is 10.2Hz, which is 80% of the predicted value. Overall transmissibility at working frequency range (25∼10.000 Hz) is less than -12.4 dB.

• Korean Journal of Community Nutrition
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• v.13 no.4
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• pp.531-539
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• 2008

The purpose of this study is to examine how nutritionists, principals and parents evaluated the importance and priorities of different selection factors for food materials suppliers in an attempt to suggest how to ensure the best supplier choice, since the selection of the best supplier was mandatory for the successful TQM of school food services. This study especially aims to develop priority alternatives based on relative rather than absolute assignments on selection of suppliers for school food service materials. To apply AHP, the selection factors of a food materials suppliers were grouped into five categories, which included quality, service, reliability, hygiene and price. And the five categories involved 28 elements. As the result, quality was considered most crucial on the whole, followed by service, reliability, hygiene and price; and food labeling in the category of quality evaluated as that of first priority in the totality evaluation elements.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.115-123
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• 2023

We introduce a new 'image-mapping' in-situ U-Pb dating method using LA-ICP-MS, proposed by Drost et al. (2018), and show the characteristics and usability of this method through several examples of absolute age results determined by first applying it to samples from the Joseon Supergroup of the Early Paleozoic Era in Korea. Unlike the previous in-situ spot analysis, this in-situ U-Pb dating method for carbonate minerals can determine the absolute age with high reliability by applying the 'image-mapping' method of micro-sized domains based on micro-textural observation, as well as determine the absolute age of multiple geological 'events' that occurred after deposition. This was confirmed in the case of determining the syn-depositional age and the multiple post-depositional ages from carbonate minerals of the Makgol and the Daegi Formations. Therefore, if the 'image-mapping' in-situ U-Pb dating method is applied to determine the absolute age of various types of carbonate minerals that exist in various geological environments throughout the geologic era, it will be possible to secure new geological age information.

• Journal of Korea Water Resources Association
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• v.57 no.3
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• pp.209-223
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• 2024

In the context of the fourth industrial revolution, data-driven decision-making has increasingly become pivotal. However, the integrity of data analysis is compromised if data quality is not adequately ensured, potentially leading to biased interpretations. This is particularly critical for water level data, essential for water resource management, which often encounters quality issues such as missing values, spikes, and noise. This study addresses the challenge of noise-induced data quality deterioration, which complicates trend analysis and may produce anomalous outliers. To mitigate this issue, we propose a noise removal strategy employing Wavelet Transform, a technique renowned for its efficacy in signal processing and noise elimination. The advantage of Wavelet Transform lies in its operational efficiency - it reduces both time and costs as it obviates the need for acquiring the true values of collected data. This study conducted a comparative performance evaluation between our Wavelet Transform-based approach and the Denoising Autoencoder, a prominent machine learning method for noise reduction.. The findings demonstrate that the Coiflets wavelet function outperforms the Denoising Autoencoder across various metrics, including Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and Mean Squared Error (MSE). The superiority of the Coiflets function suggests that selecting an appropriate wavelet function tailored to the specific application environment can effectively address data quality issues caused by noise. This study underscores the potential of Wavelet Transform as a robust tool for enhancing the quality of water level data, thereby contributing to the reliability of water resource management decisions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.39-44
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• 2017

In this study, we compared the perception of absolute purchase of equipment for broadcasting equipment purchasing demand according to the rapid change of domestic content production and distribution method, and the degree of information such as technical reliability and system stability of domestic broadcasting equipment perceived by consumer The effects were analyzed through a research model. Due to the lack of existing research data on broadcasting equipment demand, we conducted in depth interviews with surveys of broadcasting equipment and surveys. As a result of analysis, compared to foreign equipments, there are many cases of purchase of domestic equipments, systems, and block purchases. To improve the preference and satisfaction of Korean broadcasting equipment, which is recognized by domestic demand for broadcasting equipment, it is urgent to improve the technical reliability and to develop core key equipment and to expand the demand of domestic equipment limited to small power transmitter antenna and monitor equipment. It is urgent to develop in order to develop overseas and to support the domestic market to secure the domestic market.

• Journal of the Korea Society of Computer and Information
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• v.19 no.5
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• pp.61-69
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• 2014

Collaborative filtering recommendation creates similar item subset or similar user subset based on user preference about items and predict user preference to particular item by using them. Thus, if preference matrix has low density, reliability of recommendation will be sharply decreased. To solve these problems we suggest Hybrid Preference Prediction Technique Using Weighting based Data Reliability. Preference prediction is carried out by creating similar item subset and similar user subset and predicting user preference by each subset and merging each predictive value by weighting point applying model condition. According to this technique, we can increase accuracy of user preference prediction and implement recommendation system which can provide highly reliable recommendation when density of preference matrix is low. Efficiency of this system is verified by Mean Absolute Error. Proposed technique shows average 21.7% improvement than Hao Ji's technique when preference matrix sparsity is more than 84% through experiment.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.3
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• pp.87-95
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• 2005

Most of the motorcycle engines have used carburetors in the fuel system, because of its simple structure and reliability but the fuel economy and the emissions of those engines are bad when we compared with automobile engines .To meet with the tighten emission regulations and the higher requirements for fuel economy, the application of the carburetor on the motorcycle engines would be limited. Therefore, it is important to develope a ECU control system for motorcycle engines. Since the fuel injection system is expensive, it is necessary to decrease the cost of ECU system for motorcycle engines, but the accuracy of the ECU control system should be increased as high as possible. In this paper, we studied about the AFS characteristics of motorcycle engine controled by indirect method.