• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1455-1461
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• 2014

In this study, using flux data measured in Deokgokje reservoir watershed near Deokyu mountain in May, June, and July 2011, statistical analysis was conducted for outlier detection and replacement for vertical wind speed in the measurement of evapotranspiration based on eddy covariance method. To statistically analyze the outliers of vertical wind speed, the outlier detection method based on interquartile range (IQR) in boxplot was employed and the detected outliers were deleted or replaced with mean. The comparison was conducted for the measured evapotranspiration before and after the outlier replacement. The study results showed that there is a difference between evapotranspiration before outlier replacement and evapotranspiration after outlier replacement, especially during the rainy day. Therefore, based on the study results, the outliers should be deleted or replaced in the measurement of evapotranspiration.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2E
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• pp.14-23
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• 1996

This paper is a on the neural network to recognize the phonemes, the weight initialization to reduce learning speed, and LR parser for continuous speech recognition. The neural network spots the phonemes in continuous speech and LR parser parses the output of neural network. The whole phonemes recognized in neural network are divided into several groups which are grouped by the similarity of phonemes, and then each group consists of neural network. Each group of neural network to recognize the phonemes consisits of that recognize the phonemes of their own group and VGNN(Verify Group Neural Network) which judges whether the inputs are their own group or not. The weights of neural network are not initialized with random values but initialized from learning data to reduce learning speed. The LR parsing method applied to this paper is not a method which traces a unique path, but one which traces several possible paths because the output of neural network is not accurate. The parser processes the continuous speech frame by frame as accumulating the output of neural network through several possible paths. If this accumulated path-value drops below the threshold value, this path is deleted in possible parsing paths. This paper applies the continuous speech recognition system to the threshold value, this path is deleted in possible parsing paths. This paper applies the continuous speech recognition system to the continuous Korea digits recognition. The recognition rate of isolated digits is 97% in speaker dependent, and 75% in speaker dependent. The recognition rate of continuous digits is 74% in spaker dependent.

• Journal of Convergence for Information Technology
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• v.10 no.5
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• pp.23-29
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• 2020

These days, digital forensic technologies are being used frequently at crime scenes. There are various electronic devices at the scene of the crime, and digital forensic results of these devices are used as important evidence. In particular, the user's action and the time when the action took place are critical. But there are many limitations for use in real forensics analyses because of the short cycle in which user actions are recorded. This paper proposed an efficient method for recovering deleted user behavior records and applying them to forensics investigations, then the proposed method is compared with previous methods. Although there are difference in recovery result depending on the storage, the results have been identified that the amount of user history data is increased from a minimum of 6% to a maximum of 539% when recovered user behavior was utilized to forensics investigation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.4
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• pp.609-619
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• 2023

Recently, crimes using drones, one of the IoT industries have been continuously reported. In particular, drones are characterized by easy access and free movement, so they are used for various crimes such as transporting explosives, transporting drugs, and illegal recording. In order to analyze and investigate these criminal acts, drone forensic research is highly emphasized. Media data, PII, and flight records are digital forensic artifacts that can be acquired from drones, in particluar flight records are important artifacts since they can be used to trace drone activities. Therefore, in this paper, the characteristics of the deleted flight record files of DJI drones are presented and verified using the Phantom3, Phantom4 andMini2 models, two drones with differences in characteristics. Additionally, the recovery level is analyzed using the flight record file characteristics, and lastly, drones with the capacity to recover flight records for each drone model and drone models without it are classified.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.635-647
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• 2013

Imputation is a commonly used method to handle missing survey data. The performance of the imputation method is influenced by various factors, especially an outlier. The removal of the outlier in a data set is a simple and effective approach to reduce the effect of an outlier. In this paper in order to improve the precision of multiple imputation, we study a imputation method which reduces the effect of outlier using various weight adjustment methods that include the removal of an outlier method. The regression method in PROC/MI in SAS is used for multiple imputation and the obtained final adjusted weight is used as a weight variable to obtain the imputed values. Simulation studies compared the performance of various weight adjustment methods and Monthly Labor Statistic data is used for real data analysis.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.69-79
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• 2015

This research proposes a modified data hiding method to hide data in a slack space of an NTFS index record. The existing data hiding method is for anti-forensics, which uses traces of file names of an index entry in an index record when files are deleted in a direcotry. The proposed method in this paper modifies the existing method to make non-admittable ASCII characters for a file name applicable. By improving the existing method, problems of a file creation error due to non-admittable characters are remedied; including the non-admittable 9 characters (i. e. slash /, colon :, greater than >, less than <, question mark ?, back slash ${\backslash}$, vertical bar |, semi-colon ;, esterisk * ), reserved file names(i. e. CON, PRN, AUX, NUL, COM1~COM9, LPT1~LPT9) and two non-admittable characters for an ending character of the file name(i. e. space and dot). Two results of the two message with non-admittable ASCII characters by keyboard inputs show the applicability of the proposed method.

• Journal of the Korean Society of Food Culture
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• v.24 no.4
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• pp.413-418
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• 2009

Existing literature on the CRM [Customer Relationship Management] has emphasized the marketing strategies between the franchisor and franchisee. In this study, we focused instead on factors involved in forging relationships based on marketing strategies between franchisee and the customers. A survey questionnaire was completed by 250 customers of Korean-style food franchises located in Seoul and Inchon. Each questions is based on a 5-point likert-type scale. After initial data recording, 41 questionnaires were deleted from the data set because of missing or insincerely answer. Finally, the sample data of 209 questionnaires were used for the statistical analysis. The data were analyzed with SPSS version 13.0 software to assess consumer satisfaction, trust, and support/reputation on flexibility and commitment. Regression analysis was performed to analyze the relationship between flexibility and commitment. Satisfaction and support/reputation significantly influenced flexibility, both satisfaction and trust significantly influenced commitment, and both flexibility and commitment significantly influenced the restaurant-consumer relationship.

• The Journal of the Convergence on Culture Technology
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• v.2 no.3
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• pp.23-28
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• 2016

As a large portal sites are beginning to replace the function of the mass media, new risks began to raise. It remained without being deleted that data written to the internet was a serious privacy problem occurs. The sensitive information was inferred based on the personal data recorded in the past and also another personal information leakage itself. Witch-hunt through the personally identifiable rob has emerged as a serious social problem and damage to the parties not be able to live a normal life. In this paper, we propose the study on the need for a 'right to be forgotten' to delete the personal information relating to on-line through international case studies and activation measures. At the same time, we proposed improvement measures, such as encryption management, ownership inheritance, and blind treatment.

• The Korean Journal of Health Service Management
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• v.6 no.1
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• pp.219-229
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• 2012

The purpose of this study is to introduce the web database for healthy city Wonju that contains healthy city indicators and materials. It has provided diverse information to public officers who are working on healthy city projects and citizens for monitoring and evaluating the projects, effectively. The web database was made on 2006 and was updated on 2009. The new Web database system was designed for supporting that the staffs of healthy city can manage all data update by themselves. The new Web database encompasses more recent information about health city projects. After identifying users' needs and reasons for modifying the fields of data, we added new indicators to the Web database. Some redundant indicators were deleted based on users' requests. The Web database quality evaluations were performed by using 13 quality evaluations constructs. Through all 13 constructs, less than 20% of study subjects felt that it did not satisfy their needs or expectations. Well developed and verified contents of the Web database for healthy city are very essential and important. The database makes healthy city projects alive by managing and sharing healthy city related data and indicators effectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1557-1569
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• 2017

In recent times, the Internet of Things (IoT) has rapidly emerged as one of the most influential information and communication technologies (ICT). The various constituents of the IoT together offer novel technological opportunities by facilitating the so-called "hyper-connected world." The fundamental tasks that need to be performed to provide such a function involve the transceiving, storing, and analyzing of digital data. However, it is challenging to handle voluminous data with IoT devices because such devices generally lack sufficient computational capability. In this study, we examine the IoT from the perspective of security and digital forensics. SQLite is a light-weight database management system (DBMS) used in many IoT applications that stores private information. This information can be used in digital forensics as evidence. However, it is difficult to obtain critical evidence from IoT devices because the digital data stored in these devices is frequently deleted or updated. To address this issue, we propose Schema Pattern-based Recovery (SPaRe), an SQLite recovery scheme that leverages the pattern of a database schema. In particular, SPaRe exhaustively explores an SQLite database file and identifies all schematic patterns of a database record. We implemented SPaRe on an iPhone 6 running iOS 7 in order to test its performance. The results confirmed that SPaRe recovers an SQLite record at a high recovery rate.