• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.4
• /
• pp.97-106
• /
• 2008

This proposed system is a part of internal control system that national highway need to support their ITS information audit. This paper explains the design and implementation of a packet interceptor and a DB query analyzer. The packet interceptor sniffs users' query packets, and then the DB query analyzer parses the SQL queries and stores the users' DB access information such as SQL queries, access data and changing data. The information may be used as the evidences on internal control of users and users' accesses.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.956-961
• /
• 2009

When construction engineers perform their work in the jobsite, they have to record as-built conditions in the project log (Data Collection). On the other hand, the engineers often have to refer to the construction documents when necessary at the job faces (Data Access). The practice of Data Collection and Data Access in the jobsite can be greatly enhanced by utilizing mobile computing with wireless communications. In this paper, two cases of mobile computing applications for construction field management are presented; Mobile Specifications System and Mobile Data Collection System. The demonstration of the process for developing two mobile applications is the primary purpose of the paper. The problems and issues involved with adopting mobile computing for construction field are also presented. The simple information framework for mobile computing has been also proposed as an outcome of the research. As for development tools, readily available relational database and wireless network have been used. The use of commercial mobile broadband was examined for data communication where local area network is not available.

• Proceedings of the IEEK Conference
• /
• 2000.06a
• /
• pp.209-212
• /
• 2000

In this paper, effect of imperfect power control on performance of a pseudonoise (PN) code tracking loop is analyzed and simulated for a direct-sequence/code-division multiple access (DS/CDMA) system. The multipath fading channel is modeled as a two-ray Rayleigh fading model. Power control error is modeled as a log-normally distributed random variable. The tracking performance of DLL (delay-locked-loop) is evaluated in terms of tracking jitter and mean-time-to-lose-lock (MTLL). From the simulation results, it is shown that the PN tracking performance is very sensitive to the power control error.

• 한국HCI학회:학술대회논문집
• /
• 2008.02a
• /
• pp.269-273
• /
• 2008

In ubiquitous environments, clients move between domains freely and its activities in the other domains are growth. Like this environment, the service provider makes access or activity records what they are provided to clients. This record can make a privacy problem to recognize a person or trace some works. So this record must be kept and managed by user instead of the service provider. In this paper, we propose a system that can gather those records from the service provider to home domain server which client's managing by themselves. In addition, if remote domain manager requests that record by the legal process, system can transfer only a range of information which allowed by client to keep personal privacy.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.3 s.35
• /
• pp.259-265
• /
• 2005

The purpose of this study is for designing a illegal query detection system using Winpcap library for unauthorized access by internal person. The illegal query detection can be possible detecting the data in out of access control or searching illegal data by plagiarizing other user ID. The system used in this paper collects packets and analyzes the data related to SQL phrase among them, and selects the user's basic information by comparing the dispatch of MAC address and user's hardware information constructed previously. If the extracted information and user's one are different, it is considered as an illegal query. It is expected that the results of this study can be applied to reducing the snaking off unprotected data, and also contributed to leaving the audit records using user's access log which can be applied to the pattern analysis.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.29 no.2
• /
• pp.321-330
• /
• 2019

Prevention of corporate confidentiality leakage by insiders in enterprises is an essential task for the survival of enterprises. In order to prevent information leakage by insiders, companies have adopted security solutions, but there is a limit to effectively detect abnormal behavior of insiders with access privileges. In this study, we use the Unsupervised Learning algorithm of the machine learning technique to effectively and efficiently cluster the normal and abnormal access logs of the worker's work screen in the manufacturing information system, which includes the company's product manufacturing history and quality information. We propose an optimal feature selection model for anomaly detection by studying clustering methods.

• 한국HCI학회:학술대회논문집
• /
• 2008.02b
• /
• pp.460-464
• /
• 2008

To improve and optimize user interfaces of the system, the accurate understanding of users' behavior is an essential prerequisite. Direct questions depend on user' s ambiguous memory and usability tests depend on the researchers' intention instead of users'. Furthermore, they do not provide with natural context of use. In this paper we described the work which examined users' behavior through log analysis in their own environment. 50 users were recruited by consumer segmentation and they were downloaded logging-software in their mobile phone. After two weeks, logged data were gathered and analyzed. The complementary methods such as a user diary and an interview were conducted. The result of the analysis showed the frequency of menu and key access, used time, data storage and several usage patterns. Also, it was found that users could be segmented into new groups by their usage patterns. The improvement of the mobile phone user interface was proposed based on the result of this study.

• Journal of Advanced Navigation Technology
• /
• v.14 no.5
• /
• pp.767-774
• /
• 2010

Due to advantages of NAND flash memory such as non-volatility, low access latency, low energy consumption, light weight, small size and shock resistance, it has become a better alternative over traditional magnetic disk drives, and has been widely used. Traditional DBMSs including mobile DBMSs may run on flash memory without any modification by using Flash Translation Layer (FTL), which emulates a random access block device to hide the characteristics of flash memory such as "erase-before-update". However, most existing FTLs are optimized for file systems, not for DBMSs, and traditional DBMSs are not aware of them. Also, traditional DBMSs do not consider the characteristics of flash memory. In this paper, we propose a flash-conscious storage system for DBMSs that utilizes flash memory as a main storage medium, and carefully put the characteristics of flash memory into considerations. The proposed flash-conscious storage system exploits log records to avoid costly update operations. It is shown that the proposed storage system outperforms the state.

• Journal of KIISE
• /
• v.42 no.4
• /
• pp.442-450
• /
• 2015

This paper proposes a method for reducing false conflicts in signature-based eager hardware transactional memory (HTM). The method tracks the information on all cache blocks that are accessed by a transaction. If the information provides evidence that there are no conflicts for a given transactional request from another core, the method prevents the occurrence of a false conflict by forcing the HTM to ignore the decision based on the signature. The method is very effective in reducing false conflicts and the associated unnecessary transaction stalls and aborts, and can be used to improve the performance of the multicore processor that implements the signature-based eager HTM. When running the STAMP benchmark on a 16-core processor that implements the LogTM-SE, the increased speed (decrease in execution time) achieved with the use of the method is 20.6% on average.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.3 s.106
• /
• pp.272-279
• /
• 2006

In this paper, we evaluate the performance of frame synchronization words of pilot bit patterns which are used for the channel estimation and frame synchronization confirmation in W-CDMA(Wide band Code Division Multiple Access) system. W-CDMA system also uses compressed mode to make measurements from another frequency without a full dual receiver terminal. It is confirmed by using computer simulation that the proposed frame synchronization words also maintain the frame synchronization property in the compressed mode by using the complementary mapping relationship of preferred pair ROC(Receiver Operating Characteristic) curves with probability of detection and false alarm are used to analized the performance of the proposed frame synchronization words by using the various detection metrics such as LLRT(Log Likelyhood Ratio Test), GLRT(Generalied Likelyhood Ratio Test), soft and hard correlation tests in AWGN and Rayleigh fading channels. It is expected that the research results fer the performance of pilot bit patterns of this paper can be useful reference for the design and implementation of frame synchronization in 3rd generation W-CDMA system.