• Journal of the Korea Society of Computer and Information
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• v.9 no.1
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• pp.79-86
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• 2004

In general, operating system is offering the security function of OS level to support several web services. However, it is true that security side of OS level is weak from many parts. Specially, it is needed to audit/trace function in security kernel level to satisfy security more than B2 level that define in TCSEC(Trusted Computer System Evaluation Criteria). So we need to create audit data at system call invocation for this, and do to create audit data of equal format about almost event and supply information to do traceback late. This Paper Proposes audit/trace system module that use LKM(Loadable Kernel Module) technique. It is applicable without alteration about existing linux kernel to ensure safe evidence. It offers interface that can utilize external audit data such as intrusion detection system, and also offers safe role based system that is divided system administrator and security administrator These data will going to utilize to computer forensics' data that legal confrontation is Possible.

• Journal of Advanced Navigation Technology
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• v.2 no.2
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• pp.75-83
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• 1998

This paper presents a low cost and high accuracy integrated Global Positioning System (GPS)/dead reckoning (DR) system. The integrated GPS/DR system is capable of providing highly accurate position data in real-time or in post processing. Based on the analysis of the main error source affecting the DR measurements, an eight-state mathematical model for the integrated system has been developed to represent these errors. This eight-state model has been used to build a nonlinear filter for the estimation of the state vector at every epoch when DR measurements are available. The accuracy of the system has been evaluated using 1Hz DR measurements and 3Hz continuous GPS position estimates. Through numerical simulation the system performance during periods with GPS outage has been investigated by comparing two different noise models. While one model is the position estimation filter containing a single noise model, the other filter includes two-level noise model. The simulation results have shown that the estimation filter containing two-level noise model for computing the position error of the integrated GPS/DR system yields better performance than that the filter including the single-level noise model does.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1385-1391
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• 2015

A water reuse system was designed for a demonstration plant by combining fiber filtration and electrolysis. A discharged dye wastewater after treated with biomedia was used in this study. It was found that an additional removal of suspended solids (SS) was feasible with 2-stage filtration while electrolysis was not effective. Also, $COD_{cr}$ and $COD_{Mn}$ were not removed with 2 -stage filtration but electrolysis resulted in about 26.9% additional removal. This indicates that electrolysis play an important role in organic removal. Removal of T-N and T-P was negligible with 1 and 2-stage fiber filtration and low-level electrolyte. However, with 2000 ppm of electrolyte, their removal efficiencies were about 83.1 and 60%, respectively, suggesting that the removal rates are well associated with the electrolyte concentrations. With high-level electrolyte, colority was removed about 82% while chlorine ions were removed only about 10%. Therefore, to treat underground water containing high-level salinity in the follow-up study, based on the results in this paper, a combined system with selection of additional unit process and reverse osmosis will be designed.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.129-134
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• 2012

In this paper, speed control of IPMSM drives for the next generation domestic high speed railway system using NPC 3-level inverters is presented. The NPC multilevel inverter is suitable for the high-voltage and high-power motor drive system because it has advantages in that the voltage rating of the power semiconductor devices and output current harmonics are reduced. For the speed control of IPMSM using NPC 3-level inverters, maximum torque control is applied in the constant torque region, and filed weakening control is applied in the constant power region. Simulation programs based on MATLAB/Simulink are developed. Finally the designed system is verified and their characteristics are analyzed by the simulation results.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.1
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• pp.125-134
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• 2011

The research is a survey and analysis of female apparel preferences, and recognition of the KS sizing system for adult female garments. The practical surveys in this research are examined by total number of subjects, 200 women who are living in Seoul, South Korea. The homogeneity test using Chi-square statistics, and the analysis of frequencies and ratios of contingency tables were performed with the data which are classified by age, education level, income level and housing modalities. The findings in this study are as follows: 1. Women's preferences for purchasing female garments indicate significant differences between subjects, such as age, education level, income level and housing modalities. Moreover, the following five types of adult female garments were analyzed in this study: upper garment, lower garment, one-piece apparel, sportswear and sleepwear. The results of the preference study show an indirect understanding of the KSK 0051 classification system for subjects of the survey. Therefore the preference study can be used as a pilot study for the sizing recognition survey. 2. Women's recognition of the KSK 0051 sizing system for adult female adult garments do not indicate significant differences based on the characteristics of age, education level, income level and housing modalities. The low recognition of the KS sizing system is due to too many details and complex numbers of application for users. Therefore, the sizing system should be simplified and rearranged to be more effective and have more recognizable categories.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.19-29
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• 2008

In case of unit testing, White-box test can be used to closely check source code and to analyze logic and statement errors. On the other hand, in case of function testing of system level, Black-box test can be mainly used to compare actual and expected results by inputting test data because the scale of function is large. This Black-Box test in system testing level has problem in tracing errors in source code when we find errors. Moreover applying White-box test is not easy for system testing level because the levels of test target are different. Therefore this paper suggests the vertical test method of a practical and integrated system level which can checks up to source code level using White-box test style although it aims to test the highly abstract level like a system function. In addition, the experiment explains how to apply the vertical test by displaying an example which traces from UML specification model to the source code and also shows efficiency of error trace.

• Land and Housing Review
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• v.2 no.3
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• pp.249-258
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• 2011

In order to achieve an efficient urban regeneration of the nation, it is required to determine the extent of decline nation-wide and the declined areas for each district and also to evaluate the potentials of the concerned areas. For this task to be accomplished, a construction of a comprehensive diagnostic system based on spatial information considering diversity and complexity is required. In this study, a total information system architecture for urban regeneration is designed as part of the construction of such a diagnostic system. In order to develop the system, a city and district level unit decline diagnostic indicators has been constructed and a decline diagnostic system has been developed. Also, a scheme to promote the advancement of the system is proposed. The DB construction is based on the city and district level nation-wide and metadata for the concerned level is constructed as well. The system is based on the Open API and designed to be flexible for extension. Also, an RIA-based intuitive UI has been implemented. Main features of the system consist of the management of the indicators, diagnostic analysis (city and district level decline diagnosis), related information, etc. As for methods for the advancement, an information model in consideration of the spation relations of the urban regeneration DB has been designed and application methods of semantic webs. Also, for improvement methods for district unit analytical model, district level analysis models, GIS based spatial analysis platforms and linked utiliation of KOPSS analysis modules are suggested. A use of a total information system for urban regeneration is anticipated to facilitate concerned policy making through the identification of the status of city declines to identify and the understanding of the demands for regeneration.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.3
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• pp.168-172
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• 2013

A preliminary performance test of a 30RT 2-stage screw heat pump was carried out in order to develop a high performance large-scale unutilized energy source heat pump system, which will be used for district heating and cooling. In this study, two issues of the system operating control were investigated. The first issue is the mode switching control from 1-stage to 2-stage. A stable 2-stage heating operation is guaranteed, only if the load-side water inlet temperature is over a certain value, where the 1-stage heating operation should be done first from a cold start. The second issue is oil level control. An oil shortage problem in the low stage compressor, which depends on the degree of suction superheat, was solved by a proper oil level control scheme.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.4
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• pp.69-78
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• 2001

In this study optimal analysis of pipe network was performed using linear and non linear analysis method for complex real pipe network system of Mungyeong water purification field system which consists of 70 nodes and 86 elements. From the examination result of total flow which is distributed to each pipe, it is found that KYPIPE2 Model supplies less amount than NLAM. It is known that dynamic water level and pressure head of KYPIPE2 Model and NLAM are nearly in accordance with each other from each method of the pipe network analyses, and appeared that both methods of analysis shows high reliable result since the distribution of dynamic water level for every node is the short range of EL. 205.0m~EL. 210.0m besides the pressed dynamic water level. The analysis results of pressure in the methods of pipe network analysis for KYPIPE2 Model and NLAM are similar and it is satisfactory result that the pressure distributions of the tab water design criterion of 5.0kgf/cm$^2$ besides the small part of highland.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.38-44
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• 2014

This paper presents design of a FMCW (Frequency Modulated Continuous Wave) level meter as well as simulation result of the designed system. The system is designed to measure maximum range of 20m since FMCW radar can be used for measuring short range distance. The distance is measured by analyzing the beat signal which is generated as result of mixing transmitting signal with the reflected received signal. The Fast Fourier Transform is applied to analyze the beat signal for calculating the displacement and Zoom FFT technique is used to minimize measurement error as well as increase the resolution of the measurement. The resolution of the measurement of the designed system in this paper is 2.2mm and bandwidth of 1.024GHz is used for simulation. Thus the simulation results are analyzed and compared in various conditions in order to get a comprehensive idea of frequency resolution and displacement resolution.