• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.04a
• /
• pp.758-761
• /
• 2010

악성코드는 P2P, 전자메일, 메신저나 저장매체, 인터넷 사이트 등 여러 가지 경로를 통해 전파된다. 특히 USB 기반 악성코드는 USB가 시스템에 연결될 때 악성코드를 자동 실행시키고, 로컬 드라이브 영역에 자기복제를 하는 등 특정 행위를 보인다. 포렌식 수사에서는 이러한 악의적 행위를 빠르게 분석하고 여러 가지 증거를 수집하여 감염의 원인을 신속하게 파악하는 것이 요구된다. 본 논문에서는 USB 기반 악성코드에 감염된 시스템의 피해 흔적을 분석하고 패턴을 정형화하여 USB 기반 악성코드의 감염 여부를 판별하는 방법론을 제시한다.

• Journal of Power System Engineering
• /
• v.20 no.6
• /
• pp.87-92
• /
• 2016

This research dealt with performance characteristics of OTEC system applying an ejector and additional pump. Each system using five kinds of working fluids was analyzed, and primary parameters with respect to entrainment ratio were examined: Turbine gross power, evaporation capacity, pump work, efficiency and volume flow ratio. The primary results were as following. The efficiency of ejector-pump OTEC system was dependent on entrainment of the ejector. The degree of efficiency change was different from applied working fluid, and amount of pump work was turned out to be primary factor affected system efficiency. Meanwhile, optimized entrainment ratio was different from applied working fluid since their different vapor density. System efficiency at optimized entrainmet ratio of each working fluid was around 5%, showing minor difference each other.

• The Plant Pathology Journal
• /
• v.17 no.6
• /
• pp.372.2-372
• /
• 2001

• Journal of Environmental Impact Assessment
• /
• v.1 no.1
• /
• pp.13-20
• /
• 1992

We live in an age of information. We also live in an era of rising environmental awareness. As a result, efficient and judicious use of environmental information has become a prerequisite to planning and management of environmental affairs in contemporary societies. During the past few decades, we have recorded a phenomenal rate of growth. and experienced an array of environmental problems such as pollution, destruction of natural environment, and ecological disturbances. In response to these problems we has embarked on a study of Environmental Information System(EIS). This study has four major components. First, it describes the current status of EIS in Korea. Second, it provides a survey of EIS in other countries, specifically USA and Japan. Third, the study also presents an application of GIS(Geographic Information System)in Korea, USA, and Japan. Finally, the study outlines strategies to develop EIS in Korea.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.278-281
• /
• 2007

The purpose of this study is to develop snow and sea ice detection algorithm in Communication, Ocean and Meteorological Satellite (COMS) meteorological data processing system. Since COMS has only five channels, it is not affordable to use microwave or shortwave infrared data which are effective and generally used for snow detection. In order to estimate snow and sea ice coverage, combinations between available channel data(mostly visible and 3.7 ${\mu}m$) are applied to the algorithm based on threshold method. As a result, the COMS snow and sea ice detection algorithm shows reliable performance compared to MODIS products with channel limitation. Specifically, there is partial underestimation over the complicated vegetation area and overestimation over the area of high level clouds such as cirrus. Some corrections are performed by using water vapor and infrared channels to remove cloud contamination and by applying NDVI to detect more snow pixels for the underestimated area.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.282-285
• /
• 2007

Satellite observed brightness temperature simulation using a radiative transfer model (here after, RTM) is useful for various fields, for example sensor design and channel selection by using theoretically calculated radiance data, development of satellite data processing algorithm and algorithm parameter determination before launch. This study is focused on elaborating the simulation procedure, and analyzing of difference between observed and modelled clear sky brightness temperatures. For the CMDPS (COMS Meteorological Data Processing System) development, the simulated clear sky brightness temperatures are used to determine whether the corresponding pixels are cloud-contaminated in cloud mask algorithm as a reference data. Also it provides important information for calibrating satellite observed radiances. Meanwhile, simulated brightness temperatures of COMS channels plan to be used for assessing the CMDPS performance test. For these applications, the RTM requires fast calculation and high accuracy. The simulated clear sky brightness temperatures are compared with those of MTSAT-1R observation to assess the model performance and the quality of the observation. The results show that there is good agreement in the ocean mostly, while in the land disagreement is partially found due to surface characteristics such as land surface temperature, surface vegetation, terrain effect, and so on.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.2
• /
• pp.128-133
• /
• 2010

Objective : The secondary verification of Leksell Gamma Knife treatment planning system (LGP) (which is the primary verification system) is extremely important in order to minimize the risk of treatment errors. Although prior methods have been developed to verify maximum dose and treatment time, none have studied maximum dose coordinates and treatment volume. Methods : We simulated the skull shape as an ellipsoid with its center at the junction between the mammillary bodies and the brain stem. The radiation depths of the beamlets emitted from 201 collimators were calculated based on the relationship between this ellipsoid and a single beamlet expressed as a straight line. A computer program was coded to execute the algorithm. A database system was adopted to log the doses for $31{\times}31{\times}31$ or 29,791 matrix points allowing for future queries to be made of the matrix of interest. Results : When we compared the parameters in seven patients, all parameters showed good correlation. The number of matrix points with a dose higher than 30% of the maximal dose was within ${\pm}\;2%$ of LGP. The 50% dose volume, which is generally the target volume, differs maximally by 4.2%. The difference of the maximal dose ranges from 0.7% to 7%. Conclusion : Based on the results, the variable ellipsoid modeling technique or variable ellipsoid modeling technique (VEMT) can be a useful and independent tool to verify the important parameters of LGP and make up for LGP.

• Journal of Korean Port Research
• /
• v.14 no.1
• /
• pp.57-64
• /
• 2000

For composing the structure model of national maritime power system by system structural modeling, in this study, the 50 basic factors are selected by survey of the extensive and through literatures on maritime, sea, maritime power and sea power. And the basic factors are classified into 36 component factors by cluster method. The 9 attributes are extracted by the application of the principle component analysis method, one of the factor analysis method in system engineering, to component factors. In this study, we define the attributes composing the national maritime power system by integrating the result of this study and existed our studies relating to this topic. Which are showed in Table 2. and we show the structure model of national maritime power system in Fig. 3. In Table 2, the 9 attributes are as follows : the fundamental power of maritime, shipping and port power, naval power, fishing power, shipbuilding power, the power of ocean research and development, dependency on seaborne trade, the protection power of ocean environment and the will and inclination of govemment. Also, in the case of evaluating this system, we conform the importance of considering the interactions among the attributes which have strong interactions in structure model of national maritime power system.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.259-262
• /
• 2004

We propose novel schemes to enhance the expressible depth range of integral imaging. The implemented system that adopts the mirror barrier array has the compact thickness that is suitable for the practical use. With this system, the expressible depth range of the integral imaging is increased to over 120mm. The system that eliminates the mechanical motion also had been implemented. Experimental results are presented and the way to resolve the problem of occlusion is also discussed.

• Journal of Information Display
• /
• v.3 no.1
• /
• pp.22-26
• /
• 2002

Three-dimensional dynamic display system based on computer-generated integral imaging is discussed and its feasibility is verified via some basic experiments. Integrated images observed from different viewing points are seen to have full parallax and the animated 3D image was implemented successfully. Moreover, using large size Fresnel lens array was found to helps widen viewing angle and to make the system more practical.