• Convergence Security Journal
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• v.6 no.3
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• pp.59-67
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• 2006

Recently the Personal Computer hacking and game hacking for the purpose of gaining an economic profit is increased in Windows system. Malicious code often uses methods which inject dll or code into memory in target process for using covert channel for communicating among them, bypassing secure products like personal firewalls and obtaining sensitive information in system. This paper analyzes the technique for injecting and executing code into memory area in target process. In addition, this analyzes the PE format and IMPORT table for extracting injected dll in running process in affected system and describes a method for extracting and analyzing explicitly loaded dll files related with running process. This technique is useful for finding and analyzing infected processes in affected system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.556-560
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• 2013

Recently, solutions to accommodate explosively growing mobile data traffic have attracted intensive attentions since the emergence of high-performance smartphones. Spectrum which can be exploited for mobile communications is very limited. Thus, femto cell is considered as an alternative because it can efficiently offload mobile data traffic from macro cells without using additional spectrum. In this paper, we mathematically analyzed the coverage of femto cell when it is deployed in an area where there exists signals from existing macro base stations. Our numerical results indicate that the coverage of femto cell increases as the total power of femto cell increases or the ratio of power allocated to pilot channel increases. However, it is also shown that the coverage of femto cell is very limited despite its high power when interference signals from macro base stations are strong.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.24-30
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• 2014

This study investigates computing offloading effect of cloud in real-time video personal broadcast service, whose server is mobile device. Mobile device does not have enough computing resource for encoding video. The computing burden is offloaded to cloud, which has abundant resources in terms of computing, power, and storage compared to mobile device. By reducing computing burden, computation energy can be saved while transmission data amount increases because of decreasing compression efficiency. This study shows that the optimal operation point can be found adaptively to time-varying LTE communication condition result of tradeoff analysis between offloaded computation burden and increase in amount of transmitted data.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.137-141
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• 2015

Mobile cloud computing uses cloud service to solve the resource constraint problem of mobile devices. Offloading means that a task executed on the mobile device commits to cloud and many studies related to the energy consumption have been researched. In this paper, we designed a response time model considering sensing data synchronization to estimate the efficiency of the offloading scheme in terms of the response time. The proposed model considers synchronization of required sensing data to improve the accuracy of response time estimation when cloud processes the task requested from a mobile device. We found that the response time is effected by new sensing data generation rate and synchronization period through simulation results.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.188-194
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• 2006

This paper deals with the development of Engineering Model for the TCU( Thruster Control Unit) and simulation system of the reaction control system using cold gas. TCU communicates with TLM(Telemetry) and ground control console so that it transmits monitoring data of pressures and temperatures for reaction control system. The cpu/communication board performs MIL-STD-1553B communication, RS-422 communication, data input/output processing and program loading to EEPROM. We applied Intel 80386DX Microprocessor, 256Kbytes EEPROM and 256Kbytes SRAM for program storage and execution. Also, we developed the direct access interface circuit to EEPROM and simulation system for TCU.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.484-484
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• 2021

본 연구를 통해 개발된 웹기반 가뭄아틀라스에 탑재되는 가뭄인벤토리 지도서비스 모듈은 GIS기반 가뭄상황관리를 위해 일정 수준의 가공이 필요한 다양한 GIS 가뭄분석정보를 제공하여 가뭄 대응 업무 담당자가 공간에 기반한 가뭄분석 업무에 사용함을 주목적으로 해당 서비스 모듈을 개발하였다. 본 연구를 통해 개발된 지도서비스 모듈은 JAVA 언어로 개발되었으며, 오픈소스 기반의 Geosever와 Openlayer를 적용하여 167개 시군을 대상으로 가뭄 관련 분석지도를 제공하는 서비스 모듈이다. 지도 레이어별 가시화를 통한 중첩분석이 가능하며, 사용자 필요 시 해당 분석지도를 다운로드 받을 수 있도록 개발을 진행하였다. 상세 제공 정보로는 가뭄 분석을 위한 면적정보와 통계정보로 이원화하여 서비스를 제공하며, 개별 가뭄인벤토리 지도는 지역별 차트정보와 속성DB 테이블을 같이 지도화면에 표출한다. 주요기능으로는 가뭄인벤토리 지도서비스 창을 활성화하여 사용자가 필요한 가뭄인벤토리 지도를 체크하면 가뭄아틀라스 지도화면에 가시화된다. 체크된 가뭄인벤토리 지도는 테이블정보 표출과 자료 다운로드 기능을 제공한다. 해당 서비스 모듈의 관리 및 사용 방법으로는 가뭄인벤토리 지도데이터를 GIS 데이터셋화하여 Geoserver에 로딩하며, 로딩된 지도데이터는 WMS(web tilemap service) 포맷으로 변환한 뒤, 각각의 분석지도가 가지고 있는 속성DB정보를 고려해 지도 스타일을 적용하였다. 웹 브라우저 표출방법으로는 Openlayer 기반으로 GeoWebCache를 생성해 가뭄인벤토리 지도를 웹기반 가뭄아틀라스 상에 표출한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.397-400
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• 2008

무한히 발생되는 실시간 데이터와 디스크에 저장된 히스토리컬 데이터를 동시에 처리하는 하이브리드 질의에 관한 연구가 활발히 이루어지고 있다. 하이브리드 질의는 디스크에 저장된 대용량의 공간 데이터 처리를 위해 빠른 디스크 입/출력을 요구한다. 이러한 데이터를 처리하기 위해 인덱스, 데이터 축소 기법등이 연구되었다. 데이터의 빠른 검색을 위한 인덱스 기법은 디스크에 분산 저장된 데이터에 대한 탐색 비용과 입/출력 비용을 줄이지 못한다. 또한, 샘플링을 통해 디스크 입/출력 시간 비용을 줄이는 데이터 축소 기법은 데이터의 정확성을 떨어뜨려 정확성을 요구하는 하이브리드 질의에서는 이용하기가 어렵다. 이논문에서는 디스크 입/출력 시간과 디스크 탐색 시간 비용을 줄이고, 정확성을 보장하는 과거 공간질의 처리를 위한 고속로딩 기법을 제아난다. 제안기법은 공간을 그리드 형태로 나누고 인접한 공간 데이터를 함께 관리함으로써 디스크 입/출력 비용을 줄 일 수 있다. 또한, 공간적으로 인접한 데이터를 물리적으로 인접한 곳에 저장하여 디스크 탐색시간 비용을 줄일 수 있다. 이렇게 저장된 데이터는 손실 없이 모두 저장되며, 정확성 또는 보장할 수 있다.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.2
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• pp.183-192
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• 2001

In a development environment for embedded system with a connection between host and target system, the linker of host system links the cross-compiled object file and modules of target system and downloads the linked object file to the target system. In this research, we separate this linker into the module dependent on object file format and the module independent on object file format. The dependent module gets the linking information independent on file format from the object file, and the independent module actually does the linking process with this linking information_ This separation can improve the portability of development environment for a target system_ Also, our linker does the incremental remote linking that applies relocation not only to the obj ect file to be loaded but also to target's modules to have been loaded_ This incremental remote linking can reduce a linking time than linking by the united modules because of linking by module. The result of measuring linking time for SPEC95 integer benchmarks shows an average of reduction rates of 64.90%. Also, incremental remote linking can improve the comfortability of users who develop programs because users do not consider a downloading order of linking object files. Currently, we developed this linker in the embedded application development environment ESTO [1] to be prepared for a commercial product.

• Journal of the Korean Electrochemical Society
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• v.24 no.2
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• pp.28-33
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• 2021

Many researchers have increased the loading level of electrodes to improve the energy density of secondary batteries. In this study, high-loading NCM523 (LiNi_0.5Co_0.2Mn_0.3O₂) positive electrode is manufactured using a polytetrafluoroethylene (PTFE) binder, not the conventional polyvinylidene fluoride (PVdF) binder, which has been commonly used in lithium-ion batteries. Through the kneading process using PTFE suspension, not the conventional slurry process using PVdF solution in N-methyl-2-pyrrolidinone (NMP), thick electrodes with high loading are easily manufactured. When the PTFE and PVdF-based electrodes are prepared at a loading level of 5.0 mAh/cm², respectively, the PTFE-based electrode shows better cycle performance and rate capability than those of PVdF-based electrodes. The electrode manufactured by the kneading process using a PTFE binder has high electrode porosity due to insufficient roll-press, but the porosity can be lowered by high temperature roll-press over 120℃. However, there is no significant difference in cycle performance according to the roll press temperature. In addition, the cycle performance of the high loading electrode is slightly improved by increasing the content of the conductive material. Overall, the PTFE binder can improve the performance of the high loading electrode, but additional solutions will be needed.

• Journal of the Korean Electrochemical Society
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• v.27 no.1
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• pp.40-46
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• 2024

Among the electrode manufacturing processes for lithium-ion batteries, the drying process is crucial for production speed and process cost. Particularly, as the loading level of the electrode increases to enhance the energy density of the battery, optimizing process conditions for electrode drying becomes more critical. In this study, we compared the drying time and electrochemical performance of the positive electrode prepared at different drying temperatures. LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) was used as the active material and manufactured under various drying temperature conditions ranging from 120 ℃ to 210 ℃ at loading levels of 2.5 and 4.5 mAh cm^-2. The physical and electrochemical properties of the electrodes were compared. As the loading level of the electrode increases, the drying time of the electrode also increases, but this time can be reduced by increasing the drying temperature. The drying temperature used in manufacturing the NCM622 positive electrode does not significantly affect the electrochemical performance but drying above 210 ℃ resulted in an increase in the volume resistivity of the electrode and a decrease in electrochemical performance. Accordingly, in the manufacture of high-loading electrodes, the drying temperature was increased to 190 ℃ to shorten the electrode manufacturing time without a loss of performance.