• KIPS Transactions on Software and Data Engineering
• /
• v.2 no.6
• /
• pp.383-394
• /
• 2013

As a way of augmenting constrained resources of mobile devices such as CPU and memory, many works on mobile cloud computing (MCC), where mobile devices utilize remote resources of cloud services or PCs, have been proposed. Typically, in MCC, many nodes with different operating systems and platform and diverse mobile applications or services are located, and a central manager autonomously performs several management tasks to maintain a consistent level of MCC overall quality. However, as there are a larger number of nodes, mobile applications, and services subscribed by the mobile applications and their interactions are extremely increased, a traditional management method of MCC reveals a fundamental problem of degrading its overall performance due to overloaded management tasks to the central manager, i.e. a bottle neck phenomenon. Therefore, in this paper, we propose a clustering-based optimization method to solve performance-related problems on large-scaled MCC and to stabilize its overall quality. With our proposed method, we can ensure to minimize the management overloads and stabilize the quality of MCC in an active and autonomous way.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.197.1-197.1
• /
• 2010

This study was carried out to evaluate the operating performances of the evaporation desalination system with solar energy. This system was designed to use evacuated solar collector as the heat source, supplying the required heat energy and photovoltaic power as the electric source, supplying required power to pumps in the desalination system. The 5kW photovoltaic power generation system to make the electricity, the single-stage fresh water generator with plate heat exchanger, and remote control and monitoring system. Solar desalination system was designed and installed in Jeju-island, Korea in 2006, after about 4 years of operation, usability and stability of solar desalination system was guaranteed. The system comprises of the desalination unit which was designed to have daily fresh water capacity of $2m^3$, a $120m^2$ evacuated tubular solar collector to supply the heat, a $6m^3$ heat storage tank, and a 5.2kW photovoltaic power generation to supply the electricity to hydraulic pumps for the heat medium fluids. On a clear day, average daily solar irradiance in Jeju-island was measured to be $500W/m^2$ and the daily fresh water yield showed to be more than 500 liters under this condition. After around three years of a long term operation of the system from January 2007 to August 2009, average daily freshwater yield was analyzed to be around $330{\ell}$. The relationship equation between solar irradiance and freshwater yield was found to be y=1.1806x - 107.89.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.3
• /
• pp.591-603
• /
• 2018

Windows Event Log is a format that records system log in Windows operating system and methodically manages information about system operation. An event can be caused by system itself or by user's specific actions, and some event logs can be used for corporate security audits, malware detection and so on. In this paper, we choose actions related to corporate security audit and malware detection (External storage connection, Application install, Shared folder usage, Printer usage, Remote connection/disconnection, File/Registry manipulation, Process creation, DNS query, Windows service, PC startup/shutdown, Log on/off, Power saving mode, Network connection/disconnection, Event log deletion and System time change), which can be detected through event log analysis and classify event IDs that occur in each situation. Also, the existing event log tools only include functions related to the EVTX file parse and it is difficult to track user's behavior when used in a forensic investigation. So we implemented new analysis tool in this study which parses EVTX files and user behaviors.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.2
• /
• pp.99-107
• /
• 2014

In this study, aerodynamic characteristics of Kline-Fogleman airfoils are numerically investigatied which has been widely used in remote control aircraft operating at low Reynolds numbers. The comparison of aerodynamic characteristics was conducted between NACA4415 and Kline-Fogleman airfoil based on NACA4415. ANSYS Fluent was employed with the incompressible assumption and $k-{\omega}$ SST turbulence model. It was found that lift coefficient was significantly enhanced in the range of Reynolds number from $3{\times}10^3$ to $3{\times}10^6$. Especially in the region of Reynolds number below $2.4{\times}10^5$, the lift-to-drag-ratio was improved by 26% using the Kline-Folgeman airfoil compared with NACA4415 airfoil.

• Journal of Digital Contents Society
• /
• v.11 no.3
• /
• pp.291-298
• /
• 2010

Although searching service is popularized in the PC-based internet environment, it is not (or rarely) supported on TV, which is the major multimedia equipment in the living room. Several trials are made to port established PC-based searching systems onto TV-set but failed to get popularity among viewers as they did not consider the viewers' modality. Operating the searching system should not disturb viewers in watching TV (for example, TV screen should not be (even partially) covered by the searching system's graphics) and the number of pushing the remote controller's buttons should be minimized so that viewers can keep watching TV without glancing at the searching system's graphics. In this paper, the author introduces a new searching system running on TV-set, which is designed to reflect properly the viewers' modality. The searching system is also compatible with the data service standard adopted by the domestic broadcasting networks so that it can be easily implemented by them.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.2
• /
• pp.186-193
• /
• 2018

Generally, it is difficult to operate moveable-weir due to the expensive cost of the facility management and manpower consumption. Also, when it is installed in a remote area, there is a problem that the cost of connection for power system increases as well as the operating cost. Therefore, this paper proposes an optimal design algorithm to replace an existing power system with an Eco-friendly power supply system for movable-weir using PCS, PV module and lithium-ion battery. Also, this paper proposes a modeling method of environment-friendly power supply system for a movable-weir based on the PSCAD/EMTDC S/W and implements 5[kW] prototype environment-friendly power supply system. As a result of the performance test using the S/W modeling and the prototype system, it is confirmed that the proposed system has stable characteristics in the independent operation mode and the interconnection mode.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.4 no.3
• /
• pp.301-306
• /
• 2003

We have designed embedded web server system and ported Linux operating system version 2.4.1 at our system. And then We implemented to control and monitor widely separated hardware. Web server is the Boa web server with General Public License. We designed for this system using of Cirrus logic's EP7312 ARM core base processor and connecting input and output device at GPIO port of EP7312. Device driver of General purpose I/O for Linux OS is designed. And then the application program controlling driver is implemented to use of common gate interface C language. User is available to control and monitor at client PC. This method have benefit to reduce the Expenditure of hardware design and development time against PC base system and have various and capacious application against firmware base system.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.10
• /
• pp.1351-1357
• /
• 2010

Water monitoring equipments using daphnia can be used to monitor the pollution levels of a country's main rivers. Such equipments should be capable of providing a prompt warning about increase in the contamination levels, which is evaluated on the basis of impulse number or toxicity index. As unmanned remote control equipments, they must provide reliable pollution monitoring results for each season and for the annual physical changes in each river. Two different equipments based on the impulse number and toxicity index showed different results for the operating rates and for the number of emergency checks required even though both were operated at the same conditions. The results are affected by many parameters such as the presence of any air bubbles and the microscopic pressure. The purpose of this study is to develop a method that can reduce the effect of bubbles or microscopic pressure on the monitoring data. We expect to achieve reliable monitoring data for water pollutants irrespective of the location of the equipment setup.

• Journal of Satellite, Information and Communications
• /
• v.10 no.4
• /
• pp.83-86
• /
• 2015

In this paper, we propose a real-tim measurement management system UI development linked the Water treatment facilities broadband Convergence Network. The sensor and the image data received by the server develop a program to interact with Web through water treatment facilities broadband convergence network. So, Separately develop UI capable of independently operating. Building a web server for remote monitoring of the transmission sensor and the image data. And Monitoring and control is possible the sensor data and image data through the Web-based UI. We can grasp the current state such as measurement time, concentration and depth of interface through the proposed real-time measurement management system UI development liked the water treatment facilities broadband convergence network. So, we can check in whether the normal operation of water treatment facilities and whether the casualties such as fire and security. As well as real time to see the information at a glance due to UI development can be raal-time monitoring of real-time measurement management system.

• Journal of Information Technology Services
• /
• v.19 no.5
• /
• pp.33-47
• /
• 2020

In recent years, due to the demand for operating efficiency and cost reduction of industrial facilities, remote access via the Internet is expanding. the control network accelerates from network separation to network connection due to the development of IIoT (Industrial Internet of Things) technology. Transition of control network is a new opportunity, but concerns about cybersecurity are also growing. Therefore, manufacturers must reflect security compliance and standards in consideration of the Internet connection environment, and enterprises must newly recognize the connection area of the control network as a security management target. In this study, the core target of the control system security threat is defined as the network boundary, and issues regarding the security architecture configuration for the boundary and the role & responsibility of the working organization are covered. Enterprises do not integrate the design organization with the operation organization after go-live, and are not consistently reflecting security considerations from design to operation. At this point, the expansion of the control network is a big transition that calls for the establishment of a responsible organization and reinforcement of the role of the network boundary area where there is a concern about lack of management. Thus, through the organization of the facility network and the analysis of the roles between each organization, an static perspective and difference in perception were derived. In addition, standards and guidelines required for reinforcing network boundary security were studied to address essential operational standards that required the Internet connection of the control network. This study will help establish a network boundary management system that should be considered at the enterprise level in the future.