• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2003.09a
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• pp.189-201
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• 2003

Grid is a new Information Technology (IT) concept of "super Internet" for high-performance computing: worldwide collections of high-end resources - such as supercomputers, storage, advanced instruments and immerse environments. The Grid is expected to bring together geographically and organizationally dispersed computational resources, such as CPUs, storage systems, communication systems, real-time data sources and instruments, and human collaborators. The term "the Grid" was coined in the mid l990s to denote a proposed distributed computing infrastructure for advanced science and engineering. The term computational Grids refers to infrastructures aimed at allowing users to access and/or aggregate potentially large numbers of powerful and sophisticated resources. More formally, Grids are defined as infrastructure allowing flexible, secure, and coordinated resource sharing among dynamic collections of individuals, institutions and resources referred to as virtual Organizations. GRID is an emerging IT as a kind of next generation Internet technology which will fit very well with Agrometeorological services in the future. I believe that it would contribute to the resource sharing in AgroMeteorology by providing super computing power, virtual storage, and efficient data exchanges, especially for developing countries that are suffering from the lack of resources for their agmet services at national level. Thus, the establishment of CAgM-GRID based on existing RAMINSII is proposed as a part of FWIS of WMO.part of FWIS of WMO.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12A
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• pp.1303-1310
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• 2007

In IEEE 802.11b wireless network, stations synchronize themselves to the beacons periodically sent by the access point (AP) when they are running in low power mode. Stations stay awake for enough time to receive beacon because it is delayed in AP if the wireless channel has been being used by other traffic at each scheduled instant. In this paper, we propose a method that measures the delay of received beacons and calculates wake-up interval of station to receive the next one. Beacon transmission delay at the AP is analyzed. The proposed method is simulated and its characteristics are described in the analysis. The result measured in terms of station's wake-up interval shows some enhancement in energy consumption.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.407-417
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• 2005

An experimental and analytical study was performed to apply the friction pendulum system (FPS) to the main control room of a nuclear power plant. A friction pendulum bearing was fabricated, and the dynamic response of the bearing was evaluated. A partial model of a main control room attached to the FPS was tested on the shake table. The model consisted of a cabinet, a $3m\times3m$ access floor, and four friction pendulum bearings. The artificial time history based on the floor response spectrum of the main control room was used as the earthquake input signal in the test. Comparisons between the analytical study and the experimental study were conducted to verify the results and to extend the experimental study to the range of parameters that could not be experimentally studied.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.70-74
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• 2004

There are many researches being in process to develop the information storage devices applying to the portable devices recently. Based on this need, the information storage devices have to be satisfied with the fast access time, the robustness of the system, high data transfer rate and lower media price. The total size of the drive must design to adapt the portable devices such as CF II card or PC II card size. This paper proposes the swing arm type actuator to insert the designed actuator in the drive of the CF II size. Hereafter the research will be going on to be suitable to the physical standard and design the focus magnetic circuit newly. The swing arm type actuator including this circuit is designed to have the dynamic characteristic satisfying the mechanical specification as well as the BD 1x. Finally, the adaptability to the portable devices was demonstrated by the finite element analysis and optimization of structural part.

• Structural Engineering and Mechanics
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• v.87 no.3
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• pp.211-219
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• 2023

The structural health of a pipeline is usually assessed by visual inspection. In addition to the fact that this method is expensive and time consuming, inspection of the whole structure is not possible due to limited access to some points. Therefore, adopting a damage detection method without the mentioned limitations is important in order to increase the safety of the structure. In recent years, vibration-based methods have been used to detect damage. These methods detect structural defects based on the fact that the dynamic responses of the structure will change due to damage existence. Therefore, the location and extent of damage, before and after the damage, are determined. In this study, fuzzy genetic algorithm has been used to monitor the structural health of the pipeline to create a fuzzy automated system and all kinds of possible failure scenarios that can occur for the structure. For this purpose, the results of an experimental model have been used. Its numerical model is generated in ABAQUS software and the results of the analysis are used in the fuzzy genetic algorithm. Results show that the system is more accurate in detecting high-intensity damages, and the use of higher frequency modes helps to increase accuracy. Moreover, the system considers the damage in symmetric regions with the same degree of membership. To deal with the uncertainties, some error values are added, which are observed to be negligible up to 10% of the error.

• Journal of IKEEE
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• v.27 no.4
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• pp.644-649
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• 2023

As the cell spacing decreases during the scaling process of DRAM(Dynamic Random Access Memory), the reduction in STI(Shallow Trench Isolation) thickness leads to an increase in sub-threshold leakage due to the passing word line effect. The increase in sub-threshold leakage current caused by the voltage applied to adjacent passing word lines affects the data retention time and increases the number of refresh operations, thereby contributing to higher power consumption in DRAM. In this paper, we identify the causes of the passing word line effect through TCAD Simulation. As a result, we confirm the DRAM operational conditions under which the passing word line effect occurs, and observe that this effect alters the proportion of the total leakage current attributable to different causes. Through this, we recognize the necessity to consider not only leakage currents due to GIDL(Gate Induced Drain Leakage) but also sub-threshold leakage currents, providing guidance for improving DRAM structure.

• Convergence Security Journal
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• v.23 no.2
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• pp.27-36
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• 2023

In recent years, ransomware attacks have become more organized and specialized, with the sophistication of attacks targeting specific individuals or organizations using tactics such as social engineering, spear phishing, and even machine learning, some operating as business models. In order to effectively respond to this, various researches and solutions are being developed and operated to detect and prevent attacks before they cause serious damage. In particular, honeypots can be used to minimize the risk of attack on IT systems and networks, as well as act as an early warning and advanced security monitoring tool, but in cases where ransomware does not have priority access to the decoy file, or bypasses it completely. has a disadvantage that effective ransomware response is limited. In this paper, this honeypot is optimized for the user environment to create a reliable real-time dynamic honeypot file, minimizing the possibility of an attacker bypassing the honeypot, and increasing the detection rate by preventing the attacker from recognizing that it is a honeypot file. To this end, four models, including a basic data collection model for dynamic honeypot generation, were designed (basic data collection model / user-defined model / sample statistical model / experience accumulation model), and their validity was verified.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.10
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• pp.1-9
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• 2001

The MAC (Medium Access Control) protocol is needed for the OLT(Optical Line Termination) to allocate bandwidth to ONUs(Optical Network Units) and ONTs(Optical Network Terminations) dynamically in the ATM PON(Passive Optical Network). With the protocol, the OLT gathers ONUs' informations and provides grants efficiently to each ONU. Two important functions of the MAC protocol is the grant request procedure and the grant distribution algrithm. The latter has the greatest arithmetic portion in the TC(Transmission Convergence) module, occupies a relatively large portion of the overall chip area, has often been the limiting factor in terms of speed, and should be designed to guarantee the quality of service for various traffics. In this paper, we implement the MAC with the FPGA which can allocate grants dynamically according to the queue length information and the number of active ONUs and distribute grants uniformly to minimize the cell delay variation for each ONU. The structure of the MAC scheduler for the dynamic bandwidth assignment has a programmable look-up table. Also, it has a simple structure, the less chip area, and the lower delay time.

• Journal of Korean Academy of Nursing
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• v.26 no.2
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• pp.399-412
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• 1996

Even though Korean medical law stipulates that number of patients attended by a nurse is 2.5 for hospitalization and 30 for ambulatory care, the number of patients cared by a nurse per day is much greater than the standard prescribed by the medical law. Current nursing productivity of nurses is not desirable unless the quality of care considered. Moreover. nursing manpower staffing based on neither current nurses' productivity nor standard of medical law cannot respond properly to dynamic situation of the medical services. As for the nurse scheduling, the critical problem of it in the hospital is determining the day-to-day shift assignments for each nurse for the specified period in a way that satisfies the given requirements of the hospital. Nurse scheduling, however, involves many factors and requirements, manual scheduling requires much time and effort to produce an adequate schedule. Under these backgrounds, the necessity of more efficient management of nursing manpower occupying 1/3 of total hospital workers has been recognized by many nursing administrators. This study was performed to develop a system computerizing nurse staffing and scheduling based on the patient classification. As a preliminary step for the system development, nursing workload in a secondary hospital was measured from Sep. to Oct. 1994. On the grounds of this result, computerization of nurse staffing and scheduling was proceeded with three options. First one is based on the current medical law. Second one is based on the assigned number of nursing staff. And the last is based on the request by patient classification. Computer languages used in this study were MS Visual Basic 3.0 for the staffing and Access 2.0 for the scheduling, respectively. Prospective users may operate this system easily because icons and mouse are used for easier graphic user interface and reducing the need for typing efforts. This system can help nurse administrators manage nursing manpower efficiently and nurses develop quick and easy schedule generation and allow more time for the patient care.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.3
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• pp.1-6
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• 2008

Data grid shares distributed large data via wide-band network. Such grid environment consumes much time for large data transmission. Because it is implemented on internet as physical network. Many replication strategies were proposed for solving this problem, but they are not optimal in real Data grid environments. Because they were proposed that based on logical topology without consideration of real internet architecture. Grid data access time is largely influenced by internet architecture as physical network of Data grid. In this paper, we propose a new data replication strategy RSIA(Replication Strategy based on Internet Architecture) based on internet architecture. The RSIA places replicas considering structural hierarchy in each element of internet, and avoid the performance bottlenecks to reduce system performance degradation when a data transfer. Through simulation, we show that the proposed RSIA data replication strategy improves the performance of Data Grid environment compared with previous strategies.