• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2533-2539
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• 1999

Two scheme are widely used for fault-tolerant systems : one is the duplex system that has a physical redundancy, and the other one is the checkpointing scheme that rolls back to the last checkpoint at a failure. The average execution time and availability are important factors for measuring the performance of the fault-tolerant systems. However, in fault-tolerant real-time systems with a time constraint, meeting the time constrain instead of reducing the average execution time is the most important factor in the performance evaluation. We analyze and compare the performance of two fault-tolerant scheme (the duplex system and the checkpointing scheme) for real-time applications.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.181-190
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• 2005

The time required for airport process is considered more important as the airports are becoming bigger. International Civil Aviation Organization mattes this international standards and recommends not to exceed it. The passenger forecasting model is developed to predict the number of passengers at the check-in counter, and the area of formalities for departure and entry. In case of forecasting the number of outbound-passengers. the patterns of show-up lead time(SLT) at the check-in counter and lag time from check-in counter to the area of departure formalities are modeled in terms of time. On the other hand, the matter of the choice of check-in counters and areas of departure formalities are modeled in terms of space. In case of forecasting the number of inbound-passengers and transfer passengers, the time of airplane movement from arrival to block on at the gate and the time of passengers required from gate to the area of formalities for entry are modeled in terms of time. While the matter of the choice of gates and the areas of formalities for entry are modeled in terms of space. The average error of forecasting outbound-passengers and inbound-passengers is respectively 15% and 10%, which are considered excellent with the 5% error of passenger reservation information as input data. Through the development of passenger forecasting models, we assure we could provide passengers with valuable service because we allocate resource such as employees and equipments according to the degree of concentration of passengers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.346-349
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• 2015

Generally, in order to verify the degree of tire wear or abnormal wear, a driver or an auto mechanic checks the degree of tire wear and the existence of tire abnormality, directly with the naked eye or by way of using a gauge equipment. In case of such verification, individual subjective judgments may be involved or a driver may suffer heavy burdens to expend the time and cost for using the wheel alignment equipment. Therefore, this thesis will use a number of laser sensors to check the existence of abnormal wear and the degree of wear on each tire and develop a system checking the sides of tires to receive the tire information, so that subjective judgments may be overcome and objective and accurate judgments may be rendered.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.293-304
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• 2005

In this paper, we research on job migration in a grid computing environment with cactus and MPICH-C2 based on Globus. Our concepts are to perform job migration by finding the site with plenty of computational resources that would decrease execution time in a grid computing environment. The Migration Manager recovers the job from the checkpointing files and restarts the job on the migrated site. To select a migrating site, the proposed method considers system's performance index, cpu's load, network traffic to send migration job tiles and the execution time predicted on a migration site. Then it selects a site with maximal performance gains. By selecting a site with minimum migration time and minimum execution time. this approach implements a more efficient grid computing environment. The proposed method Is proved by effectively decreasing total execution time at the $K\ast{Grid}$.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.583-594
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• 2006

The reliability concept of wireless sensor network is essential to get exactly actual data from the ubiquitous environment. A rollback technique for the self-healing helps to increase it. However, a fault can occur in wireless sensor network when to use a previous rollback technique because it is designed just for the local system. So, checkpoint protocols are suggested in order to use a rollback technique in the network without the fault. However, there is trade-off among performance overhead, power consumption, and memory overhead for each of protocols. Hence, we suggest a novel global checkpoint protocol, so called address log based protocol(ALBP), based on an asynchronous protocol. It is a platform based protocol to reduce power consumption, performance overhead, and memory overhead which are the most of consideration in wireless sensor network.

• Venture DIGEST
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• s.53
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• pp.12-15
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• 2004

일년 열두 달 중 여섯 달이 지나갔으니 이제 2004년 전반전도 끝이 난 셈입니다. 이제는 후반전 준비에 돌입해야 할 하프타임. 새해 초 세웠던 무수한 계획들과 다짐들, 부도수표처럼 바람에 흩날려가진 않았는지 다시 한번 체크해보고, 점점 체력이 바닥나는 이 내 몸과 자꾸만 한 박자씩 느려지는 머리 속에 새로운 힘을 재충전하는 시간을 가져보세요. 스크롤의 압박에서 벗어나 지금 벤처인들은 로딩중!

• Journal of Digital Convergence
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• v.16 no.10
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• pp.289-299
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• 2018

The purpose of this study was to identify the effects of clinical practice education using delirium checklist for nursing students. The study was used pretest-posttest design with single group with 91 fourth year nursing students. The study measured the delirium knowledge, self-confidence and performance of delirium care using structured questionnaire from August 14 to September 30, 2017. The delirium education was composed of one hour lecture and clinical practice. Clinical practice was applied checklists of delirium assessment and prevention care. In result, significant improvements were found in delirium knowledge(t=-11.23, p<.001), self-confidence(t=-11.00, p<.001) and performance(t=-5.31, p<.001) of delirium care. Based results of this study, it was found that delirium education using checklist improved delirium knowledge, self-confidence and performance levels of delirium care for nursing students.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.477-479
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• 2017

With the recent advances in medical technology and health care, the prevention and treatment of diseases has developed. Accordingly aging has rapidly progressed. In this life span and aging society, demand for diagnostic centered medical care is increasing rapidly. In this paper, we propose a wearable patient check system based on FPGA that can be controlled by sensors. In the existing hospital, a doctor or nurse visited the patient every hour to check the condition. However, in this paper, patients, doctors and nurses can check the patient's condition at the desired time using patient check system. In addition, the tilt sensor is used for the patient who is uncomfortable to easily control. The proposed FPGA-based hardware architecture consists of an algorithm for enlarged image processing, a TFT-LCD Controller, a CIS Controller, and a Memory Controller to output the patient's status image. Implemented and validated using the DE2-115 test board with Cyclone IV EP4CE115F29C7 FPGA device and its operating frequency is 50MHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.4
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• pp.23-28
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• 2023

In a wireless smart utility network communication system, an asynchronous low power MAC is standardized and used according to IEEE 802.15.4e. An asynchronous MAC called RIT (Receiver Initiated Transmission) has a characteristic in which delay time and power consumption are greatly affected by a check-in interval (RIT period). By waking up from sleep every check-in interval and checking whether there is data to be received, power consumption in the receiving end can be drastically reduced, but power consumption in the transmitting end occurs due to an excessive wakeup sequence. If an excessive wake-up sequence is reduced by shortening the check interval, power consumption of the receiving end increases due to too frequent wake-up. In the RIT asynchronous MAC technique, power consumption performance according to traffic load and operation of check-in interval is analyzed and applied to Wi-SUN construction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.65-70
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• 2024

In recent years, research on smart factory wireless mobile communication technology that wirelessly remotely controls utilities is being actively conducted. The Wi-SUN (Wireless Smart Utility Network) Alliance proposed a Wi-SUN protocol structure suitable for building a platform such as a smart factory as a new wireless communication standardization standard based on EEE802.15.4g/e. It analyzes the performance of the IEEE802.15.4e Receiver Initiated Transmission(RIT) Mode Media Access Control (MAC) in terms of throughput and latency, and looks at considerations for efficient operation. RIT mode shows that as the check interval becomes longer, delay time and throughput decrease. It was shown that as the traffic load increases, if the RIT check interval is shortened, the delay time can be shortened and throughput can be increased. RIT mode has the advantage of low power consumption and has neutral characteristics between IEEE802.15.4 and CSL mode in terms of delay time and throughput.