• Journal of KIISE:Computer Systems and Theory
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• v.36 no.5
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• pp.412-421
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• 2009

Due to the physical characteristics of NAND flash memory, overwrite operations are not permitted at the same location, and therefore erase operations are required prior to rewriting. These extra operations cause performance degradation of NAND flash memory file system. Since it also has an upper limit to the number of erase operations for a specific location, frequent erases should reduce the lifetime of NAND flash memory. These problems can be resolved by delaying write operations in order to improve I/O performance: however, it will lower the cache hit ratio. This paper proposes a policy of page management using double cache for NAND flash memory file system. Double cache consists of Real cache and Ghost cache to analyze page reference patterns. This policy attempts to delay write operations in Ghost cache to maintain the hit ratio in Real cache. It can also improve write performance by reducing the search time for dirty pages, since Ghost cache consists of Dirty and Clean list. We find that the hit ratio and I/O performance of our policy are improved by 20.57% and 20.59% in average, respectively, when comparing them with the existing policies. The number of write operations is also reduced by 30.75% in average, compared with of the existing policies.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.228-228
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• 2015

Water reuse plays significant role in water saving and water environmental protection, and it helps alleviate the shortage of water resources. China's water reuse was put into practice since 1980s by means of pilot and promotion in National Fifth-year Plan and other strategies. The effects of water reuse is beneficial in both economic, social and environmental aspects. But some shortcomings still undermine future development of water reuse in China. To overcome and boost water reuse, Ministry of Water Resources conducted a successive survey across China. The aim of this study is to demonstrate the current condition of water reuse in China in construction, funds, legislation, planning, policy aspects, to summarize problems and its reasons underneath, to make suggestions for further development. Basically, in 2010, China's water reuse is 2.83 billion cubic meters and the utilization rate is 10.35%. Water reuse in China has four major characteristics: the first one is water reuse differences in amount occur national-widely and North of China has the main percentage as 47.3%; the second one is water reuse is mainly in environment maintenance (42.1%) and industry cooling (29.8%); the third one is funds for water reuse station and pipe construction is main in non-fiscal budget which take percentage as 56.8%; the fourth one is progresses of administrative system, political system, price management, standard system and technologies go rapidly recently. The problems of water reuse such as lack in water reuse station, delay in pipe constriction and limits on water reuse amount still exist due to some reasons. As a think tank of Ministry of Water Resources, we give some suggestions: firstly, water reuse needs to be integrated with traditional water resources allocation; secondly, public budgets need to be strengthened and income mechanism should also be constructed; thirdly, water resources integrated administrative of city and county should be boosted and roles as water reuse need to be clear and precise; fourthly, national, provincial and regional water reuse planning should be made in time; fifthly, regulations on water reuse should be programmed as soon as possible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.733-736
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• 2009

Power Line Communication(PLC) is need not additional communication line. So establishment expense is inexpensive and application is simple. Therefore, lower part network of various application field is possible. However, there are high subordinate interference and noise problem on limited transmission data and communication interference element. Wireless Sensor Network(WSN) is need not infrastructure, Self-regulating network architecture of sensor nodes is possible. So at short time, network construction is available. But, power consumption is increased by active sensing for QoS elevation and unnecessary information transmission, low electric power design and necessity of improve protocol are refered to life shortening problem and is studied. In this paper, supplement problem of power line communication and wireless sensor network mutually and because advantage becomes linkage integration control system using synergy effect of two technologies as more restriction be and tries to approach structurally control network that is improved for smooth network environment construction. Honeywell's hybrid sensor network does comparative analysis(benchmarking). Confirm performance elevation proposing teaming of power line communication and wireless sensor network. Through simulation, service delay decreases and confirms that performance elevation.

• Journal of Convergence for Information Technology
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• v.7 no.2
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• pp.43-51
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• 2017

Background/Objectives : The purpose of this study is to propose a multi-threaded web crawl using queues that can solve the problem of time delay of single processing method, cost increase of parallel processing method, and waste of manpower by utilizing multiple bots connected by wide area network Design and implement. Methods/Statistical analysis : This study designs and analyzes applications that run on independent systems based on multi-threaded system configuration using queues. Findings : We propose a multi-threaded web crawler design using queues. In addition, the throughput of web documents can be analyzed by dividing by client and thread according to the formula, and the efficiency and the number of optimal clients can be confirmed by checking efficiency of each thread. The proposed system is based on distributed processing. Clients in each independent environment provide fast and reliable web documents using queues and threads. Application/Improvements : There is a need for a system that quickly and efficiently navigates and collects various web sites by applying queues and multiple threads to a general purpose web crawler, rather than a web crawler design that targets a particular site.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.757-763
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• 2018

It is very difficult to achieve sufficient data rate and required quality of service due to the time-varying nature of the radio channel and various jammers such as path loss, delay, Doppler, shadowing and interference. Especially, the propagation path between the transmitting antenna and the tracking antenna mounted on the fuselage during the test and evaluation of the projectile system considered in this paper is based on the rapid movement of the projectile, the interference due to multipath fading due to the terrain, The propagation path may be blocked. In order to effectively improve the multipath fading occurring in the wireless communication system, a diversity combiner technique is required. In this paper, to derive the design and improvement schemes for the space diversity combiner technique among the diversity combiner schemes, the BER performance of maximum ratio combining (MRC) and selection combining (SC) In an adaptive SC / MRC diversity combiner that operates with MRC when it is lower than the specified threshold criterion when comparing the SNR between two signals received from the channel and operates with SC at high and combines the two received signals The BER performance of the system was compared and analyzed.

• Journal of the Korea Society for Simulation
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• v.33 no.2
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• pp.1-11
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• 2024

A cyber-physical system is a technology that connects the physical systems of a manufacturing environment with a cyber space to enable simulation. One of the major challenges in this technology is the seamless communication between these two environments. In complex manufacturing processes, it is crucial to adapt to various protocols of manufacturing equipment and ensure the transmission and reception of a large volume of data without delays or errors. In this study, we propose a method for constructing agent models for real-time simulation-capable cyberphysical systems. To achieve this, we design data collection units as independent agent models and effectively integrate them with existing simulation tools to develop the overall system architecture. To validate the proposed structure and ensure reliability, we conducted empirical testing by integrating various equipment from a real-world smart microfactory system to assess the data collection capabilities. The experiments involved testing data delay and data gaps related to data collection cycles. As a result, the proposed approach demonstrates flexibility by enabling the application of various internal data collection methods and accommodating different data formats and communication protocols for various equipment with relatively low communication delays. Consequently, it is expected that this approach will promote innovation in the manufacturing industry, enhance production line efficiency, and contribute to cost savings in maintenance.

• Journal of Arbitration Studies
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• v.13 no.1
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• pp.169-205
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• 2003

Arbitration means the procedure that a party inquires a third party arbitrator for a resolution on the dispute on certain matters of interest to follow through with the commitment of the arbitration, and a series of procedures performed by the arbitrator of the Korean Commercial Arbitration Board. Arbitration is implemented in accordance with the procedure determined by the Arbitration Act and Arbitration Regulations. In the event the parties reach to the reconciliation during the process of arbitration, the reconciliation is recorded in the form of arbitration award(decision), and in the event a reconciliation is not made, the arbitrator shall make the decision on the particular case. The arbitration award(decision) for reconciliation during the arbitration procedure (Article 31 of Arbitration Act, hereinafter referred to as the 'Act') or the mediation under the Arbitration Regulation of the Korean Commercial Arbitration Board (Article 18 of the Arbitration Regulations) shall have the same effectiveness with the decision rendered by a court that, in the event a party does not perform the obligation, the enforcement document is rendered under the Rules on Enforcement Document on Mediation Statement of various dispute resolution committees of the Supreme Court to carry out the compulsory enforcement. However, in the event that the party to take on the obligation to perform under the arbitration award (decision) rendered by the arbitrator (Article 32 of the Act) does not perform without due cause, a separate enforcement decision in accordance with the procedure determined under the Civil Enforcement Act shall be obtained since the arbitration award(decision) cannot be the basis of enforcement under the Civil Enforcement Act. And, in order to enforce the judgment compulsorily in accordance with the regulations under the Civil Enforcement Act under the foreign arbitration judgment (Article 39 of the A.1), it shall fulfill the requirement determined under the Civil Litigation Act (article 217 of Civil Litigation Act) and shall obtain a separate enforcement decision in accordance with the procedure determined under the Civil Enforcement Act (Article 26 and Article 27 of Civil Enforcement Act) since the arbitration judgment of foreign country shall not be based on enforcement under the Civil Enforcement Act. It may be the issue of legislation not to recognize the arbitration award(decision) as a source of enforcement right, and provide the compulsive enforcement by recognizing it for enforcement right after obtaining the enforcement document with the decision of a court, however, not recognizing the arbitration award(decision) as the source of enforcement right is against Clause 3 of Article 31 of the Act, provisions of Article 35, Article 38 and Article 39 that recognized the validity of arbitration as equal to the final judgment of a court, and the definition that the enforcement decision of a court shall require the in compulsory enforcement under Clause 1 of Article 37 of the Act which clearly is a conflict of principle as well. Anyhow, in order to enforce the arbitration award(decision) mandatorily, the party shall bring the litigation of enforcement decision claim to the court, and the court shall deliberate with the same procedure with general civil cases under the Civil Litigation Act. During the deliberation, the party obligated under the arbitration award(decision) intended to not to undertake the obligation and delay it raises the claim and suspend the enforcement of cancelling the arbitration award(decision) on the applicable arbitration decision within 3 months from the date of receiving the authentic copy of the arbitration award(decision) or the date of receiving the authentic copy of correction, interpretation or additional decision under the Regulation of Article 34 of the Act (Clause 3 of Article 36 of the Act). This legislation to delay the sentencing of the enforcement and then to sentence the enforcement decision brings the difficulties to a party to litigation costs and time for compulsory enforcement where there is a requirement of an urgency. With the most of cases for arbitration being the special field to make the decision only with the specialized knowledge that the arbitrator shall be the specialists who have appropriate knowledge of the system and render the most reasonable and fair decision for the arbitration. However, going through the second review by a court would be most important, irreparable and serious factor to interfere with the activation of the arbitration system. The only way to activate the arbitration system that failed to secure the practicality due to such a factor, is to revise the Arbitration Act and Arbitration Regulations so that the arbitration decision shall have the right to enforce under the Rules on Enforcement Document on Mediation Statement of various dispute resolution committees of the Supreme Court.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.48-52
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• 2013

Purpose: Bed, living a long time is required in adult patients with brain lesions such as stroke, traumatic brain injury, and Parkinson's disease, causing pneumonia and respiratory diseases may be due to aspiration of food or saliva. In patients with recurrent pneumonia or pulmonary symptoms, there is a need to determine the possibility of pulmonary aspiration due to aspiration of saliva. Materials and Methods: Saliva due to aspiration pneumonia diagnosis in patients with brain lesions request for inspection to the Department of Nuclear Medicine, 10 patients (male 6, female 4) were included in this study. Patients were fasted before the test, $^{99m}Tc_{O4}$ 185 MBq (5 mCi) of less than 1 mL of solution was administered in the oral cavity. Administration and 20 minutes of dynamic imaging acquisition, and immediately after that the static images were acquired. Delayed scan after 2-4 hours if necessary. Results: Positivity rate of all 10 patients was 60%. In 4 patients showed positive reactions after the administration of oral cavity in a 20-minute dynamic imaging were able to confirm whether the aspiration. In the remaining 2 patients, four hours of additional delay tests were able to confirm whether the aspiration. Conclusion: Does not require changes in patient posture compared to the other checks that can be diagnosed with aspiration pneumonia. A simple test and takes less time. Therefore be useful in providing information for the diagnosis and treatment modality.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.209-220
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• 2007

IPS(Intrusion Prevention Systems), which is installed in inline mode in a network, protects network from outside attacks by inspecting the incoming/outgoing packets and sessions, and dropping the packet or closing the sessions if an attack is detected in the packet. In the signature based filtering, the payload of a packet passing through IPS is matched with some attack patterns called signatures and dropped if matched. As the number of signatures increases, the time required for the pattern matching for a packet increases accordingly so that it becomes difficult to develop a high performance US working without packet delay. In this paper, we propose a high performance IPS based on signature hashing to make the pattern matching time independent of the number of signatures. We implemented the proposed scheme in a Linux kernel module in a PC and tested it using worm generator, packet generator and network performance measure instrument called smart bit. Experimental results show that the performance of existing method is degraded as the number of signatures increases whereas the performance of the proposed scheme is not degraded.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.383-387
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• 2014

In this paper, for a new detection system development with the better accurate dose evaluation and beam distribution imaging using the small field irradiation of linear accelerator, the compound semiconductor based detection sensors were fabricated and the performance evaluation was investigated. The special particle-in-binder sedimentation was used for a large area film sensor fabrication. The detection properties for high energy x-rays were investigated from a dark current, an output current, a rising time, a falling time, and response delay measurement. The experimental results, the $TiO_2$ mixed $HgI_2$ sensor showed the best electrical characteristics than $PbI_2$, PbO, pure $HgI_2$. Linearity, repeatability, and accuracy tests from LINAC were tested, the $TiO_2$ mixed $HgI_2$ sensor showed the better performance than the commercially available dosimetry devices.