• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.2
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• pp.141-156
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• 2009

As the TCP is the protocol designed for the wired network that packet loss probability is very low, because TCP transmitter takes it for granted that the packet loss by the wireless network characteristics is occurred by the network congestion and lowers the transmitter's transmission rate, the performance is degraded. The Snoop Protocol was designed for the wired network by putting the Snoop agent module on the BS(Base Station) that connect the wire network to the wireless network to complement the TCP problem. The Snoop agent cash the packets being transferred to the wireless terminal and recover the loss by resending locally for the error occurred in the wireless link. The Snoop agent blocks the unnecessary congestion control by preventing the dupack (duplicate acknowledgement)for the retransmitted packet from sending to the sender and hiding the loss in the wireless link from the sender. We evaluated the performance in the wired/wireless network and in various TCP versions using the TCP designed for the wired network and the Snoop designed for the wireless network and evaluated the performance of the wired/wireless hybrid network in the wireless link environment that the continuous packet loss occur.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7B
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• pp.660-666
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• 2004

Overall TCP performance represented by end-to-end throughput is largely dependent upon its loss recovery performance. In particular non-congestion packet losses caused by transmission errors degrade TCP performance seriously. Using Markov process, we analyze TCP loss recovery performance for correlated packet losses caused by multipath fading. The results show that loss recovery performance can be severely affected by burstiness in packet losses, even if overall packet loss ratio is very low.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.3
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• pp.479-491
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• 1994

In this paper, we proposed cell priority control with 2-level thresholds, which was considered cell loss and cell delay requirement, in ATM switch with output buffer. Priority control mechanism presented in this paper improved cell loss rate for cell loss censitive cell and cell delay for delay censitive cell. In this mechanism cell loss rate and mean cell delay of cell priority control mechanism were obtained theoretically. The results show that cell loss rate and mean cell delay improvement become better by adjusting two thresholds according to QOS characteristics.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.2
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• pp.89-98
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• 2007

In this paper the economic value of weather forecasts is valuated for profit-oriented enterprise decision-making situations. Value is estimated in terms of monetary profits (or benefits) resulted from the forecast user's decision under the specific payoff structure, which is represented by a profit/loss ratio model combined with a decision function and a value score (VS). The forecast user determines a business-related decision based on the probabilistic forecast, the user's subjective reliability of the forecasts, and the payoff structure specific to the user's business environment. The VS curve for a meteorological forecast is specified by a function of the various profit/loss ratios, providing the scaled economic value relative to the value of a perfect forecast. The proposed valuation method based on the profit/loss ratio model and the VS is adapted for hypothetical sets of forecasts and verified for site-specific probability of precipitation forecast of 12 hour and 24 hour-lead time, which is generated from Korea meteorological administration (KMA). The application results show that forecast information with shorter lead time can provide the decision-makers with great benefits and there are ranges of profit/loss ratios in which high subjective reliability of the given forecast is preferred.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1051-1060
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• 2010

In the plating process of the IC chips for the printed circuit board manufacturing, specification limits for the plating thickness are usually given but its target is not specified in most cases. When the target is not specified, the center point of the specification limits is used instead. When the process capability is large, however, the use of the center point for the target is not the best choice in the context of the total cost. In this paper, the total cost is defined in terms of the production cost and the loss function, and then the optimal choice for target is studied in order to minimize the expected loss. As a consequence, the optimal choice of the target reduces the expected loss significantly, while reducing the process capability slightly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.125-126
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• 2019

This study aims to recognize damage indicators of typhoon and to develop damage function's indicators, using information derived from the actual loss of typhoon Maemi. As typhoons engender significant financial damage all over the world, governments and insurance companies, local or global, develop hurricane risk assessment models and use it in quantifying, avoiding, mitigating, or transferring the risks. For the reason, it is crucial to understand the importance of the risk assessment model for typhoons, and the importance of reflecting local vulnerabilities for more advanced evaluation. Although much previous research on the economic losses associated with natural disasters has identified the risk indicators that are indispensable, more comprehensive research addressing the relationship between vulnerability and economic loss are still called for. Hence this study utilizes and analyzes the actual loss record of the typhoon Maemi provided by insurance companies to fill such gaps. In this study, natural disaster indicators and basic building information indicators are used in order to generate the vulnerability functions; and the results and indicators suggest a practical approach to create the vulnerability functions for insurance companies and administrative tasks, while reflecting the financial loss and local vulnerability of the actual buildings.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5917-5935
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• 2018

Adaptive Multi-Rate Codec is one of the codecs which is used for making voice calls. It helps to connect people who are scattered in various geographical areas. It adjusts its bit-rate according to the user's channel conditions. It plays a vital role in providing an improved speech quality of voice connection in Long Term Evolution (LTE). There are some constraints which need to be addressed in providing this service profitably. Quality of Service (QoS) is the dominant mechanism which determines the quality of the speech in communication. On several occasions, number of users are trying to access the same channel simultaneously by standing in a particular region for a longer period of time. It refers to Multi-user channel sharing problem which leads to resource loss very often. The main aim of this paper is to develop a novel RSA - QoS scheduling algorithm for reducing the Resource Loss Ratio. Eventually, it increases the throughput.The simulation result shows that the RSA - QoS increases the number of users for accessing the resources better than the existing algorithms in terms of resource loss and throughput. Ultimately, it enhances the QoS in Mobile Networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.451-453
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• 2019

Recently, as the use of wireless communication devices has increased, the wireless network usage has increased, and a wired network and a wireless network have been mixed to form a network. Existing TCP algorithms are designed for wired networks. Therefore, in the modern network environment, packet loss can not be accurately distinguished and improper congestion control is performed, resulting in degradation of TCP performance. In this paper, we propose SLDA (Support Vector Machine based Loss Discrimination Algorithm) which can accurately classify the packet loss environment to improve TCP performance and evaluate its performance.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.4
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• pp.3-14
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• 2002

In this paper we classify the possible threat and introduce the method that measures the loss resulted from the threat in the university. This is the method that the amount of the loss minimized in the case of the same quality in damage as establish a economical prediction model. The method of measuring the loss is as follows. First, asset should be clearly identified and valued. Second, threats which may result in harm to asset should be classified. Third, vulnerabilities which is weaknesses associated with asset should be analyzed. Fourth, measure the value of the loss. we explain the valued method by the example.

• Tribology and Lubricants
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• v.19 no.5
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• pp.292-297
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• 2003

The fundamental fluid mechanics associated with the rotation of a smooth plane disk enclosed within a cylindrical chamber have been studied experimentally. In order to acquire systematic information pertinent to this problem torque and friction loss data were obtained over a wide range of disk Reynolds numbers for axial clearance-disk radius ratio H/R from 0.025 to 0.2 and radial tip gap-disk radius ratio s/R from 0.021 to 0.105. Loss analysis of hard disk drive (HDD) is presented to describe the contribution of windage loss of a rotating disk. The minimum loss form factor of HDD can be obtained from this analysis at each operation conditions.