• Journal of Digital Contents Society
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• v.10 no.2
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• pp.357-365
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• 2009

To effectively exploit the underlying network bandwidth while maximizing user perceivable QoS, mandatory to make proper estimation on packet loss and queuing delay of the underling network. This issue is further emphasized in wireless network environment where network bandwidth is scarce resource. In this work, we focus our effort on developing performance model for wireless network. We collect packet trace from actually wireless network environment. We find that packet count process and bandwidth process in wireless environment exhibits long range property. We extract key performance parameters of the underlying network traffic. We develop an analytical model for buffer overflow probability and waiting time. We obtain the tail probability of the queueing system using Fractional Brown Motion (FBM). We represent average queuing delay from queue length model. Through our study based upon empirical data, it is found that our performance model well represent the physical characteristics of the IEEE 802.11b network traffic.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.7
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• pp.572-580
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• 2013

IEEE 802.15.4e is a prospective standard for low latency control application in industries. This paper proposes a framework to evaluate the closed loop IEEE 802.15.4e based WNCS performance. The framework consists of two models: closed loop control system model and network model. The network model focuses on the PHY parameters of wireless link and takes the channel parameters into consideration. The PHY model combining with MAC model gives the control system model the probability of packet loss in a super-frame. In addition, redundancy mechanism is considered in IEEE 802.15.4e to reduce to data frame loss probability. The simulation is implemented in Matlab, PHY model takes the channel parameters from empirical results. Hence our evaluation gives insight into behavior of WNCS in different environments and it provides us a tool to design wireless network to achieve a good performance for control system.

• Journal of Labour Economics
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• v.41 no.4
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• pp.107-131
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• 2018

This paper presents a model for the Minimum Wage Commission's decision process and analyzes the strategic actions of the participants in the process. The Minimum Wage Commission has used two ways of setting the minimum wage. The commission has voted either on the labor's against the management' final proposals or has voted on the public interest commissioners' proposal. According to the model, the minimum wage is determined at a level that is very close to or at a level preferred by the median voter among the public interest commissioners. But the probability of adopting labor or management proposal is ex-ante the same. Empirical evidence from the minimum wage decision process is consistent with the predictions of the model. The probability of adopting the labor's proposal in the minimum wage commission voting is not statistically significantly different from 50%. The model also suggests that the preference of the median voter among public interest commissioners determines the minimum wage level. Since the government appoints public interest commissioners and thus, in fact, the median voters, the government can decide the minimum wage level. This proposition is also consistent with data. The annual growth rate of the minimum wage under the progressive governments is higher than under conservative governments.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.755-767
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• 2020

A significant development has been made on a new fatigue damage model applicable to Gaussian wide band stress response spectra using numerical approximation methods such as data processing, time simulation, and regression analysis. So far, most of the alternative approximate models provide slightly underestimated or overestimated damage results compared with the rain-flow counting distribution. A more reliable approximate model that can minimize the damage differences between exact and approximate solutions is required for the practical design of ships and offshore structures. The present paper provides a detailed description of the development process of a new fatigue damage model. Based on the principle of the Gaussian wide band model, this study aims to develop the best approximate fatigue damage model. To obtain highly accurate damage distributions, this study deals with some prominent research findings, i.e., the moment of rain-flow range distribution MRR(n), the special bandwidth parameter μk, the empirical closed form model consisting of four probability density functions, and the correction factor QC. Sequential prerequisite data processes, such as creation of various stress spectra, extraction of stress time history, and the rain-flow counting stress process, are conducted so that these research findings provide much better results. Through comparison studies, the proposed model shows more reliable and accurate damage distributions, very close to those of the rain-flow counting solution. Several significant achievements and findings obtained from this study are suggested. Further work is needed to apply the new developed model to crack growth prediction under a random stress process in view of the engineering critical assessment of offshore structures. The present developed formulation and procedure also need to be extended to non-Gaussian wide band processes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.1-13
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• 2022

A weighted linear combination of seismic fragility models previously developed for cut-and-cover railway tunnels was presented and the appropriateness of the combined model was evaluated. The seismic fragility function is expressed in the form of a cumulative probability function of the lognormal distribution based on the peak ground acceleration. The model uncertainty can be reduced by combining models independently developed. Equal weight is applied to four models. The new seismic fragility function was developed for each damage level by determining the median and standard deviation, which are model metrics. Comparing fragility curves developed for other bored tunnels, cut-and-cover tunnels for high-speed railway system have a similar level of fragility. We postulated that this is due to the high seismic design standard for high-speed railway tunnel.

• Journal of English Language & Literature
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• v.55 no.5
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• pp.865-883
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• 2009

The mock-heroic, "the single most characteristic and individual literary form of the neoclassical era," as Brean Hammond puts it, epitomizes the process of the "novelization" of the 18th-century British culture. Bakhtin mentions that when the novel reigns supreme, almost all the remaining genres are "novelized"; Hammond borrows the term "novelization" from Bakhtin and uses it as a "shorthand way of referring to the cultural forces that render epic anachronistic." Indebted to Hammond's apprehension of novelization, this paper reads Alexander Pope's Rape of the Lock in the context of novelization, particularly focusing on 'probability,' 'contemporaneity' and 'domesticity,' three important signatures of the novelization of the 18th-century British culture. First, Sylph as a counterpart of god in epic is presented in The Rape of the Lock just as a helpless, fictional and irrelevant thing that hardly affects the empirical world. It indicates how the mock-epic 'mocks' the classical world of 'epic' and stands closer to the world of the novel. Second, Pope's poem displays an accurate picture of the author's contemporary reality, a capital concern of the novel, such as imperialism, consumer society, commodity fetishism, or reification. Lastly, The Rape of the Lock lays out the construction of modern gender ideology, another quintessential interest of the novel, particularly with the fixed female image of a coquette. It efficiently silences and nullifies Belinda, a typical coquette, who stands as a threatening force to the ascendent domestic ideology.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.167-182
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• 2016

The purpose of this study is to investigate the effects of CEO technological capability on management performance and mediating role of firm's technological capability. The empirical data for this study are taken not from subjective studies released by companies but from the Korea Technology Guarantee Fund's(KTGF) technology assessment data. The result are as follows. First, CEO technological capability has a very significant and important influence on firm's technological capabilities and on technological performance(intellectual property rights(-), technology spillover effect(+)) and on management performance. Second, mediating role of firm's technological capability is revealed negatively only between CEO technological capability and intellectual property rights. Because of CEO technological capability has a significant influence on firm's technological capability and management performance, start-up based on expertise show a higher probability of success than the founder.

• Environmental and Resource Economics Review
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• v.20 no.1
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• pp.119-153
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• 2011

This study reviews various aspects of model formulating processes of dichotomous choice responses of the contingent valuation method (CVM), which has been increasingly used in the preliminary feasibility test of Korea public investment projects. The theoretical review emphasizes the consistency between WTP estimation process and WTP measurement process. The empirical analysis suggests that two common parametric models for dichotmous choice responses (RUM and RWTP) and two commonly used probability distributions of random components (probit and logit) resulted in all most the same empirical WTP distributions, as long as the WTP functions are specified to be a linear function of the bid amounts. However, the efficiency gain of DB response compared to SB response were supported on the ground that the two CV responses are derived from the same WTP distribution. Moreover for the exponential WTP function which guarantees the non-negative WTP measures, sample mean WTP were quite different from median WTP if the scale parameter of WTP function turned out to be large.

• 한국해양학회지
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• v.24 no.1
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• pp.1-14
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• 1989

This study analyzes the interannual periodicity by using the statistical techniques of probability, spectral analysis, empirical orthogonal function analysis (EOF), and coherency analysis. The data base for this study is the time series of 1971-1985 temperature, salinity in the southern waters of the East Sea, 1960-1986 mean sea level at Pusan and Izuhara, and 1960-1986 sea level atmospheric pressure at Pusan. The appearances of anomalous temperatures higher and lower than 15-year mean monthly average with one standard deviation are about 30% of total data. The significant interannual period for temperature, salinity and sea level fluctuation is 36.6, and 23.3 months. The empirical orthogonal function analyses show that the 1st mode of the EOFs is responsible for more than 90% of total variance of the surface temperature variations, while in near-bottom waters, the relative importance of the higher EOF modes is much greater explaining more than 30% of total variance. The coherency between normalized temperatures and salinities is significant at the interannual period of 36.6 and 21.3 months.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.39-48
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• 2015

In this study, granting the optimal loan limit on SME (Small and Medium Enterprise) loans of financial institutions was proposed using the traditional newsvendor model. This study was the first domestic case study that applied the newsvendor model that was mainly used to calculate the optimum order quantity under some uncertain demands to the calculation of the loan limit (debt ceiling) of institutions. The method presented in this study made it possible to calculate the loan limit (debt ceiling) to maximize the revenue of a financial institution using probability functions, applied the newsvendor model setting the order volume of merchandise goods as the loan product order volume of the financial institution, and proposed, through the analysis of empirical data, the availability of additional loan to the borrower and the reduction of the debt ceiling and a management method for the recovery of the borrower who could not generate profit. In addition, the profit based loan money management model presented in this study also demonstrated that it also contributed to some extent to the prediction of the bankruptcy of the borrowing SME (Small and Medium Enterprise), as well as the calculation of the loan limit based on profit, by deriving the result values that the borrowing SME (Small and Medium Enterprise) actually went through bankruptcy at later times once the model had generated a signal of loan recovery for them during the validation of empirical data. accordingly, The method presented in this study suggested a methodology to generated a signal of loan recovery to reduce the losses by the bankruptcy.