• Journal of Korea Multimedia Society
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• v.14 no.6
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• pp.752-758
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• 2011

In this paper, we perform a research on a message delivery link based on visible light communication using illumination light-emitting diodes (LEDs) for car-to-car communications and the link transmission success probability is analyzed for the link. The message delivery system is modeled and the signal-to-noise ratio is calculated from the received optical power. Then, the link transmission probability is estimated from the calculated bit error rates (BERs). The message delivery system has optical links from an LED transmitter near the rear lamp of a car ahead to a receiver near the headlamp of a car behind, whose positions are assumed to follow the normal Gaussian distribution. The link transmission success probability is calculated considering the physical characteristics of the optical link. The car positions are generated according to the normal distribution and the bit error rates are calculated for all links. The link transmission success probability is defined. For the unoptimized optical car-to-car message delivery links, it is shown that the link transmission success probability is larger than 0.9 with the transmitted optical power of 400 mW and the semi-angle at half power of 30 degree.

• Journal of the Korean Home Economics Association
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• v.50 no.4
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• pp.103-113
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• 2012

In the U.S. where Direct-to-Consumer Advertising (DTCA) of prescription medications is permitted, spending on DTCA has been accelerating. As a result, it has been an issue of intense public policy attention regarding whether DTCA is beneficial to the public by promoting a healthy lifestyle. Most of the literature concerning DTCA focuses on its impact on demand and empirical evidence regarding its impact on health-related behavior is scant. This study uses a database of DTCAs for high blood cholesterol, hypertension, diabetes, and overweight treatment medications that have appeared in nationally circulated U.S. consumer magazines during 2000 to 2004 and the Simmons National Consumer Survey in order to compute the level of individual advertising exposure and examines whether those who are exposed to DTCA are more likely to engage in regular exercise and diet control. The study finds evidence that for those with chronic conditions, greater exposure to DTCA leads to less exercise but more diet control. By therapeutic class level, exposure to DTCA leads to less exercise for those with hypertension and who are overweight, whereas those with high blood cholesterol are more likely to engage in regular exercise. Looking into differential responses by socioeconomic status, those with less education are more likely to engage in exercise after being exposed to DTCA. The results imply that the effects of DTCA vary by therapeutic class. In order to enhance the benefits of DTCA, it is important to closely monitor the messages in DTCA and require it to include messages that promote lifestyle change should it be a part of the treatment.

• Korea journal of population studies
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• v.25 no.2
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• pp.163-192
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• 2002

Residential overcrowding, also called density, measured as more than one person per room, is a important variable as a principal indicator of inadequate housing. We investigated how immigrants in the US are assimilated to the host society through a lens of housing density. We estimated the probability of living in overcrowded housing of Korean, Chinese and Japanese immigrants armored with the 1980 and 1990 Public Use Microdata Sample(PUMS, A, 5%) in the US. Along with economic effects, we also consider life-cycle effects on the indicator. We applied "double cohort" method that enables duration of immigration effects to be separated from aging effects, which captures family size fluctuations due to life-cycle effects. The study found that cohort trends sharply changed during 10years. The 1970's immigrants are more likely to live in overcrowded housing than the pre-1970 immigrants. The pre-1970 immigrants are more likely to live in overcrowded housing than native-born persons. This may be explained by different assimilation processes driven by the disparities of individual human capitals or cultural differences among the ethnic groups. Especially, Korean experienced a sharp decline in overcrowding between 1980 and 1990. We also found that the major determinants that affect the level of housing density are years since migration, income, and gender. The present study concluded with some future studies related to the Korean immigrants abroad.ts abroad.

• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.89-102
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• 2004

The generated blasting pressure wave initiated under decoupled-charge condition is a function of peak blasting pressure, rise time, and wave-shape function. The peak blasting pressure and the rise time are also the function of explosive and rock properties. The probabilistic distributions of explosive and rock properties are derived from the results of their property tests. Since the probabilistic distributions of explosive and rock properties displayed a normal distribution, the peak blasting pressure and the rise time can also be regarded as a normal distribution. Parameter analysis and uncertainty analysis were performed to identify the most influential parameter that affects the peak blasting pressure and the rise time. Even though the explosive properties were found to be the most influential parameters on the peak blasting pressure and the rise time from the parameter analyses, the result of uncertainty analysis showed that rock properties constituted major uncertainties in estimating the peak blasting pressure and the rise time rather than explosive properties. Damage and overbreak of the remaining rock around the excavation line induced by blasting were evaluated by dynamic numerical analysis. A user-subroutine to estimate the rock damage was coded based on the continuum damage mechanics. This subroutine was linked to a commercial program called 'ABAQUS/Explicit'. The results of dynamic numerical analysis showed that the rock damages generated by the initiation of stopping hole were larger than those from the initiation of contour hole. Several methods to minimize those damages were proposed such as relocation of stopping hole, detailed subdivision of rock classification, and so on. It was found that fracture probability criteria and fractured zones could be distinctively identified by applying fuzzy-random probability.

• Journal of Technology Innovation
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• v.20 no.3
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• pp.57-91
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• 2012

This paper investigates determinants of litigation success in the two distinctive types of patent litigations, ex-parte and inter-parte cases, which are brought in the process where a filed application becomes a valid patent right. We regress winning rates of patent applicants on the characteristics of firms, trials, patent lawyer, and patent itself, using a probit model with sample selections. The paper finds that the relative suit rate of a firm, time to be sued, changes of patent agents by applicants, and multiple agents among explanatory variables affect ex-parte reexamination and in-parte post-grant patent trials differently in the point of average marginal effects. These variables lower the probability of applicant's victory in the ex-parte cases, while they raise the probability in the inter-parte trials. However, the experience that agents represent applicants is a winning rate-increasing factor both in inter-parte and ex-parte reexamination, unexpectedly. This result cannot be applied to the entire domain of the variable, since sample selection effects are reflected in the result. The number of claim increases the winning probability of the applicant in the both types of patent litigations. This study has some limitations because it ignores the information on the legal person to which a patent agent belongs, and confined agent's experience to patent filing. We leave it future studies to investigate the effects of lawsuit experience of patent agent, and those of characteristics of the law firm to which individual patent lawyer is affiliated.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.1
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• pp.19-35
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• 2014

A parametric sensitivity to the annual exposure dose rate to the farming exposure group has been probabilistically carried out for three principal elements associated with the nuclide transport behavior in the near-field of the pyroprocessed waste repository system. Credit time for both metal and ceramic containers, annual nuclide release rete, and the degree of loss of bentonite buffer around the container are selected as the elements and investigated for important nuclides. All the elements are shown to be sensitive to the results. Methodology studied through this study and the results are expected to make a good feedback to the repository design. As a follow-up study, separated in Part 2, the A-KRS will be deterministically assessed and then compared among each other with the normal, the worst, and the best case scenarios associated with their extreme values these elements could have.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.295-303
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• 2018

In the DBB delivery system, the design stage and the construction stage are separated. Because of this, design changes frequently occur, and problems such as construction cost overrun, schedule delay, and quality deterioration happen as well. Recently, in the construction industry CM at Risk(CM@R) delivery system, which can systematically solve the above-mentioned problems of DBB delivery system, meet various demands of clients, and overcome the limited cost and period. In the CM@R delivery system, the contractor negotiates for a maximum guaranteed price(GMP) with the client at the design stage, and the CM performer carries out the construction within the GMP. However, uncertainties are inherent in the GMP calculation because the calculation is based on unfinished drawings and documents. In this study, a Probabilistic Earlier GMP Calculation Method by combining a probabilistic tool of Monte Carlo simulation with a case based reasoning is proposed so that the uncertainty in GMP calculation is reflected. After the earlier GMP is calculated, a process to calculate the $2^{nd}$ GMP at the time of around 80 % of detailed deign and to negotiate with the client to fix the final GMP is proposed. The Probabilistic Earlier GMP Calculation Method is verified through the case study. In this study, researchers set the range of GMP through the proposed probabilistic GMP calculation and tried to reduce the risk through negotiation between the client and the CM performer. The proposed method and process would contribute to the successful introduction of CM@R in Korea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.3
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• pp.258-264
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• 2011

A MCS technique is represented to stochastically analyze the uncertainties of wave forces exerted on the upright sections of composite breakwaters. A stochastical models for horizontal and uplift wave forces can be straightforwardly formulated as a function of the probabilistic characteristics of maximum wave height. Under the assumption of wave forces followed by extreme distribution, the behaviors of relative wave forces to Goda's wave forces are studied by the MCS technique. Double-truncated normal distribution is applied to take the effects of uncertainties of scale and shape parameters of extreme distribution into account properly. Averages and variances of relative wave forces are quantitatively calculated with respect to the exceedance probabilities of maximum design wave height. It is found that the averages of relative wave forces may be decreased consistently with the increases of the exceedance probabilities. In particular, the averages on uplift wave force are evaluated slightly larger than those on horizontal wave force, but the variations of coefficient of the former are adversely smaller than those of the latter. It means that the uncertainties of uplift wave forces are smaller than those of horizontal wave forces in the same condition of the exceedance probabilities. Therefore, the present results could be useful to the reliability based-design method that require the statistical properties about the uncertainties of wave forces.

• Journal of Korea Water Resources Association
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• v.49 no.10
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• pp.835-849
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• 2016

Accurate drought outlook and drought monitoring have been preceded recently to mitigate drought damages that further deepen. This study improved the limitations of the previous MSWSI (Modified Surface Water Supply Index) used in Korea and carried out probabilistic drought forecasts based on ensemble technique with the improved MSWSI. This study investigated available hydrometeorological components in Geum river basin and supplemented appropriate components (dam water level, dam release discharge) in addition to the four components (streamflow, groundwater, precipitation, dam inflow) usedin the previous MSWSI to each sub-basin. Although normal distribution was fitted in the previous MSWSI, the most suitable probabilistic distributions to each meteorological component were estimated in this study, including Gumbel distribution for precipitation and streamflow data; 2-parameter log-normal distribution for dam inflow, water level, and release discharge data; 3-parameter log-normal distribution for groundwater. To verify the improved MSWSI results using historical precipitation and streamflow, simulated drought situations were used. Results revealed that the improved MSWSI results were closer to actual drought than previous MSWSI results. The probabilistic forecasts based on ensemble technique with improved MSWSI were performed and evaluated in 2006 and 2014. The accuracy of the improved MSWSI was better than the previous MSWSI. Moreover, the drought index of actual drought was included in ranges of drought forecasts using the improved MSWSI.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.538-538
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• 2015

농업가뭄에 대한 연구는 주로 가뭄지표의 개선과 제안 등에 초점이 맞추어져 있으며 관개기의 강수량에 중점을 둔 사례가 대부분이다. 그러나 대부분의 논 관개용수는 저수지를 통하여 공급되기 때문에 관개가 시작되는 4월 초순의 저수량은 상당히 중요한 가뭄 대응 요소이다. 이에 따라 가뭄에 대비하기 위해서는 관개가 종료되는 10월부터 이듬해 3월까지 충분한 저수량이 확보될 필요가 있다. 그러나 기후변화에 의해 대부분의 강우가 관개기에 집중될 수 있으며 이에 따라 미래에는 비관개기 동안 충분한 저수량을 확보하는데 어려움이 발생할 수 있다. 이에 본 연구에서는 기후변화에 따른 비관개기의 강수량을 확률기반으로 분석하고, 이를 관개기 필요저수량과 비교하여 저수지의 미래 가뭄 대응 능력을 분석하고자 하였다. 기후변화에 따른 비관개기의 강수량 변화를 분석하기 위하여 RCP(Representative Concentration Pathways) 시나리오를 적용하여 미래 비관개기 동안의 연도별 비관개기 누적강수량을 분석하였다. 과거와 미래시기를 30년 단위로 구분하여 1995s, 2025s, 2055s, 2085s의 비관개기 동안의 비초과확률 10%, 50%, 90%의 강수량을 분석하였다. RCP 4.5 시나리오를 기반으로 모의한 미래강우의 비초과확률 10% 누적강수량 산정 결과에 따르면 주요 곡창지대인 전라남북도는 1995s에는 10월부터 이듬해 3월까지의 누적강수량이 약 215mm 정도로 나타났으나 2025s에는 약 150mm로 줄어드는 것으로 나타났다. 즉, 비초과확률 10%의 강우가 내릴 경우 비관개기 동안에 충분한 저수량의 확보가 어렵게 되고 관개기의 심각한 가뭄을 초래할 수 있었다. 비관개기 누적강수량과 저수량변화의 관개를 모의한 개운저수지와 계룡저수지의 경우 그 관계식은 y=1.442x-198.81, y=5.8105x-752.92와 같이 나타났다. y는 비관개기의 저수량변화를 나타낸 것이고 x는 비관개기의 누적강우량을 나타낸 것이다. 식을 통해 향후 100년 중 비초과확률 10%의 강수를 가정한다면 개운저수지는 관개종료시점의 저수율이 최소 96.93% 이상이여야 다음해 관개시작시점의 저수위가 만수위가 될 수 있었고, 계룡 저수지는 최소 86.84%의 저수위를 만족해야 다음해 관개시작시점의 저수위가 만수위가 될 수 있었다.