• Spatial Information Research
• /
• v.17 no.3
• /
• pp.361-370
• /
• 2009

As the increasing interests of spatial information for different application area such as disaster management, there are many researches and development of indoor spatial data models and real-time evacuation management systems. The application requires to determine and optical paths in emergency situation, to support evacuees and rescuers. The optimal path in this study is defined to guide rescuers, So, the path is from entrance to the disaster site (room), not from rooms to entrances in the building. In this study, we propose a time-dependent optimal routing algorithm to develop real-time evacuation systems. The network data that represents navigable spaces in building is used for routing the optimal path. Associated information about environment (for example, number of evacuees or rescuers, capacity of hallways and rooms, type of rooms and so on) is assigned to nodes and edges in the network. The time-dependent optimal path is defined after concerning environmental information on the positions of evacuees (for avoiding places jammed with evacuees) and rescuer at each time slot. To detect the positions of human beings in a building per time period, we use the results of evacuation simulation system to identify the movement patterns of human beings in the emergency situation. We use the simulation data of five or ten seconds time interval, to determine the optimal route for rescuers.

• Economic and Environmental Geology
• /
• v.38 no.6 s.175
• /
• pp.663-673
• /
• 2005

This study investigates the relationship between the geochemical maps and the gold-silver deposit locations. Geochemical maps of 21 elements, which are published by KIGAM, locations of gold-silver deposits, and 1:1,000,000 scale geological map of Korea are utilized far this investigation. Pixel size of the basic geochemical maps is 250m and these data are resampled in 1km spacing for the statistical analyses. Relationship between the mine location and the geochemical data are investigated using bayesian statistics and decision tree algorithms. For the bayesian statistics, each geochemical maps are reclassified by percentile divisions which divides the data by 5, 25, 50, 75, 95, and $100\%$ data groups. Number of mine locations in these divisions are counted and the probabilities are calculated. Posterior probabilities of each pixel are calculated using the probability of 21 geochemical maps and the geological map. A prediction map of the mining locations is made by plotting the posterior probability. The input parameters for the decision tree construction are 21 geochemical elements and lithology, and the output parameters are 5 types of mines (Ag/Au, Cu, Fe, Pb/Zn, W) and absence of the mine. The locations for the absence of the mine are selected by resampling the overall area by 1 km spacing and eliminating my resampled points, which is in 750m distance from mine locations. A prediction map of each mine area is produced by applying the decision tree to every pixels. The prediction by Bayesian method is slightly better than the decision tree. However both prediction maps show reasonable match with the input mine locations. We interpret that such match indicate the rules produced by both methods are reasonable and therefore the geochemical data has strong relations with the mine locations. This implies that the geochemical rules could be used as background values oi mine locations, therefore could be used for evaluation of mine contamination. Bayesian statistics indicated that the probability of Au/Ag deposit increases as CaO, Cu, MgO, MnO, Pb and Li increases, and Zr decreases.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.6
• /
• pp.2483-2491
• /
• 2013

In order to identify and understand the crucial factors to induce traffic accident, causal relationships between diverse factors and traffic accident occurrence have been investigated continuously. It is one of most important issues all over the world to reduce the number of traffic accidents and deaths by them. Korea government is also stepping up their effort to reduce the number of traffic accidents and mitigate the severity of the accidents by establishing various traffic safety strategies. By introducing the five-day work week and increasing concern of leisure activities, the differences of trip characteristics between weekday and weekend is getting greater. According to this, the patterns and crucial factors of traffic accident occurrence in weekend appear differently from those in weekday. This study aims to understand major different factors affecting accident severity between weekday and weekend using 12,042 incident data occurred on freeways of Korea from 2006 to 2011. The model developed in this study estimated relationships among various exogenous factors of traffic accident by each type using SEM(Structural Equation Model). The result provides that road factors are related to the accident severity for weekday model, while environment factors affects on accident severity for weekend.

• Journal of Digital Convergence
• /
• v.11 no.12
• /
• pp.319-326
• /
• 2013

There are many software reliability models that are based on the times of occurrences of errors in the debugging of software. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. It is shown that it is possible to do asymptotic likelihood inference for software reliability models based on infinite failure model and non-homogeneous Poisson Processes (NHPP). Statistical process control (SPC) can monitor the forecasting of software failure and thereby contribute significantly to the improvement of software reliability. Control charts are widely used for software process control in the software industry. In this paper, we proposed a control mechanism based on NHPP using mean value function of logarithmic hazard learning effects property.

• 월간산업보건
• /
• s.379
• /
• pp.9-16
• /
• 2019

2-부톡시에탄올(2-butoxyethanol)에 대한 생물학적 노출지수 설정에 필요한 자료는 상당수 존재한다. 다양한 실험실 및 직업적 현장연구는 2-butoxyethanol에 노출된 후 소변에서 butoxyacetic acid의 배설을 조사하여 생물학적 노출지수를 구축할 데이터베이스를 제공하였다. 실험실 연구는 작업시간 동안보다는 짧은 시간을 노출시킨다. 휴식 중에 실시한 실험 자료들을 20ppm에 8시간 노출로 외삽하면 작업시작 종료 시점의 소변 중 butoxyacetic acid의 농도가 각각 192, 272, 190 mg/g creatinine이었다. 작업부하 30 watts와 50 watts의 연구 결과를 외삽하면 각각 304 butoxyacetic acid/g creatinine과 313 butoxyacetic acid/g creatinine이었다. 작업현장 연구는 소변을 가수분해시킨 후 총 butoxyacetic acid의 검출 범위가 광범위할 것으로 예상된다. 이러한 외삽의 결과는 일반적으로 1ppm 미만의 노출에서 나온 것이라는 점에 유의해야 한다. 피부 흡수의 가능성과 2-butoxyethanol의 상대적으로 낮은 휘발성을 감안할 때 현장 연구에서는 피부 경로가 흡입 연구보다 더 중요할 수 있다. 따라서 현장 조사는 휴식을 취한 자원봉사자를 대상으로 실시한 흡입 연구와 비교하면 소변 중 butoxyacetic acid 농도를 과대평가하는 경향이 있다. 활용 가능한 시뮬레이션 연구에서 휴식 시 2-butoxyethanol의 TLV-TWA 20ppm에 8시간 전신(흡입과 피부) 노출되는 경우 가수분해된 총 butoxyacetic acid가 210 mg/g creatinine이 예상되고 작업부하 50 watts에서는 373 mg/g creatinine이 예측된다. 50 watts의 작업량으로 20ppm에서 8시간 노출되는 경우 생물학적 노출지수(BEI)는 약 400 mg/g creatinine일 것이다. 그러나 생물학적 노출지수는 외삽에 대한 불확실성, 심각한 피부 노출 및 작업장 노출평가 자료의 부족을 반영하여 200 mg butoxyacetic acid/g creatinine으로 설정하였다. 인용한 자료들의 한계에도 불구하고 자원 봉사자 연구와 시뮬레이션 연구의 자료들이 일치성이 있었다. 연구에 따르면 butoxyacetic acid는 측정 가능한 양으로 존재하며 작업 교대 중에 검출될 수 있는 충분한 시간의 반감기를 가지고 있다. Sakai 등의 연구 자료와 일부 모델링 자료에서 노출농도가 높은 경우 주중에 약간의 축적 가능성을 보고하였지만 작업장에서 일반적으로 노출되는 농도 범위에서는 누적이 예상되지 않으며 작업 종료 후에 소변시료를 채취하는 것이 바람직하다. 대다수의 연구에서 소변 중 butoxyacetic acid 농도 수준의 개인 간 다양성을 보고하였다. 또한 대부분의 작업현장 연구에서는 2-butoxyethanol의 주변 환경 농도수준과 소변 중 butoxyacetic acid 수준에 유의한 상관관계를 발견하지 못하였다. 상호 연관성이 결여된 원인은 대부분 피부 노출의 영향으로 추정하였다. 개인 보호 장갑을 착용한 근로자들에게서는 유의한 상관관계가 발견되었다.

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.10
• /
• pp.33-43
• /
• 2016

The determination of in-situ capping materials is one of the most important factors to design in-situ capping in order to protect capping materials from erosion. Previous studies have established relationship between the velocity induced by wave energy and effective diameter of sediments, but they are mostly empirical and numerical researches which is too complicated for field engineers to analyze the erosion of in-situ capping materials. This study provides simple analytical solutions and reliability based on hydraulic model test results. Experimental results show that measured flow velocities with respect to depth induced by wave energy are almost the same as estimated velocities and the erosion resistances of the different effective particle diameters can be estimated.

• Journal of Korean Society of Transportation
• /
• v.32 no.2
• /
• pp.152-161
• /
• 2014

The total boarding and alighting time models have been developed by applying the multiple regression analysis with three variables; numbers of boarding or alighting passengers, non-sitting passengers, and the step-height from the ground. Such variables have influenced to the total boarding time model with the most influential in the numbers of boarding or alighting passengers and the least in the step-height. On the total alighting time model, the numbers of alighting passengers are the most strongest while the step-heights the least. The total boarding and alighting time models can be used in practices for the prediction of current and future bus stops' capacities in TOD-based towns.

• The Journal of the Korea Contents Association
• /
• v.14 no.6
• /
• pp.385-396
• /
• 2014

In the Korean mobile market, the mobile phone has reach the stage of maturity in terms of demand. Since the long-term evolution(LTE) service was introduced in 2011, there have been drastic changes in the market structure. The purpose of this paper is to examine the user intension of brand switching, to analyse the market share among 3 major mobile service companies using the brand switching matrix and to provide some insights. The results show that the smartphone subscriber rate provided by Ministry of Science, lCT and Future Planning agrees with the market share by brand switching matrix of this study. The potential rate of costumer retention would be arranges in order of SKT>KT>LGU+. The preference of mobile service company on switch be in order of SKT>KT>LGU+. The future market share be SKT 63.55%, KT 21.99%, LGU+ 14.36%. The potential rate of costumer retention fell sharply over the past year, suggesting the drastic fluctuations in market share for a while.

• Journal of Labour Economics
• /
• v.26 no.3
• /
• pp.77-114
• /
• 2003

Analyses of the special data sets constructed from the National Longitudinal Survey of Youth and the Panel Study of Income Dynamics reveal that, compared with an annual wage measure, survey week wages are significantly counter-cyclically biased due to selecting workers with strong labor market attachment. We also find that survey week wages are more counter-cyclically biased in high-wage industries than in low-wage industries, that is, inter-industry gaps of survey week wages are counter-cyclically biased. Unlike existing longitudinal studies, the current study concludes that real wages are much more procyclical in high-wage industries than in low-wage industries, which is attributed to our adoption of annual wages that is less subject to the selectivity bias. Our finding is consistent with the empirical regularity that real wages are much more procyclical for men than for women, as men are overrepresented in industries with greater real wage procyclicalities. Overall, current results do not support the predictions of segmented labor market theories for the cyclicality of real wages.

• Journal of Korean Society of Transportation
• /
• v.29 no.5
• /
• pp.19-32
• /
• 2011

There are many investment budget drafts in the filed of a road traffic safety. The traffic safety budget is spitted into following three major areas: 1) traffic safety facility (Engineering), 2) traffic enforcement (Enforcement), and 3) traffic safety education & public relation (Education). The three area are known as so-called 3E policy. This study investigates the effect of the investment in the 3E policy on the reduction of traffic accidents analyzing the data annually collected from the 15 local governments during 1992 to 2007. The analysis employing the traffic accidents as the dependent variable reveals that the effect of the investment is higher if same amount of investment is made on areas of the traffic safety education and public relation than the area of facility improvement. The similar conclusions are resulted from the separate investigation of traffic accidents data by 6 different types. All the results consistently indicate that the current traffic safety investment being primarily made on traffic safety facility needs to shift to the areas of traffic safety education and public relation budget.