• Communications for Statistical Applications and Methods
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• v.6 no.2
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• pp.397-402
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• 1999

We first derive the Fisher information identity in order statistics in terms of the hazard rate by considering the Fisher information identity in terms of the hazard rate (Efron and Johnstone, 1990). Then we use the identity and show an interesting and useful result that some identities and recurrence relations for the Fisher information in order statistics can be directly obtained from those between the c.d.f.s of order statistics.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.4
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• pp.59-73
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• 2009

In this study, we performed a GIS-based landslide hazard analysis by employing historical landslide data in Korea, coupling with geomorphological, geological, climatic and rainfall data. Based on 596 landslide data from 2001 to 2003, the correlations between landslide occurrence and various factors (elevation, slope angle, slope aspect, soil type and rainfall) that affect the occurrence were estimated by the statistical analysis, zonal statistics. The weights and hazard indices of 6 raster layers were derived from the estimated correlations in order to generate a landslide hazard map by applying raster calculation technique. As a result of this study, GIS technique can be used effectively to incorporate the landslide hazard contributions from various data sets simultaneously.

• Korean Journal of Remote Sensing
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• v.34 no.1
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• pp.75-87
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• 2018

The Baekdu volcano (2,750 m a.s.l.) is located on the border between Yanggando Province in North Korea and Jilin Province in China. Its eruption in 946 A.D. was among the largest and most violent eruptions in the past 5,000 years, with a volcanic explosivity index (VEI) of 7. In this study, we processed and analyzed lahar-inundation hazard zone data, applying a geographic information system program with menu-driven software (LAHARZ)to a shuttle radar topography mission 30 m digital elevation model. LAHARZ can simulate inundation hazard zones created by large lahar flows that originate on volcano flanks using simple input parameters. The LAHARZ is useful both for mapping hazard zones and estimating the extent of damage due to active volcanic eruption. These results can be used to establish evacuation plans for nearby residents without field survey data. We applied two different simulation methods in LAHARZ to examine six water systems near Baekdu volcano, selecting weighting factors by varying the ratio of height and distance. There was a slight difference between uniform and non-uniform ratio changes in the lahar-inundation hazard zone maps, particularly as slopes changed on the east and west sides of the Baekdu volcano. This result can be used to improve monitoring of volcanic eruption hazard zones and prevent disasters due to large lahar flows.

• International Journal of Reliability and Applications
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• v.3 no.1
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• pp.1-16
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• 2002

In reliability engineering, the bathtub-shaped hazard rates play an important role in survival analysis and many other applications as well. For the bathtub-shaped, initially the hazard rate decreases from a relatively high value due to manufacturing defects or infant mortality to a relatively stable middle useful life value and then slowly increases with the onset of old age or wear out. In this paper, we present a new two-parameter lifetime distribution function, called the Loglog distribution, with Vtub-shaped hazard rate function. We illustrate the usefulness of the new Vtub-shaped hazard rate function by evaluating the reliability of several helicopter parts based on the data obtained in the maintenance malfunction information reporting system database collected from October 1995 to September 1999. We develop the S-Plus add-in software tool, called Reliability and Safety Assessment (RSA), to calculate reliability measures include mean time to failure, mean residual function, and confidence Intervals of the two helicopter critical parts. We use the mean squared error to compare relative goodness of fit test of the distribution models include normal, lognormal, and Weibull within the two data sets. This research indicates that the result of the new Vtub-shaped hazard rate function is worth the extra function-complexity for a better relative fit. More application in broader validation of this conclusion is needed using other data sets for reliability modeling in a general industrial setting.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.252-259
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• 1997

A method to automate hazard analysis of chemical plants is proposed in this paper. The proposed system is composed of three knowledge bases - unit knowledge base, organizational knowledge base and material knowledge base, and three hazard analysis algorithms - deviation, malfunction and accident analysis algorithm. Hazard analysis inference procedure is developed based on the actual hazard analysis procedures and accident development sequence. The proposed algorithm can perform hazard analysis in two methods and represent all conceivable types of accidents using accident analysis algorithm. In addition, it provides intermediate steps in the accident propagation, and enables the analysis result to give a useful information to hazard assessment. The proposed method is successfully demonstrated by being applied to diammonium phosphate manufacturing process. A system to automate hazard analysis is developed by using the suggested method. The developed system is expected to be useful in finding the propagation path of a fault or the cause of a malfunction as it is capable to approach causes of faults and malfunctions simultaneously.

• The Korean Journal of Food And Nutrition
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• v.35 no.1
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• pp.51-61
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• 2022

This study aimed at elementary, middle, and high school dietitians who purchase ingredients for school meals. Therefore, for the study, the awareness and usage of nutritional information by 108 teachers and dieticians on 5 hazard-free meals using multivariate analysis of variance were investigated during May 18~21, 2021. Among the five questions that asked the general perceptions of school meal dietitians of 5 hazard-free meals, the perception that the "5 hazard-free foods can be easily distinguished" was the lowest. Problems were associated with using the 5 hazard-free meals such as "expensive price," "no variety in items," "disruption in the supply and demand," "inconsistent quality," and "lack of taste," in that order. Therefore, to improve 5 hazard-free school meal service, it is necessary to not only lower the price burden by providing subsidies to schools but also improve the development and distribution structure of various 5 hazard-free foods.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.20-31
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• 2007

Moral hazard and adverse selection often exist in asymmetric information environment. In this paper, quality investment decision problem is studied under moral hazard. A basic model for quality investment level decision is developed with the supplier as a principal and the buyer as an agent. And then we regard the supplier and the buyer's rational limitations to set up a model when the buyer's quality evaluation and processing activities are hidden. The model is optimized and the results under different backgrounds are discussed and compared. Results show that the buyer's quality evaluation level and processing level are mostly influenced by the supplier's quality assurance payment. Both the supplier and the buyer choose different quality investment levels under moral hazard because of the supplier's payment to the buyer in case of internal failure and external failure.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.27-30
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• 2003

The recent technology developments introduce new difficulties into the test process by the increased complexity of the chip. Most widely used method for testing high complexity and embedded systems is built-in self-test(BIST). In this paper, we describe 5-stage pipeline system as circuit under testing(CUT) and proposed a BIST scheme for the hazard detection unit of the pipeline system. The proposed BIST scheme can generate sequential instruction sets by pseudo-random pattern generator that can detect all hazard issues and compare the expected hazard signals with those of the pipelined system. Although BIST schemes require additional area in the system, it proves to provide a low-cost test solution and significantly reduce the test time.

• Journal of Environmental Science International
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• v.18 no.11
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• pp.1189-1197
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• 2009

The purpose of this research was develop tailored landslide hazard assessment table (LHAT) in Gyeongsangbuk-do Province and propose building strategies on environmental information system to estimate landslide hazard area according to LHAT. To accomplish this purpose, this research investigated factors occurring landslide at 172 landslide occurred sites in 23 city and county of Gyeongsangbuk-do Province and analyzed what factors effected landslide occurrence quantity using the multiple statistics of quantification method(I). The results of analysis, factors affecting landslide occurrence quantity were shown in order of slope position, slope length, bedrock, aspect, forest age, slope form and slope. And results of the development of LHAT for predict mapping of landslide-susceptible area in Gyeongsangbuk-do Province, total score range was divided that 107 under is stable area(IV class), 107~176 is area with little susceptibility to landslide(III class), 177~246 is area with moderate susceptibility to landslide(II class), above 247 area with severe susceptibility to landslide(I class). According to LHAT, this research built landslide attribute database and made 7 digital theme maps at mountainous area located in Goryeong Gun, Seongju-Gun, and Kimcheon-City. The results of prediction on degree of landslide hazard using environmental information system, area with little susceptibility to landslide(III class) occupied 65.56% and severe susceptibility to landslide(I class) occupied 0.51%.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.622-625
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• 2004

This paper presents multi-source spatial data integration models based on probability theory for landslide hazard assessment. Four probabilistic models such as empirical likelihood ratio estimation, logistic regression, generalized additive and predictive discriminant models are proposed and applied. The models proposed here are theoretically based on statistical relationships between landslide occurrences and input spatial data sets. Those models especially have the advantage of direct use of continuous data without any information loss. A case study from the Gangneung area, Korea was carried out to quantitatively assess those four models and to discuss operational issues.