• 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 the Korean Society of Safety
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• v.26 no.6
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• pp.20-25
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• 2011

This study presents on the fire hazard analysis of communication cable in buildings. In order to analyze fire hazards for communication cable IEC 60332-1, UL 94 and cone calorimeter test are conducted. The number of cable used to experiment is 10 communication cable which are generally applied to data communication in buildings. The results show that 9 cables do meet the performance requirement of IEC 60332-1 and 8 cables are V-0 classification. IEC 60332-1 and UL 94 test are inadequate for fire hazard classification. The various parameters obtained by cone calorimeter test such as HRR, peak HRR, smoke production rate and so on. Also it is able to evaluate multiply fire hazard for communication cable with cone calorimeter test results.

• Journal of the Korean Data and Information Science Society
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• v.14 no.3
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• pp.561-570
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• 2003

We propose a nonparametric test procedure for checking the proportionality assumption between hazard functions using a functional equation. Because of the involvement of censoring distribution function, we consider the large sample case only and obtain the asymptotic normality of the proposeed test statistic. Then we discuss the rationale of the use of the functional equation, give some examples and compare the performances with Andersen's procedure by computing powers through simulations.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.3
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• pp.237-254
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• 2021

Objectives: This study aims to classify the latent profiles in the exposure to hazard factors of salaried employees and test the determinants. Methods: Latent profile analysis(LPA) was conducted using data from the fifth Korean Working Conditions Survey(KWCS). 30,050 of salaried employees were the subjects of this study. After classifying the employees, multinomial logistic regression was used to test the determinants. Results: Salaried employees were classified with three latent profiles based on the exposure to the hazard factors. Employees included in class 1(32.8%) tend to experience low level of physical hazard factors, moderate level of psychological hazard factors, and high level of office work hazard factors. Employees included in class 2(61.8%) tend to be exposed to the moderate to high level of physical hazard factors, moderate to low level of psychological hazard factors, and low level of office work hazard factors. Employees included in class 3(5.4%) tend to experience high level of psychological and physical hazard factors, and moderate level of office work hazard factors. After classification, the demographic, health-, and employment-related variables were tested. Conclusions: This study clarified the features of each class, and proved that employees in class 3 are quite hazardous in that they are exposed to physical and psychological hazard factors much more frequently than other employees. Thus, this study can be used in predicting the high-risk employees and taking preemptive measures for preventing industrial accidents.

• Journal of the Korea Safety Management & Science
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• v.20 no.4
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• pp.15-19
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• 2018

The purpose of this study is to enhance heat insulation effect and to decrease fire hazard by attaching aluminum foil to expanded polystyrene, which is mainly used for insulating materials, to have fire retardant. The result of the test confirmed that the insulating materials, expanded polystyrene of $10kg/m^3$ and $14kg/m^3$ of density attached aluminum foil on both sides, showed 12%, 14% of improved heat transfer coefficient respectively compared to existing expanded polystyrene of the same density. Besides, they met all the standards for the testing of heat release and gas hazard. On the other hand, the one made of general expanded polystyrene could not meet the standards of the heat release test and the gas hazard test.

• Communications for Statistical Applications and Methods
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• v.26 no.6
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• pp.623-633
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• 2019

This paper proposes two distance measures between two cumulative hazard functions that can be obtained by comparing their difference and ratio, respectively. Then we estimate the measures and present goodness of t test statistics. Since the proposed test statistics are expressed in terms of the cumulative hazard functions, we can easily give more weights on earlier (or later) departures in cumulative hazards if we like to place an emphasis on earlier (or later) departures. We also show that these test statistics present comparable performances with other well-known test statistics based on the empirical distribution function for an exponential null distribution. The proposed test statistic is an omnibus test which is applicable to other lots of distributions than an exponential distribution.

• Journal of the Korean Institute of Telematics and Electronics
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• v.8 no.4
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• pp.1-6
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• 1971

This paper derives an effective method for detecting hazards in TANT networks and a synthesis procedure for hazard-free, minimal TANT networks. The basic idea of the method is analogous to McCluskey's theory for combinational switching networks, but it is characterized by introducing consensus operation to test for the presence of hazards. Illustrative examples are also given.

• Magazine of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.60-66
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• 2011

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.232-238
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• 2011

Hazard analysis provides the basic foundation for system safety. Hazard analysis is performed to identify hazards, hazard effects, and hazard causal factors. Hazard analysis is used to determine system risk, to determine the significance of hazards, and to establish design measures that will eliminate or mitigate the identified hazards. Hazard analysis is used to systematically examine systems, subsystems, facilities, components, software, personnel, and their interrelationships, with consideration given to logistics, training, maintenance, test, modification, and operational environments. This paper present hazard analysis techniques which is commonly used in railway signalling, comparised their benefits and limitations.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.25-37
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• 2011

This research aimed to investigate whether commercial drivers' situation awareness ability is related to their frequency and magnitude of caused accidents and penalty points. For the purpose of measuring drivers' situation perception and interpretation capacities, two tests named 'situation awareness test' and 'hazard perception test' were developed. The tests were based on the data from 299 commercial drivers (test drivers) using a driving simulator. The outcome of drivers' performance on situation awareness and hazard perception tests was designed to be categorized into 5 grades, classifying the best as grade 1 and the worst as grade 5. As the result, low grades on situation awareness test had positive relationship with accumulated penalty points, frequency of accidents and safety index. Grades on hazard perception test were also positively correlated with accident frequency and safety indices. This suggests situation awareness ability of commercial drivers is significantly related to traffic violations and accident causing tendencies.