• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.223-232
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• 2017

Objectives: In response to increased interest in the safety of children's products, a risk management system is being prepared through exposure assessment of hazardous chemicals. To estimate exposure levels, risk assessors are using deterministic and probabilistic approaches to statistical methodology and a commercialized Monte Carlo simulation based on tools (MCTool) to efficiently support calculation of the probability density functions. This study was conducted to analyze and discuss the usage patterns and problems associated with the results of these two approaches and MCTools used in the case of probabilistic approaches by reviewing research reports related to exposure assessment for children's products. Methods: We collected six research reports on exposure and risk assessment of children's products and summarized the deterministic results and corresponding underlying distributions for exposure dose and concentration results estimated through deterministic and probabilistic approaches. We focused on mechanisms and differences in the MCTools used for decision making with probabilistic distributions to validate the simulation adequacy in detail. Results: The estimation results of exposure dose and concentration from the deterministic approaches were 0.19-3.98 times higher than the results from the probabilistic approach. For the probabilistic approach, the use of lognormal, Student's T, and Weibull distributions had the highest frequency as underlying distributions of the input parameters. However, we could not examine the reasons for the selection of each distribution because of the absence of test-statistics. In addition, there were some cases estimating the discrete probability distribution model as the underlying distribution for continuous variables, such as weight. To find the cause of abnormal simulations, we applied two MCTools used for all reports and described the improper usage routes of MCTools. Conclusions: For transparent and realistic exposure assessment, it is necessary to 1) establish standardized guidelines for the proper use of the two statistical approaches, including notes by MCTool and 2) consider the development of a new software tool with proper configurations and features specialized for risk assessment. Such guidelines and software will make exposure assessment more user-friendly, consistent, and rapid in the future.

• Journal of IKEEE
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• v.24 no.2
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• pp.673-676
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• 2020

In this paper, we propose a whole-body management system using ultra-low temperature cyclical cooling method combined with IT technology. The proposed system has the following characteristics. First, it minimizes maintenance costs by circulating nitrogen gas cooled by ultra-low temperature inside the controller. Secondly, based on the information measured by the temperature sensor and oxygen concentration sensor, nitrogen gas is supplied to provide safe ultra-low temperature whole-body management. Thirdly, after entering the user's height, it provides convenient, ultra-low temperature whole-body care that can be controlled using an automatic lift. Fourth, it provides an easy-to-access, easy-to-manage GUI and a manager-only web program for whole-body management system operation. The results tested by the authorized testing agency to assess the performance of the proposed system were measured in the range of ±5%, the world's highest temperature sensor accuracy, and a range of -110℃ to -150℃ greater than the world's highest whole-body management temperature range(-110℃ ~ -140℃). In addition, humidity was measured at less than 40%, the world's highest, and oxygen concentration was more than 18%, the world's highest. Therefore, the effectiveness of the methods proposed in this paper was demonstrated because they produced the same results as the world's highest levels.

• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.131-143
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• 2011

Previous alerting service based on LBS was caused severe overload problem of server by using the method to confirm the location of each moving object on server. In this paper, by loading an App on smart moving object, we proposed a novel algorithm named ADAS(Active Disaster Alert Service) for accessing to the server site with oneself location information as needed and implemented the disaster alerting service system with visualization for user. In the proposed method, running App access to the server periodically with the present location coordinate gained from GPS module or network module and the ID of moving object. Then, the server compare the present location coordinate of moving object and the coordinates of disasters registered in DIDB and transmit the n NDIs existed in near distance orderly from the coordinate of present moving object to the client. The App compares the coordinate of present location for moving object and the coordinates of NDI is transmitted from server by real time and executes the service with classifying levels of alert into three steps such as danger, carefulness and safety. And new NDIs are gained by accessing DIDB on Server periodically during running App. Therefore, this will be become a novel method for reducing fundamentally the server overload problem in comparison with previous alerting service that the career of moving object is managed on server.

• Korean Journal of Optics and Photonics
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• v.29 no.5
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• pp.204-214
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• 2018

Since LIDAR is advantageous for accurate information acquisition and realization of a high-resolution 3D image based on characteristics that can be precisely measured, it is essential to autonomous navigation systems that require acquisition and judgment of accurate peripheral information without user intervention. Recently, as an autonomous navigation system applying LIDAR has been utilized in human living space, it is necessary to solve the eye-safety problem, and to make reliable judgment through accurate obstacle recognition in various environments. In this paper, we construct a single-shot LIDAR system (SSLs) using a 1550-nm eye-safe light source, and report the analysis method and results of LIDAR signals for various measurement environments, reflective materials, and material angles. We analyze the signals of materials with different reflectance in each measurement environment by using a 5% Al reflector and a building wall located at a distance of 25 m, under indoor, daytime, and nighttime conditions. In addition, signal analysis of the angle change of the material is carried out, considering actual obstacles at various angles. This signal analysis has the merit of possibly confirming the correlation between measurement environment, reflection conditions, and LIDAR signal, by using the SNR to determine the reliability of the received information, and the timing jitter, which is an index of the accuracy of the distance information.

• Journal of Korean Society of Transportation
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• v.20 no.4
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• pp.27-38
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• 2002

VTIS(Value-added Traffic Information System), among the sub-systems of ATIS, is an Advanced Traffic System which innovates efficiency and safety. And this system, having marketability and publicness, is very important. Moreover, This system offers definite traffic information according to the demand of specified users. And it is expected to produce additional spread effects because of high participation rate of private sector. However, the VTIS service media are varied and there are varied optimal Prices and payment methods according to each medium. Because of that, there needs the study on these problems or optimal criteria. But because existing studies were devoted to estimate the optimal route, the study toward the optimal price which was considered part of user and service use demand do not exist. Accordingly, we surveyed under imaginary alternative pricing scenarios and forecasted the use demand of VTIS by using Binary Logit model. Also, for the users who answered that they would use VTIS service in survey, we classified their use's behaviors as four categories and estimated the use ratio to each category by using Ordered Probit model. Last, using sensitivity analysis for results form above, we derived the optimal price that is 2800won in monthly. 145won in payment per call. Then, VTIS service use rate is respectively 65%, 75%.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.2 s.3
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• pp.31-42
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• 2003

Prepaid plastic card issued by Korea Highway Company had a lot of problems in end-user usage and management. HipassPLUS Card, which is a smart card used for a prepaid electronic payment, overcomes the problems of Prepaid Plastic card. HipassPLUS Card is also designed be compatible to other cards such as public transportation card. Thus, for the safety of using the card in such environment, the functionality and the security of HipassPLUS card should be faultless. This paper developed a test module including the test method, the test checklist, and the test procedure to examine the functionality and security of the payment mechanism of HipassPLUS card. The test module contains the method and the procedure to test the standard items according to the test checklist of HipassPLUS card. The test items and the test checklist of HirassPLUS card was selected under the provision of the specification of Korea Highway Company and ISO standard. The results of evaluation on HipassPLUS card using the proposed test module indicates that 4he HipassPLUS card satisfied the criteria under the characteristics of the functionality, security, and compatibility.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1125-1131
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• 2016

The purpose of this paper is to establish an evaluation criteria for pavement condition in bicycle road. The suggested criteria would help in the activation policy of bicycle use. The conventional evaluation criteria is difficult to be applied for the bicycle road since the bicycle road is sensitive to changes in the driving environments such as obstacles and bumps. This study presents the evaluation criteria that is suitable for bicycle road. The criteria was suggested in 5 grades through the impact acceleration range of RMSI (Road Monitoring System using ICT). The grades of the criteria are divided into a range of grade A to E. The grade A is a very good condition, while the grade E is a state that requires immediate maintenance. This study were confirmed the validity through the survey of user's satisfaction. According to the results of survey, the grade A was shown correlation of 91%. The grade E requiring immediate repair was presented correlation of 94%. It showed that the results of surveying the bicycle road users are highly correlated with the suggested criteria for pavement condition. It showed that the criteria are highly correlated with the survey results. Suggested criteria using the RMSI is expected to be effective for maintenance of the bicycle road. In addition, it is expected to ensure the serviceability and safety for the bicycle users.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.328-334
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• 2020

At the recent practice test of the Remote Controlled Munition system (for practice), nine out of 125 samples were generated. Although 7.2 % misfires occurred, the acceptance test met the defense standards. Minimizing the probability of broken fuses is essential to reducing the number of samples and improving the AQL according to the process quality. In addition, it is necessary to increase military training and ensure user safety. In the case of practical grenades, hit-type detonators are applied. Unlike the normal design, which takes a hit by strikers, a different design of a hit by pressure from a pressure generator was used. This study analyzed the detonator surface through computational fluid dynamics. The results showed that the probability of functional weakness and retraction increased with increasing slope of the detonator surface. To overcome this, design changes were made to improve the fuse crimping process and increase the detonator holder seat. A performance test with the same number of samples from the whole quantity was operated. The probability of broken fuses was 0 %. Therefore, the reliability and performance of the ammunition can be improved and is expected to contribute to the drawing and process design when developing similar ammunition.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.173-184
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• 2011

This study suggests the invigoration strategies of commercial and business functions for regeneration of old inner city as city center by examining Dangjin County which is a typical example of the local small-and-medium city where old inner city had declined as the city grew. I conducted a conjoint analysis in terms of important introduction functions and city regeneration directions for the invigoration. The results upon this are as follows. First, low-density of commercial and business places and the utilization of historical and cultural resources instead of the high-density mixed-use development should be considered. Second, It is important to promote regional specialized business and facilities rather than to attract new industry(high-tech industry) for activating local economy. Third, specific and practical countermeasures for resettlement of low-incomes and for maintenance of existing business zone should be established. Fourth, in terms of the maintenance and management, regulation on illegal commercial transactions, improvement of public spaces, and securement of user safety should be considered. Fifth, in terms of consolidation of functions, easier accessibility using public transportations, advertising and promotion of the city, and holding a number of events should be contemplated. Sixth, supporting for business activities and for establishing guides for design of old inner city should be needed. Seventh, public institutions should play a role as a bridge between local residences and experts for balanced regional development.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.4
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• pp.237-245
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• 2011

As necessity of safety re-evaluation for spent fuel storage facility has emphasized after the Fukushima accident, accuracy improvement of heat load evaluation has become more important to acquire reliable thermal-hydraulic evaluation results. As groundwork, parametric and sensitivity analyses of various storage conditions for Kori Unit 4 spent fuel storage pool and spent fuel depletion parameters such as axial burnup effect, operation history, and specific heat are conducted using ORIGEN2 code. According to heat load evaluation and parametric sensitivity analyses, decay heat of last discharged fuel comprises maximum 80.42% of total heat load of storage facility and there is a negative correlation between effect of depletion parameters and cooling period. It is determined that specific heat is most influential parameter and operation history is secondly influential parameter. And decay heat of just discharged fuel is varied from 0.34 to 1.66 times of average value and decay heat of 1 year cooled fuel is varied from 0.55 to 1.37 times of average value in accordance with change of specific power. Namely depletion parameters can cause large variation in decay heat calculation of short-term cooled fuel. Therefore application of real operation data instead of user selection value is needed to improve evaluation accuracy. It is expected that these results could be used to improve accuracy of heat load assessment and evaluate uncertainty of calculated heat load.