• Journal of the Korean Society of Safety
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• v.35 no.4
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• pp.40-47
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• 2020

Although gangform has good workability due to the integration of outer wall forms and working platforms, 22 workers were died from 21 gangform related accidents during 2012 to 2016. Quantitative risk assessment is required for evident based prevention measure selection. In this study, based on 52 accident data from 2004 to the first half of 2019, FTA is conducted for probabilities of direct causes and their contribution to accidents. Three stages are considered; gangform installation, dismantling and lifting, and using. The effectiveness of countermeasures is evaluated through minimum cut set, RAW and RRW. Complete assembly of gangform on the ground level, detailed planning, and fall prevention device are suggested as prevention measures for installation, dismantling and lifting, and using stages, respectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.5
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• pp.808-817
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• 2010

This paper proposes a novel appoach which can assess the system technical maturity for use in Defense R&D Program reviews. As the weapon systems become more complicated, the success and effectiveness of R&D outcome heavily depend on the application and tailoring of systems engineering process and methods. It is a difficult task to assess the system readiness level(SRL) of the system being developed. A system-focused approach for managing weapon systems development and making effective and efficient decisions during the development lifecycle is critical to ensure the success of the program. The proposed weighted average SRL can facilitate the system technical maturity assessment without expending heavy work load.

• Korean Journal of Remote Sensing
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• v.16 no.2
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• pp.177-188
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• 2000

Quantitative accuracy assessment of a SPOT DEM (Digital Elevation Model) generated by a fully automatic software is performed along the 90km long coast around Donghae city. The theoretical requirement on the layout of the CPS (Global Positioning System) check points is derived: the Nyquist sampling. Since in practice the Nyquist frequency of a terrain is difficult to determine, the relaxed requirements are introduced and 31 check points are collected accordingly. Accuracy of the SPOT DEM is calculated to be 8.9, 11.5 and 12.0m r.m.s. in latitudinal, longitudinal and elevation directions. The bias is distinguishable from zero only for elevation and is 2.2m. The simple comparison with the world's leading commercial softwares reveals the similar accuracy level.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.1
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• pp.113-121
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• 2021

A safety assessment of radioactive waste repositories is a mandatory requirement process because there are possible radiological hazards owing to radionuclide migration from radioactive waste to the biosphere. For a reliable safety assessment, it is important to establish a parameter database that reflects the site-specific characteristics of the disposal facility and repository site. From this perspective, solubility, a major geochemical parameter, has been chosen as an important parameter for modeling the migration behavior of radionuclides. The solubilities were derived for Am, Ni, Tc, and U, which were major radionuclides in this study, and on-site groundwater data reflecting the operational conditions of the Gyeongju low and intermediate level radioactive waste (LILW) repository were applied to reflect the site-specific characteristics. The radiation dose was derived by applying the solubility and radionuclide inventory data to the RESRAD-OFFSITE code, and sensitivity analysis of the dose according to the solubility variation was performed. As a result, owing to the low amount of radionuclide inventory, the dose variation was insignificant. The derived solubility can be used as the main input data for the safety assessment of the Gyeongju LILW repository in the future.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.3
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• pp.73-85
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• 2005

Natural disturbance and environmental pressure on natural ecosystems are gradually increasing, and the cause is significantly related to large-scale environmental pollution, global warming, decreasing biodiversity and habitat fragmentation. Environmental impact assessment(EIA) in Korea has been focused on distribution and composition of fauna and flora as major evaluation aspects in ecosystem assessment. It is well known that those characteristics of flora and fauna strongly depend on characteristics and quality of habitat and ecosystem. However, there is no items to assess habitat and ecosystems of spatial ecological system in EIA. Many countries are trying to develop the EIA items to consider the spatial characteristics of habitat and ecosystem and those ecological dynamics as well as species level. In this stream, landscape ecology is emerging discipline to examine spatial pattern and ecological process within/between habitats and ecosystems. Landscape ecological analysis, as a special tool for ecosystem evaluation, has been appropriately adopted to the EIA system in the advanced countries. This review paper tries to introducing the possibilities of landscape ecological concept into the Korean EIA system.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.23-33
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• 2011

Habitats loss and fragmentation are major threats to biodiversity. There are various kinds of environmental assessment have been developed for various problems to solve. Yet, there are no well-developed methods for quantifying and predicting about biodiversity. To achieve a sustainable conservation for biodiversity, the structural diversity of forest must be assessed by proper indexes. This study aim to quantitatively assess the diversity of forest structure as habitats and results of the verification by bird survey for objective presentation of evidence. As a result of literature review, some indexes were selected as potential prediction tools for biodiversity; area of patch, area of core regions, shape of patch and average age of stand. The assessment results were estimated by monitoring of birds for accuracy verification and the results were almost in agreement with each others. But, 1 and 2 level of forests were showed ambiguous results. Certainly, this study was limited in some valuation indexes on landscape scale. Further studies should be considered that different environmental factors such as land use, disturbances by human and vegetation index. Also, we expect that the additional monitoring of birds should give rise to the result which is improved assessment results.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.90-97
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• 2016

The objective of this study is to evaluate the operator's safety for the risk assessment method of impulsive noise division. Literature reviews on the basis of the impulsive noise study, the measuring methods and procedures, based on the results of the analysis process presents a risk assessment methods. In this study, analysis of the MIL-STD-1474D, B-duration graph for the peak noise level to cross the line from the measurement results is limited by the risk retracted. It is possible to determine whether there is quick can be determined whether the risk. Measurement positions measured by the microphone is installed on the risk of applying results are so located within the tolerance impulsive noise in the measurement position can interpret subjective safety is ensured. In addition, Proportional Dose technology was the proposed by the Patterson with the risk assessment method was applied to the indoor-impulsive noise. As results of this study, results for the same value of applying the technique of Proportional Dose technology results calculated by MIL-STD-1474D methods allows 1 count once increased in comparison to the result obtained.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1527-1534
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• 2016

Online voltage stability monitoring using real-time measurements is one of the most important tasks in a smart grid system to maintain the grid stability. Loading margin is a good indicator for assessing the voltage stability level. This paper presents an Extreme Learning Machine (ELM) approach for estimation of voltage stability level under credible contingencies using real-time measurements from Phasor Measurement Units (PMUs). PMUs enable a much higher data sampling rate and provide synchronized measurements of real-time phasors of voltages and currents. Depth First (DF) algorithm is used for optimally placing the PMUs. To make the ELM approach applicable for a large scale power system problem, Mutual information (MI)-based feature selection is proposed to achieve the dimensionality reduction. MI-based feature selection reduces the number of network input features which reduces the network training time and improves the generalization capability. Voltage magnitudes and phase angles received from PMUs are fed as inputs to the ELM model. IEEE 30-bus test system is considered for demonstrating the effectiveness of the proposed methodology for estimating the voltage stability level under various loading conditions considering single line contingencies. Simulation results validate the suitability of the technique for fast and accurate online voltage stability assessment using PMU data.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.235-243
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• 2012

Objectives: The purpose of this study is the work environment management method through risk assessment and investigation of the work place that deals with Ammonium nitrate, based on information in and outside the country. Methods: This study suggests method of work environment management through risk assessment and investigation of the work place that deals with Ammonium nitrate, and finds out cases of Ammonium nitrate causing hazard, danger and health risk, based on literature investigation. Results: Rats exposed repeatedly to $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin) which cause high level of skin irritation, reported 1 $mg/m^3$ of NOAEL, while LOAEL was less than 100 mg/kg for the rats orally administered with the $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin), for 13 weeks. Domestically 31,640 ton/y of ammonium nitrate has been used in 22 workplace and the result of workplace assessment was 0.0171-0.9983 $mg/m^3$. ADD was 8.77-59.63 ${\mu}g/kg-day$ according to the exposure scenario. In other words the result of the risk assessment goes beyond the 'standard 1'. Conclusions: Ammonium nitrate creates a high level of irritation and toxicity when coming in breathe it or contact with skin, and is classified as category3 of GHS and specific target organ toxicant (irritating respiratory system). Exposure level at work places needs to be maintained under $1mg/m^3$, to prevent workers from being damaged.

• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.562-568
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• 2014

This study is safety assessment standard for advanced surface movement guidance control system (A-SMGCS) and case study of the past research project. A-SMGCS providing routing, guidance and surveillance for the control of aircraft and vehicles in order to maintain the declared surface movement rate under all weather conditions within the aerodrome visibility operational level while maintaining the required level of safety. Recently, in korea and europe are developing A-SMGCS system for the safety control of the airport movement area. In safety oriented industry such as aviation that it is necessary to verify and ensure for operating system. In this case study, analysis of safety assessment standard for verified A-SMGCS target level of safety (TLS) and previous developed A-SMGCS research project.