• Toxicological Research
• /
• 제18권1호
• /
• pp.23-29
• /
• 2002

Disodium disulphite, the HPV chemical, was assigned to Korea in order to implement OECD SIDS program in 1999. It was produced about 3,200 ton/year in 1998. This report evaluates the toxic potency of disodium disulphite based on the environmental and mammalian effects as well as human exposure. Oral $LD_{50}$ in rats is 1,540 mg/kg b.w. and effects was observed to the stomach, liver and the GI track that was filled with blood. For repeated dose toxicity, the predominant effect was the induction of stomach lesion due to local irritation. The no observed adverse effect lever for local (stomach irritation) was about 217 mg/kg bw/day. There is no evidence that disodium disulphite is genotoxic in vivo. No reproductive or developmental toxicty of disodium disulphite was observed for the period up to 2 yr and over three generation. In humans, urticaria and asthma with itching, edema, rhinitis, and nasal congestion were reported. Disodium disulphite is unlikely to induce respiratory sensitization but may enhance symptom of asthma in sensitive individuals. This chemical would be mainly transported to water compartment when released to environmental compartments since it is highly water soluble (470 g/l at 20). Low K oc (2.447) indicates disodium disulphite is so mobile in soil that it may not stay in the terrestrial compartment. The chemical has been tested in a limited number of aquatic species. hem acute toxicity test to fish, 96 hr-$LC_{50}$ was > 100 mg/1. For algae, 72 hr-$XC_{50}$ was 48.1 mg/1. For daphnid, the acute toxicity value of 48 hr-$EC_{50}$ was 88.76 mg/1, and chronic value of 21day-NOEC was > 10 mg/1. Therefore, PNEC of 0.1 mg/l for the aquatic organism was obtained from the chronic value of daphnid using the assessment factor of 100. Based on these data the disodium disulphite was recommended as low priority for further post-SIDS work in OECD.

• Nuclear Engineering and Technology
• /
• 제39권2호
• /
• pp.123-128
• /
• 2007

In order to apply a static fault-tree (FT) method to a system or a plant whose configuration changes dynamically, condition gates and a post processing method are used to effectively accommodate these changes. An operator's performance change, which can be caused by these configuration changes, should also be considered to assess the risk to a plant in a more realistic manner. This study aims to develop an integrated framework to accommodate various configuration changes and their effect on an operator’s performance by using the FT model. We applied a condition-based human reliability assessment (CBHRA) method to consider various conditions endured by an operator. That is, we integrated the CBHRA method with the conventional post processing method for modeling the system configuration changes. The effect of the condition monitoring systems installed in a plant is also considered. In this study, we show an example application of the integrated framework to a probabilistic safety assessment for the shutdown phase of a nuclear power plant.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.2941-2948
• /
• 2011

Rialway passengers and public, workers typically have high potential on death and injury accidents, because they are to be frequently adjacent to train or train operation. In order to effectively reduce the risks associated with the passengers, the public, and the workers, a systematic risk assessment should be performed to evaluate the hazards that contribute to the accidents. This paper describes the effect of risk assessment web base system and the extension need of the classification of "The regulation of railway accident report and information in Korea", application for national or railway safety operator, sharing railway safety information.

• 한국정밀공학회지
• /
• 제17권12호
• /
• pp.157-162
• /
• 2000

The object of this work is to develop an assessment system for pipeline integrity. the system consists of four module applications for internal algorithm; the effect of corrosion in pipeline, crack, stress corrosion crack (SCC) and fatigue modules. Presently, the module of the external corrosion has been developed and the internal algorithm for the effect of corrosion in pipeline and the database of the system are described in this paper. The database of the system is separated to mainly four parts; geometry of pipeline, material properties, boundary conditions and general properties. Each components of the system are designed by user-friendly concept. This system may give a guideline for maintenance and modifications for the pipeline at the industrial sight. Furthermore, a procedure to evaluate an inspection interval is also provided.

• Nuclear Engineering and Technology
• /
• 제50권8호
• /
• pp.1372-1386
• /
• 2018

Despite recent advances in multi-hazard analysis, the complexity and inherent nature of such problems make quantification of the landslide effect in a probabilistic safety assessment (PSA) of NPPs challenging. Therefore, in this paper, a practical approach was presented for performing an earthquake-induced landslide PSA for NPPs subject to seismic hazard. To demonstrate the effectiveness of the proposed approach, it was applied to Korean typical NPP in Korea as a numerical example. The assessment result revealed the quantitative probabilistic effects of peripheral slope failure and subsequent run-out effect on the risk of core damage frequency (CDF) of a NPP during the earthquake event. Parametric studies were conducted to demonstrate how parameters for slope, and physical relation between the slope and NPP, changed the CDF risk of the NPP. Finally, based on these results, the effective strategies were suggested to mitigate the CDF risk to the NPP resulting from the vulnerabilities inherent in adjacent slopes. The proposed approach can be expected to provide an effective framework for performing the earthquake-induced landslide PSA and decision support to increase NPP safety.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2004년도 추계학술발표회 발표논문집
• /
• pp.585-586
• /
• 2004

• 한국과학교육학회지
• /
• 제18권4호
• /
• pp.617-626
• /
• 1998

본 연구의 목적은 국가적 수준에서 우리나라 초 중 고등학교 학생의 과학탐구 능력을 점검해볼 수 있는 평가체제를 개발하는 것이다. 이를 위하여 많은 전문인력이 연구에 참여하였고, 과학탐구 평가틀과 평가 문항을 개발하였다. 개발된 평가 문항을 여러 차례 수정보완한 후, 325개의 문항을 958명의 학생에게 예비 검사를 실시하여 현장 적용 가능성을 검토하였다. 예비 검사 결과 문항 특성이 만족스럽지 못한 문항은 삭제하여 240개의 문항을 본 검사 문항으로 확정하였다. 본 검사는 총 8,906명의 학생을 대상으로 실시하였으며, 검사결과를 고전검사이론과 문항반응이론에 의하여 분석한 결과 난이도, 변별도, 신뢰도 등이 매우 우수하다는 것이 판명되었다. 앞으로 본 연구에서 개발된 과학탐구 평가틀을 이용하여 더 많은 문항이 개발될 수 있으며, 이러한 문항을 이용하여 우리나라 학생들의 과학탐구능력을 주기적으로 점검할 수 있을 것이다.

• Journal of Audiology & Otology
• /
• 제24권4호
• /
• pp.180-190
• /
• 2020

Background and Objectives: Although many studies have evaluated the effect of the digital noise reduction (DNR) algorithm of hearing aids (HAs) on speech recognition, there are few studies on the effect of DNR on music perception. Therefore, we aimed to evaluate the effect of DNR on music, in addition to speech perception, using objective and subjective measurements. Subjects and Methods: Sixteen HA users participated in this study (58.00±10.44 years; 3 males and 13 females). The objective assessment of speech and music perception was based on the Korean version of the Clinical Assessment of Music Perception test and word and sentence recognition scores. Meanwhile, for the subjective assessment, the quality rating of speech and music as well as self-reported HA benefits were evaluated. Results: There was no improvement conferred with DNR of HAs on the objective assessment tests of speech and music perception. The pitch discrimination at 262 Hz in the DNR-off condition was better than that in the unaided condition (p=0.024); however, the unaided condition and the DNR-on conditions did not differ. In the Korean music background questionnaire, responses regarding ease of communication were better in the DNR-on condition than in the DNR-off condition (p=0.029). Conclusions: Speech and music perception or sound quality did not improve with the activation of DNR. However, DNR positively influenced the listener's subjective listening comfort. The DNR-off condition in HAs may be beneficial for pitch discrimination at some frequencies.

• 대한청각학회지
• /
• 제24권4호
• /
• pp.180-190
• /
• 2020

Background and Objectives: Although many studies have evaluated the effect of the digital noise reduction (DNR) algorithm of hearing aids (HAs) on speech recognition, there are few studies on the effect of DNR on music perception. Therefore, we aimed to evaluate the effect of DNR on music, in addition to speech perception, using objective and subjective measurements. Subjects and Methods: Sixteen HA users participated in this study (58.00±10.44 years; 3 males and 13 females). The objective assessment of speech and music perception was based on the Korean version of the Clinical Assessment of Music Perception test and word and sentence recognition scores. Meanwhile, for the subjective assessment, the quality rating of speech and music as well as self-reported HA benefits were evaluated. Results: There was no improvement conferred with DNR of HAs on the objective assessment tests of speech and music perception. The pitch discrimination at 262 Hz in the DNR-off condition was better than that in the unaided condition (p=0.024); however, the unaided condition and the DNR-on conditions did not differ. In the Korean music background questionnaire, responses regarding ease of communication were better in the DNR-on condition than in the DNR-off condition (p=0.029). Conclusions: Speech and music perception or sound quality did not improve with the activation of DNR. However, DNR positively influenced the listener's subjective listening comfort. The DNR-off condition in HAs may be beneficial for pitch discrimination at some frequencies.

• International Journal of Safety
• /
• 제8권1호
• /
• pp.24-31
• /
• 2009

An effective assessment for decommissioning safety of nuclear facilities requires basic knowledge about possible risks, characteristics of potential hazards, and comprehensive understanding of the associated cause-effect relationships within a decommissioning for nuclear facility. This paper proposes an approach to develop the hierarchical structure and hazards of dealing with improving the complexity and uncertainty for decommissioning safety assessment of nuclear facilities and the resolutions are proposed to improve the complexity and uncertainty for decommissioning safety assessment of nuclear facilities. These resolutions can provide a comprehensive view of the risks in the decommissioning activities of a nuclear facility.