• 해양환경안전학회지
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• 제27권5호
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• pp.618-629
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• 2021

2011년 동일본대지진에 의해 발생한 후쿠시마 원자력 발전소 사고와 최근 국내 지진 발생 빈도의 증가는 원자력 발전소의 지진 안전성에 대한 불안감을 야기하였다. 더불어 최근(2021년) 일본 동경전력은 후쿠시마 원전 오염수의 태평양 방류를 결정하였으며, 이로 인해 국내외 수산물을 통한 방사능 오염 가능성이 높아지면서 국민들의 우려가 급증하고 있다. 후쿠시마 원전사고 이후 해양으로의 인공방사능 유입에 관한 연구는 국제적으로 많이 이루어졌으나, 한국인의 주요 식재료인 동아시아 연근해의 수산물에서 인공방사능의 분포 현황 및 축적에 대한 연구는 상대적으로 부족한 실정이다. 따라서 이 논문에서는 후쿠시마 원전사고 이후, 국내산 수산물에서의 원전 기원 인공방사능(예, ¹³⁷Cs, ^239+240Pu, ⁹⁰Sr 등)의 분포 특성과 관련한 최근 연구 사례들을 소개하고자 한다. 또한, 후쿠시마 원전오염수의 방류와 더불어 2030년까지 계획된 중국의 신규 원전 시설로 인한 향후 한반도 주변해역의 방사능 유출 영향에 대한 대비 및 사전 연구가 필요한 시점이기에 향후 연구 방향들을 제안하고자 한다.

• 대한의용생체공학회:의공학회지
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• 제10권3호
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• pp.343-350
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• 1989

A new algorithm classifying ECG Arrhythmia signals using Back-propagation network is proposed. The base-line of ECG signal is detected by high pass filter and probability density function then input data are normalized for learning and classifying. In addition, ECG data are scanned to classify Arrhythmia signal which is hard to find R-wave. A two-layer perceptron with one hidden layer along with error back-propagation learning rule is utilized as an artificial neural network. The proposed algorithm shows outstanding performance under circumstances of amplitude variation, baseline wander and noise contamination.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.386-391
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• 2004

To find out the reason of accident by being stained of insulators, this paper researched and analyzed the result of electrical characteristic test and field test of EHV insulator through artificial contaminated method. The best way to evaluate contaminated level of insulator surface is getting a contamination data by regional groups continually. But it is needed a lot of time and manpower. To overcome those difficulties, this research introduced ESDD(equivalent salt deposit density) measurement method which is adapted to the international codes of IEC and compared the relation between experimental test results which contaminated insulators by going through stain procedure and electrical measurement results.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.3043-3050
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• 2022

In Korea, all nuclear power plants (NPPs) participate in annual performance tests including in vivo measurements using the FastScan, a stand type whole body counter (WBC), manufactured by Canberra. In 2018, all Korean NPPs satisfied the testing criterion, the root mean square error (RMSE) ≤ 0.25, for the whole body configuration, but three NPPs which participated in an additional lung configuration test in the fission and activation product category did not meet the criterion. Due to the low resolution of the FastScan NaI(Tl) detectors, the conventional peak analysis (PA) method of the FastScan did not show sufficient performance to meet the criterion in the presence of interfering radioisotopes (RIs), ¹³⁴Cs and ¹³⁷Cs. In this study, we developed an artificial neural network (ANN) to improve the performance of the FastScan in the lung configuration. All of the RMSE values derived by the ANN satisfied the criterion, even though the photopeaks of ¹³⁴Cs and ¹³⁷Cs interfered with those of the analytes or the analyte photopeaks were located in a low-energy region below 300 keV. Since the ANN performed better than the PA method, it would be expected to be a promising approach to improve the accuracy and precision of in vivo FastScan measurement for the lung configuration.

• Ocean and Polar Research
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• 제45권1호
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• pp.1-9
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• 2023

Marine microalgae have different collection methods depending on their habitat. In the case of adhesive microalgae, it is difficult to separate organisms from the substrate surface, and contamination is likely to occur during the sampling process. In this study, we analyzed the collection efficiency of adhesive microalgae using three artificial fiber materials (nylon, blend fabric, and viscose rayon). Each fiber showed different fiber diameter and pore characteristics (nylon 26.09 ㎛, blend fabric 56.6 ㎛, viscose rayon 101.3 ㎛). In addition, attached organisms were collected on the surface of artificial substrates at Bukseong Port in Incheon using each tested fiber material. After that, we investigated the population and species composition. The highest number of cells was found in nylon, which was 8 times higher than in the least collected viscose rayon material. In addition, we identified 24 microalgal species from the substrate, demonstrating that the species composition differed from that of surface water. The number of collected microalgae species varied depending on the fiber materials, with nylon containing all the adhesive microalgae. In contrast, only a few microalgae were observed in other fibers. These results suggest that, of the tested fibers, nylon material may be suitable for collecting adhesive microalgae. As a result, this study may be useful for future research on adhesive microalgae.

• 한국환경과학회지
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• 제11권9호
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• pp.881-895
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• 2002

Sediments and river waters form the channel of Hwasun-cheon were studied in sedimentological size and geochemical analyses of metallic elements for the purposes of identification of depositional environments and geochemical characteristics. The sizes of sediments are assigned to pebble to coarse sand in mean size and polymodal in distribution. And the sediments are poorly to very poorly sorted and positively skewed. According to the grain size distributions of the sediments, the Hwasun-cheon belongs to gravel-bed river on the basis of the grain size distribution of the sediments. The behaviors of metallic elements in the sediments mainly depend on not grain size distribution but the geology connected with geomorphological reliefs near the stream. Contamination indices(CI) of Zn, Cu and Pb are 2.83 to 6.96 with average 4.31 in the sediments. Hwasun-cheon is assigned to general stream type in accordance with water quality of physical factors and chemical characteristics by Piper's diagram. Though meaningful values of BOD, T-N, T-P were locally depicted near Masan-ri, Hwasun-eup and Jiseok-cheon areas, artificial metal concentration do not represent in the most area of the stream. Sediments and river water are considered that the relatively more or less high metallic contents in the stream are originated from coal mine and urban area.

• 방사성폐기물학회지
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• 제20권1호
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• pp.99-110
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• 2022

In decommissioning a nuclear power plant, numerous concrete structures need to be demolished and decontaminated. Although concrete decontamination technologies have been developed globally, concrete cutting remains problematic due to the secondary waste production and dispersion risk from concrete scabbling. To minimize workers' radiation exposure and secondary waste in dismantling and decontaminating concrete structures, the following conceptual designs were developed. A micro-blast type scabbling technology using explosive materials and a multi-dimensional contamination measurement and artificial intelligence (AI) mapping technology capable of identifying the contamination status of concrete surfaces. Trials revealed that this technology has several merits, including nuclide identification of more than 5 nuclides, radioactivity measurement capability of 0.1-10⁷ Bq·g^-1, 1.5 kg robot weight for easy handling, 10 cm robot self-running capability, 100% detonator performance, decontamination factor (DF) of 100 and 8,000 cm²·hr^-1 decontamination speed, better than that of TWI (7,500 cm²·hr^-1). Hence, the micro-blast type scabbling technology is a suitable method for concrete decontamination. As the Korean explosives industry is well developed and robot and mapping systems are supported by government research and development, this scabbling technology can efficiently aid the Korean decommissioning industry.

• Advances in environmental research
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• 제12권2호
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• pp.77-93
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• 2023

The water can be contaminated by natural sources or by industrial effluents. One such contaminant is fluoride. Fluoride contamination in the water environment due to natural and artificial activities has been recognized as one of the major problems worldwide. Among the commonly used treatment technologies applied for fluoride removal, the adsorption technique has been explored widely and offers a highly efficient simple and low-cost process for fluoride removal from water. This review paper the recent developments in fluoride removal from surface water by adsorption methods. Studies on fluoride removal from aqueous solutions using various carbon materials are reviewed. Various adsorbents with high fluoride removal capacity have been developed, however, there is still an urgent need to transfer the removal process to an industrial scale. Regeneration studies need to be performed to more extent to recover the adsorbent in field conditions, enhancing the economic feasibility of the process. Based on the review, technical strategies of the adsorption method including the Nano-surface effect, structural memory effect, anti-competitive adsorption and ionic sieve effect can be proposed. The design of adsorbents through these strategies can greatly improve the removal efficiency of fluoride in water and guide the development of new efficient methods for fluoride removal in the future. This paper describes brief discussions on various low-cost adsorbents used for the effective removal of fluoride from water.

• 대한환경공학회지
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• 제32권5호
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• pp.455-460
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• 2010

본 연구에서는 프탈레이트 화합물 측정 시 시료채취 및 분석과정 증에서 야기될 수 있는 공시료의 오염여부를 평가하고 clean-up 절차와 같은 적절한 개선 방안을 제시하였다. 실험도구 및 시료채취 매체에 대한 공시료를 평가한 결과 많은 종류의 실험기구 및 장치에서 DBP와 DEHP가 잔존하는 것으로 나타났다. 따라서 실험도구는 반드시 전처리하여 사용해야 하며, 이후 공시료 보정이 수반되어야 한다. 또한 본 연구에서 제시한 clean-up 방법을 통해 불순물이 많이 제거되었으며, GC/MS를 이용한 정성?정량분석에서 정도개선에 효과적인 것으로 나타났다.

• 한국정보통신학회논문지
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• 제24권1호
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• pp.57-64
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• 2020

최근 IoT 센서의 확산과 빅데이터, 인공지능 관련 기술의 발전으로 인해 미세먼지 오염도에 대한 시계열 예측 관련 연구가 활발하게 진행되고 있다. 하지만 미세먼지 오염도를 나타내는 데이터가 급격히 변하는 특성(Extreme)을 가지고 있어 기존의 시계열 예측방법으로는 현장에서 사용할 수 있는 수준의 정확도를 내지 못하고 있다. 이 논문에서는 LSTM을 활용하여 미세먼지 오염도를 예측할 때 CNN을 통한 환경상황을 분류한 결과를 반영하는 방법을 제안한다. 이 방법은 LSTM과 CNN이 독립적이지만 인터페이스를 통해 하나의 네트워크로 통합되기 때문에, 응용 LSTM보다 이해하기 쉽다. Beijing PM2.5 데이터를 활용한 제안 방법의 검증 실험에서 예측 정확도와 변화 시기에 대한 예측력이 다양한 실험 case에서 일관되게 향상된 결과를 보였다.