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        검색결과 1,269

        61.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we proposed a simulator for the development of a digital multi-process welding machine and a welding process monitoring system. The simulator, which mimics the data generation process of the welding machine, is composed of process control circuit, peripheral device circuit, and wireless communication circuit. Utilizing this simulator, we aimed to develop a welding process monitoring system that can monitor the welding situations of four multi-process welding machines and three processes each, with data transmission through wireless communication. Through the operation of the proposed simulator, sequential digital processing of multi-process welding data and wireless communication were achieved. The welding process monitoring system enabled real-time monitoring and accumulation of the process data. The selection of upper and lower limits for process variables was carried out using a deep neural network based on allowable changes in bead shape, enabling the management of welding quality by applying a process control technique based on the trend of received data.
        4,000원
        62.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fish school monitoring technology is utilized for various purposes, such as boat fishing and resource surveys. With advancements in information and communication technology, this technology has expanded its application to remote areas. Its significance has grown in fishing sites, particularly for improving the efficiency and cost-effectiveness of set-net fishing. Set-net fishing gears are not limited to coastal areas, but are also installed in inland and remote sea regions. Consequently, fishermen require technology that allows them to quickly transmit information about approaching fish schools and enables them to perform long-term monitoring. The development of remote monitoring technology for set-net fish schools must consider crucial design factors such as communication range, transmission speed, power consumption of information modules, and operational expenses. In this study, we developed a low-power remote monitoring module for set-net fish school based on WCDMA. The module was specifically designed to minimize power consumption, allowing for communication over long distances and extended operation times in set-net fishing applications. Furthermore, we developed a web server software application that enables remote access to fish schools and provides real-time weather information. The performance of the developed module was evaluated through set-net fishing site application and experiments with moving ships on the sea. The experimental results demonstrated that the remote monitoring system, consisting of the developed low-power remote monitoring module for set-net fish school based on WCDMA and a fish finder, had an average power consumption of 4.6 W, a maximum communication range of 22.84 km, and a data transmission and reception rate of 98.79%. The maximum fish school information transmission and reception rate was 97.26%.
        4,000원
        63.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 준수사항 위반행동을 종속변수로 하여 종단적 관점에서 잠재성장모형을 활용하여 각 이론에 기반에 주요 요인들이 종속변수에 어떠한 영향이 있는지를 확인 하고자 하였다. 독립변수는 각각 인구사회학적 변수, 억제이론, 사회유대이론, 사회재 통합이론, 심리적 관점을 기반으로 추출하였다. 연구분석을 위하여 각 변수들에 대한 기술통계분석과 상관관계분석을 선결적으로 진행하였으며, 최종적으로 잠재성장모형 을 활용하였다. 잠재성장모형분석은 총 3단계로 구성되며, 1단계에서는 종속변수의 평균적 발달궤적을 분석하고, 2단계에서 시간적으로 고정된 독립변수를 투입하는 방 식으로 분석하였다. 3단계는 이 연구의 최종모형으로 시간 가변적 변수를 투입하여 분석하였다. 분석결과 시간 고정적 변수 중 전자장치부착기간은 준수사항 위반행동의 발달궤적 초기치에 정(+)의 관계가 있었으며, 총 전과 횟수는 초기치와 변화율, 2차항 모두에서 유의미한 영향을 보였다. 시간 가변적 변수 중에는 부모관계, 생계안정성, 담당관의 지도・감독 횟수가 유의미한 관계가 있는 것으로 분석되었다. 이 연구는 종속변수의 평균적 궤적을 분석대상으로 하였다는 점에 한계가 있으나 그럼에도 불구하고 성폭력범죄 전자감독대상자의 준수사항 위반행동에 영향을 미치는 요인을 종단적 시각에서 검증하고자 하였다는 점, 전자장치부착기간동안 변하는 시간 가변적 변수를 주요 변수로 활용하였다는 점에 그 의의가 있다.
        8,700원
        64.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A total of 100 commercially available olive oil products were analyzed for 179 pesticide residues using gas chromatography-tandem mass spectrometry (GC/MS/MS). The olive oil samples were mixed with organic solvents, centrifuged and frozen to remove fat, and pesticide residues were analyzed using the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) method. The determination coefficient (R2) of the analysis method used in this study was ≥0.998. The detection limit of the method ranged 0.004–0.006 mg/kg and its quantitative limit ranged 0.012–0.017 mg/kg. The recovery rate (n=5) measured at the level ranging 0.01–0.02, 0.1, and 0.5 mg/kg ranged 66.8– 119.5%. The relative standard deviation (RSD) was determined to be ≤5.7%, confirming that this method was suitable for the "Guidelines for Standard Procedures for Preparing Food Test Methods". The results showed that a total of 151 pesticides (including difenoconazole, deltamethrin, oxyfluorfen, kresoxim-methyl, phosmet, pyrimethanil, tebuconazole, and trifloxystrobin) were detected in 64 of the 100 olive oil products. The detection range of these pesticide residues was 0.01–0.30 mg/kg. The percentage acceptable daily intake (%ADI) of the pesticides calculated using ADI and estimated daily intake (EDI) was 0.0001–0.1346, indicating that the detected pesticides were present at safe levels. This study provides basic data for securing the safety of olive oil products by monitoring pesticide residues in commercially available oilve oil products. Collectively, the analysis method used in this study can be used as a method to analyze residual pesticides in edible oils.
        4,000원
        65.
        2023.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present the analysis results of the simultaneous multifrequency observations of the blazar 4C +28.07. The observations were conducted by the Interferometric Monitoring of Gamma-ray Bright Active Galactic Nuclei (iMOGABA) program, which is a key science program of the Korean Very Long Baseline Interferometry (VLBI) Network (KVN). Observations of the iMOGABA program for 4C +28.07 were conducted from 16 January 2013 (MJD 56308) to 13 March 2020 (MJD 58921). We also used γ-ray data from the Fermi Large Array Telescope (Fermi-LAT) Light Curve Repository, covering the energy range from 100 MeV to 100 GeV. We divided the iMOGABA data and the Fermi-LAT data into five periods from 0 to 4, according to the prosody of the 22 GHz data and the presence or absence of the data. In order to investigate the characteristics of each period, the light curves were plotted and compared. However, a peak that formed a hill was observed earlier than the period of a strong γ-ray flare at 43–86 GHz in period 3 (MJD 57400–58100). Therefore, we assumed that the minimum total CLEANed flux density for each frequency was quiescent flux (Sq) in which the core of 4C +28.07 emitted the minimum, with the variable flux (Svar) obtained by subtracting Sq from the values of the total CLEANed flux density. We then compared the variability of the spectral indices (α) between adjacent frequencies through a spectral analysis. Most notably, α22–43 showed optically thick spectra in the absence of a strong γ-ray flare, and when the flare appeared, α22–43 became optically thinner. In order to find out the characteristics of the magnetic field in the variable region, the magnetic field strength in the synchrotron self-absorption (BSSA) and the equipartition magnetic field strength (Beq) were obtained. We found that BSSA is largely consistent with Beq within the uncertainty, implying that the SSA region in the source is not significantly deviated from the equipartition condition in the γ-ray quiescent periods.
        5,800원
        66.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Electric doors have been applied in urban trains since 2007 and operated for a long time. Recently, the failure of mechanical devices in electric doors have been increasing. The door is a device that is directly related to the safety of passengers. The rivet breakage of a ball/nut assembly may occur to an accident during train operation. In this study, the operating voltage and acceleration data of the door were collected for rivet condition monitoring, and 4 features were extracted in the frequency domain using the acceleration data. The classification performance of the rivet condition according to the axial direction of the acceleration data and 4 kernel functions was evaluated using SVM algorithm. When the X-axis data and Gaussian kernel function were used, the highest classification performance was shown for the electric door’s rivet with 90% accuracy.
        4,000원
        67.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Governments around the world are enacting laws mandating explainable traceability when using AI(Artificial Intelligence) to solve real-world problems. HAI(Human-Centric Artificial Intelligence) is an approach that induces human decision-making through Human-AI collaboration. This research presents a case study that implements the Human-AI collaboration to achieve explainable traceability in governmental data analysis. The Human-AI collaboration explored in this study performs AI inferences for generating labels, followed by AI interpretation to make results more explainable and traceable. The study utilized an example dataset from the Ministry of Oceans and Fisheries to reproduce the Human-AI collaboration process used in actual policy-making, in which the Ministry of Science and ICT utilized R&D PIE(R&D Platform for Investment and Evaluation) to build a government investment portfolio.
        4,000원
        68.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        박새는 도시생태계 내 환경변화를 측정할 수 있는 생물지표종이자 대표적인 식충성 조류로 건전성 유지와 같은 중요한 역할을 맡고 있다. 연구자들은 박새과 조류의 번식생태 파악을 위해 인공새집 조사방법을 활용하고 있으나, 공간적・시간적 한계로 거시적 관점의 연구를 진행하기에는 어려움이 있다. 본 연구는 전문가 중심으로 수행된 기존 인공새집 모니터링이 갖는 한계를 벗어나고자 시민참여 인공새집 모니터링 프로젝트를 설계하였다. ‘수원시 앞마당 조류 모니터링단’은 시민조사원 들의 자발적인 참여를 통해 경기도 수원시 내 녹지공간에 인공새집을 설치하고 박새과 조류의 번식생태를 관찰하는 프로젝트이 다. 2021년 2월 9일부터 2월 22일까지 온라인 설문조사를 통해 참가자를 모집하였고, 시민조사원은 2021년 2월 23일부터 8월 31일까지 인공새집 설치부터 관찰까지 직접 수행하였다. 비전문가인 시민조사원들의 진입장벽을 낮추고 일관된 데이터를 수집하기 위해 모니터링 과정 전반에 대한 온라인 교육을 수행하였고 모바일 애플리케이션을 이용하여 인공새집 관찰기록을 수집하였다. 시민참여 인공새집 모니터링 프로젝트에는 98명의 시민조사원이 참여하였고 배포된 206개의 인공새집 중 175(84.95%)개가 수원시 내 녹지공간에 설치되었다. 설치된 인공새집 중 위치 좌표 생성 오류가 발생한 2건을 제외한 173(83.98%)개를 대상으로 시민과학 프로젝트 결과를 확인했다. 시민조사원으로부터 수집한 인공새집 관찰기록은 총 987회 이며, 최솟값은 1회, 최댓값은 26회, 평균은 5.71±4.37회로 나타났다. 월별 인공새집 관찰 횟수는 2월 70회(7.09%), 3월 444회(44.98%), 4월 284회(28.77%), 5월 133회(13.48%), 6월 46회(4.66%), 7월 6회(0.61%), 8월 4회(0.41%)로 조사되었 다. 설치된 173개의 인공새집 중 57개(32.95%)에서 조류의 이용을 관찰할 수 있었고 박새 12개소(21.05%), 곤줄박이 7개소 (12.28%), 미동정 조류 38개소(66.67%)로 확인되었다. 본 연구는 박새과 조류의 번식생태를 조사방법으로 활용되는 인공새집 모니터링에 시민의 참여 가능성을 처음으로 검토한 연구로 향후 시민과학을 접목한 생태모니터링 설계의 기초자료로 활용될 수 있을 것으로 판단된다.
        4,200원
        69.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        견과류는 영양가가 우수하고 다양한 기능성 생리활성을 가져 건강한 식단에 중요한 요소이다. 멜라토닌은 뇌의 송 과선에서 분비되는 호르몬으로 각종 조직의 산화적 손상을 방지하는 것으로 알려져 있으며, 식물체에서도 중요한 역할 을 한다. 본 연구는 견과류의 멜라토닌 추출 및 정량을 위 한 분석법을 마련하였고, 견과류의 높은 지방함량을 고려한 최적화된 추출 절차를 이용하여 경기도에서 유통되는 견과 종실류 등의 멜라토닌 함량을 조사하였다. 땅콩 또는 견과 류, 유지종실류 및 두류의 평균 멜라토닌 함량은 각각 1200.83 (409.76-2223.56), 934.83 (454.10-1736.60), 616.46 (494.70- 825.12) pg/g으로 나타났다. 호두와 밤의 경우 속껍질을 포 함한 반탈각 상태와 과실만 있는 경우의 멜라토닌 함량을 비교한 결과, 반탈각 상태에서 멜라토닌 함량이 유의적으로 높았다. 또한 호두, 밤 및 땅콩의 경우 2022년 재배된 햇 견 과보다 2021년 재배 후 저장된 견과에서 멜라토닌 함량이 유의적으로 높았다. 이러한 결과는 견과종실류 등의 멜라토 닌 함량이 높아 우수한 기능성 식품임을 시사하였다.
        4,000원
        70.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        원전 구조물의 실시간 모니터링 기술이 요구되고 있지만, 현재 운영 중인 지진 감시계통으로는 동특성 추출 등 시스템 식별이 제한 된다. 전역적인 거동 데이터 및 동특성 추출을 위해서는 다수의 센서를 최적 배치하여야 한다. 최적 센서배치 연구는 많이 진행되어 왔 지만 주로 토목, 기계 구조물이 대상이었으며 원전 구조물 대상으로 수행된 연구는 없었다. 원전 구조물은 미미한 신호대잡음비에도 강건한 신호를 획득하여야 하며, 모드 기여도가 저차 모드에 집중되어 있어 모드별 잡음 영향을 고려해야 하는 등 구조물 특성을 고려 해야 한다. 이에 본 연구에서는 잡음에 대한 강건도와 모드별 영향을 평가할 수 있는 최적 센서배치 방법론을 제시하였다. 활용한 지표 로서 auto MAC(Modal Assurance Criterion), cross MAC, 노드별 모드형상 분포를 분석하였으며, 잡음에 대한 강건도 평가의 적합성을 수치해석으로 검증하였다.
        4,000원
        71.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 경기도 내 유통 중인 견과 종실류의 잔 류농약 실태를 조사하고자 온라인 또는 유통매장을 통해 131건을 수거하여 조사하였다. 총 14품목의 견과종실류 를 수거하였으며 339종의 잔류농약을 분석한 결과 131건 중 총 8건에서 검출되었으며 범위는 0.01 mg/kg-0.07 mg/ kg 수준으로 나타났다. 검출된 시료 8건 중 7건이 잔류 농약 기준을 초과하여 부적합으로 판정되었으며 부적합 7건 중 6건은 수입농산물에서 판정되었다. 중국산 호박씨 의 경우 PLS가 적용된 피라클로스트로빈이 5건 검출되 었으며 범위는 0.02 mg/kg-0.04 mg/kg 수준으로 나타났다. 인도산 참깨와 국내산 참깨에서도 펜디메탈린, 보스칼리 드, 비펜트린이 각각 0.04 mg/kg, 0.05 mg/kg, 0.06 mg/kg 으로 검출되어 부적합 수치를 보였다. 또한 검출된 8종 의 농약에서 EDI/ADI (%) 값이 0.002%-0.372%으로 낮 은 수준임을 확인하였다.
        4,000원
        72.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the odor emission characteristics of fertilizer manufacturing facilities. The characteristics were evaluated by measuring the odor concentration at the outlet and site boundary of the complex fertilizer and organic fertilizer manufacturing facilities. The evaluation process utilized the air dilution sensory method and PTR-ToF-MS. The complex odor dilution factor ranged from 100 to 120 times at the outlet of the compound fertilizer manufacturing facility. Specifically, the concentrations of Ammonia and Aldehydes were relatively high as designated odor substances. For the organic fertilizer facility, the dilution factor for complex odors was measured up to a maximum of 3,000. And, designated odorants such as Ammonia and Hydrogen sulfide were measured at levels up to parts per million (ppm). The odor contribution assessment of the fertilizer manufacturing facilities showed that the complex fertilizer facility exhibited similar contributions from Aldehydes and Sulfur compounds. On the other hand, the organic fertilizer facility had the highest contribution of over 62% from Sulfur compounds. As odor substances are easily changed and diffused according to weather conditions, it is difficult to obtain representative data according to the measurement time. Therefore, if continuous monitoring of odorous substances is performed using equipment that can be measured in real time without pretreatment, it becomes feasible to identify odor emission sources and regional spatio-temporal distribution. This information would then serve as a basis for analyzing odorant contamination characteristics and establishing appropriate countermeasures.
        4,000원
        73.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 국내에서 유통되는 식·약공용농산물의 잔 류농약 실태를 조사하기 위해 7품목 72건 대상으로 잔류 농약을 분석했다. 시료는 QuEChERS법으로 전처리한 후 GC-MS/MS, LC-MS/MS를 이용하여 분석했다. 식·약공용 농산물 총 7품목 72건 중 42건(58.3%)에서 잔류농약이 검 출되었으며, 검출된 농산물은 복분자 1건, 구기자 14건, 대 추 9건, 오미자 10건, 모과 1건, 생강 5건, 영지버섯 2건 이었다. 그 중 구기자 2건(11.8%), 오미자 1건(7.1%), 영 지버섯 2건(100%)에서 잔류농약 허용기준을 초과하여 검 출되었다. 검출농약은 43종으로 살균제 20종 75회, 살충제 23종 58회이었으며, 살균제 carbendazim 및 tebuconazole이 각각 11회로 가장 빈번하게 검출되었다. 허용기준을 초과 하여 검출된 농약은 acetamiprid, cadusafos, chlorpyrifos, flubendiamide, fluopyram, triazophos으로 모두 잔류농약허 용기준이 설정되지 않은 PLS 항목이었다. 결론적으로 잔 류농약 검사 건수, 검출률, 검출빈도를 종합적으로 고려해 볼 때 식·약공용농산물에 대한 지속적인 잔류농약 관리가 필요한 것으로 생각된다.
        4,200원
        74.
        2023.05 구독 인증기관·개인회원 무료
        In-situ gamma spectrometer with mobile equipment can be used for rapid determination of radioactivity in the environment within a very short interval. 2”×2” NaI(Tl) scintillator are used to build a mobile radiation measurement system (called as Monitoring of Ambient Radiations of KAERI for Backpack, MARK-B3) with a signal processing unit, and GPS and interface units to a PC for wireless controlling system. Development of the survey system is to measure ambient gamma-ray spectrometry for estimating ground radioactivity and radiation dose in the environment. The ambient dose rate is estimated using G-factor method. For determination of G-factor, we conducted MCNP simulations in assumptions of various incident photons into the detector system. And the scintillator was exposed to Cs-137 source in the range of 1- 300 mGy/hr. Calculated dose rates for different simulation results were compared to the irradiated dose rate to derive correction factor of G-factor. To evaluate performance of the MARK-B3, in-situ gamma spectrometry was conducted in Jeju island.
        75.
        2023.05 구독 인증기관·개인회원 무료
        At Nuclear Power Plant (NPP), aging management is performed as part of the Periodic Safety Review (PSR) in accordance with the Nuclear Safety Act. The purpose of the aging management program (AMP) is to manage the integrity of structures, systems and components (SSCs) in NPPs over time and use. Through this, aging deterioration is mitigated to increase equipment life and secure long-term operation safety. Fuel Oil Chemistry is one of the AMPs. Through this program, aging management is performed for storage tanks, piping and other metal components that contact with diesel fuel oil. The program is focused on managing loss of material due to general, pitting, crevice, and microbiologically-influenced corrosion (MIC) and fouling that leads to corrosion of the diesel fuel tank internal surfaces. The fuel oil aging management method currently applied to NPPs in Korea measures the concentration of water and particulate contamination in the oil, analyzed the trend, and periodically cleans and inspect the inside of tanks. Among them, in monitoring MIC, a direct analysis and monitoring of the amount of microorganisms may be more effective. In this study, a method for improving the MIC monitoring system for diesel fuel oil systems was reviewed by reviewing reference documents including NUREG 1801 and examining the methods actually applied in US NPPs.
        76.
        2023.05 구독 인증기관·개인회원 무료
        Airborne surveys are an essential analysis method for rapid response and contamination identification in the early event of a radiation emergency. On the other hand, airborne surveys are far from the ground, so it is necessary to convert the dose rate at a height of 1 m above the ground. In order to improve the accuracy of the analysis value, a lot of analysis of the measurement data is required. In our previous research, we developed MARK-A1, an instrument for rapid radiation aerial survey in high radiation environment, and MARK-M1, a multipurpose instrument for radiation detection. In this study, a large unmanned aerial vehicle (UAV) was used to conduct airborne surveys using three types of detectors in the Jeju Island environment. The NaI(Tl) detector uses one 3-inch scintillator (38 mm φ × 38 mm H), and the LaBr3 detector uses two 2-inch scintillators (25 mm φ × 25 mm H). The CZT detector uses a detector with dimensions of (15 mm × 15 mm × 7.5 mm). The UAV has a payload of 15 kg (J10, JCH systems Inc. Seoul, Korea). Three different detectors were operated at a constant height of 20 m, 30 m, and 50 m. The flight experiments were performed in the west near Jeju City. Dose rate conversion factors were used to convert the dose rate from the measured spectra, and hovering flights were conducted between 1 and 50 meters to derive altitude correction factors. In this paper, the data measured with each detector in the same area were compared and the differences were derived.
        77.
        2023.05 구독 인증기관·개인회원 무료
        After the Fukushima nuclear accident in Japan in March 2011, many Koreans were concerned that products exposed to radioactive materials released from the nuclear power plant would be imported into Korea. Systematic radiation monitoring was required for food and daily necessities imported from the nuclear accident area. The need for a legal system to support systematic radiation monitoring was also demanded. The Act on Protective Action Guidelines against Radiation in the Natural Environment was enacted to resolve concerns regarding environmental radiation in Korea in July 2011. According to this law, radiation monitoring equipment has been installed and operated at major airports and ports nationwide. This paper aims to review the radiation monitoring system of the Korean government comprehensively. The legal system and the legal basis for radiation monitoring of imported cargo conducted by each department were investigated by analyzing the laws and regulations of radiation monitoring for the relevant cargo items. In addition, the current status of radiation monitoring by the government departments was examined to determine how radiation monitoring for imported cargo is performed within the legal system. The investigation of the current radiation monitoring system for imported cargo in Korea confirmed that radiation monitoring is conducted by classifying cargo items under the jurisdiction of each government department for all imported cargo. However, the reduction in efficiency of radiation monitoring of imported cargoes, unclear legal grounds for radiation monitoring of imported cargo by some departments, the occurrence of overlapping inspections by departments, and the difficult process of issuing the radiation test certificate required for customs clearance by the Korea Customs Service were also identified. As a result of the analysis, it was found that the current radiation monitoring system for imported cargo in Korea ought to be improved, taking into account efficiency, overlapping inspection, legal background, and the difficult process of issuing the certificates.
        78.
        2023.05 구독 인증기관·개인회원 무료
        By developing plasma torch melting technology in 1996, our company has developed the first generation 150 kW (’96~’02), the second generation 500 kW (’08~’12), and the third generation MW plasma torch melting facility (’14~’18), and completed facility upgrading (’20~’23). The MW plasma torch melting facility is equipped with CCTV to monitor waste input, melting, torch integrity, and melt discharge. The lens is installed inside a metal housing made of stainless steel to prevent damage caused by external impacts and high temperatures, and supplies nitrogen to prevent cooling and lens contamination. As a result of the demonstration test, as the temperature inside the melting furnace increased after starting the plasma torch, the resolution decreased along with noise in the CCTV, and facility monitoring was difficult due to high temperatures and foreign substances (fume). Based on the test results, CCTV was changed to a non-insertion type that was not directly exposed to high temperatures, and a filter (quartz) was additionally applied to monitor the melt smoothly. As a result of applying the newly manufactured CCTV to the demonstration test, smooth monitoring ability was confirmed even at normal operating temperature (above 1,500°C). Through this facility improvement, the operation convenience of the plasma torch melting facility has been secured, and it is expected that it will be able to operate stably during long-term continuous operation in the future.
        79.
        2023.05 구독 인증기관·개인회원 무료
        Radioactive waste must be stored for at least 300 years and must bear astronomical costs. In addition, unexpected potential risk factors are also a considerable burden. In the case of low-level radioactive waste, combustible and liquid low-contamination radioactive waste can be treated relatively easily through high-temperature plasma which the volume can be reduced by 1/250 and the weight by 1/30. It is possible to permanently dispose of the ash leached after plasma treatment in a more stable manner compared to the conventional methods. Types of low-level combustible radioactive waste, including paper, vinyl, clothing, filters, and resins, account for more than 30% of the total waste volume. Furthermore, high-temperature plasma treatment of low-level radioactive waste from petrochemical plants and medical institutions have many advantages, namely astronomical cost savings, securing free space in existing storage facilities, and improving the image of nuclear energy. Korea is preparing to decommission the Kori No. 1 nuclear power plant, and small and mediumsized enterprises and related organizations are conducting various studies to incinerate radioactive waste. In foreign countries, Britain began incineration technology in the 1970s, and Plasma Energy Group, LLC, headquartered in Florida, USA, physically changed the molecular structure of the material by combining plasma chambers and plasma arcs and obtained a patent application in 1992. Germany was approved for operation in 2002, and Switzerland completed a trial run of a plasma technologybased facility in 2004. Important radionuclides in terms of radioactive gas waste treatment include inert gases, radioiodine, and radioactive suspended particles. Gas waste is compressed in a compressor through a surge tank in the gas waste treatment system and filters at each stage. after that, the shortlife nuclide is naturally collapsed for 30 to 60 days in the storage or activated carbon adsorbent in the attenuation tank and released through HEPA filters. The radioactive concentration at discharge is monitored and managed using continuous monitoring equipment, and the oxygen concentration is managed in the gas waste treatment system to prevent explosion risk. The problem of radioactive waste disposal is not only a problem for people living in the present era, but also a big social issue that brings a burden to future generations While interest in plasma treatment is increasing from the decommissioning of the Kori Unit 1. in Korea, it is showed that there is a lack of systematic management and research especially in the radioactive volatile gases fields, that’s why I propose some ideas as follows. First, the government and related institutions should invest to the continuous radioactive monitoring system to produce and distribute continuous radioactive monitoring facilities with an affordable price. Second, it is recommended that radioactive waste incineration would be connected to the GRS system of the plant’s gas radwaste treatment system, and radioactive volatile materials should be monitored through continuous monitoring system. Third, radioactive volatile materials generated according to the temperatures and times during plasma incineration treatment are different. Therefore, prior classification of each expected radioactive volatile substance must be performed before incineration.
        80.
        2023.05 구독 인증기관·개인회원 무료
        The high-level nuclear waste (HLW) repository is a 500-1,000 m deep underground structure to dispose high-level nuclear waste. The waste has a very long half-time and is exposed to a number of stresses, including high temperatures, high humidity, high pressure These stresses cause the structure to deteriorate and create cracks. Therefore, structural health monitoring with monitoring sensors is required for safety. However, sensors could also fail due to the stresses, especially high temperature. Given that the sensors are installed in the bentonite buffer and the backfill tunnel, it is impossible to replace them if they fail. That’s why it is necessary to assess the sensors’ durability under the repository’s environmental conditions before installing them. Accelerated life test (ALT) can be used to assess durability or life of the sensors, and it is important to obtain the same failure mode for reliability tests including ALT. Before conducting the test, the proper stress level must be designed first to get reliable data in a short time. After that, acceleration of life reduction with increasing temperature and temperature-life model should be determined with some statistical methods. In this study, a methodology for designing stress levels and predicting the life of the sensor were described.
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