• Nuclear Engineering and Technology
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• 제50권6호
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• pp.890-898
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• 2018

Nondestructive inspection (NDI) is an integral part of structural integrity analyses of dry storage casks that house spent nuclear fuel. One significant concern for the structural integrity is stress corrosion cracking in the heat-affected zone of welds in the stainless steel canister that confines the spent fuel. In situ NDI methodology for detection of stress corrosion cracking is investigated, where the inspection uses a delivery robot because of the presence of the harsh environment and geometric constrains inside the cask protecting the canister. Shear horizontal (SH) guided waves that are sensitive to cracks oriented either perpendicular or parallel to the wave vector are used to locate welds and to detect cracks. SH waves are excited and received by electromagnetic acoustic transducers (EMATs) using noncontact ultrasonic transduction and pulse-echo mode. A laboratory-scale canister mock-up is fabricated and inspected using the proposed methodology to evaluate the ability of EMATs to excite and receive SH waves and to locate welds. The EMAT's capability to detect notches from various distances is evaluated on a plate containing 25%-through-thickness surface-breaking notches. Based on the results of the distances at which notch reflections are detectable, NDI coverage for spent nuclear fuel storage canisters is determined.

• Geomechanics and Engineering
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• 제35권2호
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• pp.109-119
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• 2023

Ground subsidence in urban areas due to excessive development and degraded underground facilities is a serious problem. Geophysical surveys have been conducted to estimate the distribution and scale of cavities and subsidence. In this study, electrical resistivity tomography (ERT) was performed near an area of road subsidence in an urban area. The subsidence arose due to groundwater leakage that carried soil into a neighboring excavation site. The ERT survey line was located between the main subsidence area and an excavation site. Because ERT data are affected by rapid topographic changes and surrounding structures, the influence of the excavation site on the data was analyzed through field-scale numerical modeling. The effect of an excavation should be considered when interpreting ERT data because it can lead to wrong anomalous results. A method for performing 2D inversion after correcting resistivity data for the effect of the excavation site was proposed. This method was initially tested using a field-scale numerical model that included the excavation site and subsurface anomaly, which was a loosened zone, and was then applied to field data. In addition, ERT data were interpreted using an existing in-house 3D algorithm, which considered the effect of excavation sites. The inversion results demonstrated that conductive anomalies in the loosened zone were greater compared to the inversion that did not consider the effects of excavation.

• 식물병연구
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• 제15권1호
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• pp.1-7
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• 2009

Viruses diagnosed on crops including rice plants from farmers or agricultural extension agencies cover the country were 11 species including Broad bean wilt virus 2 (BBWV2) in 2008. Tomato spotted wilt virus (TSWV) was the most important virus having the detection rate of 22.9%. Two viruses of Tomato yellow leaf curl virus (TYLCV) and Tobacco leaf curl virus (TLCV) inducing leaf yellow and curl diseases on tomatoes were occurred newly with the detection rate of 12.2% and 4.0%, respectively, in 2008. Rice stripe virus (RSV) was occurred on 869.5 ha mainly at Jindo and Haenam areas in Jeollanamdo province. At Jindo area, 12 plots were damaged severely with the infected hill rate of 83.8%. At the main production area of oriental melon at Seongju, almost all fruits from whole sale market at Seongju were infected with Cucumber green mottle mosaic virus (CGMMV) as the detection rate of 87%. The areas occurred TSWV in Korea were 25 totally from 2003 including 7 areas newly reported in 2008 including Naju in Jeoallanamdo. TSWV could be reduced as 0.1 % from 5.3% by covering insect proof net in vinyl house after chemical soil sterilization. Tomato yellow leaf curl disease was occurred on April in 2008 at Tongyoung area in Kyeongsangnamdo, and detected continuously at 13 areas, 7 in Kyeongsangnamdo, 4 in Jeollabukdo and 2 in Jejudo. Potato spindle tuber viroid (PSTVd) was occurred abruptly in a confined space of a civil breeding greenhouse and a cultivar evaluation field followed by disuse 17.4 M/T of potato tubers. No PSTVd was detected at 17 fields cultivated the related potatoes to the bred company by RT-PCR.

• 한국정보과학회논문지:정보통신
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• 제37권5호
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• pp.396-402
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• 2010

지능형 주택의 상황인지 서비스를 위해서는 거주자의 현재 위치를 파악하는 것이 필수적이다. 이를 위해 본 논문에서는 사용자에게 별도의 장치 소지를 요구하지 않으며 특정 운에 대한 출/입 행동과 같은 위치 이동과 그 사람이 누구인지를 식별하는 센서 네트워크 시스템을 제안한다. 새롭게 개발된 센서 노드는 선행 연구 결과[1]의 짧은 동작 수명 문제를 해결한 것으로 2개의 초전형(PIR) 센서와 초음파 센서, 그리고 2.4 GHz 문선 통신 모듈로 구성된다. 제안된 구성원의 식별 방법은 초음파 센서를 이용한 구성원의 키 차이를 이용한다. 거주자의 위치 이동의 감지는 출/입 행동의 감지에 기초하며 이와 같은 출/입 행동 감지는 2개의 PIR 센서의 감지 순서에 기초하여 이루어진다. 전체 센서 네트워크의 구성은 각 센서 노드가 수신 노드와 과 1대 1로 연결되는 별 형태로 이루어져 있다. 제안된 시스템은 본보기주택에 설치되어 3명의 사용자를 대상으로 실험되었고 그 결과 완벽한 출/입 행동 감지와 평균 81.3%의 구성원 식별 성능을 얻었다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제15권2호
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• pp.85-90
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• 2012

Purpose: Commercial enzyme-linked immunosorbent assay (ELISA) kits have been considered less reliable for children than for adults. The aim of this study was to compare four ELISA kits and in-house immunoblotting based on the analysis of anti-H. pylori-IgG antibody reactivity. Methods: A total of 399 serum samples were collected at the GNU Hospital during 1998-1999. All sera were tested using ELISA and immunoblotting. Statistically significant differences were determined by the $x^2$ test. Results: The overall seropositivity rates using GAP IgG, Genedia IgG, HM-CAP, Pyloriset EIA-G, and immunoblotting were 13.0%, 25.1%, 18.3%, 15.8%, and 62.9%, respectively. Immunoblotting showed a higher seropositivity rate than did all four ELISA kits in all age groups. Genedia IgG had the highest seropositivity among the ELISA kits. The seropositivity rate for children aged 13 to 18 months was lowest, and that of children aged 15 years was highest (90.0%). The seropositivity rate for children aged 7 months to 5 years was significantly lower than that for children aged 6 to 15 years among the four ELISA kits (p<0.0001) and immunoblotting (p=0.02). Conclusion: Immunoblotting is the most sensitive test for detection of anti-Helicobacter pylori IgG antibodies among the serological tests in this study. These results emphasize the need for standardization when commercial ELISA tests are used in different nations or in young age groups. Immunoblotting could be a suitable noninvasive assay for serodiagnosis and seroepidemiologic study of H. pylori infection in Korean children.

• 한국임상수의학회지
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• 제30권4호
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• pp.258-263
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• 2013

The primary goal of this study was to compute sample sizes required to achieve the each aim of a variety of foot-and-mouth disease (FMD) surveillance programs, using a statistically valid technique that takes the following factors into account: sensitivity (Se) and specificity (Sp) of diagnostic test system, desired minimum detectable prevalence, precision, population size, and desired power of the survey. In addition, sample sizes to detect FMD if the disease is present and also as proof of freedom were computed. The current FMD active surveillance programs consist of clinical, virological, and serological surveillance. For the 2012 serological surveillance, annual sample sizes (n = 265,065) are planned at four separate levels: statistical (n = 60,884) and targeted (n = 115,232) at breeding pig farms and slaughter house, in together with the detection of structural proteins (SP) antibodies against FMD (n = 88,949). Overall, the sample size was not designed taking the specific aims of each surveillance stream into account. The sample sizes for statistical surveillance, assuming stratified two-stage sampling technique, was based to detect at least one FMD-infected case in the general population. The resulting sample size can be used to obtain evidence of freedom from FMD infection, not for detecting animals that have antibodies against FMD virus non-structural proteins (NSP). Additionally, sample sizes for targeted surveillance were not aimed for the population at risk, and also without consideration of statistical point of view. To at least the author's knowledge, sampling plan for targeted, breeding pig farms and slaughter house is not necessary and need to be included in the part of statistical surveillance. Assuming design prevalence of 10% in an infinite population, a total of 29 animals are required to detect at least one positive with probability of 95%, using perfect diagnostic test system (Se = Sp = 100%). A total of 57,211 animals needed to be sampled to give 95% confidence of estimating SP prevalence of 80% at the individual animal-level with a precision of ${\pm}5%$, assuming 800 herds with an average 200 heads per farm, within-farm variance of 0.2, between-farm variance of 0.05, cost ratio of 100:1 of farm against animals. Furthermore, 779,736 animals were required to demonstrate FMD freedom, and the sample size can further be reduced depending on the parameters assumed.

• 정신신체의학
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• 제24권2호
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• pp.133-139
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• 2016

연구목적 노인 우울증의 증가에 따라 예방 및 관리 대책이 시급한 상태이나 초기 우울증의 선별이 어려워 조기 발견이 쉽지 않은 것이 현실이다. 본 연구는 일도시지역에 노인 복지 시설 이용 노인들을 대상으로 PHQ-9 설문지를 이용하여 인구사회학적 요인과 우울증과의 관련성에 대해 파악하고 더 나아가 노인 우울증을 조기에 선별하기 위한 목적으로 시행되었다. 방 법 본 연구는 일도시지역에 거주하는 노인을 대상으로 PHQ-9의 검사와 면담을 통해 인구사회학적 요인(성별, 나이, 주거형태, 자녀 수, 동거인 유무, 교육 수준, 질병 상태)과 우울증과의 관련성에 대해 확인해보았다. 인구사회학적 요인에 따른 PHQ-9 점수의 평균을 비교하여 통계적으로 유의한 요인에 대해 알아보았다. 또한 PHQ-9의 우울증 진단의 절단값인 10점을 기준으로 이와 관련된 인구사회학적 요인을 비교 분석하였다. 결 과 주거 형태(자가 vs. 비자가)와 교육 수준(초등학교 졸업 미만 vs. 초등학교 졸업 이상)에 따른 PHQ-9 점수평균에서 유의한 차이를 보였다. 유사하게 PHQ-9 점수 10점을 기준으로 한 인구사회학적 요인의 비교에서도 비자가에서 거주하는 경우, 그리고 초등학교 졸업 미만인 경우 PHQ-9 점수가 유의하게 높은 것을 확인할 수 있었다. 결 론 이 연구는 노인 우울증의 위험인자에 대한 이해와 노인 우울증의 조기 평가 및 개입을 통한 대책 마련에 도움을 줄 수 있을 것으로 기대한다.

• Journal of Preventive Medicine and Public Health
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• 제20권2호
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• pp.312-321
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• 1987

뇌성마비아의 조기 발견에 관련된 모자인자를 조사하기 위하여 1987년 2월부터 1987년 4월까지 대구 장애자 복지관, 대구대학교 부설재활원, 성바오로 어린이집, 그리고 부산 뇌성마비아복지회에 통원 또는 입원치료를 받고 있는 어린이 110명중 1980년 1월 1일 이후 출생자 74명 전원의 어머니를 대상으로 면담조사 하였다. 아버지의 학력과 이상 발견시기와는 아무런 상관관계가 없었으나 어머니의 학력이 대학졸업이상 일때가 고졸이하에 비해 어린이의 이상을 일찍 발견했고, 또 아버지의 직업이 전문직 또는 관리직일 때가 그 이외의 직업에 비해, 그리고 아버지의 월수입이 610,000원이상 일때가 600,000원 이하보다 더 일찍 발견하는 경향이었다. 첫째아이가 둘째아이 보다 그리고 부모의 나이가 34세 이하인 경우가 35세 이상인 경우에 비해 좀더 일찍 이상을 발견하는 경향을 보였다. 남아에서 여아에 비해 더 일찍 이상이 발견되었고 육아상담을 정기적으로 받은 어린이에서 정기적으로 받지 않은 어린이보다 더 일찍 이상이 발견되었는데 5% 유의수준에는 약간 못미쳤다. 연구대상아를 임신했을 때 산전관리를 7회이상 받았던 경우가 6회이하 받았던 경우에 비해 통계적으로 유의하게 일찍 어린이의 이상이 발견되었다. 처음으로 이상을 발견한 사람은 부모가 85.1%, 육아 상담을 정기적으로 받은 여부와는 관계없이 의사가 발견한 것은 2.7%였고 부모가 어린이의 이상을 발견하고 의사의 진단을 받았을때 36.5%에서 뇌성마비 진단을 받았고 나머지는관찰, 정상등으로 진단이 확실하지 않았다. 부모가 어린이의 이상을 발견하고 $2{\sim}3$개월 뒤에 의사의 진단을 받았고 진단후 전문적 치료를 시작할 때까지 방치했거나 물리치료, 한약, 침술 등을 받았다. 뇌성마비아의 조기 발견을 위해 의학교육과 임상수련과정에서 어린이의 발달을 평가하는 방법의 교육과 수련이 강화되어야 할 것이며 진단을 위한 전문인력의 양성이 필요한 것으로 생각된다. 또 부모들의 뇌성마비를 비롯한 각종 장애의 진단과 치료에 대한 인식을 높이기 위한 계몽교육이 필요하다.

• 분석과학
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• 제29권1호
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• pp.35-42
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• 2016

A new nano-composite carbon ink for the development of disposable dopamine (DA) biosensors based on screen-printed carbon electrodes (SPCEs) is introduced. The method developed uses SPCEs coupled with a tyrosinase modified nano-composite carbon ink. The ink was prepared by an “in-house” procedure with reduced graphene oxide (rGO), Pt nanoparticles (PtNP), and carbon materials such as carbon black and graphite. The rGO-PtNP carbon composite ink was used to print the working electrodes of the SPCEs and the reference counter electrodes were printed by using a commercial Ag/AgCl ink. After the construction of nano-composite SPCEs, tyrosinase was immobilized onto the working electrodes by using a biocompatible matrix, chitosan. The composite of nano-materials was characterized by X-ray photoelectron spectroscopy (XPS) and the performance characteristics of the sensors were evaluated by using voltammetric and amperometric techniques. The cyclic voltammetry results indicated that the sensors prepared with the rGO-PtNP-carbon composite ink revealed a significant improvement in electro-catalytic activity to DA compared with the results obtained from bare or only PtNP embedded carbon inks. Optimum experimental parameters such as pH and operating potential were evaluated and calibration curves for dopamine were constructed with the results obtained from a series of amperometric detections at −0.1 V vs. Ag/AgCl. The limit of detection was found to be 14 nM in a linear range of 10 nM to 100 µM of DA, and the sensor’s sensitivity was calculated to be 0.4 µAµM⁻¹cm⁻².

• 천문학회보
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• 제38권2호
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• pp.68.2-68.2
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• 2013

Camera for QUasars in EArly uNiverse (CQUEAN) is an optical CCD camera system made by Center for Exploration of the Origin of the Universe (CEOU). CQUEAN is developed for follow-up observation of red sources such as high-redshift quasar candidates ($z{\geq}5$), gamma-ray bursts (GRB), brown dwarfs and young stellar objects. The CQUEAN is composed of a science camera with deep-depletion CCD chip which is sensitive at around $1{\mu}m$, a set of custom-made wide-band filters for detection of quasar candidates at z~5, and a guide camera. A focal reducer was developed to secure $4.8^{\prime}{\times}4.8^{\prime}$ field of view, and an in-house user software for efficient data acquisition. CQUEAN was attached to 2.1m Otto Struve Telescope in McDonald Observatory, USA, in August 2010. About 1000 quasar candidates including 3 confirmed with follow-up spectroscopy, have been observed so far, and many high-z galaxy cluster candidates, GRBs and supernovae were also observed. And monitoring of HBC 722, a young stellar object, is under way since 2011. Further enhancement of CQUEAN including the introduction of narrow-band filters is planned.