• 한국터널지하공간학회 논문집
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• 제24권6호
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• pp.451-464
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• 2022

고준위방사성폐기물 처분장은 심지층 처분시스템으로 사용후핵연료를 취급하는 특성상 고온, 방사선 및 지하수 등의 복합적인 환경조건에 노출되어 있다. 지속적인 노출에 의해 시간이 지남에 따라 구조물의 균열 및 열화가 발생할 수 있다. 한편 고준위방사성폐기물 처분장은 초장기 기대수명이 요구되며 이에 따른 장기적인 구조물 건전성 모니터링이 필수적이다. 구조물 건전성 모니터링에는 가속도계, 토압계, 변위계 등 다양한 센서들이 활용될 수 있으며, 이 중 일반적으로 피에조센서가 사용된다. 따라서 피에조센서의 내구성 평가를 바탕으로 고내구성 센서를 개발할 필요가 있다. 본 연구에서는 피에조센서의 내구성 평가 및 수명예측을 위한 가속수명시험을 설계하였다. 문헌연구를 바탕으로 단일 스트레스 인자에 대한 가속 스트레스 수준 수 및 각 수준 별 시료 수를 선정하였다. 또한 고준위방사성폐기물 처분장 환경조건에서 발생할 수 있는 피에조센서의 고장모드 및 고장메커니즘을 분석하였다. 온도 스트레스 인자에 대한 최대 가혹조건 탐색 실험을 두 가지 방법으로 제안하였으며 피에조센서의 신뢰도 높은 동작한계를 도출하였다. 이를 이용하여 가속수명시험의 합리적인 가속 스트레스 수준을 설정하였다. 본 연구에서 제시된 최대 가혹조건 탐색 실험방법은 경제적이며 실용적인 아이디어를 담고 있으며, 추후 피에조센서의 가속수명시험 설계에 널리 활용될 수 있을 것으로 판단된다.

• 한국재료학회지
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• 제25권8호
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• pp.391-397
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• 2015

NiO catalysts/$Al_2O_3$/FeCrAl alloy foam for hydrogen production was prepared using atomic layer deposition (ALD) and subsequent dip-coating methods. FeCrAl alloy foam and $Al_2O_3$ inter-layer were used as catalyst supports. To improve the dispersion and stability of NiO catalysts, an $Al_2O_3$ inter-layer was introduced and their thickness was systematically controlled to 0, 20, 50 and 80 nm using an ALD technique. The structural, chemical bonding and morphological properties (including dispersion) of the NiO catalysts/$Al_2O_3$/FeCrAl alloy foam were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy and scanning electron microscopy-energy dispersive spectroscopy. In particular, to evaluate the stability of the NiO catalysts grown on $Al_2O_3$/FeCrAl alloy foam, chronoamperometry tests were performed and then the ingredient amounts of electrolytes were analyzed via inductively coupled plasma spectrometer. We found that the introduction of $Al_2O_3$ inter-layer improved the dispersion and stability of the NiO catalysts on the supports. Thus, when an $Al_2O_3$ inter-layer with a 80 nm thickness was grown between the FeCrAl alloy foam and the NiO catalysts, it indicated improved dispersion and stability of the NiO catalysts compared to the other samples. The performance improvement can be explained by optimum thickness of $Al_2O_3$ inter-layer resulting from the role of a passivation layer.

• 터널과지하공간
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• 제33권5호
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• pp.348-372
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• 2023

고심도 균열암반대수층 환경에서 주로 수행되는 방사성폐기물 처분사업과 관련하여, 부지적합성 및 운영 시 안정성 평가를 평가하는데 있어 해당 대상 부지의 수리지질특성 평가는 필수적이다. 이러한 심부 수리지질 특성평가에 사용되는 인자 자료는 대상 부지에 굴착된 시추공을 이용한 원위치 수리시험을 통해 얻어지는데, 이 때 조사 결과의 정확도와 신뢰성은 적합한 시험방법의 선택, 조사 시스템의 성능, 조사절차의 표준화와 직접적으로 연결된다. 본 보고에서는 심부 암반대수층의 핵심 수리지질 평가인자인 수리전도도와 저류계수를 구하기 위한 대표적인 시험법인 정압주입시험의 상세조사절차를 소개하였다. 본 보고는 2022년도에 제안한 암반공학회 정압주입시험 관련 표준시험법 자료를 보완하여 구체화 하였으며, 본 조사절차가 실제 적용된 화산암 지역 시추공 현장적용 사례도 함께 소개하였다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제9권2호
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• pp.165-173
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• 1998

본 연구에서는 아스퍼거장애와 비전형 자폐장애 아동의 인지기능과 시각-운동 협응능력을 비교하였다. 아스퍼거장애(13명)와 비전형 자폐장애(14명) 환아 27명의 인지기능과 시각-운동 협응능력을 알아보기 위해 K-WISC와 BGT 수행결과를 비교하였다. 아스퍼거장애는 비전형 자폐장애보다 전체 지능이 유의미하게 더 높았다. 아스퍼거장애는 언어성 지능과 동작성 지능이 차이를 보이지 않은 반면, 비전형 자폐장애는 동작성 지능이 언어성 지능에 비해 유의미하게 더 높았다. 아스퍼거장애는 비전형 자폐장애에 비해 상식과 이해 소검사에서 더 우수한 수행을 보였고, 토막짜기에서는 더 낮은 점수를 받았다. 또한 비전형 자폐장애와 비교할 때, 아스퍼거장애는 시각-운동 협응에 더 어려움이 있는 것으로 나타났다. 아스퍼거 장애는 언어 및 학습능력이, 비전형 자폐장애는 시공간 기능 및 시각-운동 협응능력이 상대적으로 우수하였다. 이러한 결과는 K-WISC와 BGT가 이 두 장애를 구분하는데 유용한 평가도구가 될 수 있음을 시사해주었다.

• Journal of Gastric Cancer
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• 제22권2호
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• pp.120-134
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• 2022

Purpose: This study aimed to identify prognostic factors for patients with distant lymph node-involved gastric cancer (GC) using a machine learning algorithm, a method that offers considerable advantages and new prospects for high-dimensional biomedical data exploration. Materials and Methods: This study employed 79 features of clinical pathology, laboratory tests, and therapeutic details from 289 GC patients whose distant lymphadenopathy was presented as the first episode of recurrence or metastasis. Outcomes were measured as any-cause death events and survival months after distant lymph node metastasis. A prediction model was built based on possible outcome predictors using a random survival forest algorithm and confirmed by 5×5 nested cross-validation. The effects of single variables were interpreted using partial dependence plots. A contour plot was used to visually represent survival prediction based on 2 predictive features. Results: The median survival time of patients with GC with distant nodal metastasis was 9.2 months. The optimal model incorporated the prealbumin level and the prothrombin time (PT), and yielded a prediction error of 0.353. The inclusion of other variables resulted in poorer model performance. Patients with higher serum prealbumin levels or shorter PTs had a significantly better prognosis. The predicted one-year survival rate was stratified and illustrated as a contour plot based on the combined effect the prealbumin level and the PT. Conclusions: Machine learning is useful for identifying the important determinants of cancer survival using high-dimensional datasets. The prealbumin level and the PT on distant lymph node metastasis are the 2 most crucial factors in predicting the subsequent survival time of advanced GC.

• Clinical and Experimental Reproductive Medicine
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• 제43권2호
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• pp.112-118
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• 2016

Objective: Ovarian reserve tests are commonly used to predict ovarian response in infertile patients undergoing ovarian stimulation. Although serum markers such as basal follicle-stimulating hormone (FSH) or random $anti-M{\ddot{u}}llerian$ hormone (AMH) level and ultrasonographic markers (antral follicle count, AFC) are good predictors, no single test has proven to be the best predictor. In this study, we developed appropriate equations and novel nomograms to predict the number of oocytes that will be retrieved using patients' age, serum levels of basal FSH and AMH, and AFC. Methods: We analyzed a database containing clinical and laboratory information of 141 stimulated in vitro fertilization (IVF) cycles performed at a university-based hospital between September 2009 and December 2013. We used generalized linear models for prediction of the number of oocytes. Results: Age, basal serum FSH level, serum AMH level, and AFC were significantly related to the number of oocytes retrieved according to the univariate and multivariate analyses. The equations that predicted the number of oocytes retrieved (log scale) were as follows: model (1) $3.21-0.036{\times}(age)+0.089{\times}(AMH)$, model (2) $3.422-0.03{\times}(age)-0.049{\times}(FSH)+0.08{\times}(AMH)$, model (3) $2.32-0.017{\times}(age)+0.039{\times}(AMH)+0.03{\times}(AFC)$, model (4) $2.584-0.015{\times}(age)-0.035{\times}(FSH)+0.038{\times}(AMH)+0.026{\times}(AFC)$. model 4 showed the best performance. On the basis of these variables, we developed nomograms to predict the number of oocytes that can be retrieved. Conclusion: Our nomograms helped predict the number of oocytes retrieved in stimulated IVF cycles.

• 셀메드
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• 제11권4호
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• pp.21.1-21.9
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• 2021

Background: Unani System of Medicine (USM) has its origin to Greece. To ensure and develop the quality, authenticity of Unani drugs, standardization on modern analytical parameter is essential requirement for drugs. Objectives: The aimed of the present study was to develop a standard profile of "Qurṣ-e-Mafasil" by systematic study through authenticated ingredients, pharmacognostic identification followed by physicochemical, TLC, HPTLC fingerprinting analysis as per standard protocol. Material and Methods: In this study three batches of "Qurṣ-e-Mafasil" QM were prepared by standard method as per UPI had been followed by organoleptic properties of formulation such as appearance, color, odor, taste. Powder Microscopy and physicochemical studies were carried out such as Uniformity of weight, Friability, Disintegration time, hardness, LOD, ash vales and extractive values in like aqueous, alcohol & hexane. Further qualitative tests such as Thin-Layer Chromatography (TLC), and High-Performance Thin Layer Chromatography (HPTLC) studies were also carried out to develop fingerprint pattern of the alcoholic solvent extract of QM. Phytochemical screening was carried out in different solvent extracts such as alcoholic, aqueous and chloroform extracts to detect the presence phytoconstituents in the formulation QM. Heavy metals, Microbial Load Contamination and pesticidal residues were also determined. Results: Qurṣ-e-Mafasil showed tablet-like appearance, light brown colour, mild pungent odour and acrid taste. Uniformity of weight (mg), friability (rpm), and hardness (kg/cm) and disintegration time was ranged between (500 to 503), (0.0340 to 0.038), (8.40 to 8.67) and (4-5 minutes) respectively for the three batches. Loss in weight on drying at 105℃ was ranged between (8.3425 to 8.7346). Extracted values were calculated in distilled water ranged between (30.9091 to 31.4358), hexane (1.1419 to 1.4281), and alcohol (3.3352 to 3.3962). The ash values recorded were ranged between (3.7336 to 3.8378), and acid insoluble ash (0.5859 to 0.6112).

• 대한한방내과학회지
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• 제31권4호
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• pp.892-900
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• 2010

Objectives : To save the lives of patients with cardiac arrests, CPR must be performed rapidly and precisely. Regarding its critical necessity, there is a growing tendency to encourage whomever witnesses the cardiac arrest to perform basic CPR. However, the attitude toward basic CPR nor its current state of education in Korean Oriental Medical arena, which is one of the dual axes unique to Korean medical system, are not known. This is a kind of pilot study to research attitudes toward and the educative effect of basic CPR among oriental medical doctors in Korea. Methods : We carried out surveys and tests targeting nineteen apprentice doctors working in Dongguk University Ilsan Oriental Hospital, who were receiving training for 'AHA BLS course for healthcare providers', on the attitude toward and educative effect of basic CPR before and after the education. Results : The pre-educational survey showed that most of the participants felt the necessity to be trained in the BLS course, were not confident about performing CPR, and not well-acquainted with the whole process of performing CPR. After education, however, none of them responded with a lack of confidence to perform basic CPR, and the score of the confidence to perform basic CPR was significantly increased, too (from $2.05{\pm}0.71$ to $4.05{\pm}0.40$, n=19, p<0.001). Moreover, all of them answered they were satisfied with this BLS course, and it aroused their sense of responsibility as oriental medical doctors. All the participants passed the exam, and their average score for BLS scheme performance was $28.2{\pm}1.3$. Conclusions : It is necessary, in the future, to set up a management system for intensive, regular and continuous reeducation and expand the research on the perception and attitude targeting larger numbers and more multilevel groups of oriental medical doctors.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.1015-1026
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• 2019

Objective: The objective of this study was to evaluate three different degrees of white striping (WS) addressing their automatic assessment and customer acceptance. The WS classification was performed based on a computer vision system (CVS), exploring different machine learning (ML) algorithms and the most important image features. Moreover, it was verified by consumer acceptance and purchase intent. Methods: The samples for image analysis were classified by trained specialists, according to severity degrees regarding visual and firmness aspects. Samples were obtained with a digital camera, and 25 features were extracted from these images. ML algorithms were applied aiming to induce a model capable of classifying the samples into three severity degrees. In addition, two sensory analyses were performed: 75 samples properly grilled were used for the first sensory test, and 9 photos for the second. All tests were performed using a 10-cm hybrid hedonic scale (acceptance test) and a 5-point scale (purchase intention). Results: The information gain metric ranked 13 attributes. However, just one type of image feature was not enough to describe the phenomenon. The classification models support vector machine, fuzzy-W, and random forest showed the best results with similar general accuracy (86.4%). The worst performance was obtained by multilayer perceptron (70.9%) with the high error rate in normal (NORM) sample predictions. The sensory analysis of acceptance verified that WS myopathy negatively affects the texture of the broiler breast fillets when grilled and the appearance attribute of the raw samples, which influenced the purchase intention scores of raw samples. Conclusion: The proposed system has proved to be adequate (fast and accurate) for the classification of WS samples. The sensory analysis of acceptance showed that WS myopathy negatively affects the tenderness of the broiler breast fillets when grilled, while the appearance attribute of the raw samples eventually influenced purchase intentions.

• 한국강구조학회 논문집
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• 제9권3호통권32호
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• pp.363-375
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• 1997

절취된 세로보를 갖는 강철도교량의 바닥판에서의 피로거동 및 손상시 보수 보강의 효과를 연구하기 위해 8개 대형시험체에 대한 모형시험을 수행하였다. 실교량을 대상으로 실동응력을 측정하여 기본 응력범위 빈도히스토그램을 작성하고 이에 의한 변동응력의 등가응력범위를 산출하였다. 이 등가응력범위를 기준으로 피로시험의 응력변동범위의 크기를 조정하면서 정적 및 피로시험을 보강전과 보수 보강후로 구분하여 실시하였다. 정적시험에 의하면 재하하중의 크기가 등가실동응력 수준인 시험체의 경우에서 이미 허용응력과 비슷한 응력을 나타내므로서 피로균열의 발생조건을 충족하고 있었다. 손상된 시험체에 대해 다양한 보수 및 보강을 실시하여, 각각의 결과를 비교검토하였다. 그 결과 보수효과는 stop hole을 천공하고 고장력볼트를 체결한 경우에 피로균열성장의 지체효과가 뚜렷하게 나타났다. 한편 보강효과는 휨의 지배를 받는 세로보의 경우 인장측 플랜지의 보강이 효과적이며, 복부의 보강은 보강방법으로 적절하지 않음을 알 수 있었다. 또한 직각절취된 세로보의 피로설계등급은 우리나라 시방서 피로설계규정의 E등급에 해당한다는 것을 확인할 수 있었다.