• Nuclear Engineering and Technology
• /
• 제55권2호
• /
• pp.655-668
• /
• 2023

In radiography, an antiscatter grid is a well-known device for eliminating unexpected x-ray scatter. We investigate a new stationary grid artifact suppression method based on a nonsubsampled contourlet transform (NSCT) incorporated with Gaussian band-pass filtering. The proposed method has an advantage that extracts the Moiré components while minimizing the loss of image information and apply the prior information of Moiré component positions in multi-decomposition sub-band images. We implemented the proposed algorithm and performed a simulation and an experiment to demonstrate its viability. We did this experiment using an x-ray tube (M-113T, Varian, focal spot size: 0.1 mm), a flat-panel detector (ROSE-M Sensor, Aspenstate, pixel dimension: 3032 × 3800 pixels, pixel size: 0.076 mm), and carbon graphite-interspaced grids (JPI Healthcare, 18 cm × 24 cm, line density: 103 LP/inch and 150 LP/inch, ratio: 5:1, focal distance: 65 cm). Our results indicate that the proposed method successfully suppressed grid artifacts by reducing them without either reducing the spatial resolution or causing negative side effects. Consequently, we anticipate that the proposed method can improve image acquisition in a stationary grid x-ray system as well as in extended x-ray imaging.

• 대한한방부인과학회지
• /
• 제22권4호
• /
• pp.149-156
• /
• 2009

Purpose: To evaluate the association of sasang constitution with bone mineral density (BMD) in postmenopausal Korean women. Methods: Sasang constitution was analyzed by Phonetic System for Sasang Constitution in 92 postmenopausal Korean. The BMD was checked using dual-energy x-ray absorptiometer(DEXA) at lumbar spine, femur neck. Results: Bone mineral density of lumbar spine(T-score) according to Sasang constitution was Taeumin($-1.12{\pm}1.26$), Soyangin($-1.30{\pm}1.06$), Soeumin($-1.51{\pm}1.21$). Bone mineral density of femur neck(T-score) according to Sasang constitution was Taeumin($-0.76{\pm}1.07$), Soyangin($-0.92{\pm}0.81$), Soeumin($-0.84{\pm}0.86$). Conclusion: There was significant relationship between sasang constitution and BMD of femur neck. There was no significant relationship between sasang constitution and BMD of lumbar spine.

• 대한한방부인과학회지
• /
• 제22권3호
• /
• pp.197-204
• /
• 2009

Purpose: Obesity is the major risk factor of the heart disease and the metabolic disease. And many obese women have dysfunction of the endocrine system. There are many reports about oriental obesity treatment program. In clinics, the electroacupuncture with exercise is believed more effective. But the difference of weight loss as exercise and women was not studied. Methods: The subjects were 75 young women who visited Kangnam Kyunghee hospital for obesity management from March 2006 to July 2008. Six treatments had performed, the weight loss checked at every treatment. 52 women treated by oriental obesity treatment with exercise, 23 women treated therapy without exercise. As the exercise and the age, the weight loss was compared. Results: The weight loss of electroacupuncture with exercise was higher than that of electroacupuncture without exercise, but was not significant. The weight loss of perimenopausal women was significantly low. Conclusion: The comparison of electroacupuncture with exercise and electroacupuncture without exercise was not significantly different. The weight loss of the older women would be less than the weight loss of the younger.

• 대한한방부인과학회지
• /
• 제22권1호
• /
• pp.140-147
• /
• 2009

Purpose: This study was conducted to investigate the relationship between primary dysmenorrhea. Methods: Intensity of dysmenorrhea was evaluated by scoring system of Andersch and Milsom. Anger state, trait, expression of the patients suffering from dysmenorrhea was measured by STAXI-K. And each value was analyzed by ANOVA testm as to intensity of dysmenorrhea, student t test as to existence of dysmenorrhea. Results: The numerical value of anger expression in the primary dysmenorrhea existent group was significantly higher than that in the primary dysmenorrhea non-existent group. There were significant differences among the numerical value of anger expression in the groups classified as intensity of primary dysmenorrhea, the value of three positive group() was significantly higher than that of negative group(-). Conclusion: This study showed the relationship between anger expression and primary dysmenorrhea. But there was no clue to find out their causal relationship, because this study was cross-sectional. So further study will be needed to prove the causality between them. And more precise scale has to been developed to evaluate various type of anger accurately.

• 산업융합연구
• /
• 제21권3호
• /
• pp.117-127
• /
• 2023

본 연구는 코로나-19 범유행시 임산부의 생생한 경험을 현상학적 접근을 통해 탐구함으로 임산부의 스트레스 경험을 이해하기 위한 질적연구이다. 연구대상자는 COVID-19 범유행 기간 동안 임신한 임산부 12명을 대상자로 선정하여 심층면담하였다. 참여자의 인터뷰는 2022년 6월부터 10월까지 진행하였으며, Colaizzi (1978) 분석 방법을 사용하여 Taguette 프로그램을 통해 데이터를 분석하였다. 분석된 결과로는 경험의 범주가 4개의 주제와 12개의 하위 주제로 도출되었다. 주요 주제는 부정확한 정보로 인한 혼란, 무너진 산전관리, 통제된 삶으로 인한 스트레스, 적응해가는 몸과 마음으로 나타났다. 임산부의 건강을 위한 사회적 지원과 안정적인 의료시스템 구축이 전반적으로 이루어져야 할 필요가 있음이 확인되었다. 이를 뒷받침하기 위해서는 후속 연구들이 더 필요하다.

• 디지털산업정보학회논문지
• /
• 제19권2호
• /
• pp.27-37
• /
• 2023

The purpose of this study was to analyze the effect of the online extracurricular program operated by the university. The program contents applied in the study included learning strategies such as time management, goal setting, note taking, and memorization methods. The program used in the study was operated in an online environment, and the content was developed between 27 and 29 minutes. The developed contents can be taken using the learning management system. The variables selected to analyze the effects of this program were learning strategies and learning flow, and satisfaction was also included to examine the responses of program participants. The results of the study are as follows. First, learning strategies and learning flow showed statistically significant differences. This result is because the content was composed of meaningful sub-topics by selecting the elements necessary for learning activities. Second, as a result of program satisfaction analysis, it was confirmed that the average for all questions was high. Among them, the average of the item that the theme and contents of the program were useful was the highest. Third, open responses were analyzed by classifying them into cognitive and affective domains. In the cognitive domain, meanings such as knowledge, understanding, and application were presented as keywords, and in the affective domain, a number of keywords for motivation and attitude change were presented. This study is significant in that it provided practical programs necessary for university freshmen and analyzed their effects.

• Computers and Concrete
• /
• 제31권5호
• /
• pp.385-394
• /
• 2023

Displacement is an important element for evaluating the stability and failure mechanism of hydraulic structures. Digital image correlation (DIC) is a useful technique to measure a three-dimensional displacement field using two cameras without any contact with test material. The objective of this study is to evaluate the behavior of stacked geotextile tubes using the DIC technique. Geotextile tubes are stacked to build a small-scale temporary dam model to exclude water from a specific area. The horizontal and vertical displacements of four stacked geotextile tubes are monitored using a dual camera system according to the upstream water level. The geotextile tubes are prepared with two different fill materials. For each dam model, the interface layers between upper and lower geotextile tubes are either unreinforced or reinforced with a cementitious binder. The displacement of stacked geotextile tubes is measured to analyze the behavior of geotextile tubes. Experimental results show that as upstream water level increases, horizontal and vertical displacements at each layer of geotextile tubes initially increase with water level, and then remain almost constant until the subsequent water level. The displacement of stacked geotextile tubes depends on the type of fill material and interfacial reinforcement with a cementitious binder. Thus, the proposed DIC technique can be effectively used to evaluate the behavior of a hydraulic structure, which consists of geotextile tubes.

• 한국전자통신학회논문지
• /
• 제17권2호
• /
• pp.299-308
• /
• 2022

최근 에너지전환정책은 소규모 태양광발전기 수량을 증가시키고 있다. 계통운영자는 이러한 소규모 태양광 발전량을 정확하게 예측하기가 어렵고 급전계획을 방해할 수도 있으며, 결과적으로 비용상승이 초래될 것이다. 이러한 문제를 해결하는 방법으로 소규모 태양광발전소에서 생산되는 발전량, 전압제어에 대하여 불확실성을 줄이고 예비전력을 공급하는 소규모 태양광발전소의 집합체로서 가상발전소가 떠오르고 있다. 본 연구에서는 가상발전소 클라우드 요금산정을 위하여 순현재가치법과 수익성지수법을 사용하며, 두 종류의 비용평가법 계산결과가 상세하게 설명된다. 계산결과로부터 수익성지수가 1.22로 산정되어 수익성을 확보한 것으로 나타났으며, 순현재가치가 수익성을 충분히 만족시키기 때문에 중개사업자 관점에서 매력적이다.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2021년도 춘계학술발표대회
• /
• pp.282-284
• /
• 2021

최근 4차 산업혁명으로 의료빅데이터 기반으로 한 AI 기술이 급속도로 발전하고 있다. 특히, 의료영상을 기반으로 병변을 탐색, 분활 및 정량화 그리고 자동진단 및 예측 관련된 기술이 AI 제품으로 출시되고 있다. AI 기술개발은 많은 학습데이터가 요구되며, 임상검증에 단일기관에서 2개 이상 기관의 검증이 요구되고 있다. 그러나 아직까지도 단일기관에서 학습용 데이터와 테스트, 검증용 데이터를 달리하여 기술개발에 활용하고 있다. 본 논문은 AI 기술개발에 필요한 영상데이터에 대한 표준화된 데이터셋 변환 및 관리를 위한 시스템에 대해 기술한다. 다기관 데이터를 수집하기 위해서는 각 기관의 의료영상 데이터 수집 및 저장하는 기준이 명확하지 않아 표준화 작업이 필요하다. 제안한 시스템은 기관 또는 다기관 연구 그룹의 의료영상데이터를 표준화하여 저장할 수 있을 뿐만 아니라 의료영상 뷰어 및 의료영상 리스트를 통해 연구자가 원하는 의료영상 데이터 셋을 검색하여 다양한 데이터셋으로 제공할 수 있기 때문에 수집 및 변환 그리고 관리까지 지원할 수 있는 시스템으로 영상기반의 머신러닝 연구에 활력을 불어넣을 수 있을 것으로 기대하고 있다.

• Journal of Information Processing Systems
• /
• 제19권3호
• /
• pp.289-301
• /
• 2023

Due to the development and dissemination of modern technology, anyone can easily communicate using services such as social network service (SNS) through a personal computer (PC) or smartphone. The development of these technologies has caused many beneficial effects. At the same time, bad effects also occurred, one of which was the spam problem. Spam refers to unwanted or rejected information received by unspecified users. The continuous exposure of such information to service users creates inconvenience in the user's use of the service, and if filtering is not performed correctly, the quality of service deteriorates. Recently, spammers are creating more malicious spam by distorting the image of spam text so that optical character recognition (OCR)-based spam filters cannot easily detect it. Fortunately, the level of transformation of image spam circulated on social media is not serious yet. However, in the mail system, spammers (the person who sends spam) showed various modifications to the spam image for neutralizing OCR, and therefore, the same situation can happen with spam images on social media. Spammers have been shown to interfere with OCR reading through geometric transformations such as image distortion, noise addition, and blurring. Various techniques have been studied to filter image spam, but at the same time, methods of interfering with image spam identification using obfuscated images are also continuously developing. In this paper, we propose a deep learning-based spam image detection model to improve the existing OCR-based spam image detection performance and compensate for vulnerabilities. The proposed model extracts text features and image features from the image using four sub-models. First, the OCR-based text model extracts the text-related features, whether the image contains spam words, and the word embedding vector from the input image. Then, the convolution neural network-based image model extracts image obfuscation and image feature vectors from the input image. The extracted feature is determined whether it is a spam image by the final spam image classifier. As a result of evaluating the F1-score of the proposed model, the performance was about 14 points higher than the OCR-based spam image detection performance.