• 융합신호처리학회논문지
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• 제4권3호
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• pp.1-6
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• 2003

탱크나 경유자동차 등과 같이 지상에서 이동하는 차량들의 엔진소음은 광대역 특성을 갖고 또한 지형의 다양성 및 표적의 이동으로 인한 다양한 반사 등으로 변화가 심하기 때문에 탐지나 추적이 쉽지 않다 또한 전장 등과 같이 복잡한 환경에서는 배열안테나의 위치 선정 등의 어려움으로 앨리아싱이 일어날 수도 있다. 본 논문에서는 수동 배열 안테나의 성긴 배치로 인한 심각한 공간 앨리아싱 조건하에서 광대역 신호를 방사하는 이동체의 탐지 및 추적 문제에 대해서 연구하였다. 여기서 서브밴드 MUSIC 알고리즘에 근거한 고해상도의 방위각 추정 알고리즘을 개발하였다. 이 것은 공간 앨리아싱으로 인하여 표적의 방위각 추정 값이 변할 때에도 실제의 방위각을 추정할 수 있는 알고리즘이다 결과적으로 이 알고리즘이 성긴 안테나 배치로 인한 공간 앨리아싱 영향을 극복하고 위치 추정을 개선함을 보인다.

• 대한의용생체공학회:의공학회지
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• 제30권2호
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• pp.153-161
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• 2009

Mammogram is one of the important techniques for mass detection, which is the early diagnosis stage of a breast cancer. Especially, the CAD(Computer Aided Diagnosis) using mammogram improves the working performance of radiologists as it offers an effective mass detection. There are two types of CAD systems using mammogram; automatic and semi-automatic CAD systems. However, the automatic segmentation is limited in performance due to the difficulty of obtaining an accurate segmentation since mass occurs in the dense areas of the breast tissue and has smoother boundaries. Semi-automatic CAD systems overcome these limitations, however, they also have problems including high FP (False Positive) rate and a large amount of training data required for training a classifier. The proposed system which overcomes the aforementioned problems to detect mass is composed of the suspected area selection, the level set segmentation and SVM (Support Vector Machine) classification. To assess the efficacy of the system, 60 test images from the FFDM (Full-Field Digital Mammography) are analyzed and compared with the previous semi-automatic system, which uses the ANN classifier. The experimental results of the proposed system indicate higher accuracy of detecting mass in comparison to the previous systems.

• 한국식품영양과학회지
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• 제26권3호
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• pp.521-527
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• 1997

This study was aimed to investigate the nutriational status of Korean female college students who are attending school at a longdistance. Physique calssification by anthropomethic indexes, Body mass index(BMI) & Brocas' index and the body fat distrubition were investigated. The energy balance was also examined comparing caloric intake with caloric expenditure. The result of this study are followings; (1) Average height and weight were 158±17.8 cm, 51.7±7.8 kg. This results were not quite different from '84 Korean Adult Standard of 159.5cm, 52.5kg. (2) By Broca's index, 25.89% of subjects was underweight 67.0% was normal weight and 7.06 was overweight. By BMI, 40% of subjects was underweight, 58.8% was normal weight and 1.2% was overweight. (3) According to % fat measured. By BIA, 7% in subjects was underweight, 64.2% was normal weight, 22% was overweight and 6.1% was obesity. This result differed from BMI's result. It may be measurement error due to the difficulty of removing metal sticking to underwear and tooth correction. (4) The intakes of the nutrients except protein, P, vitamin B₁ complexes, were lower than the intakes indicated by Korean Recommended Allowances. 95) Average caloric intake a day was 1545±394.4 kcal, which was much lower than the RDA. The caloric expenditure was much more than caloric intake, which showed negative energy balance in the subjects of this study.

• 한국항해항만학회지
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• 제28권1호
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• pp.91-96
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• 2004

해양지리정보의 가장 핵심 단위인 피쳐가 근본적으로 동일함에도 불구하고 각 응용분야별로 그 피쳐의 의미와 내용을 분류하고 기술하는 방식이 서로 다르기 때문에 사용자 측면에서 매우 불합리하다. 이에 현재 세계적으로 생산자 및 이용자가 공통적으로 사용할 수 있게 피쳐들을 표준화된 방식으로 분류하고 명명, 정의하는 피쳐카탈로그화가 활발하게 진행되고 있는 추세이며, 본 논문에서는 해양지리정보의 활성화를 위해 "ISO 19110 - Methodology for Feature Cataloguing" 표준문서를 분석하여 피쳐에 대한 구성요소와 정의방식을 연구하였고, 도출된 방법을 통해 해양지리정보 피쳐카탈로그를 작성하는 표준안과 그 예를 제시하였다.

• Journal of Welding and Joining
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• 제25권1호
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• pp.57-62
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• 2007

In the coarse grained HAZ of conventional TiN steel, most TiN particles are dissolved and austenite grain growth easily occurrs during high heat input welding. To avoid this difficulty, thermal stability of TiN particles is improved by increasing nitrogen content in EH36-TM steel. Increased thermal stability of TiN particle is helpful for preventing austenite grain growth by the pinning effect. In this study, the mechanical properties and microstructures of high heat input welded Tandem EGW joint in EH36-TM steel with high nitrogen content were investigated. The austenite grain size in simulated HAZ of the steel at $1400^{\circ}C$ was much smaller than that of conventional TiN steel. Even for high heat input welding, the microstructure of coarse grained HAZ consisted of fine ferrite and pearlite and the mechanical properties of the joint were sufficient to meet all the requirements specified in classification rule.

• 방사성폐기물학회지
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• 제4권4호
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• pp.385-391
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• 2006

연구용원자로 해체비용은 해체대상물에 대한 특성 및 제원에 맞게 해체작업을 분류하고 구성요소를 설정하여 단위비용인자를 바탕으로 한 공학적 비용 산정 방법으로 해체비용을 산정한다. 연구용원자로에 대한 해체비용은 크게 인건비, 장비 및 재료비로 구성이 되는데 해체작업에 소요되는 인건비는 해체대상물에 소요되는 작업시간을 바탕으로 계산을 한다. 본 논문에서는 연구용원자로 해체비용 산정 시 인건비 계산에 필요한 단위비용인자 및 작업 난이도 인자를 산출하였다.

• Archives of Plastic Surgery
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• 제37권6호
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• pp.779-782
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• 2010

Purpose: As the evaluation of the preoperative sensibility in the orbitozygomatic complex fracture, used by most surgeons, depends on the patient's subjective judgements, it is difficult to make generalization and to use it as an objective evaluation method. We used the blink reflex study to objectively evaluate injury to the infraorbital nerve. Methods: From December 2008 to November 2009, a total of 16 patients underwent the patient's subjective report on sensory symptoms and the blink reflex study preoperatively. Among patients having orbitozygomatic complex fracture of type III or more according to Henderson's classification and simultaneously suspected as being injured along the infraorbital nerve pathway, patients who had difficulty in checking preoperative sensibility and said 'normal sensibility' were selected as candidates. Results: Fifteen patients showed abnormal R1 on the fracture side. These results suggested that most of patients had injury to the infraorbital nerve. Conclusion: Contrary to the existing tests, the blink reflex study is a useful diagnostic tool in reflecting injury to the infraorbital nerve objectively.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.827-838
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• 2023

Centrifugal pump is a key part of nuclear power plant systems, and its health status is critical to the safety and reliability of nuclear power plants. Therefore, fault diagnosis is required for centrifugal pump. Traditional fault diagnosis methods have difficulty extracting fault features from nonlinear and non-stationary signals, resulting in low diagnostic accuracy. In this paper, a new fault diagnosis method is proposed based on the improved particle swarm optimization (IPSO) algorithm-based variational modal decomposition (VMD) and relevance vector machine (RVM). Firstly, a simulation test bench for rotor faults is built, in which vibration displacement signals of the rotor are also collected by eddy current sensors. Then, the improved particle swarm algorithm is used to optimize the VMD to achieve adaptive decomposition of vibration displacement signals. Meanwhile, a screening criterion based on the minimum Kullback-Leibler (K-L) divergence value is established to extract the primary intrinsic modal function (IMF) component. Eventually, the factors are obtained from the primary IMF component to form a fault feature vector, and fault patterns are recognized using the RVM model. The results show that the extraction of the fault information and fault diagnosis classification have been improved, and the average accuracy could reach 97.87%.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.89-92
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• 2021

제조 현장에서 설비의 이상이나 고장은 곧 제품의 결함을 발생시키는 요인이 된다. 최근 스마트팩토리 서비스의 확산에 따라 고장을 예측 및 방지를 위한 인공지능 기반의 애플리케이션에 대한 연구가 활발히 이어지고 있으나, 일반적으로 설비의 이상이나 고장 데이터는 정상에 비해 그 개수가 현저히 적어 분류 모델 개발에 큰 어려움이 있다. 본 논문에서는 오토인코더 모델의 입력과 출력 간 차이를 이용한 제조 현장의 MCT 이상탐지 알고리즘을 제안하고 성능을 분석하였다. 해당 알고리즘은 비정상 데이터가 존재하지 않는 MCT 제조 데이터에서 정상 데이터에 대한 특징만을 이용하여 비정상을 탐지한다.

• 플랜트 저널
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• 제6권1호
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• pp.64-70
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• 2010

From 2000, the world plant market, especially plant developing business related to oil and gas, has been increasing. Domestic construction companies advance to overseas plant construction market actively, and proportioning to this, an importance of utility construction is increasing. However, the project becomes large and high-tech, and many companies experience difficulty of project management due to relatively high risk of overseas construction. In this study, we built the standard process with which domestic company can evaluate the risk of overseas plant utility construction. Primary factors for risk evaluation is derived, classification system is made out, primary factor is analyzed, and counter plan is suggested. And thorough management of risk is performed by risk management organization that manages the risks, risk control methods, reports and monitors through risk sheet and risk action log from the start of project to the end.