• Nuclear Engineering and Technology
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• 제36권3호
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• pp.219-228
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• 2004

[1] and [2] present an approach to diagnosing possible defects in the mechanical systems of a nuclear power plant. In this paper, by using a fault library as a database and training data, we develop a diagnostic algorithm 1) to decide whether an Air Operated Valve system is sound or not and 2) to identify the defect from which an Air-Operated Valve system suffers, if any. This algorithm is composed of three stages: a neural net stage, a non-neural net stage, and an integration stage. The neural net stage is a simple perceptron, a pattern-recognition module, using a neural net. The non-neural net stage is a simple pattern-matching algorithm, which translates the degree of matching into a corresponding number. The integration stage collects each output and makes a decision. We present a simulation result and confirm that the developed algorithm works accurately, if the input matches one in the database.

• 한국전자파학회논문지
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• 제26권3호
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• pp.283-291
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• 2015

본 논문에서는 높은 Q 인자를 갖는 수동 회로의 정합 특성을 향상시키기 위한 비 포스터 정합의 핵심 요소인 부성 임피던스 변환기를 설계하여 구현하였다. 제안된 부성 임피던스 변환기는 Linvill의 트랜지스터 부성 임피던스 변환기 회로를 채택하여 구현하였다. 전력 이득 소자와 양성 피드백으로 구성된 부성 임피던스 변환기는 동작이 매우 불안정하여 발진 등으로 인해 제작 결과를 쉽게 예측하기 어렵기 때문에, 하이브리드 회로로 먼저 구현하여 가능성을 살펴본 뒤 집적회로로 설계하여 제작하였다. 상용 $0.18{\mu}m$ SiGe BiCMOS 공정을 사용하여 제작하였고, 목표로 하는 700~960 MHz 대역에서 리액턴스를 상쇄하여 비 포스터 정합이 이뤄짐을 확인할 수 있었다.

• 한국항공우주학회지
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• 제42권3호
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• pp.191-198
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• 2014

본 연구는 유체-고체 연성 해석이 활발히 진행되고 있는 고체로켓의 3차원 연소실 상경계면 형상에 대해 정보 전달 기법 중 하나인 공통세분 기법의 적용을 목적으로 수행되었다. 본 기법은 불일치하는 경계면간 정보 전달에도 보존성과 정확도를 동시에 만족시킬 수 있다는 장점을 갖는다. 기법 구현은 상경계면에 공통표면을 구성하고 특정 오차를 최소화 시키는 최소화 내삽법을 적용하는 과정으로 수행되었다. 이를 바탕으로 다양한 다차원 상경계면 형상에서 연속 및 불연속 함수를 이용한 정보 전달 실험을 수행하였고, 다른 기법들과 해석 결과를 비교하였다.

• 지역사회간호학회지
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• 제31권spc호
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• pp.534-548
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• 2020

Purpose: This study was conducted to evaluate the prevalence and lifestyle habits of cardiovascular disease (CVD) according to the type of disability in Korean adults compared to adults without disability. Methods: This study was secondary data analysis using the National Health check-up database from 2010 to 2013. Among the total 395,627 adults aged 30~80, the physically disabled (n=21,614) and the mentally disabled (n=1,448) who met the diagnosis criteria were extracted and compared with non-disabled (n=372,565) through 1:2 propensity score matching for nine characteristics. Results: Prior to matching, the prevalence of CVD was 34.4% in individuals without disabilities, accounting for 53.8% in those with physical disabilities and 22.4% in those with mental disabilities, showing significant differences between groups (p<.001). After matching, compared to the individuals without disability, those with physically disabled had significantly higher prevalence of CVD and the average number of CVD (p<.001). The prevalence of hypertension, diabetes, and vascular disease was significantly higher in the physically disabled (p<.05). Drinking was significantly higher in the non-disabled than in the physically and mentally disabled, and smoking was more in the non-disabled than in the mentally disabled. Physical activity was found to be significantly less in both the physically and mentally disabled than in the non-disabled (p<.01). Conclusion: It is necessary to confirm the differences in the prevalence of CVD risk factors and lifestyle according to the type of disability, suggesting the development and verification of health promotion programs including physical activity for CVD prevention in the disabled with CVD risk factors.

• 한국통신학회논문지
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• 제14권2호
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• pp.146-154
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• 1989

비대칭2선 마이크로스트립선으로 구성된 DC블록(비대칭 DC블록)을 GaAs FET의 입력과 출력측에 사용하여 임피던스 정합을 시키는 새로운 증폭기 설계방법을 제시하였다. 중심파수 4(GHz)에 대하여 대칭이 되는 주파수특성을 얻을 수 있었다. 비대칭 DC블록은 \ulcorner케패시터의 DC블록의 역할뿐만 아니라 임피던스 정합도 할 수 있다는 큰 장점으로 MC 및 MMIC 용으로 사용 가능하다.

• 산업공학
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• 제23권2호
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• pp.164-175
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• 2010

In logistics e-marketplaces, brokerage agents intermediate empty vehicles and freights registered by car owners and shippers. In the previous research, we proposed constant periodic/fixed matching algorithms for the logistics brokerage agents with the objective of minimizing the total transportation lead time and the transportation due date tardiness of freights(Jeong, 2004; Jeong, 2007). However, the constant type algorithms cannot consider changes in the balance status of an e-marketplace, i.e. the difference between the numbers of freights and vehicles to wait for matching, because they use non-changing matching periods and amounts. In this paper, we propose variable type algorithms for the logistics brokerage agent, in which the matching periods and amounts are changed continuously by considering the balance status between the freights and vehicles. In order to compare performance of the variable type algorithms to the previous constant type algorithms, we carried out computational experiments on various problem instances. The results show that the variable type algorithms give better performance than the constant type algorithms. We can expect that the logistics brokerage agents can improve their performance by using the proposed variable periodic/fixed matching algorithms.

• 한국생산제조학회지
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• 제22권1호
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• pp.150-155
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• 2013

This work present a new method of sealing inspection system for vehicle in which foam rubber materials are used for sealing the vehicle parts. This system is composed from a devices comprising non-contact and real-time scanning on visual inspection in machine parts. We have been investigated qualitative factors that influenced on sealing system of vehicle structure which flexibly attenuated vibration and plenty of foam rubber materials having elastic property. However, there are different factors which still depended on outdated technique (personnel subjective judgment) in the performance inspection of rubber parts, specially for cross section inspection. Through a newly developed inspection system which recently applied for the production line, we successfully achieved more effective results of matching rate by about 80 % in the sealing performance inspection with 0.7% to 1.4% in the repeated errors. These are resulted from non-contacted response by CCD camera and vision program using geometry matching method. We expect that this system may be widely applied in the strict inspection parts of more diverse cross-section in future.

• 대한치과기공학회지
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• 제46권3호
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• pp.93-100
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• 2024

Purpose: This study aimed to generate virtual mandibular first molars using deep learning technology, specifically deep convolutional generative adversarial network (DCGAN), and evaluate the accuracy and reliability of these virtual teeth by analyzing their morphological characteristics. These morphological characteristics were classified based on various evaluation criteria, facilitating the assessment of deep learning-based dental prosthesis production's practical applicability. Methods: Based on our previous research, 1,000 virtual mandibular first molars were generated, and based on morphological criteria, categorized as matching, non-matching, and partially matching. The generated first molars or the categorization of the generated molars were analyzed through the expert judgment of dental technicians. Results: Among the 1,000 generated virtual teeth, 143 (14.3%) met all five evaluation criteria, whereas 76 (7.6%) were judged as completely non-matching. The most frequent issue, with 781 (78.1%) instances, including some overlapping instances, was related to occlusal buccal cusp discrepancies. Conclusion: The study reveals the potential of DCGAN-generated virtual teeth as substitutes for real teeth; however, additional research and improvements in data quality are necessary to enhance accuracy. Continued data collection and refinement of generation methods can maximize the practicality and utility of deep learning-based dental prosthesis production.

• 한국멀티미디어학회논문지
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• 제12권6호
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• pp.785-793
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• 2009

This paper proposes a signature using dominant singular values for video sequence matching. By considering the input image as matrix A, a partition procedure is first performed to separate the matrix into non-overlapping sub-images of a fixed size. The SVD(Singular Value Decomposition) process decomposes matrix A into a singular value-singular vector factorization. As a result, singular values are obtained for each sub-image, then k dominant singular values which are sufficient to discriminate between different images and are robust to image size variation, are chosen and normalized as the signature for each block in an image frame for matching between the reference video clip and the query one. Experimental results show that the proposed video signature has a better performance than ordinal signature in ROC curve.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.230-234
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• 1997

The matching pursuit (MP) algorithm developed by S. Mallat and Z. Zhang is applied to magnetic resonance (MR) imaging. Since matching pursuit is a greedy algorithm to find waveforms which are the best match for an object-signal, the signal can be decomposed with a few iterations. In this paper, we propose an application of the MP algorithm to the MR imaging to reduce imaging time. Inner products of residual signals and selected waveforms in the MP algorithm are derived from the MR signals by excitation of RF pulses which are fourier transforms of selected waveforms. Results from computer simulations demonstrate that the imaging time is reduced by using the MP algorithm and further a progressive reconstruction can be achieved.