• 한국항해항만학회지
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• 제28권9호
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• pp.815-820
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• 2004

In this paper, after analyzing other models with their advantages and disadvantages, we proposed a simple parametric model for calculating wind speed & direction and wave height & direction at any location around the typhoon at sea. The proposed wind-field model of typhoon is asymmetric, and consists of a circular symmetric wind-field caused by the pressure gradient of stationary typhoon and a moving wind-field caused by the movement of typhoon. By verifying this model through observed data, we found that it is accurate enough to develop the simulation software for training students and seafarers so as to take appropriate actions while being faced with the typhoon at sea.

• 한국지능시스템학회논문지
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• 제14권2호
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• pp.216-221
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• 2004

This paper describes an optimal synthesis method of binary neural network for pattern recognition. Our objective is to minimize the number of connections and the number of neurons in hidden layer by using a Newly Expanded and Truncated Learning Algorithm (NETLA) for the multilayered neural networks. The synthesis method in NETLA uses the Expanded Sum of Product (ESP) of the boolean expressions and is based on the multilayer perceptron. It has an ability to optimize a given binary neural network in the binary space without any iterative learning as the conventional Error Back Propagation (EBP) algorithm. Furthermore, NETLA can reduce the number of the required neurons in hidden layer and the number of connections. Therefore, this learning algorithm can speed up training for the pattern recognition problems. The superiority of NETLA to other learning algorithms is demonstrated by an practical application to the approximation problem of a circular region.

• 대한가정학회지
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• 제33권3호
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• pp.59-70
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• 1995

This paper is to introduce cybernetic epistemology, which is one of the nonlinear or circular epistemology and have provided the basis for the development of various theories and models of family therapy. First, the history and the concept of the term cybernetics is briefly described, and then cybernetics is compared with general systems theory. following is the discussion of different levels of cybernetics, i.e., simple cybernetics and cybernetics of cybernetics, and of their major concepts, respectively. the ways in which cybernetic epistemology is applied to family therapy are also discussed in terms of diagnosis of problems, unit of therapy, goal of therapy, and role of family therapist. Finally, some implications for training and educating cybernetic family therapist are discussed.

• 한국산업융합학회 논문집
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• 제22권6호
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• pp.627-635
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• 2019

In this study, we developed for processing complex features using CAM software that satisfies precision for example practice and related qualification tests suiTable for CNC training purposes. In addition, functions such as location control, speed control, and processing path generation, which are the main functions of CNC machining machines, were constructed using small equipment parts, servo motors, inverters, general purpose PCs, and commercial NC software and researched with the goal of developing low-cost education equipment. In the static accuracy inspection, the degree of machine when measuring the parallelism of the X, Y and Z axes and the vibration of the main shaft did not reach the allowable value. However, we have obtained a finished product that satisfies the CNC machine book sample shape machining, detailed functions of the position control function of the CNC machine tool, linear interpolation function, circular interpolation function, and tool offset function. In the qualification test shape processing, a shape with a degree of 1/100 mm was processed to obtain position accuracy that satisfied the tolerance.

• 한국통신학회논문지
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• 제27권1B호
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• pp.66-78
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• 2002

본 논문에서는 OFDM(Orthogonal Frequency-Division Multiplexing) 기반의 무선 LAN 시스템을 위한 새로운 심볼 옵셋 추정기법을 제안한다. OFDM 심볼에 심볼간 간섭(Inter-Symbol Interference: ISI)과 채널간 간섭(Inter-Channel Interference: ICI)이 없는 경우 추정된 채널의 임펄스 응답은 심볼 옵셋만큼 순환 이동한다. 전형적인 다중경로 무선채널의 전력 지연 프로파일은 지수적 감소 함수로 모델링 할 수 있으며 대부분의 에너지가 임펄스 응답의 앞부분에 주로 집중된다. 제안된 기법은 이러한 성질을 이용하여 먼저 심볼 옵셋만큼 순환 이동된 다중 경로 채널의 임펄스 응답을 추정한 후 유한 길이의 이동 윈도우를 사용하여 임펄스 응답의 부분 평균 전력을 구한다. 그리고, 부분 평균 전력 중에서 최대값을 갖는 이동 윈도우의 인덱스로부터 심볼 옵셋을 추정한다. 제안된 기법은 임펄스 응답의 추정 과정에서 잡음의 영향을 감소시키고, ISI와 ICI를 제거시키며 최소의 오버헤드를 얻기 위해 반복적 구조의 훈련 신호를 사용한다. 실내 무선 채널 모델에서의 모의실험을 통해 제안된 기법의 성능을 검증한다.

• 한국산업정보학회논문지
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• 제9권2호
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• pp.81-88
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• 2004

잡음을 갖는 영상의 크기와 회전불변 패턴인식을 위한 광 웨이블릿 CHF-fSDF((wavelet circular harmonic function-filter modulation synthetic discriminant function, WCHF-fSDF) 필터를 제안하였다. 웨이블릿 CHF-fSDF 필터는 기준영상에 대하여 크기변화된 영상들을 웨이블릿 변환한 후, 이들로부터 추출한 단일 원형고조함수를 학습영상으로 사용하여 합성한다. 제안된 광 웨이블릿 CHF-fSDF 필터는 정합필터의 형태로서 전통적인 4f 광 상관기에 적용할 수 있도록 하였다. 컴퓨터 모의실험을 통하여 제안된 필터는 크기변화와 회전에 무관한 상관출력을 나타내며 특히 잡음환경하에서 유용함을 확인하였다.

• 수산해양기술연구
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• 제48권3호
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• pp.235-241
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• 2012

The efficiency tests of automatic positioning transmitter (APT) using satellite on life jacket were carried out to minimize casualties of fishermen and to make system optimization for effective SAR (Search and Rescue) operation. As the result of the tests, average position was equaled on the comparison between SPOT using low earth orbit satellite and DGPS (Differential Global Positining System), but standard deviation of DGPS for latitude and longitude were 66.4% and 46.3% smaller than those of SPOT. The position precision of SPOT was almost two times lower than LGT using geostationary satellite to compare 95% circular error probability. However, the success rate of receiver for SPOT was revealed as 86.5~94.1% on the experiments in the South Sea and the West Sea and it was 4.5 times higher than LGT. Therefore, SPOT is expected to contribute greatly to the rapid rescue of victim.

• 한국정밀공학회지
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• 제23권4호
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• pp.124-131
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• 2006

A gerotor pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. Especially the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobes with circular shape, while the inner rotor profile is determined as conjugate to the other. For this reason the first topic presented here is the definition of the geometry of the rotors starting from the design parameters. The choice of these parameters is subject to some limitations in odor to limit the pressure angle between the rotors. Now we will consider the design optimization. The first step is the determination of the instantaneous flow rate as a function of the design parameter. This allows us to calculate three performance indexes commonly used far the study of positive displacement pumps: the flow rate irregularity, the specific flow rate, and the specific slipping. These indexes are used to optimize the design of the pump and to obtain the sets of optimum design parameter. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field, and the system could serve as a valuable one for experts and as a dependable training aid for beginners.

• 한국안광학회지
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• 제18권4호
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• pp.489-493
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• 2013

목적: 황반변성을 가진 저시력 환자의 중심외주시 훈련에 사용되는 망막 주변부의 특성을 조사하여 재활치료용 주변시 연구에 도움이 되고자 한다. 방법: 정상 시각을 가진 30명의 성인 남녀의 우안을 대상으로 중심와에서 $20^{\circ}$ 이측으로 떨어진 망막 주변부의 생리적 가중을 측정하였다. 표적은 원형의 수직형 정현파였으며 공간주파수 0.7 cpd와 3.0 cpd를 사용하여 공간적 가중과 시간적 가중의 임계값을 비교하였다. 결과: 0.7 cpd에서 시간적 가중의 임계점은 540 ms, 대비감도는 1.1이었으며 3.0 cpd에서는 315 ms, 대비감도는 0.98이었다. 0.7 cpd에서 공간적 가중의 임계점은 $11.3^{\circ}$, 대비감도는 2.8이었으며, 3.0 cpd에서 임계점은 $5^{\circ}$, 대비감도는 2.63이었다. 결론: 주변시는 중심시보다 더 빨리 임계점에 도달한다. 중심외훈련시에는 저주파대역을 대상으로 긴 시간동안 훈련하기 보다 짧은 시간동안 자주 훈련하기를 권장한다.

• 한국실내디자인학회논문집
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• 제19권6호
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• pp.47-58
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• 2010

Frank Lloyd Wright(1867-1959) was regarded as the pioneer of the modern architecture in the beginning and transition period of 20th century. His works have the pure shape form which have the deep relationship with the organic architecture. Wright told himself that the Froebel System had an influence on his works a lot. This study have researched about the three dimensional application of the Froebel System in his works with assembling and disassembling. Also the two dimensional application in the diagonal and circular plans are the one of the subjects here. The following conclusions are reached. First, The similar of the Wright's works and the Froebel System was the application of the similar principles rather than the copy of the method, which are the accent of the center, the composition of the part and whole, the understanding of the composition principle through the unit system and the unfolding of the crystal by rotation. Even thought the Wright's works have the triangle, square, hexagonal shape, the way of the expansion from the centered space was same. Also the space formed by the division of the center space, unfolds making the part and whole by overlap and continuation. The 2nd Froebel make space decided by the Net and Crystal Lattices which have the crystal characteristics by the rotation. The new geometric architecture, pinwheel, was created by this method. The application of the Froebel in the Wright's works have the several sets which are the 3th, 4th, 5th, 6th Froebels, 2nd, 7th Froebels and the 3th, 5th, 9th Froebels. The geometrical analysis of the square shape and the diagonal shape of the Wright's works was possible. The unfolding of the centered space can be found in the Guggenheim Museum using the analysis of the circular geometric of the 9th Froebel. The above study proves that the Froebel was not a mere tool for the basic shape training but also the main body of Wright's works which consists of the organic idea and philosophy of the space.