• 전자공학회논문지S
• /
• 제35S권1호
• /
• pp.80-87
• /
• 1998

In this study, a multi-element ultrasound transducer has been developed aiming at basic experiment of three-dimension endovascular ultrasound endscopy for clinical diagnos, and experimental results of two-dimensional object imaging in the water are presented by the ultrasound tranducer and neural network. Each ultrasound echo received by thirty-six angular transducer elements is inputed to the eural network, and then backpropagation is used as a learning algorithm. A three-layer artificial neural network is used for learning and imaging of targetw placed in front of the transducer. The object shape of imaging is restricted to rectangular shapes by considering experimental restraint conditions. As a result, rough visualization can be realized even for objects with unlearned shapes through the training by primitive patterns of a various sized rectangular targets.

• 한국콘텐츠학회논문지
• /
• 제6권2호
• /
• pp.99-104
• /
• 2006

이 논문은 GPS 안테나로 사용될 수 있는 Offset Slotted 직사각형 마이크로스트립 패치 안테나를 디자인하기 위한 기법을 제안하였다. 안테나 특성을 해석하기 위해 Multi-port connection 기법과 Desegmentation 기법을 사용하였고, 고유전율의($\varepsilon_{\gamma}$=10.2) 기판과 직사각형 슬롯을 이용하여 안테나의 사이즈를 줄일 수 있었다. 제작된 안테나의 치수는 $20\times30\times1.27$[mm]로 작은 사이즈이므로 GPS 안테나 또는 핸드폰에 사용될 수 있을 것이다.

• 대한수학회지
• /
• 제47권1호
• /
• pp.135-163
• /
• 2010

Motivated by [Science in China (Ser. A Mathematics) 36 (2006), no. 7, 721?732], this article deals with the following discrete type BVP $\LARGE\left\{{{\;{\Delta}[{\phi}({\Delta}x(n))]\;+\;f(n,\;x(n\;+\;1),{\Delta}x(n),{\Delta}x(n + 1))\;=\;0,\;n\;{\in}\;[0,N],}}\\{\;{x(0)-{\sum}^m_{i=1}{\alpha}_ix(n_i) = A,}}\\{\;{x(N+2)-\;{\sum}^m_{i=1}{\beta}_ix(n_i)\;=\;B.}}\right.$ The sufficient conditions to guarantee the existence of at least three positive solutions of the above multi-point boundary value problem are established by using a new fixed point theorem obtained in [5]. An example is presented to illustrate the main result. It is the purpose of this paper to show that the approach to get positive solutions of BVPs by using multifixed-point theorems can be extended to treat nonhomogeneous BVPs. The emphasis is put on the nonlinear term f involved with the first order delta operator ${\Delta}$x(n).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권11호
• /
• pp.4387-4404
• /
• 2015

The energy-efficient design of sensing-based spectrum sharing of a multi-input and multi-output (MIMO) cognitive radio (CR) system with imperfect multiple antenna spectrum sensing is investigated in this study. Optimal resource allocation strategies, including sensing time and power allocation schemes, are studied to maximize the energy efficiency (EE) of the secondary base station under the transmit power and interference power constraints. EE problem is formulated as a nonlinear stochastic fractional programming of a nonconvex optimal problem. The EE problem is transformed into its equivalent nonlinear parametric programming and solved by one-dimension search algorithm. To reduce searching complexity, the search range was founded by demonstration. Furthermore, simulation results confirms that an optimal sensing time exists to maximize EE, and shows that EE is affected by the spectrum detection factors and corresponding constraints.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권3호
• /
• pp.941-953
• /
• 2012

A novel and universal method of video image text detection is proposed. A coarse-to-fine text detection method is implemented. Firstly, the spectral clustering (SC) method is adopted to coarsely detect text regions based on the stationary wavelet transform (SWT). In order to make full use of the information, multi-parameters kernel function which combining the features similarity information and spatial adjacency information is employed in the SC method. Secondly, 28 dimension classifying features are proposed and support vector machine (SVM) is implemented to classify text regions with non-text regions. Experimental results on video images show the encouraging performance of the proposed algorithm and classifying features.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권4호
• /
• pp.1140-1152
• /
• 2012

A novel and universal method of video image text detection is proposed. A coarse-to-fine text detection method is implemented. Firstly, the spectral clustering (SC) method is adopted to coarsely detect text regions based on the stationary wavelet transform (SWT). In order to make full use of the information, multi-parameters kernel function which combining the features similarity information and spatial adjacency information is employed in the SC method. Secondly, 28 dimension classifying features are proposed and support vector machine (SVM) is implemented to classify text regions with non-text regions. Experimental results on video images show the encouraging performance of the proposed algorithm and classifying features.

• 한국금형공학회:학술대회논문집
• /
• 한국금형공학회 2008년도 하계 학술대회
• /
• pp.89-94
• /
• 2008

The injection molding process is a predominant method for producing plastic parts. In order to maximize productivity and molding quality in a injection mold, it is important that each cavity in a multi-cavity injection mold is identical. This requires that cavity dimensions should be identical and delivery system of melt to each cavity have to be the same. Despite the geometrically balanced layout in multi-cavity injection mold more than 4 cavities, it has been observed that the filling in each cavity results in imbalances. Most of cases, this phenomenon of filling imbalances have a bad effect on dimension accuracy, warpage, molding appearance and strength of molding parts. In this study, experiment were conducted to investigate the effect of filling imbalances on the molding quality(surface gloss, shrinkage, tensile strength) in the multy-cavity injection mold.

• 한국해양공학회지
• /
• 제10권2호
• /
• pp.20-27
• /
• 1996

Ice loads can determined by many factors like ice properies and dimension, velocity and type of structures. The magnitude of ice load varies with the failure mode which can be predicted by failure maps if the aspect ratio and strain rate are known. To reduce the ice force, various types of structure have been investigated and it is now known that the identor shape plays an important role in reducing ice load on Arctic offshoe structures. The conical and wedge structures are good applied examples in the Arctic region. In this study, ice forces on single wedge indentors are investigated for crushing failure mode. The ice loads on wedged indentors are compared with those on cylindrical structures. Also the concept of "ice annual"is introduced to verify the ice loads to multi and single wedge structures.tructures.

• 전기학회논문지P
• /
• 제59권3호
• /
• pp.245-252
• /
• 2010

This paper proposes a constrained multi-area dispatch scheduling algorithm applicable to interconnected power system operations. The dispatch scheduling formulated as an MIP problem can be efficiently computed by GBD algorithm. GBD guarantees adequate computation speed and solution convergence by reducing the dimension of the dispatch scheduling problem. In addition, the regional decomposition technique based on ADM is introduced to obtain efficient inter-temporal OPF solution. It can find the most economic dispatch schedule incorporating power transactions without each regional utility's private information open.

• 한국실내디자인학회:학술대회논문집
• /
• 한국실내디자인학회 2004년도 추계학술발표대회 논문집
• /
• pp.55-60
• /
• 2004

This paper aims to provide a multi-dimensional integrative model that can give a comprehensive account for human space experience. Human space experience is too complicated phenomenon, so space designer need to understand about mechanism of space cognition. From psychological point of view, I analyze the mechanism that is based on emotional reaction. This model consist of three dimensions: sensory, reflexive, and reflective dimension. Assuming this model, we have attempt the typological analysis to the space by studying human space experience. Finally, the outcome provides how space designer use this effect for application of human experience.