• 정보과학회 논문지
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• 제42권3호
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• pp.341-360
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• 2015

패턴은 소프트웨어 개발에서 얻은 경험을 구조화한 것으로 문제해결에 이용되는 반면, 문제틀은 소프트웨어 문제를 분석하는 방법이다. 문제틀은 해법이라기 보다는 문제 도메인에 중점을 두고 있기 때문에 문제를 이해하는데 유용하다. 문제틀과 소프트웨어 아키텍처를 연결하는 기존 연구들은 주어진 문제를 이해하는데 치중하여 문제틀을 이용할 뿐 문제틀과 품질속성 모두를 고려하면서 아키텍처 패턴을 도출하고 있지 않다. 본 논문에서는 문제틀과 아키텍처 패턴의 매칭을 통한 소프트웨어 패턴 기반 아키텍처 설계 방법을 제안한다. 먼저, 문제틀 방법에 따라 문제 모델을 개발한 후 기능 및 품질속성 관점에서 문제 모델을 아키텍처 패턴 후보와 매칭한다. 논문은 기능 매칭을 위해서는 문제틀 다이어그램을 이용한 아키텍처 패턴의 문제 모델을, 품질속성을 고려하기 위해서는 새로운 분석 템플릿을 사용하여 아키텍처를 설계하는 방법을 제안한다. 또한, 사례연구를 통해 제안한 방법이 올바른 아키텍처 패턴을 결정하는 체계적인 프로세스이며 잘 정제된 소프트웨어 아키텍처 설계를 위한 기초가 됨을 보인다.

• Structural Engineering and Mechanics
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• 제11권1호
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• pp.1-16
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• 2001

This paper discusses the elastic stability of unbraced frames under non-proportional loading based on the concept of storey-based buckling. Unlike the case of proportional loading, in which the load pattern is predefined, load patterns for non-proportional loading are unknown, and there may be various load patterns that will correspond to different critical buckling loads of the frame. The problem of determining elastic critical loads of unbraced frames under non-proportional loading is expressed as the minimization and maximization problem with subject to stability constraints and is solved by a linear programming method. The minimum and maximum loads represent the lower and upper bounds of critical loads for unbraced frames and provide realistic estimation of stability capacities of the frame under extreme load cases. The proposed approach of evaluating the stability of unbraced frames under non-proportional loading has taken into account the variability of magnitudes and patterns of loads, therefore, it is recommended for the design practice.

• 방송공학회논문지
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• 제8권4호
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• pp.501-504
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• 2003

본 논문에서는 프레임간 움직임 차를 이용한 워터마킹 방법을 제안한다. 이를 위하여 프레임차의 최대치를 양자화한 값을 계산하여 워터마크 삽입과 검출시에 사용되는 키값을 구한다. 실험 결과, 이 방법은 전체 프레임 중에서 l~3% 정도의 프레임에서 워터마크 삽입시에 계산한 키 값과 워터마크 검출시에 계산한 키 값이 ${\pm}1$ 정도의 오차가 발생하는데 이것은 검출된 워터마크의 BER(bit error rate)에 따라 키값을 다시 정하여 워터마크를 검출하면 해결됨을 알 수 있다. 본 논문에서 제안하는 방법은 각각의 프레임에 다른 워터마크 키를 사용하므로 프레임 삭제와 평균화 공격(averaging attack)에 강함을 보인다.

• Steel and Composite Structures
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• 제24권3호
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• pp.369-382
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• 2017

This study investigates the reliability of the performance levels of moment resisting steel frames subjected to lateral loads such as wind and earthquake. The reliability assessment has been performed with respect to three performance levels: serviceability, damageability, and ultimate limit states. A four-story moment resisting frame is used as a typical example. In the reliability assessment the uncertainties in the loadings and in the capacity of the frame have been considered. The wind and earthquake loads are assumed to have lognormal distribution, and the frame resistance is assumed to have a normal distribution. In order to obtain an appropriate limit state function a linear relation between the loading and the deflection is formed. For the reliability analysis an algorithm has been developed for determination of limit state functions and iterations of the first order reliability method (FORM) procedure. By the method presented herein the multivariable analysis of a complicated reliability problem is reduced to an S-R problem. The procedure for iterations has been tested by a known problem for the purpose of avoiding convergence problems. The reliability indices for many cases have been obtained and also the effects of the coefficient of variation of load and resistance have been investigated.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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• pp.105-112
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• 1994

In a local vibration analysis of a large steel frame, a large eigenvalue problem results. Due to computer storage and the expense of a complete solution, it is desirable to minimize the size of the resulting matrices. A new and efficient method of local vibration analysis for large steel frames is presented. It reduces the order of dynamic matrices by dynamic condensation method. Examples are given for local vibration of a plane frame. Results are compared to the complete solution of the full eigenvalue problem.

• Computers and Concrete
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• 제26권1호
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• pp.1-10
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• 2020

In this paper, a procedure for automated optimized design of reinforced concrete frames has been presented. The procedure consists of formulation and solution of the design problem in the form of an optimization problem. The minimization of total cost of R/C frame has been taken as the objective of optimization problem. In this research, consistent approximation method is applied to explicitly formulate constraints and objective function in terms of the design variables. In the presented method, the primary optimization problem is replaced with a sequence of explicit sub-problems. Each sub-problem is efficiently solved using the Sequential Quadratic Programming (SQP) method. The proposed method is demonstrated through a four-story frame and an eight-story frame, and the optimum results are compared with those in the available literature. It is shown that the proposed method can be easily applied to obtain rational, reliable, economical and practical designs for Reinforced Concrete Moment Resisting Frames (RCMRFs) while it is converged after a few analyses.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권1호
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• pp.8-16
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• 2014

We consider the visual barcode recognition problem in a noisy video data setup. Unlike most existing single-frame recognizers that require considerable user effort to acquire clean, motionless and blur-free barcode signals, we eliminate such extra human efforts by proposing a robust video-based barcode recognition algorithm. We deal with a sequence of noisy blurred barcode image frames by posing it as an online filtering problem. In the proposed dynamic recognition model, at each frame we infer the blur level of the frame as well as the digit class label. In contrast to a frame-by-frame based approach with heuristic majority voting scheme, the class labels and frame-wise noise levels are propagated along the frame sequences in our model, and hence we exploit all cues from noisy frames that are potentially useful for predicting the barcode label in a probabilistically reasonable sense. We also suggest a visual barcode tracking approach that efficiently localizes barcode areas in video frames. The effectiveness of the proposed approaches is demonstrated empirically on both synthetic and real data setup.

• 한국안광학회지
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• 제12권3호
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• pp.143-149
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• 2007

본 논문에서는 한국, 미국과 유럽연합의 의료기기의 정의, 분류, 안경테를 다루는 직종, 관리, 판매 등에 대하여 비교 분석하였다. 한국은 시력보정용 안경테를 공산품으로 지정한 반면 유럽연합과 미국은 의료기기로 분류하였다. 선글라스의 경우 한국과 유럽연합에서는 공산품이지만 미국에서는 의료기기이다. 안경테와 선글라스의 공산품 지정은 여러 가지 문제점을 유발한다. 시력보정용 안경테와 선글라스의 의료기기지정은 이러한 문제를 해결할 수 있을 것으로 본다.

• Structural Engineering and Mechanics
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• 제14권4호
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• pp.473-489
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• 2002

A static linear programming formulation for minimum weight design of frames that is based on a matrix displacement method is presented in this paper. According to elementary theory of plasticity, minimum weight design of frames can be carried out by using only the equilibrium equations, because the system is statically determinate when at an incipient collapse state. In the present formulation, a statically determinate released frame is defined by introducing hinges into the real frame and the bending moments in yield constraints are expressed in terms of unit hinge rotations and the external loads respectively, by utilizing the matrix displacement method. Conventional Simplex algorithm with some modifications is utilized for the solution of linear programming problem. As the formulation is based on matrix displacement method, it may be easily adopted to the weight optimization of frames with displacement and deformation limitations. Four illustrative examples are also given for comparing the results to those obtained in previous studies.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2011년도 하계학술대회
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• pp.294-295
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• 2011

The fundamental problem of selective protection scheme for encoded bitstreams is to find an efficient algorithm to select the set of frames required to be encrypted that can maximize protection effect with the minimum amount of protected data is required. In this paper, we propose an optimal selective protection scheme for SVC bitstreams by protecting the best combination of frames for selective protection in the sense that the amount of data required for protection is minimized and the resulting visual quality degradation is maximized. The selection of the frames to be encrypted is done by first expressing R-Q (protection rate - visual quality) relationship with Lagragian cost model. The experimental results show that, compared to protecting SVC bitstreams layer by layer, the proposed scheme gives superior performance in terms of protection effectiveness due to its better selection of frames for protection given protection bit budgets.