• Journal of KIISE:Software and Applications
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• v.32 no.5
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• pp.346-356
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• 2005

Over the past decade, several types of design pattern have been defined in the software engineering area. But these patterns have not been used so often compared with data structure and algorithm. Likewise, methods to select and apply design patterns during analysis, design, and development are not mentioned in CBD methodologies such as CBD96, RUP, and MaRMI III. This paper suggests the process of effectively selecting design patterns which can be applied to analysis, design, and development for development of application software with based on those offered by GoF and J2EE pattern catalogs. It also demonstrates how to effectively pattern-based software and shows differences and relative advantages from RUP by applying the suggested process to the development of aviation job application.

• Journal of Broadcast Engineering
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• v.15 no.5
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• pp.697-702
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• 2010

Contour artifact is known as the unintentional result of quantizing a flat area that has smooth gradients. In this letter, a decontouring algorithm is proposed to efficiently remove false contours that occur in typical block-based video coding applications. First, the algorithm goes through a refinement stage to determine candidate blocks probably having noticeable false contours with different kinds of features in a block. Then, pseudo-random noise masking is applied to those blocks to mitigate the contour artifacts. This block-based selective decontouring can efficiently remove the unnecessary processing of those blocks that have no false contour, which incidentally ensures a minor penalty in visual quality and computational complexity. The proposed algorithm was demonstrated, integrated into H.264/AVC, that visual quality can be significantly enhanced with an ignorable rate-distortion (RD) loss and an minor increase in computational complexity.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.169-174
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• 2007

식생지수 시계열 자료를 이용한 식생 및 토지피복 모니터링을 수행하기 위해서는 구름으로 인한 누락 및 왜곡된 식생지수 문제를 먼저 해결해야만 한다. 특히 한반도와 같이 여름철 집중 호우기에 대부분의 영상에 구름이 존재하는 경우 이들 구름화소를 제거하거나 복원하지 않을 경우, 분석 결과에 상당한 왜곡이 발생하거나 특정 시기의 영상자료를 분석에 반영할 수 없는 경우가 발생하게 된다. HANTS 알고리즘은 이 같은 구름 화소 문제를 해결하기 위한 알고리즘으로 연중 식생지수의 변화는 비교적 단순한 반복적 주기함수의 형태를 가지므로 소수의 cos 함수를 이용한 푸리에 근사식으로 전체 연중 식생지수를 표현할 수 있다는 가정에서 출발한다. 이 때 구름화소로 인한 원식생지수와의 차이가 특정 임계값을 초과하였을 경우 해당 관측치를 근사과정에서 제외함으로써 구름의 영향을 받지 않은 식생지수 시계열 자료만을 이용하게 된다. 이 과정을 수행하기 위해서는 몇몇 제어변수의 설정이 필요한데, 본 연구에서는 한반도와 같이 특정 시기에 장기간 구름이 분포하는 상황에서 최적의 식생지수 복원을 위한 HANTS 알고리즘의 제어변수를 선정하고 재구축된 식생지수를 평가하였다. 이를 위한 실험으로 2002년 대전 지역의 MODIS Terra 식생지수 시계열 영상을 대상으로 HANTS 알고리즘을 주요 식생피복별로 적용해 보았다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.3
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• pp.157-165
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• 2019

Recently, large and small earthquakes have occurred in the Korean peninsula. In this sense, Korea is no longer considered as an earthquake free zone. Especially, it is necessary to respond quickly to earthquake tsunami which may be caused by the influence of neighboring countries with large earthquakes. Since the occurrence of tsunamis can cause great casualties, it is very important to allocate the location of the shelter in case of an earthquake. Although many researches on shelter allocation have been conducted in various ways, but most of them have been analyzed based on administrative district resident data, resulting in a lack of reality. In this study, floating population data were used to reflect reality in case of emergency situations, and genetic algorithm, which produce good results among the heuristic algorithms, was used to select shelter locations. The number of evacuees was used as a objective function of genetic algorithm and the optimal solution was found through selection, crossover and mutation. As a result of the research on Busan Haeundae-Gu, selected as a research area, allocating eight shelters was the most efficient. The location of the new shelters was selected not only in residential areas but also in major tourist areas whose results can not be derived from administrative district resident data alone, and the importance of utilizing the floating population data was confirmed through this study.

• 대한공업교육학회지
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• v.33 no.2
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• pp.170-191
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• 2008

Many former researchers demonstrated that algorithm learning has a positive outcome on students' problem-solving abilities. One of the methods for algorithm learning, the 'programming learning' method is highly effective. However, there are numerous constraints in schools for programming learning. This study attempts to overcome these issues. Squeak Etoys, one of the educational visual programming languages for easy and interesting learning, has been selected as a learning tool. We developed the algorithm-learning curriculum for middle school students. They were divided into a control group and an experimental group. The students learned on the basis of equal curriculum but, they used other learning tools through over a total 6 sessions. The result showed that Squeak Etoys based Algorithm learning has a positive effect on improving middle school learners' problem solving abilities, self-efficacies and logical thinking abilities. Although the students' logical thinking abilities in the experimental group are improved a lot more than the students' abilities in control group, the students' logical think abilities in the both groups are improved. Therefore, algorithm education in secondary schools are necessary. In conclusion, Squeak Etoys based Algorithm learning has a positive effect on problem solving ability and self efficacy. The developed curriculum can be applicable as a basis for study on algorithm learning and educational programming language.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.573-580
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• 2018

Various studies have been conducted to analyze the location appropriateness and capacity of shelters. However, research on how to select new shelters is relatively insufficient. Since the shelter is designated in case of emergency, it is also necessary to efficiently select the location of the shelter. Therefore, this study presented a method for selecting the location of the shelter using network analysis that has been used to analyze the location appropriateness of shelters and genetic algorithm which is a representative heuristic algorithm. First, the network analysis using the existing civil defense evacuation facility data was performed and the result showed that the vulnerability of evacuation has a high deviation by region in the study area. In order to minimize the evacuation vulnerable area, the genetic algorithm was designed then the location of new shelters was determined. The initial solution consisting of candidate locations of new shelters was randomly generated and the optimal solution was found through the process of selection, crossover, and mutation. As a result of the experiment, the area with a high percentage of the evacuation vulnerable areas was prioritized and the effectiveness of the proposed method could be confirmed. The results of this study is expected to contribute to the positioning of new shelters and the establishment of an efficient evacuation plan in the future.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.115-127
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• 2021

With the development of science and technology around the world, the realm of cyberspace, following land, sea, air, and space, is also recognized as a battlefield area. Accordingly, it is necessary to design and establish various elements such as definitions, systems, procedures, and plans for not only physical operations in land, sea, air, and space but also cyber operations in cyberspace. In this research, the importance of cyber targets that can be considered when prioritizing the list of cyber targets selected through intermediate target development in the target development and prioritization stage of targeting processing of cyber operations was selected as a factor to be considered. We propose a method to calculate the score for the cyber target and use it as a part of the cyber target prioritization score. Accordingly, in the cyber target prioritization process, the cyber target importance category is set, and the cyber target importance concept and reference item are derived. We propose a TIR (Target Importance Rank) algorithm that synthesizes parameters such as Event Prioritization Framework based on PageRank algorithm for score calculation and synthesis for each derived standard item. And, by constructing the Stuxnet case-based network topology and scenario data, a cyber target importance score is derived with the proposed algorithm, and the cyber target is prioritized to verify the proposed algorithm.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.520-525
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• 2020

In this study, we developed a machine learning-based model for predicting the production stage temperature of distillation process. It is necessary to predict an accurate temperature for control because the control of the distillation process is done through the production stage temperature. The temperature in distillation process has a nonlinear complex relationship with other variables and time series data, so we used the recurrent neural network algorithms to predict temperature. In the model development process, by adjusting three recurrent neural network based algorithms, and batch size, we selected the most appropriate model for predicting the production stage temperature. LSTM₁₂₈ was selected as the most appropriate model for predicting the production stage temperature. The prediction performance of selected model for the actual temperature is RMSE of 0.0791 and R² of 0.924.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.503-506
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• 2011

최근 다양하게 등장하고 있는 운전자를 위한 보조 장치 중 운전자의 주차를 위해 사용되는 장치들 중 하나인 차량용 카메라는 주로 차량 후방의 번호판 위에 주로 위치하여 운전자의 주차에 도움을 주는 역할에 사용이 되고 있다. 최근에는 이러한 카메라를 이용하여 전 후방 및 좌 우측을 모두 보여주기 위한 AVM(Around View Monitor) 시스템이 개발되었다. 그러나 다수의 카메라를 사용하는 AVM시스템에서 운전자에게 통합된 영상을 제공하기 위해서는 카메라의 방사왜곡보정과 호모그래피(Homography) 알고리즘을 통해 정합하는 과정이 필요하다. 본 논문에서는 호모그래피 과정에서 결과 영상의 품질을 개선하기 위한 방법을 제안한다. 또한, 제안하는 방법을 구현하여 기존의 8DOF(Degree of Freedom)을 사용한 방법과 결과 영상의 품질을 비교함으로써 개선된 영상을 제공할 수 있음을 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2C
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• pp.181-188
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• 2007

This paper proposed a watermark embedding/extracting method using CABAC(Context-based Adaptive Binary Arithmetic Coding) which is the entropy encoder for the main profile of MPEG-4 Part 10 H.264/AVC. This algorithm selects the blocks and the coefficients in a block on the bases of the contexts extracted from the relationship to the adjacent blocks and coefficients. A watermark bit is embedded without any modification of coefficient or with replacing the LSB(Least Significant Bit) of the coefficient with a watermark bit by considering both the absolute value of the selected coefficient and the watermark bit. Therefore, it makes it hard for an attacker to find out the watermarked locations. By selecting a few coefficients near the DC coefficient according to the contexts, this algorithm satisfies the robustness requirement. From the results from experiments with various kinds and various strengths of attacks the maximum error ratio of the extracted watermark was 5.02% in maximum, which makes certain that the proposed algorithm has very high level of robustness. Because it embeds the watermark during the context modeling and binarization process of CABAC, the additional amount of calculation for locating and selecting the coefficients to embed watermark is very small. Consequently, it is highly expected that it is very useful in the application area that the video must be compressed right after acquisition.