• KIPS Transactions on Software and Data Engineering
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• v.2 no.1
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• pp.19-26
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• 2013

To improve the reliability and quality of software system, many studies of the testing based on state-transition diagram have been in progress. Existing studies tried to solve the complexity problem of state-transition diagram. But the development of test case demands the better way to derive and manage the state diagram with low complexity. In this paper, the STMT(State-Transition Mapping Tree) is proposed to decrease the complexity of state diagram without changing or loosing the original state or transition information. Comparing with other methods, the proposed method turns out to be less complex.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.564-564
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• 2016

개념적 수문 모형은 탱크의 개수, 탱크 간 관계구조, 그리고 저류량과 유출량 간 선형/비선형 관계 정의 방식 등에 따라 다양한 형태로 개발되어왔으며, 각 모형마다 매개변수 수 및 입력 자료가 상이하다. 모형의 매개변수가 많아지면 결과가 좋게 나타날 수 있으나, 늘어난 매개변수에 대해 물리적 의미를 부여하고 해석하기가 쉽지 않다. 단순한 모형은 보정이 용이하고 그 특성상 실무에서 널리 이용되고 있으나, 물순환 구조가 복잡한 유역에 대해서는 적용성이 떨어질 수 있다. 하지만 매개변수의 수가 많은 모형이 적은 모형에 비해 항상 결과가 좋은 것은 아니다. 복잡한 모형은 부족한 안정성에 의해 보정 기간에서는 결과가 좋았으나, 검정 기간 대해 결과가 안 좋을 수도 있으며 이에 대한 평가가 필요하다. 본 연구에서는 국내에서 주로 이용되는 개념적 모형을 대상으로 모형의 복잡성과의 정확도의 관계를 비교 평가하고자 한다. 대상 모형으로는 수정 3단 Tank 모형, Im's Tank 모형, Two-Parametric Hyperbolic Model (TPHM), 그리고 Daily Watershed Streamflow Model (DAWAST)을 선정하였고, 대상유역으로는 이동저수지 상류에 위치한 2개 유역을 선정하였다. 모형 간 비교를 위한 정량적 통계적 지표로 $R^2$, Nash-Sutcliffe efficiency (NSE), root mean square error-observations standard deviation ratio (RSR), 그리고 percent bias (PBIAS)를 이용하였다. 본 연구 결과는 개념적 수문 모형에 대한 이해를 증진하고, 장기유출 해석을 위한 수문 모형의 선택 시 모형의 복잡도 및 정확도의 관점에서 도움을 줄 수 있는 기초자료로 이용될 수 있을 것이다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.3
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• pp.32-43
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• 2010

This paper presents deblocking filter for low-complexity video decoder. Baseline profile of the H.264/AVC used for mobile devices such as mobile phones has two times higher compression performance than the MPEG-4 Visual but it has a problem of serious complexity as using 1/4-pel interpolation filter, adaptive entropy model and deblocking filter. This paper presents low-complexity deblocking filter for decreasing complexity of decoder with preserving the coding efficiency of the H.264/AVC. In this paper, the proposed low-complexity deblocking filter decreased 49% of branch instruction than conventional approach as calculating value of BS by using the CBP. In addition, a range of filtering of strong filter applied in intra macroblock boundaries was limited to two pixels. According to the experimental results, the proposed low-complexity deblocking filter decreased -0.02% of the BDBitrate comparison with baseline profile of the H.264/AVC, decreased 42% of the complexity of deblocking filter, and decreased 8.96% of the complexity of decoder.

• Management & Information Systems Review
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• v.32 no.2
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• pp.83-106
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• 2013

This study testified the influence factors like quantities of advertising, number of hardware and software that are converged, effect on feature fatigue of convergence product. When consumers perceive higher numbers of hardwares in a smart phone, they feel its higher usefulness and complexity. This means that numbers of hardwares is the major factor that enhances consumer's usefulness but, at the same time, it cause perceived leads to higher usefulness in using smart phone, it didn't effect on complexities. It is also important strategy for smart phone companies to provide a lot of useful softwares(applications) to satisfy consumers. Finally, complexity was important factor that lead to higher feature fatigue of consumers. This indicates that smart phone companies have to find adequate numbers of convergence for their new smart phone.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.6
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• pp.793-799
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• 2004

Many researches and validations for the complexity metrics of the object-oriented systems have been studied. Most of them are aimed for the measurement of the partial aspects of the systems, for example, the coupling between objects, the complexity of inheritance structures, the cohesion of methods, and so on. But the software practitioners want to measure the complexity of overall system, not partial. We studied the complexity of the overall structures of object-oriented systems by analyzing the class diagram of UML. The class diagram is composed of classes and their relations. There are three kinds of relations, association, generalization, and aggregation, which are making the structure of object-oriented systems to be difficult to understand. We proposed a heuristic metric to measure the complexity of object-oriented systems by putting together the three kinds of the relations. This metric will be helpful to the software developers for their designing tasks by evaluating the complexity of the structures of object-oriented system and redesigning tasks of the system.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.1091-1105
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• 2012

In this paper, we analyzed statistical characteristics and complexity of HEVC encoder as a leading research of acceleration, optimization and parallelization. Computational complexity of the HEVC encoder is approximately twice the compression performance compared to H.264/AVC. But, the increase of encoder complexity remains a problem to be solved in the future. Before performing the research on acceleration, optimization and parallelization to reduce high complexity of HEVC encoder, we measure the complexity each module for HEVC encoder using it's reference software HM 7.1. We also measured the predicted complexity of fast HEVC encoder software, used in real applications, using HM 7.1 applying fast encoding method. The complexity is measured in terms of the operating cycle of the encoder software under the common test sequences and conditions in the Windows PC environment. In addition, we analyze statistical characteristics of HEVC encoder software according to encoding structures and limitation using coded bitstreams.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.61-72
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• 2005

For the improvement of coding efficiency, the H.264 standard uses new coding tools such as VBS, 1/4-pel accurate ME, multiple references, intra prediction, loop filter, etc. Using these coding tools, H.264 has achieved significant improvements from rate-distortion point of view compared to existing standards. However, the encoder complexity is greatly increased due to these coding tools. We focus on the complexity reduction method of MB mode selection. Among all modes which can be selected, $8{\times}8$ and intra $4{\times}4$ mode have higher complexity than the others. So we propose the methods for reduction of the $8{\times}8$ and intra $4{\times}4$ mode complexity by using information of other modes with relatively low complexity. Simulation results show that the proposed methods save up to $54.6{\%}$ of total encoding time while keeping the average decrease about 0.012dB in PSNR.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.93-102
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• 2008

In this paper, we propose a rate control algorithm for constant quality real time video coding. To achieve constant quality, previous algorithm exploit mean absolute of difference(MAD) as measure of frame complexity. However, if scene is abruptly changed or if quantization parameter is not constant, encoder produces various output bits with same MAD. Therefore we know that MAD does not appropriately reflect characteristic of frame. To solve this problem, we exploit model parameter as measure of frame complexity. Because model parameter means slope between output bits and MAD, it reflects correctly complexity of frame. And because previous model, R-MAD model, is not considered quantization parameter, as quantization parameter increases or decreases, model parameter of frame also vary. So model parameter obtained using previous model cannot reflect internal characteristic of video. We solve this problem using proposed model, which is considered quantization parameter. Experiment results show that our algorithm provide better performance, in terms of quality smoothness than previous algorithm. Especially, when scene is abruptly changed, our algorithm alleviates quality drop.

• Journal of Elementary Mathematics Education in Korea
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• v.24 no.2
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• pp.231-257
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• 2020

As the main mathematical concepts are presented and expressed in various ways through textbooks during the teaching and learning process, it is necessary to look at the representations used in elementary math textbooks to find effective guidance. This study analyzed sentences used in the definition of mathematical terms and unit assessments of current elementary mathematics textbooks according to word depth (Yngve, 1960) from a syntactic perspective. As a result of the analysis, it could be seen that the sentences in textbook were generally concise, the word depth was lower, and the sentence structure and form were different depending on the individual characteristics of each term. Also, the sentences in the lower grade textbooks were more easily constructed, and the sentences of the term definition were more complex than the sentences of the unit assessments. Efforts should be made to help learners learn mathematical concepts, such as clarifying sentences in textbooks, presenting visual materials together, and providing additional explanations to suit the level of individual learners.

• The KIPS Transactions:PartD
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• v.9D no.3
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• pp.447-456
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• 2002

Web applications haute different structural characteristics from conventional applications. A web application typically consists of server-side script elements which run on web sowers, client-side script elements which run on the client web-browser, link elements that the user clicks, and event elements that connect user-triggered request to the client script elements. These four elements are combined to form a web application. In such environments, direct application of conventional methods for measuring application complexity may not be possible, because they are primarily designed to measure complexity of modules and classes. In this paper, therefore, we propose metrics of Cyclomatic Complexity for Web Application (CCWA). We developed a tool to measure such metrics and applied it to the real-world examples. We found that the proposed CCWA metrics can be used for measuring complexity of highly complex web applications, which is not possible with conventional module and class based measurement techniques.