• The KIPS Transactions:PartD
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• v.16D no.3
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• pp.407-416
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• 2009

To support an efficient management of software verification and validation activities, much research has been conducted to predict defects in early phase. And defect prediction models have been proposed to predict defects. But the generality of the models has not been experimentally studied for other software system. In other words, most of prediction models were applied only to the same system that had been used to build the prediction models themselves. Therefore, we performed an experiment to explore generality of major prediction models. In the experiment, we applied three defects prediction models to three different systems. As a result, we cannot find their generality of defect prediction capability. The cause is analyzed to result from a different metric distribution between the systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.47-54
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• 2019

In this paper, we consider a constant modulus (CM) based blind adaptive receiver design for downlink multi-carrier code-division multiple access (MC-CDMA) systems employing simple space-time block coding (STBC). In the paper, filter weight vectors used for the detection of the transmitted symbols are partitioned into its subvectors and then, special relations among the optimal subvectors minimizing the CM metric are derived. Using the special relations, we present a modified CM metric and propose a new blind adaptive stochastic-gradient CM algorithm (SG-CMA) by minimizing the modified CM metric. The proposed blind adaptive SG-CMA has faster convergence rate than the conventional SG-CMA because the filter weight vectors of the proposed scheme are updated in the region of satisfying the derived special relations. Computer simulation results are given to verify the superiority of the proposed SG-CMA.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.500-503
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• 2016

소프트웨어의 개발 단계에서는 검증을 위한 V&V(Verification & Validation) 프로세스를 통해 체계적인 개발 활동이 가능하도록 지원하고 있다. 이에 반해 소프트웨어 요구사항 분석 이전에 수행되는 연구 단계는 그렇지 못하며, 또한 소프트웨어 연구 사업의 평가 시 구체적인 기준의 부재, 평가 시간과 수집된 자료의 부족 등의 문제가 제기 되었다. 따라서 본 논문에서는 연구자의 연구 활동과 연구 평가자의 연구 평가 활동을 지원하기 위해 소프트웨어 관련 국제 표준에서 추출한 요구사항을 바탕으로 하여 목표 구조, 평가 메트릭을 도출하고, 평가 시나리오와 그것을 해설해주는 가이드라인을 생성하는 방법을 제안한다. 우리의 연구는 연구 평가를 위한 메트릭 가이드라인인 라이덴 선언에 일부 부합하는 것을 확인하였다. 연구 결과는 연구 평가의 효율화와 자동화를 위한 향후 연구의 기초가 될 것이다.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.353-356
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• 2019

The main functionality of occupancy sensors is to determine the existence of humans in the space. If the space is occupied, a light is on and for vacancy, the light automatically turns off. In this letter, the functionality is realized by the utilization of color information. The color information of incoming people is saved. For outgoing people, their color distribution is compared with the saved information, thus providing the recognition of the outgoing people. For the comparison, four similarity metrics are examined to validate the proposed method.

• Journal of Broadcast Engineering
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• v.13 no.2
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• pp.179-187
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• 2008

In this paper, we proposed the qualify metric based on SVC and the subjective quality. The proposed quality metric is for a general purpose. It means we can use it for any video sequences regardless of its temporal and spatial characteristics. The Quality of Service(QoS) is one of the important issues in heterogeneous environment which has diverse restrictions such as limited network bandwidth and limited display resolution. Scalable Video Coding(SVC) is the efficient video coding skill in heterogeneous environment. Because SVC can be adapted to various quality bitstreams using three scalabilities(spatial, temporal, and SNR) from one bitstream which has full scalability. To maximize the QoS in this environment, we should consider the subjective quality which is the viewer response. And also we should consider temporal and spatial characteristics of video sequence because the subjective quality is affected by temporal and spatial characteristics of video sequence. To verify the efficiency of the proposed method, we perform subjective assessments. The experimental results show that the proposed method has high correlation with subjective quality. The proposed method can be a decision tool of SVC birstream extraction.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.19-21
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• 2003

정적 프로그램 분석기는 프로그램의 결점을 찾아내는 초기 목적에서 진화하여, 역공학. 재공학. 메트릭 검증 등 도구의 front-End 모듈로 많이 쓰이고 있다. 이에 대한 다양한 연구가 진행되고 있고. 또 많은 관련 도구들이 소개되었지만, 사용자가 생각을 직접 코드형태로 구현하고, 결과를 모델형태로 표현하여, 시험하고 검증할 수 있도록 도와주는 프레임웍 수준 도구들은 거의 나와있지 않다. 본 논문에서는 정적 프로그램 분석을 쉽게 할 수 있도록 지원하는 기반도구의 설계를 제안한다. 본 연구에서는 언어의 파싱과 시각화 과정의 반복되는 작업들을 추상화하고, 분석 코드를 파싱 코드와 분리함으로써 사용자로 하여금 분석 과정에 집중할 수 있도록 도와준다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.930-933
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• 2010

침입방지시스템 솔루션은 차세대에 각광받는 보안시스템으로 국내 외 시장에서 매우 활발한 보안 분야 시장을 형성할 것으로 전망된다. 아울러 국제 시장에 진출하고자 하는 국내 업체들은 검증된 제품임을 증명하는 품질 평가가 요구되고 일반 사용자들은 검증된 제품을 선호하는 추세가 일반적이다. 본 연구에서는 침입방지시스템의 기술개요, 특징 및 침입방지시스템의 품질 평가기준을 소프트웨어 품질평가를 위해 사용되는 국제표준 ISO/IEC 9126과 ISO/IEC 14598의 참조하여 평가항목을 도출하였으며, 도출된 평가항목을 가지고 평가방법 메트릭을 개발하였다.

• Journal of Broadcast Engineering
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• v.17 no.3
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• pp.459-470
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• 2012

In this paper, we propose a method to upsample a low-resolution depth map to a high-resolution version. While conventional camera sensors produce high-resolution color images, the sizes of the depth maps of range/depth sensors are usually low. In this paper, we consider the utilization of high-frequency components to the conventional depth map interpolation methods such as bilinear, bicubic, and bilateral. The proposed method is composed of the three steps: high-frequency component extraction, high-frequency component application, and interpolation. Two objective evaluation measures such as sharpness degree and blur metric are used to examine the performance. Experimental results show that the proposed method significantly outperforms other conventional methods by a factor of 2 in terms of sharpness degree. As well, a blur metric is reduced by a factor of 14 %.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.12
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• pp.943-947
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• 2009

To support an efficient management of software verification and validation activities, many defect prediction models have been proposed based on object oriented metrics. In order to apply defect prediction models, we need to determine a threshold value. Because we cannot know actually where defects are, it is difficult to determine threshold. Therefore, we performed a series of experiments to explore the issue of determining a threshold. In the experiments, we applied defect prediction models to other systems different from the system used in building the prediction model. Specifically, we have applied three models - Olague model, Zhou model, and Gyimothy model - to four different systems. As a result, we found that the prediction capabilities varied considerably with a chosen threshold value. Therefore, we need to perform a study on the determination of an appropriate threshold value to improve the applicably of defect prediction models.

• Journal of KIISE
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• v.41 no.9
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• pp.617-624
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• 2014

Malicious traffic, such as DDoS attack and botnet communications, refers to traffic that is generated for the purpose of disturbing internet networks or harming certain networks, servers, or hosts. As malicious traffic has been constantly evolving in terms of both quality and quantity, there have been many researches fighting against it. In this paper, we propose an effective malicious traffic detection method that exploits the X-means clustering algorithm. We also suggest how to analyze statistical characteristics of malicious traffic and to define metrics that are used when clustering. Finally, we verify effectiveness of our method by experiments with two released traffic data.