• Journal of the Korea Society of Computer and Information
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• v.9 no.2
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• pp.69-79
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• 2004

For the successful IT operation outsourcing there need appropriate metrics on which both of the service clients and provider agree. The metrics are used to set up the service level objectives, which are manifested in the service level agreement with price. A study of metrics is necessary for the following reasons: First, most of the metrics used today were introduced in the early years of computers and are not satisfactory to both of the service providers and clients. Second, metrics represent the performance of system components but not end-user satisfaction. Third, because the service provider leads the outsourcing agreement, the objectives are specified more favorable to the provider. The objectives should be based on metrics that both sides fully understand and agree on.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.204-214
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• 2015

Depth map upsampling is an approach to increase the spatial resolution of depth maps obtained from a depth camera. Depth map quality is closely related to 3D perception of stereoscopic image, multi-view image and holography. In general, the performance of upsampled depth map is evaluated by PSNR (Peak Signal to Noise Ratio). On the other hand, time-consuming 3D subjective tests requiring human subjects are carried out for examining the 3D perception as well as visual fatigue for 3D contents. Therefore, if an objective metric is closely correlated with a subjective test, the latter can be replaced by the objective metric. For this, this paper proposes a best metric by investigating the relationship between diverse objective metrics and 3D subjective tests. Diverse reference and no-reference metrics are adopted to evaluate the performance of upsampled depth maps. The subjective test is performed based on DSCQS test. From the utilization and analysis of three kinds of correlations, we validated that SSIM and Edge-PSNR can replace the subjective test.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06a
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• pp.171-175
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• 1998

본 논문에서는 COFDM(Coded Orthogonal Frequency Division Multiplexing) 시스템에서 각 부채널이 갖는 신호대 잡음의 양을 수신단이 측정할 수 있는 특징을 이용하여 콘볼루셔널 디코더 메트릭 계산에 반영함으로서 콘볼루셔널 디코더의 성능이 향상될 수 있는 방안을 제안한다. 이를 위하여 먼저 OFDM 시스템에서 각 부채널이 갖는 신호대 잡음의 양은 부채널에서의 수신신호 전력에 비례함을 보인다. 또한, 콘볼루셔널 디코더의 메트릭 계산방법으로는 연판정 방법을 사용한다. 이때 부채널에서 수신된 신호의 신뢰도로 하여 신뢰도가 떨어지는 수신신호에 대하여는 메트릭 계산 과정에서 영향을 감쇄시키고 신뢰도가 높은 수신신호는 영향을 증대시키도록 한다. 제안된 방법을 경수로 20이고 직접파가 없는 다중경로채널에 적용하여 모의실험한 결과 coherent QPSK 매핑방법을 사용한 COFDM 시스템에서 10-4 BER을 기준으로 할 때 약 1.1dB의 SNR 성능향상을 얻었으며 16-QAM 매핑방법에서는 약 3.1dB 그리고 64-QAM 매핑방법을 사용한 경우 약 6.0dB의 성능향상을 얻었다.

• Journal of KIISE:Software and Applications
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• v.29 no.12
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• pp.907-925
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• 2002

Due to the emersion of J2EE(Java 2, Enterprise Edition), many enterprises inside and outside of the country have been developing the enterprise applications appropriate to the J2EE model. With the help of the component model of Enterprise Java Beans(EJH) which is the J2EE core technology, we can develop the distributed object applications quite simple. EJB application can be implemented by using the component-oriented object transaction middleware and the most applications utilize the distributed transaction. EJB developers can concentrate on the business logic because the EJB server covers the middleware service. Due to these characteristics, EJB technology became popular and then the study for EJB based application has been done quite actively However, the research of metrics for measuring the performance during run-time of the EJB applications has not been done enough. Tn this paper, we explore the workflow for the EJB application service on the run-time and classify the internal operation into several elements. We propose the metrics for evaluating the performance up to the bean level by using the classified elements. First, we analyze the lifecycle according to the bean types which comes from the EJB application on the run-time as to extract each factor used in performance measurement. We also find factors related to a performance and allocate the Performance factors to the metrics as the bean types. We also consider the characteristics like the bean's activation and message passing which happens during bean message call and then analyze the relations of the beans participating in the workflow of the application to make the workflow performance measurement possible. And we devise means to bring performance enhancement of the EJB application using the propose.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.5
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• pp.131-142
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• 2009

While users of information security products require high-quality products that are secure and have high performance, there are neither examples for evaluating the quality of information security products nor studies on the quality model and metrics for the quality evaluation. In this paper, information security products are categorized into three different types and the security and performance of various information security products are analyzed. Through this process and after consideration of information security products' security and performance, a new quality model that possesses 7 characteristics and 24 sub-characteristics has been defined. In addition, metrics consisting of 62 common and 45 extended metrics that can be used to evaluate the quality of information security products are introduced, and a proposition for a method of generating the quality evaluation metrics for specific information security products is included. The method of generating metrics proposed in this paper can be extended in order to be applied to a variety of information security products, and by generating and verifying the quality evaluation metrics for firewall, intrusion detection systems and fingerprint systems it is shown that it applicable on a variety of information security products.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.388-390
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• 2002

Java 2 Enterprise Edition(J2EE)의 등장으로 국내.외 수많은 기업들은 J27E의 모델에 맞게 엔터프라이즈 어플리케이션을 개발하고 있다. 이것은 J2EE의 핵심 기술 요소인 Enterprise JavaBeans(EJB)의 컴포넌트모델이 분산 객체 어플리케이션의 개발 과정을 간단하게 해주기 때문이다. EJB 어플리케이션은 여러 개의 빈들로 구성된다. EJB 어플리케이션의 서비스는 클라이언트의 요청에 따른 빈의 비즈니스 메소드의 실행으로 이루어진다. 따라서 EJB 어플리케이션의 성능은 클라이언트의 요청에 따라 처리하는 빈에서의 측정과 요청을 처리하는 비즈니스 메소드의 측정에 매우 중요하다. 본 논문에서는 EJB 어플리케이션에서 클라이언트의 서비스 요정에 따라 수행하는 빈 단위에서의 성능 메트릭을 제시한다. 클라이언트의 서비스 요청은 요청을 받은 번에서의 메소드 실행으로 나타난다. 메소드의 유형을 분류하고, 각 유형에 따른 메트릭을 제시한다.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.101-108
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• 2022

We propose an intrusion detection model that detects denial-of-service(DoS) and distributed reflection denial-of-service(DRDoS) attacks, based on the empirical data of each internet of things(IoT) device by training system and network metrics that can be commonly collected from various IoT devices. First, we collect 37 system and network metrics from each IoT device considering IoT attack scenarios; further, we train them using six types of machine learning models to identify the most effective machine learning models as well as important metrics in detecting and distinguishing IoT attacks. Our experimental results show that the Random Forest model has the best performance with accuracy of over 96%, followed by the K-Nearest Neighbor model and Decision Tree model. Of the 37 metrics, we identified five types of CPU, memory, and network metrics that best imply the characteristics of the attacks in all the experimental scenarios. Furthermore, we found out that packets with higher transmission speeds than larger size packets represent the characteristics of DoS and DRDoS attacks more clearly in IoT networks.

• The KIPS Transactions:PartD
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• v.15D no.2
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• pp.235-246
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• 2008

Service-Oriented Architecture (SOA) is emerging as an effective approach for developing applications by dynamically discovering and composing reusable services. Generally, the benefits of SOA are known as low-development cost, high agility, high scalability, business level reuse, etc. However, a representative problem for widely applying SOA is the performance problem. This is caused by the nature of SOA such as service deployment and execution in distributed environment, heterogeneity of service platforms, use of a standard message format, etc. Therefore, performance problem has to be overcome to effectively apply SOA, and service performance has to be measured precisely to analyze where and why the problem has occurred. Prerequisite for this is a definition of a quality model to effectively measure service performance. However, current works on service performance lacks in defining a practical and precise quality model for measuring performance which adequately addresses the execution environment and features of SOA. Hence, in this paper, we define a quality model which includes a set of practical metrics for measuring service performance and an effective technique to measure the value of the proposed metrics. In addition, we apply the metrics for Hotel Reservation Service System (HRSS) to show the practicability and usefulness of the proposed metrics.

• Journal of Digital Contents Society
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• v.18 no.5
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• pp.983-987
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• 2017

Multi-homing mobile router separates network for user connection and network for internet access using various interfaces for internet access. This paper proposes a load balancing metric in order that multi-network mobile router distributes its traffic to one of several heterogeneous network interfaces. To evaluate the performance of the load balancing metric, experiments on traffic balancing is performed on real commercial networks were used in Korea and Hong Kong.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.176-180
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• 2008

무선 메쉬 네트워크는 최근 무선 네트워크 환경에서 유선을 효율적으로 연장할 수 있는 기술로서 주목 받고 있으며 무선 백본망을 통해 저렴한 비용으로 광대역 네트워크 인프라를 구성하는 기술이다. 무선 메쉬 네트워크는 기존 네트워크 기술과는 달리 노드의 이동성이 적고 에너지 영향도 덜 제한적인 특징을 가지고 있다. 따라서 이러한 네트워크 특성을 반영할 수 있는 경로 설정 기술이 필요하며 적합한 경로를 결정하기 위한 새로운 라우팅 메트릭이 요구된다. 본 논문에서는 데이터를 효율적으로 전달하기 위해 노드 간 링크 성능과 노드의 부하를 고려한 새로운 라우팅 메트릭을 제안한다.