• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.833-841
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• 1997

In this paper, the hybrid LB-TJW(Leaky Bucket-Triggered Jumping Window) algorithm for multimedia traffic control is proposed and its performance is evaluated and analyzed. Its architecture is composed of the peak bit rate controller and the average bit rate controller. Generally, the cell which violates the peak bit rate is discraded in LBalgorithm, and the average bit rate of JW or TJW algorithm is better than that of LB algorithm. However, the hybrid LB-TJW algorithm passes it though the network if the cell does not violate the peak bit rate. If the cell violates the peak bit rate, the hybrid LB-TJW algorithm passes it to the average bit rate controller which perforithm to monitor the average bit rate of input traffic. The TJW algorithm monitors the cell that violates the average bit rate. If the cell does not violate the average bit rare, the LB-TJW algorithm passes it through the network. As simulation results, the cell loss rate and the buffer size of the LB-TJW algorithm is reduced to half as much as those of LB algortihm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2300-2305
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• 2009

Recently, Telecommunication companies have introduced a new network architecture that assigns network resources consistent and protects their systems more secure. Now, they provide multimedia services through various types of access networks. In this study, I'd like to introduce IP address assignment method based on the Dynamic Host Configuration Protocol (DHCP) and find out how success or failure of Ip address assignment will be taken place according to the booting order of xDSL modem, AP and PC.

• Journal of Multimedia Information System
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• v.5 no.2
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• pp.139-142
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• 2018

This work presents a novel architecture of phase locked loop (PLL) with the current compensating scheme to improve phase noise characteristic. The proposed PLL has two charge pumps (CP), main-CP (MCP) and sub-CP (SCP). The smaller SCP current with same time duration but opposite direction of UP/DN MCP current is injected to the loop filter (LF). It suppresses the voltage fluctuation of LF. The PLL has a novel voltage controlled oscillator (VCO) consisting of a voltage controlled resistor (VCR) and the three-stage ring oscillator with latch type delay cells. The VCR linearly converts voltage into current, and the latch type delay cell has short active on-time of transistors. As a result, it improves phase noise characteristic. The proposed PLL has been fabricated with $0.35{\mu}m$ 3.3 V CMOS process. Measured phase noise at 1 MHz offset is -103 dBc/Hz resulting in 3 dBc/Hz phase noise improvement compared to the conventional PLL.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.583-587
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• 2003

웹 서비스는 인터넷을 통해 기업 상호간에 비즈니스를 연결할 수 있도록 하는 것으로, 서비스 구축의 개발비용의 감소와 구축속도 중진이 가능하다. 또한, 다른 영역과의 통합이 쉽게 가능하며, 컴포넌트 기반으로 개발할 경우 업데이트나 수정이 재사용성(reusability)과 대체성(replace ability)을 제공함으로써 용이하다. 본 논문에서는 서비스지향 아키텍처 상에서 공급자측면에서 구현되는 웹 서비스를 개발하기 위해서 구성되는 컴포넌트를 효율적으로 통합하기 위한 아키텍처를 제안하고자 한다 비즈니스로직을 웹 서비스로 제공하기 위해 먼저 서비스 지향 아키텍처를 정의하고, 이를 지원하고 웹 서비스를 제공하기 위한 컴포넌트를 Facade와 Backside로 정의한다. 특히, 서비스지향 아키텍처상에서의 웹 서비스 지원을 위한 Facade 컴포넌트와 외부 컴포넌트간의 연결을 위해 Facade 설계 패턴을 적용하여 웹 서비스를 위한 컴포넌트 통합을 제시한다. 이를 통해 비슷한 어플리케이션을 작성시에 막대한 생산비용과 개발시간의 절감을 기대할 수 있으며, 컴포넌트를 기반으로 웹 서비스를 구성하여 재사용성과 대체성에 대한 신뢰성 향상을 가져온다.

• Journal of Korea Multimedia Society
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• v.5 no.4
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• pp.468-476
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• 2002

Nowadays for reliable software and cost reduction there are many research works on software development based on component. One of the challenge in designing a component-based system is determining which components are required and where they fit in the overall system architecture. In this paper, we developed a EJB component for transforming RDB instances to XML documents. Accordly users can build XML applications based on relational database just by assembling this component. Consequently they can reduce time and cost for developing their XML applications.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1597-1608
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• 2016

Recently, a number of solutions were proposed to address the challenges and issues of vehicular networks. Vehicular Cloud Computing (VCC) is one of the solutions. The vehicular cloud computing is a new hybrid technology that has a remarkable impact on traffic management and road safety by instantly using vehicular resources. In this paper, we study an important vehicular cloud service, content-based delivery, that allows future vehicular cloud applications to store, share and search data totally within the cloud. We design a VCC-based system architecture for efficient sharing of vehicular contents, and propose a Hierarchical Hybrid Content Delivery scheme using Bloom Filter (H2CDBF) for efficient vehicular content delivery in Vehicular Ad-hoc Networks (VANETs). The performance of the proposed H2CDBF is evaluated through an analytical model, and is compared to the proactive content discovery scheme, Bloom-Filter Routing (BFR).

• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.816-827
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• 2008

In this paper, two-stage pipelined floating-point arithmetic unit (FP-AU) is designed. The FP-AU processor supports seventeen operations to apply 3D graphics processor and has area-efficient and low-latency architecture that makes use of modified dual-path computation scheme, new normalization circuit, and modified compound adder based on flagged prefix adder. The FP-AU has about 4-ns delay time at logic synthesis condition using $0.18{\mu}m$ CMOS standard cell library and consists of about 5,930 gates. Because it has 250 MFLOPS execution rate and supports saturated arithmetic including a number of graphics-oriented operations, it is applicable to mobile 3D graphics accelerator efficiently.

• Journal of Korea Multimedia Society
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• v.24 no.10
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• pp.1403-1413
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• 2021

In this paper, we investigate automated data validation techniques for artificial intelligence training, and also disclose open-source frameworks, such as Google's TensorFlow Data Validation (TFDV), that support automated data validation in the AI model development process. We also introduce an experimental study using public data sets to demonstrate the effectiveness of the open-source data validation framework. In particular, we presents experimental results of the data validation functions for schema testing and discuss the limitations of the current open-source frameworks for semantic data. Last, we introduce the latest studies for the semantic data validation using machine learning techniques.

• Journal of Korea Multimedia Society
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• v.24 no.10
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• pp.1336-1345
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• 2021

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neurological disorders in children. The diagnosis of ADHD in children is based on the interviews and observation reports of parents or teachers who have stayed with them. Since this approach cannot avoid long observation time and the bias of observers, another approach based on Electroencephalography(EEG) is emerging. The goal of this study is to develop an assistive tool for diagnosing ADHD by EEG classification. This study explores the frequency bands of EEG and extracts the implied features in them by using the proposed CNN. The CNN architecture has three Convolution-MaxPooling blocks and two fully connected layers. As a result of the experiment, the 30-60 Hz gamma band showed dominant characteristics in identifying EEG, and when other frequency bands were added to the gamma band, the EEG classification performance was improved. They also show that the proposed CNN is effective in detecting ADHD in children.

• Journal of Korea Multimedia Society
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• v.24 no.10
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• pp.1319-1325
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• 2021

It is important to remove fog for accurate object recognition and detection during preprocessing because images taken in foggy adverse weather suffer from poor quality of images due to scattering and absorption of light, resulting in poor performance of various vision-based applications. This paper proposes an end-to-end deep learning-based single image de-fogging method using U-Net architecture. The loss function used in the algorithm is a loss function based on Mahalanobis distance with fog features, which solves the problem of domain shifts, and demonstrates superior performance by comparing qualitative and quantitative numerical evaluations with conventional methods. We also design it to generate fog through the VGG19 loss function and use it as the next training dataset.