• Review of KIISC
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• v.16 no.4
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• pp.69-76
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• 2006

센서 네트워크는 네트워크 특성상 근본적으로 기존의 네트워크와 다른 많은 제약 사항을 가지고 있다. 이러한 제약사항으로는 대량의 센서를 위한 비용 문제, 센서 자체의 물리적 취약성 문제 그리고 센서가 취합하는 데이터의 중요도에 따른 보안성 문제 등이 제기될 수 있다. 특히, 본 논문에서는 다양한 센서 네트워크의 기술 이슈 중에서 센서 네트워크의 특정 애플리케이션 지향적 정보 습득 특성에 초점을 맞추었다. 이때 센서 네트워크에서 빼놓을 수 없는 전력 소비 문제가 함께 고려된 센서 네트워크의 효율적인 데이터 수집을 위한 클러스터 기반 지연 적응적 전략과 커버리지 적응적 전략을 소개하였다. 또한 이러한 데이터 습득 과정에서 발생할 수 있는 이상 데이터에 대한 검출 문제를 제시하고 그 대응방안으로서 K-means clustering을 사용한 비교사 학습 기반 방식을 제하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.551-553
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• 2003

사용자는 기존의 간단한 아날로그 음성 서비스의 수준을 넘어서, 저렴한 서비스를 이용하여 고품질의 음성 서비스, 고속의 데이타 서비스, VOD, 화상회의 등의 서비스를 요구하고 있다. 가입자 요구에 맞는 멀티미디어 등의 광대역 서비스를 제공하는 한 방법은 가입자 댁내까지 광케이블망을 구축하는 것이다, 그러나 이런 광대역 케이블링이 예상되는 모든 가입자에게 제공되는 데는 장기간이 소요될 것이며, 막대한 비용이 투자되어야 하므로 그 실현이 요원하다. 동선을 활용한 xDSL 기술 중 VDSL 는 대칭/비대칭 서비스가 가능하며 최고 50Mbps 급의 멀티미디어 서비스가 가능하다. KT에서 현재 서비스를 제공중인 xDSL 서비스에 대해서 살펴보고 이들 장비를 관리 해주고 있는 IP-xDSL 망관리시스템 구조와 관리 기능 등을 고찰한다.

• Journal of the Semiconductor & Display Technology
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• v.14 no.3
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• pp.13-22
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• 2015

LED (Light Emitting Diode) lighting is gaining more and more market penetration as one of the global warming countermeasures. LED is the next generation of fusion source composed of epi/chip/packaging of semiconductor process technology and optical/information/communication technology. LED has been applied to the existing industry areas, for example, automobiles, TVs, smartphones, laptops, refrigerators and street lamps. Therefore, LED makers have been striving to achieve the leading position in the global competition through development of core source technologies even before the promotion and adoption of LED technology as the next generation growth engine with eco-friendly characteristics. However, there has been a point of view on the cost compared to conventional lighting as a large obstacle to market penetration of LED. Therefore, companies are developing a Chip-Scale Packaging (CSP) LED technology to improve performance and reduce manufacturing costs. In this study, we perform patent analysis associated with Flip-Chip CSP LED and flow chart for promising technology forecasting. Based on our analysis, we select key patents and key patent players to derive the business strategy for the business success of Flip-Chip CSP PKG LED products.

• Molecules and Cells
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• v.21 no.3
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• pp.315-329
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• 2006

Two, well characterized cationic channels, the ryanodine receptor (RyR) and the canonical transient receptor potential cation channel (TRPC) are briefly reviewed with a particular attention on recent developments related to the interplay between the two channel families.

• Communications of the Korean Mathematical Society
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• v.22 no.1
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• pp.65-74
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• 2007

Suppose that $\mu$ is a finite positive Borel measure on bounded symmetric domain $\Omega{\subset}\mathbb{C}^n\;and\;\nu$ is the Euclidean volume measure such that $\nu(\Omega)=1$. Suppose 1 < p < $\infty$ and r > 0. In this paper, we will show that the norms $sup\{\int_\Omega{\mid}k_z(w)\mid^2d\mu(w)\;:\;z\in\Omega\}$, $sup\{\int_\Omega{\mid}h(w)\mid^pd\mu(w)/\int_\Omega{\mid}h(w)^pd\nu(w)\;:\;h{\in}L_a^p(\Omega,d\nu),\;h\neq0\}$ and $$sup\{\frac{\mu(E(z,r))}{\nu(E(z,r))}\;:\;z\in\Omega\}$$ are are all equivalent. We will also show that the inclusion mapping $ip\;:\;L_a^p(\Omega,d\nu){\rightarrow}L^p(\Omega,d\mu)$ is compact if and only if lim $w\rightarrow\partial\Omega\frac{\mu(E(w,r))}{\nu(E(w,r))}=0$.

• Review of Korea Contents Association
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• v.15 no.4
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• pp.22-27
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• 2017

• The Journal of the Acoustical Society of Korea
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• v.28 no.2E
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• pp.35-42
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• 2009

In this paper, we present criteria of objective measurement of speech quality to provide the mobile-VoIP services efficiently over wireless mobile internet. The mobile-VoIP service, which is based on mobility and is error-prone compared to conventional VoIP over wired network, is about to be launched, but there have not been adequate quality indexes and the Quality of Service (QoS) standards for evaluating speech quality of Mobile-VoIP. In addition, there are many factors influencing on the speech quality in packet network of which packet loss contribute directly to the overall voice communication quality. For this reason, we adopt the Gilbert-Elliot Channel Model for modeling packet network based on IP and assess the voice quality through the objective speech method of ITU-T P. 862 PESQ and ITU-T P. 862.1 MOS-LQO under various packet loss rates in the transmission channel environments. Our simulation results address the specific criteria and QoS for the mobile-VoIP services in terms of the various packet loss environments.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.4
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• pp.229-236
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• 2005

This paper presents a system level architecture evaluation technique that leverages transaction level modeling but also significantly extends it to the realm of system level performance evaluation. A major issue lies with the modeling effort. To reduce the modeling effort the proposed technique develops the concept of worst case scenarios. Since the memory controller is often found to be an important component that critically affects the system performance and thus needs optimization, the paper further addresses how to evaluate and optimize the memory controllers, focusing on the test environment and the methodology. The paper also presents an industrial case study using a real state-of-the-art design. In the case study, it is reported that the proposed technique has helped successfully find the performance bottleneck and provide appropriate feedback on time.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.437-444
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• 2014

The integrated modular avionics (IMA) system has quite a number of line repalceable moduels (LRMs) in a cabinet. The LRM performs functions like line replaceable units (LRUs) in federated architecture. The video processing module (VPM) acts as a video bus bridge and gateway of ARINC 818 avionics digital video bus (ADVB). The VPM is a LRM in IMA core system. The ARINC 818 video interface and protocol standard was developed for high-bandwidth, low-latency and uncompressed digital video transmission. FPGAs of the VPM include video processing function such as ARINC 818 to DVI, DVI to ARINC 818 convertor, video decoder and overlay. In this paper we explain how to implement VPM's Hardware. Also we show the verification results about VPM functions and IP core performance.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.283-284
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• 2008

A cross-layer optimization is becoming a popular design methodology for the IP based next generation wireless network. We begin by investigating a cross-layer optimization scheme to enhance the system performance in wireless networks. By applying cross-layer optimization methodology to WiBro distributed network, the WiBro systems are expected to gain significant performance improvement and resource utilization enhanced. For further study we highlight some open challenges and new opportunities for cross-layer design.