• Title/Summary/Keyword: Telecommunication

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Wavelet Compression Technique for Efficient Image Transmission in Wireless Sensor Networks (무선 센서 네트워크에서 효율적인 이미지 전송을 위한 웨이블릿 압축 기법)

  • YoungWan Kwon;ChongMyung Park;JoaHyoung Lee;InBum Jung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2008.11a
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    • pp.946-949
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    • 2008
  • 저가형 이미지 센서와 무선 센서 네트워크의 하드웨어 성능 향상으로 인해 WMSN(Wireless Multimedia Sensor Networks) 기술이 주목받고 있다. WMSN은 기존의 무선 센서 네트워크 기술에 멀티미디어 정보를 센싱하고 처리하는 기반기술을 포함한다. 멀티미디어 컨텐츠는 많은 데이터양을 가지므로 이를 처리하기 위해서는 많은 계산량과 데이터 전송량을 필요로 하게 된다. 저사양의 센서 노드에서 이를 수용하기 위해서는 에너지 소모를 고려한 압축 기법 및 효율적인 전송에 대한 연구가 필요하다. 본 논문에서는 무선 센서 네트워크에서 이미지를 효율적으로 압축하고 전송하기 위하여 웨이블릿의 Resolution Scalability 특성을 이용한 4가지 움직임 보상/예측 기법을 제안하고, 압축 성능과 발생 패킷 수, 에너지 소모량을 비교하였다.

Sustaining Low-Carbon Emission Development: An Energy Efficient Transportation Plan for CPEC

  • Zubedi, Asma;Jianqiu, Zeng;Arain, Qasim Ali;Memon, Imran;Khan, Sehrish;Khan, Muhammad Saad;Zhang, Ying
    • Journal of Information Processing Systems
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    • v.14 no.2
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    • pp.322-345
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    • 2018
  • Climate change has become a major challenge for sustainable development of human society. This study is an attempt to analyze existing literature to identify economic indicators that hamper the process of global warming. This paper includes case studies based on various countries to examine the nexus for environment and its relationship with Foreign Direct Investment, transportation, economic growth and energy consumption. Furthermore, the observations are analyzed from the perspective of China-Pakistan Economic Corridor (CPEC) and probable impact on carbon emission of Pakistan. A major portion of CPEC investment is allocated for transportation. However, it is evident that transportation sector is substantial emitter of carbon dioxide (CO2) gas. Unfortunately, there is no empirical work on the subject of CPEC and carbon emission for vehicular transportation. This paper infers that empirical results from various other countries are ambiguous and inconclusive. Moreover, the evidence for the pollution haven hypothesis and the halo effect hypothesis is limited in general and inapplicable for CPEC in particular. The major contribution of this study is the proposal of an energy efficient transportation model for reducing CO2 emission. In the end, the paper suggests strategies to climate researchers and policymakers for adaptation and mitigation of greenhouse gases (GHG).

Mobile Telecommunication Policy Analysis of Moon Government In Korea (문재인 정부의 이동통신정책 분석)

  • Shin, Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.12
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    • pp.2387-2393
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    • 2017
  • The Moon government, launched in May 2017, regards telecommunication service as part of people's welfare and is trying to save telecommunication costs. However, the direction of policy presented is assessed as symptomatic approach. This is largely attributable to the a partial improvement approach from the framework of the present mobile telecommunication industry. However if we restart from an essential point of view, the result is likely to be much better. The nation's mobile communication costs are not adequate because the government's role was not sufficient. There is a problem with the mobile phone supply chain, the subsidy payment mechanism, and the billing system. Addressing these complex issues requires the establishment of an independent system of handset distribution from telecommunication companies, ban on discriminative subsidies payment, and adoption of volume rate system. Telecommunications Business Act that defines the service charges to normalize the market might be somewhat useful, but the normal application of the Fair Trade Act is more important.

1.31 um Uncooled DFB-LD with High Slope Efficiency for G-PON Application (G-PON용 높은 전광변환효율을 갖는 1.31 um 비냉각 DFB-LD)

  • Kim, Jeong-Ho;Pi, Joong-Ho;Kim, Deok-Hyun;Park, Chil-Sung;Ryu, Han-Gwon;Koo, Bon-Jo
    • Korean Journal of Optics and Photonics
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    • v.18 no.5
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    • pp.333-336
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    • 2007
  • A Strained Layer Multiquantum-Well (SL-MQW) distributed feedback laser at a wavelength of 1.31 um operating from $-40^{\circ}C$ to $85^{\circ}C$ without any cooling is grown by metal-organic chemical vapor deposition (MOCVD). Lasers with high slope efficiency are achieved through careful optimization of a SL-MQW active layer, especiallyoptimizing the amount of strain, the well thickness, the barrier thickness, the number of wells, and the active layer width. In this paper, we obtain the slope efficiencies of 0.38[mW/mA] and 0.26 [mW/mA] at $25^{\circ}C$ and $85^{\circ}C$, respectively. Threshold currents are 7.1[mA] and 19.8[mA] at $25^{\circ}C$ and $85^{\circ}C$, respectively.

The novel encapsulation method for organic thin-film transistor (새로운 방식의 유기박막트랜지스터 패시베이션 기술)

  • Lee, Jung-Hun;Kim, Seong-Hyun;Kim, Ki-Hyun;Lim, Sang-Chul;Cho, Eu-Na-Ri;Jang, Jin;Zyung, Tae-Hyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05a
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    • pp.177-180
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    • 2004
  • In this study, we report a novel encapsulation method for longevity of an organic thin-film transistor (OTFT) using pentaceneby means of an adhesive multiplayerincluded Al film. For encapsulation of OTFTs, the Al film adhered onto the OTFT in a dry nitrogen atmosphere using a proper adhesive. A lifetime, which was defined as the time necessary to reduce mobility to 2% of initial mobility value, was observed from the typical $I_{D-VD}$ characteristics of the field-effect transistor (FET). The initial field effect mobility ${\mu}$ was measured to be $2.0{\times}10^{-1}\;cm^2/Vs$. The characterization was maintained for long times in air. No substantial degeneration occurred. The performance and the stability are probably due to the encapsulation effect.

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