• Title/Summary/Keyword: Internet broadcasting

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Performance Analysis of a TH-PPM UWB System using Dyadic Tree Structure (다이애딕 구조를 이용한 TH-PPM UWB 시스템의 성능 분석)

  • Park, Joong-Hoo;Choi, Ginkyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.3
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    • pp.87-92
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    • 2008
  • In this paper, certain scaling functions are generated using the dyadic subband tree structure and applied to a time-hopping, pulse position modulation, ultra-wideband (TH-PPM UWB) system. Scaling functions can be obtained by iterating a lowpass filter at each level using a critically sampled dyadic tree. The performance of the TH-PPM UWB system employing scaling functions as the mono-cycle waveform is evaluated through computer simulations in a Rayleigh fading environment.

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Developing two Dimensional Film Speaker using Piezoelectric Materials

  • Um, Keehong;Lee, Dong-Soo
    • International Journal of Internet, Broadcasting and Communication
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    • v.4 no.1
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    • pp.1-2
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    • 2012
  • A speaker is a system which produces sound through electromechanical operations. It transforms electronic signals into audible sound signals. Almost all speakers are three dimensional. These days, many mobile electronic devices such as mobile electronic devices have become smaller and thinner. A problem with this miniaturization, however, is that the volume of speakers has also decreased. In contrast to conventional three dimensional speakers, we have invented a new type of two dimensional flexible speaker by utilizing the reverse piezoelectric effect.

Context-Awareness for Location Based-Service for Ubiquitous Learning with underlying Principles of Ontology, Constructivism, Artificial Intelligence

  • Gelogo, Yvette;Kim, Hye-jin
    • International Journal of Internet, Broadcasting and Communication
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    • v.4 no.2
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    • pp.7-11
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    • 2012
  • In this paper, we defined constructivism and ontology theory and associate it in ubiquitous learning. The typical ubiquitous learning involving the Context Aware Intelligent system was presented. Also the Architecture for learning environment including the key idea and technical concept is being presented in this paper. Guided with these principles and with the advancement of information and communication technology the context-awareness based on Artificial intelligence for Location based Service for ubiquitous Learning was conceptualized.

A Study of WiMAX Security threats and Their Solution

  • Woo, Seon-mi;Jeong, Gisung
    • International Journal of Internet, Broadcasting and Communication
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    • v.8 no.2
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    • pp.66-74
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    • 2016
  • In this study, we have discussed and illustrated the security issues of WiMAX technology including vulnerabilities, threats and some security solution. Both physical layer and data link layer have been considered. Jamming is a major threat in physical layer, and in data link layer we study an authentication problem and see the problem of some unencrypted messages leading to lack of confidentiality. Some of these vulnerabilities have been solved in the recent amendment of 802.16 and some still remain. Moreover WiMax is a new technology yet.

Modelling the Mode Behavior of Circular Vertical-Cavity Surface-Emitting Laser

  • Ho, Kwang-Chun
    • International Journal of Internet, Broadcasting and Communication
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    • v.4 no.2
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    • pp.22-27
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    • 2012
  • The design characteristics of circular vertical-cavity surface-emitting lasers are studied by using a newly developed equivalent network. Optical parameters, such as the stop-band or the reflectivity of periodic mirrors and the resonance wavelength, are explored for the design of these structures. To evaluate the differential quantum efficiency and the threshold current density, a transverse resonance condition of modal transmission-line theory is also utilized. This approach dramatically reduces the computational time as well as gives an explicit insight to explore the optical characteristics of circular vertical-cavity surface-emitting lasers (VCSELs).

Inductive Sensor and Target Board Design for Accurate Rotation Angle Detection

  • Hwang, Jae-Jeong;Moon, Joon
    • International Journal of Internet, Broadcasting and Communication
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    • v.9 no.1
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    • pp.64-70
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    • 2017
  • In the commercial building such as huge enterprise building, more accurate operation of the center-controlled roller blind. We design, in this work, the target disc that its shape is nonlinearly changing and the sensor coils that are differentially arranged. The performance shows less than 1% accuracy when it is implemented in the roller blind.

Design of STEAM Education Process applying 3D Printer for Computational Thinking

  • Kim, Woo Yeol
    • International Journal of Internet, Broadcasting and Communication
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    • v.10 no.1
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    • pp.23-30
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    • 2018
  • Many practitioners in educational field, recently, are seeking to improve Computational Thinking through SW education. The purpose of this paper was, for promotion of SW education, to design the STEAM education process utilizing 3D printer. The project-based education process emphasized the cooperation in the process of producing common results and proposed a new STEAM education process. The designed products are expected to be used in the elementary school classes by linking with the camp and teacher training programs and the curriculum.

A Study on the Development of ERP

  • Lee, Soowook
    • International Journal of Internet, Broadcasting and Communication
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    • v.8 no.3
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    • pp.58-62
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    • 2016
  • Due to the rapidly changing global business environment and global management environment, companies must actively act for competitiveness. By examining the development process of Enterprise Resource Planning (ERP), there is a chance to optimize the organization and find measures to improve the company competitiveness. It seems examining task process, and studying the influence of ERP introduction to management performance by considering whether the excessive maintenance cost or repetitive investment toward ERP is quiet significant. The companies which instituted ERP uses "business process model" provided by "Best Practice" compare own task to choose much efficient method. This allows simultaneous realization of ERP institution and Business Reengineering (BR).

Nonlinear Time-Varying Control Based on Differential Geometry

  • Lee, Jong-Yong;Jung, Kye-dong;Cho, Seongsoo;Strzelecki, Michat
    • International Journal of Internet, Broadcasting and Communication
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    • v.6 no.2
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    • pp.1-9
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    • 2014
  • This paper presents a study on nonlinear time varying systems based on differential geometry. A brief introduction about controllability and involutivity will be presented. As an example, the exact feedback linearization and the approximate feedback linearization are used in order to show some application examples.

Reduction of Block Overlap in Motion Estimation

  • Cho, Seongsoo;Shrestha, Bhanu;Lee, Jongsup
    • International Journal of Internet, Broadcasting and Communication
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    • v.6 no.2
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    • pp.10-12
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    • 2014
  • This work is based on the motion estimation to handle the ill-posed nature. The algorithm used in this study that performs the motion estimation for overlapped block is used to calculate with using pixel of neighborhood block with higher correlation and present block by considering the correlation level of neighborhood block. The proposed method shows in a significant improvement in the quality of the mothion field when comparing the conventional methods.