• Title/Summary/Keyword: Imperfect power control

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Whom does Harry's Magic Power Benefit?: Imperialistic Ideas of Children in The Harry Potter Books ("누구를 위한 마법능력인가?" -『해리 포터』와 영국 제국주의 아동관)

  • Park, Sojin
    • Journal of English Language & Literature
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    • v.55 no.1
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    • pp.3-24
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    • 2009
  • The Harry Potter series is considered to represent the multicultural aspect of contemporary British society and to show critical perspectives of racism. This series, however, also includes many elements of British imperialism. This paper examines the ideas about education and Harry's role in relation to British imperialism. One of the main ideas prevalent in 19th century British boys' public schools was that people's blood origin is the most important element in determining their characteristics, ability and moral qualities. The students' inherited capacity and their family background are more highly regarded than their secondary learning and training. This reflects a 19th century concept that ultimately, inborn quality makes 'a hero', a truth presented in the educational policies of Hogwarts. Hogwarts' educational policies and systems can also be related to 'developmentalism', which defines children as imperfect, in-progress and incomplete, thus needing proper training and discipline. As this concept functioned to justify the control of children while educating them, Hogwarts adopts diverse controlling devices and oppressive policies, which are mainly justified in the name of education. On the one hand, child characters are controlled and oppressed by the school authorities, on the other hand, some of the students such as Harry have remarkable magic powers enough to resist the adult authority and even to save the magic society from the evil power. Harry plays dual roles, which the British boys of the Empire were assigned from their society; they are important heirs to conquer the 'evil' or 'barbarous' world but need to be obedient to a 'good' authority to achieve the mission. Harry's magic power and self-discipline ultimately contribute to fulfilling Dumbledore's mission, which mirrors 19th century British boys' roles as the heirs of the British Empire.

Efficient Performance Enhancement Scheme for Adaptive Antenna Arrays in a Rayleigh Fading and Multicell Environments

  • Kim Kyung-Seok;Ahn Bierng-Chearl;Choi Ik-Gueu
    • Journal of electromagnetic engineering and science
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    • v.5 no.2
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    • pp.49-60
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    • 2005
  • In this paper, an efficient performance enhancement scheme for an adaptive antenna array under the flat and the frequency-selective Rayleigh fadings is proposed. The proposed signal enhancement scheme is the modified linear signal estimator which combines the rank N approximation by reducing noise eigenvalues(RANE) and Toeplitz matrix approximation(TMA) methods into the linear signal estimator. The proposed performance enhancement scheme is performed by not only reducing the noise component from the signal-plus-noise subspace using RANE but also having the theoretical property of noise-free signal using TMA. Consequently, the key idea of the proposed performance enhancement scheme is to greatly enhance the performance of an adaptive antenna array by removing all undesired noise effects from the post-correlation received signal. The proposed performance enhancement scheme applies at the Wiener maximal ratio combining(MRC) method which has been widely used as the conventional adaptive antenna array. It is shown through several simulation results that the performance of an adaptive antenna array using the proposed signal enhancement scheme is much superior to that of a system using the conventional method under several environments, i.e., a flat Rayleigh fading, a fast frequency-selective Rayleigh fading, a perfect/imperfect power control, a single cell, and a multicell.

Performance Evaluation of Convolution Coding OFDM Systems (컨볼루션 코딩 OFDM 시스템의 성능 분석)

  • Choi, Seung-Kuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.2
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    • pp.294-301
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    • 2013
  • OFDM technique uses multiple sub-carriers for the data transmission. Therefore, bit error rate increases because of inter-carrier interference caused by nonlinear high power amplifier and carrier frequency offset. Wireless OFDM transmission over multi path fading channels is characterized by small transmission gain in multiple sub-carrier frequency interval. Therefore bit error rate increases because of burst errors. Inter-leaver and convolution error control coding are effective for the reduction of this burst error. Pilot symbol is used for the channel estimation in OFDM systems. However, imperfect channel estimates in this systems degrade the performance. The performance of this convolution coding OFDM systems using inter-leaver, gauged by the bit error rate, is analyzed considering the nonlinear high power amplifier, carrier frequency offset and channel estimation error.

Performance Evaluation of Multi-User Detectors Employing Subtractive Interference Cancellation Schemes for a DS-CDMA System (감산형 간섭제거기법을 적용한 DS-CDMA 다중사용자 검파기의 성능분석)

  • Seo, Jung-Wook;Kim, Young-Chul;Oh, Chang-Heon;Ko, Bong-Jin;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
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    • v.6 no.1
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    • pp.17-26
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    • 2002
  • In this paper, we have analyzed the BER (Bit Error Rate) performance of multi-user detectors employing SIC(Successive Interference Cancellation) and PIC (Parallel Interference Cancellation) which are the representative schemes in the subtractive interference cancellation. We have considered the MUD structure employing HIC (Hybrid Interference Cancellation) which combines SIC with PIC scheme, and then analyzed the BER performance. We have evaluated the BER performance of SIC and HIC schemes which execute the soft decision to generate the tentative data bit for the purpose of the interference cancellation in MAI and noise environments. Through the numerical analysis and computer simulation, it is shown that HIC can remove the effect of MAI more efficiently than the others, that improve the BER performance and increase the capacity of DS-CDMA systems regardless of the power control conditions. The reason is that the SIC scheme in front of HIC can solve the near-far problem caused by the imperfect power control and PIC scheme in the rear of it can improve the performance much more.

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Development of Door Control Unit for the Electric Plug-in Door of Subway Train (전동차 전기식 플러그도어 출입문 제어 장치 개발)

  • Joung, Eui-Jin
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.4
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    • pp.47-53
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    • 2011
  • The Electric Multiple Unit (EMU) has many types of door system such as sliding door, plug door etc.al. according to customer's requirements. The sliding door is widely used in Korea but has weak point in the noise problem. In the low operation speed, the noise coming from outer side of the EMU is not an important factor. As the speed is higher than before, noise is increased and make a problem. The main cause of noise is the imperfect air tightness in the EMU. The plug door system has advantages for the noise reduction characteristic in the high speed area. We have been developing electric plug-in door. The door is controlled by Door Control Unit(DCU) following the order of Automatic Train Protection (ATP) that is a kind of train signalling system. DCU has to simultaneously open and close the doors and the operation of it is related to the passengers safety. So DCU is a safety device that is important to reliability and safety. DCU is composed of several devices of control, motor driving, Input/Output, communication and power. In this paper, we will describe the functions, characteristic, requirement, subsystem and test results of DCU used for the electric plug-in door.