• Title/Summary/Keyword: Walsh

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Qualitative Analysis the Family Resilience of Divorced Female Single-Parent Families (이혼한 여성 한부모가족의 가족 레질리언스에 대한 질적분석)

  • You, Soonhee;Jung, Minja
    • Human Ecology Research
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    • v.51 no.6
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    • pp.603-612
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    • 2013
  • With the increase of single-parent families in the Korean society, the perception of the function and structure of the family is changing. Thus, a public transition toward embracing single-parent families as another form of family is necessary. This study focuses on the families of divorced female single-parents using Walsh's family resilience framework with a strengths-based perspective. It aims to provide the basic data necessary for deducing policy-related and practical ways of supporting the families and for developing programs that help divorced female single-parent families maintain and reinforce resilience. Qualitative analysis was used as the research method. A preceding literature review was also carried out to collect data. The major findings of this study include the following: First, it was found that the average age of divorce is around 30-40, with children of school age. The mothers' level of education was relatively high, ranging from high school graduates to graduate school students. On Rothwell and Cohen's happiness scale, their objective level of happiness was higher (74.1) than that of the average Korean (64). Second, it was found they were very careful to avoid violence in everyday life as an after-effect of domestic violence, which was the major cause of their divorce. Third, their positive and optimistic attitudes about life even in adversity can be interpreted as Walsh's belief systems taking a more important role among other characteristics of family resilience.

An Efficient Channel Estimation Method in MIMO-OFDM Systems (MIMO-OFDM 시스템에서 효율적인 채널 추정 방식)

  • Jeon, Hyoung-Goo;Kim, Jun-Sig
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.10
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    • pp.2275-2284
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    • 2015
  • In this paper, the Walsh coded orthogonal training signals for 4 × 4 multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) systems are designed and the channel estimation equations are derived as a closed form, taking account of the inter training signal interference problems caused by the multi-path delayed signals. The performances of the proposed channel estimation method are analyzed and compared with the conventional methods[9,14] by using computer simulation. The simulation results show that the proposed methods has better performances, compared with the conventional methods[9,14]. As a result, the proposed method can be used for MIMO-OFDM systems with null sub-carriers.

High Speed Identification Method of RFID Tag (RFID 태그의 고속 인식 기법)

  • 이광재
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.1
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    • pp.6-12
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    • 2004
  • Identification rate and time are very important in the identification of RFID tag, and the tag requires simple structure to use economically large quantity of tags. These factors make the MAC protocols of wired or wireless network environment result in different requirements. In the paper, we propose a method to apply spread spectrum scheme using orthogonal channel via Walsh function as the anti-collision communication system for the purpose of non-collision identification of multiple tags, and consider its property. The proposed system use two step identification. in the first step, collision is resolved via constructing to respond after specific delay time based on unique n, and conventional polling scheme follows in the second step.

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Transceiver for Human Body Communication Using Frequency Selective Digital Transmission

  • Hyoung, Chang-Hee;Kang, Sung-Weon;Park, Seong-Ook;Kim, Youn-Tae
    • ETRI Journal
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    • v.34 no.2
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    • pp.216-225
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    • 2012
  • This paper presents a transceiver module for human body communications whereby a spread signal with a group of 64 Walsh codes is directly transferred through a human body at a chip rate of 32 Mcps. Frequency selective digital transmission moves the signal spectrum over 5 MHz without continuous frequency modulation and increases the immunity to induced interference by the processing gain. A simple receiver structure with no additional analog circuitry for the transmitter has been developed and has a sensitivity of 250 ${\mu}V_{pp}$. The high sensitivity of the receiver makes it possible to communicate between mobile devices using a human body as the transmission medium. It enables half-duplex communication of 2 Mbps within an operating range of up to 170 cm between the ultra-mobile PCs held between fingertips of each hand with a packet error rate of lower than $10^{-6}$. The transceiver module consumes 59 mA with a 3.3 V power supply.

Study of the Improved Fast Correlation Attack on Stream Ciphers (스트림 암호에 대한 향상된 고속 상관 공격 적용 가능성 연구)

  • Jeong, Ki-Tae;Lee, Yu-Seop;Sung, Jae-Chul;Hong, Seok-Hie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.5
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    • pp.17-24
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    • 2009
  • Zhang et al. proposed a improved fast correlation attack on stream ciphers at SAC'08[8]. This attack is based on the fast correlation attack proposed at Crypto'00 and combined with FWT(fast Walsh transform). Given various attack environments, they presented complexities and success probabilities of the proposed attack algorithm. However, we found that our simulation results of the proposed attack algorithm are different from them presented in [8]. In this paper, we correct results of the proposed attack algorithm by analyzing it theoretically. And we propose a threshold of valid bias.

Performance Evaluation of FD-CI-OFDM System with PAPR Reduction and Frequency Diversity Effects (PAPR 감소와 주파수 다이버시티 효과를 갖는 FD-CI-OFDM 시스템의 성능 평가)

  • Kim, Seon-Ae;Lee, Il-Jin;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.4
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    • pp.381-389
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    • 2009
  • Orthogonal frequency division multiplexing(OFDM) that is very useful for the high-speed communication system has serious problem of high peak-to-average power ratio(PAPR) in time domain. Because of this, the non-linear distortion can be produced and system performance gets worse. CI-OFDM system can get the peak power lowered. In this CI-OFDM system, each parallel data is distributed into N all sub-carriers and conveyed by the orthogonal phase factor. Also, CI-OFDM shows frequency diversity effect. Therefore, CI-OFDM system is better than ordinary OFDM system in terms of BER performance and the PAPR reduction. When it is implemented, however, there is a serious problem whether it can separate and compensate the phase factor in order in the receiver. Because all bits are transmitted simultaneously over all subcarriers and each other phase factors in transmitter. In this paper, we propose and evaluate a FD-CI-OFDM system that is a version of improved CI-OFDM. This is designed by use of the Walsh Hadamard sequence. The FD-CI-OFDM shows better performance than ordinary OFDM and CI-OFDM system.

A general fracture criterion solely in terms of stress intensity factors (용력 세기인수로만 표기되는 파괴기준 일반식)

  • Lee, Kang Y.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.2
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    • pp.94-100
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    • 1981
  • McClintock 와 Walsh 의 개념을 발전시키므로써 2차와 3차계에서의 열적 기계적 파괴 기준식을 구하였다. Griffith Theory 와 파괴역학에 기초를 두고서 전개된 응력세기 인수로만 표기된 2차와 3차계의 파괴기준식은 동일한 관계식 즉, ( $k_{2}$/ $k_{2c}$ )$^{2}$+ $k_{1}$/ $k_{1c}$ =1로 표시된다는 것을 보였다. 3차계에서 열적 기계적 하중하에서 응역세기 인수에 관한 일반식을 Crack 의 닫힘을 고려하여 유도하였다.

Thermo-Mechanical stress analysis for partial or entire crack closure (크랙의 부분 또는 완정닫힘에 관한 열 및 기계적 응력해석)

  • Lee, Kang Yong
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.3
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    • pp.193-198
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    • 1981
  • Muskhelishvili 의 복소수방법에 의해 일반적 하중 즉 열 및 기계적 하중을 받는 무한 탄성체내에 공동을 가정하고 그 주위의 응력 및 변위를 유도하였다. 선형트랙(line rack)이 부분적으로 또는 완정히 닫힐 임계하중조건과 그때의 응력세기 계수 (stress intensity factor)를 McClintork와 Walsh 의 크랙닫힘에 관한 결정에 기초를 두고 해석학적으로 유도하였다.

Algebraic Observer Design for Descriptor Systems via Block-pulse Function Expansions (블록펄스함수 전개를 이용한 Descriptor 시스템의 대수적 관측기 설계)

  • 안비오
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.6
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    • pp.259-265
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    • 2001
  • In the last two decades, many researchers proposed various usages of the orthogonal functions such as Walsh, Haar and BPF to solve the system analysis, optimal control, and identification problems from and algebraic form. In this paper, a simple procedure to design and algerbraic observer for the descriptor system is presented by using block pulse function expansions. The main characteristic of this technique is that it converts differential observer equation into an algerbraic equation. And furthermore, a simple recursive algorithm is proposed to obtain BPFs coefficients of the observer equation.

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Preliminary Simulation Analysis of the LASGIT Experiment (방사성 폐기물의 지중저장을 위한 스웨덴 LASGIT 실험의 예비적인 시뮬레이션 분석)

  • Park, Chan-Hee;Walsh, Robert
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.197.2-197.2
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    • 2011
  • Preliminary analysis on the modeling conditions and the simulation results is conducted only to evaluate the correctness of the simulation configuration further to apply for the LASGIT project. Except for the unrealistic modeling conditions for the relations of capillary pressure and relative permeability against water saturation used previously, the simulation results successfully demonstrate Helium propagation typical for two-phase flow. Further elaborated simulation with more realistic parameters should complete the weak points of the preliminary work.

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