• Title/Summary/Keyword: Adaptive Effect

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Optimum Array Processing with Variable Linear Constraint

  • Chang, Byong Kun
    • Journal of information and communication convergence engineering
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    • v.12 no.3
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    • pp.140-144
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    • 2014
  • A general linearly constrained adaptive array is examined in the weight vector space to illustrate the array performance with respect to the gain factor. A narrowband linear adaptive array is implemented in a coherent signal environment. It is shown that the gain factor in the general linearly constrained adaptive array has an effect on the linear constraint gain of the conventional linearly constrained adaptive array. It is observed that a variation of the gain factor of the general linearly constrained adaptive array results in a variation of the distance between the constraint plane and the origin in the translated weight vector space. Simulation results are shown to demonstrate the effect of the gain factor on the nulling performance.

Polyphase Representation of the Relationships Among Fullband, Subband, and Block Adaptive Filters

  • Tsai, Chimin
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1435-1438
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    • 2005
  • In hands-free telephone systems, the received speech signal is fed back to the microphone and constitutes the so-called echo. To cancel the effect of this time-varying echo path, it is necessary to device an adaptive filter between the receiving and the transmitting ends. For a typical FIR realization, the length of the fullband adaptive filter results in high computational complexity and low convergence rate. Consequently, subband adaptive filtering schemes have been proposed to improve the performance. In this work, we use deterministic approach to analyze the relationship between fullband and subband adaptive filtering structures. With block adaptive filtering structure as an intermediate stage, the analysis is divided into two parts. First, to avoid aliasing, it is found that the matrix of block adaptive filters is in the form of pseudocirculant, and the elements of this matrix are the polyphase components of the fullband adaptive filter. Second, to transmit the near-end voice signal faithfully, the analysis and the synthesis filter banks in the subband adaptive filtering structure must form a perfect reconstruction pair. Using polyphase representation, the relationship between the block and the subband adaptive filters is derived.

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On the Performances of Block Adaptive Filters Using Fermat Number Transform

  • Min, Byeong-Gi
    • ETRI Journal
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    • v.4 no.3
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    • pp.18-29
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    • 1982
  • In a block adaptive filtering procedure, the filter coefficients are adjusted once per each output block while maintaining performance comparable to that of widely used LMS adaptive filtering in which the filter coefficients are adjusted once per each output data sample. An efficient implementation of block adaptive filter is possible by means of discrete transform technique which has cyclic convolution property and fast algorithms. In this paper, the block adaptive filtering using Fermat Number Transform (FNT) is investigated to exploit the computational efficiency and less quantization effect on the performance compared with finite precision FFT realization. And this has been verified by computer simulation for several applications including adaptive channel equalizer and system identification.

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Adolescent Runaway: The Impact of Family, Individual Factors and Coping Behavior (청소년의 가출: 가족적, 개인적 요인 및 대처행동의 영향)

  • 현은민
    • Journal of the Korean Home Economics Association
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    • v.38 no.2
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    • pp.41-56
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    • 2000
  • This study focused on the effects of family, individual characteristics of adolescents and coping behaviors on adolescent runaway. The major findings were as follows: 1. Adolescent who had higher level of family violence, lower level of communication with parent, family cohesion and adaptability, and resource adequacy perception reported higher scores in runaway. 2. Adolescents who had higher level of emotional distress, lower level of self-esteem and self-control tended to have higher scores in runaway. 3. There was a significant difference in adolescent runaway according to coping behavior styles. 4. Maladaptive coping behaviors were significantly associated with the runaway adolescent group. 5. Adaptive coping behaviors were not associated with both runaways and non-runaways group. 6. Communication with father had a direct effect on adolescent runaway and also indirect effects through emotional stress and maladaptive coping behavior. 7. Maladaptive coping behaviors had a direct effect on adolescent runaway but adaptive coping behavior had no effect. 8. Emotional stress had an indirect effect through maladaptive coping behavior on adolescent runaway. 9. Communication with father had a direct effect and an indirect effect through self-esteem of adolescents on the adaptive coping behavior. 10. Family adaptability had a direct effect on the adaptive coping behavior.

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The Mediating Effect of Humor on the Relationship between Perceived Stress and Depression in College Students (대학생의 지각된 스트레스와 우울의 관계에서 유머의 매개효과)

  • Hong, Eunyoung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.20 no.4
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    • pp.558-568
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    • 2014
  • Purpose: This study examines the relationships among perceived stress, humor style, responding humor and depression among college students and the mediating effect of humor between perceived stress and depression. Method: During the period May 6-16, 2013, a convenience sample of 200 subjects was obtained from college K in city G. Data analysis was performed by Pearson's correlation coefficients and regression analysis. Results: The average BDI score was 7.7. There were 40 (20.0%), 16 (8.0%), 8 (4.0%), and 11 (9.0%) students with mild, moderate, and severe depression, respectively. The group with depressive symptoms constituted 3.5% of students. There was a significant positive correlation between negative stress perception and depression. Conversely, there was a significant negative correlation between adaptive humor style and negative stress perception. Ultimately, there were significant negative correlations between positive stress perception, adaptive humor style, maladaptive humor style, responding humor and depression. To test the mediating effect of adaptive humor style in the relationship between negative stress perception and depression, a Sobel test was performed and Z-score of 1.7736 (p=.076) obtained. Conclusion: Though the mediating effect of an adaptive humor style on the relationship between perceived stress and depression was not significant, considering the negative correlation with depression, strategies to increase an adaptive humor style and responding humor is recommended to prevent depression in college students.

The Effect of Cordyceps militaris on Adaptive Immune Responses in DBA2 Mice Immunized with Influenza Vaccine (밀리타리스 동충하초(Cordyceps militaris)의 인플루엔자백신 적응면역에 미치는 영향)

  • Lee, Hwan Hee;Cho, Hyosun
    • YAKHAK HOEJI
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    • v.59 no.1
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    • pp.1-5
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    • 2015
  • Cordyceps militaris has shown to have various pharmacological activities including an immune-modulatory effect. Previously, we reported that anti-influenza effect of C. militaris in DBA/2 mice was mediated by increased IL-12 and the activation of NK cells. In this study, we investigated the effect of C. militaris on adaptive immune responses using DBA2 mice immunized with influenza vaccine. To determine the effect of C. militaris on antigen presentation capability, we treated RAW 264.7 cells with various concentrations of ethanol extract of C. militaris, which showed a significant upregulation of CD86 (B7.2), CD284 (TLR4), CD40, H-2k (MHC I) and I-Ad (MHC II). To examine the direct effect of C. militaris on adaptive immune responses, we immunized DBA2 mice with influenza vaccine in presence or absence of C. militaris. After 2 or 4 weeks, influenza-specific T cell proliferation, HAI titers and IFN-${\gamma}$ production were measured in plasma or PBMCs isolated from animals. Influenza-specific T cell proliferation and HAI titers were not considerably increased in immunized mice in presence of C. militaris. However, the production of IFN-${\gamma}$ was much greater in immunized mice with C. militaris as adjuvant than only immunized mice.

Exploratory Study on Self-Fulfillment Effect of Self-Designing Process in Adaptive Customization Services

  • Lee, Eun-Jung;Son, Jin-Ah
    • International Journal of Human Ecology
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    • v.15 no.1
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    • pp.51-63
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    • 2014
  • Services for self-designing, or adaptive customization services, have become dominant in virtual marketplaces and are believed to create additional values both for the company as well as for the customer. While most research focused on the value from the services' outputs, this research attempts to address the customer-perceived value deriving from the process of the services, and focuses on the self-fulfillment effect of the involved mental processing. An online survey was administered with 313 U.S. shoppers. In the results, participants using adaptive customization services reported higher self-fulfillment perceptions, than did those not using the services. Furthermore, both the self-fulfillment perceptions (i.e., autonomy and competence) significantly increased perceived design utility. The results suggest that the process of adaptive customization services should be strategically managed to improve the customers' positive mental states that subsequently improve the perceived value of the output designs. Implications and suggestions for future studies are dsicussed.

Effect of Residual Frequency Offsets on the Performance of Adaptive Equalizers (잔여 주파수 옵셋이 적응 등화기의 성능에 미치는 영향)

  • Kim, Young-Wha;Cho, Sung-Ho
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.4E
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    • pp.108-111
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    • 2004
  • This paper has interest in the effect of a fine frequency offset, defined in ITU-T G.225, to the training performance of an adaptive equalizer. This paper uses Hilbert filter in configuring a transmission system model in order to let it get a frequency offset. Also additive white Gaussian noise and band-limited filter are considered. The signal received from the above transmission system applies to an adaptive equalizer with LMS algorithm, and its training procedures are investigated. As a result, we could find that even small fine frequency offset can severely deteriorate training performance of adaptive algorithm.

An adaptive control of servo motors for reducing the effect of cogging torques (코깅 토크의 영향 저감을 위한 서보 모터 적응제어)

  • 이수한;허상진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.291-294
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    • 2004
  • Many researches have been focused on optimal designs of a pole shape in order to reduce cogging torques, which are generated between permanent magnets and slots. In this paper, an adaptive controller is proposed for reducing the effect of cogging torques in servo motors. The controller stabilizes the control system and shows an excellent trajectory tracking performance compared to the conventional PD controller.

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An Adaptive Control of Servo Motors for Reducing the Effect of cogging Torques (코깅 토크의 영향 저감을 위한 서보 모터 적응제어)

  • Lee Soo Han;Heo Sang Jin;Shin Kyu Hyeon
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6 s.171
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    • pp.70-75
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    • 2005
  • Many researches have been focused on optimal designs of a pole shape in order to reduce cogging torques, which are generated between permanent magnets and slots. In this paper, an adaptive controller is proposed fur reducing the effect of cogging torques in servo motors. The controller stabilizes the control system and shows an excellent trajectory tracking performance compared to the conventional PD controller.