• Title/Summary/Keyword: threshold power

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A Study on the Validation of Phonation Threshold Power and the Clinical Usefulness of PTW: A Preliminary Study (발성역치능력(Phonation Threshold Power, PTW)의 타당도 및 임상적 유용성 연구: 예비연구)

  • Hwang, Youngjin;Lee, Inae
    • Phonetics and Speech Sciences
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    • v.6 no.2
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    • pp.133-138
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    • 2014
  • This study attempted to investigate the validation of Phonation Threshold Power of Patients who have Functional voice disorder. 50 subjects participated in the study (32 subjects were patients who had functional voice disorders and 20 subjects were normal adults). The PAS (Phonatory aerodynamic system, model 6600, KAY electronics, Inc.) was used to measure the data and to do the analysis. Data from the Phonation Threshold Power was measured multiplying Phonation Threshold Pressure and Phonation Threshold Airflow. Phonation Threshold Pressure and Phonation Threshold Airflow were measured by the PAS protocol. Those were used because of the ease of phonation. The results of this study showed that the differences in Phonation Threshold Power between patients who had functional voice disorder and normal adults could become a significant index. Patients who had functional voice disorder showed more higher figures than normal adults. The results of study showed that Phonation threshold Power is more sensitive than Phonation Threshold Pressure and Phonation Threshold Airflow. The measured data also provided useful information for diagnosing patients with vocal fold.

Current-Mode Circuit Design using Sub-threshold MOSFET (Sub-threshold MOSFET을 이용한 전류모드 회로 설계)

  • Cho, Seung-Il;Yeo, Sung-Dae;Lee, Kyung-Ryang;Kim, Seong-Kweon
    • Journal of Satellite, Information and Communications
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    • v.8 no.3
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    • pp.10-14
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    • 2013
  • In this paper, when applying current-mode circuit design technique showing constant power dissipation none the less operation frequency, to the low power design of dynamic voltage frequency scaling, we introduce the low power current-mode circuit design technique applying MOSFET in sub-threshold region, in order to solve the problem that has large power dissipation especially on the condition of low operating frequency. BSIM 3, was used as a MOSFET model in circuit simulation. From the simulation result, the power dissipation of the current memory circuit with sub-threshold MOSFET showed $18.98{\mu}W$, which means the consumption reduction effect of 98%, compared with $900{\mu}W$ in that with strong inversion. It is confirmed that the proposed circuit design technique will be available in DVFS using a current-mode circuit design.

Design of a Low-Power Carry Look-Ahead Adder Using Multi-Threshold Voltage CMOS (다중 문턱전압 CMOS를 이용한 저 전력 캐리 예측 가산기 설계)

  • Kim, Dong-Hwi;Kim, Jeong-Beom
    • The KIPS Transactions:PartA
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    • v.15A no.5
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    • pp.243-248
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    • 2008
  • This paper proposes a low-power carry look-ahead adder using multi-threshold voltage CMOS. The designed adder is compared with conventional CMOS adder. The propagation delay time is reduced by using low-threshold voltage transistor in the critical path. Also, the power consumption is reduced by using high-threshold voltage transistor in the shortest path. The other logic block is implemented with normal-threshold transistor. Comparing with the conventional CMOS circuit, the proposed circuit is achieved to reduce the power consumption by 14.71% and the power-delay-product by 16.11%. This circuit is designed with Samsung $0.35{\mu}m$ CMOS process. The validity and effectiveness are verified through the HSPICE simulation.

On geometric ergodicity and ${\beta}$-mixing property of asymmetric power transformed threshold GARCH(1,1) process

  • Lee, Oe-Sook
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.2
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    • pp.353-360
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    • 2011
  • We consider an asymmetric power transformed threshold GARCH(1.1) process and find sufficient conditions for the existence of a strictly stationary solution, geometric ergodicity and ${\beta}$-mixing property. Moments conditions are given. Box-Cox transformed threshold GARCH(1.1) is also considered as a special case.

Transmission Power-Based Spectrum Sensing for Cognitive Ad Hoc Networks

  • Choi, Hyun-Ho
    • Journal of information and communication convergence engineering
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    • v.12 no.2
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    • pp.97-103
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    • 2014
  • In spectrum sensing, there is a tradeoff between the probability of missed detection and the probability of a false alarm according to the value of the sensing threshold. Therefore, it is important to determine the sensing threshold suitable to the environment of cognitive radio networks. In this study, we consider a cognitive radio-based ad hoc network where secondary users directly communicate by using the same frequency band as the primary system and control their transmit power on the basis of the distance between them. First, we investigate a condition in which the primary and the secondary users can share the same frequency band without harmful interference from each other, and then, propose an algorithm that controls the sensing threshold dynamically on the basis of the transmit power of the secondary user. The analysis and simulation results show that the proposed sensing threshold control algorithm has low probabilities of both missed detection and a false alarm and thus, enables optimized spectrum sharing between the primary and the secondary systems.

Stagewise Weak Orthogonal Matching Pursuit Algorithm Based on Adaptive Weak Threshold and Arithmetic Mean

  • Zhao, Liquan;Ma, Ke
    • Journal of Information Processing Systems
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    • v.16 no.6
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    • pp.1343-1358
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    • 2020
  • In the stagewise arithmetic orthogonal matching pursuit algorithm, the weak threshold used in sparsity estimation is determined via maximum iterations. Different maximum iterations correspond to different thresholds and affect the performance of the algorithm. To solve this problem, we propose an improved variable weak threshold based on the stagewise arithmetic orthogonal matching pursuit algorithm. Our proposed algorithm uses the residual error value to control the weak threshold. When the residual value decreases, the threshold value continuously increases, so that the atoms contained in the atomic set are closer to the real sparsity value, making it possible to improve the reconstruction accuracy. In addition, we improved the generalized Jaccard coefficient in order to replace the inner product method that is used in the stagewise arithmetic orthogonal matching pursuit algorithm. Our proposed algorithm uses the covariance to replace the joint expectation for two variables based on the generalized Jaccard coefficient. The improved generalized Jaccard coefficient can be used to generate a more accurate calculation of the correlation between the measurement matrixes. In addition, the residual is more accurate, which can reduce the possibility of selecting the wrong atoms. We demonstrate using simulations that the proposed algorithm produces a better reconstruction result in the reconstruction of a one-dimensional signal and two-dimensional image signal.

Wavelet Transform Based Compression of Power Quality Signal (웨이브렛 변환을 이용한 전력품질 신호 압축)

  • Chung, Young-Sik;Kim, Cheol
    • Proceedings of the KIEE Conference
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    • 2006.11a
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    • pp.305-307
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    • 2006
  • The choice of threshold is an important in the compression algorithms. It plays a major role in the removal of coefficients which are not preserved the important features. In this paper two threshold method, hard threshold(HTH) and soft threshold(STH) are applied to the suggested wavelet based compression algorithm of power quality signal and compared the compression ratio and NMSE. The simulation results show that STH is bottom than HTH.

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Low Threshold Current Density and High Efficiency Surface-Emitting Lasers with a Periodic Gain Active Structure

  • Park, Hyo-Hoon;Yoo, Byueng-Su
    • ETRI Journal
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    • v.17 no.1
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    • pp.1-10
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    • 1995
  • We have achieved very low threshold current densities with high light output powers for InGaAs/ GaAs surface-emitting lasers using a periodic gain active structure in which three quantum wells are inserted in two-wavelength-thick (2${\lambda}$ ) cavity. Air-post type devices with a diameter of 20~40${\mu}m$ exhibit a threshold current density of 380~410$A/cm^2$. Output power for a 40${\mu}m$ diameter device reaches over 11 mW. A simple theoretical calculation of the threshold and power performances indicates that the periodic gain structure has an advantage in achieving low threshold current density mainly due to the high coupling efficiency between gain medium and optical field. The deterioration of power, expected from the long cavity length of $2{\lambda}$, is negligible.

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Power extraction efficiency and lasing wavelength distribution of index-coupled DEB lasers above-threshold for various facet reflectivity combinations (문턱 전류 이상에서 양 단면 반사율 조합에 따른 index-coupled DFB 레이저의 파워 추출 효율과 발진 파장 분포)

  • 김상택;김부균
    • Korean Journal of Optics and Photonics
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    • v.14 no.4
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    • pp.413-422
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    • 2003
  • We have calculated the power extraction efficiency and the lasing wavelength distribution of index-coupled DFB lasers at threshold for various kL and facet reflectivity combinations, and compared with those above-threshold. The power extraction efficiency increases as the asymmetry of the facet reflectivities increases. The power extraction efficiency above-threshold is slightly larger than that at threshold. Since the relative photon density around the center region increases as kL increases, the power extraction efficiency decreases. The uniformity of the distribution of lasing wavelength over the stop band increases due to the relief of mode degeneracy as the asymmetry of the facet reflectivities increases. In the case of AR-HR combination, the lasing wavelength distributions at threshold are similar to those above-threshold. However, in the case of AR-AR combination, the lasing wavelength at threshold is concentrated on both edges of the stop band, while it is concentrated only on the longer wavelength edge above-threshold. As kL increases, the range of the lasing wavelength distribution increases due to the increase of the stop band. The effect of AR reflectivity on the power extraction and the lasing wavelength distribution is very weak.