• Title/Summary/Keyword: Power Threshold

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Volatility-nonstationary GARCH(1,1) models featuring threshold-asymmetry and power transformation (분계점 비대칭과 멱변환 특징을 가진 비정상-변동성 모형)

  • Choi, Sun Woo;Hwang, Sun Young;Lee, Sung Duck
    • The Korean Journal of Applied Statistics
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    • v.33 no.6
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    • pp.713-722
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    • 2020
  • Contrasted with the standard symmetric GARCH models, we consider a broad class of threshold-asymmetric models to analyse financial time series exhibiting asymmetric volatility. By further introducing power transformations, we add more flexibilities to the asymmetric class, thereby leading to power transformed and asymmetric volatility models. In particular, the paper is concerned with the nonstationary volatilities in which conditions for integrated volatility and explosive volatility are separately discussed. Dow Jones Industrial Average is analysed for illustration.

Kinematic characteristics of grip force in patients with cervical spondylosis

  • Lee, Bumsuk;Noguchi, Naoto;Kakiage, Daiki;Yamazaki, Tsuneo
    • Physical Therapy Rehabilitation Science
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    • v.4 no.2
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    • pp.61-65
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    • 2015
  • Objective: The aim of this study was to objectively evaluate sensory disturbance in cervical spondylosis using grip force and investigate the relationship between the grip force and upper extremity function. Design: Cross-sectional study. Methods: Eleven cervical spondylosis patients with paresthesia conducted grip and lift tasks using a precision grip with the tips of the thumb and index finger on either side. The sum of the grip force used during the first four seconds was calculated and defined as the total grip force. The cutaneous pressure threshold of the fingers, the pinch power, the grip power and three subtests of the Simple Test for Evaluating Hand Function (STEF) were also assessed. Correlations between the total grip force and cutaneous pressure threshold, pinch power, grip power, and STEF subtest times were evaluated. Results: We found that the total grip force correlated with the cutaneous pressure threshold (p<0.05). Moreover, the total grip force of the dominant thumb correlated with the results of the three STEF subtests (p<0.05). There were no significant correlations between the total grip force and pinch/grip powers. Conclusions: We found that the total grip force correlated with cutaneous pressure threshold and upper extremity function. The results suggest that the total grip force could serve as an objective index for evaluating paresthesia in cervical spondylosis patients, and that the impaired ability of the upper extremity function is related to grip force coordination.

Design of Low Power Current Memory Circuit based on Voltage Scaling (Voltage Scaling 기반의 저전력 전류메모리 회로 설계)

  • Yeo, Sung-Dae;Kim, Jong-Un;Cho, Tae-Il;Cho, Seung-Il;Kim, Seong-Kweon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.2
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    • pp.159-164
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    • 2016
  • A wireless communication system is required to be implemented with the low power circuits because it uses a battery having a limited energy. Therefore, the current mode circuit has been studied because it consumes constant power regardless of the frequency change. However, the clock-feedthrough problem is happened by leak of stored energy in memory operation. In this paper, we suggest the current memory circuit to minimize the clock-feedthrough problem and introduce a technique for ultra low power operation by inducing dynamic voltage scaling. The current memory circuit was designed with BSIM3 model of $0.35{\mu}m$ process and was operated in the near-threshold region. From the simulation result, the clock-feedthrough could be minimized when designing the memory MOS Width of $2{\mu}m$, the switch MOS Width of $0.3{\mu}m$ and dummy MOS Width of $13{\mu}m$ in 1MHz switching operation. The power consumption was calculated with $3.7{\mu}W$ at the supply voltage of 1.2 V, near-threshold voltage.

Low-threshold Photonic Crystal Lasers from InGaAsP Free-standing Slab Structures

  • Ryu, Han-Youl;Kim, Se-Heom;Kwon, Soon-Hong;Park, Hong-Gyu;Lee, Yong-Hee
    • Journal of the Optical Society of Korea
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    • v.6 no.3
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    • pp.59-71
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    • 2002
  • Photonic band gap structures have a high potential for nearly zero-threshold lasers. This paper describes new-types of low-threshold photonic crystal lasers fabricated in InGaAsP slab waveguides free-standing in air. Two-types of photonic crystal lasers are studied. One is a single-cell nano-cavity laser formed in a square array of air holes. This photonic band gap laser operates in the smallest possible whispering gallery mode with a theoretical Q >30000 and exhibits low threshold pump power of 0.8 mW at room temperature. The nther laser does not have any cavity structure and the lasing operation originates from the enhanced optical density of states near photonic band edges. A very low threshold of 35 $\mu$W (incident pump power) is achieved from this laser at 80 K, one of the lowest values ever reported. This low threshold is benefited from low optical losses as well as enhanced material gain at low temperature.

Chaotic and Instability Effects in Brillouin-Active Fiber-Ring Sensor (광섬유링센서에서 유도되는 브루앤파의 혼돈 및 비안정화 현상)

  • Kim, Yong K.;Kim, Jin-Su
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.6
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    • pp.337-341
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    • 2004
  • In this paper the effect of chaos induced instability in Brillouin-active fiber-ring sensor is described. The inherent optical feedback by the backscattered Stokes wave in optical fiber leads to instabilities in the form of optical chaos. The paradigm of optical chaos in fiber serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in communication and sensing. At weak power, the nature of the Brillouin instability can occur at before threshold. At strong power, the temporal evolution above threshold is periodic and at higher intensity can become chaotic. The threshold for the Brillouin instability in fiber-ring sensor is much lower than the threshold of the normal Brillouin instability process.

The Effects of Rainbow Power Therapy on Neck Pain Patients (Rainbow Power Therapy의 경항통에 대한 효과)

  • Seo, Jung-Chul;Seo, Bo-Myung;Kim, Sung-Woong;Lee, Kyung-Min;Yun, Jong-Seok;Lee, Sea-Youn;Kim, Kyung-Woon;Lee, Yoon-Kyung;Lim, Seong-Chul;Jung, Tae-Young;Hwang, Jae-Wok;Han, Sang-Won
    • Korean Journal of Acupuncture
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    • v.21 no.2
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    • pp.147-159
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    • 2004
  • Objective : This study was designed to estimate the effects of Rainbow Power therapy on neck pain patients by using Visual Analogue Scale(VAS) and pressure algometer. Methods : Rainbow Power therapy group consisted of 18 patients and acupuncture therapy group consisted of 7 patients. The degree of improvement of neck pain was evaluated by VAS and pain pressure threshold(at the points of Jianjing GB21 and Jianwaishu SI14) before treatment, before 3rd treatment and before 5th treatment. Rainbow Power therapy was performed at the points of Jianjing GB21, Zhongfu LU1, Yangxi LI5, Ganshu BL18, Weishu BL21 and Shenshu, BL23. Each points were stimulated with RP-UM103(Rainbow Power therapy instrument) for 20 seconds. The points of acupuncture therapy were Jeonggeun, Jeongjong, Sangbaekn and Hegu LI4 and acupuncture was maintained for 15 minutes. After above therapy dry cupping was performed at the points of Jianjing GB21, Jianwaishu SI14, Gaohuang BL43, Tianzong, SI11 and Bingfeng SI12 for 5 minutes. Results : There was no significant difference between the two groups in VAS, pain threshold of Jianjing GB21 and Jianwaishu SI14 following treatment. In the two groups VAS was significantly decreased. In Rainbow Power therapy group the pain threshold of the two points was significantly increased. But there was no significant increase in acupuncture therapy groups about the pain threshold of Jianwaishu SI14. Conclusions : The effectiveness of Rainbow Power therapy on neck pain was shown through VAS and pressure algometer. These imply that Rainbow Power therapy may be useful for neck pain. Further study is needed about Rainbow Power therapy.

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Development of the RE indirect-heating LPE furnace and the effect of impurity in YIG film on the MSSW properties

  • Fujino, M.;Fujii, T.;Sakabe, Y.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.6
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    • pp.288-291
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    • 2002
  • We developed a new RF indirect-heating LPE furnace. The thermal gradient of our newly developed furnace is less than that of direct heating, and is as gentle as that of the resistance-heating LPE furnace. With this new furnace, the heating and/or cooling is faster than that of the resistance-heating furnace. Impurity-doped YIG film was grown from a $PbO-B_{2}O_{3}$, based flux on a (111) GGG substrate. To study the effect of the impurities on the MSSW threshold power and the saturation response time, we used two microstrip lines to excite and propagate the MSSW at 1.9 GHz. The MSSW threshold power and saturation response time was found to be related to the $\Delta$H.

A Unified Framework for Transmitter Power Control in Cellular Radio Systems

  • Chai, Chin Choy;Lu, Ying;Chew, Yong Huat;Tjhung, Tjeng Thiang
    • ETRI Journal
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    • v.26 no.5
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    • pp.423-431
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    • 2004
  • In earlier works on transmitter power control in cellular radio systems, the problem of whether a signal-to-interference ratio (SIR) threshold is achievable is determined by apparently different rules for homogeneous and heterogeneous SIR systems. In this paper, we present a unified and more universal framework for both cases. We also highlight the conditions under which a given SIR threshold vector for the heterogeneous SIR system is achievable, although so far there is no general solution to this problem.

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Laser Damage Threshold Increase of A/R Coating Films for 200MHz AOM (A/R 코팅 변화에 따른 200MHz AOM의 laser damage threshold 증가)

  • Kim, Yong-Hun;Lee, Hang-Hun;Lee, Jin-Ho;Park, Yeong-Jun;Park, Jeong-Ho
    • Korean Journal of Materials Research
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    • v.7 no.3
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    • pp.213-217
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    • 1997
  • AOhf(Hcousto-r)l)tic niodulator) with :!OOlIiz freclucncl- and Sfi(;(Seconrl harmonic generation) green lasel-Lvith 53% nm wavelength were used for Il\'IIII~Dii.it,ii v~ilco disk recorder) FOI rhe appli~aptin of high densit]. optical recording, a high po\ver I ~ c r is r c ~ ~ l i ~ i l - u l ic I !tic. s\-sti,m a n d optic.,~I io;iting l,t)c>rs of each optical device must have a high laser damage threshoid hie rn;itie ant] retlwtive coatings on a $TeO_{2}$ singlc crystal. which is used as an acoustooptic material, by E-beam evaporation method. Laser damage threshold \vas nicdsureci hy Ar laser with the input power oi 0.55LV 1,aser damage threiholti 01 $ZrO_{2}$ and $SiO_{2}$. filn-is were higher than $AI_{2}O_{3}$ f i l m U'e also investigated a long--tern1 stability of the output po\ver of St{(; green laser

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Analytical Model of Threshold Voltage for Negative Capacitance Junctionless Double Gate MOSFET Using Ferroelectric (강유전체를 이용한 음의 정전용량 무접합 이중 게이트 MOSFET의 문턱전압 모델)

  • Hakkee Jung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.36 no.2
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    • pp.129-135
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    • 2023
  • An analytical threshold voltage model is presented to observe the change in threshold voltage shift ΔVth of a junctionless double gate MOSFET using ferroelectric-metal-SiO2 as a gate oxide film. The negative capacitance transistors using ferroelectric have the characteristics of increasing on-current and lowering off-current. The change in the threshold voltage of the transistor affects the power dissipation. Therefore, the change in the threshold voltage as a function of theferroelectric thickness is analyzed. The presented threshold voltage model is in a good agreement with the results of TCAD. As a results of our analysis using this analytical threshold voltage model, the change in the threshold voltage with respect to the change in the ferroelectric thickness showed that the threshold voltage increased with the increase of the absolute value of charges in the employed ferroelectric. This suggests that it is possible to obtain an optimum ferroelectric thickness at which the threshold voltage shift becomes 0 V by the voltage across the ferroelectric even when the channel length is reduced. It was also found that the ferroelectric thickness increased as the silicon thickness increased when the channel length was less than 30 nm, but the ferroelectric thickness decreased as the silicon thickness increased when the channel length was 30 nm or more in order to satisfy ΔVth=0.