• Title/Summary/Keyword: Current-scaling

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A Performance Variation by Scaling Factor in NM-MMA Adaptive Equalization Algorithm (NM-MMA 적응 등화 알고리즘에서 Scaling Factor에 의한 성능 변화)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.2
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    • pp.105-110
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    • 2018
  • This paper compare the adaptive equalization performance of NM-MMA (Novel Mixed-MMA) algorithm which using the mixed const function by scaling factor values. The mixed cost function of NM-MMA composed of the appropriate weighted addition of gradient vector in the MMA and SE-MMA cost function, and updating the tap coefficient based on these function, it is possible to improve the convergence speed and MSE value of current algorithm. The computer simulation was performed in the same channel, step size, SNR environment by changing the scaling factor, and its performance were compared appling the equalizer output constellation, residual isi, MD, MSE, SER. As a result of computer simulation, the residual values of performance index were reduced in case of the scaling factor of MMA cost function was greater than the scaling factor of SE-MMA. and the convergence speed was improved in case of the scaling factor of SE-MMA was greater than the MMA.

Analysis of Scaling Parameters of the Batch Unscented Transformation for Precision Orbit Determination using Satellite Laser Ranging Data

  • Kim, Jae-Hyuk;Park, Sang-Young;Kim, Young-Rok;Park, Eun-Seo;Jo, Jung-Hyun;Lim, Hyung-Chul;Park, Jang-Hyun;Park, Jong-Uk
    • Journal of Astronomy and Space Sciences
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    • v.28 no.3
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    • pp.183-192
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    • 2011
  • The current study analyzes the effects of the scaling parameters of the batch unscented transformation on precision satellite orbit determination. Satellite laser ranging (SLR) data are used in the orbit determination algorithm, which consists of dynamics model, observation model and filtering algorithm composed of the batch unscented transformation. TOPEX/Poseidon SLR data are used by utilizing the normal point (NP) data observed from ground station. The filtering algorithm includes a repeated series of processes to determine the appropriate scaling parameters for the batch unscented transformation. To determine appropriate scaling parameters, general ranges of the scaling parameters of ${\alpha}$, ${\beta}$, k, $\lambda$ are established. Depending on the range settings, each parameter was assigned to the filtering algorithm at regular intervals. Appropriate scaling parameters are determined for observation data obtained from several observatories, by analyzing the relationship between tuning properties of the scaling parameters and estimated orbit precision. The orbit determination of satellite using the batch unscented transformation can achieve levels of accuracy within several tens of cm with the appropriate scaling parameters. The analyses in the present study give insights into the roles of scaling parameters in the batch unscented transformation method.

Relation of Short Channel Effect and Scaling Theory for Double Gate MOSFET in Subthreshold Region (문턱전압이하 영역에서 이중게이트 MOSFET의 스켈링 이론과 단채널효과의 관계)

  • Jung, Hak-Kee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1463-1469
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    • 2012
  • This paper has presented the influence of scaling theory on short channel effects of double gate(DG) MOSFET in subthreshold region. In the case of conventional MOSFET, to preserve constantly output characteristics,current and switching frequency have been analyzed based on scaling theory. To analyze the results of application of scaling theory for short channel effects of DGMOSFET, the changes of threshold voltage, drain induced barrier height and subthreshold swing have been observed according to scaling factor. The analytical potential distribution of Poisson equation already verified has been used. As a result, it has been observed that threshold voltage among short channel effects is grealty changed according to scaling factor. The best scaling theory for DGMOSFET has been explained as using modified scaling theory, applying weighting factor reflected the influence of two gates when scaling theory has been applied for channel length.

Relation of Threshold Voltage and Scaling Theory for Double Gate MOSFET (DGMOSFET의 문턱전압과 스켈링 이론의 관계)

  • Jung, Hak-Kee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.5
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    • pp.982-988
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    • 2012
  • This paper has presented the relation of scaling theory and threshold voltage of double gate(DG) MOSFET. In the case of conventional MOSFET, current and switching frequency have been analyzed based on scaling theory. To observe the possibility of application of scaling theory for threshold voltage of DGMOSFET, the change of threshold voltage has been observed and analyzed according to scaling theory. The analytical potential distribution of Poisson equation has been used, and this model has been already verified. To solve Poisson equation, charge distribution such as Gaussian function has been used. As a result, it has been observed that threshold voltage is grealty changed according to scaling factor and change rate of threshold voltages is traced for scaling of doping concentration in channel. This paper has explained for the best modified scaling theory reflected the influence of two gates as using weighting factor when scaling theory has been applied for channel length and channel thickness.

Analysis Characteristic the Using Surface EMG of Scaling Working of the Dental Hygienist with Upper Body Musculoskeletal Pain (상반신의 근육뼈대계 통증이 치과위생사의 스케일링 작업에 미치는 특성에 대한 표면 근전도 분석)

  • Nam, Kun-Woo;Ha, Mi-Sook
    • Journal of Korean Physical Therapy Science
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    • v.19 no.4
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    • pp.1-6
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    • 2012
  • Purpose : The current research examines the muscle activity that happens during scaling practice subject to 20 dental hygienic students with musculoskeletal pain and then propose a basic data according to the working attitude of the Dental Hygienist. Method : The Nordic-style questionnaire is used to define experimental group with musculoskeletal pain and control group. During the scaling the surface EMG device is used to measure the muscle activity of experimental and control group. Study design : The surface EMG is measure RMS(root mean square) of suboccipital muscle, biceps brachii, upper trapezius, and brachioradialis muscle activity. Results : In the experimental group, the RMS of upper trapezius and brachioradialis is increased during scaling practice(p<0.05), but the control group's RMS is not changed(p>0.05). Conclusion : Musculoskeletal pain may contribute to increase muscle activity of neck & arm during scaling practice. In the future we think there is a need to raise the office efficiency by subjecting to dental hyginiest that are in the clinics and performing experiments.

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Scaling Down Characteristics of Vertical Channel Phase Change Random Access Memory (VPCRAM)

  • Park, Chun Woong;Park, Chongdae;Choi, Woo Young;Seo, Dongsun;Jeong, Cherlhyun;Cho, Il Hwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.1
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    • pp.48-52
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    • 2014
  • In this paper, scaling down characteristics of vertical channel phase random access memory are investigated with device simulator and finite element analysis simulator. Electrical properties of select transistor are obtained by device simulator and those of phase change material are obtained by finite element analysis simulator. From the fusion of both data, scaling properties of vertical channel phase change random access memory (VPCRAM) are considered with ITRS roadmap. Simulation of set reset current are carried out to analyze the feasibility of scaling down and compared with values in ITRS roadmap. Simulation results show that width and length ratio of the phase change material (PCM) is key parameter of scaling down in VPCRAM. Thermal simulation results provide the design guideline of VPCRAM. Optimization of phase change material in VPCRAM can be achieved by oxide sidewall process optimization.

Reduction of Current Ripples due to Current Measurement Errors in a Doubly Fed Induction Generator

  • Park, Gwi-Geun;Hwang, Seon-Hwan;Kim, Jang-Mok;Lee, Kyo-Beum;Lee, Dong-Choon
    • Journal of Power Electronics
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    • v.10 no.3
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    • pp.313-319
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    • 2010
  • This paper proposes a new compensation algorithm for the current measurement errors in a DFIG (Doubly Fed Induction Generator). Generally, current measurement path with current sensors and analog devices has non-ideal factors like offset and scaling errors. As a result, the dq-axis currents of the synchronous reference frame have one and two times ripple components of the slip frequency. In this paper, the main concept of the proposed algorithm is implemented by integrating the 3-phase rotor currents into the stationary reference frame to compensate for the measured current ripples in a DFIG. The proposed algorithm has several beneficial features: easy implementation, less computation time, and robustness with regard to variations in the electrical parameters. The effectiveness of the proposed algorithm is verified by several experiments.

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.

A Fast-Locking Fractional-N PLL with Multiple Charge Pumps and Capacitance Scaling Scheme (Capacitance Scaling 구조와 여러 개의 전하 펌프를 이용한 고속의 ${\Sigma}{\Delta}$ Fractional-N PLL)

  • Kwon, Tae-Ha
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.10 s.352
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    • pp.90-96
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    • 2006
  • A novel ${\Sigma}{\Delta}$ fractional-N PLL architecture for fast locking and fractional spur suppressing is proposed based on the capacitance scaling scheme. It changes the effective capacitance of loop filter (LF) by increasing and decreasing current to the capacitor via different paths with multiple charge pumps. The effective capacitance of loop filter (LF) can be scaled up/down depending on operating status while keeping LF capacitors small enough to be integrated into a single PLL chip. Fractional spurs suppressing have been achieved by reducing the magnitude of charge pump current when the PLL is in-lock without degrading fast locking characteristic. It has been simulated by HSPICE in a CMOS $0.35{\mu}m$ process, and shows flat locking time is less than $8{\mu}s$ with the small size of LF capacitors, 200pF and 17pF, and $2.8k{\Omega}$ resistor.

Association between needs for scaling and oral and general health behaviors in middle-aged people (한국 중장년의 치면세마 필요와 구강 및 전신건강행동의 관련성)

  • Han, Su-Jin
    • Journal of the Korea Convergence Society
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    • v.11 no.5
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    • pp.51-59
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    • 2020
  • This study aimed to examine whether needs for scaling are associated with health behaviors in a representative sample of middle-aged Korean people. We examined 5120 individuals aged 40 to 64 years who participated in the Seventh Korea National Health and Nutrition Examination Survey. Multivariate logistic regression analysis was performed with adjustments for demographic variables and health status. This analysis revealed significant associations between needs for scaling and the following: current smoking, no visits to dental clinics, current drinking, non-oral checkups, and non-use of oral care products. As a result of a subgroup analysis, significant factors differed according to gender. As a result of this study, needs for scaling were associated with identified health behaviors and findings about health behaviors that are effective for maintaining and promoting periodontal health in middle-aged people were confirmed.