• 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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.11
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• pp.517-525
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• 2002

The channel region of seep-sub-micrometer MOSFET is non-uniformly doped with pocket implant. Therefore, the advanced threshold voltage model is needed to account for the Short-Channel Effect and Reverse-Short-Channel Effect due to the non-uniform doping concentration in the channel region. In this paper, A scalable analytical model for the MOSFET threshold voltage is developed. The developed model is verified with MEDICI and TSUPREM simulator.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1172-1175
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• 2007

We have investigated the threshold voltage shifts(${\Delta}Vth$) and drain current level shift (${\Delta}Ids$) in subthreshold region of a-Si:H TFTs induced by DC Bias (Vgs and Vds) - Temperature stress (BTS) condition. We plotted the transfer curves and the ${\Delta}Vth$ contour maps as Vds-Vds stress bias and Temperature to examine the severe damage cases on TFTs. Also, by drawing out the time-dependent transfer curve (Ids-Vgs) in the region of $10^{-8}\;{\sim}\;10^{-13}$ (A) current level, we can estimate the failure time of TFTs in a operating condition.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.665-670
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• 2016

In this paper, we suggest the design of OP-AMP using MOSFET in the operation of sub-threshold condition as a basic unit of an IoT. The sub-threshold operation of MOSFET is useful for an ultra low power consumption of sensor network system in the IoT, because it cause the supply voltage to be reduced. From the simulation result using 0.35 um CMOS process, the supply voltage, VDD can be reduced with 0.6 V, open-loop gain of 43 dB and the power consumption was evaluated with about $1.3{\mu}W$ and the active size for an integration was measured with $64{\mu}m{\times}105{\mu}m$. It is expected that the proposed circuit is applied to the low power sensor network for IoT.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.447-451
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• 2010

In this paper, we propose a simple but effective algorithm to increase the speed of Emphysema region classification. Emphysema region classification method based on CT image consumes a lot of time because of the large number of subregions due to the large size of CT image. Some of the sub-regions contain no Emphysema and the classification of these regions is worthless. To speed up the classification process, we create an algorithm to select Emphysema region candidates and only use these candidates in the Emphysema region classification instead of all of the sub-regions. First, the lung region is detected. Then we threshold the lung region and only select the dark pixels because Emphysema only appeared in the dark area of the CT image. Then the thresholded pixels are clustered into a region that called the Emphysema pre-detected region or Emphysema region candidate. This region is then divided into sub-region for the Emphysema region classification. The experimental result shows that Emphysema region classification using predetected Emphysema region decreases the size of lung region which will result in about 84.51% of time reduction in Emphysema region classification.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.5 s.305
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• pp.43-50
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• 2005

This paper describes some IC(integrated circuits) design and implementation techniques of low power multi-band Gm-C bandpass filter for body composition analyzer. Proposed BPF(bandpass filter) can be selected from three bands(20 KHz, 50 KHz, 100 KHz) by control signal. To minimize die area, a simple center frequency tuning scheme is used. And to reduce power consumption, operational transconductance amplifier operated in the sub-threshold region is adopted. The proposed BPF is implemented with 0.35 um 2-poly 3-metal standard CMOS technology Chip area is $626.42um\;{\times}\;475.8um$ and power consumption is 700 nW@100 KHz.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.655-661
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• 2013

In this paper, the 1/f noise characteristics of n-channel MOSFET (NMOSFET) and p-channel MOSFET (PMOSFET) are analyzed in depth as a function of body bias. The normalized drain current noise, $S_{ID}/I_D{^2}$ showed strong dependence on the body bias in the sub-threshold region for both NMOSFET and PMOSFET, and NMOSFET showed stronger dependence than PMOSFET on the body bias. On the contrary, both of NMOSFET and PMOSFET do not exhibit the dependence of $S_{ID}/I_D{^2}$ on body bias in strong inversion region, although the noise mechanisms of two MOSFETs are different from each other.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.368-374
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• 2010

Image segmentation is the basic step in the field of the image processing for pattern recognition, environment recognition, and context analysis. The Otsu's automatic threshold selection, which determines the optimal threshold value to maximize the between class scatter using the distribution information of the normalized histogram of a image, is the famous method among the various image segmentation methods. For the automatic threshold selection proposed by Otsu, it is difficult to determine the optimal threshold value by considering the sub-region characteristic of the image because the Otsu's algorithm analyzes the global histogram of a image. In this paper, to alleviate this difficulty of Otsu's image segmentation algorithm and to improve image segmentation capability, the original image is divided into several sub-images by using context fuzzy c-means algorithm. The proposed fuzzy Otsu threshold algorithm is applied to the divided sub-images and the several threshold values are obtained.

• Journal of The Korean Astronomical Society
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• v.41 no.6
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• pp.157-161
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• 2008

We have estimated the fractal dimension of the molecular clouds associated with the Hii region Sh 156 in the Outer Galaxy. We selected the $^{12}CO$ cube data from the FCRAO CO Survey of the Outer Galaxy. Using a developed code within IRAF, we identified slice-clouds (2-dimensional clouds in velocity-channel maps) with two threshold temperatures to estimate the fractal dimension. With the threshold temperatures of 1.8 K, and 3 K, we identified 317 slice-clouds and 217 slice-clouds, respectively. There seems to be a turn-over location in fractional dimension slope around NP (area; number of pixel) = 40. The fractal dimensions was estimated to be D = $1.5\;{\sim}\;1.53$ for $NP\;{\geq}\;40$, where $P\;{\propto}\;A^{D/2}$ (P is perimeter and A is area), which is slightly larger than other results. The sampling rate (spatial resolution) of observed data must be an important parameter when estimating fractal dimension. Fractal dimension is apparently invariant when varying the threshold temperatures applied to slice-clouds identification.

• Journal of Information Display
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• v.4 no.2
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• pp.1-6
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• 2003

In this paper, we demonstrate that the organic electrophosphorescent device is driven by the organic thin film transistor with spin-coated photoacryl gate insulator. It was found that electrical output characteristics in our organic thin film transistors using the staggered-inverted top-contact structure showed the non-saturated slope in the saturation region and the sub-threshold nonlinearity in the triode region, where we obtained the maximum power luminance that was about 90 $cd/m^2$. Field effect mobility, threshold voltage, and on-off current ratio in 0.45 ${\mu}m$ thick gate dielectric layer were 0.17 $cm^2/Vs$, -7 V, and $10^6$ , respectively. In order to form polyimide as a gate insulator, vapor deposition polymerization process was also introduced instead of spin-coating process, where polyimide film was co-deposited by high-vacuum thermal evaporation from 4,4'-oxydiphthalic anhydride (ODPA) and 4,4'-oxydianiline (ODA) and cured at 150${\sqsubset}$for 1hr. It was also found that field effect mobility, threshold voltage, on-off current ratio, and sub-threshold slope with 0.45 ${\mu}m$ thick gate dielectric films were 0.134 $cm^2/Vs$, -7 V, and $10^6$ A/A, and 1 V/decade, respectively.