• KIPS Transactions on Software and Data Engineering
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• v.6 no.6
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• pp.321-328
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• 2017

We have implemented a technique to correct the brightness, saturation, and contrast of an image according to the degree of light, and further compensate the backlight. Backlight compensation can be done automatically or manually. For manual backlight compensation, we have to select the region of interest (ROI). ROI can be selected by connecting the outline of the desired object. We make users select the region delicately with the new magnetic lasso tool. The previous lasso tool has a disadvantage that the start point and the end point must be connected. However, the proposed lasso tool has the advantage of selecting the region of interest without connecting the start point and the end point. We can automatically obtain various results of backlight compensation by adjusting the number of k-means clusters for texture extraction and the threshold value for binarization.

• Proceedings of the KSRS Conference
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• v.2
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• pp.639-642
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• 2006

The intensity-hue-saturation (IHS) technique has become a standard procedure in image analysis. It enhances the colour of highly correlated data. Unfortunately, IHS technique is sensitive to the properties of the analyzed area and usually faces colour distortion problems in the fused process. This paper explores the relationship of colour between before and after the fused process and the change in colour space of images. Subsequently, the fused colours are transformed back into the 'simulative' true colours by the following steps: (1) For each pixel of fused image that match with original pixel (of the coarse spectral resolution image) is transformed back to the true colour of original pixel. (2) The value for interpolating pixels is compensated to preserve the DN ratio between the original pixel and it's vicinity. The 'compensative matrix' is constructed by the DN of fused images and simulation of scaling process. An illustrative example of a Landsat and SPOT fused image also demonstrates the simulative true colour fusion methods.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.96-97
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• 1998

3D TOF MR Angiography is able to obtain thinner slice thickness, higher SNR, therefore higher spatial resolution than 2D TOF MR Angiography. Since it uses longer TR than 2D TOF MRA to allow stronger in-flow effect, the background tissue may not be fully saturated. Thus background tissue signal can be further suppressed by MTS(Magnetization Transfer Saturation). Flow-compensation was accomplished by GMN(Gradient Moment Nulling), and tracking saturation was used to suppress vein signal. The different flow signal at the entry of the slab and output of the slab can be compensated by TONE(Tilted Optimized Non-saturating Excitation) RF pulse.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5A
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• pp.484-491
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• 2004

C-band pumping effect appears in L-band EDFA because the absorption in C-band occurs dominant under the condition of such a low average population inversion. In this paper, we show how the C-band pumping effect depends on 980nm pump power, the C-band wavelength, and its input power. The C-band pumping is caused by absorbing C-band injection or backward spontaneous emission power through EDF. If the same small signal condition is given by a C-band pump, the C-band pump of a long wavelength is good for the saturation and noise characteristics of L-band signal. Finally, it is considered that in the aspect of saturation characteristics, C-band compensation is not so much efficient as L-band in Gain-Clamped L-band EDFA having a lossy resonator.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.1
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• pp.61-69
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• 1998

In this paper, discrete current control of voltage source inverters is proposed. As a current control scheme, the constant switching frequency predictive current control is adopted and implemented with DSP microprocessor system. In particular, the proposed method is for the compensation of the control lagging due to calculation delays in the microprocessor controller. In controlling the current, the inverter output voltage saturation problem is inevitable and usually affects the current control performance. So, the saturation boundary condition of the inverter output voltage and its effects on the current controal performance of the proposed current control scheme are investigated with experiment. Finally, the proposed scheme is applied to the active power filter system and some results are described for validation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.993-998
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• 2002

At Power amplifier, distortion of output is appeared because of non-linearlity, so we must study method of compensation for non-linearity. In this paper, it was studied about the characteristic of predistorter using serial schottky diode for an amplifier. As a result, we confirmed that power amplifier was able to linearize when we put predistorter using non-linearity of schottky diode before power amplifier. When input carrier level was low, input carrier was delivered directly into power amplifier but input carrier level was high, input carrier was delivered into power amplifier through predistorter with suppressed level. As a result power amplifier always was at saturation region. Through simulation using serenade 8.0, we have concluded that efficiency was improved about 3%, and predistorter got best linearity at 1.8㎓ between 800㎒∼2.2㎓.

• Journal of Magnetics
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• v.16 no.1
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• pp.74-76
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• 2011

Interior permanent-magnet synchronous motors (IPMSMs) produce both magnetic and reluctance torques. The reluctance torque is due to the difference between the d- and q-axis inductances based on the geometric rotor structure. The steady-state performance analysis and precise control of the IPMSMs greatly depend on the accurate determination of the parameters. The three essential parameters of the IPMSMs are the armature flux linkage of the permanent magnet, the d-axis inductance, and the q-axis inductance. In the basic design step of an IPMSM, the inductance parameters are very important for determining the motor characteristics, such as the input voltage, torque, and efficiency. Thus, it is very important to accurately estimate the values of the motor inductances. The inductance parameters of IPMSMs have nonlinear characteristics along the magnet size because the iron core is saturated by the magnet and armature reaction fluxes. In this study, the inductance parameters were calculated using both the magnetic-equivalent-circuit method and the finite-element method (FEM). Then the calculated parameters were compensated by the saturation coefficient function, which was also calculated via the magnetic-equivalent-circuit method and FEM.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.1
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• pp.42-49
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• 2019

Objective: Chronic obstructive pulmonary disease(COPD) is characterized by persistent airflow limitations associated with chronic inflammatory response due to noxious particles or gases in the lung. Iron deficiency is associated with chronic inflammation, such as COPD. The aim of this study was to evaluate the relationship among iron deficiency, iron homeostasis, and inflammation in retired miners with COPD. Methods: The serum levels of ferritin, soluble transferrin receptor(sTfR), and transferrin saturation(TSat) as biomarkers for iron deficiency and high-sensitivity C-reactive protein(hsCRP) as a biomarker for inflammation and hepcidin as a biomarker for iron homeostasis were measured in 93 male subjects. Iron deficiency was defined as any one or more of (1) sTfR>28.1 nmol/L, (2) TSat<16%, and (3) ferritin< $12{\mu}g/L$. Results: Iron deficiency was found 28% of the study subjects. Median levels of serum hsCRP was significantly increased related to airflow limitation of COPD(GOLD 1, $0.09{\mu}g/dL$ vs. GOLD 2, $0.17{\mu}g/dL$ vs. GOLD $3{\leq}$, $0.30{\mu}g/dL$, p=0.010), and was positively correlated with hepcidin(p=0.009). Mean level of serum hepcidin was lower in COPD subjects with iron deficiency(p=0.004) and serum levels of hepcidin was negatively correlated with %$FEV_1$ predicted(p=0.030). Conclusions: These results suggest that high serum levels of hepcidin are related to severe airflow limitation or inflammation and can decrease iron availability, regardless of iron status.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.1
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• pp.1-10
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• 2008

Coloriztion algorithms, which hide color information into gray images and find them to recover color images, have been developed recently. In these methods, it is important to minimize the loss of original information while the color components are embedded and extracted. In this paper, we propose a colorization method using a wavelet packet transform in order to embed color components with minimum loss of original information. In addition, the compensation processing of color saturation in the recovered color images is achieved. In the color-to-gray process, an input RGB image is converted into Y, Cb, and Cr images, and a wavelet packet transform is applied to the Y image. After analyzing the amounts of total energy for each sub-band, color components are embedded into two sub-bands including minimum amount of energy on the Y image. This makes it possible not only to hide color components in the Y image, but to recover the Y image with minimum loss of original information. In the gray-to-color process, the color saturation of the recovered color images is decreased by printing and scanning process. To increase color saturation, the characteristic curve between printer and scanner, which can estimate the change of pixel values before and after printing and scanning process, is used to compensate the pixel values of printed and scanned gray images. In addition, the scaling method of the Cb and Cr components is applied to the gray-to-color process. Through the experiments, it is shown that the proposed method improves both boundary details and color saturation in the recovered color images.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.1033-1036
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• 2013

A study about collision resolution is needed because huge file, video and multimedia information are transmitted to wireless LAN. CSMA/CR protocol guarantees fairness, but doesn't consider QoS. To practicalize CSMA/CR protocol in saturation fully-connected single hop network environments, this paper proposes method of collision compensation. previous CSMA/CR protocol chooses CR Slot only considering fairness, but this paper chooses front CR Slot for compensation of collision to station experiencing collisions. The station transmits jam signal and has channel priority of transmission. So transmitting efficiency and successful transmission probability rise. This proposed simple method can offer benefit to station experiencing collisions without additional hardware cost.