• Title/Summary/Keyword: High Frequency Enhancement

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MR imaging of cortical activation by painful peripheral stimulation in rats (쥐에서 말초 자극에 따른 뇌피질 활성화의 자기공명 영상)

  • Lee, Bae-Hwan;Cha, Myeoung-Hoon;Cheong, Chae-Joon;Lee, Kyu-Hong;Lee, Chul-Hyun;Sohn, Jin-Hun
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2009.11a
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    • pp.183-185
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    • 2009
  • As imaging technology develops, magnetic resonance imaging (MRI) techniques have contributed to the understanding of brain function by providing anatomical structure of the brain and functional imaging related to information processing. Manganese-enhanced MRI (MEMRI) techniques can provide useful information about functions of the nervous system. However, systematic studies regarding information processing of pain have not been conducted. The purpose of this study was to detect brain activation during painful electrical stimulation using MEMRI with high spatial resolution. Male Sprague-Dawley rats (250-300 g) were divided into 3 groups: normal control, sham stimulation, and electric stimulation. Rats were anesthetized with 2.5% isoflurane for surgery. Polyethylene catheter (PE-10) was placed in the external carotid artery to administrate mannitol and MnCl2. The blood brain barrier (BBB) was broken by 20% D-mannitol under anesthesia mixed with urethane and a-chloralose. The hind limb was electrically stimulated with a 2Hz (10V) frequency while MnCl2 was infused. Brain activation induced by electrical stimulation was detected using a 4.7 T MRI. Remarkable signal enhancement was observed in the primary sensory that corresponds to sensory tactile stimulation at the hind limb region. These results suggest that signal enhancement is related to functional activation following electrical stimulation of the peripheral receptive field.

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Enhancement of Visibility Using App Image Categorization in Mobile Device (앱 영상 분류를 이용한 모바일 디바이스의 시인성 향상)

  • Kim, Dae-Chul;Kang, Dong-Wook;Kim, Kyung-Mo;Ha, Yeong-Ho
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.8
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    • pp.77-86
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    • 2014
  • Mobile devices are generally using app images which are artificially designed. Accordingly, this paper presents adjusting device brightness based on app image categorization for enhancing the visibility under various light condition. First, the proposed method performed two prior subjective tests under various lighting conditions for selecting features of app images concerning visibility and for selecting satisfactory range of device brightness for each app image. Then, the relationship between selected features of app image and satisfactory range of device brightness is analyzed. Next, app images are categorized by using two features of average brightness of app image and distribution ratio of advanced colors that are related to satisfaction range of device brightness. Then, optimal device brightness for each category is selected by having the maximum frequency of satisfaction device brightness. Experimental results show that the categorized app images with optimal device brightness have high satisfaction ratio under various light conditions.

Least Square Channel Estimation Scheme of OFDM System using Fuzzy Inference Method (퍼지 추론법을 적용한 OFDM 시스템의 LS(Least Square) 채널추정 기법)

  • Kim, Nam;Choi, Jung-Hun
    • The Journal of the Korea Contents Association
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    • v.9 no.5
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    • pp.84-90
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    • 2009
  • In this paper, the new channel estimation was proposed that have the low complexity and high performance using Fuzzy inference method uses recently from various field for estimation about uncertainty in channel estimation of OFDM. Proposed method is channel estimation performance improve, calculation and interpolation for statistics character of channel using the pilot before LS channel estimation by Fuzzy inference method. Simulation result in QPSK proposed channel estimation method shows the enhancement of 5.5dB compared to the LS channel estimation and the deterioration of 1.3dB compared to the MMSE channel estimation in mean square error point $10^{-3}$. symbol error rate shows similarity performance the MMSE $10^{-1.96}$, proposed channel estimation $10^{-1.93}$ and enhancement of $10^{-0.35}$ compared to the LS channel estimation in signal to noise ratio point 20dB.

Transformation of Stereoscopic Images for 3D Perception Improvement (입체영상의 3D 증강을 위한 입체영상 변환)

  • Gil, Jong In;Choi, Hwang Kyu;Kim, Manbae
    • Journal of Broadcast Engineering
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    • v.17 no.6
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    • pp.911-923
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    • 2012
  • Recently, 3DTV and 3D displays have been released in the market. Accordingly, the production of stereoscopic images has gained much interest. Stereoscopic image being composed of left and right images are currently delivered to viewers without any modifications. The researches on the enhancement of depth perception using high-frequency components and the re-production of natural color by color compensation have been carried out for 2D images. The application of such 2D technologies to 3D stereoscopic images is an aim of this paper. This paper proposes the enhancement of 3D perception by color transformation. For this, we propose a stereo matching method for obtaining a depth map and two color transformation methods such as contrast transformation and background darkening. The effectiveness of the proposed method was verified through experiments.

Audio Listening Enhancement in Adverse Environment based on Loudness Restoration (라우드니스 복원에 기반한 잡음 환경에서의 오디오 청취 향상)

  • Pak, Junhyeong;Shin, Jong Won
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.12
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    • pp.210-216
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    • 2013
  • It is hard to listen to the music clearly in the presence of background noise. In this paper, a method that modifies the audio signal automatically to enhance the audio listening experience in adverse environment is proposed. Specifically, the method that amplifies the audio signal so that the perceived loudness of audio signal in each band becomes similar to that of the noiseless signal. The loudness perception model proposed by Moore et. al is utilized. Extending the previous work that is applied to speech reinforcement, the full band signal sampled at 48kHz is manipulated based on the loudness restoration principle. Moreover, based on the observation that the audio clarity is compromised even with loudness restored signal, a modification that intentionally boosts high frequency loudness more than lower band is also proposed. Experimental results showed that the proposed algorithm can enhance the audio listening experience in adverse environment.

Enhancement of Antioxidant Activities of Crataegus pinnatifida Bunge Fruit by Ultrasonification Extraction Processes (초음파추출 공정을 이용한 아가위나무 열매의 항산화 활성 증진)

  • Park, Sung-Jin;Kwon, Sung-Pil;Rha, Young-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.7
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    • pp.891-895
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    • 2017
  • This study was performed to investigate enhancement of antioxidant activities of Crataegus pinnatifida Bunge fruit by different extraction processes. Extracts were SE (stirrer extraction; 70% ethanol extract at $25^{\circ}C$, control), RE (reflux extraction at $60^{\circ}C$), and USE (ultrasonification for 3 h at $60^{\circ}C$ with 70% ethanol), respectively. Compared to SE, total phenolic and flavonoid contents in USE increased to 104.03% and 302.4%, respectively. USE showed the highest activity at 1.0 mg/mL concentration for 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. Our results suggest that extracts from the ultrasonification process have relatively high antioxidative activities, and that fruit of Crataegus pinnatifida Bunge could be considered as a candidate functional antioxidant agents. These results would be useful for chemical and biological studies on natural plants and its products.

A Postfiltering Algorithm for Enhancement in Block-based DCT Compressed Images (블록 기반 DCT 압축 영상의 화질 개선을 위한 후처리 필터링 알고리듬)

  • Kim, Yong-Hun;Jeong, Jong-Hyeog
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.1
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    • pp.22-27
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    • 2014
  • Blocking and ringing artifacts continue to be the most serious defects that occur in images and video streams compressed to low bit rates using block-based discrete cosine transform(DCT) compression standards. These artifacts contain the high frequency components near the block and the edge boundaries. Usually the lowpass filter can remove them. However, simple lowpass filter results into blur by removing important information such as edges at the same time. To overcome these problems, we propose a novel postfiltering algorithm that calculate the weight value based on the intensity similarity in the neighboring pixels and multiply this weight to the Gaussian lowpass filter coefficient. Experimental results show that the proposed technique provides satisfactory performance in both objective and subjective image quality.

Quality Characteristics and Content of Available Components of Freeze-dried Ear Mushroom by UVB (Ultraviolet B) Treatment Conditions (동결건조 목이버섯의 자외선(UVB) 처리조건에 따른 품질 특성 및 유효성분 함량)

  • So-Ra Choi;So-Hee Shin;Young-Eun Song;Hyun-Ah Han;Song-Yee Lee
    • The Korean Journal of Food And Nutrition
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    • v.36 no.2
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    • pp.129-136
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    • 2023
  • In order to investigate the optimal UVB (ultraviolet B) treatment conditions for vitamin D2 enhancement of freeze-dried ear mushroom, sample size (below 300 ㎛~whole), UV treatment temperature (30~60℃), treatment density (6.25~50.0 mg/cm2) and the samples mixing frequency (1~32 times) were treated differently. After that, chromaticity, vitamin D2 and ergosterol (vitamin D2 precursor) contents were investigated. As a result of the investigating, effective UVB treatment conditions for vitamin D2 enhancement are as follows. The sample sizes were 2~4 mm and finely crushed pieces. The treatment temperatures were 50℃ and 60℃. The treatment density was 12.5 to 25.0 mg/cm2, and the number of sample mixing was 8 times or more. As the amount of vitamin D2 increased by UVB treatment, the ergosterol content generally tended to decrease. However, under some UVB treatment conditions, the vitamin D2 content was not high despite the decrease of ergosterol content. Under the conditions set in this experiment, it was possible to obtain ear mushrooms with enhanced vitamin D2 up to 26,968.7 ㎍/100 g. Therefore, it is thought that the ear mushroom is highly likely to be used as a vitamin D source and nutritionally fortified food ingredient.

Pregnancy outcomes following the administration of high doses of dexamethasone in early pregnancy

  • Ahmadabad, Hasan Namdar;Jafari, Sabah Kayvan;Firizi, Maryam Nezafat;Abbaspour, Ali Reza;Gharib, Fahime Ghafoori;Ghobadi, Yusef;Gholizadeh, Samira
    • Clinical and Experimental Reproductive Medicine
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    • v.43 no.1
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    • pp.15-25
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    • 2016
  • Objective: In the present study, we aimed to evaluate the effects of high doses of dexamethasone (DEX) in early pregnancy on pregnancy outcomes. Methods: Pregnant BALB/c mice were treated with high-dose DEX in the experimental group or saline in the control group on gestational days (GDs) 0.5 to 4.5. Pregnant mice were sacrificed on GDs 7.5, 13.5, or 18.5 and their peripheral blood, placentas, fetuses, and uterine tissue were collected. Decidual and placenta cell supernatants were examined to evaluate the effect of DEX on the proliferation of mononuclear cells, the quantity of uterine macrophages and uterine natural killer (uNK) cells, and levels of progesterone and $17{\beta}-estradiol$, as determined by an 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay, immunohistochemistry, and enzyme-linked immunosorbent assay, respectively. We also were measured fetal and placental growth parameters on GD 18.5. Results: We found that high doses of DEX were associated with an increased abortion rate, enhancement of the immunosuppressive effect of the decidua, alterations in placental growth parameters, decreased progesterone and $17{\beta}-estradiol$ levels, and a reduced frequency of macrophages and uNK cells. Conclusion: Our data suggest that the high-dose administration of DEX during early pregnancy negatively affected pregnancy outcomes.

An Adaptive Filtering Method for Enhancement of Inter-color Plane Estimation in HEVC RExt RGB Images (HEVC RExt RGB 영상의 색평면 간 예측 향상을 위한 적응적 필터링 기법)

  • Choi, Jangwon;Choe, Yoonsik
    • Journal of Broadcast Engineering
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    • v.18 no.4
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    • pp.647-650
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    • 2013
  • HEVC RExt(High Efficiency Video Coding Range Extension) set a goal to support RGB/YUV 4:2:2 4:4:4 color sampling and over 10 bit-depth images. Unlike the previous 4:2:0 color sampling images, RGB images have the high correlation in inter-color planes. Using this characteristic, some methods which are contributed in JCT-VC standardization meetings estimate the pixel values of inter-color plane. But when we use the estimation of inter-color plane in RGB images, high frequency components of RGB images are caused to reduce the coding efficiency because they usually have the low inter-color plane correlation. Therefore, in this paper, we propose an adaptive low pass filtering method in the inter-color plane estimation. Using this method, we can improve the estimation efficiency of inter-color plane in RGB images. The experimental results with HEVC RExt RGB test sequences show that the proposed method has 0.6% BD(Bjontegaard Distortion)-rate gain and some increased complexity compared to the previous inter-color plane estimation method.