• Title/Summary/Keyword: 허수

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I/Q Imbalance Compensation Method for the Direct Conversion Receiver with Low Pass Filter Mismatch (저역 통과 필터 불일치를 포함한 직접 변환 수신기의 I/Q 불균형 보상 기법)

  • Yun, Seonhui;Ahn, Jaemin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.11
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    • pp.3-10
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    • 2014
  • Direct conversion receiver(DCR) gets noticed for integration and cost reduction of wireless communication systems instead of the heterodyne receiver which uses complex filter. But DCR has several factors in performance degradation. One of them is I/Q imbalance phenomenon, that is amplitude and phase mismatch between real and imaginary part of receiver. Accordingly, researches are being carried to improve the I/Q imbalance problem. However, the tendency of the broaden bandwidth of communication systems, low pass filter(LPF) mismatch problem affects severely in I/Q mismatch phenomenon at the DCR. To study this problem, we generated 10MHz broadband signal and shifted it ${\pm}8MHz$ from the center frequency. The signal is affected by LPF mismatch and it appears as frequency selective distortion. Thus, LPF mismatch model is added to I/Q imbalance model which conventionally dealt with amplitude and phase mismatches. In addition, we proposed the compensation method for each factors of mismatch. As the simulation results, the proposed I/Q mismatch compensator resolves the frequency selective distortion which occurred by the existing LPF mismatch.

Clinical features of the gingiva according to maxillary anterior teeth form in adult (성인 상악 전치 형태에 따른 치은의 임상적 소견)

  • An, Chi-Hyun;Heo, Soo-Rye;Cho, Ik-Hyun;Kim, Hyung-Seop
    • Journal of Periodontal and Implant Science
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    • v.35 no.2
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    • pp.359-369
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    • 2005
  • It has been suggested that morphologic characteristics of the periodontium are partly related to the shape and form of the teeth. Furthermore, the severity of symptoms of periodontal disease have been proposed to differ among these various morphologic entities or "biotypes". The purpose of the present study was to examine the relationship between the form of the crowns in the maxillary anterior tooth segment and (1) a group of morphological characteristics and (2) the thickness of the gingiva. The thickness of gingiva was measured by ultrasonic device(SDM). 100 subjects devoid of symptoms of destructive periodontal disease were examined regarding, e.g., probing depth, gingival recession, width of keratinized gingiva, thickness of the keratinized gingiva. From maxillary study cast, the width(at the apical third-CW) and the length(CL) of the crowns of the 6 anterior teeth were determined. A CW/CL-ratio was calculated for each tooth and averaged for each tooth region. The individual mean CW/CL-ratio values for the central incisors were ranked. The 10 subjects ranked highest and the 10 ranked lowest were selected as having either a long-narrow(group N) or a short-wide(group W) form of the crown of the tooth. The data for each of the examined parameters were averaged for each tooth region in each subject and mean values for subjects in groups W and N were compared using the Student t-test. Stepwise multiple regression analysis, including data from the whole sample, was performed for each tooth region with the thickness of the free gingiva as the dependent variable. The results from the analyses demonstrated that individuals with a long-narrow form of the central incisors displayed, compared to individuals with a short-wide crown, form (l) a narrow zone of keratinized gingiva, (2) a pronounced "scalloped" contour of the gingival margin. There was no significant difference between groups N and W with respect to the thickness of the keratinized gingiva. The CW/CL-ratio data revealed that a certain form of the crowns in the central incisors was accompanied by a similar form in the lateral incisors and canine tooth region. The regression analyses demonstrated that the thickness of the keratinized gingiva in central, lateral incisors and canines was significantly related to the width of the keratinized gingiva.

Biological Activity and Biochemical Properties of Silkworm (Bombyx mori L.) Powder Fermented with Bacillus subtilis and Aspergillus kawachii (유용식용 균주에 의한 발효 누에분말의 이화학적 특성과 생리활성)

  • Cha, Jae-Young;Kim, Yong-Soon;Ahn, Hee-Young;Kang, Min-Jung;Heo, Su-Jin;Cho, Young-Su
    • Journal of Life Science
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    • v.21 no.1
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    • pp.81-88
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    • 2011
  • Biological activities (${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) free radical scavenging activity, fibrinolytic activity and reducing power) and biochemical properties (protein content and electrophoretical protein patterns) were examined in solid state fermentation with Bacillus subtilis and Aspergillus kawachii using silkworm powder (SP) as substrate. The highest protein contents and free radical scavenging activities were seen in the SP fermented for 12 days with B. subtilis and A. kawachii, and these were in a time-dependent manner. The highest reducing power was seen in the SP fermented for 6 days with B. subtilis and for 12 days with A. kawachii, respectively. The highest fibrinolytic activities were seen in silkworm fermented for 6 days with B. subtilis and A. kawachii, but this activity was higher in the A. kawachii fermented SP than that of B. subtilis. When total protein patterns were analyzed by SDS-polyacrylamide gel electrophoresis (PAGE), the proteins of the SP fermented with B. subtilis for 3 days were completely degraded, while the protein degradation in the SP fermented with A. kawachii occurred after 12 days and this degradation increased proportionally to culture time. As a result, the SP fermented with both B. subtilis and A. kawachii showed higher fibrinolytic activities after 6 days of fermentation and antioxidative activity after 12 days, indicating that physiological activities of the fermented SP using these strains were highly improved compared to the unfermented SP, and that this compound could be a candidate material as a dietary supplement of healthy functional foods.

Improvement of Endoscopic Image using De-Interlacing Technique (De-Interlace 기법을 이용한 내시경 영상의 화질 개선)

  • 신동익;조민수;허수진
    • Journal of Biomedical Engineering Research
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    • v.19 no.5
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    • pp.469-476
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    • 1998
  • In the case of acquisition and displaying medical Images such as ultrasonography and endoscopy on VGA monitor of PC system, image degradation of tear-drop appears through scan conversion. In this study, we compare several methods which can solve this degradation and implement the hardware system that resolves this problem in real-time with PC. It is possible to represent high quality image display and real-time processing and acquisition with specific de-interlacing device and PCI bridge on our hardware system. Image quality is improved remarkably on our hardware system. It is implemented as PC-based system, so acquiring, saving images and describing text comment on those images and PACS networking can be easily implemented.metabolism. All images were spatially normalized to MNI standard PET template and smoothed with 16mm FWHM Gaussian kernel using SPM96. Mean count in cerebral region was normalized. The VOls for 34 cerebral regions were previously defined on the standard template and 17 different counts of mirrored regions to hemispheric midline were extracted from spatially normalized images. A three-layer feed-forward error back-propagation neural network classifier with 7 input nodes and 3 output nodes was used. The network was trained to interpret metabolic patterns and produce identical diagnoses with those of expert viewers. The performance of the neural network was optimized by testing with 5~40 nodes in hidden layer. Randomly selected 40 images from each group were used to train the network and the remainders were used to test the learned network. The optimized neural network gave a maximum agreement rate of 80.3% with expert viewers. It used 20 hidden nodes and was trained for 1508 epochs. Also, neural network gave agreement rates of 75~80% with 10 or 30 nodes in hidden layer. We conclude that artificial neural network performed as well as human experts and could be potentially useful as clinical decision support tool for the localization of epileptogenic zones.

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An Experimental study to estimate physical properties of porous media by a permittivity method (유전율법에 따른 다공질 매질의 특성 파악을 위한 실험적 연구)

  • 김만일;니시가끼마코토
    • The Journal of Engineering Geology
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    • v.13 no.4
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    • pp.405-418
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    • 2003
  • Measurements of volumetric water content and saturation of porous media are very important factors in understanding the physical characteristics of soil, groundwater recharge by rainfall, pollutant movement, and slope failure. To measure such physical parameters, a permittivity method using electromagnetic wave is applied and use is made of the special permittivity response of understand to water and ethanol. In particular, the estimation is required because permittivity is influenced by the nature of the underground environment. In this study, we carried out experiments on the relative dependency of soil density, temperature and salinity of standard sand and granitic weathered soil using FDR-V system (Frequency domain reflectometry with vector network analyzer) within a frequency range of 1 - 18 GHz. The results of the study showed that the dielectric constants of standard sand and granitic weathered soil increased with increased volumetric water content of soil. However, the dependency of soil density was found to be a little low. Changes of dielectric constant with temperature appeared definitely in the real part of 1 GHz. That is, the dielectric constant of real part at 1 GHz of water and standard sand increased with the rise of temperature. However, ethanol showed decreased tendency. The study also showed that dielectric constant increased with increase in salinity at imaginary part of 1 GHz. It could be concluded from this study FDR-V system can adequately measure the physical properties of soil and the degree of salinity concentration of porous media within 1 GHz frequency range using dielectric constant.

Composition and Cytotoxicity of Essential Oil Extracted by Steam Distillation from Horseweed (Erigeron canadensis L.) in Korea (수증기 증류로 추출한 망초(Erigeron canadensis L.) 정유의 성분 분석과 독성 평가)

  • Choi, Hae-Jin;Wang, Hai-Ying;Kim, Young-Nam;Heo, Su-Jeong;Kim, Nam-Kyung;Jeong, Mi-Soon;Park, Yu-Hwa;Kim, Song-Mun
    • Applied Biological Chemistry
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    • v.51 no.1
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    • pp.55-59
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    • 2008
  • The composition of essential oil from the aerial part of Erigeron canadensis L. was analyzed by GC-MS. Thirty-one constituents were identified from the essential oil: eighteen hydrocarbons (91.99% of the total oil), two acetates (2.92%), three alcohols (3.59%), four ethers (0.49%), one aldehyde (0.05%), and three ketone (0.23%). Major constituents of the essential oil were D,L-limonene (68.25% of the total oil) and delta-3-carene (15.9%). The $IC_{50}$ value of the essential oil was 0.027 ${\mu}g$ $mg^{-1}$ in MTT assay using HaCaT keratinocyte cell line.

Comparative Analysis on Concentration and Synthetic Amount of Water Soluble and Water Insoluble Carbohydrates with Different Plant Tissues, Growth Stages and Years Old of Panax ginseng C. A. Meyer (인삼의 연생, 생육시기 및 식물체 부위별 수용성과 불수용성 탄수화물 함량과 합성저장량 비교)

  • Park, Seong Yong;Ahn, Bok Ju;Ahn, Hee Jung;Lee, Gyeong A;Heo, Su Jeong;Jeong, Haet Nim;Song, Beom Heon
    • Korean Journal of Medicinal Crop Science
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    • v.23 no.4
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    • pp.292-297
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    • 2015
  • This study was carried out to have the basic and applied informations relating to develop the cultivation methods and to increase the productivity and quality of ginseng. 1 to 6 year old ginsengs of Jakyung cultivar were cultivated and the content and synthetic amount of carbohydrates were investigated with different plant tissues, growth stages, and years old. The concentration of total carbohydrates at six year old ginseng including water soluble and water insoluble carbohydrates was about 18.9%, 42.9%, and 43,6% in leaves, tap roots, and lateral roots, respectively. Water soluble carbohydrate of tap and lateral roots was slightly decreased from August until September, and then increased on November, whereas its water insoluble carbohydrate was increased from August to September and then decreased on November. Comparing with the content of carbohydrates of 1 to 6 year old ginsengs, it was continuously increased from one year old ginseng until five year old ginseng, however it was not increased much in six year old ginseng. The highest content of carbohydrates was at five year-old in all tissues of ginseng. Water soluble and water insoluble carbohydrates were significantly shown different in leaves, stems, tap roots, and lateral root at different growth stages and with different years old. The content of water soluble carbohydrate in the leaves was remarkedly higher compared to that of water insoluble carbohydrate, while in the root the content of water insoluble carbohydrate was clearly higher compared to the water soluble carbohydrate. Comparing with the synthetic amount of carbohydrates, water soluble carbohydrates was higher in the shoot than that in the root, whereas water-insoluble carbohydrates higher in the root than that in the shoot. Carbohydrates which would be utilized in ginseng tissues for short and long-term periods as major energy were appeared differently in between shoot and root, with different growth stages, and years old.

Determination of Pelvic Limb Alignment in Small-breed Dogs (소형견종의 후지정렬 측정)

  • Kim, Jooho;Heo, SuYoung;Na, Jiyoung;Kim, Namsoo;Lee, Kichang;Jeong, Seongmok;Lee, HaeBeom
    • Journal of Veterinary Clinics
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    • v.32 no.6
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    • pp.481-485
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    • 2015
  • The present study determined the normal reference ranges for overall pelvic limb alignment of small-breed dogs. For this purpose, 60 cadaveric canine pelvic limbs from normal small-breed dogs (Maltese, Poodle, Shih Tzu, Yorkshire Terrier). A frontal full-limb radiograph of each pelvic limb was obtained, and mechanical tibiofemoral angle (mTFA), mechanical metatarsotibial angle (mMTTA), mechanical axis-femur angle (MAFA), and mechanical axis-metatarsus angle (MAMTA) were measured from each radiograph, along with mechanical deviation of the stifle (SMAD) and tarsal joints (TMAD). The 95% CI for radiographic values of all pelvic limbs were mTFA, 5.7-7.4; mMTTA, $-2.2--0.8^{\circ}$; MAFA, $3.5-4.5^{\circ}$; MAMTA, 1.0-2.0; SMAD, 2.1-2.7%; TMAD, 0.5-1.0%. There values varied among the breeds, except for mTFA. The reference ranges can be used for diagnosing pelvic limb deformities in small-breed dogs and for planning corrective osteotomies.

Tibial Plateau Leveling Osteotomy for Treatment of Naturally Occurring Cranial Cruciate Ligament Rupture in Small Breed Dogs - Case Series (소형견에서 전 십자인대 단열의 치료를 위한 경골 고평부 평탄 골절단술의 평가)

  • Kim, Choong-Sup;Heo, Su-Young;Kim, Min-Su;Kim, Nam-Soo;Lee, Hae-Beom
    • Journal of Veterinary Clinics
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    • v.31 no.6
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    • pp.483-489
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    • 2014
  • This study describes a surgical technique and evaluates the clinical outcomes in small breed dogs with cranial cruciate ligament rupture (CCLR) treated with tibial plateau leveling osteotomy (TPLO). Seven skeletally mature dogs weighing less than 15 kg underwent unilateral TPLO to stabilize the stifle joint with CCLR. Clinical evaluation was performed via visual lameness score, range of motion (ROM), and thigh girth circumference (TC). Postoperative complications were recorded. All patients reached a grade 1 score at 1 week and grade 0 at 8 weeks postoperatively. The mean operated limb extension angle was 98.11%, 99.07%, and 98.73% of the mean extension angle of the contralateral limb at 4 weeks, 8 weeks, and 12 weeks postoperatively, respectively. The mean operated limb flexion angle was 98.07%, 95.88%, and 96.35% of the mean flexion angle of the contralateral limb at 4 weeks, 8 weeks, and 12 weeks postoperatively, respectively. The mean TC of the operated limb was 92.95%, 93.68%, and 95.44% of the mean TC of the normal limb at 4 weeks, 8 weeks, and 12 weeks postoperatively, respectively. Our outcomes for TPLO in small breed dogs are not worse than those previously reported for large breed dogs. Based on the result in the present study, CCLR in small dogs can be successfully managed with TPLO, as done in large breed dogs.

Development of Simultaneous Analysis of Ferulic Acid, Caffeic Acid, Catechin and Taxifolin from Health Functional Food Pinus Pinaster Bark Extract by UPLC-MS/MS (건강기능식품 프랑스해안송껍질추출물 중 UPLC-MS/MS를 이용한 Ferulic acid, Caffeic acid, Catechin, Taxifolin 동시분석법 개발 연구)

  • Oh, Jae-Myoung;Kim, Ji An;Hu, Soo Jung;Choi, Yoon Hee;Oh, Keum Soon
    • Journal of Food Hygiene and Safety
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    • v.34 no.5
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    • pp.431-437
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    • 2019
  • This study was conducted to develop a simultaneous analysis method for ferulic acid, caffeic acid, catechin and taxifolin from Health Functional Food (HFF) Pinus Pinaster bark extract. The simultaneous analytical method for ferulic acid, caffeic acid, catechin and taxifolin is carried out using UPLC-MS/MS. The method validation was performed to determine selectivity, linearity, accuracy, limit of detection (LOD), limit of quantification (LOQ) and precision for ferulic acid, caffeic acid, catechin and taxifolin. LC-MS/MS method was established using an Acquity UPLC BEH $C_{18}$ Column and was applied for these 4 compounds. Product-ion traces, at m/z $194.2{\rightarrow}133$, $180.2{\rightarrow}135$, $290.3{\rightarrow}245$, $304.3{\rightarrow}248$, were used for quantitative analysis of ferulic acid, caffeic acid, catechin and taxifolin, respectively. Excellent linearity ($r^2=0.999$) was observed for ferulic acid, caffeic acid, catechin and taxifolin in the concentration range (50-2500 mg/L). The observed recoveries of these 4 compounds were found to be between 84.9 and 104.9%, while precision was between 1.20 and 4.43% relative standard deviation (% RSD).