• 제목/요약/키워드: Phase average

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Analysis of Phase Noise and HPA Non-linearity in the OFDM/FH Communication System (OFDM/FH 시스템에서 위상잡음과 비선형 HPA의 특성분석)

  • Li, Ying-Shan
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.649-659
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    • 2003
  • OFDM/FH communication system Is widely used in the wireless communication for the large capacity and high-speed data transmission. However, phase noise and PAPR (peak-to-average power ratio) are the serious problems causing performance impairment. In this paper, PLL (phase locked loop) frequency synthesizer with high switching speed is used for the phase noise model. SSPA and TWTA are considered for the nonlinear HPA model. Under these conditions and by approximating $e^{j{\phi}[m]}$ into $1 + j{\phi}[m]-\frac{1}{2}{\phi}^2[m]$ for the phase noise nonlinear approximation, SINR (signal-to-interference-noise-ratio) with nonlinear HPA and phase noise is derived in the OFDM/FH system. The bit error probabilities (BER) are found by computer simulation method and semi-analytical method. The simulation results closely match with the semi-analytical results.

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Evaluation of difference in respiratory phase between amplitude- and phase-based four-dimensional computed tomography (위상 기반 사차원전산화단층촬영과 진폭 기반 사차원전산화단층촬영 영상에서의 위상차 평가)

  • Lee, So Hyang;Park, Soo Yeon;Kim, Jong Sik;Choi, Byung Ki;Park, Hee Chul;Jung, Sang Hoon
    • The Journal of Korean Society for Radiation Therapy
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    • v.27 no.1
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    • pp.73-78
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    • 2015
  • Purpose : Under the assumption of change to the amplitude based sorting, the study will use four dimensional computed tomography imaging (4DCT) arrayed using the phase based sorting to analyze the respiratory phase difference. Materials and Methods : The study analyzed the 4DCT (4-dimensional computed tomography) images of 10 liver cancer patients that were treated with respiratory gated radiotherapy from 2015 February to March. Using RPM respiratory gating (RPM 1.7.5, Varian, USA) equipment, imaging according to respiratory cycle of phase based sorting was acquired and using a treatment planning system (Pinnacle 9.2, Philips, USA) the acquired imaging according to respiratory cycle was used to measure the abdominal movement value by respiratory cycle. The measuring point was the point where the center point of the Marker Block and the body surface met in the 50% phase image and here the coordinate values Lateral, Vertical, Longitudinal (X, Y, Z) were set as reference points, and on the X, Z plane identical to the reference point, using the identical method the Y axis coordinate value of each 0%, 30%, 40%, 50%, 60%, 80% phase images were acquired to quantitatively measure the variation of distance to the Y axis. The abdominal movement value according to respiration was applied to the theoretical model that the value decreases linearly from maximum inhalation to maximum exhalation to divide the variation of my value to predict as amplitude value by respiratory cycle and conversely the variation in amplitude was recalculated with the phase variation deviation value to analyze. Results : The deviation value between expected value and actual location was the largest in the 30% phase with 0.24 cm, and standard deviation was also the largest in 30% phase with 0.13 cm. The effective value of the deviation value derived from the average of the deviation squared value of each patient appeared as minimum 0.7 cm, maximum 0.18 cm, average 0.12 cm, and standard deviation 0.4 cm. Also by dividing the actual movement distance value with the peak expiration value then converting it into %Phase, the deviation value with actual phase 16.5% in 30% phase, 10.0% and 40% phase, 10.0% and 60% phase, 15.4% and 80% phase, and overall average about 13%, and arraying based on amplitude, phase shift occurred and further it was from peak expiration the chance of deviation occurrence was increasingly measured. Conclusion : Based on the results of the study there were differences between value acquired based on theoretical model and actual value. Therefore in respiratory gated radiotherapy using external surrogates, there needs to be establishment of respiration gated radiation system that avoids the combination of two Sorting methods considering that there will be occurrence of treatment and corresponding clinical differences due to the phase difference that occur due to the Amplitude based Phase Sorting.

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An Improved PAPR Reduction Using Sub-block Phase Weighting (SPW) Method in OFDM Communication System (OFDM 시스템에서 SPW(Sub-Block Phase Weighting) 기법을 이용한 개선된 PAPR 저감 기법)

  • Kim Sun-Ae;Kang Yeong-Cheol;Suh Jae-Won;Ryu Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.11 s.102
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    • pp.1123-1130
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    • 2005
  • In this paper, we propose an improved side information processing scheme which is important in the sub-block phase weighting(SPW) method for the peak-to-average power ratio(PAPR) reduction. SPW method is to divide the input OFDM subchannels into several subblocks and to multiply phase weighting with each subblocks, properly for the reduction of the peak power. SPW method is similar to the conventional PTS method when the number of sub-carriers, signal modulation format and the number of subblocks are the same. However, unlike the conventional PTS(Partial Transmit Sequence) and SLM(Selected Mapping) method using many stages of IFFT(Inverse Fast Fourier Transform), SPW method only needs one IFFT. Although PAPR can be reduced by SPW method, complex computation burden still remains. In this paper the flipping algorithm and the full iteration algorithm are used f3r the phase control method. Through the computer simulation, we analyze and discuss the properties and the performance of the suggested method.

Design and Performance Evaluation of an Advanced CI/OFDM System for the Reduction of PAPR and ICI (PAPR과 ICI의 동시 저감을 위한 개선형 CI/OFDM 시스템 설계와 성능 평가)

  • Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.6A
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    • pp.583-591
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    • 2008
  • OFDM (orthogonal frequency division multiplexing) has serious problem of high PAPR (peak-to-average power ratio). Recently, CI/OFDM (carrier interferometry OFDM) system has been proposed for the low PAPR. However, CI/OFDM system shows another problem of ICI because of phase offset mismatch due to the phase noise. In this paper, to simultaneously reduce the PAPR and ICI effects, we propose an A-CI/OFDM (advanced-CT/OFDM). This method improves the BER performance by use of the margin of phase offset at CI codes. Propose system to reduce the effect the phase noise, even though it shows a little bit higher PAPR than conventional CI/OFDM, so we apply the PTS among the PAPR reduction techniques to proposed system to mitigate this problem. Therefore, it improves the total BER performance because the proposed method can decrease the effect of phase noise and get the gain in PAPR reduction performance. From the simulation results, we can show the performance comparison between the conventional OFDM, CI/OFDM and A-CI/OFDM.

Phylogenetics and Gene Structure Dynamics of Polygalacturonase Genes in Aspergillus and Neurospora crassa

  • Hong, Jin-Sung;Ryu, Ki-Hyun;Kwon, Soon-Jae;Kim, Jin-Won;Kim, Kwang-Soo;Park, Kyong-Cheul
    • The Plant Pathology Journal
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    • v.29 no.3
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    • pp.234-241
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    • 2013
  • Polygalacturonase (PG) gene is a typical gene family present in eukaryotes. Forty-nine PGs were mined from the genomes of Neurospora crassa and five Aspergillus species. The PGs were classified into 3 clades such as clade 1 for rhamno-PGs, clade 2 for exo-PGs and clade 3 for exo- and endo-PGs, which were further grouped into 13 sub-clades based on the polypeptide sequence similarity. In gene structure analysis, a total of 124 introns were present in 44 genes and five genes lacked introns to give an average of 2.5 introns per gene. Intron phase distribution was 64.5% for phase 0, 21.8% for phase 1, and 13.7% for phase 2, respectively. The introns varied in their sequences and their lengths ranged from 20 bp to 424 bp with an average of 65.9 bp, which is approximately half the size of introns in other fungal genes. There were 29 homologous intron blocks and 26 of those were sub-clade specific. Intron losses were counted in 18 introns in which no obvious phase preference for intron loss was observed. Eighteen introns were placed at novel positions, which is considerably higher than those of plant PGs. In an evolutionary sense both intron loss and gain must have taken place for shaping the current PGs in these fungi. Together with the small intron size, low conservation of homologous intron blocks and higher number of novel introns, PGs of fungal species seem to have recently undergone highly dynamic evolution.

Effect of acupuncture applied to Naegwan (PC6) and Joksamni (ST36) on the fullness of epigastrium or epigastric pain (내관(PC6).족삼리(ST36) 자침(刺鍼)이 심하통(心下痛) 심하만(心下滿) 등 신경성질환에 미치는 영향)

  • Sohn, In-Chul
    • Korean Journal of Acupuncture
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    • v.23 no.1
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    • pp.111-118
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    • 2006
  • Objectives : To test the therapeutic efficacy of acupuncture applied to PC6 and ST36 for the relief of fullness of epigastrium or epigastric pain. Subjects and Methods : We enrolled fifty patients in a case series study The patients were mainly female (94 %) with an average age of 55 years $({\pm}15.0)$; the average age of the male patients was 51 years $({\pm}20.0)$. Twenty four percent of patients were in acute phase which epigastric pain had lasted below 1 month. Twenty eight percent of patients were in chronic phase which the pain had lasted over 6 month. The rest were in subacute phase. Acupuncture needles were inserted into PC6 and ST36 bilaterally. The acupuncture treatments were performed 2 times a week for 4 weeks. One treat session was lasted for 30 min. At each visit, overall symptomatic improvement, frequency and intensity of symptoms were checked on a 4 scaled questionnaire. Results : After acupuncture treatment, a progressive improvement of pain intensity was reported in 46 of the 50 patients, including 23 of excellent and 23 of good. The progress of symptom was more superior in subacute phase to acute or chronic phase. The symptom of 22 of 24 patients in subacute phase was improved. No patient experienced minor side-effects during acupuncture treatment. Conclusion : These preliminary data suggest the acupuncture treatment provides good pain relief for most patients presenting with epigastric pain. Randomized trials with appropriate control groups are needed to validate the effectiveness of this therapy in the treatment of epigastric pain.

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Effects of medium chain triglycerides with organic acids on growth performance, fecal score, blood profiles, intestinal morphology, and nutrient digestibility in weaning pigs

  • Goh, Tae Wook;Hong, Jinsu;You, Dong Hyun;Han, Yeong Geol;Nam, Seung Ok;Kim, Yoo Yong
    • Animal Bioscience
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    • v.35 no.6
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    • pp.916-926
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    • 2022
  • Objective: This study was conducted to evaluate the effects of medium chain triglycerides (MCT) with organic acids (OA) on growth performance, fecal score, blood profiles, intestinal morphology, and nutrient digestibility in weaning pigs. Methods: A total of 120 weaning pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 8.00±0.87 kg were assigned in five treatments considering sex and initial BW in 3 replications with 8 pigs per pen in a randomized complete block design. The experimental diets included a corn-soybean meal based basal diet with or without 0.1% or 0.2% MCT and 0.1% OA. The pigs were fed the diets for 5 weeks (phase 1, 0 to 2 weeks; phase 2, 3 to 5 weeks). A total of 15 barrows with an average BW of 12.48±0.37 kg were used to evaluate the nutrient digestibility by total collection method. The BW and feed intake were measured at the end of each phase. Blood samples and small intestine samples were collected at the end of each phase, too. Results: Supplementing 0.1% MCT with 0.1% OA showed greater BW for week 5 and average daily gain (ADG) for overall period than control diet. Supplementing 0.1% MCT increased (p<0.05) ADG and improved (p<0.05) gain:feed ratio for phase 1. Dietary MCT and OA did not affect the fecal score and blood concentration of cortisol, immunoglobulin G, tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, and IL-10 in weaning pigs. Pigs fed the diets with 0.1% MCT had greater (p<0.05) villus height of duodenum and ileum for phase 1. Also, pigs fed the diet with 0.1% OA showed greater (p<0.05) villus height and villus height to crypt depth ratio of duodenum for phase 2. There was no significant difference in nutrient digestibility and nitrogen retention of pigs. Conclusion: Addition of 0.1% MCT with 0.1% OA in weaning pig's diet improved growth performance partly by enhancing intestinal morphology in weaning pigs.

Cancellation of Phase Noise in 1.4 GHz RF Signal Transferred to a Remote Site through 13 km Fiber (13 km 광섬유를 통하여 원격지로 전송된 1.4 GHz RF 신호의 위상잡음 제거)

  • Lee, Won-Kyu;Park, Chang-Yong;Mun, Jong-Chul;Yu, Dai-Hyuk
    • Korean Journal of Optics and Photonics
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    • v.21 no.3
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    • pp.103-110
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    • 2010
  • A fiber-phase-noise compensating system was constructed for a 1.4 GHz reference frequency transferred through a 13-km-long fiber spool. The transfer instability was dependent on the temperature variation of the compensating system. With the room temperature variation stabilized within $0.3^{\circ}C$, the transfer instability was $4.6{\times}10^{-14}$ at 0.8 s of average time and $2.5{\times}10^{-16}$ at 1000 s of average time with the fiber phase noise compensated. However, with the room temperature changed by $3.5^{\circ}C$, the transfer instability was $6.8{\times}10^{-14}$ at 1.2 s of average time and $3.0{\times}10^{-15}$ at 1000 s of average time. From this result, the temperature stability condition for the experimental setup could be determined to obtain a transfer instability of $10^{-16}$ at 1000 s of average time.

Kinematical Analysis of Endo 360° El-grip in Horizontal Bar (철봉 엔도 360°엘그립 동작의 기술분석)

  • Back, Jin-Ho;Park, Jong-Chul;Yoon, Jong-Wan;Lee, Yong-Sik;Park, Jong-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.16 no.3
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    • pp.65-74
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    • 2006
  • This study was attempted to Kinematical characteristics of the Endo $360^{\circ}$El-grip Swing on the horizontal bar. To do this, we selected and analyzed the performance of two athletes who did Endo $360^{\circ}$El-grip Swing in the horizontal bar competition of male artistic gymnastic in the 22nd Universiad Games 2003 Daegu. We drew the conclusions from the kinematical factors that were came out through analyzing three-dimensional cinematography of the athletes' movements, by using two video cameras. In point of analyzing the actual competition situation, it is expected that gymnastics and coaches have the effective informations, and the following conclusion had resulted. 1. When performing Endo $360^{\circ}$El-Grip, the average for entire required time was $1.93{\pm}0.06sec$. The average for descent phase time was $0.24{\pm}0.02sec$, ascent phase time was 0.22${\pm}0.07sec$, connecting phase time was $0.87{\pm}0.07sec$, and El-Grip phase time was $0.61{\pm}0.02sec$. The descent phase need short period of time but however to have a stable performance, ensuring ascent and connecting phase time are needed. El-Grip phase need short period of time to have a stable re-grasp. 2. To have a convenient preparation for El-Grip in descent and ascent phase, lowering CM, and ease up in sway and plunge from the High Bar would make descent and ascent even more faster and would have increase effect in trunk rotation. 3. In descent and ascent phase, if shoulder angle and arm slope is dwindling then it would effect rotation angle so might risk it from hitting a Bar when putting legs in and out. 4. In connecting phase, it requires some time to show stable performance when El-Grip phase is continued by using hip angle which would make trunk rotation angle bigger and make descent and ascent time slower. 5. In El-Grip phase, when doing motions like hand standing. using hip angle more than maximum would make CM even faster and it is stable position while performing.

Real time optical image generation using phase grating with simulated annealing algorithm (Simulated Annealing 알고리즘에 의한 위상격자를 이용한 실시간 광 영상 생성)

  • 김철수;김정우;배장근;김수중
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.6
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    • pp.149-155
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    • 1996
  • In this paper, we designed binary phase grating with SA (simulated annealing) algorithm for image generation, and used LCTV(liquid crystal television) as phase modulator. We generated optical image using LCTV which controlled by personal computer in real time. Many parameters in SA algorithm are determined by average deviation of the cost function, not experimental method. It was confirmed that the LCTV could be used as a phase modulator through mach-zehnder interferometering experiment. The various optical images are generated in real itme by fourier transforming of the phase gratings on LCTV which is controlled by personal computer and they can be used for optical interconnection in a neural network and addressing information in a volume hologram etc.

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