• Title/Summary/Keyword: Spacial frequency

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A Study on the Required Specification for the Development of Low Earth Orbit Meteorological Satellite Payload (저궤도 기상위성 탑재체 개발을 위한 요구 규격 연구)

  • Eun, Jong Won
    • Journal of Satellite, Information and Communications
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    • v.8 no.2
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    • pp.74-79
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    • 2013
  • For the purpose of drawing out a requirements (draft) for the development of low Earth orbit meteorological satellite payload, the present development situation of the foreign low Earth orbit meteorological satellite payload was analyzed, and survey and analysis on the questionnaire of the low Earth orbit meteorological satellite payload users' requirements were carried out. Through this research, some key required performance specifications (draft) were made on the basis of technological requirements such as frequency, radiation measurement, spacial, and antenna efficiency requirements, and the low Earth orbit meteorological satellite payload users' requirements.

Behavior of ultrasonic transducer in air by using finite element method simulation (FEM 시뮬레이션을 이용한 공기 중에서의 초음파 트랜스듀서의 거동)

  • Chae, Yeon-Hwa;Choi, Kyoon;Lee, Ho-Yong
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.28 no.5
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    • pp.185-190
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    • 2018
  • The Tonpilz transducer was implemented using the structural module of COMSOL which is a FEM simulation tool. In order to compare the sound pressure characteristics of the transducer with the simulated results, the spacial distribution of the sound pressure level (SPL) was simulated by the acoustic module of COMSOL and then compared with the SPL distribution measured by a microphone. As a result, the resonance frequency and the peak in SPL for the simulation were predicted to be 28 kHz and 163.5 dB, respectively. And the resonance frequency and the peak in SPL for the actual transducer were measured to be 28.84 kHz and 137.8 dB, respectively. It is also confirmed that the simulated SPL distribution and the actually measured one are formed in a similar pattern.

S-wave Velocity and Attenuation Structure from Multichannel Seismic surface waves: Geotechnical Characteristics of NakDong Delta Soil (다중채널 표면파 자료를 이용하여 구한 S파 속도와 감쇠지수 구조: 낙동강 하구의 연약 지반 특성)

  • Jung, Hee-Ok
    • Journal of the Korean earth science society
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    • v.25 no.8
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    • pp.774-783
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    • 2004
  • The S wave velocity and Q$s^{-1}$ structure of the uppermost part of the soil in Nakdong Delta area have been obtained to determine the characteristics of the forementioned soil. The phase and attenuation coefficients of multichannel seismic records were inverted to obtain the S wave velocity and Q$s^{-1}$ structure of the soil. The inversion results have been compared with the borehole measurements of the area. The seismic signal of the nearest geophone from a seismic source was used as the source signal to obtain the attenuation coefficients. Amplitude ratios of the signal at each geophone to the source signal wave plotted as a function of distance for the frequency range between 10 Hz and 45 Hz. The slope of a linear regression line which fits amplitude ratio-distance relationship best for a given frequency was used as the attenuation coefficients for the frequency. The dispersion curve of Rayleigh waves and the attenuation coefficients were inverted to obtain the S-wave velocity and Q$s^{-1}$, respectively, in the uppermost 8 meter of soil layer. The borehole measurements of the area show that are two distinct layers; the upper 4 meter of silty-sand and the lower 4 meter of silty-clay. The inversion results indicate that the shear wave velocity of the upper layer is 80 m/sec and 40m/sec in the lower silty-clay layer. The spacial resolution of the shear wave velocity structure is very good down to a depth of 8 meter. The Q$s^{-1}$ in the upper silty-sand layer is 0.02 and increase to 0.03 in the lower silty-sand layer. The spacial resolution of quality factor is relatively good down to a depth of 5 meter, but very poor below the depth. In this study, the S-wave velocity is higher in the silty-clay and the Q$s^{-1}$ is smaller silty-sand than in the silty-clay. However, much more data should be analyzed and accumulated before making any generalization on the shear wave velocity and Q$s^{-1}$ of the sediments.

Research for Bit-depth Conversion Development by Detection Lost Information to Resizing Process for Digital Photography (디지털 사진영상의 크기조절과정에서 유실되는 정보를 이용한 비트심도의 확장)

  • Cho, Do-Hee;Maik, Vivek;Paik, Joon-Ki;Har, Dong-Hwan
    • The Journal of the Korea Contents Association
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    • v.9 no.4
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    • pp.189-197
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    • 2009
  • A digital image usually has 8 bits of depth basically representing pixel intensity ranging for [0 255]. These pixel range allow 256 step levels of pixel values in the image. Thus the greyscale value for a given image is an integer. When we carry out interpolation of a given image for resizing we have to round the interpolated value to integer which can result in loss of quality on perceived color values. This paper proposes a new method for recovering this loss of information during interpolation process. By using the proposed method the pixels tend to regain more original values which yields better looking images on resizing.

Analysis of Spatial Variability for Infiltration Rate of Field Soils II. Kriging (토양중(土壤中) 물의 침투속도(浸透速度)의 공간변이성(空間變異性) 분석(分析) II. Kriging)

  • Park, Chang-Seo;Kim, Jai-Joung;Cho, Seong-Jin
    • Korean Journal of Soil Science and Fertilizer
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    • v.17 no.1
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    • pp.18-23
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    • 1984
  • Spatial variability of 96 laboratory-measured infiltration rates on the Hwadong SiCL was studied using geostatistical concepts. The measurement was made at the nodes of the regular grid consisting of 12 rows and 8 columns. Sample spacing within rows and columns was 3 and 2m, respectively. Kriging was a means of spacial prediction that can be used for the infiltration rate. It was optimal in the sense that it provided estimates at unrecorded places without bias and with minimum and known variance. An attempt has been made with original data to verily the validity of all assumptions (Stationarity, Variogram models, etc.) by Jack-knifing procedure and frequency distribution. Variogram models were not different from other models, such as linear in calculation of both kriged values and variances in justification of its choice for simplicity. Correlation coefficient for a one-to-one relationship between measured and kriged values was found to be 0.308, which was not significantly different at 1% significance level.

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Variation of PM10 Concentration in Seoul in Association with Synoptic Meteorological Conditions (종관기상장에 따른 서울 지역 미세먼지 농도 변화)

  • Lee, Jung-Young;Han, Jin-Seok;Kong, Boo-Joo;Hong, You-Deog;Lee, Jong-Hyun;Chung, Il-Rok
    • Journal of Environmental Impact Assessment
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    • v.16 no.5
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    • pp.351-361
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    • 2007
  • To evaluate dominant synoptic classes which affect on $PM_{10}$ concentration in Seoul, 64 synoptic classes are classified from four seasons, 850hPa geopotential wind and lower level stability Index. In this study, we used air monitoring and meteorological data in Seoul for five years from 2001 to 2005. The results indicate that the highest occurrence frequency of synoptic class is under a strong westerly geopotential wind and stable lower atmosphere in spring. The highest $PM_{10}$ concentration of synoptic class is associated with a weak geopotential wind speed and high lower level stability. In that class, not only $PM_{10}$ but $SO_2$, $NO_2$ and CO concentrations are also higher than other classes. The analysis of spacial distribution of $PM_{10}$ concentration in each class are indicate that the influence of synoptic class are similar in the Metropolitan area in Korea. But $PM_{10}$ concentration in some areas in Kyoung-Gi are more higher than in Seoul. The relationship between $PM_{10}$ concentration and Meteorological indicator (relative humidity, temperature, surface wind speed) under same synoptic class is more correlative in Winter than other season.

Spatial Structure Analysis of View Angle Correction reflecting Characteristics of Universal Observation (보편적 주시특성을 반영한 시야각 보정 공간구조 분석)

  • Kim, Suk-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6917-6924
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    • 2015
  • The universal nature of humans is formed by the view angle and the visibility range. However, the majority of theories on spatial structure analysis based on the visual perception do neither reflect the view angle nor consider only the flat view angle. Some theories that reflect them is a theory where the part included in the view angle and the part excluded in the view angle have been separated in a dichotomous way, excluding the universal characteristics of humans. This study applied an observing probability to a 3-D visibility analysis theory by conducting a eye-tracking experiment, empirically determining the limits of the field of view, and deriving the observing probability by view angle. In addition, it attempted to identify the probability by manufacturing an application of spacial, visual perception analysis and applying the concept of multiple frustum culling. For the characteristics of observation, the data were measured and collected regarding the walking course for 3 minutes for an optional space, aimed for 33 people as subjects. Subsequently, the data were prepared by analyzing the observation fixation frequency probability.

Species Diversity Analysis of the Aquatic Insect in Paddy Soil

  • Eom, Ki-Cheol;Han, Min-Soo;Lee, Byung-Kook;Eom, Ho-Yong
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.3
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    • pp.163-172
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    • 2013
  • The aquatic insect collected at six areas (each 2 for mountain area, plain field, and urban area) from 2009 to 2011 were classified to analyze the distribution and diversity of species. Frequency (number of aquatic insect: N), number of species (S), similarity index (C), richness index (R1, R2), variety index (V1, V2), evenness index (E1, E2, E3, E4, E5), and dominance index (D1) were investigated. Total N and S were 143 and 84, respectively. C matrix of 153 combinations was constructed with the average of 0.542. The average C of 3 years (0.659) was 9.9% P, more higher than the average C of 6 areas (0.560). The average values of the index of 18 plots were 2.28, 0.17, 1.24, 1.08, 0.07, 0.06, 0.01, 0.87, 0.31, 0.93 for R1, R2, V1, V2, E1, E2, E3, E4, E5, D1, respectively. The order in the coefficient of variation (CV) of the indicator for 18 plots was N (70.0%) > E3 (54.9%) > E1 (49.6%) > R2 (40.5%) > S (35.3%) > R1 (33.7%) > E2 (28.4%) > E5 (15.9%) > V1 (11.1%) > E4 (6.3%) > V2 (5.1%) > D1 (4.8%). The correlation matrix with 66 combinations between the indexes was constructed with statistical significance for 33 combinations. However, R1, V1, E2 and D1 were the proper indexes to represent species diversity of aquatic insect based on the correlation matrix and the theory of statistical independence. The richness index was highest in mountain, variety index in urban area, and evenness index in plain field. However, the dominance index was lowest in urban area.

Hardware Design of Rate Control for H.264/AVC Real-Time Video Encoding (실시간 영상 부호화를 위한 H.264/AVC의 비트율 제어 하드웨어 설계)

  • Kim, Changho;Ryoo, Kwangki
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.12
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    • pp.201-208
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    • 2012
  • In this paper, the hardware design of rate control for real-time video encoded is proposed. In the proposed method, a quadratic rate distortion model with high-computational complexity is not used when quantization parameter values are being decided. Instead, for low-computational complexity, average complexity weight values of frames are used to calculate QP. For high speed and low computational prediction, the MAD is predicted based on the coded basic unit, using spacial and temporal correlation in sequences. The rate control is designed with the hardware for fast QP decision. In the proposed method, a quadratic rate distortion model with high-computational complexity is not used when quantization parameter values are being decided. Instead, for low-computational complexity, average complexity weight values of frames are used to calculate QP. In addition, the rate control is designed with the hardware for fast QP decision. The execution cycle and gate count of the proposed architecture were reduced about 65% and 85% respectively compared with those of previous architecture. The proposed RC was implemented using Verilog HDL and synthesized with UMC $0.18{\mu}m$ standard cell library. The synthesis result shows that the gate count of the architecture is about 19.1k with 108MHz clock frequency.

Studies on- Electrocardiogram of the Normal Korean Native Goat 1. Standard Limb Leads and Unipolar Limb Leads (정상적인 한국 흑염소의 심전도에 관한 연구 1. 표전지유도와 단극지유도)

  • 최인혁;김선기;김추철;최인방;김남수
    • Journal of Veterinary Clinics
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    • v.14 no.2
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    • pp.319-337
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    • 1997
  • The electrocardiographic (ECG) parameters in the normal Korean black goat have been measured with a 3-channel Electrocardiograph and computed, analyzed. ECG in 243 black goats were made with the limb leads (I, II, III, aVR, aVL, aVF), that were recorded conduction parameters of wave and interval, and were analyzed as to shape and amplitude of the P and T waves and the components of the QRS complex. Heart rate were recorded by the ECG which were a mean of 106.1$\pm $21.8 beats/min. Average conduction times in the PR, the QRS complex and the QTc interval were recorded 103.9$\pm $34.9 msec., 58.3$\pm $23.2 msec. and 302.6$\pm $67.8 msec., in the P and T wave duration recorded 24.8$\pm $6.4 msec. and 51.7$\pm $10.8 msec. respectively. The shape of wave in each leads were observed various types, and any spacial wave type appeared the highest frequency in each lead that ware shown less than 60%, and these frequent rate and average amplitudes as fallow: 1. In P waver the frequent rate and average amplitudes of the positive type showed in leads I, II and aVL that were 54.8% (93.0$\pm $ 33.2 $\mu $V), 50.5% (90.1$\pm $30.5 $\mu $V) and 41.7% (58.5$\pm $ 31.1 $\mu $V). Average amplitude of the negative type showed the frequent rate of 49.8% in lead aVE which was -77.6$\pm$ 25.2 $\mu $V. Biphasic type in leads III and aVF were 46.1% (108.4 $\mu $V, -90.2 $\mu $V.) and 45.7% (137.4 $\mu $V, -105.4 $\mu $V.), and amplitudes between positive and negative of it were significant difference. 2. The highest amplitudes of the QRS complex in all leads were 534.8$\pm $ 232.3 $\mu $V of lead II. The frequent rate and amplitudes of the R wave type in the I, II, III and aVF were 30.2% (277.8 $\pm $131.3 $\mu $V), 45.1% (393.1$\pm $114.2 $\mu $V), 48.5% (349.3$\pm $178.3 $\mu $V) and 54.9% (334.4$\pm $129.7 $\mu $V), and QS ways type in the lead aVL was 49.5% (359.2$\pm $195.5$\mu $V), and RS and QS wave types in the lead a VR were 43.3% (312.4 $\mu $V, -212.7 $\mu $V.) and 41.1% (399.2$\pm $92.2 $\mu $V), respectively. 3. In T wave, the frequent rata and amplitudes of the positive type in the leads I, II, III and aVF were 44.6% (207.9$\pm $ 97.1 $\mu $V), 41.6% (245.1$\pm $92.1 $\mu $V), 46.9% (189.8$\pm $ 82.7 $\mu $V) and 53.0% (195.4197.8 $\mu $V), and the negative in the lead aVR was 41.2% (-230.7$\pm$ 103.1 $\mu $V), respectively. The positive and negative types in the lead aVe appeared with same frequent rate of 43.2%.4. Frontal plane vectors for P, QRS, and T were found to lie at 38.1$\pm $ 21.5, 142.0$\pm $ 57.2, and 117.2$\pm $ 63.9 degrees, respectively. These results in ECG of goats may be served to the limited purposes as to conduction parameters, arrhythmias except abnormal ECG because of waveforms, amplitudes and electrical axis of it were variability.

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