• Title/Summary/Keyword: difference edge

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Improved changed region detection and motion estimation for object-oriented coding (객체기반 부호화에서의 개선된 움직임 영역 추출 및 추정 기법)

  • 정의윤;박영식;송근원;한규필;하영호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.9
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    • pp.2043-2052
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    • 1997
  • The object-oriented coding technique which is one of the coding methods in very low bit rate environment is suitable for videophone image sequence. The selection of source model affect image analysis. In this paper, an image analysis method for the object-oriented coding is presented. The process is composed of changed region detection andmotion estimateion. First, we use the standard deviation of frame difference as thrreshold to extract themoving area. If thesum of gray values in mask is greater than the threshold, the center pixel of the mask is regarded as moving region. After moving is detected in changed region by edge operator, observation point is determined from moving region. The motion is estimated by 6-parameter mapping method with determined observation point. The experimantal resutls show that the proposed method can significantly improve the image quality.

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The Assessment for Mandibular Movement and Adult Facial Skeletal Structure According to Angle's Classcification (앵글씨 분류에 의한 성인 골격구조 및 하악운동량 평가)

  • Kim, Jae-Hyung;Kim, Byung-Gook;Choi, Hong-Ran
    • Journal of Oral Medicine and Pain
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    • v.26 no.2
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    • pp.147-156
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    • 2001
  • The purpose of this study was to identify the difference of vertical movement of mandible according to Angle's molar relationship and by skeletal factors affect to vertical movement of mandible. 172(age ranged from 20 to 30) subjects who go to college within territory of Kwangju city without any experience of temporomandibular disorder, extraction and orthodontic treatment. were selected for this study. The subjects were classified into class I(male:30, female:49), class II(male:18, female:24) and class III(male:18, female:33) according to Angle's molar relationship. The distance was measured between incisal edge of maxillary and mandibular central incisor and between bottom of central fossa of maxillary and mandibular 1st molar with ruler. The arch length and width were measured on the diagnostic cast. Cephalometrics were taken and then traced. Landmarks were identified and analyzed. 1. Maximal interincisal opening of male is larger than that of female in class I, class II and class III. Among each group maximal interincisal distance is the largest in class III. Maximal intermolar distance of male is superior to that of female in class I, class II, and class III, but there is no siginficant difference among them. 2. On maximal opening movement of Angle's classification class I and class II, total mandibular length, mandibular ramal length, madibular inferior border length and upper arch width were important variables and facial length, upper arch length and lower arch length had negative relationship to that. On maximal opening movement of Angle's class III, the upper arch length, the lower arch length and anterior facial length were important variables especially when compared with class I and II, and upper arch width had negative relationship. These results suggest that maximal opening movement is affected by facial morphology in all classes, but each group is affected by different facial skeletal variables. Accordingly, facioskeletal variables might be considered as diagnosis and treatment to improve the amount of mouth opening.

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Acceleration Sensor Using Optical Fibers and Film Gratings (광섬유와 필름격자를 이용한 가속도 센서)

  • Lee, Youn-Jea;Jo, Jae-Heung;Kwon, Il-Bum;Seo, Dae-Cheol;Lee, Nam-Kwon
    • Korean Journal of Optics and Photonics
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    • v.19 no.3
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    • pp.175-181
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    • 2008
  • We develop a fiber optic acceleration sensor with LED, PD, POF, and a cantilever beam, having film grating at the edge of the beam. Light is transmitted from LED to PD through the film grating. When the cantilever beam moves by external vibration, output light is modulated as sinusoidal signals. The characteristics of output signals are dominated by the spacing of the film grating and also by the size and the elasticity of the beam. Two output signals, having constant initial phase difference, are obtained by two gratings with 90 degree phase difference. Those two signals are used to determine phase angle, which is proportional to the displacement of the beam. Finally, the acceleration is determined from conversion equation between displacement and acceleration. This sensor is designed for monitoring the vibration of large and complex building in the low frequency range of below 7 Hz, and is particularly suitable to measure acceleration in electromagnetic environments.

Shot Boundary Detection of Video Sequence Using Hierarchical Hidden Markov Models (계층적 은닉 마코프 모델을 이용한 비디오 시퀀스의 셧 경계 검출)

  • Park, Jong-Hyun;Cho, Wan-Hyun;Park, Soon-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8A
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    • pp.786-795
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    • 2002
  • In this paper, we present a histogram and moment-based vidoe scencd change detection technique using hierarchical Hidden Markov Models(HMMs). The proposed method extracts histograms from a low-frequency subband and moments of edge components from high-frequency subbands of wavelet transformed images. Then each HMM is trained by using histogram difference and directional moment difference, respectively, extracted from manually labeled video. The video segmentation process consists of two steps. A histogram-based HMM is first used to segment the input video sequence into three categories: shot, cut, gradual scene changes. In the second stage, a moment-based HMM is used to further segment the gradual changes into a fade and a dissolve. The experimental results show that the proposed technique is more effective in partitioning video frames than the previous threshold-based methods.

Analysis of stress and distortion that develop during accelerated cooling of plate (가속냉각시 강판에 발생하는 응력 및 변형에 대한 연구)

  • 김호영;김창영;주웅용;장래웅
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.952-958
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    • 1988
  • To analyze the nonflatness and residual stress in accelerated cooled plate, a numerical analysis model has been developed. Two factors, i.e. temperature and phase transformation, are considered in calculating the stress distribution that develops during cooling. The plastic strain and plate-buckling, which are often shown in accelerated cooled plate, were determined from this stress. Mean temperature in through thickness direction and temperature difference in width direction are considered in the model to simplify the calculation. The temperature and stress distribution changes caused by phase transformation are involved in terms of the effective specific heat and the effective thermal expansion coefficient. With the model, accelerated cooling of 10mm(t) $^{*}$3000mm(w) plate was simulated. The condition of accelerated cooling was .deg. C/sec from just after hot rolling to 500.deg. C. The initial temperature-difference ratio, .DELTA.Tr, in width direction is an important factor in evaluating the stress distribution. When .DELTA.Tr is 0.08, buckling occurs during cooling and 7kgf/m $m^{2}$ of residual stress develops at the edge of plate. To secure the flatness, .DELTA.Tr should be less than 0.07. Small scaled cooling test was conducted to verify the exactness of the model and the results proved the usefulness of this numerical analysis model.l.

Effects of functional training on strength, function level, and quality of life of persons in intensive care units

  • Seo, Byul;Shin, Won-Seob
    • Physical Therapy Rehabilitation Science
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    • v.8 no.3
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    • pp.134-140
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    • 2019
  • Objective: The purpose of this study was to investigate the effect of exercise therapy and bedside ergometer exercise on muscle strength, function level, and quality of life of persons in intensive care. Design: Randomized Controlled Trial Methods: Sixteen patients in the ICU were randomly assigned to either the exercise group (n=8) or the bedside cycle ergometer group (n=8). Activities in the ICU exercise group (rolling, sitting at the edge of the bed, transfer from sitting to standing, standing balance training, ambulation) and bedside cycle ergometer group were performed 5 times a week for 30 minutes during the ICU admission period. Medical Research Council (MRC) and Functional Status Scale-Intensive Care Unit (FSS-ICU) parameters were assessed at the time of admission to the ICU, and reevaluation was assessed on the day of ICU discharge. The Short Form-36 (SF-36) was assessed at the time of discharge from the ICU. Results: MRC and FSS-ICU were significantly increased before and after intervention in both the experimental and control groups (p<0.05). There was a significant difference between MRC and FSS-ICU in the comparison of the changes before and after the intervention (p<0.05). SF-36 was compared between groups after intervention and there was a significant difference between the experimental and the control group (p<0.05). Conclusions: Muscle strength and functional levels improved after intervention in both the experimental and control groups. The ICU exercise group was more effective than the bedside cycle ergometer group to improve muscle strength, functional level, and quality of life performance of persons in the ICU.

Geodetic monitoring on onshore wind towers: Analysis of vertical and horizontal movements and tower tilt

  • Canto, Luiz Filipe C.;de Seixas, Andrea
    • Structural Monitoring and Maintenance
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    • v.8 no.4
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    • pp.309-328
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    • 2021
  • The objective of this work was to develop a methodology for geodetic monitoring on onshore wind towers, to ascertain the existence of displacements from object points located in the tower and at the foundation's base. The geodesic auscultation was carried out in the Gravatá 01 and 02 wind towers of the Eólica Gravatá wind farm, located in the Brazilian municipality of Gravatá-PE, using a stable Measurement Reference System. To verify the existence of displacements, pins were implanted, with semi-spherical surfaces, at the bases of the towers being monitored, measured by means of high-precision geometric leveling and around the Gravatá 02 tower, concrete landmarks, iron rods and reflective sheets were implanted, observed using geodetic/topographic methods: GNSS survey, transverse with forced centering, three-dimensional irradiation, edge measurement method and trigonometric leveling of unilateral views. It was found that in the Gravatá 02 tower the average rays of the circular sections of the transverse welds (ST) were 1.8431 m ± 0.0005 m (ST01) and 1.6994 m ± 0.0268 m of ST22, where, 01 and 22 represent the serial number of the transverse welds along the tower. The average calculation of the deflection between the coordinates of the center of the circular section of the ST22 and the vertical reference alignment of the ST1 was 0°2'39.22" ± 2.83" in the Northwest direction and an average linear difference of 0.0878 m ± 0.0078 m. The top deflection angle was 0°8'44.88" and a linear difference of ± 0.2590 m, defined from a non-linear function adjusted by Least Squares Method (LSM).

Comparative Analysis of Italian Ryegrass Vegetation Indices across Different Sowing Seasons Using Unmanned Aerial Vehicles (무인기를 이용한 이탈리안 라이그라스의 파종계절별 식생지수 비교)

  • Yang Seung Hak;Jung Jeong Sung;Choi Ki Choon
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.43 no.2
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    • pp.103-108
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    • 2023
  • Due to the recent impact of global warming, heavy rainfall and droughts have been occurring regardless of the season, affecting the growth of Italian ryegrass (IRG), a winter forage crop. Particularly, delayed sowing due to frequent heavy rainfall or autumn droughts leads to poor growth and reduced winter survival rates. Therefore, techniques to improve yield through additional sowing in spring have been implemented. In this study, the growth of IRG sown in Spring and Autumn was compared and analyzed using vegetation indices during the months of April and May. Spectral data was collected using an Unmanned Aerial Vehicle (UAV) equipped with a hyperspectral sensor, and the following vegetation indices were utilized: Normalized Difference Vegetation Index; NDVI, Normalized Difference Red Edge Index; NDRE (I), Chlorophyll Index, Red Green Ratio Index; RGRI, Enhanced Vegetation Index; EVI and Carotenoid Reflectance Index 1; CRI1. Indices related to chlorophyll concentration exhibited similar trends. RGRI of IRG sown in autumn increased during the experimental period, while IRG sown in spring showed a decreasing trend. The results of RGRI in IRG indicated differences in optical characteristics by sowing seasons compared to the other vegetation indices. Our findings showed that the timing of sowing influences the optical growth characteristics of crops by the results of various vegetation indices presented in this study. Further research, including the development of optimal vegetation indices related to IRG growth, is necessary in the future.

OCCLUSAL VARIATIONS IN THE POSTERIOR AND ANTERIOR SEGMENTS OF THE TEETH (구치부와 전치부의 교합 상태에 관한 연구)

  • Lee, Ki-Soo;Chung, Kyu-Rim;Ko, Jin-Hwan;Koo, Chung-Hoe
    • The korean journal of orthodontics
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    • v.10 no.1
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    • pp.71-79
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    • 1980
  • The purpose of this study was (1) to determine the prevalence of some causes by which dental occlusion might be affected , (2) to determine the prevalence of malocclusion, and types of molar, vertical incisor and horizontal incisor relationships, and (3) to examine the sex difference in the prevalence ratios, and (4) to determine the between-examiner differences in assessing types of dental occlusion. The material consisted of 1281 males and 811 females, total 2091 persons, aged 17 to 21 years. Two examiners who were graduate students in the orthodontic course, examined independently dental occlusion of the material. Before calculating the statistics, the subjects consisted of 156 mates and 164 females, total 320 persons, haying any one or more causes suspected to affect dental occlusion, was eliminated. Then the remained subjects, 1124 males and 647 females, total 1771 persons, were assessed. The results were as follows 1. The prevalence of some causes by which dental occlusion might be affected was 15.32 per cent. The missing rate of any one or more first molars was 8.85 percent, that of any one or more teeth positioned anterior to the first molar was 3.83 per cent. The prevalence of crossbite of the first molar was 0.48 per cent, that of retained primary teeth was 0.77 percent, and that of orthodontic treatment was 0.43 per cent. 8. The rate of between-examiner difference was 12.53 per cent in assessing the types of molar relationship, 18.86 percent in assessing the types of horizontal incisor relationship, and 26.37 percent in assessing the types of horizontal incisor relationship. 3. There was no sex difference in the prevalence ratios of the types of molar relationship. The prevalence of Class I molar relationship was 80.91 percent, that of Class II was 5,03, that of Class II subdivision was 4.01, Percent, that of Class III was 5.99 percent and that of Class III subdivision was 4.07 percent. 4. In the prevalence of the types of horizontal incisor relationship, there were no sex differences except that of Class II division 2. The prevalence of Class I horizontal incisor relationship was 73.12 percent, that of Class II division t was 12.03 percent, that of Class II division 2 was 6.58 percent in male and 4.33 percent in female, and that of Class III was 9.09 percent. 5. In the prevalence of the types of vertical incisor relationship, there were no sex differences except that of deep bite, The prevalence of open bite was 2.20 per cent, that of edge-to-edge bite was 9.15 percent, that of normal bite was 76,34 percent, and that of deep bite was 14.15 percent in male and 9.12 percent in female. 6. There was no sex difference in the prevalence of malocclusion the prevalence of malocclusion was 82.67 percent and that of normal occlusion was 17.33 percent. 7. There was a tendency that when Class I molar relationship changed to Class II, incisor relationships were to be larger overjet or upright upper incisors and deep bite, but when that changed to Class III molar relationship, these were to be cross bite and openbite.

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Diel and Tidal Distributions of the Sand-burrowing Mysids Archaeomysis kokuboi and Acanthomysis nakazatoi on a Sandy Shore Surf Zone of Yongil Bay, Eastern Korea, in Relation to Growth Stages (동해 영일만 쇄파대에 서식하는 곤쟁이 Archaeomysis kokuboi와 Acanthomysis nakazatoi의 성장단계에 따른 주야 및 조석간 분포)

  • Jo, Soo-Gun;Kim, Chung-A;Suh, Hae-Lip
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.2
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    • pp.112-119
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    • 2012
  • This study investigated the diel and tidal distributions of the two mysids, Archaeomysis kokuboi and Acanthomysis nakazatoi, in relation to their growth stages in the sandy surf zone of Yongil Bay, located on the southeastern part of Korean Peninsula. Sampling was conducted with a sledge net at every two hours for almost 24 hours at three sites: water edge, water surface and sand bottom both in 1-m deep water areas. The abundance of Archaeomysis kokuboi juveniles was too low to count both in day and night samples. While there was no difference in immature A. kokuboi abundance between day and night in the bottom or water edge, that at the water surface was significantly higher at night than daytime. The abundance of A. kokuboi adults, especially of males, in the bottom was significantly higher in daytime than night and no individuals appeared to the water surface either day or night. In comparison, the abundance of Acanthomysis nakazatoi juveniles between day and night did not differ significantly at all the three sites, with the highest number being distributed in the bottom. The abundance of immatures between day and night also did not differ significantly and no individuals appeared to the water surface either day or night. The abundance of A. nakazatoi adults, especially females, in the bottom was significantly higher at night than daytime and there was no significant difference in abundance between day and night in the other sites. There was also no significant difference in abundances of the two species between ebb and flood tides, except for A. kokuboi immatures which appeared significantly more during the ebb tides at the water surface. Overall, the distribution of the two sympatric species, A. kokuboi and A. nakazatoi, was not the same in the sandy surf zone. Its difference seems to depend on their stages of growth, and the change in their abundance may be influenced more by diurnal rhythms than tidal effects. The population density of A. nakazatoi in the sandy surf zone was much higher than that of A. kokuboi, and relatively higher densities in all growth stages of the former were found in the sandy bottom ranging from juveniles to adults. These results indicate that A. nakazatoi has exceedingly better ability of sand burrowing even from the juvenile stage, and thus is an ecologically better adapted species in the sandy surf zone than another sympatric species, A. kokuboi.