• Title/Summary/Keyword: spatiotemporal characteristics

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Analysis of Traffic Accidents Injury Severity in Seoul using Decision Trees and Spatiotemporal Data Visualization (의사결정나무와 시공간 시각화를 통한 서울시 교통사고 심각도 요인 분석)

  • Kang, Youngok;Son, Serin;Cho, Nahye
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.2
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    • pp.233-254
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    • 2017
  • The purpose of this study is to analyze the main factors influencing the severity of traffic accidents and to visualize spatiotemporal characteristics of traffic accidents in Seoul. To do this, we collected the traffic accident data that occurred in Seoul for four years from 2012 to 2015, and classified as slight, serious, and death traffic accidents according to the severity of traffic accidents. The analysis of spatiotemporal characteristics of traffic accidents was performed by kernel density analysis, hotspot analysis, space time cube analysis, and Emerging HotSpot Analysis. The factors affecting the severity of traffic accidents were analyzed using decision tree model. The results show that traffic accidents in Seoul are more frequent in suburbs than in central areas. Especially, traffic accidents concentrated in some commercial and entertainment areas in Seocho and Gangnam, and the traffic accidents were more and more intense over time. In the case of death traffic accidents, there were statistically significant hotspot areas in Yeongdeungpo-gu, Guro-gu, Jongno-gu, Jung-gu and Seongbuk. However, hotspots of death traffic accidents by time zone resulted in different patterns. In terms of traffic accident severity, the type of accident is the most important factor. The type of the road, the type of the vehicle, the time of the traffic accident, and the type of the violation of the regulations were ranked in order of importance. Regarding decision rules that cause serious traffic accidents, in case of van or truck, there is a high probability that a serious traffic accident will occur at a place where the width of the road is wide and the vehicle speed is high. In case of bicycle, car, motorcycle or the others there is a high probability that a serious traffic accident will occur under the same circumstances in the dawn time.

A Study on Spatial and Temporal Distribution Characteristics of Coastal Water Quality Using GIS (GIS를 이용한 연안수질의 시공간적 분포 특성에 대한 연구)

  • Cho, Hong-Lae;Jeoung, Jong-Chul
    • Spatial Information Research
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    • v.14 no.2 s.37
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    • pp.223-234
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    • 2006
  • In order to examine spatio-temporal characteristics of coastal water quality, we applied GIS spatial analysis to the water quality data collected from observation points located on Korean coastal area during 1997$\sim$2004. The water quality parameters measured included: chlorophyll-a, pH, DO, COD, SS, dissolved inorganic nitrogen, dissolved inorganic phosphorous, salinity, temperature. The water quality data used in this paper was obtained only at selected sites even though they are potentially available at any location in a continuous surface. Thus, it is necessary to estimate the values at unsampled locations so as to analyze spatial distribution patterns of coastal water quality, Owing to this reason, we applied IDW(inverse distance weighted) interpolation method to water quality data and evaluated the usefulness of IDW method. After IDW interfolation method was applied, we divided the Korean coastal area into 46 sections and examined spatio-temporal patterns of each section using GIS visualization technique. As a result of evaluation, we can blow that IDW interpolation and GIS are useful for understanding spatial and temporal distribution characteristics of coastal water quality data which is collected from a wide area far many years.

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Proposition for Retina Model Based on Electrophysiological Mechanism and Analysis for Spatiotemporal Response (전기생리학적 기전에 근거한 망막 모델의 제안과 시공간적 응답의 분석)

  • Lee, Jeong-Woo;Chae, Seung-Pyo;Cho, Jin-Ho;Kim, Myoung-Nam
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.39 no.6
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    • pp.49-58
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    • 2002
  • Based on electrophysiological retina mechanism, a retina model is proposed, which has similar response characteristics compared with the real primate retina. Photoreceptors, horizontal cells, and bipolar cells are modeled based on the previously studied retina models. And amacrine cells known to have relation to movements detection, and bipolar cell terminals are newly modeled using 3 NDP mechanism. The proposed model verified by analyzing the spatial response characteristics to stationary and moving stimuli, and characteristics for different speeds. Through this retina model, human vision system could be applied to computer vision systems for movement detection, and it could be the basic research for the implantable artificial retina.

Gait Characteristics of Sasang Constitution with 3-Axis Accelerometer-Based Gait Analysis (3축 가속도계를 이용한 사상체질별 보행특성 연구)

  • Lee, Dongkyu;Jeong, Seoyoon;Kim, Lakhyung
    • Journal of Oriental Neuropsychiatry
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    • v.31 no.4
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    • pp.225-233
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    • 2020
  • Objectives: This study aimed to reveal the gait characteristics of each Sasang constitution by examining the differences in gait analysis indicators using a 3-axis accelerometer. Methods: Ninety-one participants were classified through the TS-QSCD (Two-Step Questionnaire for Sasang Constitution Diagnosis) method and gait analysis was performed using a 3-Axis Accelerometer (G-WALK. BTS Bioengineering, Italy). Gait analysis in returning to the 6-meter turnaround point and 6-minute walking test were performed. The differences in the gait analysis index values were analyzed between each constitution. Results: The gait analysis of 91 subjects (37 Taeumin, 37 Soyangin, and 17 Soeumin), showed that the percent stride length/height in the Soyangin subjects was significantly higher than that of the Taeeumin and Soeuminin subjects in the spatiotemporal walking variables (p<0.05). Stride length also showed the widest tendency in the Soyangin subjects (p=0.05). In the kinesiological analysis, the range of pelvic obliquity angles in the Soeumin subjects was significantly wider than that of the Taeumin and Soyangin subjects (p<0.05). In the six-minute walking test, the Soyangin subjects walked the farthest at 309.41±35.23 m (p=0.064). Conclusions: In a comparison of the gait characteristics for each Sasang constitution using a three-dimensional accelerometer, the stride width of the Soyangin subjects was the widest compared to the Taeeumin, and Soeumin subjects, and Soyangin's walking speed showed a faster tendency than that of the Taeeumin and Soeumin subjects.

Analysis of bed change based on the geometric characteristics of channel cross-sections (유로 단면의 기하학적 특성을 이용한 하상변화량 분석)

  • Ko, Joo Suk;Lee, Kyungsu;Kwak, Sunghyun;Lyu, Siwan
    • Journal of Korea Water Resources Association
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    • v.53 no.12
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    • pp.1097-1107
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    • 2020
  • A methodology has been proposed to understand the spatiotemporal changes of the river topography through the longitudinal change of the geometric characteristics of the cross-sections and the properties related thereto. Three-dimensional spatial information of the riverbed was obtained through the detailed bathymetry survey using an acoustic echo sounder for the reach from Gumi Weir to Chilgok Weir in the Nakdong river. Geometric informations for the reference sections were extracted using the acquired bathymetry survey data. By comparing the geometric properties for the reference sections, it was possible to catch the topographic characteristics and its changes over a reach of the channel. Through comparison with past survey data, it was also possible to quantitatively grasp the amount of change in cross-sectional area and volumetric change of riverbed. It is expected that a quantitative evaluation of river topography changes will be possible by applying the method proposed in this study.

Exposure Expressed in Dress (복식에 표현된 노출)

  • 정연자
    • Journal of the Korea Fashion and Costume Design Association
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    • v.1 no.1
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    • pp.91-107
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    • 1999
  • The primary purpose of this study is to inquire into the characteristic of exposure presented in fashion, identify the correct concept of exposure from an aesthetic perspective, and grasp the contemporary meaning of exposure presented in fashion. As a result of study, the following findings were obtained: First, the surrealist style of fashion exhibited representations such as the relocation of the partial details, the harmonization of the natural and the artificial, the emphasis or expansion of each part of the body, and the like. It used highlighted the genital region with ornamentations or used the technique of paradoxically exposing the part of the body always covered. And it exbibited the paradoxical relationship of exposure and concealment by exposing the concealed part of the human body. Second, the post-modern style showed the complicated phenomenon that the values of several meanings such as the historic, the folk, and the like appeared in its fashion. It shares in spatiotemporal eclecticism, pluralistic characteristics and the like found in the post-modern culture. Third, the deconstructive style gets rid of the distinction between the external space and the private space by translating underwears into outer garments. It destroys clothing by tearing or perforating clothing whereby it represents the poor image. Coupled with women‘s psychology of exposure and the new generation’s way of thinking indifferent to others‘ eyes, this fashion of deconstruction occupies the great current of fashion. Deconstructive fashion gets away with the rule of ‘having to wear clothing to suit TPO(Time, Place and Occasion), the traditional norm of wearing clothing.

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The relationship of between apply presence cervical orthosis and temporal parameters of gait (목보조기의 적용 유무와 보행의 시공간적 변수와의 관계)

  • Choe, Han-Seong;Lee, Jae-Ryong;Shin, Hwa-Kyung
    • Journal of Korean Physical Therapy Science
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    • v.18 no.3
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    • pp.33-39
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    • 2011
  • Background : The purpose of this study was to apply cervical orthosis for temporal parameters of gait was to evaluate the effect. Methods : Seven normal adults participated in this study. Before and after applying a cervical orthosis compared to gait. Outcome measure were: general characteristics, temporal parameters of gait. General chacteristics included age, gender, height, weight. Temporal parameters included the Velocity cycle, Stride length, Step length, Cadence cycle, Initial double support time. Temporal parameters of gait, using the motion analysis system for cervical orthosis were evaluated before and after applying. The data was analyzed using SPSS 12.0 software and the Wilcoxon's signed-ranks test. Results : Velocity cycle and Step length were no significant differences(p>0.05). But Stride length, Cadence cycle, Initial double support time were significant(p<0.05). After apply Cervical orthosis in gait, Stride length and Initial double support time was decreased and Cadence cycle was increased. Conclusion : Changes in temporal of temporal parameters of gait was apply a cervical orthosis with the limitations of vision due to take effect. Therefore, Cervical orthosis does not interfere with the normal gait pattern by limiting the Range of Motion so that we consider to apply.

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Spatiotemporal characteristics of atrial $Ca^{2+}$ sparks: evidence from two-dimensional rapid confocal imaging

  • Woo, Sun-Hee;Lars Cleemann;Martin Morad
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.25-25
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    • 2003
  • Atrial myocytes have two functionally separate $Ca^{2+}$ release sites: those in peripheral sarcoplasmic reticulum (SR) adjacent to the $Ca^{2+}$ channels of surface membrane and those in central SR not associated with $Ca^{2+}$ channels. Study on the spatio-temporal properties of focal $Ca^{2+}$ releases (“sparks”) occurring spontaneously in central and peripheral sites of voltage-clamped rat atrial myocytes, using rapid two-dimensional (2-D) confocal $Ca^{2+}$ imaging revealed that peripheral and central sparks were similar in size and release time (~300,000 $Ca^{2+}$ ions for=12 ms), but significantly larger and longer than ventricular sparks. Both sites were resistant to Cd$^{2+}$ and inhibited by ryanodine. Peripheral sparks were brighter and flattened against surface membrane, had ~5-fold higher frequency, ~2 times faster diffusion coefficient, and dissipated abruptly. Central sparks, in contrast, occurred less frequently, were elongated along the cellular longitudinal axis, and dissipated slowly. Compound sparks (composed of 2-5 unitary focal releases) aligned longitudinally, occurred more frequently at the center.at the center.

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Some articulatory reflexes observed in intervocalic consonantal sequences: Evidence from Korean place assimilation

  • Son, Minjung
    • Phonetics and Speech Sciences
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    • v.12 no.2
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    • pp.17-27
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    • 2020
  • This paper examines kinematic characteristics of /pk/ clusters, as compared to /kk/ and /pp/ with varying vowel contexts and speech rate. The results of EMMA data from eight Seoul-Korean speakers indicate as follows. Firstly, comparing /pk/ to /pp/ sequences, lips closing movement was faster and spatially greater in the /a/-to-/a/ context while temporally longer in the /i/-to-/i/ context. It was smaller in spatial displacement and shorter in temporal duration in /pk/ sequences. Peak velocity did not vary. Secondly, comparing /pk/ with /pp/ and /kk/ controls, lip aperture was less constricted in the /a/-to-/a/ context than /i/-to-/i/, but the maximum contact between the upper and lower lips was invariant across different vocalic contexts within /pk/ sequences (/apka/=/ipki/). Categorical reduction of C1 in /pk/ sequences fell in with the low-vowel and fast-rate conditions with across-/within-speaker variability. Gradient reduction of C1 was observed in all C1C2 types, being more frequent in fast rate. Lastly, the jaw articulator was a stable indicator of rate effects. The implication of the current study is that gestural reduction occurs with categorical reduction and general spatiotemporal weakening in the assimilating contexts, while quantitative properties of gestures may be a reason for gradient reduction, not necessarily confined to place assimilation.

Spatial Focalization of Zen-Meditation Brain Based on EEG

  • Liu, Chuan-Yi;Lo, Pei-Chen
    • Journal of Biomedical Engineering Research
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    • v.29 no.1
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    • pp.17-24
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    • 2008
  • The aim of this paper is to report our preliminary results of investigating the spatial focalization of Zen-meditation EEG (electroencephalograph) in alpha band (8-13 Hz). For comparison, the study involved two groups of subjects, practitioners (experimental group) and non-practitioners (control group). To extract EEG alpha rhythm, wavelet analysis was applied to multi-channel EEG signals. Normalized alpha-power vectors were then constructed from spatial distribution of alpha powers, that were classified by Fuzzy C-means based algorithm to explore various brain spatial characteristics during meditation (or, at rest). Optimal number of clusters was determined by correlation coefficients of the membership-value vectors of each cluster center. Our results show that, in the experimental group, the incidence of frontal alpha activity varied in accordance with the meditation stage. The results demonstrated three different spatiotemporal modules consisting with three distinctive meditation stages normally recognized by meditation practitioners. The frontal alpha activity in two groups decreased in different ways. Particularly, monotonic decline was observed in the control group, and the experimental group showed increasing results. The phenomenon might imply various mechanisms employed by meditation and relaxation in modulating parietal alpha.