• Title/Summary/Keyword: 시간적 밀집도

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Congestion Control Method of Area of Interest in Distributed Virtual Environment (분산가상환경에서 참여자 관심영역의 혼잡도 조절기법)

  • 유석종
    • Journal of Korea Multimedia Society
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    • v.7 no.4
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    • pp.550-558
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    • 2004
  • Previous researches on scalability problem of distributed virtual environment (DVE) have been mainly focused on spatial partitioning of area of interest (AOI). Congestion phenomena by avatar groups in AOI have been neglected relatively However, AOI congestion is highly related to scalability of DVE because it exhausts system resources such as network bandwidth and rendering time, and could be a bar to perform collaboration among participants. In this paper, this will be defined as the problem that must be solved for the realization of the scalable DVE, and a model will be proposed to measure and control congestion situation in AOI. The purposes of the proposed model are to prevent high density of participants in AOI, and to protect stable collaboration in DVE. For evaluation of the performance it is compared with a previous method by defining the resource cost model which is dynamically activated to AOI congestion.

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Cell-based Participant Management Model in Distributed Virtual Environment (셀분할 모델에 기반한 가상공간 다중참여자 관리기법)

  • 유석종
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.527-531
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    • 2003
  • Previous researches on scalability problem of distributed virtual environment (DVE) have been mainly focused on spatial partitioning of area of interest (AOI). Congestion phenomena by avatar groups in AOI have been neglected relatively. However, AOI congestion is highly related to scalability of DVT because it exhausts system resources such as network bandwidth and rendering time, and could be a bar to perform collaboration among participants. In this paper, this will be defined as the problem that must be solved for the realization of the scalable DVE, and a model will be proposed to measure and control congestion situation in AOI. The purposes of the proposed model are to prevent high density of participants in AOI, and to protect stable collaboration in DVE. For evaluation of the performance it is compared with a previous method by defining the resource cost model which is dynamically activated to AOI congestion.

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The Typhoon Surge in the Southern Coast of Korea (한국 남해안의 태풍에 의한 해일)

  • Jang, Seon-Deok;Lee, In-Cheol;Park, Cheol-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.4
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    • pp.293-302
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    • 1991
  • The anomalous sea level deviation or storm surge caused by the typhoon Thelma in 1987 are studied analysing tidal observation data at 7 stations in the south coast of Korean peninsula. The surges are calculated by subtracting the predicted tidal height from the observed tidal record. The tidal deviation at these stations along the coast are discussed in association with meteorological data. The sea level anomalies are studied by means of the empirical orthogonal function (EOF) analysis and the fast fourier transform (FFT) method. The results of analysis suggest that the peak value of surges are higher at the tidal stations in semi-enclosed bay and in long narrow channel than at the ones facing with the open sea. From the result of EOF analysis, the temporal and spatial fluctuations of storm surge can be described by the first EOF mode, which explains 63% of the total variances during the passage of typhoon Thelma. The deviation of storm surge in the studied areas indicates bi-modal peak during the passage of typhoon Thelma. From the results of FFT spectrum analysis, the peak of energy of autospectrum for surge, atmospheric pressure, and wind stress appeared at low frequency fluctuations band of 0.008-0.076 cph over the 4 stations. Auto-correlation function of surge showed periodicity, while that of atmospheric pressure and wind stress indicates no periodicity. The result of FFT analysis shows that the typhoon surges are related chiefly with the change of atmospheric pressure in an open bay (Cheju Harbor), but with the wind stress in a semi-enclosed bay (Yeosu Harbor).

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The Effect of Antioxidative Change in Cardiac Muscle of Obesity Rat by Treadmill Exercise with Intensity and Time (운동강도와 지속시간에 따른 트레드밀 운동이 비만 쥐의 심장근 내 항산화에 미치는 영향)

  • Kim, Myung-Hee;Kim, Young-Eok;Yoon, Chang-Lyuk;Ryu, Ji-Won;Ahn, Jong-Mo
    • Journal of Oral Medicine and Pain
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    • v.38 no.1
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    • pp.35-51
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    • 2013
  • The aims of this study was to observed an effect of antioxidative in cardiac muscle of high fat diet induced obesity rat by treadmill exercise with intensity and time. Thirty-two Sprauge-Dawley rats which were divided into four group. Normal, Control(high fat diet induced obesity rat), Experimental I(high intensity intermittent exercise in high fat diet induced obesity rat), Experimental II(moderate intensity endurance exercise in high fat diet induced obesity rat). The results of this study were as follows: 1. In change of body weight, the outcome of each group significantly difference compared with control. Also, 1 to 3 weeks significantly different compared with pre valu experimental I and II(p<0.001). 2. In change of lipid profile, the outcome of each group significantly difference compared with control(p<0.001). Difference between experimental I and II is not significantly. 3. In change of antioxidative enzymes(SOD, CAT, GPx) in myocardium, there are significant difference between control and experimental II, and also between control and experimental I(p<0.001). 4. In change of antioxidative protein MCR-1, the outcome of each group significantly difference compared with control(p<0.01). Experimental II was most significantly difference than the other group(p<0.001). The above results suggest that treadmill exercise effectively reduced in fat. It would be considered that moderate intensity endurance exercise has an effects on improved antioxidative enzyme in cardiac muscle of high fat diet induced obesity rat.

Truck Destination Choice Behavior incorporating Time of Day, Activity duration and Logistic Activity (출발시간, 통행거리 및 물류활동 특성을 고려한 도착지 선택행태분석)

  • Sin, Seung-Jin;Kim, Chan-Seong;Park, Min-Cheol;Kim, Han-Su
    • Journal of Korean Society of Transportation
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    • v.27 no.1
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    • pp.73-81
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    • 2009
  • While various factors in passenger and freight demand analysis affect on destination choice, a key factor, in general. is an attractiveness measure by size variable (e.g., population. employment etc) in destination zone. In order to measure the attractiveness, some empirical studies suggested that disaggregate gravity model are more suitable than aggregate gravity model. This study proposes that truck travelers trip diary data among Korean commodity flow data could be used to estimate the behaviors of incorporating trip departure time, activity duration and attractiveness in destination. As a result, the main findings of size and distance variables coincide with the conventional gravity model having a positive effect of population variable and a negative effect of distance variable. Due to disaggregate gravity modeling, the unique findings of this study reports that small trucks are more likely to choose short distance and early morning, morning peak and afternoon peak departure time choice. On the other hand, large trucks are more likely to choose long distance and night time departure time choice.

Study on Computational Fluid Dynamics(CFD) simulation for NOx dispersion around combined heat and power plant (열병합발전소 질소산화물 확산에 관한 전산유체역학 simulation 연구)

  • Kim, Ji-Hyun;Park, Young-Koo
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.1
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    • pp.62-71
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    • 2015
  • In order to deal with the globally increasing electric power demand and reduce $CO_2$ emission, complex thermoelectric power plants are being constructed in densely populated downtown areas. As the environmental regulations are continuously strengthened, various facilities like low NOx burner and SCR are being installed to reduce NOx emission. This study is applied using the TMS emission of $NO_2$ from combined heat and power plant located in Goyang-si Gyeonggi-do. Applying data to the computational fluid dynamics(CFD), and compared with the actual measurement results. It is judged that even though there might be differences between actual measurements and CFD results due to the instant changes of wind direction and wind speed according to measurement time during measurement period, modeling results and actual measurement results showed similar concentration at most forecasting areas and therefore, the forecasting concentration could be deducted which is close to actual measurement by calculating the contribution concentration considering the surrounding concentration in the future.

Generative optical flow based abnormal object detection method using a spatio-temporal translation network

  • Lim, Hyunseok;Gwak, Jeonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.4
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    • pp.11-19
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    • 2021
  • An abnormal object refers to a person, an object, or a mechanical device that performs abnormal and unusual behavior and needs observation or supervision. In order to detect this through artificial intelligence algorithm without continuous human intervention, a method of observing the specificity of temporal features using optical flow technique is widely used. In this study, an abnormal situation is identified by learning an algorithm that translates an input image frame to an optical flow image using a Generative Adversarial Network (GAN). In particular, we propose a technique that improves the pre-processing process to exclude unnecessary outliers and the post-processing process to increase the accuracy of identification in the test dataset after learning to improve the performance of the model's abnormal behavior identification. UCSD Pedestrian and UMN Unusual Crowd Activity were used as training datasets to detect abnormal behavior. For the proposed method, the frame-level AUC 0.9450 and EER 0.1317 were shown in the UCSD Ped2 dataset, which shows performance improvement compared to the models in the previous studies.

Characteristics of Rainfall and Landslides according to the Geological Condition (지질조건에 따른 강우와 산사태의 특성분석)

  • Kim Kyeong-Su;Song Young-Suk;Cho Yong-Chan;Kim Won-Young;Jeong Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.16 no.2 s.48
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    • pp.201-214
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    • 2006
  • To study the relationship between rainfall conditions and landslides according to a geological condition in land-slides areas such asJangheung Kyounggi, Sangju and Pohang Kyoungbuk, the data of rainfall and landslides are investigated and analyzed. Many landslides occurred at these areas because of the heavy rainfall in two or four days of the summer 1998. The data of rainfall are collected in observatories within a 50km radius from landslides occurrence areas, and the data of landslides are investigated directly in landslides areas. The data of rainfall are the accumulative rainfall and the rainfall intensity, and the data of landslides are the occurrence frequency considering the geological condition. These data are analyzed statistically to know the relationship the rainfall and landslides. The landslides are concentrated in the heavy rainfall area from the analysis of these data. It knows that the land-slides are triggered by the heavy rainfall. Meanwhile, the rainfall factors such as the accumulative rainfall, the rain-fall intensity and the dropping time are different in each landslides area, and the shape and frequency of landslides are different respectively. The landslides have occurred in the area of high accumulative rainfall, while the land-slides have not occurred around that area. Therefore, the rainfall is very important factor induced by the landslides, and the accumulative rainfall is really related to the frequency of landslides.

The Study on the Ultrastructure and Distribution of Dopaminergic Cells in the Brain of Mongolian Gerbil after Water Deprivation (절수에 의한 Mongolain gerbil 뇌 Dopamine성 면역반응세포의 분포와 미세구조의 변화에 관한 연구)

  • Song, Chi-Won;Lee, Kyoung-Youl;Park, Il-Kwon;Kwon, Hyo-Jung;Kim, Moo-Kang;Lee, Kang-Lee
    • Applied Microscopy
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    • v.30 no.2
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    • pp.193-204
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    • 2000
  • Nowadays, mongolian gerbil is widely utilized in the research of brain and water deprivation because of congenitally incomplete Willis' circle, audiogenic seizure in low noise, and special cholesterol metabolism without water absorption for a long time. In this study, we intended to identify the time lapse changes in the general morphoogy and ultrastructure of the catecholaminergic neurons of mongolian gerbil brain in after long-term water deprivation. Fifteen mongolian gerbils were divided into 3 groups (5, 10, and 20-day water deprivation groups), each with 5 mongolian gerbils. Additional 5 mongolian gerbils which received water without limitation were used as a control. The brain sections were immunostained using tyrosine hysroxylase (TH), $ dopamine-\beta-hydroxylase$ (DBH), and phenylethanolamine-N-methyltrasferase (PMNT) antibodies. And immunoreactive cells were observed by electromicroscopy for the ultrastructural changes . The TH-immunoreactive (TH-IR) nerve cells were observed in the para- and peri-ventricular nucleus of the 3 rd ventricle in the hypothalamus and the substantia nigra. The number of TH-IR neurons in these areas was decreased from the 5th day of the water deprivation to the 10 th day and reincreased until 20 th day water deprivation. The shape and density of the dopamine-secreting cells identified by immunohistochemistry showed changes in the continuous water deprivation. Electron microscopy revealed a round nucleus in the neurons of control group but 5-day water deprivation group showed a dense and irregularly shaped nucleus. Also in the 5-day water-deprived group, mitochondria was decreased in number and junctins were disappered. Endoplasmic reticulum, Golgi complex did not show changes after water-deprivation. In this results, we can conclude that dopamine are involved in the water metabolism in mongolian gerbil, and mongolian gerbil could be used as an animal model for the researches of water deprivation.

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An Investigation of Selection and Transfer Factors on the Admission of Rehabilitation Hospital (재활병원 입원 시 선택 및 전원 요인 조사)

  • Lee, Jae Hong;Kwon, Won An;Lee, Jin Hwan;Min, Dong Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2819-2827
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    • 2013
  • The purpose of his study was to analyze the environmental and the medical factors of prematurely discharged patients in a rehabilitation hospital. The subjects were 107 inpatients. The data were collected using self-report questionnaire and analyzed using the SPSS Win 19.0 program. In result, Firstly, general selection of hospitals was the 'Recommendation' 35.5%, Environmental dissatisfaction factors are Hospital facilities 37.4%. Hospital choice is the highest 'Acquaintances' 23.4%. Second, the lowest group about professionalism, kindness, and description of explanation on satisfaction in survey is group of care workers for the sick. The highest group is physical and occupational therapist. Third, the satisfaction regarding medical procedures of administrative work, waiting time and medical expenses is the highest normal. Hospital facilities in one of the highest factors in environmental dissatisfaction is can be considered as an element of patient departure because of not much number of nervous special hospitals. Medical dissatisfaction factors is the lowest satisfaction of care worker even if those spend much time. this is the focus leaving hospital. Therefore, factors care workers on service satisfaction and dissatisfaction in analysis and problem solving is considered that the need to find ways to improve the quality of service care workers.