• Title/Summary/Keyword: Dynamic Graph

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A Study on the Deduction of 3-Dimmensional Visual Structure and measurement of Quantitative Openness in Accordance with Spatial Probe Routes (공간탐색경로에 따른 3차원 시각구조 도출과 정량적 개방도 측정에 관한 연구)

  • Kim, Suk-Tae
    • Korean Institute of Interior Design Journal
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    • v.19 no.6
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    • pp.112-120
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    • 2010
  • Human can recognize the environment by detecting spatial perception, and most of environmental perception depends on visual perception. In view that the acquisition of spatial information is accomplished through visual recognition, analysis of visual structure contained in the space is thought to be very important sector in studying the characteristic of the space. The history of studies on visual structure of space, however, wasn't too long, and furthermore most of the theories up to now focused on static and planar principles. Under this circumstance, this study is intended to suggest new theory by combining Isovist theory and VGA theory that have been actively discussed as the theory on visual perception-based spatial structure and supplementing them between each other to expand into 3-dimensional model. The suggested theory is a complex principle in dimensional and dynamic form in consideration of visual direction, which forms 3-dimentional virtual model that enables visualization of the property of spatial structure as the routine discriminating whether visual connection is made between viewing point and target point, and the target point is included in the visual field quadrangular pyramid or not. Such model was built up by an analysis application where four probe paths were applied to simulate the visual structure that occurs in virtual space, and then the characteristics were analyzed through quantification. In result, in spite of the path with equal space and equal length, significant difference in the acquired quantity of spatial information could be found depending on the probe sequence. On the contrary, it was found that probe direction may not affect the acquired quantity of information and visual property of the space.

A Study of Routing based on Adjacency Matrix in Ad hoc Networks (애드 혹 네트워크에서 인접 행렬 기반의 라우팅 연구)

  • Lee, Sung-Soo;Kim, Jeong-Mi;Park, Hee-Joo;Kim, Chong-Gun
    • The KIPS Transactions:PartC
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    • v.15C no.6
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    • pp.531-538
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    • 2008
  • With the dynamic and mobile nature of ad hoc networks, links may fail due to topology changes. So, a major challenge in ad hoc network is dynamically to search paths from a source to destination with an efficient routing method, which is an important issue for delay-sensitive real-time application. The main concerns of graph theory in communications are finding connectivity and searching paths using given nodes. A topology of the nodes in ad hoc networks can be modeled as an adjacency matrix. In this paper, based on this adjacency matrix, we propose new path search algorithms using a sequence of matrix calculation. The proposed algorithms can search paths from a destination to a source using connectivity matrix. Two matrix-based algorithms for two different purposes are proposed. Matrix-Based Backward Path Search(MBBS) algorithm is designed for shortest path discovery and Matrix-Based Backward Multipath Search(MBBMS) algorithm is for multipath search.

Differences in Large-scale and Sliding-window-based Functional Networks of Reappraisal and Suppression

  • Jun, Suhnyoung;Lee, Seung-Koo;Han, Sanghoon
    • Science of Emotion and Sensibility
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    • v.21 no.3
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    • pp.83-102
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    • 2018
  • The process model of emotion regulation suggests that cognitive reappraisal and expressive suppression engage at different time points in the regulation process. Although multiple brain regions and networks have been identified for each strategy, no articles have explored changes in network characteristics or network connectivity over time. The present study examined (a) the whole-brain network and six other resting-state networks, (b) their modularity and global efficiency, which is an index of the efficiency of information exchange across the network, (c) the degree and betweenness centrality for 160 brain regions to identify the hub nodes with the most control over the entire network, and (d) the intra-network and inter-network functional connectivity (FC). Such investigations were performed using a traditional large-scale FC analysis and a relatively recent sliding window correlation analysis. The results showed that the right inferior orbitofrontal cortex was the hub region of the whole-brain network for both strategies. The present findings of temporally altering functional activity of the networks revealed that the default mode network (DMN) activated at the early stage of reappraisal, followed by the task-positive networks (cingulo-opercular network and fronto-parietal network), emotion-processing networks (the cerebellar network and DMN), and sensorimotor network (SMN) that activated at the early stage of suppression, followed by the greater recruitment of task-positive networks and their functional connection with the emotional response-related networks (SMN and occipital network). This is the first study that provides neuroimaging evidence supporting the process model of emotion regulation by revealing the temporally varying network efficiency and intra- and inter-network functional connections of reappraisal and suppression.

Analysis of Threshold Voltage Characteristics for FinFET Using Three Dimension Poisson's Equation (3차원 포아송방정식을 이용한 FinFET의 문턱전압특성분석)

  • Jung, Hak-Kee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.11
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    • pp.2373-2377
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    • 2009
  • In this paper, the threshold voltage characteristics have been analyzed using three dimensional Poisson's equation for FinFET. The FinFET is extensively been studing since it can reduce the short channel effects as the nano device. We have presented the short channel effects such as subthreshold swing and threshold voltage for PinFET, using the analytical three dimensional Poisson's equation. We have analyzed for channel length, thickness and width to consider the structural characteristics for FinFET. Using this model, the subthreshold swing and threshold voltage have been analyzed for FinFET since the potential and transport model of this analytical three dimensional Poisson's equation is verified as comparing with those of the numerical three dimensional Poisson's equation.

A Logical Simulation of Dynamic Natural Phenomena Based on Event Propagation Graph (사건 전파그래프에 기반한 동적인 자연현상의 논리적 시뮬레이션)

  • Park, Jung-Yong;Park, Jong-Hee
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.4
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    • pp.10-21
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    • 2001
  • This paper develops a logical simulation method for by dyversity of situations. Most existing systems, for example, games and infant tutoring systems lead users to virtual environment with unfolding situations, but are not designed to induce the change of the environment itself. In this paper, a logically simulated environment is created by defining situations and single events based on situation hierarchy structure. We elaborate the occurrence of events by classifying the causality. The occurrence or natural phenomena is dictated by physical laws and natural phenomena are expressed as the transition of the event based on event association. Specifically we define the source of the event for natural phenomena and we consider the existence of objects as a primary factor in event occurrence. The advantages of this approach include the reuse of events, that is, different events can be generated in the same flow with fresh conditions. This allows us to implement a more practical and logical environment. A drawback to this method is the difficulty in dividing a situation into events. The proposed method was implemented in the context of the change of season among natural phenomena.

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A Study on the Selective Visual Vision and Cinemagraph Expression (영상미디어의 선택적 시각과 시네마그래프 표현 연구)

  • Yu, Jung-Sun;Chung, Jean-Hun
    • Journal of Digital Convergence
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    • v.15 no.5
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    • pp.325-331
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    • 2017
  • The purpose of this study is optional cinemagraph ads based on the case through the psychological theory of visual multimedia story qualitative analysis, quantitative analysis. Cinemagraph analysis would like to present the model. The analysis popular advertising model who starred with the higher profile in 2016 Gmaket of cinemagraph series of ads research, literature research, and Internet media. Analysis, case studies, etc. The analysis appeared around 10 percent was the most effective in the form of moving the form of copper wire. Part of the video cinema than the overall movement of the graph bigger visual flow effects is a dynamic. Moving the direction of the model used copper wires and broadly consistent with the product. Subject & Surrounding and margins are being used within one point or two points. The story of probability model in the short and expressing simple action of the product. Direction of the action, the proportion of multimedia for quantitative analysis of space story for the qualitative analysis of the periphery and jujebu, stories, such as the probability of four.For consideration the terms.

Software-Defined HoneyNet: Towards Mitigating Link Flooding Attacks (링크 플러딩 공격 완화를 위한 소프트웨어 정의 네트워크 기반 허니넷)

  • Kim, Jinwoo;Lee, Seungsoo;Shin, Seungwon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.152-155
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    • 2018
  • Over the past years, Link Flooding Attacks (LFAs) have been introduced as new network threats. LFAs are indirect DDoS attacks that selectively flood intermediate core links, while legacy DDoS attacks directly targets end points. Flooding bandwidth in the core links results in that a wide target area is affected by the attack. In the traditional network, mitigating LFAs is a challenge since an attacker can easily construct a link map that contains entire network topology via traceroute. Security researchers have proposed many solutions, however, they focused on reactive countermeasures that respond to LFAs when attacks occurred. We argue that this reactive approach is limited in that core links are already exposed to an attacker. In this paper, we present SDHoneyNet that prelocates vulnerable links by computing static and dynamic property on Software-defined Networks (SDN). SDHoneyNet deploys Honey Topology, which is obfuscated topology, on the nearby links. Using this approach, core links can be hidden from attacker's sight, which leads to effectively building proactive method for mitigating LFAs.

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Efficient Route Determination Technique in LBS System

  • Kim, Sung-Soo;Kim, Kwang-Soo;Kim, Jae-Chul;Lee, Jong-Hun
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.843-845
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    • 2003
  • Shortest Path Problems are among the most studied network flow optimization problems, with interesting applications in various fields. One such field is the route determination service, where various kinds of shortest path problems need to be solved in location-based service. Our research aim is to propose a route technique in real-time locationbased service (LBS) environments according to user’s route preferences such as shortest, fastest, easiest and so on. Turn costs modeling and computation are important procedures in route planning. There are major two kinds of cost parameters in route planning. One is static cost parameter which can be pre-computed such as distance and number of traffic-lane. The other is dynamic cost parameter which can be computed in run-time such as number of turns and risk of congestion. In this paper, we propose a new cost modeling method for turn costs which are traditionally attached to edges in a graph. Our proposed route determination technique also has an advantage that can provide service interoperability by implementing XML web service for the OpenLS route determination service specification. In addition to, describing the details of our shortest path algorithms, we present a location-based service system by using proposed routing algorithms.

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Hot and average fuel sub-channel thermal hydraulic study in a generation III+ IPWR based on neutronic simulation

  • Gholamalishahi, Ramin;Vanaie, Hamidreza;Heidari, Ebrahim;Gheisari, Rouhollah
    • Nuclear Engineering and Technology
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    • v.53 no.6
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    • pp.1769-1785
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    • 2021
  • The Integral Pressurized Water Reactors (IPWRs) as the innovative advanced and generation-III + reactors are under study and developments in a lot of countries. This paper is aimed at the thermal hydraulic study of the hot and average fuel sub-channel in a Generation III + IPWR by loose external coupling to the neutronic simulation. The power produced in fuel pins is calculated by the neutronic simulation via MCNPX2.6 then fuel and coolant temperature changes along fuel sub-channels evaluated by computational fluid dynamic thermal hydraulic calculation through an iterative coupling. The relative power densities along the fuel pin in hot and average fuel sub-channel are calculated in sixteen equal divisions. The highest centerline temperature of the hottest and the average fuel pin are calculated as 633 K (359.85 ℃) and 596 K (322.85 ℃), respectively. The coolant enters the sub-channel with a temperature of 557.15 K (284 ℃) and leaves the hot sub-channel and the average sub-channel with a temperature of 596 K (322.85 ℃) and 579 K (305.85 ℃), respectively. It is shown that the spacer grids result in the enhancement of turbulence kinetic energy, convection heat transfer coefficient along the fuel sub-channels so that there is an increase in heat transfer coefficient about 40%. The local fuel pin temperature reduction in the place and downstream the space grids due to heat transfer coefficient enhancement is depicted via a graph through six iterations of neutronic and thermal hydraulic coupling calculations. Working in a low fuel temperature and keeping a significant gap below the melting point of fuel, make the IPWR as a safe type of generation -III + nuclear reactor.

Quality Assurance of Leaf Speed for Dynamic Multileaf Collimator (MLC) Using Dynalog Files (Dynalog file을 이용한 동적다엽조준기의 Leaf 속도 정도관리 평가)

  • Kim, Joo Seob;Ahn, Woo Sang;Lee, Woo Suk;Park, Sung Ho;Choi, Wonsik;Shin, Seong Soo
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.2
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    • pp.305-312
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    • 2014
  • Purpose : The purpose of this study is to analyze the mechanical and leaf speed accuracy of the dynamic multileaf collimator (DMLC) and determine the appropriate period of quality assurance (QA). Materials and Methods : The quality assurance of the DMLC equipped with Millennium 120 leaves has been performed total 92 times from January 2012 to June 2014. The the accuracy of leaf position and isocenter coincidence for MLC were checked using the graph paper and Gafchromic EBT film, respectively. The stability of leaf speed was verified using a test file requiring the leaves to reach maximum leaf speed during the gantry rotation. At the end of every leaf speed QA, dynamic dynalog files created by MLC controller were analyzed using dynalog file viewer software. This file concludes the information about the planned versus actual position for all leaves and provides error RMS (root-mean square) for individual leaf deviations and error histogram for all leaf deviations. In this study, the data obtained from the leaf speed QA were used to screen the performance degradation of leaf speed and determine the need for motor replacement. Results : The leaf position accuracy and isocenteric coincidence of MLC was observed within a tolerance range recommanded from TG-142 reports. Total number of motor replacement were 56 motors over whole QA period. For all motors replaced from QA, gradually increased patterns of error RMS values were much more than suddenly increased patterns of error RMS values. Average error RMS values of gradually and suddenly increased patterns were 0.298 cm and 0.273 cm, respectively. However, The average error RMS values were within 0.35 cm recommended by the vendor, motors were replaced according to the criteria of no counts with misplacement > 1 cm. On average, motor replacement for gradually increased patterns of error RMS values 22 days. 28 motors were replaced regardless of the leaf speed QA. Conclusion : This study performed the periodic MLC QA for analyzing the mechanical and leaf speed accuracy of the dynamic multileaf collimator (DMLC). The leaf position accuracy and isocenteric coincidence showed whthin of MLC evaluation is observed within the tolerance value recommanded by TG-142 report. Based on the result obtained from leaf speed QA, we have concluded that QA protocol of leaf speed for DMLC was performed at least bimonthly in order to screen the performance of leaf speed. The periodic QA protocol can help to ensure for delivering accurate IMRT treatment to patients maintaining the performance of leaf speed.