• Title/Summary/Keyword: avoidance-based

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Vehicle-to-Vehicle Broadcast Protocols Based on Wireless Multi-hop Communication (무선 멀티 홉 통신 기반의 차량간 브로드캐스트 프로토콜)

  • Han, Yong-Hyun;Lee, Hyuk-Joon;Choi, Yong-Hoon;Chung, Young-Uk
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.4
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    • pp.53-64
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    • 2009
  • Inter-vehicular communication that propagates information without infrastructures has drawn a lot of interest. However, it is difficult to apply conventional ad-hoc routing protocols directly in inter-vehicular communication due to frequent changes in the network topology caused by high mobility of the vehicles. MMFP(Multi-hop MAC Forwarding) is a unicast forwarding protocol that transport packets based on the reachability information instead of path selection or position information. However, delivering public safety messages informing road conditions such as collision, obstacles and fog through inter-vehicular communication requires broadcast rather than unicast since these messages contain information valuable to most drivers within a close proximity. Flooding is one of the simplest methods for multi-hop broadcast, but it suffers from reduced packet delivery-ratio and high transmission delay due to an excessive number of duplicated packets. This paper presents two multi-hop broadcast protocols for inter-vehicular communication that extend the MMFP. UMHB(Unreliable Multi-Hop Broadcast) mitigates the duplicated packets of MMFP by limiting the number of nodes to rebroadcast packets. UMHB, however, still suffers from low delivery ratio. RMHB(Reliable Multi-Hop Broadcast) uses acknowledgement and retransmission in order to improve the reliability of UMHB at the cost of increase in transmission delay, which we show through simulation is within an acceptable range for collision avoidance application.

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A Study on the Learning Strategies and Academic Achievements of the Students in the Department of Health Science (보건계열 대학생의 학습전략과 학업 성취도 연구)

  • Kim, Tae-Hoon;Yoon, Tae-Hyung;Kim, Yoseob
    • The Journal of Korean society of community based occupational therapy
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    • v.1 no.1
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    • pp.49-57
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    • 2011
  • This study investigated the relationship between learning strategies and achievements of the students in the department of health science, and differences between higher academic achievers and lower academic achievers in the use of the learning strategies. The results were as follows. First, there was a correlation between academic achievements and self-efficacy and power of execution in the personality area. Second, there was a positive correlation between academic achievements and academic motivation, a negative correlation between academic achievements and avoidnat motivation, in the motivation area. Third. there was a correlation between academic achievements and all 8 factors in the behavior area. In the use of learning strategies, there was a difference found in self-efficacy and the power of execution between the higher academic achievers and the lower academic achievers. It also was found that the lower academic achievers perceived more depression, showed remarkably lower motivation and higher avoidance motivation, than the higher academic achievers. Lastly, the lower academic achievers was lagged behind noticeably compared to the higher academic achievers in the ability of using all factors of the behavior area.

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A Comparative Study of Motivation Factors between the Gifted and Average Students based on Implicit Theory (과학영재의 동기에 대한 암묵적 이론 접근)

  • 김언주;육근철;김성수;윤여홍
    • Journal of Gifted/Talented Education
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    • v.11 no.3
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    • pp.99-129
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    • 2001
  • The purpose of the present study is to determine antecedents in the area of subject matters and to compare these factors between average student group and gifted student group, based on the implicit theory proposed by Sternberg(1993). The average group consisted of 350 primary school students (boy 172; girl 178) from a primary school and 380 middle school students (boy 221; girl 159) from a middle school in Taejeon Metropolitan City. The gifted group consisted of 181 primary school students (boy 130; girl 51) and 154 middle school students (boy 92; girl 62) from the Center for the Gifted Education of the Kong Ju National University. A questionnaire was developed by the authors. It consisted of 30 research questions related to reasons why they studied those subject matters hard. It took about 40 minutes to complete the questionnaire. Several exploratory factor analyses and confirmative analyses were conducted. The main results obtained were as follows: The subject matters all the students of the present study were English and Math. The main reasons why they studied those subject matters hard were interest, utility, competition, self-esteem, entrance examination, recognition, punishment avoidance, etc. A factor analysis revealed that, for the elementary school students, recognition and interest were factors for the average students, whereas knowledge acquisition was an unique factor for the gifted. Utility was common factor for both groups. A factor analysis revealed that, for the middle school students, knowledge acquisition was the main factor for the average students, whereas competition was the unique factor for the gifted. Recognition, interest, and utility were common factors for the both groups.

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Effectiveness of a Health Educational Program Based on Self-Efficacy and Social Support for Preventing Liver Fluke Infection in Rural People of Surin Province, Thailand

  • Kaewpitoon, Soraya J;Thanapatto, Sirisuda;Nuathong, Wimonya;Rujirakul, Ratana;Wakkuwattapong, Parichart;Norkaew, Jun;Kujapun, Jirawoot;Padchasuwan, Natnapa;Kaewpitoon, Natthawut
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1111-1114
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    • 2016
  • Opisthorchiasis is a major problem in Thailand particularly in northeast region which also has a high incidence of cholangiocarcinomas. Since health modification is needed, this quasi-experimental study aimed to assess the effectiveness of a health education program based on self-efficacy and social support in Tha Tum district, Surin province, Thailand. A total of 70 participants were purposive selected with a history of opisthorchiasis. Participants were divided into experimental and control groups, each with 35 subjects. The experimental group received a health education program composed of: (1) knowledge improvement, lectured with multimedia, demonstration, brochure, and handbook; (2) group discussion about their health beliefs, sharing their ideas and experience; and (3) social support from village health volunteers (VHV), heads of villages (HV), friends, and members of families, and public health officer (PHO). Follow-up was by PHO/VHV/HV, with provision of certificates and flasg for household that did not eat raw fish. Data were collected by predesigned questionnaires after implementation of the program for 3 months. Comparative data was analyzed by paired simple t-test and independent t-test. The results revealed that the experimental group had mean score of knowledge higher more than before the experiment (mean difference=3.1, t=3.915, 95%CI-3.3, -1.8 p-value=0.001), and the control group (mean difference=2.5, t=4.196, 95%CI=1.4, 3.6, p-value=0.001) with statistical significance. The mean scores of practice were higher than before the experiment (mean difference=4.6, t=4.331, 95%CI-5.3, -3.1, p-value=0.001), and control group (mean difference=4.4, t=6.142, 95%CI=4.2, 7.9, p-value=0.001). The mean scores of perceived susceptibility and perceived severity of opisthorchiasis, al well as perceived benefits and perceived barriers to prevention of opisthorchiasis, were also higher than before the experiment and in the control group (p-value <0.001). In conclusion, this was a successful health education program for liver fluke avoidance. Therefore, it may useful for further behavior modification in the other epidemic areas.

On the Development of Agent-Based Online Game Characters (에이전트 기반 지능형 게임 캐릭터 구현에 관한 연구)

  • 이재호;박인준
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2002.11a
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    • pp.379-384
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    • 2002
  • 개발적인 측면에서 온라인 게임 환경에서의 NPC(Non Playable Character)들은 환경인식능력, 이동능력, 특수 능력 및 아이템의 소유 배분 등을 원활히 하기 위한 능력들을 소유해야 하며, 게임 환경을 인식, 저장하기 위한 데이터구조와 자신만의 독특한 임무(mission)를 달성하기 위한 계획을 갖고 행위를 해야 한다. 이런 의미에서 NPC는 자신만의 고유한 규칙과 행동 패턴, 그리고 목표(Goal)와 이를 실행하기 위한 계획(plan)을 소유하는 에이전트로 인식되어야 할 것이다. 그러나, 기존 게임의 NPC 제어 구조나 구현 방법은 이러한 요구조건에 부합되지 못한 부분이 많았다. C/C++ 같은 컴퓨터 언어들을 이용한 구현은 NPC의 유연성이나, 행위에 많은 문제점이 있었다. 이들 언어의 switch 문법은 NPC의 몇몇 특정 상태를 묘사하고, 그에 대한 행위를 지정하는 방법으로 사용되었으나, 게임 환경이 복잡해지면서, 더욱더 방대한 코드를 만들어야 했고, 해석하는데 많은 어려움을 주었으며, 동일한 NPC에 다른 행동패턴을 적용시키기도 어려웠다. 또한, 대부분의 제어권을 게임 서버 폭에서 도맡아 함으로써, 서버측에 많은 과부하 요인이 되기도 하였다. 이러한 어려움을 제거하기 위해서 게임 스크립트를 사용하기도 하였지만, 그 또한 단순 반복적인 패턴에 사용되거나, 캐릭터의 속성적인 측면만을 기술 할 수 있을 뿐이었다 이러한 어려움을 해소하기 위해서는 NPC들의 작업에 필요한 지식의 계층적 분화를 해야 하고, 현재 상황과 목표 변화에 적합한 반응을 표현할 수 있는 스크립트의 개발이 필수 적이라 할 수 있다 또한 스크립트의 실행도 게임 서버 측이 아닌 클라이언트 측에서 수행됨으로써, 서버에 걸리는 많은 부하를 줄일 수 있어야 할 것이다. 본 논문에서는, 대표적인 반응형 에이전트 시스템인 UMPRS/JAM을 이용하여, 에이전트 기반의 게임 캐릭터 구현 방법론에 대해 알아본다.퓨터 부품조립을 사용해서 Template-based reasoning 예를 보인다 본 방법론은 검색노력을 줄이고, 검색에 있어 Feasibility와 Admissibility를 보장한다.매김할 수 있는 중요한 계기가 될 것이다.재무/비재무적 지표를 고려한 인공신경망기법의 예측적중률이 높은 것으로 나타났다. 즉, 로지스틱회귀 분석의 재무적 지표모형은 훈련, 시험용이 84.45%, 85.10%인 반면, 재무/비재무적 지표모형은 84.45%, 85.08%로서 거의 동일한 예측적중률을 가졌으나 인공신경망기법 분석에서는 재무적 지표모형이 92.23%, 85.10%인 반면, 재무/비재무적 지표모형에서는 91.12%, 88.06%로서 향상된 예측적중률을 나타내었다.ting LMS according to increasing the step-size parameter $\mu$ in the experimentally computed. learning curve. Also we find that convergence speed of proposed algorithm is increased by (B+1) time proportional to B which B is the number of recycled data buffer without complexity of computation. Adaptive transversal filter with proposed data recycling buffer algorithm could efficiently reject ISI of channel and increase speed of convergence in avoidance burden of computational complexity in reality when it was experimented having

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The Lived Experiences of Inpatients' Families in the Intensive Care Units (중환자실 입원환자 가족의 경험)

  • Hwang, Hye Nam;Kim, Kwuy Bun
    • Korean Journal of Adult Nursing
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    • v.12 no.2
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    • pp.175-183
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    • 2000
  • The study was done by applying a phenomenological study, which is qualitative research methods, in order to understand the meaning of the lived experiences, to confirm and describe the meaning structure, and to prepare nursing interventive strategies centering around the meanings of the inpatients' families in the intensive care units. In the study, the family members were the main important nursing providers for in the inpatients' who were admitted in the neurosurgical intensive care unit in K-university hospital and who agreed to participate in the study after being given on explanation about the purpose of the study. The data were collected from the seven participants who had feelings of trust and intimacy favorable toward the researcher as they were families of patients who had been cared for by the researcher in the ICU where the researcher has been assigned. The data were collected from April to October, 1999. The participants described their experiences as candidly as possible. The researcher described closely the lived experiences with their own words and the observations of the researcher. A tape recorder was used with the consent of the participants to prevent nursing information and communication. The analysis of the data was made through the phenomenological analytic method suggested by Giorgi; as an unit of description, which include the participants' expressions and the researcher's observations, the analysis was used based on the data described from the expressions of the participants and the details of observations of the researcher. The conclusions of the study were as follows : The meanings of the lived experience of the inpatients' families in the ICU was confirmed by indepth interviews and observations including these of the participatants : (1) Psychological impact: confusion, impatience, surprise, insensibility; (2) Physical suffering: fatigue, discomfort, indigestion; (3) Psychological suffering: heartbreaking emotion, anxiety, annoyance, fear, compassion, grief; (4) Economical suffering: economical difficulties; (5) Psychological disagreement: escape from reality, personnel avoidance, grudge, powerlessness, carefulness, transposition of life-tract, abandonment, role-crisis, hope, lack of understanding, regret, feeling of ambivalence(progressive process, medical personnel interest); (6) Psychological dependency; self-reliance group support, family support, religious support; (7) Psychological acceptance; acquaintance, gratitude, reassurance; The study will offer better understanding of experiences therefore, based on the experiences confirmed by the study, it may facilitate more appropriate nursing interventive strategies for health maintenance and to prevent occurrence of possible problems with the inpatients' families in the ICUs.

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Intelligent Motion Planning System for an Autonomous Mobil Robot (자율 이동 로봇을 위한 지능적 운동 계획 시스템)

  • 김진걸;김정찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.8
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    • pp.1503-1517
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    • 1994
  • Intelligent Motion Planning System(IMPS) is presented for a robot to achieve an efficient path toward the given target point in two dimensional unknown environment is constructed with unrestricted obstacle shapes. IMPS consists of three components for making intelligent motion. These components are real-time motion planning algorithm based on a discontinous boundary method, fuzzy neural network decision system for heuristic knowledge representation, and world modeling with forgetting and reinforcing memory cells. First of all, in real-time motion planning algorithm, the behavior-based architectural method is used to generate subgoal. A behavior generates a subgoal independently by using the method of discontinuous boundary in sensed area. The discontinuous boundary method is a new proposed fast obstacle avoidance algorithm. The second component is fuzzy neural network decision system for accomplishing the subgoal. The heuristic rules are imbedded on the fuzzy neural network to make an intelligent decision. The last one is a forgetting, reinforcing memory technique for the construction of external world map. The activation values of all activated memory cells in grid space are decreased monotonically and after all they are burned out. Therefore, after sufficient journey, robot can have a stationary world map even if the dynaic obstacles exist. Using the IMPS, several simulations show the efficient achievement of target point in unknown enviroment with obstcles of various shapes.

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A Robust Disjoint Multipath Scheme based on Geographic Routing in Irregular Wireless Sensor Networks (불규칙적 무선센서네트워크에 강한 위치기반 다중경로 제공 방안)

  • Kim, Sung-Hwi;Park, Ho-Sung;Lee, Jeong-Cheol;Oh, Seung-Min;Kim, Sang-Ha
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.1B
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    • pp.21-30
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    • 2012
  • Sensor networks are composed of a great number of sensor nodes with constrained battery. Disjoint multipath scheme based flooding method has a merit that efficiently construct multipath in irregular networks, but causes lots of energy consumption in networks. Flooding method is not a suitable technology in wireless sensor networks with constrained battery. We introduce energy-efficient geographic routing scheme considered as an efficient, simple, and scalable routing protocol for wireless sensor networks. The geographic routing scheme on multipath generates a problem with a congestion. So we introduce the concept of multipath pipeline as a congestion avoidance strategy. But multipath pipelines have a big problem on the boundary of holes under irregular networks. We propose a novel disjoint multipath scheme as combined method with geographic routing scheme and hole detouring algorithm on multipath. A novel disjoint multipath scheme constructs disjoint multipath pipelines efficiently for reliability without a collision in irregular wireless sensor networks. Simulation results are provided to validate the claims.

An Analysis on the Prevention Effects of Forward and Chain Collision based on Vehicle-to-Vehicle Communication (차량 간 통신 기반 전방추돌 및 연쇄추돌 방지 효과 분석)

  • Jung, Sung-Dae;Kim, Tae-Oh;Lee, Sang-Sun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.4
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    • pp.36-43
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    • 2011
  • The forward collision of vehicles in high speed can cause a chain collisions and high fatality rate. Most of the forward collisions are caused by insufficient braking distance due to detection time of driver and safe distance. Also, accumulated detection time of driver is cause of chain collisions after the forward collision. The FVCWS prevents the forward collision by maintaining the safety distance inter-vehicle and reducing detection time of driver. However the FVCWS can cause chain collisions because the system that interacts only forward vehicle has accumulated detection time of driver. In this paper, we analyze forward and chain collisions of normal vehicles and FVCWS vehicles on static traveling scenario. And then, we analyze and compare V2V based FVCWS with them after explaining the system. The V2V FVCWS reduces detection time of driver alike FVCWS as well as remove accumulated detection time of driver by broadcasting emergence message to backward vehicles at the same time. Therefore, the system decrease possibility of forward and chain collisions. All backward normal vehicles and 3~4 backward FVCWS vehicles have possibility of forward and chain collisions in result of analysis. However V2V FVCWS vehicles almost do not chain collisions in the result.

Design and evaluation of a VPRS-based misbehavior detection scheme for VANETs (차량애드혹망을 위한 가변정밀도 러프집합 기반 부정행위 탐지 방법의 설계 및 평가)

  • Kim, Chil-Hwa;Bae, Ihn-Han
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.6
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    • pp.1153-1166
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    • 2011
  • Detecting misbehavior in vehicular ad-hoc networks is very important problem with wide range of implications including safety related and congestion avoidance applications. Most misbehavior detection schemes are concerned with detection of malicious nodes. In most situations, vehicles would send wrong information because of selfish reasons of their owners. Because of rational behavior, it is more important to detect false information than to identify misbehaving nodes. In this paper, we propose the variable precision rough sets based misbehavior detection scheme which detects false alert message and misbehaving nodes by observing their action after sending out the alert messages. In the proposed scheme, the alert information system, alert profile is constructed from valid actions of moving nodes in vehicular ad-hoc networks. Once a moving vehicle receives an alert message from another vehicle, it finds out the alert type from the alert message. When the vehicle later receives a beacon from alert raised vehicle after an elapse of time, then it computes the relative classification error by using variable precision rough sets from the alert information system. If the relative classification error is lager than the maximum allowable relative classification error of the alert type, the vehicle decides the message as false alert message. Th performance of the proposed scheme is evaluated as two metrics: correct ratio and incorrect ratio through a simulation.