• 제목/요약/키워드: problem situations

검색결과 965건 처리시간 0.032초

Solution of Noise-Vibration Problems of Urban Public Housing Adjacent to Railway

  • Park, Jong-Bae;Jang, Yeon-Soo;Kim, Hyo-Jin
    • 토지주택연구
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    • 제5권3호
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    • pp.169-177
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    • 2014
  • Constructing urban public housing built adjacent railway site has the noise and vibration problem coming from operation of trains. Thus, anti-vibration plans utilizing anti-vibration pads must be established to minimize the impact of train noise and vibration from the tunnels on the residents of the public housing. Under various difficulties and expectation from the citizens, many efforts were taken to satisfy the amenity requirements on noise and vibration for the residential area. As a results, it can be recognized that amenity standards can be satisfied. But great caution is required to prepare ourselves for various situations that might occur during construction, especially considering that the relevant railroads are still under operation.

MASF 적용을 위한 계층적 움직임 추정 기법 (Hierarchical Motion Estimation Method for MASF)

  • 김상연;김성대
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 1995년도 학술대회
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    • pp.137-141
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    • 1995
  • MASF is a kind of temporal filter proposed for noise reduction and temporal band limitation. MASF uses motion vectors to extract temporal information in spatial domain. Therefore, inaccurate motion information causes some distortions in MASF operation. Currently, bilinear interpolation after MBA(Block Matching Algorithm) is used for the motion estimation sheme of MASF. But, this method results in unreliable estimation when the object in image sequence has larger movement than the maximum displacement assumed in BMA or the input images are severely corrupted with noise. In order to solve this problem, we propose a hierarchical motion estimation algorithm for MASF. Experimental results show that the proposed method produces reliable output under large motion and noisy situations.

통신 네트워크에서 상태 추정에 의한 군집병합의 원격제어 (Vehicle Platooning Remote Control via State Estimation in a Communication Network)

  • 황태현;최재원;김영호
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.192-192
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    • 2000
  • In this paper, a platoon merging is considered as a remote-controlled system with the state represented by a stochastic process. In this system, it becomes to encounter situations where a single decision maker controls a large number of subsystems, and observation and control signals are sent over a communication channel with finite capacity and significant transmission delays. Unlike classical estimation problem in which the observation is a continuous process corrupted by additive noise, there is a constraint that the observation must be coded and transmitted over a digital communication channel with finite capaci쇼. A recursive coder-estimator sequence is a state estimation scheme based on observations transmitted with finite communication capacity constraint. Using the coder-estimator sequence, the remote control station designs a feedback controller. In this paper, we introduce a stochastic model for the lead vehicle in a platoon of vehicles considering the angle between a road surface and a horizontal plane as a stochastic process. The simulation results show that the inter-vehicle distance and the deviation from the desired inter-vehicle distance are well regulated.

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모서리 부위 연속 용접을 위한 아크 용접 로봇과 포지셔너의 협업 (The Cooperation of Arc Welding Robot and Manipulator for Continuous Welding of Corner Area)

  • 장교근;유범상
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 1996년도 특별강연 및 춘계학술발표 개요집
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    • pp.96-98
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    • 1996
  • Welding of corner area across the edge is a difficult problem in robotized arc welding system, especially when continuously-welded leakage-proof product is required. This paper presents the methodology of cooperation plan of an arc welding robot and 1 or 2 axis welding manipulators for corner area welding. Welding trajectory for the robot is generated using clothoid curves; symmetrical double clothoid curve or unsymmetrical clothoid curve depending on the nature of the workpiece. The clothoid curve is first formulated for the case of linear type positioning table and then applied to the case of rotary type manipulator. The methodology is then illustrated for practical downhand welding situations.

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약물부하 검사법의 현재와 미래 (Current Trends and Future Development in Pharmacologic Stress Testing)

  • 배진호;이재태
    • 대한핵의학회지
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    • 제39권2호
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    • pp.107-113
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    • 2005
  • Pharmacologic stress testing for myocardial perfusion imaging is a widely used noninvasive method for the evaluation of known or suspected coronary artery disease. The use of exercise for cardiac stress has been practiced for over 60 years and clinicians are familial with its using. However, there are inevitabe situations in which exorcise stress is inappropriate. A large number of patients with cardiac problems are unable to exercise to their full potential due to comorbidity such as osteoarthritis, vascular disease and pulmonary disease and a standard exercise stress test for myocardial perfusion imaging is suboptimal means for assessment of coronary artery disease. This problem has led to the development of the pharmacologic stress test and to a great increase in its popularity. All of the currently used pharmacologic agents have well-documented diagnostic value. This review deals the physiological actions, clinical protocols, safety, nuclear imaging applications of currently available stress agents and future development of new vasodilating agents.

ADAPTIVE, REAL-TIME TRAFFIC CONTROL MANAGEMENT

  • Nakamiti, G.;Freitas, R.
    • International Journal of Automotive Technology
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    • 제3권3호
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    • pp.89-94
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    • 2002
  • This paper presents an architecture for distributed control systems and its underlying methodological framework. Ideas and concepts of distributed systems, artificial intelligence, and soft computing are merged into a unique architecture to provide cooperation, flexibility, and adaptability required by knowledge processing in intelligent control systems. The distinguished features of the architecture include a local problem solving capability to handle the specific requirements of each part of the system, an evolutionary case-based mechanism to improve performance and optimize controls, the use of linguistic variables as means for information aggregation, and fuzzy set theory to provide local control. A distributed traffic control system application is discussed to provide the details of the architecture, and to emphasize its usefulness. The performance of the distributed control system is compared with conventional control approaches under a variety of traffic situations.

품질경영시대의 유연성을 갖는 생산시스템의 성능분석 및 평가 (Performance Analysis and Evaluation for Flexibility of Manufacturing Systems in QM era)

  • 이승현;유왕진
    • 품질경영학회지
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    • 제27권2호
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    • pp.251-262
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    • 1999
  • In the automated manufacturing systems, the problem regarding how to make production activities flexible is even more important and critical than that regarding how to product large quantities, and the more flexible, if possible, the manufacturing system is, the more competitiveness and profitable factors it gets. This research, therefore, concentrated on establishing the flexibility and evaluating performance on the manufacturing system, operational flexibility is considered because of enabling the manufacturing system to get both the improvement of production rate and the adaptive ability of environment changes. For it, we used the analytical tool, GSPNs, which is a kind of timed Petri-Nets. GSPNs is competent enough to consider practical situations just like operation priorities, machine failure, randomness, concurrency and so on. Through the GSPNs analysis, it is confirmed that in the manufacturing system with operational flexibility is compatible with the traditional performances such as production rate or mean waiting time.

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다구찌 손실함수 하에서 최적 공정평균 및 스크리닝 한계선의 결정 (Determination of Optimum Process Mean and Screening Limits under a Taguchi's Loss Function)

  • 홍성훈
    • 품질경영학회지
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    • 제28권2호
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    • pp.161-175
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    • 2000
  • The problem of jointly determining the optimum process mem and screening limits for each market is considered in situations where there are several markets with different price/cost structures. Two inspection procedures are considered; an inspection based on the quality characteristic of interest, and an inspection based on a surrogate variable which is highly correlated with the quality characteristic. The quality characteristic is assumed to be a normal distribution with unknown mean and known variance. A Taguchi's quadratic loss function is utilized for developing the economic model for determining the optimum process mean and screening limits. A numerical example is given.

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Asymptotic Properties of the Stopping Times in a Certain Sequential Procedure

  • Kim, Sung-Lai
    • Journal of the Korean Statistical Society
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    • 제24권2호
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    • pp.337-347
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    • 1995
  • In the problem of some sequential estimation, the stopping times may be written in the form $N(c) = inf{n \geq n_0; n \geq c^2 S^2_n/\delta^2 (\bar{X}_n)}$ where ${s^2_n}$ and ${\bar{X}_n}$ are the sequences of sample variance and sample mean of the independently and identically distributed (i.i.d.) random variables with distribution $F_{\theta}(x), \theta \in \Theta$, respectively, and $\delta$ is either constant or any given positive real valued function. We obtain some asymptotic normality and asymptotic expectation of the N(c) in various limiting situations. Specially, uniform asymptotic normality and uniform asymptotic expectation of the N(c) are given.

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수학교육용 소프트웨어의 활용에 대한 질적 연구 (A qualitative study in applying mathematical software for mathematics education)

  • 전영국
    • 대한수학교육학회지:학교수학
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    • 제1권2호
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    • pp.433-449
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    • 1999
  • This paper introduces a branch of qualitative method, called an in-depth interview method. By collecting data from the stories of Korean middle school students and a 9th grade American girl who used Geometer's Sketchpad and various software respectively for their mathematical problem solving, the qualitative analysis leads us to understand how such software affect their lives with mathematics subject. The unique characteristics and strands of each student's utterances reflect how software plays a role of learning aid for their mathematics learning. The arm of this study is both to get a good picture of each student's self-perceived relationship to mathematics as well as to explore external and objective parameters and factors in each student's internal situations. The qualitative descriptions of the collected data help us guide the students to the points where they could develop their interests and satisfaction with subject matter better. In this way, teachers may have more realistic understandings of how students become interested and motivated by mathematics, so that they are better able to find out ways of grasping the totalities of how the use of technology is interwoven into the school curricular.

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