• Title/Summary/Keyword: time-delay effect

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Development of a Prototype of FEM Simulation Environment for Temperature Controller Design (온도 제어기 설계를 위한 유한 요소법을 이용한 시뮬레이션 환경 프로토타입 구현)

  • Jang, Yu-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.2
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    • pp.696-702
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    • 2010
  • In many industrial applications, it is very important to control the temperature of the controlled object to the target temperature as closely as possible. Although it is apparent that the great obstacles in controller design are time-delay of the thermal responses of the controlled object and the effect of thermal interference between neighboring heating zones, one more fundamental obstacle is a very large amount of time which is required during repeated experiments in controller design process. Therefore, a convenient simulation environment, which can represent thermal behavior accurately within appropriate time, is needed. In this paper, a prototype of 2D FEM (finite element method) heat transfer simulation environment using MATLAB is constructed to be usefully adopted into industrial applications with temperature controller design.

Estimation of the effect on the autonomic nervous system using the return-map (리턴맵을 이용한 자율신경계 영향 평가)

  • Jo, Heung-Kuk;Ye, Soo-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.9
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    • pp.2099-2104
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    • 2010
  • In this paper, HRV signal which was appeared RR intervals from ECG was analyzed using return-map during anesthesia. We intended to estimate the depth of anesthesia observing the change of autonomic nervous activity(ANS) because HRV showed change of cardio-vascular system of the body according to state of ANS. Return-map analysis is to reconstruct time series of HRV to phase space after calculating delay time and embedded time. After approximating the signal distribution which was reconstructed in phase space in elliptic, we calculated the lengths of major and minor axises of the elliptic and the values was used to estimate the depth of anesthesia. Stages of the anesthesia were 7 levels to evaluate the depth of anesthesia. At induction stage of strong external stimulation, the length of major and minor axis were statistically high and at the operation stage of non-external stimulation, the values were statistically low. Conclusively, the stages of anesthesia were discriminated by HRV signal mapped in the phase space during operation.

Enhancing the Blast Resistance of Structures Using HPFRCC, Segmented Composites, and FRP Composites (HPFRCC, 분절 복합체 및 FRP를 활용한 구조물의 내폭 성능 향상)

  • Yoon, Young-Soo;Yang, Jun-Mo;Min, Kyung-Hwan;Shin, Hyun-Oh
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.745-748
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    • 2008
  • The past structures were just required bearing capacity to service load, serviceability, and resistance to corrosion. However this point of view has changed after 9.11 terrorism, capacities which can bear impact loading by explosion, and heat by fire happening at the same time, become to be important as a basic condition. The blast resistance capacity of structures is very important part against all over the world is intimidated by terrorism everyday in current point of time. The target of this research is a development of segmented composites and layered structures with high blast resistance using cementitious composites, concrete and FRP composites, which has high tensile strength and ductility, to apply in not only existing facilities but also new ones. Through the improvement of blast resistance, casualties and economic loss can be minimized, and it is possible to diminish the structure collapse and delay the time of structure collapse by thermal effect, impact loading, dynamic loading and high strain.

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Research of QoS Control for Standardization on Real-time Multimedia Service Using MAC/PHY Feedback (MAC/PHY 정보를 이용한 실시간 멀티미디어 서비스의 QoS 제어 방식의 표준화를 위한 연구)

  • Kim, Min-Geon;Kim, Jun-Oh;Suh, Doug-Young
    • Journal of Broadcast Engineering
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    • v.16 no.5
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    • pp.738-749
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    • 2011
  • In this paper, we study QoS(Quality of Service) control protocols and the effect using MAC/PHY parameters of client device in mobile network. We proposes the way of controling the bit-rate by estimating the channel condition of the client with measured MAC/PHY parameters which is sent from the client. With the proposed method, more accurate available bit-rate can be estimated compared to conventional protocol, RTCP(Real-time Transport Control Protocol). The accurate bit-rate estimation can decrease wasted bit-rate and transport delay. In the result of the advantages, the transported video quality can be enhanced. In this paper, we show the effects of enhancement using client's the field data measured in WiMAX.

Study on Error Correction of Impact Sound Position Estimation Using Ray Tracing (음선 추적을 이용한 폭발음 위치추정 오차 보정에 대한 연구)

  • Choi, Donghun;Go, Yeong-Ju;Lee, Jaehyung;Na, Taeheum;Choi, Jong-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.1
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    • pp.89-96
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    • 2016
  • TDOA(time delay of arrival) position estimate from acoustic measurement of artillery shell impact is studied in order to develop a targeting evaluation system. Impact position is calculated from the intersections of hyperbolic estimates based on the least square Taylor series method. The mathematical process of Taylor series estimation is known to be robust. However, the concern lays with the accuracy because it is sensitive to the bias caused by the randomness of measurement situation. The measurement error typically occurs from the distortion of waveform, change of travelling path, and sensor position error. For outdoor measurement, a consideration should be made on the atmospheric condition such as temperature and wind which can possibly change the trajectories of rays of sound. It produces wrong propagation time events accordingly. Ray tracing and optimization techniques are introduced in this study to minimize the bias induced by the ray of sound. The numerical simulation shows that the atmospheric correction improves the estimation accuracy.

Impact of Time Interval Between Chemoradiation and Surgery on Pathological Complete Response and Survival in Rectal Cancer

  • Akbar, Ali;Bhatti, Abu Bakar Hafeez;Niazi, Samiullah Khan;Syed, Amir Ali;Khattak, Shahid;Raza, Syed Hassan;Kazmi, Ather Saeed
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.1
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    • pp.89-93
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    • 2016
  • Background: Limited data are available regarding the impact of time duration between chemoradiation (CRT) and surgery on pathological complete response (PCR). A PCR translates into better overall and disease free survival. The objective of this study was to determine effect of time duration on outcome after preoperative CRT in rectal cancer. Materials and Methods: A retrospective review of patients undergoing operations for rectal adenocarcinoma between January 2005 and December 2010 was performed. Patients were divided in two groups: Group 1 underwent surgery in ${\leq}8weeks$ post neoadjuvant CRT and Group 2 after 8 weeks. Patient characteristics, surgical procedure, histopathological details and number of loco-regional and distant failures were compared. Expected 5 year overall survival and disease free survival was calculated using Kaplan Meier curves and significance was determined using the log rank test. Results: There were 66 patients in group 1 and 93 in group 2. No significant difference in PCR was observed between the two. However, estimated 5 year DFS was significantly higher in Group 1 (66.7%) as compared to Group 2 (53.8%) (P=0.04). Estimated overall 5 year overall survival was not significantly different at 68.2% versus 54.3% (P= 0.09). Conclusions: Delaying surgery more than 8 weeks after preoperative CRT does not impact for PCR in rectal cancer.

An Approach for Multi-User Multimedia Requests Service to Overlay Multicast Trees (다중 사용자의 멀티미디어 요구 서비스를 위한 오버레이 멀티캐스트 트리의 구성과 복구 방안)

  • Kang, Mi-Young;Yang, Hyun-Jong;Nam, Ji-Seung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.12B
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    • pp.1058-1065
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    • 2008
  • In the Internet, as computer resource is developed, multimedia data request being increase more and more. It is effective way that process both high capacity-data and real-time data. Overlay Multicast is an effective method for efficient utilization of system resources and network bandwidth without using hardware customization. Overlay Multicast is an effective method for multimedia data service to multi-users. Multicast tree reconstruction is required when a non-leaf host leaves or fails. In this paper, relay-frame interval is selected as revealed network-state with jitter. In our proposal, multi-user service control algorithm gives a delay effect in multimedia request time. The simulation results show that our proposal takes shorter period of time than the other algorithms to reconstruct a similar tree and that it is a more effective way to deal with a lot of nodes that have lost their multi-user nodes.

A study on Increasing Cngestion of Container Terminal as Berthing Mega Ship (Mega Ship 접안이 컨테이너 터미널 체선에 미치는 영향)

  • Kim, Nam-Kyoung;Shin, Jae-Young
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.05a
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    • pp.228-229
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    • 2018
  • To deal with the increasing volume of the vessel's cargo in the container flow and the enlargement trend of the vessels, Pusan port is making efforts from various perspectives such as the creation of global infrastructure and the promotion and development of new wharves. If Pusan port can provide and prepare the eligible infrastructures for future berthing of larger vessels. It will be able to operate with vessels larger than 20,000TEU, and it will also be able to grow into one of the main port of the Mega max era.. However, when large vessels dock, many berths, equipment, working time and labors are required. As a result, the problem of delaying time of other consecutive vessels will inevitably arise. In response to this, we analyze the impact and effect of the birthing of a large vessel on other congestion vessels at a container terminal.

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Congestion Control of Self-Similar Traffic in Two-way Network (양방향 네트워크에서 자기유사성 트래픽 혼잡 제어)

  • 석경휴;송선희;김철영;나상동
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.295-303
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    • 2004
  • In this Paper, we discuss an active TCP link of unsynchronized transmission mode network in two-way traffic and the Improvement of its traffic patron thorough the network pathway of protocol is shown. This is because the traffic pattern is performed on the basis of existing windows which are distributing information in several periods of time in the way of interfacing LTS control module, which is controlling by an information of exceeding the time limit of feedback loop determined by RTP, with TCP. The simulation to utilize this efficiently is performed with the circumstance of bench mark based on physical modeling of the self-similarity traffic in the performance of TCP. In this paper, we use a methodology to understand and evaluate the effect of change of transmitting protocol in sticks under the condition of the self-similar traffic in two-way network and it is shown that an improvement of congestion control by self-similarity under a heavy condition.

A New RFID Multi-Tag recognition Algorithm using Collision-Bit (RFID 충돌 비트를 이용한 다중 태그 인식 알고리즘)

  • Ji, Yoo-Kang;Cho, Mi-Nam;Hong, Sung-Soo;Park, Soo-Bong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.6
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    • pp.999-1005
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    • 2008
  • RFID(Radio Frequency IDintification) leader is collision of data, when recognizing the multiple tag the inside area. This collision became the cause which delays the tag recognition time of the leader. The protocol which prevents the delay of tag recognition time of the leader the place where representative it uses QT(Query Tree) algorithms, it uses a collision bit position from this paper and are improved QT-MTC(Query Tree with Multi-Tag Cognition) algorithms which it proposes. This algorithm stored the bit position which bit possibility and the collision where the collision happens occurs in the stack and goes round a tree the number of time which, it reduced could be identified two tags simultaneously in order, it was planned. A result of performance analysis, It compared in QT protocols and the this algorithm against the tag bit which is continued a high efficiency improvement effect was visible.