• 제목/요약/키워드: Adaptation Time

검색결과 1,028건 처리시간 0.027초

연속냉간압연기 제어모델의 적응수정방법에 관한 연구 (A study on the adaptive method of control model for tandem cold rolling mill)

  • 이원호;이상룡
    • 대한기계학회논문집A
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    • 제21권7호
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    • pp.1030-1041
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    • 1997
  • The control model in the tandem cold rolling mill consists of many mathematical theories and is used to calculate the reference values such as the roll gap and the rolling speed for good operation of rolling mill. But, the control model used presently has a problem causing inaccurate prediction of the rolling force. By the parameter identification, it was found that the main factor causing inaccurate prediction of the rolling force was incorrect modeling of the friction coefficient and the flow stress. To get rid of the erroneous factor new adaptive schemes are suggested in this work. Those are a long-time adaptation by the iterative least-square method and a short-time adaptation by the recursive weighted least-square method respectively. The new equations for the friction coefficient and the flow stress are derived by applying the suggested adaptive algorithms. Through the on-line test in an actual mill, it is proved that the rolling force predicted by the new equations is more accurate than the one by the existing equations ever used.

체표 온도 변화에 대한 문헌 고찰 (A literature study on change of surperficial temperature)

  • 김상록;이창훈;조정훈;장준복;이경섭
    • 대한한방체열의학회지
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    • 제4권1호
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    • pp.54-60
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    • 2005
  • Object: A study on the changes of superficial temperature as the ambient temperature varies. Method: After performing research on the physiologic mechanism of heat loss from skin, heat transfer to skin and heat productions of body, the conclusions would be drawn from experiments on temperature changes in every parts of the body as ambient temperature varies . Result and conclusion: Superficial temperature is in equilibrium with ambient temperature after a certain period. Part of the body with big change in superficial temperature tends to have slower temperature change and longer time for adaptation than the part with small change in superficial temperature. The temperature difference between left and right side of the body needs no attention. If adequate adaptation time, a short-period living supervision prior to measurements and appropriate indoor environment management are provided, meaningful conclusion would be attained for infrared thermal diagnosis.

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주 조절점 핸들링이 편마비 환자의 한발서기 자세적응에 미치는 영향 - 보바스의 신경발달치료 중심 - (The Effect of Key Point Control Handling for One-leg Standing Postural Adaptation in Hemiplegia)

  • 김대영
    • 대한물리치료과학회지
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    • 제8권2호
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    • pp.1059-1064
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    • 2001
  • This study is aimed at diagnosing transmutation aspect with the respective of hemiplegia patient's static adaptation of posture which is influenced by anti-gravity excercise, center of gravity shifting movement and segmental movement adaption of the legs and arms by key-point control in the process of Bobatli's treatment approach. The patients for the investigation of this study were selected as a total 17 patients who were doing the physical-therapy in Tae-gu Rehabilitation Center, and diagnosed as hemiplegia patients by Rehabilitation Medicine department in Kyung-buk University hospital. And also, there investigated into temporal transition that keep the attitude with one-leg standing on the ground concerning static attitude adaption on the basis of the before of anti-gravity movement and the after of 4-weeks movement. The findings of this study were as follows: With the respective the time to keep standing pose by one-leg at static attitude transmutation, affected side showed meaningful differences as a l.86/sec, 2.62/sec at 4 weeks later considering the before and after of this experiment.(p<0.01), non-affected side at the aspect of attitude keeping time, but there didn't showed meaningful differences statistically.

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A Hybrid Active Queue Management for Stability and Fast Adaptation

  • Joo Chang-Hee;Bahk Sae-Woong;Lumetta Steven S.
    • Journal of Communications and Networks
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    • 제8권1호
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    • pp.93-105
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    • 2006
  • The domination of the Internet by TCP-based services has spawned many efforts to provide high network utilization with low loss and delay in a simple and scalable manner. Active queue management (AQM) algorithms attempt to achieve these goals by regulating queues at bottleneck links to provide useful feedback to TCP sources. While many AQM algorithms have been proposed, most suffer from instability, require careful configuration of nonintuitive control parameters, or are not practical because of slow response to dynamic traffic changes. In this paper, we propose a new AQM algorithm, hybrid random early detection (HRED), that combines the more effective elements of recent algorithms with a random early detection (RED) core. HRED maps instantaneous queue length to a drop probability, automatically adjusting the slope and intercept of the mapping function to account for changes in traffic load and to keep queue length within the desired operating range. We demonstrate that straightforward selection of HRED parameters results in stable operation under steady load and rapid adaptation to changes in load. Simulation and implementation tests confirm this stability, and indicate that overall performances of HRED are substantially better than those of earlier AQM algorithms. Finally, HRED control parameters provide several intuitive approaches to trading between required memory, queue stability, and response time.

Image Processed Tracking System of Multiple Moving Objects Based on Kalman Filter

  • Kim, Sang-Bong;Kim, Dong-Kyu;Kim, Hak-Kyeong
    • Journal of Mechanical Science and Technology
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    • 제16권4호
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    • pp.427-435
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    • 2002
  • This paper presents a development result for image processed tracking system of multiple moving objects based on Kalman filter and a simple window tracking method. The proposed algorithm of foreground detection and background adaptation (FDBA) is composed of three modules: a block checking module(BCM), an object movement prediction module(OMPM), and an adaptive background estimation module (ABEM). The BCM is processed for checking the existence of objects. To speed up the image processing time and to precisely track multiple objects under the object's mergence, a concept of a simple window tracking method is adopted in the OMPM. The ABEM separates the foreground from the background in the reset simple tracking window in the OMPM. It is shown through experimental results that the proposed FDBA algorithm is robustly adaptable to the background variation in a short processing time. Furthermore, it is shown that the proposed method can solve the problems of mergence, cross and split that are brought up in the case of tracking multiple moving objects.

신규간호사의 임상실무 적응을 위한 가상현실 시뮬레이션 교육 요구도 조사: 혼합연구 적용 (The educational needs of virtual reality simulation training for novice nurses' adaptation to clinical practice: A mixed methods study)

  • 이미경;엄정희;김진영
    • 한국간호교육학회지
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    • 제29권4호
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    • pp.339-351
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    • 2023
  • Purpose: The purpose of this study is to identify the educational needs of virtual reality simulations that can be applied to novice nurses during the waiting period before starting work in a hospital. Methods: A convergent mixed methods was used. The survey data were collected from 230 novice nurses, and a focus group interview was conducted with 6 new nurses. The data were collected from November 2022 to January 2023. Descriptive statistics, a frequency analysis, independent t-test, and an Importance-Performance Analysis were performed using SPSS 24.0. Results: Appropriate topics for virtual reality simulation education were indicated to be medications and intravenous injections, which are high priority topics in quantitative and qualitative research. The novice nurses wanted group activity training three to four times a week for two weeks before beginning work in a hospital. They also wanted an immersive virtual reality system based on a real hospital environment. Conclusion: Based on the above results, this study provides basic data for the development of a virtual reality simulation education that can improve the adaptation of novice nurses to clinical practice. A strategy was suggested to utilize the waiting time before beginning work in a hospital as educational time.

Investigating Regions Vulnerable to Recurring Landslide Damage Using Time Series-Based Susceptibility Analysis: Case Study for Jeolla Region, Republic of Korea

  • Ho Gul Kim
    • Journal of Forest and Environmental Science
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    • 제39권4호
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    • pp.213-224
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    • 2023
  • As abnormal weather events due to climate change continue to rise, landslide damage is also increasing. Given the substantial time and financial resources required for post-landslide recovery, it becomes imperative to formulate a proactive response plan. In this regard, landslide susceptibility analysis has emerged as a valuable tool for establishing preemptive measures against landslides. Accordingly, this study conducted an annual landslide susceptibility analysis using the history of landslides that occurred over many years in the Jeolla region, and analyzed areas with a high potential for landslides in the Jeolla region. The analysis employed an ensemble model that amalgamated 10 data-based models, aiming to mitigate uncertainties associated with a single-model approach. Furthermore, based on the cumulative data regarding landslide susceptible areas, this research identified regions vulnerable to recurring landslide damage in Jeolla region and proposed specific strategies for utilizing this information at various levels, including local government initiatives, adaptation plan development, and development approval processes. In particular, this study outlined approaches for local government utilization, the determination of adaptation plan types, and considerations for development permits. It is anticipated that this research will serve as a valuable opportunity to underscore the significance of information concerning regions vulnerable to recurring landslide damage.

확률적 퍼지 룰 기반 학습 시스템의 적응 방법 (Adaptation Methods for a Probabilistic Fuzzy Rule-based Learning System)

  • 이형욱;변증남
    • 한국지능시스템학회:학술대회논문집
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    • 한국지능시스템학회 2007년도 추계학술대회 학술발표 논문집
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    • pp.223-226
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    • 2007
  • 지식 발견 (knowledge discovery)의 관점에서, 단기간 동안 취득된 데이터 패턴을 학습하고자 하는 경우 데이터에 비일관적인(inconsistent) 패턴이 포함되어 있다면 확률적 퍼지 룰(probabilistic fuzzy rule) 기반의 지식 표현 방법 및 적절한 학습 알고리즘을 이용하여 효과적으로 다룰 수 있다. 하지만 장기간 동안 지속적으로 얻어진 데이터 패턴을 다루고자 하는 경우, 데이터가 시변(time-varying) 특성을 가지고 있으면 기존에 추출된 지식을 변화된 데이터에 활용하기 어렵게 된다. 때문에 이러한 데이터를 다루는 학습 시스템에는 패턴의 변화에 맞추어 갈 수 있는 지속적인 적응력(adaptivity)이 요구된다. 본 논문에서는 이러한 적응성의 측면을 고려하여 평생 학습(life-long learning)의 관점 에 서 확률적 퍼지 룰 기반의 학습 시스템에 적용될 수 있는 두 가지 형태의 적응 방법에 대해서 설명하도록 한다.

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시간경과에 따른 유아의 유치원생활 적응행동연구 (A Longitudinal Study on the Child's Adaptive Behavior in Kindergarten Measured by Attachment Style)

  • 오재연
    • 아동학회지
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    • 제27권2호
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    • pp.71-84
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    • 2006
  • This study investigated the relationship between types of attachment and social adaptation of kindergarten children. Subjects were 108 3-year-old children, their mothers, and their teachers. Results showed that children securely attached to both mother and teacher adapted better than children who were insecurely attached to both mother and teacher. Children who were securely attached to mother but insecurely attached to teacher, and children who were insecurely attached to mother but securely attached to teacher adapted better than children who were insecurely attached to both mother and teacher. This study suggests that the quality of child-mother or child-teacher attachment affects children's social adaptation with the passage of time in kindergarten.

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Numerical Simulation of Unsteady Rotor Flow Using an Unstructured Overset Mesh Flow Solver

  • Jung, Mun-Seung;Kwon, Oh-Joon
    • International Journal of Aeronautical and Space Sciences
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    • 제10권1호
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    • pp.104-111
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    • 2009
  • An unstructured overset mesh method has been developed for the simulation of unsteady flow fields around isolated rotors and rotor-fuselage configurations. The flow solver was parallelized for the efficient calculation of complicated flows requiring a large number of cells. A quasi-unsteady mesh adaptation technique was adopted to enhance the spatial accuracy of the solution and to better resolve the rotor wake. The method has been applied to calculate the flow fields around rotor-alone and rotor-fuselage configurations in forward flight. Validations were made by comparing the predicted results with those of measurements. It was demonstrated that the present method is efficient and robust for the prediction of unsteady time-accurate flow fields involving multiple bodies in relative motion.