• 제목/요약/키워드: time-critical domains

검색결과 44건 처리시간 0.031초

실시간 환경에서 긴급한 정도의 계산을 통한 자율적인 에이전트의 유연한 의사결정 (Flexible Decision-Making for Autonomous Agent Through Computation of Urgency in Time-Critical Domains)

  • 노상욱
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권9호
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    • pp.1196-1203
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    • 2004
  • 자율적인 에이전트들은 이성적인 의사결정을 위하여 상당한 양의 계산자원을 필요로 하며, 실시간 환경에서 항상 최적의 행동을 수행하는 완벽하게 이성적인 에이전트(rational agent)의 구현은 실질적으로 가능하지 않다. 이러한 실시간 문제 해결기법에서의 전통적인 접근 방식은 미리 정의된 규약에 의존한 조건-행동 추론 방식이다. 조건-행동 추론 방식은 주어진 상황에 빠르게 반응하지만, 문제 영역이 다양하거나 문제의 재설계가 필요한 경우에는 아무런 해법을 갖지 못한다. 따라서 이러한 문제점을 해결하기 위해 본 논문에서는 주어진 행동들의 유틸리티를 실시간에 계산하고, 긴급한 정도(urgency)를 측정하여 상황이 긴급할 경우에는 더 이상의 계산을 중단하고 즉각적인 행동을 취하며, 반면에 상황이 긴급하지 않을 경우에는 최선의 의사결정을 위하여 추가적인 정보를 고려하여 더 바람직한 행동을 결정하는 방법론을 제안한다. 제안한 방법론의 평가를 위하여 시간 제약적인 환경에서 최선의 의사결정을 수행하는 실질적이며 유연한 에이전트를 구현하고자 한다.

Petri Net 형식론을 이용한 철도차량 주차단기 제어회로 모델링 (MCB ladder diagram modeling for Rolling stock using Petri Net formalism)

  • 최권희;안홍관;김재기;송중호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.1897-1902
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    • 2008
  • The computer system is used in many application domains and any system error in these domains may either cause critical loss or threaten environment or human life. Though examples of these domains can be found in many areas, the system, which is used in domains for carrying passengers including rolling stocks in particular, is expected to show satisfactory operation all the time. The relay control logic, which is used in rolling stocks, is complex in hardware and occupies considerably large volume. Nevertheless, it has been used for a long time, to let the system safely operate even in the occurrence of an error in the computer system. However, the relay control logic circuit is so complex that the analysis of proper circuit operation and interlocking tends to be dependent only on the designer's experiences instead of being systematically performed. Especially, the analysis following a change, addition and deletion of a previous circuit according to the requirements from a source of demand is significantly limited. In this paper, the accuracy of relay control logic is verified by the use of properties of Petri Net model. In addition, how main circuit breaker (MCB) control circuit is modeled and analyzed by the design methodology is shown.

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Investigation of allowable time-step sizes for generalized finite element analysis of the transient heat equation

  • O'Hara, P.;Duarte, C.A.;Eason, T.
    • Interaction and multiscale mechanics
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    • 제3권3호
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    • pp.235-255
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    • 2010
  • This paper investigates the heat equation for domains subjected to an internal source with a sharp spatial gradient. The solution is first approximated using linear finite elements, and sufficiently small time-step sizes to yield stable simulations. The main area of interest is then in the ability to approximate the solution using Generalized Finite Elements, and again explore the time-step limitations required for stable simulations. Both high order elements, as well as elements with special enrichments are used to generate solutions. When compared to linear finite elements, the high order elements deliver better accuracy at a given level of mesh refinement, but do not offer an increase in critical time-step size. When special enrichment functions are used, the solution can be approximated accurately on very coarse meshes, while yielding solutions which are both accurate and computationally efficient. The major conclusion of interest is that the significantly larger element size yields larger allowable time-step sizes while still maintaining stability of the time-stepping algorithm.

Pediatric postintensive care syndrome: high burden and a gap in evaluation tools for limited-resource settings

  • Chaiyakulsil, Chanapai;Opasatian, Rapee;Tippayawong, Paweethida
    • Clinical and Experimental Pediatrics
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    • 제64권9호
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    • pp.436-442
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    • 2021
  • This article aimed to summarize the impact and burden of pediatric postintensive care syndrome (PICS-p) in the physical, mental, cognitive, and social health domains after a review of the current pediatric literature in MEDLINE and PubMed. We also aimed to elucidate the limitations of the current evaluation tools used in limited-resource settings. PICS-p can impact a child's life for decades. Most validated tools are time-consuming, require qualifications, and expertise, are often limited to older children, and can evaluate only one domain. A novel, simple, and comprehensive surveillance tool can aid healthcare providers in the early detection and intervention of PICS-p. Further studies should validate and refine the parameters that will enhance the outcomes of pediatric intensive care unit survivors.

Experimental identification of multiple faults in rotating machines

  • Mahfoud, Jarir;Breneur, Claire
    • Smart Structures and Systems
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    • 제4권4호
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    • pp.429-438
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    • 2008
  • The aim of this paper is to define the required measurements and processing tools necessary for developing a maintenance approach applied to rotating machines in the presence of multiple faults. The system responses measured were accelerations and transmission errors. Acceleration measurements provide most of the information on bearing conditions, while transmission error measurements provide pertinent information on gear conditions. The measurements were carried out for several operating conditions (loads and speeds). System responses were processed in several analyzing domains (Time, Spectrum, and Cepstrum domains). The approach developed enables the detection and identification of combined faults and it can be applied to other types of rotating machines once the critical elements and their associated faults have been defined.

Microstructure and Trapped Magnetic Field of Multi-Seeded Single Domain YBCO

  • Bierlich, J.;Habisreuther, T.;Litzkendorf, D.;Zeisberger, M.;Gawalek, W.
    • Progress in Superconductivity
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    • 제8권1호
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    • pp.8-15
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    • 2006
  • The size of the superconducting domains and the critical current density inside these domains have to be enhanced for most of cryomagnetic applications of melt-textured YBCO bulks. To enlarge the size of the domains we studied the multi-seeding technique based on a well-established procedure for preparing high quality YBCO monoliths using self-made SmBCO seeds. The distance between the seeds was optimised as a result of the investigation of the effects of various seed distances on the characteristics of the grain boundary Junctions. The influences of a-b plane intersections and c-axis misalignments were researched. Thereby, a small range of tolerance of the misorientations between the seed crystals was found. Field mapping was applied to control the materials quality and the superconductor's grain structure was investigated using polarisation microscopy. YBCO function elements with iou. seeds in a line and an arrangement of making type (100)/(100) and (110)/(110) boundary junctions, respectively, were processed. The trapped field profile in both sample types shows single domain behaviour. To demonstrate the potential of the multi-seeding method a ring-shaped sample was processed by placing sixteen seeds in a way to make both (100)/(100) and (110)/(110) grain junctions at the same time. The results up to now are very promising to prepare large single domain melt-textured YBCO semi-finished products in complex shapes.

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Comparative Modeling and Molecular Dynamics Simulation of Substrate Binding in Human Fatty Acid Synthase: Enoyl Reductase and β-Ketoacyl Reductase Catalytic Domains

  • John, Arun;Umashankar, Vetrivel;Krishnakumar, Subramanian;Deepa, Perinkulam Ravi
    • Genomics & Informatics
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    • 제13권1호
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    • pp.15-24
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    • 2015
  • Fatty acid synthase (FASN, EC 2.3.1.85), is a multi-enzyme dimer complex that plays a critical role in lipogenesis. This lipogenic enzyme has gained importance beyond its physiological role due to its implications in several clinical conditions-cancers, obesity, and diabetes. This has made FASN an attractive pharmacological target. Here, we have attempted to predict the theoretical models for the human enoyl reductase (ER) and ${\beta}$-ketoacyl reductase (KR) domains based on the porcine FASN crystal structure, which was the structurally closest template available at the time of this study. Comparative modeling methods were used for studying the structure-function relationships. Different validation studies revealed the predicted structures to be highly plausible. The respective substrates of ER and KR domains-namely, trans-butenoyl and ${\beta}$-ketobutyryl-were computationally docked into active sites using Glide in order to understand the probable binding mode. The molecular dynamics simulations of the apo and holo states of ER and KR showed stable backbone root mean square deviation trajectories with minimal deviation. Ramachandran plot analysis showed 96.0% of residues in the most favorable region for ER and 90.3% for the KR domain, respectively. Thus, the predicted models yielded significant insights into the substrate binding modes of the ER and KR catalytic domains and will aid in identifying novel chemical inhibitors of human FASN that target these domains.

중풍 입원 환자 관리를 위한 임상경로 개발 (Development of a Critical Pathway for a Korean Medicine Hospital Inpatient with Stroke)

  • 김미경;한창호
    • 대한한의학회지
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    • 제42권2호
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    • pp.62-71
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    • 2021
  • Objectives: This study was aimed to share the development process of the critical pathway (CP) for the treatment and management of stroke patients admitted to a Korean medicine hospital. Methods: A draft CP was prepared based on a review of relevant literature and medical records in the hospital, and its validity was reviewed by the in-hospital CP review committee. Each member evaluated all items in the CP on a 5-point Likert scale. Items with an average score of 3.5 or higher or an agreement rate of more than 80% were considered valid. In addition, free described opinions to improve the CP were also received from the review committee. Results: The horizontal axis of the CP was composed of a time domain, including 7 time points from hospitalization to discharge. The vertical axis was composed of 9 domains of medical practice. All items in the CP satisfied the validity criteria. The CP was revised, supplemented, and completed by reflecting the opinions of the committee. Conclusions: This CP will be taught to in-hospital users and will continue to be used with regular monitoring and a feedback plan. This study is expected to serve as a useful reference for standardizing the treatment process and delivering measures to improve the adequacy of Korean medicine treatment for stroke patients.

중환자실 간호행위에 대한 간호소요시간 측정 및 분석 (Measurement and Analysis of the Standard Nursing Practice Times of the ICU Nursing Activities)

  • 유정숙;김금순
    • 중환자간호학회지
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    • 제2권2호
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    • pp.56-67
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    • 2009
  • Purpose: This study was done to suggest the standard ICU nursing procedure and standard ICU nursing practice time carried out according to the standard ICU nursing procedure. Methods: Through the literature review, 35 standard ICU nursing activities were selected and classified under 6 categories. Standard nursing procedures were described by research team and 4 clinical practice experts. Content validity of descripted nursing procedure was performed by 6 clinical practice experts. After that standard ICU nursing procedures were identified, standard nursing practice times were checked through 1:1 observation. Results: 35 ICU nursing activities were identified and categorized into 6 domains of activities. Also, their standard nursing procedures were identified, and finally 33 standard nursing practice times were measured and analyzed. The result of the measurement, 1 ICU nursing activity was spent above 30 minutes, 3 activities done within 10-20 minutes, 4 activities done within 5-10 minutes, and 25 activities were spent below 5 minutes. Conclusion: Through this study, 35 standard ICU nursing procedures were described and 33 standard ICU nursing practice times which carried out according to standard ICU nursing procedures were checked. The result can be as fundamental data for the study of nursing activity time in the ICU.

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Advanced Design Environmental With Adaptive And Knowledge-Based Finite Elements

  • Haghighi, Kamyar;Jang, Eun
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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    • pp.1222-1229
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    • 1993
  • An advanced design environment , which is based on adaptive and knowledge -based finite elements (INTELMESH), has been developed. Unlike other approaches, INTEMMESH incorporates the information about the object geometry as well as the boundary and loading conditions to generate an ${\alpha}$-priori finite element mesh which is more refined around the critical regions of the problem domain. INTEMMESH is designed for planar domains and axisymmetric 3-D structures of elasticity and heat transfer subjected to mechanical and thermal loading . It intelligently identifies the critical regions/points in the problem domain and utilize the new concepts of substructuring and wave propagation to choose the proper mesh size for them. INTEMMESH generates well-shaped triangular elements by applying trangulartion and Laplacian smoothing procedures. The adaptive analysis involves the intial finite elements analyze and an efficient ${\alpha}$-posteriori error analysis involves the initial finite element anal sis and an efficient ${\alpha}$-posteriori error analysis and estimation . Once a problem is defined , the system automatically builds a finite element model and analyzes the problem though automatic iterative process until the error reaches a desired level. It has been shown that the proposed approach which initiates the process with an ${\alpha}$-priori, and near optimum mesh of the object , converges to the desired accuracy in less time and at less cost. Such an advanced design/analysis environment will provide the capability for rapid product development and reducing the design cycle time and cost.

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