• Title/Summary/Keyword: minimal model

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Selection of Optimal Model for Structural System Identification (SI기법 적용을 위한 최적 모델의 선택)

  • Kwak, Hyun-Seok;Kwon, Soon-Jung;Lee, Hae-Sung;Shin, Soobong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.2
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    • pp.217-224
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    • 2005
  • A methodology of selecting an optimal model is proposed for applying a frequency-domain SI method effectively. Instead of using a reduced finite element model, a reasonably detail finite element model is established first and then the model is identified. To satisfy the identifiability criterion, a parameter grouping scheme is applied to control the number of unknowns. Among the simulated member grouping cases, an optimal model is selected as the one with the minimal statistical error. The proposed approach has been examined through simulation studies on a single span box-girder bridge.

Design of Lateral Force Estimation Model for Rough Terrain Mobile Robot and Improving Estimation Reliability on Friction Coefficient (야지 주행 로봇을 위한 횡 방향 힘 추정 모델의 설계 및 마찰계수 추정 신뢰도의 향상)

  • Kim, Jiyong;Lee, Jihong;Joo, Sang Hyun
    • The Journal of Korea Robotics Society
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    • v.13 no.3
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    • pp.174-181
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    • 2018
  • For a mobile robot that travels along a terrain consisting of various geology, information on tire force and friction coefficient between ground and wheel is an important factor. In order to estimate the lateral force between ground and wheel, a lot of information about the model and the surrounding environment of the vehicle is required in conventional method. Therefore, in this paper, we are going to estimate lateral force through simple model (Minimal Argument Lateral Slip Curve, MALSC) using only minimum data with high estimation accuracy and to improve estimation reliability of the friction coefficient by using the estimated lateral force data. Simulation is carried out to analyze the correlation between the longitudinal and transverse friction coefficients and slip angles to design the simplified lateral force estimation model by analysing simulation data and to apply it to the actual field environment. In order to verify the validity of the equation, estimation results are compared with the conventional method through simulation. Also, the results of the lateral force and friction coefficient estimation are compared from both the conventional method and the proposed model through the actual robot running experiments.

Vital Area Identification of Nuclear Facilities by using PSA (PSA기법을 이용한 원자력시설의 핵심구역 파악)

  • Lee, Yoon-Hwan;Jung, Woo-Sik;Hwang, Mee-Jeong;Yang, Joon-Eon
    • Journal of the Korean Society of Safety
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    • v.24 no.5
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    • pp.63-68
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    • 2009
  • The urgent VAI method development is required since "The Act of Physical Protection and Radiological Emergency that is established in 2003" requires an evaluation of physical threats in nuclear facilities and an establishment of physical protection in Korea. The VAI methodology is developed to (1) make a sabotage model by reusing existing fire/flooding/pipe break PSA models, (2) calculate MCSs and TEPSs, (3) select the most cost-effective TEPS among many TEPSs, (4) determine the compartments in a selected TEPS as vital areas, and (5) provide protection measures to the vital areas. The developed VAI methodology contains four steps, (1) collecting the internal level 1 PSA model and information, (2) developing the fire/flood/pipe rupture model based on level 1 PSA model, (3) integrating the fire/flood/pipe rupture model into the sabotage model by JSTAR, and (4) calculating MCSs and TEPS. The VAT process is performed through the VIPEX that was developed in KAERI. This methodology serves as a guide to develop a sabotage model by using existing internal and external PSA models. When this methodology is used to identify the vital areas, it provides the most cost-effective method to save the VAI and physical protection costs.

A Review of Dose-response Models in Microbial Risk Assessment (미생물 위해성 평가의 용량-반응 모델에 대한 고찰)

  • 최은영;박경진
    • Journal of Food Hygiene and Safety
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    • v.19 no.1
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    • pp.19-24
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    • 2004
  • Dose-response models in microbial risk assessment can be divided into biologically plausible models and empirical models. Biologically plausible models are formed by the assumptions in dose distribution of microbes, host sensitivity to microbes, and minimal infectious dose of microbes : there are Exponential model and $\beta$-Poisson model, representatively. Empirical models are mainly used to express the toxicity of chemicals : there are Weibull-Gamma model etc. Deviance function (Y) is used to fit available data to dose-response models, and some dose-response models for food-borne pathogens are developed in humans and experimental animals.

Estimation of the vibration fatigue of a linear elastic system based on a desiign sensitivity analysis (설계 만감도 해석을 활용한 선형 시스템 진동내구 평가)

  • Kim, Chan-Jung;Kim, Ku-Sik;Kang, Ho-Young;Jin, Yeo-Hwa;Lee, Bong-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2010.10a
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    • pp.491-496
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    • 2010
  • The direct design modification of problematic component is disallowed in order to sacrifice other major factors such as a stability or a major performance. So, the best design policy is to risvise the immature structural medchanism under the minimal design change as soon as possible. For this paper presents a new design sensitivity analysis based on transmissibility rtio (TR) of response acceleration to find a proper candidate for the minimal design modification. The new sensitivity analysis is based on the fact that the sensitivity of TR over a small design change is inversly proportinal to the magnitude of TR. The theory of proposed design sensitivity analysis is simulated with the variance of TR over a dynamic change. Then, new methodology is appplied for a linear elastic specimen to detect the most sensitive node over a design change using measured accleration data during uni-axial vibration test, The physical verification of the sensitivity method is conducted on the CAE model of a linear elastic specimen by adding concentration mass and the vibration fatigue of the simple specimen is analyzed to estimate the relationship between fatigue behaviors and sensitivity consequences.

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각국 대학도서관 장서구성기준의 비교고찰-기준범위의 모형정립을 위한 비교분석

  • 손정표
    • Journal of Korean Library and Information Science Society
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    • v.2
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    • pp.1-21
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    • 1975
  • Thc purposc of this .study is for ri~aking a model of building a library collcction dcnizn~cd on th.3 curriculum through thc inter-comparison of 15 standards for collcgc ant1 anivcrsily libraries in 5 countries (U. S. A.. Great Ikitain, Canada, Japan, and Icorca) Thc rcsult of thcscl colnpsrisons is as follow.. (1) Qu;~nlitalivc scope: of thc cull(:ction: (r/ Standards for a minimal collcction arc presented to about 100,000 vols (20-30 vols per student) for a ncw university and about 40,000 vols (40 vols pcr studcnt) for a nrnr collcge. $)$ Standards for a working collcction arc prescnted to 70-80 vols per student for a univer:aity and 50-60 vols per student for a college. $$ Standard for an intcnsive rescc~rch collcction is presented to morc than 100 vols p::r studcnt. (2) Stop: of the annual incrc;lsc cf thc collection: (i: Standard for a minimal collcction is ~~rescntcdto 1.4-2 vols per studcnt. $$ Standard for an intensive rrscarch or working collection is pcrsented to 4-5 vols pcr studcnt. (3) Scope of thc anni.1a1 budgetary standards: In Grcat I3ritain and U.S. A.. th-re aro assigned to 1 . 5 ~ 2 % of the collcge and university cxpcnditurr for books. $,$ In our country, it is prcscntcd to 3.5% of thc collcge and university expenditure for books, whcn my calculating by thc various factor analysis.

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A study on Determining Maintenance Intervals Considering the Maintenance Effect for the PDS in Metro EMU (전동차 승객용도어시스템의 유지보수 효과를 고려한 유지보수 주기 산정에 관한 연구)

  • Lee, Duk-Gyu;Son, Young-Jin;Lee, Hi-Sung
    • Journal of the Korean Society for Railway
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    • v.14 no.3
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    • pp.216-221
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    • 2011
  • An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, many of maintenances performed by domestic subway operators are imperfect maintenances which have the effect between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals based on failure data in units of the PDS(passenger door system) in Metro EMU. This paper deals with a case study on determining imperfect maintenance interval by using the level of maintenance effect through reliability analysis of PDS.

Tyrosine Kinase Inhibitors in Ph+ Chronic Myeloid Leukemia Therapy: a Review

  • Shah, Krupa;Parikh, Sonia;Rawal, Rakesh
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3025-3033
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    • 2016
  • Chronic myeloid leukaemia (CML) is a clonal myeloproliferative hematopoietic stem cell disorder. Deregulated BCR-ABL fusion tyrosine kinase activity is the main cause of CML disease pathogenesis, making BCR-ABL an ideal target for inhibition. Current tyrosine kinase inhibitors (TKIs) designed to inhibit BCR-ABL oncoprotein activity, have completely transformed the prognosis of CML. Interruption of TKI treatment leads to minimal residual disease reside (MRD), thought to reside in TKI-insensitive leukaemia stem cells which remain a potential reservoir for disease relapse. This highlights the need to develop new therapeutic strategies for CML either as small molecule master TKIs or phytopharmaceuticals derived from nature to achieve chronic molecular remission. This review outlines the past, present and future therapeutic approaches for CML including coverage of relevant mechanisms, whether ABL dependent or independent, and epigenetic factors responsible for developing resistance against TKIs. Appearance of mutant clones along the course of therapy either pre-existing or induced due to therapy is still a challenge for the clinician. A proposed in-vitro model of generating colony forming units from CML stem cells derived from diagnostic samples seems to be achievable in the era of high throughput technology which can take care of single cell genomic profiling.

An authenticated key distribution protocol for the CDMA mobile communication network (부호 분할 다중 접속 이동 통신망을 위한 인증 키 분해 프로토콜)

  • Hak S. Jeon;Dong K. Kim
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.7 no.2
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    • pp.43-54
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    • 1997
  • In this paper, we introduce a secure and minimal protocol for authenticated key distribution over the CDMA mobile communication network. The CDMA mobile communication network has been developed the security protocol that provides a means for user authentication and subsequent protection of user traffic. However, this model has no security assumptions for the intermediate, fixed networks. To avoiding these drawbacks, we introduce a minimal authenticated key distribution protocol. This protocol provides the security of the intermediate and fixed network in mobile environment, and maintains the confidentiality of user identification and the minimum size of information flow compared with the existing protocols.

IEEE 802.15.4e TSCH-mode Scheduling in Wireless Communication Networks

  • Ines Hosni;Ourida Ben boubaker
    • International Journal of Computer Science & Network Security
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    • v.23 no.4
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    • pp.156-165
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    • 2023
  • IEEE 802.15.4e-TSCH is recognized as a wireless industrial sensor network standard used in IoT systems. To ensure both power savings and reliable communications, the TSCH standard uses techniques including channel hopping and bandwidth reserve. In TSCH mode, scheduling is crucial because it allows sensor nodes to select when data should be delivered or received. Because a wide range of applications may necessitate energy economy and transmission dependability, we present a distributed approach that uses a cluster tree topology to forecast scheduling requirements for the following slotframe, concentrating on the Poisson model. The proposed Optimized Minimal Scheduling Function (OMSF) is interested in the details of the scheduling time intervals, something that was not supported by the Minimal Scheduling Function (MSF) proposed by the 6TSCH group. Our contribution helps to deduce the number of cells needed in the following slotframe by reducing the number of negotiation operations between the pairs of nodes in each cluster to settle on a schedule. As a result, the cluster tree network's error rate, traffic load, latency, and queue size have all decreased.