• Title/Summary/Keyword: Deviation

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Three-dimensional analysis of the outcome of different scanning strategies in virtual interocclusal registration

  • Jiansong, Mei;Liya, Ma;Jiarui, Chao;Fei, Liu;Jiefei, Shen
    • The Journal of Advanced Prosthodontics
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    • v.14 no.6
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    • pp.369-378
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    • 2022
  • PURPOSE. The purpose of this in vitro study was to assess whether scanning strategies of virtual interocclusal record (VIR) affect the accuracy of VIR during intraoral scanning. MATERIALS AND METHODS. Five pairs of reference cubes were added to the digital upper and lower dentitions of a volunteer, which were printed into resin casts. Subsequently, the resin casts were articulated in the maximal intercuspal position in a mechanical articulator and scanned with an industrial computed tomography system, of which the VIR was served as a reference VIR. The investigated VIR of the upper and lower jaws of the resin master cast were recorded with an intraoral scanner according to 9 designed scanning strategies. Then, the deviation between the investigated VIRs and reference VIR were analyzed, which were measured by the deviation of the distances of six selected reference points on the upper reference cubes in each digital cast to the XY-plane between the investigated VIRs and reference VIR. RESULTS. For the deviation in the right posterior dentitions, RP group (only scanning of right posterior dentitions) showed the smallest deviation. Besides, BP group (scanning of bilateral posterior dentitions) showed the smallest deviation in the left posterior dentitions. Moreover, LP group (scanning of left posterior dentitions) showed the smallest deviation in the anterior dentitions. For the deviation of full dental arches, BP group showed the smallest deviation. CONCLUSION. Different scanning strategies of VIR can influence the accuracy of alignment of virtual dental casts. Appropriate scanning strategies of VIR should be selected for different regions of interest and edentulous situations.

Interpretation and Generalization by Neuroscience and Material Mechanics on Deviation in Temporomandibular Joint Balancing Medicine (턱관절균형의학에서 편차발생현상의 신경과학 및 재료역학적 해석과 일반화)

  • Gyoo-yong Chi
    • Journal of TMJ Balancing Medicine
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    • v.12 no.1
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    • pp.1-6
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    • 2022
  • Objectives: For the deviation phenomenon occurring during the treatment process in temporo-mandibular balancing medicine (TBM), hypotheses were established regarding the cause and mechanism of formation from the perspective of neuro-science and material mechanics, and a verification method was proposed. Methods: The deviation phenomenon was theoretically analyzed based on the structure theories of material mechanics of the joint and the neurological pain mechanism. Results: Deviation occurs due to temporary yield by the accumulation of heterogeneous stress in the temporo-mandibular joint and the affected joint. Because the joint structures are corresponding with material mechanics showing compressive and tensile properties. The size of the deviation is expressed in terms of strain. The occlusal surface of the teeth is level with the axial joint. Since the magnitude of the deviation has a proportional relationship with the degree of abnormality of the temporo-mandibular joint, the magnitude of the deviation calculated by the balance measurement can be replaced by the strain. The major variables involved in the occurrence of deviations are the strength of joint structures and neurological conditions. Therefore plastic deformation and adaptation occur as a long-term depression of neural circuits is strengthened in different ways at different locations each time in various clinical situations. This is the reason why the sequence of the restoration process while correcting deviations is following reverse order of the accumulation in many layers in the muscular nervous system. Conclusions: From the above results, it can be inferred that the occurrence and correction of the deviations are corresponding with the plastic deformation and neuro-plasticity.

LARGE DEVIATION PRINCIPLE FOR DIFFUSION PROCESSES IN A CONUCLEAR SPACE

  • CHO, NHAN-SOOK
    • Communications of the Korean Mathematical Society
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    • v.20 no.2
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    • pp.381-393
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    • 2005
  • We consider a type of large deviation principle obtained by Freidlin and Wentzell for the solution of Stochastic differential equations in a conuclear space. We are using exponential tail estimates and exit probability of a Ito process. The nuclear structure of the state space is also used.

A STUDY ON THE PROBABILISTIC PRODUCTION COST SIMULATION BY THE EFFICIENT LARGE DEVIATION METHOD (효율적인 LARGE DEVIATION 방법에 의한 발전 시뮬레이션에 관한 연구)

  • Song, K.Y.;Cha, J.M.;Kim, Y.H.;Oh, K.H.
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.244-246
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    • 1990
  • This paper describes the Large Deviation Method for computing the loss-of-load-probability (L.O.L.P.) index for a generating system. Also, we introduce a rule to prevent the initial value from diverging in Newton-Raphson method which we have to use to determine the value of t. By applying the Large Deviation Method to computing the L.O.L.P. index for some representative reliability test systems, it is verified that the Large Deviation Method is generally very accurate and very fast.

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Development of a Finite Element for Vibration Analysis of an Annular Plate with Slight Deviation (미소한 비대칭이 존재하는 원판의 진동해석을 위한 유한요소 개발)

  • 김민중;정진태;이장무
    • Journal of KSNVE
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    • v.10 no.2
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    • pp.361-366
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    • 2000
  • In this paper, a new finite annular plate element is developed, which considers the effects of the slight deviation from a perfect axisymmetry. It is assumed that, when a local deviation is introduced to an axisymmetric plate, the natural modes are separated into the symmetric and asymmetric modes. The proposed method is very efficient because a few elements are demanded and lots of active degrees of freedom are reduced in comparison with commercial numerical analysis programs. In addition, when the deviation is small enough. It is more accurate than the result of using usual plate elements of commercial FEM programs.

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The Relationships among the Degree of Quality Cost Deviation, Quality Management Activities and Performance (품질비용 발생편차와 품질관리활동 그리고 성과간의 관계:품질성과와 납기성과를 중심으로)

  • 김달곤;김순기;정순여
    • Journal of Korean Society for Quality Management
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    • v.31 no.4
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    • pp.1-18
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    • 2003
  • Quality is a critical competitive factor in today's environment because of the impact of quality on costs and delivery. Many companies regard quality as a key concept of company strategy in order to achieve the competitive edge. Measuring and reporting quality cost is the first step in quality management program. The supposition of quality cost model is that investment in prevention activities will bring rewards from reduced failure costs, and that further investment in prevention activities will show profits from reduced appraisal costs. In this study, the degree of quality cost deviation is conceptualized. This means a deviation between the ideal and present ranking in the amounts of quality cost categories. This study analysed that the effect of its deviation on quality management activity and performance variables. However, there are no difference in these variables. The major reason is that most of companies are endeavoring for quality management but operating quality cost system unsystematically. The review against a prevention and appraisal activity is necessary.

Asymptotic Properties of Nonlinear Least Absolute Deviation Estimators

  • Kim, Hae-Kyung;Park, Seung-Hoe
    • Journal of the Korean Statistical Society
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    • v.24 no.1
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    • pp.127-139
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    • 1995
  • This paper is concerned with the asymptotic properties of the least absolute deviation estimators for nonlinear regression models. The simple and practical sufficient conditions for the strong consistency and the asymptotic normality of the least absolute deviation estimators are given. It is confirmed that the extension of these properties to wide class of regression functions can be established by imposing some condition on the input values. A confidence region based on the least absolute deviation estimators is proposed and some desirable asymptotic properties including the asymptotic relative efficiency also discussed for various error distributions. Some examples are given to illustrate the application of main results.

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Variable Sampling Interval $\bar{X}$ Control Chart Using Weighted Standard Deviation Method (가중표준편차를 이용한 가변표본채취간격 $\bar{X}$ 관리도)

  • Chang, Youngsoon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.39 no.1
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    • pp.1-12
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    • 2014
  • This article proposes a variable sampling interval (VSI) $\bar{X}$ control chart using weighted standard deviation (WSD) method for skewed populations. The WSD method decomposes the standard deviation of a quality characteristic into upper and lower deviations and adjusts control limits and warning limits of a control chart in accordance with the direction and degree of skewness. A control chart constant is derived for estimating the standard deviation of skewed distributions with the mean of sample standard deviations. The proposed chart is compared with the conventional VSI $\bar{X}$ control chart under some skewed distributions. Simulation study shows that the proposed WSD VSI chart can control the in-control average time to signal (ATS) as an adequate level better than the conventional VSI chart, and the proposed chart can detect a decrease in the process mean of a quality characteristic following a positively skewed distribution more quickly than the standard VSI chart.