The immediate reason for the creation of this book has been the advent of Basel II.
This has forced many institutions with loan portfolios into building risk models, and,
as a consequence, a need has arisen to have these models validated both internally and
externally. What is surprising is that there is very little written that could guide consultants
in carrying out these validations. This book aims to fill that gap.
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Stochastic modeling of oligodendrocyte generation in cell culture: model validation with time-lapse data
(BQ) In this paper, an easily implemented method is developed to describe the variations of EDM process, represented by gap states. On the basis of a time series of gap states from a machining process, the paper first studied a general descriptive model for EDM process, and then equivalently simplified the model for application; after spectral
analysis, preprocessing of data, parameters selection and model validation proposed a well-defined model. Finally, by using this model structure and size, an online time-varied predictive model was developed.
The estimation process begins by assuming or hypothesizing that the least squares linear regression
model (drawn from a sample) is valid. The formal two-variable linear regression model is based on
the following assumptions:
(1) The population regression is adequately represented by a straight line: E(Yi) = μ(Xi) = β0 + β1Xi
(2) The error terms have zero mean: E(∈i) = 0
(3) A constant variance (homoscedasticity): V(∈i) = σ2
Validation of Communications Systems with SDL provides a clear practical guide to validating, by simulation, a telecom system modelled in SDL. SDL, the Specification and Description Language standardised by the International Telecommunication Union (ITU-T), is used to specify and develop complex systems such as GSM, GPRS, UMTS, IEEE 802.11 or Hiperlan. Since the downturn in the telecom industry, validating a system before its implementation has become mandatory to reduce costs.
Given a collection of records (training set )
Each record contains a set of attributes, one of the attributes is the class.
Find a model for class attribute as a function of the values of other attributes.
Goal: previously unseen records should be assigned a class as accurately as possible.
A test set is used to determine the accuracy of the model. Usually, the given data set is divided into training and test sets, with training set used to build the model and test set used to validate it.
ORGANIZATIONL CHANGE THROUGH THE MANDATED IMOLEMENTATION OF NEW INFORMATION SYSTEMS TECHNOLOGY : A MODIFIED TECHNOLOGY ACCEPTANCE MODEL A second shortcoming of the validity literature is more fundamental. In a world in
which student background characteristics are known to be correlated with academic success
(i.e. with both SAT scores and collegiate grades), it is quite difficult to interpret validity
estimates that fail to take account of these background characteristics.
SWAT model was used to assess the impacts of climate change on the streamflow of Ben Hai River Basin. The daily streamflow for 1979 - 1996 and 1997 - 2006 was used to calibrate and validate the SWAT model, respectively. Nash efficiency values for the daily comparison were 0.72 for the calibration period and 0.74 for the validation period. Three scenarios were analyzed relative to the baseli ne with 28-year time series. A doubling of the atmospheric C02 content to 660 ppm (while holding other climatic variables) resulted in a 7.
This study has two main goals: to construct a measuring instrument with which to evaluate the structural quality of faceted thesauri; and to determine the validity and reliability of this measuring instrument. The measuring instrument consists of gods, objectives, and criteria against which to measure the structural quality of faceted thesauri.
The second question requires that we build an understanding of how the policy
instrument effects production and productive efficiency. Our approach is similar to
recent stochastic frontier analyses with panel data (Cornwell et al. (1990), Kumbhakar
(1990)), which allow intercepts and some coefficients of the production function to vary
between firms and over time.
Medical imaging has been transformed over the past 30 years by the advent
of computerized tomography (CT), magnetic resonance imaging (MRI), and
various advances in x-ray and ultrasonic techniques. An enabling force behind
this progress has been the (so far) exponentially increasing power of
computers, which has made it practical to explore fundamentally new approaches.
Examines the potential of rule-based modeling as an analysis tool for investigating resource allocation policy issues.Focus is on resource allocation within B-52 flying organizations of the Strategic Air Command (SAC). A rule-based computer system, DOSS (Decision Oriented Scheduling System), is demonstrated to provide a valid model of many variables that affect resource allocation of aircrews and ......
Frequency distribution models tuned to words and other linguistic events can predict the number of distinct types and their frequency distribution in samples of arbitrary sizes. We conduct, for the ﬁrst time, a rigorous evaluation of these models based on cross-validation and separation of training and test data. Our experiments reveal that the prediction accuracy of the models is marred by serious overﬁtting problems, due to violations of the random sampling assumption in corpus data. We then propose a simple pre-processing method to alleviate such non-randomness problems. ...
This paper presents a new model for word alignments between parallel sentences, which allows one to accurately estimate different parameters, in a computationally efficient way. An application of this model to bilingual terminology extraction, where terms are identified in one language and guessed, through the alignment process, in the other one, is also described. An experiment conducted on a small English-French parallel corpus gave results with high precision, demonstrating the validity of the model. ...
Abstract-like text summarisation requires a means of producing novel summary sentences. In order to improve the grammaticality of the generated sentence, we model a global (sentence) level syntactic structure. We couch statistical sentence generation as a spanning tree problem in order to search for the best dependency tree spanning a set of chosen words. We also introduce a new search algorithm for this task that models argument satisfaction to improve the linguistic validity of the generated tree. ...
The task of paraphrase acquisition from related sentences can be tackled by a variety of techniques making use of various types of knowledge. In this work, we make the hypothesis that their performance can be increased if candidate paraphrases can be validated using information that characterizes paraphrases independently of the set of techniques that proposed them. We implement this as a bi-class classiﬁcation problem (i.e. paraphrase vs. not paraphrase), allowing any paraphrase acquisition technique to be easily integrated into the combination system. ...
This lecture will teach you how to fit nonlinear functions by using bases functions and how to control model complexity. The goal is for you to: Learn how to derive ridge regression; understand the trade-off of fitting the data and regularizing it; Learn polynomial regression; understand that, if basis functions are given, the problem of learning the parameters is still linear; learn cross-validation; understand model complexity and generalization.
In recent years, research in natural language processing has increasingly focused on normalizing SMS messages. Different well-deﬁned approaches have been proposed, but the problem remains far from being solved: best systems achieve a 11% Word Error Rate. This paper presents a method that shares similarities with both spell checking and machine translation approaches. The normalization part of the system is entirely based on models trained from a corpus. Evaluated in French by 10-fold-cross validation, the system achieves a 9.3% Word Error Rate and a 0.83 BLEU score. ...
(BQ)In this paper a new contribution to the simulation and modelling of the EDM process is presented. Temperature fields within the workpiece generated by the superposition of multiple discharges, as it happens during an actual EDM operation,
are numerically calculated using a finite difference schema. The characteristics of the discharge for a given operation, namely energy transferred onto the workpiece, diameter of the discharge channel and material removal efficiency can be estimated using inverse identification from the results of the