Improvement of olfactometric measurement accuracy and repeatability by optimization of panel selection procedures

2010 ◽  
Vol 61 (5) ◽  
pp. 1267-1278 ◽  
Author(s):  
L. Capelli ◽  
S. Sironi ◽  
R. Del Rosso ◽  
P. Céntola ◽  
S. Bonati
Keyword(s):  
Degrees Of Freedom ◽  
Selection Procedure ◽  
Selection Procedures ◽  
Accuracy And Precision ◽  
Repeated Analysis ◽  
The Right ◽  
Accuracy And Repeatability ◽  
Selection Of ◽  
Dynamic Olfactometry

The EN 13725:2003, which standardizes the determination of odour concentration by dynamic olfactometry, fixes the limits for panel selection in terms of individual threshold towards a reference gas (n-butanol in nitrogen) and of standard deviation of the responses. Nonetheless, laboratories have some degrees of freedom in developing their own procedures for panel selection and evaluation. Most Italian olfactometric laboratories use a similar procedure for panel selection, based on the repeated analysis of samples of n-butanol at a concentration of 60 ppm. The first part of this study demonstrates that this procedure may originate a sort of “smartening” of the assessors, which means that they become able to guess the right answers in order to maintain their qualification as panel members, independently from their real olfactory perception. For this reason, the panel selection procedure has been revised with the aim of making it less repetitive, therefore preventing the possibility for panel members to be able to guess the best answers in order to comply with the selection criteria. The selection of new panel members and the screening of the active ones according to this revised procedure proved this new procedure to be more selective than the “standard” one. Finally, the results of the tests with n-butanol conducted after the introduction of the revised procedure for panel selection and regular verification showed an effective improvement of the laboratory measurement performances in terms of accuracy and precision.

scholarly journals 'n psigometriese oudit op ‘n bestaande keuringsprosedure

2002 ◽  
Vol 28 (3) ◽  
Author(s):  
E. Cross ◽  
W. Marais ◽  
H. Steel ◽  
C. C. Theron
Keyword(s):  
Selection Procedure ◽  
Developmental History ◽  
Selection Procedures ◽  
Ideal Approach ◽  
History Of ◽  
Selection Of

The validity and credibility of assertions on the efficiency and equity of selection procedures is dependent on the methodology with which the procedure was developed and justified. An ideal approach to the development and justification of a selection procedure was derived from standard guidelines and operationalized in the form of a comprehensive checklist. A psychometric audit on the developmental history of the selection procedure for the selection of commission advisors was undertaken. Various shortcomings were identified and rectified or recommendations were made on rectifying them. The audit found that the selection procedure had zero validity, negative utility and discriminated unfairly. Opsomming Die geldigheid en geloofwaardigheid van uitsprake oor die effektiwiteit en billikheid van ‘n keuringsprosedure is ‘n funksie van die metodologie waarmee die prosedure ontwikkel en regverdig is. ‘n Ideale benadering tot die ontwikkeling en regverdiging van ‘n keuringsprosedure is uit standaard riglyne afgelei en geoperasionaliseer in die vorm van ‘n omvattende kontrolelys. ‘n Psigometriese oudit is onderneem op die ontwikkelingsgeskiedenis van ‘n keuringsprosedure vir die keuring van kommissie-adviseurs. Verskeie tekortkominge is geïdentifiseer en reggestel of aanbevelings ten opsigte van regstelling is gemaak. Die oudit het bevind dat die keuringsprosedure oor zero geldigheid beskik, negatiewe nutwaarde toon en onbillik diskrimineer.

Parametric Optimization of Structures Under Combined Base Motion Direct Forces and Static Loading

1998 ◽  
Vol 124 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Izhak Bucher
Keyword(s):  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Operating Conditions ◽  
Design Parameters ◽  
Power Spectral ◽  
Loading Patterns ◽  
The Cost ◽  
Selection Of ◽  
Eigenvectors And Eigenvalues

This paper deals with the optimization of vibrating structures as a mean for minimizing unwanted vibration. Presented in this work is a method for automatic determination of a set of preselected design parameters affecting the geometrical layout or shape of the structure. The parameters are selected to minimize the dynamic response to external forcing or base motion. The presented method adjusts the structural parameters by solving an optimization problem in which the constraints are dictated by engineering considerations. Several constraints are defined so that the static deflection, the stress levels and the total weight of the structure are kept within bounds. The dynamic loading acting upon the structure is described in this work by its power spectral density, with this representation the structure can be tailored to specific operating conditions. The uncertain nature of the excitation is overcome by combining all possible spectra into one PSD encompassing all possible loading patterns. An important feature of the presented method is its numerical efficiency. This feature is essential for any reasonably sized problem as such problems are usually described by thousands of degrees of freedom arising from a finite-element idealization of the structure. In this paper, efficient, closed form expressions, for the cost function and its gradients are derived. Those are computed with a partial set of eigenvectors and eigenvalues thus increasing the efficiency further. Several numerical examples are presented where both shape optimization and the selection of discrete components are illustrated.

scholarly journals The effect of continued selection of phenotypic intermediates on gene frequency

1964 ◽  
Vol 5 (3) ◽  
pp. 341-353 ◽  
Author(s):  
R. N. Curnow
Keyword(s):  
Gene Frequency ◽  
Selection Procedure ◽  
High Variability ◽  
Considerable Importance ◽  
Selection Procedures ◽  
Population Mean ◽  
Section 8 ◽  
Selection Of

The selection of animals or plants for high values of a certain character may favour not only genotypes associated with these high values but also genotypes associated with high variability. Any differences between genotypes in variability may therefore be of considerable importance in plant and livestock improvement programmes as well as in evolution. The effects of various selection procedures on variability have been studied in three recent experiments [Falconer & Robertson (1956) Falconer (1957) and Prout (1962)]. In these experiments one line was continued by selecting, in each generation, parents with values of a particular character near the population mean. Manning (1955, 1956) has described the effects of this kind of selection applied to cotton. Robertson (1956) derived and discussed the theory of such selection procedures when certain simplifying approximations can be made We shall obtain some more general results and show that Robertson was incorrect in saying that the selection procedure would lead to gene fixation even if the heterozygotes are less variable than the homozygotes. The importance of the results is discussed in section 8.

Comparison of Model Selection Method Using Data from Classical Designed Experiment

2013 ◽  
Vol 677 ◽  
pp. 357-362
Author(s):  
Natthasurang Yasungnoen ◽  
Patchanok Srisuradetchai
Keyword(s):  
Model Selection ◽  
Quantitative Research ◽  
Selection Procedure ◽  
Information Criterion ◽  
P Value ◽  
Selection Procedures ◽  
Final Model ◽  
Designed Experiment ◽  
Using Data ◽  
Selection Of

Model selection procedures play important role in many researches especially quantitative research. . In several area of sciences, the analysis and model selection of experiments are often used and often contains two fundamental goals associated with the experimental response of interest which are to determine the best model. The way to address these goals is to implement a model selection procedure. Then, the objectives of this research are to determine whether or not the final models selected are in agreement or differ substantially across the three approaches to model selection: using Akaike’s Information Criterion, using a p-value criterion, and using a stepwise procedure.. Generally, results from these three models are usually compare to each other. All selected models are based on the heredity principle to design the possible model for each design. The actual data from literature, consisting of the 2x3 and 32 and 3x4 factorial designs are used to determine the final model. The results show that the P-Value WH and Stepwise methods give the highest percentage of matched model.

scholarly journals Determination of the dependence of competitive results on the procedure of sports selection among Greco-Roman wrestlers

2019 ◽  
Vol 23 (4) ◽  
pp. 182-188 ◽  
Author(s):  
R.S. Nagovitsyn ◽  
A.Yu. Osipov ◽  
A.G. Kapustin ◽  
O.V. Anfilatova ◽  
S.Yu. Senator
Keyword(s):  
Martial Arts ◽  
Objective Assessment ◽  
Selection Procedure ◽  
Test Results ◽  
Greco Roman ◽  
Motor Tests ◽  
Student’S T ◽  
Selection Of ◽  
Sports Selection

Introduction : the problems of sports selection and selection of prospective children in martial arts schools are quite relevant in the sports practice. It was revealed the use of various selection techniques in the practice of martial arts. There is no unified methodological system for selection in martial arts schools. The purpose of the study : to determine the dependence of the dynamics of sports results of elite athletes on the procedure of sports selection (for example, the Greco-Roman wrestling). Material and methods : elite Greco-Roman wrestlers (n = 114) took part in the research. Age of athletes: 25-45 years. Qualification: International masters of sport (n = 8), masters of sport (n = 49), candidates in masters of sport (n = 57). Athletes filled out a diagnostic card with data on the procedure of sports selection. It was indicated the dynamics of competitive results during the sports career. Indicators of performance and stability of athletes were calculated applying the mathematical statistics methods ( ). The reliability of the results was determined by Student's t-test. Results : Data analysis showed that a significant part of athletes did not pass the selection procedure (n = 23). Many athletes passed only a partial selection procedure (n = 39). Some athletes did not pass the selection procedure. These athletes are not inferior in terms of stability to athletes who passed the selection at the 1st and 2nd levels of competitive results. In subsequent competitions, these athletes demonstrated the reliable (P <0.05) decrease in indicators of stability in comparison with other athletes. It was revealed a significant (P <0.05) advantage in indicators of stability among athletes who passed a partial selection procedure at the 4th level of competitive results. Conclusions : It was found the dependence of stability indicators at high levels of competitive results on the selection procedure of athletes. The athletes who passed the selection procedure demonstrate higher stability at high levels of competitive results. It was revealed a formal attitude to the selection procedure in some coaches and specialists. The trainers do not pay due attention to the indicators of maintaining body balance and coordination abilities during the selection of candidates. It has been revealed that the motor tests applied in the selection procedure do not allow an objective assessment of the potential of athletes' competitive achievements.

scholarly journals PENENTUAN JURUSAN PADA PROSES PENERIMAAN MAHASISWA DENGAN PENDEKATAN LOGIKA FUZZY

2021 ◽  
Vol 8 (1) ◽  
pp. 193-200
Author(s):  
Ari Purno Wahyu ◽  
Umi Hayati
Keyword(s):  
Membership Function ◽  
Fuzzy Inference ◽  
Function Type ◽  
Academic Field ◽  
Computer Knowledge ◽  
Selection Test ◽  
The Right ◽  
High Level ◽  
Selection Of

Choosing a major is not an easy matter. There are many factors that must be taken into account and carefully thought out so that in choosing a major, it will cause big losses. There are many ways to determine the selection of majors, one of which is by using fuzzy logic. Determination of majors is determined from the results of the selection test in the academic field with the subjects of Mathematics, English and Computer Knowledge. With the aim of recommending the selection of the right major according to academic abilities and improving quality. By using the fuzzy inference model Mamdani max-min method. The system simulation was tried using the MATLAB Fuzzy Toolbox software. The system design is carried out in several stages, namely: (1) formation of fuzzy sets, (2) formation of rules, (3) determination of the composition of rules, and (4) confirmation (defuzzification). Defuzzification is carried out using the Composite Moment method, with the types of membership functions used are mf-triangular, mf-trapezoid and mf-gaussian. From the results of the tests carried out, it shows that the mf-triangular and mf-trapezoid membership function types produce almost the same level of accuracy. While the membership function type mf-gaussian produces a high level of accuracy for mathematics by 87.50%, English 100% and computer knowledge 81.58%.  

scholarly journals PROCEDURA KONKURSOWEGO DOBORU KADR KIEROWNICZYCh. PROBLEMATYKA PRAWNA

2016 ◽  
Vol 12 (3) ◽  
pp. 79
Author(s):  
Tomasz Duraj
Keyword(s):  
Significant Influence ◽  
Selection Procedure ◽  
Legal Issues ◽  
Legal Regulations ◽  
Legal Analysis ◽  
Selection Procedures ◽  
Competitive Selection ◽  
The Subject ◽  
Management Staff ◽  
Selection Of

THE COMPETITIVE SELECTION PROCEDURE FOR MANAGEMENT STAFF: LEGAL ISSUES Summary This analysis relates to the legal issues in the competitive selection of management staff. Under the current provisions in Poland many legal acts pertain to this issue, giving an inhomogeneous set of regulations for the principles of conducting such procedures in particular domains of public, social and economic affairs. The subject of this article is a detailed description of the stages of the procedure for the competitive selection of management staff. Good legislation to regulate the selection procedures for competitions for management appointments will have a significant influence on the effectiveness of the adopted method of selection. The author presents the successive stages of the procedures for such competitions and conducts an in-depth legal analysis, paying specific attention to legal doubts arising in connection with the application of the current law. On the basis of his analysis he formulates some proposals de lege ferenda addressed to the legislator on the introduction of requisite amendments and supplements to the legal regulations for the procedure of competitive selection of management staff.

SISTEM PENDUKUNG KEPUTUSAN PENENTUAN MITRA KERJASAMA PADA HOTEL GRAND SIRAO DENGAN MENGGUNAKAN METODE PSI (Preference Selection Index)

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Hendri Cahaya Putra
Keyword(s):  
Decision Making ◽  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Index Selection ◽  
Short Supply ◽  
Cooperation Partners ◽  
The Right ◽  
Selection Of

Grand Sirao Hotel is a hotel that stands in the middle of Medan City, located on Jl. Semarang. Grand Sirao Hotel is an attractive hotel in the sector of cooperation in certain fields, but in this hotel it often happens in cooperation with outside companies. One of the problems that often occurs at the Grand Sirao Hotel is the constrained stock of goods needed for guests staying at the hotel, items that are often constrained which are usually in the form of sandals and toiletries that are in short supply. This problem often arises because of the many other factors between companies related to hotel owners themselves, debates that often arise from hotel owner claims include quality of goods that are sometimes incompatible with reservations and need to be taken into account, inventory can be exhausted, prices always go up because of skyrocketing market prices and other problems. This collaboration problem arises due to lack of success in determining partnerships with related companies that are not appropriate and in company selection is also still manual and there are appropriate systems and criteria. Therefore a decision support system is needed in the selection of partners upon the proposed approval. One solution to this problem that is right is to make a decision system in the decision of the company's business partners so that the determination of cooperation in accordance with the right requirements. By using a Decision Support System (SPK) is expected to help the company in making decisions made by the right company partners in increasing the efficiency of the decision. PSI (Index Selection Preference Method) is a method for solving multi-decision making (MCDM) decisions. In the proposed method it is not necessary to submit among the attributes. There are no attributes required in computing that are involved in decision making. It is hoped that by using the PSI (Index Selection Preference) Method, it is necessary to establish a decision support system which can assist in the selection of corporate cooperation partners at the Grand Sirao Hotel.Keywords: Determination of Cooperation Partners, Decision Support System, PSI (Index Selection Preference)

How to obtain valid tests and confidence intervals after propensity score variable selection?

2019 ◽  
Vol 29 (3) ◽  
pp. 677-694 ◽  
Author(s):  
Oliver Dukes ◽  
Stijn Vansteelandt
Keyword(s):  
Propensity Score ◽  
Variable Selection ◽  
Confidence Intervals ◽  
Selection Procedure ◽  
Routine Practice ◽  
Finite Sample ◽  
Major Drawback ◽  
Sample Distribution ◽  
Selection Procedures ◽  
Selection Of

The problem of how to best select variables for confounding adjustment forms one of the key challenges in the evaluation of exposure or treatment effects in observational studies. Routine practice is often based on stepwise selection procedures that use hypothesis testing, change-in-estimate assessments or the lasso, which have all been criticised for – amongst other things – not giving sufficient priority to the selection of confounders. This has prompted vigorous recent activity in developing procedures that prioritise the selection of confounders, while preventing the selection of so-called instrumental variables that are associated with exposure, but not outcome (after adjustment for the exposure). A major drawback of all these procedures is that there is no finite sample size at which they are guaranteed to deliver treatment effect estimators and associated confidence intervals with adequate performance. This is the result of the estimator jumping back and forth between different selected models, and standard confidence intervals ignoring the resulting model selection uncertainty. In this paper, we will develop insight into this by evaluating the finite-sample distribution of the exposure effect estimator in linear regression, under a number of the aforementioned confounder selection procedures. We will show that by making clever use of propensity scores, a simple and generic solution is obtained in the context of generalized linear models, which overcomes this concern (under weaker conditions than competing proposals). Specifically, we propose to use separate regularized regressions for the outcome and propensity score models in order to construct a doubly robust ‘g-estimator’; when these models are sufficiently sparse and correctly specified, standard confidence intervals for the g-estimator implicitly incorporate the uncertainty induced by the variable selection procedure.

Modified joint connectivity approach for identification of topological characteristics of planar kinematic chains

2011 ◽  
Vol 225 (11) ◽  
pp. 2700-2717 ◽  
Author(s):  
G S Bedi ◽  
S Sanyal
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Kinematic Chains ◽  
Multiple Degrees Of Freedom ◽  
Preferred Frame ◽  
Topological Characteristics ◽  
Synthesis Stage ◽  
Different Levels ◽  
Selection Of

In a kinematic chain, the links are connected to each other through joints. The connectivity of a joint indicates the number of joints to which it is connected. The connectivity level of a joint indicates the distance by which it is separated from the adjacent joints. The concept of joint connectivity and its application to detect isomorphism among kinematic chains and their inversions has been already reported by authors. The method utilizes the connectivity of joints at different levels to detect isomorphism and inversions among planar kinematic chains. The method is applied to eight-, nine-, and ten-link planar kinematic chains. The results so obtained are in agreement with those available in the literature. In this study, the method is further improved by incorporating the type of joint to make it more effective for the detection of isomorphism and distinct inversions. A joint connectivity table completely representing the kinematic chain is proposed. The application of the method is extended for the determination of additional topological characteristics of chains such as categorization of kinematic chains and selection of preferred frame, input and output links for function and path generation. The concept of ‘Motion Transfer Ability’ is introduced and utilized to develop numerical measures for comparing and categorizing the chains at the synthesis stage of mechanism design for a specific application. The method was successfully tested on planar kinematic chains with single and multiple degrees of freedom and the results for eight- and nine-link kinematic chains are appended.

Sign in / Sign up

Export Citation Format

Share Document