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About 10,000 papers for “variable combinations”

PRACTICAL INSIGHTS FROM OCA VARIABLE COMBINATIONS

Itir Ozer, Ibrahim Ozkan · RePEc: Research Papers in Economics

This study aims to identify optimum currency areas (OCA) variables that distinguish certain Economic and Monetary Union (EMU) member countries from the other EMU members. In the previous studies, EMU members were identified in the light of criteria suggested by the OCA theory. In this study, in order to obtain additional insights, we analysed OCA variables and the performance of European countries with respect to these variables. Our analysis shows that some of the EMU member countries are dissimilar to the rest of the EMU members with respect to certain OCA criteria.

Cited by 0

Practical insights from OCA variable combinations

Itır Özer, İbrahim Özkan · Economic Annals · 2008

This study aims to identify optimum currency areas (OCA) variables that distinguish certain Economic and Monetary Union (EMU) member countries from the other EMU members. In the previous studies, EMU members were identified in the light of criteria suggested by the OCA theory. In this study, in order to obtain additional insights, we analyzed OCA variables and the performance of European countries with respect to these variables. Our analysis shows that some of the EMU member countries are dissimilar to the rest of the EMU members with respect to certain OCA criteria.

Cited by 2Open access

Missing-Data Matrix by Variable Combinations.

Chun-Fang Ma (20074122), Xiang-Xiang Li (11449665), Shan Liu (193759) et al. · Figshare · 2025

<div> Background Hypertension (HTN) progression is linked to insulin resistance (IR), yet the association between Metabolic Score for Insulin Resistance (METS-IR) and HTN remains underexplored. Methods This study included 4,051 individuals without a history of HTN from the China Health and Retirement Longitudinal Study (CHARLS). Participants were stratified into four groups according to their baseline METS-IR values. It was the development of incident HTN that was the primary outcome. We used Cox regression to assess this association, conducted subgroup and sensitivity analyses, and evaluated METS-IR’s incremental predictive value over conventional risk factors (age, sex, systolic blood pressure) using C-statistic, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA). Results Over the 9-year follow-up, 1,572 participants (38.81%) experienced their first incident of HTN. Participants were categorized into quartiles (Q1-Q4) based on their METS-IR levels. After full adjustment for confounders, the hazard ratio (HR) with a 95% confidence interval (CI) for incident HTN demonstrated a progressive increase across ascending METS-IR quartiles, with Q1 as reference: Q2, 0.99 (0.85–1.15); Q3, 1.17 (1.01–1.36); Q4, 1.31 (1.13–1.52). The restricted cubic spline (RCS) model revealed a linear dose-response relationship between METS-IR and the incidence of HTN (<i>P</i> for overall trend < 0.001; <i>P</i> for nonlinear = 0.310). Adding METS-IR to a base model (age/sex/systolic blood pressure) improved HTN prediction (C-statistic Δ= + 0.004; NRI = 16.58%, IDI = 0.75%; all <i>P</i> < 0.001). DCA confirmed greater net benefit across risk thresholds. Subgroup and sensitivity analyses consistently supported the primary findings. Conclusion Elevated METS-IR independently predicts HTN risk in Chinese adults, suggesting METS-IR as a potential indicator. </div>

Cited by 0Open access

Rotifer communities under variable predation-turbulence combinations

Jukka Horppila, Laura H. Härkönen, Noora Hellén et al. · Hydrobiologia · 2018

The effects of water turbulence on rotifer communities were experimentally studied under different predation pressures. When the larvae of the phantom midge (Chaoborus flavicans) were present in turbulent water, the abundance of most rotifer taxa was enhanced. Especially the genera Chromogaster, Keratella, Polyarthra, and Trichocerca, increased in abundance. In calm water, chaoborids did not affect the rotifer community. In turbulent water predation by chaoborids was targeted more towards cladocerans (Bosmina sp.) and predation pressure on rotifers was relaxed. Additionally, reduced competition with cladocerans probably contributed to the increase of rotifer abundance. Turbulence alone had no significant effect on rotifer abundance because their individual size was small compared with the diameter of the turbulent eddies. The study suggested that the effects of turbulence on rotifers is not direct but takes place through changed predator–prey relations, i.e., the effect depends on the abundance of invertebrate predators. In aquatic ecosystems with a high density of chaoborids, increasing turbulence can considerably increase the abundance of rotifers.

Cited by 12Open access

The Selection of Variable Combinations for Predicting House Characteristics

William M. Shenkel, Cathie Bennett · Review of Regional Studies · 1973

Housing characteristics and their prediction have assumed increased importance among urban economists. Of major importance are special purpose models that treat housing values as the dependent variable relative to a series of housing characteristics. The general objective of these studies is to formulate an equation to predict housing values from a set of independent varaibles. This paper discusses and examines these predictive models applied to the housing market.

Cited by 0Open access

On Locality of One-Variable Axioms and Piecewise Combinations

Swen Jacobs, Viktor Kunčak · Infoscience (Ecole Polytechnique Fédérale de Lausanne) · 2010

Local theory extensions provide a complete and efficient way for reasoning about satisfiability of certain kinds of universally quantified formulas modulo a background theory. They are therefore useful in automated reasoning, software verification, and synthesis. In this paper, we 1) provide a sufficient condition for locality of axioms with one variable specifying functions and relations, 2) show how to obtain local axiomatizations from non-local ones in some cases, 3) show how to obtain piecewise combination of different local theory extensions.

Cited by 0Open access

Recognition of Word Combinations Recognition of Common Word Combinations: Towards a Lexicon of Variable-Sized Units

Catherine L. Harris · 2007

Connectionist approaches to word learning and word recognition imply that the units of lexical representation are not part of a fixed architecture. If the size of stored units is determined by extracting co-occurrence regularities, then we expect the lexicon to include multi-word units which have become entrenched due to repeated use. Experiments using Reicher&amp;apos;s two-alternative forced-choice procedure revealed that letterdetection was superior in high-frequency word combinations compared to the same word presented as part of a random combination or syntactically legal combination. This &amp;quot;collocation effect&amp;quot; held even when both letter choices made a collocation (prop/ crop up, faced/laced with, next step/stop). A second type of evidence came from drastically impaired letter detection on `trick&amp;apos; items -- word pairs in which the incorrect letter choice creates a collocation (first kid, odd man). It was also found that accuracy was better in semantically coherent `trick&amp;apos; items (first kid, ...

Cited by 0

Optimal combinations and variable departure intervals for micro bus system

Jiaoyang Li, Jianming Hu, Yi Zhang · Tsinghua Science & Technology · 2017

It is becoming increasingly difficult for Chinese citizens to access traditional public transport because of overcrowded community structures. Therefore, novel ideas are required to improve the transport system. In this respect, this study considers the design of a public transport scheduling model for a micro system. The model aims to minimize passenger waiting time and maximize number of passengers one bus carries, by simultaneously optimizing departure intervals and use of traditional and rapid buses. The model is superior to traditional models, as it analyzes the phenomena of vehicle overtaking, vehicle capacity limit, and passenger determination uncertainty. In addition, the model is a sophisticated nonlinear multi-objective optimization problem and contains more than one type of decision variable, therefore two composite algorithms, HPSO and GAPSO, are proposed, which are improvements of the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). These two algorithms are compared to the classical GA with respect to stability and effect, and the results show them to be strong in both respects. In addition, the simultaneous optimization method has evident advantages compared to single-method optimizations.

Cited by 12Open access

Efficiency Evaluation in Indonesia's Quarrying Industry Using Variable Combinations DEA

Erni Puspanantasari, Ivan A. Parinov, Chuleeporn Wongloucha · SPEKTRUM INDUSTRI · 2024

Data Envelopment Analysis (DEA) is a method considered to evaluate a company's performance. DEA applies multiplies the input and output variables for analyzing the efficiency but does not provide guidance in selecting those variables. As a rule, researchers use several methods. If the number of variables used is too many, it will affect the efficiency value. This will reduce the strength of the efficiency value, which can cause all DMU values to be efficient. DEA and variable selection are important in performance evaluation because DEA aids in determining relative efficiency, whereas variable selection guarantees that the evaluation is based on the most relevant and significant aspects. The purpose of this study is to suggest the variable combination method for subtracting the number of variables that will be utilized in implementing the DEA. The method used in this study is the Average Input Variable Combinations (VCs)-Variable Returns-to-Scale (VRS) DEA. The data were classified, defined, and processed with a view to computing efficiency scores and DMU classifications. The research result indicated that the proposed method (VCs-DEA) treats the variable reduction factor and the average calculation factor to obtain the final result of the efficiency score. These two factors contribute to the accuracy of the efficiency value. Some real-world implications of these findings, such as making better use of resources, streamlining operations, and coming up with new plans, Furthermore, the evidence may be used to benchmark performance as well as help decision-makers in creating more effective policy. This study finds that only 1 out of 12 DMUs is efficient (8%), while the remaining 11 are inefficient (92%). Indonesia quarrying establishment can be classified into 3 categories such as Optimal Category (S-Sand); Middle Category (LS-Lime-Stone; F-Feldspars; Gr-Granite; SA-Stone and Andesite; K-Kaolin; Q-Quartz; and G-Gravel); and Less Category (So-Soil; C-Clay; M-Marble; and O-Others).

Cited by 0Open access

Steady-State Traffic Signal Control With Variable Phase Combinations and Sequences

Zhonghe He, Yafei Hua, Li Wang · IFAC-PapersOnLine · 2016

The space distribution of traffic flows is often unbalanced, resulting in regional congestion, and even oversaturation of the network. In this paper, the steady-state traffic signal control design approach, with consensus-based control objective of network states, is proposed. A traffic flow model is first introduced based on store-and-forward modeling procedures. Furthermore, a link-based distributed signal control law is proposed with the consensus of link occupancies as control objective, and moreover control approach for phase combinations and sequences is introduced, especially in case of higher network demands. At last, simulation investigations for a topological network in Beijing are conducted in VISSIM software, which shows that the proposed approaches can improve performance indices of the network and then reduce local traffic congestion.

Cited by 1Open access