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This paper explores whether the spread of air conditioning in the United States from 1960 to 1990 affected quality of life in warmer areas enough to influence decisions about where to live, or to change North-South wage and rent differentials. Using measures designed to identify climates in which air conditioning would have made the biggest difference, I found little evidence that the flow of elderly migrants to MSAs with such climates increased over the period. Following Roback (1982), I analyzed data on MSA wages, rents, and climates from 1960 to 1990, and find that the implicit price of these hot summer climates did not change significantly from 1960 to 1980, then became significantly negative in 1990. This contrary to what one would expect if air conditioning made hot summers more bearable. I presented evidence that hot summers are an inferior good, which would explain part of the negative movement in the implicit price of a hot summer, and evidence consistent with the hypothesis that the marginal person migrating from colder to hotter MSAs dislikes summer heat more than does the average resident of a hot MSA, which would also exert downward pressure on the implicit price of a hot summer.

The recession in the late 1990s in Hong Kong has triggered many commercial building owners to cut operation and maintenance (O&M) cost via outsourcing. The purpose of this paper is to investigate the dominant expenditure on O&M service and examine the relation between extent of outsourcing and rental income of the buildings.

Experienced O&M practitioners were interviewed to collect both quantitative and qualitative data of the commercial buildings they looked after. The in‐house and outsourced O&M costs, air‐conditioning energy costs, rental incomes, and management and air‐conditioning fees for the buildings were analysed.

The total air‐conditioning O&M cost is the principal cost item, with the energy cost being the dominant element. The analysis reveals that the extent of outsourcing bore little correlation with the air‐conditioning O&M cost and the rental income.

Further work may take a similar approach to identify the extent and effect of outsourcing other kinds of services that underpin the core business of an organisation.

Varying the extent of outsourcing O&M service was found to be unpromising for enhancing rental performance or cutting O&M expenditure. This is an important point that the building managers should address when considering whether to go for outsourcing.

The findings imply that in the building O&M service industry, it would be more economical to outsource or undertake in‐house the vast majority of O&M work. The focus for cost minimization should be to improve building energy performance rather than reducing labour resources through outsourcing.

To evaluate the oxide formation characteristics of tin (Sn) as a function of conditioning treatment and define a conditioning methodology that rapidly produces a tin oxide thickness and oxide species morphology similar to those formed in ambient oxidation.

Electrochemical reduction analysis and scanning electron microscopy techniques were utilized to identify tin oxide species and oxide quantities on tin samples which were subjected to a variety of conditioning methodologies.

Tin oxide species were identified and oxide quantities measured. Comparisons of tin oxide species/quantities were completed for the different conditioning methodologies used and for other industry oxide investigations. The following conclusions were reached: all conditioning methodologies produced both SnO and SnO₂ tin oxide species; steam conditioning produced the thickest oxides; the conditioning methodologies investigated were found to produce oxide thicknesses similar to those formed under ambient conditions.

Further investigation would be beneficial using this study as a foundation. Additional conditioning methodologies and a larger selection of various tin surfaces would provide a future understanding of the impact of oxide species and thickness on solderability.

The electronics industry has attempted to “predict” a surface's susceptibility to oxidation by using accelerated conditioning techniques. An understanding of the formation of tin oxidation products created by accelerated conditioning techniques could be highly beneficial to the electronics industry. The standardization and use of a realistic accelerated conditioning technique would reduce testing cycle time, increase the predictability and consistency of test results, and lower testing costs.

This paper was incorporated into an original electronics manufacturer's solderability testing/analysis procedures, and the results are being utilized by the electronics industry solderability specification task groups/committees.

This paper aims to illuminate mechanisms through which memorable experiences with brands create lasting preferences. It is based on the proposition that intense positive (negative) affective consumption in the consumer’s youth creates powerful imprints, which influence brand preference (distaste) throughout life.

Autobiographical memories with Nutella are retrieved from three different user groups, i.e. heavy-, light- and non-users. The retrieved memory narratives are analysed using conditioning theory, i.e. operant, classical or no conditioning are identified and compared across groups.

The research’s central proposition is affirmed, yet the dominant form of conditioning mechanism differs per group. Operant conditioning outperforms classical conditioning in creating strong and lasting preferences. Heavy- and non-users predominantly exhibit in-tensely positive and negative operant conditioning, respectively. Light-users on the other hand recall less affectively intense consumption experiences, mainly featuring classical conditioning. The light-users’ recollections suggest a mere exposure effect to be more appropriate in describing the preference formation in this user group.

Users not having experienced affectively intense consumption, i.e. light-users, are likely to be influenced in their preference over time through other factors, which this paper does not focus on.

Memory elicitation and exploration provides valuable insights to shape both promotional as well as advertising strategies.

The study extends existing theory on conditioning in marketing by first using a novel qualitative approach to analyse conditioning procedures in real-life settings, and second, it highlights operant conditioning’s superior ability in creating lasting preferences.

This study aims to examine the impact of local air pollution on the presence of central air conditioners in apartments in Lebanon.

This study applies a Probit model in a unique data set on apartments’ listings for sale in Lebanon collected by Marrouch and Sayour (2021). The data set includes information about air pollution concentrations, dwellings’ characteristics, geographic features and location characteristics.

This study finds that local air pollution positively and significantly affects the presence of central air conditioning in dwellings. The estimated increase in the probability of having central air conditioning for a one microgram per cubic meter increase in Particulate Matter 2.5 concentration is 6.4%.

The data set in this study is cross-sectional and thus does not capture variations over time for the examined variables.

The Probit regression approximates an equation that can predict the presence of central air conditioners in dwellings, which might be useful to policymakers.

The findings suggest that local pollution is a significant factor in household behavior in Lebanon.

This paper adds to the scant literature studying the effects of air pollution on the presence of central air conditioning in developing countries. To the best of the authors’ knowledge, this is the first paper to study the impact of air pollution on the presence of central air conditioning in the Middle East and North Africa Region.

The purpose of this paper is to describe and categorize calculation methods for conducting a complete air conditioning study. More specifically, this paper is a general review of cooling loads calculation methods, psychrometric calculations for installing a central air conditioning unit, ways of fan coil units connection and air duct calculation methods.

This paper was based on two pillars: a dissertation for an industrial facility and technical information found after methodical research.

After a brief reference of the calculation methods and the air conditioning systems installed in this industrial facility, this paper concludes with the most appropriate calculation methods for this industrial facility.

This study describes some calculation methods. Thus, future research could be addressed toward the analysis of more methods.

This paper includes implications for choosing the most appropriate calculation method according to the air conditioning system installed.

The originality of this paper lies in the fact that, except for the theoretical part, there are some examples taken from a case study, thus it can be used as a future guide for selecting methods and systems of industrial air conditioning.

The purpose of this paper is to investigate the effects of aging, pre‐conditioning, and build orientation on the mechanical properties of test samples fabricated using stereolithography (SL) and a commercially available resin.

American Society for Testing and Materials (ASTM) Standard D638 Type I specimens were manufactured in a Viper si2 SL system using WaterShed™ 11120 resin. The specimens were manufactured in two different build setups, designed to fit batches of 18 or 24 specimens with different build orientations. The specimens were randomly tested in tension, and a design of experiments (DOE) was used to determine the effect of aging (4, 30 or 120 days), pre‐conditioning (ambient, desiccant, or ASTM recommended conditioning), and build orientation (flat, on an edge, or vertical) on the ultimate tensile stress (UTS) and elastic modulus (E) of SL fabricated samples. Additionally, the fractured samples were imaged using scanning electron microscopy (SEM) to characterize the fractured surfaces.

Results showed that aging, pre‐conditioning, and build orientation each had an effect on the mechanical properties of the SL samples. In general, the samples aged at the shortest time frame (4 days) and the samples preconditioned according to ASTM recommendations had the lowest values of UTS. Regarding the effect of build orientation, the specimens built flat (with layers oriented along the thickness of the sample) had the lowest UTS and E values and the mechanical properties were statistically different from those built vertically or on an edge. The specimens built in the vertical orientation (with layers oriented along the length of the sample) had the highest values of UTS and E, yet the mechanical properties of the samples built on an edge (with layers oriented along the width of the sample) were not statistically different from the samples built vertically. SEM images of the fractured specimens showed fracture surfaces typical of polymers with a mirror zone and changes in surface texture from smooth to coarse.

The research was limited to a single commercially available resin. Through a statistical DOE approach, statistically significant differences in mechanical properties of SL fabricated samples were found as functions of aging, pre‐conditioning, and build orientation. These results can assist the ASTM F42 Committee with developing test standards specific to SL and the additive manufacturing community.

The statistical analyses presented here can help identify and classify the effects of fabrication, storage, and conditioning parameters on mechanical properties for SL fabricated parts. Understanding how the mechanical properties of SL resins are affected by different parameters can help improve the use of SL for a variety of applications including direct manufacturing of end‐use products.

The conditioning of the redundancy equations is discussed and a method is given for drastically reducing any serious coupling between primary redundancies originating at the same ring station. Making use of the latent root programme of the computer, a revised transformation matrix, for the definition of the primary redundancies, is developed for the specific cross‐sectional shape and geometry when this is markedly non‐circular. The method is illustrated by application to a number of sample cases. Coupling between redundancies at different ring stations is also discussed, but is not considered to be serious except with unusual patterns of frame flexibility.

The purpose of this paper is to use investor sentiment (IS) as a conditioning information variable for the cross-sectional return predictability tests of alternative asset pricing models (APMs).

Cross-sectional tests of alternative APMs in the linear beta representation and stochastic discount factor specifications, Fama and Macbeth and generalized method of moments techniques have been used.

Results reveal that IS as a conditioning information variable contains significant information for making the discount factors time varying. Model comparison test statistics suggests that among the alternative APMs, the conditional five-factor model (FFM) performs better.

Empirical analysis does not extend to the inclusion of the business-cycle conditioning information variables for the test of APMs.

The potential benefit of the conditional FFM can be leveraged upon for cost of capital determination, and mutual fund manager’s portfolio performance evaluation when the portfolio is heavily weighted with sentiment-sensitive hard to value and difficult to arbitrage stocks. During volatile and boom periods in stock markets the IS scaled conditional APMs may be useful for the fundamental value determination of sentiment-sensitive stocks.

This study extends available literature in the context of both developed and emerging equity markets by exploring the cross-sectional tests of conditional APMs using IS as the conditioning information variable. To the author’s knowledge, this is perhaps the first study that examines IS as conditioning information for the cross-sectional tests of alternative APMs.

The purpose is to reduce round-off errors in numerical simulations. In the numerical simulation, different kinds of errors may be created during analysis. Round-off error is one of the sources of errors. In numerical analysis, sometimes handling numerical errors is challenging. However, by applying appropriate algorithms, these errors are manageable and can be reduced. In this study, five novel topological algorithms were proposed in setting up a structural flexibility matrix, and five different examples were used in applying the proposed algorithms. In doing so round-off errors were reduced remarkably.

Five new algorithms were proposed in order to optimize the conditioning of structural matrices. Along with decreasing the size and duration of analyses, minimizing analytical errors is a critical factor in the optimal computer analysis of skeletal structures. Appropriate matrices with a greater number of zeros (sparse), a well structure and a well condition are advantageous for this objective. As a result, a problem of optimization with various goals will be addressed. This study seeks to minimize analytical errors such as rounding errors in skeletal structural flexibility matrixes via the use of more consistent and appropriate mathematical methods. These errors become more pronounced in particular designs with ill-suited flexibility matrixes; structures with varying stiffness are a frequent example of this. Due to the usage of weak elements, the flexibility matrix has a large number of non-diagonal terms, resulting in analytical errors. In numerical analysis, the ill-condition of a matrix may be resolved by moving or substituting rows; this study examined the definition and execution of these modifications prior to creating the flexibility matrix. Simple topological and algebraic features have been mostly utilized in this study to find fundamental cycle bases with particular characteristics. In conclusion, appropriately conditioned flexibility matrices are obtained, and analytical errors are reduced accordingly.

(1) Five new algorithms were proposed in order to optimize the conditioning of structural flexibility matrices. (2) A JAVA programming language was written for all five algorithms and a friendly GUI software tool is developed to visualize sub-optimal cycle bases. (3) Topological and algebraic features of the structures were utilized in this study.

This is a multi-objective optimization problem which means that sparsity and well conditioning of a matrix cannot be optimized simultaneously. In conclusion, well-conditioned flexibility matrices are obtained, and analytical errors are reduced accordingly.

Engineers always finding mathematical modeling of real-world problems and make them as simple as possible. In doing so, lots of errors will be created and these errors could cause the mathematical models useless. Applying decent algorithms could make the mathematical model as precise as possible.

Errors in numerical simulations should reduce due to the fact that they are toxic for real-world applications and problems.

This is an original research. This paper proposes five novel topological mathematical algorithms in order to optimize the structural flexibility matrix.