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The creation of a forest bioeconomy based on the extraction of non-timber forest products (NTFP) is being recommended to create wealth from standing forests and halt deforestation in Amazonia. Current proposals do not recognize the limits of this system, nor the impacts of capitalism that drive NTFPs with elastic demand into monoculture plantations. We use a narrative review to revisit the history of these ideas and examine public policies. Among 2,253 Amazonian NTFPs, 1,037 produce edible fruits and 131 of these are extremely abundant (hyperdominant) across the biome and common in the extractive economy. Low productivity per hectare in the forest, low return on labor to harvest the production, and scarcity of labor are three critical limits to expanding supply, with the last being the most critical in forest areas. Overcoming these limitations requires changes in public policies and public investment for health care, communication, logistics, and especially for quality education designed for rural areas and a forest bioeconomy. A mix of public policies to alleviate market failures and increase supply, efficiency, and demand via R&D, minimum prices, payment for environmental services, distinct types of certifications may be able to make food NTFP harvesting, processing, and commercialization lucrative enough to halt rural exodus and keep forest specialists in standing forests. An Amazonian forest bioeconomy depends upon both social and biodiversity, and the full participation and collaboration of Indigenous People and local communities in developing these value chains that can contribute to food security.

The placement of bracing can affect the seismic response and energy balance in the outrigger braced systems. In this study, it is attempted to investigate the effect of placement optimization of outrigger braced system on the seismic response of a 50-story structure. IDA curves are used to investigate the seismic responses. Sa and Sd are considered as intensity measure (IM) Parameters. Maximum story drift and inelastic strain energy considered as Engineering Demand Parameters (EDP). At first, IDA curves are derived based on maximum story drift in the structures. When the performance level is determined, their fragility curves are derived and compared. In the next step, the energy balance is investigated in the structures and the strain energy parameter is selected as EDP, which the damage level is determined in accordance with. Fragility curves are plotted and the results are assessed using the plastic strain energy. The results show that the placement optimization of outrigger braced system improves all structural parameters and reduces the collapse probability. Moreover, the fragility curves obtained from plastic strain energy as EDP are quite similar to the fragility curve derived from the selection of story drift as EDB. [ABSTRACT FROM AUTHOR]

Like all economic agents government must actively manage its cash position in order to meet obligations. In the U.S., when the short-term cash position is not adequate, Treasury offers bills that are not previously scheduled—Cash Management Bills. Using data from Treasury's proprietary Domestic Finance Database, this paper finds unscheduled bills have consistently higher yields than normally scheduled bills, suggesting the more inelastic demand represented by this type of finance has an impact on costs. Several factors are identified which contribute to the costs of Cash Management for Treasury. [ABSTRACT FROM AUTHOR]

Seasoned offers were underpriced by an average of 2.2 percent during the 1980s and 1990s, with the discount increasing substantially over time. The increase appears to be related to Rule 10b-21 and to economic changes affecting both IPOs and SEOs. Consistent with temporary price pressure, underpricing is positively related to offer size especially for securities with relatively inelastic demand. Underpricing is also positively related to price uncertainty and, after Rule 10b-21, to the magnitude of preoffer returns. Additionally, I find that underpricing is significantly related to underwriter pricing conventions such as price rounding and pricing relative to the bid quote. [ABSTRACT FROM AUTHOR]

In seismic codes, the force strength reduction factor is proposed to transform elastic to inelastic strength. The ductility reduction factor, Rμ, plays a key role on R factor if no overstrength is present. The Rμ is determined by SDOF systems. But the higher mode (HM) and Multi-Degree-of-Freedom (MDOF) effects need to be considered to extract the R factor. These effects are studied by proposing αv-MDOF via at least 1764 Nonlinear dynamic Analysis of 2D-frames. Also a sensitivity study has been performed on Rμ and αv-MDOF. Results obtained from studies conducted on the frames, indicate that HM and MDOF effects have a considerable influence on the base shear. Also the αv-MDOF is typically higher than unity both for ordinary and for near-field earthquakes and it is affected by period, span number and ductility level. These effects are remarkable for near-field motions. Finally, a simplified practical expression is proposed to estimate the αv-MDOF.

Understanding the onset and nature of inelastic deformation in porous rock is important for a range of geological and geotechnical problems. In particular for sandstones and siliciclastic sediments, which often act as hydrocarbon reservoirs, inelastic strain can significantly alter the permeability affecting productivity or storativity. The onset of inelastic strain is defined by a yield curve plotted in effective mean stress (P) versus differential stress (Q) space. Yield curves for porous sandstone typically have a broadly elliptical shape, with the low‐pressure side associated with localized brittle faulting (dilation) and the high‐pressure side with distributed ductile deformation (compaction). However, recent works have shown that, for different porous rocks, the curve shape can evolve significantly with the accumulation of inelastic strain. Here yield curve shape and evolution of two high‐porosity sandstones (36–38%) is mapped along different loading paths using a high‐resolution technique on single samples. The data reveal yield curves with a relatively shallow geometry and with a compactive side that is partly comprised of a near‐vertical limb. Yield curve evolution is found to be strongly dependent on the nature of inelastic strain with samples compacted under a deviatoric load (i.e., with a component of shear strain) having peak stress values that are approximately 3 times greater than similar porosity samples compacted under a hydrostatic load (i.e., purely volumetric strain). These results have important implications for predicting how the strength of porous rock evolves along different stress paths, which differ in reservoirs during burial, fluid extraction, or injection. Plain Language Summary: Porous rocks are the geological sponge of the Earth's crust as they store and transmit vast amounts of fluids such as groundwater and hydrocarbons and can also be used for CO2 storage projects. As porous rocks are subject to increased stresses above the rock strength (either tectonic or from pumping fluids in or out), the porosity will change, restricting the amount of storage the rock can provide, as well as the ability for fluid flow through it. As porosity changes, strength also changes. Deformation of porous rock can occur from an increase in pressure, where the stresses are equal in all directions, or from a differential stress where force is applied more strongly in one direction. We show that the change in strength of sandstone as it is deformed depends on the stress path. Sandstones deformed under differential stress become three times stronger than sandstones deformed to the same porosity by increasing only pressure. This is because of differences in microstructural development that significantly affects the rock strength. These results have important implications for predicting the strength, storage capacity, and permeability of sandstone reservoirs during burial or uplift or as fluids are removed or injected during groundwater/hydrocarbon production or CO2 storage. Key Points: Sandstone yield curve evolution, in response to inelastic compaction, is strongly dependent on stress pathYield curves of samples compacted under a deviatoric load are greater than those compacted hydrostatically to the same porosityMicrostructural evolution along different loading paths controls the strength evolution of porous rock [ABSTRACT FROM AUTHOR]

Laminar pipe flow with a controllable wall swirl has been studied both numerically and experimentally to explore the behavior of inelastic shear-dependent fluids. The pipe consists of two smoothly joined sections that can be rotated independently about the same axis. The circumstance of flow entering a stationary pipe from a rotating pipe (decaying swirl) has been investigated. Numerical parametric studies using both a power-law model and a simplified Carreau model are conducted to investigate the effect of shear-thinning and shear-thickening on the flow structure and the critical swirl ratio required to induce the breakdown at a range of Reynolds numbers. A new method of scaling (i.e., a new Reynolds number) is presented that accounts for the shear-dependent viscosity. Using this Reynolds number, the data for all fluids (shear-thickening, Newtonian, and shear-thinning) approximately collapses. Experimental visualisations using an aqueous solution of xantham gum confirm the conclusions drawn from the numerical results. [ABSTRACT FROM AUTHOR]

The article discusses some of the merchandising trends among independent tire dealers. Throughout the 1940s, the author believes tire dealers have started to stock more lines of merchandise in different fields. A questionnaire was developed by the National Association of Independent Tire Dealers Inc. to ask tire dealers about the types of merchandise they stock. The Association received 1,433 completed questionnaires, which show that many dealers are selling a diverse array of products, including new and used tires, vulcanizing and recapping services, batteries, spark plugs, and heaters. The author believes that without a close relationship to their customers, tire dealers should aim to create a relationship by factors other than cost, or branch out and offer more merchandise.

This article asserts the concept that monopolistic or oligopolistic industries provide bigger wage increases than competitive industries in the U.S. The hypothesis that those workers who enjoy the most rapidly rising wages are employed in partially monopolistic or oligopolistic industries, was discussed and tested. A significant association was found on the relationship of annual earnings changes and concentration ratios by industry. It was suggested that such relationship may be false and that oligopoly lag may be a better explanation than the alleged inelasticity of labor demand of monopolists and oligopolists.

This paper attempts to develop evidence on the elasticity of demand for the consumer loans at an individual lender by comparing the actual structure of rates used by the lender with the rates that would be expected under two extreme assumptions: (1) that the demand for the lender's loans is highly inelastic and (2) that the demand is highly elastic. In the first case, if the demand for the loans of an individual lender is highly inelastic, we would expect (1) that the lender would charge the maximum legal rate on all loans and (2) that he would charge the same rate on all types of loans regardless of differences in costs or risk. At the other extreme, if the demand is highly elastic, we would expect (1) a wide variety of preferential rates associated with the desirability of the loan from the lender's point of view and (2) correspondence between known elements of cost and finance charges. [ABSTRACT FROM AUTHOR]

The research aimd to identify changes of food expenditure patterns among Saudis and resident foreigners in the Kingdom of Saudi Arabia, by estimating expenditure functions for both the Saudis and resident foreigners, and estimate expenditure elasticity and marginal propensity to expend for household of major food groups. The study relied on cross-sectional data from the family budget survey conducted in Kingdom. Quantitative analysis and statistical tests were utilized. Means and indexes number, simple regression in linear and double logarithmic form for estimating expenditure food functions, in addition to the test of homogeneity of regression using chow test. The results of the study showed that the average monthly expenditure for Saudi household on miscellaneous goods and personal services as agroup, housing, water, electricity, fuel as asecond groups, food and drinks as athird groups, respectively 21.2 % , 20.7 % , 16.9 % of total expenditure. this classification differed for resident foreigners were the top three ranked expenditure groups were the housing, water, electricity, gas and fuel as one group, food and drinks as asecond groups, the miscellaneous goods and personal services as athird groups, respectively 21.8 %, 20.1% , 14.7% of total expenditure . The results of the study also showed that the Saudis are more flexible than resident foreigners in expenditure on food and drinks in general, where the consumption expenditure elasticity on food and drinks for Saudis was equal to 0.70, which was bigger than that for foreigners 0.61, yet the situation varied between commodities. The first group included the food commodities with consumption expenditure functions that were homogenous for Saudis and foreigners. These commodities were Fish and seafood, milk and milk products, eggs, sugar, jam, honey, food products are not classified, and coffee, tea and cocoa. Expenditure elasticity has been estimated was equal 0.85, 0.77, 0.78, 0.95, and 0.89, respectively. As for the food groups that expenditure pattern differs between Saudis and foreigners, this group included the food commodities with consumption bread and cereals, meat and poultry, adible oils and fats, pulses, fruits, vegetables, mineral water , soft drinks and juices, for Saudis was 0.50, 0.65, 0.62, 0.77, 0.78, 0.90, respectively. While for foreigners amounted to 0.29, 0.35, 0.51, 0.64, 0.56, 0.70, respectively, all of which are less than one, which indicates that demand for these food groups, is inelastic demand i.e. necessary good.

This paper is concerned with the assessment of seismic drift demands in steel moment frames designed to comply with Eurocode 8 provisions, with due account for cyclic and in-cycle degradation. In addition to degradation effects, the main parameters examined include the ground motion frequency content as well as the level of constant relative strength or inelasticity. To represent a wide range of structural characteristics, a set of 54 multi-storey frames are considered, in which the number of stories, steel profiles, seismic hazard and compliance criteria are varied. Detailed incremental dynamic analyses are performed on the full set of frames using a suite of 56 far-field ground motion records, which are scaled appropriately to achieve different levels of inelastic demand or equivalent behaviour factors. The seismic performance is evaluated in terms of maximum global and local drifts as well as beam chord rotations. Characteristic results show that maximum response in terms of global deformations and inter-storey drifts is significantly affected by degradation phenomena, along with the ground motion frequency content and the level of inelastic demand. For medium rise typologies subjected to earthquakes with relatively high frequency content, concentration of seismic demand in terms of inter-storey drift is captured by the degrading models and leads to early development of plastic mechanisms. The seismic demand scenarios used in this study, through spectral acceleration-based scaling of ground motions, indicate that the influence of degradation can be significant not only at collapse levels but also at those associated with typical design situations. Finally, based on the extensive analyses carried out in this investigation, expressions for predicting the global and local demands are proposed and discussed. [ABSTRACT FROM AUTHOR]

In 2017, disruptions in the global supply of helium reminded consumers, distributors, and policy makers that the global helium supply chain lacks flexibility, and that attempts to increase production from the U.S. Federal Helium Reserve (the FHR) may not be able to compensate for the loss of one of the few major producers in the world. Issues with U.S. and global markets for helium include inelastic demand, economic availability of helium only as a byproduct, only 4-5 major producers, helium’s propensity to escape earth’s crust, an ongoing absence of storage facilities comparable to the FHR, and a lack of consequences for the venting of helium. The complex combination of these economic, physical, and regulatory issues is unique to helium, and determining helium’s practical availability goes far beyond estimating the technically accessible volume of underground resources. Although most of these issues have been analyzed since helium was recognized to be a valuable mineral commodity in the early 1900s, very few economic models have been developed that adequately consider the unique characteristics of helium and helium markets. In particular, there is a notable lack of recent empirical work to estimate the responsiveness of helium demand, supply, prices, and trade patterns to the ongoing drawdown and sale of helium reserves stored in the FHR. In general, existing models of helium either do not account for an oligopoly controlling supply, or they do not evaluate potential helium extraction and storage programs based on an intertemporal maximization of the value of the resource. Such models could be of very limited use to decision makers. This review found only one working paper with a helium market model that has incorporated both of these vital considerations. That and other economic studies along similar lines could be very useful in helping inform current helium policy discussions and decisions. [ABSTRACT FROM AUTHOR]

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A model shows that the price-dependent Chinese margin system differs from the fixed-amount American margin system by altering the risk of underlying positions, resulting in a more elastic demand by long-term buyers but a more inelastic demand by long-term sellers, whereas demand by day traders is not affected. The simulation results show a reduction in price volatility when trading is switched to the Chinese floating system. Empirical evidence shows that futures price volatility in China is lower in general and on market-down days than that in the United States, both of which are consistent with the predictions of the model. [ABSTRACT FROM AUTHOR]

Implications of incidence angle of ground motions on inelastic demand of bridge piers under bi-directional seismic excitation have been studied against the corresponding uni-directional counterparts. Recognizing that the bi-directional analysis is complex and computationally intensive, to improve the use of less-rigorous uni-directional analysis, present study identifies the most and the least preferred orientations for a given pair of horizontal ground motion. We define the most and least preferred orientations , where the difference between bi-directional and uni-directional response is respectively minimized and maximized. These orientations can be uniquely identified for both peak and cumulative demand in terms of appropriate ground motion parameters (energetic length and characteristic intensity respectively for peak and cumulative demand) independent of structural properties. It has been shown that the improved estimate of bi-directional response may be obtained from simplified uni-directional analysis by utilizing these preferred incidence angles in conjunction with appropriate combination rules (30% for peak and 40% for cumulative demand). [ABSTRACT FROM AUTHOR]

This study attempts to investigate the higher-mode effects on the constant-ductility inelastic displacement factors of multi-degree-of-freedom (MDOF) systems considering soil-structure interaction. These factors were computed for 12,600 two-dimensional superstructure models of shear buildings and their corresponding equivalent single-degree-of-freedom (ESDOF) systems under 26 ground motions recorded on alluvium and soft soil. An intensive parametric study was carried out for a wide range of non-dimensional parameters, which completely define the problem. The underlying soil is considered as a homogeneous half-space based on the concept of cone model. The higher-mode effects were then investigated through defining the ratio of inelastic displacement factor of MDOF system to that of the corresponding ESDOF one. The influence of soil-structure interaction key parameters, fundamental period, ductility ratio, the number of stories, and dispersion of the results are evaluated and discussed. Results indicate that as the base becomes very flexible, unlike to the fixed-base systems, in which the defined ratios are greater than unity, using the inelastic displacement factors of ESDOF models for MDOF ones would result in a remarkable overestimation of maximum inter-story displacement demand. A new expression is proposed to estimate the ratio of inelastic displacement factor of MDOF soil-structure systems to that of SDOF counterpart. [ABSTRACT FROM AUTHOR]

Dynamic site response is usually implemented using an equivalent-linear approach through analyses based on time-histories or random vibration theory (RVT). In the RVT approach the input motion is characterized in the frequency domain by means of Fourier Amplitude Spectra (FAS) or power spectral densities so that the need for selecting/developing multiple suitable time-histories is avoided. Nevertheless, past studies have found that RVT may produce results that differ significantly from empirically determined site amplification functions and from the time history approach. This work is aimed to further understand the potential differences in the results from RVT and time-histories based approaches by performing a comprehensive numerical evaluation that takes into account the effect of the input intensity level, input spectral shape, site conditions, and the methodology used to produce the input FAS. The results obtained corroborate that RVT over-predictions occur mainly at the site fundamental frequencies and are larger for relatively soft soil deposits with significant impedance contrast at the soil/rock interface. However, in the soft site evaluated the magnitude of the over-prediction was rather insensitive to the increase in the inelastic demand, conversely, the over-prediction in the stiffer site increased as the site softened due to the rising inelastic demand. [ABSTRACT FROM AUTHOR]

This paper shows that a horizontal merger between two stores (or firms) that are relatively close can enhance efficiency in a model of spatial competition (or spatial product differentiation), if the spacing between them (or between their products) is relatively small compared to the spacing between other stores (or firms) in the market. The basic model assumes that consumers with completely inelastic demand are spread along an infinite line that has infinitely many stores (or firms), but cases with different assumptions are also considered. [ABSTRACT FROM AUTHOR]

This paper examines how sales force impacts competition and equilibrium prices in the context of a privatized pension market. We use detailed administrative data on fund manager choices and worker characteristics at the inception of Mexico's privatized social security system, where fund managers had to set prices (management fees) at the national level, but could select sales force levels by local geographic areas. We develop and estimate a model of fund manager choice where sales force can increase or decrease customer price sensitivity. We find exposure to sales force lowered price sensitivity, leading to inelastic demand and high equilibrium fees. We simulate oft proposed policy solutions: a supply-side policy with a competitive government player and a demand-side policy that increases price elasticity. We find that demand-side policies are necessary to foster competition in social safety net markets with large segments of inelastic consumers. [ABSTRACT FROM AUTHOR]

This study focuses on evaluating the responses of five variants of simple implicit and explicit beam-column joint modeling schemes. A non-linear open-source finite element platform, OpenSees, was employed in performing the structural analysis of a beam-column joint sub-assemblage and a reinforced concrete frame building subjected to pseudo-static and dynamic analysis, respectively. The explicit rotational spring models with rigid links (SLM) and without rigid links (SM) were fairly able to estimate the hysteresis behaviour accurately, whilst the explicit ACI/ASCE joint model (ASCEM) was conservative in predicting the joint shear strength and post peak drift capacity, in addition to its inability to capture the stiffness and strength degradation accurately. The implicit centerline models (CLM and CLRBM) were unable to mimic the energy dissipation as well as the induced flexibility of the non-ductile joint imposed on the system. The explicit joint models (CM, CLM and ASCEM) generally observed an incremental shift in the modal periods of vibration, whilst for the implicit joints, there was no change in individual modal periods of vibration and the associated mass participations. The SLM, ASCEM and CLRBM joint models experienced fairly the same peak drift and rotational angle distribution along the story levels, whilst the other models were outliers. [ABSTRACT FROM AUTHOR]

A common analysis method of soil-structure systems in seismic design procedures such as FEMA-440 is to replace the entire soil-structure system by a fixed-base oscillator with an equivalent fundamental period and damping ratio to consider inertial effect of soil-structure interaction. It is generally believed by researchers that ignoring kinematic effect of soil-structure interaction is conservative to determine response of structures and FEMA-440 supports this idea by defining a reduction factor applying to elastic response spectra. Also, the improvements of nonlinear static procedures in FEMA-440 are achieved for fixed-base structures and the soil effects are not perfectly obtained in coefficients and relations of these procedures. Thus, it seems necessary to assess the accuracy of proposed procedures of FEMA-440 to include soil-structure interaction. In this paper, the accuracy of equivalent replacement oscillator and nonlinear static Procedures of Equivalent Linearization and Coefficient methods, defined in FEMA-440, to analyze soil-structure systems with surface and embedded foundations are evaluated. Both kinematic and inertial effects of soil-structure interaction are investigated by conducting a parametric study using 20 ground motions recorded on soft soil site E, on which the more SSI effects are probable. [ABSTRACT FROM AUTHOR]

The prediction of the behavior of an existing structure against an earthquake, and prior knowledge of the level of damage can endure seem decisive, especially when it comes to listed buildings of vital importance and public utility for the population such as hospitals. They are called to ensure the continuity of the functionality of their services with minor or no damage, especially in case of calamity or serious earthquake disaster genre. The present work consists to assess the seismic vulnerability of a clinic in Agadir, Morocco city, reputed for its high seismicity, using the non-iterative spectral method. Firstly, we will use a Pushover analysis by modeling the structure in the SAP 2000. Then, the capacity curve of the substructure of the building, thus obtained, will be transformed to ADRS format (Acceleration, Displacement, Response Spectral), then it will be overlaid with the inelastic response spectrum of the considered site, which converted to AD Format (Acceleration Displacement), according to the RPS 2011 (revised) in order to determine the performance point. Finally, we will proceed to the interpretation of fragility curves according RISK UE, to deduce the vulnerability. [ABSTRACT FROM AUTHOR]

The nonlinear seismic responses of steel buildings with perimeter moment resisting frames (MRF), modeled as complex 3D MDOF systems, are calculated and the ductility demands, ductility reduction factors and the force reduction factors (R), are studied. Equivalent 3D models with spatial MRF, two-dimensional models, and equivalent SDOF systems (SD), are also considered. Results indicate that the global and local force reduction factors significantly vary from one structural representation to another and that they are much larger for the SD models. One of the reasons for this is that, although there is equivalence between the SD and MDOF models, the dissipated energy and the number of incursions in the inelastic range are significantly larger for the SD models. In addition, while for the SD models total plasticization occurs, for the SAC and EQ models, even for significant yielding, plastic hinges are developed only in a relatively small number of structural members; therefore, using the R factors of the SD models may be conservative. According to the results obtained in this research for the more realistic representation of the steel building (3D), the value of 8 suggested in many codes for the R factor for ductile MRF cannot be justified. It is only justified for the SD systems. The implication of this is that non-conservative designs may be obtained if so large value is used. More transparence is needed in the codes regarding the magnitude and the components involved in the R factor. [ABSTRACT FROM AUTHOR]

In seismic codes, the force strength reduction factor is proposed to transform elastic to inelastic strength. The ductility reduction factor, R μ , plays a key role on R factor if no overstrength is present. The R μ is determined by SDOF systems. But the higher mode (HM) and Multi-Degree-of-Freedom (MDOF) effects need to be considered to extract the R factor . These effects are studied by proposing α v-MDOF via at least 1764 Nonlinear dynamic Analysis of 2D-frames. Also a sensitivity study has been performed on R μ and α v-MDOF . Results obtained from studies conducted on the frames, indicate that HM and MDOF effects have a considerable influence on the base shear. Also the α v-MDOF is typically higher than unity both for ordinary and for near-field earthquakes and it is affected by period, span number and ductility level. These effects are remarkable for near-field motions. Finally, a simplified practical expression is proposed to estimate the α v-MDOF . [ABSTRACT FROM AUTHOR]

Results of an extensive study aiming to properly extend the well known pushover analysis into 3-D problems of asymmetric buildings are presented in this paper. The proposed procedure uses simple, 3 DOF, one-story models with shear-beam type elements in order to quantify the effects of inelastic torsional response of such buildings. Correction coefficients for the response quantities at the "stiff" and "flexible" sides are calculated using results from non-linear time history analyses of the simple models. Their values are then applied to the results of a simple, plane pushover analysis of the detailed building models. Results from the application of the new method for a set of three, conventionally designed, five-story buildings with high values of uniaxial eccentricities are compared with those obtained from multiple non-linear dynamic time history analyses, as well as from similar pushover methods addressing the same problem. This initial evaluation indicates that the proposed procedure is a clear improvement over the simple (conventional) pushover method and, in most cases, more accurate and reliable than the other methods considered. The accuracy, however, of all these methods is reduced substantially when they are applied to torsionally flexible buildings. Thus, for such challenging problems, use of inelastic dynamic analyses for a set of two component earthquake motions appears to be the preferable solution. [ABSTRACT FROM AUTHOR]

A simple relationship is proposed in this paper to construct damage-based inelastic response spectra including the effect of ground motion duration that it can be used for damage control in seismic design of structures. This relation is established for three groups of ground motions with short-duration, moderate-duration, and long-duration ranges. To develop the model, the duration effect is included in the cyclic ductility of structures by an energy-based method, and then strength reduction factors are computed based on this modified ductility (named [ABSTRACT FROM AUTHOR]

The standard displacement based inelastic beam element suffers of approximations related to the inability of the cubic polynomial interpolation functions to properly describe the displacement response of the beam when exhibiting inelastic behaviour. The increase of the number of finite elements, or the use of higher order functions with additional internal degrees of freedom, are common remedies suggested to improve the approximation leading to an unavoidable reduction of the computational efficiency. Alternatively, it has been shown that the development of force based finite elements, based on the adoption of exact force shape functions, lead to more accurate results, although requiring different and more complicated iterative solution strategies. Within this scenario, this paper proposes a new inelastic beam element, within the context of the displacement based approach, based on variable displacement shape functions, whose analytic expressions are related to the plastic deformation evolution in the beam element. The adaptive generalised displacement shape are obtained by identifying, at each step, an equivalent tangent beam, characterised by abrupt variations of flexural stiffness, as a suitable representation of the current inelastic state of the beam. The presented approach leads to the formulation of a Smart Displacement Based (SDB) beam element whose accuracy appears to be comparable to those obtained through a force based approach but requiring a reduced implementation effort and a more straightforward approach. The term ‘smart’ aims at emphasizing the ability of the element to upgrade the displacement field according to the current inelastic state. [ABSTRACT FROM AUTHOR]

The research looks at comparing the different performance offered by two types of one-way car sharing services. In particular, we compare the "traditional" service in which users can return vehicles to a pre-determined permitted parking space to the "modified" service in which the decision of where to return the vehicle to is made at the end of its usage and vehicles can be returned also outside the permitted parking areas. The comparison is based on common and given demand/offer assumptions. The mathematical modelling uses state of the art algorithms that allow us to determine for both types of service the optimal number of personnel to re-position the vehicles in order to maximise profit. In particular, the attractiveness of the two services herewith compared, has been analysed both in terms of overall profitability as well as in terms of maximum number of users. The results show and quantify how the "modified" service, whilst allowing a greater degree of flexibility to users in terms of return locations, causes lower economic returns for the service company and lowers the number of users that can be served. Finally, the model allows us to calculate the required tariff increase necessary to transform a "traditional" service into a "modified" service assuming an inelastic demand curve as well as constant profits for the service company. [ABSTRACT FROM AUTHOR]

An improved consecutive modal pushover (ICMP) procedure is proposed to enhance the accuracy of conventional CMP procedure for estimating seismic demands of tall buildings. It accounts for inelastic structural properties and interaction between vibration modes. The displacement increment at the roof of buildings used in each stage of pushover analyses is modified based on the displacement contribution of each mode. The performance of the proposed ICMP procedure is verified against three high-rise frames subjected to various ground motions. The results obtained from the ICMP procedure are compared with those from the nonlinear time history analysis, conventional pushover analysis, and CMP analysis. The comparison shows the advantages of the ICMP over the other pushover procedures. It is concluded that the ICMP procedure is more accurate than the CMP procedure. [ABSTRACT FROM AUTHOR]

We investigate the effect major catastrophes are expected to have on equilibrium price and quantity in the insurance market. In particular, we examine whether investors expect total industry revenue to increase following a disaster's shock to insurers' financial capital. Rather than examine insurers directly, we study insurance brokers, who earn commissions on premium revenue but do not pay losses following a disaster. We conduct an event study on insurance broker stock returns surrounding the 43 largest insured-loss catastrophes since 1970. We find that brokers earn positive abnormal returns on the day of the event, and that these returns are sustained following the top 20 largest events. We then investigate factors influencing these returns and find that returns are positively related to the size of the loss and negatively related to existing insurer capital. From this, we conclude that catastrophe shocks are expected to increase net industry revenue, benefiting brokers most immediately. This investor response is consistent with economic theories of a negative relationship between capital and insurance prices and price-inelastic demand for commercial insurance. [ABSTRACT FROM AUTHOR]

The paper presents the study of organizational-and-economic mechanism of industrial railway transport enterprises in the conditions of inelastic demand.

Consider a chain as leader that wants to open p new facilities in a linear market, like metro. In this market, there is a competitor, called follower. The leader and the follower have established some facilities in advance. When the leader opens p new facilities, its competitor, follower, reacts the leader’s action and opens r new facilities. The optimal locations for leader and follower are chosen among predefined potential locations. Demand is considered as demand points and is assumed inelastic. Considering huff model, demand points are probabilistically absorbed by all facilities. The leader’s objective is maximization of its market share after opening follower’s new facilities. For solving leader problem, first the follower’s problem is solved for all leader’s potential locations and the best location for leader is obtained and then, a heuristic model is proposed for leader problem when the leader and the follower want to open one new facility. Computational results show that the proposed method is efficient for large scale problems.

This paper presents how the length of the critical plastic region ( L pr ) in slender columns is significantly larger than what is estimated from current models, which were developed for shorter columns. Experimental results from three large-scale slender reinforced concrete columns with aspect ratios (length to depth) up to 12 were used to explore the effect of slenderness on L pr . Components of L pr , including linear moment gradient, nonlinear moment gradient, and tension shift effect were extracted from the test data and the contribution from each component was determined. Experimental L pr values were compared with American, European, and New Zealand design guidelines. All design codes considered in this study significantly underestimated L pr except for seismic design provisions provided by Caltrans. Previous expressions for the length of the plastic region were reexamined in light of the new experimental data and strong disagreement between experimental and predicted L pr was observed. A new expression for L pr , which correlates well with test data is thus proposed. The expression varies according to the magnitude of inelastic demands, defined by displacement ductility, and includes the effect of nonlinear moment gradient due to P-δ effects. [ABSTRACT FROM AUTHOR]

Different models of a perfectly inelastic collision of rigid bodies in plane motion are compared. Formulas for the impact impulses are derived for the Kane-Levinson-Whittaker model based on the kinematic restitution factor, the Routh model based on the kinetic restitution factor, and the Stronge model based on the energy restitution factor. It is shown that these formulas coincide if the collision of rough rigid bodies in plane motion is perfectly inelastic [ABSTRACT FROM AUTHOR]

Nonlinear static procedures, which relate the seismic demand of a structure to that of an equivalent single-degree-of-freedom oscillator, are well-established tools in the performance-based earthquake engineering paradigm. Initially, such procedures made recourse to inelastic spectra derived for simple elastic-plastic bilinear oscillators, but the request for demand estimates that delve deeper into the inelastic range, motivated investigating the seismic demand of oscillators with more complex backbone curves. Meanwhile, near-source (NS) pulse-like ground motions have been receiving increased attention, because they can induce a distinctive type of inelastic demand. Pulse-like NS ground motions are usually the result of rupture directivity, where seismic waves generated at different points along the rupture front arrive at a site at the same time, leading to a double-sided velocity pulse, which delivers most of the seismic energy. Recent research has led to a methodology for incorporating this NS effect in the implementation of nonlinear static procedures. Both of the previously mentioned lines of research motivate the present study on the ductility demands imposed by pulse-like NS ground motions on oscillators that feature pinching hysteretic behaviour with trilinear backbone curves. Incremental dynamic analysis is used considering 130 pulse-like-identified ground motions. Median, 16% and 84% fractile incremental dynamic analysis curves are calculated and fitted by an analytical model. Least-squares estimates are obtained for the model parameters, which importantly include pulse period Tp. The resulting equations effectively constitute an R − μ − T − Tp relation for pulse-like NS motions. Potential applications of this result towards estimation of NS seismic demand are also briefly discussed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Purpose A standard result of firm theory is that a monopoly maximizes profit somewhere along the elastic portion of its demand curve. However, empirical studies of sports ticket pricing routinely find that (home) teams price along the inelastic portion of demand. Despite compelling theoretical explanations of this finding, at least one important factor remains unconsidered. A profit-maximizing team considers not only direct marginal revenue and direct marginal cost when setting a ticket price but also deferred, strategic benefit (revenue) from present game success. The paper aims to discuss these issues.Design/methodology/approach Prior literature finds that a given win is valued in that it generates additional future revenue and likelihood of home victory rises, ceteris paribus, in crowd density. The authors construct a firm profit maximization problem in which a sports team considers both present and future revenue when pricing home games in the present period.Findings If the deferred benefit is sufficiently large, a forward-looking, profit-maximizing team prices along the inelastic portion of its static demand curve. Importantly, this same price falls along the elastic portion of the firm’s (empirically unobserved) dynamic demand curve.Originality/value This is the first model of sports ticket pricing to recognize the intertemporal nature of demand for a sports match. [ABSTRACT FROM AUTHOR]