Homogeneous Product Research Articles

Probabilistic Approach in the Problem of International Competition of Manufacturers with Random Variables

Game-theoretic models of manufacturers’ competition in the international market of a homogeneous product are constructed provided that the strategic variables of the manufacturers are random. A class of distributions of random variables that guarantees the existence of a solution to non-cooperative games describing international trade is distinguished. Explicit formulas for the “corrected” Nash equilibrium are established in the constructed models.

Designing competitive loyalty programs: a stochastic game-theoretic model to guide the choice of reward structure

We develop a game-theoretic model to guide the choice of the reward structure in customer loyalty programs. We model a duopoly market in which one firm adopts a loyalty program. Firms independently and simultaneously set the prices and rewards. Heterogeneous customers buy homogeneous products in a multi-period setting. Customers are segmented into three groups based on their level of strategic behavior, which is expressed in terms of their degree of forward-lookingness. We use two exogenous parameters to represent the size of each segment. A third parameter captures the point pressure effect, which refers to the increase in customer spending as they approach a reward threshold. In each period, customers choose the firm that maximizes their utility, which is a function of offered prices, rewards, and the distance to the next reward. We use the logit model to model the customer choice behavior. Customers’ accumulated purchases evolve as a Markov chain. We derive the limiting distribution of accumulated purchases, which is subsequently used to formulate the firm’s expected revenue functions. We develop two algorithms to find the Nash equilibrium for both the linear and nonlinear rewards in term of the three parameters. Using a thorough numerical analysis, we show that the choice of the structure becomes more critical as the size of the strategic segment increases. The nonlinear scheme is superior when the size of the highly-strategic segment is very small. The linear rewards is superior in markets where the size of the highly-strategic segment and the sensitivity to distance are simultaneously not small.

Is equatorial Africa getting wetter or drier? Insights from an evaluation of long‐term, satellite‐based rainfall estimates for western Uganda

Long‐term trends in equatorial African rainfall have proven difficult to determine because of a dearth in ground‐measured rainfall data. Multiple, satellite‐based products now provide daily rainfall estimates from 1983 to the present at relatively fine spatial resolutions, but in order to assess trends in rainfall, they must be validated alongside ground‐based measurements. The purpose of this paper is twofold: (a) to assess the accuracy of four rainfall products covering the past several decades in western Uganda; and (b) to ascertain recent, multi‐decadal trends in annual rainfall for the region. The four products are African Rainfall Climatology Version 2 (ARC2), Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks–Climate Data Record (PERSIANN‐CDR), and TAMSAT African Rainfall Climatology And Timeseries (TARCAT). The bias and accuracy of 10‐day, monthly, and seasonal rainfall totals of the four products were assessed using approximately 10 years of data from 10 rain gauges. The homogeneity of the products over multiple time periods was assessed using change‐point analysis. The accuracy of the four products increased with an increase in temporal scale, and CHIRPS was the only product that could be considered sufficiently accurate at estimating seasonal rainfall totals throughout most of the region. TARCAT tended to underestimate totals, and ARC2 and PERSIANN were in general the least accurate products. Only annual rainfall estimates from CHIRPS and TARCAT were significantly correlated with ground‐measured rainfall totals. TARCAT was the most homogeneous product, while ARC2, CHIRPS, and PERSIANN had significant negative change points that caused a drying bias over the 1983–2016 period. After adjusting the satellite‐based rainfall estimates based on the timing and magnitude of the change points, annual rainfall totals derived from all four products indicated that western Uganda experienced significantly increasing rainfall from 1983 to 2016.

Abstract P6-20-16: BAT8003, a potent anti-Trop-2 antibody-drug conjugate, for the treatment of triple negative breast cancer

Abstract Trophoblast cell surface antigen 2 (Trop-2) is overexpressed on many epithelial carcinomas, yet is expressed at much lower level on normal tissue. Overexpression of Trop-2 has been correlated with poor prognosis in several solid tumors. These two characteristics make Trop-2 a potential drug target. An antibody-drug conjugate (ADC) targeting Trop-2, IMMU-132, has recently been demonstrated to be effective in treating triple negative breast cancer (TNBC) and gastric cancer patients. Here we present a Trop-2 ADC, BAT8003, which contains an uncleavable linker and a maytansine derivative as the payload. An A114C mutation on antibody heavy chain was introduced to BAT8003 for site-specific conjugation, in order to generate a more homogeneous product for a better pharmacokinetics profile. BAT8003 is also completely devoid of fucose modification, to allow for enhanced ADCC effect. We show that BAT8003 is effectively internalized upon binding to Trop-2, and inhibits proliferation of Trop2-overexpressed tumor cells with IC50s of ˜1 nM. In a TNBC (MDA-MB-468 cell) mouse xenograft model, BAT8003 strongly inhibits tumor growth at a dose level as low as 5 mg/kg. BAT8003 also demonstrates potent activity in another TNBC (MX-1 cell) mouse tumor model, in which it shows the same inhibition activity as the naked antibody conjugated heterogeneously with almost two fold payload (DAR 3.5), suggesting the effect caused by site-specific conjugation. We are currently developing BAT8003 for clinical evaluation in TNBC and other cancer indications. Citation Format: Tang W, Huang X, Ou Z, Yan H, Gan J, Dong Q, Tan B, Yang Y, Guo Y, Li S, Thomas B, Yu J-C. BAT8003, a potent anti-Trop-2 antibody-drug conjugate, for the treatment of triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-20-16.

The volumetric stability, chloride binding capacity and stability of the Portland cement-GBFS pastes: An approach from the viewpoint of hydration products

An optimization of Portland cement (PC)-supplementary cementitious materials (SCMs) system focusing on the characteristics of hydration products is significantly important to decrease the thermal and chemical shrinkages and increase the chloride binding capacity, consequently to decline the diffusion rate of chloride into cement-based materials. In the present study, ultrafine granulated blast furnace slag (GBFS) was added into ultrafine Portland cement (PC) pastes to obtain homogenous hydration products, and then the hydration heat, chemical shrinkage, chloride binding capacity and stability of the PC-GBFS pastes were investigated. The results show that with the increase of the GBFS addition, the ultimate hydration heat of the PC-GBFS pastes increased initially and then decreased sharply, and the chemical shrinkage increased slightly with the increase of the GBFS addition. The cement pastes with 40–60% GBFS had acceptable hydration heat and chemical shrinkage, more important, its total bound chloride and non-water-soluble bound chloride increased by 24% and 177%, respectively, compared to those of Portland cement paste. Additionally, about 50% of chemically bound chloride in the form of Friedel’s salt was water-soluble chloride due to ion-exchange, and 5–20% of physically bound chloride in C-S-H was non-water-soluble chloride after desorption.

System efficiency evaluation of homogeneous parallel production systems: An aggregation approach

Existing models, for efficiency evaluation of DMUs with homogeneous parallel production-units, have limitations in the sense that production process of a DMU is compared with the production possibility set of all production-units. Moreover, same set of input-output weights is used to evaluate the efficiency, project inputs-outputs of a DMU and all its production-units. This means, all the production-units of a DMU operate in a similar way in the long run as if they are not separate production-units but one single entity. We propose an aggregation approach to evaluate the efficiency of DMUs with homogeneous parallel production-units. We also introduce Weighted Average Efficiency and System Efficiency. As opposed to the existing methodology, different set of weights are used to evaluate efficiency of different production-units of a DMU. Finally, the proposed methodology has been used to evaluate the efficiency of higher education sector of Bihar, one of the largest states in India.

Galenic Preparations of Therapeutic Cannabis sativa Differ in Cannabinoids Concentration: A Quantitative Analysis of Variability and Possible Clinical Implications.

Introduction: Magistral preparations of therapeutic cannabis are extracted from standardized products imported from Holland or from the Florence Military Pharmaceutical Chemical Works, but extraction protocols differ among galenic laboratories. This study assessed the inter-laboratory variability in concentrations of cannabidiol (CBD), cannabinol (CBN), tetrahydrocannabinol (THC), and tetrahydrocannabinolic acid (THCA) among different magistral oil preparations.Methods: 219 samples of Bediol, Bedrobinol, Bedrolite or FM-2 70 or 100 mg/ml in oil were collected from 3 laboratories. Concentrations of CBD, CBN, THC, and THCA were quantified by high-pressure liquid chromatography; inter-laboratories variability was assessed using the Kruskal–Wallis test.Results: A significant variability in CBD and THC concentrations was found for Bediol 70 mg/ml samples from 2 laboratories [for CBD: median 5.4 (range 4.8–6.6) vs. 6.1 (4.9–7.2) mg/ml, p = 0.033; for THC: 3.6 (3.1–3.9) vs. 4.0 (2.6–5.1) mg/ml, p = 0.020]. As for Bediol 100 mg/ml, a significant variability emerged in THC concentrations among the three considered laboratories [5.7 (-) vs. 4.2 (1.5–4.8) vs. 5.2 (4.2–6.9), p = 0.030]. No significant inter-laboratory variability emerged for Bedrocan and Bedrolite. Concentrations of CBD, CBN, and THC were <LOQ in all Bedrocan samples, and CBN and THCA were <LOQ in all Bedrolite samples. As for FM-2, a significant inter-laboratories variability was found for CBD concentrations.Conclusion: Quantitative variability of cannabinoids in magistral preparations might impact on the efficacy and safety of therapeutic cannabis. A standardized protocol is needed to guarantee a homogeneous product and patients’ therapeutic continuity.

Prominence, complexity, and pricing

This paper analyzes prominence in a homogeneous product market where two firms simultaneously choose both prices and price complexity levels. Market-wide complexity results in consumer confusion. Confused consumers are more likely to buy from the prominent firm. In equilibrium, there is dispersion in both prices and price complexity. The nature of equilibrium depends on prominence. Compared to its rival, the prominent firm makes higher profit, associates a smaller price range with lowest complexity, puts lower probability on lowest complexity, and sets a higher average price. However, higher prominence may benefit consumers and, conditional on choosing lowest complexity, the prominent firm’s average price is lower, which is consistent with confused consumers’ bias.

A study of stereoselective adsorption in smectites using thin-layer chromatography

The stereoselective center in a group of smectite-layered clay minerals was investigated to determine chiral discrimination at either the crystal edge of the smectite or in the interlayer space. In this study, thin-layer chromatography (TLC) was used to probe the stereoselective adsorption site in the smectites. Because uniform-sized particles are crucial for facile, homogeneous, and reproducible production of a TLC plate, core-shell type particles were used, in which a hectorite-like layered silicate was directly grown on monodisperse silica spheres with a 2.6 μm diameter. The core-shell microspheres prepared by the hydrothermal reaction of lithium fluoride, magnesium chloride, and silica in the presence of urea at 373 K for two days were deposited on a glass plate using a splendor. The formation of the resulting layered silicate on the TLC plate was achieved via ion-exchange reactions with enantiomeric Δ-tris(1,10-phenanthroline)nickel(II). The intercalated Ni complex formed pores at the molecular level in the interlayer spaces. The optical resolution of tris(acetylacetonato)ruthenium(III) using methanol as a mobile phase was found to be influenced by the size of the pores and could be adjusted by changing the negative-layer charge density that was varied according to the molar ratio of the Li/Mg added into the hydrothermal reactions. Two split TLC spots attributed to the Δ- and Λ-isomers of the acetylacetonato Ru complex were observed with no tailing when the TLC plate included the layered silicate with a greater density of charged layers. These findings indicated that an increase in the spatial density of the interlayer Ni complex (a narrower pore) enhanced interactions between the Ru complex and the intercalation compound, leading to optical resolution. The TLC experiments showed that the interlayer void space plays an important role when stereoselective adsorption sites are located in the interlayer space.

Assessment of the binder blending in bituminous mixtures based on the development of an innovative sustainable infrared imaging methodology

Reclaimed Asphalt (RA) is more and more used in the road recycling industry because it allows reducing the consumption in non-renewable raw materials such as virgin bitumen which comes from the petroleum distillation. As bitumen is oxidation-sensitive, some technical issues are however raised about the mix design and the binder blending between the aged and virgin binders. Particularly, the question lies on the ability of the virgin binder to mix with the RA aged binder to form a homogeneous product in defined manufacturing conditions. To answer this question, most of road studies extract with a chlorinated solvent the total bituminous binder from the asphalt mixture to characterize then oxidation or rheological properties. However, this solvent extraction technique is based on a complete binder dissolution which may alter physicochemical properties of the mixture. The objective is also to develop a solvent-free and non-destructive methodology to in situ assess the binder blending in manufactured mixtures. Using infrared imaging ATR microscopy, homogeneity is defined from spatial distributions in carbonyl functions and the methodology is developed on modeled binder mixtures. The influence of the aged binder temperature and mixing time is then investigated on the binder blending. Results show that high and close temperatures between binders are necessary but not sufficient to obtain a homogeneous mixture whereas a longer mixing time improves the binder blending. The developed chemomap methodology also allows demonstrating the influence of manufacturing process parameters on the binder blending in road asphalt mixtures. At the binder scale, the present work constitutes an interesting, rapid and economical approach to optimize the manufacturing parameters of the asphalt mixture design. The innovative infrared imaging methodology also opens perspectives to gain a better knowledge about molecular distributions and homogeneity of any hydrocarbon mixture which constitutes an essential criterion for the performance of more sustainable materials.

Fourier Spaces and Completely Isometric Representations of Arens Product Algebras

AbstractMotivated by the definition of a semigroup compactication of a locally compact group and a large collection of examples, we introduce the notion of an (operator) homogeneous left dual Banach algebra (HLDBA) over a (completely contractive) Banach algebra $A$ . We prove a Gelfand-type representation theorem showing that every HLDBA over A has a concrete realization as an (operator) homogeneous left Arens product algebra: the dual of a subspace of $A^{\ast }$ with a compatible (matrix) norm and a type of left Arens product $\Box$ . Examples include all left Arens product algebras over $A$ , but also, when $A$ is the group algebra of a locally compact group, the dual of its Fourier algebra. Beginning with any (completely) contractive (operator) $A$ -module action $Q$ on a space $X$ , we introduce the (operator) Fourier space $({\mathcal{F}}_{Q}(A^{\ast }),\Vert \cdot \Vert _{Q})$ and prove that $({\mathcal{F}}_{Q}(A^{\ast })^{\ast },\Box )$ is the unique (operator) HLDBA over $A$ for which there is a weak $^{\ast }$ -continuous completely isometric representation as completely bounded operators on $X^{\ast }$ extending the dual module representation. Applying our theory to several examples of (completely contractive) Banach algebras $A$ and module operations, we provide new characterizations of familiar HLDBAs over A and we recover, and often extend, some (completely) isometric representation theorems concerning these HLDBAs.

Product Line Pricing under Marginal Moment Model with Network Effect

The complex network effect of the product exhibits has a significant impact on the product line optimization design. The multinomial logit (MNL) model which is used to simulate consumer choice behavior is applied in most of product line optimization problems. However, its assumptions, independence of irrelevant alternatives (IIA) and the same Gumbel distribution of random error terms, are usually difficult to be met in practice. The marginal moment model (MMM) can be used when the mean and variance of consumer’s utility error are known. The MMM not only has weak assumption conditions but also overcomes the IIA problem of MNL model. In this paper, we study the product pricing problem based on MMM with endogenous negative network effect. Firstly, we construct a variant of MMM considering network effect in product line optimization design. Secondly, we prove that the revenue function is concave in market share. We propose the solving methods of the model to obtain the optimal price, the corresponding market share, and the revenue under three different scenarios, i.e., developing single product, homogeneous products, and heterogeneous products. Finally, numerical experiments show that the proposed model can better simulate consumer choice behavior and potentially increase revenue.

Bertrand Game with Nash Bargaining Fairness Concern

The classical Bertrand game is assumed that players are perfectly rational. However, many empirical researches indicate that people have bounded rational behavior with fairness concern, which is important in the two‐person game and has attracted much attention. In this paper, fairness concern is incorporated into the Bertrand game with two homogeneous products and the effect of fairness concern on this extended Bertrand game is explored. Nash bargaining solution of player is applied to be his own fairness reference point. Then, a Bertrand game model with fairness concern is established, and its equilibrium price is also derived and analyzed. It is shown from some numerical examples that fairness concern and bargaining power of players have a significant influence on their equilibrium price, expected profits, and utilities. As a player gets more fair‐minded, if the other player has a less focus on fairness, the price competition between them will be intensified and both of them suffer loss. Thus, fairness concern may be advantageous or disadvantageous for players. In most situations, the fairness concern behavior is not beneficial for players. Additionally, the effect of bargaining power is relative to fairness concern. A player who manufactures a low‐cost product should have a weak bargaining power if he terribly focuses on fairness and should have a strong bargaining power if he pays little attention to fairness. However, a player who manufactures a high‐cost product should have a weak bargaining power if he is rarely concerned about fairness. Anyway, the same bargaining power is the best for two players.

On the Nature of Equilibrium in Monopolistic Competition

This paper shows that product differentiation is compatible with perfect competition under free entry and exit and small firm size relative to size of market. Thus, monopolistic competition is a form of perfect competition. Although no product sold under monopolistic competition has a perfect substitute, each product has many close, albeit imperfect, substitutes, which have a cumulative effect on own-price elasticity of demand. With infinitely elastic demand, excess capacity and sub-optimal firm size disappear from monopolistic competition in equilibrium. The number of basic industrial structures is reduced to three—monopoly or single seller, oligopoly or competition among the few, and perfect competition or competition among the many. Perfect competition can be divided into perfect competition with homogeneous products and perfect competition with differentiated products. Advertising can pay off under the latter, since products have separate identities and price depends on quality, even though firms are price takers for any given quality. Under oligopoly, firms will behave like Chamberlin’s monopolistic competitors when certain conditions are met, but there is no guarantee that these conditions ever will prevail. Finally, I ask how small a firm’s share of industry output value must be if it is to be a de facto price taker.

On a Three-Level Competitive Pricing Problem with Uniform and Mill Pricing Strategies

Under study is a three-level pricing problem formulated as a Stackelberg game in which the two companies, the Leader and the Follower, compete with each other for customers demand by setting prices for homogeneous products on their facilities. The first decision is made by the Leader. Then, having full information about the Leader’s choice, the Follower makes his own decision.After that each customer chooses the facilitywithminimal service costs to be serviced from. The Leader and the Follower use different pricing strategies: uniform and mill pricing respectively. We study the behavior of company revenues depending on the number of facilities. For this, an exact decomposition type algorithm is proposed. Moreover, we developed a hybrid approximation algorithm that is based on the variable neighborhood descent and coordinate descent.

Product Innovation With Partial Capacity Rollover

This paper analyzes how the transferability of production capacities from an established to a new product influences the incentives of a firm to invest in R&D. A dynamic duopoly model is considered, where initially both firms offer a homogeneous product. The firms invest in production capacities and simultaneously in R&D which determines their innovation rate. The firm that innovates first extends its product line and obtains a patent for the new product that prevents the other firm from catching up. Upon the launch of the new product, the innovator then has the option to transfer part of the capacity for the established product to the production process of the new product. If capacities can be rolled over to the new product, a trade-off can be detected in that this rollover option gives the larger firm more incentive to innovate, whereas the cannibalization effect gives the smaller firm a higher innovation incentive. As a logical consequence we find that the larger firm is expected to innovate first when the capacity transfer does not involve a too high capacity loss. However, if the losses of capacity transfer are considerable, the cannibalization effect starts to dominate and the smaller firm’s incentive to innovate is larger.

Competitive Imperfect Price Discrimination and Market Power

Two duopolists compete in price on the market for a homogeneous product. They can 'profile' consumers, i.e., identify their valuations with some probability. If both firms can profile consumers but with different abilities, then they achieve positive expected profits at equilibrium. This provides a rationale for firms to (partially and unequally) share data about consumers, or for data brokers to sell different customer analytics to competing firms. Consumers prefer that both firms profile exactly the same set of consumers, or that only one firm profiles consumers, as this entails marginal cost pricing (so does a policy requiring list prices to be public). Otherwise, more protective privacy regulations have ambiguous effects on consumer surplus.

Estimation of Consistency of Production of the Pertussis Component of DTP Vaccine in Terms of Immunogenic Activity and Specific Safety Using Shewhart Charts

WHO experts attribute the resurgence of whooping cough to the wide use of acellular pertussis vaccines (aPs) as components of combination products. In this regard, WHO encourages countries that have not yet switched to the use of aPs to continue to use whole-cell pertussis vaccines (wPs) for primary vaccination. The experience of using pertussis vaccines has shown that companies do not always produce highly efficacious products. The use of statistical methods of samples quality control helps to ensure consistency of the technological process, which results in the production of more homogeneous products, and rules out the possibility of producing low-quality products. This paper presents the results of retrospective evaluation of the consistency of the wP (as a pertussis component of the DTP vaccine) production using Shewhart control charts. It was shown that at some points in time during the analyzed period from January 2017 until March 2018 the technological process of the company lacked proper statistical control. This increased the risk of producing non-uniform and defective products. In order to improve the quality and consistency of pertussis component batches, the company’s quality control and quality assurance services should make extensive use of Shewhart charts on a real-time basis.

The Dutch retail electricity market

This paper examines market structure, regulation, and market performance of the Dutch electricity retail market for households since its opening in 2004. Using data containing monthly prices for all products offered in the Dutch retail electricity markets over the period 2008–2014, we provide quantitative results on the intensity of retail competition and the benefits to consumers. Regulation of the retail electricity market is relatively intensive and encompasses structural measures, contractual restrictions, rules on information provision, price surveillance and market monitoring. In contrast to most other countries, the Dutch regulation includes a kind of price regulation which is that the regulator surveys all new retail prices before market introduction in order to prevent too high retail prices. The Dutch retail electricity market has remained relatively concentrated, with retailers offering an increasing variety of retail products, often using multiple brands. Competition is characterized by product innovation, especially for green energy, rather than price competition on homogenous products. Gross retail margins remain relatively high, as is price dispersion across retailers. The market matured, as evidenced by fewer consumer complaints and higher switching rates.

RETRACTED ARTICLE: Network evolution analysis of e-business entrepreneurship: big data analysis based on taobao intelligent information system

In recent years, the entrepreneurial development of taobao village based on e-business has led to a new round growth of rural economy in China. This paper constructs a evolution analysis framework of taobao village entrepreneurial network based on the big data of taobao intelligent information system from the year 2007–2016. The social network analysis software Gephi was applied to analyze the data. The result is that: Firstly, the early emerged online shops with high betweenness centrality degree, which mastered important resources and power within the network, formed a strong entrepreneurial demonstration effect to the other shops. Secondly, in taobao village, the number of strong relationship shops increased, entrepreneurial network gradually dispersed characteristics of clustering, entrepreneurial network community structure strength enhanced, division quality optimization, and the transmission performance and efficiency of entrepreneurial network improved. The entrepreneurial network has a typical characteristic of “acquaintance” network business conduction. Thirdly, the entrepreneurial network density of Lin’an taobao village showed a significant downward trend, which may be more conducive to the homogeneous agricultural products sales shops to access to heterogeneous resources, so as to obtain more long-term future development.