Bundling strategy in base-supplemental goods markets: the case of Microsoft

We show that bundling is the optimal pricing strategy for a base good monopolist who also supplies a supplemental good under zero marginal cost of product. Without the exit of the rival firm, bundling is a profitable strategy because it increases the profits in the base good market. We show that bundling lowers social welfare as well as rival firms' profit if the supplemental goods are close substitutes. Otherwise, bundling may actually generate welfare enhancements. Our analysis applies directly to the computer software markets and the case of Microsoft.     

Intelligent agents in electronic markets for information goods: customization, preference revelation and pricing

Electronic commerce has enabled the use of intelligent agent technologies that can evaluate buyers, customize products, and price in real-time. Our model of an electronic market with customizable products analyzes the pricing, profitability and welfare implications of agent-based technologies that price dynamically based on product preference information revealed by consumers. We find that in making the trade-off between better prices and better customization, consumers invariably choose less-than-ideal products. Furthermore, this trade-off has a higher impact on buyers on the higher end of the market and causes a transfer of consumer surplus towards buyers with a lower willingness to pay. As buyers adjust their product choices in response to better demand agent technologies, seller revenues decrease since the gains from better buyer information are dominated by the lowering of the total value created from the transactions. We study the strategic and welfare implications of these findings, and discuss managerial and technology development guidelines.     

On the stabilization of the homogeneous bilinear systems

The problem of stabilizing the single-input homogeneous bilinear systems is considered. A special class of these systems is considered: the matrix of the linear (i.e., control independent) term of the right-hand side is semitable while the matrix of the bilinear term is skew-symmetric. Two types of stabilization are investigated: constant feedback global asymptotic stabilization and practical stabilization by a family of the linear feedbacks. It will be shown for the planar case that the above system is always practically stabilizable by a family of the linear feedbacks. For n = 3, the solution of both stabilization problems depends on the mutual position of the expanding direction of the linear part and the direction of the infinitesimal rotation defined by the bilinear term.     

On the asymptotic stability of switched homogeneous systems

The stability of switched systems generated by the family of autonomous subsystems with homogeneous right-hand sides is investigated. It is assumed that for each subsystem the proper homogeneous Lyapunov function is constructed. The sufficient conditions of the existence of the common Lyapunov function providing global asymptotic stability of the zero solution for any admissible switching law are obtained. In the case where we can not guarantee the existence of a common Lyapunov function, the classes of switching signals are determined under which the zero solution is locally or globally asymptotically stable. It is proved that, for any given neighborhood of the origin, one can choose a number L>0 (dwell time) such that if intervals between consecutive switching times are not smaller than L then any solution of the considered system enters this neighborhood in finite time and remains within it thereafter.     

On homogeneous controlied Markov models in continuous time

We study controlled jump models in continuous time using the average reward criterion. We show that the synthesis problem reduces to the construction of a canonical triple and formulate a characteristic property of the canonical triple and a sufficient condition for its existence.Translated from Kibernetika, No. 1, pp. 45–49, January–February, 1989.     

On transfer function representations for homogeneous nonlinear systems

For stationary, homogeneous, nonlinear systems described via the Volterra functional representation, the Laplace transform of the system kernel is commonly used as a "transfer function." Corresponding to the symmetric and triangular forms of the kernel, special forms are obtained for the transfer function. We propose a new form for both the time-domain and transform-domain representation of homogeneous systerns. Properties of these so-called regular forms in relation to the other two forms and in regard to input/output computation, stability, and bilinear realization theory are discussed.     

On jointly optimising the changes of seasonable goods and inventory replenishment

Retailers often need to replace soon-to-be-unseasonable products with new seasonable goods when the season changes. The trade-off for such activities involves choosing between the salvage loss of the unseasonable product and the profit of selling the seasonable product early. This article develops a periodic-review inventory model for planning the changes of seasonable goods with state-dependent demand and cost parameters. We show that the single-period optimal policy for product changes is a threshold policy based on the initial inventory of the unseasonable goods. The corresponding optimal inventory policy follows a Purchase-Keep-Dispose policy if the incumbent product is kept or a base-stock policy if the incumbent product is replaced. Numerically, we find that the structure of the multi-period optimal policy resembles that of the single-period model. We propose a heuristic to solve the multi-period model and demonstrate its effectiveness. Our research provides insights into dynamically managing seasonable goods.     

On nonlinear controllability of homogeneous systems linear in control

This paper considers small-time local controllability (STLC) of single- and multiple-input systems, x/spl dot/=f/sub 0/(x)+/spl Sigma//sub i=1//sup m/f/sub i/u/sub i/ where f/sub 0/(x) contains homogeneous polynomials and f/sub 1/,...,f/sub m/ are constant vector fields. For single-input systems, it is shown that even-degree homogeneity precludes STLC if the state dimension is larger than one. This, along with the obvious result that for odd-degree homogeneous systems STLC is equivalent to accessibility, provides a complete characterization of STLC for this class of systems. In the multiple-input case, transformations on the input space are applied to homogeneous systems of degree two, an example of this type of system being motion of a rigid-body in a plane. Such input transformations are related via consideration of a tensor on the tangent space to congruence transformation of a matrix to one with zeros on the diagonal. Conditions are given for successful neutralization of bad type (1,2) brackets via congruence transformations.     

On multidimensional generalized homogeneous random fields inR n

Theory of Computing Systems -     

On the evolution of homogeneous two-robot teams: clonal versus aclonal approaches

This study compares two different evolutionary approaches (clonal and aclonal) to the design of homogeneous two-robot teams (i.e. teams of morphologically identical agents with identical controllers) in a task that requires the agents to specialise to different roles. The two approaches differ mainly in the way teams are formed during evolution. In the clonal approach, a team is formed from a single genotype within one population of genotypes. In the aclonal approach, a team is formed from multiple genotypes within one population of genotypes. In both cases, the goal is the synthesis of individual generalist controllers capable of integrating role execution and role allocation mechanisms for a team of homogeneous robots. Our results diverge from those illustrated in a similar comparative study, which supports the superiority of the aclonal versus the clonal approach. We question this result and its theoretical underpinning, and we bring new empirical evidence showing that the clonal outperforms the aclonal approach in generating homogeneous teams required to dynamically specialise for the benefit of the team. The results of our study suggest that task-specific elements influence the evolutionary dynamics more than the genetic relatedness of the team members. We conclude that the appropriateness of the clonal approach for role allocation scenarios is mainly determined by the specificity of the collective task, including the evaluation function, rather than by the way in which the solutions are evaluated during evolution.     

On the asymptotic behaviors of time homogeneous Markov chains in two-inertia systems

Microsystem Technologies - In this study, we construct a time homogeneous Markov chain $$\left\{ {X_{n} } \right\}_{n = 0}^{\infty }$$ considering both friction and probability. By investigating...     

On the realization problem for stationary,homogeneous, discrete-time systems

For degree 2, stationary, homogeneous systems, we consider realizations in the form of state-affine difference equations, and in the form of feedback-free interconnections of stationary linear systems, adders, and multipliers. Realizability conditions are presented in terms of the symmetric transfer function (or kernel), and in terms of a new representation called the regular transfer function (or kernel). A procedure is given for constructing a minimal dimension state-affine realization, and the corresponding interconnection.     

Positional scoring-based allocation of indivisible goods

We define a family of rules for dividing m indivisible goods among agents, parameterized by a scoring vector and a social welfare aggregation function. We assume that agents’ preferences over sets of goods are additive, but that the input is ordinal: each agent reports her preferences simply by ranking single goods. Similarly to positional scoring rules in voting, a scoring vector \(s = (s_1, \ldots , s_m)\) consists of m nonincreasing, nonnegative weights, where \(s_i\) is the score of a good assigned to an agent who ranks it in position i. The global score of an allocation for an agent is the sum of the scores of the goods assigned to her. The social welfare of an allocation is the aggregation of the scores of all agents, for some aggregation function \(\star \) such as, typically, \(+\) or \(\min \). The rule associated with s and \(\star \) maps a profile to (one of) the allocation(s) maximizing social welfare. After defining this family of rules, and focusing on some key examples, we investigate some of the social-choice-theoretic properties of this family of rules, such as various kinds of monotonicity, and separability. Finally, we focus on the computation of winning allocations, and on their approximation: we show that for commonly used scoring vectors and aggregation functions this problem is NP-hard and we exhibit some tractable particular cases.     

On the blow-up criterion for the quasi-geostrophic equations in homogeneous Besov spaces

In this paper, we consider the blow-up criterion for the quasi-geostrophic equations with dissipation ${\Lambda }^{\gamma }$ ($0<\gamma <1$). By establishing a new trilinear estimate, we show that if

$\theta \in L^{\frac{\gamma }{\gamma +s?1}}(0,T;{\stackrel{?}{B}}_{\infty ,\infty }^s\left({\mathbb{R}}^2\right))$

for some $s\in \left(1?\frac{\gamma }{2},1\right)$, then the solution can be extended smoothly past $T$. This improves and extends the corresponding results in Dong and Pavlovi? (2009) ([32]) and Yuan (2010).     

On the selection of the access path in inverted database organization

The query in inverted file organization can be expressed in the form of a Boolean expression, that states the data selection criterion. In response to a query the system accesses inverted lists, merges them and then accesses those records in the secondary storage, that satisfy the search logic. Because the stored inverted lists are selected by taking into consideration the file organization as a whole, it is not always advantageous to use all the stored inverted lists. The remaining conditions will be examined from the records that fulfil the conditions, which are examined using inverted lists, In this paper we present an optimization algorithm for the selection of the address lists that are worth using.