A theory of supplier network-based innovation value

To understand how a supplier helps a buying company create value through innovations, studies have focused on a supplier's internal resources or its relationship with a buying company. Building upon this body of literature, we develop a theory of supplier network-based innovation value in this conceptual paper. This theory explains how a supplier's upstream and downstream value network can be a source of competitive advantage for a buying company. Specifically, it proposes that the levels and types of supplier innovation value is contingent on the configuration of a dual-ego value network, characterized by the locus and degree of buyer-supplier structural equivalence. This theory also explains how a supplier's ties with a buying firm's competitors can pose both opportunity and risk to buying company innovation. This theory contributes to the literature by showing when “seemingly undesirable” suppliers, due to a lack of technical capability or strong relationship with a buying company, might still be valuable to a buying company's innovation.     

浅谈如何提高医院招聘的有效性

在经济高速发展的时代,如何招聘一支高素质的员工队伍,塑造医院的良好社会形象,拓宽医院的生存发展空间成为当务之急。本文以某三级医院人力资源部门招聘工作为例,对怎样提高人员招聘的效率进行了探讨。     

转型期的企业战略

本文通过对某大学设计院的发展历程,对企业成长中遇到的困难和问题进行深入剖析,阐述企业 转型期的战略对企业的飞跃的重要性以及对转型期企业战略的制定规则,并通过对企业的SWOT分析,利 用迈克尔·波特五力模型分析,制定出企业转型期的战略及战略目标,并提出具体的实施措施,以期对处于 转型期的科研院所有一定的借鉴意义。     

Coalitional stability in the location problem with single-dipped preferences: An application of the minimax theorem

This study considers a situation in which agents choose the location of a public facility from a street according to a given mechanism. Agents have single-dipped preferences over a set of feasible locations. We analyze coalitional behavior for any given mechanism for this situation. We identify a necessary and sufficient condition for a mechanism to possess a strong Nash equilibrium by applying the minimax theorem of von Neumann and Morgenstern (1944). We introduce a class of core solutions and show that these solutions are characterized by strong Nash implementability. As a byproduct of these results, we propose a simple mechanism that implements any core solution in strong Nash equilibria.     

Age-test Markov chains for drug testing and detection

Random urinalysis strategies stratified by time since the last test are characterized with a set of Markov chain models. The probability of a person being tested depends on the amount of time since the person's last test. The Nuclear Regulatory Commission (NRC) has proposed a two strata drug testing strategy based on time since last test. The proposal included a high testing rate for people not yet tested in a given time period and a low testing rate for people testing negative in a given time period. Southern California Edison has implemented a variation of the NRC proposal. These strategies can be modeled within a Markov chain framework. Time to detection is calculated as a function of testing probabilities and drug usage levels. Drug user gaming strategies are discussed with illustrations. These models are implemented as part of a U.S. Navy drug policy analysis system.     

NIT picking: The macroeconomic effects of a Negative Income Tax

I study a revenue-neutral reform of the U.S. income tax and welfare system that involves the adoption of a Negative Income Tax (NIT). The reform is undertaken in a life-cycle economy with individual heterogeneity and uninsurable idiosyncratic labor risk. The optimal NIT consists of a 22% rate and a transfer equivalent to 11% of per-capita GDP. The ex-ante average welfare gain is a 2.1% annual increase of individual consumption. I show that a NIT outperforms a flat tax reform (income tax plus deduction) by a considerable margin. The key consequence of the reform is that high-productivity agents increase their relative importance in the labor supply at the expense of low-productivity agents.     

A model of influence with a continuum of actions

We generalize a two-action (yes–no) model of influence to a framework in which every player has a continuum of actions, among which he has to choose one. We assume the set of actions to be an interval. Each player has an inclination to choose one of the actions. Due to the influence among players, the final decision of a player, i.e., his choice of one action, may be different from his original inclination. In particular, a coalition of players with the same inclination may influence another player with different inclination, and as a result of this influence, the decision of the player is closer to the inclination of the influencing coalition than his inclination was. We introduce a measure of such a positive influence of a coalition on a player. Several unanimous influence functions in this generalized framework are considered. Also the set of fixed points under a given influence function is analyzed. Furthermore, we study linear influence functions and discuss their convergence. For a linear unanimous function, we find necessary and sufficient conditions for the existence of the positive influence of a coalition on a player, and we calculate the value of the influence index. We also introduce a measure of a negative influence of a coalition on a player.     

Stochastic labelling of biological images

Many hypotheses made by experimental researchers can be formulated as a stochastic labelling of a given image. Some stochastic labelling methods for random closed sets are proposed in this paper. Molchanov (I. Molchanov, 1984, Theor. Probability and Math. Statist. 29 , 113–119) provided the probabilistic background for this problem. However, there is a lack of specific labelling models. Ayala and Simó (G. Ayala and A. Simó, 1995, Advances in Applied Probability 27 , 293–305) proposed a method in which, given the whole set of connected components, every component is classified in a certain phase or category in a completely random way. Alternative methods are necessary in case the random labelling hypothesis is not reliable. A different kind of labelling method is proposed that considers the environment: the type of every connected component is a function of its location.
Two different biphase images are studied: a cross section of a nerve from a rat, and a cross section of an optic nerve from a lizard.     

Optimal requirement allocation among quantity-discount quoting suppliers

We consider a problem motivated by a central purchasing organization for a major office products distributor. This purchasing organization must source a quantity of a particular resale item from a set of capacitated suppliers. In our case each supplier offers an incremental quantity discount purchase price structure. The purchaser’s objective is to obtain a quantity of a required item at minimum cost. The resulting problem is one of allocating order quantities among an approved supply base and involves minimizing the sum of separable piecewise linear concave cost functions. We develop a branch and bound algorithm that arrives at an optimal solution by generating linear knapsack subproblems with feasible solutions to the original problem. This research was partially supported by a 2007 Summer Research Grant awarded to Asoo J. Vakharia.     

Tenure choice and the riskiness of non-housing consumption

This paper analyzes a household's choice of housing tenure within a dynamic utility maximization model that yields simple analytical results under uncertainty of income, housing prices, and rents. Given a housing consumption plan, we show that a decrease in the covariance between a household's earnings and housing rents increases the likelihood of ownership. A household who plans to remain in its home over a long period is more likely to own; a household who plans to remain in its home over a short period is more likely to rent. The higher the covariance between the user cost of a home and that of other properties a household is likely to consider in the future, the more likely the household is to own this home. These predictions of our model find support in recent empirical studies.     

Preference symmetries,partial differential equations,and functional forms for utility

A discrete symmetry of a preference relation is a mapping from the domain of choice to itself under which preference comparisons are invariant; a continuous symmetry is a one-parameter family of such transformations that includes the identity; and a symmetry field is a vector field whose trajectories generate a continuous symmetry. Any continuous symmetry of a preference relation implies that its representations satisfy a system of PDEs. Conversely the system implies the continuous symmetry if the latter is generated by a field. Moreover, solving the PDEs yields the functional form for utility equivalent to the symmetry. This framework is shown to encompass a variety of representation theorems related to univariate separability, multivariate separability, and homogeneity, including the cases of Cobb–Douglas and CES utility.     

Optimal strategy for a fund manager with option compensation

I consider the problem of portfolio optimization for a manager whose compensation is given by the sum of a constant and a variable term. The constant term is a fixed percentage of the managed funds that is payed to the manager independently of his performance. The variable term is a premium that is proportional to the profit earned by the manager over a benchmark at a certain evaluation date. I find the optimal strategy and the optimal portfolio value in the Black–Scholes setting when the benchmark is a linear combination of the risky asset and the money market account.     

A geometric approach to finite sample and large deviation properties in two-way ANOVA with spherically distributed error vectors

This article investigates a two-way ANOVA model with interactions assuming that the vector of error variables possesses a general spherically symmetric distribution instead of a multivariate normal one. Via a geometric approach we study a test for the usual hypothesis of non-interaction under this general assumption. Moreover, based on a certain geometric representation formula, we establish exponential large deviation rates of the least squares estimators in the above model for a specific class of spherical distributions.This research was partially supported by a special research grant from Alexander von Humboldt-Stiftung, Bonn, F. R. Germany.     

Consistent graphs with signed points

A signed graph is obtained from a graph when each line is given either a positive or a negative sign. We now define a marked graph analogously by signing the points of a graph. In both of these the sign of a cycle is the product of the signs of the lines or points, respectively. In a balanced signed graph or in a consistent marked graph, every cycle is positive. Our object is to investigate consistent marked graphs. It is shown that if such a graph has both positive and negative points, it cannot be highly connected; more precisely, it is not 3-connected. We conclude with a series of constructions which show that a given consistent marked graph can often be reduced to smaller ones.     

International joint ventures: Theoretical considerations

This paper constructs models to investigate the rationale for a multinational corporation to enter into a joint venture to serve a host market. In particular, the model examines the impact of profit sharing, cost reductions, risk reductions, and competition reductions on the profits of international joint ventures. The results may explain the ‘recent’ popularity of international joint ventures. The models show that (1) a joint venture is the dominant entry strategy when there is a formidable local competitor and the risks of operation are high, (2) a wholly owned subsidiary is preferred if a multinational corporation has a significant cost advantage, (3) a joint venture is preferred to a wholly owned subsidiary if significant cost reductions can be achieved through combining the strengths of a multinational corporation and a local firm, and (4) multiple licensing is preferred if the number of local firms is large.     

Commitment and strikes in wage bargaining

This paper analyzes the long-run strategic relationship between a firm and a union as a repeated bargaining game, where there is incomplete information on the player's motivation on both sides and each party has a fall-back position. The firm and the union will engage in a reputation-building activity, that will produce a limited number of strikes over time. The bargainer that succeeds in building up a reputation for toughness and obtains a favorable payoff in the long-run is, either the more patient (or alternatively the more centralized), or the party with a higher initial probability of stubbornness, or the party with a smaller fall-back position. Our model also offers predictions on the dependence of strike incidence over time on several parameters.     

Time dependency of trade union membership

Event-history analysis is used to model the time dependency of two decisions: the decision to join a trade union, and the decision to leave a trade union. We formulate two hypotheses with regard to these two decisions and parametric regression models are used to investigate these hypotheses. The process of joining a trade union can be described by a decreasing rate, using a Weibull. For the process of leaving a trade union, we suggest an increasing rate that decreases after several years, a process best described by a log-logistic model.     

Sustainable Entrepreneurship: A Convergent Process Model

Sustainable entrepreneurship pursues a triple bottom line approach of economic, social and ecological goals. The main aim of this paper is to add to our understanding of the process of sustainable entrepreneurship. Since the field of sustainable entrepreneurship is in a nascent stage, we conduct a qualitative study. We employ a multiple case study design to build theory. Based on four case studies we develop a model, which describes the process of sustainable entrepreneurship, including six phases: 1) recognizing a social or ecological problem; 2) recognizing a social or ecological opportunity; 3) developing a double bottom line solution; 4) developing a triple bottom line solution; 5) funding and forming of a sustainable enterprise; 6) creating or entering a sustainable market. By developing a convergent process model with two pathways, we make theoretical contributions to the emerging fields of sustainable entrepreneurship and social entrepreneurship. A key finding is that the triple bottom line of ecological, social and economic goals is integrated sequentially, not simultaneously. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment.