FARM EQUIPMENT INDUSTRY PERFORMANCE: PAST AND FUTURE

This paper assesses the agricultural equipment industry through the perspective of the three leading firms in the United States. It reviews the salient events of the 1990s and relates the business environment to the firmsÂ’ financial performance. It then assesses the factors likely to impact performance in the future, drawing on lessons from historical performance and on new environmental factors. The firmsÂ’ capital market valuations appear consistent with the expectation that farm equipment firms will resume growth after the farm recession.Agribusiness,

RISK AND RETURN IN AGRICULTURE: EVIDENCE FROM AN EXPLICIT-FACTOR ARBITRAGE PRICING MODEL

This article develops and estimates an explicit-factor Arbitrage Pricing Theory (APT) model in an endeavor to uncover (a) the systematic risk properties of returns to agricultural assets, (b) the relationship between agricultural returns and returns on comparable-risk nonagricultural assets, and (c) the possible relevance of agriculture-related risks in general capital markets. The article concludes that: (a) farmer-held assets have exhibited significant systematic/ factor risk over the 1963-82 estimation interval, but U.S. farmland has not exhibited such risk; (b) a grain-price index has been a priced factor in general capital markets; and (c) average returns on farmer-held assets have been significantly lower; and average returns on U.S. farmland significantly higher, than those on comparable-risk nonagricultural assets.Agricultural Finance,

Fundamental Asymptotic Behavior of (Two-User) Distributed Massive MIMO

This paper considers the uplink of a distributed Massive MIMO network where $N$ base stations (BSs), each equipped with $M$ antennas, receive data from $K=2$ users. We study the asymptotic spectral efficiency (as $M\to \infty$) with spatial correlated channels, pilot contamination, and different degrees of channel state information (CSI) and statistical knowledge at the BSs. By considering a two-user setup, we can simply derive fundamental asymptotic behaviors and provide novel insights into the structure of the optimal combining schemes. In line with [1], when global CSI is available at all BSs, the optimal minimum-mean squared error combining has an unbounded capacity as $M\to \infty$, if the global channel covariance matrices of the users are asymptotically linearly independent. This result is instrumental to derive a suboptimal combining scheme that provides unbounded capacity as $M\to \infty$ using only local CSI and global channel statistics. The latter scheme is shown to outperform a generalized matched filter scheme, which also achieves asymptotic unbounded capacity by using only local CSI and global channel statistics, but is derived following [2] on the basis of a more conservative capacity bound.Comment: 6 pages, 2 figures, to be presented at GLOBECOM 2018, Abu Dhab

VERTICAL AND HORIZONTAL COORDINATION IN THE AGRO-BIOTECHNOLOGY INDUSTRY: EVIDENCE AND IMPLICATIONS

Agro-biotechnology is evolving from a pre-commercial phase dominated by basic research science to a commercial phase oriented around marketing products. In pursuing innovation rents in the commercial phase, firms are reorienting their strategies around complementary marketing and distribution assets. This is impacting vertical and horizontal industry structure. Conversely, industry structure is also impacting firm strategies. Horizontal alliances and consolidation continue from the pre-commercial phase into the commercial phase, while vertical coordination and integration strategies are accelerating rapidly. Interplay between firm strategy and industry structure is too complex for firms to anticipate early in the pre-commercial phase for long-term strategy formulation.Acquisitions, Agricultural biotechnology, Firm strategy, Industry consolidation, Industry structure, Mergers, Industrial Organization, Research and Development/Tech Change/Emerging Technologies,

CHANGE AND FIRM VALUATION IN U.S. FOOD RETAILING AND MANUFACTURING

The competitive environment in the agri-food sector is evolving as the food manufacturing and retailing industries become more concentrated. Evolving industry structure and new firm investment portend changes in future firm competitiveness and performance. This research describes how large food-manufacturing and retail firm performance has shifted and how firm valuation signals expected future change in performance. While there have been expectations that return on investment of large food retailers would increase relative to large packaged-food manufacturers, we find that this has not yet happened and that market valuations imply that retailers are not likely to gain on manufacturers in the future.Agribusiness,

Optimal Linear Precoding in Multi-User MIMO Systems: A Large System Analysis

We consider the downlink of a single-cell multi-user MIMO system in which the base station makes use of $N$ antennas to communicate with $K$ single-antenna user equipments (UEs) randomly positioned in the coverage area. In particular, we focus on the problem of designing the optimal linear precoding for minimizing the total power consumption while satisfying a set of target signal-to-interference-plus-noise ratios (SINRs). To gain insights into the structure of the optimal solution and reduce the computational complexity for its evaluation, we analyze the asymptotic regime where $N$ and $K$ grow large with a given ratio and make use of recent results from large system analysis to compute the asymptotic solution. Then, we concentrate on the asymptotically design of heuristic linear precoding techniques. Interestingly, it turns out that the regularized zero-forcing (RZF) precoder is equivalent to the optimal one when the ratio between the SINR requirement and the average channel attenuation is the same for all UEs. If this condition does not hold true but only the same SINR constraint is imposed for all UEs, then the RZF can be modified to still achieve optimality if statistical information of the UE positions is available at the BS. Numerical results are used to evaluate the performance gap in the finite system regime and to make comparisons among the precoding techniques.Comment: 6 pages, 2 figures, IEEE Global Communications Conference (GLOBECOM), Austin, Texas, Dec. 2014. An extended version of this work is available at http://arxiv.org/abs/1406.598

Energy Consumption in multi-user MIMO systems: Impact of user mobility

In this work, we consider the downlink of a single-cell multi-user multiple-input multiple-output system in which zero-forcing precoding is used at the base station (BS) to serve a certain number of user equipments (UEs). A fixed data rate is guaranteed at each UE. The UEs move around in the cell according to a Brownian motion, thus the path losses change over time and the energy consumption fluctuates accordingly. We aim at determining the distribution of the energy consumption. To this end, we analyze the asymptotic regime where the number of antennas at the BS and the number of UEs grow large with a given ratio. It turns out that the energy consumption is asymptotically a Gaussian random variable whose mean and variance are derived analytically. These results can, for example, be used to approximate the probability that a battery-powered BS runs out of energy within a certain time period.Comment: 5 pages, 3 figures, 1 table, conference. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2014

Middle Class Ideology and the Autonomous Self: The Emergence of the Novel in Europe and Africa

There is no single source of the novel as a literary genre, nor is there any single ideology which is most appropriate to it. Narrative techniques and devices associated with the novel are present in earlier epics, romances, novella collections, travel accounts, fables, miscellanies, jest books, lives of saints, and chronicles, just as most ideological perspectives have at one time or another found expression in the novel. Nevertheless, novel-writing has tended to develop in different places, when similar socio-cultural concerns were beginning to surface; in particular, it can often be identified with an emergent belief that individuals constitute a primary locus of meaning and value in the world. During the sixteenth, seventeenth, and eighteenth centuries in Europe and shortly after the second world war in Africa, this idea stood in strong opposition to one of the major tenets of traditional belief: that individuals are only important in terms of their positions within a larger social and genealogical matrix. In Europe a growing interest in the individual\u27s responsibility for self-definition can be correlated with the evolution of a middle-class ideology to sanction the social status of people whose talents and ambitions had enabled them to acquire wealth and, as a consequence, to desire a higher position than one they had inherited by birth. In Africa, a similar ideology was disseminated by the European colonizers who, even before the twentieth century, had thoroughly assimilated it themselves. Early novels written in both places do not necessarily espouse the intrusive ideology; in fact, many of them explicitly condemn it. Yet even they were defining their stance in opposition to the new individualism. In other words, the emergence of a middle class ideology provoked a need to clarify the nature and role of individual experience in a social context, and the novel offered writers a particularly congenial way of responding to this need

Large System Analysis of the Energy Consumption Distribution in Multi-User MIMO Systems with Mobility

In this work, we consider the downlink of a single-cell multi-user MIMO system in which the base station (BS) makes use of $N$ antennas to communicate with $K$ single-antenna user equipments (UEs). The UEs move around in the cell according to a random walk mobility model. We aim at determining the energy consumption distribution when different linear precoding techniques are used at the BS to guarantee target rates within a finite time interval $T$. The analysis is conducted in the asymptotic regime where $N$ and $K$ grow large with fixed ratio under the assumption of perfect channel state information (CSI). Both recent and standard results from large system analysis are used to provide concise formulae for the asymptotic transmit powers and beamforming vectors for all considered schemes. These results are eventually used to provide a deterministic approximation of the energy consumption and to study its fluctuations around this value in the form of a central limit theorem. Closed-form expressions for the asymptotic means and variances are given. Numerical results are used to validate the accuracy of the theoretical analysis and to make comparisons. We show how the results can be used to approximate the probability that a battery-powered BS runs out of energy and also to design the cell radius for minimizing the energy consumption per unit area. The imperfect CSI case is also briefly considered.Comment: 8 figures, 2 tables, to appear on IEEE Transactions on Wireless Communication

Random Access for Massive MIMO Systems with Intra-Cell Pilot Contamination

Massive MIMO systems, where the base stations are equipped with hundreds of antenna elements, are an attractive way to attain unprecedented spectral efficiency in future wireless networks. In the "classical" massive MIMO setting, the terminals are assumed fully loaded and a main impairment to the performance comes from the inter-cell pilot contamination, i.e., interference from terminals in neighboring cells using the same pilots as in the home cell. However, when the terminals are active intermittently, it is viable to avoid inter-cell contamination by pre-allocation of pilots, while same-cell terminals use random access to select the allocated pilot sequences. This leads to the problem of intra-cell pilot contamination. We propose a framework for random access in massive MIMO networks and derive new uplink sum rate expressions that take intra-cell pilot collisions, intermittent terminal activity, and interference into account. We use these expressions to optimize the terminal activation probability and pilot length