scholarly journals Long time horizon for adaptive management to reveal predation effects in a salmon fishery

2016 ◽  
Vol 26 (8) ◽  
pp. 2695-2707 ◽  
Author(s):  
Timothy E. Walsworth ◽  
Daniel E. Schindler
Keyword(s):  
Adaptive Management ◽  
Time Horizon ◽  
Long Time ◽  
Predation Effects ◽  
Salmon Fishery

scholarly journals Towards High-Level Intrinsic Exploration in Reinforcement Learning

2020 ◽  
Author(s):  
Nicolas Bougie ◽  
Ryutaro Ichise
Keyword(s):  
Reinforcement Learning ◽  
Time Horizon ◽  
State Of The Art ◽  
Experimental Results ◽  
Prior Work ◽  
Extrinsic Rewards ◽  
Intrinsic Reward ◽  
Long Time ◽  
End To End ◽  
High Level

Deep reinforcement learning (DRL) methods traditionally struggle with tasks where environment rewards are sparse or delayed, which entails that exploration remains one of the key challenges of DRL. Instead of solely relying on extrinsic rewards, many state-of-the-art methods use intrinsic curiosity as exploration signal. While they hold promise of better local exploration, discovering global exploration strategies is beyond the reach of current methods. We propose a novel end-to-end intrinsic reward formulation that introduces high-level exploration in reinforcement learning. Our curiosity signal is driven by a fast reward that deals with local exploration and a slow reward that incentivizes long-time horizon exploration strategies. We formulate curiosity as the error in an agent’s ability to reconstruct the observations given their contexts. Experimental results show that this high-level exploration enables our agents to outperform prior work in several Atari games.

Bipartite matching model with dynamic arrivals and departures

2018 ◽  
Vol 09 (04) ◽  
pp. 1850031 ◽  
Author(s):  
Weiwei Jiang
Keyword(s):  
Time Horizon ◽  
Strategic Behavior ◽  
Matching Markets ◽  
Matching Model ◽  
Bipartite Matching ◽  
Long Time ◽  
Classical Models ◽  
Matching Mechanism ◽  
Finite Time Horizon ◽  
Dynamic Arrivals

In this paper, we introduce a bipartite matching model for matching markets with dynamic arrivals and departures. Different from classical models with a finite-time horizon, our model has a long-time horizon with infinite vertices. In our model, the matching goal is to maximize the ratio of matched vertices, i.e., matched ratio. We define two types of online algorithms, i.e., Greedy and Patient, analyze their performance with evaluation metrics of both upper bounds and competitive ratios, and conduct extensive simulations to validate our analysis. To further simulate the real situation, we extend our model with the user’s strategic behavior and prove the existence of a specific Nash equilibrium under a differentiated matching mechanism.

Are There Types of Dictatorship?

2019 ◽  
pp. 285-310
Author(s):  
Ronald Wintrobe
Keyword(s):  
North Korea ◽  
Time Horizon ◽  
Long Time

The idea of different kinds of dictatorships can be traced back to Aristotle. In contemporary thinking, three classifications are common: tinpot vs. totalitarian, personal/military/single-party or civilian/military/monarchy, and short vs. long time horizon. This chapter argues that classification is useful if it can be theoretically grounded, the types can be distinguished empirically, and especially if they behave differently. It concludes with an analysis of seemingly “unclassifiable” regimes such as Chinese totalitarian capitalism, Putin’s Russia, and North Korea.

scholarly journals Output controllability in a long-time horizon

Automatica ◽  
2020 ◽  
Vol 113 ◽  
pp. 108762
Author(s):  
Martin Lazar ◽  
Jérôme Lohéac
Keyword(s):  
Time Horizon ◽  
Long Time ◽  
Output Controllability

The congruence of entrepreneurship and India’s excellence in information technology

2017 ◽  
Vol 10 (2) ◽  
pp. 159-184 ◽  
Author(s):  
Sankalpa Bhattacharjee ◽  
Debkumar Chakrabarti
Keyword(s):  
Information Technology ◽  
Time Horizon ◽  
Structural Changes ◽  
Close Association ◽  
Critical Role ◽  
Austrian Economics ◽  
It Industry ◽  
Content Type ◽  
Long Time ◽  
Historical Contextualisation

Purpose The paper aims to unravel the congruence of entrepreneurship and India’s excellence in information technology (IT). Considering the fact that entrepreneurship is a multifaceted concept encompassing a complex set of contiguous and overlapping constructs, the study takes into consideration interlinkages between the institutional environment, the nature of the industry and the responses and expectations that influenced entrepreneurship. The study complements these factors by analysing the sequential transformation of the Indian IT industry owing to the advent of outsourcing opportunities and concomitant ramifications on entrepreneurial activities. In effect, the study highlights the endogeneity in the system wherein entrepreneurs have continually adapted to the industry dynamics resulting in its significant expansion. Design/methodology/approach The methodology adopted is the historical research method. Fundamentally idiographic, it helps in understanding contemporary issues, how they arose and how their characteristics unfolded over time. To this end, historical contextualisation has been carried out as an interpretative or analytical activity to capture the dynamic process of entrepreneurship. The idea was to capture the broad consequences of entrepreneurial interactions and processes over a long-time horizon classified into six different phases since inception. The historical contextualisation enabled us not only to pinpoint the disequilibrium processes at each phase of development that ushered in structural changes in the industry but also to identify and examine the complex interactions between the various factors that led to the growth of entrepreneurship. Findings Findings reveal that the Indian IT industry has undergone a series of disruptive changes since inception. Disequilibrium in the market plays a critical role in the initiation of entrepreneurship. In the formative phases, disequilibrium is initiated by the “adaptive” responses of the entrepreneurs, whereas in the advanced phases, entrepreneurial process is augmented by the “creative” responses resulting in the perpetuation of disequilibrium. Such shifts in entrepreneurial responses indicate a gradual progression from “gradient” to more “heuristic” search efforts on the part of the entrepreneurs. This progression testifies the perpetuation of entrepreneurship in imparting sustainability to the growth momentum of the industry in the foreseeable future. Research limitations/implications The study attempts to fill three important gaps in the literature: First, enrich the Austrian economics with empirical findings. Second, integrate two different strands of literature on entrepreneurship and evolution of India’s IT sector using unique configuration. Third, extend the literature on entrepreneurship in the Indian context to capture entrepreneurial prudence in the Indian IT sector and thereby enrich the literature with newer findings and richer insights. Practical implications Analysis of factors that imparted entrepreneurial prudence in the Indian IT sector can endow policymakers with valuable information for enhancing growth in industries that are having a close association with the IT industry in the “product space”. Originality/value The study is original on account of the unique configuration that it has adopted to unravel the complexity embedded in the concept of entrepreneurship considering a long-time horizon of six decades since inception which includes the analysis of disequilibrium; the entrepreneurship-institution interlinkages; the nature of the industry; and the role of outsourcing.

scholarly journals Empirical Studies of Financial Innovation: Lots of Talk, Little Action?

2004 ◽  
Vol 42 (1) ◽  
pp. 116-144 ◽  
Author(s):  
W. Scott Frame ◽  
Lawrence J White
Keyword(s):  
Environmental Conditions ◽  
Time Horizon ◽  
Empirical Studies ◽  
Financial Innovation ◽  
Long Time

This paper reviews the extant empirical studies of financial innovation. Adopting broad criteria and spanning a long time horizon, we found surprisingly few studies (39), with most (23) having been conducted since 1998. Especially striking is that only two studies test hypotheses advanced in many descriptive articles as to the economic/environmental conditions that encourage financial innovation. We offer conjectures as to why empirical studies of financial innovation are comparatively rare, including as a culprit the absence of accessible data. We urge financial regulators to undertake more surveys of financial innovation and to make the resulting data available to researchers.

Greenhouse-gas emissions from Amazonian hydroelectric reservoirs: the example of Brazil's Tucuruí Dam as compared to fossil fuel alternatives

1997 ◽  
Vol 24 (1) ◽  
pp. 64-75 ◽  
Author(s):  
PHILIP M. FEARNSIDE
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Transmission Lines ◽  
Carbon Dioxide Emissions ◽  
Time Horizon ◽  
Alternative Energy ◽  
Fossil Fuel ◽  
Decay Rates ◽  
Long Time ◽  
Better Than

Hydroelectric dams in tropical forest areas emit carbon dioxide and methane. How these emissions and their impacts should be calculated, and how comparisons should be made with global warming contributions of alternative energy sources such as fossil fuels, can lead to sharp differences in conclusions on the relative advantages of these options. The example of Brazil's Tucuruí Dam is examined to clarify these differences. The present paper extends an earlier analysis to 100 years and explores the differences between these and comparable fossil fuel emissions.Factors considered here in calculating emissions for Tucuruí Dam include the initial stock and distribution of carbon, decay rates and pathways (leading to carbon dioxide and methane), and losses of power in transmission lines. Factors not considered include forest degradation on islands and reservoir shores, nitrous oxide sources in drawdown zones and transmission lines, additional methane emission pathways for release from standing trees, water passing through the turbines, etc. Construction-phase emissions are also not included; neither are emissions from deforestation by people displaced by and attracted to the project. A complete accounting of the alternative landscape is also lacking. Standardization of the level of reliability of the electricity supply is needed to compare hydroelectric and thermoelectric options.Types of emission calculations commonly used include the ultimate contribution to emissions, the annual balance of emissions in a given year, and emissions over a long time horizon (such as 100 years). The timing of emissions differs between hydroelectric and thermal generation, hydro producing a large pulse of carbon dioxide emissions in the first years after filling the reservoir while thermal produces a constant flux of gases in proportion to the power generated. The impacts of emissions are related to the atmospheric load (stocks) of the gases rather than to the emissions (flows), and therefore last over a long time. According to the calculations in the present paper, the average carbon dioxide molecule in the atmospheric load contributed by Tucuruí was present in the atmosphere 15 years earlier than the average molecule in the comparable load from fossil fuel generation. This means that, considering a 100-year time horizon, a tonne of CO2 emitted by Tucuruí has 15% more global warming impact than a tonne emitted by fossil fuel, assuming no discounting. If discounting is applied, then the relative impact of the hydroelectric option is increased.Time preference, either by discounting or by an alternative procedure, is a key factor affecting the attractiveness of hydroelectric power. At low annual discount rates (say 1–2%), the attractiveness of Tucuruí, although less than without discounting, is still 3–4 times better than fossil-fuel generation. If the discount rate reaches 15%, the situation is reversed, and fossil-fuel generation becomes more attractive from a global-warming perspective. Tucuruí, with a power density (installed capacity/reservoir area) of 1.63 W m-2 is better than both the 0.81 W m-2 average for Brazilian Amazonia's 5500 km2 of existing reservoirs and the 1 W m-2 estimated by Brazil's electrical authorities as the mean for all planned hydroelectric development in the region.

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