Unified Tradeoff Research Articles

The unified tradeoff model.

Evidence is steadily mounting that attribute-based models offer a more accurate description of intertemporal choices than traditional alternative-based models. Among the attribute-based models, the tradeoff model offers the broadest coverage of research findings, but at the cost of considerable complexity: There now are various instantiations of the model dealing with partially overlapping universes of choice options and preference patterns. Moreover, there are reports of preference patterns in intertemporal decisions about monetary losses that contradict all attribute-based models proposed so far. Taking stock of these core challenges, and all other evidence, we develop an account of intertemporal choice, the unified tradeoff model, that is simpler, yet more comprehensive, than all currently available versions of the tradeoff model taken together. It borrows extensively from its predecessors, but it introduces a new element, time bias, that enables it to accommodate an extraordinarily broad range of preference patterns, and also generate new predictions that contradict all existing models of intertemporal choice. We report four studies that test and confirm its predictions regarding delay, interval, sign, and magnitude dependence in choices between single-dated outcomes, and a fifth study that tests and confirms its predictions regarding the relation between delay preference in choices that only involve single-dated payments and duration preference in choices that also involve sequences of payments. Having subjected the unified tradeoff model to an elevated risk of disconfirmation, we discuss its parsimony and scope in relation to yet other phenomena, most notably, preference patterns in consumption decisions, the final frontier for attribute-based models. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The triangular space of abiotic stress tolerance in woody species: a unified trade-off model.

Tolerance of abiotic stress in woody plants is known to be constrained by biological trade-offs between different forms of stress, especially shade and drought. However, there is still considerable uncertainty on the relationship between tolerances and the limits on tolerance combinations. Using the most extensive database available on shade, drought, waterlogging and cold tolerance for 799 northern hemisphere woody species, we determined the number of dimensions needed to summarise their tolerance combinations, and the best trade-off model among those currently available, for description of the interdependence between tolerances. Two principal component analysis (PCA) dimensions summarised stress tolerance combinations. They defined a triangular stress tolerance space (STS). The first STS dimension reflected segregation between drought-tolerant and waterlogging-tolerant species. The second reflected shade tolerance, which is independent of the other tolerances. Cold tolerance scaled weakly with both dimensions. Tolerance combinations across the species in the database were limited by boundary-line trade-offs. The STS reconciles all major theories about trade-offs between abiotic stress tolerances, providing a unified trade-off model and a set of coordinates that can be used to examine how other aspects of plant biology, such as plant functional traits, change within the limits of abiotic stress tolerance.

Unified trade-off optimization of quantum Otto heat engines with squeezed thermal reservoirs

We consider a quantum Otto heat engine cycle operating between two squeezed thermal reservoirs that are characterized by a temperature as well as additional parameters that quantify the degree of squeezing. The optimal efficiency at the unified trade-off optimization criterion representing a compromise between energy benefits and losses for a quantum Otto heat engine is systematically investigated. The analytical expressions for the optimal efficiency are determined in the limit adiabatic and nonadiabatic processes as well as in the high- and low-temperature regimes, respectively. The general unified trade-off efficiency is given as a nonequilibrium efficiency that extends the standard unified trade-off efficiency to a more general nonequilibrium condition.

Understanding Tradeoffs Between Throughput, Quality, and Cost of Alert Analysis in a CSOC

Intrusion detection systems (IDSs) analyze data that are collected by sensors, which monitor the network traffic. Any alert generated by the IDS is transmitted to a cybersecurity operations center (CSOC), which performs the important task of analyzing the alerts. In order to deliver a strong security against threats, an efficient CSOC requires the following characteristics: 1) all alerts must be analyzed in a timely manner; 2) there must be an ideal mix of analyst expertise levels in the organization because the quality of analysis performed depends on the mix; and 3) there must be adequate operating budget to hire the required number of analyst personnel. However, it is non-trivial for a CSOC manager to establish the parameter settings for the above characteristics for a desired CSOC efficiency, and current literature lacks a thorough analysis of the tradeoffs between them. This void is filled by this paper whose research objective is to develop an optimized tradeoff study model of the CSOC that studies and quantifies the interactions between the above characteristics, and to use the knowledge gained from the above study to provide the foundation principles to establish and operate an efficient CSOC. A constraint-optimization tradeoff study model is built to drive the decisions that optimize the above characteristics of the CSOC, which is then tested via several simulation runs of the alert arrival and service processes at the CSOC. The paper serves as the first step toward a unified tradeoff study model that integrates the throughput performance, the quality of analysis, and the cost metrics to design and establish an efficient CSOC. Results from the above optimization-simulation tests capture several valuable insights along with parameter settings of the metrics that explain how to operate an efficient CSOC, and quantifies the economic impact of scaling-up the CSOC operation.

Preference‐based unified criterion in virtual MIMO systems

Virtual multiple-input multiple-output (V-MIMO) is an advanced technology in uplink systems, and a well-designed user pairing and resource allocation scheme in V-MIMO systems can effectively exploit multi-user diversity to yield a significant performance gain. Recently, main attention has been devoted to the crucial user pairing issue with consideration of three key metrics, i.e. spectrum efficiency, energy efficiency and fairness. In this study, the authors investigate the unified tradeoff among all the three metrics for V-MIMO systems with user pairing and resource allocation. They first formulate the three key metrics in a united form and derive a straightforward unified criterion based on the user-specific preference to depict system performances. Through discussing several preference-based cases, they observe that a portion of spectrum efficiency is considered redundantly. Thus, a modified unified criterion is proposed to remove the partial redundancy provided by spectrum efficiency contribution to the objective function. Based on the two unified criteria, they propose a user pairing scheme in flat fading channels and a joint user pairing and resource allocation scheme in frequency-selective fading channels to balance the tradeoff flexibly. Simulation results show that, compared with existing schemes, the proposed scheme achieves a dynamical tradeoff among spectrum efficiency, energy efficiency and fairness.

Thermoelectric energy converters under a trade-off figure of merit with broken time-reversal symmetry

We study the performance of a three-terminal thermoelectric device such as heat engine and refrigerator with broken time-reversal symmetry by applying the unified trade-off figure of merit ( criterion) which accounts for both useful energy and losses. For the heat engine, we find that a thermoelectric device working under the maximum criterion gives a significantly better performance than a device working at maximum power output. Within the framework of linear irreversible thermodynamics such a direct comparison is not possible for refrigerators, however, our study indicates that, for refrigerator, the maximum cooling load gives a better performance than the maximum criterion for a larger asymmetry. Our results can be useful to choose a suitable optimization criterion for operating a real thermoelectric device with broken time-reversal symmetry.

Universal Optimization Efficiency for Nonlinear Irreversible Heat Engines

AbstractWe introduce a multi-parameter combined objective function of heat engines under the strong coupling and symmetry condition and derive the universal expression of the optimization efficiency. The results obtained show that the optimization efficiency derived from the multi-parameter combined objective function include a variety of optimization efficiencies, such as the efficiency at the maximum power, efficiency at the maximum efficiency-power state, efficiency at the maximum ecological or unified trade-off function, and Carnot efficiency. It is further explained that these results are also suitable for the endoreversible cycle model of the Carnot heat engines operating between two heat reservoirs.

Quantified Cost-Balanced routing scheme for overlay multicast

This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem between overlay path delay and access bandwidth at Multicast Server Nodes (MSN) for real-time applications over Internet. Besides implementing a dynamic priority to MSNs by weighing the size of its service clients for better efficiency, QCost-Balanced tradeoffs these two metrics by a unified tradeoff metric based on quantitative analysis. Simulation experiments demonstrate that the scheme achieves a better tradeoff gain in both two metrics, and effective performance in metric quantitative control.

A Military Effectiveness Analysis and Decision Making Framework for Naval Ship Design and Acquisition

AbstractThis paper describes research that develops a new framework for performing military effectiveness analyses and design tradeoff decisions. It provides an extensive survey of literature for effectiveness analysis and multi‐criteria decision making to develop a single consistent philosophy for such analyses. This philosophy is applied to a requirements and effectiveness analysis case study of a conventional submarine that is performed using response surface methods to facilitate design space visualization and decision maker interaction. Measures of merit are developed and applied to the case study. The resulting requirements space and methods to visualize and explore it in a decision making context are presented and discussed. Lastly, a framework is proposed that would facilitate the concurrent consideration of requirements and effectiveness analyses with design and technology forecasting to create a unified tradeoff environment that would provide decision makers with pertinent information to facilitate better informed requirements derivation and design selection.