Kai Virtanen

Prof. Kai Virtanen


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2016 in Applied Ergonomics
Verified
Journal Article
Closed access
HMHeikki Mansikka
Heikki Mansikka
KVKai Virtanen
Kai Virtanen
DHDon Harris
Don Harris
PSPetteri Simola
Petteri Simola

1 February 2019 in IEEE Transactions on Human-Machine Systems
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Journal Article
Closed access
HMHeikki Mansikka
Heikki Mansikka
KVKai Virtanen
Kai Virtanen
DHDon Harris
Don Harris
The purpose of this study was to demonstrate how the inclusion of a tactical task goal awareness measure complemented mental workload and performance measures in a simulated air combat mission. It was hypothesized that the evaluation of the tactical task goal awareness could provide additional information concerning the cognitive demands a pilot is exposed to during a complex air combat task. A test setting was developed to test this hypothesis in a virtual flight training device. To highlight the impact of task complexity, high performance aircraft pilots’ heart rate (HR), interbeat-interval (IBI), and performance in two simple flying tasks were first compared. Then, a similar comparison, complemented with the tactical task goal awareness measure, was made with two complex flying tasks. It was found that when the pilot's awareness of the tactical goals was low, a combination of low performance and low mental workload occurred. It was concluded that when the pilots’ performance is evaluated on a complex air combat task, the awareness of the tactical goals, performance, and mental workload should be studied together as the pilot's awareness can explain some of HR/IBI responses that could be otherwise misinterpreted. More generally, mental workload, performance, and task goal awareness should all be considered when the operator's performance in any complex human–machine system is assessed.

11 August 2019 in Human Factors and Ergonomics in Manufacturing & Service Industries
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Journal Article
Closed access
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HMHeikki Mansikka
Heikki Mansikka
DHDon Harris
Don Harris
KVKai Virtanen
Kai Virtanen

30 June 2020 in Theoretical Issues in Ergonomics Science
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Journal Article
Closed access
HMHeikki Mansikka
Heikki Mansikka
KVKai Virtanen
Kai Virtanen
DHD. Harris
D. Harris
MJM. Jalava
M. Jalava
In air combat, a traditional way of evaluating team’s taskwork performance is to measure its performance output. However, it provides a narrow view about the team’s performance and potentially misses the complexity of air combat and the team’s taskwork when tactical operating procedures, teams’ competencies and applicability of aircraft systems are evaluated in live-, virtual- and live-virtual-constructive- simulations. This paper introduces a model of an air combat system, which explains the dynamically interacting elements relevant to the measurement of team performance in air combat. Shared situation awareness, mental workload, task performance and normative performance are proposed as supplementary measures for the performance output. Recommendations for the selection of measurement techniques are provided. The multidimensional measurement approach presented in this paper can prevent potential misunderstanding of team performance. The principles of the system model and the associated measuring techniques can be applied to the analysis of any military system where the objective is to achieve a holistic measure of team performance.

26 October 2018 in Defence Technology
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Journal Article
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JLJanne Lahti
Janne Lahti
TSTimo Sailaranta
Timo Sailaranta
MHMikko Harju
Mikko Harju
KVKai Virtanen
Kai Virtanen
This paper introduces a novel approach for controlling the exterior ballistic properties of spin-stabilized bullets by optimizing their internal mass distributions. Specifically, the properties of interest are the bullets’ stability characteristics that are examined through dynamic and gyroscopic stability parameters. New analytical expressions for aerodynamic quantities are also derived to address the compressibility of air. These expressions are utilized in a bullet model that enables efficient computation of the stability parameters for a given mass distribution. The bullet model is used in the formulation of nonlinear optimization problems that provide optimal mass distributions with respect to given goals, i.e., desired stability characteristics. The bullet types investigated in this paper are a long range bullet and a limited range training bullet. In the optimization of the mass distribution of the long range bullet, the goal is that the bullet stays stable for as long as possible. The mass distribution of the training bullet is optimized such that the bullet is stable at launch but becomes unstable shortly afterwards. The global optimal solutions obtained with the new approach fulfill the desired stability characteristics better than currently used uniformly filled bullets. Overall, the optimization approach reveals a new goal focused philosophy for bullet design compared to current trial and error design practices.

3 December 2018 in Theory and Decision
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Journal Article
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JKJuho Kokkala
Juho Kokkala
KBKimmo Berg
Kimmo Berg
KVKai Virtanen
Kai Virtanen
JPJirka Poropudas
Jirka Poropudas
This paper introduces a new solution concept for games with incomplete preferences. The concept is based on rationalizability and it is more general than the existing ones based on Nash equilibrium. In rationalizable strategies, we assume that the players choose nondominated strategies given their beliefs of what strategies the other players may choose. Our solution concept can also be used, e.g., in ordinal games where the standard notion of rationalizability cannot be applied. We show that the sets of rationalizable strategies are the maximal mutually nondominated sets. We also show that no new rationalizable strategies appear when the preferences are refined, i.e., when the information gets more precise. Moreover, noncooperative multicriteria games are suitable applications of incomplete preferences. We apply our framework to such games, where the outcomes are evaluated according to several criteria and the payoffs are vector valued. We use the sets of feasible weights to represent the relative importance of the criteria. We demonstrate the applicability of the new solution concept with an ordinal game and a bicriteria Cournot game.