Remove \VO and \AE acronym

4-conclusion/conclusion.tex

@@ -6,9 +6,9 @@
 \section{Summary}
 
 In this manuscript we have shown how wearable haptics, worn on the outside of the hand, can improve direct hand interaction in immersive \AR. % by augmenting the perception of the real and manipulation of the virtual.
-Wearable haptics can provide rich tactile feedback on \VOs and augment the perception of real objects, both directly touched by the hand, while preserving freedom of movement and interaction with the \RE.
+Wearable haptics can provide rich tactile feedback on virtual objects and augment the perception of real objects, both directly touched by the hand, while preserving freedom of movement and interaction with the \RE.
 However, their integration with \AR is still in its infancy and presents many design, technical and human challenges.
-We have structured our research around two axes: \textbf{(I) modifying the visuo-haptic texture perception of real surfaces} and \textbf{(II) improving the manipulation of \VOs}.
+We have structured our research around two axes: \textbf{(I) modifying the visuo-haptic texture perception of real surfaces} and \textbf{(II) improving the manipulation of virtual objects}.
 
 \noindentskip In \partref{perception} we focused on modifying the perception of wearable and immersive virtual visuo-haptic textures that augment real surfaces.
 Texture is a fundamental property of an object, perceived equally by sight and touch.
@@ -28,17 +28,17 @@ In \chapref{vhar_textures}, we investigated the perception of co-localized visua
 We transposed the \textbf{data-driven visuo-haptic textures} from the \HaTT database to the system presented in \chapref{vhar_system} and conducted a user study with 20 participants to rate the coherence, realism, and perceived roughness of the combination of nine visuo-haptic texture pairs.
 Participants integrated roughness sensations from both visual and haptic modalities well, with \textbf{haptics dominating perception}, and consistently identified and matched \textbf{clusters of visual and haptic textures with similar perceived roughness}.
 
-\noindentskip In \partref{manipulation} we focused on improving the manipulation of \VOs directly with the hand in immersive \OST-\AR.
+\noindentskip In \partref{manipulation} we focused on improving the manipulation of virtual objects directly with the hand in immersive \OST-\AR.
 Our approach was to design visual augmentations of the hand and delocalized haptic feedback, based on the literature, and evaluate them in user studies.
-We first considered \textbf{(1) the visual augmentation of the hand} and then the \textbf{(2)} combination of different \textbf{visuo-haptic feedback of the hand when manipulating \VOs}.
+We first considered \textbf{(1) the visual augmentation of the hand} and then the \textbf{(2)} combination of different \textbf{visuo-haptic feedback of the hand when manipulating virtual objects}.
 
 In \chapref{visual_hand}, we investigated the visual feedback of the virtual hand as augmentation of the real hand.
-Seen as an \textbf{overlay on the user's hand}, such visual hand rendering provide feedback on hand tracking and interaction with \VOs.
+Seen as an \textbf{overlay on the user's hand}, such visual hand rendering provide feedback on hand tracking and interaction with virtual objects.
 We compared the six commonly used visual hand augmentations in the \AR literature in a user study with 24 participants, where we evaluated their effect on user performance and experience in two representative manipulation tasks.
 The results showed that a visual hand augmentation improved user performance, perceived effectiveness and confidence, with a \textbf{skeleton-like rendering being the most performant and effective}.
 This rendering provided a detailed view of the tracked phalanges while being thin enough not to hide the real hand.
 
-In \chapref{visuo_haptic_hand}, we then investigated visuo-haptic feedback to direct hand manipulation with \VOs using wearable vibrotactile haptics.
+In \chapref{visuo_haptic_hand}, we then investigated visuo-haptic feedback to direct hand manipulation with virtual objects using wearable vibrotactile haptics.
 In a user study with a similar design and 20 participants, we compared two vibrotactile contact techniques, provided at \textbf{four different delocalized positions on the user's hand}, and combined with the two most representative visual hand augmentations from the previous chapter.
 The results showed that providing vibrotactile feedback \textbf{improved the perceived effectiveness, realism, and usefulness when provided close to the fingertips}, and that the visual hand augment complemented the haptic contact feedback well in providing a continuous feedback on hand tracking.
 
@@ -102,12 +102,12 @@ It would be interesting to determine the importance of these factors on the perc
 We also rendered haptic textures captured by a hand-held probe to be touched with the bare finger, but finger based captures of real textures should also be considered \cite{balasubramanian2024sens3}.
 Finally, the virtual texture models should also be adaptable to individual sensitivities \cite{malvezzi2021design,young2020compensating}.
 
-\subsection*{Visual Augmentation of the Hand for Manipulating \VOs in AR}
+\subsection*{Visual Augmentation of the Hand for Manipulating virtual objects in AR}
 
 \paragraph{Other AR Displays}
 
 The visual hand augmentations we evaluated were displayed on the Microsoft HoloLens~2, which is a common \OST-\AR headset \cite{hertel2021taxonomy}.
-We purposely chose this type of display because in \OST-\AR the lack of mutual occlusion between the hand and the \VO is the most challenging to solve \cite{macedo2023occlusion}.
+We purposely chose this type of display because in \OST-\AR the lack of mutual occlusion between the hand and the virtual object is the most challenging to solve \cite{macedo2023occlusion}.
 We therefore hypothesized that a visual hand augmentation would be more beneficial to users with this type of display.
 However, the user's visual perception and experience is different with other types of displays, such as \VST-\AR, where the \RE view is seen through cameras and screens (\secref[related_work]{ar_displays}).
 While the mutual occlusion problem and the hand tracking latency could be overcome with \VST-\AR, the visual hand augmentation could still be beneficial to users as it provides depth cues and feedback on the hand tracking, and should be evaluated as such.
@@ -119,12 +119,12 @@ While these tasks are fundamental building blocks for more complex manipulation
 Similarly, a broader experimental study might shed light on the role of gender and age, as our subject pool was not sufficiently diverse in this regard.
 Finally, all visual hand augmentations received low and high rank rates from different participants, suggesting that users should be able to choose and personalize some aspects of the visual hand augmentation according to their preferences or needs, and this should also be evaluated.
 
-\subsection*{Visuo-Haptic Augmentation of Hand Manipulation With \VOs in AR}
+\subsection*{Visuo-Haptic Augmentation of Hand Manipulation With virtual objects in AR}
 
 \paragraph{Richer Haptic Feedback}
 
 The haptic feedback we considered was limited to vibrotactile feedback using \ERM motors.
-While the simpler contact vibration technique (Impact technique) was sufficient to confirm contact with the cube, richer vibrotactile renderings may be required for more complex interactions, such as rendering hardness (\secref[related_work]{hardness_rendering}), textures (\secref[related_work]{texture_rendering}), friction \cite{konyo2008alternative,jeon2011extensions,salazar2020altering}, or edges and shape of \VOs.
+While the simpler contact vibration technique (Impact technique) was sufficient to confirm contact with the cube, richer vibrotactile renderings may be required for more complex interactions, such as rendering hardness (\secref[related_work]{hardness_rendering}), textures (\secref[related_work]{texture_rendering}), friction \cite{konyo2008alternative,jeon2011extensions,salazar2020altering}, or edges and shape of virtual objects.
 This will require considering a wider ranger of haptic actuators and sensations (\secref[related_work]{wearable_haptic_devices}), such as pressure or stretching of the skin.
 More importantly, the best compromise between well-rounded haptic feedback and wearability of the system with respect to \AR constraints should be analyzed (\secref[related_work]{vhar_haptics}).
 
@@ -137,7 +137,7 @@ It remains to be explored how to support rendering for different and larger area
 
 \section{Perspectives}
 
-Our goal was to improve direct hand interaction with \VOs using wearable haptic devices in immersive \AR by providing more plausible and coherent perception and more natural and effective manipulation of the visuo-haptic augmentations.
+Our goal was to improve direct hand interaction with virtual objects using wearable haptic devices in immersive \AR by providing more plausible and coherent perception and more natural and effective manipulation of the visuo-haptic augmentations.
 Our contributions have enabled progress towards a seamless integration of the virtual into the real world.
 They also allow us to outline longer-term research perspectives.
 
@@ -147,7 +147,7 @@ We have seen how complex the sense of touch is (\secref[related_work]{haptic_han
 Multiple sensory receptors all over the skin allow us to perceive different properties of objects, such as their texture, temperature, weight or shape.
 Particularly concentrated in the hands, their sensory feedback, together with the muscles, is crucial for grasping and manipulating objects.
 In this manuscript, we have shown how wearable haptic devices can provide virtual tactile sensations to support direct hand interaction in immersive \AR:
-We have investigated both the visuo-haptic perception of texture augmenting real surfaces (\partref{perception}) and the manipulation of \VOs with visuo-haptic feedback of hand contact with \VOs (\partref{manipulation}).
+We have investigated both the visuo-haptic perception of texture augmenting real surfaces (\partref{perception}) and the manipulation of virtual objects with visuo-haptic feedback of hand contact with virtual objects (\partref{manipulation}).
 
 However, unlike the visual sense, which can be fully immersed in the virtual using an \AR/\VR headset, there is no universal wearable haptic device that can reproduce all the haptic properties perceived by the hand (\secref[related_work]{wearable_haptics}).
 Thus, the haptic renderings and augmentations we studied were limited to specific properties of roughness (\chapref{vhar_system}) and contact (\chapref{visuo_haptic_hand}) using vibrotactile feedback.
@@ -158,7 +158,7 @@ This would allow to assess the relative importance of visual and haptic feedback
 
 One of the main findings of studies on the haptic perception of real objects is the importance of certain perceived properties over others in discriminating between objects \cite{hollins1993perceptual,baumgartner2013visual,vardar2019fingertip}.
 It would therefore be interesting to determine which wearable haptic augmentations are most important for the perception and manipulation of virtual and augmented objects with the hand in \AR and \VR.
-Similar user studies could then be conducted, to reproduce as many haptic properties as possible in \VO discrimination tasks.
+Similar user studies could then be conducted, to reproduce as many haptic properties as possible in virtual object discrimination tasks.
 These results would enable the design of more universal wearable haptic devices that provide rich haptic feedback that best meets users' needs for interaction in \AR and \VR.
 
 % systematic exploration of the parameter space of the haptic rendering to determine the most important parameters their influence on the perception
@@ -169,7 +169,7 @@ These results would enable the design of more universal wearable haptic devices
 We have reviewed the diversity of \AR and \VR reality displays and their respective characteristics in rendering (\secref[related_work]{ar_displays}) and the manipulation of virtual content with the hand (\chapref{visual_hand}).
 The diversity of wearable haptic devices and the different sensations they can provide is even more important (\secref[related_work]{wearable_haptics}) and an active research topic \cite{pacchierotti2017wearable}.
 Coupling wearable haptics with immersive \AR also requires the haptic actuator to be placed on the body other than at the hand contact points (\secref[related_work]{vhar_haptics}).
-In particular, in this thesis we have investigated the perception of haptic texture augmentation using a vibrotactile device on the median phalanx (\chapref{vhar_system}) and also compared different positions of the haptics on the hand for manipulating \VOs (\chapref{visuo_haptic_hand}).
+In particular, in this thesis we have investigated the perception of haptic texture augmentation using a vibrotactile device on the median phalanx (\chapref{vhar_system}) and also compared different positions of the haptics on the hand for manipulating virtual objects (\chapref{visuo_haptic_hand}).
 
 Haptic feedback should be provided close to the point of contact of the hand with the virtual, to enhance the realism of texture augmentation (\chapref{vhar_textures}) and to render contact with virtual objects (\chapref{visuo_haptic_hand}), \eg rendering fingertip contact with a haptic ring worn on the middle or proximal phalanx.
 However, the task at hand, the user's sensitivity and preferences, the limitations of the tracking system, or the ergonomics of the haptic device may require the use of other form factors and positions, such as the wrist or arm.