To “Sketch-a-Scratch”

A surface can be harsh and raspy, or smooth and silky, and everything in between. We are used to sense these features with our fingertips as well as with our eyes and ears: the exploration of a surface is a multisensory experience. Tools, too, are often employed in the interaction with surfaces, since they augment our manipulation capabilities. “Sketch-a-Scratch” is a tool for the multisensory exploration and sketching of surface textures. The user’s actions drive a physical sound model of real materials’ response to interactions such as scraping, rubbing or rolling. Moreover, different input signals can be converted into 2D visual surface profiles, thus enabling to experience them visually, aurally and haptically

Multisensory texture exploration at the tip of the pen

A tool for the multisensory stylus-based exploration of virtual textures was used to investigate how different feedback modalities (static or dynamically deformed images, vibration, sound) affect exploratory gestures. To this end, we ran an experiment where participants had to steer a path with the stylus through a curved corridor on the surface of a graphic tablet/display, and we measured steering time, dispersion of trajectories, and applied force. Despite the variety of subjective impressions elicited by the different feedback conditions, we found that only nonvisual feedback induced significant variations in trajectories and an increase in movement time. In a post-experiment, using a paper-and-wood physical realization of the same texture, we recorded a variety of gestural behaviors markedly different from those found with the virtual texture. With the physical setup, movement time was shorter and texture-dependent lateral accelerations could be observed. This work highlights the limits of multisensory pseudo-haptic techniques in the exploration of surface textures

Vibrotactile sensitivity in active touch: effect of pressing force

An experiment was conducted to study the effects of force produced by active touch on vibrotactile perceptual thresholds. The task consisted in pressing the fingertip against a flat rigid surface that provided either sinusoidal or broadband vibration. Three force levels were considered, ranging from light touch to hard press. Finger contact areas were measured during the experiment, showing positive correlation with the respective applied forces. Significant effects on thresholds were found for vibration type and force level. Moreover, possibly due to the concurrent effect of large (unconstrained) finger contact areas, active pressing forces, and long duration stimuli, the measured perceptual thresholds are considerably lower than what previously reported in the literature

SELEKSI KETAHANAN BEBERAPA GENOTIPE PADI TERHADAP PENYAKIT HAWAR DAUN BAKTERIRN(XANTHOMONAS ORYZAE PV. ORYZAE)

WIRA HADIANTO. Seleksi ketahanan beberapa genotype padi terhadap penyakit hawar daun bakteri (Xanthomonas oryzae pv. oryzae), dibawah bimbingan Bakhtiar sebagai pembimbing ketua dan Lukman Hakim sebagai pembimbing anggota.Penelitian ini bertujuan untuk mengetahui dan mendapatkan genotipe padi yang tahan terhadap penyakit hawar daun bakteri (HDB). Penelitian ini dilaksanakan di rumah plastic Fakultas Pertanian Universitas Syiah Kuala, Banda Aceh, mulai bulan Februari 2014 sampai Januari 2015. Inokulum daun padi yang terinfeksi HDB dikumpulkan dari Gampong Blang Kecamatan Blang Bintang Kabupaten Aceh Besar, pada musim tanam 2013/2014. Semua bahan tanam (71 genotipe), masing-masing terdiri atas 5 tanaman dalam 1 ulangan dan diulang 3 kali. Penanaman dilakukan dalam bak plastic dan ditempatkan dalam rumah plastic Fakultas Pertanian Unsyiah Banda Aceh. Inokulasi bakteri dilakukan dengan cara pengguntingan daun padi untuk pelukaan sebagai jalan masuk bagi infeksi bakteri pada saat tanaman berumur 42 hari setelah tanam (HST). Pengamatan percobaan 1 dilakukan terhadap periode inkubasi dan panjang lesio. Percobaan 2 dilakukan untuk mengevaluasi reaksi ketahanan terhadap bakteri Xoo. Varietas yang tahan terhadap HDB pada fase vegetatif ditanam kembali dalam pot dengan menggunakan Rancangan Acak Kelompok (RAK) non factorial dengan 3 ulangan. Adapun peubah-peubah yang diamati meliputi tinggi tanaman dan jumlah anakan umur 15, 30, 45 dan 60 HST, umur berbunga, tinggi tanaman saat panen, jumlah anakan produktif, umur panen, panjang malai, jumlah biji per malai, presentase gabah bernas, presentase gabah hampa, bobot 1000 butir gabah dan berat biji per pot.Percobaan 1. Uji hipersensitivitas menunjukkan bahwa gejala penyakit (nekrosis) terlihat jelas akibat terinfeksi bakteri Xoo yang diamati 48 jam setelah penyuntikan. Masa inkubasi paling lama dijumpai pada IR-BB27, Limboto, Inpari 10, Situ Patenggang, Sirendeh Semantuk Wayla, Tamboen, Sepasie, Bontok dan Arias. Genotipe yang menunjukkan reaksi tahan terhadap HDB dengan tingkat keparahan penyakit berdasarkan panjang lesio adalah IR-BB27, Inpari 1, Limboto, Tuwoti, Inpari 10, Lekat Rambot Linuet, Rom Mokot, Paki Gajah, Tamboen, Bo 100, Sipasie, Bo Minyek, Bontok, Sirendeh Semantuk Wayla dan Sambei.Percobaan 2. Berdasarkan seleksi terhadap 7 genotipe yang menunjukkan reaksi tahan pada fase vegetatif yaitu genotipe Rom Mokot, Situ Bagendit, Tamboen, Towuti dan IR-BB27. Namun pada fase generatif yaitu genotipe IR-BB27 menunjukkan reaksi tahan, dua genotipe agak tahan terhadap bakteri Xoo yaitu Rom Mokot dan Tamboen. Hasil penelitian menunjukkan bahwa genotipe berpengaruh sangat nyata terhadap tinggi tanaman umur 30, 45, 60 HST, tinggiiitanaman saat panen, jumlah anakan umur 15, 30, 45, 60 HST, jumlah anakan produktif, umur berbunga, umur panen, jumlah biji per malai, persentase gabah berisi, persentase gabah hampa, berat 1000 butir dan berat biji per pot. Namun berpengaruh tidak nyata terhadap tinggi tanaman umur 15 HST dan panjang malai. Hasil terbaik berdasarkan berat 1000 butir gabah dijumpai pada genotipe Towuti dan berat biji per pot dijumpai pada genotipe IR-64.Kata kunci : Xanthomonas oryzae pv. oryzae, hawar daun bakteri, genotipe padi.Banda Ace

Sound modeling issues in interactive sonification - From basic contact events to synthesis and manipulation tools

Questa tesi affronta una varietà di temi di ricerca, spaziando dalla interazione uomo-macchina alla modellizzazione fisica. Ciò che unisce queste ampie aree di interesse è l'idea di utilizzare simulazioni numeriche di fenomeni acustici basate sulla fisica, al fine di implementare interfacce uomo-macchina che offrano feedback sonoro coerente con l'interazione dell'utente. A questo proposito, negli ultimi anni sono nate numerose nuove discipline che vanno sotto il nome di -- per citarne alcune -- auditory display, sonificazione e sonic interaction design. In questa tesi vengono trattate la progettazione e la realizzazione di algoritmi audio efficienti per la sonificazione interattiva. A tale scopo si fa uso di tecniche di modellazione fisica di suoni ecologici (everyday sounds), ovvero suoni che non rientrano nelle famiglie del parlato e dei suoni musicali.The work presented in this thesis ranges over a variety of research topics, spacing from human-computer interaction to physical-modeling. What combines such broad areas of interest is the idea of using physically-based computer simulations of acoustic phenomena in order to provide human-computer interfaces with sound feedback which is consistent with the user interaction. In this regard, recent years have seen the emergence of several new disciplines that go under the name of -- to cite a few -- auditory display, sonification and sonic interaction design. This thesis deals with the design and implementation of efficient sound algorithms for interactive sonification. To this end, the physical modeling of everyday sounds is taken into account, that is sounds not belonging to the families of speech and musical sounds

BIVIB: A Multimodal Piano Sample Library Of Binaural Sounds And Keyboard Vibrations

An extensive piano sample library consisting of binaural sounds and keyboard vibration signals is made available through an open-access data repository. Samples were acquired with high-quality audio and vibration measurement equipment on two Yamaha Disklavier pianos (one grand and one upright model) by means of computer-controlled playback of each key at ten different MIDI velocity values. The nominal specifications of the equipment used in the acquisition chain are reported in a companion document, allowing researchers to calculate physical quantities (e.g., acoustic pressure, vibration acceleration) from the recordings. Also, project files are provided for straightforward playback in a free software sampler available for Windows and Mac OS systems. The library is especially suited for acoustic and vibration research on the piano, as well as for research on multimodal interaction with musical instruments

Augmenting Sonic Experiences Through Haptic Feedback

Sonic experiences are usually considered as the result of auditory feedback alone. From a psychological standpoint, however, this is true only when a listener is kept isolated from concurrent stimuli targeting the other senses. Such stimuli, in fact, may either interfere with the sonic experience if they distract the listener, or conversely enhance it if they convey sensations coherent with what is being heard. This chapter is concerned with haptic augmentations having effects on auditory perception, for example how different vibrotactile cues provided by an electronic musical instrument may affect its perceived sound quality or the playing experience. Results from different experiments are reviewed showing that the auditory and somatosensory channels together can produce constructive effects resulting in measurable perceptual enhancement. That may affect sonic dimensions ranging from basic auditory parameters, such as the perceived intensity of frequency components, up to more complex perceptions which contribute to forming our ecology of everyday or musical sounds

Evidence of Lateralization Cues in Grand and Upright Piano Sound

In a previous experiment we have measured the subjective perception of auditory lateralization in listeners who were exposed to binaural piano tone reproductions, under different conditions (normal and reversed-channel listening, manual or automatic tone production by a Disklavier, and disclosure or hiding of the same keys when they were autonomously moving during the automatic production of a tone.) This way, participants were engaged in a localization task under conditions also involving visual as well as proprioceptive (that is, relative to the position and muscular effort of their body parts) identification of the audio source with the moving key, even when the binaural feedback was reversed. Their answers, however, were clustered on a limited region of the keyboard when the channels were not reversed. The same region became especially narrow if the channels were reversed. In this paper we report about an acoustic analysis of the localization cues conducted on the stimuli that have been used in the aforementioned experiment. This new analysis employs a computational auditory model of sound localization cues in the horizontal plane. Results suggest that listeners used interaural level difference cues to localize the sound source, and that the contribution of visual and proprioceptive cues in the localization task was limited especially when the channels were reversed

Evidence of Lateralization Cues in Grand and Upright Piano Sounds

(Abstract to follow

Path Following in Non-Visual Conditions

Path-following tasks have been investigated mostly under visual conditions, that is when subjects are able to see both the path and the tool, or limb, used for navigation. Moreover, only basic path shapes are usually adopted. In the present experiment, participants must rely exclusively on audio and vibrotactile feedback to follow a path on a flat surface. Two different, asymmetric path shapes were tested. Participants navigated by moving their index finger over a surface sensing position and force. Results show that the different non-visual feedback modes did not affect the task's accuracy, yet they affected its speed, with vibrotactile feedback causing slower gestures than audio feedback. Conversely, audio and audio-tactile feedback yielded similar results. Vibrotactile feedback caused participants to exert more force over the surface. Finally, the shape of the path was relevant to the accuracy, and participants tended to prefer audio over vibrotactile and audio-tactile feedback