Vibration analysis of a tyre model using the wave finite element method

The vibration of a tyre is predicted using the wave finite element (WFE) method. The material properties are considered to be frequency dependent. The WFE method starts from a conventional finite element (FE) model of only a short section of a structure, which is uniform in one direction. Existing element libraries can be fully utilised and the size of the FE model can be very small. Free wave propagation characteristics are extracted from the dynamic stiffness matrix of the FE model. The forced response is calculated using the wave approach. An approach for determining the amplitudes of the directly excited wave is proposed to reduce numerical difficulties. The method is applied to a tyre FE model formed using ANSYS. The material properties of rubber are considered to be frequency dependent. The free wave propagation is shown including nearfield waves. The predicted forced response is compared with experimental data. Good agreement can be seen on the whole

Three New Cool Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer (WISE) and an Improved Spectrum of the Y0 Dwarf WISE J041022.71+150248.4

As part of a larger search of Wide-field Infrared Survey Explorer (WISE) data for cool brown dwarfs with effective temperatures less than 1000 K, we present the discovery of three new cool brown dwarfs with spectral types later than T7. Using low-resolution, near-infrared spectra obtained with the NASA Infrared Telescope Facility and the Hubble Space Telescope we derive spectral types of T9.5 for WISE J094305.98+360723.5, T8 for WISE J200050.19+362950.1, and Y0: for WISE J220905.73+271143.9. The identification of WISE J220905.73+271143.9 as a Y dwarf brings the total number of spectroscopically confirmed Y dwarfs to seventeen. In addition, we present an improved spectrum (i.e. higher signal-to-noise ratio) of the Y0 dwarf WISE J041022.71+150248.4 that confirms the Cushing et al. classification of Y0. Spectrophotometric distance estimates place all three new brown dwarfs at distances less than 12 pc, with WISE J200050.19+362950.1 lying at a distance of only 3.9-8.0 pc. Finally, we note that brown dwarfs like WISE J200050.19+362950.1 that lie in or near the Galactic plane offer an exciting opportunity to measure their mass via astrometric microlensing.Comment: Accepted for publication in the Astronomical Journa

Heterogeneous recognition of bioacoustic signals for human-machine interfaces

Human-machine interfaces (HMI) provide a communication pathway between man and machine. Not only do they augment existing pathways, they can substitute or even bypass these pathways where functional motor loss prevents the use of standard interfaces. This is especially important for individuals who rely on assistive technology in their everyday life. By utilising bioacoustic activity, it can lead to an assistive HMI concept which is unobtrusive, minimally disruptive and cosmetically appealing to the user. However, due to the complexity of the signals it remains relatively underexplored in the HMI field. This thesis investigates extracting and decoding volition from bioacoustic activity with the aim of generating real-time commands. The developed framework is a systemisation of various processing blocks enabling the mapping of continuous signals into M discrete classes. Class independent extraction efficiently detects and segments the continuous signals while class-specific extraction exemplifies each pattern set using a novel template creation process stable to permutations of the data set. These templates are utilised by a generalised single channel discrimination model, whereby each signal is template aligned prior to classification. The real-time decoding subsystem uses a multichannel heterogeneous ensemble architecture which fuses the output from a diverse set of these individual discrimination models. This enhances the classification performance by elevating both the sensitivity and specificity, with the increased specificity due to a natural rejection capacity based on a non-parametric majority vote. Such a strategy is useful when analysing signals which have diverse characteristics, false positives are prevalent and have strong consequences, and when there is limited training data available. The framework has been developed with generality in mind with wide applicability to a broad spectrum of biosignals. The processing system has been demonstrated on real-time decoding of tongue-movement ear pressure signals using both single and dual channel setups. This has included in-depth evaluation of these methods in both offline and online scenarios. During online evaluation, a stimulus based test methodology was devised, while representative interference was used to contaminate the decoding process in a relevant and real fashion. The results of this research provide a strong case for the utility of such techniques in real world applications of human-machine communication using impulsive bioacoustic signals and biosignals in general

Home Fires

To view the screenplay as a viable form of literature, as significant a genre as the novel, play, or the short story, is not a completely absurd premise. John Gassner believes that the screenplay has "been fashioned out of a body of writing that commands respect as writing: that is, as theme, story, style, and drama." Gassner makes clear, however, that the screenplay is different from other forms of writing, because "its form has been shaped by the requirements of cinematic art, which makes it unique among the forms of writing hitherto familiar to the reader, but it is nonetheless literature that can stand scrutiny."l If the screenplay is to be studied, then it must be examined on its own terms, keeping in mind that the screenplay deals with a visual medium, where emphasis is put more on the camera than on the word. Using Home Fires as a basis for my argument, I intend to show how this distinction works, emphasizing how the screenplay functions in relation to other facets of filmmaking such as directing and editing, how structure becomes the most important element in the writing of the screenplay, and how screenwriting borrows from fiction such aspects as verisimilitude, conflict, and point of view to create a medium that is both original and dynamic in the world of literature.Wolf Rilla defines the screenplay as "the creative blueprint" for a film, a definition not uncommon among other critics and filmmakers.2 David Freeman suggests that the screenplay is ''the bare bones of a film."3 Ellen Oumano agrees: she believes that the screenplay "serves as a blueprint of theme, mood, and story for those collaborating in creating the film."4 Yet without the screenplay, the director has no film. He will have nothing but a screen full of images that have no structure, meaning, or voice. He is left, in other words, with absolutely nothing. In this sense, the screenplay is not only a blueprint, but it is also a guide for the director to follow, one that will express the story in terms both cinematic and dramatic. In Home Fires, for example, I set the period in which the story takes place (World War II), the place (a small army installation in Ohio), and I suggest theme (racism as a destructive and violent disease), while keeping my story (a young officer investigating the shooting of seven black soldiers) firmly planted in the foreground. If I have done my job correctly, then I have also given people other than the director something to start with. By setting scenes either in the day or night, I am suggesting lighting for the cinematographer; by using such terms as montage and intercut sequence, I am giving the editor an idea of how to cut the film; and by suggesting how characters think, how they emotionally express themselves, I have given the actors an idea of what the characters are looking for,and whether they find it by the story's end. In Home Fires, George Edwards, the story's protagonist, may appear unmilitary not only in the clothes he wears, but also in his speech. The truth, however, is that Edwards believes very much in the Army; it is the actor's job to find the right balance between surface unconventionality and an inner respect for military tradition. No matter how brilliant the director's job, or the actor's performance, their work (or anyone else's) would not mean anything if the screenplay was nothing more than a rambling and incoherent mess. True, the director's responsibilities lie with the screenplay, but only if it tells a story in an intelligent and logical manner. Thus, structure plays an important part in the writing of the screenplay, or as William Miller puts it, "structure is the prime element in a film or television script."S William Goldman goes one step further: "screenplays are structure.'' According to Goldman, a writer can employ the most interesting characters a screenplay can have, have them speak the most colorful and incisive dialogue a writer can create, but "if the structure is unsound, forget it."6 Douglas Garrett Winston defines two elements that are important to understanding how film structure works. One is the "external structure" that involves narrative, plot, characterization, and other devices a writer needs to tell a story. The second element is "internal structure." This type of structure derives from the author's point of view, or attitude, toward thesubject matter that he is dealing with in hisstory. With Home Fires, I discovered that the writer must treat both structures with equal importance in writing a screenplay; if he does not, he may run the risk of creating an imbalance in his story. In writing the first draft of Home Fires, for example, I made the mistake of letting my attitudes toward racism carry more significance than the plot. The first draft was filled with characters who expressed their feelings on the evils of racism through long sections of dialogue that made the screenplay appear more like a philosophical essay on racism than a story that dramatizes the mistreatment of the black soldier during World War II. The second draft, however, concentrates on the story; the theme is expressed through Edwards' conflict with Bolyn and Steigert; and it is shown visually, as the camera records the inferior conditions of the black soldiers' barracks and weapons. Whatever structure he employs (and most screenplays include both), the writer's main objective is to create movement; connected with movement is the audience's participation with the film. As Miller states, an audience's involvement in narrative story is complex and dynamic," while watching a film is not "the monotonic response of a captured, 'sutured' subject," but "rather it is an active process of shifting attention and involvement."B Creating movement, then, becomes tantamount to the screenwriter's craft; the writer must grab the audience's attention asquickly as possible, or he runs the risk of not having viewer interest at all. Syd Field believes that the first thirty pages of a screenplay are the most important, because it is within these thirty pages that the audience is introduced to the main character and the conflict in which he becomes involved. In Home Fires, I follow Field's principle very closely. The story begins with the killing of the black soldiers; this incident introduces us to the only survivor, Pvt. Charles McGuire, and to the two men responsible, Captain Brian Steigert and Lt. Bolyn. After the shooting, we move to the investigation and the man who conducts the inquiry, Major George w. Edwards. Although the audience knows who is responsible for the black soldiers' deaths, Edwards does not have the faintest idea; thus, the first thirty pages establishes the conflict with which the story deals: what will Steigert and Bolyn do to obstruct the investigation, and will Edwards eventually find the truth that the audience already knows? Such a story carries with it suspense and drama that I develop in the course of the screenplay. Home Fires belongs to a genre that may be defined as the social awareness film; that is, a film that reveals insight into racial, social, or moral problems. Such films include In the Heat of the Night (1967), Coming Home (1978), The Killing Fields (1984), and~ Soldier's Story (1984). Such films take a social issue and dramatize it on the screen. The screenwriter must remember, however, that he is tellingit. The theme that racism leads to violence and death is inherent in a story like Horne Fires; the problem that I had with the screenplay dealt with how I could show the mistreatment of black soldiers in the Army during World War II without pontificating about the ills of racism. To remedy the problem, I make the investigation the focal point of the story. Through Edwards' inquiry, we see the effects of the black soldiers' mistreatment at the camp. The camera records the inferior condition of the black soldiers' barracks and weapons; what the camera relates to the audience is the only comment needed on what is seen. Camp Ordinance 2213B is another device I use to show how the blacks are mistreated. This ordinance states that black soldiers are not allowed in the white section of camp without the base commander's permission. When the ordinance is violated by a young black private who enters the PX to order a beer, Captain Steigert, who is in charge of the camp's security, takes it upon himself to arrest the private. What happens instead is that seven men are coldbloodedly gunned down because of their refusal to obey an ordinance they feel is unfair. Although inspired by historical events, Horne Fires is a work of fiction. Such an incident in which seven black soldiers were mercilessly gunned down did take place on an army base in Ohio during World War II; however, to my knowledge, there was never an inquiry made into the incident. The investigation in Horne Fires is one that I have made upmyself, and all the characters in the story, including Private McGuire, are also fictional. Since I am dealing with an actual period in history, an incident that really did happen, and with characters who could be real, I owe my audience a certain degree of reality in the story. In fiction, according to John Gardner, it is "the writer's first job to convince the reader that the events he recounts really happened, or to persuade the reader that they might have happened (given small changes in the laws of the universe), or else to engage the reader's interest in the patent absurdity of the lie." Gardner calls such fiction "verisimilar fiction,'' a term that refers to writing which attempts to convince the reader of the authenticity of the world that it is trying to represent.lO Verisimilitude may be found not only in the story's locations and characters; it may also be found in the writer's use of images to help recreate reality: He must present, moment by moment, concrete images drawn from a careful observation of how people behave, and he must render the connections between moments, the exact gestures, facial expressions, or turns of speech that, within any given scene, move human beings to emotion, from one instant of time to the next. Verisimilitude also plays an especially important role in screenwriting; what appears on the screen must seem believable to the audience or the film will not work. With Home Fires, it is my task to make the locations,incidents and the characters as real as possible. For example, I try to make the PX a setting that has its own unique identity, from the juke box that plays popular songs of the 1940s to the people who work there. Its thematic purpose is equally important. The PX is off limits to black soldiers, as Ordinance 2213B makes clear. Thus the black private entering the PX at the beginning of the story incites the action that brings Edwards' investigation into the picture. The ordinance is fictional too, but it carries enough dramatic and thematic weight that the audience may accept its authenticity within the context of the story. The screenplay itself is structured around an actual three week period in 1943, beginning on Saturday, June 12, and concluding on Thursday, July 1. If Home Fires were made into a film, we would see a number of scenes begin in the following manner: a date with a specific time attached to it would flash on the screen. For example, the first scene begins with the logo "Saturday, June 12, 1943: 9:45P.M." Structuring the film in this way adds authenticity to the story; if the structure succeeds, then the audience will have felt that it has participated in events as they happened, watching them unfold on the day and time that they occurred. As for characters, I make their physical descriptions brief, because in writing the screenplay, a character's actions often dictate his emotional and moral makeup. With Edwards and Bolyn, we have two characters who are extremely dissimilar not only in their actions, but also in the wayaudience may accept its authenticity within the context of the story. The screenplay itself is structured around an actual three week period in 1943, beginning on Saturday, June 12, and concluding on Thursday, July 1. If Home Fires were made into a film, we would see a number of scenes begin in the following manner: a date with a specific time attached to it would flash on the screen. For example, the first scene begins with the logo "Saturday, June 12, 1943: 9:45P.M." Structuring the film in this way adds authenticity to the story; if the structure succeeds, then the audience will have felt that it has participated in events as they happened, watching them unfold on the day and time that they occurred. As for characters, I make their physical descriptions brief, because in writing the screenplay, a character's actions often dictate his emotional and moral makeup. With Edwards and Bolyn, we have two characters who are extremely dissimilar not only in their actions, but also in the way that they speak and feel toward other characters in the story. Physically, Edwards is a young officer in his thirties, but in his determination to find the ones responsible for the black soldiers' deaths, we learn that he is a man of courage and compassion. Edwards is also something of an eccentric. When we first meet him, he is whistling a Cole Porter song in a light, carefree manner. Edwards is, in fact, a Porter fan, and throughout the story, he sings, hums, or whistles various Porter tunes. I chose Porterfor Edwards because the composer has always been associated with music that has an upbeat tempo to it; there is something undeniably beguiling and offbeat about such Porter songs as "Begin the Beguine," "My Heart Belongs to Daddy,'' and "Let's Face It," songs that Edwards becomes associated with through the course of the story. What symbolizes Edwards' character, however, is the old, battered officer's cap that the Major wears for much of the story. The cap becomes a symbol for two reasons: it represents Edwards' individuality, his nonconformist attitudes toward the Army, while, at the same time, it reveals a strong admiration that he has for military tradition. At one point, we discover that the cap belonged to Edwards' father who was once commander at Camp Harrison during the 1930s. What we learn about the father comes from his son; the love that Edwards has for his father who represents military tradition to his son is shown by wearing the cap. In Lt. Bolyn, however, Horne Fires has its antagonist; he becomes the opposing force to Edwards' investigation. His attempts to stop the investigation maintain the conflict that is so essential to a narrative or dramatic structure. Bolyn wields a strong influence in the story. He controls Company E more than Captain Steigert, since the Captain is too involved with political aspirations to really know or care about what is going on within the company. Bolyn's two goons, Geick and Reuss, follow his orders to the letter. Whether it means beating up Edwards in an effort to makehim leave the camp before he discovers the truth, fracturing McGuire's hip that much more so he will not talk, or murdering Private Craig because Bolyn feels that he will tell Edwards everything about the black soldiers' deaths, Geick and Reuss never fail to carry out the Lieutenant's demands. As for being a racist, Bolyn's hatred of blacks stems from an incident in which he saw his older brother killed by a negro. The incident has always stayed with Bolyn, and at one point, he tells Geick and Reuss that one day he vowed to get even. The shooting of the black soldiers tragically represents Bolyn's revenge. Screenwriting not only borrows verisimilitude and conflict from fiction, but it also makes use of point of view. William Miller states that "film uses uniquely cinematic variations on literary points of view." A film may use first person narration; it may use omniscient, objective, or what Miller calls "central intelligence'' narration. This last type of narration combines all three other points of view in that it maintains third person narration throughout the story, the viewer is limited only to that character the film centers on, and the author is often not evident in the telling of the story.l2 In Home Fires, I do not restrict the story�to one central point of view; I use a number of different characters to interpret incidents as they happen or after they have taken place. Edwards and Bolyn are two points of view that I make use of; two others would be Captain Halloway, the commander of the black soldiers at the camp, and ColonelScott, the man in charge of Camp Harrison. These two men view their positions at the camp in two distinct ways: Halloway has grown angry and discouraged at the mistreatment of his men while Scott would rather ignore that any problem between the white and black soldiers exists. They view Edwards in ways that are different too. Scott sees Edwards as a threat to his chances for a promotion; he resists helping Edwards for much of the story because he feels this way. Halloway, on the other hand, wants to help the Major, but he is not sure if it would do any good. Halloway's mistrust of the white man extends to Edwards as well; it is only at the story's climax, when Edwards has proof of who killed the black soldiers, that Halloway assists the Major. In fact, the story ends with both men sitting down at the bar in the PX; Edwards orders a beer for the two of them, a gesture that surprises Halloway in its sincerity. George Bluestone believes that "cinema exhibits a stubborn antipathy to novels," whereas, the novel "emerges as a medium antithetical to film."l3 I cannot help but feel tnat Bluestone misses the point on a very important factor. The relationship between novel and film is an extremely close one; true, the novel is a discursive medium, while the film is a visual one; yet they share elements instrumental in telling a story. One element they share which is significant is that both media are a form of expression. Again, the forms differ, but literature is made up of genres that are distinct from one another and still have much in common.The screenplay, then, is deserving of study as an important genre of literature: it should be examined with the same care and treatment that is afforded the novel, play, or the short story. The screenwriter's contribution should not be taken for granted either; he uses the tools of his craft much in the same way as the novelist does. To this extent, the end result of both kinds of writers is the same: to create a work of art that eloquently expresses its story, the memory of which stays with the audience long after it has been experienced.Englis

The Young Substellar Companion ROXs 12 B: Near-Infrared Spectrum, System Architecture, and Spin-Orbit Misalignment

ROXs 12 (2MASS J16262803-2526477) is a young star hosting a directly imaged companion near the deuterium-burning limit. We present a suite of spectroscopic, imaging, and time-series observations to characterize the physical and environmental properties of this system. Moderate-resolution near-infrared spectroscopy of ROXs 12 B from Gemini-North/NIFS and Keck/OSIRIS reveals signatures of low surface gravity including weak alkali absorption lines and a triangular $H$-band pseudo-continuum shape. No signs of Pa$\beta$ emission are evident. As a population, however, we find that about half (46 $\pm$ 14\%) of young ($\lesssim$15 Myr) companions with masses $\lesssim$20 $M_\mathrm{Jup}$ possess actively accreting subdisks detected via Pa$\beta$ line emission, which represents a lower limit on the prevalence of circumplanetary disks in general as some are expected to be in a quiescent phase of accretion. The bolometric luminosity of the companion and age of the host star (6$^{+4}_{-2}$ Myr) imply a mass of 17.5 $\pm$ 1.5 $M_\mathrm{Jup}$ for ROXs 12 B based on hot-start evolutionary models. We identify a wide (5100 AU) tertiary companion to this system, 2MASS J16262774-2527247, which is heavily accreting and exhibits stochastic variability in its $K2$ light curve. By combining $v$sin$i_*$ measurements with rotation periods from $K2$, we constrain the line-of-sight inclinations of ROXs 12 A and 2MASS J16262774-2527247 and find that they are misaligned by 60$^{+7}_{-11}$$^{\circ}$. In addition, the orbital axis of ROXs 12 B is likely misaligned from the spin axis of its host star ROXs 12 A, suggesting that ROXs 12 B formed akin to fragmenting binary stars or in an equatorial disk that was torqued by the wide stellar tertiary.Comment: AJ, accepte

Hubble Space Telescope Spectroscopy of Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer

We present a sample of brown dwarfs identified with the {\it Wide-field Infrared Survey Explorer} (WISE) for which we have obtained {\it Hubble Space Telescope} ({\it HST}) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (twenty-two in total) was observed with the G141 grism covering 1.10$-$1.70 $\mu$m, while fifteen were also observed with the G102 grism, which covers 0.90$-$1.10 $\mu$m. The additional wavelength coverage provided by the G102 grism allows us to 1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.\ ammonia bands) and 2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35$+$280548.5 (Y0.5), WISE J120604.38$+$840110.6 (Y0), and WISE J235402.77$+$024015.0 (Y1) are the nineteenth, twentieth, and twenty-first spectroscopically confirmed Y dwarfs to date. We also present {\it HST} grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments.Comment: Accepted for publication in the Astrophysical Journal. 20 pages, 18 figures, 7 table