Decoding Hidden Markov Models Faster Than Viterbi Via Online Matrix-Vector (max, +)-Multiplication

In this paper, we present a novel algorithm for the maximum a posteriori decoding (MAPD) of time-homogeneous Hidden Markov Models (HMM), improving the worst-case running time of the classical Viterbi algorithm by a logarithmic factor. In our approach, we interpret the Viterbi algorithm as a repeated computation of matrix-vector $(\max, +)$-multiplications. On time-homogeneous HMMs, this computation is online: a matrix, known in advance, has to be multiplied with several vectors revealed one at a time. Our main contribution is an algorithm solving this version of matrix-vector $(\max,+)$-multiplication in subquadratic time, by performing a polynomial preprocessing of the matrix. Employing this fast multiplication algorithm, we solve the MAPD problem in $O(mn^2/ \log n)$ time for any time-homogeneous HMM of size $n$ and observation sequence of length $m$, with an extra polynomial preprocessing cost negligible for $m > n$. To the best of our knowledge, this is the first algorithm for the MAPD problem requiring subquadratic time per observation, under the only assumption -- usually verified in practice -- that the transition probability matrix does not change with time.Comment: AAAI 2016, to appea

Gli “anime” verso la pedagogia dei diritti e dei valori fondamentali

[The “anime” towards the pedagogy of fundamental rights and values]. In the mid-1970s, just as the Italian Constitutional Court was affirming the legitimacy of private television stations for the first time, the monopolist state television (Rai) included in its programming the animation works of Japanese production better known under the denomination “anime” (アニメ). Strongly criticized in the period of their first programming, due to the contents, according to some, not suitable for children, “anime” were subsequently accepted by most, albeit mainly confined to the context of entertainment. This report, briefly retracing the most compelling plots of the anime revolution of the 70s, pursues the intention of stimulating some reflections on the contents of greatest interest to the jurist and which can be placed in the pedagogy of fundamental rights and values

Intellectual property rights in the era of Italian “artificial” public decisions: time to collapse?

Considering that the Public Administration may not be able to internally develop the technologies necessary for its digital transformation process, having to procure them on the private market, the exclusivity of copy-right could affirm an unprecedented dominance of private operators over the entire public decision-making process. On the other hand, claiming the right to reveal the source code of the algorithm constitutes a guarantee of transparency, freedom of information and civic engagement, in line with Open Government policies. Leaving aside the legal debate about the qualification of the source code as an administrative act, which recently took place in Italy, this work aims to investigate the morphology of intellectual property in the era of algorithmic Administration in order to understand whether intellectual property rights should, or not, to succumb whenever it is necessary to choose, acquire and use information technology to carry out administrative activities

Cloud Computing in the health sector

L’elaborato tratta della tecnologia cloud computing, con particolare riferimento al settore sanitario pubblico e privato. Il percorso seguito è di tipo interdisciplinare tra la tecnologia informatica e il diritto. La tesi è suddivisa in sei parti, di cui: le prime due dedicate principalmente agli aspetti informatici del cloud computing; la parte terza illustra la diffusione di tale tecnologia nella Pubblica Amministrazione come strumento di e-health; la quarta parte tratta dei vantaggi e delle criticità del cloud computing con particolare attenzione alla disciplina dettata in materia di protezione dei dati personali; la quinta parte analizza gli aspetti negoziali delle fattispecie maggiormente utilizzate, nella prassi commerciale, per l’erogazione di servizi in cloud; e, infine, la sesta parte presenta alcune eccellenze e casi d’uso italiani, pubbliche e private, di adozione della tecnologia suddetta. Nell’elaborato sono contemplate anche le più recenti evoluzioni normative e giurisprudenziali compreso il Regolamento UE 2016/679, del 27 aprile 2016, e la sentenza della corte di giustizia dell’Unione Europea che ha determinato l’invalidità dell’accordo “Safe Harbor”. Sono state, inoltre, illustrate le norme più tecniche contenute nel nuovo standard 27018 pubblicato dall’ente internazionale ISO per i cloud providers.This essay aims to provide a discussion about cloud computing technology with specific referral to the sector of private and public healthcare. The methodology we have applied consists of an interdisciplinary approach between Information science and Law. The composition is divided into six parts: the first two are mainly dedicated to the Information science cloud computing; the third one illustrates the adoption of that technology by Public Administration as an instrument of e-health; the forth takes into account advantages and critical points of cloud computing with specific referral to data protection regulation; the fifth analyzes the negotiable features of the most frequent facti-species, in commercial practice, for cloud services providing; and, lastly, the sixth part refers to some excellence and some Italian practice, both private and public, adopting the above-mentioned technology. The exposition covers the most recent evolutions of Law and Jurisprudence, including EU Regulation 2016/679, issued on April 27th 2016, and the EUCJ judgment calling-off the “Safe Harbour” agreement. Furthermore, we have exposed the technical rules of the new 27018 standard published by ISO with regard to cloud providers

Estimation of Phantom Arm Mechanics About Four Degrees of Freedom After Targeted Muscle Reinnervation

The intuitive control of bionic arms requires estimation of amputee's phantom arm movements from residual muscle bio-electric signals. The functional use of myoelectric arms relies on the ability of controlling large sets of degrees of freedom (>3 DOFs) spanning elbow, forearm, and wrist joints. This would assure optimal hand orientation in any environment. As part of this paper we recorded high-density electromyograms with >190 electrodes from the residual stump of a trans-humeral amputee who underwent targeted muscle reinnervation. We employed clustering to determine eight spatially separated sub-sets of channels sampling electromyograms associated to the actuation of four phantom arm DOFs. We created a large-scale musculoskeletal model of the phantom arm encompassing 33 musculo-tendon units. For the first time, this enabled the accurate electromyography-driven simulation of complex phantom joint rotations about elbow flexion-extension, forearm pronation-supination, wrist flexion-extension, and radial-ulnar deviation. These results support the potential for a new class of bionic limbs that are controlled as natural extensions of the body, an important step toward next-generation prosthetics that mimic human biological functionality and robustness

Robust simultaneous myoelectric control of multiple degrees of freedom in wrist-hand prostheses by real-time neuromusculoskeletal modeling

Objectives: Robotic prosthetic limbs promise to replace mechanical function of lost biological extremities and restore amputees' capacity of moving and interacting with the environment. Despite recent advances in biocompatible electrodes, surgical procedures, and mechatronics, the impact of current solutions is hampered by the lack of intuitive and robust man-machine interfaces. Approach: Based on authors' developments, this work presents a biomimetic interface that synthetizes the musculoskeletal function of an individual's phantom limb as controlled by neural surrogates, i.e. electromyography-derived neural activations. With respect to current approaches based on machine learning, our method employs explicit representations of the musculoskeletal system to reduce the space of feasible solutions in the translation of electromyograms into prosthesis control commands. Electromyograms are mapped onto mechanical forces that belong to a subspace contained within the broader operational space of an individual's musculoskeletal system. Results: Our results show that this constraint makes the approach applicable to real-world scenarios and robust to movement artefacts. This stems from the fact that any control command must always exist within the musculoskeletal model operational space and be therefore physiologically plausible. The approach was effective both on intact-limbed individuals and a transradial amputee displaying robust online control of multi-functional prostheses across a large repertoire of challenging tasks. Significance: The development and translation of man-machine interfaces that account for an individual's neuromusculoskeletal system creates unprecedented opportunities to understand how disrupted neuro-mechanical processes can be restored or replaced via biomimetic wearable assistive technologies

A 1.9 ps-rms Precision Time-to-Amplitude Converter With 782 fs LSB and 0.79%-rms DNL

Measuring a time interval in the nanoseconds range has opened the way to 3-D imaging, where additional information as distance of objects light detection and ranging (LiDAR) or lifetime decay fluorescence-lifetime imaging (FLIM) is added to spatial coordinates. One of the key elements of these systems is the time measurement circuit, which encodes a time interval into digital words. Nowadays, most demanding applications, especially in the biological field, require time-conversion circuits with a challenging combination of performance, including sub-ps resolution, ps precision, several ns of measurement range, linearity better than few percent of the bin width (especially when complex lifetime data caused by multiple factors have to be retrieved), and operating rates in the order of tens of Mcps. In this article, we present a time-to-amplitude converter (TAC) implemented in a SiGe 350 nm process featuring a resolution of 782 fs, a minimum timing jitter as low as 1.9 ps-rms, a DNL down to 0.79% LSB-rms, and conversion rate as high as 12.3 Mcps. With an area occupation of 0.2 mm2 [without PADs and digital-to-analog converter (DAC)], a FSR up to 100 ns, and a power dissipation of 70 mW, we developed a circuit suitable to be the core element of a densely integrated, faster and high-performance system

Recent advances in the surgical care of breast cancer patients

A tremendous improvement in every aspect of breast cancer management has occurred in the last two decades. Surgeons, once solely interested in the extipartion of the primary tumor, are now faced with the need to incorporate a great deal of information, and to manage increasingly complex tasks