Primitive Class Research Articles

Recent Advancements and Developments in the Biological Importance of 1,3,5‐Triazines

AbstractNitrogen‐bearing heterocycles are ubiquitous in landscapes and have a great impact on living nature. Structural motifs are present in diverse natural products like vitamins, antibiotics, and alkaloids, as well as pharmaceuticals. The 1,3,5‐Triazines are the primitive class of heterocyclic motifs and are used in various synthetic and medicinal applications. This review covers an exhaustive exploration of literature reports and describes various synthetic strategies and pharmacological activities of 1,3,5‐triazine moiety. Synthetic strategies include multicomponent reaction, metal catalyst reaction, microwave‐assisted strategy, etc. to construct 1,3,5‐triazine moiety. Pharmacological activities include anticancer, antimalarial, antibacterial, antifungal, antiviral, anti‐tubercular, anti‐leishmanial, anti‐inflammatory, histamine antagonist, serotonin antagonist, etc. For anticancer activity, 1,3,5‐triazine moiety‐containing compounds were tested on different cell lines, and inhibitory activity was also mentioned. The involvement of this scaffold in the treatment of various diseases and disorders makes this scaffold important from a research perspective. Therefore, there is a need to present the combined data of research and reviews to the researchers to develop new molecules. For that reason, the review included information from articles published from 1978 onwards.

Families of rational curves on holomorphic symplectic varieties and applications to 0-cycles

We study families of rational curves on irreducible holomorphic symplectic varieties. We give a necessary and sufficient condition for a sufficiently ample linear system on a holomorphic symplectic variety of $K3^{[n]}$ -type to contain a uniruled divisor covered by rational curves of primitive class. In particular, for any fixed $n$ , we show that there are only finitely many polarization types of holomorphic symplectic variety of $K3^{[n]}$ -type that do not contain such a uniruled divisor. As an application, we provide a generalization of a result due to Beauville–Voisin on the Chow group of $0$ -cycles on such varieties.

『五行大義』의 五行 배속 고찰

Wuxingdayi(五行大義), written by So-gil of Su-Dynasty, is a book that collects and describes the records related to the five elements that remained until that time, everything, from the five intestines of the human body to insects, was assigned to the five elements, and it was intended to be widely used in various fields. In the text, the five flavors, five colors, and five tones that appear in common in various literature among the primitive classes of five elements are considered, focusing on 『Wuxingdayi(五行大義)』, also looked at the assignment of the five elements that appeared in 『Gwanja』, Jin Dynasty's 『YeoCiChunchu』, Han Dynasty’s 『Hui NamNa』, 『Chunchuburn-ro』, and 『 Baekho Tongui』, which began to deal with the Yinyang Five Elements theory in earnest after the Warring States Period. For the five flavors, both the 『Wuxingdayi』 and the comparative literature assigned as sour taste for trees, bitter taste for fire, sweet taste for earth, spicy taste for gold, and salty taste for water. The five flavors emphasized that it is inseparable from diet, and that the energy of the five elements that is lacking should be supplemented through diet. Regarding the five colors, 『Wuxingdayi』 assigned by dividing the five genuine colors and the five mixed colors. For the genuine colors, it was assigned as blue for trees, red for fire, yellow for earth, white for gold, and black for water, for the mixed colors, as green (blue+yellow) for trees, as pink for fire (red+white), as olive (yellow+black) for earth, as sky blue (white+blue) for gold, and as purple(black+red) for water. The assignment of the mixed color was made up of a superpolar relationship, and it is characterized by explaining the cause of the assignment using the clues for the combination of the ten celestial stems. Citing various documents, 『Wuxingdayi』 assigned the five tones with Gung (Earth), Sang (Gold), Gak (Tree), Chi (Fire), and Woo (Water), and only 『Gwanja』 assigned Chi and Woo differently, respectively. It was explained that the selection can be determined through sound, and that the basis of the calendar and the seasonal ordinances is the melody, which comes from the five tones.
 In short, if the assignment of the five elements for the five flavors and the five colors is related to physical health, it can be said that the assignment of five tones is related to politics.

Electromagnetically unclonable functions generated by non-Hermitian absorber-emitter.

Physically unclonable functions (PUFs) are a class of hardware-specific security primitives based on secret keys extracted from integrated circuits, which can protect important information against cyberattacks and reverse engineering. Here, we put forward an emerging type of PUF in the electromagnetic domain by virtue of the self-dual absorber-emitter singularity that uniquely exists in the non-Hermitian parity-time (PT)-symmetric structures. At this self-dual singular point, the reconfigurable emissive and absorptive properties with order-of-magnitude differences in scattered power can respond sensitively to admittance or phase perturbations caused by, for example, manufacturing imperfectness. Consequently, the entropy sourced from inevitable manufacturing variations can be amplified, yielding excellent PUF security metrics in terms of randomness and uniqueness. We show that this electromagnetic PUF can be robust against machine learning-assisted attacks based on the Fourier regression and generative adversarial network. Moreover, the proposed PUF concept is wavelength-scalable in radio frequency, terahertz, infrared, and optical systems, paving a promising avenue toward applications of cryptography and encryption.

Algebraic Attacks against Grendel: An Arithmetization-Oriented Primitive with the Legendre Symbol

The rise of modern cryptographic protocols such as Zero-Knowledge proofs and secure Multi-party Computation has led to an increased demand for a new class of symmetric primitives. Unlike traditional platforms such as servers, microcontrollers, and desktop computers, these primitives are designed to be implemented in arithmetical circuits. In terms of security evaluation, arithmetization-oriented primitives are more complex compared to traditional symmetric cryptographic primitives. The arithmetization-oriented permutation Grendel employs the Legendre Symbol to increase the growth of algebraic degrees in its nonlinear layer. To analyze the security of Grendel thoroughly, it is crucial to investigate its resilience against algebraic attacks. This paper presents a preimage attack on the sponge hash function instantiated with the complete rounds of the Grendel permutation, employing algebraic methods. A technique is introduced that enables the elimination of two complete rounds of substitution permutation networks (SPN) in the sponge hash function without significant additional cost. This method can be combined with univariate root-finding techniques and Gröbner basis attacks to break the number of rounds claimed by the designers. By employing this strategy, our attack achieves a gain of two additional rounds compared to the previous state-of-the-art attack. With no compromise to its security margin, this approach deepens our understanding of the design and analysis of such cryptographic primitives.

Polarisation of SKT Calabi-Yau ∂∂̄-manifolds by Aeppli classes

Given a ∂ ∂ ¯ \partial \bar \partial -manifold X X with trivial canonical bundle and carrying a metric ω \omega such that ∂ ∂ ¯ ω = 0 \partial \bar \partial \omega =0 , we introduce the concept of small deformations of X X polarised by the Aeppli cohomology class [ ω ] A [\omega ]_A of a strong Kähler with torsion metric ω \omega . There is a correspondence between the manifolds polarised by [ ω ] A [\omega ]_A in the Kuranishi family of X X and the Bott-Chern classes that are primitive in a sense that we define. We also investigate the existence of a primitive element in an arbitrary Bott-Chern primitive class and compare the metrics on the base space of the subfamily of manifolds polarised by [ ω ] A [\omega ]_A within the Kuranishi family.

Classification of primitive manufacturing tasks from filtered event data

Collaborative robots are increasingly present in industry to support human activities. However, to make the human–robot collaborative process more effective, there are several challenges to be addressed. Collaborative robotic systems need to be aware of the human activities to (1) anticipate collaborative/assistive actions, (2) learn by demonstration, and (3) activate safety procedures in shared workspace. This study proposes an action classification system to recognize primitive assembly tasks from human motion events data captured by a Dynamic and Active-pixel Vision Sensor (DAVIS). Several filters are compared and combined to remove event data noise. Task patterns are classified from a continuous stream of event data using advanced deep learning and recurrent networks to classify spatial and temporal features. Experiments were conducted on a novel dataset, the dataset of manufacturing tasks (DMT22), featuring 5 classes of representative manufacturing primitives (PickUp, Place, Screw, Hold, Idle) from 5 participants. Results show that the proposed filters remove about 65% of all events (noise) per recording, conducting to a classification accuracy up to 99,37% for subjects that trained the system and 97.08% for new subjects. Data from a left-handed subject were successfully classified using only right-handed training data. These results are object independent.

Geometry of Lines on a Cubic Four-Fold

Abstract For a general cubic four-fold $X\subset {\mathbb {P}}^5$ with Fano scheme of lines $F$, we prove a number of properties of the universal family of lines $I\to F$ and various subloci. We first describe the moduli and ramification theory of the genus four fibration $p:I\to X$ and explore its relation to a birational model of $F$ in $I$. The main part of the paper is devoted to describing the locus $V\subset F$ of triple lines, i.e., the fixed locus of the Voisin map $\phi :F\dashrightarrow F$, in particular proving it is an irreducible projective singular surface of class $21\textrm {c}_2({\mathcal {U}}_F)$ and detailing its intersection with the locus $S$ of second type lines. A consequence of the analysis of the singularities of $V$ is a geometric proof of the fact that if $X$ is very general, then the number of singular (necessarily 1-nodal) rational curves in $F$ of primitive class is 3780.

Instability of LRTF multiclass queueing networks

We provide an example of a strictly subcritical multiclass queueing network which is unstable under the longest remaining time first (LRTF) service discipline. It is a reentrant line with two servers and four customer classes, Poisson arrivals and deterministic service times. Our instability proof can be generalized to a class of light-tailed stochastic model primitives, including independent, identically distributed exponential service times. A similar example of an unstable deterministic, strictly subcritical LRTF network is also given. Our arguments work for any service discipline such that there are no departures from any network station during its busy period.

Shrink Generator-based Strong PUF Architecture with Improved Uniqueness and Reliability on an FPGA

Silicon-based Physically Unclonable Functions (PUFs) are a source of physical security primitive that is either implemented on ASICs or FPGAs. A class of these security primitives that provide an exponentially large set of Challenge- Response Pairs (CRPs) is termed Strong PUF. That notwithstanding, the Arbiter and Feedforward Arbiter PUFs which are traditionally Strong PUFs, are not suitable for FPGA implementation. In this paper, a newly proposed PUF architecture that improves on the existing Configurable Ring Oscillator (CRO) PUF by increasing its dynamic configurability and its level of entropy is presented. To maintain the exponentially large set of CRPs, the Shrink Generator is applied to the traditionally Weak CRO-PUF. The proposed design is implemented and tested on a spartan-6 FPGA board using the Xilinx ISE tool. The proposed architecture demonstrates a uniqueness of 50.01% and is 96.43% reliable.

Commitments via Physically Related Functions

Commitment schemes are one of the basic building blocks to construct secure protocols for multi party computation. Many recent works are exploring hardware primitives like physically unclonable functions to build keyless cryptographic protocols, with minimal assumptions. The asymmetric nature and non-invertibility property of PUFs are widely exploited to build oblivious transfer protocols that are extended to build bit-commitment schemes. However, these schemes require the physical transfer of the PUF device between the interacting parties. In this work, we introduce a new class of hardware-based primitives called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">physically related functions</i> that enable hardware circuits to securely communicate with each other over insecure channels. We propose a bit-commitment protocol based on this hardware primitive without needing any physical transfer. Our scheme is statistically hiding and computationally binding, requiring only one round of communication while being practically deployable. We explore the security properties of physically related functions, under which we prove the security of our scheme. We experimentally show that it is impossible to break the security of the scheme with more than negligible probability.

Toward a unifying framework for the modeling and identification of motor primitives.

A large body of evidence suggests that human and animal movements, despite their apparent complexity and flexibility, are remarkably structured. Quantitative analyses of various classes of motor behaviors consistently identify spatial and temporal features that are invariant across movements. Such invariant features have been observed at different levels of organization in the motor system, including the electromyographic, kinematic, and kinetic levels, and are thought to reflect fixed modules—named motor primitives—that the brain uses to simplify the construction of movement. However, motor primitives across space, time, and organization levels are often described with ad-hoc mathematical models that tend to be domain-specific. This, in turn, generates the need to use model-specific algorithms for the identification of both the motor primitives and additional model parameters. The lack of a comprehensive framework complicates the comparison and interpretation of the results obtained across different domains and studies. In this work, we take the first steps toward addressing these issues, by introducing a unifying framework for the modeling and identification of qualitatively different classes of motor primitives. Specifically, we show that a single model, the anechoic mixture model, subsumes many popular classes of motor primitive models. Moreover, we exploit the flexibility of the anechoic mixture model to develop a new class of identification algorithms based on the Fourier-based Anechoic Demixing Algorithm (FADA). We validate our framework by identifying eight qualitatively different classes of motor primitives from both simulated and experimental data. We show that, compared to established model-specific algorithms for the identification of motor primitives, our flexible framework reaches overall comparable and sometimes superior reconstruction performance. The identification framework is publicly released as a MATLAB toolbox (FADA-T, https://tinyurl.com/compsens) to facilitate the identification and comparison of different motor primitive models.

One of the isoamylase isoforms, CMI294C, is required for semi-amylopectin synthesis in the rhodophyte Cyanidioschyzon merolae.

Most rhodophytes synthesize semi-amylopectin as a storage polysaccharide, whereas some species in the most primitive class (Cyanidiophyceae) make glycogen. To know the roles of isoamylases in semi-amylopectin synthesis, we investigated the effects of isoamylase gene (CMI294C and CMS197C)-deficiencies on semi-amylopectin molecular structure and starch granule morphology in Cyanidioschyzon merolae (Cyanidiophyceae). Semi-amylopectin content in a CMS197C-disruption mutant (ΔCMS197C) was not significantly different from that in the control strain, while that in a CMI294C-disruption mutant (ΔCMI294C) was much lower than those in the control strain, suggesting that CMI294C is essential for semi-amylopectin synthesis. Scanning electron microscopy showed that the ΔCMI294C strain contained smaller starch granules, while the ΔCMS197C strain had normal size, but donut-shaped granules, unlike those of the control strain. Although the chain length distribution of starch from the control strain displayed a semi-amylopectin pattern with a peak around degree of polymerization (DP) 11–13, differences in chain length profiles revealed that the ΔCMS197C strain has more short chains (DP of 3 and 4) than the control strain, while the ΔCMI294C strain has more long chains (DP ≥12). These findings suggest that CMI294C-type isoamylase, which can debranch a wide range of chains, probably plays an important role in semi-amylopectin synthesis unique in the Rhodophyta.

Reconstructing Superquadrics from Intensity and Color Images.

The task of reconstructing 3D scenes based on visual data represents a longstanding problem in computer vision. Common reconstruction approaches rely on the use of multiple volumetric primitives to describe complex objects. Superquadrics (a class of volumetric primitives) have shown great promise due to their ability to describe various shapes with only a few parameters. Recent research has shown that deep learning methods can be used to accurately reconstruct random superquadrics from both 3D point cloud data and simple depth images. In this paper, we extended these reconstruction methods to intensity and color images. Specifically, we used a dedicated convolutional neural network (CNN) model to reconstruct a single superquadric from the given input image. We analyzed the results in a qualitative and quantitative manner, by visualizing reconstructed superquadrics as well as observing error and accuracy distributions of predictions. We showed that a CNN model designed around a simple ResNet backbone can be used to accurately reconstruct superquadrics from images containing one object, but only if one of the spatial parameters is fixed or if it can be determined from other image characteristics, e.g., shadows. Furthermore, we experimented with images of increasing complexity, for example, by adding textures, and observed that the results degraded only slightly. In addition, we show that our model outperforms the current state-of-the-art method on the studied task. Our final result is a highly accurate superquadric reconstruction model, which can also reconstruct superquadrics from real images of simple objects, without additional training.

A note on primitive classes of arithmetric rings

A note on primitive classes of arithmetric rings

Residual Learning From Demonstration: Adapting DMPs for Contact-Rich Manipulation

Manipulation skills involving contact and friction are inherent to many robotics tasks. Using the class of motor primitives for peg-in-hole like insertions, we study how robots can learn such skills. Dynamic Movement Primitives (DMP) are a popular way of extracting such policies through behaviour cloning (BC) but can struggle in the context of insertion. Policy adaptation strategies such as residual learning can help improve the overall performance of policies in the context of contact-rich manipulation. However, it is not clear how to best do this with DMPs. As a result, we consider several possible ways for adapting a DMP formulation and propose ``residual Learning from Demonstration`` (rLfD), a framework that combines DMPs with Reinforcement Learning (RL) to learn a residual correction policy. Our evaluations suggest that applying residual learning directly in task space and operating on the full pose of the robot can significantly improve the overall performance of DMPs. We show that rLfD offers a gentle to the joints solution that improves the task success and generalisation of DMPs \rb{and enables transfer to different geometries and frictions through few-shot task adaptation}. The proposed framework is evaluated on a set of tasks. A simulated robot and a physical robot have to successfully insert pegs, gears and plugs into their respective sockets. Other material and videos accompanying this paper are provided at https://sites.google.com/view/rlfd/.

Revisiting the Concrete Security of Goldreich’s Pseudorandom Generator

Local pseudorandom generators are a class of fundamental cryptographic primitives having very broad applications in theoretical cryptography. Following Couteau <i>et al.&#x2019;s</i> work at ASIACRYPT 2018, this paper further studies the concrete security of one important class of local pseudorandom generators, i.e., Goldreich&#x2019;s pseudorandom generators. Our first attack is of the guess-and-determine type. Our result significantly improves the state-of-the-art algorithm proposed by Couteau <i>et al.</i>, in terms of both asymptotic and concrete complexity, and breaks all the challenge parameters they proposed. For instance, for a parameter set suggested for 128 bits of security, we could solve the instance faster by a factor of about 2⁷⁷, thereby destroying the claimed security completely. Our second attack further exploits the extremely sparse structure of the predicate <inline-formula> <tex-math notation="LaTeX">$P_{5}$ </tex-math></inline-formula> and combines ideas from iterative decoding. This novel attack, named guess-and-decode, substantially improves the guess-and-determine approaches for cryptographic-relevant parameters. All the challenge parameter sets proposed in Couteau <i>et al.&#x2019;s</i> work in ASIACRYPT 2018 aiming for 80-bit (128-bit) security levels can be solved in about 2⁵⁸ (2⁷⁸) operations. We suggest new parameters for achieving 80-bit (128-bit) security with respect to our attacks. We also extend the attacks to other promising predicates and investigate their resistance.

Gromov–Witten theory and Noether–Lefschetz theory for holomorphic-symplectic varieties

Abstract We use Noether–Lefschetz theory to study the reduced Gromov–Witten invariants of a holomorphic-symplectic variety of $K3^{[n]}$ -type. This yields strong evidence for a new conjectural formula that expresses Gromov–Witten invariants of this geometry for arbitrary classes in terms of primitive classes. The formula generalizes an earlier conjecture by Pandharipande and the author for K3 surfaces. Using Gromov–Witten techniques, we also determine the generating series of Noether–Lefschetz numbers of a general pencil of Debarre–Voisin varieties. This reproves and extends a result of Debarre, Han, O’Grady and Voisin on Hassett–Looijenga–Shah (HLS) divisors on the moduli space of Debarre–Voisin fourfolds.

The reflectance spectra of CV–CK carbonaceous chondrites from the near-infrared to the visible

ABSTRACT Carbonaceous chondrite meteorites are so far the only available samples representing carbon-rich asteroids and in order to allow future comparison with samples returned by missions such as Hayabusa 2 and OSIRIS-Rex, it is important to understand their physical properties. Future characterization of asteroid primitive classes, some of them targeted by sample-return missions, requires a better understanding of their mineralogy, the consequences of the exposure to space weathering, and how both affect the reflectance behaviour of these objects. In this paper, the reflectance spectra of two chemically related carbonaceous chondrites groups, precisely the Vigrano (CVs) and Karoonda (CKs), are measured and compared. The available sample suite includes polished sections exhibiting different petrologic types: from 3 (very low degree of thermal metamorphism) to 5 (high degree of thermal metamorphism). We found that the reflective properties and the comparison with the Cg asteroid reflectance class point towards a common chondritic reservoir from which the CV–CK asteroids collisionally evolved. In that scenario, the CV and CK chondrites could be originated from 221 Eos asteroid family, but because of its collisional disruption, both chondrite groups evolved separately, experiencing different stages of thermal metamorphism, annealing, and space weathering.

Immunization against complete subversion without random oracles

We seek constructions of general-purpose immunizers that take arbitrary cryptographic primitives, and transform them into ones that withstand a powerful “malicious but proud” adversary, who attempts to break security by possibly subverting the implementation of all algorithms (including the immunizer itself!), while trying not to be detected. This question is motivated by the recent evidence of cryptographic schemes being intentionally weakened, or designed together with hidden backdoors, e.g., with the scope of mass surveillance.Our main result is a subversion-secure immunizer in the plain model, that works for a fairly large class of deterministic primitives, i.e. cryptoschemes where a secret (but tamperable) random source is used to generate the keys and the public parameters, whereas all other algorithms are deterministic. The immunizer relies on an additional independent source of public randomness, which is used to sample a public seed.Assuming the public source is untamperable, and that the subversion of the algorithms is chosen independently of the seed, we can instantiate our immunizer from any one-way function. In case the subversion is allowed to depend on the seed, and the public source is still untamperable, we obtain an instantiation from collision-resistant hash functions. In the more challenging scenario where the public source is also tamperable, we additionally need to assume that the initial cryptographic primitive has sub-exponential security.Previous work in the area only obtained subversion-secure immunization for very restricted classes of primitives, often in weaker models of subversion and using random oracles.