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Decoupling of a heavy flavor in QCD is discussed in a pedagogical way. First we consider a simpler case: decoupling of muons in QED. All calculations are done up to two loops.

I revisit here the decoupling theorem in top-quark productions/decays, which states that the angular distribution of any final-particle produced in those processes does not depend on any possible nonstandard top-quark decay interactions at their leading order when certain conditions are satisfied. Toward a simple, intuitive and visual understanding of this theorem, I will study to what extent we could explain why such a theorem holds without relying on any specific/detailed calculations.

In this paper a simple method for multi-channel Active Noise Control (ANC) is introduced. The proposed structure is a combination of an adaptive FIR filter, based on the FXLMS algorithm, and the ALIGN algorithm resulting in a decoupled matrix for secondary path transfer function.

This structure thus converts a multi-channel ANC system to decoupled systems which results in the reduction in computational load without affecting the convergence behavior of the FXLMS system.

Modularity — the decoupling of software units — is essential for composition of real software systems from ready-made components. But for a long time one lacked a formal theory of modularity. Recently we have been developing Linear Software Models as rigorous theoretical modularity standards based upon plain Linear Algebra. By these models, decoupling means just linear independence, within a modularity matrix. This paper applies Linear Software Models to software systems, obtaining three consequences: (1) besides decoupling, various informal notions of software engineering, such as software modules, cohesion, and single responsibility, have for the first time a well-defined formal counterpart; (2) canonical building blocks like Software Design Patterns strictly obey the Linear Software Models; (3) larger software systems obey bordered Linear Models, allowing precise location and visualization of residual coupling. The latter consequences are demonstrated by case studies of software systems from the literature. The applicability of the Linear Software Models is quantitatively shown to scale well with system size, for the given case studies.

Modularity Matrices for software systems can be put in block-diagonal form, where blocks are higher-level software modules, in a hierarchy of modules. But the exact module boundaries are often blurred by the uncertainty whether given matrix elements are module members or outliers. This paper provides an algorithm to determine module sizes. As a consequence the algorithm also decides which matrix elements are outliers. Matrix elements are weighted by their Affinity — an exponential function of the off-diagonality. The module size is given by the positive consecutive elements of the eigenvectors corresponding to the largest eigenvalues of this weighted symmetrized Modularity Matrix. By means of case studies, we illustrate the idea that outliers not only indicate the need for system redesign, but explicitly point out to problematic design spots. This work extends the applicability of linear algebra spectral methods to Modularity Matrices, at higher software abstraction levels than previously shown.

A general definition of the model-space effective interaction is given. The energy-independent effective Hamiltonians derived in a time-independent way are classified systematically.

A symbolic innovation is one that stands for something else. Here we will explore eight conditions resulting from a bipolar configuration of stakeholder interests, extrinsic benefits, and intrinsic benefits that have different consequences for the decoupling of innovation adoption and of implementation for symbolic innovations. The underlying forces, or generative motors, that drive these processes are quite different with stakeholder interests and extrinsic social, bandwagon effects much more important in adoption and more immediate, intrinsic benefits coming to the fore in implementation. The degree to which these factors converge produces conditions that are more likely to result in innovations that have positive performance impacts.

We consider an open Dicke model comprising a single infinite-component vector spin and a single-mode harmonic oscillator which are connected by Jaynes–Cummings-type interaction between them. This open quantum model is referred to as the OISD (Open Infinite-component Spin Dicke) model. The algebraic structure of the OISD Liouvillian is studied in terms of superoperators acting on the space of density matrices. An explicit invertible superoperator (precisely, a completely positive trace-preserving map) is obtained that transforms the OISD Liouvillian into a sum of two independent Liouvillians, one generated by a dressed spin only, the other generated by a dressed harmonic oscillator only. The time evolution generated by the OISD Liouvillian is shown to be asymptotically equivalent to that generated by an adjusted decoupled Liouvillian with some synchronized frequencies of the spin and the harmonic oscillator. This asymptotic equivalence implies that the time evolution of the OISD model dissipates completely in the presence of any (tiny) dissipation.

The paper explores process management standards in software development organisations. It centres on the question how organisations manage the compliance with process standards as well as the need for ongoing technical innovation at the same time. It refers to former studies where it was concluded that process management standards tend to crowd out technical innovations in organisations. By reconsidering the coupling approach of Orton and Weick (1990) we show based on four case studies that it does not apply to those organisations which allow innovating activities being loosely coupled or decoupled from the reigning standard script. These organisations sustain their chances for incremental and fundamental technical innovations. Dealing with loosely coupled or decoupled innovating activities implies a dialectical standard management. It means that potentially contradictory and conflict-ridden activities like standardised practices and innovating activities are manageable by specific institutional, temporarily limited and formal/informal solutions. Furthermore, we scrutinise in this paper the decoupling discussion of some parts of the standard management literature. Standard decoupling is often seen as an unfortunate, but necessary solution to cope with external pressure for internal standardisation. In contrast to this, we develop an understanding where standard decoupling is not defined as a set of activities without affecting the 'technical core' of an organisation. (Brunsson and Jacobsson, 2000b; Meyer and Rowan, 1967). Rather, decoupling is seen as a temporary and locally limited situation of an innovating subsystem within an organisation where it is allowed to detach from reigning standardised practices and to test and develop innovative ideas under less formalised conditions.

Prior literature highlights the competing institutional logics corporate venture capital (CVC) units have to face due to their intermediary position between the two environments in which they operate — the VC industry and the corporate firm. By conducting an inductive case study of 20 CVC units, we unravel how novel organisational subunits reconcile the conflicting logics in terms of their organisational structure. We show that, instead of fully aligning with one or the other environment, most units form hybrid organisations incorporating elements of both logics. Our data suggest that CVC units tend to follow the hybridisation strategy of selective coupling rather than apply strategies of compromising or decoupling. The type of structure depends on factors on the intra-, inter-organisational and industry level. We further suggest a specific hybridisation pattern that is especially beneficial in the achievement of a unit’s strategic objectives. Our findings contribute to both institutional theory and CVC literature.

Full encapsulating rock bolts are widely used in mining and civil engineering to keep the stability of underground excavations. Nevertheless, decoupling at the interface between the bolt and grout (first interface) still occurs. To disclose the loading mechanism of the bolting system and preventing decoupling at the first interface, experimental and analytic studies were conducted in this paper. First, a nonlinear shearing-slipping law is used to describe the coupling and decoupling behavior of the first interface. Then, this shearing-slipping law is merged into the anchorage body. Following this, the whole loading process is divided into two components: elastic period and elastic-plastic period. Consequently, the analytic force-deformation relation of bolts is obtained. To confirm the rationality of this solution, experimental tensile tests on bolts were performed. It shows that there was a good match between analytic results and experimental tests. With the confirmed analytic solution, a parameter study is performed to investigate the impact of shearing-slipping parameters on the bolting performance. It indicates that increasing the shearing strength of the first interface and the shearing slipping have a positive impact in improving the bearing capacity of bolts. Inversely, the softening coefficient for the post-failure stage has a negative impact on determining the bearing capacity of bolts. Overall, the shearing strength of the first interface has a major impact in determining the loading performance of bolts.

We prove the universal asymptotically almost sure non-singularity of general Ginibre and Wigner ensembles of random matrices when the distribution of the entries are independent but not necessarily identically distributed and may depend on the size of the matrix. These models include adjacency matrices of random graphs and also sparse, generalized, universal and banded random matrices. We find universal rates of convergence and precise estimates for the probability of singularity which depend only on the size of the biggest jump of the distribution functions governing the entries of the matrix and not on the range of values of the random entries. Moreover, no moment assumptions are made about the distributions governing the entries. Our proofs are based on a concentration function inequality due to Kolmogorov, Rogozin and Kesten, which allows us to improve universal rates of convergence for the Wigner case when the distribution of the entries do not depend on the size of the matrix.

In this paper, we study the condition number of a random Toeplitz matrix. As a Toeplitz matrix is a diagonal constant matrix, its rows or columns cannot be stochastically independent. This situation does not permit us to use the classic strategies to analyze its minimum singular value when all the entries of a random matrix are stochastically independent. Using a circulant embedding as a decoupling technique, we break the stochastic dependence of the structure of the Toeplitz matrix and reduce the problem to analyze the extreme singular values of a random circulant matrix. A circulant matrix is, in fact, a particular case of a Toeplitz matrix, but with a more specific structure, where it is possible to obtain explicit formulas for its eigenvalues and also for its singular values. Among our results, we show the condition number of a non-symmetric random circulant matrix ${{𝒞}}_n$ of dimension $n$ under the existence of the moment generating function of the random entries is $\kappa ({{𝒞}}_n)=\text{O}(\frac{1}{𝜀}{n}^{\rho +1/2}{(logn)}^{1/2})$ with probability $1-\text{O}(({𝜀}^2+𝜀)n^{-2\rho }+n^{-1/2+\text{o}(1)})$ for any $𝜀>0$, $\rho \in (0,1/4)$. Moreover, if the random entries only have the second moment, the condition number satisfies $\kappa ({{𝒞}}_n)=\text{O}(\frac{1}{𝜀}{n}^{\rho +1/2}logn)$ with probability $1-\text{O}(({𝜀}^2+𝜀)n^{-2\rho }+{(logn)}^{-1/2})$. Also, we analyze the condition number of a random symmetric circulant matrix ${{𝒞}}_n^{\mathrm{\text{sym}}}$. For the condition number of a random (non-symmetric or symmetric) Toeplitz matrix ${{𝒯}}_n$ we establish $\kappa ({{𝒯}}_n)\le \kappa ({{𝒞}}_{2n}){({\sigma }_{min}(C_{2n}){\sigma }_{min}({{𝒮}}_n))}^{-1}$, where ${\sigma }_{min}(A)$ is the minimum singular value of the matrix $A$. The matrix $C_{2n}$ is a random circulant matrix and ${{𝒮}}_n:=F_{2,n}^{\ast }{D}_{1,n}^{-1}{F}_{2,n}+F_{4,n}^{\ast }{D}_2^{-1}{F}_{4,n}$, where $F_{2,n},F_{4,n}$ are deterministic matrices, $F^{\ast }$ indicates the conjugate transpose of $F$ and $D_{1,n},D_{2,n}$ are random diagonal matrices. From random experiments, we conjecture that ${{𝒮}}_n$ is well-conditioned if the moment generating function of the random entries of ${{𝒞}}_{2n}$ exists.

“Technological decoupling” has become a key factor that affects China-U.S. relations. The United States has been trying to cut its ties with China in the field of emerging technologies in an attempt to win the bilateral strategic competition. Compared with traditional high technologies, emerging technologies have lots of uncertain implications, and the security problems brought by these technologies have made the United States fall into the dilemma of “insecurity.” As a result, successive U.S. administrations view “decoupling” as both a strategic move to address challenges from emerging technologies and a means to suppress China’s development. Taken together, national security, ideology, and competition in the digital industry are distinct motivations behind the U.S. technological decoupling with China. Toward this end, the United States has formulated whole-of-government and whole-of-society measures, aiming at decoupling through a combination of domestic and foreign policy tools. As the target of technological decoupling, China holds the belief that the U.S. policy is a strategic misjudgment which is incompatible with the development trends of emerging technologies. Instead, China and the United States should strengthen their collaboration at levels of technology, industry, security, and ideology to reduce the risk of miscalculation and enhance ties in emerging technologies.

Developed countries, led by the United States and the European Union, have stepped up security review of supply chains and adopted a series of restrictive policies and protectionist measures to reshape a more secure, sustainable, and risk-controllable supply chain. A key objective of the West’s supply chain strategy is to wean their economies off Chinese influence by resorting to discriminatory policies. Supply chain interventionism on national security grounds violates market rules on which the global supply chain is based, and also runs counter to the principles of nondiscrimination and liberalization embedded in the multilateral trade governance architecture. Global supply chain reshuffles will take time and incur huge costs, leaving ample room for Beijing to make necessary adjustments and bolster its position in global supply networks.

Microbial cell factories are subjected to rewiring of basic metabolism to enhance the carbon flux towards the desired product pathway. Conventionally, this metabolic engineering approach often involves over-expression of pathway genes and knocking out genes in the competing pathways. However, these approaches result in severe metabolic burden and eventual poor performance of the cells. Particularly, where biomass formation and product synthesis depend on common precursors, permanent changes like knocking out genes will only result in poor titer. Hence, temporary decoupling of biomass formation and product synthesis is considered to be a potential alternative. In this study, we designed synthetic riboregulators, which are RNA-based genetic switches, to shunt metabolic pathways in Lactococcus lactis bacteria, a GRAS organism employed as a cell factory for many biocompounds. The riboregulators are then subjected to evaluation by tagging the cis-repressive sequence (crRNA) to mCherry, a fluorescent reporter and regulated by the constitutive promoter, $PpepN$. The trans-activating RNA (taRNA) that interacts with the crRNA is placed under the control of another inducible promoter, $Pnis$. First, we observed that when there is no induction of taRNA, there is negligible fluorescence of mCherry indicating the successful repression of translation by the cis-sequence as expected. This has been further verified by comparing this expression level with the expression level of $PpepN$-mCherry without the cis-sequence, using fluorometer. Results from this analysis suggest that there is $\sim 97$% repression by the designed crRNA sequence. Next, we induced the cells with 2ng/mL of nisin in the mid-log phase. Upon induction, there is a maximum of three fold increase in the fluorescence levels when compared to the uninduced cells, suggesting that the trans-activation takes place inside the live cells. However, further studies are necessary to optimize the cis-trans ratio to achieve better dynamic range for expression modulation and time window for operating metabolic shunting of competing pathways successfully in L. lactis.

Experts and scholars are increasingly discussing the trend of US–China decoupling in the context of the two countries’ intensifying strategic conflict. This inevitable trend, though only in the early stages, has already had a significant impact in a variety of fields, including technology, investing, and banking, and is predicted to continue to grow in the future. In areas including capital markets, financial services, investments, and financial institutions, the paper clarifies the financial decoupling between the US and China. As a result of the two countries’ intense competitiveness with one another in a wide range of industries, there was a financial decoupling between the US and China. China is seeking to create its own system which includes independent financial institutions from the US-established or US-based institutions, thereby, creating independence and competing with US’s position. The US, for its part, has been proactive in conducting strong decoupling in the stock market by restricting investment in China and increasing scrutiny of the presence of some Chinese military-related companies on the US stock market. However, due to mutual interests, both countries seem to have the dilemma of separating from each other. The two countries continue the trend of decoupling but at the same time, increase cooperation in various areas including financial services. The decoupling process between the world’s two leading powers has a direct, multi-dimensional, lasting and profound impact not only on the two countries but also on the global system of institutions, rules and standards, in which the challenge side is bigger than the opportunity side. As a partner of both the US and China, Vietnam also faces direct challenges from the financial decoupling of these two powers.

We consider the renormalization of the one-loop effective action for the Yukawa interaction. We compute the beta functions in the generalized DeWitt-Schwinger subtraction scheme. For the quantized scalar field we obtain that all the beta functions exhibit decoupling for heavy fields as stated by the Appelquist-Carazzone theorem including also the gravitational couplings. For the quantized Dirac field, decoupling appears for almost all of them. We obtain the atypical result that the mass parameter of the background scalar field, does not decouple.

Recent results on four-loop tadpoles amplitudes and their implications for precision calculations are presented.

In this paper, a printed MIMO antenna for WLAN application is presented. With two planar antenna elements, a compact size of 36×17 mm² is achieved and two operating bands for WLAN (at 2.4 GHz and 5.5 GHz) are obtained. Each antenna element consists of two folded strips, which generate the two operating bands respectively. A ground stub is introduced between two elements to improve the isolation and high isolation of more than 15 dB at the entire operating bands is achieved.