arXiv subjects

Iwan Setiawan

Publications and source records attributed to Iwan Setiawan.

7 recordsLinked to original sources

arXiv2026

Designing Core Layer in Campus Network Using Software-Defined Networking

As one of the layers in campus network, core layer or backbone network should provide interconnectivity and routing between internal and external networks, including other campus networks or the Internet. With that requirement, designing this layer to be highly available to interconnect and route traffic is a high priority. By using software-defined networking (SDN) paradigm, we attempt to design core layer in campus network employing best practices of network topology and routing protocol at the layer with a use case of core layer in a university campus network. We use RouteFlow as the SDN platform supporting a traditional routing protocol, i.e. Open Shortest Path First (OSPF), over OpenFlow (OF) network infrastructure. The experimental testbed/environment consists of two virtual machines (VMs). The first VM is used as the SDN/OF data plane with Open vSwitch in Mininet network emulator, and the second one representing SDN control plane comprising RouteFlow with POX controller. We evaluated the design by testing the interconnectivity using ping for the OF switches in the topology and hosts that are connected to the switches. We also tracked the route of the packets by monitoring traffic passed through all network interfaces of the switches using tcpdump. This case was evaluated since we need to make sure that packets were routed with the shortest path from source to destination using OSPF that was implemented in the virtual network at the top of the SDN platform.

cs.NI↗

arXiv2026

Redshift Suppression of Nonlinear Scalar Fields in Accelerating FLRW Spacetimes

We study small--data solutions of a nonlinear scalar field equation on spatially flat $d$--dimensional FLRW spacetimes ($d\ge4$). In conformal time $\tau$ the field satisfies a damped semilinear wave/Klein--Gordon equation with time--dependent coefficients determined by the scale factor $a(\tau)$ and the conformal Hubble rate $H(\tau)=\dot a/a$. We focus on accelerated conformal expansion of the form $H(\tau)=H_0(1+\tau)^{-\alpha}$ with $H_0>0$ and $0\le\alpha<1$, for which $a(\tau)$ grows stretched--exponentially, and we assume a power potential $V(\varphi)=-\frac{\varepsilon}{m+1}|\varphi|^{m+1}$. For global solutions arising from sufficiently small, spatially localized initial data, we introduce the conformal rescaling $\phi=a^{(d-2)/2}\varphi$, which removes the first--order Hubble damping and exposes the interaction as a \emph{time--dependent coupling}. In the rescaled equation the nonlinearity is weighted by $g(\tau)=a(\tau)^{\sigma}$ with $\sigma=\frac{d+2-(d-2)m}{2}$, so the conformal power $m_{\mathrm{conf}}=\frac{d+2}{d-2}$ is the sharp threshold for redshift suppression: $g$ decays for $m>m_{\mathrm{conf}}$, is constant for $m=m_{\mathrm{conf}}$ (classical conformal invariance), and grows for $1 m_{\mathrm{conf}}$, we prove that $g\in L^1([0,\infty))$ and deduce small--data global existence together with scattering/asymptotic linearization for $\phi$. As a complementary result in the diffusion--dominated regime $1<m<1+\frac{2}{d-1}$, we adapt a weighted energy method for variable damping to deduce explicit $L^2$ and $L^1$ decay rates. These bounds provide a quantitative PDE formulation of redshift--induced suppression of nonlinear scalar self--interactions at late conformal times.

math.AP↗

arXiv2023

Energy-Efficient Softwarized Networks: A Survey

With the dynamic demands and stringent requirements of various applications, networks need to be high-performance, scalable, and adaptive to changes. Researchers and industries view network softwarization as the best enabler for the evolution of networking to tackle current and prospective challenges. Network softwarization must provide programmability and flexibility to network infrastructures and allow agile management, along with higher control for operators. While satisfying the demands and requirements of network services, energy cannot be overlooked, considering the effects on the sustainability of the environment and business. This paper discusses energy efficiency in modern and future networks with three network softwarization technologies: SDN, NFV, and NS, introduced in an energy-oriented context. With that framework in mind, we review the literature based on network scenarios, control/MANO layers, and energy-efficiency strategies. Following that, we compare the references regarding approach, evaluation method, criterion, and metric attributes to demonstrate the state-of-the-art. Last, we analyze the classified literature, summarize lessons learned, and present ten essential concerns to open discussions about future research opportunities on energy-efficient softwarized networks.

cs.NI↗

arXiv2023

Fast-forward adiabatic quantum dynamics of XY spin model on three spin system

We discussed a method to accelerate an adiabatic quantum dynamics of XY spin model by using the fast-forward method proposed by Masuda and Nakamura. The Accelerated scheme is constructed by adding the driving Hamiltonian to the original Hamiltonian and speeding it up with a large time-scaling factor and an adiabatic parameter that realizes adiabatic quantum dynamics in a shortened time. Accelerated adiabatic dynamics start by assuming the candidate of driving Hamiltonian consists of the pair-wise exchange interaction and magnetic field. The driving Hamiltonian terms multiplied by the velocity function together with the original Hamiltonian give fast-forward driving for adiabatic states. We apply our method to XY spin model by considering three spin systems on the Kagome lattice. In this model, we obtained the XY pair-wise exchange interaction of nearest neighbors and next-nearest neighbors should be added to the original Hamiltonian as a driving interaction to accelerate the adiabatic motion. This pair-wise driving interaction in the fast-forward scheme guarantees the complete fidelity of accelerated states.

quant-ph↗

arXiv2022

Bound States of Central Force System in Special Relativity

In this paper we consider the central force problem in the special theory of relativity. We derive the special relativistic version of the Binet equation describing the orbit of a body. Then, the motion of a planet in a solar-like system where the gravitational potential is modified by adding a term that is proportional to the inverse of the square of the radial coordinate is discussed. Using perturbative method, we obtain the explicit orbital function. At the end, the orbital precession of the planet and its relation to the result from general relativity are also discussed.

physics.class-ph↗

arXiv2019

Fast-forward approach to adiabatic quantum dynamics of regular spin clusters: nature of geometry-dependent driving interactions

The fast forward scheme of adiabatic quantum dynamics is applied to finite regular spin clusters with various geometries and the nature of driving interactions is elucidated. The fast forward is the quasi-adiabatic dynamics guaranteed by regularization terms added to the reference Hamiltonian, followed by a rescaling of time with use of a large scaling factor. With help of the regularization terms consisting of pair-wise and 3-body interactions, we apply the proposed formula (Phys. Rev.A 96, 052106(2017)) to regular triangle and open linear chain for N = 3 spin systems, and to triangular pyramid, square, primary star graph and open linear chain for N = 4 spin systems. The geometry-induced symmetry greatly decreases the rank of coefficient matrix of the linear algebraic equation for regularization terms. Choosing a transverse Ising Hamiltonian as a reference, we find: (1) for N = 3 spin clusters, the driving interaction consists of only the geometry-dependent pairwise interactions and there is no need for the 3-body interaction; (2) for N = 4 spin clusters, the geometry-dependent pair-wise interactions again constitute major part of the driving interaction, whereas the universal 3-body interaction free from the geometry is necessary but plays a subsidiary role. Our scheme predicts the practical driving interaction in accelerating the adiabatic quantum dynamics of structured regular spin clusters.

quant-ph↗

arXiv2017

Fast forward of adiabatic spin dynamics of entangled states

We develop a scheme of fast forward of adiabatic spin dynamics of quantum entangled states. We settle the quasi-adiabatic dynamics by adding the regularization terms to the original Hamiltonian and then accelerate it with use of a large time-scaling factor. Assuming the experimentally-realizable candidate Hamiltonian consisting of the exchange interactions and magnetic field, we solved the regularization terms. These terms multiplied by the velocity function give rise to the state-dependent counter-diabatic terms. The scheme needs neither knowledge of full spectral properties of the system nor solving the initial and boundary value problem. Our fast forward Hamiltonian generates a variety of state-dependent counter-diabatic terms for each of adiabatic states, which can include the state-independent one. We highlight this fact by using minimum (two-spin) models for a simple transverse Ising model, quantum annealing and generation of entanglement.

quant-ph↗