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L. T. Handoko

Publications and source records attributed to L. T. Handoko.

At least 37 records · Page 2Linked to original sources
arXiv2011

Fluid QCD approach for quark-gluon plasma in stellar structure

The quark-gluon plasma in stellar structure is investigated using the fluid-like QCD approach. The classical energy momentum tensor relevant for high energy and hot plasma having the nature of fluid bulk of gluon sea is calculated within the model. The transition of gluon field from point particle field inside stable hadrons to relativistic fluid field in hot plasma and vice versa is briefly discussed. The results are applied to construct the equation of state using the Tolman--Oppenheimer--Volkoff equation to describe the hot plasma dominated stellar structure.

hep-ph↗
arXiv2011

Conformation changes and protein folding induced by ϕ^4 interaction

A model to describe the mechanism of conformational dynamics in protein based on matter interactions using lagrangian approach and imposing certain symmetry breaking is proposed. Both conformation changes of proteins and the injected non-linear sources are represented by the bosonic lagrangian with an additional ϕ^4 interaction for the sources. In the model the spring tension of protein representing the internal hydrogen bonds is realized as the interactions between individual amino acids and nonlinear sources. The folding pathway is determined by the strength of nonlinear sources that propagate through the protein backbone. It is also shown that the model reproduces the results in some previous works.

physics.bio-ph↗
arXiv2011

Proton decay in 5D SU(6) GUT with orbifold S^1/Z_2 breaking in Scherk-Schwarz mechanism

Proton decay within 5-dimensional SU(6) GUT with orbifold S^1/Z_2 breaking is investigated using Scherk-Schwarz mechanism. It is shown that in the model neither leptoquark like heavy gauge bosons nor violation of baryon number conservation are allowed due to the orbifold breaking parity splitting. These results prevent too short proton lifetime within the model.

hep-ph↗
arXiv2011

Pattern discovery for semi-structured web pages using bar-tree representation

Many websites with an underlying database containing structured data provide the richest and most dense source of information relevant for topical data integration. The real data integration requires sustainable and reliable pattern discovery to enable accurate content retrieval and to recognize pattern changes from time to time; yet, extracting the structured data from web documents is still lacking from its accuracy. This paper proposes the bar-tree representation to describe the whole pattern of web pages in an efficient way based on the reverse algorithm. While previous algorithms always trace the pattern and extract the region of interest from \textit{top root}, the reverse algorithm recognizes the pattern from the region of interest to both top and bottom roots simultaneously. The attributes are then extracted and labeled reversely from the region of interest of targeted contents. Since using conventional representations for the algorithm should require more computational power, the bar-tree method is developed to represent the generated patterns using bar graphs characterized by the depths and widths from the document roots. We show that this representation is suitable for extracting the data from the semi-structured web sources, and for detecting the template changes of targeted pages. The experimental results show perfect recognition rate for template changes in several web targets.

cs.IR↗
arXiv2011

Real-time inclinometer using accelerometer MEMS

A preliminary design of inclinometer for real-time monitoring system of soil displacement is proposed. The system is developed using accelerometer sensor with microelectromechanical system (MEMS) device. The main apparatus consists of a single MEMS sensor attached to a solid pipe and stucked pependicularly far away below the soil surface. The system utilizes small fractions of electrical signals from MEMS sensor induced by the pipe inclination due to soil displacements below the surface. It is argued that the system is accurate enough to detect soil displacements responsible for landslides, and then realizes a simple and low cost landslide early warning system.

physics.ins-det↗
arXiv2011

The thermodynamic properties of Davydov-Scott's protein model in thermal bath

The thermodynamic properties of Davydov-Scott monomer contacting with thermal bath is investigated using Lindblad open quantum system formalism. The Lindblad equation is investigated through path integral method. It is found that the environmental effects contribute destructively to the specific heat, and large interaction between amide-I and amide-site is not preferred for a stable Davydov-Scott monomer.

cond-mat.stat-mech↗
arXiv2010

openPC : a toolkit for public cluster with full ownership

The openPC is a set of open source tools that realizes a parallel machine and distributed computing environment divisible into several independent blocks of nodes, and each of them is remotely but fully in any means accessible for users with a full ownership policy. The openPC components address fundamental issues relating to security, resource access, resource allocation, compatibilities with heterogeneous middlewares, user-friendly and integrated web-based interfaces, hardware control and monitoring systems. These components have been deployed successfully to the LIPI Public Cluster which is open for public use. In this paper, the unique characteristics of openPC due to its rare requirements are introduced, its components and a brief performance analysis are discussed.

cs.DC↗
arXiv2010

The effects of bio-fluid on the internal motion of DNA

The internal motions of DNA immersed in bio-fluid are investigated. The interactions between the fragments of DNA and the surrounding bio-fluid are modeled using the gauge fluid lagrangian. In the model, the bio-fluid is coupled to the standard gauge invariant bosonic lagrangian describing the DNA. It is shown that at non-relativistic limit various equation of motions, from the well-known Sine-Gordon equation to the simultaneous nonlinear equations, can be constructed within a single framework. The effects of bio-fluid are investigated for two cases : single and double stranded DNA. It is argued that the small and large amplitudes of a single stranded DNA motion immersed in bio-fluid can be explained in a natural way within the model as a solitonic wave regardless with the fluid velocity. In contrary the double stranded DNA behaves as regular or damped harmonic oscillator and is highly depending on the fluid velocity.

physics.bio-ph↗
arXiv2010

Modeling comminution processes in ball mills as a canonical ensemble

A new approach to describe comminution processes in general ball mills as a macroscopic canonical ensemble is proposed. Using hamiltonian method, the model is able to take simultaneously into account the internal dynamics from mechanical motions inside the vial and external effects like electromagnetic and gravitational forces. Relevant physical observables are extracted using statistical mechanics approach through partition function at finite temperature. The method enables numerical calculation using Monte Carlo technique to obtain, for instance particle number evolution in term of system temperature. It is argued that the method is experimentally more verifiable than the conventional approaches based on geometrical displacements. An example of simulation for typical spex mill is also given.

cond-mat.mes-hall↗
arXiv2010

Public Infrastructure for Monte Carlo Simulation: publicMC@BATAN

The first cluster-based public computing for Monte Carlo simulation in Indonesia is introduced. The system has been developed to enable public to perform Monte Carlo simulation on a parallel computer through an integrated and user friendly dynamic web interface. The beta version, so called publicMC@BATAN, has been released and implemented for internal users at the National Nuclear Energy Agency (BATAN). In this paper the concept and architecture of publicMC@BATAN are presented.

cs.DC↗
arXiv2010

Anharmonic oscillation effect on the Davydov-Scott monomer in thermal bath

The dynamics of Davydov-Scott monomer in a thermal bath with higher order amide-site's displacement leads to anharmonic oscillation effect is investigated using full-quantum approach and the Lindblad formulation of master equation. The specific heat is calculated based on the thermodynamic partition function using the path integral method. The temperature dependence of the specific heat is studied. In the model the specific heat anomaly as pointed out in recent works by Ingold et.al is also observed. However it is found that the anomaly occurs at high temperature region, and the anharmonic oscillation restores the positivity of specific heat.

cond-mat.stat-mech↗
arXiv2009

Preliminary simulation of temperature evolution in comminution processes in ball mills

A model for comminution processes in ball mills is presented. The model provides an empirical approach using the physically realistic modelization of the ball mill system, but also deployes the statistical method to extract relevant thermodynamics observables. Those physical observables are investigated by treating the whole system as a statistical macroscopic ensemble.

physics.comp-ph↗
arXiv2009

Extracting physical observables using macroscopic ensemble in the spex-mixer/mill simulation

A technique to simulate the spex-mixer/mill system as a macroscopic ensemble rather than a pure dynamical system is proposed. The treatment is suitable especially for comminution processes generating the nanomaterial up to nanometers scale where the geometrical displacements are unobservable. It is argued that the method is simple and experimentally verifiable since relevant physical observables can be extracted using partition function without solving the equation of motions.

physics.comp-ph↗
arXiv2009

Reverse method for labeling the information from semi-structured web pages

We propose a new technique to infer the structure and extract the tokens of data from the semi-structured web sources which are generated using a consistent template or layout with some implicit regularities. The attributes are extracted and labeled reversely from the region of interest of targeted contents. This is in contrast with the existing techniques which always generate the trees from the root. We argue and show that our technique is simpler, more accurate and effective especially to detect the changes of the templates of targeted web pages.

cs.IR↗
arXiv2009

Microcontroller based distributed and networked control system for public cluster

We present the architecture and application of the distributed control in public cluster, a parallel machine which is open for public access. Following the nature of public cluster, the integrated distributed control system is fully accessible through network using a user-friendly web interface. The system is intended mainly to control the power of each node in a block of parallel computers provided to certain users. This is especially important to extend the life-time of related hardwares, and to reduce the whole running and maintainance costs. The system consists of two parts : the master- and node-controllers, and both are connected each other through RS-485 interface. Each node-controller is assigned with a unique address to distinguish each of them. We also discuss briefly the implementation of the system at the LIPI Public Cluster.

cs.DC↗
arXiv2009

A new approach for scientific data dissemination in developing countries: a case of Indonesia

This short paper is intended as an additional progress report to share our experiences in Indonesia on collecting, integrating and disseminating both global and local scientific data across the country through the web technology. Our recent efforts are exerted on improving the local public access to global scientific data, and on the other hand encouraging the local scientific data to be more accessible for the global communities. We have maintained well-connected infrastructure and some web-based information management systems to realize such objectives. This paper is especially focused on introducing the ARSIP for mirroring global as well as sharing local scientific data, and the newly developed Indonesian Scientific Index for integrating local scientific data through an automated intelligent indexing system.

cs.CY↗
arXiv2009

Gauge invariant fluid lagrangian and its application to cosmology

A lagrangian for relativistic fluid systems with matters inside is developed using gauge principle. In the model, the gauge boson represents the fluid field in a form $A_μ\equiv ε_μϕ$, where $ε_μ$ contains the fluid kinematics and $ϕ$ is an auxiliary field representing the fluid distribution. This leads to a new relativistic equation of motion for fluid, but which further coincides to the classical Euler equation at non-relativistic limit. The lagrangian is applied to model homogeneous universe as a bulk pure fluid system. Taking the simplest case of fluid with radial velocity and uniform distribution, the free energy density is calculated and its behaviour around Hubble distance is discussed.

physics.flu-dyn↗