3,266 research outputs found
Face Validation Method Alternatives for Shiphandling Fuzzy Logic Difficulty Model
The development of shiphandling difficulty model for ferry is based on the empirical experience through the Master of Ro-Ro ferries. The SHDMF is consisted from two parts which are the Analytic Hierarchy Process (AHP) and Fuzzy Inference System. Both parts had been validated through internal validation in the form of consistency test for the first part and robustness test for the second part. Further, the external/face validation is required to compare the proposed model with similar model through benchmarking approach. The benchmarking approaches are elaborated for the reliability, validity, possibility, efficiency and effectiveness. Through fuzzy group decision making method, the questionnaire survey is performed to verify the most appropriate approach based on the shiphandling simulator as the most preferred benchmarking tool by experts. Next, the proposed scenario is overviewed and discussed especially related to the advantages and drawbacks of shiphandling simulator. Keywords: shiphandling difficulty, fuzzy group decision making, internal validation Model pengukuran kesulitan pengendalian feri didasarkan pada pengalaman empiris melalui pernyataan nahkoda kapal feri Ro-Ro. SHDMF terdiri atas dua bagian, yaitu Analytic Hierarchy Process dan Fuzzy Inference System. Kedua bagian ini telah divalidasi melalui validasi internal dalam bentuk uji konsistensi untuk bagian pertama dan uji kehandalan untuk bagian kedua. Selanjutnya validasi atau wajah eksternal diperlukan untuk membandingkan model yang diusulkan dengan model yang diperoleh dari benchmarking. Pendekatan benchmarking dijabarkan untuk kehandalan, validitas, kemungkinan, efisiensi, dan efektivitas. Melalui metode fuzzy kelompok pembuatan keputusan, survei kuesioner dilakukan untuk memverifikasi pendekatan yang paling tepat dengan simulator pengendalian kapal sebagai alat yang paling disukai oleh para ahli untuk benchmarking. Selanjutnya skenario yang ditinjau-ulang dan dibahas terutama terkait dengan keuntungan dan kelemahan simulator pengendalian kapal. Kata
Pemanfaatan Bottom Ash Sebagai Agregat Buatan
The aim of this study is to explore the possible use of bottom ash as artificial aggregates. It is found that the pelletizer method by using mixer without blade is one possibility to manufacture artificial aggregates. The optimum mixture composition of artificial aggregate is found to be 3 BA : 1FA : 0,5 C , by weight, and immersed once in cement slurry. The water content in ssd condition is 27% with the compressive strength of the aggregate 2.4 MPa on the seventh day. Concrete produced with mixture compositition of 1 cement : 1.5 sand by weight, resulted in water content of 14.63% in ssd condition and compresive strength of 14.20 MPa at 28th day
Nonlinear mechanics with photonic crystal nanomembranes
Optomechanical systems close to their quantum ground state and nonlinear
nanoelectromechanical systems are two hot topics of current physics research.
As high-reflectivity and low mass are crucial features to improve
optomechanical coupling towards the ground state, we have designed, fabricated
and characterized photonic crystal nanomembranes, at the crossroad of both
topics. Here we demonstrate a number of nonlinear effects with these membranes.
We first characterize the nonlinear behavior of a single mechanical mode and we
demonstrate its nonlocal character by monitoring the subsequent
actuation-related frequency shift of a different mode. We then proceed to study
the underlying nonlinear dynamics, both by monitoring the phase-space
trajectory of the free resonator and by characterizing the mechanical response
in presence of a strong pump excitation. We observe in particular the frequency
evolution during a ring-down oscillation decay, and the emergence of a phase
conjugate mechanical response to a weaker probe actuation. Our results are
crucial to understand the full nonlinear features of the PhC membranes, and
possibly to look for nonlinear signatures of the quantum dynamics
Inhomogeneous Quasi-stationary States in a Mean-field Model with Repulsive Cosine Interactions
The system of N particles moving on a circle and interacting via a global
repulsive cosine interaction is well known to display spatially inhomogeneous
structures of extraordinary stability starting from certain low energy initial
conditions. The object of this paper is to show in a detailed manner how these
structures arise and to explain their stability. By a convenient canonical
transformation we rewrite the Hamiltonian in such a way that fast and slow
variables are singled out and the canonical coordinates of a collective mode
are naturally introduced. If, initially, enough energy is put in this mode, its
decay can be extremely slow. However, both analytical arguments and numerical
simulations suggest that these structures eventually decay to the spatially
uniform equilibrium state, although this can happen on impressively long time
scales. Finally, we heuristically introduce a one-particle time dependent
Hamiltonian that well reproduces most of the observed phenomenology.Comment: to be published in J. Phys.
Anomalous diffusion as a signature of collapsing phase in two dimensional self-gravitating systems
A two dimensional self-gravitating Hamiltonian model made by
fully-coupled classical particles exhibits a transition from a collapsing phase
(CP) at low energy to a homogeneous phase (HP) at high energy. From a dynamical
point of view, the two phases are characterized by two distinct single-particle
motions : namely, superdiffusive in the CP and ballistic in the HP. Anomalous
diffusion is observed up to a time that increases linearly with .
Therefore, the finite particle number acts like a white noise source for the
system, inhibiting anomalous transport at longer times.Comment: 10 pages, Revtex - 3 Figs - Submitted to Physical Review
KASCADE: Astrophysical results and tests of hadronic interaction models
KASCADE is a multi-detector setup to get redundant information on single air
shower basis. The information is used to perform multiparameter analyses to
solve the threefold problem of the reconstruction of (i)the unknown primary
energy, (ii) the primary mass, and (iii) to quantify the characteristics of the
hadronic interactions in the air-shower development. In this talk recent
results of the KASCADE data analyses are summarized concerning cosmic ray
anisotropy studies, determination of flux spectra for different primary mass
groups, and approaches to test hadronic interaction models. Neither large scale
anisotropies nor point sources were found in the KASCADE data set. The energy
spectra of the light element groups result in a knee-like bending and a
steepening above the knee. The topology of the individual knee positions shows
a dependency on the primary particle. Though no hadronic interaction model is
fully able to describe the multi-parameter data of KASCADE consistently, the
more recent models or improved versions of older models reproduce the data
better than few years ago.Comment: to appear in Nucl. Phys. B (Proc. Suppl.), Proc. of the XIII
ISVHECRI, Pylos 2004 - with a better quality of the figure
Pengaplikasian Lumpur Sidoarjo Kadar Tinggi Pada Mortar Dan Beton
Berbagaipenelitian mengenai pemanfaatan material lumpur Sidoarjo, khususnya sebagai material pengganti semen (pozzolan) telah dilakukan. Penelitian ini berfokus pada penggunaan lumpur Sidoarjo dengan kadar yang tinggi, yaitu >50%, serta membandingkan hasil tersebut dengan fly ash. Analisa terhadap materialdilakukan menggunakan XRF (X-Ray Flouresence) untuk mengetahui karakteristik dari material tersebut. Analisa juga dilakukan terhadap pengaruh ukuran butiranmenggunakan PSA (Particle Size Analysis).Lumpur dilakukan treatment dari pengeringan, pembakaran hingga digiling menggunakan bar-mill dengan lama penggilingan bervariasi untuk mendapatkan ukuran butiran berbeda. Presentase kadar yang digunakan adalah 50%, 55% dan 60% dari total cementitious material. Mortar dan beton digunakan ukuran 5x5x5 cm3 dan 15x15x15 cm3 lalu dilakukan pengujian berupa kuat tekan, workability dan setting time. Hasil menunjukkan semakin halus ukuran butiran, semakin tinggi kuat tekan dan workability-nya. Diantara kadar 50%-60% penggantian semen dengan lumpur Sidoarjo, kadar 50% merupakan yang paling efektif.Pada beton dengan lumpur Sidoarjo menghasilkan slump test sebesar 8,5 cm dengan kuat tekan 34,07 MPa pada umur 37 hari
First and second order clustering transitions for a system with infinite-range attractive interaction
We consider a Hamiltonian system made of classical particles moving in
two dimensions, coupled via an {\it infinite-range interaction} gauged by a
parameter . This system shows a low energy phase with most of the particles
trapped in a unique cluster. At higher energy it exhibits a transition towards
a homogenous phase. For sufficiently strong coupling an intermediate phase
characterized by two clusters appears. Depending on the value of the
observed transitions can be either second or first order in the canonical
ensemble. In the latter case microcanonical results differ dramatically from
canonical ones. However, a canonical analysis, extended to metastable and
unstable states, is able to describe the microcanonical equilibrium phase. In
particular, a microcanonical negative specific heat regime is observed in the
proximity of the transition whenever it is canonically discontinuous. In this
regime, {\it microcanonically stable} states are shown to correspond to {\it
saddles} of the Helmholtz free energy, located inside the spinodal region.Comment: 4 pages, Latex - 3 EPS Figs - Submitted to Phys. Rev.
Perendaman Benih Saga (Adenanthera Pavonina L.) dengan Berbagai Konsentrasi Air Kelapa untuk Meningkatkan Kualitas Kecambah
This research aimed to determine the effect of soaking Adenanthera pavonina in various of coconut water concentration to improve the quality of seed germinated and know the best concentration Adenanthera pavoninasoaking in coconut water to maintain the quality of seed germinated. The research method used in completely randomized design (CRD) with 4 treatments, 1 control and 3 replications. The treatment consisted of: K0= saga seeds without soaking coconut water; K1=soakingsaga seeds in 25% coconut water; K2= soaking saga seeds in 50% coconut water; K3= soaking sagaseeds in 75% coconut water; K4= soaking sagaseeds in 100% coconut water. Research has shown that soaking the Adenanthera pavonina seedin 50% coconut water has significant effect tothe high increase of seed germination(10,3cm) and soaking the Adenanthera pavonina seed in coconut water has no significant effect on power of germinated, speed of seed germinated, speed ofseed germination at 80% and percentage of seeds germinate
Solvable model of a phase oscillator network on a circle with infinite-range Mexican-hat-type interaction
We describe a solvable model of a phase oscillator network on a circle with
infinite-range Mexican-hat-type interaction. We derive self-consistent
equations of the order parameters and obtain three non-trivial solutions
characterized by the rotation number. We also derive relevant characteristics
such as the location-dependent distributions of the resultant frequencies of
desynchronized oscillators. Simulation results closely agree with the
theoretical ones
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