Prediction for Irregular Ocean Wave and Floating Body Motion by Regularization: Part 1. Irregular Wave Prediction

Ocean waves can be explained in terms of many factors, including wave spectrum, which has the characteristics of wave height and periodicity, directional spreading function, which has a directional property, and random phase, which randomly represents a certain property. Under the assumption of a linear system, ocean waves show irregular behaviours, which can be observed in the forms of wave spectrum, directional spreading function, and complex phase calculations using the method of linear superposition. Ocean waves, which include a variety of periodic elements, exhibit direct proportionality between their period and propagation velocity. The purpose of this study was to understand the phase components of the period and to make exact calculations on the deterministic phase in order to make predictions on ocean waves. However, measurements of actual ocean waves exist only in the form of information on wave elevation, so we faced an inverse problem of having to analyse this information and calculate the deterministic phase. Regularization was used as part of the solution, and various methods were used to obtain stable values

Prediction for Irregular Ocean Wave and Floating Body Motion by Regularization: Part 2. Motion Prediction

In the analysis of the motion of a floating body, the domains can broadly be divided into the frequency domain and the time domain. The essence of the frequency domain analysis lies in calculating the hydrodynamic coefficient from the equation of motion, which has six degrees of freedom, by applying several methods. In this research, Bureau Veritas’s “HydroStar” software was used, and the comparison and the verification were carried out by experiments. For the time domain analysis, we used an existing method proposed by Cummins and made motion predictions by using deterministic random phases calculated in the time domain calculations of the excitation force. Lastly, the potential of wave and motion predictions was verified through the data obtained from a motion analysis experiment using a tension leg platform in the context of irregular waves

Two-dimensional heterogeneous photonic bandedge laser

We proposed and realized a two-dimensional (2D) photonic bandedge laser surrounded by the photonic bandgap. The heterogeneous photonic crystal structure consists of two triangular lattices of the same lattice constant with different air hole radii. The photonic crystal laser was realized by room-temperature optical pumping of air-bridge slabs of InGaAsP quantum wells emitting at 1.55 micrometer. The lasing mode was identified from its spectral positions and polarization directions. A low threshold incident pump power of 0.24mW was achieved. The measured characteristics of the photonic crystal lasers closely agree with the results of real space and Fourier space calculations based on the finite-difference time-domain method.Comment: 14 pages, 4 figure

PPIRank - an advanced method for ranking protein-protein interations in TAP/MS data

Background: Tandem affinity purification coupled with mass-spectrometry (TAP/MS) analysis is a popular method for the identification of novel endogenous protein-protein interactions (PPIs) in large-scale. Computational analysis of TAP/MS data is a critical step, particularly for high-throughput datasets, yet it remains challenging due to the noisy nature of TAP/MS data. Results: We investigated several major TAP/MS data analysis methods for identifying PPIs, and developed an advanced method, which incorporates an improved statistical method to filter out false positives from the negative controls. Our method is named PPIRank that stands for PPI ranking in TAP/MS data. We compared PPIRank with several other existing methods in analyzing two pathway-specific TAP/MS PPI datasets from Drosophila. Conclusion: Experimental results show that PPIRank is more capable than other approaches in terms of identifying known interactions collected in the BioGRID PPI database. Specifically, PPIRank is able to capture more true interactions and simultaneously less false positives in both Insulin and Hippo pathways of Drosophila Melanogaster

Wave Run-Up Phenomenon on Offshore Platforms: Part 1. Tension Leg Platform

This study reports on an extensive experimental campaign carried out to evaluate non-linear waves applied to offshore structures in extreme marine environments. An offshore tension leg platform (TLP) model was used to observe the waves around a fixed-type offshore structure. The wave amplitude measured in the experiments of this study was indicated as a wave run-up ratio. Both the first-order analysis and the analysis of the entire wave amplitude were described. The experimental results were compared with the calculations from a potential-based code in order to verify the effectiveness of the developed technology

REMOTE SENSING OF WAVE DIRECTIONALITY BY TWO-DIMENSIONAL DIRECTIONAL WAVELETS: PART 1. THE DETECTION TOOLS OF DIRECTIONALITY IN SIGNALS

This paper presents the results of a study investigating methods of wave directionality based on wavelet transform. In part 1 of this paper, the theoretical background and characteristics of directional wavelet were discussed. Morlet wavelet and Cauchy wavelet were examined to test their efficiency in detection of directionality in signals. These wavelets were tested on numerical images which were considered to describe the basic characteristics of directionality of ocean waves

A STUDY ON THE TWO-ROW EFFECT IN THE SLOSHING PHENOMENON

In this study, changes in fluid impact loads inside a tank were examined according to a two-row tank arrangement in an LNG-FPSO (Liquefied Natural Gas-Floating Production Storage Offloading) vessel. The motion RAO (Response Amplitude Operator) of the LNG-FPSO, coupled with the sloshing phenomenon inside the tank, was calculated by using HydroStar by Bureau Veritas. The motion simulation in the tank was conducted under filling ratios of 30%H, 60%H, and 80%H. The RAO in each condition was calculated according to the one-row and the two-row tank arrangement. The motion response spectrum using the calculated RAO and the JONSWAP (Joint North Sea Wave Analysis Project) spectrum were computed by implementing irregular motion according to each filling ratio and tank arrangement. The sloshing phenomenon inside the tank was implemented by using a 6-DOF (Degree Of Freedom) sloshing motion platform; impact pressure on the walls of the tank was measured with pressure sensors installed inside the tank. The sloshing experiment was conducted under the three filling ratios in the one-row and the two-row tank arrangement and impact loads were compared under each filling ratio according to the one-row and the two-row tank arrangement

Methano­ldinitrato[N-(2-pyridylmethyl­ene)aniline]copper(II)

The Cu atom in the title compound, [Cu(NO3)2(C12H10N2)(CH3OH)], adopts a square-pyramidal geometry, being ligated by two N atoms of the bidentate N-(2-pyridylmethyl­ene)­aniline (ppma) ligand, two O atoms of NO3 ligands and one O atom of a methanol molecule, which occupies the apical position. The phenyl ring on the ppma ligand is twisted out of the pyridine plane, forming a dihedral angle of 42.9 (1)°. In the crystal, inter­molecular O—H⋯O hydrogen bonds between methanol and NO3 ligands form an extensive one-dimensional network extending parallel to [100]