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Indonesia has the largest archipelago in the world and more than 2 million people work as traditional fishermen. Traditional fishermen usually use small ships with sizes lower than 30 GT (gross tonnage). This traditional ship is greatly endangered by weather variability and high sea variability, as well as rough seas. Marine risk information is important for comfort and safety in fishing. Marine risk information could be determined by a risk matrix as consequences of rainfall, high wave hazard, and the likelihoods of these events. Wave prediction was simulated by Wavewatch III based on wind prediction from Weather Research and Forecasting (WRF) simulation. Rainfall was obtained from the Tropical Rainfall Measuring Mission (TRMM). The wind spatial value of WRF processed between 1 and 15 March 2017 and averaged from 00 to 12 Universal Time Coordinate (UTC) to represent risk information at daytime and averaged from 12 to 00 UTC to represent risk information at night-time. Mapping of the significant wave information was created by the ArcGis application to generate the marine risk information. Adding rainfall factors from the Tropical Rainfall Measuring Mission (TRMM) to the ArcGis results in marine risk information maps was based on significant wave and rainfall for day and night-time. When the marine risk information maps (both daytime and night-time) were based only on the significant wave factor, the marine risk level in the southern part of Cenderawasih Bay was generally low. The addition of the rainfall factor increased the general risk level at night to medium. In March, in the southern part of this bay, traditional fishermen were safer fishing in the daytime.

The rate of rotation of the Earth is slowly decreasing in time. Universal Time (UT) is a time scale based on the rotation of the Earth and ΔT is defined as the difference between the uniform time‐scale (Dynamical Time), and the Universal Time, it is clear that ΔT will vary with time, but it does not vary uniformly, because there are irregular fluctuations. It is not possible to obtain past exact values for ΔT, being the only possibility its deduction a posteriori from ancient observations, in particular from occultations and total or annular eclipses.However, the derived relative error from ΔT obtained from ancient eclipsed is quite large, mainly because of the large width of the totality zone and the inaccuracy in the definition of the observational place. These former problems may be partially solved with the analysis of eclipbse records from multiple sites, which could give a narrower parameter range.

The Earth rotation response to El‐Nino/Southern Oscillation (ENSO) events is investigated by means of Fourier approximation of the universal time (UT1‐TAI) variations according solution C04 of the IERS. The UT1 variations at ENSO frequencies are approximated by 21 oscillations with periods between 1.5 and 5.4 years, whose superposition yields time series with behavior rather similar to the variations of ENSO Index. The delay of the UT1 response to the ENSO events is about 0.5a. The correlation between the variations of ENSO Index and UT1 is negative and with coefficients between −0.59 and −0.68 for some periods. A linear regression UT1−TAI = −73.78EI−8.53 [ms] between UT1 variations and ENSO Index EI is determined. The comparisons between the EI variations for the past epochs and the UT1‐TAI backward extrapolation shows that the model of UT1, based on Fourier approximation, has weak prediction ability.

The aim of the paper is to create a model of decadal variations of the universal time UT1 for the period 1623.5–2005.5. This model includes polynomial terms of power 2 and Fourier approximation of the periodical part using 100 harmonics, where some of them represent the intrinsic periods of natural phenomena: solar equatorial asymmetry—45a, solar magnetic cycle—22a, lunar node—18.6a and sunspot variations—11a. The coefficients of this model are determined by the Least Squares Method with amplitude estimation accuracy about 11 ms. A separation between the UT1 responses to the sunspots cycles and 12‐year core signals is made.

Modern space‐based astrometric observations made by Hipparcos satellite yielded two principal catalogs in optical wavelength: Hipparcos and Tycho. These catalogs, that recently celebrated ten years of existence, contain star positions with unprecedented accuracy. However, their proper motions are, due to a relatively short interval of Hipparcos mission, quite often not as good as their formal standard errors indicate. This deficiency is especially significant for about twenty per cent of double or multiple stars contained in these catalogs. The combination with ground‐based astrometric observations that have much longer history is therefore very important for improving the Hipparcos proper motions. Significant improvement in this respect was achieved during the past years by creating combined catalogs, such as Tycho‐2, FK6, GC+HIP, TYC2+HIP, or ARIHIP. Yet a large and important group of astrometric observations of latitude/universal time variations, made in the programs of monitoring Earth orientation, st...

The emerging technology of gravitational wave control is used to augment a communication system using a development roadmap suggested in Stephenson (2003) for applications emphasized in Baker (2005). In the present paper consideration is given to the value of a High Frequency Gravitational Wave (HFGW) channel purely as providing a method of frequency and time reference distribution for use within conventional Radio Frequency (RF) telecommunications networks. Specifically, the native value of conventional telecommunications networks may be optimized by using an unperturbed frequency time standard (FTS) to (1) improve terminal navigation and Doppler estimation performance via improved time difference of arrival (TDOA) from a universal time reference, and (2) improve acquisition speed, coding efficiency, and dynamic bandwidth efficiency through the use of a universal frequency reference. A model utilizing a discounted cash flow technique provides an estimation of the additional value using HFGW FTS technology could bring to a mixed technology HFGW/RF network. By applying a simple net present value analysis with supporting reference valuations to such a network, it is demonstrated that an HFGW FTS could create a sizable improvement within an otherwise conventional RF telecommunications network. Our conservative model establishes a low‐side value estimate of approximately $50B USD Net Present Value for an HFGW FTS service, with reasonable potential high‐side values to significant multiples of this low‐side value floor.

The measure of the mutation, or change, any material elementary particle unceasingly undergoes, is defined as that of the displacement of a point moving in a three‐dimensional Euclidean space, at the velocity of light, on a trajectory decomposable in a rotation and a translation. The rotation accounts for the spin angular momentum of the particle, the translation for its change of location. Then, an elementary mutation is proportional to an elementary interval of universal time. The connection between space and time is such that the operation of universal time conjugation, that is, the change of sign of t, involves space inversion, so coinciding with the operation currently defined as TCP. It implies that to a given physical process, another equally possible one corresponds in which the sequence of events (that still follow the same time course) is reversed, and actors are the enantiomorphic counterparts (anti‐particles instead of particles, and vice versa) of those playing in the first physical process. Since no alternative is left to any elementary particle, that exists in that it undergoes an everlasting mutation, the unidirectionality of time must not be understood as a choice between two alternative directions. Many formalisms of Special Relativity can be derived from the above definition of the mutation of a material elementary particle. Anyhow, some discordances seems to crop out whose discussion is beyond the purpose of the present paper.

The time evolutions of dispersive diffusion‐controlled bimolecular reactions and recombinations are considered in the light of a universal time correlation function ψn (t) which comes from a recently proposed fundamental process. The predictions are in excellent agreement with available experimental data for electron‐hole recombinations in a‐Si:H while those of another currently accepted event‐time distribution function fails to agree.