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We analyse the acceleration of integrated public transportation management in DKI Jakarta. Here we focus on the case of Bus Rapid Transit (BRT) or called TransJakarta. In this study the qualitative research methods are used through post-positivism paradigm. We collect the data through observation, interviews, and literature studies. We found that the acceleration of BRT-based integrated public transportation management in DKI Jakarta can be well carried out if each stakeholder understands and implements the transportation management system that has been approved whether it is for planning, organizing, or supervising. Meanwhile, there are several components that are needed for accelerating BRT-based integrated public transportation management: route restructuring, transportation integration, single bus operators, and fair law enforcement. It is also important to realize the collaboration among Indonesian regional-own enterprises (BUMD), Indonesian state-own-enterprises (BUMN), and all stakeholders for creating sustainable and equitable bus-based public transportation in DKI Jakarta.

In the near future, two radio telescopes will be installed in the Indonesian region. These telescopes are proposed to be integrated into the existing Very Long Baseline Interferometry (VLBI) network both for astronomical and geodetical purposes. Here we simulate the impact of the inclusion of the future Indonesian antennas to the estimates of Earth Orientation Parameters and the station position. The simulation was performed in two types of VLBI sessions. First, we analyse the contribution of Indonesian antennas to the existing intensive session INT3 (IN320-314), which focuses on the estimation of dUT1. We found that the addition of Indonesian antennas has reduced the estimated dUT1 repeatability value by about 25%. Next, we simulate the 24-hour session by considering two existing network configurations, which are R4 (R4934) and AOV (AOV049). Overall we found that the addition of Indonesian antennas to each network configuration decreases the repeatability value of the Earth Orientation Parameter by about 20%. Meanwhile, the repeatability value of station position is reduced up to 12%. This reduction is already achieved even when we include only one Indonesian antenna.

SUMMARYThe rotational motions of the internal Earth layers induce resonances in the Earth nutations and tidal gravimetric response to external luni-solar gravitational forcings. The characterization of these resonances is a mean of investigating the deep Earth properties since their amplitudes and frequencies depend on a few fundamental geophysical parameters. In this work, we focus on the determination of the free core nutation and free inner core nutation periods and quality factors from the Bayesian inversion of VLBI and gravimetric data. We make a joint inversion of data from both techniques and show that, even if the results are only slightly different from the inversion of VLBI data alone, such approach may be valuable in the future if the accuracy of gravimetric data increases. We also briefly discuss the polar motion resonance, which is related to the Chandler Wobble as seen from the diurnal frequency band. Our overall estimates of the FCN period and quality factor, TFCN = (−430.2, −429.8) solar days and QFCN = (15 700, 16 700), respectively, are in good agreement with other studies, albeit slightly different for unclear reasons. Despite some concerns about the detection and characterization of the FICN, it seems that we could also successfully estimate its period, TFICN = (+600, +1300) solar days, and give a loose estimate of the upper bound on its quality factor.

We revisit the work of Kilston and Knopoff (1983) to study the correlation of earthquakes with the main lunisolar tidal components in the limited zone of the Southern California region, with a considerably bigger amount of data. By adopting the same methodology as these authors, we confirm their results, i.e. that strong earthquakes with M >= 6 show a statistically significant correlation with half day and precession cycles, with respective periods 12 hr. and 18.6 y., while weaker earthquakes show a correlation with the annual cycle. Moreover we extended the study to the analysis of bi-modal phase to phase diagrams, leading to a very high probability of a lack of earthquake occurrences when both phases of the 12 hr. and 18.6 y. cycles are inside the [0 - 0.5] interval. Furthermore, we demonstrate that the statistical method is not really appropriate to study the correlation with the semi-lunar day and the fortnightly tidal components., 15 pages; 5 figures; accepted for publication in the Romanian Astronommical Journal

Since the beginning of the 20th century, the observation of the Earth rotation variations through astro-geodetic techniques enables to investigate the global rheological properties of the Earth, in particular, the resonance parameters of the free rotation modes reflect the solid Earth anelasticity, the ocean response to an external forcing, and the properties of the fluid inner core, eventually of the solid inner core. Better constraints on these resonance parameters can be obtained by confronting the observed terrestrial motion of the rotation pole (the so-called polar motion) - including nutation as a retrograde diurnal polar motion - to the modeled excitation producing it. The more precise the modeled excitation and the observed polar motion are, the better theEarth rheological properties will be determined. For now, the best precision is reached in thenutation band. So, the analysis has been first dedicated to a direct adjustment of the nutation componentsfrom VLBI delays, then the adjustment of the resonance parameters in the transfer function between the observed nutation terms and the corresponding rigid nutation terms that reflects the luni-solar forcing. The obtained resonance parameters confirms in particular the shortening of the polar motion resonance period of about 40 - 50 day in the retrograde diurnal band. Then, we show that the dynamical behavior of the oceans in the diurnal band is mostly responsible for that. We also predicted a supplementary change of the resonance parameters in the vicinityof the free core nutation resonance, as expected from the solid Earth response, and confirmed by the adjustment of these parameters through the nutation terms. In addition to the nutation band, we revisit the estimation of the polar motion resonance parameters in the seasonal band, dominated by the Chandler wobble, in light of the most recent global circulation models of the hydro-atmospheric layers. Finally, we extend the investigation of polar motion resonance to theprograde diurnal polar motion, where the excitations mostly result from the ocean tides. We obtain a resonance period of about 393 days, and confirmed by our prediction based on the ocean tidal models. These results allow us to impose constraints on the frequency dependence of the Love number k2 and the Love number oceanic ko, characterizing respectively the response of the solid Earth and the oceans to an external potential of degree 2.

A member of Near-Earth Asteroids (NEAs) has orbit (at least a part) moving across a distance within 1.3 astronomical unit from the Sun. Many of them, however, lack of physical properties that are important for studying their global dynamics. Results of long-term dynamical study of NEAs can be more significant if the Yarkovsky thermal effects are included, meaning that this needs the physical properties. To overcome this problem, here we propose a scheme to estimate unknown physical properties of NEAs, i.e. albedo, size, rotation period, pole orientation, bulk and surface densities, thermal conductivity, thermal capacity, and infrared emissivity. The scheme is started with the known absolute magnitudes and the known taxonomy classes of NEAs. Albedos are derived from the taxonomy classes, and eventually sizes can be determined. The sizes provide rotation periods and pole orientations using recent published results. Finally, by modeling some types of asteroid surfaces, the rest properties can be obtained. The scheme is used to provide the estimated physical properties of more than ten thousands NEAs representing their general picture needed for global dynamical study.

By observing continuously a single field of view in the sky, Kepler mission reveals outstanding results on discoveries of exoplanets. One of its recent progress is the discoveries of circumbinary planets. A circumbinary planet is an exoplanet that moves around a binary system. In this study we investigate motions of Kepler circumbinary planets belong to six binary systems, namely Kepler-16, -34, -35, -38, -47, and -413. The motions are considered to follow the Restricted Three-Body Problem (RTBP). Because the primaries (central massive objects) are stars, they are both radiatives, while the planet is an infinitesimal object. The primaries move in nearly circular and elliptic orbits with respect to their center of masses. We describe, in general, motions of the circumbinary planets in RTBP under radiating primaries. With respect to the averaged zero velocity curves, we show that motions of the exoplanets are stable, in accordance with their Hill stabilities.

The Circular Restricted Three-Body Problem (CRTBP) possesses five equilibrium points, that comprise three collinear (L1, L2, and L3) and two triangular points (L4 and L5). The classical study (with the primaries are point mass) suggests that the equilibrium points may cause the velocity of infinitesimal object relatively becomes zero and reveals the zero velocity curve. We study the motion of infinitesimal object near triangular equilibrium point (L4) and determine its zero velocity curve. We extend the study by taking into account the effects of radiation of the bigger primary (q1 ≠ 1, q2 = 1) and oblateness of the smaller primary (A1 = 0, A2 ≠ 0). The location of L4 is analytically derived then the stability of L4 and its zero velocity curves are studied numerically. Our study suggests that the oblateness and the radiation of primaries may affect the stability and zero velocity curve around L4.

The Restricted Three-Body Problem (R3BP) considers motion of a third infinitesimal object under the gravitational influences of the primaries (bigger and smaller massive bodies) whose orbits are around the center of mass. If the orbits are elliptical, this belongs to Elliptic R3BP (ER3BP). In planar case it possesses five equilibrium points consisting of three collinear (L1, L2, and L3) and two triangular (L4 and L5). To mimic a better astrophysical R3BP, such as motion of a satellite in star-planet system, the classical problem can be generalized by considering the effects of radiation pressure and oblate spheroid shape on the primaries. We study analytically the locations and the stability of L4 and L5 equilibrium points in the frame of ER3BP with incorporating the effects of radiation for bigger primary and oblateness for smaller primary. Our study suggests that the oblateness factor (A2) and the radiation factor (q1) shift the positions of L4 and L5 points compared with the classical ones. We also find that there is a stability limit for motion of the third body around these points.

Among comets there are several groups of Sun- grazers. Sun-grazing comets are comets whose motions encounter very closely to the Sun and may eventually plunge into the Sun. Sun-grazing comet C/2011 W3 (Lovejoy) was not expected to survive during close encounter with the Sun on December 16, 2011 due to the extreme conditions in the corona. We study numerically orbit of the comet during this event. We developed numerical codes of additional forces (i.e. cometary outgassing, general relativity, and the oblateness/quadrupole moment of the Sun) and incorporated them into the new integrator package REBOUND. These additional forces yield small changes in motion of the comet near the event. As expected, at about the event we find that contributions of the general relativity and the outgassing forces to the comet's motion are larger than the oblateness correction of the Sun. This study also shows that the role of the outgassing force may shift event of the next encounter for at least about a hundred days. Keywords-comet C/2011 W3 (Lovejoy), cometary dynamics, N-body. j i j i i j m G P r r r r r       1 3  

Exoplanetary system HD 4732 harbors two planets (b and c) in elliptic orbits. The host star (HD 4732) is more energetic than the Sun, while the planets are Jupiter-class. In this work we deal with the triangular equilibrium points with respect to planet HD 4732c because, interestingly, its orbit is located in habitable zone. For this purpose, we set this system to the elliptical restricted three-body problem with primaries (two massive bodies) consisting of the host star and planet HD 4732c. Based on Newtonian gravity in the rotating coordinate frame, we analytically derive the triangular equilibrium points by simply modeling the energetic radiation of the star. We then find that the triangular equilibrium points (Trojans) are stable. This implies an opportunity to discover stable Trojan o bjects (or a low-mass planet) residing around the triangular points and also in habitable zone.