1,891 research outputs found
Economic Growth with Mechanization of the Production Process
This paper considers endogenous technological changes of inputs from labor to capital in operations of a production process, i.e., a kind of mechanization of the production process. While retaining the property of decreasing returns in capital, we can show that because of complementary relationships between the accumulation of capital and the mechanization of the production process, long-run growth is possible through the accumulation of capital only. It involves no growth of total factor productivity. Furthermore, our model can partly present a micro-foundation of constant-elasticity-of-substitution production function. Investigating our model empirically, we confirm both technological progress and our technological change.Capital Accumulation, Mechanization of a Production Process, Total Factor Productivity, Envelope, Elasticity of Substitution
The outlook on white space utilization policy in Korea: Lessons from the DTV leading countries, namely, the US, the UK, and Japan
Some countries have already finished or are progressing toward a transition to Digital Television (DTV). In particular, the US and UK have conducted technical analyses of white space, and its management strategy is under review. They are also working on determining what kind of service could be used for white space. According to this trend, a special research team led by the Japanese government was formed to study DTV white spaces utilization, and its study was conducted at the end of July 2010 [1]. In Korea, a study was recently begun on Cognitive Radio (CR) that could be applied for white spaces. However, no official research is being conducted to quantify the available spaces and their management strategy depending on the service applications. In this paper, we propose an appropriate spectrum management scheme for white space in Korea considering the results of a survey, Spectrum Requirement According to DTV Transition, and an iconography review based on tentatively assigned DTV channels around three DTV pilot test areas, Uljin, Danyang, and Gangjin. --White space,DTV transition,Spectrum policy,Spectrum demand survey,Iconography review,Spectrum management
Evaluation of Mechanical Torque Acting on Scatterer in Microwave Vortex Fields
This letter discusses the generation of vortex fields in microwave frequency range using a corrugated waveguide and a dielectric plate which has a spiral structure. Quantitative investigation of the microwave vortex field is carried out by numerical simulations of the finite-difference time domain (FDTD) method. In addition, the mechanical torque acting on a scatterer in the microwave vortex field is evaluated aiming to use the application for remote manipulation of macroscopic objects
IMPACTS OF GROUP-BASED SIGNAL CONTROL POLICY ON DRIVER BEHAVIOR AND INTERSECTION SAFETY
Unlike the typical stage-based policy commonly applied in Japan, the group-based control (often called movement-based in the traffic control industry in Japan) refers to such a control pattern that the controller is capable of separately allocating time to each signal group instead of stage based on traffic demand. In order to investigate its applicability at signalized intersections in Japan, an intersection located in Yokkaichi City of Mie Prefecture was selected as an experimental application site by the Japan Universal Traffic Management Society (UTMS). Based on the data collected at the intersection before and after implementing the group-based control policy respectively, this study evaluated the impacts of such a policy on driver behavior and intersection safety. To specify those impacts, a few models utilizing cycle-based data were first developed to interpret the occurrence probability and rate of red-light-running (RLR). Furthermore, analyses were performed on the yellow-entry time (Ye) of the last cleared vehicle and post encroachment time (PET) during the phase switching. Conclusions supported that the group-based control policy, along with certain other factors, directly or indirectly influenced the RLR behavior of through and right-turn traffics. Meanwhile, it has potential safety benefits as well, indicated by the declined Ye and increased PET values
Collinear and triangular solutions to the coplanar and circular three-body problem in the parameterized post-Newtonian formalism
This paper investigates the coplanar and circular three-body problem in the
parameterized post-Newtonian (PPN) formalism, for which we focus on a class of
fully conservative theories characterized by the Eddington-Robertson parameters
and . It is shown that there can still exist a collinear
equilibrium configuration and a triangular one, each of which is a
generalization of the post-Newtonian equilibrium configuration in general
relativity. The collinear configuration can exist for arbitrary mass ratio,
, and . On the other hand, the PPN triangular configuration
depends on the nonlinearity parameter but not on . For any
value of , the equilateral configuration is possible, if and only if
three finite masses are equal or two test masses orbit around one finite mass.
For general mass cases, the PPN triangle is not equilateral as in the
post-Newtonian case. It is shown also that the PPN displacements from the
Lagrange points in the Newtonian gravity , and depend on
and , whereas those to and rely only on .Comment: 8 pages, 2 figures, title and text improved, Eq. (45) expanded, typos
corrected, accepted for PR
Triangular solution to the planar elliptic three-body problem in the parametrized post-Newtonian formalism
A triangular solution [Phys. Rev. D 107, 044005 (2023)] has recently been
found to the planar circular three-body problem in the parametrized
post-Newtonian (PPN) formalism, for which they focus on a class of fully
conservative theories characterized by the Eddington-Robertson parameters
and . The present paper extends the PPN triangular solution to
quasi-elliptic motion, for which the shape of the triangular configuration
changes with time at the PPN order. The periastron shift due to the PPN effects
is also obtained.Comment: 5 pages, 2 figures. arXiv admin note: text overlap with
arXiv:2212.0019
Symbol Emergence in Robotics: A Survey
Humans can learn the use of language through physical interaction with their
environment and semiotic communication with other people. It is very important
to obtain a computational understanding of how humans can form a symbol system
and obtain semiotic skills through their autonomous mental development.
Recently, many studies have been conducted on the construction of robotic
systems and machine-learning methods that can learn the use of language through
embodied multimodal interaction with their environment and other systems.
Understanding human social interactions and developing a robot that can
smoothly communicate with human users in the long term, requires an
understanding of the dynamics of symbol systems and is crucially important. The
embodied cognition and social interaction of participants gradually change a
symbol system in a constructive manner. In this paper, we introduce a field of
research called symbol emergence in robotics (SER). SER is a constructive
approach towards an emergent symbol system. The emergent symbol system is
socially self-organized through both semiotic communications and physical
interactions with autonomous cognitive developmental agents, i.e., humans and
developmental robots. Specifically, we describe some state-of-art research
topics concerning SER, e.g., multimodal categorization, word discovery, and a
double articulation analysis, that enable a robot to obtain words and their
embodied meanings from raw sensory--motor information, including visual
information, haptic information, auditory information, and acoustic speech
signals, in a totally unsupervised manner. Finally, we suggest future
directions of research in SER.Comment: submitted to Advanced Robotic
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