scholarly journals The Level of Efficiency in Handling Container Traffic at Penang Port: A Simulation Study

Author(s):  
Abdul Razak Saleh ◽  
Razman Mat Tahar

The six-month period (January 1995 - June 1995) data was extracted from "Pelabuhan Kontena" (PELKON) system and tested using SIMAN simulation process. Among the data available from the PELKON system are: arrival time of a ship, departure time of a ship, operation time for loading and unloading, total number of equipment used, number of containers unloaded, number of containers loaded, size of a ship, country of registration, last port of call, and next port of call. The arrival pattern of large ships (having a capacity to carry 507 or more containers) and small ships (having a capacity to carry less than 507 containers) follows Weibull distribution and Log-normal distribution, respectively. As a whole, there is no significant differences between the number of ships recorded by the PELKON data and the simulation process. A number of experimental studies such as acquiring less Port Crane, improve­ment of management service and integrated Prime Mover operation have been carried out to determine the effect on the container handling operations. The findings show that when one of the four port cranes did not work, the number of export containers decreased by 14.2% and 11.5% for import containers, If the services had been upgraded by 25%, the average time for unloading export containers could be shortened by 27.1% and the average time for loading import containers could be reduced by 7.9%. If the movement of prime movers had been integrated, the handling of export containers could be upgraded by 8.0% and 4.3% for import containers.  

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Arnaud Millet

The mechanosensitivity of cells has recently been identified as a process that could greatly influence a cell’s fate. To understand the interaction between cells and their surrounding extracellular matrix, the characterization of the mechanical properties of natural polymeric gels is needed. Atomic force microscopy (AFM) is one of the leading tools used to characterize mechanically biological tissues. It appears that the elasticity (elastic modulus) values obtained by AFM presents a log-normal distribution. Despite its ubiquity, the log-normal distribution concerning the elastic modulus of biological tissues does not have a clear explanation. In this paper, we propose a physical mechanism based on the weak universality of critical exponents in the percolation process leading to gelation. Following this, we discuss the relevance of this model for mechanical signatures of biological tissues.


2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Ryuho Kataoka

Abstract Statistical distributions are investigated for magnetic storms, sudden commencements (SCs), and substorms to identify the possible amplitude of the one in 100-year and 1000-year events from a limited data set of less than 100 years. The lists of magnetic storms and SCs are provided from Kakioka Magnetic Observatory, while the lists of substorms are obtained from SuperMAG. It is found that majorities of events essentially follow the log-normal distribution, as expected from the random output from a complex system. However, it is uncertain that large-amplitude events follow the same log-normal distributions, and rather follow the power-law distributions. Based on the statistical distributions, the probable amplitudes of the 100-year (1000-year) events can be estimated for magnetic storms, SCs, and substorms as approximately 750 nT (1100 nT), 230 nT (450 nT), and 5000 nT (6200 nT), respectively. The possible origin to cause the statistical distributions is also discussed, consulting the other space weather phenomena such as solar flares, coronal mass ejections, and solar energetic particles.


Fractals ◽  
2001 ◽  
Vol 09 (04) ◽  
pp. 463-470 ◽  
Author(s):  
WATARU SOUMA

We investigate the Japanese personal income distribution in the high income range over the 112 years (1887–1998), and that in the middle income range over the 44 years (1955–1998). It is observed that the distribution pattern of the log-normal with power law tail is the universal structure. However, the indexes specifying the distribution differ from year to year. One of the index characterizing the distribution is the mean value of the log-normal distribution; the mean income in the middle income range. It is found that this value correlates linearly with the gross domestic product (GDP). To clarify the temporal change of the equality or inequality of the distribution, we analyze Pareto and Gibrat indexes, which characterize the distribution in the high income range and that in the middle income range, respectively. It is found for some years that there is no correlation between the high income and the middle income. It is also shown that the mean value of Pareto index equals to 2, and the change of this index is effected by the change of the asset price. From these analysis, we derive four constraints that must be satisfied by mathematical models.


1990 ◽  
Vol 195 ◽  
Author(s):  
L. F. Chen ◽  
Ping Sheng ◽  
B. Abeles ◽  
M. Y. Zhou

ABSTRACTElectrical conduction in granular metals is simulated by mapping the hopping conductance between pairs of metal grains onto a simple cubic lattice with bonds between neighbors. By considering a log-normal distribution of grain sizes and the effect of disorder potential, the numerically calculated network conductance exhibit clear deviation from simple activation. Plotting -log a vs. T-½, where σ denotes conductivity and T the temperature, gives good straight line behavior with slopes comparable to those measured experimentally. Our results are noted to differ from those of Adkins et al.


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