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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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International Journal of Ocean System Engineering
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Journal DOI :
Korean Society of Ocean Engineers
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Volume & Issues
Volume 2, Issue 4 - Nov 2012
Volume 2, Issue 3 - Aug 2012
Volume 2, Issue 2 - May 2012
Volume 2, Issue 1 - Feb 2012
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The Effect of Cross-Shore Sediment Transport on Bar Parameters: an Experimental Study
Demirci, Mustafa ; Akoz, M. Sami ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 1~7
DOI : 10.5574/IJOSE.2012.2.1.001
The cross-shore sediment transport in a coastal region causes the important changes in beach morphological properties. The accurate estimation of the cross-shore sediment transport is important for the designing of the marine structures such as seawalls, jetties, breakwaters etc, and the preventing coastal erosion and accretion due to on-off shore sediment transportation. In this study, the experiments on cross- shore sediment transport carried out in a laboratory wave channel for initial beach slopes of 1/8, 1/10 and 1/15. Using the regular waves with different deep-water wave steepness generated by a pedal-type wave generator, the geometrical characteristics of beach profiles under storm conditions and the parameters affecting on-off shore sediment transport are investigated for the beach materials having medium diameters of
=0.25, 0.32, 0.45, 0.62 and 0.80 mm. The experimental results obtained from this study compared with previous experimental work and found to be of the same magnitude as the experimental measurements and followed the expected basic trend.
A study of flow structure of bichromatic waves through PIV analysis
Jo, Hyo-Jae ; Lee, Seung-Jae ; Choi, Je-Eun ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 8~15
DOI : 10.5574/IJOSE.2012.2.1.008
An experimental study was carried out in order to understand the kinematics of bichromatic waves. Bichromatic waves are generated in a two-dimensional wave tank, and measured by panorama PIV technique, which allows the flow fields to be captured with respect to a spatial coordinate system. We compared wave profiles and velocities of wave particles obtained by experiment with theoretical results using Stokes 1st and 2nd order waves. The velocity distribution at wave crest and trough of the highest and lowest point of a bichromatic wave are investigated in this study.
Combining Different Distance Measurements Methods with Dempster-Shafer-Theory for Recognition of Urdu Character Script
Khan, Yunus ; Nagar, Chetan ; Kaushal, Devendra S. ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 16~23
DOI : 10.5574/IJOSE.2012.2.1.016
In this paper we discussed a new methodology for Urdu Character Recognition system using Dempster-Shafer theory which can powerfully estimate the similarity ratings between a recognized character and sampling characters in the character database. Recognition of character is done by five probability calculation methods such as (similarity, hamming, linear correlation, cross-correlation, nearest neighbor) with Dempster-Shafer theory of belief functions. The main objective of this paper is to Recognition of Urdu letters and numerals through five similarity and dissimilarity algorithms to find the similarity between the given image and the standard template in the character recognition system. In this paper we develop a method to combine the results of the different distance measurement methods using the Dempster-Shafer theory. This idea enables us to obtain a single precision result. It was observed that the combination of these results ultimately enhanced the success rate.
A Methodology for Urdu Word Segmentation using Ligature and Word Probabilities
Khan, Yunus ; Nagar, Chetan ; Kaushal, Devendra S. ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 24~31
DOI : 10.5574/IJOSE.2012.2.1.024
This paper introduce a technique for Word segmentation for the handwritten recognition of Urdu script. Word segmentation or word tokenization is a primary technique for understanding the sentences written in Urdu language. Several techniques are available for word segmentation in other languages but not much work has been done for word segmentation of Urdu Optical Character Recognition (OCR) System. A method is proposed for word segmentation in this paper. It finds the boundaries of words in a sequence of ligatures using probabilistic formulas, by utilizing the knowledge of collocation of ligatures and words in the corpus. The word identification rate using this technique is 97.10% with 66.63% unknown words identification rate.
Comparison of Potential and Viscous Codes for Water Entry Problem
Kwon, Sun-Hong ; Park, Chang-Woo ; Shin, Jae-Young ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 32~36
DOI : 10.5574/IJOSE.2012.2.1.032
This paper presents a comparison of potential and viscous computational codes for the water entry problem. A po-tential code was developed which adopted the boundary element method to solve the problem. A nonlinear free surface boundary condition was integrated to find new locations of free surface. The dynamic boundary condition was simplified by taking constant potential values for every time steps. The simplified dynamic boundary condition was applied in the new position of the free surface not at the mean level, which is the usual practice for linearized theory. The commercial code FLUENT was used to solve the water entry problem from the viscosity point of view. The movement of the air-liquid interface is traced by distribution of the volume fraction of water in a computational cell. The pressure coefficients were compared with each other, while experimental results published by other researchers were also examined. The characteristics of each method were discussed to clarify merits and limitations when they were applied to the water entry problems.
Methodology for Risk Assessment for Exposure to Hurricane Conditions
Edge, Billy L. ; Jung, Kwang-Hyo ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 37~49
DOI : 10.5574/IJOSE.2012.2.1.037
An analysis of potential flooding by storm surge and wave run-up and overtopping can be used to evaluate protection afforded by the existing storm protection system. The analysis procedure can also be used to evaluate various protection alternatives for providing typhoon flood protection. To determine risk, the storm surges for both historical and hypothetical are compiled with tide conditions to represent high, slack and low water for neap, spring and mid range tides to use with the statistical procedure known as the Empirical Simulations Technique (EST). The EST uses the historic and hypothetical events to generate a large population of life-cycle databases that are used to compute mean value maximum storm surge elevation frequency relationships. The frequency-of-occurrence relationship is determined for all relevant locations along the shoreline at appropriate locations to identify the effect using the Empirical Storm Simulation (EST). To assist with understanding the process, an example is presented for a study of storm surge analysis for Freeport, Texas. This location is in the Gulf of Mexico and is subject to hurricanes and other tropical storms that approach from the Atlantic Ocean.
Experimental Study of Flow Fields around a Perforated Breakwater
Ariyarathne, H.A. Kusalika S. ; Chang, Kuang-An ; Lee, Jong-In ; Ryu, Yong-Uk ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 50~56
DOI : 10.5574/IJOSE.2012.2.1.050
This study investigates flow fields and energy dissipation due to regular wave interaction with a perforated vertical breakwater, through velocity data measurement in a two-dimensional wave tank. As the waves propagate through the perforated breakwater, the incoming wave energy is reflected back to the ocean, dissipated due to very turbulent flows near the perforations and inside the chamber, and transmitted through the perforations of the breakwater. This transmitted energy is further reduced due to the presence of the perforated back wall. Hence most of the energy is either reflected or dissipated in the vicinity of the structure, and only a small amount of the incoming wave energy is transmitted through the structure. In this study, particle image velocimetry (PIV) technique was employed to measure two-dimensional instantaneous velocity fields in the vicinity of the structure. Measured velocity data was treated statistically, and used to calculate mean flow fields, turbulence intensity and turbulent kinetic energy. For investigation of the flow pattern, time-averaged mean velocity fields were examined, and discussed using the cross-sections through slot and wall for comparison. Flow fields were obtained and compared for various cases with different regular wave conditions. In addition, turbulent kinetic energy was estimated as an approach to understand energy dissipation near the perforated breakwater. The turbulent kinetic energy was distributed against wave height and wave period to see the dependence on wave conditions.
Recognize Handwritten Urdu Script Using Kohenen Som Algorithm
Khan, Yunus ; Nagar, Chetan ;
International Journal of Ocean System Engineering, volume 2, issue 1, 2012, Pages 57~61
DOI : 10.5574/IJOSE.2012.2.1.057
In this paper we use the Kohonen neural network based Self Organizing Map (SOM) algorithm for Urdu Character Recognition. Kohenen NN have more efficient in terms of performance as compare to other approaches. Classification is used to recognize hand written Urdu character. The number of possible unknown character is reducing by pre-classification with respect to subset of the total character set. So the proposed algorithm is attempt to group similar character. Members of pre-classified group are further analyzed using a statistical classifier for final recognition. A recognition rate of around 79.9% was achieved for the first choice and more than 98.5% for the top three choices. The result of this paper shows that the proposed Kohonen SOM algorithm yields promising output and feasible with other existing techniques.