scholarly journals WAVE-PRODUCED MOTION OF MOORED SHIPS

2000 ◽  
Vol 1 (2) ◽  
pp. 5
Author(s):  
Robert T. Knapp

This paper presents a brief description of some ship motion measurements made in Los Angeles Harbor in conjunction with the model study of inner mole at that location. It also includes the description of the battery of recording instruments which was developed as the result of the difficulties encountered in making the ship motion measurements by conventional means.

1993 ◽  
Vol 37 (02) ◽  
pp. 138-147
Author(s):  
Ross Graham ◽  
Barbara-Ann Juszko

An approach to parameterizing directional spectra proposed by Hogben & Cobb based on a combination of the Ochi & Hubble 6-parameter spectrum and the Longuet-Higgins et al cos2p model is adopted for a study of directional parameterizations and their influence on ship motion predictions. Two schemes for evaluating the directional spreading parameters are assessed in terms of their ability to reproduce highly resolved measured directional spectra, and the best approach, termed the 10-parameter spectrum, is adopted. The applicability of the 10-parameter spectrum to hindcast spectra is investigated, and acceptable fits obtained for 93% of the spectra considered. An evaluation of the ability of the hindcast model to reproduce the measured spectral data is also made. In general, it is found that the differences between the hindcast spectra and associated 10-parameter fits are significantly smaller than the differences between the hindcast spectra and the field data, and it is concluded that the 10-parameter spectrum is a suitable basis for developing statistical descriptions of directional wave climates. The effects of directional parameterization on ship motion predictions are investigated by computing the ship responses as a function of heading for sample hindcast spectra, and the associated 10-parameter and Bretschneider 2-parameter spectra. The responses calculated using the 10-parameter spectrum are found to be in better agreement with the hindcast results than those obtained with the Bretschneider 2-parameter spectrum, with a significant improvement in modeling accuracy in the case of bi-modal spectra. The potential advantages of incorporating the 10-parameter spectrum in future operability analyses of flight operations is examined by comparing the head-to-wind roll response computed using hindcast spectra with that predicted using 10-parameter and Bretschneider spectra.


1991 ◽  
Vol 1 (1) ◽  
pp. 8-23
Author(s):  
Roger Rouse

In a hidden sweatshop in downtown Los Angeles, Asian and Latino migrants produce automobile parts for a factory in Detroit. As the parts leave the production line, they are stamped “Made in Brazil.” In a small village in the heart of Mexico, a young woman at her father’s wake wears a black T-shirt sent to her by a brother in the United States. The shirt bears a legend that some of the mourners understand but she does not. It reads, “Let’s Have Fun Tonight!” And on the Tijuana-San Diego border, Guillermo Gómez-Peña, a writer originally from Mexico City, reflects on the time he has spent in what he calls “the gap between two worlds”: “Today, eight years after my departure, when they ask me for my nationality or ethnic identity, I cannot answer with a single word, for my ‘identity’ now possesses multiple repertoires: I am Mexican but I am also Chicano and Latin American. On the border they call me ‘chilango’ or ‘mexiquillo’; in the capital, ‘pocho’ or ‘norteno,’ and in Spain ‘sudaca.’… My companion Emily is Anglo-Italian but she speaks Spanish with an Argentinian accent. Together we wander through the ruined Babel that is our American postmodemity.”


1995 ◽  
Author(s):  
William C. Seabergh ◽  
Leonette J. Thomas

1971 ◽  
Vol 6 (4) ◽  
pp. 429-431
Author(s):  
William J. Woolbright

Part of the responsibility of a reading therapist is to report to the parents the results of specialized programs developed for their children. Whether the report is made in person or sent to the parents or teachers of the children, there can be confusion or misunderstanding when grade-level scores are used. Over a period of time, and after a review of numerous parent conferences and discussions with local school administrators and teachers, the following report was prepared by the Academic Achievement and Learning Group, Los Angeles, California, to better communicate with parents and school personnel who are concerned about students' work in remedial reading.


Author(s):  
George T.J. Tzong ◽  
Ching-Piau Lai ◽  
Jiin-Jen Lee ◽  
Fei Zhuang

2021 ◽  
Author(s):  
Kyriaki - Maria Fameli ◽  
Evangelos Papadopoulos ◽  
Vasiliki Assimakopoulos

<p>Due to its complex topography (many islands) and extended coastline, Greece has numerous ports (about 200) which serve both commercial and touristic purposes. Almost 85 of them were in use in 2017. According to the FEI-GREGAA emissions inventory, navigation accounted for the 12% to the annual NOx emissions and by 3% to the PM<sub>10</sub> emissions in 2017. Consequently, it is an important source of emissions especially for areas which are close to major ports, such as the Athens basin; because it affects the local air quality (almost 32% of total NOx emissions in Athens for the year 2017 came from shipping).</p><p>In this study a comprehensive emissions inventory for the navigation sector was developed covering the period 2006 – 2017 and used as input to a photochemical model study.  The shipping emissions were calculated for each Greek port and ship type based on the ship arrivals. The relevant data for each ship type were provided by Eurostat in seasonal basis. The methodology followed was the Tier 2 approach suggested by the EMEP/EAA emissions inventory guidebook. Harbour (hotelling and manoeuvring) and cruise emissions of both the main and auxiliary engine were calculated for the main pollutants (such as NOx, NMVOCs, CO, etc), particulates (PM<sub>10</sub>, PM<sub>2.5</sub>), heavy metals (e.g. Pb, As, Cr, Zn), PCB and HCB.</p><p>In Greece the movement of passenger ships is very frequent. Consequently the spatial disaggregation of emissions was carried out with two different methodologies. Emissions from passenger ships were distributed on the ferry lines, as these have been recorded by OpenStreetMap, in which the necessary completion was made in order to cover the itineraries of the ships in all the Greek islands. The emissions from the other ship categories were distributed in the coastal zones around the respective ports, considering the probability of being in the specific zones significant. Finally, a part of the total emissions (10%) was placed in the ports.</p><p>Results revealed that in 2017 NOx emissions (27.5 ktonnes) prevailed among other pollutants contributing by 69% to the total maritime emissions, while SOx emissions followed (16%). This is due to the use of diesel fuel. Concerning the annual variation of pollutants for the period 2006 – 2017, it was found that in 2011 there was a significant reduction of emissions compared to 2010 (9,921 ktonnes for NOx and 3,913 ktonnes for sulfur oxides - SOx) while the decrease was lower for the rest pollutants. From 2012 onwards, the results showed a stabilization trend. The majority of pollutant emissions are attributed to the port of Piraeus (3704.7 ktonnes NOx emissions from passenger ships), which is the busiest passenger and commercial port in Greece (20228 passenger ships and 3168 container ships arrived in 2017).</p>


1978 ◽  
Vol 7 (1) ◽  
pp. 37-39 ◽  
Author(s):  
Isabelle F. Hunt ◽  
Norma J. Ostergard ◽  
Leo P. Carroll ◽  
Betty Hsieh ◽  
Robert Brown ◽  
...  
Keyword(s):  
Made In ◽  

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