This study investigates depth and temporal variability of organic carbon (POC), total nitrogen (TN) and their isotopic compositions in sinking particulate organic matter collected at station KK (18¢X15¡¦N; 115¢X5¡¦E), northern South China Sea. Sinking particles collected from two separate sediment trap moorings conducted from August 8, 2004 to February 16, 2005 (KK-3) and from April 1, 2005 to October 10, 2005 (KK-4). Results show that their variations respond closely to the strong seasonality in the surface layer, but are modified considerably by subsequent remineralization and large terrigeneous input in the deep water. The highest of Al concentrations at 3500m is equivalent approximately to 58% of lithogenic material. Sinking particles of terrestrial origins has lower £_13C values of POM. Terrigeneous input should make the £_13C values increase but decrease from 600m to 3500m. Based upon data measured in this study, a C/N increase rate of 0.21 unit per 1 km of water depth. The C/N ratio of POM collected in the winter is significantly higher than those collected in the rest of the year (9.05 vs. 7.02). With this regard, cyanobacteria, which have been reported as an important N2-fixer may attribute to the insufficiency in new production sources. The £_15N values prove the occurrence of nitrogen fixation in the surface water of the South China Sea in summer.

Syftet med denna uppsats är att modellera och prognostisera Sveriges varuexport, varuimport och handelsnetto. Vi använder oss av data från januari 1975 till och med augusti 2010 för respektive serie. Dessa data testas och jämförs i olika ARIMA- och SARIMA-modeller samt skattas även medelst säsongsreningsprogrammet TRAMO/SEATS. För de modeller som bäst passar serierna genomförs därefter in sample- och out of sample-analyser med felmåtten RMSE och MAPE. Modellerna med bäst felmått och som därpå väljs ut för att göra prognoser för serierna till och med augusti 2012 är (3,1,0)x(0,1,1) för export, (2,1,1)x(0,1,1) för import samt (0,1,1)x(0,1,1) skattad i TRAMO/SEATS för handelsnetto.

Depth and temporal variability of organic carbon (POC) and total nitrogen (TN) and their isotopic compositions (£_13C and £_15N) in sinking particulate organic matter (POM) collected at the SEATS time-series station (18¢X15¡¦ N; 115¢X50¡¦ E), northern South China Sea, respond closely to the strong seasonality (changes in sea surface temperatures and mixed layer depths) in the surface layer, but are modified considerably by subsequent microbial degradation/remineralization and probably by re-suspension of sediments from the surrounding shelf region in the deep water. Lower C/N and £_15N in summer than the other seasons reflects the change of nutrient supply from NO3-rich, 15N-enriched subsurface waters to N2-fixation-dominated nitrogen source in the surface waters. Below the euphotic zone (>100m), both POC and TN decrease, whereas C/N increases progressively with depth owing to the biodegradation and the preferential removal of more degradable nitrogen-containing compounds through the water column. The C/N increase rate is estimated to be 0.4 unit per 1 km water depth, which is significantly higher than the world average (0.2/km) as a result of the input of higher C/N organic matter from sediments deposited nearby the SEATS site. POC and TN and total particulate mass fluxes decrease sharply within the euphotic zone and continue to decrease all way through the water column to seafloor. For site comparison and global synthesis, an average fraction (e-ratio) of 0.22 of POC exported from the euphotic zone and a POC attenuation rate (b value) of 0.97 are derived. Since the results of this study were obtained from a marginal sea characteristic of strong monsoonal modulation, they should contribute to a better understanding of the fate and pathway of POC in the world ocean.

No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 60-61). Also available via the Internet.

In this study, a one-dimensional model based on the Mellor and Yamada level 2.5 turbulence closure model was coupled with a biogeochemical model to investigate the inter-annual variation of biogeochemistry at the South-East Asian Time-series Study (SEATS) Site in the northern South China Sea (SCS) from 1997 to 2003. During the study period there were two El Niño Events and two La Niña Events. This study was focused on the hydrographic and biogeochemical conditions during these events. In order to better understand the model performance in the physical and biogeochemical aspects, numerical experiments were conducted to investigate the key processes. Numerical experiments by using idealized forcing conditions revealed that stronger wind stresses resulted in stronger cooling and deeper mixed layer. The model results were as sensitive to the initial density structure of the water column as to wind stress. Numerical experiments with the coupled model revealed that the biogeochemical results are insensitive to the initial biogeochemical conditions except the nitrate profile. Sensitivity tests indicated that primary production was sensitive to the remineralization rate constant for the detritus and parameters related to zooplankton, such as growth rate, grazing constant and mortality rate constant. It is less sensitive to iv aggregation constant of phytoplankton. The SEATS project of the National Center for Ocean Research provided data of sea surface chlorophyll-a (S-chl) concentrations, which were derived from SeaWiFS data for the period from Jan. 1997 to Dec. 2003 by calibrating against shipboard observations. The time-series showed decreases of mean S-chl by 35% and 9% below the climatological mean in the winter months (DJF) of the two El Niño Events. The negative S-chl anomalies corresponded to elevated sea surface temperature (SST) by 1.4oC and 0.4oC above the climatological mean, while the mean wind speed (WS) was reduced by 20% and 13%, and the surface heat exchange reverted from net loss to net gain or null. It is hypothesized that the anomalously low S-chl may have been caused by the weakened wind mixing and strengthened stratification. A 1-dimensional coupled physical-biogeochemical model was developed to test this hypothesis. The model driven by wind stress and surface heat fluxes successfully reproduced the seasonal cycles of S-chl and integrated primary productivity (IPP) as compared to shipboard observations and SeaWiFS data derived values, and predicted the negative anomalies of S-chl and IPP under the 1997-98 and 2002-03 El Niño conditions. However, the model-predicted strong positive anomalies of S-chl and IPP under the 1998-99 and 1999-2000 La Niña conditions, which brought v stronger wind and heat loss, were not substantiated by observations. Hydrographic conditions at the SEATS station indicated that, under La Niña conditions, unusual accumulation of warm and nutrient-depleted water occurred in the upper water column cancelled out the effect of stronger mixing. Therefore, the biogeochemical responses of the northern SCS to surface forcing during the recent El Niño/La Niña conditions displayed in a highly asymmetrical manner.

No description available.

This study conducted a series of tests on a shock mitigating seat designed for high speed craft using various input excitations to better understand the relationship between various seat and operational conditions, and the response of the seat. A seat model of the test seat is used for a parametric study of various spring, damping and operational configurations. A seat shake rig is implemented to simulate motions of multiple high-speed craft as well as various defined inputs. At each test input the occupant weight and suspension preload is varied and the response is analyzed to find changes in acceleration, which is representative of the changes in force and displacement. By representing the seat as a based-excitation two-degree-of-freedom system, we develop the equations of motion and model them in Simulink to analyze the effects of various spring rates and damping coefficients. Based on the results it is found that an increase in occupant mass results in a decrease in observed acceleration. Increasing suspension preload is found to be detrimental to the mitigating abilities of the seat, changing the dynamics to those similar of a rigid-mounted seat. An analysis of the defined inputs resulted in confirming various seat characteristics. The analysis of the Simulink model revealed that increasing the spring rate results in an increase in acceleration. An increase in damping coefficient resulted in an increase in acceleration and ride harshness. / Master of Science

[pt] Esta dissertação tem como objetivo comparar procedimentos de ajuste sazonal em séries temporais. As metodologias utilizadas são a do X12-ARIMA e a metodologia TRAMO/SEATS. Utilizaram-se as séries agregadas das Contas Trimestrais Brasileiras, fornecidas pelo Instituto Brasileiro de Geografia e Estatística - IBGE, no período compreendido entre o primeiro trimestre de 1991 e o segundo trimestre de 2000. Os aplicativos utilizados no decorrer do trabalho foram SPSS, FORECAST PRO, X12-ARIMA (versão DOS), SAS e TRAMO/SEATS (versão DOS). Também foram utilizadas séries simuladas com diferentes formulações para a tendência e sazonalidade, a fim de melhor analisar os resultados. / [en] This paper intends to perform a comparison of seasonal adjustment procedures. The compared methodologies are X12- ARIMA and TRAMO/SEATS. This current work encompasses the Brazilian Quarterly aggregated accounts which were obtained from the Brazilian Governmental Statistical Office (IBGE - Instituto Brasileiro de Geografia e Estatística) in the period between the first quarter of 1991 and the second quarter of 2000. This data, in the process of analysis, went trough the following software: SPSS, FORECAST PRO, X12-ARIMA (DOS version) and TRAMO/SEATS (DOS version). Some simulated series (with different structures for trend and seasonality) were also used in order to provide further and more accurate comparisons of the two methodologies. / [es] Esta disertación tiene como objetivo comparar procedimientos de ajuste estacional en series de tiempo. Las metodologías utilizadas son X12-ARIMA y TRAMO/SEATS. Se utilizaron las series agregadas de las Cuentas Trimestrales Brasileras, proporcionadas por el Instituto Brasilero de Geografía y Estadística - IBGE, en el período comprendido entre el primer trimestre de 1991 y el segundo trimestre de 2000. Los aplicativos utilizados en este trabajo fueron SPS, FORECAST PRO, X12-ARIMA (versión DOS), SAS y TRAMO/SEATS (versión DOS). También fueron utilizadas series simuladas con diferentes formulaciones para la tendencia y estacionalidad, a fin de analizar mejor los resultados.

Motor vehicle crashes are the leading cause of unintentional injury-related death among children ages 14 and under and of these children who were fatally injured more that 60 % were not using safety restraints at the time of the collision. Children who are too large for child safety seats are often restrained improperly or not at all. In addition, many children are being shifted from child safety seats to adult safety belts prematurely. For proper protection, children who have outgrown child safety seats require booster seats combined with vehicle lap/shoulder belts. A booster seat raises a child up so that the lap and shoulder belts fit properly. The current research went through a systematic approach, from several perspectives, to develop an effective pamphlet to increase behavioral compliance of purchasing a booster seat. The pamphlet developed throughout these studies had a substantial and positive effect on intention and perceived control as well as a meaningful and substantial impact on actual purchase behavior. In addition, the associated guidelines that were developed allow others to produce effective printed educational materials. This research consisted of five studies described below. Study 1 consisted of 43 subject matter experts who were used to determine pertinent information that should be included in a complete booster seat pamphlet. Nine of the 20 items showed significance and were included in the first iteration of the pamphlet. Study 2 consisted of 5 parents of children who should be in booster seats and were not at the time of the study, evaluated the usability of the first iteration pamphlet. A total of 18 items were changed in the pamphlet and a subsequent second iteration of the pamphlet was developed. Study 3 consisted of 30 parents of children who should be in booster seats and were not at the time of the study, were used to assess the comprehensibility (Cloze test), hazard-risk judgments (carefulness ratings), and understandability (questionnaire) of three booster seat pamphlets. Significance was found for the second iteration pamphlet in both comprehensibility and understandability, but no significance was found in risk perception. Study 4 consisted of 8 human factors graduate students who were used to assess the reading level (SMOG test), instructional design and inclusion of learning principles (BIDS-3 test), and readability (RAINS test) of three booster seat pamphlets. The second iteration pamphlet and two existing industry pamphlets were used in Studies 3 and 4 and significance was found for the second iteration pamphlet in both instructional design and learning principles as well as readability and was the only pamphlet to have a reading level under 8th grade. Subsequent to these studies a third iteration of the new pamphlet was developed. Study 5 consisted of 45 parents of children who should be in booster seats and were not at the time of the study. Three booster seat pamphlets, two from the child passenger safety industry and the third iteration pamphlet were used as treatments (15 participants per group). Effectiveness of the intervention was tested by assessing three variables, intent to purchase (revealed that when intent was high purchase was high), perceived control of purchasing (revealed that when perceived control was high purchase was high), and actual purchase behavior (third iteration pamphlet showed a significantly higher purchase rate than the industry pamphlets). Of the 19 participants who purchased a booster seat, there were 12 (63%) in the third iteration pamphlet group, 2 (11%) in the alternate 1 pamphlet group, and 5 (26%) in the alternate 2 pamphlet group, and 100% of those who purchased, reported that they use them each time their child rides in a vehicle. This research increased our understanding of information design and well as generating general design guidelines for pamphlets. In addition, this research produced a pamphlet for credible sources to use as an education tool for parents who have children who should be in booster seats and are not placed in them when riding in a vehicle. / Ph. D.