The influence of sponge-dwelling gobies (Elacatinus horsti) on the feeding efficiency of their Caribbean tube sponge ( Aplysina sp.) hosts

Mutualistic associations between benthic marine invertebrates and reef taxa are common. Sponge-dwelling gobies benefit from protection within sponge tubes and greater food availability. Sponge-dwelling gobies are hypothesized to increase sponge pump rates by consuming polychaete parasites, but such increases have not yet been demonstrated. We investigated the association between sponge-dwelling gobies (Elacatinus horsti) and two species of tube sponge (Aplysina lacunosa and Aplysina archeri) in Bonaire, Caribbean Netherlands. We visually assessed goby presence in sponges and used in situ methods with fluorescein dye to measure estimate feeding rates via pump rates. Aplysina archeri were more likely to host a goby than A. lacunosa. For both sponge species, pump rates of tubes with gobies were higher on average than those of tubes without gobies. Our observations, therefore, suggest that E. horsti associations with Aplysina are likely mutualistic relationships in which sponges benefit from higher feeding rates when gobies are present.

Rapid Strain Demand Estimation of Pipelines Deformed by Lateral Ground Movements

In strain-based design and assessment, accurate measurement of pipe longitudinal strain demand is a key element in performing proper strain assessments. Quick pipeline strain assessments are usually needed after widespread natural disasters such as earthquakes or heavy rainfalls that affect multiple lines at several sites. Finite Element Analyses (FEA) and In-line Inspection (ILI) tools are the most common methods to measure/estimate the longitudinal strain demand of in-service pipelines. However, because they are rather time-consuming methods, they cannot be relied on when quick fitness-for-service evaluations of pipelines is needed. ILI needs considerable amount of time for planning and preparation as well as post-run analyses, and FEA needs extensive efforts to gather input data which might not be readily available for each site. Enbridge recently used a method of strain demand estimation during a rapid response process to several sites affected by lateral landslides after major weather events. The method involves gathering basic field measurements of pipe deformed shape and performing analytical strain calculation by using curve-fitted deformed shape functions. This paper describes this method, its key elements, and the assumptions on which it is based. It also presents the evaluation of this method via FEA of several pipes, soil conditions, and landslides scenarios. And finally, it concludes the capability of this method for different cases of pipes and landslides.

ESTIMASI KARBON TERSIMPAN TANAMAN KELAPA SAWIT (Elaeis guineensis Jacq) VARIETAS SOCFINDO PADA KELAS KESESUAIAN LAHAN S3 DI KEBUN AEK TOROP PTPN III

The expansion of oil palm plantations has led to debate over the negative impacts on soil fertility, hydrology, biodiversity and global warming. Climate change occurs due to changes in the composition of the atmosphere, mainly due to an increase in the concentration of greenhouse gases (GHGs). The usefulness of photosynthesis using CO2 is important to note. The purpose of this study is to measure / estimate the stored carbon absorbed by the 13-year-old Socfindo palm oil plant in the land suitability class S3. The study was conducted in May to June 2019 at PT Aek Torop Kebun III. Using descriptive design with Destructive and Non-Destructive methods based on ICRAF. The parameters are Above Surface Biomass (BAP) and Substance Biomass (BTB). The results showed that the oil palm surface surface biomass (BAP) at the age of 13 years was 117,855 tons / ha. The results of observations of Undergrowth Biomass (BTB) are 0.392 Ton / ha, the potential carbon stored is 54.394 Ton C / Ha and carbon dioxide absorption is 199.625 Ton CO2 / Ha.

An Improved Differential Evolution Algorithm for Data Stream Clustering

A Few algorithms were actualized by the analysts for performing clustering of data streams. Most of these algorithms require that the number of clusters (K) has to be fixed by the customer based on input data and it can be kept settled all through the clustering process. Stream clustering has faced few difficulties in picking up K. In this paper, we propose an efficient approach for data stream clustering by embracing an Improved Differential Evolution (IDE) algorithm. The IDE algorithm is one of the quick, powerful and productive global optimization approach for programmed clustering. In our proposed approach, we additionally apply an entropy based method for distinguishing the concept drift in the data stream and in this way updating the clustering procedure online. We demonstrated that our proposed method is contrasted with Genetic Algorithm and identified as proficient optimization algorithm. The performance of our proposed technique is assessed and cr eates the accuracy of 92.29%, the precision is 86.96%, recall is 90.30% and F-measure estimate is 88.60%.

Solving Assembly Sequence Planning Using Distance Evaluated Simulated Kalman Filter

This paper presents an implementation of simulated Kalman filter (SKF) algorithm for optimizing an assembly sequence planning (ASP) problem. The SKF search strategy contains three simple steps; predict-measure-estimate. The main objective of the ASP is to determine the sequence of component installation to shorten assembly time or save assembly costs. Initially, permutation sequence is generated to represent each agent. Each agent is then subjected to a precedence matrix constraint to produce feasible assembly sequence. In this paper, the distance evaluated SKF (DESKF) is proposed for solving ASP problem. The performance of the proposed DESKF is compared against previous works in solving ASP by applying BGSA, BPSO, and MSPSO. Using a case study of ASP, the results show that DESKF outperformed all the algorithms in obtaining the best solution.