The heavy metal concentration of sewage sludge increased during composting for cadmium, chromium, lead and zinc and decreased for copper and nickel. Cadmium and lead were the most variable of the metals, copper and zinc the least. Variability within a batch was small (variation of 4-12%). Variability attributable to batch-to-batch differences was generally larger (variation of 4-37%). The varia...

Classical stochastic gradient methods for optimization rely on noisy gradient approximations that become progressively less accurate as iterates approach a solution. The large noise and small signal in the resulting gradients makes it difficult to use them for adaptive stepsize selection and automatic stopping. We propose alternative “big batch” SGD schemes that adaptively grow the batch size o...

When designing steady-state computer simulation experiments, one is often faced with the choice of batching observations in one long run or replicating a number of smaller runs. Both methods are potentially useful in simulation output analysis. In its simplest form, the choice boils down to: Should we divide one long run into b adjacent, nonoverlapping batches, each of size m? Or should we cond...

Parameter settings profoundly impact the performance of machine learning algorithms and laboratory experiments. The classical grid search or trial-error methods are exponentially expensive in large parameter spaces, and Bayesian optimization (BO) offers an elegant alternative for global optimization of black box functions. In situations where the black box function can be evaluated at multiple ...

a two server queueing system with single and batch service is considered in this paper. the arrival process is assumed to be poisson and the service rate follows an exponential distribution. server-i serves the customers in both single and batch service, while server-ii serves the customers in batch service only. the laplace transform of the transient and steady state behavior of the model is c...

Data Warehouses and Business Intelligence (BI) applications are the top two priorities for CIO/CTOs (Celent report on December 14, 2005). A data warehouse IT infrastructure needs to support the requirement of (day time) ad hoc query response time and (night time) batch workload completion time. The following tasks need to be finished in a batch window: (1) Apply one day’s delta data to the base...

Batch and fed batch cultures of Azospirillum brasilense Sp245 were conducted in a bioreactor. Growth response, IAA biosynthesis and the expression of the ipdC gene were monitored in relation to the environmental conditions (temperature, availability of a carbon source and aeration). A. brasilense can grow and produce IAA in batch cultures between 20 and 38 degrees C in a standard minimal medium...

We present a new method for obtaining confidence intervals in steady-state simulation. In our replicated batch means method, we do a small number of independent replications to estimate the steady-state mean of the underlying stochastic process. In order to obtain a variance estimator, we further group the observations from these replications into nonoverlapping batches. We show that for large ...

We propose Batch-Expansion Training (BET), a framework for running a batch optimizer on a gradually expanding dataset. As opposed to stochastic approaches, batches do not need to be resampled i.i.d. at every iteration, thus making BET more resource efficient in a distributed setting, and when disk-access is constrained. Moreover, BET can be easily paired with most batch optimizers, does not req...