Aggregate computation, such as selecting the minimum attribute value of a relation, is expensive, especially in a temporal database. We describe the basic techniques behind computing aggregates in conventional databases and show that these techniques are not efficient when applied to temporal databases. We examine the problem of computing constant intervals (intervals of time for which the aggr...

We present a new solution to the problem of expressing single-pass, space-eecient list and tree computations in a modular fashion. Synchronized lazy aggregates augment existing methods for expressing programs as networks of operators acting on aggregate data, but overcome many limitations. The technique is based on a dynamic model of lock step processing that enables the operators in a network ...

We propose an extension of the Constraint Handling Rules language with aggregates like sum, count, findall, and min in the heads of rules. We define the semantics of aggregate expressions formally and informally. Our prototype implementation allows nested aggregate expressions over guarded conjunctions of constraints, using either an ondemand or an incremental computation strategy. Case studies...

This is a new, extended version of a report with the same number.

Fuzzy set theory represents a uniform framework for extending the relational database model to han-, dle imprecision of information found in the real world. None of the existing proposals for data models handling imprecision has dealt with queries involvin aggregate operators. This paper presents a framewor for ek handling aggregates in the context of imprecise information. Two kinds of aggrega...

BACKGROUND Circulating platelet-neutrophil aggregates play a crucial role in amplifying acute inflammation and could promote adverse effects involving vascular injury. The aim of this study was to evaluate the role of platelet-neutrophil aggregates in Kawasaki disease (KD). METHODS AND RESULTS Forty patients with KD (30 intravenous immunoglobulin [IVIG] responders and 10 IVIG non-responders),...

We have investigated scattering properties of aggregates, emphasizing the size of constituent monomers comparable with the wavelength of visible light, in order to model the scattering properties of cometary dust. This has differentiated our study from previous investigations of aggregates in which the size of the monomers was much smaller than the wavelength. For aggregates, the absorption cro...

Bone marrow involvement (BMI) is a well-known poor prognostic factor in patients with diffuse large B-cell lymphoma (DLBCL). This study robustly investigated the significance of monoclonal immunoglobulin gene rearrangement combined with histologic B-cell aggregates in bone marrow (BM) in the detection of a poor prognostic group. Pretreatment BM samples of 394 DLBCL patients were analyzed via th...

The ultimate goal of tissue engineering is to design and fabricate functional human tissues that are similar to natural cells and are capable of regeneration. Preparation of cell aggregates is one of the important steps in 3D tissue engineering technology, particularly in organ printing. Two simple methods, hanging drop (HD) and conical tube (CT) were utilized to prepare cell aggregates. The si...