Minimum cost path problems are considered for time-varying networks which possess piecewise linear travel costs/transit delays on edges and constant parking costs/enterable-unenterable restrictions ...on nodes. The arrival characteristics and departure characteristics are formulated, and their computation algorithms are designed. These characteristics are not values but curves with respect to generic time, which are novel features contrasted with the conventional time-invariant problems. Piecewise linearity of costs and delays drastically reduces the computational complexity.< >
Four patients with untreated congenital virilizing adrenal hyperplasia (partial 21-hydroxylase deficiency) were studied by bilateral adrenal vein catheterization. Simultaneous right and left adrenal ...and peripheral blood samples were collected for determination of oestrone (E1) and oestradiol (E2). The concentrations of both were higher in the adrenal effluents than in the peripheral blood samples, indicating their secretion by the adrenals. All patients were also studied during a sequential test of suppression (0.5 h after i.v. administration of 4 mg dexamethasone) and stimulation (5 min after i.v. administration of 250 microgram ACTH 1-24; Synacthen). Mean peripheral E2 concentrations did not change significantly whereas E1 increased above control levels after stimulation. In contrast, suppression of adrenal venous blood concentrations with dexamethasone, and stimulation with ACTH, was demonstrated for every patient. The results indicate that in congenital adrenal hyperplasia the adrenal glands secrete significant amounts of E1 and E2.
The progress of computer architecture has increased the necessity to design efficient scheduling algorithms according to the types of computer systems. We survey recent results of optimization and ...approximation algorithms for deterministic models of computer scheduling. We deal with identical, uniform and unrelated parallel processor systems, and flowshop systems. Optimality criteria considered in this paper are schedule-length and mean (weighted) flow-time. These are important measures for evaluating schedules in computer systems. Results on practical algorithms such as list scheduling are emphasized.
A tree-connected processor system (TPS) is one where m (>or=1) processors are connected to constitute a rooted tree. The authors study the problem of finding a feasible schedule for a TPS for n jobs ...with release times and deadlines. It is shown that the problem can be solved in O(mn log n) time if jobs have unit processing times.< >
Object-stacking in the World-Wide Web Shinjo, Y.; Zakimi, S.; Kyan, S.
Proceedings of International Workshop on Object Orientation in Operating Systems,
1995
Conference Proceeding
Object-stacking is a model for structuring object based systems. The main feature of object-stacking is that layers of objects with a uniform interface are constructed, and the functions of these ...objects are integrated. The effectiveness of object-stacking has been shown for file systems of distributed operating systems. The paper presents the application of the object-stacking model to the World-Wide Web, an information exploring/providing system on the Internet. Object-stacking gives powerful tools to information providers who use the World-Wide Web. The paper describes the implementation method of object-stacking in the World-Wide Web. The paper proposes the new concepts of demand stacking, virtual stackable objects, and pointer swizzling in the World-Wide Web.
Mutual exclusion is treated in distributed autonomous environments. The most important property of the autonomous network treated here is its membership variability, that is, frequency occurrence of ...entries of new nodes and exits of old nodes. Thus, when the network is large-scale, it is not possible for each node to keep up the information of all other nodes. The authors have previously designed a mutual exclusion algorithm of the single shared resource case for distributed environments of autonomous nodes, based on the Chandy-Misra protocol for Dining Philosopher (diners) problems (K. M. Chandy and J. Misra, 1984). Mutual exclusion of multiple shared resource cases is considered. The condition that no more than k nodes can use the shared resource is given. Since the acyclic graph model used in the model can be represented by a marked graph model, this model is used in analysis.< >
A study is made of the control algorithms for the transmission of time-critical messages. Each message comprises packets with unit data length. The objective is to minimize the maximum tardiness of ...the messages. Optimal algorithms are presented for communication nets with in-tree or out-tree structures. A heuristic algorithm is presented for more general hierarchical communication nets.< >
In the presence of a diarylborinic acid catalyst, glycosyl methanesulfonates engage in regio- and stereoselective couplings with partially protected pyranoside and furanoside acceptors. The ...methanesulfonate donors are prepared in situ from glycosyl hemiacetals, and are coupled under mild, operationally simple conditions (amine base, organoboron catalyst, room temperature). The borinic acid catalyst not only influences site-selectivity via activation of 1,2- or 1,3-diol motifs, but also has a pronounced effect on the stereochemical outcome: 1,2-trans-linked disaccharides are obtained selectively in the absence of neighboring group participation. Reaction progress kinetic analysis was used to obtain insight into the mechanism of glycosylation, both in the presence of catalyst and in its absence, while rates of interconversion of methanesulfonate anomers were determined by NMR exchange spectroscopy (EXSY). Together, the results suggest that although the uncatalyzed and catalyzed reactions give rise to opposite stereochemical outcomes, both proceed by associative mechanisms.
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