Smooth Scheduling under Variable Rates or the Analog-Digital Confinement Game

This work considers non-terminating scheduling problems in which a system of multiple resources serves clients having variable needs. The system has m identical resources and n clients; in each time slot each resource may serve at most one client; in each such slot t each client γ has a rate, a real number ρ _γ (t), that specifies his needs in this slot. The rates satisfy the restriction ∑ _γ ρ _γ (t)≤m for any slot t. Except of this restriction, the rates can vary in arbitrary fashion. (This contrasts most prior works in this area in which the rates of the clients are constant.) The schedule is required to be smooth as follows: a schedule is Δ -smooth if for all time intervals I the absolute difference between the amount of service received by each client γ to his nominal needs of ∑ _t∈I ρ _γ (t) is less than Δ. Our objective are online schedulers that produce Δ-smooth schedules where Δ is a small constant which is independent of m and n. Our paper constructs such schedulers; these are the first online Δ-smooth schedulers, with a constant Δ, for clients with arbitrarily variable rates in a single or multiple resource system. Furthermore, the paper also considers a non-concurrent environment in which there is an additional restriction that each client is served at most once in each time slot; it presents the first online smooth schedulers for variable rates under this restriction. The above non-concurrent restriction is crucial in some applications (e.g., CPU scheduling). It has been pointed out that this restriction “adds a surprising amount of difficulty” to the scheduling problem. However, this observation was never formalized and, of course, was never proved. Our paper formalizes and proves some aspects of this observation. Another contribution of this paper is the introduction of a complete information, two player game called the analog-digital confinement game. In such a game pebbles are located on the real line; the two players, the analog player and the digital player, take alternating turns and each one, in his turn, moves some of the pebbles; the digital player moves the pebbles backwards by discrete distances while the analog player moves the pebbles forward by analog distances; the aim of the analog player is to cause one pebble (or more) to escape a pre-defined real interval while the aim of the digital player is to confine the pebbles into the interval. We demonstrate that this game is a convenient framework to study the general question of how to approximate an analog process by a digital one. All the above scheduling results are established via this game. In this derivation, the pebbles represent the clients, the analog player generates the needs of the clients and the digital player generates the schedule. Dedicated to the memory of Professor Shimon Even for his inspiration and encouragement     

Advanced methods for displays and remote control of robots

An in-depth evaluation of the usability and situation awareness performance of different displays and destination controls of robots are presented. In two experiments we evaluate the way information is presented to the operator and assess different means for controlling the robot. Our study compares three types of displays: a “blocks” display, a HUD (head-up display), and a radar display, and two types of controls: touch screen and hand gestures. The HUD demonstrated better performance when compared to the blocks display and was perceived to have greater usability compared to the radar display. The HUD was also found to be more useful when the operation of the robot was more difficult, i.e., when using the hand-gesture method. The experiments also pointed to the importance of using a wide viewing angle to minimize distortion and for easier coping with the difficulties of locating objects in the field of view margins. The touch screen was found to be superior in terms of both objective performance and its perceived usability. No differences were found between the displays and the controllers in terms of situation awareness. This research sheds light on the preferred display type and controlling method for operating robots from a distance, making it easier to cope with the challenges of operating such systems.     

"Where similarity beats redundancy: The importance of context, higher order similarity, and response assignment": Correction to Eidels, Townsend, and Pomerantz (2008).

Reports an error in "Where similarity beats redundancy: The importance of context, higher order similarity, and response assignment" by Ami Eidels, James T. Townsend and James R. Pomerantz (Journal of Experimental Psychology: Human Perception and Performance, 2008[Dec], Vol 34[6], 1441-1463). The DOIs for the article and the supplemental materials were incorrectly listed. The correct DOIs are provided in the erratum. (The following abstract of the original article appeared in record 2008-16831-008.) People are especially efficient in processing certain visual stimuli such as human faces or good configurations. It has been suggested that topology and geometry play important roles in configural perception. Visual search is one area in which configurality seems to matter. When either of 2 target features leads to a correct response and the sequence includes trials in which either or both targets are present, the result is a redundant-target paradigm. It is common for such experiments to find faster performance with the double target than with either alone, something that is difficult to explain with ordinary serial models. This redundant-targets study uses figures that can be dissimilar in their topology and geometry and manipulates the stimulus set and the stimulus-response assignments. The authors found that the combination of higher order similarity (e.g., topological) among the features in the stimulus set and response assignment can effectively overpower or facilitate the redundant-target effect, depending on the exact nature of the former characteristics. Several reasonable models of redundant-targets performance are falsified. Parallel models with the potential for channel interactions are supported by the data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analytical modeling of energy efficiency in heterogeneous processors

Energy efficiency is increasingly critical for multi-core processors and many-core accelerators. In order to increase energy efficiency, chip manufacturers are developing heterogeneous CMP chips.     

A Study on the Distances of Small Mobile Robot Moves towards Infants

In recent years, it is remarkable that various robots are being developed, and the development of robot technology is beginning to be taken into an actual living space. There are still many questions that we will have to answer for the harmonization of living together with a robot. This study is focused on ＂the study of how to plan and design a living space in harmonizing with robots＂, and focused on the effects of infants （subjects） along with the distance between robots and themselves. The study is to seek for the minimum distance for the subjects who felt that ＂I do not want a robot to be any closer being approached to me＂. This experiment was conducted among 30 infants at the kindergarten, utilizing a small experimental robot. A small robot whose dimension is 120 mm （W） ×130 mm （D） × 70 mm （H）, approaching infants as is to see if it would make any differences to the infant＇s reactions.     

Consumer segmentation based on food neophobia and its application to product development

When evaluating the acceptability of food products, companies often focus on specific demographics for recruiting and screening consumers. However, this information may not necessarily explain the variability in the test results. Other elements, such as consumer psychographic profiles, may help better understand test participants’ responses. The objective of this study was to investigate the effect of food neophobia (reluctance to/avoidance of novel foods) on acceptability of novel food items. Six salad dressings with novel flavor combinations were chosen for evaluation in a central location test. Consumers were screened using the food neophobia scale (Pliner & Hobden, 1992) as well as liking of salad dressings. Each subject evaluated three of six dressings for hedonic and diagnostic attributes. Neophobic subjects rated the salad dressings significantly lower (p < 0.05) than neophilics for all hedonic attributes with the exception of appearance. These results were consistent for all dressings. However, when looking at the hedonic mean scores from both groups, the products were ranked in similar order in that the best liked and least liked dressing for the neophilic group was the same as those for the neophobic group. For diagnostic attributes, while the mean scores were significantly different for neophobics and neophilics, the percentage of “just-about-right” scores did not differ. These results suggest that food neophobia may impact the degree with which a product is liked or disliked by consumers, but it may not affect how products are ranked based on hedonic mean scores. Therefore, while understanding the psychographic composition of a consumer test respondent base may help explain why some products score higher or lower in acceptability, it may not alter the sensory guidance provided to product development regarding the specific flavor and texture attributes that were tested.     

Mos: A multicomputer distributed operating system

This paper describes the goals and the internal structure of MOS, a Multicomputer distributed Operating System. MOS is a general-purpose time-sharing operating system which makes a cluster of loosely connected independent homogeneous computers behave as a single-machine UNIX system. The main goals of the system include network transparency, decentralized control, site autonomy and dynamic process migration. The main objective in the design of the system was to reduce the complexity of the system, while maintaining good performance. The internal structure of the system can be characterized by modularity, a high degree of information hiding, hierarchical organization and remote procedure calls.