229 research outputs found
On Optimal Mechanisms in the Two-Item Single-Buyer Unit-Demand Setting
We consider the problem of designing a revenue-optimal mechanism in the
two-item, single-buyer, unit-demand setting when the buyer's valuations, , are uniformly distributed in an arbitrary rectangle
in the positive quadrant. We provide a complete and
explicit solution for arbitrary nonnegative values of . We
identify five simple structures, each with at most five (possibly stochastic)
menu items, and prove that the optimal mechanism has one of the five
structures. We also characterize the optimal mechanism as a function of , and . When is low, the optimal mechanism is a posted price
mechanism with an exclusion region; when is high, it is a posted price
mechanism without an exclusion region. Our results are the first to show the
existence of optimal mechanisms with no exclusion region, to the best of our
knowledge
Mechanism design for single leader Stackelberg problems and application to procurement auction design
In this paper, we focus on mechanism design for single leader Stackelberg problems, which are a special case of hierarchical decision making problems in which a distinguished agent, known as the leader, makes the first move and this action is followed by the actions of the remaining agents, which are known as the followers. These problems are also known as single leader rest follower (SLRF) problems. There are many examples of such problems in the areas of electronic commerce, supply chain management, manufacturing systems, distributed computing, transportation networks, and multiagent systems. The game induced among the agents for these problems is a Bayesian Stackelberg game, which is more general than a Bayesian game. For this reason, classical mechanism design, which is based on Bayesian games, cannot be applied as is for solving SLRF mechanism design problems. In this paper, we extend classical mechanism design theory to the specific setting of SLRF problems. As a significant application of the theory developed, we explore two examples from the domain of electronic commerce-first-price and second-price electronic procurement auctions with reserve prices. Using an SLRF model for these auctions, we derive certain key results using the SLRF mechanism design framework developed in this paper. The theory developed has many promising applications in modeling and solving emerging game theoretic problems in engineering
Psychopharmacological activities of acorus calamus roots in rat and mice models
Acorus calamus (Araceae) is commonly known in India as sweet flag and has been used in
traditional medicine as a remedy for pain, convulsion, inflammation, and ulcer. In the present work, the
methanolic extract of Acorus calamus roots (MEAC) was assessed for different psychopharmacological activities
in rats and mice by evaluation of general, exploratory behaviour, phenobarbitone sodium-induced
sleeping time and muscle relaxant activity. The extract at doses 100 mg/kg and above exhibited a reduction
in spontaneous activity and a decrease in exploratory behavioural pattern was observed. Also a significant
reduction in muscle relaxant activity and potentiated phenobarbitone sodium-induced sleeping time
in mice was noted in MEAC treated groups. From our study, the results indicates that MEAC appears to
have effects on alteration in general behavior pattern, evident from the spontaneous activity, sound, touch
and pain responses of the MEAC treated groups.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Water-triggered frontal polymerization
A totally new mode of frontal polymerization (FP) of acrylamide is established which is triggered by the simple addition of a minute, specific volume of water. Experimental conditions under which this mode of polymerization yields linear and water-soluble polyacrylamide were carefully established, paving the way to synthesize commercially pertinent homo- and copolymers. A new redox couple was identified to circumvent the imidization and the ensuing gelation, hitherto associated with FP of acrylamide. Effects of reaction variables such as type and concentration of redox couple and volume of water on measurable parameters of FP such as front velocity, front temperature, shape of front and yield have been studied. Two types of redox couples are reported. Nonplanar frontal regime was observed in few redox couples. We could visually observe helical patterns with naked eyes, while layered patterns were observable under SEM. Additionally, micro-phase separation and heterogeneity in the polymer matrix was observed due to unreacted pockets of monomer which evolve via bulk mode. This nonlinear phenomenon is described
PUF Probe: A PUF-based Hardware Authentication Equipment for IEDs
Intelligent Electronic Devices (IEDs) are vital components in modern
electrical substations, collectively responsible for monitoring electrical
parameters and performing protective functions. As a result, ensuring the
integrity of IEDs is an essential criteria. While standards like IEC 61850 and
IEC 60870-5-104 establish cyber-security protocols for secure information
exchange in IED-based power systems, the physical integrity of IEDs is often
overlooked, leading to a rise in counterfeit and tainted electronic products.
This paper proposes a physical unclonable function (PUF)-based device (IEDPUF
probe) capable of extracting unique hardware signatures from commercial IEDs.
These signatures can serve as identifiers, facilitating the authentication and
protection of IEDs against counterfeiting. The paper presents the complete
hardware architecture of the IEDPUF probe, along with algorithms for signature
extraction and authentication. The process involves the central computer system
(CCS) initiating IED authentication requests by sending random challenges to
the IEDPUF probe. Based on the challenges, the IEDPUF probe generates
responses, which are then verified by the CCS to authenticate the IED.
Additionally, a two-way authentication technique is employed to ensure that
only verified requests are granted access for signature extraction.
Experimental results confirm the efficacy of the proposed IEDPUF probe. The
results demonstrate its ability to provide real-time responses possessing
randomness while uniquely identifying the IED under investigation. The proposed
IEDPUF probe offers a simple, cost-effective, accurate solution with minimal
storage requirements, enhancing the authenticity and integrity of IEDs within
electrical substation
Multiattribute electronic procurement using goal programming
One of the key challenges of current day electronic procurement systems is to enable procurement decisions transcend beyond a single attribute such as cost. Consequently, multiattribute procurement have emerged as an important research direction. In this paper, we develop a multiattribute e-procurement system for procuring large volume of a single item. Our system is motivated by an industrial procurement scenario for procuring raw material. The procurement scenario demands multiattribute bids, volume discount cost functions, inclusion of business constraints, and consideration of multiple criteria in bid evaluation. We develop a generic framework for an e-procurement system that meets the above requirements. The bid evaluation problem is formulated as a mixed linear integer multiple criteria optimization problem and goal programming is used as the solution technique. We present a case study for which we illustrate the proposed approach and a heuristic is proposed to handle the computational complexity arising out of the cost functions used in the bids
Preferred reporting items for studies mapping onto preference-based outcome measures: The MAPS statement
'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. The primary audiences for the MAPS statement are researchers reporting mapping studies, the funders of the research, and peer reviewers and editors involved in assessing mapping studies for publication. A de novo list of 29 candidate reporting items and accompanying explanations was created by a working group comprised of six health economists and one Delphi methodologist. Following a two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community, a final set of 23 items deemed essential for transparent reporting, and accompanying explanations, was developed. The items are contained in a user friendly 23 item checklist. They are presented numerically and categorised within six sections, namely: (i) title and abstract; (ii) introduction; (iii) methods; (iv) results; (v) discussion; and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document. It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by eight health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years' time. This statement was published jointly in Applied Health Economics and Health Policy, Health and Quality of Life Outcomes, International Journal of Technology Assessment in Health Care, Journal of Medical Economics, Medical Decision Making, PharmacoEconomics, and Quality of Life Research
Psychopharmacological activities of acorus calamus roots in rat and mice models
Acorus calamus (Araceae) is commonly known in India as sweet flag and has been used in
traditional medicine as a remedy for pain, convulsion, inflammation, and ulcer. In the present work, the
methanolic extract of Acorus calamus roots (MEAC) was assessed for different psychopharmacological activities
in rats and mice by evaluation of general, exploratory behaviour, phenobarbitone sodium-induced
sleeping time and muscle relaxant activity. The extract at doses 100 mg/kg and above exhibited a reduction
in spontaneous activity and a decrease in exploratory behavioural pattern was observed. Also a significant
reduction in muscle relaxant activity and potentiated phenobarbitone sodium-induced sleeping time
in mice was noted in MEAC treated groups. From our study, the results indicates that MEAC appears to
have effects on alteration in general behavior pattern, evident from the spontaneous activity, sound, touch
and pain responses of the MEAC treated groups.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Average flow constraints and stabilizability in uncertain production-distribution systems
We consider a multi-inventory system with controlled flows and uncertain demands (disturbances) bounded within assigned compact sets. The system is modelled as a first-order one integrating the discrepancy between controlled flows and demands at different sites/nodes. Thus, the buffer levels at the nodes represent the system state. Given a long-term average demand, we are interested in a control strategy that satisfies just one of two requirements: (i) meeting any possible demand at each time (worst case stability) or (ii) achieving a predefined flow in the average (average flow constraints). Necessary and sufficient conditions for the achievement of both goals have been proposed by the authors. In this paper, we face the case in which these conditions are not satisfied. We show that, if we ignore the requirement on worst case stability, we can find a control strategy driving the expected value of the state to zero. On the contrary, if we ignore the average flow constraints, we can find a control strategy that satisfies worst case stability while optimizing any linear cost on the average control. In the latter case, we provide a tight bound for the cost
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