A comparison of signal-to-noise characteristics : Fourier transform enhanced magnetic rotation spectroscopy and dispersive spectrometry

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1996.Includes bibliographical references (leaf 26).by Neme O. Nnolim.M.S

Voting by Committees under Constraints

We consider social choice problems where a society must choose a subset from a set of objects. Specifically, we characterize the families of strategy-proof voting procedures when not all possible subsets of objects are feasible, and voters' preferences are separable or additively representable.Voting, strategy-proofness, additive and separable preferences

The Multiple-partners Assignment Game with Heterogeneous Sells and Multi-unit Demands: Competitive Equilibria

A multiple-partners assignment game with heterogeneous sells and multi-unit demands consists of a set of sellers that own a given number of indivisible units of (potentially many different) goods and a set of buyers who value those units and want to buy at most an exogenously fixed number of units. We define a competitive equilibrium for this generalized assignment game and prove its existence by only using linear programming. We show that the set of competitive equilibria (pairs of price vectors and assignments) has a Cartesian product structure: each equilibrium price vector is part of a competitive equilibrium with all equilibrium assignments, and vice versa. We also show that the set of (restricted) equilibrium price vectors has a natural lattice structure and we study how this structure is translated into the set of agents' utilities that are attainable at equilibrium.Matching, Assignment Game, Indivisible Goods, Competitive Equilibrium, Lattice

Bribe-proof Rules in the Division Problem

The division problem consists of allocating an amount of a perfectly divisible good among a group of n agents with single-peaked preferences. A rule maps preference profiles into n shares of the amount to be allocated. A rule is bribe-proof if no group of agents can compensate another agent to misrepresent his preference and, after an appropriate redistribution of their shares, each obtain a strictly preferred share. We characterize all bribe-proof rules as the class of efficient, strategy-proof, and weak replacement monotonic rules. In addition, we identify the functional form of all bribe-proof and tops-only rules.Bribe-proofness, Strategy-proofness, Efficiency, Replacement Monotonicity, Single-peakedness

Assess Sanitary Condition and Food Handling Practices of Restaurants in Jimma Town, Ethiopia: Implication for Food Born Infection and Food Intoxication

A descriptive cross sectional study was conducted to assess sanitary conditions and food handling practice of restaurants in Jimma town for the implication of food born infection and food intoxication. Out of 75 restaurants registered in the town forty of them were randomly selected by lottery method to have a representative sample. Two food handlers from each restaurant were selected for the questionnaire. Majority of the food handlers working in Jimma town restaurants were aged less than twenty years old (55%), elementary education (62.5%), service years less than two years (42.5%) and income below 500 birr (55%). Concerning the personal hygiene about 65%, 55%, 50%, 50% were not worn gown, had not hair cover, worn unclean gown and hair cover and not trimmed finger nails, respectively. Hand washing habits of food handlers before handling food was found poor. The study revealed that most of the food handlers about 87.5% had not taken any training on food hygiene and regular medical checkup. Majority (57.5%) of them were not heard about food borne disease, causes and mode of food borne diseases. Age, educational background, service years and absence of training may affect the knowledge of food handlers on food borne diseases. Latrine facility, solid and liquid waste disposal system, sanitary and physical condition of the kitchen and dining room were found poor. Awareness creation on food hygiene through training and regular follow up is important to increase the knowledge of food handlers. There should be also a guide line for the establishment of kitchen and dining room of restaurants. Keywords: Restaurants, food handlers, food borne disease, Food Born Infection, Food Intoxicatio

Study of Productive and Reproductive Performances and Farmers’ Traits Preferences for Breeding of Small Ruminants in Ada Barga and Ejere Districts of West Shoa Zone, Oromia, Ethiopia

The productive and reproductive performances of small ruminants and producers’ traits preferences were studied in the three agro- ecologies (AEZs) of Ada Barga and Ejere districts, West Shoa Zone, Oromia, Ethiopia. The two districts were stratified into highland (HL), midland (ML) and lowland (LL) agro ecologies. A total of 180 households comprising of 69 from HL, 74 from ML and 37 from LL were purposively selected for this study. Detailed structured questionnaires, respondent interviews and farmers’ group discussions (FGD) were employed to capture relevant information. The overall age at first lambing (AFL) / age at first kidding (AFK), weaning age, age at sexual maturity of male (ASMM), reproductive life span of both sheep and goat were significantly affected by AEZs. The overall mean of slaughter age and ASMM was 6.43, 8.91 in sheep and 6.27, 8.39 in goat, respectively. High intensive kidding and lambing months was April to June. Keywords: Small ruminants, Producers’ trait preference, production, reproduction, agro-ecologies, Ethiopia.

A Maximal Domain of Preferences for Tops-only Rules in the Division Problem

The division problem consists of allocating an amount M of a perfectly divisible good among a group of n agents. Sprumont (1991) showed that if agents have single-peaked preferences over their shares, the uniform rule is the unique strategy-proof, efficient, and anonymous rule. Ching and Serizawa (1998) extended this result by showing that the set of single-plateaued preferences is the largest domain, for all possible values of M, admitting a rule (the extended uniform rule) satisfying strategy-proofness, efficiency and symmetry. We identify, for each M and n, a maximal domain of preferences under which the extended uniform rule also satisfies the properties of strategy-proofness, efficiency, continuity, and "tops-onlyness". These domains (called weakly single-plateaued) are strictly larger than the set of single-plateaued preferences. However, their intersection, when M varies from zero to infinity, coincides with the set of single-plateaued preferences.Strategy-proofness, single-plateaued preferences

Why Microsoft Arabic Spell checker is ineffective

International audienceSince 1997, the MS Arabic spell checker was integrated by Coltec-Egypt in the MS-Office suite and till now many Arabic users find it worthless. In this study, we show why the MS-spell checker fails to attract Arabic users. After spell-checking a document (10 pages -3300 words in Arabic), the assessment procedure spots 78 false positive errors. They reveal the lexical resource flaws: an unsystematic lexical coverage of the feminine and the broken plural of nouns and adjectives, and an arbitrary coverage of verbs and nouns with prefixed or suffixed particles. This unsystematic and arbitrary lexical coverage of the language resources pinpoints the absence of a clear definition of a lexical entry and an inadequate design of the related agglutination rules. Finally, this assessment reveals in general the failure of scientific and technological policies in big companies and in research institutions regarding Arabic

On the Invariance of the Set of Core Matchings with Respect to Preference Profiles

We consider the general many-to-one matching model with ordinal preferences and give a procedure to partition the set of preference profiles into subsets with the property that all preference profiles in the same subset have the same Core. We also show how to identify a profile of (incomplete) binary relations containing the minimal information needed to generate as strict extensions all the (complete) preference profiles with the same Core. This is important for applications since it reduces the amount of information that agents have to reveal about their preference relations to centralized Core matching mechanisms; moreover, this reduction is maximal.Matching, Core