NASA TileWorld manual (system version 2.2)

The commands are documented of the NASA TileWorld simulator, as well as providing information about how to run it and extend it. The simulator, implemented in Common Lisp with Common Windows, encodes a particular range in a spectrum of domains, for controllable research experiments. TileWorld consists of a two dimensional grid of cells, a set of polygonal tiles, and a single agent which can grasp and move tiles. In addition to agent executable actions, there is an external event over which the agent has not control; this event correspond to a 'gust of wind'

Kola Nut as a Symbol of Welcome Among the Igede of Benue State

The concepts hospitality and welcome are closely related if not synonymous. Both concepts connote friendly behaviours to guests or a person who has just arrived one’s place on a short or long term visit. Thus, if a host is happy with a visit, he/she is normally glad and expresses his/her gladness by the manner the guest is treated. As such, someone who is welcome is gladly accepted in a place. The fact that Africans are hospitable and welcome guests in their midst and abode is uncontestable. Various ethnic nationalities in Africa have different ways of saying welcome to their guests/visitors. For the Tiv of Central Nigeria, any of a piece of roasted yam, groundnuts, ginger, garden eggs, water and smoking pipe (for smokers) symbolises welcome. To the Idoma and Igala of Central Nigeria, it is Kunu (gruel) and water respectively. The paper established that for the Igede of Oju and Obi Local Government Areas of Benue State, Kola nut symbolises welcome. Therefore, the Igede way of expressing greetings to guests and showing that such guests are accepted is to offer them kola nut. This clearly depicts that the Igede are glad that such a visitor has come. Also, the Igede gives kola nuts in odd numbers to their guest because even numbers are reserved for royalties (kings/chiefs). The paper also established that palm wine, soft drinks and any other form of alcoholic drinks accompany the kola to “wash” it down the throat. This paves the way for fruitful discussions and cross-fertilization of ideas. The Igede belief that only the elders can break kola nut hence they are the only ones by virtue of the wisdom, who understand the language of kola nut and the spirits. Thus, Kola nut has both social and religious implications. The paper calls for the preservation of African cultural values on hospitality for the maintenance of peace, growth and developing of African societies.Key Words: symbol, kola nut, Iged

The or U Varen Iwa (Blacksmith) and the Or U Gban Agbe (Hoe Handle Maker) as Agricultural Technologists among the Tiv: Issues in Africaas Technological Development

The Tiv are traditionally farmers by occupation This implies that they till the soil and keep animals These provide them with food meat and a source of income As agriculturalists the roles of the or u varen iwa black smith and the or u gban agbe hoe handle maker is indispensable in the process of food production This has to do with the fact that they produce the equipments needed for farming such as hoes sickles machetes axes knives and hoe handles to which hoe blades are fixed for the making of heaps mounds and lines for planting various crops This makes these craftsmen agricultural technologists The research adopts both the primary and secondary sources of data This involves oral interview with blacksmiths and hoe handle makers for the primary source For documented source the paper makes use of books journals newspapers and magazines The paper established that without these craftsmen in Tiv land farm work would be a mirage However despite their indispensable roles no meaningful progress has been achieved as the hoes and their handles used by the Tiv for over 400years have remained the same and neither has the process of making mounds and lines changed The paper examines the factors responsible for this apparent lack of development in Tiv agricultural technology and calls for improvement in Tiv agricultural implements baring in mind particularly the issue of technological transfer This is necessary and fundamental if the Tiv and indeed the rest of Africa do not wish to remain technological lagers in a world that is fast assuming a technological dimensio

An analysis of commitment strategies in planning: The details

We compare the utility of different commitment strategies in planning. Under a 'least commitment strategy', plans are represented as partial orders and operators are ordered only when interactions are detected. We investigate claims of the inherent advantages of planning with partial orders, as compared to planning with total orders. By focusing our analysis on the issue of operator ordering commitment, we are able to carry out a rigorous comparative analysis of two planners. We show that partial-order planning can be more efficient than total-order planning, but we also show that this is not necessarily so

Construction Cost Sensitivity of a Lignocellulosic Ethanol Biorefinery

The technology has been developed to convert feedstock with cellulose content into ethanol. However, ethanol produced from cellulosic feedstock is the same as ethanol distilled from grain. The objective of research is to determine the price per gallon of ethanol needed so that producing lignocellulosic based ethanol become economically feasible.Environmental Economics and Policy, Production Economics,

The min-conflicts heuristic: Experimental and theoretical results

This paper describes a simple heuristic method for solving large-scale constraint satisfaction and scheduling problems. Given an initial assignment for the variables in a problem, the method operates by searching through the space of possible repairs. The search is guided by an ordering heuristic, the min-conflicts heuristic, that attempts to minimize the number of constraint violations after each step. We demonstrate empirically that the method performs orders of magnitude better than traditional backtracking techniques on certain standard problems. For example, the one million queens problem can be solved rapidly using our approach. We also describe practical scheduling applications where the method has been successfully applied. A theoretical analysis is presented to explain why the method works so well on certain types of problems and to predict when it is likely to be most effective

Applying artificial intelligence to the control of space telescopes (extended abstract)

The field of astronomy has recently benefited from the availability of space telescopes. The Hubble Space Telescope (HST), for instance, despite its problems, provides a unique and valuable view of the universe. However, unlike HST, a telescope need not be in low Earth orbit to escape our thickening atmosphere: it is currently technologically feasible to put a telescope on the moon, and there are excellent reasons for doing this. Either in low Earth orbit or on the moon, a space telescope represents an expensive and sought-after resource. Thus, the planning, scheduling, and control of these telescopes is an important problem that must be seriously studied

An extended abstract: A heuristic repair method for constraint-satisfaction and scheduling problems

The work described in this paper was inspired by a surprisingly effective neural network developed for scheduling astronomical observations on the Hubble Space Telescope. Our heuristic constraint satisfaction problem (CSP) method was distilled from an analysis of the network. In the process of carrying out the analysis, we discovered that the effectiveness of the network has little to do with its connectionist implementation. Furthermore, the ideas employed in the network can be implemented very efficiently within a symbolic CSP framework. The symbolic implementation is extremely simple. It also has the advantage that several different search strategies can be employed, although we have found that hill-climbing methods are particularly well-suited for the applications that we have investigated. We begin the paper with a brief review of the neural network. Following this, we describe our symbolic method for heuristic repair

Impact of chromophores on colour appearance in a computational skin model

Early diagnosis of skin cancer offers the patient more favorable treatment options. Color fidelity of skin images is a major concern for dermatologists as adoption of digital dermatoscopes is increasing rapidly. Accurate color depiction of the lesion and surrounding skin are vital in diagnostic evaluation of a lesion. We previously introduced VCT-Derma, a pipeline for dermatological Virtual Clinical Trials (VCTs) including detailed and flexible models of human skin and lesions, which represent the patient in the entire dermatoscopy-based diagnostic process. However, those initial models of skin and lesions did not properly account for tissue colors. Our new skin model accounts for tissue color appearance by incorporating chromophores (e.g., melanin, blood) into the tissue model, and simulating the optical properties of the various skin layers. The physical properties of the skin and lesion were selected from clinically plausible values. The model and simulated dermatoscope images were created in open modelling software, assuming a linear camera model. We have assumed ambient white lighting, with a 6mm distance to the camera. Our model of color appearance was characterised by comparing the brightness of the lesion to its depth. The brightness of the lesion is compared through the variability of the mean gray values of a cropped region around the lesion. We compare two skin models, one without extensive chromophore content and one with. Our preliminary evaluation of increasing chromophore content shows promise based on the results presented here. Further refinement and validation of the model is ongoing