Shared Autonomy via Hindsight Optimization

In shared autonomy, user input and robot autonomy are combined to control a robot to achieve a goal. Often, the robot does not know a priori which goal the user wants to achieve, and must both predict the user's intended goal, and assist in achieving that goal. We formulate the problem of shared autonomy as a Partially Observable Markov Decision Process with uncertainty over the user's goal. We utilize maximum entropy inverse optimal control to estimate a distribution over the user's goal based on the history of inputs. Ideally, the robot assists the user by solving for an action which minimizes the expected cost-to-go for the (unknown) goal. As solving the POMDP to select the optimal action is intractable, we use hindsight optimization to approximate the solution. In a user study, we compare our method to a standard predict-then-blend approach. We find that our method enables users to accomplish tasks more quickly while utilizing less input. However, when asked to rate each system, users were mixed in their assessment, citing a tradeoff between maintaining control authority and accomplishing tasks quickly

Anti-inflammatory activity of theophylline on carrageenan-induced paw edema in male wistar rats

Background: Evaluate the anti-inflammatory property of theophylline on rat hind paw edema using carrageenan-induced acute inflammatory model.Methods: Wistar male rats (150-200 gm) were divided into 7 groups- 3 standard groups, 3 test groups and 1 control group. Each group consists of six rats. A control group was treated with 0.2ml of normal saline, 3 standard groups were treated with different doses of Diclofenac (Standard drug): 5 mg/kg, 10 mg/kg, 15 mg/kg body weight, respectively and 3 test groups  were  treated with different doses of Theophylline (Test drug):  5 mg/kg , 10 mg/kg  and 15 mg/kg, respectively. The anti-inflammatory property was assessed by plethysmograph.Results: Theophylline demonstrated a significant anti-inflammatory property at different dose levels when compared to controls (p > 0.05). However this anti-inflammatory activity was less as compared to standard drug.Conclusions: Theophylline exhibited a dose dependent anti-inflammatory activity in a carrageenan model of inflammation

Facile preparation of agarose-chitosan hybrid materials and nanocomposite ionogels using an ionic liquid via dissolution, regeneration and sol-gel transition

We report simultaneous dissolution of agarose (AG) and chitosan (CH) in varying proportions in an ionic liquid (IL), 1-butyl-3-methylimidazolium chloride [C4mim][Cl]. Composite materials were constructed from AG-CH-IL solutions using the antisolvent methanol, and IL was recovered from the solutions. Composite materials could be uniformly decorated with silver oxide (Ag2O) nanoparticles (Ag NPs) to form nanocomposites in a single step by in situ synthesis of Ag NPs in AG-CH-IL sols, wherein the biopolymer moiety acted as both reducing and stabilizing agent. Cooling of Ag NPs-AG-CH-IL sols to room temperature resulted in high conductivity and high mechanical strength nanocomposite ionogels. The structure, stability and physiochemical properties of composite materials and nanocomposites were characterized by several analytical techniques, such as Fourier transform infrared (FTIR), CD spectroscopy, differential scanning colorimetric (DSC), thermogravimetric analysis (TGA), gel permeation chromatography (GPC), and scanning electron micrography (SEM). The result shows that composite materials have good thermal and conformational stability, compatibility and strong hydrogen bonding interactions between AG-CH complexes. Decoration of Ag NPs in composites and ionogels was confirmed by UV-Vis spectroscopy, SEM, TEM, EDAX and XRD. The mechanical and conducting properties of composite ionogels have been characterized by rheology and current-voltage measurements. Since Ag NPs show good antimicrobial activity, Ag NPs -AG-CH composite materials have the potential to be used in biotechnology and biomedical applications whereas nanocomposite ionogels will be suitable as precursors for applications such as quasi-solid dye sensitized solar cells, actuators, sensors or electrochromic displays

Succinct Representations of Permutations and Functions

We investigate the problem of succinctly representing an arbitrary permutation, \pi, on {0,...,n-1} so that \pi^k(i) can be computed quickly for any i and any (positive or negative) integer power k. A representation taking (1+\epsilon) n lg n + O(1) bits suffices to compute arbitrary powers in constant time, for any positive constant \epsilon <= 1. A representation taking the optimal \ceil{\lg n!} + o(n) bits can be used to compute arbitrary powers in O(lg n / lg lg n) time. We then consider the more general problem of succinctly representing an arbitrary function, f: [n] \rightarrow [n] so that f^k(i) can be computed quickly for any i and any integer power k. We give a representation that takes (1+\epsilon) n lg n + O(1) bits, for any positive constant \epsilon <= 1, and computes arbitrary positive powers in constant time. It can also be used to compute f^k(i), for any negative integer k, in optimal O(1+|f^k(i)|) time. We place emphasis on the redundancy, or the space beyond the information-theoretic lower bound that the data structure uses in order to support operations efficiently. A number of lower bounds have recently been shown on the redundancy of data structures. These lower bounds confirm the space-time optimality of some of our solutions. Furthermore, the redundancy of one of our structures "surpasses" a recent lower bound by Golynski [Golynski, SODA 2009], thus demonstrating the limitations of this lower bound.Comment: Preliminary versions of these results have appeared in the Proceedings of ICALP 2003 and 2004. However, all results in this version are improved over the earlier conference versio

Potential utility of selected research methods and techniques for determining the needs of extensions clientele with application to Mysore State, India

Program planning is an educational process of great importance. It is the responsibility of the extension staff to help the planning committee in carrying out the five phases of the program projection process. The extension educational process is conceptually based on the needs of the clientele. The quote mentioned below makes this position clears: The Cooperative Extension Service is responsible for exercising the leadership necessary to determine the problems of the people, working through democratic processes. Its personnel, working cooperatively with the people determine family and community needs as the basis for developing programs of informal education. Hence, the extension staff should have available to it facts which are reliable and representative so that unbiased data for determining the needs of the clientele may be used in developing extension programs. Therefore, the extension staff is faced with the problem of how to help the planning committee to arrive at decisions and develop programs which are sound and purposeful. Methods and techniques the extension staff adopts in solving this problem would influence the quality and success of the program developed. It is, therefore, important that both the extension agents who are involved directly in determining the needs of their clientele and those of the extension staff who are helping these field workers are equipped with the knowledge of methods and techniques that are helpful in their respective jobs. Importance of this aspect may be illustrated by a case cited by the authors of the textbook on Research Methods in the Behavioral Sciences. This case concerns program changes to help the organizations– the Agricultural War Boards in the Great Lakes dairy states—achieve its objective more effectively. Hence, It seems appropriate to consider this case as an Illustration to show that the group responsible to lead a program needs full facts and reliable facts. The X State Agricultural War Board members in 1941 while planning to undertake a compaign to Increase the production of milk were confident that they knew the situation In the state well and had planned the following measures: 1. To assure an adequate supply of feed grains and protein concentrates at a reasonable price. 2. To facilitate the building of additional barn space. 3. To increase the available farm labor for dairy operation. This plan was based on their appraisal of the situation as: (a) that the state had larger numbers of cows than at any previous time and the bams were overflowing (state agricultural statisticians data) and their own farms and their neighbors Indicated this, so no further increase in number of cows was practicable, (b) The price of milk In relation to the price of feed made It highly profitable to feed milk cows heavily, Including grains and protein concentrates In order to Increase the milk production per cow. The members were following this practice and they knew that other farmers known to them also followed the practice. However, the Division of Program Surveys was asked by the Department of Agriculture to help guide the War Board\u27s campaign conducting a study. It undertook the survey In close consultation with the board. The board, though it wanted to get all help, was not sure that such a study could help. They were confident that their assessment of the situation was sound. Later, the study, which was carried to find out the extent to which farmers were producing the maximum amount of milk and the steps which could be taken to make possible a further increase in dairy production, revealed quite a different situation from what the board expected. The study revealed that lack of barn space, labor shortage, equipment, and price were not at all factors preventing expanding dairy industry. But they were apprehensive of a collapse in price, they lacked information about the actions of government and also lacked knowledge about the possibility of increased output through better feeding practices. These results were used by the board in revising their plans for the campaign. This is an excellent illustration of the critical need for accurate facts for adequate analysis of a particular situation. In the above case, the Division of Program Surveys obtained information concerning resources, if any, the farmers felt they needed to increase their dairy production. They also obtained information useful in determining the extent to which dairy farmers in X state were motivated to attempt to produce a maximum amount of milk, what the influences were that were motivating them to increase dairy production and what the motivational forces were that were acting in the opposite direction. The interviews were conducted in a period of ten days (September 20 and October 1, 1941) with a sufficiently large sample—the design provided to treat the three major milk producing areas separately—and the results were made available immediately. The value of such study as a basis for planning was evidenced by a 6.7 per cent increase in milk production for the following twelve-month period; the highest recorded for the war period. The revised plan made it possible to conserve the scarce materials of steel, lumber, and cement called for in the earlier plan. Thus, the importance of such studies to develop plans for action in the field of agriculture is demonstrated in the case cited above. The survey has been accepted as a method of collecting relevant facts needed for situation analysis in the process of program planning. Pauline V. Young discussing The Social Survey in Retrospect and Prospect states: The survey initiated the idea of gathering and possessing facts as the only basis for sound planning. Interest gradually shifted from ready made programs, evolved in distant Central Headquarters to the development of plans made through surveys to fit the particular needs of the community concerned. (Italics in original.) Young also pointed out that the survey method has been accepted by a wide variety of organizations not only as a basis for planning but as a medium for educating the public relative to social questions, policies, needed new legislation, and so on. This study, as stated earlier, is concerned with the selection and development of suitable research methods and techniques which could be employed for determining the needs of the extension\u27s clientele. Survey, therefore, is one of the most important research methods which needs close study for its application in the extension educational process. Considerable work has been done In improving the techniques of survey in planning, conducting and evaluating programs. This study, therefore, attempts to examine many of these techniques as well as other research methods and techniques with a view to select and utilize them in the program projection process. It is hoped that the findings of this study will be helpful to all extension workers in their efforts to select methods and techniques that could be utilized by them in their task as educators to determine more effectively the needs of their clientele