This paper studies the effect of private information on the capital allocation decisions of firms who operate under imperfect competition. I analyze two interactive firms, one with private information and the other without, who must decide when to undertake an irreversible and uncertain investment decision. Traditional non-strategic models of irreversible investment under uncertainty involve a single decision maker and result in an optimal period of delay before the investment is undertaken. In a strategic setting, firms must balance their desire to delay against competitive advantages from early investment. I find that an equilibrium may not exist within the standard continuous framework when the private information is over revenues. Moreover, when an equilibrium does exist the competitive pressures from the uninformed firm are weak. This is in contrast to existing models with asymmetric information over costs, where an equilibrium always exists and the competitive pressures remain strong (Hsu and Lambrecht, 2007). This work shows that the investment timing decision, and thus the value of the private information, is highly sensitive to the nature of incomplete information.

For decades, marketers have trumpeted the importance of word of mouth in influencing purchase choice, but have still spent billions on brand advertising-without any proof of the link between the two. Using newly available data, we sought to resolve this contradiction by searching for the "missing link" between positive word of mouth about brands and brand advertising. We also tested the relationship between advertising and measurable behaviors of brand interest-namely, brand searches and website visits. The analysis involved 35 brands over a 26-week period using six sources of data. The results indicate that brands should redouble their efforts in using advertising to grow brand advocacy through the integration of online and offline branded consumer contact points.

This position paper describes an approach to building spoken dialogue systems for environments containing multiple human speakers and hearers, and multiple robotic speakers and hearers. We address the issue, for robotic hearers, of whether the speech they hear is intended for them, or more likely to be intended for some other hearer. We will describe data collected during a series of experiments involving teams of multiple human and robots (and other software participants), and some preliminary results for distinguishing robot-directed speech from human-directed speech. The domain of these experiments is Mars-analogue planetary exploration. These Mars-analogue field studies involve two subjects in simulated planetary space suits doing geological exploration with the help of 1-2 robots, supporting software agents, a habitat communicator and links to a remote science team. The two subjects are performing a task (geological exploration) which requires them to speak with each other while also speaking with their assistants. The technique used here is to use a probabilistic context-free grammar language model in the speech recognizer that is trained on prior robot-directed speech. Intuitively, the recognizer will give higher confidence to an utterance if it is similar to utterances that have been directed to the robot in the past.

The central premise in developing effective human-assistant planetary surface robots is that robotic intelligence is needed. The exact type, method, forms and/or quantity of intelligence is an open issue being explored on the ERA project, as well as others. In addition to field testing, theoretical research into this area can help provide answers on how to design future planetary robots. Many fundamental intelligence issues are discussed by Murphy [2], including (a) learning, (b) planning, (c) reasoning, (d) problem solving, (e) knowledge representation, and (f) computer vision (stereo tracking, gestures). The new social interaction/emotional form of intelligence that some consider critical to Human Robot Interaction (HRI) can also be addressed by human assistant planetary surface robots, as human operators feel more comfortable working with a robot when the robot is verbally (or even physically) interacting with them. Arkin [3] and Murphy are both proponents of the hybrid deliberative-reasoning/reactive-execution architecture as the best general architecture for fully realizing robot potential, and the robots discussed herein implement a design continuously progressing toward this hybrid philosophy. The remainder of this chapter will describe the challenges associated with robotic assistance to astronauts, our general research approach, the intelligence incorporated into our robots, and the results and lessons learned from over six years of testing human-assistant mobile robots in field settings relevant to planetary exploration. The chapter concludes with some key considerations for future work in this area.

Humans have dreamed of exploring Mars for many years. However, the recent mandate by President Bush directing NASA to send humans to Mars (after first returning to the moon) has transformed the work in planetary exploration from the realm of paper studies and theory back into the realm of a near-term reality [4]. As humans prepare to venture out of low Earth orbit, robots will be integral teammates in this endeavor, if for no other reason than size of the area to be explored. The moon has a surface area approximately the size of the continents of North and South America combined, and Mars has a surface area approximately the size of the entire land mass of Earth. Because of the shear scale of this exploration area (and the limited number of humans who will be able to visit on any given mission), robots will be involved in any realistic exploration scenario. Many of these robots will operate on their own (or with other robots) and never work alongside humans. However, other robots (akin to the lunar rovers used during the later Apollo missions) will be specifically designed to assist humans and maximize their effectiveness during Extravehicular Activities (EVAs). These robots will afford the astronauts the mobility to explore much larger areas of the surface than they would be able to reach on their own, allow them to transport scientific equipment, and provide task assistance at several levels. Commands sent from Earth cannot travel faster than the speed of light, and data/images from the robots are also subject to this limit. This intergalactic speed limit leads to minimum round trip signal delays between Earth and the moon of about 2.5 sec, and for Mars the time varies from about 8 to 42 minutes, depending on the planetary alignment. Because of these delays, robots will be most effective if they primarily receive high level commands and goals from Earth. Deploying robots capable of accepting high level commands will require them to be more self-sufficient (and self-monitoring) so that they can work autonomously to achieve those high level goals. Designing these autonomous mobile robots will require careful planning and utilize a wide range of engineering and scientific disciplines/technologies which are currently in various stages of maturity. All robots intended to be used as human assistants will need to be designed to maximize the effectiveness of EVAs. Furthermore, these robots must be safe around

The Mars Society s Desert Research Station (MDRS) Rotation 38, April 3-17, 2005, was dedicated to field tests of NASA's Mobile Agents EVA communications system. MDRS provided an excellent, cost-effective venue for bringing together eighteen scientists and engineers from NASA Ames and Johnson Space Center, in an intensive two weeks of system integration and experiments. The Mobile Agents architecture and collaborative engineering methodology provides a flexible toolkit for configuring extravehicular activity (EVA) components, visualizing and formalizing EVA plans, and automating key supervisory functions.

NASA Ames’ Mobile Agents Architecture is a distributed agent-based architecture, which integrates diverse mobile entities in a wide-area wireless system for lunar and planetary surface operations. Software agents, implemented in the Brahms multiagent language, run in Brahms virtual machines onboard laptops for space suits, robots, and surface habitats. “Personal agents” support the habitat crew and surface astronauts, as well as the their robotic assistant. People communicate with their personal agents via a speech dialogue system and via a meeting-capture hyperlink database tool.

We have developed and tested an advanced EVA communications and computing system to increase astronaut self-reliance and safety, reducing dependence on continuous monitoring and advising from mission control on Earth. This system, called Mobile Agents (MA), is voice controlled and provides information verbally to the astronauts through programs called personal agents. The system partly automates the role of CapCom in Apollo-including monitoring and managing EVA navigation, scheduling, equipment deployment, telemetry, health tracking, and scientific data collection. EVA data are stored automatically in a shared database in the habitat/vehicle and mirrored to a site accessible by a remote science team. The program has been developed iteratively in the context of use, including six years of ethnographic observation of field geology. Our approach is to develop automation that supports the human work practices, allowing people to do what they do well, and to work in ways they are most familiar. Field experiments in Utah have enabled empirically discovering requirements and testing alternative technologies and protocols. This paper reports on the 2004 system configuration, experiments, and results, in which an EVA robotic assistant (ERA) followed geologists approximately 150 m through a winding, narrow canyon. On voice command, the ERA took photographs and panoramas and was directed to move and wait in various locations to serve as a relay on the wireless network. The MA system is applicable to many space work situations that involve creating and navigating from maps (including configuring equipment for local topology), interacting with piloted and unpiloted rovers, adapting to environmental conditions, and remote team collaboration involving people and robots.

A model-based, distributed architecture integrates diverse components in a system designed for lunar and planetary surface operations: spacesuit biosensors, cameras, GPS, and a robotic assistant. The system transmits data and assists communication between the extra-vehicular activity (EVA) astronauts, the crew in a local habitat, and a remote mission support team. Software processes ("agents"), implemented in a system called Brahms, run on multiple, mobile platforms, including the spacesuit backpacks, all-terrain vehicles, and robot. These "mobile agents" interpret and transform available data to help people and robotic systems coordinate their actions to make operations more safe and efficient. Different types of agents relate platforms to each other ("proxy agents"), devices to software ("comm agents"), and people to the system ("personal agents"). A state-of-the-art spoken dialogue interface enables people to communicate with their personal agents, supporting a speech-driven navigation and scheduling tool, field observation record, and rover command system. An important aspect of the engineering methodology involves first simulating the entire hardware and software system in Brahms, and then configuring the agents into a runtime system. Design of mobile agent functionality has been based on ethnographic observation of scientists working in Mars analog settings in the High Canadian Arctic on Devon Island and the southeast Utah desert. The Mobile Agents system is developed iteratively in the context of use, with people doing authentic work. This paper provides a brief introduction to the architecture and emphasizes the method of empirical requirements analysis, through which observation, modeling, design, and testing are integrated in simulated EVA operations.

The Mobile Agents model-based, distributed architecture, which integrates diverse components in a system for lunar and planetary surface operations, was extensively tested in a two-week field "technology retreat" at the Mars Society s Desert Research Station (MDRS) during April 2003. More than twenty scientists and engineers from three NASA centers and two universities refined and tested the system through a series of incremental scenarios. Agent software, implemented in runtime Brahms, processed GPS, health data, and voice commands-monitoring, controlling and logging science data throughout simulated EVAs with two geologists. Predefined EVA plans, modified on the fly by voice command, enabled the Mobile Agents system to provide navigation and timing advice. Communications were maintained over five wireless nodes distributed over hills and into canyons for 5 km; data, including photographs and status was transmitted automatically to the desktop at mission control in Houston. This paper describes the system configurations, communication protocols, scenarios, and test results.

Human missions to the Moon or Mars will likely be accompanied by many useful robots that will assist in all aspects of the mission, from construction to maintenance to surface exploration. Such robots might scout terrain, carry tools, take pictures, curate samples, or provide status information during a traverse. At NASA/JSC, the EVA Robotic Assistant (ERA) project has developed a robot testbed for exploring the issues of astronaut-robot interaction. Together with JSC's Advanced Spacesuit Lab, the ERA team has been developing robot capabilities and testing them with space-suited test subjects at planetary surface analog sites. In this paper, we describe the current state of the ERA testbed and two weeks of remote field tests in Arizona in September 2002. A number of teams with a broad range of interests participated in these experiments to explore different aspects of what must be done to develop a program for robotic assistance to surface EVA. Technologies explored in the field experiments included a fuel cell, new mobility platform and manipulator, novel software and communications infrastructure for multi-agent modeling and planning, a mobile science lab, an InfoPak for monitoring the spacesuit, and delayed satellite communication to a remote operations team. In this paper, we will describe this latest round of field tests in detail.

Mobile robots require fast, low-power motion tracking systems. Popular systems require much power to move the mass of two cameras on a pan-tilt-verge head, and thus are not suited well for battery-powered mobile robots. In this paper, we present a new system for motion tracking that utilizes a mirror-based optical system to produce a stereo image on one camera. Processing one image solves synchronization challenges common in stereo systems and requires fewer computing resources than processing two images. We have developed a system that uses about1=50th of the power of a popular system with similar performance speciflcations.

Antiretroviral medications are effective at improving the health and increasing the survival of people living with HIV/AIDS. However, studies have shown that a substantial number of HIV-infected people do not receive antiretroviral treatments. The current study examined the physical and mental health, substance use, and perceptions of medical care of 163 men and 78 women living with HIV/AIDS. Results of a confidential survey showed that 79 (33%) were not currently treated for HIV. These persons did not differ from those who were treated in chart-abstracted CD4 cell counts, years living with HIV infection, HIV-related symptoms, and HIV-related hospitalizations. Unlike past studies, gender was not found to be a factor in treatment status. However, untreated persons had higher chart-abstracted viral loads and were more likely to be ethnic minorities, have a lower level of education, greater level of depression, and greater pessimistic attitude. They were significantly more likely to have used alcohol, powder cocaine, and crack cocaine in the previous 3 months, were likely to know their own viral load and CD4 count, and held significantly more negative views of their health care and their health care providers. There were no differences between untreated and treated persons in their meeting the year 1999 antiretroviral treatment guidelines that were in effect at the time of data collection. These results suggest that persons who are not receiving antiretroviral medications may be in need of mental health and substance use interventions and may benefit from interventions designed to engage and retain them in medical treatment.

The EVA Robotic Assistant is a prototype for an autonomous rover designed to assist human astronauts. The primary focus of the research is to explore the interaction between humans and robots, particularly in extreme environments, and to develop a software infrastructure that could be applied to any type of assistant robot, whether for planetary exploration or orbital missions. This paper describes the background and current status of the project, the types of scenarios addressed in field demonstrations, the hardware and software that comprise the current prototype, and future research plans.

Manned missions to other planetary bodies will rely heavily on robotics and automation to enhance the operational safety and capabilities of the crew. In particular, the movement and sensing capabilities of humans in spacesuits are severely constrained. Thus, an important class of robot will be those that accompany humans during extra-vehicular activity (EVA) and provide assistance -- tool transport, video documentation, sample collection, etc. In 1999, NASA engaged in a set of field tests in California called ASRO (AStronaut-ROver), in which a space-suited test subject collaborated with the tele-operated Marsokhod mobile robot, controlled by scientist at a remote location.From the lessons learned in the ASRO tests, the EVA Robotic Assistant project was started at NASA's Johnson Space Center to provide a testbed for continued research in astronaut-robot interaction and cooperation. In September 2000, NASA conducted two weeks of field tests in Arizona at three planetary surface analog sites. Three scenarios were tested requiring cooperation between a space-suited astronaut and the autonomous EVA Robotic Assistant: "Power Cable Deployment", "Solar Panel Deployment", and "Geologist's Assistant". In this paper, we describe the ERA project in detail, and report on results from the Arizona field tests.

We have developed a model-based, distributed architecture that integrates diverse components in a system designed for lunar and planetary surface operations: an astronaut’s space suit, cameras, rover/All-Terrain Vehicle (ATV), robotic assistant, other personnel in a local habitat, and a remote mission support team (with time delay). Software processes, called “agents,” implemented in the Brahms language (Clancey, et al. 1998; Sierhuis 2001), run on multiple, mobile platforms. These “mobile agents” interpret and transform available data to help people and robotic systems coordinate their actions to make operations more safe and efficient. The Brahms-based mobile agent architecture (MAA) uses a novel combination of agent types so the software agents may understand and facilitate communications between people and between system components. A state-of-the-art spoken dialogue interface is integrated with Brahms models, supporting a speech-driven field observation record and rover command system (e.g., "return here later and bring this back to the habitat"). This combination of agents, rover, and model-based spoken dialogue interface constitutes a “personal assistant.” An important aspect of the methodology involves first simulating the entire system in Brahms, then configuring the agents into a run-time system

As many as one in three HIV-positive people continue unprotected sexual practices after learning that they are HIV infected. This article reports the outcomes of a theory-based intervention to reduce risk of HIV transmission for people living with HIV infection.Men (n=233) and women (n=99) living with HIV-AIDS were randomly assigned to receive either (1) a five-session group intervention focused on strategies for practicing safer sexual behavior, or (2) a five-session, contact-matched, health-maintenance support group (standard-of-care comparison). Participants were followed for 6 months post-intervention.The intervention to reduce risk of HIV transmission resulted in significantly less unprotected intercourse and greater condom use at follow-up. Transmission-risk behaviors with non-HIV-positive sexual partners and estimated HIV transmission rates over a 1-year horizon were also significantly lower for the behavioral risk-reduction intervention group.This study is among the first to demonstrate successful HIV-transmission risk reduction resulting from a behavioral intervention tailored for HIV-positive men and women.

BACKGROUND:As many as one in three HIV-positive people continue unprotected sexual practices after learning that they are HIV infected. This article reports the outcomes of a theory-based intervention to reduce risk of HIV transmission for people living with HIV infection. METHODS:Men (n=233) and women (n=99) living with HIV-AIDS were randomly assigned to receive either (1) a five-session group intervention focused on strategies for practicing safer sexual behavior, or (2) a five-session, contact-matched, health-maintenance support group (standard-of-care comparison). Participants were followed for 6 months post-intervention. RESULTS:The intervention to reduce risk of HIV transmission resulted in significantly less unprotected intercourse and greater condom use at follow-up. Transmission-risk behaviors with non-HIV-positive sexual partners and estimated HIV transmission rates over a 1-year horizon were also significantly lower for the behavioral risk-reduction intervention group. CONCLUSIONS:This study is among the first to demonstrate successful HIV-transmission risk reduction resulting from a behavioral intervention tailored for HIV-positive men and women.

Current wireless LANs that are small enough for portable computing devices have transmission rates up to a few Mbit/s, at the lower end of that obtained in IEEE 802compliant wired LANs. These LANs can provide a useful service when the application demands and number of users are kept low. Much higher performance, from several 10’s of Mbit/s to over 100 Mbit/s, is needed to accommodate more users and multimedia traffic.