Collaborative planning and situation awareness in Army command and control

We conducted a theoretical investigation of a complex command and control (C2) operation--the manoeuvres planning processes in Army land-battle situations, to improve understanding of how technology can best be designed to support planning and course of action development. We drew upon results from cognitive task analyses and interviews with subject matter experts and insights gleaned from observations of Army training exercises and experiments to make inferences on the C2 activities carried out in preparation for tactical manoeuvres. In this paper, we summarize several critical human factors issues associated with planning in a rapidly evolving environment, as identified in our investigation, and describe system design concepts aimed at addressing these challenges to distributed collaborative planning of C2 activities. We conclude with implications for the application of these findings to other C2 domains.     

Zero principles for implicit feedback systems

A basic control engineer's adage-the poles of a feedback compensator become zeros of the closed-loop system-admits difficulties of interpretation even in the most simple of cases; that of single-input, single-output. An earlier investigation has provided an analysis of this adage in a module-theoretic context for systems in state space form while avoiding restrictive assumptions on system minimality or squareness. The main result is expressed concisely in terms of an exact sequence of modules which include -zero modules corresponding to the feedback system and the plant. Extended zero modules of -type incorporate both finite invariant zero structure, and generic zero information which occurs when a system fails to be right-invertible. In the case of compensation in the feedback path, this main exact sequence reduces to a mathematically clear expression of the aforementioned adage: the -zero module of the feedback system is precisely the direct sum of the -zero module of the plant and the system pole module of the feedback compensator. This paper extends the previous work in order to avoid assumptions on causality in the plant. Implicit dynamical systems are employed, in lieu of systems in state space form. Once again, it is not assumed that the system is one-to-one or onto; and so the concepts of generic zeros and their modules are brought into the arena of implicit systems. The implicit system itself is assumed in this work to be regular; however, decoupling zeros are permitted. Moreover, input-decoupling zeros and system pole feedback relationships are considered.This work was supported in part by the Frank M. Freimann Chair in Electrical Engineering at the University of Notre Dame, by the American Association of University Women Selected Professions Fellowship, and by the Zonta Amelia Earhart Fellowship.     

Health-Related Behavior and Beliefs of Pregnant Smokers.

To determine the association of smoking with other health-compromising behavior and beliefs during pregnancy, a cross-sectional survey of 1,203 women in the United Kingdom assessed smoking status, stage of change, fetal health locus of control, alcohol consumption, folic acid intake, and use of vitamin and iron supplements. Twenty percent were current smokers, and 33% were alcohol users. Pregnant smokers (especially those in the precontemplative stage) were less likely to increase folic acid intake, less likely to take vitamin and iron supplements, and less likely to feel personally responsible for the health of the fetus. Infants of smokers may be placed at an intrauterine disadvantage, not only in terms of smoking, but also in terms of nutrition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Internet use and multitasking among older adolescents: An experience sampling approach

Internet use is challenging for individuals to quantify and describe. Previous internet use studies have relied on self-report measures, which may be subject to recall bias. This studied aimed to assess college student internet use using a real-time methodology, experience sampling method (ESM). Undergraduate students participated in a 7-day ESM campaign using text message surveys sent at 6 random times each day. Survey questions evaluated current internet use time and activities. Analyses included hierarchical clustering analysis, multilevel and probability modeling. Among the 189 participants, mean age was 18.9 (SD = 0.9), 58.8% were female and most were Caucasian (90.5%). The modeled average total amount of daily internet time was 56 min, 95% CI [51, 62]. The correlation between self-reported internet use time and ESM data was 0.31 (p < 0.001). Over half of the time participants were on the internet they reported multitasking (56.5%, 95% CI [52.7%, 60.4%]). Study findings suggest that multitasking is frequent among college students, which may explain over-reported internet use.     

Explaining Disproportionately High Rates of Adverse Birth Outcomes Among African Americans: The Impact of Stress, Racism, and Related Factors in Pregnancy.

Compared with European Americans, African American infants experience disproportionately high rates of low birth weight and preterm delivery and are more than twice as likely to die during their 1st year of life. The authors examine 5 explanations for these differences in rates of adverse birth outcomes: (a) ethnic differences in health behaviors and socioeconomic status; (b) higher levels of stress in African American women; (c) greater susceptibility to stress in African Americans; (d) the impact of racism acting either as a contributor to stress or as a factor that exacerbates stress effects; and (e) ethnic differences in stress-related neuroendocrine, vascular, and immunological processes. The review of literature indicates that each explanation has some merit, although none is sufficient to explain ethnic disparities in adverse birth outcomes. There is a lack of studies examining the impact of such factors jointly and interactively. Recommendations and cautions for future research are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of genotype and pretreatment of field peas (Pisum sativum) on their dehulling and cooking quality

Field peas (Pisum sativum), an important pulse crop in Australia, are consumed as human food either as whole seeds or as splits after decortication. The yield of splits is an important economic factor for processors and the cooking quality is important for consumers. Effects of genotype, other physical characteristics and pretreatment in various solutions on both dehulling and cooking quality were studied for 23 known genotypes and are market sample of unknown genotype. Large variations were found for most characteristics. Seed size was positively correlated with yield of splits while husk content and broken seeds were negatively correlated with yield. Preconditioning seeds in salt solutions improved yield of splits. Variation in cooking quality among genotypes was reduced following splitting and cooking time was reduced by decortication and splitting and by presoaking in salt solutions (10 or 20 g kg⁻¹), particularly with sodium tripolyphosphate. Loss of seed material into cooking water was correlated with cooking time. No characteristic was found that could be used to predict cooking time. © 1998 SCI.     

X-ray Diffraction Analysis of the Pyrolytic Conversion of Perhydropolysilazane into Silicon Nitride

A detailed investigation using X-ray diffraction and other supportive techniques was performed on a preceramic polysilazane to study its pyrolytic conversion to silicon nitride (Si₃N₄). Analytical techniques were developed to determine the volumetric degree of crystallinity with respect to pyrolysis temperature. Quantitative data for crystallite size, phase composition, and degree of crystallinity versus pyrolysis temperature and atmosphere (nitrogen and ammonia) are presented. Pyrolytic products produced under nitrogen and ammonia atmospheres consist of microcrystals of silicon, α-Si₃N₄, and β-Si₃N₄. Under both atmospheres, a majority of the char is crystalline at ≅1270°C, and the entire char is crystallized at 1400°C. Pyrolysis under an ammonia atmosphere produces nearly stoichiometric Si₃N₄, while pyrolysis under nitrogen produces silicon-rich material.     

Measurement issues associated with conditional reasoning tests: Indirect measurement and test faking.

Conditional reasoning is a new measurement technique used to measure cognitive biases associated with latent personality motives. The current article describes 3 studies examining 2 related measurement issues associated with conditional reasoning tests (CRTs). Study 1 examined the necessity of maintaining indirect assessment when administering CRTs. Results indicated that, compared with a control condition, 2 experimental conditions that disclosed the purpose of assessment yielded significant mean shifts on a CRT. Study 2 explored whether CRTs could be faked when the purpose of assessment was not disclosed. Results indicated that when indirect measurement was maintained, CRTs appeared to be resistant to faking. Study 3 compared scores on the Conditional Reasoning Test for Aggression across student, applicant, and incumbent samples. Results indicated no significant mean differences among these samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Organizational change in a human service agency.

An organizational change consultation was conducted with a large nonprofit human service organization. The consultation began with negotiations to gain entry to the agency followed by start-up activities at all levels of the organization. Seventy-two individual interviews were conducted. Interviews surfaced issues and concerns related to the climate, management, and operations of the agency and its eight programs. The mirroring (feedback) activity brought attention to the most critical issues in the organization for which action plans were developed and implemented. Employee follow-up survey results indicate favorable ratings for most action items. Lessons learned in the SHARE (pseudonym) consultation are presented for consideration by consultants working in human service and other organization settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of advance information about target location and visual feedback on movement planning and execution.

This study was designed to determine if movement planning strategies incorporating the use of visual feedback during manual aiming are specific to individual movements. Advance information about target location and visual context was manipulated using precues. Participants exhibited a shorter reaction time and a longer movement time when they were certain of the target location and that vision would be available. The longer movement time was associated with greater time after peak velocity. Under conditions of uncertainty, participants prepared for the worst-case scenario. That is, they spent more time organizing their movements and produced trajectories that would be expected from greater open-loop control. Our results are consistent with hierarchical movement planning in which knowledge of the movement goal is an essential ingredient of visual feedback utilization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)