CUSTOMIZING APPLICATION HEADERS FOR IMPROVED WARFIGHTING COMMUNICATIONS

Currently, U.S. Navy shipboard communications have a great disadvantage: the data rates of satellite links are limited, typically below 4 Mbps for each link. Improving efficient utilization of these links while out to sea is paramount to maintaining our military advantage. Also, any improvement must be transparent to end user functionality. This thesis first explored implementing a free version of a commercial-off-the-shelf wide area network (WAN) optimizer, Artica, on a simulated shipboard network consisting of three local area networks (LAN). Artica works by performing auto-corrections on some web traffic and changing the transmission control protocol (TCP) window sizes. Results from browsing Alexa's top 1,000 websites on the LANs show that Artica can speed up web traffic by 13–26% at link speeds between 1.544 and 8 Mbps. It then explored compressing Domain Name System (DNS) traffic by filtering out IPv6-related queries and removing unused fields of DNS queries and responses. Experimental results show that DNS compression did not significantly improve web traffic performance, which highlights the importance of selecting traffic-intensive applications to compress and control compression-induced processing overhead. Finally, the thesis explored whether Artica and the custom DNS compression program can be deployed together. In summary, this thesis shows that using WAN optimization techniques and saving bits over a slow data rate link can effectively speed up web traffic.NIWC PACLieutenant, United States NavyApproved for public release. Distribution is unlimited

Parents’ experiences of childhood abuse and neglect are differentially associated with behavioral and autonomic responses to their offspring

Although childhood maltreatment has been shown to compromise adaptive parental behavior, little is known what happens in terms of physiological regulation when parents with a history of childhood maltreatment interact with their offspring. Using a sample of 229 parents (131 women), the present study examined whether childhood maltreatment experiences are associated with parents’ behavioral and autonomic responses while resolving conflict with their offspring. Self‐reported experienced child maltreatment was measured using a questionnaire assessing abuse and neglect. Parents (Mage = 52.7 years, rangeage = 26.6–88.4 years) and their offspring (Mage = 24.6 years, rangeage = 7.5–65.6 years) participated in a videotaped parent–offspring conflict interaction task. Parental warmth, negativity, and emotional support were coded. In addition, their pre‐ejection period and respiratory sinus arrhythmia were measured as indicators of underlying sympathetic and parasympathetic nervous system reactivity, respectively. Findings demonstrated that experiences of abuse and neglect were associated with behavioral and physiological responses in different ways. Separating these two types of maltreatment in research and in clinical practice might be important

Not the Root of the Problem-Hair Cortisol and Cortisone Do Not Mediate the Effect of Child Maltreatment on Body Mass Index.

BACKGROUND: Experiencing maltreatment during childhood exerts substantial stress on the child and increases the risk for overweight and obesity later in life. The current study tests whether hair cortisol-a measure of chronic stress-and its metabolite cortisone mediate the relation between abuse and neglect on the one hand, and body mass index (BMI) on the other. METHOD: The sample consisted of 249 participants aged 8 to 87 years (M = 36.13, SD = 19.33). We collected data on child abuse and neglect using questionnaires, measured cortisol and cortisone concentrations in hair, and BMI. In a structural model, the effects of abuse and neglect on hair cortisol, hair cortisone, and BMI were tested, as well as the covariance between hair cortisol and BMI, and hair cortisone and BMI. RESULTS: Within the sample, 23% were overweight but not obese and 14% were obese. Higher levels of experienced abuse were related to higher cortisone concentrations in hair (β = 0.24, p < .001) and higher BMI (β = 0.17, p =.04). Neglect was not related to hair cortisol, hair cortisone, or BMI. Hair cortisol and cortisone did not mediate the association between maltreatment, and BMI. Sensitivity analyses demonstrate the same pattern of results in a subsample of adult participants currently not living with their parents. However, in younger participants who were still living with their parents, the associations between abuse and cortisone (β = 0.14, p =.35) and abuse and BMI (β = 0.02, p =.92) were no longer significant. CONCLUSION: These findings confirm that experiencing abuse is related to higher BMI but suggest that hair cortisol and cortisone are not the mechanism underlying the association between child maltreatment and BMI. This is the first study to show abuse may be associated to elevated concentrations of hair cortisone-evidence of long-term alterations in chronic stress levels. Future research may benefit from exploring the effects of maltreatment on weight gain in longitudinal designs, including measures of other potential mediators such as eating as a coping mechanism, and more direct indicators of metabolic health

Yang-Baxter equation and reflection equations in integrable models

The definitions of the main notions related to the quantum inverse scattering methods are given. The Yang-Baxter equation and reflection equations are derived as consistency conditions for the factorizable scattering on the whole line and on the half-line using the Zamolodchikov-Faddeev algebra. Due to the vertex-IRF model correspondence the face model analogue of the ZF-algebra and the IRF reflection equation are written down as well as the $Z_2$-graded and colored algebra forms of the YBE and RE.Comment: 21 pages, Latex, Lectures in Schladming school of theoretical physics (March 1995