The dynamics of combining self-employment and employment

This study examines the extent to which wage-earning workers are simultaneously self-employed, a phenomenon not thoroughly investigated in earlier studies. We use matched employee-employer databases to present a detailed investigation of self-employment patterns within the post industrial sectors in Sweden from 1990 to 2002. We find that persons that combine self-employment with waged work constitute a majority of the total number of self-employed, and that most people enter self-employment by engaging first in combinatory work, indicating that the decision to move to self-employment is more complex than characterized in earlier research.Self-employment; income dynamics; entrepreneurship

Orbit determination and orbit control for the Earth Observing System (EOS) AM spacecraft

Future NASA Earth Observing System (EOS) Spacecraft will make measurements of the earth's clouds, oceans, atmosphere, land and radiation balance. These EOS Spacecraft will be part of the NASA Mission to Planet Earth. This paper specifically addresses the EOS AM Spacecraft, referred to as 'AM' because it has a sun-synchronous orbit with a 10:30 AM descending node. This paper describes the EOS AM Spacecraft mission orbit requirements, orbit determination, orbit control, and navigation system impact on earth based pointing. The EOS AM Spacecraft will be the first spacecraft to use the TDRSS Onboard Navigation System (TONS) as the primary means of navigation. TONS flight software will process one-way forward Doppler measurements taken during scheduled TDRSS contacts. An extended Kalman filter will estimate spacecraft position, velocity, drag coefficient correction, and ultrastable master oscillator frequency bias and drift. The TONS baseline algorithms, software, and hardware implementation are described in this paper. TONS integration into the EOS AM Spacecraft Guidance, Navigation, and Control (GN&C) System; TONS assisted onboard time maintenance; and the TONS Ground Support System (TGSS) are also addressed

Hybrid Entrepreneurship

In contrast to previous efforts to model the individual’s movement from wage work into entrepreneurship, we consider that individuals might transition incrementally by retaining their wage job while entering into self-employment. We show that these hybrid entrepreneurs represent a significant share of all entrepreneurial activity. Theoretical arguments are proposed to suggest why hybrid entrants are distinct from self-employment entrants, and why hybrid entry may facilitate subsequent entry into full self-employment. We demonstrate that there are significant theoretical and empirical consequences for this group and our understanding of self-employment entry and labor market dynamics. Using matched employee-employer data over eight years, we test the model on a population of Swedish wage earners in the knowledge-intensive sector.Hybrid entrepreneurship; Self-employment; Labour market dynamics; Transition determinants; Employee-employer data

The Reaction-Diffusion of Range Expansion of American Black Bears (Ursus Americanus) In North Carolina, USA

By the early 19th century, many big-game species were extirpated from much of their historic range. Implementation of harvest regulations or restrictions, habitat succession, and changes in land use practices have facilitated the return of many of these species. It is necessary, for proper management, to be able to estimate with precision or certainty, abundance and other demographic parameters as well as range expansion often with personnel and financial limitations. New advancements in analyses allow for greater extraction of information from commonly collected data. White oak (subgenus Leucobalanus) mast production had a strong correlation with non-harvest mortality of American black bears (Ursus americanus; r = 0.89). Using white oak mast as a surrogate for hunter effort, I used a catch-effort likelihood within statistical population reconstruction (SPR) using an N- mixture multinomial model to estimate the abundance and other demographic parameters of black bears in the Mountain region of North Carolina. Abundance was estimated at 3365 (95% B.C.I. = 3165-3569) for females and 3882 (95% B.C.I. = 3696-4080) for males in 2016, with numbers continuing to increase at a rate of approximately 5% annually. SPR estimates tracked estimates from Downing population reconstruction (DPR until approximately 2008 when DPR indicated population growth to be slowing in contrast to SPR estimates. The probability of harvest ranged from 6.7-15.6% (95% B.C.I. = 6.3-16.3%) for females and 11.6-26.1% (95% B.C.I. = 11.2-26.9%) for males. Additional parameters could be estimated with the inclusion of additional data and likelihoods. The velocity of range expansion of the Mountain and Coastal black bear populations into the Piedmont was tracked using reliable sightings, frequency and location of bear-vehicle collisions, and demographic parameters in five methods of reaction-diffusion models. The rate of expansion was approximately 4-8 km/year. Each of the five methods yielded similar velocities of range expansion, indicating the simplest method that used commonly-collected data was just as informative as more elaborate methods. Likelihoods using other food resources availability may be necessary to modify this SPR to fit other species or bear populations in agriculturally-dominated regions, but is easily adaptable. Collecting animal- vehicle mortality locations is an inexpensive way to be estimate range expansion of elusive species

The Effects of a Caloric Restrictive Diet on Bone Mineral Density and Bone Strength in Male and Female Rats

The purpose of this study was to determine the existence of sex differences following a 40% caloric restrictive diet and its impact on tibial bone mineral density (BMD) and bone strength between male and female rats. Thirty-two, six-week old Sprague Dawley rats (16 males and 16 females) were randomly divided into an ad libitum fed control group (MC, n=8 and FC, n=8) and a pair fed diet group placed on the 40% caloric restriction (MD, n=8 and FD, n=8) for a 6 week period. The caloric restrictive diet was equivalent to the normal fed diet in vitamin and mineral content where the only difference was 40% less calories. After 6 weeks, there were no significant interaction effects, therefore main effects (i.e., sex and diet) were examined. While the tibial BMD was equivalent between males (0.206 ± 0.003 g/cm2) and females (0.207 ± 0.004 g/cm2), bone strength (amount of force required to break the tibia expressed in Newtons, N) was significantly greater for males (112.0 ± 2.4 N) compared to females (74.8 ± 3.1 N). The BMD was significantly lower for caloric restrictive fed groups (0.200 ± 0.003 g/cm2) compared to normal fed animals (0.213 ± 0.003 g/cm2). In like manner, bone strength significantly lower for diet fed animals (86.5 ± 5.6 N) compared to control fed animals (100.3 ± 5.1N). The results indicate that caloric restriction lowers BMD and bone strength irrespective of sex. However, bone strength was greater for males compared to females

Theoretical Video Game Analysis: The Creation of Experience

The creation of experiences is a focused Masters by Research thesis in the field of media and specifically game studies. The purpose of this study is to introduce and investigate the effects of game design, specifically through the open world genre on the player's experience. This approach involves applying a phenomenological theory to games participation in order to analyses the ways in which narratives are unfolded for the gamer. This thesis specifically aims to determine how the individual gaming sessions determines the connection one makes in order to create memorable and meaningful participation. Qualitative research was conducted, such as observation and textual analysis, to collect material and evidence to support the subject of the thesis. Features include: comprehensive approaches and theory for analysing video games: exploration of the methodology to provide new perspective on video games both as an art and as a cultural medium: accounts of specific case studies as a focal point expanding on the academic, social and cultural dynamics of video games. The meaning games create whilst experiencing the content, cannot be defined and to a certain degree identified until brought into the range of human interaction. These features, combined within this thesis, allow for the conclusion that the experience of playing a game depends on the individual and their formulation of the subjective projection of the content. This thesis hopes to offer access to further research and detailed analysis, and thus make a small contribution to improving the understanding on the connection between the player[s], hardware and the software

Analysis of navigation performance for the Earth Observing System (EOS) using the TDRSS Onboard Navigation System (TONS)

Use of the Tracking and Data Relay Satellite System (TDRSS) Onboard Navigation System (TONS) was proposed as an alternative to the Global Positioning System (GPS) for supporting the Earth Observing System (EOS) mission. The results are presented of EOS navigation performance evaluation with respect to TONS based orbit, time, and frequency determination (OD/TD/FD). Two TONS modes are considered: one uses scheduled TDRSS forward link service to derive one way Doppler tracking data for OD/FD support (TONS-I); the other uses an unscheduled navigation beacon service (proposed for Advanced TDRSS) to obtain pseudorange and Doppler data for OD/TD/FD support (TONS-II). Key objectives of the analysis were to evaluate nominal performance and potential sensitivities, such as suboptimal tracking geometry, tracking contact scheduling, and modeling parameter selection. OD/TD/FD performance predictions are presented based on covariance and simulation analyses. EOS navigation scenarios and the contributions of principal error sources impacting performance are also described. The results indicate that a TONS mode can be configured to meet current and proposed EOS position accuracy requirements of 100 and 50 m, respectively

Characterization of a plasma source simulating solar wind plasma in a vacuum chamber

The United States has set an aggressive time line to not only return to the Moon, but also to establish a sustained human presence. In the Apollo missions dust was a significant factor, but the duration of those missions was short so dust and surface charging were problems, but they did not pose an immediate threat. For a long-term mission, these problems instead become incredibly detrimental. Because of this, research needs to be conducted to investigate these phenomena so that mitigation techniques can be developed and tested. To this end, this thesis serves to demonstrate the Gas and Plasma Dynamics Lab\u27s (GPDL) ability to recreate the lunar plasma environment, and to establish competence to conduct meaningful experimental research on this topic. This work may also serve as a guide for future researchers in the GPDL. Further, this work suggests avenues of near-future experimental work, as well as inexpensive improvements to the facility, which will increase the capability of the GPDL in the long term --Abstract, page iii

Reproduction, survival, and denning ecology of black bears on the Dare County Peninsula, North Carolina

Increases in the number of black bear (Ursus americanus) sightings, nuisance complaints, and bear-vehicle collisions on Alligator River National Wildlife Refuge (ARNWR or refuge) and Dare County Bombing Range (DCBR), North Carolina prompted sportsmen and local residents to request that the United States Fish and Wildlife Service and the North Carolina Wildlife Resources Commission open a bear hunting season on ARNWR and the DCBR. Data on reproduction and survival were needed to determine if the population could sustain a harvest. Data on denning chronology were needed to determine potential effects of denning on harvest. I estimated reproductive rates by examining family groups in natal dens and after den emergence and by examining reproductive tracts for the presence of corpora lutea and placental scars. Mean litter size was 2.1 (SD = 0.8) and ranged from 1 to 3 based on cub observations. Mean litter size of females ≥5 years old was 2.7 (SD = 0.5) and 2.5 (SD = 0.7) based on corpora lutea and placental scar counts, respectively. Females on the Alligator River National Wildlife Refuge and Dare County Bombing Range reproduced earlier than many other black bear populations in North America. Successful breeding, indicated by the presence of corpora lutea, occurred in females ≥1.5 years old. Eighty-one percent of tracts from 2.5-year-old females contained corpora lutea. Placental scars were present in tracts from females ≥2.75 years old. By age 4, 50% of the tracts contained corpora lutea and 50% contained placental scars