Asteroid Lightcurve Inversion

The application of convex profile inversion (CPI) to the interpretation of asteroid lightcurves is discussed. This technique investigates the problem of extracting information about an asteroid's shape from its lightcurve. Whenever four ideal conditions are met, P is an estimator for the asteroids mean cross section C, a convex set defined as the average of all cross sections C(Z) cut by planes a distance z above the asteroids equatorial plane. C is therefore a 2-D average of the asteroids 3-D shape. The method is tested by inverting lightcurves generated analytically for geometrically scattered ellipsoids (GSE's) with semiaxes a or = B or = C. Using a defined 'distance measure' to quantify the difference between any two profiles, the deviation of P from C for GSE's as a function of lightcurve noise level, rotation phase sampling interval delta theta, and departure from ideal conditions is calibrated. The distance between P and a circle provides a gauge of the asteroid's nonsphericity and incorporates all the information contained in the lightcurve

Microelectromechanical Systems (MEMS) Resistive Heaters as Circuit Protection Devices

With increased opportunities for the exploitation (i.e., reverse engineering) of vulnerable electronic components and systems, circuit protection has become a critical issue. Circuit protection techniques are generally software-based and include cryptography (encryption/decryption), obfuscation of codes, and software guards. Examples of hardware-based circuit protection include protective coatings on integrated circuits, trusted foundries, and macro-sized components that self-destruct, thus destroying critical components. This paper is the first to investigate the use of microelectromechanical systems (MEMS) to provide hardware-based protection of critical electronic components to prevent reverse engineering or other exploitation attempts. Specifically, surface-micromachined polycrystalline silicon to be used as meandering resistive heaters were designed analytically and fabricated using a commercially available MEMS prototyping service (i.e., PolyMUMPs), and integrated with representative components potentially at risk for exploitation, in this case pseudomorphic high-electron mobility transistors (pHEMTs). The MEMS heaters were initiated to self-destruct, destroying a critical circuit component and thwart a reverse engineering attempt. Tests revealed reliable self-destruction of the MEMS heaters with approximately 25 V applied, resulting in either complete operational failure or severely altering the pHEMT device physics. The prevalent failure mechanism was metallurgical, in that the material on the surface of the device was changed, and the specific failure mode was the creation of a short-circuit. Another failure mode was degraded device operation due to permanently altered device physics related to either dopant diffusion or ohmic contact degradation. The results, in terms of the failure of a targeted electronic component, demonstrate the utility of using MEMS devices to protect critical components which are otherwise vulnerable to exploitation

Novel Microelectromechanical Systems Image Reversal Fabrication Process Based on Robust SU-8 Masking Layers

This paper discusses a novel fabrication process that uses a combination of negative and positive photoresists with positive tone photomasks, resulting in masking layers suitable for bulk micromachining high-aspect ratio microelectromechanical systems (MEMS) devices. MicroChem\u27s negative photoresist Nano™ SU-8 and Clariant\u27s image reversal photoresist AZ 5214E are utilized, along with a barrier layer, to effectively convert a positive photomask into a negative image. This technique utilizes standard photolithography chemicals, equipment, and processes, and opens the door for creating complementary MEMS structures without added fabrication delay and cost. Furthermore, the SU-8 masking layer is robust enough to withstand aggressive etch chemistries needed for fabrication research and development, bulk micromachining high-aspect ratio MEMS structures in silicon substrates, etc. This processing technique was successfully demonstrated by translating a positive photomask to an SU-8 layer that was then utilized as an etching mask for a series of trenches that were micromachined into a silicon substrate. In addition, whereas the SU-8 mask would normally be left in place after processing, a technique utilizing Rohm and Haas Microposit™ S1818 as a release layer has been developed so that the SU-8 masking material can be removed post-etching

Crystallizing Alex: A Qualitative Case Study of What Influences One Second Grade Teacher\u27s Literacy Instruction

New teachers face enormous pressure- to understand and assess student learning, to work well with parents, and to ensure their curricula are aligned with state and national standards. Nowhere is this pressure more evident than in literacy instruction, where competing notions of best practice can be confusing and overwhelming. This qualitative case study of an early career teacher, Alex Christopher, explores in-depth what influences her second grade literacy program. Her decisionmaking process during reading and writing instruction is analyzed within the context of local, state and national literacy reform initiatives, university/school partnerships, and professional development opportunities. Alex was selected for study because she has been teaching less than five years, is involved in a university/public school partnership, and has recently completed a series of professional development experiences designed to improve her literacy instruction. The research was completed using qualitative case study methods. Data collection included interviews, classroom observations, classroom and school artifacts, email exchanges, and informal conversations. Data analysis included triangulation, peer review and debriefing, and member checks. Special emphasis during the data analysis phase of the study was placed on crystallization, a newer analysis technique developed by Richardson (2000), and further extended by Janesick (2000). Crystallization provided multiple lenses for viewing the changes in Alex\u27s practice and belief system throughout the course of the study. Crystallization techniques are also used in the presentation of the findings. The research draws on both traditional research reporting methods, and emerging artistic or aesthetic methods (Eisner, 1998) through poetry and visual representation of implications of the study. The findings of the study support a need for more sustained support of new teachers beyond preservice preparation, a more systematic understanding of how teachers can develop reflective skills, and a reconsideration of the role of university faculty in professional development school partnerships. Eisner, E.W. (1998). The kind of schools we need: Personal essays. Porstmouth, NH: Heinemann. Janesick, V. (2000). The choreography of qualitative research designs: Minuets, improvisations, and crystallization. In N. Denzin & Y. Lincoln (Eds.), Handbook of qualitative research (pp. 379-400). Thousand Oaks, CA: SAGE Publications, Inc. Richardson, L. (2000). Writing: A method of inquiry. In N. Denzin & Y. Lincoln (Eds.), Handbook of qualitative research (pp. 923-948). Thousand Oaks, CA: SAGE Publications, Inc

Dipo and Other Rites of Passage in Odumase Krobo

I was based in Odumase Krobo for about three weeks. There, I completed over twenty interviews with people ranging from young boys and girls, elders, parents, Queen Mothers, priests and priestesses, devout Christians, and many others I met around town. I also lived with a family who had one boy and one girl and was able to observe how their upbringing differed according to their genders. I was able to discover the dipo process mostly in its entirety, save for the parts which are considered sacred and which I was therefore unable to hear about. I also discovered that dipo has changed in many ways due to formal education and Christianity. I also learned that the traditional rites of passage for boys were circumcision, learning to raise a lamb, learning to cultivate land, and receiving a gun for farming. I learned that of these rites, only circumcision remains today, and that the other practices have gone away as the Krobos have shifted away from their agricultural economy. Finally, I found that rites of passage for both boys and girls in Krobo reveal that both manhood and womanhood are defined primarily by one’s relationship to the family as well as one’s relationship to Krobo itself. Hence, womanhood is about being a good wife and mother, while manhood is about being a good father and husband. For both genders, taking pride in being from Krobo is an essential facet of the transition into adulthood. I concluded that despite certain limitations, ultimately these rites of passage are empowering for both boys and girls. They are empowering because achieving full personhood in Ghana meaning being a part of a community, and so the Krobo rites of passage, which provide boys and girls with access to the family community as well as to the greater Krobo community, allow the young people to become fulfilled adults

The Next Reapportionment Revolution

In the 1960s, the Supreme Court famously imposed the one-person, one-vote requirement on federal, state, and local legislatures. The doctrine rapidly resolved the problem of malapportioned districts. Within just a few years, legislatures across the nation were reapportioned to equalize the population between districts. Sadly, however, the national commitment to equal-population districts has led directly to the current crisis of political gerrymandering. The boundaries of equal-population districts must be redrawn every ten years to maintain population equality. Even with rigid adherence to population requirements, district boundaries are easily manipulated to secure incumbent seats and advance partisan interests. Redistricting is rightly condemned for allowing politicians to pick their voters, instead of the other way around. Rather than reform the redistricting process, this Article proposes eliminating it by using weighted voting to comply with the one-person, one-vote requirement. To that end, this Article identifies several innovative countywide apportionment plans that use political units as electoral districts and allocate legislative votes to each district in proportion to its population. Weighted voting eliminates the need for strict population equality and enables the formation of fixed districts that reflect multiple dimensions of political representation. The Supreme Court’s notably flexible approach to the one-person, one-vote requirement at the local level grants local governments substantial discretion to experiment with local political institutions and electoral arrangements. Policy innovations that succeed in one locality can spread to others and stimulate change at the state and national level. This Article seeks to stimulate change at the state and national level by drawing attention to local weighted-voting apportionment plans

When is primary anastomosis safe in the colon?

No Abstrac

Self perception of immediate family support by manic depressive ex-patients.

Dept. of Sociology and Anthropology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1986 .O777. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.)--University of Windsor (Canada), 1986

Examining the Viability of Computational Psychiatry: Approaches into the Future

As modern medicine becomes increasingly personalized, psychiatry lags behind, using poorly-understood drugs and therapies to treat mental disorders. With the advent of methods that capture large quantities of data, such as genome-wide analyses or fMRI, machine learning (ML) approaches have become prominent in neuroscience. This is promising for studying the brain’s function, but perhaps more importantly, these techniques can potentially predict the onset of disorder and treatment response. Experimental approaches that use naive machine learning algorithms have dominated research in computational psychiatry over the past decade. In a critical review and analysis, I argue that biologically realistic approaches will be more effective in clinical practice, and research trends should reflect this. Hybrid models are considered, and a brief case study on major depressive disorder is presented. Finally, I propose a novel four-step approach for the future implementation of computational methods in psychiatric clinics

Sensor performance analysis

The theory is described and the equations required to design are developed and the performance of electro-optical sensor systems that operate from the visible through the thermal infrared spectral regions are analyzed. Methods to compute essential optical and detector parameters, signal-to-noise ratio, MTF, and figures of merit such as NE delta rho and NE delta T are developed. A set of atmospheric tables are provided to determine scene radiance in the visible spectral region. The Planck function is used to determine radiance in the infrared. The equations developed were incorporated in a spreadsheet so that a wide variety of sensor studies can be rapidly and efficiently conducted