INCREMENTAL REFINEMENT STRUCTURES FOR APPROXIMATE SIGNAL PROCESSING (SIGNAL PROCESSING, FOURIER TRANSFORM, IMAGE DECODING, SPECTRAL ANALYSIS)

WINOGRAD, JOSEPH M BOSTON UNIVERSITY 1997 국내박사

A multi-blanker for parallel electron beam lithography

Winograd, Gil Israel Stanford University 2001 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

An ever present need exists in the field of semiconductor lithography for delineating smaller features to support the trend towards faster, cheaper, and denser semiconductor chips. Lithography is the most expensive component of the semiconductor manufacturing process, consuming 35%–50% of the total production cost. This cost is expected to escalate over the next several technology generations. For many chips, the mask production alone can be as high as 50% of the lithography cost. However, electron-beam mask production tools in use today are not scalable to the mask-writing requirements of the next decade because present-day tools use a single beam to serially expose an entire lithography mask. This dissertation describes a multi-electron-beam lithography technology based on a MEMS-fabricated multi-blanker chip. Demonstrations of multi-blanker chips modulating eight beamlets in a 20kV test stand are presented. Images of the beamlets are viewed on a YAG scintillator and captured by CCD camera, and line-scan data are obtained from Faraday cup/knife-edge experiments. A multi-blanker system is proposed that can deliver 1μA of beam current at 50kV into 144 beamlets. A 6-inch mask for the 100nm technology generation can then be exposed in 40 minutes using a 15μC/cm<super>2</super> resist. Results from a novel Coulomb interaction Monte Carlo algorithm indicate that the multi-blanker can support 3μA of beam current while maintaining a 100nm spot size using present-day electron optics technology. In addition to often reported stochastic blur, electron beams induce a space-charge lens that introduces third-order aberrations that may prevent electron projection technology from becoming a viable replacement to optical lithography at the 70nm technology node and beyond. A technique is presented to dissect the beam blur predicted by Monte Carlo simulators into the respective third-order aberration effects plus residual stochastic beam blur. For example, space-charge induced aberrations in a typical 250mm length column with 4:1 telecentric projection reduction optics is predicted to result in nearly 300nm of blur at the corner of a 250μm image field at 20μm of beam current and 100kV beam energy. Stochastic beam blur contributes an additional 130nm of beam blur.

Predictors of counseling expectations among students in an opportunity program

Winograd, Greta City University of New York 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

There is a gap in the literature regarding factors relevant to help-seeking among students from racial and ethnic backgrounds who attend universities where they are in the minority (Heppner, Witty, & Dixon, 2004). This dissertation study attempted to address this gap by focusing on the counseling expectations of 102 first-year African American, Hispanic, and biracial students (mean age = 18.55 years; 83 females, 19 males) who participated in an Opportunity Program on their universities campus. The purpose of this study was to investigate the extent to which counseling expectations, as measured by Tinsley's (1982) Expectations About Counseling-Brief Form (EAC-B), were predicted by three individual characteristics---self-esteem, as measured by the Rosenberg Self-Esteem Scale (RSE; Rosenberg, 1965); attributional style, as measured by the Children's Attributional Style Questionnaire-Revised (CASQ-R; Thompson, Kaslow, Weiss, & Nolen-Hoeksema, 1998); and self-appraised problem-solving skills, as measured by the Problem Solving Inventory (PSI; Heppner & Petersen, 1982). A supplementary analysis examined whether background variables (SES, prior counseling experience, gender, cultural congruity, level of acculturation) moderated these relationships. Ethnic society immersion, as measured by the Stephenson Multigroup Acculturation Scale (SMAS, Stephenson, 2000) emerged as an important moderator variable in the relationship between counseling expectations and individual characteristics. Lower self-esteem combined with higher degrees of ethnic society immersion contributed to lower overall counseling expectations and lower expectations for facilitative conditions and nurturance. A more depressive attributional style combined with higher degrees of ethnic society immersion contributed to lower overall counseling expectations and lower expectations for personal commitment. Regardless of ethnic society immersion, a more depressive attributional style contributed to lower expectations for facilitative conditions and nurturance. Finally, a more negative view of oneself as a problem-solver combined with higher degrees of ethnic society immersion contributed to higher expectations for counselor expertise.

The effects of trained moderation in online asynchronous distance learning

Winograd, David Mark Arizona State University 2000 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Online computer conferences used to assist distance learning courses often fail because the moderator—usually the instructor responsible for the conference—is not properly trained in techniques that build a community of learners. It has often been assumed that the skills required to create a vibrant classroom discussion translated easily to an online forum. This has been rarely the case. This study utilized the qualitative methods of grounded theory and narrative research to explore how a moderator, after undergoing training, would affect students in one of three segregated computer conferences supporting an online course. The training was based on both the academic literature on educational computer conference moderation and situational examples taken from the experiences of online moderators. The students' experiences with the trained moderator were compared with those students in the other two computer conferences without a trained moderator. The data analyzed were comprised of the messages collected from the three computer conferences, selected interviews, extensive journals written by the researcher, and an online survey. The study also considered the problems and pressures stemming from unclear policies for constructing an online course in an environment of overlapping departmental mandates. These mandates resulted in more emphasis being given to putting courses online than the choice of the most appropriate pedagogy. The results indicated that a trained moderator had a positive effect on computer conferences as a community of support and warmth was built; while another group, without such a moderator, constructed a community based on group dissent. No community of any sort was found in the third group.

Induction of T cell immunity overcomes resistance to PD-1 and CTLA-4 blockade and improves survival in pancreatic cancer

Winograd, Rafael University of Pennsylvania 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Disabling the function of immune checkpoint molecules can unlock T cell immunity against cancer, yet despite remarkable clinical success with monoclonal antibodies (mAb) that block PD-1 or CTLA-4 resistance remains common and essentially unexplained. Certain tumors, especially pancreatic carcinoma, are fully refractory to these antibodies. As reported in this thesis, I used a genetically engineered mouse model of pancreatic carcinoma in which spontaneous immunity is minimal, and found that PD-L1 is prominent in the tumor microenvironment, a phenotype confirmed in patients. Tumor infiltrating T cells express PD-1 even more prominently than T cells in a classical model of chronic infection, in which alphaPD-1 mAb mediates clinical benefit. Despite this striking expression of PD-1 and PD-L1 in the pancreatic tumor microenvironment, treatment with anti-PD-1 mAb, with or without anti-CTLA-4 mAb, fails in well-established tumors, recapitulating clinical results. Agonist anti-CD40 mAb with chemotherapy, deployed as a vaccine, induces T cell immunity and reverses the complete resistance of pancreatic tumors to alphaPD-1 and alphaCTLA-4. The combination of alphaCD40/chemotherapy plus alphaPD-1 and/or alphaCTLA-4 induces regression of subcutaneous tumors, improves overall survival, and confers curative protection from multiple rechallenges, consistent with immune memory not otherwise achievable. Combinatorial treatment nearly doubles survival of mice with spontaneous pancreatic cancers, revealing a clinical opportunity. These findings suggest that in non immunogenic tumors, epitomized by pancreatic carcinoma, baseline refractoriness to checkpoint inhibitors may be rescued by the priming of a T cell response with an antitumor vaccine. These studies indicate that understanding the immunobiology of differing tumor types may improve the ability to rationally design combinatorial immunotherapies in oncology.

Effects, Asynchrony, and Choice in Arrowized Functional Reactive Programming

Winograd-Cort, Daniel Yale University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Stochastic Self-Energy in a Self-Consistent Second-Order Green’s Function Scheme

Winograd, Blair ProQuest Dissertations & Theses University of Mich 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The description of electron correlation has been a critical problem among theoretical and computational chemistry researchers. To describe the physics of many new materials, this interaction is crucial. Typically, chemists and physicists have constructed approximations to classic electronic structure methods - wavefunction methods and density functional theory - to attempt to solve this problem. Both have had many successes in the computational chemistry field, but are hindered by either their computational cost or ability to rigorously describe the electron correlation. More recently, researchers have come back to investigating how Green's functions can be of use to study this correlation. This thesis focuses on the second-order Green's function which has shown successes in its moderate computational cost and ability to describe electron correlation. However, in solid-state chemistry where the systems to be studied are quite large, the method still must be implemented by other means. Instead of exploring this method deterministically, this thesis moves towards investigating the method via a stochastic method. While stochastic methods such as diagrammatic Monte Carlo are quite common in the physics community, they are far lesser explored among theoretical chemists.This work attempts to develop a computationally feasible way to implement diagrammatic Monte Carlo within the second-order Green's function scheme. This method is preferred to be implemented in a fully self-consistent matter. Thus, chapter 4 of this work will explore the algorithmics required to sample for the second-order self-energy component of the method. Further in chapter 5, the correct statistical exploration required to obtain important expectation values such as the one-body and two-body energies are discussed. It is found that due to the non-linearity of the data, non-parametric statistical resampling methods are required. In this work, it is shown that via a jackknife algorithm built into the second-order Green's function scheme, the stochastic error from a Monte Carlo evaluation of the self-energy can be controlled. To show the power of this analysis, in chapter 6 self-consistency is shown to be possible via calculations of a few model systems as well as larger more realistic chemical systems.Finally, chapter 7 of this thesis segues into a problem within the chemistry community. Coding skills are at the core of developing the methods described in this thesis; however, coding is not required in the chemistry curriculum in the United States. This chapter describes a curriculum that encouraged chemistry students to develop coding skills in a low stakes environment. While the overall hypothesis going into the study was that students who use coding to study a quantitative problem in chemistry will increase their understanding of that problem, the study left with further results. Via surveys, it was discovered that many chemistry students desire to learn coding and feel that developing the skill positively impacts their studies and future goals.Overall, this thesis has made great progress in developing a diagrammatic Monte Carlo technique that could be of interest to the chemistry community. The method has proven to be computationally feasibly and quantitatively correct in comparison to the analogous deterministic method. This work has formulated a scheme that can provide an accessible approach to solving other Green's function methods of interest and hopefully bring us closer to finding a method that is computationally approachable to quantitatively describing electronic correlation.