A Microeconomic Study of Commercial Real Estate Brokerage Firms

While residential brokerage has been widely studied, the operating characteristics on income property brokerage firms have received little attention in the literature. In this paper, we analyze results from a survey of income property brokers to measure profitability scale effects, and expenditures at the firm level. We find that while scale economies exist for expenses, net income per producer falls as firms grow; the optimally sized firm is comparatively small. Although inconsistencies with results from recent residential brokerage studies may relate to the survey period, they may also support a view that residential and income brokerage firms are structurally different.

Preservice mathematics teachers’ professional noticing of students’ mathematical thinking with technology

The purpose of this study is to examine the ways in which preservice secondary mathematics teachers (PSMT) professionally notice middle school students’ mathematical thinking on a technology enhanced mathematical task. The middle school students’ work was captured as a videocase for PSMTs to examine. Findings show that every PSMT included a discussion of the middle school students’ interaction with the technology in their noticing prompts, demonstrating that PSMTs recognized that the middle school students’ mathematical understanding was tied to their interactions with the technology. Additionally, results from PSMTs’ justifications for their predictions of middle school students’ responses to the task, incorporated the middle school students language and described how the middle school students would interact with the technology

Numerical modeling of turbulent flow in a channel

Two-dimensional incompressible turbulent flow in a channel with a backward-facing step was studied numerically by Chorin's Random Vortex Method (RVM), an algorithm capable of tracing the action of elementary turbulent eddies and their cumulative effects without imposing any restrictions upon their motions. The step occurs in one side of a channel with otherwise flat, parallel walls; its height equals 1/3, 1/4 or 1/5 the width of the channel downstream. The main objective was to investigate the behavior of the large-scale turbulent eddies in a flow and the flow characteristics in the separated shear layer, the reattached zone, and the rebuilding boundary layer after reattachment. The unsteady vorticity field and the distribution of time-averaged turbulent statistics were obtained. The effects of expansion step height and initial boundary layer state were also studied. Comparisons were made with the available experimental results. The agreement is satisfactory in the velocity profiles and in the reattachment length, and fairly good in the turbulence profiles. Also a mechanism of the development of the reattaching turbulent flow was suggested by the numerical results

Gettysburg College Sustainability Proposal

In the fall of 2011, the Environmental Studies capstone class led by Professor Rutherford Platt was asked to write Gettysburg College’s first Sustainability Plan. The goal of the plan was to develop specific sustainable practices for the campus that were related to the three pillars of sustainability: economic, social, and environmental, and how integrating diligent sustainable practices into each of these respected pillars will result in a more conscious campus, community, and future. In 2010, Gettysburg College turned to the Sustainability Tracking Assessment and Rating System (STARS) to quantify the institution’s sustainability efforts, providing a self-check mechanism to encourage sustainability applications to all aspects of the College. The American College and University Presidents’ Climate Commitment was signed in 2007 by former Gettysburg College President Katherine Haley Will, declaring that Gettysburg College would become carbon neutral by 2032. Gettysburg College has made large strides in the search for sustainability, and aims to continue its dedication to furthering sustainable practice. The following plan outlines the six priority areas identified by the Capstone class: progress of the American College and University Presidents’ Climate Commitment, Dining Services, campus green space, community outreach, integration of sustainability into the Gettysburg College Curriculum, and the Sustainability Advisory Committee. The first priority area identified was monitoring and upholding the American College and University Presidents’ Climate Commitment (ACUPCC). Though creating new sustainability initiatives on campus is the driving force towards an increasingly sustainable college and community, it is imperative that these goals be carried out in full to maximize beneficial returns. In order to reach carbon neutrality, Gettysburg College hopes to increase energy efficiency in buildings, incorporate renewable energy sources on campus, and mitigate remaining emissions through the purchase of carbon offsets. To further the College’s progress, it is proposed that Gettysburg College continue its energy-efficient appliance purchasing policy, as well as create a policy to offset all greenhouse gas emissions generated by air travel for students study abroad. As stated by the ACUPCC, a Sustainability Committee should take responsibility for the updates and progress reports required to meet the goal of carbon neutrality. The second priority area identified was sustainability in Dining Services. Gettysburg College is home to 2,600 students, all of whom require three full meals a day. Dining Services accounts for a large fraction of Gettysburg College’s sustainability efforts, already implementing sustainability through composting, buying local produce, and using biodegradable products. The proposed on-campus sales cuts of non-reusable to-go items, a change in campus mentality on food waste, and improved composting practices will translate to an increasingly sustainable campus, as well as a well-fed campus body. The third priority was maintaining green space on campus. Ranked as the 23rd most beautiful campus in the United States by The Best Colleges, Gettysburg College utilizes campus green space to create an atmosphere that is conducive to activity as well as tranquility. The plan proposes that Gettysburg College and its grounds facilities continue their exceptional efforts, focusing on increasing the use of the student garden, creating a new rain garden or social area on campus, and converting unnecessary parking lots into green space. As these additions are completed, they must be introduced to the student body and faculty alike to assure these areas are known and utilized. The fourth priority was utilizing community outreach to spread awareness of sustainability initiatives on and off campus. To connect the sustainability-geared changes proposed in this plan, community outreach at Gettysburg College is assessed to estimate how well these initiatives are communicated and promoted to both potential and enrolled students, faculty, and other concerned parties. To evaluate the efficiency of communication at Gettysburg College, a quantitative assessment is presented to measure the ease of finding the sustainability webpage, the quality of sustainability-related topics available on the webpage, and quality of webpage design. The webpage is in need of improved text to image ratios, locations of sustainability topics, and data displays. Despite not having a link to the sustainability webpage on the Gettysburg College homepage, sustainability events should be covered and presented on the rotational news feed found on the homepage to maximize outreach to interested parties or simply to add to the definition of Gettysburg College. The fifth priority was integrating sustainability into the Curriculum to build a culture on campus that values academic rigor, supports students as they cultivate intellectual and civic passions, and promotes the development of healthy social relationships and behaviors. The proposed Sustainability Committee on Sustainability in the Curriculum (SCC) will hold sustainability workshops for faculty with the aim to instill sustainability into all academic disciplines, providing all Gettysburg graduates with a means to approach their professional careers in a fashion that is conscious of sustainability. The sixth and last priority was the Sustainability Advisory Committee. Established in 2007, the Sustainability Advisory Committee is currently under review, but it is recommended that the committee restructure itself in accordance with the new Sustainability Committee Bylaws. These bylaws aim to define the purposes, membership, governance, and involvement with the college. With a clearly defined set of goals and methodology, the Sustainability Advisory Committee will be able to improve the solidarity of the sustainability movement on campus as a whole. By following the propositions laid out in the Gettysburg College Sustainability Plan, the student body, faculty, and community alike will become a part of a multi-faceted progression toward a more sustainable future

Why do we love the Lion King? Perception of animation among young adults

Our lives are easily driven or transformed by technologies, different forms of communication and information available, creating (new) realities or representations of reality. But how can these virtual worlds transform our social world, and our sense of reality? The present study is focused on the way how animation films are percept by young adults, and the importance they have for them. So, we aim to contribute to the understanding of possible connections between a social or practical reality, and the fantasy of virtual worlds. In this paper, we will analyze the answers of some young adults (N=210), men and women with an average age of 30 years, to three open questions concerning the films that marked them the most, the importance of animation on their life and how is animation present on their everyday life. The data gathered from their answers were classified in categories and analyzed with an automatic content analysis software – Leximancer – that permits advanced text analytics visualization. Results showed that animation films are really important in our participants’ lives, as part of the social life and well-being of the individuals, even if an adaptation of reality is not conscious, thus building the virtual worlds that connect us with what we know as reality.info:eu-repo/semantics/acceptedVersio

Radiative Reactions and Coherence Modeling in the High Altitude Electromagnetic Pulse

A high altitude nuclear electromagnetic pulse (EMP) with a peak field intensity of 5 x 10^4 V/m carries momentum that results in a retarding force on the average Compton electron (radiating coherently to produce the waveform) with magnitude near that of the geomagnetic force responsible for the coherent radiation. The retarding force results from a self field effect. The Compton electron interaction with the self generated magnetic field due to the other electrons accounts for the momentum density in the propagating wave; interaction with the self generated electric field accounts for the energy flux density in the propagating wave. Coherent addition of radiation is also quantitatively modeled.Comment: 23 pages, 0 figure

Forward-Secure Searchable Encryption on Labeled Bipartite Graphs

Forward privacy is a trending security notion of dynamic searchable symmetric encryption (DSSE). It guarantees the privacy of newly added data against the server who has knowledge of previous queries. The notion was very recently formalized by Bost (CCS \u2716) independently, yet the definition given is imprecise to capture how forward secure a scheme is. We further the study of forward privacy by proposing a generalized definition parametrized by a set of updates and restrictions on them. We then construct two forward private DSSE schemes over labeled bipartite graphs, as a generalization of those supporting keyword search over text files. The first is a generic construction from any DSSE, and the other is a concrete construction from scratch. For the latter, we designed a novel data structure called cascaded triangles, in which traversals can be performed in parallel while updates only affect the local regions around the updated nodes. Besides neighbor queries, our schemes support flexible edge additions and intelligent node deletions: The server can delete all edges connected to a given node, without having the client specify all the edges

Linearized model Fokker-Planck collision operators for gyrokinetic simulations. II. Numerical implementation and tests

A set of key properties for an ideal dissipation scheme in gyrokinetic simulations is proposed, and implementation of a model collision operator satisfying these properties is described. This operator is based on the exact linearized test-particle collision operator, with approximations to the field-particle terms that preserve conservation laws and an H-Theorem. It includes energy diffusion, pitch-angle scattering, and finite Larmor radius effects corresponding to classical (real-space) diffusion. The numerical implementation in the continuum gyrokinetic code GS2 is fully implicit and guarantees exact satisfaction of conservation properties. Numerical results are presented showing that the correct physics is captured over the entire range of collisionalities, from the collisionless to the strongly collisional regimes, without recourse to artificial dissipation.Comment: 13 pages, 8 figures, submitted to Physics of Plasmas; typos fixe

Quality and turnaround times of viral load monitoring under prevention of mother-to-child transmission of HIV Option B+ in six South African districts with a high antenatal HIV burden

Background. Barriers to monitoring maternal HIV viral load (VL) and achieving 90% viral suppression during pregnancy and breastfeeding still need to be understood in South Africa (SA).Objectives. To measure quality of VL care and turnaround times (TATs) for returning VL results to women enrolled in the prevention of mother-to-child transmission of HIV (PMTCT) programme in primary healthcare facilities.Methods. Data were obtained from a 2018 cross-sectional evaluation of the PMTCT Option B+ programme in six SA districts with high antenatal and infant HIV prevalence. Quality of VL care was measured as the proportion of clients reporting that results were explained to them. TATs for VL results were calculated using dates abstracted from four to five randomly selected facility-based client records to report overall facility ‘short TAT’ (≥80% of records with TAT ≤7 days). Logistical regression and logit-based risk difference statistics were used.Results. Achieving overall short TAT was uncommon. Only 50% of facilities in one rural district, zero in one urban metro district and 9 - 38% in other districts had short TAT. The significant difference between districts was influenced by the duration of keeping results in facilities after receipt from the laboratory. Expected quality of VL care received ranged between 66% and 85%. Client-related factors significantly associated with low quality of care, observed in two urban districts and one rural district, included lower education, recent initiation of antiretroviral treatment and experiencing barriers to clinic visits. Experiencing clinic visit barriers was also negatively associated with short TATs.Conclusions. We demonstrate above-average quality of care and delayed return of results to PMTCT clients. Context-specific interventions are needed to shorten TATs