213,822 research outputs found
Price Impact of Block Trades and Price Behavior Surrounding Block Trades in Indian Capital Market
No full textWe analyze the permanent (information effect) and temporary (liquidity effect) impact of block trades transacted in the National Stock Exchange of India. Block trades are identified using multiple criteria based on trade value and trade volume. Overall, the permanent price impact is more for block purchases than for block sales indicating that block purchases are more informative than block sales, which may be motivated by liquidity need. Unlike in other markets, we observe that the temporary impact is greater than the permanent impact in case of block purchase. We classify the block trades as All-or-None (AON) and Not-AON trades depending on the number of transactions through which a block order is executed. As expected, the price impact is higher for Not-AON trades as compared to AON trades (which can be assumed to be pre-negotiated trades). Further, arrival of multiple block trades increases market confidence on the information. The permanent price impact is higher for days where there are more than one block trade of similar nature than for days with only one block trade. To analyze the speed of market response to the information associated with block trades, we have used the ‘transaction time event approach’, as used by Holthausen et al. (1990). We find that the prices start increasing (front running) 8 minutes before block purchases but not in case of block sales i.e. some information about the impending block purchase is factored in by the market when the block trade is for purchases. Further, in the case of block sales, prices revert quickly leaving very small permanent price impact.
Teaching in the block: perceptions from an agricultural education classroom
No full textPlan BA relatively new initiative called block scheduling is being used in high schools all over the country. Several schools are investigating and adopting block schedules to replace traditional schedules. Block scheduling has several benefits to educators, for example, the larger blocks of class time allow for a variety of teaching methods and activities. The purpose of the study was to research the teachers' attitudes of the effectiveness of block scheduling design. The study focused on four questions (1) What are agricultural education teachers' perceptions of the overall effectiveness of block scheduling? (2) Have teaching methods in agricultural education changed in response to block scheduling? (3) Has enrollment in agriculture classes changed as a result of the block schedule? (4) What are important benefits and drawbacks of block scheduling specific to agricultural education classrooms? Surveys were distributed to Wisconsin Agricultural Education Instructors at the end of the 2002 school year. The survey consisted of demographic information, 30 Likert type items, and a comment section. A total of 48 surveys were mailed to participants and thirty-two (67%) were returned. Results show that many teachers feel overall that block scheduling is effective for their agricultural education programs. Many participants stated advantages to block scheduling such as hands-on and lab activities, more time for fieldtrips, and the opportunity to have more individualized contact with students. However, participants also mentioned disadvantages such as challenges with FFA recruitment and member involvement
Data for Alternating Gyroid in Block Polymer Blends
No full textWith the data provided here, users can reproduce all the results of self-consistent field theory (SCFT) calculations presented in the paper "Alternating gyroid in block polymer blends" by Park et al. (doi/10.1021/acsmacrolett.2c00115). Each folder contains input files and output converged solutions of the SCFT simulations for the corresponding figures in the paper. Information about the open-source C++ SCFT program is available at GitHub (https://github.com/dmorse/pscfpp) and the user manual page (https://dmorse.github.io/pscfpp-man/).This data set contains the input and output files from the PSCF C++ program used for the self-consistent field theory (SCFT) simulation in "Alternating gyroid in block polymer blends" by Park et al. (doi/10.1021/acsmacrolett.2c00115). Self-consistent field theory was used to investigate the stability of alternating gyroid phase in the ternary AB/BC/ABC block polymer mixture. With this dataset, users should be able to regenerate all the calculations that appeared in the paper, using the open-source C++ SCFT program.Sponsorship: This work was supported primarily by the National Science Foundation primarily through the University of Minnesota Materials Science Research and Engineering Center under Award No. DMR-2011401.Park, Sojung; Bates, Frank S; Dorfman, Kevin D. (2022). Data for Alternating Gyroid in Block Polymer Blends. Retrieved from the University Digital Conservancy, https://doi.org/10.13020/mz9b-4r42
Parallel and pipeline architectures for 2-D block processing
No full textThis paper is concerned with the development and design of parallel and pipeline architectures for 2-D recursive and nonrecursive block digital filter. In this regard, several high speed structures using single-instruction multiple-data stream (SIMD) machines have been developed. These structures are designed based upon the specific nature of the block convolution processor, block recursive processor and block state-space processor both at the block and scalar levels
XLBlocks: a Block-based Formula Editor for Spreadsheet Formulas
No full textSpreadsheets are frequently used in industry to support critical business decisions. Unfortunately, they also suffer from error-proneness, which sometimes results in costly consequences. Experiments in the field of program education have shown that programmers tend to make fewer errors and can better focus on the logic of a program if they use a block-based language instead of a textual one. We hypothesize that a block-based formula editor could support spreadsheet users in a similar way. Therefore, we develop XLBlocks and conduct a think-aloud study with 13 experienced spreadsheet users from industry. Participants are asked to create and edit several formulas, using our block-based language. We then ask them to evaluate this editor using the Cognitive Dimensions of Notations framework. We found that for all dimensions the block-based formula editor received a better evaluation than the default text-based formula editor.Accepted author manuscriptSoftware Engineerin
The optimal design of an experiment with blocks of size two for quadratic regression on one variable.
No full textExact D-optimal designs are derived for an optometry experiment for the estimation of a quadratic polynomial in one explanatory variable. Two observations are made for each subject participating in the experiment, such that each subject serves as a block of two possibly correlated observations. The exact D-optimal designs are compared to the best possible three-level designs and to the continuous D-optimal designs.Optimal;
Price impact of block trades in the Saudi stock market
No full textThis paper examines the price impact of block trades for the 124 companies that comprise all listed firms in the Saudi stock market (SSM). We use high frequency intraday data (one minute intervals) for the period 2005-2008 to provide out of sample evidence of the determinants of price impact. We find an asymmetric price impact of 0.5% for block purchases and -0.38% for block sales. We document a price continuation post block trades and a price reversal after block sales. Sellers of block trades in the Saudi market pay higher liquidity premiums than
buyers of block trades. However, on average, the price effect of a block trade is small and short-lived suggesting that resiliency is high in the market. Moreover, we find a direct relationship between the size of the trades and the level of information asymmetry in the market. Despite the structural differences of the SSM, the intraday pattern of price impacts is similar to patterns documented in other markets, namely an inverse J-shaped pattern. Finally,
sophisticated traders can gain abnormal profits in the SSM through “free riding”, a trader can benefit from the overreaction before the block trade and price reversal after the block trade
Estimating the intercept in an orthogonally blocked experiment when the block effects are random.
No full textAbstract: For an orthogonally blocked experiment, Khuri (1992) has shown that the ordinary least squares estimator and the generalized least squares estimator of the factor effects in a response surface model with random block effects coincide. However, the equivalence does not hold for the estimation of the intercept when the block sizes are heterogeneous. When the block sizes are homogeneous, ordinary and generalized least squares provide an identical estimate for the intercept.Effects;
PERMEANT ION AND SUBUNIT DEPENDENCE OF EXTERNAL Mg2+ BLOCK OF NMDA RECEPTORS
No full textN-methyl-D-aspartate (NMDA) receptors are broadly involved in the CNS physiological and pathological processes. The voltage-dependent block by external Mg2+ is a signature characteristic of the NMDA receptors and is partly responsible for the many important roles NMDA receptors play. The work included in this Dissertation was designed to advance our understanding of the mechanism of Mg2+ block of NMDA receptors by exploring the permeant ion and subunit dependence of this process. Whole-cell and outside-out patch recordings from primary cultures of rat cortical neurons or heterologous mammalian cell lines were performed in combination with kinetic modeling. I report that Mg2+ inhibition of whole-cell NMDA currents in cortical neurons, which express NMDA receptors with NR2A or NR2B NR2 subunits, is very sensitive to ionic conditions. This phenomenon can be explained by a kinetic model which incorporates external permeant ion binding sites within the pore. Permeant ions binding to these sites prevents Mg2+ blocking or unblocking the channel. The general mechanisms of Mg2+ channel block of NR1/2D receptors is fundamentally similar to that of cortical receptors. However, Mg2+ block of NR1/2D receptors is much weaker than cortical receptors, mostly due to faster Mg2+ unblocking. Permeant ions also greatly affect Mg2+ block of NR1/2D receptors. The results can be explained by a kinetic model that incorporates two external and one internal permeant ion binding sites in the channel of NMDA receptors. When these sites are occupied by permeant ions, Mg2+ blocking or unblocking is affected. Thus, the research included in this Dissertation has deepened our understanding of the mechanism of Mg2+ block . The work also provides insights into NMDA receptor structure and gating
Teachers' perceptions of the block schedule
No full textPlan BThis study was developed to investigate Menomonie High School teachers’ perceptions of the block schedule regarding modifications to departmental courses and services, advantages and disadvantages of the block schedule, and suggestions for modifications to the current block schedule. A researcher-developed questionnaire was sent via school mailbox to 66 faculty, with 28 returning the questionnaire and participating in the study. The findings indicate that modifications made to departmental courses and services included: the compacting of curriculum, the addition of terms to some courses, the inclusion of additional grade levels in some courses, and the creation of new courses. The advantages that were indicated included: longer class time allowed for more in-depth discovery type learning, varied teaching practices and activities, integration of content areas such as U.S. history/U.S. literature and speech/composition, fewer teacher preparations, longer preparation time, fewer courses for students to manage, less stress for teachers and students, improved relationships between students and teachers, and the creation of new elective course offerings. The disadvantages indicated included: less developmental time for learning, an increase in class sizes, some curriculum lost due to compacting, some departments could not service all student requests, some departments dropped electives to accommodate more sections of required courses, no safety net for failing students, difficulty of placing transfer students in the schedule, class balances unequally distributed, some students had difficulty maintaining attention for the longer period of time, retention loss during gaps between related courses, curriculum watered down due to necessary review time, difficulties for substitute teachers, no study halls for remediation, and student absences are more detrimental. Suggestions for modifying the current block schedule included: going to a trimester schedule with twelve or thirteen week grading terms and five sixty to sixty-five minute periods, increasing staff, modifying the block with skinnies, implementing an A/B block schedule, adding electives in all areas, keeping students with the same teacher for all terms of a course, building in more one on one time for students who are failing, and having three terms for lower level courses
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