Technological advances in recent years have promoted the development of virtual reality systems that have awide variety of hardware and software characteristics, providing varying degrees of ...immersion. Immersionis an objective property of the virtual reality system that depends on both its hardware and softwarecharacteristics. Virtual reality systems are currently attempting to improve immersion as much as possible.However, there is no metric to measure the level of immersion of a virtual reality system based onits characteristics. To date, the influence of these hardware and software variables on immersion hasonly been considered individually or in small groups. The way these system variables simultaneously affectimmersion has not been analyzed either. In this paper, we propose immersion metrics for virtualreality systems based on their hardware and software variables, as well as the development process that ledto their formulation. From the conducted experiment and the obtained data, we followed a methodology togenerate immersion models based on the variables of the system. The immersion metrics presented in thiswork offer a useful tool in the area of virtual reality and immersive technologies, not only to measurethe immersion of any virtual reality system but also to analyze the relationship and importance of thevariables of these systems.
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Research has demonstrated that students in dual‐language immersion programs perform as well as, or better than, their peers in core academic content areas by late elementary school. However, the ...extent to which immersion education fosters bilingualism has received less attention in the literature. Using data from a four‐year efficacy study of dual‐language immersion education in the Portland Public Schools in Oregon, this study reports the skill levels that 1,284 dual‐language immersion students achieved in their classroom partner languages (Spanish, Japanese, and Mandarin Chinese) between third and eighth grades. The authors found that by eighth grade, the average dual‐language immersion student, regardless of language, performed at least at the Intermediate Low sublevel, and often higher, on Standards‐Based Measurement of Proficiency assessments of nearly all language skills tested (listening, reading, writing, and speaking). In comparison, eighth graders in the Portland Public Schools who began taking Spanish as an elective in upper elementary or middle school scored only at about the Novice Mid sublevel. After four years of immersion learning (grades K–3), fourth‐grade students whose home language was Spanish scored similarly in reading and speaking to their immersion peers whose home language was not Spanish; however, they outperformed their immersion peers in listening and writing.
Video and Discussion
The effects of three freezing methods, air blast freezing (ABF), immersion freezing (IF) and ultrasound-assisted immersion freezing (UIF), on quality and microstructure of lotus roots were ...investigated. The parameters used to evaluate the freezing methods effect were the freezing time, color, firmness, drip loss, vitamin C and microstructure of the final frozen products. The results showed that the UIF products had several advantages in terms of the freezing time, color, firmness and drip loss over ABF and IF. No significant difference (p > 0.05) of vitamin C content was observed between the ABF and IF products, while significant difference (p < 0.05) of vitamin C was observed between UIF and ABF/IF products. ABF caused the largest destruction to the tissue, while the microstructure of the UIF products was the best preserved. It is concluded that UIF processing was a better freezing method for lotus root with improved quality and less damaged microstructure than the two other methods.
•Lotus root was frozen by three different methods.•Ultrasound-assisted immersion freezing (UIF) was quickest and gave best quality.•Air blast freezing and immersion freezing gave slightly higher vitamin C retention.•Microstructure was best preserved with UIF.•Overall UIF was the best of the three freezing method considered.
Abstract
This paper gives a precise structure theorem for the class of graphs which do not contain as an immersion. This strengthens a previous result of Belmonte et al. that gives a rough ...description of this class. In fact, we prove a stronger theorem concerning rooted immersions of where one terminal is specified in advance. This stronger result is key in a forthcoming structure theorem for graphs with no immersion.
This study concerns integration in a two-way dual language immersion (DLI) context. Specifically, the present study examines parents of students in Korean-English DLI programs with the intent to ...understand the extent of their satisfaction with their child's ability to get along with children of different cultures and languages. This study also examines parental views on integration among parents themselves. Using the survey data collected from over 450 parents in seven elementary schools in southern California, this quantitative study also investigates to what degree the variables of integration among children and among parents are associated with other parental demographic characteristics and parental experiences in their child's DLI program. Based on the study findings, this study argues that integration in DLI must be a school-wide commitment and not simply a program's goal. Moreover, to achieve integration in DLI, all stakeholders of the program need to be considered, including students, educators, and families of students in the school. This study also highlights the need to diversify discussions regarding DLI programs in terms of target languages, program types, and school locations.
•Total porosity measurement for gas shales without using crushed rock is presented.•The method uses a modified saturation – immersion technique with deionized water.•Porosity values are reproducible ...within a low average absolute uncertainty.•Swelling in gas shales during saturation with deionized water is not significant.•Solvent extraction pretreatment can remove solid organic matter.
Over the past decade interest in shale properties has increased due to the commercial success of gas shale plays. Despite their commercial importance, porosity measurement from gas shale samples is still challenging due to their extremely low permeability and complex pore structure. This leads to a significant uncertainty in the economic assessment of these plays. The current energy industry standard technique for measuring porosity in gas shales is based on methodology developed by the Gas Research Institute (GRI) that involves crushing a rock and aggressive pretreatment. The objective of this study is to develop an alternative method of measuring total porosity in gas shales. A porosity measurement using a liquid saturation and immersion technique with deionized water was adopted and modified for such applications. The water immersion porosimetry (WIP) technique was used to measure total porosity of shale samples from an Eastern Europe Silurian gas shale play and the Haynesville Shale from East Texas, USA. The samples were characterized for whole rock quantitative mineral and elemental composition, along with cation exchange capacity (CEC) and organic matter. The results from the WIP measurements are compared with other standard techniques including the GRI method and mercury intrusion porosimetry (MIP). An assessment of the advantages, potential errors, pitfalls and reproducibility of this method are also presented.
The experimental results indicate that WIP provides (i) highly reproducible porosity, grain density, and bulk density measurements for gas shales, (ii) the average absolute experimental uncertainty is ±0.22 porosity unit (p.u.), compared to the reported uncertainty level of 0.5p.u. for GRI measurements, (iii) standard MIP techniques systematically underestimate the porosity and grain density compared to WIP, because mercury cannot access the entire pore structure in shales, and (iv) grain density values obtained by the GRI method in samples with high organic matter content are higher compared to WIP measurements, probably because of dissolution of solid organic matter during solvent extraction pretreatment.
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