Estimating the quantity and quality of coarse woody debris in Yellowstone post-fire forest ecosystem from fusion of SAR and optical data

The Coarse Woody Debris (CWD) quantity, defined as biomass per unit area (t/ha), and the quality, defined as the proportion of standing dead logs to the total CWD quantity, greatly contribute to many ecological processes such as forest nutrient cycling, tree regeneration, wildlife habitat, fire dynamics, and carbon dynamics. However, a cost-effective and time-saving method to determine CWD is not available. Very limited literature could be found that applies remote sensing technique to CWD inventory. In this paper, we fused the wall-to-wall multi-frequency and multi-polarization Airborne Synthetic Aperture Radar (AirSAR) and optical Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) to estimate the quantity and quality of CWD in Yellowstone post-fire forest ecosystem, where the severe 1988 fire event resulted in high spatial heterogeneity of dead logs. To relate backscatter values to CWD metrics, we first reduced the terrain effect to remove the interference of topography on AirSAR backscatter. Secondly, we removed the influence of regenerating sapling by quadratic polynomial fitting between AVIRIS Enhanced Vegetation Index (EVI) and different channels backscatters. The quantity of CWD was derived from P_hh and P_hv, and the quality of CWD was derived from P_hh aided by the ratio of L_hv and P_hh. Two maps of Yellowstone post-fire CWD quantity and quality were produced. The calculated CWD quantity and quality were validated by extensive field surveys. Regarding CWD quantity, the correlation coefficient between measured and predicted CWD is only 0.54 with mean absolute error up to 29.1 t/ha. However, if the CWD quantity was discretely classified into three categories of “≤ 60”, “60-120”, and “≥ 120”, the overall accuracy is 65.6%; if classified into two categories of “≤ 90” and “≥ 90”, the overall accuracy is 73.1%; if classified into two categories of “≤ 60” and “≥ 60”, the overall accuracy is 84.9%. This indicates our attempt to map CWD quantity spatially and continuously achieved partial success; however, the general and discrete categories are reasonable. Regarding CWD quality, the overall accuracy of 5 types (Type 1—standing CWD ratio ≥ 40%; Type 2—15% ≤ standing CWD ratio < 40%; Type 3—7% ≤ standing CWD ratio< 15%; Type 4—3% ≤ standing CWD ratio < 7%; Type 5—standing CWD ratio < 3%) is only 40.32%. However, when type 1, 2, 3 are combined into one category and type 4 and 5 are combined into one category, the overall accuracy is 67.74%. This indicates the partial success of our initial results to map CWD quality into detailed categories, but the result is acceptable if solely very coarse CWD quality is considered. Bias can be attributed to the complex influence of many factors, such as field survey error, sapling compensation, terrain effect reduction, surface properties, and backscatter mechanism understanding.     

Hands-free administration of subjective workload scales: Acceptability in a surgical training environment

Introduction

Subjective workload measures are usually administered in a visual-manual format, either electronically or by paper and pencil. However, vocal responses to spoken queries may sometimes be preferable, for example when experimental manipulations require continuous manual responding or when participants have certain sensory/motor impairments. In the present study, we evaluated the acceptability of the hands-free administration of two subjective workload questionnaires - the NASA Task Load Index (NASA-TLX) and the Multiple Resources Questionnaire (MRQ) - in a surgical training environment where manual responding is often constrained.

Method

Sixty-four undergraduates performed fifteen 90-s trials of laparoscopic training tasks (five replications of 3 tasks - cannulation, ring transfer, and rope manipulation). Half of the participants provided workload ratings using a traditional paper-and-pencil version of the NASA-TLX and MRQ; the remainder used a vocal (hands-free) version of the questionnaires. A follow-up experiment extended the evaluation of the hands-free version to actual medical students in a Minimally Invasive Surgery (MIS) training facility.

Results

The NASA-TLX was scored in 2 ways - (1) the traditional procedure using participant-specific weights to combine its 6 subscales, and (2) a simplified procedure - the NASA Raw Task Load Index (NASA-RTLX) - using the unweighted mean of the subscale scores. Comparison of the scores obtained from the hands-free and written administration conditions yielded coefficients of equivalence of r = 0.85 (NASA-TLX) and r = 0.81 (NASA-RTLX). Equivalence estimates for the individual subscales ranged from r = 0.78 (“mental demand”) to r = 0.31 (“effort”). Both administration formats and scoring methods were equally sensitive to task and repetition effects. For the MRQ, the coefficient of equivalence for the hands-free and written versions was r = 0.96 when tested on undergraduates. However, the sensitivity of the hands-free MRQ to task demands (η_partial² = 0.138) was substantially less than that for the written version (η_partial² = 0.252). This potential shortcoming of the hands-free MRQ did not seem to generalize to medical students who showed robust task effects when using the hands-free MRQ (η_partial² = 0.396). A detailed analysis of the MRQ subscales also revealed differences that may be attributable to a “spillover” effect in which participants’ judgments about the demands of completing the questionnaires contaminated their judgments about the primary surgical training tasks.

Conclusion

Vocal versions of the NASA-TLX are acceptable alternatives to standard written formats when researchers wish to obtain global workload estimates. However, care should be used when interpreting the individual subscales if the object is to make comparisons between studies or conditions that use different administration modalities. For the MRQ, the vocal version was less sensitive to experimental manipulations than its written counterpart; however, when medical students rather than undergraduates used the vocal version, the instrument’s sensitivity increased well beyond that obtained with any other combination of administration modality and instrument in this study. Thus, the vocal version of the MRQ may be an acceptable workload assessment technique for selected populations, and it may even be a suitable substitute for the NASA-TLX.     

Internet administration of self-report measures commonly used in research on social anxiety disorder: A psychometric evaluation

The Internet has become increasingly popular as a way to administer self-report questionnaires, especially in the field of Internet delivered psychological treatments. Collecting questionnaire data over the Internet has advantages, such as ease of administration, and automated scoring. However, psychometric properties cannot be assumed to be identical to the paper-and-pencil versions. The aim of this study was to test the equivalence of paper-and-pencil and Internet administered versions of self-report questionnaires used in social phobia research. We analyzed data from two trials in which samples were recruited in a similar manner. One sample (N = 64) completed the paper-and-pencil version of questionnaires and the second sample (N = 57) completed the same measures online. We included the Liebowitz Social Anxiety Scale-self-assessment (LSAS-SR), the Social Interaction and Anxiety Scale (SIAS), and the Social Phobia Scale (SPS) as measures of social anxiety. Also included were the Montgomery Åsberg Depression Rating Scale-self-assessment (MADRS-S), the Beck Anxiety Inventory (BAI), and the Quality of Life Inventory (QOLI). Results showed equivalent psychometric properties across administration formats. Cronbach’s α ranged between 0.77 and 0.94. There was an indication of a somewhat higher construct validity when participants filled out questionnaires using paper-and-pencil. We conclude that the LSAS-SR, SIAS, and SPS can be administered via the Internet with maintained psychometric properties.     

Comments on “Generalised finite Radon transform for N × N images”

In Kingston and Svalbe [1], a generalized finite Radon transform (FRT) that applied to square arrays of arbitrary size N × N was defined and the Fourier slice theorem was established for the FRT. Kingston and Svalbe asserted that “the original definition by Matúš and Flusser was restricted to apply only to square arrays of prime size,” and “Hsung, Lun and Siu developed an FRT that also applied to dyadic square arrays,” and “Kingston further extended this to define an FRT that applies to prime-adic arrays”. It should be said that the presented generalized FRT together with the above FRT definitions repeated the known concept of tensor representation, or tensor transform of images of size N × N which was published earlier by Artyom Grigoryan in 1984-1991 in the USSR. The above mentioned “Fourier slice theorem” repeated the known tensor transform-based algorithm of 2-D DFT [5-11], which was developed for any order N₁ × N₂ of the transformation, including the cases of N × N, when N = 2^r, (r > 1), and N = L^r, (r ≥ 1), where L is an odd prime. The problem of “over-representation” of the two-dimensional discrete Fourier transform in tensor representation was also solved by means of the paired representation in Grigoryan [6-9].     

Aggression,impulsivity, and health functioning in a veteran population: equivalency and test–retest reliability of computerized and paper-and-pencil administrations

The present study examined the equivalency and test–retest reliability of two administration methods (paper-and-pencil and computerized) of the Aggression Questionnaire (AQ), Barratt Impulsiveness Scale-11 (BIS-11), and SF-36 Health Survey (SF-36) in a sample of 97 veterans. The two-week test–retest reliability for the conventional paper-and-pencil administrations of the AQ, BIS-11, and the SF-36 in the veteran population were generally reliable and comparable to the test–retest reliability of these measures noted in the research for other populations. Equivalence of the computer vs. paper-and-pencil administrations were examined and results indicated that for the AQ, ICCs for all four subscales and total score were substantially lower for the PC administration. For the BIS-11, ICCs were comparable with the exception of the Motor subscale, which was lower in the PC condition. For the SF-36, two of the domains were higher in the PC condition, with four more being comparable. Overall, the computerized administration of the BIS-11 and SF-36 was found to be equivalent to the “gold standard” paper-and-pencil administration of these measures and can be utilized successfully among veterans. The computerized administration of the AQ, however, was not found to be equivalent to the paper-and-pencil administration of the measure.     

A Lookup Table Decoding of systematic (47, 24, 11) quadratic residue code

A new decoding algorithm for the binary systematic (47, 24, 11) quadratic residue (QR) code, a code that allows error-correction of up to five errors, is presented in this paper. The key idea behind this decoding technique is based on the existence of a one-to-one mapping between the syndromes “S₁” and correctable error patterns. By looking up a pre-calculated table, this algorithm determines the locations of errors directly, thus requires no multiplication operations over a finite field. Moreover, the algorithm dramatically reduces the memory required by approximately 89%. A full search confirms that when five or less errors occur, this algorithm decodes these errors perfectly. Since the implementation is written in the C-language, it is readily adaptable for use in Digital Signal Processing (DSP) applications.     

Social desirability effects on computerized and paper-and-pencil questionnaires

The objectives of the present study were to determine the impact of computer administration of questionnaires on impression management (IM) and self-deceptive enhancement (SDE) and on the disclosure of sensitive information such as alcohol use and risky sex. College students (N = 301) completed several questionnaires in either a computer-administered or paper-and-pencil condition. Respondents who completed the survey on the computer scored significantly higher on SDE than those completing the survey on paper. No differences were found for IM. Respondents in the computer condition also reported a higher level of alcohol consumption and riskier sexual behaviors than those in the paper-and-pencil condition. It is possible that computer administration of surveys creates a social situation that produces a sense of disinhibition in respondents, and this sense of disinhibition may lead to greater reports of risky behaviors.     

Structure and function of maladaptive cognitions in Pathological Internet Use among Chinese adolescents

This study empirically investigated the structure and function of maladaptive cognitions related to Pathological Internet Use (PIU) among Chinese adolescents. To explore the structure of maladaptive cognitions, this study validated a Chinese Adolescents’ Maladaptive Cognitions Scale (CAMCS) with two samples of adolescents (n1 = 293 and n2 = 609). The results of the exploratory factor analysis and confirmatory factor analysis revealed that CAMCS included three distinct factors, namely, “social comfort,” “distraction,” and “self-realization.” To examine the function of maladaptive cognitions, this study tested an updated cognitive-behavioral model in the third sample of 1059 adolescents. The results of structural equation model analyses verified both the direct effect of maladaptive cognitions on PIU and their mediating role in the relationships between distal factors (social anxiety and stressful life events) and PIU among Chinese adolescents. Theoretical and practical implications of these findings were discussed.     

Innovations in science teacher education: Effects of integrating technology and team-teaching strategies

The purpose of this study was to integrate technology and team-teaching techniques into science teacher education method courses in order to explore the effects of such integration on preservice teachers. The participants included one instructor and a total of 42 preservice teachers. A technology team-teaching model (TTT) was designed in this study to restructure science method courses with technology. This study used a mixed-method design, incorporating both quantitative and qualitative techniques. The results revealed that there were significant differences in “designing an appropriate science topic to be taught with technology” and “integrating computer activities with appropriate pedagogy in classroom instruction” (F = 5.260, p < 0.05, and F = 10.260, p < 0.01, respectively). The results also showed that the TTT model could enhance the integration of science teaching theories and practice. Team-teaching technique facilitated the integration of technology in science lesson design and teaching practice, and enhanced friendship through interaction. The TTT model could better the science learning experience of preservice teachers and serve as useful reference for other teacher education institutes.     

The effects of integrating technology,observation and writing into a teacher education method course

The purpose of this study was to integrate asynchronous learning technology with teaching strategies on observation and writing into a teacher education method course. The research questions were to explore the effects of the innovative teaching method and to compare it with the traditional teaching method. There were 134 preservice teachers involved in this study. This study used a mixed method design, incorporating both quantitative and qualitative techniques. The main data included questionnaires, observation reports, and on-line information. According to the findings, there were significant differences in the “teaching and learning interaction” and “application of technology and theories” (F = 9.728, P < 0.01, and F = 16.88, P < 0.001, respectively.), but there were no significant differences in the other aspects. The results also showed the experimental teaching method combined the effect of both traditional classroom and online teaching, and reinforced the integration of teaching theories and practices. The preservice teachers reflected that they had learned how to integrate technologies with teaching through the learning environment of the asynchronous learning network and teaching observation. The interactive teaching and learning of this study could supplement the any existing deficiencies in traditional teaching. Therefore, the experimental teaching method is not only a way to construct knowledge, theories and experiences of teaching, but also a good strategy to promote the utilization of instructional technology within teaching for preservice teachers. The limitations in the asynchronous learning technology and the difficulties associated with the preservice teachers’ learning processes were also discussed.     

Regranulation: A granular algorithm enabling communication between granular worlds

In this paper, we describe a granular algorithm for translating information between two granular worlds, represented as fuzzy rulebases. These granular worlds are defined on the same universe of discourse, but employ different granulations of this universe. In order to translate information from one granular world to the other, we must regranulate the information so that it matches the information granularity of the target world. This is accomplished through the use of a first-order interpolation algorithm, implemented using linguistic arithmetic, a set of elementary granular computing operations. We first demonstrate this algorithm by studying the common “fuzzy-PD” rulebase at several different granularities, and conclude that the “3 × 3” granulation may be too coarse for this objective. We then examine the question of what the “natural” granularity of a system might be; this is studied through a 10-fold cross-validation experiment involving three different granulations of the same underlying mapping. For the problem under consideration, we find that a 7 × 7 granulation appears to be the minimum necessary precision.     

Flow pattern around an appended tanker hull form in simple maneuvering conditions

A detailed computational study is presented of the flow pattern around the Esso Osaka with rudder in simple maneuvering conditions: “static rudder” and “pure drift”. The objectives are: (1) apply RANS for maneuvering simulation; (2) perform verification and validation on field quantities; (3) characterize flow pattern; and (4) correlate behavior of the integral quantities with the flow field. The general-purpose code CFDSHIP-IOWA is used. The free surface is neglected and the two-equation k-ω turbulence model is used. The levels of verification of the velocity components for the “straight-ahead”, “static rudder” and “pure drift” conditions show ranges from 5.5% to 28.3% of free stream, U₀, for the axial velocity U and 2.5-29.1%U₀ for the cross flow (V, W). Qualitative validation against limited experimental data shows encouraging results with respect to trends and levels. The flow pattern is characterized by fore and aft body bilge and side vortices, which are similar for “straight-ahead” and “static rudder” conditions, except in close vicinity of the rudder. The “pure drift” condition shows strong asymmetry on windward vs. leeward sides and a more complex vortex system with additional bilge vortices. Similarities and differences with data for other tanker, container, and surface combatant hulls and relation between flow pattern and forces and moments are discussed. Future work focuses on influence of propeller.     

An exploration of social networking site use,multitasking, and academic performance among United States and European university students

Studies have shown that multitasking with technology, specifically using Social Networking Sites (SNSs), decreases both efficiency and productivity in an academic setting. This study investigates multitasking’s impact on the relationship between SNS use and Grade Point Average (GPA) in United States (US; n = 451) and European (n = 406) university students using quantitative and qualitative data analysis. Moderated Multiple Regression analysis results showed that the negative relationship between SNS use and GPA was moderated by multitasking only in the US sample. This may be due to European students being less prone to “disruptive” multitasking. The results provide valuable cautionary information about the impact of multitasking and using SNSs in a learning environment on university students’ GPAs.     

Do millennial undergraduates’ views of writing differ when surveyed online versus on paper?

The purpose of this study was to test whether different survey delivery conditions made a difference in assessing college students’ practices, affect, and conceptions of academic and nonacademic writing. The delivery conditions represented combinations of three underlying factors: survey format (online versus paper-and-pencil), location (classroom, lab, home), and supervision (proctored or not). Participants (N = 268) were randomly assigned to one of three conditions: (1) a paper version of the survey administered in classrooms at scheduled proctored sessions; (2) an online version administered in scheduled proctored sessions in a computer lab; (3) an online version at a location and time of the students’ choice. The survey had 103 closed-ended and three open-response questions. Results showed different participation rates across conditions and more variability in time spent for the “home online” group. However, there were few differences by condition to substantive questions regarding the students’ practices, conceptions, and affective responses associated with writing. The only place where responses differed by condition was in response to the optional open-ended evaluation of the survey.     

Estimation of surface area and surface area measure of three-dimensional sets from digitizations

A local method for estimating surface area and surface area measure of three-dimensional objects from discrete binary images is presented. A weight is assigned to each 2 × 2 × 2 configuration of voxels and the total surface area of an object is given by summation of the local area contributions. The method is based on an exact asymptotic result that holds for increasing resolution of the digitization. It states that the number of occurrences of a 2 ×  2 × 2 configuration is asymptotically proportional to an integral of its “h-function” with respect to the surface area measure of the object. We find explicit representations for these h-functions. Analyzing them in detail, we determine weights that lead to an asymptotic worst case error for surface area estimation of less than 4%. We show that this worst case error is the best possible. Exploiting the local nature of the asymptotic result, we also establish two parametric estimators for the surface area measure. The latter allow to quantify anisotropy of the object under consideration. Simulation studies illustrate the validity of the estimation procedure also for finite, but sufficiently high resolution.     

Youth independent living assessment: testing the equivalence of web and paper/pencil versions of the Ansell–Casey Life Skills Assessment

This study compared a paper-and-pencil and a web-based (i.e. Internet) version of the Ansell–Casey Life Skills Assessment (ACLSA) for mode equivalence. Youth (n=97) completed an age-appropriate ACLSA version in both formats, administered in a repeated measures, counterbalanced design. No significant main effects between modes of administration emerged. However, higher scores were achieved on the second administration regardless of format. These findings demonstrate the equivalence of Internet and paper-and-pencil formats for all three ACLSA levels and a predictable learning effect across the first and second testings.     

Automatic measurement of ad preferences from facial responses gathered over the Internet

We present an automated method for classifying “liking” and “desire to view again” of online video ads based on 3268 facial responses to media collected over the Internet. The results demonstrate the possibility for an ecologically valid, unobtrusive, evaluation of commercial “liking” and “desire to view again”, strong predictors of marketing success, based only on facial responses. The area under the curve for the best “liking” classifier was 0.82 when using a challenging leave-one-commercial-out testing regime (accuracy = 81%). We build on preliminary findings and show that improved smile detection can lead to a reduction in misclassifications. Comparison of the two smile detection algorithms showed that improved smile detection helps correctly classify responses recorded in challenging lighting conditions and those in which the expressions were subtle. Temporal discriminative approaches to classification performed most strongly showing that temporal information about an individual's response is important; it is not just how much a viewer smiles but when they smile. The technique could be employed in personalizing video content that is presented to people while they view videos over the Internet or in copy testing of ads to unobtrusively quantify ad effectiveness.     

Effects of different sensors and leaf-on and leaf-off canopy conditions on echo distributions and individual tree properties derived from airborne laser scanning

The objectives of this study were to quantify and analyze differences in laser height and laser intensity distributions of individual trees obtained from airborne laser scanner (ALS) data for different canopy conditions (leaf-on vs. leaf-off) and sensors. It was also assessed how estimated tree height, stem diameter, and tree species were influenced by these differences. The study was based on 412 trees from a boreal forest reserve in Norway. Three different ALS acquisitions were carried out. Leaf-on and leaf-off data were acquired with the Optech ALTM 3100 sensor, and an additional leaf-on dataset was acquired using the Optech ALTM 1233 sensor. Laser echoes located within the vertical projection of the tree crowns were attributed to different echo categories (“first echoes of many”, “single echoes”, “last echoes of many”) and analyzed. The most pronounced changes in laser height distribution from leaf-on to leaf-off were found for the echo categories denoted as “single” and “last echoes of many” where the distributions were shifted towards the ground under leaf-off conditions. The most pronounced change in the intensity distribution was found for “first echoes of many” where the distribution was extremely skewed towards the lower values under leaf-off conditions compared to leaf-on. Furthermore, the echo height and intensity distributions obtained for the two different sensors also differed significantly. Individual tree properties were estimated fairly accurately in all acquisitions with RMSE ranging from 0.76 to 0.84 m for tree height and from 3.10 to 3.17 cm for stem diameter. It was revealed that tree species was an important model term in both and tree height and stem diameter models. A significantly higher overall accuracy of tree species classification was obtained using the leaf-off acquisition (90 vs. 98%) whereas classification accuracy did not differ much between sensors (90 vs. 93%).     

Solutions of fuzzy relation equations based on continuous t-norms

This study is concerned with fuzzy relation equations with continuous t-norms in the form ATR = B, where A and B are the fuzzy subsets of X and Y, respectively; R ⊂ X × Y is a fuzzy relation, and T is a continuous t-norm. The problem is how to determine A from R and B. First, an “if and only if” condition of being solvable is presented. Novel algorithms are then presented for determining minimal solutions when X and Y are finite. The proposed algorithms generate all minimal solutions for the equations, making them efficient solving procedures.