Permutation tests of scale using deviances

Robust tests for comparing scale parameters, based on deviances—absolute deviations from the median—are examined. Higgins (2004) proposed a permutation test for comparing two treatments based on the ratio of deviances, but the performance of this procedure has not been investigated. A simulation study examines the performance of Higgins’ test relative to other tests of scale utilizing deviances that have been shown in the literature to have good properties. An extension of Higgins’ procedure to three or more treatments is proposed, and a second simulation study compares its performance to other omnibus tests for comparing scale. While no procedure emerged as a preferred choice in every scenario, Higgins’ tests are found to perform well overall with respect to Type I error rate and power.     

The Relationships between Activity and Quality of Life for Older Men and Women at Different Ages in Taiwan

This study investigated the relationships between types of activity and quality of life (QOL) for older men and women at different ages. Based on cross-sectional data that included 220 community-dwelling elderly persons aged 65 and older in southern Taiwan, the results showed that the participation rates in many activities declined with age for both genders. Social activity and solitary leisure activity were significantly associated with QOL for old-old men, but not for young-old men. Only social activity was significantly associated with QOL for young-old women, but there was no significant association between any activity and QOL for old-old women.     

Estimating urban lawn cover in space and time: Case studies in three Swedish cities

Lawns are considered monocultures and lesser contributors to sustainability than diverse nature but are still a dominating green area feature and an important cultural phenomenon in cities. Lawns have esthetical values, provide playground, are potential habitat for species, contribute to carbon sequestration and water infiltration, but also increase pesticides, fertilization, are monocultures and costly to manage at the same time. To evaluate the potential impact of lawns, whether positive or negative, it is of interest to estimate the total lawn cover in cities and its change over time. This is not a straightforward process, e.g., because many lawns are small and covered by trees. In this study we review the existing literature of lawn cover in cities and the different methodologies used for cover estimation. We found both pros and cons with NDVI and LiDAR data as well as manually interpreted aerial photos. The total cover of lawns in three case study cities was estimated to 22.5%. By extrapolating these percentages to all Swedish cities lawn cover was estimated to 2589 km² (0.6% of the terrestrial surface). The approximated total municipal management cost of lawns in all Swedish cities was 910,000,000 USD/ year. During 50 years lawn area almost doubled in relative cover and 56% of them were continuously managed. Since lawns constitute large parts of the urban greenery and are costly to manage it is highly relevant to consider their social, ecological and cultural value compared to alternatives, e.g., meadows with less intensive management.     

The effects of state-dependent human behavior on the design of a serial line

Most research on line design assumes that human operators perform independently from the status of the line. Recent empirical evidence is contradictory. Humans are likely to change their working speed if they might otherwise cause idle time (Schultz et al., Manage Sci 44(12):1595–1607, 1998). This peculiarity of worker behavior is observed in a variety of settings but little is still known about optimal line design that accounts for this more realistic modeling of worker behavior. Therefore, we analyze work allocation in a serial line with limited buffer capacity and adaptive human behavior. An extensive simulation study reveals that optimal work allocation in state-dependent models is different from classical state-independent models. A bowl-shaped work allocation might be suboptimal and design guidelines are more complicated. Depending on the extent of human reactions, a bowl-shaped, balanced, or reversed-bowl work allocation can be preferable.     

Effects of Leadership Style,Creativity Technique and Personal Initiative on Employee Creativity

Transformational leadership is assumed to enhance employees' creativity. However, results of meta‐analytic research on the relations between transformational leadership and creativity have fallen short of expectations. The authors argue that, besides leadership style, the creativity technique that a leader employs is an important means of stimulating employees' creativity. In addition, it is assumed that leadership styles and creativity techniques may have different effects, depending on the measure of creativity output (quantitative vs qualitative). Therefore, in an experimental setting, the effects of different creativity techniques (provocation technique vs brainwriting) and leadership styles (transformational vs transactional) on both quantitative and qualitative creativity were examined. Results showed that transformational leadership and provocation technique led to higher levels of qualitative creativity than transactional leadership and brainwriting, respectively. Conversely, transactional leadership and brainwriting were more effective for quantitative creativity. The additional benefit of the provocation technique in qualitative creativity was found to be higher in the transactional leadership condition than in the transformational leadership condition. Moreover, personal initiative made a significant and independent contribution to both qualitative and quantitative creativity. Implications for practice and future research are discussed.