Combining economic and social goals in the design of production systems by using ergonomics standards

In designing of production systems, economic and social goals can be combined, if ergonomics is integrated into the design process. More than 50 years of ergonomics research and practice have resulted in a large number of ergonomics standards for designing physical and organizational work environments. This paper gives an overview of the 174 international ISO and European CEN standards in this field, and discusses their applicability in design processes. The available standards include general recommendations for integrating ergonomics into the design process, as well as specific requirements for manual handling, mental load, task design, human-computer-interaction, noise, heat, body measurements, and other topics. The standards can be used in different phases of the design process: allocation of system functions between humans and machines, design of the work organization, work tasks and jobs, design of work environment, design of work equipment, hardware and software, and design of workspace and workstation. The paper is meant to inform engineers and managers involved in the design of production systems about the existence of a large number of ISO and CEN standards on ergonomics, which can be used to optimize human well-being and overall system performance.review;standard;standardization;ergonomics;CEN;ISO;human factors;production engineering;production planning

Preventing Incomplete/Hidden Requirements: Reflections on Survey Data from Austria and Brazil

Many software projects fail due to problems in requirements engineering (RE). The goal of this paper is analyzing a specific and relevant RE problem in detail: incomplete/hidden requirements. We replicated a global family of RE surveys with representatives of software organizations in Austria and Brazil. We used the data to (a) characterize the criticality of the selected RE problem, and to (b) analyze the reported main causes and mitigation actions. Based on the analysis, we discuss how to prevent the problem. The survey includes 14 different organizations in Austria and 74 in Brazil, including small, medium and large sized companies, conducting both, plan-driven and agile development processes. Respondents from both countries cited the incomplete/hidden requirements problem as one of the most critical RE problems. We identified and graphically represented the main causes and documented solution options to address these causes. Further, we compiled a list of reported mitigation actions. From a practical point of view, this paper provides further insights into common causes of incomplete/hidden requirements and on how to prevent this problem.Comment: in Proceedings of the Software Quality Days, 201

Mapping of submerged vegetation and fish breeding grounds in the Mönsfladan, Åland

During the summer of 2013 mapping of the Mönsfladan, Åland, was performed under assignment of the Åland Government. There is a local wish to plan to digging of a canal between the Mönsfladan and the Engrundsfjärden in order to increase water exchange and create a new boating route. The goal of this study is to determine the ecological state of the Mönsfladan, predict the possible consequences of the proposed canal and to establish an ecological baseline to serve as reference for future monitoring. The ecological state of the Mönsfladan was established by mapping the submerged vegetation, fishing for juvenile fish and taking hydrographical samples together with temperature reading from three locations in Mönsfladan and one in Engrundsfjärden. The vegetation mapping showed that the flad was dominated by Najas marina, Chara tomentosa, Chara aspera and Potamogeton pectinatus. Other species that were found are Chara baltica, Chara canescens and the red listed Chara horrida. The abundance and cover of Charophytes (26.2 % cover of the total Mönsfladan) indicates a healthy ecological situation. The status is further supported by the low turbidity of the water. Charophytes also form important spawning and nursery habitats for fish. This nursery function is also indicated by the catch of fish in Mönsfladan, which caught in the proximity of charophyte beds, was dominated in number by juvenile perch and roach (36 % and 29 %, respectively). The temperature readings together with the hydrographical results indicate that the inside of Mönsfladan and Engrundsfjärden are sheltered and have little water exchange with the sea compared with the outer Mönsfladan. Possible consequences of increased water exchange due to the construction of a canal and increased boat traffic are eutrophication and increased turbidity caused by resuspension of sediment, which may result in decline or disappearance of charophytes and their ecological functions. Another effect is that the overall temperature of the flad may drop, rendering it too cold for the survival of small fry and larvae of fish

Combining economic and social goals in the design of production systems by using ergonomics standards

In designing of production systems, economic and social goals can be combined, if ergonomics is integrated into the design process. More than 50 years of ergonomics research and practice have resulted in a large number of ergonomics standards for designing physical and organizational work environments. This paper gives an overview of the 174 international ISO and European CEN standards in this field, and discusses their applicability in design proces

LED belichting en Het Nieuwe Telen bj tomaat: Proof of Principle

In dit Proof of Principle project is een belichte tomatenteelt geteeld met als doel 30% energiebesparing bij een gelijke productie. De LEDs hingen in 2 rijen: op ca. 40 cm boven de onderste bladeren en de tweede streng op 40 of op 70 cm hoogte daarboven. Bij de start van de teelt is zoveel licht gebruikt als het gewas aankon, en omdat het gewas zich goed ontwikkelde, is er al relatief vroeg besloten tot het verhogen van de stengeldichtheid. Dit heeft geleid tot een té hoge plantbelasting relatief vroeg in de teelt, terwijl er eigenlijk onvoldoende licht beschikbaar was om het aan te kunnen in de winter met weinig zonlicht. In het 192 cm rijafstanden systeem zijn de planten té dicht bij elkaar komen te staan. In vergelijking met een referentieteelt met 79 kg m-2 tomaten, is er onder productie LEDs 75 kg m-2 tomaten geproduceerd, en 80 kg m-2 bij de interlighting LEDs, vnl. omdat laatst genoemde LEDs langer brandde in de zomer

Influence of diffuse glass on the growth and production of tomato

There is a great deal of interest for diffuse glass in Dutch horticulture ever since higher light transmission values and the diffusing characteristics of diffuse glass have increased production for some crops. Thus an experiment was designed to examine the effects of a variation in haze factors and light transmissions for diffuse glass or a diffuse coating on the growth and production of tomato. The influence of diffuse glass with a haze factor of 45, 62 and 71% and light transmission equal to or greater than that of standard glass, as well as standard glass with a commercial coating with a haze factor of 50% and 6% less light transmission than that of standard glass was compared to that of standard glass. The crops were planted mid-December 2010 and grown to the middle of November 2011. The influence of diffuse light on light interception, crop morphology, photosynthesis and growth was measured and analysed. Light penetrated deeper into the crop resulting in a higher photosynthetic capacity in the lower canopy, but only in winter. Tomato grown under diffuse glass was more generative, transferring more into fruit production than vegetative growth, in comparison to standard glass or coated glass. The production under the three diffuse glass coverings showed a 7-9% increase in June relative to that under standard glass, and retained this increased production to the end of the year, ending with 8-11% more production. The most important reason for the increased production was an increase in individual fruit weight by 5-8 g. Plants grown under diffuse glass or coating were less susceptible to Botrytis spp. during the last months of the crop, possibly due to a higher dry matter content. The coating was applied in the beginning of May and the treatment continued through August when the global radiation diminished and more light was necessary in the crop and the coating was removed. The overall production under the coating was 5% higher than that under standard glass. An estimation of the benefits and consequences of diffuse light characteristics on the growth, development and production of tomato under Dutch conditions are discussed, along with recommendations for the optimal characteristics for diffuse glass

Influence of diffuse glass on the growth and production of tomato

There is a great deal of interest for diffuse glass in Dutch horticulture ever since higher light transmission values and the diffusing characteristics of diffuse glass have increased production for some crops. Thus an experiment was designed to examine the effects of a variation in haze factors and light transmissions for diffuse glass or a diffuse coating on the growth and production of tomato. The influence of diffuse glass with a haze factor of 45, 62 and 71% and light transmission equal to or greater than that of standard glass, as well as standard glass with a commercial coating with a haze factor of 50% and 6% less light transmission than that of standard glass was compared to that of standard glass. The crops were planted mid-December 2010 and grown to the middle of November 2011. The influence of diffuse light on light interception, crop morphology, photosynthesis and growth was measured and analysed. Light penetrated deeper into the crop resulting in a higher photosynthetic capacity in the lower canopy, but only in winter. Tomato grown under diffuse glass was more generative, transferring more into fruit production than vegetative growth, in comparison to standard glass or coated glass. The production under the three diffuse glass coverings showed a 7-9% increase in June relative to that under standard glass, and retained this increased production to the end of the year, ending with 8-11% more production. The most important reason for the increased production was an increase in individual fruit weight by 5-8 g. Plants grown under diffuse glass or coating were less susceptible to Botrytis spp. during the last months of the crop, possibly due to a higher dry matter content. The coating was applied in the beginning of May and the treatment continued through August when the global radiation diminished and more light was necessary in the crop and the coating was removed. The overall production under the coating was 5% higher than that under standard glass. An estimation of the benefits and consequences of diffuse light characteristics on the growth, development and production of tomato under Dutch conditions are discussed, along with recommendations for the optimal characteristics for diffuse glass

Temperatuurstrategieën in geconditioneerde kassen: Effecten op groei, ontwikkeling en onderliggende processen bij tomaat

In de jaren 2003 tot 2007 is het aantal bedrijven waarop (semi)gesloten geteeld wordt geleidelijk toegenomen. Op alle bedrijven bleken echter vragen te bestaan over de reacties van het gewas op het nieuwe klimaat. Daarom is in 2008 door Wageningen UR Glastuinbouw een onderzoek gestart naar de groei van tomaat in geconditioneerde kassen, waarin veel aandacht wordt besteed aan de fysiologische processen in de plant. Het onderzoek wordt gefinancierd vanuit het programma Kas als Energiebron door Productschap Tuinbouw en het ministerie van EL&I en wordt begeleid door een aantal tomatentelers en een adviseur. Het onderzoek dat in dit rapport wordt beschreven had als centrale vragen hoe verschillende temperatuurstrategieën de processen in de plant beïnvloeden en hoe CO2 in de kas efficiënt benut kan worden

Impact of critical illness and withholding of early parenteral nutrition in the pediatric intensive care unit on long-term physical performance of children:a 4-year follow-up of the PEPaNIC randomized controlled trial

Background: Many critically ill children face long-term developmental impairments. The PEPaNIC trial attributed part of the problems at the level of neurocognitive and emotional/behavioral development to early use of parenteral nutrition (early-PN) in the PICU, as compared with withholding it for 1 week (late-PN). Insight in long-term daily life physical functional capacity after critical illness is limited. Also, whether timing of initiating PN affects long-term physical function of these children remained unknown. Methods: This preplanned follow-up study of the multicenter PEPaNIC randomized controlled trial subjected 521 former critically ill children (253 early-PN, 268 late-PN) to quantitative physical function tests 4 years after PICU admission in Leuven or Rotterdam, in comparison with 346 age- and sex-matched healthy children. Tests included handgrip strength measurement, timed up-and-go test, 6-min walk test, and evaluation of everyday overall physical activity with an accelerometer. We compared these functional measures for the former critically ill and healthy children and for former critically ill children randomized to late-PN versus early-PN, with multivariable linear or logistic regression analyses adjusting for risk factors. Results: As compared with healthy children, former critically ill children showed less handgrip strength (p &lt; 0.0001), completed the timed up-and-go test more slowly (p &lt; 0.0001), walked a shorter distance in 6 min (p &lt; 0.0001) during which they experienced a larger drop in peripheral oxygen saturation (p ≤ 0.026), showed a lower energy expenditure (p ≤ 0.024), performed more light and less moderate physical activity (p ≤ 0.047), and walked fewer steps per day (p = 0.0074). Late-PN as compared with early-PN did not significantly affect these outcomes. Conclusions: Four years after PICU admission, former critically ill children showed worse physical performance as compared with healthy children, without impact of timing of supplemental PN in the PICU. This study provides further support for de-implementing the early use of PN in the PICU. Trial registration ClinicalTrials.gov, NCT01536275; registered on February 22, 2012.</p