The work load of warehouse workers in three different working systems

An investigation was conducted in five companies in the distribution branch. These companies were divided into three different working systems, i.e., highly mechanized (HM), moderately mechanized (MM), and slightly mechanized (SM). The three systems differed in logistics and kind of appliances used. The purpose of this study was to compare the three working systems with different degrees of mechanization concerning the time spent on tasks, activities during the working day, postures that occurred, physiological work load, perceived exertion and recovery from work. To investigate the different tasks, activities and working postures, 50 warehouse workers, originating from the three working systems, were observed by means of a direct observation method, called: ‘TRAC’. To investigate the physiological work load the heart rate was recorded continuously during the working day and related to the individually determined relation between heart rate and oxygen uptake. This relation was constructed with the results of a cycle ergometer test done in the laboratory. During lunch and at the end of the working day the warehouse workers filled in a questionnaire concerning their perceived exertion and recovery from work.

In the slightly mechanized system more time was spent with the trunk flexed more than 75° as compared with the other two systems. This posture was very common during lifting of objects, and lifting was done more often in this system than in the other systems. In the MM system the warehouse workers had the highest estimated oxygen uptake and reported the highest perceived exertion at the end of the working day. The workers in the HM system had a shorter working day and had less problems with recovery from work than the workers of the other two systems. Poor working postures like rotation and lateroflexion were commonly found in the HM working system. An important explanation was the difference in time spent driving an electric car. This activity was done mostly in the HM system. In conclusion, the HM system was considered most favourable when it concerned work load and recovery from work. The appliances used in the HM system, and especially the electric car, need to be designed according to ergonomic guidelines to avoid poor working postures.     

Management and enterprise architecture click: The FAD(E)E framework

Enterprises are living things. They constantly need to be (re-)architected in order to achieve the necessary agility, alignment and integration. This paper gives a high-level overview of how companies can go about doing ‘enterprise architecture’ in the context of both the classic (isolated) enterprise and the Extended Enterprise. By discussing the goals that are pursued in an enterprise architecture effort we reveal some basic requirements that can be put on the process of architecting the enterprise. The relationship between managing and architecting the enterprise is discussed and clarified in the FAD(E)E, the Framework for the Architectural Development of the (Extended) Enterprise. Frank G. Goethals completed his Master studies in economics (option informatics), at the Katholieke Universiteit Leuven, Belgium, in 2000. He is presently researching for a Ph.D. under the theme of `Managing data in the Extended Enterprise'. This research is conducted at the K.U.Leuven under the guidance of professor J. Vandenbulcke, and is financed by SAP Belgium. Frank has a strong interest in coordination and dependency theory and Enterprise Architecture. Monique Snoeck obtained her Ph.D. in May 1995 from The Department of Computer Science of the Katholieke Universiteit Leuven with a thesis that lays the formal foundations of the object-oriented business modelling method MERODE. Since then she has done further research in the area of formal methods for object-oriented conceptual modelling. She now is Full Professor with the Management Information Systems Group of the Faculty of Economics and Applied Economics at the Katholieke Universiteit Leuven in Belgium. She has been involved in several industrial conceptual modelling projects. Her research interests are object oriented conceptual modelling, software architecture and software quality. Wilfried Lemahieu holds a Ph.D. from the Department of Applied Economic Sciences of the Katholieke Universiteit Leuven, Belgium (1999). At present, he is associate professor at the Management Informatics research group of the Faculty of Economics and Applied Economics. His teaching includes Database Management, Data Storage Architectures and Management Informatics. His research interests comprise distributed object architectures and web services, object-relational and object-oriented database systems and hypermedia systems. Jacques A. Vandenbulcke is professor at the Faculty of Economics and Applied Economics of the Katholieke Universiteit Leuven, Belgium. His main research interests are in Database management, Data modelling, and Business Information Systems. He is co-ordinator of the Leuven Institute for Research on Information Systems (LIRIS) and holder of the SAP-chair on ‘Extended enterprise infrastructures’. He is president of ‘Studiecentrum voor Automatische Informatieverwerking (SAI)’, the largest society for computer professionals in Belgium, and co-founder of the ‘Production and Inventory Control Society (PICS)’ in Belgium.     

Lien entre la qualité des relations familiales et sociales à l'adolescence et à l'age adulte.

Fifty-seven families with adolescent children participated in a study of a) the quality of family and friendship relationships in adolescence, and b) the quality of family, friendship, and romantic relationships of adolescents 7 years later. Observation measures and self-report questionnaires were used to examine the variables. Regression analyses showed that mothers' marital satisfaction, conjugal conflict, and quality of mother-daughter relationship in adolescence predicted daughters' satisfaction with romantic relationships in adulthood. However, only the parental variables during adolescence predicted the quality of friendship relationships in adulthood. This study highlighted the contribution that quality of family relationships in adolescence makes to the quality of interpersonal relationships in adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Morphology and electrochemistry of spinel Li–Mn–O optimized by composite technology

This paper presents a composite technology, which combines doping and modifying to optimize the performance of spinel Li–Mn–O. Co ion-doped Li–Mn–O was synthesized by a wet chemical process. The homogeneously distributed C layer was chemically grown on the surface of LiCo_0.1Mn_1.9O₄ by the hydrothermal method. The products were analyzed and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Their electrochemical performances were tested with the Arbin instruments. The results showed that a different concentration of C influenced both the morphologies and the cycling performances of the cathode materials greatly.     

The performance of rolling production schedules in a process industry

In this paper we study lot-sizing and changeover decisions in production schedules that are implemented on a rolling-horizon basis. The study is carried out by comparing production schedules for the packaging operations of a pharmaceutical company that produces various products on several capacitated production lines. The schedules are obtained by solving a mixed-integer programming formulation by using a heuristic procedure. We examine the effects of the number of periods in the planning horizon, the starting inventory and the demand fluctuation on the schedules. We show empirically that the saving in annual production cost diminishes rapidly as more demand periods are added to the planning horizon. Computational results are reported.     

Effect of the Melt Temperature on the Solidification Process of Liquid Garnets Ln3Al5O12 (Ln = Dy, Y, and Lu)

The solidification process of liquid garnets Ln₃Al₅O₁₂ (Ln = Dy, Y, Lu) was probed by differential thermal analysis. A critical temperature T _clg was evidenced in the liquid. Cooling from temperatures under T _clg leads to the crystallization of the single garnet phase. Cooling from temperatures above T _clg leads to the solidification of a mixture of perovskite LnAlO₃ and aluminum oxide α-Al₂O₃. For Ln = Y, the results are in agreement with stable and metastable phase diagrams previously proposed. The YAIO₃ melt was shown to display a critical temperature T _clp also. Its metastable solidification from temperatures above T _clp leads to the formation of the perovskite at around 1550°C.     

Determination of tocopherols and phytosterols in sunflower seeds by NIR spectrometry

The objective of this work was to develop a near‐infrared reflectance spectrometry (NIRS) calibration estimating the tocopherol and phytosterol contents in sunflower seeds. Approximately 1000 samples of grinded sunflower kernels were scanned by NIRS at 2‐nm intervals from 400 to 2500 nm. For each sample, standard measurements of tocopherol and phytosterol contents were performed. The total tocopherol content was obtained by high‐performance liquid chromatography coupled with a fluorescence detector, while the total phytosterol content was assessed by gas chromatography. For tocopherol, the calibration data set ranged from 175 to 1005 mg/kg oil (mean value around 510 ± 140 mg/kg oil), whereas for the phytosterol content, the calibration data set ranged from 180 to 470 mg/100 g oil (mean value of 320 ± 50 mg/100 g oil). The NIRS calibration showed a relatively good correlation (R² = 0.64) between predicted by NIRS and real values for the total tocopherol content but a poor correlation for the total phytosterol content (R² = 0.27). These results indicate that NIRS could be useful to classify samples with high and low tocopherol content. In contrast, the estimation of phytosterol contents by NIRS needs further investigation. Moreover, in this study, calibration was obtained by a modified partial least‐squares method; the use of other mathematical treatments can be suitable, particularly for total phytosterol content estimation.     

Inhibition by Lactobacillus sakei of other species in the flora of vacuum packaged raw meats during prolonged storage

The abilities of five Lactobacillus sakei strains and one Lactococcus lactis strain to retain inhibitory activity against several target organisms in the flora of product during 12 weeks storage of vacuum-packaged lamb and beef was investigated. L. sakei strains were generally found capable of developing dominant populations on both beef and lamb. L. lactis 75 grew poorly on lamb did not inhibit co-inoculated Brochothrix thermosphacta. Lamb inoculated with the Sakacin-A producer L. sakei Lb706 had lower Listeria monocytogenes populations than lamb inoculated with a bacteriocin-negative variant. In beef packs inoculated with Clostridium estertheticum spores and L. sakei strain 27, 44 or 63, the development of blown-pack spoilage was delayed by up to one week. Campylobacter jejuni inoculated onto beef was recovered from fewer packs when it was co-inoculated with 3000 CFU cm⁻² of L. sakei strain 27, 44 or 63. Observed inhibition did not always correlate with inhibition observed in earlier media-based studies, supporting the view that functionality identified using simple media-based screening methods may not be replicated in the complex environment of stored foods, and vice-versa. These findings further define a set of L. sakei strains with potential for the extended bio-preservation of minimally processed fresh beef and lamb.     

Skeletal categories

We examine in this paper skeletons of deformed image categories and their connection with structures and projections. First we state under which conditions a subcategory Σ of the deformed image category ^Δ is a skeleton. Second, we consider the particular case when all deformations reduce themselves to similarities and compare Σ to the category of structures. Third, we establish a link between skeletons and projections. Indications are given about the topological explanation of the properties which skeletons and projections possess in common as well as about the connection existing between our formalism and current applications.