Improving GPS time series for geodynamic studies

Accurate and stable time series of geodetic parameters can be used to help in understanding the dynamic Earth and its response to global change. The Global Positioning System, GPS, has proven to be invaluable in modern geodynamic studies. In Fennoscandia the first GPS networks were set up in 1993. These networks form the basis of the national reference frames in the area, but they also provide long and important time series for crustal deformation studies. These time series can be used, for example, to better constrain the ice history of the last ice age and the Earth s structure, via existing glacial isostatic adjustment models. To improve the accuracy and stability of the GPS time series, the possible nuisance parameters and error sources need to be minimized. We have analysed GPS time series to study two phenomena. First, we study the refraction in the neutral atmosphere of the GPS signal, and, second, we study the surface loading of the crust by environmental factors, namely the non-tidal Baltic Sea, atmospheric load and varying continental water reservoirs. We studied the atmospheric effects on the GPS time series by comparing the standard method to slant delays derived from a regional numerical weather model. We have presented a method for correcting the atmospheric delays at the observational level. The results show that both standard atmosphere modelling and the atmospheric delays derived from a numerical weather model by ray-tracing provide a stable solution. The advantage of the latter is that the number of unknowns used in the computation decreases and thus, the computation may become faster and more robust. The computation can also be done with any processing software that allows the atmospheric correction to be turned off. The crustal deformation due to loading was computed by convolving Green s functions with surface load data, that is to say, global hydrology models, global numerical weather models and a local model for the Baltic Sea. The result was that the loading factors can be seen in the GPS coordinate time series. Reducing the computed deformation from the vertical time series of GPS coordinates reduces the scatter of the time series; however, the long term trends are not influenced. We show that global hydrology models and the local sea surface can explain up to 30% of the GPS time series variation. On the other hand atmospheric loading admittance in the GPS time series is low, and different hydrological surface load models could not be validated in the present study. In order to be used for GPS corrections in the future, both atmospheric loading and hydrological models need further analysis and improvements.

Work Stress in the Nursing Profession : An Evaluation of Organizational Causal Attribution

The goal of this study was to examine the role of organizational causal attribution in understanding the relation of work stressors (work-role overload, excessive role responsibility, and unpleasant physical environment) and personal resources (social support and cognitive coping) to such organizational-attitudinal outcomes as work engagement, turnover intention, and organizational identification. In some analyses, cognitive coping was also treated as an organizational outcome. Causal attribution was conceptualized in terms of four dimensions: internality-externality, attributing the cause of one’s successes and failures to oneself, as opposed to external factors, stability (thinking that the cause of one’s successes and failures is stable over time), globality (perceiving the cause to be operative on many areas of one’s life), and controllability (believing that one can control the causes of one’s successes and failures). Several hypotheses were derived from Karasek’s (1989) Job Demands–Control (JD-C) model and from the Job Demands–Resources (JD-R) model (Demerouti, Bakker, Nachreiner & Schaufeli, 2001). Based on the JD-C model, a number of moderation effects were predicted, stating that the strength of the association of work stressors with the outcome variables (e.g. turnover intentions) varies as a function of the causal attribution; for example, unpleasant work environment is more strongly associated with turnover intention among those with an external locus of causality than among those with an internal locuse of causality. From the JD-R model, a number of hypotheses on the mediation model were derived. They were based on two processes posited by the model: an energy-draining process in which work stressors along with a mediating effect of causal attribution for failures deplete the nurses’ energy, leading to turnover intention, and a motivational process in which personal resources along with a mediating effect of causal attribution for successes foster the nurses’ engagement in their work, leading to higher organizational identification and to decreased intention to leave the nursing job. For instance, it was expected that the relationship between work stressors and turnover intention could be explained (mediated) by a tendency to attribute one’s work failures to stable causes. The data were collected from among Finnish hospital nurses using e-questionnaires. Overall 934 nurses responded the questionnaires. Work stressors and personal resources were measured by five scales derived from the Occupational Stress Inventory-Revised (Osipow, 1998). Causal attribution was measured using the Occupational Attributional Style Questionnaire (Furnham, 2004). Work engagement was assessed through the Utrecht Work Engagement Scale (Schaufeli & al., 2002), turnover intention by the Van Veldhoven & Meijman (1994) scale, and organizational identification by the Mael & Ashforth (1992) measure. The results provided support for the function of causal attribution in the overall work stress process. Findings related to the moderation model can be divided into three main findings. First, external locus of causality along with job level moderated the relationship between work overload and cognitive coping. Hence, this interaction was evidenced only among nurses in non-supervisory positions. Second, external locus of causality and job level together moderated the relationship between physical environment and turnover intention. An opposite pattern of interaction was found for this interaction: among nurses, externality exacerbated the effect of perceived unpleasantness of the physical environment on turnover intention, whereas among supervisors internality produced the same effect. Third, job level also disclosed a moderation effect for controllability attribution over the relationship between physical environment and cognitive coping. Findings related to the mediation model for the energetic process indicated that the partial model in which work stressors have also a direct effect on turnover intention fitted the data better. In the mediation model for the motivational process, an intermediate mediation effect in which the effects of personal resources on turnover intention went through two mediators (e.g., causal dimensions and organizational identification) fitted the data better. All dimensions of causal attribution appeared to follow a somewhat unique pattern of mediation effect not only for energetic but also for motivational processes. Overall findings on mediation models partly supported the two simultaneous underlying processes proposed by the JD-R model. While in the energetic process the dimension of externality mediated the relationship between stressors and turnover partially, all the dimensions of causal attribution appeared to entail significant mediator effects in the motivational process. The general findings supported the moderation effect and the mediation effect of causal attribution in the work stress process. The study contributes to several research traditions, including the interaction approach, the JD-C, and the JD-R models. However, many potential functions of organizational causal attribution are yet to be evaluated by relevant academic and organizational research. Keywords: organizational causal attribution, optimistic / pessimistic attributional style, work stressors, organisational stress process, stressors in nursing profession, hospital nursing, JD-R model, personal resources, turnover intention, work engagement, organizational identification.

Työhön liittyvien psykososiaalisten kuormitustekijöiden tunnistaminen – Case Fazer Leipomot Oy

Tutkimuksen tavoitteena oli selvittää Fazer Leipomot Oy:n tuotannon työntekijöiden hyvinvointia ja heidän työssään havaitsemiaan psykososiaalisia riski- ja kuormitustekijöitä. Taustalla oli organisaation ja työntekijän kehittäminen sekä työn mielekkyyden lisääminen. Työntekijän kuormituksesta johtuva stressi on myös yhteydessä työssäpysymisasenteeseen. Tutkimuksen avulla pyrittiin luomaan kehitysehdotuksia kohti terveempää organisaatiota. Tutkimusaineisto kerättiin teemahaastattelujen avulla (n=12). Haastatteluiden pohjana toimi Maailman terveysjärjestö WHO:n luomat linjaukset psykososiaalisten riskien hallintaan (PRIMA–EF). Nämä teemat olivat työn sisältö, työmäärä ja –tahti, työaikamuoto, työn hallinta, työympäristö ja välineet, organisaatiokulttuuri ja toiminta, sosiaaliset suhteet, rooli organisaatiossa, työuran kehitys sekä työn ja muun elämän yhteensovittaminen. Haastatteluilla pyrittiin kuvaamaan työntekijöiden tunteita kuormituksesta ja tuomaan esille kehitysehdotuksia kohti parempaa huomista. Teemahaastattelut analysoitiin sisällönanalyysilla. Tulosten perusteella ”fazerilaisuutta” on edelleen havaittavissa ja Fazerilla on asioita, jotka ovat melko hyvin. Kuitenkin kehitettävää löytyy työntekijän kuormittuneisuuden parantamiseksi. Erityisesti esille nousivat arvostuksen tunne ja takaisinpäin viestintä. Lisäksi työntekijän motivoimiseksi ja sitouttamiseksi toivottiin lisää vaikutus- ja päätöksentekomahdollisuuksia. Vahvuuksia ilmeni muun muassa joustavuudessa ja työn ja muun elämän yhteensovittamisessa. Tuloksien luotettavuutta kuvaa muun muassa se, että Fazerin vuotuinen henkilöstökysely oli tuonut kyselylomakkeella esiin osittain samoja asioita. Fazerilla viihtyvyys on jo pitkään ollut hyvällä tasolla. Lisäksi työsuhteet ovat olleet ilmeisen pitkiä. Työympäristön nopea ja jatkuva muuttuminen ja työntekijöiden kasvava epävarmuus koettelevat työntekijöitä. Täten katseen suuntaaminen tulevaisuuteen sekä työntekijöiden hyvinvointiin ja työkykyyn panostaminen ovat tärkeässä roolissa. Fazer on vahva brändi, mutta huomio työntekijöiden kuormittuneisuuteen tulee jatkossakin olla osa Fazerin toimintaa.