La mortalité par tumeur maligne chez les ouvriers d'une fabrique de caoutchouc en Suisse: étude épidémiologique, 1955-1975. [Cancer mortality among the workers of a Swiss rubber goods factory. Epidemiological study, 1955-75].

In an epidemiologic investigation of mortality among workers in a Swiss rubber-goods factory the cancer mortality in the period 1955-1975 has been studied in all male workers active on 1 January 1955 in (a) a rubber-goods factory and (b) a munitions factory, the latter as reference population. The two groups numbered some 1000 each. Both factories were located in the same Central Swiss village where no other industry was present. Mortality in each industry is compared with that in the Swiss population in general (SMR) and the mortalities of the two industries are compared with each other. The results tend to confirm that rubber workers are exposed to a higher risk of cancer mortality. Three particular types of cancer are briefly discussed: cancer of the stomach, of the lower urinary tract, and glioblastoma.

The determinants of queen size in a socially polymorphic ant.

In social animals, body size can be shaped by multiple factors, such as direct genetic effects, maternal effects, or the social environment. In ants, the body size of queens correlates with the social structure of the colony: colonies headed by a single queen (monogyne) generally produce larger queens that are able to found colonies independently, whereas colonies headed by multiple queens (polygyne) tend to produce smaller queens that stay in their natal colony or disperse with workers. We performed a cross-fostering experiment to investigate the proximate causes of queen size variation in the socially polymorphic ant Formica selysi. As expected if genetic or maternal effects influence queen size, eggs originating from monogyne colonies developed into larger queens than eggs collected from polygyne colonies, be they raised by monogyne or polygyne workers. In contrast, eggs sampled in monogyne colonies were smaller than eggs sampled in polygyne colonies. Hence, eggs from monogyne colonies are smaller but develop into larger queens than eggs from polygyne colonies, independently of the social structure of the workers caring for the brood. These results demonstrate that a genetic polymorphism or maternal effect transmitted to the eggs influences queen size, which probably affects the social structure of new colonies.

When several queens reign: how polygyny affects social life in ants

Astract: The aim of this thesis was to investigate how the presence of multiple queens (polygyny) affects social organization in colonies of the ant Formica exsecta. This is important because polygyny results in reduced relatedness among colony members and therefore reflects a potential paradox for altruistic cooperation being explained by inclusive fitness theory. The reason for this is that workers in polygynous colonies rear no longer only their siblings (high inclusive fitness gain) but also more distantly ox even unrelated brood (low or no inclusive fitness gain). All research projects conducted in this thesis are novel and significant contributions to the understanding of the social evolution of insect societies. We used a mixture of experimental and observational methodologies in laboratory and field colonies of F. exsecta to examine four important aspects of social life that are impacted by polygyny. First, we investigated the influence of queen number on colony sex allocation and found that the number of queens present in a colony significantly affects colony sex ratio investment. The data were consistent with the queen-replenishment hypothesis, which is based on the observation that newly mated queens are often recruited back to their parental nest. According to this theory, colonies containing many queens should only produce males due to local resource competition (i.e. related queens compete for common resources), whereas colonies hosting few queens benefit most from producing new queens to ensure colony survival. Second, we examined how reproduction is partitioned among nestmate queens. We detected a novel pattern of reproductive partitioning whereby a high proportion of queens were completely specialized in the production of only a subset of offspring classes produced within a colony, which might translate into great differences in reproductive success between queens. Third, we could demonstrate that F. exsecta workers indiscriminately reared highly related and unrelated brood although such nepotistic behaviour (preferential rearing of relatives) would be predicted by inclusive fitness theory. The absence of nepotism is probably best explained by its negative effects on overall colony efficiency. Finally, we conducted a detailed population genetic analysis, which revealed that the genetic population structure is different for queens and workers. Our data were best explained with queens forming family-based groups (multicolonial population structure), whereas workers from several nests seemed to be grouped into larger unites (unicolonial population structure) with workers moving freely between neighbouring nests. Altogether, the presented work significantly increased our understanding of the complex organization of polygynous social insect colonies and shows how an important life history trait such as queen number affects social organization at various levels. Résumé: Le but de cette thèse était d'étudier comment la présence de plusieurs reines par colonie (polygynie) influence la vie sociale chez la fourmi Formica exsecta. Ce sujet est important parce que la polygynie chez les insectes sociaux présente un passible paradoxe au niveau de la théorie du "fitness inclusive". Ce paradoxe est basé sur le fait que les ouvrières n'élèvent plus uniquement leurs frères et soeurs (gain de "fitness inclusive" maximale), mais également des individus moins ou pas du tout apparentés (gain de "fitness inclusive" réduit ou absent). Tous les projets de recherche présentés au cours de cette thèse apportent une meilleure compréhension et connaissance au niveau de l'organisation des colonies chez les insectes sociaux. Nous avons employé des méthodes d'observation et de laboratoire afin de mettre en évidence des aspects importants de la vie sociale chez les fourmis influencés par la polygynie. Quatre aspects ont été caractérisés : (1) l'influence du nombre de reines sur le sexe ratio produit par la colonie. Nous avons démontré que les colonies contenant beaucoup de reines produisaient rarement des reines tandis que les colonies contenant peu de reines souvent investissaient beaucoup de ressources dans la production des reines. Ces résultats sont en accord avec la "queen-replenishment hypothesis" qui est basé sur l'observation que les nouvelles reines sont recrutées dans la colonie où elles étaient nées. Cette hypothèse postule que la production des reines est défavorable dans les colonies contenant beaucoup de reines, parce que ces reines apparentées, rentrent en compétition pour des ressources communes. Au contraire, la production des reines est favorable dans des colonies contenant peu de reines afin d'assurer la survie de la colonie ; (2) comment les reines dans une colonie répartissent leur reproduction. Nous avons mis en évidence un nouveau pattern de cette répartition où une grande proportion de reines est complètement spécialisée dans la production d'un seul type de couvain ce qui probablement aboutit à des différences significatives entre reines dans le succès reproducteur ; (3) la capacité des ouvrières à discriminer un couvain de soeur d'un couvain non apparenté. Les résultats ont montré que les ouvrières ne font pas de discrimination entre le couvain de soeur et le couvain non apparenté ce qui n'est pas en accord avec la théorie de la "fitness inclusive". Cette absence de discrimination est probablement due à des effets négatifs comme par exemple la diminution de la production du couvain; (4) la structure génétique d'une population de F. exsecta. Nous avons mis en évidence que la structure génétique entre des groupes de reines est significativement différente de la structure génétique entre des groupes d'ouvrières. Les données suggèrent que les reines forment des groupes basés sur une structure familiale tandis que les ouvrières sont groupées dans des unités plus grandes.

Evolutionary implications of polygyny in the Argentine ant, Iridomyrmex humilis (Mayr) (Hymenoptera: Formicidae): an experimental study

A comparison of several physiological parameters of queens of Iridomyrmex humilis in experimental monogynous and polygynous colonies showed that queens in monogynous colonies became heavier, had more developed ovaries and laid about twice as many eggs. Workers in monogynous colonies were more attracted to queens, which therefore probably received more food. This may partially explain the higher weight and fecundity of queens in monogynous colonies of Iridomyrmex humilis and possibly other ant species. In polygynous colonies, queens differed greatly in their fecundity. These differences did not appear to be the result of a dominance hierarchy. These results are discussed from an evolutionary point of view. Two hypotheses of mutualism and colony level selection are proposed as an alternative to kin selection which is unlikely to be the exclusive selective influence in the evolution of polygyny either in I. humilis or in most other ant species.

Developing an Effective Construction Training Program for Hispanic and American Supervisors and Craft Workers, 2007

Hispanics are a large and growing part of the United States workforce. Projections of the U.S. Census Bureau (2001) state that, by the year 2050, Hispanics will account for 25% of the population. For the Midwest in particular, the Hispanic population is expected to increase 35% by the year 2025. The construction industry is expected to experience a greater percentage increase of its Hispanic population, due to the labor-intensive nature of the industry. This study addresses the expected increase of Hispanic workers in the construction industry by testing the best approaches for delivering training to construction crews with Hispanic workers as well as American supervisors and laborers in the state of Iowa. The research methodology consisted of assessing the effects on communication, safety, work environment, and productivity as a result of the integration training. Results show that integration on-site training decreases workers’ desire to move and increases quality of work and productivity. Most importantly, experimental design was used to show the increasing levels of direct construction communication due to the Toolbox Integration Course for Hispanic Workers and American Supervisors (TICHA) designed as part of this project. This study recommends the creation of a quasi-governmental or association program that can offer continuous research and training that can benefit the construction industry as well as society as a whole. The industry involvement in this process is crucial for contractors. Not only do contractors benefit from reduced insurance premiums when workers act safely, but workers with better communication skills are more productive.

Developing an Effective Construction Training Program for American Supervisors with Hispanic Craft Workers, 2005

In the construction industry, Hispanics have the highest rate of fatal work injuries among the racial/ethnic groups, and productivity in the field is limited by the language barrier between Hispanic workers and their supervisors and the level of education of many Hispanic craft workers. This research developed a training program designed to facilitate the integration process between American supervisors and Hispanic craft workers in a practical and cost-effective way, thus improving productivity and lowering fatality rates. The Iowa State University research team conducted a survey of 38 American supervisors, representing 14 Iowa construction companies. Survey results confirm that communication is the main problem experienced by American supervisors in the job site. Many American supervisors also use or depend on a link-person (an individual who interprets tasks to the rest of the Hispanic crew) to communicate to the Hispanic crew members. Research findings show that language differences affect productivity and workplace safety in the construction industry. Additionally, the educational levels of Hispanic workers indicate that they may not have the literacy skills necessary to understand training materials. This research developed two training courses designed to expand the Spanish communication skills of American supervisors. The research team modified the English-as-a-second-language course developed in Phase I into the Spanish as a Second Language (SSL) Survival Course. A series of technical training courses were also developed, titled Concrete Pavement Construction Basics (CPCB), that cover general practices in concrete pavement construction. They are much shorter and more specialized than the SSL course. The CPCB courses provide American supervisors simple and practical communication tools on a variety of topics to choose from according to their specific needs.

Molecular and social regulation of worker division of labour in fire ants.

Reproductive and worker division of labour (DOL) is a hallmark of social insect societies. Despite a long-standing interest in worker DOL, the molecular mechanisms regulating this process have only been investigated in detail in honey bees, and little is known about the regulatory mechanisms operating in other social insects. In the fire ant Solenopsis invicta, one of the most studied ant species, workers are permanently sterile and the tasks performed are modulated by the worker's internal state (age and size) and the outside environment (social environment), which potentially includes the effect of the queen presence through chemical communication via pheromones. However, the molecular mechanisms underpinning these processes are unknown. Using a whole-genome microarray platform, we characterized the molecular basis for worker DOL and we explored how a drastic change in the social environment (i.e. the sudden loss of the queen) affects global gene expression patterns of worker ants. We identified numerous genes differentially expressed between foraging and nonforaging workers in queenright colonies. With a few exceptions, these genes appear to be distinct from those involved in DOL in bees and wasps. Interestingly, after the queen was removed, foraging workers were no longer distinct from nonforaging workers at the transcriptomic level. Furthermore, few expression differences were detected between queenright and queenless workers when we did not consider the task performed. Thus, the social condition of the colony (queenless vs. queenright) appears to impact the molecular pathways underlying worker task performance, providing strong evidence for social regulation of DOL in S. invicta.

Smooth transition or permanent exit? Evidence on job prospects of displaced industrial workers

This article examines the job prospects of displaced industrial workers in Switzerland. Based on a survey of 1,203 workers who were dismissed after their manufacturing plants closed down, we analyse the determinants of re-employment, the sector of re-employment and the change in wages. Two years after displacement, a majority of workers were back in employment: 69% were re-employed, 17% un-employed and 11% retired. Amongst re-employed workers, two thirds found a job in manufacturing and one third in services. Contrary to a common belief, low-end services are not the collecting vessel of redundant industrial workers. Displaced workers aged 55 and older seem particularly vulnerable after a plant closes down: over 30% were long-term unemployed, and those older workers who found a new job suffered disproportionate wage losses. Advanced age-and not low education-appears as the primary handicap after mass redundancy.

Can smartphones and tablets improve the management of childhood illness in Tanzania? A qualitative study from a primary health care worker's perspective.

BACKGROUND: The impact of the Integrated Management of Childhood Illness (IMCI) strategy has been less than anticipated because of poor uptake. Electronic algorithms have the potential to improve quality of health care in children. However, feasibility studies about the use of electronic protocols on mobile devices over time are limited. This study investigated constraining as well as facilitating factors that influence the uptake of a new electronic Algorithm for Management of Childhood Illness (ALMANACH) among primary health workers in Dar es Salaam, Tanzania. METHODS: A qualitative approach was applied using in-depth interviews and focus group discussions with altogether 40 primary health care workers from 6 public primary health facilities in the three municipalities of Dar es Salaam, Tanzania. Health worker's perceptions related to factors facilitating or constraining the uptake of the electronic ALMANACH were identified. RESULTS: In general, the ALMANACH was assessed positively. The majority of the respondents felt comfortable to use the devices and stated that patient's trust was not affected. Most health workers said that the ALMANACH simplified their work, reduced antibiotic prescription and gave correct classification and treatment for common causes of childhood illnesses. Few HWs reported technical challenges using the devices and complained about having had difficulties in typing. Majority of the respondents stated that the devices increased the consultation duration compared to routine practice. In addition, health system barriers such as lack of staff, lack of medicine and lack of financial motivation were identified as key reasons for the low uptake of the devices. CONCLUSIONS: The ALMANACH built on electronic devices was perceived to be a powerful and useful tool. However, health system challenges influenced the uptake of the devices in the selected health facilities.

Metsäpalveluyritysten menestyminen ja siihen vaikuttavat tekijät

Tutkimuksessa kartoitettiin metsäpalveluyritysten toimintaympäristöä sekä menestymistä ja siihen vaikuttavia tekijöitä. Tutkimusta varten haastateltiin 27 metsäpalveluyrittäjää kesäkuussa 1999. Heikommin menestyneiden ja Menestyneimpien metsäpalveluyritysten löytämiseksi luotiin kaksi menestyspistejärjestelmää: KASKARA (KASvu, KAnnattavuus & RAhoitus) -mittaristo ja Tasapainotettu (Balanced Scorecard) mittaristo. KASKARA-mittaristossa tarkastelun kohteena olivat yrityksen kasvu (yrityksen liikevaihdon kasvuprosentti ja investoinnit) ja kannattavuus sekä rahoituksellinen tila (maksuvalmius ja vakavaraisuus) yrittäjän itsensä arvioimana. Toisaalta käytettäessä Tasapainotettua mittaristoa KASKARA-mittaristoon liitettiin vielä neljä muuttujaa: yrityksen tärkeimmän asiakkaan antama palaute yrittäjälle, yrittäjän hankkima täydennyskoulutus, kovien kilpailijoiden lukumäärä yrityksen nykyisellä toiminta-alueella ja yrittäjän oma arvio yrityksensä paremmuudesta kilpailijoihin nähden. Tutkimuksen Menestyneimpiä yrityksiä voitiin kuvata seuraavasti: yrittäjä kertoi olleensa luottavainen yritystä perustaessaan; yhtenä tärkeimmistä motiiveista yrityksensä perustamiseen yrittäjä piti pyrkimystä ansiotulojen kasvattamiseen; hieman alle puolet yrityksistä oli hakkuuseen painottuneita yrityksiä - muut päätoimialat olivat puukauppa, metsätalouden suunnittelupalvelut sekä mittauspalvelut; yrittäjän lisäksi yritykseen on palkattu keskimäärin kaksi vakinaista työntekijää; yrityksen kirjanpidosta huolehtii joku muu (useimmiten tilitoimisto) kuin yrittäjä; yrityksen kaluston määrä on kasvanut yrityksen perustamisvuodesta, mutta yrityksen asiakaskunta on pysynyt lähes samana; yrityksen tärkeimmän asiakkaan osuus yrityksen liikevaihdosta on 90%; tulevaisuudessa yrittäjä haluaa ylläpitää nykyisiä asiakassuhteita; ja kartoitettaessa yrittäjän halukkuutta ryhtyä uudelleen yrittäjäksi saamien kokemustensa pohjalta valtaosin yrittäjät sanoivat varmasti ryhtyvänsä uudelleen metsäpalveluyrittäjäksi. Vastaavasti Heikommin menestyneitä yrityksiä ja niiden toimintaa voitiin luonnehtia seuraavien tekijöiden avulla: yrittäjä oli ollut iältään yli 40-vuotias, kun hän oli perustanut metsäpalveluyrityksensä; yrittäjä oli toiminut maanviljelijänä ennen metsäpalveluyrittäjäuraansa; lähes puolet yrittäjistä olivat olleet melko epävarmoja yritystä käynnistäessään; yrityksen päätoimiala on useimmiten hakkuu; yrityksessä ei ole yrittäjän lisäksi palkattua, vakinaista henkilöstöä; yrityksen toiminta-alueen säde on alle 40 kilometriä; valtaosin yrittäjät hoitavat itse yrityksensä kirjanpidon; yrityksen kaluston määrä ei ole kasvanut yrityksen perustamisvuodesta; yrityksellä on nykyisin alle viisi asiakasta; tärkeimmän asiakkaan osuus yrityksen liikevaihdosta on noin 60%; tulevaisuudessa yrittäjä suunnittelee hankkivansa uusia asiakkaita nykyisten asiakassuhteiden ylläpidon lisäksi; ja jos yrittäjä saisi tehdä uudelleen yrityksensä perustamispäätöksen, runsas kaksi kolmasosaa yrittäjistä kertoi harkitsevansa tarkkaan perustamispäätöstä, mutta perustavansa uudelleen metsäpalveluyrityksen.

Factors affecting foster care breakdown in Spain

La ruptura del acogimiento familiar se ha definido como aquella situación en la que alguna de las partes implicadas causa una terminación de la intervención antes de haber alcanzado los objetivos establecidos en el plan de caso. Este trabajo presenta un estudio llevado a cabo en una muestra española de 318 casos cerrados de niños que fueron acogidos en familia ajena y extensa. Los datos se obtuvieron a través de la revisión exhaustiva de los expedientes de protección y acogimiento, complementada conentrevistas a los técnicos encargados de cada caso. La tasa de ruptura del conjunto de la muestra fue de 26,1%, si bien fuesignificativamente diferente en familia extensa (19,7%) que en familia ajena (31,2%). Los resultados de este estudio indican que las variables relacionadas con la ruptura dependen de la modalidad del acogimiento, en familia ajena o extensa. En el primer caso destacamos las variables relacionadas con las características del niño, especialmente los problemas de conducta y escolares, con especial relevancia en el grupo de 9-12 años, y el haber estado en acogimiento residencial previamente. En cambio, en extensaresulta más importante la problemática en los padres (prisión, salud mental) y el tener una medida de tutela. También el hecho de que se realice el acogimiento tras pasar por hogares de acogida resulta trascendental. Finalmente, la disponibilidad de recursos económicos e incluso los estudios de los acogedores parecen ser variables relacionadas con la ruptura de la acogida

Efficiency of the ISM Code in Finnish Shipping Companies

Due to increasing waterborne transportation in the Gulf of Finland, the risk of a hazardous accident increases and therefore manifold preventive actions are needed. As a main legislative authority in the maritime community, The International Maritime Organization (IMO) has set down plenary laws and recommendations which are e.g., utilised in the safe operations in ships and pollution prevention. One of these compulsory requirements, the ISM Code, requires proactive attitude both from the top management and operational workers in the shipping companies. In this study, a crosssectional approach was taken to analyse whether the ISM Code has actively enhanced maritime safety in the Gulf of Finland. The analysis included; 1) performance of the ISM Code in Finnish shipping companies, 2) statistical measurements of maritime safety, 3) influence of corporate top management to the safety culture and 4) comparing safety management practices in shipping companies and port operations of Finnish maritime and port authorities. The main results found were that maritime safety culture has developed in the right direction after the launch of the ISM Code in the 1990´s. However, this study does not exclusively prove that the improvements are the consequence of the ISM Code. Accident prone ships can be recognized due to their behaviour and there is a lesson to learn from the safety culture of some high standard safety disciplines such as, air traffic. In addition, the reporting of accidents and nearmisses should be more widely used in shipping industry. In conclusion, there is still much to be improved in the maritime safety culture of the Finnish Shipping industry, e.g., a “no blame culture” needs to be adopted.

Rikottujen ikkunoiden nollatoleranssi. Tutkimus New Yorkin rikoksentorjunnan uuskonservatiivi-mallista Suomessa

Väitöskirja on kriminologista kontrollin ja rikoksentorjunnan tutkimusta sekä poliisitutkimusta. Kohteena on ympäri maailmaa levinnyt nollatoleranssiksi kutsuttu järjestyspoliisistrategia. Strategiaa kokeiltiin vuosituhannen vaihteessa vuoden kestäneessä järjestyksenvalvonnan hankkeessa Tampereella. Vaikka kyseessä oli kokeilu, niin tutkimuksessa osoitetaan toimintatavan olleen ja olevan pitkälti kiinteä osa perinteistä suomalaisen järjestyspoliisin toimintaperiaatetta. Artikkeliväitöskirja sisältää viisi vuosina 1998–2005 julkaistua kirjoitusta. Kokoavan yhteenvetoartikkelin tutkimusongelmat ovat seuraavat: Millaisia ovat Yhdysvaltojen ja Suomen järjestyspoliisitoiminnan nollatoleranssien mekanismien, kontekstien ja vaikutusten keskeiset erot ja yhtäläisyydet? Millainen on Tampereen nollatoleranssikokeilu ja New Yorkin rikottujen ikkunoiden nollatoleranssi rikoksentorjunnan arvioinnin ja moraalisäätelyn esimerkkeinä? Tampereen kokeilun prosessi- ja vaikuttavuusarviointitutkimus koostaa tutkimuksen empiirisen aineiston. Hankkeen alku- ja loppumittauksena toimi lomakekysely tamperelaisille (2 x n2000). Lisäksi analyysissä käytettiin kansalaiskyselyn uhrikyselyä, poliisin rikos- ja päivystyskeskustilastoja, Tilastokeskuksen tilastoja, hankkeen suoritelomakkeita sekä rangaistusvaatimus- ja rikesakkolomakkeita sekä kouluterveystutkimuksia. Tampereen poliiseille tehtiin lomakekysely ja teemahaastatteluja. Sosiaali-, nuoriso- ja vapaaehtoistyöntekijöitä sekä yli viisikymmentä tamperelaista nuorta sekä kymmenkunta tamperelaista aikuista haastateltiin. Yhdysvaltojen osalta nojaudutaan verrattain suureen määrään julkaistua korkeatasoista ja ajankohtaista kriminologista tutkimusta. New Yorkiin ja Yhdysvaltoihin sovelletussa hallintavalta- ja moraalisäätelyanalyysissa rikotut ikkunat -teoria osoittautuu uuskonservatiiviseksi moraaliprojektiksi, joka opastaa kaupunkeja hankkimaan itselleen oikeuden tiukkaan järjestyksenvalvontaan. Aiemmin sen oli estänyt kansalaisoikeusmyönteinen lakien tulkinta. New Yorkissa ja Tampereella syntyi useita kielteisiä sivu- ja vastavaikutuksia, kuten ongelmien siirtymistä (displacement). Tämä on yksi keskeinen tulos tilannetorjunnan ja kontrollin tehostamisen ja kohdistamisen hankkeissa. Tulokset haastavat arvioimaan kriittisesti, ovatko kaikki lapsiin ja nuoriin kohdistuvat varhaisen puuttumisen hankkeet seuraustensa perusteella oikeutettuja.

Suitability of LiDAR technology for forest inventory in Russia

LiDAR is an advanced remote sensing technology with many applications, including forest inventory. The most common type is ALS (airborne laser scanning). The method is successfully utilized in many developed markets, where it is replacing traditional forest inventory methods. However, it is innovative for Russian market, where traditional field inventory dominates. ArboLiDAR is a forest inventory solution that engages LiDAR, color infrared imagery, GPS ground control plots and field sample plots, developed by Arbonaut Ltd. This study is an industrial market research for LiDAR technology in Russia focused on customer needs. Russian forestry market is very attractive, because of large growing stock volumes. It underwent drastic changes in 2006, but it is still in transitional stage. There are several types of forest inventory, both with public and private funding. Private forestry enterprises basically need forest inventory in two cases – while making coupe demarcation before timber harvesting and as a part of forest management planning, that is supposed to be done every ten years on the whole leased territory. The study covered 14 companies in total that include private forestry companies with timber harvesting activities, private forest inventory providers, state subordinate companies and forestry software developer. The research strategy is multiple case studies with semi-structured interviews as the main data collection technique. The study focuses on North-West Russia, as it is the most developed Russian region in forestry. The research applies the Voice of the Customer (VOC) concept to elicit customer needs of Russian forestry actors and discovers how these needs are met. It studies forest inventory methods currently applied in Russia and proposes the model of method comparison, based on Multi-criteria decision making (MCDM) approach, mainly on Analytical Hierarchy Process (AHP). Required product attributes are classified in accordance with Kano model. The answer about suitability of LiDAR technology is ambiguous, since many details should be taken into account.

Use of airborne laser scanner data in demanding forest conditions

Most of the applications of airborne laser scanner data to forestry require that the point cloud be normalized, i.e., each point represents height from the ground instead of elevation. To normalize the point cloud, a digital terrain model (DTM), which is derived from the ground returns in the point cloud, is employed. Unfortunately, extracting accurate DTMs from airborne laser scanner data is a challenging task, especially in tropical forests where the canopy is normally very thick (partially closed), leading to a situation in which only a limited number of laser pulses reach the ground. Therefore, robust algorithms for extracting accurate DTMs in low-ground-point-densitysituations are needed in order to realize the full potential of airborne laser scanner data to forestry. The objective of this thesis is to develop algorithms for processing airborne laser scanner data in order to: (1) extract DTMs in demanding forest conditions (complex terrain and low number of ground points) for applications in forestry; (2) estimate canopy base height (CBH) for forest fire behavior modeling; and (3) assess the robustness of LiDAR-based high-resolution biomass estimation models against different field plot designs. Here, the aim is to find out if field plot data gathered by professional foresters can be combined with field plot data gathered by professionally trained community foresters and used in LiDAR-based high-resolution biomass estimation modeling without affecting prediction performance. The question of interest in this case is whether or not the local forest communities can achieve the level technical proficiency required for accurate forest monitoring. The algorithms for extracting DTMs from LiDAR point clouds presented in this thesis address the challenges of extracting DTMs in low-ground-point situations and in complex terrain while the algorithm for CBH estimation addresses the challenge of variations in the distribution of points in the LiDAR point cloud caused by things like variations in tree species and season of data acquisition. These algorithms are adaptive (with respect to point cloud characteristics) and exhibit a high degree of tolerance to variations in the density and distribution of points in the LiDAR point cloud. Results of comparison with existing DTM extraction algorithms showed that DTM extraction algorithms proposed in this thesis performed better with respect to accuracy of estimating tree heights from airborne laser scanner data. On the other hand, the proposed DTM extraction algorithms, being mostly based on trend surface interpolation, can not retain small artifacts in the terrain (e.g., bumps, small hills and depressions). Therefore, the DTMs generated by these algorithms are only suitable for forestry applications where the primary objective is to estimate tree heights from normalized airborne laser scanner data. On the other hand, the algorithm for estimating CBH proposed in this thesis is based on the idea of moving voxel in which gaps (openings in the canopy) which act as fuel breaks are located and their height is estimated. Test results showed a slight improvement in CBH estimation accuracy over existing CBH estimation methods which are based on height percentiles in the airborne laser scanner data. However, being based on the idea of moving voxel, this algorithm has one main advantage over existing CBH estimation methods in the context of forest fire modeling: it has great potential in providing information about vertical fuel continuity. This information can be used to create vertical fuel continuity maps which can provide more realistic information on the risk of crown fires compared to CBH.