Metrics for Distribution Similarity Applied to the Bucking to Demand Procedure

In the computerized bucking to demand procedure bucking is done according to a given price list and demand matrix, which defines the demands for different log length-diameter class proportions. To achieve as good a log length-diameter distribution as possible, the computer compares demand and actual output to appropriately direct bucking. A comparison has been made with a variable called distribution level, which, however, is unable to distinguish between error that is close to the optimum log length-diameter class proportion and error that is further away. In addition, the distribution level does not distinguish between log length-diameter classes, even though error in one class can be far more undesirable than in another. In this study, bucking to demand using the distribution level was compared to bucking to value and bucking to demand using the penalty segmented distribution level, squared distribution level, chi-square formula and flexible penalty segmented distribution level. The bucking outcome employing these various techniques was achieved by using a bucking simulator and artificially generated stand and stem data. The results show that the best bucking outcomes were produced by methods with a squared error term, i.e. the squared distribution level, chi-squared formula and flexible penalty segmented distribution level. In addition, it was possible to direct error toward preferred log length-diameter classes without substantial loss in overall goodness of fit

Käytettyjen puutavara-autojen ja -nostureiden jälleenmyyntiarvo sekä ominaisuudet Euroopan eri osissa

Euroopassa pääosa puutavaran kaukokuljetuksesta tehdään erityisesti sitä käyttötarkoitusta varten suunnitelluilla ja rakennetuilla puutavara-autoilla ja perävaunuilla, joiden ominaisuudet vaihtelevat maittain ja alueittain. Vaikuttavia tekijöitä ovat esimerkiksi infrastruktuuri, pinnanmuodot, kuljetettavien puutavaralajien katkontapituudet ja kansalliset säädökset. Maakohtaista vaihtelua esiintyy etenkin puutavara-autojen ja perävaunujen enimmäismitoissa ja akselipainoissa, jotka vaikuttavat hyötykuorman kokoon. Autokuljetuksessa puutavaran kuormauksella ja purulla, niiden ajanmenekillä sekä toteutustavalla on suuri vaikutus kuljetuskustannuksiin. Puutavaran kuormaus voidaan jakaa kahteen päämenetelmään. Erilliskuormaukseen perustuvassa menetelmässä puutavaran kuormaus tehdään erillisellä koneella tai nosturilla. Selvästi yleisemmin käytetään autokohtaista puutavaranosturia, joka voidaan asentaa kiinteästi ajoneuvoon tai niin, että se voidaan irroittaa kuljetuksen ajaksi ja lisätä sillä tavoin autokuljetuksen hyötykuormaa. Autokohtaista puutavaranosturia käytettäessä kuljettaja sekä kuormaa puutavaran varastopaikalla että ajaa puutavara-autoa. Tämän tutkimuksen tavoitteena oli selvittää käytettyjen puutavara-autojen ja -nostureiden teknisten ominaisuuksien vaihtelua Euroopan eri osissa, sekä käyttöiän ja ajettujen kilometrien määrän vaikutusta myyntihintoihin. Aineistona olivat www.mascus.fi-vaihtokonesivustolta myynnissä olleet puutavara-autot ja puutavaranosturit. Myynti-ilmoitukset painottuivat puutavara-autojen osalta Suomeen, Ruotsiin, Saksaan ja Alankomaihin. Pääosa myytävänä olleista puutavara-autoista oli telivetoisia ja kolmiakselisia (6x4). Tutkimuksessa havaittiin puutavara-autojen hintapyyntöjen korreloivan vuosimallin suhteen selvästi enemmän kuin mittarilukeman suhteen. Puutavaranostureiden kohdalla suurin osa havainnoista tuli Suomesta, ja niiden osalta hintapyynnöt olivat selvästi riippuvaisia vuosimallista.201

Productivity of Cut-to-Length Harvesting by Operators’ Age and Experience

In the study, the relationship between operators’ age, experience and mechanized cut-to-length (CTL) harvesting productivity was examined. The data were five-year follow-up data from 28 operators and 38 CTL harvesters collected from southern Finland. Productivities were converted to relative productivities and average productivity models were created. Case specific productivities were compared to modelled values, and productivity ratio models including separate lower and upper quartile models were produced. The relative productivity of operators at the age of 45 years in clear cuttings was 17.8% higher and in thinnings 14.9% higher than that of operators at the age of 25 years. The relative lower quartile productivity increased from operators aged 25 to operators aged 45 years by 38.6% in clear cuttings and 29.4% in thinnings. The relative productivity of operators having experience of 20 years was 23.6% higher in clear cuttings and 16.2% higher in thinnings than that of operators having experience of 3 years. Operators’ experience of 20 years produced 43.1% better lower quartile relative productivity in clear cuttings and 29.1% in thinnings compared to 3 years’ experience. The relative upper quartile productivity was 5.7% higher in clear cuttings for operators aged 45 years than for operators aged 25 years, but otherwise, there was no statistical correlation between upper quartile productivity and age or experience. As a conclusion, CTL harvester operators’ average productivity increases slowly after the initial learning phase up to 15 years of experience. The peak productivity was uncorrelated to age or experience, but the experience raised the bottom productivity values

Application of Most Similar Neighbor Inference for Estimating Marked Stand Characteristics Using Harvester and Inventory Generated Stem Databases

The purpose of this study was to develop and test the application of non-parametric Most Similar Neighbor Inference (MSN) for wood procurement planning. An application developed using this method would be a part of a stem database in Finnish forest enterprises and could predict characteristics of a marked stand with accuracy demanded by bucking simulation. A stem database includes representative samples of stands and stems, applications to control and update data and applications to utilize the database. The study materials used consist of two different kinds of data: data collected by harvesters and historical forest inventory data. The harvester collected stem data came from stands in central Finland, whereas forest inventory data was obtained from all over Finland. The accuracy of the MSN method was analyzed by estimating characteristics of tree stocks and by comparing simulated spruce, pine and birch log length-diameter distributions with the information from actual stands. The application presented was found to be a useful and flexible tool for predicting characteristics of marked stands based on the stem data collected by a harvester. The forest inventory data was found less suitable for reference data. The most efficient way to create a length-diameter distribution was to calculate length-diameter class estimates from reference stands as weighted averages of the corresponding length-diameter class. The proposed method appears robust against measurement errors of search variables

Comparison of alternative roundwood pricing systems - a simulation approach

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Metsäkoneiden vuotuiset käyttötunnit ja vaihtokonemarkkinoiden rakenne Euroopassa

Metsäkoneteollisuus on voimakkaasti edustettuna Suomessa ja muissa Pohjoismaissa. Tavaralajimenetelmän koneiden valmistusmäärien uskotaan lisääntyvän tulevina vuosina, mikäli tavaralajimenetelmä yleistyy odotetulla tavalla. Näin ollen alalla on hyvä kasvupotentiaali. Käytettyjen koneiden markkinat ovat kokeneet merkittävän muutoksen internetmarkkina-alustojen myötä. Tämä on laajentanut käytettyjen tavaralajimenetelmän koneiden markkinoita myös maantieteellisesti katsottuna. Tässä työssä selvitettiin tavaralajimenetelmän metsäkoneiden vuotuiset käyttötuntimäärät Euroopassa. Lisäksi selvitettiin koneiden teknisten ominaisuuksien vaihtelu Euroopan eri osissa. Aineistona olivat 2014 syys- ja lokakuussa myynnissä olleet käytetyt tavaralajimenetelmän hakkuukoneet ja kuormatraktorit, jotka oli kerätty mascus.fi-vaihtokonesivustolta. Tulokset osoittavat hakkuukoneiden ja kuormatraktoreiden käyttötuntien ja teknisten ominaisuuksien vaihtelevan eri alueilla Euroopassa. Aineiston perusteella hakkuukoneille kertyy vuosittain keskimääriin 1791 tuntia ja kuormatraktoreille 2013 tuntia. Kokonaiskäyttötuntien ja koneen iän vaikutusta käytettyjen koneiden hintaan tarkasteltaessa selvisi, että hinnan lasku on voimakkainta uusimmissa koneissa. Käytettyjen koneiden kokoluokat vaihtelivat Euroopan alueilla. Molemmissa konetyypeissä yleisin kokoluokka oli ns. yleiskone kokoluokka. Hakkuukoneissa Saksassa ja Pohjois-Euroopassa käytetään keskimääräistä suurempia koneita ja vastaavasti Puolassa pienempiä koneita. Kuormatraktoreissa järeimpiä koneita käytetään Ruotsissa ja pieninpiä Puolassa.201

Workability and productivity among CTL machine operators - associations with sleep, fitness, and shift work

Operational performance of fully mechanized cut-to-length (CTL) harvesting varies greatly due to the human factor i.e. the machine operator. This study investigated how CTL machine operators' workability index (WAI), personal lifestyle choices, seasons, and shift work affected operational performance. Research evaluated 14 volunteer CTL machine operators for a longitudinal study with continuous data collection of productivity, activity level, sleep, and follow-up on a workability index questionnaire and fitness test every three months over a year. The study analyzed the production of 152 745.5 m(3) of timber combined with self-tracking data. Operators' relative productivity (P-r) had an increasing trend whilst WAI increased, thus WAI seems to work well also for forestry applications. Physical fitness (VO2max) didn't seem to connect with P-r and WAI had only a slightly increasing trend when VO2max increased. The participants slept longer in the evening shift than in the morning shift (p < 0.000) consequently catching up on their sleep deficit from the morning shift period. Furthermore, operators' higher sleep value (SV) in the evening shift increased P-r in the final fellings. The results should be of interest to both practitioners and researchers interested in the productivity of harvesting operations

Prospects and Challenges of Timber Trucking in a Changing Operational Environment in Finland

The objective was to study how entrepreneurs taking care of the transport of wood perceive the current challenges in the operating environment and reflect these challenges in the changing climate. The data was collected in spring 2012 by mail questionnaire, which was answered by a total of 86 entrepreneurs giving a response rate of 19.1%. According to the respondents, the most debilitating factors in the changing infrastructure in future will be the challenges of the low volume road network, especially winter maintenance including removing snow and ice and preventing slippery conditions. The entrepreneurs were concerned about labour costs caused by a possible shortage of skilled drivers. The main problem concerning Information and Communication Technology (ICT) in timber trucking logistics is the inability to use one ICT system for two or more clients, which leads to problems in handling multiple clients. Almost all respondents agreed that timber trucking enterprises are too dependent on clients’ ICT systems

Modeling Backhauling on Finnish Energy-Wood Network Using Minimizing of Empty Routes

This study introduces a support method to use in modeling backhauling. The method minimizes a truck's on-road driving while empty. The backhauling model is based on a commonly used timber transport allocation model. Here, this model is applied to a simulated energy-wood network. The resulting optimization provides two different delivery plans for two-way transportation: one with a constraint to minimize travel distances when empty and the other without this constraint. By applying the empty-route minimization method, the best return routes for trucks are determined beforehand with fewer alternatives then left to be solved by the backhauling model. The results prove that the method can be used to minimize empty-route driving, but further development of the empty-route minimization method is still needed before it can be used in combination with the optimization of backhauling. Therefore, the effects of empty-route minimization on the transportation distances with respect to stand and hauling alternatives are discussed. In addition, the possibility of increasing the profitability of transportation, through the use of the method to optimize energy-wood backhauling, is also discussed

Responses of food web to hypolimnetic aeration in Lake Vesijärvi

We studied the responses of a food web, especially fish and zooplankton, to summertime aeration, pumping of oxygen-rich epilimnetic water to the hypolimnion in Lake Vesijärvi, southern Finland. The aim of hypolimnetic aeration was to reduce internal loading of phosphorus from sediment. The population of smelt (Osmerus eperlanus L.), the main planktivore of the pelagial area, collapsed during the two 1st years of aeration due to increased temperature and low oxygen concentrations in the hypolimnion. The population recovered after the 4th year of hypolimnetic aeration, when oxygen conditions were improved. Despite elevated hypolimnetic temperature, smelt reached exceptionally high abundance, which led to a significant reduction in cladoceran body size. The density of perch (Perca fluviatilis L.) increased at first, but then decreased when the proportion of smelt and cyprinids increased. Biomasses of Daphnia decreased probably as a result of the disappearance of dark, low-oxygen deep-water refuge against fish predation and low availability of nutritionally high-quality algae. Occasionally filamentous cyanobacteria, such as turbulence tolerant Planktothrix agardhii (Gomont), were abundant, suggesting deteriorated food resources for zooplankton. The responses of food web were controversial with respect to the aim of the management, which was to prevent the occurrence of harmful algal blooms.Peer reviewe