Differences in volume of round timber caused by different determination methods

Različite metode mjerenja i izračunavanja obujma trupaca u šumi nakon rušenja (“ručno mjerenje”) i na stovarištima pilana (“elektroničko mjerenje”) daju različite vrijednosti. Tema ovog rada jest kvantifikacija razlika prouzročena brojem i smjerom skeniranja, zaokruživanjem dobivenih vrijednosti i izračunavanjem obujma. Glavni rezultati mjerenja dobiveni u stvarnim pilanskim uvjetima jesu: skeniranje u jednom smjeru može se provoditi za orijentaciju ili grubo mjerenje, a ne za točno mjerenje oblovine (nužna su najmanje dva unakrsna smjera skeniranja); zaokruživanje (ne odsijecanje) općenito vrlo malo utječe na razlike u vrijednostima obujma; izračunavanje obujma po sekcijama rezultira većom vrijednošću obujma u usporedbi sa standardnom Huberovom metodom izračunavanja prema srednjem promjeru trupca.Different methods of measuring and calculating the volume of logs in the forest after felling (“hand measuring”) and in log yards of sawmills (“electronic measuring”) give different results – volume of logs. The subject of this paper is the quantification of differences caused by the number and direction of scanning, by rounding and by volume calculation. The main results of measuring carried out under the actual sawmill conditions are as follows: single direction scanning is used for orientation or rough measuring, and not for exact measuring of round timber (at least two perpendicular directions are necessary), rounding (no cutting) has a very low influence (generally, not by single pieces), calculation of volume by sections results in a higher volume level when compared to the standard Huber’s method of calculation based on mid diameter

Razlike u mjerenju oblog drva elektroničkim 2D i 3D sustavima i standardnom ručnom metodom

This paper describes the use of electronic scanning systems for round wood in the Czech Republic. It analyses the two most widespread systems (2D and 3D), compares the values of diameters and volumes measured by these systems with the results of measurements using the Huber method and evaluates differences. The volume of the logs determined by the 2D system was 0.4 – 0.5% higher than the volume determined by manual comparative measurement. The deviation is in the range of possible measuring accuracy. The log volume determined by the 3D system was 2.5 – 5.5% lower than by careful manual measurement. The log volumes stated in the delivery bills are very rough and they cannot be used to assess the accuracy of electronic measurement systems. The study briefly outlines the present state and trends of the electronic reception of logs in the Czech Republic.U radu se opisuje uporaba elektroničkih sustava za mjerenje oblog drva u Republici Češkoj. Analiziraju se dva najčešće rabljena sustava za mjerenje (2D i 3D), uspoređuju se vrijednosti promjera i obujma mjerene tim sustavima s rezultatima mjerenja standardnom Huberovom metodom te se određuju razlike. Obujam oblog drva dobiven mjerenjem elektroničkim sustavom 2D bio je za 0,4 – 0,5 % veći od obujma dobivenog usporednim mjerenjem ručnom metodom. Razlike su u rasponu realno mogućih pogrešaka pri mjerenju. Obujam oblog drva dobiven mjerenjem elektroničkim sustavom 3D bio je za 2,5 – 5,5% manji od rezultata dobivenih pažljivim ručnim mjerenjem. Podaci za obujam trupaca koji se nalaze na dostavnicama samo su približni podaci i ne mogu se koristiti za ocjenu točnosti elektroničkog mjerenja. Autor u radu iznosi i podatke o sadašnjem stanju te o trendovima uporabe elektroničkog mjerenja oblog drva u Republici Češkoj

Metode filtriranja podataka elektroničkog mjerenja dimenzija trupaca

The article deals with the processing of log dimension data collected by electronic measurement during reception at sawmills. The subject of the work concerns the fi ltration of data before their use for calculation. Filtration methods were designed based on simple mathematical and statistical methods, and compared and evaluated with the use of a designed comparative methodology. As a result, five filtration methods were selected that best suit the reception requirements. At the same time, the impact of filtration on the measurement results is evaluated in relation to the calculation method of wood volume. Furthermore, the calculation by sections is recommended, as it is less affected by filtration errors.Članak se bavi obradom podataka dobivenih elektroničkim mjerenjem dimenzija trupaca pri ulasku u pilanu. Posebna se pozornost pridaje filtriranju podataka prije upotrebe za izračun. Metode filtriranja dizajnirane su na osnovi jednostavnih matematičkih i statističkih metoda te uspoređene i vrednovane primjenom dizajnirane komparativne metodologije. Rezultat rada je pet odabranih metoda filtriranja podataka koje najbolje odgovaraju zahtjevima preuzimanja trupaca. Također, procijenjen je utjecaj metode filtriranja podataka na metodu proračuna obujma trupaca. Osim toga, preporučena je metoda za izračun obujma trupaca na koju najmanje utječu pogreške pri filtriranju podataka

Utjecaj veličine nadmjere na isporuku trupaca

This paper deals with differences between the declared and actually supplied volume of round wood, which can be seen in the sawmill log yards in taking log deliveries. These differences usually mean the losses for the suppliers. Authors focus on the length accuracy of supplied logs. They start with a comprehensive manual checking of log deliveries (2639 logs) and with calibration of electronic measuring equipment (238 logs) made by an accredited laboratory. Authors analyse the origins of the differences, they quantify the volume “voluntarily” given by the suppliers in the form of oversized allowances and the volume of the losses caused by classifying the logs to a lower length group if the necessary allowance lengths are not observed (the volume is counted using e.g. 1 m shorter nominal length). The term “extra allowance” is introduced for allowances longer than wanted, and the dependences among the length of extra allowances, log diameter, volume of extra allowances and number of logs with too short allowance are defined. Losses caused by both of these defects (over- or under-sized logs) are counted and compared. If the log length value is exactly the required one or close to it (it means nominal length and required allowance), the measuring equipment can still measure a lower value because of the required precision of 1 %. Losses are also caused by reclassifying the logs to a lower group. Suppliers cut the logs longer (make “extra allowances”) to ensure that the volume calculation is based on the right nominal length and not shorter. The research shows big differences between particular suppliers and their losses caused by extra allowances or reclassification of logs. The authors searched the optimum allowance in order to minimise the losses of the supplier. The results of the analysis give the following recommendations: for suppliers who do not use harvesters for felling and logging, it would be preferable to supply round timber in tree lengths due to the volume lost by reclassification. Today, however, this is not possible in most cases because large customers buy only logs because of technological reasons. Another aspect is the price, which is usually higher for raw material in logs. In the production of logs, it is preferable to increase the required 2 % allowance by 4-5 cm, if it is possible to produce the logs relatively accurately. If accuracy cannot be maintained, it is preferable to increase the allowance to about 7 cm (e.g. mountainous terrain, poor quality and curved timber, lack of experienced staff).Tema rada su razlike između prijavljene i stvarno isporučene količine trupaca koje se događaju na stovarištima tijekom isporuke trupaca. Te razlike obično znače gubitke za dobavljače. Autori iznose svoja promišljanja o točnosti dužine isporučenih trupaca. Polazišta analize su rezultati ručnog mjerenja dimenzija velikog broja isporučenih trupaca (2639 komada) i rezultati dobiveni mjerenjima pri kalibraciji elektroničke mjerne opreme (rezultati mjerenja 238 trupaca) koju je obavio akreditirani laboratorij. Autori analiziraju izvor razlika, kvantificiraju volumen koji dobavljači „dobrovoljno“ daju kao prevelike nadmjere te volumen gubitaka uzrokovanih razvrstavanjem trupaca u skupine manje dužine u slučajevima nedovoljno velikih nadmjera dužine trupaca (npr. volumen se izračunava uz pomoć metar kraće nominalne dužine). Uveden je pojam „ekstranadmjere“ za nadmjere veće od potrebnih, definirane su relacije između veličine ekstranadmjere, promjera trupaca, volumena ekstranadmjere i broja trupaca s premalom nadmjerom dužine. Izračunani su i uspoređeni gubitci uzrokovani navedenim greškama u dimenzijama isporučenih trupaca (trupci prevelike ili premale dužine). Ako je dužina trupaca jednaka zahtijevanoj ili je blizu njezine vrijednosti (zahtijevana je dužina zbroj nominalne dužine i potrebne nadmjere), mjernom se opremom zbog tražene preciznosti od 1 % ipak može izmjeriti manja dužina. Gubitci nastaju i zbog svrstavanja trupaca u skupinu manje dužine. Dobavljači režu trupce na veću dužinu (daju ekstranadmjere) kako bi osigurali da se volumen isporučenih trupaca računa sa stvarnom nominalnom dužinom, a ne s kraćom. Istraživanje je pokazalo da postoji velika razlika između pojedinih dobavljača i njihovih gubitaka koji su posljedica ekstranadmjera ili skraćivanja trupaca zbog nedovoljne nadmjere na duljinu trupaca. Autori su tražili optimalnu veličinu nadmjere dužine trupaca kako bi se umanjili gubitci dobavljača. Na temelju rezultata analize dane su ove preporuke: za dobavljače koji se ne koriste harvesterima za sječu, poželjna je isporuka oblovine u dužini stabla zbog gubitka volumena uzrokovanih reklasifikacijom. Međutim, danas to najčešće nije moguće jer veliki kupci kupuju trupce samo zbog tehnoloških razloga. Drugi je aspekt cijena, koja je obično veća za trupce kao sirovinu. Pri izradi trupaca poželjno je povećati nadmjeru na dužinu od 2 %, što je otprilike 4-5 cm, ako je trupce moguće relativno precizno izraditi. Ako se ne može postići točnost izrade trupaca, nadmjeru je poželjno povećati na 7 cm (npr. zbog planinskog terena, nekvalitetne i zakrivljene oblovine, nedostatka iskusnog osoblja)

Harmonization of excise duties in the European Union

The aim of this work is to evaluate the results of harmonization of excise duties in the European Union based on comparison of excise duty rates in selected member states. An analysis of the fiscal benefit of excise taxes for the state budgets of the Czech and Slovak Republics and an outlook for the development of excise duties in the next years is done, as well. The theoretical part of the thesis contains the historical development of excise taxes, their brief characteristics and the progress of harmonization of excise taxes in the countries of the European Union. The following is a practical part which focuses on the harmonization process in the field of excise duties in the European Union. Based on the comparison of excise taxes in selected EU countries, the success of the harmonization process is assessed. The conclusion of the practical part is devoted to the fiscal contribution of excise taxes to the state budgets of the Czech and Slovak Republics. On the basis of this assessment, the company's own forecast of the level of excise tax revenues in the coming years is made.Cílem této práce je provést hodnocení výsledků harmonizace spotřebních daní v Evropské unii na základě provedené komparace výše spotřební daně ve vybraných členských státech. Zároveň je proveden rozbor fiskálního přínosu spotřebních daní pro státní rozpočty České a Slovenské republiky a predikce vývoje v oblasti spotřebních daní v dalších letech. Teoretická část práce obsahuje historický vývoj spotřebních daní, jejich stručnou charakteristiku a průběh harmonizace spotřebních daní v zemích Evropské unie. Následuje praktická část, která je zaměřena na harmonizační proces v oblasti spotřebních daní v Evropské unii. Na základě komparace výše spotřebních daní ve vybraných státech Evropské unie je provedeno zhodnocení úspěšnosti harmonizačního procesu. Závěr praktické části je věnován fiskálnímu přínosu spotřebních daní pro státní rozpočty České a Slovenské republiky. Na základě tohoto hodnocení je provedena vlastní predikce vývoje v oblasti výše příjmů ze spotřebních daní v dalších letech