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Chiorescu, Sorin
Publications (10 of 11) Show all publications
Chiorescu, S. & Grönlund, A. (2004). The fingerprint approach: using data generated by a 3D log scanner on debarked logs to accomplish traceability in the sawmill's log yard (ed.). Paper presented at . Forest products journal, 54(12), 269-276
Open this publication in new window or tab >>The fingerprint approach: using data generated by a 3D log scanner on debarked logs to accomplish traceability in the sawmill's log yard
2004 (English)In: Forest products journal, ISSN 0015-7473, Vol. 54, no 12, p. 269-276Article in journal (Refereed) Published
Abstract [en]

Technological advances in the area of optical scanning have made sophisticated equipment such as three-dimensional (3D) log scanners available to the sawmill industry. In a typical Swedish sawmill, the measurements obtained from the 3D log scanner placed at the log sorting station is used exclusively for scaling and sorting the sawlogs. In the same way, the information obtained from the 3D log scanner placed at the saw intake is used exclusively for optimal positioning of the sawlog into the headrig. Meanwhile, large knowledge gaps regarding the flow and the origin of the sawlogs persist in the sawmill's daily routine. For the Swedish sawmills performing presorting of sawlogs, the most critical information gap exists between the log sorting station and the saw intake, where the forest log batch identity disappears, and the logs are mixed according to various sorting criteria. This study attempts to use the data generated by 3D log scanners together with advanced recognition algorithms to develop a traceability system, marking/reading free, between the log sorting station and the saw intake when working with debarked logs. The originality of the fingerprint approach rests on the hypothesis that logs are separate entities with individual features. Measuring these features with the same type of measuring device at both the log sorting station and at the saw intake and then connecting the data to a common database will permit each individual sawlog to be tracked within the sawmill and will thus make it possible to develop an advanced raw material flow control.

National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-3716 (URN)18b8de50-bb53-11db-b560-000ea68e967b (Local ID)18b8de50-bb53-11db-b560-000ea68e967b (Archive number)18b8de50-bb53-11db-b560-000ea68e967b (OAI)
Note
Validerad; 2004; 20061017 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Chiorescu, S. & Grönlund, A. (2004). The fingerprint method: using over-bark and under-bark log measurement data generated by three-dimensional log scanners in combination with radiofrequency identification tags to achieve traceability in the log yard at the sawmill (ed.). Paper presented at . Scandinavian Journal of Forest Research, 19(4), 374-383
Open this publication in new window or tab >>The fingerprint method: using over-bark and under-bark log measurement data generated by three-dimensional log scanners in combination with radiofrequency identification tags to achieve traceability in the log yard at the sawmill
2004 (English)In: Scandinavian Journal of Forest Research, ISSN 0282-7581, E-ISSN 1651-1891, Vol. 19, no 4, p. 374-383Article in journal (Refereed) Published
Abstract [en]

In the forestry-wood chain the concept and the technologies of traceability are in a mature development phase. Important advances in marking and reading techniques have been made in different parts along the forestry-wood chain. For Swedish sawmills the most critical information gap is located between the log sorting station and the saw intake, where the forest log batch identity disappears and the logs are mixed according to different sorting criteria. This study utilizes radiofrequency identification tags for automatic log marking/reading to develop a traceability system for logs, which is free of marking/reading, between the log sorting station and the saw intake, i.e. the fingerprint method. The originality of the fingerprint approach rests on the hypothesis that logs are separate entities with individual features. The results show that the log parameters and the search algorithm developed, combined with the negative influence of the measurement uncertainty due to bark thickness and bark damage, made it possible to achieve an individual separation for 57% of the tested logs.

National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-4672 (URN)10.1080/02827580410030118 (DOI)000223135100009 ()2-s2.0-4344660649 (Scopus ID)2a6df310-bb53-11db-b560-000ea68e967b (Local ID)2a6df310-bb53-11db-b560-000ea68e967b (Archive number)2a6df310-bb53-11db-b560-000ea68e967b (OAI)
Note
Validerad; 2004; 20061025 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Chiorescu, S., Berg, P. & Grönlund, A. (2003). The fingerprint approach: using data generated by a 2-axis log scanner to accomplish traceability in the sawmill's log yard (ed.). Paper presented at . Forest products journal, 53(2), 78-86
Open this publication in new window or tab >>The fingerprint approach: using data generated by a 2-axis log scanner to accomplish traceability in the sawmill's log yard
2003 (English)In: Forest products journal, ISSN 0015-7473, Vol. 53, no 2, p. 78-86Article in journal (Refereed) Published
Abstract [en]

Today the sawmill industry is in possession of sophisticated measuring devices for sawlogs. This equipment is employed in practice for measuring log dimensions, and the data gathered are used for sorting out sawlogs according to different criteria or for judging potential quality for future end-uses. However, a lot of these data are not fully utilized. Meanwhile, large knowledge gaps regarding the flow and the origin of the wood material persist in the sawmill's daily routine. For sawmills performing presorting of sawlogs, the most significant information gap is located between the log sorting station and the saw intake where the log batch identity disappears and the logs are mixed according to different sorting criteria. This study attempts to use the data generated by 2-axis log scanners to develop a traceability system, the fingerprint approach (a marking/reading free system), between the log sorting station and the saw intake. The originality of the fingerprint approach is based on the biological variability of the wood material; the assumption is that each sawlog is a unique individual with unique features. Measuring these features at the log sorting station and at the saw intake and then connecting them to a common database will in fact permit each individual sawlog to be followed within the sawmill and thus enable the development of an advanced raw material flow control. The results of this work entirely indicate the promising potential of the fingerprint approach, which is based on the hypothesis that logs are separate entities with individual features. Being able to separate logs at the individual level is essentially a question of taking advantage of the right log features, measuring them with high accuracy, and employing appropriate search/recognition algorithms. The log parameters and the measurement accuracy generated by the 2-axis log scanner used in this study were not enough to accomplish individual separation for more than 34 percent of the logs. An improvement of measurement accuracy by 30 percent would allow 50 percent of the logs to be individually separated.

National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-4207 (URN)21eb25a0-bb53-11db-b560-000ea68e967b (Local ID)21eb25a0-bb53-11db-b560-000ea68e967b (Archive number)21eb25a0-bb53-11db-b560-000ea68e967b (OAI)
Note
Validerad; 2003; 20061017 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Chiorescu, S. (2003). The forestry-wood chain: simulation technique, measurement accuracy, traceability concept (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>The forestry-wood chain: simulation technique, measurement accuracy, traceability concept
2003 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A customer-oriented production philosophy, an integrated forestry-wood chain and the global vision of Precision Forestry are concepts that researchers and people involved in the forest and wood industry have to deal with in the beginning of this new millennium. Fulfilling the specific requirements for dimension, length, biological features and proof-of-origin that customers demand for the wood products entails the existence of advanced methods and tools for understanding and thus controlling the production process along the forestry-wood value chain. The two overall objectives of this thesis were a) to study the prerequisites of using the simulation technique together with advanced simulation tools in understanding the role of the measurement accuracy at different locations within the forestry-wood production chain and b) to study the prerequisites of developing a marking/reading free traceability system for sawlogs based on log measurement data as generated today at the sawmill site.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2003. p. 46
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544 ; 2003:03
National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-17605 (URN)4425aeb0-7026-11db-962b-000ea68e967b (Local ID)4425aeb0-7026-11db-962b-000ea68e967b (Archive number)4425aeb0-7026-11db-962b-000ea68e967b (OAI)
Note
Godkänd; 2003; 20061109 (haneit)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Chiorescu, S. & Grönlund, A. (2003). The visual grading system for Scots pine logs in relation to the quality of sideboards produced (ed.). Paper presented at . Forest products journal, 43(1), 53-60
Open this publication in new window or tab >>The visual grading system for Scots pine logs in relation to the quality of sideboards produced
2003 (English)In: Forest products journal, ISSN 0015-7473, Vol. 43, no 1, p. 53-60Article in journal (Refereed) Published
Abstract [en]

Presorting logs in the sawmill's log yard is one of the strategies used by the Swedish sawmilling industry in order to maximize profits. Almost 96 percent of Swedish sawmills perform the presorting of logs according to their dimension, most commonly by the top diameter. Only a very small number of sawmills use log grade information as a sorting criterion. However, the grade information at individual log level, together with the estimated volume, is always used for the calculation of log payment. The quality assessment of the log is done on a visual basis, i.e., the measurer grades the log on what he/she sees on the outside of the log. This judging should correspond to the expected quality of the Centerboards produced after sawing. Current studies have only related the centerboards' quality to the log quality grade arrived at by visual inspection. In view of the economic importance of the sideboards in the lumber yield and in the entire functioning of a sawmill, a real need for information on the recovery of sideboards in relation to log and centerboard quality is now arising and becoming a key issue. In this study, with the help of the entire Swedish Pine Stem Bank material, the relationship between the sideboard's quality and the log's quality and the relationship between the quality of sideboards and of centerboards were studied. Results show that sideboard quality cannot be predicted from the visual quality assessment of the logs. Nevertheless, fairly good correlation exists between sideboard quality and the quality of the corresponding centerboards. A financial analysis focusing on the relationship between the commercial values of the sawlogs and the corresponding lumber output for the Swedish Pine Stem Bank material is also included in this study. The study shows that the actual Swedish log pricing system should be improved because the commercial values of the logs are not in accord with the real values of the lumber produced.

National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-6257 (URN)47593570-bb53-11db-b560-000ea68e967b (Local ID)47593570-bb53-11db-b560-000ea68e967b (Archive number)47593570-bb53-11db-b560-000ea68e967b (OAI)
Note
Validerad; 2003; 20061025 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Chiorescu, S. & Grönlund, A. (2001). Assessing the role of the harvester within the forestry-wood chain (ed.). Paper presented at . Forest products journal, 51(2), 77-84
Open this publication in new window or tab >>Assessing the role of the harvester within the forestry-wood chain
2001 (English)In: Forest products journal, ISSN 0015-7473, Vol. 51, no 2, p. 77-84Article in journal (Refereed) Published
Abstract [en]

In recent years, a lot of effort has been devoted to implementing the concept of an integrated forestry-wood chain. Good management of such a complex system requires a clear understanding of the effects that different factors involved may have on the final output of the chain. Raw material databases and simulation software capable of spanning the wood-processing operations have now been developed and are being used as a support tool in understanding and optimizing the forestry-wood chain. This paper reports results of simulation tests using the virtual SawMill software and the Swedish Pine Stem Bank database. The simulated scenario tries to mirror a very customer-oriented production philosophy. The bucking, the sawing, the crosscutting, and the board-grading procedures were simulated for different end-user requirements and a statistical model was built. The purpose of the model was to investigate the theoretical sensitivity of the final product to parameters such as external sawlog features (taper, ovality, bow), harvester measurement accuracy (for length and diameter), sawing pattern optimization, and log positioning in the saw line. Special emphasis was put on evaluating the role of the harvester within this "puzzle." The results show that small improvements of the harvester's measuring performance could lead to considerable improvements in the wood transformation chain.

National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-7646 (URN)60ca34b0-b37d-11db-bf94-000ea68e967b (Local ID)60ca34b0-b37d-11db-bf94-000ea68e967b (Archive number)60ca34b0-b37d-11db-bf94-000ea68e967b (OAI)
Note
Validerad; 2001; 20061026 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Nordmark, U. & Chiorescu, S. (2001). Satisfying Consumer Demand: A Comprehensive View of Sawmill Economy Using Simulation Techniques (ed.). In: (Ed.), Ryzard Szymani (Ed.), Proceedings / SawTech 2001, the Seventh International Conference on Sawing Technology : November 8 - 9, 2001, Holiday Inn, Seattle International Airport, Seattle, Washington, USA: . Paper presented at International Conference on Sawing Technology : 07/11/2001 - 09/11/2001. : Wood machining institute
Open this publication in new window or tab >>Satisfying Consumer Demand: A Comprehensive View of Sawmill Economy Using Simulation Techniques
2001 (English)In: Proceedings / SawTech 2001, the Seventh International Conference on Sawing Technology : November 8 - 9, 2001, Holiday Inn, Seattle International Airport, Seattle, Washington, USA / [ed] Ryzard Szymani, Wood machining institute , 2001Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Wood machining institute, 2001
National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-34480 (URN)8b1944a0-9697-11dd-aadc-000ea68e967b (Local ID)8b1944a0-9697-11dd-aadc-000ea68e967b (Archive number)8b1944a0-9697-11dd-aadc-000ea68e967b (OAI)
Conference
International Conference on Sawing Technology : 07/11/2001 - 09/11/2001
Note
Godkänd; 2001; 20081010 (cira)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Chiorescu, S. & Grundberg, S. (2001). The influence of missing bark on measurements performed with a 3D log scanner (ed.). Paper presented at . Forest products journal, 51(8), 78-86
Open this publication in new window or tab >>The influence of missing bark on measurements performed with a 3D log scanner
2001 (English)In: Forest products journal, ISSN 0015-7473, Vol. 51, no 8, p. 78-86Article in journal (Refereed) Published
Abstract [en]

Nowadays the sawmill industry is in possession of sophisticated measurement equipment, which is the key to the successful running of the wood transformation process. New technologies such as three-dimensional (3D) scanners are becoming more and more common in Swedish sawmills. These scanners are used for sorting sawlogs according to different criteria such as diameter, length, or quality. They also perform the automatic scaling of the sawlogs that is the basis for estimating volume. Both scaling and sorting are done on bark, i.e., before debarking the logs. Specific functions for the double bark thickness are used to estimate the diameter under bark of the logs. However, these functions do not take into account the eventual missing/damaged bark from the surface of the logs. The errors caused by this lack of precision negatively affect the quality of both scaling and sorting procedures. In this study, with the aid of a simulation technique and field tests, questions regarding the size of these errors and how missing bark affects the measurement procedure when using a 3D log scanner are tackled. Finally, a new system for bark deduction is proposed, implemented, and evaluated in a Swedish sawmill. The results show that paying more attention to missing bark when scaling and sorting sawlogs can considerably increase the accuracy of these operations, thus leading to improvements in the forestry-wood chain.

National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-5253 (URN)34f82940-bb53-11db-b560-000ea68e967b (Local ID)34f82940-bb53-11db-b560-000ea68e967b (Archive number)34f82940-bb53-11db-b560-000ea68e967b (OAI)
Note
Validerad; 2001; 20061025 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Chiorescu, S. (2000). Measurement accuracy in the forestry-wood chain (ed.). (Licentiate dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Measurement accuracy in the forestry-wood chain
2000 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

A customer-oriented production philosophy and an integrated forestry-wood chain are concepts that researchers and people involved in the forest industry have to deal with in the beginning of this new millennium. Fulfilling the specific requirements for dimension, length or biological features that customers demand for the wood products entails the existence of accurate measurement equipment at each location along the conversion chain. The overall objective of this thesis was to assess the role of measurement accuracy within the production chain. This work focuses on the accuracy of the measurement procedure performed at two key locations in the chain: the bucking operation performed by the harvester in the forest and the scaling-sorting operation performed by the optical scanner at the sawmill's log sorting station. A simulation technique based on the Swedish Pine Stem Bank (SPSB) data and the virtual SawMill (vSM) software, along with field tests and ample sawmill statistics acquired through the Timber Data System (TDS), was employed in this thesis. Simple regression and multivariate statistical technique were used as modeling tools. The overall conclusion of this thesis is that measurement accuracy plays a significant role in the efficiency of the wood conversion chain. Understanding where the biggest problems are located and thereby where development efforts should be concentrated in the future is a step that has to be continually undertaken in further research studies. This might be quite laborious to achieve practically, but is relatively easy with the help of the simulation technique. The Stem Bank data and the vSM are very efficient tools with great potential for simulation and analysis of the measurement accuracy in the forestry-wood chain.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2000. p. 6
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757 ; 2000:29
National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-25770 (URN)b0e2f2e0-d568-11db-8550-000ea68e967b (Local ID)b0e2f2e0-d568-11db-8550-000ea68e967b (Archive number)b0e2f2e0-d568-11db-8550-000ea68e967b (OAI)
Note
Godkänd; 2000; 20070318 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-24Bibliographically approved
Chiorescu, S. & Grönlund, A. (2000). Validation of a CT-based simulator against a sawmill yield (ed.). Paper presented at . Forest products journal, 50(6), 69-76
Open this publication in new window or tab >>Validation of a CT-based simulator against a sawmill yield
2000 (English)In: Forest products journal, ISSN 0015-7473, Vol. 50, no 6, p. 69-76Article in journal (Refereed) Published
Abstract [en]

Over the past decade, the sawmill sector has made significant advancements in developing methods for measuring inner properties of sawlogs. Noninvasive scanning, e.g., x-ray scanning, has proven to have good prospects for on-line implementation in sawmills. When the internal scanning technique does come on-line in sawmills, software able to utilize the scanned information becomes a useful tool to control the sawing process. Thus, the validation of such a computed tomography (CT)-based software against sawmill cutting becomes an important step in the development of the whole scanning approach. This paper presents the results of an effort to simulate the 1-year lumber production of a medium-sized Swedish sawmill with the aid of a CT-based simulator, the virtual SawMill (vSM). This saw simulation program is able to utilize the parametrical description of the logs achieved from x-ray CT-scanning. When performing the simulation, the vSM used 625 Scots pine (Pinus sylvestris L.) logs from the Swedish Stem Bank as raw material supply for the sawing process. The simulated sawing process was adjusted to keep, as much as possible, the same attributes as the sawing process from the sawmill. The output data collected from the sawmill was compared with the simulated one with respect to the quality and the length distribution of the yielded boards. The results showed good agreement between the real and the simulated cutting for both quality and length criteria. This study suggests that the Swedish Stem Bank along with the vSM software could be used as an efficient tool in further research and strategic production planning.

National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
urn:nbn:se:ltu:diva-3788 (URN)19ec0130-b37e-11db-bf94-000ea68e967b (Local ID)19ec0130-b37e-11db-bf94-000ea68e967b (Archive number)19ec0130-b37e-11db-bf94-000ea68e967b (OAI)
Note
Validerad; 2000; 20061025 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved

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