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The role of digital technologies for fostering sustainability and efficiency in forest-based supply chains is well acknowledged and motivated several studies in the scope of precision forestry. Sensor technologies can collect relevant data in forest-based supply chains, comprising all activities from within forests and the production of the woody raw material to its transformation into marketable forest-based products. Advanced planning systems can help to support decisions of the various entities in the supply chain, e.g., forest owners, harvest companies, haulage companies, and forest product processing industry. Such tools can help to deal with the complex interdependencies between different entities, often with opposing objectives and actions—which may increase efficiency of forest-based supply chains. This paper analyzes contemporary literature dealing with digital technologies in forest-based supply chains and summarizes the state-of-the-art digital technologies for real-time data collection on forests, product flows, and forest operations, as well as planning systems and other decision support systems in use by supply chain actors. Higher sustainability and efficiency of forest-based supply chains require a seamless information flow to foster integrated planning of the activities over the supply chain—thereby facilitating seamless data exchange between the supply chain entities and foster new forms of collaboration. Therefore, this paper deals with data exchange and multi-entity collaboration aspects in combination with interoperability challenges related with the integration among multiple process data collection tools and advanced planning systems. Finally, this interdisciplinary review leads to the discussion of relevant guidelines that can guide future research and integration projects in this domain.

A simple approach to develop a novel photosensitive radio-frequency (RF) tag to be used as non-volatile wireless light exposure detector is presented. This chipless tag is based on the coupling of a standard high frequency (HF) inductor–capacitor (LC) resonator with an interdigitated planar sensor featuring a micrometric inter-electrode gap optimized for a thin acrylamide photosensitive polymer layer. Exposure to ambient light within the absorbance band of the photosensitizer (∼530 nm) triggers polymerization, which irreversibly modifies the electrical properties of the film, producing a significant decrease of the dielectric constant of 27%, thereby changing the resonance frequency (540 kHz shift) of the resonator. This allows the straightforward wireless detection of the light exposure event as demonstrated here. The sensor fabrication is fully compatible with high-throughput printing processes, therefore fostering a dramatic reduction of tag production costs and enabling mass application of disposable tags that can, for instance, be embedded into the packaging of light-sensitive goods.

This paper presents the development of passive high frequency (HF) and ultrahigh frequency (UHF) radio frequency identification (RFID) sensor transponders for humidity and temperature monitoring. The transponders use RFID integrated circuits with a digital interface for communicating with a ultralow-power microprocessor. The microprocessor handles the measurement, either by charging sensor and reference capacitors, or by commanding a digital sensor. The read ranges of the sensor nodes are 5 cm and up to 40 cm at HF and UHF, respectively. The sensor nodes are demonstrated in concrete casts, where the HF node provides better than 5%RH-repeatability of the moisture measurements from sensor node to another. At UHF the repeatability is about 15%RH.

A cryogenic dual compensated calorimeter was constructed for energy loss measurements in superconducting materials. The losses induced by slowly varying periodic magnetic fields (amplitudes

This paper describes a prototype of a UHF RFID based log marking and tracking system developed for the challenging four-season outdoor conditions in Scandinavia. The RFID system comprises of novel pulping compatible EPC Class 1 Generation 2 transponders, and of robust readers with novel performance boosting features. A wedge-shaped transponder is inserted into the log end with a special tool so that it is protected and held firmly in place by wood during the transportation and processing of timber. A robust EPC-compliant RFID reader featuring an adaptive RF front end was developed for use in a harvesting machine. Readability tests at saw mills with test logs using specially adapted commercial UHF readers show nearly a 100% readability for the transponders inside fresh moist logs. (14 refs.)

RFID has been identified as one of the cornerstones of the upcoming Internet of Things (IoT) and the focus is moving from conventional RFID towards next generation pervasive networked and interconnected systems. In the future IoT billions of objects are envisioned to report their identity, location, environmental conditions and history over wireless connections. An on-going effort that will support this gradual change is the development of "smart RFID tags", tags that are able to sense, monitor, and adapt to their changing environment. RFID systems alone provide item and product visibility within the supply chain. This visibility can further be translated into actionable data and predictive changes with additional information attained through sensing capabilities. Intelligent RFID tags can combine sensing, computation and communication into a single, small device. The need for new sensing solutions is highlighted further by the fact that legislation, regulatory and quality demands are setting requirements for certain branches (pharmaceuticals, explosives, transportation of dangerous goods, foods, etc). Cold chain compliance is a key requirement for pharmaceuticals, hospital transfusions, clinical trials, foods and perishable items. RFID can be used to fight counterfeiting and RFID can provide the electrical pedigree of a product. Most efforts on RFID tag design so far have been concentrated on the ultra low price tag segment. This has led to compromised performance when label tags have been applied in “unsuitable” environments and has been evidenced as low reading accuracy in many RFID pilots. In order to reach a high reading accuracy and reliable long distance operation, RFID tags ought to be immune or adapt to their environment (e.g. presence of metals, liquids, gas...) to avoid detuning and other impairing effect caused by their surroundings. New solutions to implement platform insensitive/platform tolerant and platform adaptive RFID tags are emerging.

We are constructing a cryogenic dual compensated calorimeter for loss measurements in superconducting materials. We plan to measure the losses due to the incomplete Meissner effect in slowly varying small magnetic fields appropriate for levitation. These measurements bear importance for the realization of the kilogram using the superconducting magnetic levitation method.

A wideband adaptive isolator for a UHF RFID reader with a minimum component count is introduced. The operation of the device is based on a reflection from a variable load, which is connected to a port of a hybrid coupler. The other ports are connected to the receiver (RX), transmitter (TX) and antenna ports of the reader. The isolator provides an isolation of 50 dB from TX to RX at the 800 MHz-1 GHz band, covering the worldwide UHF RFID bands. The adaptive system ensures high isolation up to an antenna return loss of 6 dB, or reflection coefficient of 0.5. The measured loss in the TX-to-antenna and antenna-to-RX paths is 4 dB.