SNR-based evaluation of coexistence in wireless system of hospital

Abstract. The wireless system (IEEE Std. 802.11) of North Karelian Central Hospital (NKCH) has been studied in the newly opened J2 building of the hospital. The measurements have been carried out using Ekahau Sidekick spectrum analyser and Ekahau Pro software. Signal propagation has been modelled in the control ward of the Emergency department because many coexisting systems are used with critical requirements of data communication over there. The analytical models have been developed to understand the radio-frequency (RF) signal propagation in the entire building. Measurements have also been carried out on the entire first floor, in the Department of the Abdominal Diseases on the ground floor and in the Children’s wards on the third floor. The multi-slope path-loss propagation models with shadowing have been generated based on the Received Signal Strength Indicator (RSSI) measurements for typical hospital environment at the 2.4 GHz and 5 GHz Industrial, Scientific, and Medical (ISM) band. The measurements have been carried out within the two predefined routes. The models have also been compared to the empirically derived path-loss models. The probability of signal outage has been calculated for both measured routes. The aggregate interference has been measured within the routes that cover the area where remarkable signal variations and the high level of interference has been indicated based on the heatmaps of Ekahau. The use of Ekahau Sidekick and Ekahau Pro software in the coexistence study has been described. The noise floor has been determined based on the averaged values of the six measurement campaigns. The local changes in signal strength of the desired signal and aggregated power of interference have been studied. The Signal-to-Interference Ratio (SIR) models have been generated within the measured routes. The rapid decreases of Signal-to-Noise Ratio (SNR) have been indicated on all measured floors of building J2. They have been studied and their effect on the network performance has been evaluated. The evaluation has been done by comparing the measured values of RSSI, SNR and SIR to the requirements of the respective Modulation and Coding Scheme (MCS). The link margins have been calculated based on the chosen bit error probability and the given SNR requirement of the respective MCS. The comparison between the measured RSSI readings and the required threshold of the respective MCS has been done using the defined shadowing as a link margin. It has been shown that the measured difference between the signal strength of the 2.4 GHz and 5 GHz bands has been caused by the reduced transmit power at the 2.4 GHz band. Based on the SIR measurements, it has been shown that the access points of the neighbouring building have contributed locally to the measured aggregate interference in the Control ward. However, the primary reason for the decrease of SIR at the 2.4 GHz band has been the decrease of desired signal power that has been contributed by the above mentioned reduced transmit power. The strong SNR drops have been indicated on every measured floor before the roaming has occurred.Sairaalan langattoman järjestelmän arviointi signaali-kohina-suhteen avulla. Tiivistelmä. Tässä diplomityössä on tutkittu Pohjois-Karjalan keskussairaalan (PKKS) langatonta verkkoa (IEEE Std. 802.11) äskettäin avatussa sairaalan laajennusosassa (J2-rakennus). Mittaukset on toteutettu käyttäen Ekahau Sidekick spektrianalysaattoria ja Ekahau Pro -ohjelmaa. Päivystyksen valvontaosasto on valittu tutkimuskohteeksi, koska siellä käytetään paljon eri teknologioihin perustuvia järjestelmiä, joiden välinen tiedonsiirto on luonteeltaan kriittistä. Luotujen mallien avulla rakennuksen langatonta toimintaympäristöä tutkitaan RF-järjestelmän (Radio-Frequency) näkökulmasta myös muissa mittausten kohteina olleissa tiloissa. Mittauksia on tehty myös valvontaosaston ulkopuolella 1. kerroksessa sekä 3. kerroksen lastenosastoilla ja Vatsakeskuksen tiloissa pohjakerroksessa. RSSI-mittausten perusteella on luotu radiotiehäviöihin perustuvat etenemismallit molemmilla käytössä olevilla ISM-taajuuskaistoilla (Industrial, Scientific and Medical bands). Varjostuminen ja etenemishäviökertoimen muutokset on otettu huomioon etenemismalleissa. Mittaukset on suoritettu ennalta määritellyillä reiteillä. Luotuja malleja on verrattu myös tutkimuskirjallisuudessa esitettyihin, empiirisesti johdettuihin etenemishäviömalleihin. Signaalikatkoksen todennäköisyys on laskettu molemmille reiteille 2.4 GHz:n taajuuskaistalla. Vastaanotetun häiriötehon summa on mitattu koko mallinnettavan tilan alueelle ulottuvien mittausreittien pohjalta. Mittausreitit on määritelty Ekahau Pron tuottamien kuuluvuus- ja häiriökarttojen avulla ottaen huomioon havaitut signaalitason vaihtelut. Ekahau Sidekick -spektrianalysaattorin ja Ekahau Pro -ohjelman käyttöä on kuvattu tämän tutkimuksen kontekstissa. Kohinataso on määritelty kaikissa kuudessa mittauskampanjassa mitattujen kohina-tehoarvojen keskiarvona. Paikallisten hyötysignaalinvoimakkuus- ja häiriötehovaihteluiden vaikutusta verkon suorituskykyyn on tutkittu ja molemmat mittausreitit kattavat SIR-mallit (Signal-to-Interference Ratio) on luotu. Kaikissa tutkituissa kerroksissa havaittuja äkillisiä signaali-kohinasuhteen vaihteluita on tutkittu ja niiden vaikutusta järjestelmän suorituskykyyn on arvioitu. Mitattujen hyöty- ja häiriösignaalivaihteluiden arviointi on toteutettu vertaamalla mittaamalla saatuja SNR- (Signal-to-Noise ratio), SIR- ja RSSI-arvoja (Received Signal Strength Indicator) eri tiedonsiirtonopeuksia käyttävien MCS-indeksien vaatimiin signaalinvoimakkuus- ja signaali-kohina-suhteen arvoihin. Kynnysarvoille on laskettu linkkimarginaalit käyttäen mitoitusvaatimuksena valittua bittivirhetodennäköisyyden arvoa. Mitattuja RSSI-arvoja on verrattu käyttäen linkkimarginaalina etenemismallinnuksessa määritettyjä varjostumisvaikutuksen arvoja. 2.4 ja 5 GHz:n taajuusalueiden välillä mitatun signaalinvoimakkuuseron on tutkimuksessa saatujen tulosten perusteella osoitettu olevan seurausta alennetusta lähetystehosta 2.4 GHz:n kaistalla. SIR-mittausten perusteella on todettu viereisen rakennuksen tukiasemien kasvattaneen vastaanotettua häiriötehosummaa valvontaosastolla paikallisesti. Ensisijainen syy mitattuihin SIR-arvojen vaihteluihin ovat kuitenkin alhainen signaalinvoimakkuus 2.4 GHz:n kaistalla, mikä osittain johtuu edellä kuvatusta alennetusta lähetystehosta. Voimakkaita SNR-vaihteluita on mitattu kaikissa kerroksissa ennen kuin päätelaite kytkeytyy uuteen tukiasemaan

Sulautettujen suorittimien muistityypit

Tiivistelmä. Tässä kirjallisuuskatsauksessa tutustutaan sulautettujen suorittimien muistityyppeihin. Muistiteknologioiden nopea kehittyminen viime vuosina on tuonut perinteisesti sulautetuissa suorittimissa käytettyjen muistityyppien rinnalle myös uusia ratkaisuja. Ferrosähköinen muisti (FRAM) ja faasimuutokseen perustuva muisti (PRAM) edustavat tässä työssä uusia, jo kaupallistettuja muistityyppejä. Sulautettujen järjestelmien suunnittelussa energiankulutus on keskeinen kriteeri. Niinpä muistityyppien ominaisuuksia tarkastellaan ja muistityyppejä vertaillaan keskenään ennen muuta energiankulutuksen näkökulmasta. Lopuksi tutustutaan kahteen mikro-ohjaimeen, joissa käytetään eri muistityypeistä koostuvia muistikonfiguraatioita. Tämän kirjallisuuskatsauksen perusteella voidaan todeta, että korvaamalla nykyisissä mikro-ohjaimissa yleisimmin haihtumattomana muistina käytetty flashmuisti ferromagneettisella muistilla (FRAM), voitaisiin saavuttaa energiatehokkaampi ja erityisesti langattomiin IoT-sovelluksiin paremmin soveltuva muistiratkaisu. FRAM soveltuisi yksinään käytettäväksi yhdistettynä käsky- ja datamuistina esim. energiankeruusovelluksissa. Vaikka sulautettu muisti voidaan toteuttaa pelkällä FRAM:lla, tarjoaa SRAM:iin ja FRAM:iin perustuva muistikonfiguraatio kuitenkin energiatehokkaamman ratkaisun, jonka energiankulutusta voidaan edelleen pienentää tehokkaalla muistiviittausten optimoinnilla.Memory types of the embedded memory. Abstract. The memory types used as embedded memory in microcontrollers are discussed in this literature review. There has been a rapid technical development in the area of the memory technologies during the last few years. As a result, it has emerged some new memory types that have been used in the memory configurations of the microcontrollers in parallel with more traditional memory types. The ferromagnetic memory (FRAM) and phase change memory (PRAM) are in the scope of the review. The properties of the memory types are specially considered from the perspective of energy consumption. Finally, two widely used microcontrollers representing two different memory configurations are discussed as examples of embedded memory types. On the basis of this literature review, it seems that the replacement of the flash as a non-volatile memory by the ferromagnetic memory (FRAM) makes sense from the perspective of energy consumption. FRAM can also be implemented as unified memory which makes it a very attractive memory type for the IoT and energy-harvesting applications too. However, the memory configuration based on SRAM and FRAM is more energy efficient. The energy efficiency of SRAM-FRAM hybrid configuration can be further increased by optimizing the memory access routines

A molecular-based identification resource for the arthropods of Finland

Publisher Copyright: © 2021 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd.To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the improvement in identification accuracy enabled by the current reference library, we ran 1000 Finnish insect and spider species through the Barcode of Life Data system (BOLD) identification engine. Of these, 91% were correctly assigned to a unique species when compared to the new reference library alone, 85% were correctly identified when compared to BOLD with the new material included, and 75% with the new material excluded. To capitalize on this resource, we used the new reference material to train a probabilistic taxonomic assignment tool, FinPROTAX, scoring high success. For the full-length barcode region, the accuracy of taxonomic assignments at the level of classes, orders, families, subfamilies, tribes, genera, and species reached 99.9%, 99.9%, 99.8%, 99.7%, 99.4%, 96.8%, and 88.5%, respectively. The FinBOL arthropod reference library and FinPROTAX are available through the Finnish Biodiversity Information Facility (www.laji.fi) at https://laji.fi/en/theme/protax. Overall, the FinBOL investment represents a massive capacity-transfer from the taxonomic community of Finland to all sectors of society.Peer reviewe

The standard point-of-care Hemochron Jr. ACT+ test in monitoring heparin administration for cardiopulmonary bypass in severe factor XII deficiency

Abstract Coagulation factor XII (FXII) is a plasma serine protease that belongs to the contact activation complex responsible for initiating the intrinsic coagulation pathway. FXII deficiency is a rare congenital disorder that is not associated with an increased tendency for bleeding. However, as contact activation is impaired in FXII deficiency, both the celite- and kaolin-initiated activated clotting time (ACT) measurements are prolonged markedly, which poses a challenge for anticoagulation monitoring in patients undergoing cardiac surgery. The authors successfully have used the standard Hemochron Jr. ACT+ test, which is activated by silica and phospholipid in addition to kaolin, to monitor anticoagulation for cardiopulmonary bypass in two patients with severe FXII deficiency. The ACT+ test showed low baseline values, increased adequately in response to heparin, and decreased to baseline after protamine. Importantly, there was no abnormal intra- or postoperative bleeding nor any thrombotic complications. Furthermore, in vitro dose-response ACT+ testing of FXII-deficient blood with increasing heparin concentrations supports the use of ACT+ in FXII deficiency

Simple Temporal Networks with Partially Shrinkable Uncertainty (extended version)

The Simple Temporal Network with Uncertainty (STNU) model focuses on the representation and evaluation of temporal constraints on time-point variables (timepoints), of which some (i.e. contingent timepoints) cannot be assigned (i.e. executed by the system), but only be observed. Moreover, a temporal constraint is expressed as an admissible range of delays between two timepoints. Regarding the STNU model, it is interesting to determine whether it is possible to execute all the timepoints under the control of the system, while still satisfying all given constraints, no matter when the contingent timepoints happen within the given time ranges (controllability check). Existing approaches assume that the original contingent time range cannot be modified during execution. In real world, however, the allowed time range may change within certain boundaries, but cannot be completely shrunk. To represent such possibility more properly, we propose Simple Temporal Network with Partially Shrinkable Uncertainty (STNPSU) as an extension of STNU. In particular, STNPSUs allow representing a contingent range in a way that can be shrunk during run time as long as shrinking does not go beyond a given threshold. We further show that STNPSUs allow representing STNUs as a special case, while maintaining the same efficiency for both controllability checks and execution