The three-dimensional (3D) coordinate measurement of radio frequency identification (RFID) multi-tag
networks is one of the important issues in the field of RFID, which affects the reading performance of
RFID multi-tag networks. In this paper, a novel method for 3D coordinate measurement of RFID multitag
networks is proposed. A dual-CCD system (vertical and horizontal cameras) is used to obtain images of
RFID multi-tag networks from different angles. The iterative threshold segmentation and the morphological
filtering method are used to process the images. The template matching method is respectively used to
determine the two-dimensional (2D) coordinate and the vertical coordinate of each tag. After that, the
3D coordinate of each tag is obtained. Finally, a back-propagation (BP) neural network is used to model
the nonlinear relationship between the RFID multi-tag network and the corresponding reading distance.
The BP neural network can predict the reading distances of unknown tag groups and find out the optimal
distribution structure of the tag groups corresponding to the maximum reading distance. In the future work,
the corresponding in-depth research on the neural network to adjust the distribution of tags will be done.
The Silurian fishes from north-western Hunan, China are characterised by the earliest known galeaspids
Dayongaspis Pan and Zeng, 1985 and Konoceraspis Pan, 1992, and the earliest known antiarch Shimenolepis
Wang J.-Q., 1991, as well as rich sinacanth fin spines. Shimenolepis from Lixian County in north-western
Hunan, which was dated as the Telychian (late Llandovery), has long been regarded as the oldest representative
of the placoderms in the world. As such, in addition to eastern Yunnan and the Lower Yangtze Region,
north-western Hunan represents another important area in South China that yields important fossil material
for the research of early vertebrates and related stratigraphy. Here we summarise the Silurian fishes known in
north-western Hunan so far, and classify them into three vertebrate assemblages (i.e., the Wentang, Maoshan,
and Yangtze assemblages). Based on the updated Silurian vertebrate and stratigraphic databases, the Silurian
fish-bearing strata in north-western Hunan can be subdivided into the Rongxi, Huixingshao, and Xiaoxi formations
in ascending chronological order, which can be correlated with the Lower Red Beds, the Upper Red Beds,
and the Ludlow Red Beds in South China, respectively. A new look at the Silurian strata in Lixian suggests that
the age of Shimenolepis is late Ludlow rather than late Llandovery as previously suggested. The research on
Silurian fishes and biostratigraphy in north-western Hunan not only provides morphological data of early vertebrates,
but also offers new palaeoichthyological evidence for the subdivision, correlation, and age assignment of
the Silurian marine red beds in South China. The establishment of a related high-precision Silurian stratigraphic
framework in north-western Hunan will help to elucidate the temporal and spatial distribution of Silurian fossil
fishes, deepen the understanding of the evolution of early vertebrates, and unravel the coevolution between
Silurian vertebrates and the palaeoenvironment.
Little is known about the genealogy and the biography of Eleonora Ziemięcka née Gagatkiewicz. Poland’s first female philosopher (1819–1869). This article, the fruit of extensive archival research, now supplies the missing data. It not only fi xes her birth date – hitherto unknown – but also gives us an insight into the circumstances and reasons of her being brought up away from her parents. It has also been possible to collect a good deal of information about her relations, especially the Gagatkiewicz family (she was the granddaughter of Walenty Gagatkiewicz, the most distinguished physician of late 18th century Warsaw), and the family connections and the profi le of her husband, the portrait painter Antoni Ziemięcki.