|Last modified date：2023.11.22
Professor / Environmental Engineering, Planning and Design Section / Department of Architecture and Urban Design / Faculty of Human-Environment Studies
|OGAWA,T., HORI,Y., A Detailed Structural Classification of Cross Vault in Ostia" 13th Annual International Conference on Architecture, 13th Annual International Conference on Architecture, 2023.07.
|ZHAO, X. , OGAWA,T., HORI,Y., Accuracy of 3D point clouds generated by photogrammetry by comparison with the laser scanning, 29th EAA Annual Meeting, 2023.08.
|LIM, Y. B. , OGAWA,T., HORI,Y., Paving Process of The Black and White Mosaics in Herculaneum, 29th EAA Annual Meeting, 2023.08.
|Y. B. Lim, T. Ogawa, Y. Hori, DETECTION OF RESTORATION WORK BY APPLYING THE RANSAC ALGORITHM TO THE POINT CLOUD DATA FROM LASER SCANNING: CASE STUDY AT OSTIA, Workshop 3D-ARCH, 2022.02, [URL], In Ostia, the huge range of excavation carried out by Guido Calza under Mussolini (1938-1942), the zone of contiguous city blocks unearthed in those massive campaigns. From 2012, new survey by a Japanese team of standing remains using laser scanners formed the basis for an analysis of building history, and for a reconstruction of the original building. There is a considerable amount of undocumented reconstruction work in the upper part of the structure which has been identified from analysis of the surface of the walls. The seam and the absence of coursing between the original walls and the later restored works sometimes including in the Roman phase, and sometimes modern using original part of the walls, make difficult to identify which part of walls were original and which were restorations or re-use 80 years later from the excavation. In this paper, the case that the seams are invisible, but its existence is known from the photographic record of the progress of the excavations. The detection by applying the RANSAC algorithm to the point cloud data from laser scanning relies on several cases of invisible seams running on the surfaces. Additionally, this method allows us without any special knowledge and experience to find detailed characteristics on the surface of the walls, such as slight unevenness or weathering parts, to extrapolate the building history..
|OGAWA, T.and HORI, Y., Applying RANSAC Algorism to Analyse Archaeological and Architectural Materials from Ostia Antica., 27th EAA Annual Meeting, 2021.09, There are not the same shapes in ancient Roman artifacts strictly, and they usually confuse a geometry shape and free-form surfaces in themselves. It’ s difficult to precisely measure objects because of these shapes which were made by hand labour regardless of object’ s type and scale.
For example, “ mensa ponderariae ” , standard measurement gauges were used for cubic and dry measure in ancient Roman period, and these shapes of cavities chiselled in a marble brock are different from each other region.
In this poster presentation, we have two main aims.
1) To extract a geometrical shape (a sphere in this case) from a cavity of the mensa ponderaria in Ostia
2) To reconstruct the chiselling cavity process
To accomplish the first aim, mensa ponderariae were accurately measured by OPT scanner keeping a side length of each triangle of mesh data
within 3mm, and point cloud data were made from vertexes of these mesh data. Then, RANSAC algorism, the process which excludes “gross error” from point cloud were applied, and it enables us to exclude shapes of free-form surfaces, which could be made by hand labour in the Roman empire. A sphere was extracted from a point cloud, which is remaining through this process, by least square method.
For the second aim, these extracted spheres were used as the criterion of analysing shapes of free-form surfaces excluded in RANSAC algorism process. Then, the chiselling cavity process will be reconstructed based upon scientific evidences.
Five mensa ponderariae in Ostia were measured by Kyushu University in 2015..
|OGAWA,T., HORI,Y., and AYATSUKA, I., Measurement Conversion in Pompeii and Herculaneum, 27th EAA Annual Meeting, 2021.09, In a small room beside the western perimeter wall of the Sanctuary of Apollo, a copy of the Mensa Ponderaria, the original of which is kept at the National Archaeological Museum of Naples, is displayed. It is a counter used to check the exact capacity measures used for liquid and solid goods in trade, such as oils and cereals, could be trans-measured between Roman and Oscan capacity feet (OCF and RCF). This counter has already existed in the Oscan period, as proved by the epigraph on carved into the face of the marble counter. When the colony was founded, the Romans upgraded to the system of Roman weights and measures, but traditional Oscan foot has been survived for a long while. Using 5 cavities on this counter Pompeiians could easily convert measures by OCF into those by RCF, for example 20 OCF into 16 RCF, as the result of three- dimensionally measuring this copy of counter applying OPT scanner in 2015, where each main cavity was modeled in mesh data and its volume was exactly provided. Of course, we believed that the copy has been produced carefully and exactly into the same shape. This counter appears to have functioned as a standard measure of capacity in trade between the Oscan and the Roman. However, it is not unclear whether the standard measure had been given for vessels or container in daily use at Pompeii and Herculaneum. In the later part of this paper, the capacities of a lead bucket coming from House of Mosaic atrium and a bronze bathtub from House of the Stags are measured by OCF and RCF. Conclusively standard measures of capacity both in Oscan and Roman system could be applied into the containers in daily use at Pompeii and also Herculaneum..
|Yoshiki HORI, Laser scanning of the city of Ostia and some consideration on upper structures, Ancient Architecture Discussion Group, 2019.06.
|Ogawa, T., and Y. Hori., Comparison with Accuracy of Terrestrial Laser Scanner by Using Point Cloud Aligned with Shape Matching and best Fitting Methods., International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019.02, Recently operation systems of laser scanning have been obviously improved; for instance shape matching has been equipped with software on a post processing stage so measurement without any targets is a prerequisite condition of field surveying with laser scanners. Moreover a shape matching method enables us to easily register a pair of point clouds with some errors even if those data are scanned by several type scanners. Those slightly errors can influence accuracy of alignments if the object is large to require a lot of scans. Laser scanning data has random errors and accuracy of alignments can be improved by matching error distributions of pairs of point clouds to natural distributions. This method is called "best fitting" in contrast "shape matching" in a software, PolyWorks |Inspector. In this paper, accuracy of alignments between shape matching and best fitting is discussed. The scan data of three phaseshift laser scanners (FARO Focus 3D MS120, FARO Focus 3D X330 and Z+F Imager 5016) and two time-of-flight scanners (Leica BLK 360 and Leica Scan station C5) are used for analyses. Accuracy of alignments by using shape matching and best fitting methods is demonstrated by showing points of scan data with histograms of error distributions..
|堀 賀貴, 小川拓郞, VISUALIZATION OF THE CONSTRUCTION OF ANCIENT ROMAN BUILDINGS IN OSTIA USING POINT CLOUD DATA, International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2017.03, The implementation of laser scanning in the field of archaeology provides us with an entirely new dimension in research and surveying. It allows us to digitally recreate individual objects, or entire cities, using millions of three-dimensional points grouped together in what is referred to as ‘point clouds’. In addition, the visualization of the point cloud data, which can be used in the final report by archaeologists and architects, should usually be produced as a JPG or TIFF file. Not only the visualization of point cloud data, but also re-examination of older data and new survey of the construction of Roman building applying remote-sensing technology for precise and detailed measurements afford new information that may lead to revising drawings of ancient buildings which had been adduced as evidence without any consideration of a degree of accuracy, and finally can provide new research of ancient buildings. We used laser scanners at fields because of its speed, comprehensive coverage, accuracy and flexibility of data manipulation. Therefore, we “skipped” many of post-processing and focused on the images created from the meta-data simply aligned using a tool which extended automatic feature-matching algorithm and a popular renderer that can provide graphic results..
|Brief History of Ancinet Roman Cities Pompeii and Ostia in disasters.
|Laser scanning the walls in block work (Opus Quadratum) in Pompeii and Ostia： the relationship between the walls and streets.
|From Pompeii to Ostia Roman Houses in the Development of Architectural Structure and Urbanization.
|Drainage System of the rainwater and the excess water discharged on the streets of Pompeii , [URL].
|Measuring the City Walls of Pompeii, 3 Dimensional Digital-data and New Measuring Method.
|Preliminary Report on a Yamasoko-no-hana Beacon in Shimonoseki, Yamaguchi Pref..
|A study on the restoration of the iron column used in the KAGOSHIMA cotton mill of the SATSUMA.
|Composition of the local shrine from 18th century to 19th century.
-In the case of some shrines around Munakata,Fukuoka Pref.-.