560 research outputs found
A Nearly Linear Time Construction of Approximate Single-Source Distance Sensitivity Oracles
No full textAn α-approximate vertex fault-tolerant distance sensitivity oracle (α-VSDO) for a weighted input graph G = (V, E, w) and a source vertex s ∈ V is the data structure answering an α-approximate distance from s to t in G-x for any given query (x, t) ∈ V × V. It is a data structure version of the so-called single-source replacement path problem (SSRP). In this paper, we present a new nearly linear-time algorithm of constructing a (1 + ε)-VSDO for any directed input graph with polynomially bounded integer edge weights. More precisely, the presented oracle attains Õ(m log (nW)/ ε + n log² (nW)/ε²) construction time, Õ(n log (nW) / ε) size, and Õ(1/ε) query time, where n is the number of vertices, m is the number of edges, and W is the maximum edge weight. These bounds are all optimal up to polylogarithmic factors. To the best of our knowledge, this is the first non-trivial algorithm for SSRP/VSDO beating Õ(mn) computation time for directed graphs with general edge weight functions, and also the first nearly linear-time construction breaking approximation factor 3. Such a construction has been unknown even for undirected and unweighted graphs. In addition, our result implies that the known conditional lower bounds for the exact SSRP computation does not apply to the case of approximation
Almost self-duality and Harada rings
No full textAbstractThe existence of self-duality for left Harada rings was investigated by J. Kado and K. Oshiro [J. Algebra 211 (1999) 384–408]. Recently the author constructed examples of left Harada rings without self-duality [J. Algebra 241 (2001) 731–744]. In this paper, we investigate almost self-duality and rings of a certain class, which contains right co-Harada rings (equivalently left Harada rings). Here almost self-duality is a generalization of self-duality. The main purpose of the paper is to show that every ring of the class (particularly every right co-Harada ring) has an almost self-duality
A study on Harada Shigeyoshi's Jujireki Chukai (Study of the History of Mathematics 2022)
No full textAfter being introduced to Japan, the important ancient Chinese calendar, the Shoushi Calendar, was reprinted and disseminated. The Shoushili Yi in Yuan Shi·Li zhi is an important document about the ancient Chinese calendar theory. No one studied it in the Ming and Qing dynasties, but Japanese scholars in the Edo period commented on it, such as Takebe Katahiro (1664-1739), Nishimura Tōsato (1718-1787), and Harada Shigeyoshi (1740-1807), they annotated the Shoushili Yi. The article firstly verifies that the author of the Jujireki Chukai in the library affiliated to Tohoku University is Harada Shigeyoshi, not Takahashi Yoshitoki (1764-1804). Secondly, an investigation was carried out on Harada Shigeyoshi and his writings. The investigation found that there were three manuscripts of Harada Shigeyoshi's Jujireki Chukai, and the contents of the annotations and knowledge sources were verified and sorted out. It is believed that the Jujireki Chukai cited the contents of Tianwen Tujie Fahui (Nakane Genkei), Lisuan Quanshu (Mei Wending) and Juji Kai (Nishimura Tōsato) mostly. Finally, the article analyzes the annotations on “Yanqi (Collect or modify data for the solar terms)” and “Buyong Jinian Rifa (Abolition of the calendar epoch)” in Harada Shigeyoshi's Jujireki Chukai, and thinks that Harada's annotations in “Yanqi” through diagrams are commendable. The “Buyong Jinian Rifa” section is rich in annotations, which supplement the three possible situations that Li Qian and Qi Lvqian proposed to calculate Yanji Shangyuan. The two new situations which do not provide calculation procedures are similar to the methods of Li Qian and Qi Lvqian, and the other two situations are caculated by Seki Takakazu's Jianguan-Method. This method is essentially the same as that of Dayan-Zongshu-Method (Da-yan Rule) [大衍總數術]
A successful model of regional healthcare information exchange in Japan: Case Study in Kagawa Prefecture
No full textIn this study, we focused on analysis of healthcare data exchange over the network. For the advance of broadband capability development, many governments expect online medical information exchange between medical institutions. Japanese government also has tried to deploy ICT in the healthcare field. In Japan, many healthcare ICT projects started, but almost of all the projects face many issues and failed to continue. This situation caused us to clarify the success factor of healthcare information exchange network. For inspecting the success factors, we analyzed information access of healthcare systems in Kagawa prefecture of Japan. Kagawa prefecture is one of the most advance areas for healthcare information technology. We analyzed four medical ICT projects in Kagawa prefecture: K-MIX, Critical Pathway for Diabetes, E-prescription, and PHR. In addition, we inspected characteristics of exchanged data in the network, and stakeholder involved in these projects. This analysis lets us find various types of healthcare ICT projects. Characteristic of data processed in the projects caused differences of characteristic of the projects. On the other hand, multiple systems process same data, though the project does not share the data itself. Considering various types of medical information exchanges projects, we propose classification and standard format of exchanged data according to their characteristic are critical for efficient business deployment. --e-Health,regional healthcare information exchange,EHR
Choroidal thickening prior to anterior recurrence in patients with Vogt-Koyanagi-Harada disease
No full textAim: To assess choroidal thickness changes associated with anterior segment recurrences in patients with Vogt-Koyanagi-Harada (VKH) disease using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: EDI-OCT images were obtained periodically from 11 VKH disease patients (22 eyes) who were followed-up due to anterior segment recurrences. Subfoveal choroidal thickness (SCT) values at the following stages were evaluated: (1) during the remission phase, (2) one month before detecting the anterior recurrence, (3) during the anterior recurrence, and (4) after systemic prednisolone (PSL) treatment leading to remission. In comparison with SCT values in remission as baseline, the changing ratios of SCT were statistically analyzed at subsequent three stages. Results: The average of the SCT changing ratios compared to the remission phase significantly increased to 1.45 ± 0.11 during anterior segment recurrences (P=0.00044) lacking any funduscopic signs of posterior involvement. Interestingly, the average SCT ratio one month before detecting the recurrence had already increased to 1.30 ± 0.08 (P=0.002). After the PSL treatment, the ratio of SCT recovered to 0.95 ± 0.03 which was equivalent with the remission level. However, in patients with their remission SCT values less than 240 μm, the SCT ratio did not increase significantly at any time points evaluated. Conclusions: The choroid in eyes with VKH disease thickened in association with the anterior segment recurrence, and this thickening was observed prior to the recurrence. EDI-OCT may be useful for detecting latent choroidal inflammation in VKH disease, whereas it may not for patients with the relatively thin choroid
Vogt-Koyanagi-Harada disease: inquiry into the genesis of a disease name in the historical context of Switzerland and Japan
No full textPurpose: To delineate the historical steps associated with the genesis of the name and the definition of Vogt-Koyanagi-Harada (VKH) disease. Methods: A bibliographical review of the major publications that were relevant to the original development of the name of the clinical entity known today as Vogt-Koyanagi-Harada disease, in the historical context of the early 20th century. Results: Three distinct time periods can be considered to be important in terms of providing a historical perspective on VKH disease. Given that the cutaneous manifestations of VKH disease are so characteristic, these could not have been missed even before the actual clinical entity of VKH was recognized in the early 20th century. Indeed, several authors, including the Arabic doctor Mohammad-al-Ghâfiqî in the 12th century as well as Jacobi, Nettelship and Tay in the 19th century, described poliosis, neuralgias and hearing disorders. Many of these cases were probably due to sympathetic ophthalmia, but some were clearly VKH cases. The second phase is characterized by the surge of articles that appeared early in the 20th century that defined the disease more precisely. A number of these authors subsequently became associated with the disease name, the first being Alfred Vogt from Switzerland, followed by Japanese researchers. Yoshizo Koyanagi was in fact not the first Japanese author to describe the disease; this honor goes to the first Japanese Professor of Ophthalmology at the University of Tokyo, Dr. Jujiro Komoto, who published in a German language journal, Klinische Monatsblätter für Augenheilkunde in 1911. Yoshizo Koyanagi published his first report in the Nippon Ganka Gakkai Zasshi 3 years later, in 1914, but it was a much later article, one published in 1929, that definitively associated his name with the disease. In this review article, Koyanagi reported 16 cases, of which six were his own cases, that beautifully illustrate the natural course of the disease. In this same time period, Einosuke Harada, in an article published in Nippon Ganka Gakkai Zasshi in 1926 that was based on several case studies, comprehensively described a syndrome that included (1) a prodromal phase of malaise and meningeal irritation; (2) bilateral uveitis of diverse intensity; (3) bilateral retinal detachments spontaneously resolving; (4) integumentary changes; (5) lymphocytosis of the spinal fluid; (6) dysacousia. It is now accepted that Vogt-Koyanagi disease and the syndrome described by Harada are one entity with a diverse clinical spectrum bearing the universally accepted name of Vogt-Koyanagi-Harada disease. The third phase and most recent phase is characterized by the rapid progress made in terms of knowledge of the physiopathology of the disease, primarily due to the development of immunological methods. The evidence accumulated to date clearly points towards an autoimmune Th1 disease directed against proteins associated with choroidal melanin. Other analytical techniques, such as indocyanine green angiography, have enabled researchers to monitor more closely the primary lesional process at the level of the choroid, and standardized diagnostic criteria have been generated in the recent past. Conclusion: Those who earn scientific merit in clinical medicine are the ones who are able to visualize an overview based on the synthesis of ‘new' medical facts that have been made available, usually reported singly by several, unassociated authors concomitantly. This is certainly the case for Yoshizo Koyanagi and Einosuke Harada. Conversely, Alfred Vogt was primarily lucky in that he encountered and subsequently precisely described the first case in the literatur
MR vessel-encoded arterial spin labeling with the placement of metallic items to visualize the territorial blood flow after extracranial-intracranial bypass surgery : a proof-of-concept study
No full textBackground Depiction of bypass blood flow in patients who received extracranial-intracranial (EC-IC) bypass surgery is important for patient care. Purpose To develop a vessel-encoded arterial spin labeling (VE-ASL) method using surgical staples as a magnetic resonance (MR)-conditional product in patients who received EC-IC bypass surgery. Material and Methods Pseudo-continuous labeling was used for VE-ASL acquisition with a 3-T MR unit. First, an experimental study was conducted to determine the appropriate number of surgical staples to obtain a spatially sufficient saturation effect. Thereafter, four healthy normal volunteers underwent a VE-ASL study to confirm the sufficiency of the saturation effect to the right or left common carotid artery. Finally, VE-ASL scanning was performed in seven patients after EC-IC bypass surgery to confirm the ability of VE-ASL to visualize the territorial bypass perfusion. All qualitative evaluation was performed by two neuroradiologists using a 3-point grading system (2 = good, 1 = moderate, 0 = poor). Results A quantity of 200 staples was found to be appropriate for VE-ASL scanning. In healthy volunteers, one neuroradiologist rated the images of all four cases as good, while the other rated three cases as good and one case as moderate. For the seven patients after EC-IC bypass surgery, one neuroradiologist rated all seven cases as good, and the other rated six cases as good and one case as moderate. Conclusion VE-ASL using surgical staples might be useful for the evaluation of territorial bypass perfusion in patients after EC-IC bypass surgery
Explanation of the Plate: Study for “Susanoo no Mikoto Slaying the Serpent” by Harada Naojiro (1895, The Okayama Prefectural Cultural Center)
No full textHARADA Naojirō (1863–1889) who made the study painting in question is one of the important artists of Western-style painting in the mid-Meiji Period. He studied under Gabriel MAX (18401915), a historical-painting artist, at the Munich Academy from 1884 to 1886. After his return to Japan, HARADA executed the two paintings with a dramatized composition, “Avalokiteśvara Mounted on a Dragon” (1890) and “Susanō no Mikoto Slaying the Serpent” (1895), for which he is particularly known. Shown in Plate IX is the study for the latter work. As the completed work was destroyed by fire in 1923 and can be appreciated only through black and white photographs of it, the remaining study is of great academic value.
This study is in oil, its canvas measuring 77.5 cm by 53.3 cm. The wooden frame bears an inscription by ARISHIMA Ikuma as a connoisseur. The theme is taken from the legend of a mythological god Susanō no Mikoto who slew the eight-headed serpent. The dog painted in it has nothing to do with the story itself.
Interestingly, as in the case of “Avalokiteśvara Mounted on a Dragon,” the artist showed strong interest in the serpent, a grotesque and fantastic motif. This indicates that while HARADA was studying the Romantic-like historical paintings in Munich he was attracted to the decadent taste and to the apocalyptic subjects. Such artistic interest of HARADA was straightforwardly expressed in his “Avalokiteśvara Mounted on a Dragon.” However, the “Susanō no Mikoto Slaying the Serpent,” completed five years later, seems to be dominated by explicatory tendency rather than the painter's purely artistic expressiveness.
The difference between the two works shows that there was some kind of limitation in the development of Western-style painting in Japan in its early stage. The author feels that HARADA had to restrain from expressing his own taste, thinking that it was his task to expand the field of historical painting which was still foreign to the Westernstyle painting movement of Japan in those days.journal articl
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