22 research outputs found
Dynamic Programming for the Subset Sum Problem
Get PDFThe subset sum problem is a basic problem in the field of theoretical computer science, especially in the complexity theory [3]. The input is a sequence of positive integers and a target positive integer. The task is to determine if there exists a subsequence of the input sequence with sum equal to the target integer. It is known that the problem is NP-hard [2] and can be solved by dynamic programming in pseudo-polynomial time [1]. In this article we formalize the recurrence relation of the dynamic programming.This work was supported by JSPS KAKENHI Grant Numbers JP16K00033, JP17K00013 and JP17K00183.Hiroshi Fujiwara - Shinshu University, Nagano, JapanHokuto Watari - Nagano Electronics Industrial Co., Ltd., Chikuma, JapanHiroaki Yamamoto - Shinshu University, Nagano, JapanMichael R. Garey and David S. Johnson. Computers and Intractability: A Guide to the Theory of NP-Completeness. W. H. Freeman & Co., New York, NY, USA, 1979. ISBN 0716710447.Richard M. Karp. Reducibility among combinatorial problems. In Miller et al. [3], pages 85–103. ISBN 978-1-4684-2001-2. doi:10.1007/978-1-4684-2001-2_9.Raymond E. Miller, James W. Thatcher, and Jean D. Bohlinger, editors. Complexity of Computer Computations, 1972. Springer US. ISBN 978-1-4684-2001-2. doi:10.1007/978-1-4684-2001-2_9.Wojciech A. Trybulec. Non-contiguous substrings and one-to-one finite sequences. Formalized Mathematics, 1(3):569–573, 1990.899
On the “Shunanzan Mandara” Owned by the Matsuodera: A Rare Mandala Painting of Variant of the “Hokuto Mandara,” Mandala of the Plough, Based on the Chinese Original
Get PDFThe “Shūnanzan Mandara 終南山曼荼羅” is described in the Kakuzenshō and other books on Buddhist iconography of the Kamakura Period as an example of the “Tōhon (Chinese original) Hokuto Mandara (Maṇḍala of the Plough)”. According to them, it depicted a scene where Emperor Ming-ti of (Hou) Han China encountered one of the Seven Stars of the Plough. The same story is mentioned in some Esoteric Buddhist ritual books in the Late Heian Period in which the mandala is merely called “Tōhon Hokuto Mandara”. Dr. ONO, Gemmyō, once proposed the identification of the “Shūnanzan Mandara” with a Maṇḍowned by the Tokyo University of Arts which has an inscription of “Tōhon Hokuto Mandara”, but it is incorrect.
The present author affirms that the work shown in Plates I-IV in this number is none other than “Shūnanzan Mandara”.
The owner of this work, Matsuodera, in the suburbs of Maizuru City, Kyoto Prefecture, is old temple of the Shingon sect and is famous for the painting of Vajrāmoghasamayasattva done in the Late Heian Period. The work in question, which is first introduced here to the public, as can be seen from the colour plate, is rather darkened and is by no means well preserved. Nevertheless, it is an important painting from not only an art historical but also a religious point of view. Its contents can be identified by the aid of inscriptions which are written in rectangular cartouches on the picture, though they are rather difficult to decipher. A painting of the same subject, owned by the Dōryūji, Kagawa Prefecture, that was worked out in a later period, will be useful for the identification because it also bears inscribed cartouches.
The “Shūnanzan Mandara” of the Matsuodera consists of three scenes in the main portion, with mainor figures arranged in the upper and lower parts, (the one of the Dōryūji lacks these two parts). Three main scenes, divided one from the other by mountain ranges with rock-cut openings, are as follows: the lower of the main scenes represents Emperor Ming-ti encountering one of the Seven Stars of the Plough at Mt. Chung-nan (Jap. Shūnanzan). The middle is the hall where the Seven Stars live (Ch'i-hsing-kao ten 七星閣). In front of the hall is shown the deity which rules over human life, Pen-ming-yüan-ch'en 本命元辰 and his attendants (三尸,三魂,七魄,五臓). The upper scene illustrates the Pole-star which governs the Seven Stars of the Plough and its palace, Miao-chien-tien 妙見殿. Thus this painting is a unique work in which Taoist faith in the Plough and a phase of Chinese Esoteric Buddhism of its later stage are blended.
The figures at the upper end of the picture are personified constellations that are found in the “Hoshi (Constellation) Mandara”, and those at the lower end are identified with the thirty-six animals and birds which correspond to the twelve hours, and are a very rare representation.
The painting is an extraordinary version of the Plough Maṇḍala which is composed not in the form of the usual “Hokuto Mandara”, but as a scenic representation. And it is to be noted that Chinese elements in expression and in style have been greatly incorporated into it. This suggests that it is a comparatively faithful copy of the Chinese (T'ang or Five Dynasties) original. Judging from the features of the lines and colours, which are minutely analyzed by the author, it should be dated in the first half of the thirteenth century. The painting of the same subject of the Dōryūji, on the other hand, is probably a work of the fourteenth century.journal articl
FOURIER–MUKAI PARTNERS OF ELLIPTIC RULED SURFACES OVER ARBITRARY CHARACTERISTIC FIELDS
Get PDFThe first author explicitly describes the set of Fourier–Mukai partners of elliptic ruled surfaces over the complex number field in [30]. In this article, we generalize it over arbitrary characteristic fields. We also obtain a partial evidence of the Popa–Schnell conjecture in the proof
Fourier--Mukai partners of elliptic ruled surfaces over arbitrary characteristic fields
Get PDFThe first author explicitly describes the set of Fourier--Mukai partners of
elliptic ruled surfaces over the complex number field in \cite{Ue17}. In this
article, we generalize it over arbitrary characteristic fields. We also obtain
a partial evidence of the Popa--Schnell conjecture in the proof.Comment: Lots of improvements due to referee's comments. To appear in Osaka
Journal of Mathematic
Proposal of A New Place Name ; "Gulf of Hitakami" : Concerning the National Land Policy "Shin-Kokudojiku-Koso"
Get PDFThe author proposes a new place name, "Gulf of Hitakami" for a hitherto nameless gulf situated between the islands of Hokkaido and Honshu, east of the Tsugaru Strait. If the author's idea is accented, it will adequately describe and explain the geographical nature of the gulf and its coastal area. It will be useful not only for geography but also for the national land policy, especially "Shin-Kokudojiku-Ko-so" (literally, "New National Land Axes Plan"), because the New National Land Axis "Hokuto" crosses over "Gulf of Hitakami" and creates many connections between Honshu and Hokkaido.6KJ00000700273論文Articledepartmental bulletin pape
Seasonal variations in the call presence of bearded seals in relation to sea ice in the southern Chukchi Sea
Get PDFThe seasonal habitat use of bearded seals is important information in terms of conservation of this species. However, their distribution outside the breeding season has not been well documented. We investigated seasonal variations in the call occurrence of bearded seals by using passive acoustic monitoring in the southern Chukchi Sea, which has some of the greatest benthic biomass in the Pacific sector of the Arctic Ocean. Underwater sounds were recorded between 2012 and 2015. Calls of bearded seals were detected from mid-September or early October to the end of each recording period (mid-May 2013, early March 2014, and mid-June 2015). Two peaks in call occurrence were noted; the first peak occurred during the open-water periods in November, and the second peak occurred during ice-covered periods. This suggest that bearded seals utilize the southern Chukchi Sea not only for the breeding site but also for the autumn foraging site. We could complement the information about the southward autumn migration pattern of bearded seals, and the southern Chukchi Sea was suggested as the south limit of bearded seals' autumn distribution. Additionally, their vocal activity during autumn in this site was suggested to have some role in social interaction. Our results indicated that the southern Chukchi Sea would be an important monitoring site for understanding the habitat use and the vocal activity of bearded seals, especially outside the breeding season
Spatial niche partitioning among three small cetaceans in the eastern coastal area of Hokkaido, Japan
Get PDFSpatial niche partitioning of marine mammals is thought to be caused by dietary differences. However, due to the difficulty involved with conducting simultaneous marine predator and prey distribution surveys at the same scale, marine mammals have not been studied alongside their prey distribution. To understand the spatial niche overlap between 3 small cetaceans observed in the eastern coastal waters of Hokkaido, Japan (Pacific white-sided dolphin Lagenorhynchus obliquidens, Dall's porpoise Phocoenoides dalli, and harbor porpoise Phocoena phocoena), and the mechanisms behind the differences in their distributions, visual and hydroacoustic surveys using a quantitative echosounder were concurrently conducted. A clear spatial niche overlap was observed between the Pacific white-sided dolphin and Dall's porpoise, whereas the spatial overlap was moderate between the harbor porpoise and the other 2 species. In areas where Pacific white-sided dolphins were observed, potential prey was abundant in a shallower layer, at approximately 80-90 m depth. On the other hand, potential prey was more abundant in deeper layers in areas where Dall's and harbor porpoises were observed. Water depth affected the potential prey abundance at all depth layers (0-300 m), as potential prey were more abundant in areas with a shallower water depth. Additionally, potential prey were more abundant in shallower layers (3-200 m) than in deeper layers (200-300 m), where the maximum water depth was 3000 m. The differences in spatial niche among Pacific white-sided dolphin, Dall's porpoise, and harbor porpoise might cause their dietary differences, as they are epipelagic feeders, midwater feeders, and both epipelagic and midwater feeders, respectively
Effects of multiple stressors on recruitment of long‐lived endangered freshwater mussels
No full textMultiple stressors can affect populations interactively. However, the process by which they affect recruitment remains unclear, especially in long-lived organisms with complex life cycles.This study explored the bottleneck stages of juvenile recruitment in the endangered freshwater pearl mussel Margaritifera togakushiensis and the interactive effects of nutrients and fine sediments on these stages. The proportion of M. togakushiensis juveniles aged & LE;10 years was investigated in 24 rivers from north-eastern Japan. Margaritifera togakushiensis has a complex life cycle with an obligate parasitic larval stage. Gravid female density, glochidia density (the number of glochidial infections per stream area), and juvenile survival rate, used as indices for adult, parasitic, and post-parasitic juvenile stages, respectively, were obtained from 11 of these rivers.Twenty-four population status assessments showed that the proportion of juveniles aged & LE;10 years ranged from 0.00 to 0.23, and that they were absent in 12 rivers. Parasitic and post-parasitic juvenile stages were bottlenecks for recruitment; juvenile survival rates had a stronger positive effect on recruitment in rivers with high glochidia density. Juvenile survival rate was negatively associated with the synergistic effects of nutrients and fine sediments, although factors limiting glochidia density were not identified.These findings suggest that the interaction between nutrients and fine sediments can synergistically reduce the recruitment of M. togakushiensis, indicating an underestimated impact of stressors on mussel recruitment if treated individually. Future mitigation measures should consider both nutrient levels and fine sediments to restore mussel recruitment. These results also emphasize the importance of considering both parasitic and post-parasitic juvenile stages of mussels to maximize the success of future restoration actions
Delta-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes polymorphisms in children residing in an abandoned lead-zinc mine area in Kabwe, Zambia
Get PDFLead is a ubiquitous environmental pollutant that poses serious health problems to humans, especially to children. However, genetic variability in individuals varies their susceptibility to lead poisoning. One possible factor is genetic polymorphism. Thus, this study aimed to investigate the association between blood lead level (BLL), and polymorphisms in the delta-aminolevulinic acid dehydratase (ALAD) MspI (rs1800435) and vitamin D receptor (VDR) FokI (rs19735810), BsmI (rs15444410), ApaI (rs7975232) and TaqI (rs731236) genes in children exposed to lead. A total of 140 children (aged 2-10 years) were recruited in areas living closer to and far away from an abandoned lead-zinc mine in Kabwe, Zambia. Blood samples were collected from each child for BLLs and polymorphisms analysis. All children were homozygous for the ALAD 1 allele, indicating there might be bioavailable lead in the children's blood which can transfer to the soft tissues and the brain. The distribution of the VDR gene polymorphisms showed major alleles prevalence's of 81%, 80%, 68%, and 75% for FokI, BsmI, ApaI, and TaqI polymorphisms, respectively. The aa genotype of VDR ApaI showed significantly higher BLL compared to other genotypes of the VDRs polymorphism. The TaqI - TT genotype was associated with an increase of lead exposure risk in female children (OR = 2.06; 95% CI:1.04-4.06, p = 0.03). The haplotype analysis showed 10 haplotypes with a frequency above 1%, and the FbAt haplotype showed a protective role against lead toxicity. In conclusion, the children, especially female children, which exposed to lead mainly from the abandoned lead-zinc mine might be at a higher risk of developing lead poisoning. Further, larger scale sample sizes are needed to corroborate the role of ALAD and VDR genetic variants on the implications of lead toxicity in the general population, particularly in children
Insights on hazardous metal bioaccessibility, and groundwater impacted by Zn residues from a legacy mine and risk evaluation of adjacent soils
No full textThis study explored the legacy impact of Zinc plant residues (ZPRs) in Kabwe, Zambia, on the environment and human health, particularly in light of the town's reputation for Pb pollution. ZPRs solid samples and groundwater within and around ZPRs zone were collected from the legacy mine, along with soils in a 10 km radius from the mine site. Bioaccessible fractions of Pb and Zn were elucidated by Japanese leaching test (JLT) and simple bioaccessibility extraction test (SBET). Cationic speciation of Pb and Zn from inhalable and ingestible ZPRs particles was investigated via sequential extraction. Groundwater in the ZPRs area showed higher Zn levels (1490 mg/L) compared to Pb (1.7 mg/L). Elevated Zn concentration were facilitated by the presence of soluble Zn sulfates while Pb was constrained due to its precipitation as anglesite. Groundwater sampled outside the ZPRs area was within the Zambia regulatory limits (< 0.5 mg/L for Pb and < 1 mg/L for Zn). Inhalation exposure to < 30 mu m dust particles from ZPRs and soils near the mine indicated negligible risk, with < 3% of bioaccessible Pb in artificial lysosomal fluid. Meanwhile, oral intake of ZPRs particles < 250 mu m revealed elevated bioaccessible fractions (36% for Pb and 70% for Zn). ZPRs cationic speciation of ingestible particles < 30 mu m, 30-75 mu m, 75-150 mu m and 150-250 mu m indicated that the bioaccessible Pb predominantly emanated from labile Pb fractions under gastric conditions with pH < 1. This was due to the dissolution of Pb associated with the exchangeable phase, carbonates and iron/manganese oxides; however, only exchangeable/carbonate Pb was bioaccessible at pH < 2. Hazard quotients indicated increased risks of Pb intoxication through the ingestion of ZPRs and soils near the legacy mine, with higher risks observed in children, emphasizing the need to remediate legacy mine wastes to reduce health risks and protect groundwater through monitoring in mining-affected regions
