DYNAMIC ANALYSIS OF THE EFFECT OF CENTRIFUGAL AND CORlOLlS FORCES IN SWINGING A BAT

This paper reports a dynamic analysis by computer simulation of bat swinging, taking into account inertial forces at the wrist joint, and which consist of centrifugal and Coriolis forces generated from a body turn and internal rotation of the upper limbs. The ideal bat swing generated by optimisation using a mathematical model is also described. Based on the dynamic analysis, it is shown that the inertial forces play an important role in the process of flexion and extension between a bat and the upper limbs during a bat swing, and that the effects of gravity on a bat is much smaller than those from inertial forces. It was also proven from the optimisation that an ideal bat swing, a swing using minimal torque at the wrist, exists

DYNAMICS ANALYSIS OF PEDALING MOTION IN RACING CYCLE WITH COMPUTER SIMULATION

This paper reports the new method based on the computer simulation for the dynamics analysis of the pedaling motion in a racing cycle. At first, we describe three-dimensional mathematical models of lower limbs and the cycle, and then explain the formulation as the systems of Lagrange equations. Time-series angular displacements of each joint, the crank arm, and each pedal were obtained by capturing actual human pedaling motions. The 'ideal' pedal forces were computed by using the model of the cycle. The method for solving the 'inverse kinematics problem' is also proposed. As the results of the dynamic simulation, we obtained several dynamic properties of the three-dimensional pedaling motion. And the differences between the three-dimensional pedaling motion and the two dimensional motion were also described

Looking for the right outcrop: Ceramic petrography in the Peruvian Andes

Looking for the Right Outcrop Ceramic Petrography in the Peruvian Andes Isabelle C. Druc, Kinya Inokuchi, Victor Carlotto, and Pedro Navarro. In 2010 a series of compositional analysis was initiated to study the production and provenance of the ceramics found at the archaeological site of Kuntur Wasi, in the department of Cajamarca, Peru. Kuntur Wasi is a ceremonial site of the Formative Period occupied during most of the first millennium BC. The site is located at 2,300 m above sea level, 35 km west of the city of Cajamarca in the north-­ central Peruvian highlands (fig. 10.1). Excavations were carried out from 1988 to 2002 by the Kuntur Wasi archaeological project and a Japanese-­ led team. The site acquired much fame when eight intact tombs were excavated, bearing many gold objects, crowns, pendants, beads, and beautiful ceramics (Onuki et al. 1995; Onuki and Inokuchi 2011). In addition to the burials, the four occupation levels (spanning some 900 years) yielded a very large quantity of ceramic fragments. The major architectural and stylistic changes at the beginning of the second archaeological phase point to a strong foreign influence or a nonlocal origin of some of the people responsible for many of the changes observed (Onuki et al. 1995; Inokuchi 2010). Stylistic analysis also suggests the presence of local styles as well as foreign styles related to the coast and to the northern highlands. Paste analysis involved petrography, X-­ ray diffraction (XRD), and scanning electron microscopy (SEM) of archaeological and comparative samples, in conjunction with the ethnoarchaeological study of the modern local ceramic tradition. The first step was to investigate the availability of potting materials around the archaeological site, the local geology, and the type of clay, temper, and practices of traditional potters in the region (Druc 2011; Druc et al. 2013). The analysis of the archaeological ceramics showed the existence of several paste groups, one of which was characterized by the presence of intrusive materials. The absence of intrusive bodies at the local level prompted the search for the provenance of the intrusive temper seen in the Kuntur Wasi ceramics. This search for the right outcrop is also an inquiry into understanding whether the wares manufactured with intrusive temper were produced on site with foreign material or brought to the site. This query was dictated by questions of interregional sociocultural or economic relationships in view of the architectural and stylistic changes observed at Kuntur Wasi. We first briefly present the archaeological and ethnographic background of the research and then describe the local and regional geology. Later we turn to the compositional analysis of the archaeological and comparative samples related to this aspect of the study. The analysis results are discussed in light of the recent studies of the archaeological ceramics. We conclude with a tentative interpretation of ceramic production at or for the ceremonial site of Kuntur Wasi. Looking for the Right Outcrop 145 Research Background The Archaeological Data The ceremonial center of Kuntur Wasi (fig. 10.2) was occupied during the first millennium BC (Inokuchi 2010). The study of the construction phases, tombs, ceramics, and other cultural materials suggested a local initial occupation period (Idolo phase, 950–800 BC), followed by an important transformation in the ceremonial center and a population input of possible coastal provenance (Kuntur Wasi phase, 800–550 BC). New constructions and expansion of the site mark the third major occupation phase (Copa phase, 550–250 BC), while the last phase is characterized by drastic construction changes and quasi abandonment of the site as a major ceremonial center (Sotera phase, 250–50 BC). Apart from these four phases is the “Sangal complex” within the Kuntur Wasi phase, identified on the basis of a set of ceramics displaying similar stylistic characteristics (Inokuchi 2010; Onuki et al. 1995). In terms of ceramic production, so far no evidence was found suggesting on-­ site production . But excavations have targeted the cere­mon­ ial area, where ceramic production was probably not taking place. Sixty-­one different ceramic stylistic types have been identified (Ino­kuchi 2010). Several stylistic ceramic types display local characteristics, with a paste matching resources available within a 7–9 km range, as petrographic analysis showed. Albeit fitting chronologically within the stylistic and cultural Chavín Horizon, Kuntur Wasi does not appear to have received direct impact from the ceremonial center of Chavín de Huántar in the north-­ central Andes (Inokuchi 1998). Rather, stylistic analysis suggests influences..

63/65^{63/65}Cu- and 35/37^{35/37}Cl-NMR Studies of Triplet Localization in the Quantum Spin System NH4_4CuCl3_3

$^{63/65}$Cu- and $^{35/37}$Cl-NMR experiments were performed to investigate triplet localization in the $S=1/2$ dimer compound NH$_4$CuCl$_3$, which shows magnetization plateaus at one-quarter and three-quarters of the saturation magnetization. In $^{63/65}$Cu-NMR experiments, signal from only the singlet Cu site was observed, because that from the triplet Cu site was invisible due to the strong spin fluctuation of onsite 3$d$-spins. We found that the temperature dependence of the shift of $^{63/65}$Cu-NMR spectra at the singlet Cu site deviated from that of macroscopic magnetization below T=6 K. This deviation is interpreted as the triplet localization in this system. From the $^{35/37}$Cl-NMR experiments at the 1/4-plateau phase, we found the two different temperature dependences of Cl-shift, namely the temperature dependence of one deviates below T=6 K from that of the macroscopic magnetization as observed in the $^{63/65}$Cu-NMR experiments, whereas the other corresponds well with that of the macroscopic magnetization in the entire experimental temperature region. We interpreted these dependences as reflecting the transferred hyperfine field at the Cl site located at a singlet site and at a triplet site, respectively. This result also indicates that the triplets are localized at low temperatures. $^{63/65}$Cu-NMR experiments performed at high magnetic fields between the one-quarter and three-quarters magnetization plateaus have revealed that the two differently oriented dimers in the unit cell are equally occupied by triplets, the fact of which limits the theoretical model on the periodic structure of the localized triplets.Comment: 19 pages, 9 figures, submitted to PRB (in press

Kernels for graphs

This chapter contains sections titled: Introduction, Label Sequence Kernel between Labeled Graphs, Experiments, Related Works, Conclusion

An Efficient Algorithm for Enumerating Chordless Cycles and Chordless Paths

A chordless cycle (induced cycle) $C$ of a graph is a cycle without any chord, meaning that there is no edge outside the cycle connecting two vertices of the cycle. A chordless path is defined similarly. In this paper, we consider the problems of enumerating chordless cycles/paths of a given graph $G=(V,E),$ and propose algorithms taking $O(|E|)$ time for each chordless cycle/path. In the existing studies, the problems had not been deeply studied in the theoretical computer science area, and no output polynomial time algorithm has been proposed. Our experiments showed that the computation time of our algorithms is constant per chordless cycle/path for non-dense random graphs and real-world graphs. They also show that the number of chordless cycles is much smaller than the number of cycles. We applied the algorithm to prediction of NMR (Nuclear Magnetic Resonance) spectra, and increased the accuracy of the prediction

Infrared photodissociation spectroscopy of H+•(CH3COOH)n and H+•(CH3COOH)n•H2O (n=1–5)

第17回化学反応討論会, 2001年5月23日-26日, 九州大学箱崎キャンパス(福岡