METHOD OF FATIGUE LIFE PREDICTION FOR SPOT WELDED STRUCTURE

Okabe, A.,Kaneko, T.,Tomioka, N. The Korean Society of Automotive Engineers 2006 International journal of automotive technology Vol.7 No.3

The nominal structural stress calculation method proposed by Radaj has included some problems as follows: (a) How the value of the diameter D is decided in the method; (b) It is not possible to estimate nominal structural stress of the spot welded joints with the balanced sheet in-plane load that no general loads are obtained by FE shell analysis. In this paper, the new method for calculating nominal structural stress was proposed to solve above-mentioned problems. The proposed method calculates the nominal structural stress through the circular plate theory in theory of elasticity. This theoretical analysis uses not only general loads but also nodal displacements around spot welding provided by FE shell analysis as boundary condition. Fatigue test data of various spot-welded joints could be arranged in a narrow bandwidth on S-N chart using the nominal structural stresses calculated by proposed method. The fatigue life prediction method using the proposed method for calculating nominal structural stress is useful for the prior evaluation technique that can predict the fatigue life of spot welding by CAE.

Smart Honeycomb Sandwich Panels With Damage Detection and Shape Recovery Functions

Okabe, Yoji,Minakuchi, Shu,Shiraishi, Nobuo,Murakami, Ken,Takeda, Nobuo The Korean Society for Composite Materials 2008 Advanced composite materials Vol.17 No.1

In this research, optical fiber sensors and shape memory alloys (SMA) were incorporated into sandwich panels for development of a smart honeycomb sandwich structure with damage detection and shape recovery functions. First, small-diameter fiber Bragg grating (FBG) sensors were embedded in the adhesive layer between a CFRP face-sheet and an aluminum honeycomb core. From the change in the reflection spectrum of the FBG sensors, the debonding between the face-sheet and the core and the deformation of the face-sheet due to impact loading could be well detected. Then, the authors developed the SMA honeycomb core and bonded CFRP face-sheets to the core. When an impact load was applied to the panel, the cell walls of the core were buckled and the face-sheet was bent. However, after the panel was heated over the reverse transformation finish temperature of the SMA, the core buckling disappeared and the deflection of the face-sheet was relieved. Hence the bending stiffness of the panel could be recovered.

GENERATION OF MAGNETIC FIELDS BY TEMPERATURE GRADIENTS

OKABE NOBUHIRO,HATTORI MAKOTO The Korean Astronomical Society 2004 Journal of The Korean Astronomical Society Vol.37 No.5

We showed that magnetic fields are generated in the plasma which have the temperature inhomogeneities. The mechanism is the same as the Weibel instability because the velocity distribution functions are at non-equilibrium and anisotropic under the temperature gradients. The growth timescale is much shorter than the dynamical time of structure formation. The coherence length of magnetic fields at the saturated time is much shorter than kpc scale and then, at nonlinear phase, become longer by inverse-cascade process. We report the application of our results to clusters of galaxies, not including hydrodynamic effects.

Structural Design of High-Rise Building with RC Frame Using Core Wall and Damping Device; Toranomon-Azabudai Project (B2 Block)

Okabe, Kazumasa,Toyama, Kai,Furuta, Takuya,Nakao, Akihiro,Karasaki, Hidenori,Kobayakawa, Hiraku,Uehara, Daisuke,Saito, Yuya Council on Tall Building and Urban Habitat Korea 2021 International journal of high-rise buildings Vol.10 No.3

DYNAMIC CHANGES IN SPATIAL MICROBIAL DISTRIBUTION IN MIXED-POPULATION BIOFILMS : EXPERIMENTAL RESULTS AND MODEL SIMULATION

Okabe, Satoshi,Hirata, Kikuko,Watanabe, Yoshimasa 嶺南大學校 環境問題硏究所 1996 環境硏究 Vol.16 No.1

ABSTRACT Dynamic changes in spatial microbial distribution in mixed-population biofilms were experimentally determined using a microslicer technique and simulated by a biofilm accumulation model (BAM). Experimental results were compared with the model simulation. The biofilms cultured in partially submerged rotating biological contactors (RBC) with synthetic wastewater were used as test materials. Experimental results showed that an increase of substrate loading rate (i.e., organic carbon and NH4-N) resulted in the microbial stratification in the biofilms. Heterotrophs defeated nitrifiers and dominated in the outer biofilm, whereas nitrifiers were diluted out in the outer biofilm and forced into the inner biofilm. At higher organic loading rates, a stronger stratified microbial spatial distribution was observed, which imposed a severe internal oxygen diffusion limitation on nitrifiers and resulted in the deterioration of nitrification efficiency. Model simulations described a general trend of the stratified biofilm structure. However, the actual stratification was stronger than the simulated results. For implication in the reactor design, when the specific carbon loading rate exceeds a certain limit, nitrification will be deteriorated or require a long start-up period due to the interspecies competition resulting in oxygen diffusion limitation. The extend of microbial stratification in the biofilm is especially important for determination of feasibility or nitrification in the presence of organic matters.

JAPANESE TRANSLATIONS OF WORKS ON WESTERN RHETORIC IN THE MEIJI ERA AND THEIR INTERCULTURAL ADAPTATION

Roichi Okabe 한국수사학회 2006 수사학 Vol.0 No.4

Western rhetorical theory and practice began to emerge in Japan during the Meiji era (1868-1912). One culmination of this intellectual development was the publication of a hugebody of books on rhetoric and speechmaking by rhetorically-motivated aspirants of the day along the line of Western rhetorical theory and practice. One student of rhetoric located 145 originally-written or translated works on Western rhetorical theory, practice, and criticism. Sixteen of them are Japanese translations. By examining three representative Japanese translations out of these sixteen on Western rhetoric, this paper will ascertain the level of accuracy in translation and explicate several techniques of intercultural adaptation including omission, elaboration, modulation, and transformation which the translators employed to help Japanese readers to understand Western ideas better. The translated works to be examined in this study include Hyu Bureeru, Taisei Ronbengsku Yoketsu(Essentials of Western Logical Speechmaking), Ryoji Ko, trans., Osaka: Shoshodo, 1880 [Hugh Blair, Lectures on Rhetoric and Belles Lettres, publisher unknown, 1869]; Furederikku Roton, Seiyo Toron Kihan(Principles of Western Debate), Gendo Nishimura, trans., Tokyo: Nishimura Gendo, 1881 [Frederic Rowton, The Debater: A New Theory of Art of Speaking, publisher and publication year unknown]; and [Joji P.] Kuwakkenbosu, Yuben Bijiho (The Art of Oratorical Belles Lettres), 3rd ed., Dai Kuroiwa, trans., Tokyo: Yoronsha, 1882 [George P. Quackenbos, Advanced Course of Composition and Rhetoric, New York: D. Appleton and Co., 1875]. They were selected for review here because the original authors all represent the best tradition of the nineteenth-century Western rhetorical theory. This paper will show that these three Japanese translations played an important role in introducing the tenets of Western rhetoric to the knowledge-hungry Meiji people. It will further demonstrate that they filled the gap pf rhetorical theory which had existed in the first two decades of the Meiji era before Japanese writers started to publish their own works in their vernacular in the subsequent decades of the era.

On an Improvement of the Averaging Method Using the Jacobian Elliptic Function

Tadashi Okabe,Takahiro Kondou 대한기계학회 1997 Asia-Pacific Vibration Conference Vol.2 No.1

RESEARCHING JAPANESE RHETORICAL THEORY AND PRACTICE

Roichi Okabe,Kim Jonggab(토론자) 한국수사학회 2006 한국수사학회 학술대회 Vol.- No.-

Feasibility Studies of a Vibration Wire Monitor and a Halo Scraper in the J-PARC L3BT

Kota Okabe,Kazami Yamamoto,Masahiro Yoshimoto,Michikazu Kinsho 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.7

In the Japan Proton Accelerator Research Complex (J-PARC) 3-GeV rapid cycle synchrotron(RCS), transverse beam halo diagnostics and scraping are required to increase the output beampower. Wire scanners and halo scrapers were used to measure the projected beam distributions todetermine the extent of beam halo formation at the linac 3-GeV beam transport line (L3BT). Inorder to determine more details of halo formation, we installed a vibration wire monitor (VWM) inthe L3BT for the beam halo measurement. The high sensitivity of the VWM makes it a prospectivetool for investigating the beam halo and weak beam scanning. Also, we developed a new verticalscraper system with a thin carbon foil to collimate the beam halo in the L3BT. In this paper, wewill report a preliminary result for the beam-halo measurement by using a VWM and a halo scraperat the L3BT, and we will discuss the potential of the VWM for beam-halo diagnostics.

A mite Ensliniella parasitica parasitic to as well as a bodyguard of a host wasp, Allodynerus delphinalis

Kimiko Okabe,Shun’ichi Makino 한국응용곤충학회 2008 한국응용곤충학회 학술대회논문집 Vol.2008 No.10

Some solitary wasps and bees exhibit peculiar structures, i.e., acarinaria, which are invaginated chambers harbouring certain mite species for transfer to brood cells of hosts. Acarinaria have long been considered morphological adaptations that evolved to securely transfer beneficial mites into nests but there is little compelling evidence to support this hypothesis. The dispersal deutonymphs of the mite Ensliniella parasitica are housed in acarinaria of the host A. delphinalis during phoresy. The mite life cycle has been investigated in detail; the deutonymphal mite using acarinaria invades into a host cell during wasp oviposition, the tritonymph feeds on heamolymph from lepidopteran prey, then adults from the juvenile host, the female begins laying eggs on the host after the host pupates, and larvae and protonymphs acquire nutrition from the pupa, developing into deutonymphs by host eclosion. Although totally parasitic to the juvenile host throughout its life cycle, the mite did not negatively affect on the host. Nests were sometimes infested with other natural enemies, which included a parasitoid wasp (Melittobia acasta), a kleptoparasitic fly, and unknown pathogens. When the parasitoid and adult mites co-existed in a host cell, we found that either all mites or all parasitoids died. A single adult parasitoid (female) and adult mites were placed in transparent acrylic tubes containing a single prepupal host. In some cases, the parasitoids harbouring mites eventually died. However, in other cases, the parasitoid counterattacked mites by possibly biting them on their dorsum. This experiment demonstrated that the probability that the parasitoid was killed depended on the number of mites. Although mutualisms to protect a partner are common, this wasp-mite interaction is exceptional, because the mite is non-predacious and much smaller in body size than the enemy but protects the host wasp.