<研究ノート> 海外派遣者の増減および海外子会社のパフォーマンス

Previous studies on the effect of subsidiary staffing on subsidiary performance have examined the relationship between the two variables at certain points in time. These studies demonstrate that subsidiaries with more (or fewer) parent country nationals (PCNs) tend to demonstrate higher performance. However, these studies do not fully analyze whether the performance of a focal subsidiary improves by increasing (or decreasing) the number of PCNs assigned to the subsidiary. To answer this research question, this study addresses the way in which changes in a focal subsidiary’s staffing affect the subsidiary’s performance. It analyzes a panel dataset consisting of 11,286 observations of foreign subsidiaries owned by multinational corporations. This study demonstrates that a change in the deployment of PCNs has a U-shaped relationship with subsidiary performance, and the curve indicates that the performance of a focal subsidiary improves by both increasing and decreasing the deployment of PCNs. This study also finds that the slope of the U-shaped curve is flatter in institutionally distant host countries than in institutionally similar countries. This finding indicates that institutional differences between the host and home countries diminish the positive effect of increasing and decreasing the deployment of PCNs

The Dominant Practice for Foreign Subsidiary Staffing and the Subsidiary Performance

This study examines whether isomorphic behavior by multinational corporations positively or negatively affect the performance of foreign subsidiaries. Although previous studies find that multinational corporations have a tendency to mimic practices adopted by other firms, the financial consequences of mimetic behavior remains uncovered. This study addresses multinational corporations\u27 isomorphic behavior regarding foreign subsidiary staffing and hypothesizes the relationship between the imitation of the dominant practice for subsidiary staffing and the subsidiary performance. The panel dataset consisting of 3,284 foreign subsidiaries of multinational corporations are used to test the hypotheses. The results obtained from a fixed effect model indicate that the imitation of the dominant practice adopted in the host country negatively affects the subsidiary performance. This study also finds that the negative relationship between mimetic behavior and subsidiary performance becomes greater as the institutional distance between the host country and the home country increases. The results of this study suggest that isomorphic behavior in pursuit of legitimacy is accompanied by the loss of efficiency

State Concentration Exponent as a Measure of Quickness in Kauffman-type Networks

We study the dynamics of randomly connected networks composed of binary Boolean elements and those composed of binary majority vote elements. We elucidate their differences in both sparsely and densely connected cases. The quickness of large network dynamics is usually quantified by the length of transient paths, an analytically intractable measure. For discrete-time dynamics of networks of binary elements, we address this dilemma with an alternative unified framework by using a concept termed state concentration, defined as the exponent of the average number of t-step ancestors in state transition graphs. The state transition graph is defined by nodes corresponding to network states and directed links corresponding to transitions. Using this exponent, we interrogate the dynamics of random Boolean and majority vote networks. We find that extremely sparse Boolean networks and majority vote networks with arbitrary density achieve quickness, owing in part to long-tailed in-degree distributions. As a corollary, only relatively dense majority vote networks can achieve both quickness and robustness.Comment: 6 figure

Cross Correlation of the Extragalactic Gamma-ray Background with Thermal Sunyaev-Zel'dovich Effect in the Cosmic Microwave Background

Cosmic rays in galaxy clusters are unique probes of energetic processes operating with large-scale structures in the Universe. Precise measurements of cosmic rays in galaxy clusters are essential for improving our understanding of non-thermal components in the intracluster-medium (ICM) as well as the accuracy of cluster mass estimates in cosmological analyses. In this paper, we perform a cross-correlation analysis with the extragalactic gamma-ray background and the thermal Sunyaev-Zel'dovich (tSZ) effect in the cosmic microwave background. The expected cross-correlation signal would contain rich information about the cosmic-ray-induced gamma-ray emission in the most massive galaxy clusters at $z\sim0.1-0.2$. We analyze the gamma-ray background map with 8 years of data taken by the Large Area Telescope onboard Fermi satellite and the publicly available tSZ map by Planck. We confirm that the measured cross-correlation is consistent with a null detection, and thus it enables us to put the tightest constraint on the acceleration efficiency of cosmic ray protons at shocks in and around galaxy clusters. We find the acceleration efficiency must be below 5\% with a $2\sigma$ confidence level when the hydrostatic mass bias of clusters is assumed to be 30\%, and our result is not significantly affected by the assumed value of the hydrostatic mass bias. Our constraint implies that the non-thermal cosmic-ray pressure in the ICM can introduce only a $\le 3\%$ level of the hydrostatic mass bias, highlighting that cosmic rays alone do not account for the mass bias inferred by the Planck analyses. Finally, we discuss future detectability prospects of cosmic-ray-induced gamma rays from the Perseus cluster for the Cherenkov Telescope Array.Comment: 19 pages, 15 figures, 1 table. Accepted for publication in Phys. Rev.

Isolation and gene analysis of interferon α-resistant cell clones of the hepatitis C virus subgenome

AbstractHepatitis C virus (HCV) proteins appear to play an important role in IFN-resistance, but the molecular mechanism remains unclear. To clarify the mechanism in HCV replicon RNA harboring Huh-7 cells (Huh-9-13), we isolated cellular clones with impaired IFNα-sensitivity. Huh-9-13 was cultured for approximately 2 months in the presence of IFNα, and 4 IFNα-resistant cell clones showing significant resistances were obtained. When total RNA from clones was introduced into Huh-7 cells, the transfected cells also exhibited IFNα-resistance. Although no common mutations were present, mutations in NS3 and NS5A regions were accumulated. Transactivation of IFNα and IFNα-stimulated Stat-1 phosphorylation were reduced, and the elimination of HCV replicon RNA from the clones restored the IFNα signaling. These results suggest that the mutations in the HCV replicon RNA, at least in part, cause an inhibition of IFN signaling and are important for acquisition of IFNα resistance in Huh-9-13

Pre-DECIGO can get the smoking gun to decide the astrophysical or cosmological origin of GW150914-like binary black holes

Pre-DECIGO consists of three spacecraft arranged in an equilateral triangle with 100km arm lengths orbiting 2000km above the surface of the earth. It is hoped that the launch date will be in the late 2020s. Pre-DECIGO has one clear target: binary black holes (BBHs) like GW150914 and GW151226. Pre-DECIGO can detect $\sim 30M_\odot-30M_\odot$ BBH mergers up to redshift $z\sim 30$. The cumulative event rate is $\sim 1.8\times 10^{5}\,{\rm events~yr^{-1}}$ in the Pop III origin model of BBHs like GW150914, and it saturates at $z\sim 10$, while in the primordial BBH (PBBH) model, the cumulative event rate is $\sim 3\times 10^{4}\,{\rm events~ yr^{-1}}$ at $z=30$ even if only $0.1\%$ of the dark matter consists of PBHs, and it is still increasing at $z=30$. In the Pop I/II model of BBHs, the cumulative event rate is $(3-10)\times10^{5}\,{\rm events~ yr^{-1}}$ and it saturates at $z \sim 6$. We present the requirements on orbit accuracy, drag free techniques, laser power, frequency stability, and interferometer test mass. For BBHs like GW150914 at 1Gpc, SNR$\sim 90$ is achieved with the definition of Pre-DECIGO in the $0.01-100$Hz band. Pre-DECIGO can measure the mass spectrum and the $z$-dependence of the merger rate to distinguish various models of BBHs like GW150914. Pre-DECIGO can also predict the direction of BBHs at $z=0.1$ with an accuracy of $\sim 0.3\,{\rm deg}^2$ and a merging time accuracy of $\sim 1$s at about a day before the merger so that ground-based GW detectors further developed at that time as well as electromagnetic follow-up observations can prepare for the detection of merger in advance. For intermediate mass BBHs at a large redshift $z > 10$, the QNM frequency after the merger can be within the Pre-DECIGO band so that the ringing tail can also be detectable to confirm the Einstein theory of general relativity with SNR$\sim 35$. [abridged]Comment: 17 pages, 10 figures, added some references, modifications to match the published version in PTE

Non-learning Stereo-aided Depth Completion under Mis-projection via Selective Stereo Matching

We propose a non-learning depth completion method for a sparse depth map captured using a light detection and ranging (LiDAR) sensor guided by a pair of stereo images. Generally, conventional stereo-aided depth completion methods have two limiations. (i) They assume the given sparse depth map is accurately aligned to the input image, whereas the alignment is difficult to achieve in practice. (ii) They have limited accuracy in the long range because the depth is estimated by pixel disparity. To solve the abovementioned limitations, we propose selective stereo matching (SSM) that searches the most appropriate depth value for each image pixel from its neighborly projected LiDAR points based on an energy minimization framework. This depth selection approach can handle any type of mis-projection. Moreover, SSM has an advantage in terms of long-range depth accuracy because it directly uses the LiDAR measurement rather than the depth acquired from the stereo. SSM is a discrete process; thus, we apply variational smoothing with binary anisotropic diffusion tensor (B-ADT) to generate a continuous depth map while preserving depth discontinuity across object boundaries. Experimentally, compared with the previous state-of-the-art stereo-aided depth completion, the proposed method reduced the mean absolute error (MAE) of the depth estimation to 0.65 times and demonstrated approximately twice more accurate estimation in the long range. Moreover, under various LiDAR-camera calibration errors, the proposed method reduced the depth estimation MAE to 0.34-0.93 times from previous depth completion methods.Comment: 15 pages, 13 figure