Shin-ichiro Mori

First In Situ Observation of the LiCoO2 Electrode/Electrolyte Interface by Total-Reflection X-ray Absorption Spectroscopy†

Rechargeable lithium-ion batteries (LIBs) are widely used as electrical energy storage devices for technologies such as portable electronics and electric and hybrid vehicles, and they are considered to be serious power storage candidates for smart-grid electricity systems. Traditionally, research in the field has focused on battery improvement through a selective use of new or existing materials for positive and negative electrodes, as the bulk properties of electrodes primarily limit charge capacity and power. However, the durability of LIBs is largely rooted in side reactions that occur at the electrode/ electrolyte interface, especially those at the positive electrode. Thus, controlling the chemical stability of any electrode material with respect to the operating liquid electrolyte medium, which requires a control of the electrode/electrolyte interface through surface chemistry, is as important as designing new materials. The scale of such an interfacial region is speculated to be on the order of a few nanometers, which shall be deemed as approximately the Debye length. This scale indicates that structural and chemical information should be tracked with a resolution of a few nanometers to reveal the phenomena of the electrode/ electrolyte interface. Previous research has focused on a detailed examination of the interfacial reactions at the positive electrode surface by using methods such as X-ray photoelectron spectroscopy (XPS) and surface X-ray diffraction (SXRD). However, characterization of the electrode surface at the nanoscale under conditions of an operating battery remains insufficient because of the lack of suitable observation techniques. A proposed degradation mechanism for electrodes has been extrapolated from indirect information obtained from analysis of disassembled, deteriorated electrodes. To obtain concise and meaningful surface data, a technique that enables high-resolution analysis of chemical information at the solid electrode surface is required. X-ray absorption spectroscopy (XAS), which makes it possible to identify the electronic and local structures of a certain atom, is a potent and versatile technique to resolve the chemical states of a lithium-ion electrode material independently of its crystallinity. To extract information about the interfacial phenomena by XAS, total-reflection fluorescence XAS (TRF-XAS), which integrates the fluorescence yield obtained under total reflection, can be applied. A recent study has shown that polycrystalline thin films are preferred relative to epitaxial thin films (that are strongly influenced by the substrate) to simulate the conditions of applied composite electrodes. We herein use polycrystalline LiCoO2 thin films prepared by pulsed laser deposition (PLD) as the model electrodes; these electrodes are flat at the nanoscale and have structural properties similar to those of the applied composite electrode (see section S1 in the Supporting Information). Figure 1 shows the charge/discharge cycle dependencies of cyclic voltammograms (CVs) and electrochemical impedance spectra (EIS) of the LiCoO2 thin films used in this study (see section S1 in the Supporting Information). Typical CVs

A high-speed dynamic instruction scheduling scheme for superscalar processors

The wakeup logic is a part of the issuing window and is responsible to manage the ready flags of the operands for dynamic instruction scheduling. The conventional wakeup logic is based on association, and composed of a RAM and a CAM. Since the logic is not pipelinable and the delays of these memories are dominated by the wire delays, the logic will be more critical with deeper pipelines and smaller feature sizes. This paper describes a new scheduling scheme not based on the association but on matrices which represent the dependences between instructions. Since the update logic of the matrices detects the dependencies between instructions as the register renaming logic does, the wakeup operation is realized by just reading the matrices. This paper also describes a technique to reduce the effective size of the matrices for small IPC penalties. We designed the layouts of the logics guided by a 0.18µm CMOS design rule provided by Fujitsu Limited, and calculated the delays. We also evaluated the penalties by cycle-level simulation. The results show that our scheme achieves 2.7GHz clock speed for the IPC degradation of about 1%.

A distributed shared memory multiprocessor: ASURA - Memory and cache architectures

ASURA is a large scale, cluster-based, distributed, shared memory, multiprocessor being developed at Kyoto University and Kubota Corporation. Up to 128 clusters are interconnected to form an ASURA system of up to 1024 processors. The basic concept of the ASURA design is to take advantage of the hierarchical structure of the system. Implementing this concept, a large shared cache is placed between each cluster and the inter-cluster network. The shared cache and the shared memories distributed among the clusters form part of ASURAs hierarchical memory architecture, providing various unique features to ASURA. In this paper, the hierarchical memory architecture of ASURA and its unique cache coherence scheme, including a proposal of a new hierarchical directory scheme, are described with some simulation results.

Impact of HLA mismatch direction on the outcome of unrelated bone marrow transplantation: a retrospective analysis from the Japan Society for Hematopoietic Cell Transplantation.

The relative desirability of an unrelated donor with a bidirectional 1-locus mismatch (1MM-Bi), a 1-locus mismatch only in the graft-versus-host direction (1MM-GVH), or a 1-locus mismatch only in the host-versus-graft direction (1MM-HVG) is not yet clear. We analyzed adult patients with leukemia or myelodysplastic syndrome who received a first allogeneic stem cell transplant from an HLA-A, -B, -C, and -DRB1 matched or 1-allele mismatched unrelated donor in Japan. The effects of 1MM-Bi (n = 1020), 1MM-GVH (n = 83), and 1MM-HVG (n = 83) compared with a zero mismatch (0MM) (n = 2570) were analyzed after adjusting for other significant variables. The risk of grades III to IV acute graft-versus-host disease (GVHD) was higher with marginal significance in the 1MM-GVH group than in the 0MM group (hazard ratio, 1.85; P = .014). However, there was no significant difference in overall or nonrelapse mortality between the 1MM-GVH and 0MM groups. There was no significant difference in acute GVHD or overall or nonrelapse mortality between the 1MM-HVG and 0MM groups. The risks of acute GVHD and overall mortality were significantly higher in the 1MM-Bi group than in the 0MM group. These findings indicate that unrelated donors with 1MM-GVH and 1MM-HVG are both good candidates for patients without an HLA-matched unrelated donor in a Japanese cohort.

Donor Lymphocyte Infusion for Relapsed Hematological Malignancies after Unrelated Allogeneic Bone Marrow Transplantation Facilitated by the Japan Marrow Donor Program

To evaluate the safety and efficacy of donor lymphocyte infusion (DLI), we retrospectively analyzed 414 recipients who received unrelated DLI (UDLI) for the treatment of relapsed hematological malignancy after unrelated bone marrow transplantation (BMT). UDLI was administered for acute myelogenous leukemia (n = 184), myelodysplastic syndrome (n = 69), acute lymphocytic leukemia (n = 57), chronic myelogenous leukemia (CML, n = 36), lymphoid neoplasms (n = 38), adult T cell leukemia/lymphoma (n = 18), and multiple myeloma (n = 12). Sixty-five patients (16%) were in cytogenetic/molecular relapse and 349 (84%) were in hematological relapse after BMT. In total, 266 out of 414 (64%) patients received chemotherapy and/or molecular-targeted agents in combination with UDLI. The median time from BMT to UDLI was 244 days. The median number of infused CD3+ cells was 3.51 × 107/kg. Response and survival rates were evaluated at 100 days after UDLI. Complete response was obtained in 37 (57%) of 65 patients with cytogenetic/molecular relapse and in 69 (20%) of 349 patients with hematological relapse (P < .001). Two hundred forty-seven patients (60%) were alive, whereas 110 (26%) had died because of disease progression, 26 (6%) because of infections, 12 (3%) because of graft-versus-host disease (GVHD), and 13 (3%) because of organ failure. Multivariate analysis identified molecular/cytogenetic relapse, GVHD after UDLI, and CML but not combination with chemotherapy as significant prognostic factors. These results indicate that UDLI may have efficacy in relapsed patients with CML, low tumor burden, or occurrence of GVHD after UDLI.

Program phase detection based dynamic control mechanisms for pipeline stage unification adoption

To reduce the power consumption in mobile processors, a method called Pipeline Stage Unification (PSU) is previously proposed to work as an alternative for Dynamic Voltage Scaling (DVS). Based on PSU, we proposed two mechanisms which dynamically predict a suitable unification degree according to the knowledge of the program behaviors. Our results show that the mechanisms can achieve an average Energy Delay Product (EDP) decrease of 15.1% and 19.2%, respectively, for SPECint2000 benchmarks, compared to the processor without PSU.

Vertex-preserving Cutting of Elastic Objects

This paper proposes vertex-preserving cutting methods on finite element models for interactive soft tissue simulation. Unlike existing methods, we aim to shape variety of incisions using only initial vertices of tetrahedral meshes. Neither tetrahedral decomposition nor vertex creation is used. The number of vertices is preserved. This avoids increase of computation cost as well as allows fast update of physical status of finite element models. To preserve 3D shape and sharp feature of initial meshes through on-the-fly mesh modification, constraints are introduced to the topological update scheme. In our model, the size of stiffness matrix is constant. Our framework efficiently simulates several varieties of smooth incisions with sufficient quality for surgical simulation, and also achieves interactive performance in complex meshes with thousands of elements.

The intelligent cache controller of a massively parallel processor JUMP-I

This paper describes the intelligent cache controller of JUMP-I, a distributed shared memory type MPP. JUMP-I adopts an off-the-shelf superscalar as the element processor to meet the requirement of peak performance, but such a processor lacks the ability to hide inter-processor communication latency, which may easily become too long on MPPs. Therefore JUMP-I provides an intelligent memory system to remedy the weak point. The cache controller is one of the main components of the memory system, and provides many cache-level supports for inter-processor communication; explicit cache control, high-bandwidth cache prefetching, and a few types of synchronization structures for fine-grained message communication.

Optimized code generation for heterogeneous computing environment using parallelizing compiler TINPAR

This paper presents a compiling technique to generate optimized codes for heterogeneous computing environment. This paper also proposes a new dynamic load redistribution mechanism which can adaptively and dynamically distribute tasks among computers according to their available computing power which may vary during the computation. As the results of the performance evaluation, we could confirm that the generated codes are effectively executed in a heterogeneous computing environment with dynamic load change.

Amon: a parallel slice algorithm for wire routing

In thk paper a new parallel global and detailed wire routing algorithm called “Amen” is introduced. Both of them are done in parallel using different processor elements (PEs). We introduce a new way of dividing the multilayer grid into layers, and dividing layers into slices. Each PE, in the detailed routing, has a responsibility for one or more slice. This way of division obtains a high degree of parallelism. A new detailed routing algorithm which routes nets under the condition that these net paths do not prevent other nets from being routed later is also introduced. Amen gives high routing quality by using fewer vias and shorter wire length than the other algorithms. The results show that this algorithm obtains higher connection ratio than maze running algorithm.