First principles calculations on the crystal and electronic structure of a layered Li(Ni 1/3 Mn 1/3 M 1/3 )O 2 (M = Al, Ti, Cr, Fe and Mo) were undertaken as part of a search for new positive electrode materials for advanced lithium ion batteries. The formal charge of Ni, Mn and M (Ti and Mo) were estimated to be +2, +3 and +4, respectively, from electronic structures and interatomic distances. In the cases of the Al, Cr and Fe substitution, the compounds had trivalent M and tetravalent Mn ions. The solid-state redox reactions of Li(Ni 1/3 Mn 1/3 M 1/3 )O 2 were calculated assuming a Li deinsertion scheme, and the reactions were shown to be Ni 2+ /Ni 3+ /Ni 4+ and M 3+ /M 4+ for the Cr and Fe substitution. Al substitution will lead to higher voltages, as fixed 3+ valence of Al forces more electron exchange with oxygen. The cases of Ti and Mo substitution, Ti and Ni ions do not participate in the redox reactions over the entire range, respectively. The substitutive cation-oxygen bonding has a more covalent character, when the redox energy of Ni is lowered, resulting in an increase in potential. As described above, the voltage profiles are very different because the types of metals are different and participate in electrochemical reactions according to the substituted.

First-principles calculations were performed on the electronic structure and x-ray-absorption near-edge structure (XANES) of amorphous Zr-oxide and Hf-oxide thin films. Using the discrete variational X-α method, the authors simulated the films with (Zr4O17)−18 and (Hf4O18)−20 clusters. The O–Zr and O–Hf bonds were found to have different characteristics along the bond orientation. By comparing the experimental and calculated XANES, we analyze the absorption mechanism of amorphous Zr-oxide and Hf-oxide thin films for energies up to 10eV above the OK edge.

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Mobile applications are software systems running on handheld devices, such as smartphones, PDAs, tablets and so on. The market of mobile application has rapidly expanded in the past few years. In this paper, we present a novel approach to track smartphone application usage from a event logs on the mobile device and analyzed both on client system and usage analysis server. We implemented our client system on Android device based usage analytics platform. Based on the analysis server system, we obtained over 47,000 user base, and we get the user's app usage informations on realtime. In this paper, we describe a large scale deployment-based research for a smartphone usage patterns and usage information visualization techniques.

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