Toward Security Verification against Inference Attacks on Data Trees

This paper describes our ongoing work on security verification against inference attacks on data trees. We focus on infinite secrecy against inference attacks, which means that attackers cannot narrow down the candidates for the value of the sensitive information to finite by available information to the attackers. Our purpose is to propose a model under which infinite secrecy is decidable. To be specific, we first propose tree transducers which are expressive enough to represent practical queries. Then, in order to represent attackers' knowledge, we propose data tree types such that type inference and inverse type inference on those tree transducers are possible with respect to data tree types, and infiniteness of data tree types is decidable.Comment: In Proceedings TTATT 2013, arXiv:1311.505

"Communication and Coordination in Organizations" (in Japanese)

This paper analyzes a model of coordination where two agents attempt to coordinate their actions through communication. One agent (Sender) is engaged in finding the true state of nature in a stochastic environment and the action that best fits the state. The other agent (Receiver) in turn tries to ``understand'' the Sender's message and chooses his own action. Since the communication succeeds only probilistically, so does the coordination. In our model, two different modes of coordination are identified: the integral-type coordination based on the communication of soft information and the default-type coordination based on the predetermined default value. We find that the agents might choose the latter mode of coordination when the cost arising from the failed communication is high relative to the benefit from coordinating on the state-contingent best actions. Applications to the economics of organization are also discussed.

"Increasing Complexity of Artifacts and the Role of Product Architecture"(in Japanese)

The purpose of the paper is twofold: One is to explain the concept of product architecture in the context of increasing complexity of artifacts; The other is to examine the condition under which the open-standard strategy is likely to be adopted. Dramatic decreases in mechanical information processing cost due to IT development induced hierarchical subdivision of artifacts with a modular structure consisting of numerous parts. This brought to the fore the question of how to solve the complicated coordination/integration problem between development of whole product system and that of individual parts. There are two ways of classifying solutions to this problem: One is the distinction between coordination by humans and coordination by product architecture; The other is the distinction between decentralized coordination through markets and cooperative coordination via organizations or networks. We argue that precommitted standardization and open development strategies are complements. We then set up a model for examining the problem faced by a monopolist with a core technology to decide to choose between open-standard strategy or closed-integral strategy. Some comparative analytic results are provided.

Fan-shaped aurora as seen from Japan during a great magnetic storm on February 11, 1958

During a great magnetic storm on Feb 11, 1958, a fan-shaped aurora was photographed at Memambetsu, Hokkaido, Japan – the first and oldest photograph record of auroras observed in Japan, accompanied by many hand-made drawings, thus, portraying a rare opportunity of coexistence between photograph images and hand-made drawings. In fact, the same portrayal reminds us of the great red aurora with fan-shaped white pillars observed during the 1872 and 1770 great magnetic storms. The hand-made sketches, photographs, and the spectral data revealed that the white pillars and red glow of the fan-shaped aurora were dominated by auroral green and red lines, respectively. From the analysis of newly digitized microfilm data and hand-made drawings, we found that the fan-shaped aurora appeared during the peak activity of magnetic storm and moved westward at 0.4 km/s at 400-km altitude at 38°–40° magnetic latitudes, which is consistent with the enhanced convection pattern in the middle latitude at storm time. Such a fan-shaped aurora can fundamentally characterize the middle-latitude evening-to-midnight auroras during great magnetic storms, which show the most destabilized transient appearance of the inner magnetosphere

Information Sharing in Joint Research and Development

In today's science-driven industries, such as the semiconductor industry, firms are increasingly engaged in across-firm research and development projects in the form of a research consortium or a strategic alliance. Those collaboration processes, however, have complex aspects due to the competing relationship of the firms in product markets and will not be successful unless the participating firms have enough incentives to reveal their private information and to exert sufficient efforts. The paper attempts to explore the conditions under which firms have enough incentives to reveal their information and/or to expend collaborative efforts. Three existing economic models are examined for this purpose. It is argued that those incentives depend upon the nature of competition in the product markets, information structure, and the way that each firm's private information affects this competition. The models examined in the paper suggest that some mechanism is necessary to evaluate private technical information of each firm and to convey it to the other firms without distortion. This conclusion coincides with the observed fact that a neutral third-party plays an indispensable role in a successful research consortium.

Molecular contribution to cleft palate production in cleft lip mice

Cleft palate following cleft lip may include a developmental disorder during palatogenesis. CL/Fr mice fetuses, which develop cleft lip and palate spontaneously, have less capability for in vivo cell proliferation in palatal mesenchyme compared with CL/Fr normal fetuses. In order to know the changes of signaling molecules contributing to cleft palate morphogenesis following cleft lip, the mRNA expression profiles were compared in palatal shelves oriented vertically (before elevation) in CL/Fr fetuses with or without cleft lip. The changes in mRNA profile of cleft palate morphogenesis were presented in a microarray analysis, and genes were restricted to lists contributing to cleft palate development in CL/Fr fetuses with cleft lip. Four candidate genes (Ywhab, Nek2, Tacc1 and Frk) were linked in a gene network that associates with cell proliferation (cell cycle, MAPK, Wnt and Tgf beta pathways). Quantitative real-time RT-PCR highlighted the candidate genes that significantly changed in CL/Fr fetuses with cleft lip (Ywhab, Nek2 and Tacc1). The results of these molecular contributions will provide useful information for a better understanding of palatogenesis in cleft palate following cleft lip. Our data indicated the genetic contribution to cleft palate morphogenesis following cleft lip