We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved "Out of Africa" to explore the more severe climates of Eurasia.

We have developed a virtual reality collaborative environment on volume communications environment, which is a tele-immersive collaboration environment on a grid infrastructure. The system is targeted to develop this tools; it is an integrated environment consisting of a real time information sharing system between remotely located researchers and a three-dimensional (3D) image-based real-time communication system. To evaluate the system's functionality and performance, we have used it for real research problems, in the medical areas. This paper describes the system and effectiveness of virtual reality.

We have constructed a diagnostic support system for circulatory disease based on a volume communications environment. This system is based on a VizGrid environment, i.e. an integrated environment consisting of a data archiving system, a collaboration system, and a computational grid system. In this system, we simulate blood flow in a patient's individual blood vessel geometry and blood vessel wall using a weak coupling method. This system can be used with three-dimensional images from CT/MRI, for medical treatment and for simulating blood flow in a blood vessel with circulatory disease in a volume communications environment. With this system, it becomes easy for researchers in remote locations to collaboratively discuss the relevant object, even for complex explanations like the simulation results.

In cardiovascular biomechanics the fluid-structure interaction within large blood vessel is required to understand the aortic wall tear, aortic dissection and so on. A loosely coupled method was used to study the complex mechanical interaction under pulsatile flow in a three-layered aortic arch model. The results showed the variations of wall stress along arch portion, and wall stress distribution in three-layered wall. The study provide insight into the biomechanics of aortic dissection: at systolic acceleration phase, the highest normal stress in the media layer may be responsible for the tear and dissection extending into the media layer; at foot entrance flow, the shear stress might contribute to the dissection in the media near the adventitia layer.

We developed a real-time network-based visualization system, using Jini technology and UNICORE. Jini technology provides an environment for creating dynamically networked components. UNICORE is grid middleware, that effectively uses computer resources. With this system a user can easily check the results of a CFD calculation in the middle of the calculation.

Topology is important for any type of networks because it has great impact on the performance of the network. For wireless sensor networks (WSN), regular topologies, which can help to efficiently save energy and achieve long networking lifetime, have been well studied in [1, 4, 5, 7, 9]. However, little work is focused on routing in patterned WSNs except the shortest path routing with the knowledge of global location information. In this paper, we propose a routing protocol based on random walk. It doesn’t require global location information. Moreover, the random walk routing achieves load balancing property inherently for WSNs which is difficult to achieve for other routing protocols. We also prove that the random walk routing consumes the same amount of energy as the shortest path routing in the scenarios where the message required to be sent to the base station is in comparatively small size with the inquiry message among neighboring nodes. Since in many applications of WSNs, sensor nodes often send only beeplike small messages to the base station to report their status, our proposed random walk routing is a viable scheme. Though the random walk routing provides load balancing in the WSN, the nodes near to the base station (BS) are inevitably under heavier burden than the nodes far from the base station. Therefore we further propose a density-aware deployment scheme to guarantee that the heavy-load nodes do not affect the network lifetime even if they are exhausted.

We are developing a volume communications environment, which is a teleimmersive collaboration environment on a grid infrastructure. The system is targeted to develop this tools; it is an integrated environment consisting of a real time information sharing system between remotely located researchers and a three-dimensional (3D) image-based real-time communication system. To evaluate the system’s functionality and performance, we have used it for real research problems, in the medical areas. This paper describes the current prototype and development status.

A new method for two-dimensional (2D) photolithography simulation is proposed. Lightwaves in photoresist are assumed to be polarized, and the layer beneath the photoresist is assumed to be a perfect conductor. In order to analyze lightwave behavior in a 2D region, Maxwell equations for electromagnetic fields are simplified into a Helmholtz equation which is solved in the photoresist region, taking lightwave damping in the infinite vacuum region surrounding the photoresist into account. The finite-element method and boundary-element method are used in the calculations. The bleaching model proposed by Drill et al. is applied to describe photoresist behavior on irradiation by exposure light. When this simulation is applied to a photoresist system on a reflective stepped surface, the simulated photoresist image is found to be in reasonably good agreement with an actually developed profile.

A two-dimensional etching simulator named ESPRIT (FOOTNOTE: ESPRIT--Etching Simulation PRogram with an Improved sTring model.) has been developed to simulate LSI patterning. The etching simulator includes isotropic and anisotropic components. Its calculation method is based on the string model. ESPRIT can simulate etched profiles for multilayers with different etching rates and calculate side etching using sloped incidental anisotropic components. In addition, location correction, loop elimination, point insertion, and point elimination are provided for stable and accurate calculations. Simulated profiles coincide well with those from experiments in terms of relationship between the groove width and etched depth. ESPRIT can support to design LSI patterning process.