Kohta Ohshima

Learn More
This paper proposes a high-speed reverse geocoding method for Location-based Service. In geocoding, the longitude and latitude become mutually convertible with the “area name.” The “area name” is an address and landmark name such as “Koganei City” and “Tokyo Tower” that are easy for the user to(More)
We propose a group synchronization method for VoD services based on syncing user PC internal clocks. A group synchronization video watching service enables users to simultaneously watch video along with communication functions. This service enables users to communicate with other group members online as if the group members were watching the video in the(More)
One of the problems affecting sensor networks for natural environments is the attenuation of radio waves due to high humidity, and the attenuation is worst in the case of a 2.4 GHz radio wave. We are developing a transmission control method that estimates communication environment fluctuations caused by changes in the natural environment. This paper(More)
We have implemented an FPGA accelerator, which realizes higher performance by executing a part of a Java source code executable in hardware, to accelerate Java execution in an Android mobile terminal. Between an Intel Atom processor which executes a Dalvik virtual machine and an FPGA accelerator, we have implemented PCI Express interface which performs high(More)
We designed a scalable distributed wireless network emulator for high-speed mobility. Wireless network emulators provide various conditions of mobile nodes' dynamics and wireless links to real implementation of protocols to be evaluated based on user-defined mobility scenarios. The target of the proposed emulator is IP-based protocols for large-scale mobile(More)
A Lens Free Imager (LFI) is one of promising candidates for massive visual inspection systems in biology and medical science. In a practical application, millions of samples need to be inspected in a short period of time, which a single Lens Free Imager (LFI) system cannot accomplish. Therefore, we propose a high performance parallel LFI system called(More)
One of the problems affecting sensor networks in natural environments is the attenuation of radio waves due to high humidity. This attenuation is greatest in the case of a 2.4-GHz radio wave. A system is being developed that uses a transmission control method to estimate communication environment fluctuations caused by changes in the natural environment.(More)
The IEEE 1588 Precision Time Protocol Version 2 (PTP v2) standard was developed to establish precise synchronization protocols for distributed nodes, and thus facilitate the development of distributed time-based systems. As an example of an applied system, we developed a distributed wireless network emulator that permits precise and stable synchronized(More)