Communication Information Systems Course 2017 Colloquium Overview
2nd
- 日時
- 2017年5月19日(金) 16:30-18:00
- 場所
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※YRPで聴講される場合は世話人まで事前にご連絡ください。
- Speaker
- Prof. Akinori Ihara(Nara Institute of Science and Technology)
- Title
- Open Source Software Engineering
- Abstract
- Open Source Software (OSS) is often used by individuals/organizations, and many industrial systems with OSS are developed. In order to lead to use/develop safe and secure OSS, this presentation overviews a research field called Open Source Software Engineering, through introducing existing academic studies.
3rd
- 日時
- 2017年6月16日(金) 16:30-18:00
- 場所
-
※YRPで聴講される場合は世話人まで事前にご連絡ください。
- Speaker
- Dr. Hiroshi Harada(Professor, Graduate School of Informatics, Kyoto University)
- Title
- A Fact of International Standardization In Wireless Communications
- Abstract
-
Standardization defines a common technical specification by which venders easily develop their interoperable products. The standardized products will involve other cross-industrial products and systems and finally create a big market.
In the international standardization body, contributors bring their own fundamental technologies and patents and need to form consensus beyond race, religion and sense of values. But the contributors also need to maximize their benefits. This is a magnificent game.
This lecture will introduce a fact of international standardization in wireless communications from the experience of operational and technical contributions to IEEE standardizations related to wireless communications.
4th
- 日時
- 2017年7月21日(金) 16:30-18:00
- 場所
-
※YRPで聴講される場合は世話人まで事前にご連絡ください。
- Speaker
- Dr. Kornyanat Hozumi(国立研究開発法人 情報通信研究機構)
- Title
- Study of low-latitude ionosphere through radio propagation and multi-instrument
- Abstract
- Latitudinal variation of the Earth ionosphere is mainly due to different physical processes associated with different geomagnetic field line (B) configurations. In low latitude, the magnetic inclination is nearly zero. Upward component of ExB drift plays an important role in the up-down motion of plasma. After uplifted by ExB drift, plasma diffuses along B. Then two plasma density crests are formed around 15º apart from the dip equator, so-called Equatorial Ionization Anomaly (EIA). Large plasma density gradient around the EIA crests introduces a considerable time delay that impacts on GPS navigation system. There is another ionospheric irregularity, so-called plasma bubble, at latitudes between the dip equator and EIA crests. Plasma bubble envelop has large plasma density gradient. Various irregularity scales coexist inside plasma bubble. It causes a scintillation in trans-ionospheric radio signals, and loss of lock of the signal in the worst case scenario. Then satellite communication breaks down. I have been studied the physical process, irregular characteristic, and impact of low latitudes irregularities. In this talk, radio propagation simulator and multi-instrument technique for low latitudes ionospheric study will be introduced. Socio impact of space weather via ionosphere will be discussed.
5th
- 日時
- 2017年10月20日(金) 16:30-18:00
- 場所
-
※YRPで聴講される場合は世話人まで事前にご連絡ください。
- Speaker
- Prof. David W Matula(Computer Science and Engineering Southern Methodist University)
- Title
- Hierarichal Cluster Analysis Employing a Network Flow Duality Model
- Abstract
- Transportation networks, communication networks, neural networks, and social networks arise from different subjects but share some common goals. One is to partition the objects (nodes of the network) into component clusters where objects in the same cluster have relatively more affinity (connectivity) to each other and objects in different clusters are relatively less similar (sparsely connected). In contrast to many existing approaches we model this dual objective employing the integrated natural duality between cuts and paths (flows) introduced by Menger in 1927 and furthered by the maxflow/mincut logistics models in the 1950’s. This integrated approach is extended to an all pairs peer-to-peer model. We describe a linear program (LP) formulation of the maximum concurrent flow problem(MCFP) and a hierarchical version (HMCFP) which assures polynomially bounded time computation and a theoretical foundation to the hierarchical clustering (partitioning) problem. The solution exhibits a natural duality where the paths with flow identify the more strongly connected partition components and relatively sparse cuts separate the components.
At any level of the hierarchy the solution identifies a topology between the components not found by other existing cluster methods.
6th
- 日時
- 2017年11月17日(金) 16:30-18:00
- 場所
-
※YRPで聴講される場合は世話人まで事前にご連絡ください。
- Speaker
- 西尾理志先生 (京都大学大学院情報学研究科 通信情報システム専攻 助教)
- Title
- Wireless Networks with Computer Vision
- Abstract
- This talk introduces a new paradigm of wireless networks, which leverages computer vision in order to analyze and predict communication environments. Mobility of things in the communication environment affects the quality of wireless communication, especially the quality of high frequency wireless such as millimeter wave and visible light communications. Computer vision enable the wireless network to foresee dynamics of wireless environment. This talk introduces works to predict communication quality from imagery and to control wireless network predictively, and show proof of concept experiments.
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8th
- 日時
- 2018年1月19日(金) 16:30-18:00
- 場所
-
※YRPで聴講される場合は世話人まで事前にご連絡ください。
- Speaker
- 吉原 貴之氏 (国立研究開発法人海上・港湾・航空技術研究所 電子航法研究所 主幹研究員)
- Title
- Study on observations of Earth’s atmosphere to support civil aviation operation
- Abstract
- Weather information is very important for safe and efficient aircraft operations. For an example, aircraft must fly avoiding meteorological disturbance areas such as cumulonimbus clouds and strong wind shear to ensure safety. The aircraft approach direction to the runway also depends on local wind direction around the airport. As a future aircraft operation, trajectory-based operation is proposed. Where, aircraft operation is controlled with a three dimensional trajectory and a series of transit time to pass each waypoint. Therefore, wind condition on a trajectory affects accuracy of aircraft’s estimated arrival time, and reliable weather forecast information is required to realize the trajectory-based operation.
GNSS (Global Navigation Satellite System)-based navigation system is an enabler to support the trajectory-based operation because it gives aircraft accurate position and time information. However, GNSS signals are affected by Earth’s atmosphere as signal propagation delay. Consequently, the effect brings errors to users in positioning and timing solution. Earth’s atmospheric effects are summarized as ionospheric and tropospheric delay. To improve weather forecast reliability, it is expected to extract information on water vapor content from the tropospheric delay with correction information on other error sources because water vapor content is an important parameter to forecast meteorological disturbances and it is generally difficult to measure it. As one of topics in this presentation, airborne-based occultation technique is introduced as a GNSS-based remote sensing to measure water vapor information. Another topic is wind measurement with information combined between aircraft’s in-situ observation and aircraft position information tracked by aircraft surveillance radar on the ground. In the current, weather forecast system uses downlinked data, which are pressure, temperature and wind conditions, from aircraft to the ground. However, the air-to- ground communication capacity is limited. The combination information mentioned above is expected to add complement information to the current observations to improve weather forecast performance. In the presentation, these topics are mainly introduced with background of air traffic managements.