The Mars Global Surveyor (MGS) spacecraft, launched on November 7, 1996, carries an experimental space-to-ground telecommunications link at 32 GHz (Ka-band) along with the primary 8.4-GHz (X-band) downlink used for operational MGS project activities. The signals are simultaneously transmitted from a 1.5-m-diameter parabolic antenna on MGS and received by 34-meter beamwaveguide (BWG) antennas lo...

Global Precipitation Measurement (GPM) is poised to be the next generation precipitation observations from space after the TRMM mission. The GPM will carry a dual-frequency precipitation radar (DPR), operating at Ku and Ka band frequencies. Since space-borne precipitation observations have never been done in Ka band before, extensive research work on dualfrequency radar, including electromagnet...

This paper studies nominal expressions in Japanese that are formed by conjoining two or more nominal expressions with conjunctions, and presents a theory of nominal expressions that captures their behaviors. In what follows, such nominal expressions are referred to as conjoined nominal expressions. In terms of their behaviors, the conjoined nominal expressions in Japanese form three categories....

The Khan Academy platform enables powerful on-line courses in which students can watch videos, solve exercises, or earn badges. This platform provides an advanced learning analytics module with useful visualizations. Nevertheless, it can be improved. In this paper, we describe ALAS-KA, which provides an extension of the learning analytics support for the Khan Academy platform. We herein present...

We report on a successful pr oject for transference of advanced planning and sche duling technology for out age management a collab orationbetween R omeL ab oratory the Electrical Power R esear ch Institute Ka man Science and Kestrel Institute as part of DOD s dual use program The main goal of the project was to evaluate the use of transformational approaches and AI te chnology to solve real wo...

For any positive integers a, b, c, d, let Ra,b,c,d be the graph obtained from the complete graphs Ka,Kb,Kc and Kd by adding edges joining every vertex in Ka and Kc to every vertex in Kb and Kd. This paper shows that for arbitrary positive integers a, b, c and d, every root of the chromatic polynomial of Ra,b,c,d is either a real number or a non-real number with its real part equal to (a + b + c...

Different satellite systems have been defined to provide broadband communications and internet access in remote geographical areas in Ka band (20-30 GHz) [1-2], being the up-link at 30 GHz and the down-link at 20 GHz. Costeffective antennas are required for fixed and portable terminals in Ka-band. Conventional reflectors are a preferred option to maintain reduced costs. However, the different r...

This paper discusses system and technology aspects crucial to the development of satellite communications at Ka band (20–30 GHz) and beyond. It surveys the evolution of Ka band geostationary Earth orbit (GEO) satellite communications until the present stage of development of systems for direct-to-user (DTU) provision of interactive multimedia services worldwide. Then it discusses the attenuatio...

It is now more than ten years since Linearizer Technology, Inc. (LTI) introduced the first millimeter wave (MMW) linearizers. During this time the capabilities of MMW linearizers have advanced tremendously. Today’s MMW linearizers operate at higher frequency (> 45 GHz), provide wider bandwidth (> 10 GHz), and give greater performance (> 20 dB NPR at 4 dB OPBO). They also operate with a wider va...