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Klas M.,Fraunhofer Institute for Experimental Software Engineering | Nakao H.,Japan Manned Space Systems Corporation | Elberzhager F.,Fraunhofer Institute for Experimental Software Engineering | Munch J.,Fraunhofer Institute for Experimental Software Engineering
Empirical Software Engineering | Year: 2010

Planning quality assurance (QA) activities in a systematic way and controlling their execution are challenging tasks for companies that develop software or softwareintensive systems. Both require estimation capabilities regarding the effectiveness of the applied QA techniques and the defect content of the checked artifacts. Existing approaches for these purposes need extensive measurement data from historical projects. Due to the fact that many companies do not collect enough data for applying these approaches (especially for the early project lifecycle), they typically base their QA planning and controlling solely on expert opinion. This article presents a hybrid method combining commonly available measurement data and context-specific expert knowledge. To evaluate the method's applicability and usefulness, we conducted a case study in the context of independent verification and validation activities for critical software in the space domain. A hybrid defect content and effectiveness model was developed for the software requirements analysis phase and evaluated with available legacy data. One major result is that the hybrid model provides improved estimation accuracy when compared to applicable models based solely on data. The mean magnitude of relative error (MMRE) determined by crossvalidation is 29.6% compared to 76.5% obtained by the most accurate data-based model. © Springer Science + Business Media, LLC 2009. Source


Ueyama K.,Japan Manned Space Systems Corporation
61st International Astronautical Congress 2010, IAC 2010 | Year: 2010

The life science experiments operations conducted in Japan Experiment Module (JEM) 'KIBO' so far are outlined briefly. 'KIBO', which means 'hope' in Japanese, is the largest science module in the ISS, and has been providing great opportunities to perform long duration life science experiments in space. In 2009, cell incubation, plant cultivation, and animalcule growth experiment were held in SAIBO rack which contains Cell Biology Experiment Facility (CBEF) and Clean Bench (CB). Operations life cycle of the life science experiments in KIBO will be presented. Life science experiments in KIBO are leaded by the payload's fight controller teams; JEM-Payload, JPOC and 'BIO' from Tsukuba Space Center (TKSC). Issues of the life science experiments operations and some solution examples are described. It is desired that the solution methods could help to propose new ideas for some malfunctions. Clearly-stated operations rules, enough training, carefully written and checked procedures and scheduling must be needed for mission success. BIO often required expeditious and accurate judgments in real-time operations because living samples have a critical time limit if they were exposed to inappropriate environments. Some unique solution methods using common stuffs are advanced by BIO for problems. Life science experiments in the ISS will generate great contribution to the progress of manned space programs. All operational knowledge should be shared among international parties. Copyright ©2010 by the International Astronautical Federation. All rights reserved. Source


Miura A.,Wireless Network Research Institute | Hamamoto N.,Japan Manned Space Systems Corporation | Fujino Y.,Toyo University
Journal of the National Institute of Information and Communications Technology | Year: 2015

Evaluations are carried out in order to verify the feasibility of frequency sharing scheme between satellite and terrestrial links in Satellite/Terrestrial Integrated mobile Communication System (STICS), considering radio-wave interference between those links. The interference level for each interference path is evaluated by using the simple interference model. The capacity of terrestrial and satellite links under co-channel interference is evaluated by using the detailed interference model. Minimum separation distance between satellite terminal and base station is evaluated. From these evaluations, the feasibility of frequency sharing scheme between satellite and terrestrial links is confirmed. Source


Hamamoto N.,Japan Manned Space Systems Corporation
Journal of the National Institute of Information and Communications Technology | Year: 2015

In a handheld satellite phone system using a large onboard reflector and a phased array feed system, multi beams with low side-lobe level are important for frequency reuse. In the beam pattern design, a search method combining constraint points is usually used for obtaining an optimized set of excitation distributions of the feed system. This paper studies a simple method of deriving the excitation distributions for low side-lobe beams and evaluates the effectiveness and the limits of the method by computer simulation. Source


Fujino Y.,Toyo University | Hamamoto N.,Japan Manned Space Systems Corporation
Journal of the National Institute of Information and Communications Technology | Year: 2015

In this paper, we describe design of onboard antenna system for STICS. Source

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