• The KIPS Transactions:PartD
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• v.12D no.7 s.103
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• pp.1049-1064
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• 2005

The demands of increasingly complicated software have led to the proliferation of object-oriented design methodologies in embedded systems. To execute a system designed with objects in target hardware, a task set should be derived from the objects, representing how many tasks reside in the system and which task processes which event arriving at an object. The derived task set greatly influences the responsiveness of the system. Nevertheless, it is very difficult to derive an optimal task set due to the discrepancy between objects and tasks. Therefore, the common method currently used by developers is to repetitively try various task sets. This paper proposes Scenario-based Implementation Synthesis Architecture (SISA) to solve this problem. SISA encompasses a method for deriving a task set from a system designed with objects as well as its supporting development tools and run-time system architecture. A system designed with SISA not only consists of the smallest possible number of tasks, but also guarantees that the response time for each event in the system is minimized. We have fully implemented SISA by extending the ResoRT development tool and applied it to an existing industrial PBX system. The experimental results show that maximum response times were reduced $30.3\%$ on average compared to when the task set was derived by the best known existing methods.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.199-205
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• 2000

The vibration and noise of gears is due to the vibration exciting force caused by the tooth stiffness which changes periodically as the mesh of teeth proceeds and by the transmission error, that is, the rotation delay between driving gear and driven gear caused by manufacturing error and alignment error in assembly and so on. The purpose of this study is to develop how to calculate simultaneously the optimum amounts of tooth profile modification, end relief and crowning by minimizing the vibration exciting force of helical gears. We estimate the vibration exciting force by the mesh analysis of gears. The constraints of this problem consist of contact ratio and strengths of gear teeth such as tooth fillet stress, surface durability and scoring. ADS(Automated Design Synthesis) is used as an optimization tool. And, since the aspect ratio is an important parameter of tooth modification, we investigate the relation between it and the optimum values of tooth modification. The proposed method can calculate the optimum amount of tooth modification automatically and is to be utilized to resolve the problem of vibration of helical gears.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.174-182
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• 2002

The object-oriented design methods and their CASE tools are widely used in practice by many real-time software developers. However, object-oriented CASE tools require an additional step of identifying tasks from a given design model. Unfortunately, it is difficult to automate this step for a couple of reasons: (1) there are inherent discrepancies between objects and tasks; and (2) it is hard to derive tasks while maximizing real-time schedulability since this problem makes a non-trivial optimization problem. As a result, in practical object-oriented CASE tools, task identification is usually performed in an ad-hoc manner using hints provided by human designers. In this paper, we present a systematic, schedulability-aware approach that can help mapping real-time object-oriented models to multi-threaded implementations. In our approach, a task contains a group of mutually exclusive transactions that may possess different periods and deadline. For this new task model, we provide a new schedulability analysis algorithm. We also show how the run-time system is implemented and how executable code is generated in our frame work. We have performed a case study. It shows the difficulty of task derivation problem and the utility of the automated synthesis of implementations as well as the Inappropriateness of the single-threaded implementations.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.10 no.1
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• pp.21-26
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• 2024

Purpose: The objective of this study was to evaluate the estimated radiochemical yield (RCY) and quality of routine [¹⁸F]FDG production over two years (2022 and 2023) at Mongolia's first cyclotron facility, utilizing the MINItrace Qilin cyclotron (GE Healthcare, 9.6 MeV) and FASTLab 2 radiosynthesizer (GE Healthcare). Methods: [¹⁸F]Fluoride was generated using a MINItrace Qilin cyclotron, producing up to 2 Ci of radioactivity per run, 2-3 runs per week. The [¹⁸F]FDG production was carried out using the FASTLab 2 radiosynthesizer utilizing FDG Duo and Single Citrate cassettes through nucleophilic radiofluorination of mannose triflate followed by basic hydrolysis. Quality Controls, including radiochemical purity, radionuclidic purity and identity, chemical purity, residual solvents, assay for radioactivity, bacterial endotoxins, and sterility, were performed in accordance with United States Pharmacopeia (USP) standards using bSCAN TLC Scanner, Captus-3000 MCA, Scion-456 GC, and Endosafe nexgen-PTS. Facility design and operation were managed in accordance with International Atomic Energy Agency guidelines to ensure GMP compliance. Results: All quality control tests met the USP requirements, ensuring safe injections for patients. The RCY were within acceptable ranges. The RCY of the FASTLab 2 Duo cassette was consistently higher than that of the Single Citrate cassette throughout the study period. The RCY for both cassettes were gradually decreased over time, with no significant correlation between cyclotron maintenance and subsequent RCY. Conclusions: Further investigation is needed to identify factors contributing to the decreasing radiochemical yield.