• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.10
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• pp.827-832
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• 2013

Heating wire cutting type separation mechanism has been widely used for cube satellite applications due to its design constraints such as small size of $10cm{\times}10cm{\times}10cm$ and light weight of less than 1kg. In addition, usage of pyro technic device is not allowed for cube satellite application. The conventional methods have some disadvantages of relatively small mechanical constraint force and the system complexity for the multi-deployable systems. In this paper, a separation nut type non-explosive separation mechanism has been proposed and investigated. The effectiveness of the design has been verified through the qualification tests of the mechanism.

• Progress in Medical Physics
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• v.30 no.4
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• pp.120-127
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• 2019

Purpose: This study was designed to evaluate the dosimetric performance of Mobius3D by comparison with an aSi-based electronic portal imaging device (EPID) and Octavius 4D, which are conventionally used for patient-specific prescription dose verification. Methods: The study was conducted using nine patients who were treated by volumetric modulated arc therapy. To evaluate the feasibility of Mobius3D for prescription dose verification, we compared the QA results of Mobius3D to an aSi-based EPID and the Octavius 4D dose verification methods. The first was the comparison of the Mobius3D verification phantom dose, and the second was to gamma index analysis. Results: The percentage differences between the calculated point dose and measurements from a PTW31010 ion chamber were 1.6%±1.3%, 2.0%±0.8%, and 1.2%±1.2%, using collapsed cone convolution, an analytical anisotropic algorithm, and the AcurosXB algorithm respectively. The average difference was found to be 1.6%±0.3%. Additionally, in the case of using the PTW31014 ion chamber, the corresponding results were 2.0%±1.4%, 2.4%±2.1%, and 1.6%±2.5%, showing an average agreement within 2.0%±0.3%. Considering all the criteria, the Mobius3D result showed that the percentage dose difference from the EPID was within 0.46%±0.34% on average, and the percentage dose difference from Octavius 4D was within 3.14%±2.85% on average. Conclusions: We conclude that Mobius3D can be used interchangeably with phantom-based dosimetry systems, which are commonly used as patient-specific prescription dose verification tools, especially under the conditions of 3%/3 mm and 95% pass rate.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.1-8
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• 2011

The requirement of a system-on-a-chip (SoC) design is increasing, which combines various and complex functional units on a single device. However, short time to market prohibits to release the device. To satisfy this shorter time-to-market, verification of both hardware and software at the same time is important. A virtual platform-based design method supports faster verification of these combined software and hardware by reusing pre-defined intellectual properties (IP). In this paper, we introduce the virtual platform-based design and redesign the existing ARM processor based S3C2440A system using the virtual platform-based method. In addtion, we implement and evaluate the performance of a JPEG decoder on the S3C2440A virtual platform. Furthermore, we introduce an optimized technique of the JPEG decoder using the ARM based inline assembly language, and then verify the performance improvement on the virtual platform. Such virtual platform-based design allows to verify both software and hardware at the same time and can meet the requirement of the shorter time-to-market.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.6
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• pp.488-501
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• 2009

In ubiquitous environments, invisible devices and software are connected to one another to provide convenient services to users. In order to provide such services, we must have mobile devices that connect users and services. But such services are usually limited to those served on a single mobile device. To resolve the resource limitation problem of mobile devices, a nearby resource sharing research has been studied. Also, not only the nearby resource share but also a resource recommendation through context-based resource reasoning has been studied such as an UMO Project. The UMO Project share and manage the various context information for the personalization resource recommendation and reason based on current context information. Also, should verify resource inference rules for reliable the resource recommendation. But, to create various context information requires huge cost and time in actuality. Thus, we propose a inference verification tool called USim to resolve problem. The proposed inference verification tool provides convenient graphic user interfaces and it easily creates context information. The USim exactly verifies new inference rules through dynamic changes of context information.

• International Journal of Aerospace System Engineering
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• v.9 no.1
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• pp.1-15
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• 2022

Pyrotechnic initiators provide a source of pyrotechnic energy used to initiate a variety of space mechanisms. Pyrotechnic systems build in electromagnetic environment that may lead to critical or catastrophic hazards. Special precautions are need to prevent a pulse large enough to trigger the initiator from appearing in the pyrotechnic firing circuits at any but the desired time. The EMC verification shall be shown by analysis or test that the pyrotechnic systems meets the requirements of inadvertent activation. The MIL-STD-1576 and two range safeties, AFSPC and CSG, require the safety margin for electromagnetic potential hazards to pyrotechnic systems to a level at least 20 dB below the maximum no-fire power of the EED. The PC23 is equivalent to NASA standard initiator and the 1EPWH100 squib is ESA standard initiator. This paper verifies the two safety margins for electromagnetic potential hazards. The first is verified by analyzing against a RF power. The second is verified by testing against a DC current. The EMC safety margin requirement against RF power has been demonstrated through the electric field coupling analysis in differential mode with 21 dB both PC23 and 1EPWH100, and in common mode with 58 dB for PC23 and 48 dB for 1EPWH100 against the maximum no-fire power of the EED. Also, the EMC safety margin requirement against DC current has been demonstrated through the electrical isolation test for the pyrotechnic firing circuits with greater than 20 dB below the maximum no-fire current of the EED.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1139-1144
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• 2008

In this paper, we propose an automatic generation method of transaction level(TL) model from algorithmic model to verify system specification fast and effectively using virtual platform. The TL virtual platform including structural properties such as timing, synchronization and real-time is one of the effective verification frameworks. However, whenever change system specification or HW/SW mapping, we must rebuild virtual platform and additional design/verification time is required. And the manual description is very time-consuming and error-prone process. To solve these problems, we build TL library which consists of basic components of virtual platform such as CPU, memory, timer. We developed a set of design/verification tools in order to generate a virtual platform automatically. Our tools generate a virtual platform which consists of embedded real-time operating system (RTOS) and hardware components from an algorithmic modeling. And for communication between HW and SW, memory map and device drivers are generated. The effectiveness of our proposed framework has been successfully verified with a Joint Photographic Expert Group (JPEG) and H.264 algorithm. We claim that our approach enables us to generate an application specific virtual platform $100x{\tims}1000x$ faster than manual designs. Also, we can refine an initial platform incrementally to find a better HW/SW mapping. Furthermore, application software can be concurrently designed and optimized as well as RTOS by the generated virtual platform

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2083-2088
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• 2015

The transient characteristics of the tri-axial High Temperature Superconducting (HTS) power cable are different from those of a conventional power cable depending on whether the cable is under a steady or transient state due to the quench. Verification using simulation tools is required to confirm both the characteristics of the cable and the effect of the cable when it is applied to a real utility. However, a component for the cable has not been provided in simulation tools; thus the RTDS-based model component of the tri-axial HTS power cable was developed, and a simulation was performed under the transient state. The considered properties of model component include resistance, reactance and temperature. Simulation results indicate the variation of HTS power cable condition. The results are used for the transient characteristic analysis and stability verification of the tri-axial HTS power cable. In the future, the RTDS-based model component of the cable will be used to implement the hardware-in-the-loop simulation with a protection device.

• Journal of the Korea Computer Industry Society
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• v.3 no.2
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• pp.149-158
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• 2002

This paper deals with design and verification of an arithmetic logic unit(ALU) to be used for development of optical computers. The ALU is based on optical switching device, $LiNbO_3$, which is easy to interface with electronic technology and most common in the market. It consists of an arithmetic/logic circuit performing logic operations, memory devices storing operands and the results of operations, and supplementary circuits to select instruction codes, and operates in bit-serial manner. In addition, a simulator is developed for verification of the design, and a set of basic instructions are executed in sequence and step-by-step changes in the accumulator and the memory are examined through simulations, to show that various operations are performed correctly.

• Journal of Drive and Control
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• v.20 no.4
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• pp.17-26
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• 2023

A forklift is an industrial vehicle that lifts or transports heavy objects using a hydraulically operated fork, and is equipped with an automatic transmission for the convenience of repetitive transportation, loading, and unloading work. The Transmission Control Unit (TCU) is a key component in charge of the shift control function of an automatic transmission. It consists of an electric circuit with an input/output signal interface function and firmware running on a microcontroller. To develop TCU firmware, the development process of shifting algorithm design, firmware programming, verification test, and performance improvement must be repeated. A simulator is a device that simulates a mechanical system having dynamic characteristics in real time and simulates various sensor signals installed in the system. The embedded transmission simulator is a simulator that is embedded in the TCU firmware. information related to the mechanical system that is necessary for TCU normal operation. In this study, an embedded transmission simulator applied to the originally developed forklift TCU firmware was designed and used to verify various forklift shift control algorithms.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.226-228
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• 2006

In this paper we describe a simulation and development framework for designing mobile 3D graphics architectures. We are developing a simple and flexible simulation and verification environment (SVE) that uses gITrace's ability to intercept and redirect an OpenGL/ES streams. In combination wlth gITrace to trace OpenGL/ES commands, the SVE simulates the behavior of mobile 3D graphics pipeline during playback of traces, and then produces the second geometry trace that can be used as a test vector for the Verilog/HDL RT-level model. By comparing the frame-by-frame results, we can conduct architectural verification. To demonstrate the functionality of the SVE, we show the implementation of the verified mobile 3D architecture on a FPGA board. For this, we also present an application development environment (ADE) includes a mobile graphics API and a device driver interface (DDI). The proposed two software environments, the SVE and the ADE could be used fer developing and testing mobile applications, architectural study and speculative hardware designs.