• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.105-113
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• 2011

During the development of flight software, the processor emulator and satellite simulator are essential tools for software development and verification, which can be substituted for the actual hardware. LEO satellites being developed by KARI recently use the MCM-ERC32SC processor for on-board computer (OBC). For the flight software (FSW) development and testing, the software-based spacecraft simulator was developed using TSIM-ERC32 processor emulator from Aeroflex Gaisler. It is needed to get rid of the constraints and dependencies of TSIM-ERC32 processor emulator and to obtain high performance processor emulator to develop full satellite simulator. This paper presents the development of the ERC32 emulator based on open source dynamic translator, QEMU, as the first step. And it describes the software development and testing/debugging on the developed emulator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1247-1255
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• 2016

The safety and autonomous flight function of micro UAV or drones is crucial to its commercial application. The requirement of own building stable drones is still a non-trivial obstacle for researchers that want to focus on the intelligence function, such vision and navigation algorithm. The paper present a GCS using commercial drone and hardware platforms, and open source software. The system follows modular architecture and now composed of the communication, UI, image processing. Especially, lane-keeping algorithm. are designed and verified through testing at a sports stadium. The designed lane-keeping algorithm estimates drone position and heading in the lane using Hough transform for line detection, RANSAC-vanishing point algorithm for selecting the desired lines, and tracking algorithm for stability of lines. The flight of drone is controlled by 'forward', 'stop', 'clock-rotate', and 'counter-clock rotate' commands. The present implemented system can fly straight and mild curve lane at 2-3 m/s.

• The KIPS Transactions:PartA
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• v.12A no.2 s.92
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• pp.87-94
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• 2005

Pattern matching is one of critical parts of Network Intrusion Prevention Systems (NIPS) and computationally intensive. To handle a large number of attack signature fattens increasing everyday, a network intrusion prevention system requires a multi pattern matching method that can meet the line speed of packet transfer. In this paper, we analyze Snort, a widely used open source network intrusion prevention/detection system, and its pattern matching characteristics. A multi pattern matching method for NIPS should efficiently handle a large number of patterns with a wide range of pattern lengths and case insensitive patterns matches. It should also be able to process multiple input characters in parallel. We propose a multi pattern matching hardware accelerator based on Shift-OR pattern matching algorithm. We evaluate the performance of the pattern matching accelerator under various assumptions. The performance evaluation shows that the pattern matching accelerator can be more than 80 times faster than the fastest software multi-pattern matching method used in Snort.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.674-680
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• 2008

An SDR (Software Defined Radio) system based on general purpose computing platform has benefits of ease of software development process, high degree of software compatibility, and cost-effectiveness of general purpose processors. This paper discusses design and implementation of a dual-mode SDR system that supports both cordless phone and walkie-talky system running on Linux-based general purpose computing platform. For this purpose, we designed modulation and demodulation software on open source-based GNU radio middleware. We also designed a customized RF front-end hardware which performs frequency conversion between RF and IF. The proposed SDR system successfully exhibited its ability to operate both cordless phone and walkie-talky communication on Intel processor-based general purpose computing platform. But experience with the prototype SDR system shows that further research is required for run-time software reconfiguration and efficient integration with conventional TCP/IP protocol stacks.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.64-64
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• 2018

하천에서 수위는 가장 기본적인 수리 수문학적 자료로서, 홍수나 가뭄 등의 피해를 막기 위한 치수와 물을 잘 통하게 하거나 물을 이용하기 위한 이수에 주로 사용된다. 예를 들면, 댐, 보, 저수지 등의 하천시설물 설계 및 관리를 위해 수위를 이용하며, 유량 산정을 위해서 수위-유량 관계 곡선식을 구축하여 수위를 이용한다. 따라서 하천에서 수위는 현재 국내에서 수자원분야에서 사용되는 자료 중에서 가장 중요하며, 동시에 광범위하게 사용되고 있으므로 수위를 관측하는 것이 수자원의 기초라 할 수 있다. 수위 관측의 필요성과 확장 필요성에 대한 인식에도 불구하고, 국내의 수위 관측소는 한강, 낙동강, 금강 등 대하천 위주로 설치되어 있어, 중소규모 하천에서 발생하는 다양한 수문사상에 대한 분석 및 예측이 어려운 실정이다. 특히, 홍수의 경우 같은 강우 사상에도 대하천보다는 중소규모의 하천이 더 극단적으로 유출이 발생하기 때문에, 즉각적인 수위의 계측이 필요한 실정이다. 하지만 한정된 예산 및 인프라의 부족은 중소규모 하천에 대한 수위 관측 시스템의 적용이 대하천에 비해 그 우선수위가 밀리는 원인이 되고 있으며, 지속적으로 중소규모 하천에 대한 수위 관측시스템 적용에 대한 수요가 증가를 야기 시키고 있다. 최근, 과거에 제품을 만들기 위한 전자회로, 자재명세서, 기판도면 등의 정보를 공개하지 않는 폐쇄적인 환경을 벗어나 제품을 만들기 위한 하드웨어 정보를 공개하고, 공개된 정보를 통해 기술을 개발하기 위한 움직임이 활발하다. 이러한 개념을 오픈소스 하드웨어라는 개념으로서, 하드웨어의 제작 없이 간단한 코딩을 통해 하드웨어를 컨트롤 하는 기술이다. 즉, 오픈소스 하드웨어는 초소형화된 PC를 활용하여 센서를 작동하는 것이라 할 수 있다. 이를 통해 기존의 기술을 저렴한 가격으로 제품으로 생산할 수 있다. 또한 사물인터넷(IOT)를 활용하여 온라인 상에서 이러한 오픈소스 하드웨어를 컨트롤 할 수 있으며, 웹서비스와 결합할 경우 센서를 통해 수집된 결과를 인터넷 상에서 확인 할 수 있는 기술들이 지속적으로 개발하고 있다. 이러한 기술이 접목되면 과거에 비해 적은 비용으로 고효율의 자료 수집을 수행 할 수 있다. 본 연구에서는 지속적으로 증가하고 있는 중소규모 하천에 대한 수위 관측시스템 적용에 대한 수요를 해결하기 위해서 기존의 시스템이 가지고 있는 경제적, 기술적 한계를 극복하기 위하여 오픈소스 하드웨어 플랫폼인 아두이노와 사물인터넷 기반 기술을 활용하기 위한 웹서비스를 이용하여 실시간 수위 관측기술을 개발하고, 적용성을 검토하고자 한다.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.31-40
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• 2018

We designed and implemented the attachable smart adapter for the general management of each company's agricultural machine regardless of whether it is equipped with a CAN (Controller Area Network) module. The smart adapter consists of a main board (Raspberry Pi3B), which operates agricultural machine's management software in Linux environment, and a self-developed interface board for power adjustment and status sensing. For the status monitoring, a sensing interface using a serial input was defined between the smart adapter and the sensors of the agricultural machine, and the state diagram of the agricultural machine was defined for diagnosis. We made a panel to simulate the sensors of the agricultural machine using the switch's on/off contact point, and confirmed the status monitoring and diagnostic functions by inputting each state of the farm machinery from the simulator panel.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.139-143
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• 2018

Arduino, based on open source hardware, is used in many IoT devices, and IoT devices require multitasking for various inputs and outputs. Among the several methods used for multitasking based on Arduino, we compare three methods: Timing Call by using millis(), Simple Timer library method, and Timer library method. In order to measure the execution error caused by measurement and time delay of each method, two situations are created and analyzed. In the first case, 10 random tasks of a certain size are generated to measure the time delay of each method. In the second situation, 10 random tasks of a certain size are generated to compare execution errors caused by the time lag of the Timer library. In the first case, the millis() timing call method and the Simple Timer library method have a similar time delay and the Timer library method has more time delay. In the second situation, an execution error occurred in which small-size tasks were not called back at the correct timing due to the time delay.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.11
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• pp.1351-1356
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• 2019

The purpose of this study is to investigate the effect of personal factors and community factors on the quality of life based on the presence of chronic patients based on the Big Data Platform. As a method of study, second data of 2017 community health survey and Statistics Korea by City·Gun·Gu public office were used and a multi-level analysis was conducted after separating EQ-5D index, individual factor and community factor. As a result, men, age, education level, monthly household income, having economic activity, the number of sports infrastructure were positively associated with the quality of life, and subjective health not good, extremely perceived stress were negatively associated with the quality of life. Research will continue to provide a platform independent of hardware that can utilize the cloud and open source for medical big data analysis in the future.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1047-1054
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• 2022

With the advent of SDN, a next-generation network technology that separates the hardware and software areas of network equipment and defines the network using open source-based software, it solves the problems of complexity and scalability of the existing network system. It is now possible to configure a custom network according to the requirements. However, it has a structural disadvantage that a load on the network may occur due to a lot of control communication occurring between the controller and the switch, and many studies on network load distribution to effectively solve this have been preceded. In particular, in previous studies of load balancing techniques related to flow tables, many studies were conducted without consideration of flow entries, and as the number of flows increased, the packet processing speed decreased and the load was increased. To this end, we propose a new network load balancing technique that monitors flows in real time and applies dynamic flow management techniques to control the number of flows to an appropriate level while maintaining high packet processing speed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.5
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• pp.486-493
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• 2024

Lighting has been used for a long time as a medium to convey brightness from darkness, and through incandescent lamps and fluorescent lamps, LED light sources have now become the standard in the lighting industry. Recently, the lighting equipment industry has been undergoing rapid digital transformation, starting with smart lighting, and is evolving into smart lighting customized for individuals and spaces through the development of IoT technology, cloud-based services, and data analysis. However, the blue light emitted from digital devices (computers, smartphones, tablets, etc.) or LED lights stimulates the melanopsin in the optic ganglion cells in the retina of the eye, which in turn stimulates the secretion of melatonin through the pineal gland, which regulates the secretion of melatonin. This can reduce sleep quality or disrupt biological rhythms. This interaction between blue light and melatonin has such a significant impact on human sleep patterns and overall health that it is essential to reduce exposure to blue light, especially in the evening. Human-centered lighting refers to lighting that takes into account the effects of light on the physical and mental areas, such as human activity and awakening, improvement of sleep quality, and health management. Many research institutes study the effects in the visible area and the non-visible area. By studying the impact, it is expected to improve the quality of human life. In this study, we plan to study ways to implement human-centered lighting by collecting sunrise and sunset data and linking commercialized LED packages and control devices with open-source hardware.