• Title/Summary/Keyword: startup time

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Linux-based ARINC 653 Space Separation for Spacecraft Computer (인공위성 탑재컴퓨터를 위한 리눅스 기반 ARINC 653 공간 분리)

  • Kim, Duksoo;Joe, Hyunwoo;Kim, Hyungshin
    • IEMEK Journal of Embedded Systems and Applications
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    • v.9 no.5
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    • pp.253-260
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    • 2014
  • European Space Agency has recognized Integrated Modular Avionics and ARINC specification 653 as avionics computer system for space application. Integrated Modular Avionics specification reduces the space by integrating a system composed of many electronic devices into a computer. recent researches have been studying how to apply the ARINC 653 into an open source operating system, such as Linux. These studies have concentrated on partition scheduling for time separation. However, requirements to guarantee spatial separation should be further analyzed to ensure deterministic execution time. Therefore, memory management is needed to verify spatial isolation on Linux systems. This research proposes a new method to accomplish spatial isolation for the ARINC 653 specification in Linux. We have added new data structures and system calls to handle functionalities for spatial separation. They are used during the partition startup process. The proposed method was evaluated on the LEON4 processor, which is the next generation microprocessor to be used in the future space missions. All implementations confirm that spatial isolation of the ARINC 653 specification was accomplished.

A Study on Loose Part Monitoring System in Nuclear Power Plant Based on Neural Network

  • Kim, Jung-Soo;Hwang, In-Koo;Kim, Jung-Tak;Moon, Byung-Soo;Lyou, Joon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.2 no.2
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    • pp.95-99
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    • 2002
  • The Loose Part Monitoring System(LPMS) has been designed to detect. locate and evaluate detached or loosened parts and foreign objects in the reactor coolant system. In this paper, at first, we presents an application of the back propagation neural network. At the preprocessing step, the moving window average filter is adopted to reject the reject the low frequency background noise components. And then, extracting the acoustic signature such as Starting point of impact signal. Rising time. Half period. and Global time, they are used as the inputs to neural network . Secondly, we applied the neural network algorithm to LPMS in order to estimate the mass of loose parts. We trained the impact test data of YGN3 using the backpropagation method. The input parameter for training is Rising clime. Half Period amplitude. The result shored that the neural network would be applied to LPMS. Also, applying the neural network to thin practical false alarm data during startup and impact test signal at nuclear power plant, the false alarms are reduced effectively.

LASER WELDING APPLICATION IN CAR BODY MANUFACTURING

  • Shin, Hyun-Oh;Chang, In-Sung;Jung, Chang-Ho
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.181-186
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    • 2002
  • Laser welding application for car body manufacturing has many advantages in the stiffness and the lightness of vehicle, the productivity of assembly line, and the degree of freedom in design. This presentation will express the innovation of car body manufacturing including parameter optimization, process modeling, and system integration. In this application the investment for systems was cut down dramatically by real time switching over the laser path between two welding stations. Points of technical discussion are as follows: optimization of parameters such as laser power, robot speed and trajectory, compact and useful design of jig & fixture to assure welding quality for 3 sheet-layer zinc-coated steel, system integration between 4kW Nd:YAG laser device and the other systems, on-line real time welding quality monitoring system, perfect safety standards for high power laser, minimization of consumption costs such as arc lamp, protective glass for optic, etc. Laser welding has found a place on Hyundai's production plant in conjunction with the startup of mass production of new sports car, and this production system is the result of a collaboration of its engineers. Outer side sheets are joined to inner side sheets by 122 stitch welds totally. And the length is about 2.4meter.

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Transitional Behavior of a Supersonic Flow in a Two-dimensional Diffuser

  • Kim, Sehoon;Kim, Hyungjun;Sejin Kwon
    • Journal of Mechanical Science and Technology
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    • v.15 no.12
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    • pp.1816-1821
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    • 2001
  • Two-dimensional blow-down type supersonic wind tunnel was designed and built to investigate the transient behavior of the startup of a supersonic flow from rest. The contour of the divergent part of the nozzle was determined by the MOC calculation. The converging part of the nozzle, upstream of fille throat was contoured to make the flow uniform at the throat. The flow characteristics of the steady supersonic condition were visualized using the high-speed schlieren photography. The Mach number was evaluated from the oblique shock wave angle on a sharp wedge with halt angle of 5 degree. The measured Mach number was 2.4 and was slightly less than the value predicted by the design calculation. The initial transient behavior of the nozzle was recorded by a high-speed digital video camera with schlieren technique. The measured transition time from standstill to a steady supersonic flow was estimated by analyzing the serial images. Typical transition time was approximately 0.1sec.

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Systems Engineering for System Design and Fabrication of CubeSats (큐브위성의 시스템 설계 및 제작을 위한 시스템 공학)

  • In-Hoi Koo;Myung-Kyu Lee;Seul-Hyun Park
    • Journal of Space Technology and Applications
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    • v.3 no.4
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    • pp.342-354
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    • 2023
  • The paradox of cubesat development process in the New Space paradigm is related to a complicated and time-consuming system engineering procedure. Due to their low cost and quick production time, cubesats are a highly accessible space asset in the startup-driven "New Space" industry. In reality, however, the development process experienced by the student teams selected through the national cubesat competition is quite different from what we expect. This is because cubesats are designed and implemented using a lengthy and tedious procedure defined by the systems engineering perspective. The purpose of this work is to explain to developers who are unfamiliar with systems engineering the role and function of systems engineering in each step of the cubesat development process.

A Study on Investors Determinants Addressed by Startup Entrepreneurs : In the Center of Startups in Water Industry (창업기업관점에서 바라본 투자자의 투자결정요인에 관한 연구 : 물산업 창업기업을 중심으로)

  • Park, Dong Il;Yang, Young Seok;Kim, Myung Seuk
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.1
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    • pp.1-19
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    • 2021
  • The purpose of this research is to improve the investment success rate for startups in the water industry for the development of the entrepreneurial environment of the Korean water industry. In this research, we identified investment determinants through prior research and stratified them, and then surveyed the investor group at the beginning of the start-up using the FGI method, and determined the order of the investment determinants of investors. At the same time, we classified 41 start-ups related to the water industry into two groups: the group that received investment and the group that did not in the early stages of the start-up. Then we investigated the understanding of the investor's investment determinants, ranked them, and compared them by using the AHP technique. Through this, this research proposes five implications. First, it is important for start-ups in the early stages to receive seed investment to revitalize investment for startups in the water industry. For this, startups need to understand investors and prepare to attract investment with the perspective of angel investors rather than the perspective of VC investors. Second, Start-ups in the water sector should consider that the characteristics of the founder are important in order to receive seed investment, and also need to define their business at the industry and market level, and provide relevant rationale to meet the expectations of investors who value industry expertise and experience, and to increase the possibility of seed investment, which is important in the early stages of a startup. Third, institutions, such as K-water(Korea Water Resources Corporation), that support water industry startups need to conduct open innovation business opportunities discovery programs linked to startups so that startups currently participating in the startup support program could have business opportunities from the business infrastructure of platform-forming companies in the water industry. In particular, such institutions should help founders develop their industrial expertise and careers by supporting this type of start-up preparation process through the participation of in-house venture founders. Fourth, when K-water uses the government start-up support fund to discover and foster founders, it should increase initial contact with seed investors, conduct more thorough verification of business plans, and develop programs that use government start-up support funds to prepare a business suitable for seed angel investors. Fifth, K-water should support seed by connecting funds for initial investment among funds operated by itself. It is also necessary to develop a program that links the company receiving the seed investment with VC investment, not angel investment in cooperation with the VC fund operation entity participating as an LP so that companies that have attracted seed investment could attract follow-up VC investment.

Effects of Knowledge-based Startups on Employment Growth (지식기반산업 창업기업의 고용창출 효과)

  • Lee, Jeong Hyun;Lee, Hee Yeon
    • Journal of the Economic Geographical Society of Korea
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    • v.20 no.2
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    • pp.137-157
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    • 2017
  • As unemployment rises and economic growth slows, interest in startups, which is considered to be the driving force of job creation, is increasing. This study aimed to analyze the employment effects of knowledge-based startups in South Korea. In particular, startups were divided into three categories (knowledge-based manufacturing, knowledge-based service, and other industries) and the region were divided into the capital region and the other regions. The result of the analysis, which used census on Establishments Data from Statistics Korea(KOSIS), showed that the employment effects of startups change in three steps over time. When new firms were created, employment increases instantly. However, as the competition among firms increases, some firms exit the market and employment decreases. In the long-term, some firms will survive the market competition and increase their firm size and the number of jobs they offer. The total employment effect was greater for knowledge-based startups than the other industries startups. The total employment effect of knowledge-based startups are 2.84%p for the period of 6 years. Startups in the Capital region showed higher employment effect than startups in other regions. This implies that in the capital region, employment increases more after the startups are created, but due to fierce competition, employment also decreases relatively more than it does in other regions. However, companies that survive competition create more employment. This study may give some policy implications that startup policies should be tailored to the startup's type and regional characteristics in order to achieve more effective job creation performance.

A Study on the Economic Impact of Public Technology Startup (공공기술창업의 경제적 파급효과 분석 연구)

  • Jieun Jeon;Jungsub Yoon
    • Knowledge Management Research
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    • v.24 no.2
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    • pp.87-115
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    • 2023
  • This study aims to examine the causal relationships between sales and employment for public technology-based startups. Although there is a limit to statistical generalization due to the poor understanding of the actual conditions of public technology start-up companies, these companies were analyzed by classifying them into high-growth companise, potential growth companies, and other companies. In order to understand the causal relationship, and to estimate the time required to be effective, panel vector autoregression was applied. As a result, the performance creation mechanism was identified as government supoort and private investment was mutually causal with employment, sales did not cause employment, and employment caused sales. In other words, it was found that employment plays an mediator role in public technology based startups' performance mechanism. In addition, private investment had the effect of improving employment and sales in the short time than governments support, and showed that firms with high employment can attract government support and private investment. This study are academically meaningful in that they empirically revealed the process of performance creation, whereas previous studies had only shown whether there was an effect on performance. It also has a policy contribution by suggesting the need for effective policy promotion by considering the 'employment' factor, such as human resource support, as more important.

A Study of Product Development Projects of Startup Ventures on Product Development Performance: Exploring the Role of Entrepreneurial Business Model (벤처기업의 제품개발 프로젝트와 제품개발 성과: 비즈니스 모델의 역할 탐색)

  • Yoon, HyunJoong
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.5
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    • pp.265-278
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    • 2022
  • R&D projects for product development are crucial for ventures' growth and success. Current study summarizes existing studies that identify the relationship between startup ventures' R&D department, R&D investment, and R&D cooperation on product development performance, and highlights the effects of business model as well as the roles of R&D activities for product development project that have been traditionally emphasized. In order to consider the effects of business models that were not previously available, the effects of these factors on product development performance were comprehensively analyzed. The research results with 180 venture cases surveyed on venture companies in the growth stage in Korea, showed that the effect of product development project activities measured by R&D department, R&D investment and R&D cooperation on product development performance is not evident. However, the effect of business model on product development time and product development performance measured by product innovation was confirmed. In particular, it was found that the clarity and uniqueness of the business model interacted with the R&D investment to shorten the product development time and directly increase the innovativeness of the developed product. Based on these analysis results, the implications of this study, limitations of the study, and the future research directions were described.

A Study on Loose Part Monitoring System in Nuclear Power Plant Based on Neural Network (원전 금속파편시스템에 신경회로망 적용연구)

  • Kim, Jung-Soo;Hwang, In-Koo;Kim, Jung-Tak;Moon, Byung-Soo;Lyou, Joon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2002.05a
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    • pp.227-230
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    • 2002
  • The Loose Part Monitoring System(LPMS) has been designed to detect, locate and evaluate detached or loosened parts and foreign objects in the reactor coolant system. In this paper, at first, we presents an application of the back propagation neural network. At the preprocessing step, the moving window average filter is adopted to reject the low frequency background noise components. And then, extracting the acoustic signature such as Starting point of impact signal, Rising time, Half period, and Global time, they are used as the inputs to neural network. Secondly, we applied the neural network algorithm to LPMS in order to estimate the mass of loose parts. We trained the impact test data of YGN3 using the backpropagation method. The input parameter for training is Rising Time, Half Period, Maximum amplitude. The result showed that the neural network would be applied to LPMS. Also, applying the neural network to the Practical false alarm data during startup and impact test signal at nuclear power Plant, the false alarms are reduced effectively. 1.

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