• Title/Summary/Keyword: harsh environment

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The Implementation of High speed Memory module Interface in the Military Single Board Computer (군용Single Board Computer에서의 고속메모리모듈 I/F구현)

  • Lee, Teuc-Soo;Kim, Young-Kil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.3
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    • pp.521-527
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    • 2011
  • POWER PC series are common to the Central Processing Unit for Military Single Board Computer. Among them, G4 group, which contains the 74xx series supported by Freescale manufacturer is mainly used in the Military applications. We focus on the Interface between memory and controller. PCB stacking method, component routing, impedance matching and harsh environment for Military spec are the main constraints for implementation. Also, we developed memory as a module for the consideration of Military environments. The overall type of SBC should be designed by the form of 6U VME or 3U VME. Therefore this study suggests the electrically optimum Interface matching, Artwork technology based on the signal cross over and PCB stacking method on the harsh environment.

A Formal Specification of Reusable Framework of Embedded System (임베디드 시스템의 재사용 프레임워크에 대한 정형명세)

  • Cho, Eun-Sook;Kim, Chul-Jin;Song, Chee-Yang
    • The KIPS Transactions:PartD
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    • v.17D no.6
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    • pp.431-442
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    • 2010
  • Because embedded system is combined system of hardware and software, we should design by considering elements such as real-time, reactive, small size, low weight, safe, reliable, harsh environment, low cost, and so on. However, those are poorly reflected on current embedded system development. Especially, there is few existed framework-based embedded system development. As a result, there are many internal codes which is not related with system operation in currently developed embedded system, and reusability or variability is not considered into embedded system development. Therefore we propose a formal specification technique using Z language to guarantee completeness or consistency of design of reusability framework proposed for improving reusability of embedded system. Also we assure correctness of framework design by checking Z model through Z-Eves Tool.

Quality Assessment of GPS L2C Signals and Measurements

  • Yun, Seonghyeon;Lee, Hungkyu
    • Journal of Positioning, Navigation, and Timing
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    • v.10 no.1
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    • pp.13-20
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    • 2021
  • A series of numerical experiments with measurements observed at continuously operating reference stations (CORS) of the international GNSS services (IGS) and the national geographical information institute of Korea (NGII) have been intensively carried out to evaluate the quality of pseudo-ranges and carrier-phases of GPS L2C signal obtained by various receiver types, benign and harsh operational environment. In this analysis, some quality measures, such as signal-to-noise ratio (SNR), the magnitude of multipath, and the number of cycle slips, the pseudo-range and carrier phase obtaining rate were computed and compared. The SNR analysis revealed an impressive result that the trend in the SNR of C/A and the L2C comparably depends upon type of receivers. The result of multipath analysis also showed clearly different tendency depending on the receiver types. The reason for this inconsistent tendency was seemed to be that the different multipath mitigation algorithm built-in each receiver. The number of L2C cycle slip was less than P2(Y), and L2C measurements obtaining rate was higher than that of P2(Y) in three receiver types. In the harsh observational environment, L2C quality was not only superior to P2(Y) in all aspects such as SNR, multipath magnitude, the number of cycle slips, and measurement obtaining rate, but also it could maintain a level of quality equivalent to C/A. According to the results of this analysis, it's expected that improved positioning performance like accuracy and continuity can be got through the use of L2C instead of existing P2(Y).

Development of Wearable Device for Monitoring Working Environment in Pig House (양돈장 작업환경 모니터링을 위한 웨어러블 장비개발)

  • Seo, Il-Hwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.1
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    • pp.71-81
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    • 2020
  • Enclosed pig house are creating an environment with high concentrations of gas and dust. Poor conditions in pig farms reduce pig weight and increase disease and accidents for livestock workers. In the pig house, the high concentration of harmful gas may cause asphyxiation accidents to workers and chronic respiratory disease by long-term exposure. As pig farm workers have been aging and feminized, the damage to the health of the harsh environment is getting serious, and real-time monitoring is needed to prevent the damage. However, most of the measuring devices related to humidity, harmful gas, and fine dust except temperature sensors are exposed to high concentrations of gas and dust inside pig house and are difficult to withstand for a long time. The purpose of this study is to develop an wearable based device to monitor the hazardous environment exposed to workers working in pig farms. Based on the field monitoring and previous researches, the measurement range and basic specifications of the equipment were selected, and wearable based device was designed in terms of utilization, economic efficiency, size and communication performance. Selected H2S and NH3 sensors showed the average error of 5.3% comparing to standard gas concentrations. The measured data can be used to manage the working environment according to the worker's location and to obtain basic data for work safety warning.

Development of Joint Controller and Collision Detection Methods for Series Elastic Manipulator of Relief Robot (구호로봇용 연성 매니퓰레이터를 위한 조인트 제어 및 충돌감지 알고리즘)

  • Jung, Byung-jin;Kim, Tae-Keun;Won, Geon;Kim, Dong Sup;Hwang, Junghun
    • The Journal of Korea Robotics Society
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    • v.13 no.3
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    • pp.157-163
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    • 2018
  • This paper deals with the development and application of control algorithms for series elastic relief robots for rescue operations in harsh environment like disasters or battlefield. The joint controller applied in this paper has a cascade structure combining inner loop for torque control and outer loop for position control. The torque loop contains feedforward and feedback controller and disturbance observer for independent, decentralized joint control. The effect of the elastic component and motor dynamics are treated as the nonlinear disturbance and compensated with the disturbance observer of torque controller. For the collision detection, Band Designed Disturbance Observer is configured to recognize/respond to external disturbance robustly in the continuously changing environment. The controller is applied to a 7-dof series elastic manipulator to evaluate the torque tracking and collision detection/response performance.

Strategy for the Successful Bio-venture in GMO Environment (성공적인 바이오벤처의 경영전략)

  • Park, Han-Oh
    • Proceedings of the Korean Society of Plant Biotechnology Conference
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    • 2003.04a
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    • pp.31-36
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    • 2003
  • Bio-venture companies have undertaken harsh environment after 2000 bubble corruption. It is unlike to be changed in the near future. The business model of near-term cash flow, financial stability and survival is a key issue to be discussed. The company shall be rearranged to achieve fast recovery from investment and have to show clear and quantitative business model to the investors. Nevertheless, bio-venture should not drop long-term value creation by sacrificing the possibility of emerging technologies. Prior to clarifing agro-bioventure business model, GMO strategy should have broad supports from stakeholders. The interests and worries of stakeholders are discussed and SWOT is analyzed. For sustainable economy of future, new technology continuously should be invested to fit ROI model of genomics-based GMO developments. Hybrid of products ${\varepsilon}$ technologies may be one of the favorites in this stormy season.

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Field Test of High-Speed Transponder System for Rail Transport (철도교통용 고속 트랜스폰더시스템 실차 시험)

  • Park, Sungsoo;Kim, Seong Jin;Lee, Jae-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.1
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    • pp.208-213
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    • 2016
  • In order to detect the exact position of high-speed train, it is necessary to obtain location information from the transponder tag installed along the track. When the transponder tag receives the energizing signal from the train, it sends a telegram to the reader, which includes location information. In high-speed railway environment, this telegram can be corrupted by electromagnetic interference caused by onboard electric train power equipments or wayside devices. In order to assess the performance of transponder system under this harsh environment, we carried out field test using HEMU-430X. Field test results are briefly introduced and discussed for the evaluation of the transponder system under development.

Emission Control of Fine Dust from Gas-Solid Cyclone (PoC 부착 싸이클론의 미세분진 유출 제어에 관한 연구)

  • 조영민
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.2
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    • pp.201-210
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    • 1999
  • Cyclones have been extensively used in the industry for removing fine particles from the gaseous streams, based on simplicity in design and construction in association with low cost and flexibility to operate in extreme and harsh environments. However, industrial cyclones are typically not very efficient for particles smaller than 10μm. In this work, in order to improve the separation efficiency of reverse flow cyclones, a simple device named Post Cyclone(Poc) in installed on the top of an existing cyclone. Thereby the residual swirl present at the outlet (vortex finder) of a conventional cyclone has been used to capture the escaped dust from the cyclone in the PoC. The performance of PoC was closely evaluated by changing configuration of the PoC and operation condition. In addition, the dust behaviour in th PoC was investigated based on the hypothesis of residual vortex.

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Experimental Study on the Improvement of Surface Treatment of Mechanical Structures in Field Environment (야전 환경에서 기계구조물 표면처리 개선에 관한 실험적 연구)

  • Kim, Jongwha;Hyun, Jonghun;Kang, Seokjoong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.2
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    • pp.197-203
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    • 2021
  • Mechanical structures of military equipment have been mainly applied with black oxide coating due to the limitation of surface treatment thickness. However, the mechanical structures applied by the black oxide coating treatment is constantly being corroded by calcium chloride and humidity. Since this can cause serious problems in the operation of equipment, a review to improve surface treatment and corrosion resistance is required. Therefore, in this study, surface treatment methods that can enhance corrosion resistance were selected and corrosion resistance performance was verified through experiments describing harsh field conditions. Thus, applying a proven surface treatment method to future military equipment will prevent corrosion.

Prediction of RC structure service life from field long term chloride diffusion

  • Safehian, Majid;Ramezanianpour, Ali Akbar
    • Computers and Concrete
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    • v.15 no.4
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    • pp.589-606
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    • 2015
  • It is well-documented that the major deterioration of coastal RC structures is chloride-induced corrosion. Therefore, regional investigations are necessary for durability based design and evaluation of the proposed service life prdiction models. In this paper, four reinforced concrete jetties exposed to severe marine environment were monitored to assess the long term chloride penetration at 6 months to 96 months. Also, some accelerated durability tests were performed on standard samples in laboratory. As a result, two time-dependent equations are proposed for basic parameters of chloride diffusion into concrete and then the corrosion initiation time is estimated by a developed probabilistic service life model Also, two famous service life prediction models are compared using chloride profiles obtained from structures after about 40 years in the tidal exposure conditions. The results confirm that the influence of concrete quality on diffusion coefficients is related to the concrete pore structure and the time dependence is due to chemical reactions of sea water ions with hydration products which lead a reduction in pore structure. Also, proper attention to the durability properties of concrete may extend the service life of marine structures greater than fifty years, even in harsh environments.