• Title/Summary/Keyword: AT697F

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Design and Implementation of OBCP Engine based on Lua VM for AT697F/VxWorks Platform (AT697F/VxWorks 플랫폼에서 Lua 가상머신 기반의 OBCP 엔진 설계 및 구현)

  • Choi, Jong-Wook;Park, Su-Hyun
    • Journal of Satellite, Information and Communications
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    • v.12 no.3
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    • pp.108-113
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    • 2017
  • The OBCP called 'operator on board' is that of a procedure to be executed on-board, which can be easily be loaded, executed, and also replaced, without modifying the remainder of the FSW. The use of OBCP enhances the on-board autonomy capabilities and increases the robustness to ground stations outages. The OBCP engine which is the core module of OBCP component in the FSW interprets and executes of the procedures based on script language written using a high-level language, possibly compiled, and it is relying on a virtual machine of the OBCP engine. FSW team in KARI has studied OBCP since 2010 as FSW team's internal projects, and made some OBCP engines such as Java KVM, RTCS/C and KKOMA on ERC32 processor target only for study. Recently we have been studying ESA's OBCP standard and implementing Lua and MicroPython on LEON2-FT/AT697F processor target as the OBCP engine. This paper presents the design and implementation of Lua for the OBCP engine on AT697F processor with VxWorks RTOS, and describes the evaluation result and performance of the OBCP engine.

System Software Design and Simulation for LEON2-FT Processor based on PCI (PCI 기반 LEON2-FT 프로세서를 위한 시스템 소프트웨어 설계 및 시뮬레이션)

  • Choi, Jong-Wook;Nam, Byeong-Gyu
    • Journal of Satellite, Information and Communications
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    • v.8 no.1
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    • pp.54-60
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    • 2013
  • The need for high performance of on-board computer (OBC) is essential due to the growing requirements and diversified missions, and so OBC has been developed on the basis of the standard design and reconfigurable modularization in order to improve the utilization of OBC for different missions. The processor in OBC of next generation satellite which is currently developed by KARI is adopted the LEON2-FT/AT697F processor based SPARC v8 as main processor and controls various devices such as SpaceWire, MIL-STD-1553B and CAN through PCI on the standardized communication chips. This paper presents the architecture and design of system software for LEON2-FT processor based on PCI, and development of PCI software component. Also it describes the porting of VxWorks 6.5 for LEON2-FT and the test under the simulation environment for LEON2-FT and PCI with communication chips.

Performance Analysis of Processors for Next Generation Satellites (차세대 위성 프로세서 선정을 위한 성능 분석)

  • Yoo, Bum-Soo;Choi, Jong-Wook;Jeong, Jae-Yeop;Kim, Sun-Wook
    • IEMEK Journal of Embedded Systems and Applications
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    • v.14 no.1
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    • pp.51-61
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    • 2019
  • There are strict evaluation processes before using new processors to satellites. Engineers evaluate processors from various viewpoints including specification, development environment, and cost. From a viewpoint of computation power, manufacturers provide benchmark results with processors, and engineers decide which processors are adequate to their satellites by comparing the benchmark results with requirements of their satellites. However, the benchmark results depends on a test environment of manufacturers, and it is quite difficult to achieve similar performance in a target environment. Therefore, it is necessary to evaluate the processors in the target environment. This paper compares performance of a processor, AT697F/LEON2, in software testbed (STB) with three development boards of XC2V/LEON3, GR712RC/LEON3, and GR740/LEON4. Seven benchmark functions of Dhrystone, Stanford, Coremark, Whetstone, Flops, NBench, and MiBench are selected. Results are analyzed with hardware and software properties: hardware properties of core architecture, number of cores, cache, and memory; and software properties of build options and compilers. Based on the analysis, this paper describes a guideline for choosing processors for next generation satellites.

An Evaluation of Boar Pheromone Spray to Aid the Stimulation and Detection of Estrus in Small Farms in Nepal

  • Shrestha, N.P.;Edwards, S.A.;English, P.R.;Robertson, J.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.5
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    • pp.697-700
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    • 2001
  • A prolonged farrowing interval is common on small farms in Nepal and may be attributable to the absence of boar contact at the time of weaning. To examine whether synthetic boar pheromone spray might be of value to aid the stimulation and detection of estrus, 30 village farms, each with a single sow, were recruited into a field study. All sows entered the study on final weaning from their first lactation at 56 days post partum. For 13 treatment sows, a boar pheromone spray (SOA, Intervet, Boxmeer, The Netherlands) was applied each day after weaning whilst 17 other sows did not receive any stimulus (negative control). When estrous was detected by the farmer, sows were taken to the nearest boar for service. There was a significantly shorter weaning to re-mating interval for treatment sows (42.9 V 82.2 day, p<0.05), with a significantly higher proportion of treatment sows rebred by day 60 after weaning (p=0.024, Fishers Test). It is concluded that use of boar pheromones can improve reproductive efficiency of sows kept under Nepalese village conditions.

Design and Development of PCI-based 1553B Communication Software for Next Generation LEO On-Board Computer (차세대 저궤도 위성의 PCI 기반의 1553B 통신 소프트웨어 설계)

  • Choi, Jong-Wook;Jeong, Jae-Yeop;Yoo, Bum-Soo
    • Journal of Satellite, Information and Communications
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    • v.11 no.3
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    • pp.65-71
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    • 2016
  • Currently developing the OBC of the next-generation LEO satellite by Korea Aerospace Research Institute adopts the LEON2-FT/AT697F processor to achieve high performance. And various communication devices such as SpaceWire, MIL-STD-1553B, DMAUART and CAN Master are integrated to the separated standard communication FPGAs within the OBC, where they can be controlled by the processor and flight software (FSW) through PCI interface. The Actel 1553BRM IP core is used for the 1553B in the next-generation LEO OBC and the B1553BRM wrapper from Aeroflex Gaisler is used for connecting it to the AMBA bus in FPGA. This paper presents the design and development of PCI-based 1553B communication software, and describes the handling mechanism of 1553B operation in FSW task level. Also it shows the test results on real-hardware and simulator.

Design and Implementation of a Processor Monitor and Fault Injection System for Next Generation Spacecraft Computer Board (차세대 위성탑재컴퓨터를 위한 프로세서 모니터 및 고장주입 시스템의 설계 및 구현)

  • Jeong, Jae-Yeop;Choi, Jong-Wook;Cheon, Yee-Jin
    • Journal of Satellite, Information and Communications
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    • v.9 no.4
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    • pp.97-103
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    • 2014
  • In order to verify normal operation of satellite OBC(On Board Computer), it is essential that processor monitoring and debugging. So we are using the GRMON of Aeroflex Gaisler. It provides a lot of features for debugging of LEON processor but we can't use that features on the NGSCB(Next Generation Spacecraft Computer Board) except a few things. So the cost-effectiveness is very low. And for hardware fault injection, we are using a method of modify satellite flight software, because we can't modify GRMON. This method can not guarantee normal operation of the satellite flight software. So in this paper we were developed the processor monitoring and fault injection tool for NGSCB.

Effects of Phytoncides Inhalation on Serum Cortisol Level and Life Stress of College Students (피톤치드 흡입이 대학생의 활력징후, 생활 스트레스 및 혈중 코티졸 수치에 미치는 효과)

  • Nam, Eun-Sook;Uhm, Dong-Choon
    • Korean Journal of Adult Nursing
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    • v.20 no.5
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    • pp.697-706
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    • 2008
  • Purpose: The purpose of this study was to identify the effects of the phytoncides on serum cortisol level, vital signs and life stress of college students. Methods: This study was nonequivalent control group non-synchronized design. The subjects consisted of 60(control group: 28, experimental group: 32). The phytoncides mixed the pine(pinus sylvestris) oil with the cypress(cupressus sempervirens) oil in the same rate. In the experiment, it was put in an aroma-necklace bottle and inhaled 3 times per day(9AM, at noon, before going to bed) for 2 weeks. The data were analyzed by the SPSS version 12.0 program. Results: In the experimental group systolic BP(F=15.603, p=.000), diastolic BP(F=29.489, p=.000) and serum cortisol level(F=4.968, p=.000) were significantly decreased. Conclusion: The phytoncides inhalation is a partly help to reduce college students' life stress. The phytoncides is the incense of the familial tree. We recommended to examine what differences between the green shower and the phytoncides inhalation for the stress reduction.

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The Effect of Meridian Massage on the Reduction of Pain and Subjective Symptoms of Myofascial Pain Syndrome (경락마사지가 근막동통 증후군의 동통과 자각증상 감소에 미치는 효과)

  • Sung, Kyung-Suk;Jung, Hyang-Mi
    • The Korean Journal of Rehabilitation Nursing
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    • v.6 no.2
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    • pp.248-256
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    • 2003
  • Purpose: This research was for checking the effect of meridian massage on the reduction of pain and subjective symptoms of myofascial pain syndrome. Method: The method of the research was interruptive time series design. The research objects are 25 hospital workers with myofascial pain syndrome at B hospital in Busan from July 22, 2002 to August 18, 2002. SPSS Win 10.0 was used for data analysis, paired t-test and repeated measures ANOVA for hypothesis test. Result: The recipients of meridian massage felt less pain than before(F=12.587, p=.000). The recipients of meridian massage felt less often than before (F=6.705, p=.001). The recipients of meridian massage got lower score on subjective symptoms of myofascial pain than before(F=12.857, p=.000). The recipients of meridian massage had lower blood pressure than before(systolic blood pressure; t=4.697, p=.000, diastolic blood pressure; t=3.426, p=.002). The recipients of meridian massage did not get the lower number of pulse than before(t=0.33, p=.744). Conclusion: The above results show that meridian massage is effective on the reduction of pain and subjective symptoms of myofascial pain syndrome and makes stable the blood pressure. Therefore meridian massage can be apply as the effective intervention for the reduction of pain and subjective symptoms of myofascial pain syndrome.

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Flora Colonization and Oral Glucose Levels During the Early Postnatal Period in High-Risk Newborns (고위험신생아의 생후 초기 구강 내 균집락 형성과 당농도 및 영향요인)

  • Ahn, Young-mee;Sohn, Min;Jun, Yong-hoon;Kim, Nam-hee
    • Child Health Nursing Research
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    • v.22 no.4
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    • pp.379-389
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    • 2016
  • Purpose: A longitudinal study was conducted to explore flora colonization and oral glucose high-risk newborns during the first 7 days after birth. Methods: Oral secretions of hospitalized newborns were obtained for microbial cultures and glucose test at days 1-7 after birth. Results: Among the total 112 newborns, 40% were girls and 73% were premature. Mean gestational age was $34.4{\pm}3.2$ weeks and weight was $2,266{\pm}697.5$ grams. The most common flora included Streptococcus (28.2%), Methicillin-resistant Staphylococcus aureus (MRSA, 10.9%), Staphylococcus (6.0%) and Coagulase-Negative Staphylococcus (CNS, 4.0%). The average oral glucose level was $29.2{\pm}23.0mg/dL{\sim}58.2{\pm}39.5mg/dL$. Newborns with higher oral glucose than serum (crude odds ratio [ORc] =1.75; 95% confidence interval [CI] =1.03-2.97), phototherapy (ORc=3.30; 95% CI=2.29-4.76) and prone position (ORc= 2.04; 95% CI=1.13-3.69) were more likely to be colonized. Having oral tubes (ORc=0.42; 95% CI=0.29-0.59), parental nutrition (ORc=0.21; 95% CI=0.13-0.32) and antibiotics (ORc=0.51; 95% CI=0.36-0.73) had protective effects. For oral glucose statistical significances existed on time effect among newborns with Streptococcus (F=9.78, p=.024), MRSA (F=7.60, p=.037) or CNS (F=11.15, p=.019) and interaction between time and colonization among newborns with all of four flora (F=2.73, p=.029) or colonization with only Staphylococcus (F=2.91, p=.034). Conclusion: High-risk newborns develop flora colonization at an early period of life. Their clinical features were associated with types and time of oral flora colonization. They need close monitoring and multifaceted intervention to improve oral environment and infection control.

A study on the VDT syndrome and relating work factors of office workers (사무직 근로자의 VDT 증후군과 관련요인에 관한 연구)

  • Sim, Mi-Jung;Lee, Young-Sook
    • Korean Journal of Health Education and Promotion
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    • v.25 no.3
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    • pp.95-109
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    • 2008
  • Objectives: The study was conducted to investigate visual display terminal(VDT) and related risk factors in office workers. Method: The study subjects were 539 officers at 3 places of business in Gwangju. The data were collected by self-administered questionnaire between October 12 and October 17, 2007. and they agreed to participate in this study. The tool was developed by Moon, Jaedong(1991) for VDT syndrome. Data analysis by using SPSS/win 10.0 was performed with descriptive statistics, t-test and ANOVA. Results: The summary of results is as follows: 1) The mean score of total VDT syndrome was $1.17{\pm}.65$ of full score 4.00, which was lower than other research. 2) For relation between general characteristics and total VDT, sex (t=-5.777, p=.000), age (F=3.516, p=.015), satisfaction of job (F=9.540, p=.000), self-awareness of health (F=25.015, p=.000) had statistically significant difference. 3) For relation between behavioral work factors and total VDT, break time of work(t=-5.363, p=.000), eye movement during computer work(t=2.176, p=.031), wrist exercise during(t=2.337, p=.020), distance between monitor and eyes(F=3.682, p=.012) had statistically significant difference. 3) For relation between environmental work factors and total VDT, height of chair(F=8.801, p=.000), space under desk(F=4.244, p=.015), reflection of monitor(t=2.697, p=.008) had statistically significant difference. Conclusion: To prevent and relieve VDT syndrome and musculoskeletal disorders in office workers, it is important to teach good posture and stretching exercise during work.