• Title, Summary, Keyword: AGPS

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Real-time Fault Detection Method for an AGPS/INS Integration System

  • Oh, Sang-Heon;Yoon, Young-Seok;Hwang, Dong-Hwan
    • 제어로봇시스템학회:학술대회논문집
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    • pp.974-977
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    • 2003
  • The GPS/INS integration system navigation can provide improved navigation performance and has been widely used as a main navigation system for military and commercial vehicles. When two navigation systems are tightly coupled and the structure is complicated, a fault in either the GPS or the INS can lead to a disastrous failure of the whole integration system. This paper proposes a real-time fault detection method for an AGPS/INS integration system. The proposed fault detection method comprises a BIT and a fault detection algorithm based on chi-square test. It is implemented by real-time software modules to apply the AGPS/INS integration system and van test is carried out to evaluate its performance.

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The AGPS/INS Integrated Navigation System Design Using Triple Difference Technique (삼중 차분 기법을 이용한 AGPS/INS 통합 항법 시스템 설계)

  • 오상헌;박찬식;이상정;황동환
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.9
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    • pp.736-744
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    • 2003
  • The GPS attitude output or carrier phase observables can be effectively utilized to compensate the attitude error of the strapdown inertial navigation system. However, when the integer ambiguity is not correctly resolved and/or a cycle slip occurs, an erroneous GPS output can be obtained. If the erroneous GPS information is directly applied to the AGPS/INS integration system, the performance of the system can be rapidly degraded. This paper proposes an AGPS/INS integration system using the triple difference carrier phase observables. The proposed integration system contains a cycle slip detection algorithm, in which inertial information is combined. Computer simulations and van test were performed to verify the proposed integration system. The results show that the proposed system gives an accurate and reliable navigation solution even when the integer ambiguity is not correct and the cycle slip occurs.

Investigation of industries's perception on the ban of antibiotics growth promoter in commercial mixed feed (항생제 사용금지에 관한 산업체 인식조사)

  • Kim, Ki-Hyun;Kim, Kwang-Sik;Kim, Jo-Eun;Seol, Kuk-Hwan;Kim, Young-Hwa
    • Korean Journal of Agricultural Science
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    • v.42 no.4
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    • pp.389-396
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    • 2015
  • This study was performed to investigate the opinions of various related-industries on ban of antibiotics growth promoters (AGPs) in commercial mixed feed. The answers on a total of 21 questions were summarized by response number and percentage. 93% of those surveyed were in agreement of a ban of dietary AGPs. The agreement reasons were the livestock safety (61.5%), the reduction of antibiotic use (23.1%), and decrease of antibiotic-resistant bacteria (11.5%). The negative effects expected by the ban of AGPs were poor growth performance (44.2%), elevated disease emergence (31.4%), increasing the feed cost (18.6%), and quality degradation of livestock (5.8%). As the efficient plans for decline of AGPs use, the feeding environment improvement was the highest with 43%, and farmer training and the consolidation inspection of residual substance on antibiotics in livestock product was 27.9% and 22.1%, respectively. 46.5% of respondent are considering the modification of feed spec and 39.5% of those surveyed have staged a modified feed spec. In conclusion, livestock related-industries approve a ban of AGPs, and they assert that the policy support, improvement of management and environment in the farm, providing technology from related-industries are multiply essential for a stable settlement of a ban policy of AGPs.

Performance Analysis of a Residual Frequency Estimator for Weak AGPS Signals in Frequency Domain (약 신호 환경의 AGPS를 위한 잔여주파수 추정기의 주파수 영역 성능 분석)

  • Park, Ji-Hee;Im, Hyun-Ja;Song, Seung-Hun;Sung, Tae-Kyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.7
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    • pp.720-725
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    • 2010
  • In AGPS method, user position can be obtained even in the shadow region by improving signal sensitivity. A hybrid long integration scheme employing both coherent and non-coherent integration method is commonly used in AGPS receivers. Because coherent loss increases as residual frequency become large, residual frequency should be minimized to maximize coherent integration gain. This paper presents performance analysis of residual frequency estimator using FFT in fine-time assistance AGPS method. Considering the hardware complexity and the estimation accuracy, optimal length of FFT is proposed for GPS L1 C/A signal. Signal sensitivity for estimating the residual frequency is also analysed. By field experimental results, it is found that the residual frequency can be successfully estimated using 1 second snap-shot data when GPS signal strength is larger than -150 dBm and its RMS error is 3Hz.

Alkylglyceronephosphate Synthase (AGPS) Alters Lipid Signaling Pathways and Supports Chemotherapy Resistance of Glioma and Hepatic Carcinoma Cell Lines

  • Zhu, Yu;Liu, Xing-Jun;Yang, Ping;Zhao, Meng;Lv, Li-Xia;Zhang, Guo-Dong;Wang, Qin;Zhang, Ling
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.3219-3226
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    • 2014
  • Chemotherapy continues to be a mainstay of cancer treatment, although drug resistance is a major obstacle. Lipid metabolism plays a critical role in cancer pathology, with elevated ether lipid levels. Recently, alkylglyceronephosphate synthase (AGPS), an enzyme that catalyzes the critical step in ether lipid synthesis, was shown to be up-regulated in multiple types of cancer cells and primary tumors. Here, we demonstrated that silencing of AGPS in chemotherapy resistance glioma U87MG/DDP and hepatic carcinoma HepG2/ADM cell lines resulted in reduced cell proliferation, increased drug sensitivity, cell cycle arrest and cell apoptosis through reducing the intracellular concentration of lysophosphatidic acid (LPA), lysophosphatidic acid-ether (LPAe) and prostaglandin E2 (PGE2), resulting in reduction of LPA receptor and EP receptors mediated PI3K/AKT signaling pathways and the expression of several multi-drug resistance genes, like MDR1, MRP1 and ABCG2. ${\beta}$-catenin, caspase-3/8, Bcl-2 and survivin were also found to be involved. In summary, our studies indicate that AGPS plays a role in cancer chemotherapy resistance by mediating signaling lipid metabolism in cancer cells.

Effects of Antibiotic Growth Promoter and Characterization of Ecological Succession in Swine Gut Microbiota

  • Unno, Tatsuya;Kim, Jungman;Guevarra, Robin B.;Nguyen, Son G.
    • Journal of Microbiology and Biotechnology
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    • v.25 no.4
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    • pp.431-438
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    • 2015
  • Ever since the ban on antibiotic growth promoters (AGPs), the livestock death rate has increased owing to pathogenic bacterial infections. There is a need of developing AGP alternatives; however, the mechanisms by which AGP enhances livestock growth performance are not clearly understood. In this study, we fed 3-week-old swine for 9 weeks with and without AGPs containing chlortetracycline, sulfathiazole, and penicillin to investigate the effects of AGPs on swine gut microbiota. Microbial community analysis was done based on bacterial 16S rRNA genes using MiSeq. The use of AGP showed no growth promoting effect, but inhibited the growth of potential pathogens during the early growth stage. Our results showed the significant increase in species richness after the stabilization of gut microbiota during the post-weaning period (4-week-old). Moreover, the swine gut microbiota was divided into four clusters based on the distribution of operational taxonomic units, which was significantly correlated to the swine weight regardless of AGP treatments. Taxonomic abundance analysis indicated a negative correlation between host weight and the abundance of the family Prevotellaceae species, but showed positive correlation to the abundance of the family Spirochaetaceae, Clostridiaceae_1, and Peptostreptococcaeae species. Although no growth performance enhancement was observed, the use of AGP inhibited the potential pathogens in the early growth stage of swine. In addition, our results indicated the ecological succession of swine gut microbiota according to swine weight. Here, we present a characterization of swine gut microbiota with respect to the effects of AGPs on growth performance.

Comparison of Algal Growth Potentials in the Large Reservoirs and River Mainstream of Naktong River Watershed (낙동강 수계 대형 인공호 및 하천본류의 조류성장 잠재력 비교)

  • You, Kyung-A;Shin, Jae-Ki;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.39 no.1
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    • pp.138-144
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    • 2006
  • Algal growth potential test (AGPT) has been used as a tool for assessing biological productivity potential in the aquatic ecosystems. This study was conducted to compare the productivity potentials of large reservoirs (Lakes Andong, Hapchon and Jinyang, and Naktong estuarine dam) and river sites (Sangju, Koryung, and Samlangjin) located in the Naktong River watershed. AGPT was conducted in both non-monsoon and mosoon season (February, April, July and September) of 2003, using Microcystis aeruginosa as a test alga. The AGPs in the reservoirs were relatively much lower than those of river sites. The river AGPs increased towards upstream close to the influent streams, while it generally decreased towards downstream. Immediately after the abrupt increase in influent discharge in summer, the AGP became similar between midstream and downstream sites. The water quality of river and reservoirs deteriorated during the drought period in accordance with AGP: it was the highest during this period. The AGPs showed the closest correlation with the P concentration, leading to the conclusion that bioavailable P is highly influential to the algal growth in both lentic and lotic ecosystems in the Naktong River watershed. Based on the AGPs, the water quality of tested sites was likely eutrophic. Our results suggest that AGPT be a useful tool in evaluating the productivity potential and trophic state of the water body as well as determining the nutrients that limit the growth of algae.

Initial Alignment Algorithm for the SDINS Using an Attitude Determination GPS Receiver (자세 측정용 GPS 수신기를 이용한 SDINS의 초기정렬 알고리즘)

  • Kim, Young-Sun;Oh, Sang-Heon;Hwang, Dong-Hwan;Lee, Sang-Jeong;Jeon, Chang-Bae;Song, Ki-Won;Park, Chan-Ju
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.3
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    • pp.249-255
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    • 2002
  • Since the stationary alignment process of the SDINS is not completely observable, some furls of the aided alignment have been applied. The purpose of this paper is to propose a new initial alignment algorithm, which utilizes the attitude output from the AGPS(Attitude Determination GPS) receiver and to demonstrate the feasibility of the proposed algorithm with several experimental results. A Kalman filter is designed for utilizing the attitude output as well as the zero velocity information. Also analyzed is the observability of the SDINS error model. To show the feasibility of the proposed scheme, we implement an alignment system where HG1700AE IMU (Inertial Measurement Unit) from Honeywell and an AGPS receiver designed at Chungnam National University are used. Test trials are done to evaluate the performance of the proposed alignment scheme. The proposed algorithm provides as good initial alignment performance as a high accurate navigation system, MAPS(Modular Azimuth Positioning System) INS.