• Title/Summary/Keyword: KAS

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KaVA and EAVN large program on two Supermassive Black Holes, Sgr A∗ and M87

  • Sohn, Bong Won;Kino, Motoki
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.52.1-52.1
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    • 2019
  • Exploring the vicinity of super-massive black holes (SMBHs) is one of the frontiers in astrophysics. KaVA AGN Science WG has launched its Large Program in 2014 focusing on two SMBHs, Sgr A∗ and M87. They are selected based on their large apparent size. Sgr A∗ is the excellent laboratory for studying gas accretion process onto SMBH and M87 is well known as the best case for investigating plasma outflow ultimately driven by SMBH. For Sgr A∗, KaVA and EAVN provides superb UV-coverage on its emitting region and its scattering medium. In the case of M87, we have conducted high cadence dual-frequency (22and 43GHz )VLBI monitoring to clarify the global profile of the M87 jet velocity field and the spectral index map, which should reflect global structure of magnetic fields in the jet. From 2017, the AGN LP is recognized as multi-wavelength EHT project, conducting quasi-simultaneous coherent observations of M87 and Sgr A∗ with the Event Horizon Telescope (EHT) during its campaign observation periods. AGN WG is reviewing and revising its LP to convert it to EAVN LP. We will briefly report our scientific results and future plan which includes even broader international collaboration, namely East-Asia to Italy Nearly Global (EATING) VLBI to reach higher angular resolution.

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Lived Experiences of Parents of Children with Celiac Disease: A Descriptive Qualitative Study

  • Nesibe S. Kutahyalioglu;Gamze Kas Alay
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.27 no.3
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    • pp.146-157
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    • 2024
  • Purpose: Celiac disease (CD) is one of the most prevalent food-related illnesses in children, with a global prevalence of approximately 1.4%. CD can create an emotional burden, particularly on mothers, who are mainly responsible for managing challenges related to adherence to a gluten-free diet, high food costs, and food problems in schools and social areas. There is a gap in the literature, and parental experiences of raising children with CD should be explicitly examined. This qualitative study sought to provide insights into the experiences of parents raising a child with CD in the Turkish context. Methods: This study used a descriptive qualitative research methodology and conducted individual semi-structured video-based dyadic interviews with 19 parents. Results: Participants experienced both challenges and motivators through management of their children's CD. Analyses of the interview transcripts through the data uncovered three main themes focusing primarily on parental concerns: (1) parental challenges in child's disease management, (2) supportive care needs, and (3) parental expectations. Conclusion: A multidisciplinary team should approach the child and family immediately after diagnosis, and facilities should support parents with continuing education and psychological, financial, and social assistance.

A Study on 6-pulse-shift Current-source PWM Inverter for Photovoltaic System (태양광발전을 위한 6-pulse-shift 전류형 인버터에 관한 연구)

  • Lim, Joung-Min;Lee, Sang-Hun;Park, Sung-Jun;Moon, Chae-Joo;Chang, Young-Hak;Lee, Man-Hyung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.3
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    • pp.193-200
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    • 2006
  • This paper suggests a 6-pulse-shift converter structure with PWM current-source inverter based on buck-boost configuration to improve the efficiency and to reduce the switching frequency of inverter for photovoltaic generation system, the device can be operated as interface system between solar module system and power system grid without energy storage cell. The circuit has six current-source buck-boost converter which operate chopper part and kas one full bridge inverter which make a decision the polarity of AC output. Therefore, the proposed PWM power inverter has advantages such as the reduction of witching loss and realization of unity power factor operation. The theoretical backgrounds are discussed and the input-output characteristics for the implemented prototype inverter using TMS320F2812 are verified experimentally in this paper.

Development of Evaluation Items and Measurement Indices for Knowledge Management Performance of Government-funded Research Institutes (정부출연연구소의 지식관리 성과 평가항목 및 측정지표 개발)

  • Jung, Taik-Yeong;Kim, Sang-Hoon;Park, Il-Kyu;Kim, Chang-Kyu
    • Journal of Information Technology Services
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    • v.10 no.4
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    • pp.171-189
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    • 2011
  • KAs information and knowledge are increasingly becoming more important in the knowledge-driven society, knowledge management, as a very important management paradigm, is securing firm position in private and public sectors. Complying with this paradigm, government-funded research institutes in science-technology sector are actively utilizing knowledge management by employing knowledge management system and evaluating its applications' performance. The purpose of this study is to develop evaluation items and measurement indices to rationally measure knowledge management performance of the government-funded research institutes and to verify the feasibility of applying these evaluation items and indices. To achieve this research goal, the evaluation model of knowledge management performance was constructed by reviewing and integrating the existing studies, and subsequently, evaluation areas, evaluation items, measurement indices were derived from this evaluation model. Also, the feasibility analysis on the evaluation items and measurement indices was performed by means of FGI(Focus Group Interview) with the knowledge management experts belonging to Korean government-funded institutions in science-technology sector. The implications of this study are as follows : in theoretical perspective, this study has proposed a criterion frame to evaluate knowledge management performance, and has rationally drawn evaluation items and measurement indices from the criterion frame. And in practical perspective, this study has improved the validity and practicality of the measurement indices, which can lead to more reasonable and easier evaluation of knowledge management performance of the government-funded research institutes.

The Design of Monitoring & Control(M&C) for KUS RFS in KASS (KASS 위성통신국 RF시스템 감시제어장치 설계)

  • Kim, Taehee;Sin, Cheonsig
    • Journal of Satellite, Information and Communications
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    • v.12 no.4
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    • pp.50-55
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    • 2017
  • In this paper, the design of the RF system monitoring and control system of KUS (KASS: KASS Uplink Station) which constitutes KASS (Korea Augmentation Satellite System) is described. The Korean satellite calibration system is named KASS and aims to develop the SBAS system of the APV-1 level SoL service level and the CAT-1 test operation technology. Software and hardware development environment, function and algorithm of supervisory control device, structure of supervisory control device, and user interface were designed to implement KUS / RFS monitoring control device. We have secured the stability and reliability of the system by using the monitoring and control system design of the COMS (Communication Ocean & Meteorological Satellite) and the Korea Satellite 5A / 7 control system, which has already been used for the design of the surveillance control system. In addition, we have made it possible to provide the user interface according to the actual operator's request more conveniently.

An Analysis of Reference Station Distribution Impact on KASS UDRE Performance (기준국 배치에 따른 한국 위성기반 보강 시스템 UDRE 성능 영향 분석)

  • Yun, Youngsun
    • Journal of Advanced Navigation Technology
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    • v.19 no.3
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    • pp.207-216
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    • 2015
  • Since the distribution of SBAS reference stations is one of the most important factors that affect the system performance, the effects of the distribution should be analyzed carefully from the beginning of the program to develop the system conforming to given performance requirements. The reference stations of KASS, the Korean SBAS, are planned to be installed only inside South Korea, which limits the number and area of those. It differentiates KASS from others that have much larger sites. In this paper, the author analyzes the performance impact on UDRE and ${\delta}UDRE$ for GPS and GEO due to the limitations by a series of simulations, which showed that the UDRE performance depends on the diversity of the reference station distribution and the impact on the GEO UDRE is significant. The paper concludes by providing KASS design and development considerations to minimize the possible performance risks due to the limitations of KASS reference station distribution.

DEEP-South: The Progress and the Plans of the First Year

  • Moon, Hong-Kyu;Kim, Myung-Jin;Roh, Dong-Goo;Park, Jintae;Yim, Hong-Suh;Lee, Hee-Jae;Choi, Young-Jun;Oh, Young-Seok;Bae, Young-Ho
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.48.2-48.2
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    • 2016
  • The wide-field and the round-the clock operation capabilities of the KMTNet enables the discovery, astrometry and follow-up physical characterization of asteroids and comets in a most efficient way. We collectively refer to the team members, partner organizations, the dedicated software subsystem, the computing facility and research activities as Deep Ecliptic Patrol of the Southern Sky (DEEP-South). Most of the telescope time for DEEP-South is devoted to targeted photometry of Near Earth Asteroids (NEAs) to push up the number of the population with known physical properties from several percent to several dozens of percent, in the long run. We primarily adopt Johnson R-band for lightcurve study, while we employ BVI filters for taxonomic classification and detection of any possible color variations of an object at the same time. In this presentation, the progress and new findings since the last KAS meeting will be outlined. We report DEEP-South preliminary lightcurves of several dozens of NEAs obtained at three KMTNet stations during the first year runs. We also present a physical model of asteroid (5247) Krylov, the very first Non principal Axis (NPA) rotator that has been confirmed in the main belt (MB). A new asteroid taxonomic classification scheme will be introduced with an emphasis on its utility in the LSST era. The progress on the current version of automated mover detection software will also be summarized.

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Characterization of Putative Capsaicin Synthase Promoter Activity

  • Kim, June-Sik;Park, Minkyu;Lee, Dong Ju;Kim, Byung-Dong
    • Molecules and Cells
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    • v.28 no.4
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    • pp.331-339
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    • 2009
  • Capsaicin is a very important secondary metabolite that is unique to Capsicum. Capsaicin biosynthesis is regulated developmentally and environmentally in the placenta of hot pepper. To investigate regulation of capsaicin biosynthesis, the promoter (1,537 bp) of pepper capsaicin synthase (CS) was fused to GUS and introduced into Arabidopsis thaliana (Col-0) via Agrobacterium tumefaciens to produce CSPRO::GUS transgenic plants. The CS was specifically expressed in the placenta tissue of immature green fruit. However, the transgenic Arabidopsis showed ectopic GUS expressions in the leaves, flowers and roots, but not in the stems. The CSPRO activity was relatively high under light conditions and was induced by both heat shock and wounding, as CS transcripts were increased by wounding. Exogenous capsaicin caused strong suppression of the CSPRO activity in transgenic Arabidopsis, as demonstrated by suppression of CS expression in the placenta after capsaicin treatment. Furthermore, the differential expression levels of Kas, Pal and pAmt, which are associated with the capsaicinoid biosynthetic pathway, were also suppressed in the placenta by capsaicin treatment. These results support that capsaicin, a feedback inhibitor, plays a pivotal role in regulating gene expression which is involved in the biosynthesis of capsaicinoids.

Immunochemical Detection of Soybean Mosaic Virus Infections in the Seeds of Soybean Cultivars in Korea (면역이중확산법에 의한 콩 종자의 모자이크 바이러스(SMV) 감염상 조사)

  • La Yong-Joon;Bak Won-Chull;Oh Jeung-Haing
    • Korean journal of applied entomology
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    • v.22 no.1 s.54
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    • pp.26-30
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    • 1983
  • Soybean mosaic virus (SMV) infection in seeds wits investigated by an immunochemical method Seven soybean cultivars or lines Bughae No.1, KAS 662-7, Chungbugbaeg, Gwanggyo Clark, Bongeui, and Gangrim were tested using hypocotyls of germinated seeds and presence of SMV was detected in six soybean cultivars but Gangrim. The level of SMV infection in the assayed cultivars varied from 2.1 to $12.5\%$. It seemed that seed coat mottling had no correlation with seeds. SMV infection of the seeds since virus has not always been detected from the mot tled seeds SMV has not been detected in the seeds of variety Gwanggyo which showed necrotic symptoms.

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A Study on Certification System for Aircraft Engines and Auxiliary Power Units (항공기 엔진 및 보조동력장치 인증제도 현황)

  • Lee, Eunhee;Lee, Kang-Yi;Kim, Jinhee
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.194-197
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    • 2017
  • Aircraft engine and auxiliary power units are certified in processes of design, production according to airworthiness requirements. The aircraft engines shall demonstrate compliance with the design and production through the Type Certificate and the auxiliary power unit shall demonstrate compliance with the design and production through the Technical Standards Order Approval. MOLIT(Ministry of Land, Infrastructure and Transport) established the law and the airworthiness requirements for aircraft engines such as KAS Part 33 but didn't issue the Technical Standards Order for auxiliary power unit. In this paper, we proposed and explained the plan for improvement of our aircraft engines industry through building and expanding the certification infra-structure for aircraft engines and auxiliary power unit.

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