• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.36.2-36.2
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• 2020

Intensive Monitoring Survey of Nearby Galaxies (IMSNG) has been managed over 6 years. It aimed to constrain the progenitor system and explosion mechanism of SNe by detection of very early signal from shock heated emission. We have conducted monitoring observation of nearby bright galaxies those were carefully selected using global network of 1-m class telescopes. More than 20 SNe have occured in our target fields. As One of result of the survey, we present light curve analysis of type Ia SN 2018kp, which was discovered in NGC 3367. Based on photometric analysis, we calculated explosion parameters and set constraints of physical conditions of this supernova. We compared the results with theoretical model progenitor systems to find out which scenario is the most fitted to SN 2018kp case. Moreover, we estimate the distance to the galaxy and look into the relation between SNe and galactic physical parameters.

• Journal of Aerospace System Engineering
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• v.10 no.4
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• pp.35-40
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• 2016

Mid-course correction maneuvers (MCCMs) are necessary to correct the launch-vehicle dispersion to go to the Moon. There were 3 or 4 MCCMs needed for a direct transfer trajectory. But the strategy for MCCMs of the phasing-loop trajectory is different, because it has a longer trans-lunar trajectory than direct transfer does. An orbiter using a phasing-loop trajectory has several rotations of the Earth, so the orbiter has several good places, such as perigee and apogee, to correct the launch-vehicle dispersion. Although launch dispersion is relatively high, the launch vehicle is not as accurate as we expected. A good MCCM strategy can overcome the high dispersion by using small-magnitude correction maneuvers. This paper describes the phasing-loops sequence and strategy to correct high launch-vehicle dispersions.

• Journal of Space Technology and Applications
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• v.3 no.4
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• pp.373-384
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• 2023

Initiated as Korea's inaugural space exploration endeavor, the lunar exploration development project has resulted not only the Danuri lunar orbiter but also payloads designed to achieve mission objectives and the associated Korea Pathfinder Lunar Orbiter (KPLO) Deep-space Ground System for the operation and control of the Danuri. Scientific data gathered by four scientific payloads, developed by domestic institutions and installed on board the Danuri, will be publicly available starting January 2024. To facilitate this, the first-ever Korean space exploration scientific data management and public release system, KARI Planetary Data System (KPDS), has been developed. This paper provides details on the configuration and functions of the established KPDS website.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.2
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• pp.75-79
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• 2009

A system-on-a-chip communication architecture has a significant impact on the performance and power consumption of modern multi-processors system-on-chips (MPSoCs). However, customization of such architecture for a specific application requires the exploration of a large design space. Thus, system designers need tools to rapidly explore and evaluate communication architectures. In this paper we present the method for application-specific low-power bus architecture synthesis at system-level. Our paper has two contributions. First, we build a bus power model of AMBA AXI bus communication architecture. Second, we incorporate this power model into a low-power architecture exploration algorithm that enables system designers to rapidly explore the target bus architecture. The proposed exploration algorithm reduces power consumption by 20.1% compared to a maximally connected reduced matrix, and the area is also reduced by 20.2% compared to the maximally connected reduced matrix.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.250-255
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• 2005

For navigation of a service robot, mapping and localization are very important. To estimate the robot pose, the map of the environment is required and it can be built by exploration or SLAM. Exploration is the fundamental task of guiding a robot autonomously during mapping such that it covers the entire environment with its sensors. In this paper, an efficient exploration scheme based on the position probability of the end nodes of a topological map is proposed. In this scheme, a topological map is constructed in real time using the thinning-based approach. The robot then updates the position probability of each end node maintaining its position at the current location based on the Bayesian update rule using the range data. From this probability, the robot can determine whether or not it needs to visit the specific end node to examine the environment around this node. Various experiments show that the proposed exploration scheme can perform exploration more efficiently than other schemes in that, in most cases, exploration for the entire environment can be completed without directly visiting everywhere in the environment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.492-498
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• 2008

In this paper are described recent studies about variable nozzles, that are a rectangular type nozzle and an axisymmetric type nozzle, of the precooled turbojet engine(S-engine) which are developed for the demonstration of the key technologies for the propulsion system of the hypersonic airplane and the first stage propulsion of the TSTO space plane. For the rectangular nozzle, three types of C-shaped carbon/carbon composite cowls which includes subscale model of the precooled turbojet engine are fabricated and the fine attachment to the ramp is confirmed. For the firing of the S-engine, stainless steel cowl with concrete heat insulator are fabricated and tested for 20 sec. Axisymmetric variable plug nozzle which is made of C/C material is fabricated and pressurized by the cold flow test. The axisymmetric plug nozzle can be operative up to 0.57 MPa of nozzle inlet pressure.

• Journal of Astronomy and Space Sciences
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• v.27 no.1
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• pp.11-20
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• 2010

This paper designs a data link between a Lunar Orbiter (LO) and an Earth Station (ES), and analyzes the downlink performance of a space communications system for lunar exploration, conforming to the recommendations by the Consultative Committee for Space Data Systems (CCSDS). The results provided in the paper can be useful references for the design of reliable communication link for the Korean lunar exploration in the near future.

• Journal of The Korean Association For Science Education
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• v.22 no.5
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• pp.1071-1081
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• 2002

This article describes the status of science teacher education in Taiwan. The pre-service and in-service science teacher training system, institutes, curricula, programs, and evaluation on the institutes were briefly introduced. The differences before and after the 1996 reform of science teacher training system were compared. Finally, the attempts and efforts that have been done through the channels of research to promote science teachers' professional development were addressed. These efforts include the Case studies of exemplary science teachers' teaching performances, the development of licensure instruments for the certification of science teachers, the use of computers and distance education for supervising student teachers, the exploration of promoting science teachers' understanding about the nature of science, the exploration of promoting science teachers' pedagogical content knowledge, the exploration of promoting science teachers' ability of increasing effective student-teacher and student-student interactions, and the exploration of effective teaching strategies.

• Journal of Aerospace System Engineering
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• v.9 no.4
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• pp.73-80
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• 2015

For Korean first lunar exploration program, KARI(Korea Aerospace Research Institute) has been researching in various fields and investigating cases of abroad lunar exploration spacecrafts. In the field of the flight software, KARI has been analysing some cases such as NASA LRO, and this paper describes the result of the case study on LRO flight software.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.693-698
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• 2004

This paper describes development status and program of ATREX engine as a propulsion system of future spaceplane. Development activities using ATREX-500 engine from 1990 were finished in 2003 with large number of outcomes. We made system-level validation of the hydrogen fuel turbojet engine with air precooling device under sea level static condition. As a next step, we started design of the flight-type ATREX engine with large thrust and lightweight.