• Journal of The Korean Astronomical Society
• /
• v.47 no.6
• /
• pp.201-207
• /
• 2014

We report the development of solar flux receivers operating at 2.8 GHz to monitor solar radio activity. Radio waves from the sun are amplified, filtered, and then transmitted to a power meter sensor without frequency down-conversion. To measure solar flux, a calibration scheme is designed with a noise source, an ambient load, and a hot load at $100^{\circ}C$. The receiver is attached to a 1.8 m parabolic antenna in Icheon, owned by National Radio Research Agency, and observation is being conducted during day time on a daily basis. We compare the solar fluxes measured for last seven months with solar fluxes obtained by DRAO in Penticton, Canada, and by the Hiraiso solar observatory in Japan, and finally establish equations to convert observed flux to the so-called Penticton flux with an accuracy better than 3.2 sfu.

• Journal of Satellite, Information and Communications
• /
• v.1 no.1
• /
• pp.20-25
• /
• 2006

The link of Geostationary Communication Satellite has transit delay and noise environments by physical distance. This situation exerts an influence on the degradation of baseband performance of Earth Station. Therefore, it is very important that degradation of baseband performance is grasped previously. This paper is presented that developed the simulator which can evaluate the baseband performance of earth station of a military satellite communication system during the current development. The simulator can mock delay on a satellite channel and bit errors without being used actual satellite links.

• Journal of Magnetics
• /
• v.18 no.3
• /
• pp.308-310
• /
• 2013

Translation induced by the field-gradient force is being observed for a single ferromagnetic iron grain and a ferrimagnetic grain of a ferrite sample ($CuFe_2O_4$). From measurements on the translation, precise saturated magnetization of $M_S$ is possible for a single grain. The method is based on the energy conservation rule assumed for the grain during its translation and the grain is translated through a diffuse area under microgravity conditions. The results of the two materials indicate that a field-induced translation of grain bearing spontaneous moment is generally determined by a field-induced potential $-mM_SH(x)$ where m denotes the mass of sample. According to the above translations, the detection of $M_S$ is not interfered by any signals from the sample holder. The $M_S$ measurement does not require m value. By observing translations resulting from fieldinduced volume forces, the magnetization of a single grain is measurable irrespective of its size; the principle is also applicable to measuring susceptibility of diamagnetic and paramagnetic materials.

• Journal of the Korean earth science society
• /
• v.40 no.4
• /
• pp.315-328
• /
• 2019

Since the Coastal Zone Color Scanner (CZCS)/Nimbus-7 was launched in 1978, a variety of studies have been conducted to retrieve ocean color variables from multi-satellites. Several algorithms and formulations have been suggested for estimating ocean color variables based on multi band data at different wavelengths. Chlorophyll-a (chl-a) concentration is one of the most important variables to understand low-level ecosystem in the ocean. To retrieve chl-a concentrations from the satellite observations, an appropriate algorithm depending on water properties is required for each satellite sensor. Most operational empirical algorithms in the global ocean have been developed based on the band-ratio approach, which has the disadvantage of being more adapted to the open ocean than to coastal areas. Alternative algorithms, including the semi-analytical approach, may complement the limits of band-ratio algorithms. As more sensors are planned by various space agencies to monitor the ocean surface, it is expected that continuous monitoring of oceanic ecosystems and environments should be conducted to contribute to the understanding of the oceanic biosphere and the impact of climate change. This study presents an overview of the past and present algorithms for the estimation of chl-a concentration based on multi-satellite data and also presents the prospects for ongoing and upcoming ocean color satellites.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2007.04a
• /
• pp.363-366
• /
• 2007

Road Design is being reached to the working design to produce drawings, calculate construction quantity and cost, through the basic design that contained feasibility study and all impact assessment. In general, to plan the route we use topographic map. The vertical positional accuracy is 30cm and horizontal positional accuracy is 35cm in 1:1,000 scale topographic map. In LiDAR, vertical positional accuracy is 15cm and horizontal positional accuracy is 30cm. So if we use LiDAR on road design, more accurate earth-volumn will be calculated when we plan the route. In this paper we try to find the method to use the LiDAR data on road design by drawing the profile and cross sectional view and comparing the earth-volumn to the road that working design is in process adopting the topographic map and LiDAR data.

• Journal of The Korean Astronomical Society
• /
• v.36 no.spc1
• /
• pp.151-154
• /
• 2003

During the past decade the world solar physics community has made significant progress in understanding the Sun and its interaction with the heliosphere and Earth's magnetosphere. NASA in coordination and cooperation with many other countries has had impressive results with the SOHO, YOHKOH, POLAR, GEOTAIL, etc spacecraft. These successes have given us a sound foundation to proceed into the new century. The two current main efforts in the U.S. are the Solar Terrestrial Probes (STP) and Living With A Star (LWS) programs. The STP program is basically science driven with new missions being selected on the basis of basic science discovery. The LWS program is focused on understanding the basic physics of solar variability and its effects on Earth systems. The current plans for these two programs are discussed.

• Journal of Conservation Science
• /
• v.5 no.2 s.6
• /
• pp.25-34
• /
• 1996

The essential point to be considered when restoring lacquered ware is to know its materials and properties, and prior studios from the conservational and scientific examination is the way to achieve it. Recently, to get a close examination of its materials and methods involved in lacquered ware making, cross section microscope studies are being applied. Cross section microscope studies shows that lacquering process has been simplified and that bone and earth substances have been added to the materials, a method also traced from the lacquered wooden coffin excavated from the 'Nak Rang Tomb' and by the lacquered wares of the 'Kyongjoo An Ap' areas. The significance of this Chosun Dynasty lacquered wares's inlaid with mother-of pearl restoration can be found in that we have been able to harmonize the very traditional and the very modern scientific method of our time and that we were able to launch a step forward from using only the synthetics to open up a new range of natural materials such as lacquers, bone and earth substances, oxhide-glue and nacres and of referring to the traditional methods.

• Journal of the Korean Professional Engineers Association
• /
• v.37 no.6
• /
• pp.29-36
• /
• 2004

Human being have destroyed environment through rapid industrialization, so that the world is increasingly faced with golbal environmental problem such as destruction of ozone layer, global warming., acid rain, decertification and we are heading toward impending disaster of the earth. Especially, recent environmental pollution of China from rapid economic development threatens neighboring Korea and Japan. Regional development are necessary for promotion of national prosperity, but theses regional developments must have brought about environmental and preservation. Actually there are so many conflict cases; Saemankum reclamation project, construction of nuclear waste storage facility, dam construction of China etc. Here, harmony and balance between development and preservation are needed to solve these great crux. Under theses condition, the concept of ESSD(Environmentally Sound and Sustainable Development) emerged as a global issue. And staring point to solve present environmental problems is to perceive the truth that we have inherited only one earth and hence owe a debt to preserve its environment for the benefit of the future generations.

• The Research Journal of the Costume Culture
• /
• v.5 no.1
• /
• pp.57-69
• /
• 1997

The environment and the ecologic balance of the earth had been destructed by both man and ecological catastrophes and are no longer sustainable. We have no future unless we conserve our natural resourses and make efforts to change our basic patterns of consuming, production and recycling. Our earth had been contaminated without our recognition. We became indifferent to environmental problems and even more we hve lost our interest completely. To overcome this period of crisis, the concept of 'green imperative'has emerged. Since design powerfully influences our lives and the environment for good or ill, those at the forefront of design to consumers and the end-users can contribute to the well-being of the people and planet through new awareness of environmental and ecological based design. The spiritual awareness of green design will enrich the work of design through lasting performance of continuty and will make the future work.

• Vacuum Magazine
• /
• v.1 no.2
• /
• pp.4-8
• /
• 2014

On this earth, we usually encounter three states of matter: solid, liquid, and gas. Those are the states we experience directly and most often in everyday life. However, if we consider the whole universe, more than 99.99 percent of our visible universe is in plasma state. The earth is in very unusual situation in the universe, and it is great virtue to whole creatures on this planet. In the beginning of the universe, however, there was only plasma. The other stuff came later after then. The Big Bang, beginning of our universe, was dominated by high-temperature plasma. It is where we all came from, and it continues to play a major role not only in our universe but also in various industrial applications of human being.