• Publications of The Korean Astronomical Society
• /
• v.15 no.spc1
• /
• pp.133-145
• /
• 2000

Symbiotic stars are known as binary systems with both cool and hot components with enshrounding nebulous gas. The cool component, M-type giant, is presumably loosing its mass into a hot white or main sequence companion star through the inner Lagrangian point. The lines emit from the ionized nebulous region around the hot star while the mass loss or accretion activity is believed to be the main cause of sudden variation of the continuum and line fluxes. We selected 17 symbiotics for which the emission line fluxes were measured from the IUE SWP, LWR data, to find variability of spectrum. We also investigated the periodic variation of emissions or eclipsing effect from the IUE lines. All of our symbiotics show very high electron densities in the emission regions. For other optical symbiotics, the observations had been carried in 1999 with BOAO mid-resolution spectrometer. We classified symbiotics based on their outburst activities, or emission line characteristics, i.e., $OVI{\lambda}6830.\;The\;OVI{\lambda}6830$ emission lines are also found in S-type symbiotics, which have been known as charateristics of D-types.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.1
• /
• pp.33.1-33.1
• /
• 2012

We investigate the disk-jet connection of Young Radio Galaxies (YRGs) by comparing emission-line properties with radio luminosity and jet size. By combining new optical spectra for 21 objects with SDSS archival data for 15 objects, we selected a sample of 36 low-redshift YRGs at z < 0.4. We find that YRGs are classified in high- and low-excitation galaxies based on the relative strength of high-to-low excitation line strengths, suggesting that there are two populations in YRGs as similarly found in large radio galaxies, i.e., FRIs and FRIIs. High-excitation galaxies (HEGs) have higher emission line luminosities than low-excitation galaxies (LEGs) at fixed black hole mass and radio luminosity, suggesting that the Eddington ratio is higher in HEGs than in LEGs and that for given radio activity HEGs have higher accretion activity than LEGs. The difference between HEGs and LEGs is probably due to either mass accretion rate or radiative efficiency.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.21 no.10
• /
• pp.951-959
• /
• 2011

In this study, an OTM(on-the-move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite while moving was addressed. Since LOS(line-of-sight) of antenna should direct satellite consistently while vehicle moving to guarantee high satellite communication quality, active antenna LOS stabilization is a core technology for OTM antenna. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. In consideration of driving mechanism which consists of gear train and flexible driving shafts, a two-mass-system dynamic model coupled with vehicle motion was presented. An internal PI-control loop + outer PI-control loop structure has been suggested in order to damp the torsional vibration and stabilize control system. The classical pole-placement method was applied to design control gains. In addition, a vehicle motion compensation control beside of the feedback control loop has been suggested to improve LOS stabilization performances. The feasibility of the proposed control design was verified along with some experimental results.

• Journal of Information Technology Services
• /
• v.11 no.4
• /
• pp.295-308
• /
• 2012

Software and Systems Product Line(SSPL) is a paradigm that has been developed and applied by European Union(EU) to achieve the productivity and competitiveness of EU industries on the world market. It is not just a simple system or software development methodology, but a sophisticated technology requiring capabilities for a high level of mass customization, platforms, processes and convergence of software and systems. EU has applied SSPL for the five selected industrial sectors including aerospace, automobile, medical equipment, consumer electronics and telecommunication equipment since 1990s and led the way to other industry sectors to stimulate the application of SSPL from 2006. In order for Korea to secure competitiveness in the manufacturing and service industries in the competitive borderless market, it is essential to gain the high level of capabilities for software development and convergence of software and systems. SSPL can be a powerful means to achieve this end. This paper discusses the paradigmatic concept of SSPL, how EU's major industries and companies have secured competitiveness through SSPL, key capabilities that are necessary for successful institutionalization of SSPL in Korea, and finally suggestions on core strategies to materialize the benefits of SSPL for Korea.

• Journal of the Korean earth science society
• /
• v.41 no.1
• /
• pp.1-18
• /
• 2020

This study presented the effects of the assumed mass-size relationship for snow on the simulated surface precipitation by using cloud microphysics parameterizations in Weather Research and Forecasting (WRF) model. The selected cloud microphysics parameterizations are WRF Double-Moment 6-class (WDM6) and WRF Single-Moment 6-class (WSM6) in the WRF model. We replaced the mass-size relationship for snow in WDM6 and WSM6 with Thompson's mass-size relationship retrieved from measurement data. The sensitivity of the modified WDM6 and WSM6 was tested for the idealized 2-dimensional squall line and winter precipitation system over the Korean peninsula, respectively. The modified WDM6 and WSM6 resulted in the increase of graupel/rain mixing ratios and the decrease of snow mixing ratio in the low atmosphere. The changes of hydrometeor mixing ratio and surface precipitation could be due to the collision-coalescence process between raindrops and snow and the graupel melting process.

• YAKHAK HOEJI
• /
• v.13 no.4
• /
• pp.121-124
• /
• 1969

인삼의 "methanolic extract"을 분획하여 염기성 성분을 모으고 GLC-Mass on line, NMR spectrum에 의하여 $\alpha$-pyrrolidone과 수종의 염기성성질이 공존함을 증명하였다.

• Proceedings of the PSK Conference
• /
• 2000.04a
• /
• pp.212.1-212.1
• /
• 2000

• Korean journal of communication and information
• /
• v.36
• /
• pp.423-462
• /
• 2006

This thesis explores the relationship between self-construal and online communication pattern. The Internet has changed human-to human communication. This study was to analyze how the self-construal was appeared and what relationship self-construal had with several variables: the motivation of the on-line community member, the on-line community's character, the communication behavior, the level of relationship between on-line community members- in on-line communities. The data was collected through the on-line survey research(N=79) and off-line survey research(N=255). The results lead us to conclude that the self-construals in on-line communities reflect two factors, which is similar to the off-line community. Nevertheless, self-construals in on-line communities are more complicated. In addition, uniqueness of self-construals which is the tendency to express the self and think connection with others critical is the important factor in on-line communities' communication. It is also central that the impact of self-construals on communication behavior is significant. I think this study was a small touch to explore cyber communication applying to self-consturals. And I hope this small touch would spread out and help to understand human communication as well as cyber communication.

• Korean journal of communication and information
• /
• v.52
• /
• pp.154-176
• /
• 2010

Rooted in the work of Pierre Bourdieu, the cultural intermediaries have recently developed as a focus of attention for the Anglo-saxon sociology of culture and cultural studies. This paper tries to critically examine the debate around the definition and role of cultural intermediaries. It also explores the applicability of the notion ‘cultural intermediaries’ to a changing digital mediascape. In the first part of the paper, I clarify the critical problematics inherent in the Bourdieusian conception which focuses on the function of cultural intermediaries for the ‘production of the belief’ in cultural goods. Consequently, I draw attention to the mediation and transformation process of ‘legitimate culture’ by critics in mass media as ‘new cultural intermediaries’. In the second part, I attempt to constitute a typology of cultural intermediaries, proposing the notion of ‘on-line cultural mediation’ and ‘on-line cultural intermediaries’. I also outline the characteristics of three different types (‘traditional’, ‘new' and 'on-line') of cultural intermediaries. I argue this new conception of cultural intermediaries can help to understand the complex power relations and their transmutation in various cultural fields under digital environment.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.25 no.2
• /
• pp.41-51
• /
• 2013

The tidal creek dependent mass transport characteristic in Gyeong-Gi Bay (west coast of Korea) was studied using field measured data and numerical model. Gyeong-Gi Bay consists of 3 main tidal channels and contains a well-developed vast tidal flat. This region is famous for its large tidal difference and strong current. We aim to study the effect of tidal creek in the tidal flat on the mass exchange between the estuary and the ocean. For numerical application, the application of unstructured grid feature is essential, since the tidal creek has complicated shape and form. For this purpose, the FVCOM is applied to the study area and simulation is performed for 2 different cases. In case A, geographic characteristics of the tidal creek is ignored in the numerical grid and in case B, the tidal creek are constructed using unstructured grid. And these 2 cases are compared with the field measured cross-channel mass transport data. The cross-channel mass transport at the Yeomha waterway mouth and Incheon harbor was measured in June, 9~10 (Spring tide) and 17~18 (Neap tide), 2009. CTD casting and ADCP cross-channel transect was conducted 13 times in one tidal cycle. The observation data analysis results showed that mass transport has characteristic of the ebb dominance Line 1 (Yeomha waterway mouth), on the other hand, a flood dominant characteristic is shown in Line 2 (Incheon harbor front). By comparing the numerical model (case A & B) with observation data, we found that the case B results show much better agreement with measurement data than case A. It is showed that the geographic feature of tidal creek should be considered in grid design of numerical model in order to understand the mass transport characteristics over large tidal flat area.