• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.1
• /
• pp.45.2-45.2
• /
• 2018

CS molecule is known to be adsorbed onto dust in cold dense cores, causing its significant depletion in the center region of cores. This study is aimed to investigate the depletion of CS molecule with optically thin $C^{34}S$ molecular line observations, including significance of its differentiation depending on the evolutionary status of the dense cores. We mapped five evolved starless cores, L1544, L1552, L1689B, L694-2 and L1197 using two molecular lines, $C^{34}S$ (J=2-1) and $N_2H^+$ (J=1-0) with NRO 45 m telescope. The $H^2$ column density and temperature structures of each targets were obtained by SED fitting for Herschel continuum images and the internal number density profiles by model fitting. All of the integrated intensity maps of $C^{34}S$ show depletion holes and 'semi-ring-like' distribution, indicating that the depletion of CS is clear and general. The radial profiles of CS abundance also show significant decrease towards the core center, while $N_2H^+$ abundance is almost constant or enhanced. We find that the more evolved cores with higher $H^2$ density tend to have a stronger depletion of CS. Our data strongly support claims that CS molecule generally depletes out in the central regions of starless dense cores and such chemical differentiation is closely related to their evolution.

• Journal of The Korean Association of Information Education
• /
• v.3 no.1
• /
• pp.13-21
• /
• 1999

'Interactivity' is considered as a key factor of user-centered interactive instructional systems design in Web environments. To provide an optimal level of interactivity for learners is an ideal goal in instructional systems design(ISD) process. Based on the primary concern of interactive systems design which pursues how the power of interactivity can be utilized and put to work, several interactive design strategies in Web-based systems are recommended through this research.

• Journal of The Korean Association of Information Education
• /
• v.7 no.3
• /
• pp.275-283
• /
• 2003

Web-based instructional system gives us the greatest potential for supporting face-to-face classroom instruction in many ways. With the help of the Web in high school setting, all of the participants including teachers can share many different experiences, active interactions, and even learning outcomes. In this paper, web-based instructional strategy based on constructivism for extending the geographical thought is suggested. The results from the formative assessment, as well as the statistical results from regression analysis concerning the learners' satisfaction, are also provided.

• Natural Product Sciences
• /
• v.20 no.2
• /
• pp.126-129
• /
• 2014

Bioactivity-guided investigation on whole plant of Euphorbia supina, using LPS-induced Raw264.7 cells, led to the identificaiton of a tannin which was not reported from this plant along with four known constituents (quercetin, astragalin, juglanin and methyl gallate). The structure of the tannin was determined as corilagin by the interpretation of NMR (1D and 2D) and MS spectroscopic data. All the isolates were tested for the inhibitory activity against NO production in LPS-induced Raw264.7 cells. Among the tested isolates, corilagin was found to be the most active compound.

• Journal of Internet Computing and Services
• /
• v.9 no.6
• /
• pp.127-139
• /
• 2008

The value of up-to-date Mobile PC such as UMPC (Ultra Mobile Personal Computer) is recognized greatly in learning environment that busywork such as characteristic of transfer easy and real time communication possibility etc. and conversation with a colleague student, free sending of studying data and public ownership etc. is required. Wish to recognize whether is acting relevant role in u - unfold learning that inflect UMPC in integration research model, and UMPC is u searching for relevant element at studying activity unfolding process u - integration Inquiry-Based Learning that present in Korean education & research information service (KERIS) at fifth-year student science time In primary school in this research. This research result could take charge role of UMPCs' studying-activity though there is persistent feedback with teacher among studying-activity although UMPC's role is utilized on constituent that can be related with studying-activity in learning process.

• Journal of Digital Convergence
• /
• v.15 no.9
• /
• pp.211-221
• /
• 2017

The semiconductor industry develops and maintains software embedded in computer-controlled tools and facilities, to process and manufacture high-tech products. Upgrading embedded softwares for semiconductor processing robots and machinery is one of the basic activities that must be performed in order to maintain product quality and integrity. Maintenance and enhancement of embedded software consume a major portion of the total life cycle cost of a system. However, the area has been given little attention in the literature. 502 maintenance and enhancement cases, related to embedded softwares in wafer processing machines, were selected at random for analysis. Practical implications are also discussed.

• Korean Management Science Review
• /
• v.24 no.2
• /
• pp.95-114
• /
• 2007

The main attractant of portable multimedia player(PMP), is often their versatility : being able to load and play different formats of video, audio, digital images, and interactive media. In this paper, we investigate the factors influencing the usage the PMP, based on the extended version of the Technology Acceptance Model. Using the data collected from online survey, we show that perceived usefulness, perceived ease of use, and perceived enjoyment are the major determinants for using PMP. Factors, including ubiquitousness, community, and image are shown to directly or indirectly determine the level of perceived usefulness and ease of uses. In addition, we classify PMP users into two groups, users seeking hedonic value and utilitarian value, and examine the differences in path coefficients. Properties of the causal paths, including standardized path coefficients, the significance of difference, in the hypothesized model, are also presented, so that we can investigate the relative influences of different dominants, demonstrating how two groups differ in their decision-making processes regarding the PMP usage.

• The Journal of Korean Association of Computer Education
• /
• v.3 no.1
• /
• pp.75-86
• /
• 2000

No matter how a great value the classwork through Internet may be, the value of Internet can be of negative value if teachers do not intend to make good use of it. Based on this assumption, this research is to show how to draw up a plan for utilizing a effective course of the classwork in high school through Internet, which is now being given attention to an educational environment as a innovative way supporting various educational possibilities compared with a traditional system of education. In addition, this study focuses on the investigation on the classwork through Internet by on-the-spot teachers as a part of all possible efforts for spreading the classwork with network.

• The Journal of Korean Association of Computer Education
• /
• v.19 no.1
• /
• pp.77-86
• /
• 2016

This paper is concerned with identifying the determinants of committing digital piracy in university settings. Using a theoretical model based on Theory of Reasoned Action, the causal relationship among the research variables, including intention to commit digital piracy, attitude, subjective norm and fear of legal consequences, is developed. Results from 295 survey responses indicate that fear of legal consequences affect the subjective norm and the attitude, which in turn influence the intention to commit digital piracy. In addition, relativism based on EPQ(Ethics Perception Questionnaire) is introduced as a moderating variable. The relative influences of path coefficients are investigated and implications from findings are also discussed.

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.1
• /
• pp.62.1-62.1
• /
• 2014

We present preliminary results on the chemical differentiation of two dense gas tracers CS and $N_2H^+$ in five 'evolved' starless cores, L1544, L1552, L1689B, L694-2 and L1197, using our mapping observations in $C^{34}S$(J=2-1) and $N_2H^+$(J=1-0) with Nobeyama 45-m telescope. We compared the intensity maps of two molecular lines with 850 ${\mu}m$ continuum data which precisely trace the density distribution of the dense cores, finding that all of our targets show the central depletion holes in CS distribution, but the similar distribution in $N_2H^+$ to the one in dust continuum. Our data confirm the claim that CS molecule generally deplete out in the central region in starless cores, while $N_2H^+$ keep abundant as they get evolved. The detailed quantitative analysis on CS depletion in the dense cores, for example, the size of CS depletion area and radial (or gas density) dependence of CS depletion, is underway and will be presented in the meeting.