• Economic and Environmental Geology
• /
• v.38 no.3 s.172
• /
• pp.347-353
• /
• 2005

The geology of the Tumbang Lapan area consists of Permian to Carboniferous metamorphic rocks, Cretaceous granitic rocks, and Permian to Tertiary sedimentary and volcanic rocks. Three faults are developed in surveyed area, and are functioned as channels of the hydrothermal solution which farmed quartz veins within tuff3. In the mineralized area, argillic and propylitic alterations are dominant. Argillic altered rocks show the alteration mineral assemblages of kaolinte+sericite+quartz+chlorite+pyrite. Mineral association in propylitic alteration is chlorite+epidote+feldspar+quartz+pyrite+ magnetite. Vein type, fracture filling, stockwork are observed in survey area. As a result of analysis of samples from quartz veins and altered rocks, some mineralized rocks showed $0.01\~4.6g/t$ of gold.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.3 s.258
• /
• pp.209-216
• /
• 2007

Bacterial chemotaxis is essential to the study of structure and function of bacteria. Although many studies have accumulated the knowledge about chemotaxis in the past, the motion of a single bacterium has not been studied much yet. In this study, we have developed a device microfabricated by soft lithography and consisting of microfluidic channels. The microfluidic assay generates a concentration gradient of chemoattractant linearly in the main channel by only diffusion of the chemicals. Bacteria are injected into the main channel in a single row by hydrodynamic focusing technique. We measured the velocity of bacteria in response to a given concentration gradient of chemoattractant using the microfludic assay, optical systems with CCD camera and simple PTV (Particle Tracking Velocimetry) algorithm. The advantage of this assay and experiment is to measure the velocity of a single bacterium and to quantify the degree of chemotaxis by statistically analyzing the velocity at the same time. Specifically, we measured and analyzed the motility of Escherichia coli strain RP437 in response to various concentration gradients of L-aspartate statistically and quantitatively by using this microfluidic assay. We obtained the probability density of the velocity while RP437 cells are swimming and tumbling in the presence of the linear concentration gradient of L-aspartate, and quantified the degree of chemotaxis by analyzing the probability density.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.41 no.9
• /
• pp.579-586
• /
• 2017

In this study, new materials and shapes for a residential humidifying element were investigated. These elements could replace the current Japanese folded-type rayon/PE elements. Samples were taken from three different materials - rayon/PET (50:50), kraft/PET (40:60), kraft/PET/carbon. Results showed that the humidification efficiencies of the new samples were lower than those of the Japanese product. The efficiencies were 59% for the Japanese product (rayon/PET), 62% for kraft/PET and 84% for kraft/PET/carbon. This could be due to lower rayon or kraft content in the present samples than that in the Japanese product. However, pressure drops in the present samples were significantly lower than that in the Japanese product, due to improved channel configuration. The humidification capacity at the same pumping power ($j_m/f^{1/3}$) was 60% to 82% higher for the kraft/PET/carbon sample compared with the Japanese product. Furthermore, the results are compared with theoretical predictions.

• Molecules and Cells
• /
• v.21 no.3
• /
• pp.418-427
• /
• 2006

Ionotropic glutamate receptors (iGluRs) are ligand-gated nonselective cation channels that mediate fast excitatory neurotransmission. Although homologues of the iGluRs have been identified in higher plants, their roles are largely unknown. In this work we isolated a full-length cDNA clone (RsGluR) encoding a putative glutamate receptor from small radish. An RsGluR:mGFP fusion protein was localized to the plasma membrane. In Arabidopsis thaliana overexpressing the fulllength cDNA, glutamate treatment triggered greater $Ca^{2+}$ influx in the root cells of transgenic seedlings than in those of the wild type. Transgenic plants exhibited multiple morphological changes such as necrosis at their tips and the margins of developing leaves, dwarf stature with multiple secondary inflorescences, and retarded growth, as previously observed in transgenic Arabidopsis overexpressing AtGluR3.2 [Kim et al. (2001)]. Microarray analysis showed that jasmonic acid (JA)-responsive genes including defensins and JA-biosynthetic genes were up-regulated. RsGluR overexpression also inhibited growth of a necrotic fungal pathogen Botrytis cinerea possibly due to up-regulation of the defensins. Based on these results, we suggest that RsGluR is a glutamate-gated $Ca^{2+}$ channel located in the plasma membrane of higher plants and plays a direct or indirect role in defense against pathogen infection by triggering JA biosynthesis.

• Molecules and Cells
• /
• v.27 no.3
• /
• pp.307-312
• /
• 2009

The interstitial cells of Cajal (ICC) are pacemaking cells required for gastrointestinal motility. The possibility of whether DA-9701, a novel prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, modulates pacemaker activities in the ICC was tested using the whole cell patch clamp technique. DA-9701 produced membrane depolarization and increased tonic inward pacemaker currents in the voltage-clamp mode. The application of flufenamic acid, a non-selective cation channel blocker, but not niflumic acid, abolished the generation of pacemaker currents induced by DA-9701. Pretreatment with a $Ca^{2+}$-free solution and thapsigargin, a $Ca^{2+}$-ATPase inhibitor in the endoplasmic reticulum, abolished the generation of pacemaker currents. In addition, the tonic inward currents were inhibited by U-73122, an active phospholipase C inhibitor, but not by $GDP-{\beta}-S$, which permanently binds G-binding proteins. Furthermore, the protein kinase C inhibitors, chelerythrine and calphostin C, did not block the DA-9701-induced pacemaker currents. These results suggest that DA-9701 might affect gastrointestinal motility by the modulation of pacemaker activity in the ICC, and the activation is associated with the non-selective cationic channels via external $Ca^{2+}$ influx, phospholipase C activation, and $Ca^{2+}$ release from internal storage in a G protein-independent and protein kinase C-independent manner.

• Journal of Internet Computing and Services
• /
• v.19 no.2
• /
• pp.69-75
• /
• 2018

Over the years, the types of media and media usage patterns have rapidly changed and communication channels in society have diversified. The courses in the universities on "media" have accordingly been altered to adapt to these changes. To investigate the ways in which the higher learning institutions in Korea have adapted to the changes in the media environment, this study analyzed the curriculum provided by the communication/media departments in the areas of Seoul and Gyeonggi-do. For the curricula analysis,names of the course soffered at the selected universitie swere analyzed; then keywords were extracted from morphological analysis of thes enames. Also, to investigate the changes over time, the courses offered in the years 2008 and 2017 were selected. The network analysis was done by using Netminer; the shape, main components, and major nodes of the network were compared. The results showed that firstly, overall shape of network from 2008 and 2017 looked similar. Due to the existence of concentrations within the major, the overall shape of the network showed several independent components, rather than one network. However, the analysis revealed differences in major nodes in the 2008 case from 2017. In the 2008 case, 'programming,' 'media,' 'introduction' among others were the major nodes; in 2017, 'editing' was the most important node. This signifies that in 2017, the curricula in the selected universities emphasized more practical and technical media education. In other words, the universities have adapted to the changing environments by including new topics, paying more attention to video media, and providing students with more direct field experiences.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.8
• /
• pp.5288-5293
• /
• 2014

This paper presents the characterization of the wavelength selective switch using a LCOS display instead of a MEMS device, which is a core technology for the next generation ROADM. We constructed a five-port WSS, and examined the basic characteristics of the WSS, such as the response time, beam steering, insertion loss, and channel isolation. The response time of WSS was 11.6 mS and the beam steering characteristics of LCOS was well performed. The measured insertion loss at 40 channels in the c-band were 5.5~12.7 dB and channel isolation was 16~18 dB. Although the characteristics of LCOS-based WSS are inferior to the conventional MEMS-based WSS, it can be improved by additional experiments that secure the technology competitiveness.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.33 no.1
• /
• pp.92-103
• /
• 2009

The study is interested in the consumer's mixed choice of the internet and the offline stores. Therefore the purpose of study is to investigate if the clothing shopping orientation of consumers varies when they shop internet and offline, instead of classifying consumers into internet shoppers and offline shoppers. For the purpose, quantitative survey was carried out using 201 questionnaires from men and women in their twenties. The data were analyzed using factor analysis, Pearson's correlation analysis, Spearman's rank order correlation coefficient, t-test, and frequency analysis. The results are as following. First, the clothing shopping orientation structures of offline and internet stores were different each other. As the result of factor analysis, positive, brand oriented, economic, convenient conformity, convenient impulsive factors were extracted from offline store and rational, enjoying, goal oriented, conformity, brand oriented, convenient impulsive purchase factors were extracted from internet store respectively. Second, as the results of investigating the relationship between the clothing shopping orientation structures of offline and internet stores, positive(off)-enjoying(on), brand oriented(off)-brand oriented(on), convenient conformity(off)-conformity(on) had strong correlation s and the rest were peculiar to the each store type. Specifically, the goal oriented factor peculiar to the internet store was noticeable. Third, as the results of investigating the differences between clothing shopping orientation of offline and internet stores, the ranks of strong orientation dimension were different between two channels. As well, the mean differences were significant in goal oriented, conformity, brand oriented, and convenient impulsive purchase dimensions. This study has the significance that it investigated the variance of clothing shopping orientation according to the mixed selection trend of internet/offline.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.11
• /
• pp.998-1007
• /
• 2015

The $H_{\infty}$ control theory using LMI method is applied to design an attitude controller of radial type satellite that has strongly coupled channels due to the large product of inertia. It is observed that the cross-over frequency of open-loop with $H_{\infty}$ controller is lower than that of open-loop without controller, which is not typical phenomenon in an optimal control design result: it is interpreted that due to a large product of inertia, there is certain limit in increasing agility of satellite by just tuning weighting function. ${\mu}$-analysis is performed to verify the stability and performance robustness with the assumption of +/-5% MOI variation. ${\mu}$-analysis result shows that the variation of principal MOI degrades the stability and performance robustness more than the variation of POI does.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.8
• /
• pp.4006-4020
• /
• 2018

In recent years, one of the most remarkable 5G technologies is massive multiple-input and multiple-output (MIMO) system which increases spectral efficiency by deploying a large number of transmit-antennas (eg. tens or hundreds transmit-antennas) at base station (BS). However, conventional massive MIMO system using single-polarized (SP) transmit-antennas increases the size of the transmit-array proportionally as the number of transmit-antennas increases. Hence, size reduction of large-scale transmit-array is one of the major concerns of massive MIMO system. To reduce the size of the transmit-array at BS, dual-polarized (DP) transmit-antenna can be the solution to halve the size of the transmit-array since one collocated DP transmit-antenna deploys vertical and horizontal transmit-antennas compared to SP transmit-antennas. Moreover, proposed DP massive MIMO system increases the spectral efficiency by not only in the space domain but also in the polarization domain whereas the conventional SP massive MIMO system increases the spectral efficiency by space domain only. In this paper, the comparative performance of DP and SP massive MIMO systems is analyzed by space division multiple access (SDMA) and space-polarization division multiple access (SPDMA) respectively. To analyze the performance of DP and SP massive MIMO systems, DP and SP spatial channel models (SCMs) are proposed which consider depolarized propagation channels between transmitter and receiver. The simulation results show that the performance of proposed 32 transmitter (Tx) DP massive MIMO system improves the spectral efficiency by about 91% for a large number of user equipments (UEs) compare to 32Tx SP massive MIMO system for identical size of the transmit-array.