• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.113-120
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• 2010

This research is to evaluate the arousal level by using cardiovascular response. PPG was used in this study as one of the method of measuring it rather than ECG (Electrocardiography) for the purpose of solving ergonomic problem of sensing. The participants were in the age group of 20 (mean=24, standard deviation=1.25): five men and five women. Each experiment composed with four identical sets. First, a black screen was displayed for 30 second rest. Then, the prepared 6 pair images were randomly presented for 10 second stimulation and for 30 second non-stimulation. PPG was measured on the earlobes of experimenters at 200Hz sampling frequency. PPG amplitude, PPI(Pulse to Pulse Interval), and PRV(Pulse Rate Variability) were analyzed according to arousal level. T-test was performed to compare between the PPG variables of rest and relaxation, rest and arousal, and relaxation and arousal. Relative to the rest state, PPG amplitude decreased in relaxed state and increased in aroused state. Relative to the rest state, PPI decreased in both emotional states. However, more significant decline was observed in aroused state. PRV's LF and HF were used in the form of LF/HF to compare between the relaxed and the aroused state. Therefore, PPG signal showed significant differences between relaxed and aroused state. In conclusion, evaluation of human arousal level used in the PPG analysis demonstrated that PPG has better usability and comforter measurement than ECG and is clearly an alternative method of measuring arousal level.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1102-1107
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• 2003

The ES cell can provide a useful system for studying differentiation and development in vitro and a powerful tool for producing transgenic animalds. To investigate the culture condition of chicken embryonic stem (CES) cells which can retain their multipotentiality or totipotency, three kinds of feeder layer cells, SNL cells, primary mice embryonic fibroblasts (PMEF) cells and primary chicken embryonic fibroblasts (PCEF) cells, were used as the feeder cells in media of DMEM supplemented with leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF) and stem cell factor (SCF) for co-culture with blastoderm cells from stage X embryos of chicken. The alkaline phosphatase (AKP) test, differentiation experiment in vitro and chimeric chicken production were carried out. The results showed that culture on feeder layer of PMEF yielded high quality CES cell colonies. The typical CES cells clone shape revealed as follows: nested aggregation (clone) with clear edge and round surface as well as close arrangement within the clone. Strong alkaline phosphatase (AKP) reactive cells were observed in the fourth passage cells. On the other hand, the fourth passage CES cells could differentiate into various cells in the absence of feeder layer cells and LIF in vitro. The third and fourth passage cells were injected into the subgerminal cavity of recipient embryos at stage X. Of 269 Hailan embryos injected with CES cells of Shouguang Chickens, 8.2% (22/269) survived to hatching, 5 feather chimeras had been produced. This suggests that an effective culture system established in this study can promote the growth of CES cells and maintain them in the state of undifferentiated and development, which lays a solid foundation for the application of CES cells and may provide an alternative tool for genetic modification of chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1360-1366
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• 2001

The aims of this study were first to evaluate the effects of different levels (20, 40 and 100%) and sources (follicular size: large, >7 mm; medium, >5-7 mm; small, 3-5 mm) of porcine follicular fluid (pFF) on the in vitro maturation (IVM) of porcine oocytes, and the effects of fertilization treatments and different culture conditions on development of fertilized oocytes were also investigated. No differences in the maturation (63.6-76.6%) and cleavage (24.8-34.3%) rates were observed among the 20,40 and 100% pFF groups (p>0.05). The cleavage rates of oocytes cultured and fertilized in 40% and 100% pFF maturation media were significantly higher than those fertilized in m199-NBCS (51.0-61.2% vs. 12.8-31.8%. p<0.05), regardless of sources of the pFF. When oocytes were fertilized in m199-NBCS followed by culture in rabbit oviducts for 4 days, the cleavage rate in 40% pFF group was better than that in 100% pFF group (46.9% vs. 32.5%, p<0.05). Two oocytes recovered from the oviducts in the 40% pFF group developed to blastocysts after IVC. However, none developed to blastocysts when fertilized in the IVM medium after being transferred to rabbit oviducts. In conclusion, addition of pFF accompanied with gonadotropins (FSH, LH) in IVM medium enhanced maturation and cleavage rates of porcine oocytes. Direct addition of sperm suspension to IVM medium may be an alternative to simplify the fertilization procedures and to reduce the mechanical lesion during manipulation. Furthermore, rabbit oviducts provide a better environment for the in vitro fertilized oocyte developing to the morula and blastocyst stages.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.226-239
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• 2020

The study seeks to present ways to form and express political opinions while monitoring, regulating and critically accepting the production and distribution of false information and platforms, which are spread channels, through the participation of citizens. First, it logically identified the unfairness of legal regulations on false information. In other words, it is often practically impossible to judge whether false information is false or not, and even false information can sometimes fall within the category of freedom of expression protection. It also revealed that voluntary regulation by platform operators was limited. As an alternative, it was theoretically clear whether civil society should participate in the maintenance and development of democratic public debate sites and create social discourse. The specific method is to find and classify false information and share it with citizens to raise awareness. Second, it forms an autonomous cooperative system with platform operators and others. Third, develop critical media capacity of citizens. Fourth, it responds to producers and platform operators of false information while engaging in community activities as a direct practitioner.

• Journal of Broadcast Engineering
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• v.16 no.2
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• pp.305-318
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• 2011

Since switched digital video (SDV) provides specific programs only to the subscribers who request the programs, SDV has attracted considerable interest of MSOs for bandwidth efficiency. In North America, MSOs service over 2.3 million households with the SDV for cable networks. In Korea, since demand of HD program, high-speed Internet, VoD, and VoIP is noticeably rising, the SDV is considered as the alternative for bandwidth saving and efficient managing. In this paper, the characteristics, operating structure, and bandwidth saving of the SDV are discussed and technical requirements for the SDV are also introduced. The channel switching performance and stability of the SDV are analyzed through the test-bed.

• Journal of Game and Entertainment
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• v.2 no.3
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• pp.24-29
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• 2006

Nowadays, 'Interaction' is discussed not only in the multimedia field but also as a topic of daily life at the various viewpoints. And as the permmited limit of Interaction by Mutimedia Technology and audiovisual function is getting more activated, It is the time for us to have new understanding of a 'POSTER'. The Poster, as a one-sided information transmission media till now, is faced with its limitation in transmitting messages due to its unconformity between satisfaction of receiver' sdesire for information and installation space. This fact speaks for need of study about Digital Poster as an alternative communication method, and activation of Digital Poster Design Field. Therefore, I would like to present Design process and Examples by using Digital Poster for Maximizing the Communication Effect. And I expect the activation of Digital Poster Field by studying the possibility of development and various method of practical use of digital posters through presenting the examples.

• Journal of Korean Society for Quality Management
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• v.44 no.4
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• pp.883-895
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• 2016

Purpose: The demand for ordinary mail services supplied by 'Korea POST' is decreasing due to the opening of mail service market and the growth of alternative communication media such as e-mail and SNS. To overcome this situation it is urgent to introduce new services that can be able to appeal customers and to improve existing services. Methods: A field survey is conducted to corporate customers who send ordinary mails and individual customers who receive these mails, respectively. Quality attributes of ordinary mail services are classified by two-dimensional perspectives in terms of Kano model. Decision tree model is utilized for classifying the quality attributes. Comparative analyses are done whether there are perceived differences on each quality attributes between corporate customers and individual customers. Results: Quality attributes such as 'discount postal charges', 'sending small packages by simply dropping it into a mail box', 'sending a mail of any appearance', 'delivering a mail anywhere', and 'receiving a mail at a preferred time where a customer is located ' are classified differently according to some market segments, while most of the quality attributes are classified as attractive or one-dimensional. Conclusion: Decision tree model has been found to be most effective to classify quality attributes for each market segment especially when trying to classify quality attributes belonging to 'gray areas'. Based on the perceived differences on quality attributes among customers, strategic implications are suggested to obtain potential customers and to have competitive advantages.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.670-675
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• 2004

Humic acids are macromolecules originated from natural water, soil, and sediment. The characteristics of humic acid enable it to change the distribution of metals as well as many kinds of organic contaminants and to determine the sorption of them from soil solution. To see the effect of humic acid on the removal rate of organic contaminants and heavy metals, batch-scale experiments were performed. As a natural geosorbent, black shale was used as a sorbent media, which showed hight sorption capacity of trichloroethylene (TCE), lead, cadmium and chromium. The effect of sorption-desorption, pH, ionic strength and the concentration of humic acid was taken into consideration. TCE sorption capacity by black shale was compared to natural bentonite and hexadecyltrimethylammonium (HDTMA) modified bentonite. The removal rate was good and humic acid also sorbed onto black shale very well. The organic part of humic acid could effectively enhance the partition of TCE and it act as an electron donor to reduce Cr(VI) to Cr(III). Cationic metal of Pb(II) and Cd(II) also removed from the water by black shale. With 3 mg/L of humic acid, both Pb(II) and Cd(II) were removed more than without humic acid. That could be explained by sorption and complexation with humic acid and that was possible when humic acid could change the hydrophobicity and solubility of heavy metals. Humic acid exhibited desorption-resistivity with black shale, which implied that black shale could be an alternative sorbent or material for remediation of organic contaminants and heavy metals.

• Journal of Embryo Transfer
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• v.27 no.3
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• pp.189-192
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• 2012

Although embryonic stem cells (ESCs) or ES-like cells are reported from many mammalian species other than the mouse, the culture system for murine ESCs may not be suitable to the other species. Previously many other research groups have modified either human or mouse ESC culture systems for bovine ESC culture. In this study, we compared three different culture mediums consisting of DMEM, ${\alpha}$-MEM or KnockOut$^{TM}$-DMEM (KO), which are modified from human or mouse ESC culture system, for the generation of bovine ESCs. In this study, some pre-requisite events which are important for establishment and long-term propagation of ESCs such as inner cell mass (ICM) attachment on feeder cells, primary colony formation and sustainability after passaging. Once the ICM clumps attached on feeder cells, this was designated as passage 0. In regards to the rate of ICM attachment, ${\alpha}$-MEM was superior to the other systems. For primary colony formation, there was no difference between DMEM and ${\alpha}$-MEM whereas KO showed lower formation rate than the other groups. For passaging, the colonies were split into 2~4 pieces and passed every 5~6 days. From passage 1 to passage 3, DMEM system seemed to be appropriate for maintaining putative bovine ESCs. On the other hand, ${\alpha}$-MEM tended to be more suitable after passage 6. Although ${\alpha}$-MEM support to maintain a ES-like cell progenies to passage 15, all three culture systems which are modified from human or mouse ESC culture media failed to retain the propagation and long-term culture of putative bovine ESCs. Our findings imply that more optimized alternative culture system is required for establishing bovine ESC lines.

• Journal of Information Technology Services
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• v.16 no.4
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• pp.177-195
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• 2017

Traditionally, news was consumed only through printed newspapers and broadcasting media, such as radio and television. However, the Internet has enabled people to consume news content online. Since most of online news content has been provided for free, it is not easy for news providers to charge the fixed subscription fee for online news content. Therefore, as an alternative strategy, some online news providers have tried to adopt the Pay-What-You-Want (PWYW) pricing model, which allows users (readers) to pay as much as they want after consuming news content. As this pricing model shows some possibility to grow and replace the unsuccessful monetization strategy of online news content, we therefore examined the comparative importance of seven heuristic attributes (i.e., article evaluation, article share, article comment, article information design, article length, writer SNS, and writer information) affecting readers' voluntary payment behavior through a conjoint analysis with 379 news articles collected from online news Website (i.e., Ohmynews.com) where the PWYW model has been working successfully. This study found that article share and article length are the most important factors which affect online news content users' voluntary payment. Finally, two major and eight minor propositions are suggested based on the findings of the study. This study would suggest guidelines for how to create online news content which induces much more voluntary payment.