• Proceedings of the Korean Society of Laser Processing Conference
• /
• 2004.10a
• /
• pp.22-28
• /
• 2004

Pit and rim formation on the Acrylonitrile Butadiene Styrene(ABS) plastic surface was evaluated after it was irradiated by $CO_2$ and Nd:YAG laser beams. Our results show that thermal effect floor was well observed at the outer wall of pit with $CO_2$ laser irradiated while it was not the case with Nd:YAG laser irradiated. Also the volume and depth of pit formation increase proportionally with the energy intensities of two laser irradiations, but there are significant differences in the slope, width, and FWHM of the Pit formation with two types of laser irradiations. This result shows that $CO_2$ laser irradiation leads to better cooling contraction effect while Nd:YAG laser irradiation induces better recoil pressure effect during the interaction between ABS plastic and laser beam irradiation. The shape of the laser marking could vary significantly depending on the traveling path of molten plastic during injection molding of ABS plastic. Therefore, the selection of material and molding process can have a great impact on the performance of optical storage media.

• Plant Resources
• /
• v.7 no.1
• /
• pp.39-46
• /
• 2004

To demonstrate the importance of transformation efficiency in independent event, molecular and cytogenetic analysis were conducted with genomic DNA and chromosome of transgenic plants produced by Agrobacterium tumefeciens LBA4404 (pSBM-PPGN: gusA and bar). Selection ratios of putative transgenic calli were similar in independent experiments, however, transformation efficiencies were critically influenced by the type of regeneration media. MSRK5SS-Pr regeneration mediun, which contains 5 mgL$^{-1}$ kinetin, 2% (w/v) sucrose in combination with 3% (w/v) sorbitol, and 500 mgL$^{-1}$ proline, was efficient to produce transgenic plant of rice from putative transgenic callus in the presence of L-phosphinotricin (PPT). With MSRK5SS-Pr medium, transformation efficincies of Nagdongbyeo were significantly enhanced from 3.7% to 6.3% in independent callus lines arid from 7.3% to 19.7% in plants produced, respectively. Stable integration and expression of bar gene were confirmed by basta herbicide assay, PCR amplification and Southern blotting of bar gene, and fluorescence in situ hybridization (FISH) analysis using pSBM-PPGN as a probe. In Southern blot analysis, diverse band patterns were observed in total 44 transgenic plants regenerated from 20 independent PPT resistant calli showing from one to five copies of T-DNA segments, however, the transformants obtained from one callus line showed the same copy numbers with the same fractionized band patterns.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2018.11a
• /
• pp.110-113
• /
• 2018

최근 인터넷 미디어 스트리밍 수요의 증가로 인해 CDN(Content Delivery Network) 서버 비용이 크게 증가하였으며 이를 절감하기 위한 방안의 필요성이 날로 증가하고 있다. 이러한 상황에 맞춰 최근 CDN 서버 비용을 절감할 수 있는 WebRTC(Web Real-Time Communication) 표준 기반의 P2P(Peer-to-Peer) 통신을 병용하는 DASH(Dynamic Adaptive Streaming over HTTP) 기술이 등장하였다. 본 논문에서는 이 기술의 CDN 서버 부하 절감 효과를 크게 개선할 수 있는 알고리듬을 제안한다. 또한 실제 모바일 네트워크 환경과 유사하게 실험 조건을 설정한 후, 이 알고리듬을 구현하여 그 성능을 측정한 결과, 기존과 비교하여 더 높은 절감 효과를 달성할 수 있음을 실험실 내 실험을 통해 보인다.

• Child Health Nursing Research
• /
• v.27 no.1
• /
• pp.34-42
• /
• 2021

Purpose: The purpose of this study was to identify the supportive care needs of parents of preterm children in South Korea using text data from a portal site. Methods: In total, 628 online newspaper articles and 1,966 social network service posts published between January 1 and December 31, 2019 were analyzed. The procedures in this study were conducted in the following order: keyword selection, data collection, morpheme analysis, keyword analysis, and topic modeling. Results: The term "yirundung-yi", which is a native Korean word referring to premature infants, was confirmed to be a useful term for parents. The following four topics were identified as the supportive care needs of parents of preterm children: 1) a vague fear of caring for a baby upon imminent neonatal intensive care unit discharge, 2) real-world difficulties encountered while caring for preterm children, 3) concerns about growth and development problems, and 4) anxiety about possible complications. Conclusion: Supportive care interventions for parents of preterm children should include general parenting methods for babies. A team composed of multidisciplinary experts must support the individual growth and development of preterm children and manage the complications of prematurity using highly accessible media.

• International Journal of Computer Science & Network Security
• /
• v.22 no.3
• /
• pp.396-404
• /
• 2022

Online social networks contain a large amount of data that can be converted into valuable and insightful information. Text mining approaches allow exploring large-scale data efficiently. Therefore, this study reviews the recent literature on text mining in online social networks in a way that produces valid and valuable knowledge for further research. The review identifies text mining techniques used in social networking, the data used, tools, and the challenges. Research questions were formulated, then search strategy and selection criteria were defined, followed by the analysis of each paper to extract the data relevant to the research questions. The result shows that the most social media platforms used as a source of the data are Twitter and Facebook. The most common text mining technique were sentiment analysis and topic modeling. Classification and clustering were the most common approaches applied by the studies. The challenges include the need for processing with huge volumes of data, the noise, and the dynamic of the data. The study explores the recent development in text mining approaches in social networking by providing state and general view of work done in this research area.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.1
• /
• pp.387-397
• /
• 2022

The purpose of this study is to examine the effects of emotional arousals of guilt versus shame on health message compliance. The study also investigates the moderation impact of two individual factors that have not been studied much in health communications, including regulatory focus and self-construal. This study employs a 2 (guilt versus shame appeals/arousals) between-subjects experiment and a survey to test the conceptual model. The context of the study is binge drinking, and the survey respondents (n = 330) are male university students in Ho Chi Minh City, Vietnam. The results confirm the positive effects of guilt and shame arousals on health message compliance. In addition, the results show moderating effects of the two individual characteristics of regulatory focus and self-construal on the relationships between guilt/shame arousals and health message compliance. The findings of this study have not only theoretical implications but also practical implications in the field of health communications. The insights could help health marketers, policymakers, and health promotion agencies to effectively develop health communications campaigns with more appealing message content (guilt versus shame) and relevant media selection (regulatory focus and self-construal).

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.1249-1252
• /
• 2022

In this paper, we propose a conceptual framework that identifies video frames in motion containing the movement of people and vehicles in traffic videos. The automatic selection of video frames in motion is an important topic in security and surveillance video because the number of videos to be monitored simultaneously is simply too large due to limited human resources. The conventional method to identify the areas in motion is to compute the differences over consecutive video frames, which has been costly because of its high computational complexity. In this paper, we reduced the overall complexity by examining only the keyframes (or I-frames). The basic assumption is that the time period between I-frames is rather shorter (e.g., 1/10 ~ 3 secs) than the usual length of objects in motion in video (i.e., pedestrian walking, automobile passing, etc.). The proposed method estimates the possibility of videos containing motion between I-frames by evaluating the difference of consecutive I-frames with the long-time statistics of the previously decoded I-frames of the same video. The experimental results showed that the proposed method showed more than 80% accuracy in short surveillance videos obtained from different locations while keeping the computational complexity as low as 20 % compared to the HM decoder.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.1
• /
• pp.37-41
• /
• 1997

The in vitro regeneration and genetic transformation systems in hot pepper(Capsicum annuum L.) have not been routinely available, which has been a major limiting factor in the application of new genetic manipulations. An efficient procedure to regenerate whole pepper plants and to generate transgenic plants expressing a foreign gene was established. A relatively high frequency of plant regeneration was observed when hypocotyl and cotyledon explants were cultured on MS medium supplemented with NAA 0.1 mg/L plus zeatin 2.0 mg/L or IBA 10.0 mg/L plus BAP 1.0 mg/L. Addition of AgNO$_3$5 $\mu$M to these media improved the regeneration frequency up to 8%. For plant transformation, hypocotyl and cotyledon explants of hot pepper were precultured on shoot induction media without kanamycin added for 2 days, and then cocultured with Agrobacterium tumefaciens pDY183 for 2 days. Putative transformants were obtained from selection media containing 100 mg/L kanamycin sulfate and 500 mg/L carbenicillin. Putatively selected transformants were confirmed by amplification of selectable marker genes (ADA and NPT II) by polymerase chain reacion. Successful transcripts of ADA gene were detected by Northern blot analysis. Enzyme activity of ADA was also examined by spectrophotometric analysis, and expression of ADA gene in hot pepper suggests the potential application of ADA gene as a selectable marker in plants.

• The Korean Journal of Mycology
• /
• v.36 no.1
• /
• pp.51-57
• /
• 2008

To develop artificial cultivation and improve some problems such as auto-lysis on commercialization of Coprinus comatus that has been known edible and medicinal mushroom, they were conducted for selection of superior strain, suitable culture methods for mycelial growth and fruiting, and morphological characteristics of fruit body. Strain CM 980301 of Coprinus comatus was selected as a superior strain for artificial cultivation. Wheat grain and rice straw full-grown compost media were most effective for preparation of spawn and artificial cultivation of C. comatus, respectively. Spawn running of Coprinus spp. on the rice straw full-grown compost media required to be 15 days from 24 to $28^{\circ}C$. The casing layer incubation before initiation of fruit body formation, required for 13 days at same temperature for spawn running. And then require $10{\sim}11$ days for initiation and $7{\sim}8$ days for development of fruit body from 20 to $24^{\circ}C$. The fruit body of strain CM 980301 was harvested within a week from initiation of primordium formation. The hardness of pileus and stipe that were harvested in optimal stage showed 102 to 169, and 128 to $182\;g/cm^2$, respectively. Yields of srain CM 980301 from the rice straw full-grown compost media was $37.7kg/3.3m^2$. Weight of individual fruit body was 17.9 g in average.

• Korean Journal of Soil Science and Fertilizer
• /
• v.38 no.1
• /
• pp.8-14
• /
• 2005

Mass culturing of two beneficial organisms used as biofertilizers for crops would reduce the risks in production and minimize the capital involved and this demands appropriate media that supports both organism and also selection of organisms that are not antagonistic to each other. A study was initiated to culture a nitrogen fixer (Rhizobium) and phosphate solubilizer (Bacillus megaterium) in a single medium and to study their growth patterns and shelf life in carrier. The growth of Rhizobium and Bacillus megaterium was assessed in different media and a slight modification in the traditional yeast extract mannitol media promoted the growth of both the organisms. The growth of the individual organisms in the modified medium was assessed by estimating the population at regular intervals and compared to their original medium. Maximum population of Rhizobium and phosphobacteria was at 60 hr when the phosphiobacteria inoculation of later was after 48 hr of Rhizobium inoculation. The shelf life of the individual inoculants in the inoculant containing both the organism in a sterile carrier base revealed no significant differences compared to individual organisms inoculated in a sterilized carrier. The population of both organisms in carrier based mixed inoculant remained at $10^8$ cells till 90 days.