• Interdisciplinary Bio Central
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• v.1 no.2
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• pp.7.1-7.7
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• 2009

"To be, or not to be?" This question is not only Hamlet's agony but also the dilemma of mitochondria in a cancer cell. Cancer cells have a high glycolysis rate even in the presence of oxygen. This feature of cancer cells is known as the Warburg effect, named for the first scientist to observe it, Otto Warburg, who assumed that because of mitochondrial malfunction, cancer cells had to depend on anaerobic glycolysis to generate ATP. It was demonstrated, however, that cancer cells with intact mitochondria also showed evidence of the Warburg effect. Thus, an alternative explanation was proposed: the Warburg effect helps cancer cells harness additional ATP to meet the high energy demand required for their extraordinary growth while providing a basic building block of metabolites for their proliferation. A third view suggests that the Warburg effect is a defense mechanism, protecting cancer cells from the higher than usual oxidative environment in which they survive. Interestingly, the latter view does not conflict with the high-energy production view, as increased glucose metabolism enables cancer cells to produce larger amounts of both antioxidants to fight oxidative stress and ATP and metabolites for growth. The combination of these two different hypotheses may explain the Warburg effect, but critical questions at the mechanistic level remain to be explored. Cancer shows complex and multi-faceted behaviors. Previously, there has been no overall plan or systematic approach to integrate and interpret the complex signaling in cancer cells. A new paradigm of collaboration and a well-designed systemic approach will supply answers to fill the gaps in current cancer knowledge and will accelerate the discovery of the connections behind the Warburg mystery. An integrated understanding of cancer complexity and tumorigenesis is necessary to expand the frontiers of cancer cell biology.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.719-727
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• 2013

Four-step travel-demand modeling based on a trip-level has been widely used over many decades. However, there has been a wide variance between forecasted- and real-travel demands, which leads less reliable on the model implications. A primary reason is that person's real travel behavior is not properly captured throughout the model developments. An activity-based modeling (ABM) approach was proposed and developed toward increasing the accuracy and reality of person's travel behavior in the U.S. since 1990', and stands as a good alternative to replace the existing trip-based approach. The paper contributes to the understanding of how the ABM approaches are dissimilar to the trip-based modeling approach in terms of estimation units, estimation process, their pros and cons and etc. We examined three activity-based travel demand model systems (DaySim, CT-Ramp, and CEMDAP) that are most commonly applied by many MPOs (Metropolitan Planning Organization). We found that the ABM approach can effectively explain multi-dimensional travel decision-makings and be expected to increase the predictive accuracy. Overall, the ABM approach can be a good substitute for the existing travel-demand methods having unreliable forecasts.

• Progress in Medical Physics
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• v.13 no.1
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• pp.32-36
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• 2002

For Intensity Modulated Radiation Therapy(IMRT), the spatial resolution of intensity map(IM) is limited by the width of multi-leaf collimator, which would make an effect on the conformity of the target, as well as organs at risk. Several Methods are suggested to increase the spatial resolution, which can be categorized by the hardware-dependent technique and the software-based technique. However the best solution might be to make the width of MLC finer. it has several obstacles in the respects of technical difficulty and cost. This preliminary study is designed to investigate the clinical effectiveness of the virtual-micro IMRT(VMIMRT) technique, one of the software-based technique. A particular intensity map was created, which has 42$\times$54 pixel dimension ,0.5cm pixel size and 15 intensity levels. Using this intensity map, segment fields of IMRT were generated with 1$\times$lcm, 0.5$\times$1cm, 0.5$\times$0.5cm(VMIM) beamlet size, respectively As results, we found that there was no evidence of improvement for VMIMRT, compared with the 0.5$\times$lcm beamlet size which can be delivered by 1cm width MLC. The reason seems to be due to the constraint of VMIMRT. Further study is required to prove the benefit of the VIMRT in clinical case like head and neck cancer, where is expected that higher resolution than 1cm is necessary.

• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.113-124
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• 2010

In this study, the hybrid authorization quotation technique is based on the device ID for the integrity of the source region guarantee of user certificate, in order to improve the convenience and security for user in the hybrid PKI certificate Mechanism for authentication. The feature of the model in which it is presented from this paper is 5. First, because the user can select the policy himself in which it matches with each authentication situation and security level, the convenience can be improved. Second, the integrity of the source region of the user certificate can be guaranteed through the comparison of the DLDI Key, that is the hash-value of the device ID. Third, the security can be improved by continuously changing an encoding, and the value of the key in which it decodes through the EOTP Key. Fourth, the index value is added to a certificate, and the storage of a certificate is possible at the Multi-Device. Fifth, since the addi the inan aratus for the integrity of the source region guarantee of a certificate is not needed, the authentication process time can be reduced and the computational load of the certificate server can be reduced also.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.97-109
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• 2017

Domestic vehicle penetration rate is growing at 3% per year, but consumers are increasingly buying used cars due to steady price hikes Nevertheless, the used car export market is expected to decline due to import regulations of major countries and the low grade environment of Used car export complex. Therefore, this study using Fuzzy-AHP was aimed to find operational factors of Used car logistics complex and establish a practical management plan of Used car logistic complex in incheon port. Fuzzy-AHP is the method that can be calculated weight of multi-level criteria and change linguistic ambiguity of human to Fuzzy Number. So it's able to propose the realistic decision making alternatives. As a result of the literacture reviews, present study focused on the analysis of the present situation of the logistics of the used car and the activation of the complex, suggested the activation plan and activation of the logistics complex. In the analysis of operational factors, logistic complex cost factors were found to be the most important factors by recording the weighted value of 0.306 in the above factors. The detailed factors were as follows: rent, accessibility, and logistics site size. It is necessary to compute competitive rent for the highly-advanced used car logistics complex, and to realize the rental support policy and to consider designating the free trade zone. In addition, it is necessary to expand the access infrastructure and secure the scale of the company for overseas buyers, and it is necessary to improve the overall government laws and introduce IT system for the future.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.621-630
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• 2011

This research examines the push and pull factors of temple stay in Korean national parks. 152 participants of temple stay in Woljeongsa and Guryongsa in national parks in Gangwon-do area completed a survey to access their reasons for participating in temple stay(push factors) and to evaluate how well the visiting experience performed on a selected set of attributes(push factors). Demographics of respondents were similar to the visitor characteristics of Korean national parks. The result of factor analysis identified 6 push factor domains of 'self actualization', 'health enhancement', 'nature assimilation', 'relationship elevation', 'religious experience', and 'leisure experience'. 6 pull factor domains were 'recuperative quality', 'quality of a temple stay program', 'attributes of a temple', 'user convenience', 'tourism experience' and 'accessibility and transportation'. Satisfaction level of temple stay in a national park was very high of 4.71 in a 5 Likert scale. Gangwon- Do was most preferred with the percentage of 89.2 as a suitable area for temple stay in a national park. Findings of multi-dimensional tourism motivations of temple stay in a national park that encompass nature tourism, cultural tourism and religious tourism is expected to provide useful information for the future development of a more competitive temple stay program and a marketing strategy. However, more defined successive research work is required to generalize findings of wellness oriented push and pull factors of temple stay based on nature in national parks.

• Korean journal of communication and information
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• v.36
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• pp.7-41
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• 2006

This study criticizes the wave of liberalization, privatization, thoughtless and uncontrolled over-competition in the electronic communication networks area. This criticism is based on the 'transport economics' on one side, the 'network neutrality debate' on the other side. Through these standpoints, this study insists that it needs to deal with a social agenda related to the problems such as unplanned and unbalanced development of electronic communication networks, double/tripple-investment in the communication industry, conflicts among network companies and the decline of public values. Also does this study stress on the new ideas in the electronic communication network policy and planning to manage these problems. Electronic communication networks are converging and their borders are blurred. As a result of these flows, the field of information technology, media and contents is faced with radical changes. These changes could be so critical and complicated that nobody can diagnose their multi-level implications. However, the one thing sure is that we should start from the communication networks to think and control a communication system. Therefore, we should discuss and plan the now-and-future of communication infrastructure and its management. we need not only a market mentality but also a socio-cultural mentality. In this respect, this study does insist that it requires the vision of digital democracy and democratic communication ecology to put the steps toward social communication system.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.4
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• pp.173-181
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• 2018

Recently composite materials have dominated most engineering fields, owing to their better performance, increased durability and flexibility to be customized and designed for a specific required property. This has given them unprecedented superiority over conventional materials. With the help of the ever increasing computational capabilities of computers, researchers have been trying to develop accurate material models for the complex and integrated properties of these composites. This has led to advances in virtual testing of composite materials as a supplement or a possible replacement of laboratory experiments to predict the properties and responses of composite materials and structures. This paper presents a review on the complex multi-scale modelling framework of the virtual testing machines, which involve computational mechanics at various length-scales starting with nano-mechanics and ending in structure level computational mechanics, with a homogenization technique used to link the different length scales. In addition, the paper presents the features of some of the biggest integrated virtual testing machines developed for study of concrete, including a multiscale modeling scheme for the simulation of the constitutive properties of nanocomposites. Finally, the current challenges and future development potentials for virtual test machines are discussed.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1511-1517
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• 1999

Effects of washing methods using electrolyzed acid water on lettuce(Lactuca sativa) and quality changes during storage were investigated. The multi-stage immersion treated 3 times in 2 min showed more effective than others to remove microorganisms. Total count of lettuce after immersion in electrolyzed acid water was decreased to 1/100-1/300 of $5.8\;{\times}\;l0^5CFU/g$ of non-immersed lettuce and $2.3\;{\times}\;l0^5CFU/g$ of tap water immersed lettuce. Also coliforms was significantly decreased to 1/3,000 of $3.1\;{\times}\;10^3CFU/g$ after electrolyzed acid water washing. However, microbial levels of electrolyzed acid water treated one became to be similar to those of non-treated lettuce after 3 days of storage at $10^{\circ}C$. The color values of L and b of lettuce treated with electrolyzed acid water were somewhat higher than those of others. Though chlorophyll content of lettuce just after immersion in electrolyzed acid water was 9% lower than those of non-treated one, the content was decreased to the same level of other treatments during storage. Decaying ratio showed the lowest value in lettuce immersed in electrolyzed acid water until 6 days of storage. The sensory tests for overall acceptability and appearance of lettuce immersed in electrolyzed acid water showed higher than those of others until $3{\sim}6$ days of storage.

• Korean Journal of Acupuncture
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• v.27 no.2
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• pp.95-105
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• 2010

Objectives : The purpose of this study is to investigate the effect of Bacillus-fermented Scutellariae Radix acupuncture solution (SB) on interleukin(IL) production in mouse macrophage stimulatedby lipopolysaccaride(LPS). Methods : Productions of interleukins were measured y High-throughput Multiplex Bead based Assay with Bio-plex Suspension Array System based on $xMAP^{(R)}$(multi-analyte profiling beads) technology. To begin with, cell culture supernatant was obtained after treatment with LPS(1 ${\mu}g/mL$) and SB for 24 hour. Then, it was incubated with the antibody-conj${\mu}g$ated beads for 30 minutes. And detection antibody was added and incubated for 30 minutes. After incubating for 30 minutes, Strepavidin-conjugated Phycoerythrin(SAPE) was then added. Incubating for another 30 minutes, the level of SAPE fluorescence was analyzed on Bio-plex Suspension Array System. Results : The results of the experiment are as follows. SB significantly inhibited the LPS-induced production of IL-3($9.15{\pm}0.35$ pg/mL) by $6.92{\pm}0.05,\;7.21{\pm}0.11,\;6.96{\pm}0.33,\;and\;7.45{\pm}0.74$ pg/mL at the concentration of 25, 50, 100, and 200 ${\mu}g/mL$ in mouse macrophage RAW 264.7 cells (p<0.05). SB significantly inhibited the LPS-induced production of IL-5($7.30{\pm}0.48$ pg/mL) by $6.50{\pm}0.29,\;6.30{\pm}0.25,\;6.30{\pm}0.25,\;and\;5.80{\pm}0.25$ pg/mL at the concentration of 25, 50 100, and 200 ${\mg}g/mL$ in RAW 264.7 cells (p<0.05). SB significantly inhibited the LPS-induced productiion of IL-9($17.26{\pm}0.19$ pg/mL) by $15.01{\pm}0.43$ pg/mL at the concentration of 25 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). SB significantly inhibited the LPS-induced productioh of IL-13($187.80{\pm}2.90$ pg/mL) by $152.80{\pm}4.25,\;172.80{\pm}3.97,\;162.10{\pm}6.67,\;and\;165.30{\pm}11.80$ pg/mL at the concentration fo 25, 50, 100, and 200 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). SB significantly inhibited the LPS-induced production of IL-17($18.30{\pm}0.95$ pg/mL) by $13.30{\pm}1.25,\;13.80{\pm}1.11,\;13.30{\pm}0.75,\;and\;14.00{\pm}1.08$ pg/mL at the concentration of 25, 50 100, and 200 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). SB significantly inhibited the LPS-induced production of IL-23($43.90{\pm}0.83$ pg/mL by $39.50{\pm}1.26,\;38.00{\pm}1.78,\;and\;39.60{\pm}2.49$ pg/mL at the concentration of 25, 100, and 200 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). Conclusions : These results suggest that SB has anti-inflammatory activity related with its inhibition of IL-3, IL-5, IL-13, IL-17, and IL-23 production in macrophages.