• Archives of Pharmacal Research
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• 제29권2호
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• pp.113-122
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• 2006

Among the effector molecules connected with the group of cell surface receptors, Ras proteins have essential roles in transducing extracellular signals to diverse intracellular events, by controlling the activities of multiple signaling pathways. For over 20 years since the discovery of Ras proteins, an enormous amount of knowledge has been accumulated as to how the proteins function in overlapping or distinct fashions. The signaling networks they regulate are very complex due to their multiple functions and cross-talks. Much attention has been paid to the pathological role of Ras in tumorigenesis. In particular, human tumors very frequently express Ras proteins constitutively activated by point mutations. Up to date, three members of the Ras family have been identified, namely H-Ras, K-Ras (A and B), and N-Ras. Although these Ras isoforms function in similar ways, many evidences also support the distinct molecular function of each Ras protein. This review summarizes differential functions of Ras and highlights the current view of the distinct signaling network regulated by each Ras for its contribution to the malignant phenotypic conversion of breast epithelial cells. Four issues are addressed in this review: (1) Ras proteins, (2) membrane localization of Ras, (3) effector molecules downstream of Ras, (4) Ras signaling in invasion. In spite of the accumulation of information on the differential functions of Ras, much more remains to be elucidated to understand the Ras-mediated molecular events of malignant phenotypic conversion of cells in a greater detail.

• 통합자연과학논문집
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• 제2권2호
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• pp.101-130
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• 2009

In recent years, South Korea has often witnessed damages by gusts caused by thunderstorms in summer. The Korea Meteorological Administration defines that a gust happens when the maximum instantaneous wind velocity is 10m/s or more and draws up hourly observation reports. When a cumulonimbus develops due to an ascending current and reaches the height of 12~16 km, the temperature of the cloud top drops and a lightening happens, which causes a gust accompanied by a thunderstorm and further regional meteorological damage. It's difficult to predict a regional gust with the mesoscale prediction model at the administration. Thus this study set out to analyze the damage cases by a gust accompanied by a thunderstorm and to make a contribution to the prediction and understanding of a gust by a thunderstorm. A gust by a thunderstorm happens where potential equivalent temperature converges or is higher than the surrounding areas. The convergence area of potential equivalent temperature matches the track of thunderstorm cells. The Kimje gust took place where high potential equivalent temperature converged, and the Jangsu gust did as the area of high potential equivalent temperature approached. There should be a good amount of vapor supply with the moisture flux converging at the bottom layer in order to bring instability. In addition, it should collide into a dry and cold atmosphere at 700 hPa. The moving track at the center of the low dew point spread corresponds to that of a gust.

• 천문학회보
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• 제38권1호
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• pp.60.1-60.1
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• 2013

Numerous dust particles are scattered in the interplanetary space of the solar system (Interplanetary Dust Particles; IDPs). The origin of the IDPs is one of the major questions in the solar system astronomy because IDPs are being removed from the solar system within a few million years by photon drag. Comets and asteroids were pointed out as the possible sources of IDPs. Although several dust supplying mechanisms from comets and asteroids have been revealed, amount of contribution from each sources are still not clear. Zodiacal light is sunlight scattered by IDPs. Spectra of zodiacal light can supply important observational clue to reveal the origin of the IDPs, because comets and each type of asteroids have different kind of spectra. However, reflectance spectrum of zodiacal light was not measured at the wavelength of weak atmospheric contamination. We measured the reflectance spectra of zodiacal light from $5000{\AA}$ to $7000{\AA}$. We used open data obtained by the Subaru/FOCAS instruments archived in the SMOKA database. From the longslit spectrum data, we measured spectrum of sky background and estimated flux from the sources other than the zodiacal light. We compared it with the spectra of each type of minor bodies in the solar system, and meteorites originated from these bodies.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2877-2883
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• 2010

The folding kinetics of $WT^*$ ubiquitin variant with valine to alanine mutation at sequence position 26 (HubWA) was studied by stopped-flow fluorescence spectroscopy. While unfolding kinetics showed a single exponential phase, refolding reaction showed three exponential phases. The semi-logarithmic plot of urea concentration vs. rate constant for the first phase showed v-shape pattern while the second phase showed v-shape with roll-over effect at low urea concentration. The rate constant and the amplitude of the third phase were constant throughout the urea concentrations, suggesting that this phase represents parallel process due to the configurational isomerization. Interestingly, the first and second phases appeared to be coupled since the amplitude of the second phase increased at the expense of the amplitude of the first phase in increasing urea concentrations. This observation together with the roll-over effect in the second folding phase indicates the presence of intermediate state during the folding reaction of HubWA. Quantitative analysis of Hub-WA folding kinetics indicated that this intermediate state is on the folding pathway. Folding kinetics measurement of a mutant HubWA with hydrophobic core residue mutation, Val to Ala at residue position 17, suggested that the intermediate state has significant amount of native interactions, supporting the interpretation that the intermediate is on the folding pathway. It is considered that HubWA is a useful model protein to study the contribution of residues to protein folding process using folding kinetics measurements in conjunction with protein engineering.

• 수산해양교육연구
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• 제29권2호
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• pp.586-592
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• 2017

This study analyzed the effect of four control factors, RPM, load, EGR rate and cooling water temperature on the exhaust emissions of the small DI diesel engine. The amount of NOx and smoke emissions were measured through experiments for three levels of four control factors according to orthogonal array table, and the effect of four factors on NOx and smoke emissions was analyzed quantitatively. The main results obtained in this study are summarized as follows: 1. RPM, load and EGR rate have a great influence on NOx and smoke emissions, and the effect of cooling water temperature is negligible. 2. As RPM and load increases NOx emission increases and decreases sharply as the EGR rate increases. 3. Smoke emission decreases or increases randomly according to RPM and load, but increases sharply in proportion to the EGR rate. 4. EGR rate has the greatest effect on NOx and smoke emissions by more than 60% of contribution to variance, especially in the case of NOx emission, EGR rate represents a significant result even under the confidence level of 99% on ANOVA.

• 한국태양에너지학회 논문집
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• 제32권1호
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• pp.32-39
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• 2012

New and renewable energy systems(solar thermal system, photovoltaic system, geothermal system, wind power system) are environmentally friendly technologies and these in South Korea are very important measures to reduce greenhouse-gas(GHG) and to push ahead with Green Growth. The purpose of this paper is to analyze GHG mitigation potential by distribution of solar thermal system in housing sector with bottom-up model called 'Long-range Energy Alternative Planning system'. Business as usual(BAU) was based on energy consumption characteristic with the trend of social-economic prospects and the volume of housing. The total amount of GHG emission of BAU was expected to continuous increase from 66.0 million-ton $CO_{2e}$ in 2007 to 73.1 million-ton $CO_{2e}$ in 2030 because of the increase of energy consumption in housing. The alternative scenario, distribution of solar thermal system in housing sector had GHG mitigation potential 1.54 million-ton $CO_{2e}$ in 2030. The results of this study showed that new and renewable energy systems made a contribution of reducing the use of fossil fuel and the emission of greenhouse-gas in building.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.175-180
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• 2009

Today, the amount of energy consumption at the university campuses is huge. The effort for the energy consumption reduction in university campuses is certainly needed by the following reason; first, contribution for the reduction request about green house gas emission. Second, energy cost reduction in university campus. Third, emotional spreading influence consideration as the maximum higher educational institutions. For the energy consumption reduction in university campus, the energy consumption analysis of current situation has to be executed. The energy reduction possibility in which it exists in university campus can be understood through the energy consumption analysis. And the application is possible as fundamental data of the policy establishment for the effective energy reduction in university campuses. This research analyzed the energy consumption present state of the major university campus of the Korea as the fundamental research for the energy consumption reduction plan preparation of the university campus. Moreover, surveys were performed and analyzed for the energy manager in charge of the university campus.

• 대한산업공학회지
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• 제42권4호
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• pp.296-303
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• 2016

In public transportation, smart cards have been introduced for the purpose of convenient payment systems. The smart card transaction data can be utilized not only for the exact and convenient payment but also for civil planning based on travel tracking of citizens. This paper focuses on the analysis of the transportation convenience using the smart card big data. To this end, a new index is developed to measure the transit convenience of each region by considering how passengers actually experience the transportation network in their travels. The movement data such as movement distance, time and amount between regions are utilized to access the public transportation convenience of each region. A smart card data of five working days in March is used to evaluate the transit convenience of each region in Seoul city. The contribution of this study is that a new transit convenience measure was developed based on the reality data. It is expected that this measure can be used as a means of quantitative analysis in civil planning such as a traffic policy or local policy.

• Industrial Engineering and Management Systems
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• 제13권2호
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• pp.185-192
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• 2014

This study stems from the work of Lehman et al. (Ergonomics, 2001) which concluded that standing yields better work performance, and from the growing health trend of recommending the reduction of the amount of time spent in sitting (Owen et al., Exercise and Sport Science Reviews, 2010). Lajoie et al. (Experimental Brain Research, 1993) provided an initial significant contribution to a theory that standing requires a person to control balance, equating to demand higher productive output from the cognitive system than when a person is sitting. An assumption was formulated that standing position during class is feasible and can be adopted on the belief that it might contribute positive results to students' performance. The purpose of this study is to identify whether a body position during exams tested along with exposure durations has a significant effect on college students' performance. Mathematical analysis and reading comprehension exam was used to measure the cognitive performance of the students. Two factors, position and duration, were tested for significance with two levels each subjected to six replicates. Twenty-four students from the College of Engineering and Agro-Industrial Technology, University of the Philippines Los Ba$\tilde{n}$os were randomly selected. The experiment showed that the body position during exams is a significant factor for the Math exam, but insignificant for the Reading Comprehension exam.

• Journal of Information Processing Systems
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• 제13권4호
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• pp.834-851
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• 2017

The amount of sources of information available on the web using ontologies as support continues to increase and is often heterogeneous and distributed. Ontology alignment is the solution to ensure semantic interoperability. In this paper, we describe a new ontology alignment approach, which consists of combining structure-based and reasoning-based approaches in order to discover new semantic correspondences between entities of different ontologies. We used the biblio test of the benchmark series and anatomy series of the Ontology Alignment Evaluation Initiative (OAEI) 2012 evaluation campaign to evaluate the performance of our approach. We compared our approach successively with LogMap and YAM++ systems. We also analyzed the contribution of our method compared to structural and semantic methods. The results obtained show that our performance provides good performance. Indeed, these results are better than those of the LogMap system in terms of precision, recall, and F-measure. Our approach has also been proven to be more relevant than YAM++ for certain types of ontologies and significantly improves the structure-based and reasoningbased methods.