• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.49-56
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• 2014

Background: Propofol (2.6-diisopropylphenol) is a widely used intravenous anesthetic agent for the induction and maintenance of anesthesia during surgeries and sedation for ICU patients. Propofol has a structural similarity to the endogenous antioxidant vitamin E and exhibits antioxidant activities.13) However, the mechanism of propofol on hypoxia/reoxygenation (H/R) injury has yet to be fully elucidated. We investigated how P-PostC influences the autophagy and cell death, a cellular damage occurring during the H/R injury. Methods: The groups were randomly divided into the following groups: Control: cells were incubated in normoxia (5% CO2, 21% O2, and 74% N2) without propofol treatment. H/R: cells were exposed to 24 h of hypoxia (5% CO2, 1% O2, and 94% N2) followed by 12 h of reoxygenation (5% CO2, 21% O2, and 74% N2). H/R + P-PostC: cells post-treated with propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation. 3-MA + P-PostC: cells pretreated with 3-MA and post-treated propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation Results: The results of our present study provides a new direction of research on mechanisms of propofol-mediated cytoprotection. There are three principal findings of these studies. First, the application of P-PostC at the onset of reoxygenation after hypoxia significantly increased COS-7 cell viability. Second, the cellular protective effect of P-PostC in H/R induced COS-7 cells was probably related to activation of intra-cellular autophagy. And third, the autophagy pathway inhibitor 3-MA blocked the protective effect of P-PostC on cell viability, suggesting a key role of autophagy in cellular protective effect of P-PostC. Conclusions: These data provided evidence that P-PostC reduced cell death in H/R model of COS-7 cells, which was in agreement with the protection by P-PostC demonstrated in isolated COS-7 cells exposed to H/R injury. Although the this study could not represent the protection by P-PostC in vivo, the data demonstrate another model in which endogenous mechanisms evoked by P-PostC protected the COS-7 cells exposed to H/R injury from cell death.

• Korean Journal of Remote Sensing
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• v.32 no.4
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• pp.365-382
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• 2016

The results from the Global Positioning System (GPS) measurements of the Mobile Observation Vehicle (MOVE) on the eastern coast of Korea have been compared with REFerence (REF) values from the fixed GPS sites to assess the performance of Precipitable Water Vapor (PWV) retrievals in a kinematic environment. MOVE-PWV retrievals had comparatively similar trends and fairly good agreements with REF-PWV with a Root-Mean-Square Error (RMSE) of 7.4 mm and $R^2$ of 0.61, indicating statistical significance with a p-value of 0.01. PWV retrievals from the June cases showed better agreement than those of the other month cases, with a mean bias of 2.1 mm and RMSE of 3.8 mm. We further investigated the relationships of the determinant factors of GPS signals with the PWV retrievals for detailed error analysis. As a result, both MultiPath (MP) errors of L1 and L2 pseudo-range had the best indices for the June cases, 0.75-0.99 m. We also found that both Position Dilution Of Precision (PDOP) and Signal to Noise Ratio (SNR) values in the June cases were better than those in other cases. That is, the analytical results of the key factors such as MP errors, PDOP, and SNR that can affect GPS signals should be considered for obtaining more stable performance. The data of MOVE can be used to provide water vapor information with high spatial and temporal resolutions in the case of dramatic changes of severe weather such as those frequently occurring in the Korean Peninsula.

• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.57-65
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• 2007

Over the past few decades, considerable numbers of studies on the durability of concrete have been carried out extensively. A lot of improvements have been achieved especially in both measuring techniques as well as modeling of ionic flows. However, the majority of these researches have been performed on sound uncracked concrete, although most of in-situ concrete structures have more or less micro-cracks. It is only recent approach that the attention has shifted towards the influence of cracks and crack width on the penetration of chloride into concrete. The penetration of chlorides into concrete through the cracks can make a significant harmful effect on reinforcement corrosion. On the other hand, a general acceptable crack width of 0.3 mm has been recognized for keeping the serviceability of concrete structures in accordance with a lot of codes. However, there seems to be rare established description to explain the critical crack width in terms of the durability of concrete. To make a bad situation worse, there is little agreement on critical crack width among a few of literatures for this issue. Critical crack width is still controversial problem. Nevertheless, since the critical crack width is important key for healthy assessment of concrete structures exposed to marine environment, it should be established. The objective of this study is to define a critical crack width. The critical crack width in this study is designed for a threshold crack width, which contributes to the first variation of chloride diffusion coefficient in responsive to the existence of cracks. A simple solution is formulated to realize the quantifiable parameter, chloride diffusion coefficient for only cracked zone excluding sound concrete. From the examination on the trend of chloride diffusion coefficient of only cracked zone for various crack widths, a critical crack width is founded out.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.2
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• pp.86-97
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• 2005

Accurate estimation of the wave-induced pore water pressure in the seabed is key factor in studying the stability of the seabed in the vicinity of coastal structure. Most of the existing numerical models for wave structure seabed interaction have been linked through applying hybrid numerical technique which is analysis method separating the wave field and seabed regime. Therefore, it is necessary to develope a numerical model f3r simulating accurately wave$\cdot$structure$\cdot$ seabed interaction under wave loadings by the single domain approach for wave field and seabed regime together. In this study, direct numerical simulation is newly proposed. In this model, modeled fluid drag has been used to detect the hydraulic properties according to the varied geometrical shape inside the porous media by considering the turbulence resistance as well as laminar resistance. Contrary to hybrid numerical technique, direct numerical simulation avoids the explicit formulation of the boundary conditions at the fluid/porous media interface. A good agreement has been obtained by the comparison between existed experimental results by hydraulic model test and direct numerical simulation results far wave $\cdot$structure$\cdot$seabed interaction. Therefore, the newly proposed numerical model is a powerful tool for estimating the nonlinear dynamic responses among a structure, its seabed foundation and water waves.

• Journal of Life Science
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• v.27 no.1
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• pp.38-43
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• 2017

Glycosyl aesculin, a potent anti-inflammatory agent, was synthesized by transglycosylation reaction, catalyzed by Thermotoga neapolitana ${\beta}-glucosidase$, with aesculin as an acceptor. The key reaction parameters were optimized using response-surface methodology (RSM) and $2{\mu}g$ of the enzyme. As shown by a statistical analysis, a second-order polynomial model fitted well to the data (p<0.05). The response surface curve for the interaction between aesculin and other parameters revealed that the aesculin concentration and reaction time were the primary factors that affected the yield of glycosyl aesculin. Among the tested factors, the optimum values for glycosyl aesculin production were as follows: aesculin concentration of 9.5 g/l, temperature of $84^{\circ}C$, reaction time of 81 min, and pH of 8.2. Under these conditions, 61.7% of glycosyl aesculin was obtained, with a predicted yield of 5.86 g/l. The maximum amount of glycosyl aesculin was 6.02 g/l. Good agreement between the predicted and experimental results confirmed the validity of the RSM. The optimization of reaction conditions by RSM resulted in a 1.6-fold increase in the production of glycosyl aesculin as compared to the yield before optimization. These results indicate that RSM can be effectively used for process optimization in the synthesis of a variety of biologically active glycosides using bacterial glycosidases.

• Korean Journal of Cognitive Science
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• v.17 no.4
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• pp.303-321
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• 2006

According to Harris'(1966) distributional hypothesis, understanding the meaning of a word is thought to be dependent on its context. Under this hypothesis about human language ability, this paper proposes a computational model for native speaker's language processing mechanism concerning word sense disambiguation, based on two sets of experiments. Among the three computational models discussed in this paper, namely, the logic model, the probabilistic model, and the probabilistic inference model, the experiment shows that the logic model is first applied fer semantic disambiguation of the key word. Nexr, if the logic model fails to apply, then the probabilistic model becomes most relevant. The three models were also compared with the test results in terms of Pearson correlation coefficient value. It turns out that the logic model best explains the human decision behaviour on the ambiguous words, and the probabilistic inference model tomes next. The experiment consists of two pans; one involves 30 sentences extracted from 1 million graphic-word corpus, and the result shows the agreement rate anong native speakers is at 98% in terms of word sense disambiguation. The other pm of the experiment, which was designed to exclude the logic model effect, is composed of 50 cleft sentences.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.37-44
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• 1970

Human body volumes were calculated from the measurments of body height and body weight. Equations Suited to express the relations of height, weight, and surface area to show the body volume were derived from the body volume measurements by means of underwater. weighing method. Underwater body weights were corrected for the residual volume of long obtained by the Rahn's three breath method. Underwater weighing was performed on 173 male subjects aged between 13 and 51 years. Subjects were divided into 4 age groups, namely, 13-16 years group of 47 subjects, 16-19 years group of 46 subjects, adult group aged between 22 and 38 years comprising 45 subjects, and middle-aged group (40-51 years) of 35 subjects. The group division was made on .the basis of physical growth and development. The following results were obtained. 1. Body height (H, cm), body weight (W, kg), body surface area $S,\; m^{2})$, and body volume (V, liter.) interrelated closely. V/S showed a high correlation with W/H and the coefficient of correlation was r=0.97 irrespective of age group differences of the subjects. The coefficients of correlation between V/S and W/H in the total mate subjects as a single group was r=1.983. Subsequently the following regression equation was obtained. V = S X (54.84 W/H + 14.08) The agreement of body volume values obtained by the calculation and underwater weighing in the total subject group was better than that of the separate age group division. 2. The calculated values of body volume were: 40.4 l (euiqvalent to the body density value of 1.0562 kg/1) in 13-16 years group; 52.0 l (equivalent to density value of 1.0723 kg/l) in 16-19 years group; 55.3 l (equivalent to density value of 1.0570 kg/l) In the adult group; and 54. 0 l (equivalent to density value of 1.074 kg/l) in the middle-age group. The mean deviation of calculated from the measured volume value ranged between ${\pm}0.55$ and ${\pm}0.81$ liters. 3. The correlation between V/S and mean skinfold thickness of 4 sites (arm, back, iliac and chest) was high, namely, the coefficient of correlation was r=0.656. The coefficients of correlation between V./S and the $R\"{o}hrer$ index ranged between r=0.668 and r=0.810 affected by the difference in group age of the subject. The body volume (V) alone correlated poorly than V/S with mean skinfold thickness (r=0.606) and the $R\"{o}hrer$ index (r ranged between 0.274 and 0.588).

• Korean journal of communication and information
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• v.34
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• pp.34-62
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• 2006

The World Summit on the Information Society (WSIS) was held in two phases. The first phase took place in Geneva, December 2003, and the second phase took place in Tunis, November 2005. The objective of the WSIS was to establish the foundations for an Information Society for all, reflecting all the different interests at stake. In relation to, this article explore the vision and paradigm of WSIS. For this, this article review the historical context of International information order and International agreements, and examine the issues of WSIS. As a result, I recognize, It is valuable that the process of WSIS for Global governance was held among governments and other stakeholders, i.e. the private sector, civil society and international organization. In addition, developing countries's voice are deeply reflected on the WSIS. It is noticeable that ITU played key role as coordinator. However, we are anxious that WSIS's vision for Information society have a bias toward Technology determinism. Eventually, this article argue that WSIS discourse is the lack of any serious and critical structural analysis of the politico-economic context.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9417-9421
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• 2014

Background: Esophageal cancer is one of the most frequently occurring malignancies and the seventh leading cause of cancer-related deaths in the world. The esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer worldwide. Materials and Methods: Our goal in this study was to detect phospholipase A2 Group IIA (PLA2G2A) and cyclooxygenase-2 (COX-2) immuno-expression in ESCC in a high-risk population in China. Results: Positive expression of PLA2G2A protein was observed in 57.2% (166/290) of the cases, while COX-2 was found in 257 of 290 samples (88.6%), both PLA2G2A and COX-2 being expressed in 153 cases (52.8%), with a significant agreement (Kappa=0.091, p=0.031).Overexpression of PLA2G2A was significantly correlated with the depth of invasion (p=0.001). Co-expression of PLA2G2A and COX-2 not only significantly correlated with the depth of invasion (p=0.004) but also with TNM stage (p=0.04). Conclusions: Our results showed that in patients with ESCC, PLA2G2A overexpression and PLA2G2A co-expression with COX-2 is significantly correlated with advanced stage. The biological role and pathophysiologic regulation of PLA2G2A and COX-2 overexpression in ESCC deserve further investigation.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.51-58
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• 2004

The input-oriented project promotion system private participation in infrastructure projects currently in use in Korea has encountered difficulties in securing the primary benefits of private sector creativity problem solving and inflow of private capital. As such, the performance (or output)-oriented procurement process implemented in England and other developed countries should be evaluated for introduction. In Korea, private participation projects are currently identified as either solicited or unsolicited projects, each with different promotional procedures, the problem with these procedures is that competition is not pre-activated, the private sectors creativity is under utilized, and the rationality of project evaluations is inconsistent. Korea should, in order to raise the level of private sector creativity and efficiency, go beyond the currently applied Input Specification project promotion system to a Performance-oriented system similar to those implemented in England and other countries. To achieve this, we mate several proposals for the introduction of the performance-oriented system. We divide the main features of our proposals into three categories, including a reformed concessionaire selection system, a performance orientation in preparation of the concession agreement, and a performance orientation in contract management, and discuss each. 1'his study describes performance-oriented promotion systems in an output-focused way As this is an initial study on the introduction of performance orientation in private participation, various key points and proposals were identified. However, in the future, detailed research in technical fields and systems, legal research, and practical projects will be needed for implementation