• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.36 no.1
• /
• pp.181-190
• /
• 2016

Improvements in disaster management has become a global necessity because the magnitude of disasters is intensifying in parallel with the increased disaster damage. The disaster risk in Korea is also increasing due to the emergence of new types of disaster; such as the Middle East respiratory syndrome coronavirus, the increase of complex disasters, and the heightened probability of a catastrophic event due to climate change. This paper aimed to identify the disaster loss-frequency relationship from 1948 to 2014 in Korea by using four types of variables. In addition, this paper found major disasters that resulted in the reformation of disaster response organizations, and inputted the deaths and economic loss attributed to those disasters into the disaster loss-frequency graph. The research result substantiated that the disaster loss-frequency relationship in Korea follows the Power Law and found the coefficients of each Power Function. Additionally, this paper found that most of the reformations of disaster response organizations happened after major disasters that concentrated societies attention and anger due to the high human and economic impact; such events are labelled as "focusing events." These focusing events, with the characteristics of a low probability and high impact, are located in the long tail of the Power Law Distribution. This paper suggests that the effective public policy for disaster response needs to be developed by paying attention to 'low probability and high impact' focusing events that are located in the long tail of the Power Law Distribution.

• The Korean Journal of Physiology and Pharmacology
• /
• v.8 no.6
• /
• pp.339-344
• /
• 2004

Recent data have shown the importance of oxidative stresses in the pathogenesis of inflammatory bowel disease, crohn's disease and ulcerative colitis. $H_2O_2$, reactive oxygen species (ROS) donor, has been reported to act as a signaling molecule involved in a variety of cellular functions such as apo/ptosis and proliferation. In the present study, we investigated viability of cultured ileal smooth muscle cells (ISMC) after stimulation with $H_2O_2$. Trypan blue method revealed that the cell viability of ISMC treated with 1 mM $H_2O_2$ was not different from that of controls at up to 2 h time point, while treatment of ISMC with 1 mM $H_2O_2$ for 48 h finally induced significant decrease in the cell viability. Therefore, we evaluated whether $H_2O_2$ was capable of ERKs activation in ISMC for the short-term exposure and examined whether tyrosine kinase was involved in the process of ERK activation by $H_2O_2$ in ISMC. We also investigated the effects of $H_2O_2$ on activation of SAPK/JNK and p38 MAP kinase in ISMC. Thus, ISMC were cultured and exposed to $H_2O_2$, and western blot analysis was performed with phosphospecific MAP kinase antibodies. Robust activation of ERK occurred within 30 min of 1 mM $H_2O_2$ treatment. $H_2O_2-induced$ ERK activation was attenuated by a tyrosine kinase inhibitor, genistein, indicating that tyrosine kinase was probably involved in the ERK activation by $H_2O_2$. $H_2O_2$ was a moderate activator of SAPK/JNK, while p38 MAP kinase was not activated by $H_2O_2$. We suggest that ERK activation induced by short-term $H_2O_2$ treatment plays a critical role in cellular protection in the early stage of response to oxidative stress. The present study suggests the necessity of identification of MAPK signaling pathways affected by ROS, since it could ultimately elucidate cellular consequences involved in initiation and perpetuation of intestinal tissue damage in the diseases such as crohn's disease and ulcerative colitis, resulted from excessive ROS.

• Korean journal of applied entomology
• /
• v.13 no.2 s.19
• /
• pp.93-97
• /
• 1974

This paper describes experiments made to develop a technique for marking insects and get the informations for ecological studies as a means of tagging flies with radioactive phosphorus, and also to learn the effect on the subsequent generation of flies. Tests were conducted with house flies, Musca domestica L. emerged front the larvae that had reared in a media containing various concentrations of P-32. Radioactivity of the flies was measured with end-window type $(2mg/cm^2)$ Geiger-Muller counter and proportional counter made by Aloka. In following the daily increases in counting rates by 6-day-old larvae it was apparent the larvae in the starting media containing the higher concentrations of P-32 were showing high counting rates. It was found that about 13.2 per cent of the radioactive material remained in the empty puparia after the flies emerged. Radioactivity of the emerged flies decreased gradually and the biological halflife of phosphorus-32 was approximately 6.14 days with considerable variation. A significant amount of P-32 were detected in the abdominal and thoracic sections as compared with other parts of adult. The activity of phosphorus·32 in eggs and larvae produced by adults reared in medium containing 0.2 microcurie or more of P-32 per gram were readily detected with Geiger-Mi·lier counter. On the other hand, the radioactivity of eggs and larvae produced by the treated males crossed with untreated normal females could be only detected in the medium containing more of 2.0 microcurie with G.M. counter. There was no apparent damage to the flies at dosages as high as 0.5 microcurie per gram of medium. For field studies a concentration of 0.5 microcurie of P-32 per gram of artificial medium appears to give adequate labeling for positive identification of flies and their egg masses.

• Journal of Ginseng Research
• /
• v.40 no.2
• /
• pp.135-140
• /
• 2016

Background: Nephrotoxicity is a common side effect of medications. Panax ginseng is one of the best-known herbal medicines, and its individual constituents enhance renal function. Identification of its efficacy and mechanisms of action against drug-induced nephrotoxicity, as well as the specific constituents mediating this effect, have recently emerged as an interesting research area focusing on the kidney protective efficacy of P. ginseng. Methods: The present study investigated the kidney protective effect of fermented black ginseng (FBG) and its active component ginsenoside 20(S)-Rg3 against cisplatin (chemotherapy drug)-induced damage in pig kidney (LLC-PK1) cells. It focused on assessing the role of mitogen-activated protein kinases as important mechanistic elements in kidney protection. Results: The reduced cell viability induced by cisplatin was significantly recovered with FBG extract and ginsenoside 20(S)-Rg3 dose-dependently. The cisplatin-induced elevated protein levels of phosphorylated c-Jun N-terminal kinase (JNK), p53, and cleaved caspase-3 were decreased after cotreatment with FBG extract or ginsenoside 20(S)-Rg3. The elevated percentage of apoptotic LLC-PK1 cells induced by cisplatin treatment was significantly abrogated by cotreatment with FBG and the ginsenoside 20(S)-Rg3. Conclusion: FBG and its major ginsenoside 20(S)-Rg3, ameliorated cisplatin-induced nephrotoxicity in LLC-PK1 cells by blocking the JNKep53ecaspase-3 signaling cascade.

• Korean Journal of Plant Tissue Culture
• /
• v.21 no.1
• /
• pp.23-28
• /
• 1994

This study was rimed out to examine the difference in the cell vitality between mesophyII protoplast (MP) and paraveinal mesophyII protoplast (PVMP) of Nicotiana tabaccum 'Xanti', Petunia hybrida 'Blue Star' and Chrysanthemum morifolium 'Baeckwang' by using urea permeability technique. The effects of various enzyme solutions and incubation time, NAA and thidiazron on plant regeneration from isolated protoplasts were also investigated. The vibratome technique was used for protoplast isolation and urea permeability test because the fresh living, thin tissue stripes (50 ${\mu}{\textrm}{m}$ of thickness) could be obtained with minimal damage with the vibratome. For the three plants examined, the urea permeability on the tested tissue stripes was relatively higher in PVMP than in MP by about Ks = 2.0 $\times$ 10$^{-5}$ cm/sec. The treatment of an enzyme mixture of 1.5% cellulase R-10, 1% Driselase, 0.5% Macerozyme R-10, and 0.5% Pectinase for 4 to 8 h was effective on the isolation of PVMP. The highest frequency of callus formation and plant regeneration from the isolated protoplasts was obtained with NAA 2 mg/L and thidiazuron 0.01 mg/L. Furthermore, the results demonstrated that cell devision and plantlet regeneration was more frequent in the PVMP than in the MP of the same leaf or plant We, therefore, conclude that UM is an excellent experimental material for the callus formation and regeneration from isolated protoplasts.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.8 no.2
• /
• pp.185-196
• /
• 1997

By considering the definition and application of resolution as well as the concept and theory of SAR, the essential contents of the SAR design and analysis are described. This paper is to compare and analyze the resolution performance capability of three techniques for achieving azimuth resolution such as the real aperture, the unfocused and the focused techniques, through the simulation. Simulation is performed to make the restricted conditions for the unfocused technique that can be implemented by the less commputing load of signal processingand the lower cost. Through the mission analysis, the use of SAR image can be applied for estimation of whole situation at the regional area in the field of military demands for tactical purpose as well as civilian demands for the damage of disaster. RPV and sall or medium aircraft are selected to carry the SAR for these purposes and the proper resolution turns ou 5~15 m. The trade-off study of variables through the simulations results in the proper conditions such that range is less 3, 000 m, Wavelength is 1~10 m, and the raw signals and results processed by three techniques for two point targets are exhibited undr such conditions. Therefore, at some points, the result of this paper si proposed for useful applications of unforcused technique in the restricted conditions except the identification of the small target at a long range re- quired for high resolution.

• Earthquakes and Structures
• /
• v.11 no.6
• /
• pp.1101-1121
• /
• 2016

Base isolation, one of the popular seismic protection approaches proven to be effective in practical applications, has been widely applied worldwide during the past few decades. As the techniques mature, it has been recognised that, the biggest issue faced in base isolation technique is the challenge of great base displacement demand, which leads to the potential of overturning of the structure, instability and permanent damage of the isolators. Meanwhile, drain, ventilation and regular maintenance at the base isolation level are quite difficult and rather time- and fund- consuming, especially in the highly populated areas. To address these challenges, a number of efforts have been dedicated to propose new isolation systems, including segmental building, additional storey isolation (ASI) and mid-storey isolation system, etc. However, such techniques have their own flaws, among which whipping effect is the most obvious one. Moreover, due to their inherent passive nature, all these techniques, including traditional base isolation system, show incapability to cope with the unpredictable and diverse nature of earthquakes. The solution for the aforementioned challenge is to develop an innovative vibration isolation system to realise variable structural stiffness to maximise the adaptability and controllability of the system. Recently, advances on the development of an adaptive magneto-rheological elastomer (MRE) vibration isolator has enlightened the development of adaptive base isolation systems due to its ability to alter stiffness by changing applied electrical current. In this study, an innovative semi-active storey isolation system inserting such novel MRE isolators between each floor is proposed. The stiffness of each level in the proposed isolation system can thus be changed according to characteristics of the MRE isolators. Non-dominated sorting genetic algorithm type II (NSGA-II) with dynamic crowding distance (DCD) is utilised for the optimisation of the parameters at isolation level in the system. Extensive comparative simulation studies have been conducted using 5-storey benchmark model to evaluate the performance of the proposed isolation system under different earthquake excitations. Simulation results compare the seismic responses of bare building, building with passive controlled MRE base isolation system, building with passive-controlled MRE storey isolation system and building with optimised storey isolation system.

• Smart Structures and Systems
• /
• v.21 no.5
• /
• pp.687-694
• /
• 2018

The problem of wheel tread defects has become a major challenge for the health management of high-speed rail as a wheel defect with small radius deviation may suffice to give rise to severe damage on both the train bogie components and the track structure when a train runs at high speeds. It is thus highly desirable to detect the defects soon after their occurrences and then conduct wheel turning for the defective wheelsets. Online wheel condition monitoring using wheel impact load detector (WILD) can be an effective solution, since it can assess the wheel condition and detect potential defects during train passage. This study aims to develop an FBG-based track-side wheel condition monitoring method for the detection of wheel tread defects. The track-side sensing system uses two FBG strain gauge arrays mounted on the rail foot, measuring the dynamic strains of the paired rails excited by passing wheelsets. Each FBG array has a length of about 3 m, slightly longer than the wheel circumference to ensure a full coverage for the detection of any potential defect on the tread. A defect detection algorithm is developed for using the online-monitored rail responses to identify the potential wheel tread defects. This algorithm consists of three steps: 1) strain data pre-processing by using a data smoothing technique to remove the trends; 2) diagnosis of novel responses by outlier analysis for the normalized data; and 3) local defect identification by a refined analysis on the novel responses extracted in Step 2. To verify the proposed method, a field test was conducted using a test train incorporating defective wheels. The train ran at different speeds on an instrumented track with the purpose of wheel condition monitoring. By using the proposed method to process the monitoring data, all the defects were identified and the results agreed well with those from the static inspection of the wheelsets in the depot. A comparison is also drawn for the detection accuracy under different running speeds of the test train, and the results show that the proposed method can achieve a satisfactory accuracy in wheel defect detection when the train runs at a speed higher than 30 kph. Some minor defects with a depth of 0.05 mm~0.06 mm are also successfully detected.

• Korean Journal of Veterinary Service
• /
• v.40 no.3
• /
• pp.201-208
• /
• 2017

BVDV causes significant infections in ruminants, resulting in reproductive disorders, diarrhea, reduced milk production and enormous damage to farms. In particular, identification and culling of persistent infectious calf is an important task to eliminate infectious nidus in cattle households. However, studies on physiological characteristics of PI bull are still insufficient to understand reproductive effects of BVDV. In this study, one PI bull was confirmed in herd and complete blood analysis was performed. The lymphocyte count of PI at age 4 was below the normal range and the number of WBCs was also in the lower level of normal range in blood. The sperm number produced by PI male becomes lower and the viability of fresh sperm comes to poor with ages (P<0.05). The sperm abnormality was also increased, especially in nuclear vacuoles of head and droplets of midpeace (P<0.05). The PI male becomes infertile due to poor semen quality at age 4. With these results, we concluded that BVDV in PI bull cause decreased sperm cell and abnormality in semen so causes infertility. However, it appears that BVDV could not be transmitted by indirect contact of PI bull, because there was no evidence of BVDV infection in the herd, when regular vaccination program was applied.

• Journal of Mushroom
• /
• v.11 no.4
• /
• pp.201-207
• /
• 2013

Fungus gnats are usually found in mushroom farm and have recently become important pest because they can cause severe damage and reduce the production on shiitake mushroom. Usually shiitake mushrooms are cultivated on both oak bed logs and in the artificial sawdust beds in greenhouses. Using yellow sticky trap, the dipteran species in shiitake mushroom farm were collected from May to September in Kyonggi-do and Chungcheong-do in 2013. To identify the main species of fungus gnat on the shiitake farm in Korea, the collected samples were determined the sequence of cytochrome c oxidase subunit I (COI) by DNA barcoding. The phylogeny based on maximum likelihood analyses from COI sequence showed that Bradysia difformis and B. alpicola were main species of shiitake bed log and Scatopsidae sp. and B. difformis were dominant species of sawdust beds.