• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.03a
• /
• pp.63-70
• /
• 2002

In tunnel construction, the information on the rock quality and the location of fault or fracture are crucial for economical design of support pattern and for safe construction of the tunnel. The grade of rock is commonly estimated through the observation with the naked eye of recovered cores in drilling or from physical parameters obtained by their laboratory test. Since drilling cost is quite expensive and terrains of planned sites for tunnel construction are rough in many cases, however, only limited information could be provided by core drilling Electrical resistivity and EM surveys may be a clue to get over this difficulty. Thus we have investigated electrical resistivity and EM field data providing regional Information of the rock Quality and delineating fault and fracture over a rough terrain. In this paper, we present some case histories using electrical resistivity and EM survey for the site investigation of tunnel construction. Through electrical resistivity and EM survey, the range and depth of coal seam was clearly estimated, cavities were detected in limestone area, and weak zones such as joint, fault and fracture have been delineated.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.8 no.2
• /
• pp.83-90
• /
• 2008

Social infrastructures have been built when the growth of economy in Korea significantly increases in 1960s. Nowadays, these infrastructures have been aged with an inappropriate maintenance and management and the citizens have rare recognition for human disasters. In addition, the government has law or regulations responding to human disasters but these are not complementary. Since these human disasters have been issued as social problems and have induced social and economic loss, the improvement schemes for human disasters are currently being demanded. In this study, the case histories of damages and improvement schemes with respect to the types of damages for human disasters are comprehensively investigated.

• Parasites, Hosts and Diseases
• /
• v.61 no.1
• /
• pp.72-77
• /
• 2023

Human babesiosis is a tick-borne disease induced by the genus Babesia and has been significantly reported in the Republic of Korea. This report shows the cases of 2 patients with human babesiosis who traveled to the USA in 2019. The 2 patients experienced fever and had travel histories to babesiosis-endemic regions. The diagnoses of both cases were verified by the identification of Babesia-infected red blood cells on blood smears. One patient was found to be infected with Babesia microti using polymerase chain reaction (PCR) for 18S rRNA, which discovered the phylogenetic link to the B. microti strain endemic in the USA. The 2 patients recovered from fever with subsequent hemoparasite clearance. Babesiosis could be diagnosed in anyone with histories of travel to babesiosis-endemic countries and tick bites. Furthermore, Babesia-specific PCR is required for determining geno-and phenotypic characteristics.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.10a
• /
• pp.329-336
• /
• 2001

The numbers of geogrid-reinforced walls are widely used in Korea. This papers present the results of two failure case histories of geogrid-reinforced segmental retaining walls. The geological background of the construction sites, detailed construction sequences, and the amount of rainfall were examined. The failure of these reinforced walls are caused by the improper drainage system and foundation treatment, too sharpened curvature of corner work, and too high height of wall.

• Geomechanics and Engineering
• /
• v.21 no.2
• /
• pp.179-186
• /
• 2020

Investigating damage potential of the railway infrastructure requires either large amount of case histories or in-depth numerical analyses, or both for which large amounts of effort and time are necessary to accomplish thoroughly. Rather than performing comprehensive studies for each damage case, in this study we collect and analyze a case history of the high-speed railway system damaged by the 2004 M6.6 Niigata Chuetsu earthquake for the development of the seismic fragility curve. The development processes are: 1) slice the railway system as 200 m segments and assigned damage levels and intensity measures (IMs) to each segment; 2) calculate probability of damage for a given IM; 3) estimate fragility curves using the maximum likelihood estimation regression method. Among IMs considered for fragility curves, spectral acceleration at 3 second period has the most prediction power for the probability of damage occurrence. Also, viaduct-type structure provides less scattered probability data points resulting in the best-fitted fragility curve, but for the tunnel-type structure data are poorly scattered for which fragility curve fitted is not meaningful. For validation purpose fragility curves developed are applied to the 2016 M7.0 Kumamoto earthquake case history by which another high-speed railway system was damaged. The number of actual damaged segments by the 2016 event is 25, and the number of equivalent damaged segments predicted using fragility curve is 22.21. Both numbers are very similar indicating that the developed fragility curve fits well to the Kumamoto region. Comparing with railway fragility curves from HAZUS, we found that HAZUS fragility curves are more conservative.

• Journal of Korean Medical classics
• /
• v.22 no.4
• /
• pp.221-239
• /
• 2009

Background: The recent outbreak of the novel strain of influenza A (H1N1) virus has raised a global concern of the future risk of pandemic. Traditional Korean Medicine(TKM) has been combatting against contagious diseases and developed its own particular and efficient way in treating those diseases. Objectives: Provide a distinctive and effective TKM method in understanding the principles of treatment, prevention, and contraindications against influenza A through case histories. Method: We revised case histories of eminent doctors of Ming and Qing dynasties according to their clinical manifestations similar to those of influenza A. We also verified prescriptions of the "Dong-uibogam(東醫寶鑑)" through examining clinical practices of China today. Results: 1. The subtypes of Warm disease; Wind Warmth and Pestilence has the most similar clinical manifestation in comparison to Influenza A. Specifying these terms is important in recognizing and classifying various diseases under the name of Warm disease. 2. TKM considered not only external factors but also individual factors like general condition, diet, emotion, constitutional types, etc in the treatment of febrile diseases. 3. TKM developed a new way in the treatment of contagious diseases. considering the characteristics of each pathogen. TKM described the Warm pathogen being light as a feather, which enters through the nose, principally affecting the Lung. Therefore, they emphasized treatment with Pungent Sweet Cooling Moistening[辛甘凉潤] method. 4. As the conservation of fluid and humor is the primordial concern in the treatment of Warm disease, they restricted release of the exterior with pungent-warm and purgation method. The purgation methods was used exclusively to decrease fever and preserve fluid and humor. 5. The only differentiating characteristics of Influenza A with seasonal influenza are vomiting and diarrhea. Case research revealed the possibility of these manifestations to be a mechanism of restoration. 6. TKM provides alimento prevention method like Mint Pear Porridge, mung bean, and etc also combination of herbal medicine. Also emphasized in the conservation of essence for the prevention of contagious diseases. Conclusions: TKM developed its unique way in understanding the pathogenesis, diagnosis, treatment, and prevention of contagious diseases and formed its independent scheme of Warm Disease. This knowledge in febrile contagious disease is relevant today in providing diverse treatment and prevention for influenza A.

• The Journal of Engineering Geology
• /
• v.26 no.2
• /
• pp.197-205
• /
• 2016

Rainfall-induced landslide disaster case histories are typically required to establish critical lines based on the decrease coefficient for judging the likelihood of slope collapse or failure; however, reliably setting critical lines is difficult because the number of nationwide disaster case histories is insufficient and not well distributed across the region. In this study, we propose a method for setting the critical area to judge the risk of slope collapse without disaster case history information. Past 10 years rainfall data based on decrease coefficient are plotted as points, and a reference line is established by connecting the outermost points. When realtime working rainfall cross the reference line, warning system is operating and this system can be utilized nationwide through setting of reference line for each AWS (Automatic Weather Station). Warnings were effectively predicted at 10 of the sites, and warnings could have been issued 30 min prior to the landslide movement at eight of the sites. These results indicate a reliability of about 67%. To more fully utilize this model, it is necessary to establish nationwide rainfall databases and conduct further studies to develop regional critical areas for landslide disaster prevention.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1999.10a
• /
• pp.441-448
• /
• 1999

The load distribution in a ground anchor is very complex because it involves three different materials(soil, grout, and steel), which sometimes act as composite sections (bonded length) or separately (unbounded length). Therefore it is very hard to understand load transfer mechanism on the anchor. In order to understand the load transfer, it is essential to consider the load distribution In the three different materials. On these purposes, full scale anchor test is planned on the geotechnical site at Sunkyunkwan University Prior to the test, modeling and analyses of the load transfer mechanism were performed on the data from the case histories.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2002.10a
• /
• pp.409-412
• /
• 2002

In this presentation, the methods that is appropriate to remediate the farmland contaminated by petroleum hydrocarbon was considered using the case histories of the abroad. As a result of a consideration, most remediation procedures were based risk assessment and management, risk-based procedure. It is also useful to use natural attenuation mechanism to remediate petroleum-contaminated sites. However, more research efforts are demanded for developing a cost-effective and efficient technologies.

• Magazine of the Korea Concrete Institute
• /
• v.8 no.3
• /
• pp.84-92
• /
• 1996

구조물 붕괴사례에 대한 연구는 항상 공학관련 문헌에 한 부분이 되어 왔으나 교량기술의 향상에 기여할 수 있었던 1840년대와 1930년대 사이에 발생했던 여러 붕괴사례들은 기술혁신이 진행되면서 큰 관심사는 되지 못했던 것 같다. 끊임없이 향상되었던 해석이론 및 구조적 규모면에서 커다란 도약을 성취하였떤 이 시대에도 몇몇 중요한 교량 붕괴사례를 목격하였다. 특히 Tacoma Narrow Bridge의 붕괴가 발생한 후 구조물 붕괴사례에 대한 연구는 구조설계와 시공분야에서 공학적인 통찰력과 판단력을 위한 중요한 자료로 인식되어지게 되었다.