• Journal of Korean Tunnelling and Underground Space Association
• /
• v.6 no.3
• /
• pp.213-225
• /
• 2004

The number of tunnels are in fact increasing as a part of linear improvement project of general national highway and road enlargement and pavement project. Recently, collapses of portal slope are also occurring considerably, due to local raining from severe rain storm and abnormal weather. Accordingly, it was risen a necessity to efficiently respond to tunnel portal slope damage and maintenance in Korea and oversea nations. This paper is a basic proposal to execute a survey on the current status and state of the tunnel portal slopes that were already installed and are now being operated along general national highways, and also to execute state evaluation for the purpose of managing those effectively. As a research method, domestic tunnels were analyzed in accordance with geometrical shape such as access type, portal form, and tunnel type, etc. via field survey to analyze the types of tunnel portal slopes along national highways. State evaluation classification sheet is presented to divide classes for the danger state of the surveyed portal slopes, and then the related grades are divided. It is mainly aimed at classifying the tunnel portal slope along national highways with using this state evaluation, to use it as basic data so that continuous maintenance can be executed in the future in accordance with danger classes.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.12 no.1
• /
• pp.27-33
• /
• 1979

In early August 1978, a huge red tide occurred off Chilcheon Is, , at the mouth of Jinhae Bay. It expanded rapidly into the central part and then soon covered all the bay except the innermost part of the bay. After staying for a week it disappeared, and thereafter several small scale red tides partially occurred and disappeared untill the end of August. It differed from the red tides hitherto recorded from this bay in respect of the dominant plankter, the geographical extent and the severe damaging effect to local oyster resources. During the red tide period, nevertheless, no oyster damage was found. In September, however, oyster mortailty was found from all rafts and longlines in the bay. Except the inner most part of the bay the oyster farms were completely destroyed. Of the oyster Production in the winter 1978, $96\%$ of an estimated yield of 5,879 tons (shucked meat) was lost and it was estimated to be 2,275 million won, equivalent to $US\$$ 4.55 million. The dominant species was a dinoflagellate, Ceratium fusus and it constituted about $45\%$ of the total phytoplankton. Cell count showed $7.0\times10^4\;cells/\iota$ and chlorophyll-a, $50mg/m^3$ during red tide peak. No oxygen was found ill the bottom waters in September. Sulphides in bottom waters and in the superficial mud increased to 15 and 8-fold respectively in September compared with July ana August. Precipitation from January to May of 1978 was about a third in comparison with the past ten years average but rainfall ill June was two and half-fold more than normal year, and thereafter drought persisited till September Air and water temperatures were also higher, and sunny days continued for a long time without strong winds. Therefore, water was calm for a long time after the red tide extinguished. The result indicated that the occurrence of the Ceratium red tide occurred in that year which was characterized by the combination of the formation of almost anoxic bottom water before the red tide occurrence, high air temperature and the calmness after a great quantity of rainfall in June. The mass mortality of oysters was presumed not to be directly related with the red tide but with the depression of dissolved oxygen in the environmental waters at the bottom due to settling of the red tide organisms.

• The Journal of the Korea Contents Association
• /
• v.20 no.5
• /
• pp.525-535
• /
• 2020

This study aims to evaluate the economic value of the heat wave watch/warning (HW/W) forecast provided by the KMA (Korea Meteorological Administration) for the public sector. Local govermenments of Korea currently use the HW/W forecasts as a major input variable to determine the preparative requisite level for reducing potential damage by extreme heat events. To assess the value of the HW/W, which is not a marketable commodity, a decision-making model taking into account the cost and loss was established. The 'cost' variable was defined as the heat wave countermeasures budget for Seoul and Busan in 2016, and the 'loss' variable was set as the amount of health insurance claims for those 65 and older obtained from the Health Insurance Review and Assessment Service. Using this model, the value of the HW/W in 2016 was calculated as KRW 4,133M and KRW1,090M for Seoul and Busan, respectively. In addition, if the KMA reduces the False Alarm of the HW/W by a single instance, the value will be increased by KRW 76.6M and KRW 16.8M for the two cities. The results of this study are useful in quantitatively estimation of the value of the HW/W forthe public sector.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.5
• /
• pp.611-617
• /
• 2018

The application of health monitoring, including a fault detection technique, is needed to secure the structural safety of large structures. A 2-step crack identification method for detecting the crack location and size of the beam structure is presented. First, a crack occurrence region was estimated using the modified Laplacian operator for the strain mode shape obtained from the distributed local strain data. The crack location and size were then identified based on the natural frequencies obtained from the acceleration data and the neural network technique for the pre-estimated crack occurrence region. The natural frequencies of a cracked beam were calculated based on an equivalent bending stiffness induced by the energy method, and used to generate the training patterns of the neural network. An experimental study was carried out on an aluminum cantilever beam to verify the present method for crack identification. Cracks were produced on the beam, and free vibration tests were performed. A crack occurrence region was estimated using the modified Laplacian operator for the strain mode shape, and the crack location and size were assessed using the natural frequencies and neural network technique. The identified crack occurrence region agrees well with the exact one, and the accuracy of the estimation results for the crack location and size could be enhanced considerably for 3 damage cases. The presented method could be applied effectively to the structural health monitoring of large structures.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.12
• /
• pp.7569-7576
• /
• 2013

Background: The purpose of this article is to present preliminary results of simultaneous boost irradiation radiotherapy for locally advanced nasopharyngeal carcinoma (NPC). Methods: Fifty-eight patients who underwent simultaneous boost irradiation radiotherapy for NPC in Cancer Center of Sun Yat-sen University between September 2004 and December 2009 were eligible. Acute and late toxicities were scored weekly according to the Radiation Therapy Oncology Group (RTOG) acute and late radiation morbidity scoring schemes. An especial focus was on evidence of post-radiation brain injury. Also quality of life was analysed according to the EORTC (European Organisation for Research and Treatment of Cancer) recommendations. Discrete variables were compared by ${\chi}^2$ test. The Kaplan-Meier method was used to calculate the survival rates and generate survival curves. Results: A total of 58 patients with a mean follow-up time of 36 months completed clinical trials.Fifty-seven patients (98.3) achieved complete remission in the primary sites and cervical lymph nodes, with only one patient (1.7%) showing partial remission.The most frequently observed acute toxicities during the concurrent chemoradiotherapy were mucositis and leucopenia. Four patients (6.9%) had RTOG grade 3 mucositis, whereas four patients (6.9%) had grade 3 leucopenia. No patient had grade 4 acute toxicity. Three (5.17%) of the patients exhibited injury to the brain on routine MRI examination, with a median observation of 32 months (range, 25-42months). All of them were RTOG grade 0. The 3-year overall, regional-free and distant metastasis-free survival rates were 85%, 94% and 91%, respectively. Conclusion: Simultaneous boost irradiation radiotherapy is feasible in patients with locally advanced nasopharyngeal carcinoma. The results showed excellent local control and overall survival, with no significant increase the incidence of radiation brain injury or the extent of damage. A larger population of patients and a longer follow-up period are needed to evaluate ultimate tumor control and late toxicity.

• The Korean Journal of Pain
• /
• v.30 no.1
• /
• pp.3-17
• /
• 2017

Background: Postherpetic neuralgia (PHN) is a common and painful complication of acute herpes zoster. In some cases, it is refractory to medical treatment. Preventing its occurrence is an important issue. We hypothesized that applying nerve blocks during the acute phase of herpes zoster could reduce PHN incidence by attenuating central sensitization and minimizing nerve damage and the anti-inflammatory effects of local anesthetics and steroids. Methods: This systematic review and meta-analysis evaluates the efficacy of using nerve blocks to prevent PHN. We searched the MEDLINE, EMBASE, Cochrane Library, ClinicalTrials.gov and KoreaMed databases without language restrictions on April, 30 2014. We included all randomized controlled trials performed within 3 weeks after the onset of herpes zoster in order to compare nerve blocks vs active placebo and standard therapy. Results: Nine trials were included in this systematic review and meta-analysis. Nerve blocks reduced the duration of herpes zoster-related pain and PHN incidence of at 3, 6, and 12 months after final intervention. Stellate ganglion block and single epidural injection did not achieve positive outcomes, but administering paravertebral blockage and continuous/repeated epidural blocks reduced PHN incidence at 3 months. None of the included trials reported clinically meaningful serious adverse events. Conclusions: Applying nerve blocks during the acute phase of the herpes zoster shortens the duration of zoster-related pain, and somatic blocks (including paravertebral and repeated/continuous epidural blocks) are recommended to prevent PHN. In future studies, consensus-based PHN definitions, clinical cutoff points that define successful treatment outcomes and standardized outcome-assessment tools will be needed.

• The Korean Journal of Pharmacology
• /
• v.27 no.2
• /
• pp.197-205
• /
• 1991

Local extravasation during intravenous administration of adriamycin (doxorubicin HCl) can cause severe skin ulceration and necrosis. To investigate the mechanism of adriamycin-induced skin toxicity, effects of adriamycin on reactive oxygen radical metabolism using cultured skin cells of fetal rat. Adriamycin produced significant release of lactic dehydrogenase from cultured skin cell preparations dose- and time-dependently. The production of superoxide anion in sonicated suspensions of cultured skin cells was significantly increased by adriamycin under the presence of NADPH and NADH. The drug also stimulated malondialdehyde (MDA) production, an index of lipid peroxidation, in NADPH- and NADH-supported cell preparations. The increased production of MDA was significantly inhibited by oxygen radical scavengers (superoxide dismutase, catalase, thiourea) and antioxidants (butylated hydroxytoluene, ${\alpha}-tocopherol$). Treatment of cultured skin cells with 1, 3,-bis (2-chloroethyl)-1-nitrosourea (BCNU), an inhibitor of glutathione reductase, enhanced the lipid peroxidation induced by adriamycin. The present study suggests that lipid peroxidation which is resulted from the stimulated production of reactive oxygen radical causes cellular damage in adriamycin-treated skin cells of rat.

• Journal of Pharmacopuncture
• /
• v.17 no.3
• /
• pp.40-49
• /
• 2014

Objectives: The gastric ulcer is a common disorder of the stomach and duodenum. The basic physiopathology of a gastric ulcer results from an imbalance between some endogenous aggressive and cytoprotective factors. This study examined whether Ganoderma lucidum pharmacopuncture (GLP) would provide protection against acute gastric ulcers in rats. Methods: Sprague-Dawley rats were divided randomly into 4 groups of 8 rats each: normal, control, normal saline (NP) and GLP groups. The experimental acute gastric ulcer was induced by using an EtOH/HCl solution and the normal group received the same amount of normal saline instead of ethanol. The NP and the GLP groups were treated once with injections of saline and GLP, respectively. Two local acupoints were used: CV12 (中脘) which is the alarm point of the Stomach Meridian, and ST36 (足三里), which is the sea point of the Stomach Meridian. The stomachs from the rats in each group were collected and analyzed for gross appearance and histology. Also, immunohistochemistry staining for BAX, Bcl-2 and TGF-${\beta}1$ was performed. Results: Histological observations of the gastric lesions in the control group showed comparatively extensive damage of the gastric mucosa and necrotic lesions had penetrated deeply into the mucosa. The lesions were long, hemorrhagic, and confined to the glandular portions. The lesions were measured microscopically by using the clear depth of penetration into the gastric mucosal surface. The length and the width of the ulcer were measured and the inhibition percentage was calculated. Wound healing of the acute gastric ulcer was promoted by using GLP, and significant alterations of indices in gastric mucosa were observed. Such protection was shown by gross appearance, histology and immunohistochemistry staining for BAX, Bcl-2 and TGF-${\beta}1$. Conclusion: These results suggest that GLP administered at CV12 and ST36 can provide significant protection to the gastric mucosa against an ethanol-induced acute gastric ulcer.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.3
• /
• pp.600-608
• /
• 2017

The presence of piping in a levee body allows water seepage to occur by producing a large cavity or water tunnel within it, ultimately resulting in the failure of the river levee and differential settlement. In order to properly cope with river levee failure due to piping and establish a proper remediation method for this problem, it is necessary to analyze the failure mechanism of the river levee due to piping. Therefore, this study analyzed the shape and mechanism of river levee failure due to piping through small-scale and large-scale models and evaluated the seepage pressure distribution characteristics in the hydraulic well, which has been suggested as a remediation method for piping. According to the results of this study, as the safety factor for the piping in the river levee decreased, the river levee failure shape was more clearly shown through the small-scale model test. In the large-scale model test, the type of local damage to the levee due to the piping was identified and the evaluation showed that the hydraulic well had the largest effect on the inhibition of piping below the center of the well. A follow-up study is needed to confirm the reliability of the results. However, it is thought that this study can be utilized as the baseline data for research into the piping-induced river levee failure mechanism and for the preparation of a remediation method.

• Journal of Korean Society of Transportation
• /
• v.36 no.1
• /
• pp.13-22
• /
• 2018

Buses, one of the representative public transportation modes, are divided into a vareity of service types according to the purpose of operation, operating distance, and management agencies. Although bus-involved crashes may cause large amount of damage due to the higher number of passengers boarded on a bus, prior research has little focused on crash severity according to bus service types. This study aims to investigate factors influencing crash severity in bus-involved crashes and to present policy implications to reduce crash severity by bus service type. To do this, bus-involved crash data from the Traffic Accident Analysis System (TAAS) during five-year period are used. Ordered probit models for three types of bus service, i.e., city bus, suburban and express buses, and charter buses, are estimated to analyze the factors of accident severity. The results show that there are significant differences of factors affecting crash severity among the types of bus services while speed and road surface influence all the types of buses. In case of local buses, time of day, roadway alignment, and installation of a traffic signal are found to be statistically significant factors. Seat belt and road class have significant effects on injury severity of the intercity and express buses. Chartered buses have time of day, driving experience, seatbelt, traffic signal, and day of week as the significant factors. The results of this study are expected to contribute to the reduction of the crash severity by each bus service type.