• Journal of the Korean Geotechnical Society
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• v.23 no.9
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• pp.5-16
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• 2007

The simple linear elastic-perfectly plastic model with soil parameters $s_u,\;E_u$ and n of undrained condition is usually applied to predict the displacement of a constructed diaphragm wall(DW) on soft soils during excavation. However, the application of this soil model for finite element analysis could not interpret the continued increment of the lateral displacement of the DW for the large and deep excavation area both during the elapsed time without activity of excavation and after finishing excavation. To study the characteristic behaviors of soil behind the DW during the periods without excavation, a series of tests on soft Bangkok clay samples are simulated in the same manner as stress condition of soil elements happening behind diaphragm wall by triaxial tests. Three kinds of triaxial tests are carried out in this research: $K_0$ consolidated undrained compression($CK_0U_C$) and $K_0$ consolidated drained/undrained unloading compression with periodic decrement of horizontal pressure($CK_0DUC$ and $CK_0UUC$). The study shows that the shear strength of series $CK_0DUC$ tests is equal to the residual strength of $CK_0UC$ tests. The Young's modulus determined at each decrement step of the horizontal pressure of soil specimen on $CK_0DUC$ tests decreases with increase in the deviator stress. In addition, the slope of Critical State Line of both $CK_0UC$ and $CK_0DUC$ tests is equal. Moreover, the axial and radial strain rates of each decrement of horizontal pressure step of $CK_0DUC$ tests are established with the function of time, a slope of critical state line and a ratio of deviator and mean effective stress. This study shows that the results of the unloading compression triaxial tests can be used to predict the diaphragm wall deflection during excavation.

• Economic and Environmental Geology
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• v.40 no.4
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• pp.445-459
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• 2007

Superconducting Gravimeter(SG) was installed and has been successfully operated at MunGyung, Kyungsang province in Korea in March 2005. It was registered as the 21st observatory of the Global Geodynamics Project. Since SG can precisely measure the gravity variations below the 1mHz frequency band, it has the outstanding capability to sense and resolve many different periodic gravity components from each other. From the raw data collected between 18 March 2005 and 21 February 2006 diurnal and semi-diurnal tidal band's residual gravity components were analyzed. During this process, the instrumental noises, air pressure, and ground water corrections were carried out. Values of $-3.18nm/s^2/hPa\;and\;17nm/s^2/m$ were used respectively in the air pressure and groundwater corrections. Hartmann-Wenzel and Whar-Dehant Earth tide models were adopted to compute the residual gravity for Q1, O1, P1, K1, M2, N2, S2, K2 tidal bands. For the ocean loading correction, SCW80, FES952, and FES02 models were used and compared. As a result, FES02 ocean loading model has shown the best match for the data processing at MunGyung SG MunGyung SG gravity was compared with GRACE satellite gravity. The correlation coefficient between the two gravity after groundwater correction was 0.628, which is higher than before ground water correction. To evaluate sensitivity at MunGyung SG gravity statition, the gravity data measured during 2005 Indodesian earthquake was compared with STS-2 broad band seismometer data. The result clearly revealed that the SG could recorded the same period of earthquake with seismometer event and a few after-shock events those were detected by seismometer.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.83-96
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• 2017

A constructed sea stream in Yeongdo, Busan, Republic of Korea is mostly static due to the lifted stream bed and tidal characters, and receives domestic wastewater nearby, causing a consistent odor production and water quality degradation. Bioaugmentation of a microbial consortium was proposed as an effective and economical restoration technology to restore the polluted stream. The microbial consortium activated on site was augmented on a periodic basis (7~10 days) into the most polluted site (Site 2) which was chosen considering the pollution level and tidal movement. Physicochemical parameters of water qualities were monitored including pH, temperature, DO, ORP, SS, COD, T-N, and T-P. COD and microbial community analyses of the sediments were also performed. A significant reduction in SS, COD, T-N, and COD (sediment) at Site 2 occurred showing their removal rates 51%, 58% and 27% and 35%, respectively, in 13 months while T-P increased by 47%. In most of the test sites, population densities of sulfate reducing bacterial (SRB) groups (Desulfobacteraceae_uc_s, Desulfobacterales_uc_s, Desulfuromonadaceae_uc_s, Desulfuromonas_g1_uc, and Desulfobacter postgatei) and Anaerolinaeles was observed to generally decrease after the bioaugmentation while those of Gamma-proteobacteria (NOR5-6B_s and NOR5-6A_s), Bacteroidales_uc_s, and Flavobacteriales_uc_s appeared to generally increase. Aerobic microbial communities (Flavobacteriaceae_uc_s) were dominant in St. 4 that showed the highest level of DO and least level of COD. These microbial communities could be used as an indicator organism to monitor the restoration process. The alpha diversity indices (OTUs, Chao1, and Shannon) of microbial communities generally decreased after the augmentation. Fast uniFrac analysis of all the samples of different sites and dates showed that there was a similarity in the microbial community structures regardless of samples as the augmentation advanced in comparison with before- and early bioaugmentation event, indicating occurrence of changing of the indigenous microbial community structures. It was concluded that the bioaugmentation could improve the polluted water quality and simultaneously change the microbial community structures via their niche changes. This in situ remediation technology will contribute to an eco-friendly and economically cleaning up of polluted streams of brine water and freshwater.

• Journal of the Korean Society for Railway
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• v.17 no.3
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• pp.193-200
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• 2014

In this study, fatigue tests on existing continuous welded rail (CWR) on a concrete track were carried out. Based on the test results, a S-N curve expressing the remaining life of the CWR at a fracture probability of 50% was obtained using weighted probit analysis suitable for small-sample fatigue data sets. As rails had different histories in terms of accumulated passing tonnage, the test data were corrected to average out the accumulated passing tonnage. The remaining service life for the CWR on the concrete track in an urban railway was estimated using the prediction equation for the bending stress of rail developed in the past to estimate rail base bending stress and taking the surface irregularities into consideration. Estimating the remaining service life of the CWR in an urban railway showed that the rail replacement period could be extended over 200MGT. In addition, comparing the concrete track to the ballast track, the fatigue life of rail was analyzed as approximately 300MGT higher than. Therefore, the rail replacement criteria needs to distinguish between the ballast track and the concrete track, and not the criteria needs to be changed as a target for the maintenance, although it is necessary to remove longitudinal rail surface irregularities at welds by grinding.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.280-285
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• 2016

Mandible defects could be caused by congenital malformations, trauma, osteomyelitis, tumor resection. If large areas are included for reconstruction, those are primarily due to tumor resection defects. The large jaw defect results in a problem about mastication, swallowing, occlusion and phonetics, and poor esthetics causes a lot of inconvenience in daily life. It is almost impossible to be a part underwent mandibular resection completely reproduced, should be rebuilt artificially. This case is of a patient who was diagnosed with squamous cell carcinoma pT1N0M0, stage I in February 2004 and received surgery (combined mandibulectomy and neck dissection operation (COMMANDO) in oromaxillofacial surgery) in March 2004, by implant assisted removable partial denture. We could obtain good retention and stability through sufficient coverage and implant holding. Follow up period was about four years. Mandibular left third molar regions have been observed to have resorption of surrounding bone, and periodic check-ups are necessary conditions.

• Journal of Veterinary Clinics
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• v.30 no.2
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• pp.115-118
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• 2013

An 8-year-old spayed female domestic shorthair cat was presented with a chief complaint of chronic nasal discharge and dyspnea. Physical examination revealed pyohemorrhagic nasal discharge, inspiratory dyspnea and stertor, and an enlarged right mandibular lymph node. Abnormalities of blood works and serum chemistry included mildly increased hematocrit, and globulin concentration. Serologic tests for FeLV and FIV, and a panel of polymerase chain reaction tests for Chlamydophila felis, Feline Calicivirus, Herpesvirus, Bordetella, Mycoplasma felis, and H1N1 influenza was all negative. Only radiographic finding showed increasing soft tissue density in the right nasal cavity and computed tomography disclosed soft tissue/fluid opacification in the right nasal cavity, paranasal sinus, and pharyinx along with slight deviation to the right of the osseous nasal septum. Focal lysis of ventral nasal septum was also suspected in CT scan. Cytological evaluation of fine needle aspirate smears of the enlarged mandibular lymph nodes revealed numerous fungal yeasts having variably thick capsule both extracellularly and intracellularly with low numbers of macrophages. Some yeasts showed narrow based budding, which was a consistent finding with Cryptococcus organisms. Serum protein electrophoresis was a polyclonal consistent with chronic infection and serum was submitted for a fungal serology panel test. In serologic tests Cryptococcus antigen titer was 1 : 32,768. In vitro culture was unsuccessful. Treatment was initiated with administration of fluconazole, clindamycin, and tocopherol. Clinical signs resolved within 3 days after the initial treatment. The cat was discharged and scheduled for periodic evaluation and continued therapy, but was lost to follow-up thereafter.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.333-343
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• 2004

Impression cytology refers to application of cellulose acetate filter material to the ocular surface to remove the superficial layers of the conjunctival epithelium. The technique is non-invasive, is easy to perform, causes minimal discomfort to the patient, and can be used to follow changes in the conjunctival ocular surface over time. With this method, the morphology of the conjunctival ocular surface can be studied and the degree of squmaous metaplasia assessed. This study was performed to evaluate the conjunctival surface by impression cytology in dry eye patients. A total of 70 students with no contact lens wearing history were recruited. Subjects were required to fill in a McMonnies dry eye symptom questionnaire. The non-invasive tear thinning time(TIT) test of each subject was measured, followed by Schirmer tear test(STI), tear film break-up time(TBUT) tests and Rose-bengal staining were performed as a baseline. Conjunctival epithelial cells from the inferior bulbar conjunctiva were harvested by the impression cytology technique. The specimens collected were labelled and stained with PAS(Periodic Acid Schift)-haematoxylin. The goblet cells and conjunctival epithelial cells were observed under a light microscope of 400x magnification. The specimens were classified according to the Nelson Grading scale which was based on the degree of squamous metaplasia such as changes of goblet cells density, size/form, N:C(nucleus : cytoplasm) ratio. Dry eye patients were observed morphological changes of the epithelial cells, different nuclear alterations, decrease of the goblet cells density. The degree of cytological changes was related to severity of dry eye conditions. When the epithelial cell morphology was graded according to the system described by Nelson, specimens from the control group revealed 91.43% of the eyes to be grade 0 and 8.57% to be grade 1, whereas of the dry eye patients, 20% were grade 0, 42.86% grade 1, 34.29% grade 2 and 2,86% grade 3. Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. This technique is a safe, simple method and may help increase understanding of various ocular surface alterations in dry eye patients.

• Journal of Life Science
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• v.8 no.5
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• pp.509-519
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• 1998

The effect of N-Nitrosodimethylamine(NDMA) on the glycoconjugates of rat lingual salivary gland was examined by prelectin histochemical methods. Sprague-Dawley rats weighing about 250-300g were divided into control and experimental groups. Each rat of experimental groups was administrated NDMA(17mg/kg) orally and sacrificed in 3, 6, 12, 24, 48, 72, 96 and 120 hours after NDMA administration. The regional differences and change of glycoco-njugates were elucidated by prelectin histochemical methods, such as periodic acid Schiff's(PAS) reaction, alcian blue (AB) pH 2.5, AB pH 0.4, AB pH 2.5-PAS, aldehyde fuchsin(AF) pH 1.7-AB pH 2.5 and high iron diamine(HID)-AB pH 2.5 staining. The major morphological changes in the von Ebner’s gland of NDMA administrated groups were withering and des-truction of serous acini, diminution and disappearance of cytoplasmic granules and vacuolation in cytoplasm of serous cells, and mucinous changes of duct epithelial cells. These changes were noted in NDMA administrated groups for 12 to 72 hours. In the lingual mucous gland of NDMA administrated groups, the major morphological changes were enlargement, fusion and destruction of mucous acini, loss of cytoplasmic granules and vacuolated generation in cytop-lasm of mucous cells, and mucinous change of duct epithelial cells. These changes were severe in NDMA administra-ted groups for 12 to 72 hours. In NDMA administrated groups of lingual von Ebner's gland for 12 and 72 hours, the neutral glycoconjugates be-come diminished remarkably compared to the control group. The decreased amount of neutral glycoconjugates tended to be gradually recovered from 96 hours group. The acidic glycoconjugates which were not detected in control group were found in a few serous cells of these gland of NDMA administrated groups for 6 to 48 hours and 120 ho-urs. The remarkable decrease of neutral and acidic glycoconjugates was observed in the lingual mucous glands 3, 24 and 48 hours after NDMA administration, and the striking decrease of acidic glycoconjugates was found in 72 hours groups. Among acidic glycoconjugates, sulfated glycoconjugates tended to decrease in NDMA administrated groups for 72 hours, while sialic glycoconjugates were increased in NDMA administrated groups for 3, 12 and 48 hours.

• Neonatal Medicine
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• v.18 no.2
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• pp.272-279
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• 2011

Purpose: The incidence of nosocomial infection caused by Gram-negative bacilli (GNB) has increased in neonatal intensive care units (NICU). This study identified the progression of sepsis caused by GNB colonization and analyzed the risk factors associated with using periodic stool culture surveillance. Methods: We included 86 newborns admitted to the NICU, Kosin University Gospel Hospital from October 2007 to May 2008. Three stool specimens were collected right after birth and two more were collected at 2 week intervals. The risk factors related to GNB colonization were established from each medical record and related references. Results: The incidence of colonization by GNB was 22 (25.6%) per 86 neonates but none had culture-proven sepsis. The three most commonly isolated GNB were Pseudomonas aeruginosa, Enterobacter cloacae, and Citrobacter freundii. Approximately 89% (32/36) of isolated GNB were susceptible to amikacin. The probability of GNB colonization increased in infants who were fed a small volume during enteral feeding. In contrast, delayed enteral feeding resulted in a decreased probability for GNB colonization. Conclusion: Colonized GNB in the intestine was confirmed by enteric surveillance culture of newborns admitted to the NICU. However, we found no evidence of culture-proven GNB sepsis. As lower feeding volume on the colonization day is a risk factor for GNB colonization, the chance for GNB colonization should be considered when feeding intolerance is present.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.145-148
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• 2003

The Kunang cave paleolithic site is located at Tanyang [$N37^{\circ}2'$, $128^{\circ}21'E$], Chungbuk Province, which is in the Central part of the Korean peninsula. The cave is developed at 312 amsl in a karstic mountainous area. The South Han River flows across this region and other caves can also be found near the river. The site was discovered in 1986 and excavated 3 times by the Chungbuk National University Museum until now. The cave was wellpreserved from modem human activities until the first discovery. The full length of the cave is estimated to be ca. 140 m. However, a spacious part up to 11 m from the entrance has been excavated. Eight lithological units are divided over the vertical profile at a depth of 5 m. Each unit is deposited in ascending order as follow: mud layer (Unit 9), lower complex (Unit 8) which is composed of angular blocks and fragments with a muddy matrix, lower travertine layer (Unit 7； flowstone), middle complex (Unit 6; cultural layer) which is composed of fragments with a muddy matrix, middle travertine layer (Unit 5； flowstone), yellowish muddy layer (Unit 4), upper complex (Unit 3； cultural layer) which has a similar composition to Unit 8. the upper travertine layer (Unit 2； flowstone), and finally surface soil layer (Unit 1). The most abundant vestiges in the cultural layers are the animal bones. They are small fractured pieces and mostly less than 3 cm in length. About 3,800 bone pieces from 25 animal species have been collected so far, 90 percent of them belonging to young deers. Previous archaeological study of these bone pieces shows thatprehistoric people occupied the cavenot for permanent dwelling but for temporary shelter during their seasonal hunting activity. More extensive studies of these bones together with pollen analysis are in progress to reconstruct the paleoenvironment of this cave. Only a single date (12,500 BP) obtained from a U-Th measurement of the upper travertine layer was previously available. In spite of the importance of the cave stratigraphy, there was no detail chronological investigation to establish the depositional process of the cultural layers and to understand the periodic structure of the cave strata, alternating travertine floor and complex layers. We have measured five 14C age dating (38900+/-1000, 36400+/-900, 40600+/-1600, more than 51000 and 52000 14C BP) using Seoul National University 14C AMS facility, conducted systematic process of the collagen extraction from bone fragments samples. From the result, we estimate that sedimentation rate of the cave earth is constant, and that the travertine layers, Unit 2 and Unit 3, was formed during MIS 5a(ca. 80 kBP) and MIS 5c (ca. 100 kBP) respectively. The Kunang Cave site is located at Yochonli of the region of Danyang in the mid-eastern part of Korea. This region is compased of limestones in which many caves were found and the Nam-han river flows meanderingly. The excavations were carried out three times in 1986, 1988, and 1998.