• The Journal of Korean Society for School & Community Health Education
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• v.24 no.1
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• pp.1-15
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• 2023

Objectives: The purpose of this study was to identify the major influencing factors of breast cancer death and to suggest policy measures to promote the health of breast cancer patients. Methods: The method of this study performed statistical analysis by applying weights to 2,300 cases of breast cancer registration statistics in Korea collected in 2018 due to the relatively small number of mortality data compared to survival. Statistical processing of the collected data was analyzed using SPSS 26.0. Results: The epidemiologic characteristics of death in breast cancer patients were 31.8% in those aged 70 years or older, and the mortality rate was 5.25 times higher in patients aged 70 years or older than those aged 39 years or younger. The anatomical site code was 36.4% in C50.4~C50.6, and the mortality rate was 1.82 times higher in C50.4~C50.6 than in C50.0~C50.1. The tumor size was 40.4% and larger than 4cm, and the mortality rate was 4.53 times higher in tumors larger than 4cm than those smaller than 1cm. The degree of differentiation was 13.9% in the poorly differentiated group, and the mortality rate was 4.38 times higher in the poorly differentiated group than in the highly differentiated group. In the hormone receptor test, non-triple negative cases were 59.6%, and the mortality rate was 0.57 times lower in non-triple negative cases than in triple negative cases. As for lymph node involvement, the presence or absence of lymph node involvement was 78.8%, and the mortality rate with lymph node involvement was 1.36 times higher than that without lymph node involvement. The survival period of 13 to 24 months was the highest at 26.5%, and the average survival period was 25.68 months (±14.830). Conclusion: A policy to advance the timing of national health examinations for early detection of breast cancer is necessary. In addition, a bill for the mandatory placement of health educators in medical institutions for patients with special diseases such as breast cancer should be prepared.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2A
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• pp.259-267
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• 2008

The ultimate strengths of reinforced concrete deep beams are governed by the capacity of the shear resistance mechanism composed of concrete and shear reinforcing bars, and the structural behaviors of the beams are mainly controlled by the mechanical relationships according to the shear span-to-effective depth ratio, flexural reinforcement ratio, load and support conditions, and material properties. In this study, a simple indeterminate strut-tie model reflecting all characteristics of the ultimate strengths and complicated structural behaviors is presented for the design of simply supported reinforced concrete deep beams. In addition, a load distribution ratio, defined as a magnitude of load transferred by a vertical truss mechanism, is proposed to help structural designers perform the design of simply supported reinforced concrete deep beams by using the strut-tie model approaches of current design codes. In the determination of a load distribution ratio, a concept of balanced shear reinforcement ratio requiring a simultaneous failure of inclined concrete strut and vertical steel tie is introduced to ensure the ductile shear failure of reinforced concrete deep beams, and the prime design variables including the shear span-to-effective depth ratio, flexural reinforcement ratio, and compressive strength of concrete influencing the ultimate strength and behavior are reflected upon based on various and numerous numerical analysis results. In the companion paper, the validity of presented model and load distribution ratio was examined by employing them to the evaluation of the ultimate strengths of various simply supported reinforced concrete deep beams tested to failure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3B
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• pp.311-319
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• 2006

A bed level change model(SED-FLUX) is introduced based on the realistic sediment transport process including bed load and suspended load behaviours at the bottom boundary layer. The model SED-FLUX includes wave module, hydrodynamic module and sediment transport and diffusion module that calculate suspended sediment concentration, net sediment erosion flux($Q_s$) and bed load flux. Bed load transport rate is evaluated by the van Rijn's TRANSPOR program which has been verified in wave-current fields. The net sediment erosion flux($Q_s$) at the bottom is evaluated as a source/sink term in the numerical sediment diffusion model where the suspended sediment concentration becomes a verification parameter of the $Q_s$. Bed level change module calculates a bed level change amount(${\Delta}h_{i,j}$) and updates a bed level. For the model verification the limit depth of the bed load transport is compared with the field experiment data and some formula on the threshold depth for the bed load movement by waves and currents. This model is applied to the beach profile changes by waves, then the model shows a clear erosion and accumulation profile according to the incident wave characteristics. Finally the beach evolution by waves and wave-induced currents behind the offshore breakwater is calculated, where the model shows a tombolo formation in the landward area of the breakwater.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5C
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• pp.209-218
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• 2010

In residual soils, large particles such as rock fragments or gravel are surrounded by sand or clay. The strength of such granular mixtures can be controlled by the concentration of fine or coarse grains. The percentage by weight, size or shape of gravel in the mixture that can control the strength of the mixture has not been clearly determined for various granular mixtures. In this study, the effect of dispersed gravels on the shear characteristics of sand was evaluated. Large and small gravels were inserted in the middle of each layer with moist Nakdong River sand and compacted into a cylindrical sample with five equal layers. Embedded gravel ratios by weight were 0, 3, 9, and 14%. After consolidation, a series of undrained triaxial compression tests was performed on Nakdong River sand with dispersed gravels. Maximum deviator stresses of the Nakdong River sand with large gravels decrease up to 38% as a percentage of embedded gravels increases. Such strength degradation decreases as a confining pressure increases. The maximum deviator stress increases as the percentage by weight of small gravel increases; at 3 or 9% of gravel weight it slightly increases but at 14% of gravel weight it increases up to 34%.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.416-424
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• 2023

Concrete emits a large amount of carbon dioxide throughout its life cycle, and due to the societal demand for carbon dioxide reduction, research on storing carbon dioxide in concrete in the form of minerals is ongoing. In this study, cyanobacteria, which absorb carbon dioxide through photosynthesis and fix it as calcium carbonate, were applied to a porous concrete substrate, and the changes in the properties of the concrete substrate due to their special environmental curing condition were analyzed. The results showed that the calcium carbonate precipitation by the microorganisms was concentrated in the light-exposed surface area, and most of the precipitation occurred in the cement paste part, not in the aggregate. This microbially induced calcium carbonate precipitation enhanced the mechanical performance of the paste and improved the overall compressive strength as the curing age progressed. In addition, the increase in microbial biofilm and calcium carbonate improved the pore structure, which influenced the reduction in water permeability.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.115-124
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• 2024

The emergence and spread of Staphylococcus aureus, which is resistant to quinolone antibacterial agents, has made it difficult to treat infectious diseases. Accordingly, this study examined the molecular epidemiological characteristics of quinolone-resistant S. aureus (QRSA) to obtain helpful data for treatment. Mutations in mecA and SCCmec typing, gyrA, and gyrB genes were investigated for QRSA strains isolated from the blood culture specimens at a general hospital in Daejeon Metropolitan City. The ciprofloxacin-resistant strains in SCCmec typing were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains (11 strains, 18%), and levofloxacin (LVX) and moxifloxacin (MXF) strains were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains were 10 (17%). In both gyrA and gyrB regions, there were 58 mutations, or 96.7%. In LVX, there were 56 mutations or 93.3%, and in MXF, there were 57 mutations or 95%. Twelve mutations, six mutations each in gyrA and gyrB, were identified for the QRSA strain. The resistance rate for the quinolone antibiotics of QRSA studied was approximately 98%, and 12 mutations, six each in gyrA and gyrB, were identified in the QRSA strain. Therefore, the rational use of antibiotics needs to be improved.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.157-164
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• 2023

The estuary dam is a structure installed and operated in a closed state except when flood event occurs to prevent inland saltwater intrusion and secure freshwater supply. However, the closed state of dam leads to issues such as eutrophication, so it is necessary to examine the extent of saltwater intrusion resulting from the opening of sluice gates. Groundwater, due to its subsurface conditions and slow flow characteristics, is widely analyzed using numerical models. OpenGeoSys, an open-source software capable of simulating Thermal- Hydraulic- Mechanical- Chemical phenomena, was adopted for this study. Simulations were conducted assuming natural flow conditions without dam and operating considering busy farming season, mostly from March to September. Verification of the model through analytical solutions showed error of 3.7%, confirming that OpenGeoSys is capable of simulating saltwater intrusion for these cases. From results simulated for 10 years, considering for the busy farming season, resulted in about 46% reduction in saltwater intrusion length compared to natural flow conditions, approximately 74.36 m. It may be helpful to make choices to use groundwater as a water resource.

• Journal of Chest Surgery
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• v.30 no.7
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• pp.663-669
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• 1997

This is a report on the clinical outcome and hemodynamic profile of the ATSwcardiac valve prosthesis, which is a recently introduced pyrolytic carbon bileaflet prosthesis. We retrospectively reviewed the early outcome of 100 consecutive patients who underwent isolated cardiac valve replacement with the ATS(w prosthesis from October 1994 through June 1996 at our hospital. All patients were evaluated with Doppler echocardiography before discharge from the hospital. The mean age of the patients was 48.6 years(range: 2 to 74). A tota of 124 prosthesis were implanted; 71 mitral, 46 aortic, and 7 tricuspid. The two most frequently used sizes were 27 mm(40.8%) and 29 mm(35.2%) in the mitral position, and 23 mm(30.4%) and 21 mm(28.3%) in the aortic position. There was no early or late death. The total follow-up period was 950 patient-months with 99% follow-up rate. Serious late morbidity occurred in three patients; reoperation in two patients for late rupture of Sinus of Valsava in one and for endocarditis with prosthetic dehiscence in the other, and intracranial hemorrhage due to hypertension in one patient. There has been no thromboembolic complication or structural valval deterioration. In the mitral position, the average values of peak and mean transprosthetic pressure gradients and valve area calculated from pressure half time were 6.9$\pm$2.8 mmHg, 2.6$\pm$ 1.5 mmHg, and 2.7 $\pm$0.8 cm2 respectively. In the aortic position, the peak and mean pressure gradients'were 26.4 $\pm$ 15.9 mmHg and 14.2 $\pm$ 7.9 mmHg. For the mitra prostheses larger than 25-mm size, there was no significant difference among prosthetic sizes in terms of transprosthetic gradients, whereas there was a significant negative correlation between the prosthesis size and the transprosthetic gradients for the aortic valves. The peak and mean Pressere pradients were 52.2 $\pm$ 17.6 tmHg and 26.9$\pm$ 7.4 mmHg across the 19-mm aortic Prostheses, and 27.1 $\pm$ 11.9 mmHg and 13.3$\pm$6.6 mmHg across the 21-mm size. Above results can lead to the conclusion that the early clinical outcome of the ATS valve prosthesis is quite satisfactory, And the hemodynamic characteristics are comparable, if not better, with other bileaflet prostheses.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.4
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• pp.180-195
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• 2011

A balanced trophic model for Sinjido marine ecosystem was constructed using ECOPATH model and data obtained 1994 in the region. The model integrates available information on biomass and food spectrum, and analyses ecosystem properties, dynamics of the main species populations and the key trophic pathways of the system, and then compares these results with those of other marine environments. The model comprises 17 groups of benthic algae, phytoplankton, zooplankton, gastropoda, polychaeta, bivalvia, echinodermata, crustacean, cephalopoda, goby, flatfish, rays and skates, croaker, blenny, conger, flatheads, and detritus. The model shows trophic levels of 1.0~4.0 from primary producers and detritus to top predator as flathead group. The model estimates total biomass(B) of 0.1 $kgWW/m^2$, total net primary production(PP) of 1.6 $kgWW/m^2/yr$, total system throughput(TST) of 3.4 $kgWW/m^2/yr$ and TST's components of consumption 7%, exports 43%, respiratory flows 4% and flows into detritus 46%. The model also calculates PP/TR of 0.012, PP/B of 0.015, omnivory index(OI) of 0.12, Fin's cycling index(FCI) of 0.7%, Fin's mean path length(MPL) of2.11, ascendancy(A) of 4.1 $kgWW/m^2/yr$ bits, development capacity(C) of 8.2 $kgWW/m^2/yr$ bits and A/C of 51%. In particular this study focuses the analysis of mixed trophic impacts and describes the indirect impact of a groupb upon another through mediating one based on 4 types. A large proportion of total export in TST means higher exchange rate in the study region than in semi enclosed basins, which seems by strong tidal currents along the channels between islands, called Sinjido, Choyakdo and Saengildo. Among ecosystem theory and cycling indices, B, TST, PP/TR, FCI, MPL and OI are shown low, indicating the system is not fully mature according to Odum's theory. Additionally, high A/C reveals the maximum capacity of the region is small. To sum up, the study region has high exports of trophic flow and low capacity to develop, and reaches a development stage in the moment. This is a pilot research applied to the Sinjido in terms of trophic flow and food web system such that it may be helpful for comparison and management of the ecosystem in the future.

• Journal of Oral Medicine and Pain
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• v.38 no.1
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• pp.19-28
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• 2013

With Korea's rapid entry to aged society, elderly population has become a major age group both in the whole society and medical field and its importance will be constantly stressed out. Elderly population is also important in the field of oral medicine which deals with chronic and recurrent diseases in the orofacial region of non-dental origin but there exist few studies indicating epidemiology of elderly patients in this regards. This study aimed to investigate change of age distribution of new patients in a university-based dental hospital and oral medicine clinic for last decade and to investigate clinical epidemiology of elderly patients (${\geq}$ 65 years) of oral medicine clinic. This study was performed retrospectively using medical records of the new patients in Dankook University Dental Hospital in 2001 and 2011. According to the study, percentage of elderly new patients increased in both dental hospital and oral medicine clinic and degree of the increase was greater in oral medicine clinic than in the whole hospital (p=0.000). 13.5% of adult patients ${\geq}$ 18 years of oral medicine clinic were elderly patients ${\geq}$ 65 years. 83% of elderly patients were suffering from one or more systemic diseases. Although TMD was the most common reason for elderly patients who visited oral medicine clinic, oral soft tissue diseases, dry mouth, burning mouth syndrome and oromandibular dystonia was more frequently diagnosed in elderly patients compared to adult patients aged 18 to 64 years. Pain severity and interference of Brief Pain Inventory and depression and anxiety scores of Hospital Anxiety Depression Scales were higher in elderly patients than in the adult patients (p<0.05). Increase of elderly patients with chronic oral diseases and pain needs more attention of dentists and specialists of oral medicine to improvement of assessment and development of tailored management because large portion of the elderly patients have systemic diseases, polypharmacy and impaired communication, possibly restricting treatment options.