• Journal of Yeungnam Medical Science
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• v.32 no.2
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• pp.80-84
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• 2015

Background: Rotavirus is the most common cause of severe gastroenteritis in children <5 years of age. The first vaccine, RotaShield was developed, but withdrawn because of its association with increased risk of intussusception. Then, RotaTeq and Rotarix were developed. Although in pre-licensure studies, they were not associated with an increased risk of intussusceptions, in recent studies, it has been controversial. Regarding increased risk of intussusception, we studied the difference in the age of intussusception after rotavirus vaccination. Methods: A retrospective analysis was conducted on 136 patients diagnosed with intussusception at Yeungnam University Medical Center for 4 years in the pre-vaccination period (group A) and in the post vaccination period (group B). Sex, mean age and age distribution of intussusceptions were compared according to the type of rotavirus vaccine (group B-1, RotaTeq; group B-2, Rotarix). Results: The median ages of group A and group B were $18.8{\pm}19.6months$ and $15.5{\pm}10.2months$, with no significant differences (p=0.23). The median ages of group B-1 and group B-2 were $15.3{\pm}9.3months$ and $15.6{\pm}10.8months$, with no significant differences (p=0.91). And No significant difference in the distribution of onset age was observed between groups, and only 6 patients were diagnosed with intussusceptions within 1 month after vaccination. Conclusion: No difference was observed in the distribution of onset age of intussusception after rotavirus vaccination and according to the type of rotavirus vaccine. Our study has a limitation in that it was conducted in part of the Daegu area. Additional study is needed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.5
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• pp.323-330
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• 2005

Monthly distributions of fishing boats at night in the East Sea are described, using defense meteorological satellite program (DMSP)/operational linescan system (OLS) images and common squid (Todarodes pacificus) catches data. We also estimated temperature in 50m, which is main catch depth of the squid, by MCSST (multi-channel sea surface temperature). We examined DMSP/OLS, MCSST and other observation data from 1993 to 2000. We assumed that squid were caught in areas where fishing boats were located. Fishing boats at night appeared only near the Korea/Tsushima Strait from January to March. Fishing boats moved to the northward from April to Jun, distribution of fishing boats in spring appeared greater than those in winter. In summer (July-September), center of fishing grounds was formed near the Uleung Island in the south east coast of Korea. The north-south distribution range of fishing boats in October appeared to be greater than that in other months. In particular, we estimated main season of squid catches based on distribution range reflecting the number of fishing boats of north-south and east-west directions from September to December. Relationship between satellite estimate SST and in situ SST showed high correlation (0.91). The correlation between the SST and 50m depth temperature, estimated based on the satellite SST, was relatively high in February, April and October.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.103-111
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• 2017

In this study, we estimate the NNI(Nearest Neighbor Index) which is considered altitude of rain gauge network as a method for evaluating appropriateness of spatial distribution and the current rain gauge network is evaluated. The altitude is divided by equal-area-ratio and optimal NNI within given basin condition is estimated using harmony search method for considering geographical conditions that vary from altitude to altitude. After calculating current state and optimal NNI for each altitude, the distribution of the rain gauge network is evaluated based on the difference between the two NNIs. As a result, it founds that the density of rain gauge networks is relatively thin as the altitude increases. Furthermore, it will be possible to construct an efficient rain gauge network if the characteristics of different altitudes are considered when a new rain gauge network is newly constructed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.73-78
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• 2010

In this paper, the analysis of the harmonics of distribution power system interconnected with DG(distributed generation) is simulated by using PSCAD/EMTDC and evaluated the harmonics. The modeling system for simulation is similar to the actual distribution system, and solar power system. The simulation analyses are performed at connection points for each sector. Harmonic standards of interconnection with DG (IEEE Std 1547 and IEEE Std 519) are applied to the evaluation algorithm, converted the simulated data through FFT method, evaluated by THD and TDD separately. The harmonic contents in the case of without DG and each sector with DG are evaluated and compared. The results of evaluation showed the effect that the harmonic contents are appropriated at all sector with DG (without DG) in the distribution power systems but the large induction motor(50KW) is increased the harmonic contents.

• Ocean and Polar Research
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• v.30 no.2
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• pp.181-191
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• 2008

This study aims at assessment of spatio-temporal distribution of demersal fish aggregations near the west coast of Jeju Island using hydroacoustic survey. A 200 kHz split beam transducer attached to a small towed body was used for all acoustic investigations. The received acoustic data were in situ acoustic target strength (TS, dB) for all pings and nautical area scattering coefficient(NASC, $m^2/mile^2$) for 0.1 mile along 12 acoustic transects. Demersal fish aggregations are distributed around the coastal slope having 20 to 30 m depth throughout all seasons. The concentration is higher during the summer season. With regard spatial distribution, higher demersal fish aggregations have been detected near the West coast of Shinchang and especially near Chagwi-do. Pelagic fish aggregations were higher to the south of Chagwi-do during the spring season. Additionally, standing stock of demersal fish aggregations from the NASC data, TS function, and length-weight function of dominant species was estimated as follows: 3.2 ton (CV 21.8%) in December 2006, 17.9 ton (CV 21.6%) in April 2007, 30.8 ton (CV 17.8%) in June 2007, and 22.5 ton (CV 24.2%) in October 2007. The application of hydroacoustic methods offers a new approach to understanding spatiotemporal structure and estimate the biomass of demersal fish aggregations in the coastal area. And the results can be made up limitations of qualitative analysis through net and diving for fisheries resources survey in coastal area.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.87-96
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• 2007

In this paper a methodology of identifying individual pipes according to the internal and external characteristics of pipe is developed, and the methodology is applied to a case study water distribution pipe break database. Using the newly defined individual pipes the hazard rates of the cast iron 6 inch pipes are modeled by implementing the proportional hazards modeling approach for consecutive pipe failures. The covariates to be considered in the modeling procedures are selected by considering the general availability of the data and the practical applicability of the modeling results. The individual cast iron 6 inch pipes are categorized into seven ordered survival time groups according to the total number of breaks recorded in a pipe to construct distinct proportional hazard model (PHM) for each survival time group (STG). The modeling results show that all of the PHMs have the hazard rate forms of the Weibull distribution. In addition, the estimated baseline survivor functions show that the survival probabilities of the STGs generally decrease as the number of break increases. It is found that STG I has an increasing hazard rate whereas the other STGs have decreasing hazard rates. Regarding the first failure the hazard ratio of spun-rigid and spun-flex cast iron pipes to pit cast iron pipes is estimated as 1.8 and 6.3, respectively. For the second or more failures the relative effects of pipe material/joint type on failure were not conclusive. The degree of land development affected pipe failure for STGs I, II, and V, and the average hazard ratio was estimated as 1.8. The effects of length on failure decreased as more breaks occur and the population in a GRID affected the hazard rate of the first pipe failure.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.1
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• pp.30-37
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• 2016

Objectives: This study was performed to measure and evaluate the concentration, size distribution and fugitive emission of particulate matter from process operations at foundries. Methods: Particle matter was collected from three foundries, and samples were also collected from a background site for calculating the fugitive emission concentration of the foundries. For the collection of the samples, a Nanosampler cascade impactor was used. Results: The concentration of TSP in the samples collected from the three foundries was $0.675{\sim}1.222mg/m^3$, $PM_{10}$ was $0.525{\sim}1.018mg/m^3$ and $PM_{2.5}$ was $0.192{\sim}0.615mg/m^3$. The mass size distribution was bimodal or monomodal with maximum peak at two stage(size $2.5{\sim}10{\mu}m$). The mass median aerodynamic diameter(MMAD) was $1.80{\sim}3.98{\mu}m$. The fugitive emission concentration of TSP varies in the range of 0.65 to $1.21mg/m^3$, which exceeds the emission standard of fugitive dust($0.5mg/m^3$). Conclusions: Particle concentration and size is an important industrial hygiene factor to protect foundry workers. Furthermore, the presence of high emission of particulate pollutants has a significant negative impact on the ambient air of the study area. Therefore, it is important to improve both the process and prevention facility in oder to reduce particulate pollutants in foundries.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.4
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• pp.313-326
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• 2007

With rising prevalency of mouth breathing children caused by developing civilization and increasing pollution, there are many maxillary transverse discrepancy patients with undergrowth of maxilla. For improving this, maxillary mid-palatal suture splitting was often performed. The purpose of this study was to analyse the stress distribution on the craniofacial suture and cranium after rapid maxillary expansion by finite element model. The boy(13Y6M) was chosen for taking computed-tomography for finite element model. Three-dimensional model of maxilla, first premolar, first molar, buccal and lingual part of rapid maxillary expansion were constructed. 1. The alveolar bone adjacent to the first molar and the first premolar that was affected directly by rapid maxillary expansion was displaced laterally approximately 4.04mm at maximum. The force decreased toward anterior region and frontal alveolar bone displaced laterally about 3.18mm. 2. A forward maximum displacement was exhibited at zygomatic process middle region. 3. At maximum, maxillary median part experienced 0.973mm downward repositioning and 0.65mm upward repositioning at lateral alveolar bone. 4. Von mises stress was observed the largest stress distribution around teeth and zygomatic buttress. 5. The largest tensile force was observed around alveolar bone of teeth, while compression force was observed at zygomatic buttress.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.283-292
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• 1998

The community dynamics and distribution of dinoflagellates and their cysts were monitored monthly from June 1996 to May 1997 at six stations in Masan-Chinhae Bay, one of the famous bays for red-tide occurrence in Korea. The dinoflagellate standing crops ranged from the minimum of 306 cells $ml^{-1}$ in February to the maximum of 37,959 cells $ml^{-1}$ in May. The species causing massive blooms were Prorocentrum micans Ehrenberg and Ceratium furca (Ehrenberg) Claparede & Lachmann in July, Gymnodinium sanguineum Hirasaka in October, Alexandrium tamarense (Lebour) Balech in April and Proroeentrum minimum (Pavillard) Schiller in May. Twenty-seven taxa of dinoflagellate cysts were isolated, including 20 identified species and 7 unidentified species. The mean cyst abundance ranged from the minimum of 556 cysts $cm^{-3}$ in June to the maximum of 5,727 cysts$cm^{-3}$ in February. The spatial pattern of cyst distribution showed the gradual increase in abundance from offshore to inshore stations. The cyst genera of Protoperidinium, Gymnodinium, Serippsiella, Gyrodinium and Alexandrium were abundant throughout the year. The vertical distribution of cysts showed the surface miximum at the 0-2cm layer and the sub-surface maximum at the 2-4cm layer. Total abundance of cysts showed the most significant relationships with water temperature, and some minor relationship with dissolved oxygen, salinity, pH, phosphate and total inorganic nitrogen of surface and bottom layer in the water column. The number of dinoflagellate species decreased, while the abundance of cysts increased 4.5 times as compared with the observation of 10 years prior to the present study at the same stations of Masan-Chinhae Bay.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.181-185
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• 2005

Mast cell distribution was quantified in acidified toluidine blue sections of normal skin from 8 different sites in 10 dogs and compared to the predilection sites of canine atopic dermatitis. Mast cell counts varied significantly from site to site (p<0.0001) and counts in the superficial dennis were significantly higher than the deeper dennis (p<0.05). The highest mast cells distribution sites were the concave surface of the ear (mean $74.88{\pm}17.93\;per\;mm^{2}$) and the interdigital skin of the forefeet (mean $28.326{\pm}6.24\;per\;mm^{2}$). Counts in these sites were $280\%$ higher than all the other sites. Our results may provide some evidence that cutaneous mast cell distribution may be a factor in the frequent occurrence of ear and foot pruritus in atopic dermatitis. However, the low mast cell count in the predilection sites of atopic dermatitis did not explain the common occurrence of atopic lesions. Therefore, other factors or more complicated pathogenesis may be correlated with these predilection sites.