• Parasites, Hosts and Diseases
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• v.53 no.3
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• pp.355-359
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• 2015

Hydatid disease imposing serious threat on human health and great loss in live-stock pastoralism remains a major public health problem in western China. To assess and monitor the effect of control program on transmission dynamics, we used the prevalence of cystic echinococcosis in slaughtered sheep at slaughterhouse as an indicator during the period of 2007 to 2013 in Emin County, Xinjiang Uygur Autonomous Region, China. The results showed a significant decline trend of prevalence in all age groups during the 7 years when the control program was implemented; particularly, the rate was reduced by 72% after first 3 years. Among the sheep slaughtered, the age distribution evidenced that the prevalence increased significantly as the sheep grew older. The baseline data indicated that the rate was 4.5% at the age <1, 6.7% at age 2~, and reached to the highest 17.9% at age ${\geq}4$ years. Earlier response to the intervention pressure was seen in the sheep at the younger age. Significant decline started from 2008 at the age <1, from 2009 at age of 1~, 2010 at 2~ to 3~, and the latest, in 2012 at age ${\geq}4$. This study demonstrated that the prevalence of cystic echinococcosis in slaughtered sheep may be used as an indicator to assess and monitor the transmission status during and after control program providing information for betterment of performance to sustain control strength.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.75-76
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• 2006

LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LCP (Light Guide Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50{\sim}200{\mu}m$ in diameter on it by erosion method. But the surface of the erosion dots of LGP is very rough due to the characteristics of the erosion process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current dot patterned LGP, optical pattern design with $50{\mu}m$ micro-lens was applied in the present study. Especially, the negative and positive micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different pattern conditions to the brightness distribution of BLU with micro-lens patterned LGP. Finally, negative micro-lens patterned LGP showed superior results to the one made by positive in average luminance.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.39-45
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• 2010

Quantification of carbon absorption and understanding the human induced land use changes (LUC) forms one of the major study with respect to global climatic changes. An attempt study has been made to quantify the carbon absorption by LUC through remote sensing technology. The Landsat imagery four time periods was classified with the hybrid classification method in order to quantify carbon absorption by LUC. Thereafter, for estimating the amount of carbon absorption, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated with the crown width extracted from digital forest cover type map. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the IPCC guideline, was used to convert the stand biomass into the amount of carbon absorption. Total carbon absorption has been modeled by taking areal estimates of LUC of four time periods and carbon factors for land use type and standing biomass. Results of this study, through LUC suggests that over a period of construction, 7.10 % of forest and 9.43 % of barren were converted into urban. In the conversion process, there has been a loss of 6.66 t/ha/y (7.94 %) of carbon absorption from the study area.

• Korean Journal of Optics and Photonics
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• v.9 no.2
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• pp.63-69
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• 1998

For detailed characterization of scattering losses occurring in VCSEL's distributed Bragg reflectors, we performed scattering experiment and obtained the information about surface roughness through the analysis of a modified transmission matrix method. The various wafers grown for VCSELs were used for the scattering experiment. The fractal surface assumption and extrapolation is used to estimate the scattered intensity near specular angle. The modified transmission matrix method employed in the analysis considers the scattering loss at each interface and calculates the reflectivity efficiently and easily. As a result, the surface roughness ranges from $4{\AA}$ to $10{\AA}$ The reduction of reflectivity due to the scattering amounts to 0.26% in case of $10{\AA}$ roughness.

• Journal of Preventive Medicine and Public Health
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• v.27 no.2 s.46
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• pp.299-312
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• 1994

This survey was performed to obtain the basic information for the prevention and management of occupational low back injury (LBI). The subjects of this survey were 952 workers (male, 892 ; female, 60) who had taken occupational LBI in some industries of Pusan area from January 1 to December 31, 1991. Observation period was 2.6 years from the beginning to the end of medical treatment. The obtained results were summarized as follows ; 1. The proportion of LBI workers was 15.9% of the workers who had taken any occpational injuries and 0.32% of all workers in this surveyed area. 2. 8.0% of the workers had taken LBI on the 1st day of employment and 55.2% of the workers were within one year, 91.4% of the workers were within 10 years according to cumulative frequency distribution. 3. Handling of heavy objects was the most common cause of LBI (32.0%) and fall down (26.9%) and slip down (16.3%) were the next in order. 4. The most common causes of both lumbar sprain and HNP were handling of heavy objects and that of lumbar fracture was fall down. 5. The mean duration for medical treatment of LBI workers was 143 days. 6. The total direct compensation cost for LBI workers was 6,736 million Won and the proportion of medical, resting, disability compensation costs were 25.0%, 37.0%, 38.0 % respectively. 7. The percentages of retreated workers and disabled workers were 11.9% (113 persons) and 22.9% (218 persons) of total LBI workers respectively.

• Tribology and Lubricants
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• v.23 no.5
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• pp.201-206
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• 2007

The bent-axis type piston pump which is driven by the piston rod works on the way that the piston rod drives the cylinder block, so the taper angle of the piston rod and the swivel angle between the cylinder block and the shaft are very important design factors. If the above factors cannot satisfy the conditions of optimum design, the friction loss between the cylinder bore and the piston increases, and the pump can even fail to work under conditions of severe friction and wear. Since the piston reciprocates in the cylinder bore with high velocity, and at the same time it rotates on its own axis and revolves on the center of the cylinder block, the decrease of the volume efficiency generated on account of the leakage between the cylinder bore and the piston. Therefore, to prevent this case, the piston ring is designed at the end of the piston, and the friction characteristics between the piston ring and the cylinder bore are in need of research due to its great influence on the performance of piston pump. Thus, in this paper, the elastic hydraulic oil's lubrication analyses of the film thickness, the pressure distribution, and the friction force, and so on, have been performed, and the lubrication characteristics between the piston ring and the cylinder bore are explored by the results of the numerical analysis, and it is contributed to realize the higher efficiency and the more advanced performance of the bent-axis type piston pump.

• Parasites, Hosts and Diseases
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• v.35 no.3
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• pp.181-188
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• 1997

In order to clarify the effect of cryptosporidiosis on immune response, histopathological changes associated with experimentally occurring bursal cryptosporidiosis in chickens were chronologically observed as the first step. A total of 150 2-day-old chickens was each inoculated orally with a single dose of 5 × 105 Cryptospori,mum bailevi oocysts. The chickens showed a normal profile of oocyst shedding in droppings. The bursa indices throughout the experimental period indicated negligible reactions. Numerous cryptosporidia occurred in the microvillous border of bursal epithelium between days 4 and 16 postinoculation (PI). Appearance of the most mast cells was followed by a dramatic loss of the protozoa in the bursa of Fabricius (BF). The distribution of the coccidium coincided with heterophil infiltration in the epithelium and adjacent lamina propria. The histopathological lesion was marked diffuse chronic superficial purulent bursitis with heterophil infiltration in the epithelium and adjacent lamina proprla and mucosal epithelial hyperplasia. These results suggest that the bursitis may induce immunosuppressive effect.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.77-85
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• 2000

Simulation of local external forcing and its response in the rotation table experiment has been investigated. Spatially-uniform external forcings have been applied in many experimental studies, however, based on the fact that the north-south distribution of the wind-stress curl and the existence of local maximum of the sea surface heat loss in the northern part of the East Sea, new method of combined effects of local forcings has been employed in separate experiments. Carefully designed local source or sink at the bottom of the cylindrical container can produce horizontal pressure gradient within the Ekman layer, and consequently the interior also attains the same pressure gradient that produces geostrophic interior circulation. In order to keep free surface during the local-surface cooling, a side-wall cooling method is suggested. For the various type of local forcing including the effects local cooling and the periodic change of local wind-stress curl, western-boundary flow in terms of its strength, position of separation from the boundary have been observed.

• 한국해양학회지
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• v.21 no.4
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• pp.193-202
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• 1986

Spatio-temporal variabilities of seawater temperature at 0 and 30m in the southeastern Hwanghae were studied by variance and empirical orthogonal function(EOF) analysis of long records of temperature between 1967 and 1982. The spatial distribution of monthly mean sea surface temperature has a pattern similar to the long-term annual mean which decreases from south to north. On the contrary, the total variance computed from the annual mean of sea surface temperature(SST) increases from south to north. The variance of SST is found to be two times greater than that at 30m in the study area except coastal area south of Kyunggi Bay. The important variance of temperature seem s to be closely associated with the seasonal change of temperature because the first and second modes of EOF having a seasonal cycle explain 97.6% and 85.2% of variances at 0 and 30m, respectively. There is a large difference in temperature between the northern and southern parts of the study area during winter, while the difference becomes very small during summer. This might reflect that in summer the heat gain of sea surface from the incoming radiation is much more important than the heat loss or the oceanic heat advection. In summer coastal waters south of the Kyunggi Bay and around Mokpo are observed to be colder than offshore waters due to tidal mixing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.92-97
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• 2005

A series of combustion test was done to verify the optimization result of a gas generator for a 10 ton thrust liquid rocket engine. An injector element is F-O-F impinging type injector and the test was conducted with kerosene/LOX propellants. Test results of combustion temperature and pressure show a very good agreement with optimal design result and verify that the design method was properly established. And turbulence ring revealed its effectiveness in enhancing combustion gas mixing and temperature difference in the radial direction showed only less than 15K. Also turbulence ring induced only 3.2% pressure loss in the combustion chamber, which is far less than conventional level observed in a gas turbine engine. Axial temperature distribution also shows that turbulence ring could effectively reduce about 10% or more in gas generator length if its location is properly selected.