• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.95-99
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• 2001

Giardia lamblia is a parasitic protozoa which is transmitted in the form of a cyst through untreated water and also treated drinking water. Since its presence in water has led to frequent outbreaks of giardiasis and death in many countries, the removal and disinfection of this protozoan cyst from the water supply are of great concern for public health. This study examined the disinfection characteristics of G. lamblia cysts isolated from a Korean patient with giardiasis. When using sodium hypochlorite including 5 or 10 ppm chlorine, the killing rate was initially rapid, however, the disinfection slowed down and a 3log reduction could not be achieved even after 2h. The disinfection effectiveness was also reduced at a lower temperature, thereby implying that the risk o a giardiasis outbreak will be higher in the winter season. A CT (concentration$.$time) curve was constructed based on the results with sodium hypochlorite for use in designing and predicting disinfection performance. The organic chlorination disinfectant SDIS (sodium dichloroisocyanurate) produced a lower pH and a much higher residual effect than sodium hypochlorite. The disinfection of cysts by SDIC continued steadily throughout 2h of contact, although the initial killing rate was lower than that with sodium hypochlorite.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.409-429
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• 1997

Problems encountered during software development or pteration nay result from defects in the software,ghrdware,or their oterations.Because of their diversity,the determination of the sources of a problem and its corrective adtion requires a centrally controlled system for monitoring provlems and detemining systematiccauses. In the paper,the SPR/SCR management system was developed and applied for the collection and analysis of the error data,process data and product data delected by each phasd in SDLC.There are four objectibes in the SPR/SCR management system.The first is to assure that software errors are documented,corrected,and vot forgottem. The second is to assure that SPR.are assessed for their validity.The third is to provide feedback on SPR status to the developer and the user.The fourth is ot prvide data for measuring and prediciting sofware quality and reliability.These goals could be satisfied by the application of the SPR/SCR mangement system.Also,the accomplishment rate of software reliability,criterion of test completion,estimation of release time, efficient development and management can be reflected by applying the SPR/SCR management system.