전자의무기록의 기계학습 기반 익명화 기법

학위논문(석사) - 한국과학기술원 : 로봇공학학제전공, 2012.2, [ vi, 38 p. ]Electronic Medical Records (EMRs) enable the sharing of patient medical data whenever it is needed and also are used as a tool for building new medical technology and patient recommendation systems. Since EMRs include patients’ private data there exist restriction to researchers for access. Thus an anonymizing technique is necessary that keeps patients’ private data safe while undamaging useful medical information. Conventional research has been focusing on de-identification which can lead to unexpected privacy exposure issue. To prevent unexpected privacy exposure issues anonymization techniques based on k-anonymity has been previously introduced. k-member clustering anonymization is a technique that approaches the k-anonymization as a clustering issue. The objective of the k-member clustering problem is to gather (i.e. cluster) records that will minimize the data distortion during data generalization process. Most of the clustering techniques include random seed selection and iteration process to gather record that gives minimum information distortion. However, dealing with massive medical patient dataset, randomly selecting a cluster seed will provide inconsistent performance. This paper proposes a seed selection method based on closeness centrality which not only provides consistent information loss but at the same time reduces the information loss and execution time. We experimentally compare our algorithm with two previous studies. The experiments show that our algorithm provides better performance with respect to information loss.한국과학기술원 : 로봇공학학제전공

Enzymatic synthesis of ester0linked conjugates of amino acid and monosaccharide

In this study the enzymatic synthesis of ester-linked conjugates of amino acid and monosaccharide in pyridine was tested by the catalysis of Optimase M-440, an alkaline serine pretense. Optimase M-440 showed the higher activity in the reaction of monosaccharides which have one or more primary -OH groups. And also Optimase M-440 showed high regioselectivity; The transesterification of primary -OH group selectively occurred

테트라 부틸 암모늄 퍼옥시 디 술페이트를 이용한 키랄 비닐 술폭사이드의 비대칭 포르밀화 반응

학위논문(석사) - 한국과학기술원 : 화학과, 1997.2, [ iii, 47 p. ]Tetra-n-butylammonium peroxydisulfate [$(n-Bu_4N)_2S_2O_8$] has been successfully prepared and turned out to be a useful source of tetra-n-butylammonium sulfate radical in organic solvents. Various alkenes reacted with tetra-n- butylammonium peroxydisul fate in anhydrous 1,3-dioxolane to give one carbon homologated products which were typed as β-masked formylating form. Vinyl p-tolyl sulfoxides with the optically active center at the sulfur atom have been used successfully in various asymmetric syntheses. We have examined that the asymmetric addition of 1,3-dioxolane to various vinyl chiral sulfoxides using tetra-n-butylammonium peroxydisulfate. When (-) - (R) - (Z)- propenyl p-tolyl sulfoxide reacted with 1,3-dioxolane in the presence of tetra-n-butyl ammonium peroxydisulfate and Lewis acid, titanium we could obtain 1,3-dioxolanylated adduct with good diastereoselectivity.한국과학기술원 : 화학과