블록체인 환경에서 EID를 이용한 사용자 통합 인증 시스템

김재용(Jai-Yong Kim),정용훈(Yong-Hoon Jung),전문석(Moon-Seog Jun),이상범(Sang-Beon Lee) 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.3

기존의 컴퓨팅 환경에서 사용되는 중앙 집중형 시스템은 해킹에 의한 개인정보 침해 사례와 시스템 장애 발생시 가용성 침해 문제 등의 다양한 문제점을 가지고 있다. 현재 신뢰받는 차세대 융합 정보 핵심 기술 중 하나인 블록체인은 다양한 문제점을 가지고 있던 기존의 중앙 집중형 시스템의 대안 기술로 기대 되고 있으며, 블록체인 환경에 맞는 사용자 인증 시스템의 필요성이 증가 하고 있다. 본 논문은 온라인 환경에서 EID를 이용하여 사용자 식별이 가능한 블록체인 기반의 사용자 통합 인증 시스템을 제안한다. 기존 ID/PW 인증 방식은 사용자가 여러 사이트에 개인정보를 저장하고 각각의 ID를 발급 받아 사용해야 한다. 그러나 제안하는 시스템은 EID 발급 후 여러 사이트에서 회원가입 없이 사용이 가능하다. 제안 시스템은 이메일 및 전화번호 등 최소한의 정보로 EID를 발급한다. 기존 중앙 집중형 시스템과 제안하는 통합 인증 시스템의 안정성과 효율성을 비교하여 우수함을 입증하였다. 컴퓨팅 환경에서 발생하는 공격방법과 침해요소를 선택하여 기존 시스템과의 안정성을 비교 하였다. 또한 효율성의 검증을 위하여 인증과정에서 발생하는 사용자의 App, 발행 및 인증기관의 서버, 서비스 제공기관 서버 사이의 총 처리량을 트랜잭션 당 처리시간으로 비교 분석하였다. Centralized systems in computing environments have various problems, such as privacy infringement due to hacking, and the possibility of privacy violations in case of system failure. Blockchain, one of the core technologies for the next generation of converged information, is expected to be an alternative to the existing centralized system, which has had various problems. This paper proposes a blockchain-based user authentication system that can identify users using EID in an online environment. Existing identification (ID)/password (PW) authentication methods require users to store personal information in multiple sites, and receive and use their respective IDs. However, the proposed system can be used without users signing up at various sites after the issuing of an EID. The proposed system issues an EID with a minimum of information, such as an e-mail address and a telephone number. By comparing the stability and efficiency of a centralized system, the proposed integrated authentication system proved to be excellent. In order to compare stability against existing systems, we chose attack methods and encroachments on the computing environment. To verify efficiency, the total throughput between the user"s app, the issuance and certification-authority"s servers, and the service provider"s servers was compared and analyzed based on processing time per transaction.

골전도 스피커의 성능향상을 위한 전자기력 예측과 Monte Carlo Simulation에 의한 성능 분포에 대한 고찰

이재혁(Jai Hyuk Lee),허덕재(Deog Jae Hur),고동신(Dong Shin Ko),김재용(Jae Yong Kim) 한국소음진동공학회 2015 한국소음진동공학회 학술대회논문집 Vol.2015 No.10

This study is about the probabilistic characteristics of electromagnetic force of bone conduction speaker, which is applied to the smart glass, a smart wearable device. There is a variety of design parameters related to improve the bone conduction speaker performance. In this paper, the factors which improve the electromagnetic force were selected plate thickness, magnet height and coil turn. To consider the effect of these factors on electromagnetic force improvement, this paper has studied both an independent analysis by a single variable and characteristics of the multi variable. Factors for multiple variables were analyzed by applying a full factorial design of experiment. In addition, the Monte Carlo Simulation was used for the prediction of the electromagnetic force for distribution of the physical design parameters, and the prediction equation was used by creating a nonlinear regression. A significance analysis of the independence and interaction factors was conducted in F-test, and it was found three independent variables and one interaction effect to be valid. It was able to satisfy the design target value in the analysis of the reliability over 99%, and the distribution was obtained in a standard deviation of 0.003 and a mean value of 0.057, which is increased 18.8% from the design target value. It is suggested to be able to verify the impact on performance if utilizing this statistical analysis method in design step, and to be able to make a reliable verification of the prediction result accordingly.

만성질환 관리 평가도구를 이용한 보건소 만성질환 관리수준 평가

최용준 ( Yong Jun Choi ),신동수 ( Dong Soo Shin ),강민아 ( Min Ah Kang ),배상수 ( Sang Soo Bae ),김재용 ( Jai Yong Kim ) 한국보건행정학회 2014 보건행정학회지 Vol.24 No.4

Background: To evaluate the quality of chronic care provided by public health centers located in a South Korean metropolitan city using a modified Assessment of Chronic Illness Care (ACIC). Methods: We conducted self-evaluation surveys and collected data using a modified ACIC from twenty five public health centers. Cultural validity of the original ACIC was examined by the public health and nursing science experts. Based on expert reviews, cog-nitive interviews, pre-test results, five items of the original ACIC that were not relevant were deleted. The response scale was changed from twelve-point Likert scale to Guttman scale but its scoring system was maintained. Results: Eighty eight percent of public health centers in this study reported that their overall quality of chronic care was at a limited or basic level. About 68% of the centers reported that the organization was as reasonably good or fully developed to provide chronic care. On the other hand, 96% of the public health centers reported that the clinical information system was at a very limited or basic support level. The decision support, the integration of Chronic Care Model components, the delivery system design, the community linkages, and the self-management support were evaluated as limited or basic level of support by more than half of the public health centers, respectively. Conclusion: In a metropolitan area of South Korea, quality of chronic care in public health centers was not found to reach accept-able levels of services. It is critical to enhance the quality of chronic care in public health centers.

중년 남성에서 혈압과 관련한 허리-엉덩이 둘레비 산출

김대성,김재용,안윤옥,배종면,Kim, Dae-Sung,Kim, Jai-Yong,Ahn, Yoon-Ok,Bae, Jong-Myon 대한예방의학회 1999 Journal of Preventive Medicine and Public Health Vol.32 No.3

Backgroud: Excess abdominal fat, expressed as an increased ratio of waist to hip circumferences (WHR), is independently associated with higher levels of blood pressure. Although a WHR greater than 1.0 in men has been shown to predict complications from obesity, the WHR has not been evaluated in all ethnic groups. Methods: In order to ascertain the association between WHR and classification of blood pressure and to investigate the critical value of WHR as a predictive factor of hypertension in Korean middle-aged men, we compared the mean of WHRs according to the classification of blood pressure in Seoul Cohort participants. Results: Through a surrey of direct measurement of waist and hip girth, 452 subjects were recruited from the cohort. The mean of WHR was 0.88 and its standard deviation was 0.04. The mean of WHRs was higher in the systolic blood pressure group (above 140 mmHg), diastolic blood pressure group (above 90 mmHg), and hypertension group than in the systolic blood pressure group (below 140 mmHg), diastolic blood pressure group (below 90 mmHg), and normotensive group, respectively. And WHR of above 0.89 was associated with hypertension (z-value =6.66). Conclusion: It is necessary for Korean males with WHR greater than 0.89 to recommend the primary prevention and early defection of hypertension.

우리나라 당뇨병의 역학적 규모와 당뇨병 관리현황 파악을 위한 표본설계의 평가

이지성,김재용,백세현,박이병,이준영,Lee, Ji-Sung,Kim, Jai-Yong,Baik, Sei-Hyun,Park, Ie-Byung,Lee, June-Young 대한예방의학회 2009 예방의학회지 Vol.42 No.2

Objectives : An appropriate sampling strategy for estimating an epidemiologic volume of diabetes has been evaluated through a simulation. Methods : We analyzed about 250 million medical insurance claims data submitted to the Health Insurance Review & Assessment Service with diabetes as principal or subsequent diagnoses, more than or equal to once per year, in 2003. The database was re-constructed to a 'patient-hospital profile' that had 3,676,164 cases, and then to a 'patient profile' that consisted of 2,412,082 observations. The patient profile data was then used to test the validity of a proposed sampling frame and methods of sampling to develop diabetic-related epidemiologic indices. Results : Simulation study showed that a use of a stratified two-stage cluster sampling design with a total sample size of 4,000 will provide an estimate of 57.04%(95% prediction range, 49.83 - 64.24%) for a treatment prescription rate of diabetes. The proposed sampling design consists, at first, stratifying the area of the nation into "metropolitan/city/county" and the types of hospital into "tertiary/secondary/primary/clinic" with a proportion of 5:10:10:75. Hospitals were then randomly selected within the strata as a primary sampling unit, followed by a random selection of patients within the hospitals as a secondly sampling unit. The difference between the estimate and the parameter value was projected to be less than 0.3%. Conclusions : The sampling scheme proposed will be applied to a subsequent nationwide field survey not only for estimating the epidemiologic volume of diabetes but also for assessing the present status of nationwide diabetes control.

서울지역 대기오염이 천식에 미치는 급성영향: 연구대상의 특성에 따른 비교

김선영,김재용,김호,Kim, Sun-Young,Kim, Jai-Yong,Kim, Ho 대한예방의학회 2006 예방의학회지 Vol.39 No.4

Objectives: Korean epidemiological studies have used reduced samples according to the subject's characteristics, such as the health services provided, the historical note with asthma, and age, to examine the acute effect of air pollution on asthma using the Korean National Health Insurance records. However, there have been few studies on whether the effects shown in these reduced samples are different from those of all samples. This study compared the effects of air pollution on asthma attacks in three reduced samples with those of entire samples. Methods: The air pollution data for $PM_{10},\;CO,\;SO_2,\;NO_2,\;and\;O_3$, and weather conditions including temperature, relative humidity, and air pressure in Seoul, 2002, were obtained from outdoor monitoring stations in Seoul. The emergency hospital visits with an asthma attack in Seoul, 2002 were extracted from the Korean National Health Insurance records. From these, the reduced samples were created by health service, historical notes with asthma, and age. A case-crossover design was adopted and the acute effects of air pollution on asthma were estimated after adjusting for weather, time trend, and seasonality. The model was applied to each reduced sample and the entire sample. Results: With respect to the health service, the effects on outpatients were similar to those for the total sample but were different for inpatients. These similar effect sizes were also observed in the reduced samples according to the historical note with asthma and age. The relative risks of $PM_{10},\;CO,\;SO_2,\;NO_2,\;and\;O_3$, among the reduced and entire samples were 1.03, 1.04-1.05, 1.02-1.03, 1.04-1.06, and 1.10-1.17, respectively. Conclusions: There was no clear evidence to show a difference between the reduced samples and the entire samples.

수돗물 불소화와 노령 인구의 고관절 골절에 대한 생태학적 연구

박은영,황승식,김재용,조수헌,Park, Eun-Young,Hwang, Seung-Sik,Kim, Jai-Yong,Cho, Soo-Hun 대한예방의학회 2008 예방의학회지 Vol.41 No.3

Objectives : Fluoridation of drinking water is known to decrease dental caries, particularly in children. However, the effects of fluoridated water on bone over several decades are still in controversy. To assess the risk of hip fracture related to water fluoridation, we evaluated the hip fracture-related hospitalizations of the elderly between a fluoridated city and non-fluoridated cities in Korea. Methods : Cheongju as a fluoridated area and Chungju, Chuncheon, Suwon, Wonju as non-fluoridated areas were chosen for the study. We established a database of hip fracture hospitalization episode based on the claims data submitted to the Health Insurance Review Agency from January 1995 to December 2002. The hip fracture hospitalization episodes that satisfied the conditions were those that occurred in patients over 65 years old, the injuries had a hip fracture code (ICD-9 820, ICD-10 S72) and the patients were hospitalized for at least 7days. A total of 80,558 cases of hip fracture hospitalization episodes were analyzed. Results : The admission rates for hip fracture increased with the age of the men and women in both a fluoridated city and the non-fluoridated cities (p<0.01). The relative risk of hip fracture increased significantly both for men and women as their age increased. However, any difference in the hip fracture admission rates was not consistently observed between the fluoridated city and the non-fluoridated cities. Conclusions : We cannot conclude that fluoridation of drinking water increases the risk of hip fracture in the elderly.

장애보정손실연수 ( DALY ) 를 이용한 우리나라 주요 심혈관계 질환의 질병부담 측정

이태진(Tae Jin Lee),김재용(Jai Yong Kim),성주헌(Joo Hon Sung) 한국보건경제정책학회(구 한국보건경제학회) 2002 보건경제와 정책연구 Vol.8 No.1

우리나라 성인 2형 당뇨환자의 외래진료 지속성과 관련요인 분석

홍재석 ( Jae Seok Hong ),김재용 ( Jai Yong Kim ),강희정 ( Hee Chung Kang ) 한국보건행정학회 2009 보건행정학회지 Vol.19 No.2

Background: Previous studies have reported that enhanced continuity of care prevented a sudden worsening in progress among chronic disease patients, and as a result was favorable for efficient spending of health care funds. This study aims to estimate the continuity of care of Korean with diabetes and to identify factors affecting the continuity of care. Methods: This study used the Korean National Health Insurance Claims Database which includes E11 (ICD-10) as a primary or secondary disease as of 2006. Study population is 1,160,725 type 2 diabetics (20-84 years). Continuity of Care Index (COC), Modified, Modified Continuity Index (MMCI), and Most Frequent Provider Continuity (MFPC) were used as indexes of continuity of care. Results: The continuity of care in the study population was 0.94±0.10 as calculated by MMCI, 0.91±0.16 as calculated by MFPC and 0.86±0.23 as calculated by COC. The lower continuity of care was shown in the patients who were female, 65 and over years old, Medical Aid recipients, 13 times or more visitors, hospital users as main attending medical institution, patients experienced hospitalizations or comorbidities. Conclusion: The continuity of care for adult patients with type 2 diabetes was high in Korea, and showed variation according to patients` characteristics. This result provides empirical evidence for policymakers to develop or strengthen programs for managing patients showing low continuity of care.

우리나라 손상의 사회경제적 비용

박건희,이진석,김윤,김용익,김재용,Park, Kun-Hee,Lee, Jin-Seok,Kim, Yoon,Kim, Yong-Ik,Kim, Jai-Yong 대한예방의학회 2009 예방의학회지 Vol.42 No.1

Objectives : This study was conducted to estimate the socioeconomic cost of injuries in South Korea. Methods : We matched claims data from national health insurance, automobile insurance and industrial accident compensation insurance(IACI), and mortality data obtained from the national statistical office from 2001 to 2003 by patients unique identifier. Socioeconomic cost included both direct cost and indirect cost: the direct cost was injury-related medical expenditure and the indirect cost included loss of productivity due to healthcare utilization and premature death. Results : The socioeconomic cost of injuries in Korea was approximately 1.9% of the GDP from 2001 to 2003. That is, 12.1 trillion KRW(Korean Won) in 2001, 12.3 trillion KRW in 2002, and 13.7 trillion KRW in 2003. In 2003, direct medical costs were 24.6%(3.4 trillion KRW), the costs for loss of productivity by healthcare utilization were 13.0%(1.8 trillion KRW), and the costs for loss of productivity by premature death were 62.4%(8.6 trillion KRW). Conclusions : In this study, the socioeconomic cost of injuries in Korea between 2001 and 2003 was estimated by using not only health insurance claims data, but also automobile insurance, IACI claims and mortality data. We conclude that social efforts are required to reduce the socioeconomic cost of injuries in Korea, which represented approximately 1.9% of the GDP for the time period specified.