국내 반복입원의 현황과 환자 특성: 외래진료 민감질환을 중심으로

정혜민,김현주,이진용 한국의료질향상학회 2021 한국의료질향상학회지 Vol.27 No.2

Purpose: Repeated hospitalization could be a proxy of unnecessary or preventive admission in South Korea where barriers to hospitalization are relatively low. This study aimed to estimate the current status of repeated hospitalization due to ambulatory care sensitive conditions (ACSC) in South Korea. Methods: Using the National Health Information Database, repeated hospitalization databases were constructed in units of episodes for patients who had been admitted more than twice between January 2017 and December 2018. The number of hospitalizations, total in-hospital days, and total medical expenditure were calculated and compared by patient characteristics in both of the entire patient group and the ACSC patient group. Results: Of total hospitalization episodes, 26.6% reported repeated admission, and 6.7% of repeated hospitalization was due to ACSC. A total of 183,110 patients with ACSC had been admitted an average of 2.9 times and spent an average of KRW5,630,118. In other words, KRW1,309 billion had been spent for repeated hospitalization due to ACSC. The scale of medical expenditure was relatively large in the highest and lowest socioeconomic status. Conclusion: Repeated hospitalization for ACSC can be considered a simple and intuitive indicator when assessing unnecessary hospitalizations or evaluating healthcare policy.

현탁중합에 의한 폴리비닐알코올/점토 나노복합체의 합성 및 특성분석

정혜민,지병철,염정현 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.4

PVdF 나노섬유와 Graphene Oxide 하이브리드막에 관한 연구

정혜민,진유동,변홍식,양우석 한국막학회 2013 멤브레인 Vol.23 No.3

본 연구는 microfiltration (MF) 적용을 위한 PVdF/GO 하이브리드 나노섬유막(FG) 제조에 관한 것이다. 지지체인 PVdF (polyvinylidene difluoride) 나노섬유막은 N,N-Dimethylacetamide (DMAc)와 아세톤에 PVdF를 녹여 방사용액 제조 후 전기방사법을 이용하여 제조하였다. 본 연구에서 사용된 GO (grapheme oxide) sheets는 Hummer’s 방법에 따라 제조되었으며, PVdF 나노섬유 지지체 위에 에탄올에 분산시킨 GO용액을 분사함으로써, 최종적으로 PVdF/GO 하이브리드 나노섬유막(FG)을 제조하였다. FG막은 SEM, Raman, 접촉각, 기공특성분석장치(Porometer), 만능인장시험기(UTM)를 사용하여 조사하였고, 수투과도 분석은 제작된 셀(Dead-End Cell)을 이용하여 측정하였다. 접촉각 측정 결과로부터 제조된 FG막의 표면이 친수성으로 개질되었음을 확인할 수 있었으며, 수투과도값은 PVdF막에 비해 약 2.5배 향상된 것을 확인할 수 있었다. Recently, many applications with grapheneoxide (GO) have been reported. But GO membrane for water treatment has not been developed. In this study we prepared polyvinylidene difluoride (PVdF) nanofiber/GO hybrid membrane (FG) for the microfiltration application. The PVdF substrate membrane was prepared by using the electrospinning method with a solution of PVdF in N,N-dimethylacetamide (DMAc) and acetone. GO sheets used in this study were prepared by modified Hummer’s method. The PVdF/GO hybrid membrane was finally prepared by spraying the GO solution dispersed in ethanol on the PVdF nanofiber. The successfully prepared FG was thoroughly examined by SEM, Raman, contact angle, porometer and UTM, and water-flux was measured with designed cell (Dead-End Cell). From the contact angle results, it was found that the surface of FG membrane was reformed by hydrophilic property and the water permeability was increased about 2.5 times than that of the nascent PVdF membrane, indicating the possible alternative of the commercial MF membrane.

The Impact of an Emergency Fee Increase on the Composition of Patients Visiting Emergency Departments

정혜민,도영경,김윤,노준수 대한예방의학회 2014 Journal of Preventive Medicine and Public Health Vol.47 No.6

Objectives: This study aimed to test our hypothesis that a raise in the emergency fee implemented on March 1, 2013 has increased the proportion of patients with emergent symptoms by discouraging non-urgent emergency department visits. Methods: We conducted an analysis of 728 736 patients registered in the National Emergency Department Information System who visited level 1 and level 2 emergency medical institutes in the two-month time period from February 1, 2013, one month before the raise in the emergency fee, to March 31, 2013, one month after the raise. A difference-in-difference method was used to estimate the net effects of a raise in the emergency fee on the probability that an emergency visit is for urgent conditions. Results: The percentage of emergency department visits in urgent or equivalent patients increased by 2.4% points, from 74.2% beforeto 76.6% after the policy implementation. In a group of patients transferred using public transport or ambulance, who were assumedto be least conscious of cost, the change in the proportion of urgent patients was not statistically significant. On the other hand, the probability that a group of patients directly presenting to the emergency department by private transport, assumed to be most conscious of cost, showed a 2.4% point increase in urgent conditions (p<0.001). This trend appeared to be consistent across the level 1 and level 2 emergency medical institutes. Conclusions: A raise in the emergency fee implemented on March 1, 2013 increased the propoEmergency fee, Hospital emergency service, Overcrowding, Difference-in-differencertion of urgent patients in the total emergency visits by reducing emergency department visits by non-urgent patients. Objectives: This study aimed to test our hypothesis that a raise in the emergency fee implemented on March 1, 2013 has increased the proportion of patients with emergent symptoms by discouraging non-urgent emergency department visits. Methods: We conducted an analysis of 728 736 patients registered in the National Emergency Department Information System who visited level 1 and level 2 emergency medical institutes in the two-month time period from February 1, 2013, one month before the raise in the emergency fee, to March 31, 2013, one month after the raise. A difference-in-difference method was used to estimate the net effects of a raise in the emergency fee on the probability that an emergency visit is for urgent conditions. Results: The percentage of emergency department visits in urgent or equivalent patients increased by 2.4% points, from 74.2% beforeto 76.6% after the policy implementation. In a group of patients transferred using public transport or ambulance, who were assumedto be least conscious of cost, the change in the proportion of urgent patients was not statistically significant. On the other hand, the probability that a group of patients directly presenting to the emergency department by private transport, assumed to be most conscious of cost, showed a 2.4% point increase in urgent conditions (p<0.001). This trend appeared to be consistent across the level 1 and level 2 emergency medical institutes. Conclusions: A raise in the emergency fee implemented on March 1, 2013 increased the proportion of urgent patients in the total emergency visits by reducing emergency department visits by non-urgent patients.

서비스직 유무에 따른 아르바이트 종사자 대학생의 자가구취인식도가 구강보건관리실천도에 미치는 영향

정혜민,조한아,정성균,김아영,김예린,김유림,이예진,이은아,정민주,임도선 대한치과위생학회 2019 대한치위생과학회지 Vol.2 No.2

Background: The purpose of this study was to investigate the effect of self-perception of halitosis on oral health behaviors of college students according to whether they worked in a non-service or service-related job. Methods: A self-reporting questionnaire of 150 university students working in service jobs and 150 university students working in non-service jobs in the metropolitan area was conducted from 26th April to 5th May 2018. The survey tool consisted of 3 general topic areas. There were 5 questions on oral health awareness behavior, 3 questions related to their self-perception of halitosis, and 8 questions on their oral health care practice. All were measured on the Likert 5-point scale. The frequency of their oral health behaviors and their self-perception of halitosis were analyzed according to the subjects’ occupation. Pearson’s correlation analysis and a linear regression analysis were conducted to confirm the influence of the two. The significance level for the statistical significance test was set to α = 0.05 (two-tailed). Results: In both the service and non-service groups, a coated tongue and food debris were found to influence halitosis(x2=10.95, p=0.027). According to the t-test, taking into account the self-perception of halitosis and oral health behaviors, both were higher in those that had a service job. Self-perception of halitosis and oral health behaviors were found to have a negative correlation(γ=-0.11, p<0.05). As the self-perception of halitosis increased, oral health care practices also increased(Beta=-0.185, p=0.020). Conclusions: Systematic interventions such as oral health programs and health promotion are needed to improve the oral health of service workers.

이상근의 음악관 : 1) Through Thesis 1) 그의 논문을 중심으로

정혜민 민족음악연구소 1993 음악과 민족 Vol.6 No.-

조현병 환자와 건강한 대조군에서 성별에 따른 뇌파 동시성의 차이

정혜민,이유상,김성수,김성균,정재승,오진석,이승연,김범준,장재승,Jung, Hye Min,Lee, Yu Sang,Kim, Seongsu,Kim, Seongkyun,Jeong, Jaeseung,Oh, Jin-Seok,Lee, Seungyeoun,Kim, Bum Joon,Chang, Jae Seung 대한생물정신의학회 2013 생물정신의학 Vol.20 No.4

Objectives Alteration of epigenetic effects of testosterone during early development was suggested as an ancillary mechanism for the genesis of schizophrenia. EEG coherence was thought to be a marker for cerebral laterality of which important determinant was testosterone during early development. We studied sex-related differences of EEG coherences between patients with schizophrenia and controls to examine the sex effects in the genesis of schizophrenia. Methods EEG was recorded in 35 patients with schizophrenia and 46 healthy controls in the eyes closed resting state. Pair-wise EEG coherences were calculated over delta, theta, alpha, beta and gamma frequency bands. To examine the differences of EEG coherence according to sex in each group, ANCOVA was performed using Statistical Analysis system (SAS, Ver 9.3) and R (Ver 2.15.2). Results Healthy control males showed more increased right intrahemispheric coherences than healthy control females in delta, theta, alpha and beta frequency bands. In patients with schizophrenia, this male dominant pattern in right intrahemispheric coherences was attenuated especially in alpha and beta bands. Healthy control females showed more increased interhemispheric coherences than healthy control males in delta, theta, beta and gamma frequency bands. In patients with schizophrenia, these female dominant patterns in interhemispheric coherences were attenuated especially in delta, theta, and beta bands, which were commonly observed in frontal to central areas. Conclusion Sex differences in resting EEG coherences were attenuated in schizophrenia patients. These results imply that sex-related aberrant cerebral lateralization might exist in patients with schizophrenia, which are partly due to sex hormones via epigenetic mechanisms.

EQPS를 이용한 미생물 고정화담체의 하수 속의 질소처리특성분석

정혜민,국영롱,김한슬,박철휘 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.12

아끼바레 및 밀양 23호 쌀전분의 이화학적 성질비교

정혜민,안승요,김성곤 한국응용생명화학회 1982 Applied Biological Chemistry (Appl Biol Chem) Vol.25 No.2

아끼바레 및 밀양 23호 쌀 전분의 이화학적 성질, 전분 gel의 노화 및 음이온에 의한 호화양상을 조사하였다. 두 전분입자의 성상은 다각형이며 입자의 크기는 3~6㎛정도였으며, 아끼바레가 밀양 23호 보다 다소 작았다. 두 전분의 X-ray 회절도는 A형으로 peak 형태와 강도에서 약간의 차이를 보였다. 아끼바레 및 밀양 23호 쌀 전분의 아밀로스 함량은 각각 18.5 및 19.5%이었고 물 결합능력은 106 및 100%이었다. 팽화력은 50℃까지는 큰 변화가 없었으나 이후에 급격히 증가하였고 밀양 23호 쌀 전분의 팽화력이 더 컸다. 전분 현탁액(0.1%)의 광투과도는 두 전분 모두 60℃ 이후에서 급격히 증가하였으며 밀양 23호 쌀 전분이 더 큰 광투과도를 보였다. 음이온에 의한 아밀로그람 pattern은 NaCl과 NaF는 동일하였고, NaSCN과 NaI는 유사였다. 호화온도 및 최고점도시의 온도는 SCN^(-)<I^(-)<Cl^(-)<F^(-)<SO₄^(=)의 순으로 증가하였고 SCN^(-) 및 I^(-)이온은 최고 점도를 증가시켰으나 NaCl은 감소시켰다. SO₄^(=)이온을 첨가한 경우 점도는 계속 증가하였고 최고점도에 도달하지 않았다. 아끼바레 및 밀양 23호 전분 gel율 21℃에서 저장한 경우 시간 상수가 각각 6.72 및 6.42일이었다. Morphology, pbysicochemical properties, pasting properties in the presence of various anionic ions and aging of gels of Akibare (Japoica type) and Milyang 39 (Indica type)rice starch were studied Both starches. were polygonal with length in the range of 3~6㎛. Starch granules of Akibare were somewhat smaller than those of Milyang 23. X-ray diffraction study demonstrated that peak shape and intensity were significantly different between the two starches. Akibare and Milyang 23 rice starch had amylose content of 18.5 and 19,5% and water binding capacity of 106 and 100%, respectively. Milyang 23 rice starch had a higher swelling power than Akibare starch. A relationship between percent solubility and swelling power implied that bonding forces within the granules of the both starches were different. The optical transmittance of 0.1% suspension of the two starches increased rapidly from 60℃. In the range of 60~90℃, the two starches showed a single gelatinization pattern. Amylograms of the two starches in the presence of various anionic ions showed that pasting temperature and peak temperature were progressively increased in the order of SCN-<I-<CI-<F-<SO₄=. SCN- and I- ions increased the peak height of Akibare rice starch white only SCN- ion was effective for Milyang 23 rice starch. There were no differences in the rates of retrogradation of 45% gels of the two starches stored at 21℃.

GAN에서의 점진학습을 위한 잠재벡터 저장 기반 리허설 방법

정혜민,최동완 한국정보과학회 2023 정보과학회논문지 Vol.50 No.4

Unlike humans, sequential learning of multiple tasks is a difficult problem in a deep learning model. This problem is not only for discriminative models, but also for generative models, such as GAN. The Generative Replay method, which is frequently used in GAN continual learning, uses images generated by GAN provided in the previous task together for learning new tasks, but does not generate good images for CIFAR10, which is a relatively challenging task. Therefore, we can consider a rehearsal-based method that stores a portion of the real data, which cannot store a huge amount of images in limited memory because of large dimension of the real image. In this paper, we propose LactoGAN and LactoGAN+, continual learning methods that store latent vectors that are the inputs of GANs rather than storing real images, as the existing rehearsal-based approaches. As a result, more image knowledge can be stored in the same memory; thus, showing better results than the existing GAN continual learning methods. 인간과 달리 딥러닝 모델에게 다수의 태스크에 대한 순차적 학습은 어려운 문제이다. 이는 비단 분류모델뿐만 아니라 GAN과 같은 생성모델도 해당한다. GAN 지속학습 연구에서 주로 사용하는 Generative Replay 방식은 직전 태스크까지 학습된 GAN이 생성한 이미지를 새로운 태스크 학습 시 함께 사용하는데, 비교적 어려운 태스크에 속하는 CIFAR10에 대해서 좋은 품질의 이미지를 생성하지 못한다. 따라서 실제 이미지의 일부를 저장하는 리허설 기반 방법을 고려해볼 수 있는데, 실제 이미지는 큰 차원을 가지기 때문에 제한된 메모리에 많은 양을 저장할 수 없다. 본 논문에서는 기존 리허설 기반 방식에서 이미지를 저장하는 대신에 GAN의 입력이 되는 잠재벡터를 저장하는 지속학습 방법 LactoGAN과 LactoGAN+를 제안한다. 그 결과 같은 메모리에 더 많은 이미지 정보의 저장이 가능하게 되어 기존 GAN 지속학습 방법들에 비해 더 우수한 결과를 보임을 확인하였다.