• 해양환경안전학회지
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• 제25권2호
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• pp.159-168
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• 2019

본 연구는 수중활동에서 나타나는 인체의 생리적 변화와 알코올 섭취로 인한 생리적 변화를 살펴보고 알코올 섭취가 스쿠버다이버에게 미치는 영향을 규명하는데 그 목적이 있다. 미국 내부통제연구소위원회의 내부통제 프레임워크를 기초로 본 연구에 적합하도록 새롭게 정립한 '리스크 평가 및 분석(RAA, risk assessment and analysis)' 기법을 활용하여 알코올 섭취 전과 후의 리스크 분석을 실시하였다. RAA기법은 리스크 간 상관관계를 분석하는 1단계, 리스크를 정량화하고 리스크 데이터베이스를 구축하는 2단계, 그리고 이를 도식화하여 리스크맵을 분석하는 3단계로 이루어져 있다. RAA기법을 통해 알코올 섭취로 인한 수중활동의 리스크수준이 전반적으로 증가하여 고위험군의 비율이 높아진 것을 확인하였고 리스크수준의 정량화와 고위험군 분류를 통해 리스크관리 측면에서 우선통제대상을 지정할 수 있었다. 본 연구 결과는 알코올 섭취 후 행해지는 스쿠버다이빙의 위험성을 명확하게 알리고 이에 대한 스쿠버다이버들의 의식 개선을 도모하여 보다 안전한 스쿠버다이빙 환경을 제시할 수 있을 것으로 기대한다.

• 보건행정학회지
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• 제29권1호
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• pp.4-10
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• 2019

The term new tobacco products (NTPs) refers to the new alternatives to conventional cigarettes. There are several kinds of NTPs in South Korea. The present study discusses the most widely used NTPs namely electronic cigarette (ECs) and heated tobacco products (HTPs). The aims of this study are to evaluate the risk related to the use of ECs and HTPs, introduce policy examples across different countries of management of this issue, and finally, present some policy implications of the problem and our response strategies. Since the advent of ECs, there has been a lot of debate about its risk. Some studies have reported that ECs are less harmful than conventional cigarettes and that they are effective in aiding smoking cessation. Nevertheless, the efficacy of ECs in smoking cessation and its potential health risks are still unclear. However, the obvious fact is that it is not harmless. Regulations on ECs differ from country to country. In many countries, they are strictly regulated as tobacco or toxic substances; however, in the United Kingdom, the use of ECs are included as part of their smoking cessation policy, and in Japan, they are treated as a form of medication. On the other hand, HTPs are the most recently introduced NTPs and they have attained sensational popularity because of the wrongly held belief that they are less harmful to health. So, what about our policy response to these two tobacco products? The research on ECs requires more systematic statistical monitoring, such as monitoring the ratio of dual-users. Further, the new EC smokers should be identified taking into account that the arguments for the use of ECs often emphasize smoking cessation or less risks to health, the government should further strengthen its policy to prevent those claims. The HTPs market experienced a very sharp growth and continues to grow because the government policy is too passive. Taking this as a lesson, it is necessary to approach NTPs, such as HTPs, proactively and increase their contribution to the National Health Promotion Fund by imposing greater taxes on them. Finally, considering the likelihood of NTPs being promoted as a less harmful tobacco product, it is essential to strictly regulate tobacco companies' publicity from the very beginning to ensure that potential consumer s are not mislead.

• 대한소아치과학회지
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• 제46권2호
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• pp.139-146
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• 2019

본 연구는 7세부터 15세사이의 소아청소년을 대상으로 촬영하여 획득한 Cone beam computed tomography(CBCT) 영상을 이용하여 정중구개봉합의 성숙도를 평가하고 골 성숙도 및 연령과의 연관성을 분석하여 Rapid maxillary expansion(RME) 적용 시 적절한 치료계획 수립의 참고자료로 활용하고자 하였다. 남아 240명, 여아 240명, 총 480명의 CBCT 수평면 영상에서 정중구개봉합의 성숙도를 5단계로 평가하였고 수집된 자료를 경추골 성숙도 측정법에 의해 평가된 골 성숙도 및 연령에 따라 통계분석을 시행하였다. 정중구개봉합 성숙도와 골 성숙도는 0.602의 강한 상관관계를 보였으며, 특히 정중구개봉합 성숙도 A - C단계의 예측을 위한 경추골 성숙도 1 - 3단계의 양성 검정우도비는 44.79로서 예측을 위한 타당한 지표임을 나타내었다. 정중구개봉합 성숙도와 연령의 상관관계는 남아에서 0.499, 여아에서 0.560으로 나타나 경추골 성숙도 보다는 낮으나 비교적 높은 상관관계를 보였다. 따라서 경추골 성숙도 측정법은 정중구개봉합의 성숙도 예측을 위한 신뢰할 만한 지표라고 할 수 있으며, 연령은 경추골 성숙도 측정이 어려운 경우에 한하여 임상에서 간편하고 직관적인 지표로 쓰일 수 있다. 연구 결과를 종합해보면 RME 사용 시 골격성 효과를 충분히 얻을 수 있는 것으로 기대 할 수 있는 시기는 경추골 성숙도 1 - 3단계, 남녀 모두 연령 12세 이하이며 경추골 성숙도 4단계 혹은 여아 연령 13세 및 남아 연령 15세까지는 conventional RME의 사용은 가능하나 골격성 효과는 감소하고 치성 효과가 증가할 것으로 예상된다. 경추골 성숙도 5, 6단계 혹은 여아 연령 14세 이상에서는 RME 필요 시 사용 형태를 결정하기 위해 정중구개봉합 성숙 단계 평가 시 CBCT 촬영이 고려되어야 한다.

• Neonatal Medicine
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• 제25권4호
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• pp.161-169
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• 2018

Purpose: We assessed the influence of antenatal corticosteroid (ACS) on the inhospital outcomes of intrauterine growth restriction (IUGR) infants. Methods: A retrospective study was conducted with singletons born at $23^{+0}$ to $33^{+6}weeks$ of gestation at Seoul National University Hospital from 2007 to 2014. We compared clinical outcomes between infants who received ACS 2 to 7 days before birth (complete ACS), at <2 or >7 days (incomplete ACS), and those who did not receive ACS in IUGR and AGA infants. Multivariate logistic regression using Firth's penalized likelihood was performed. Results: 304 neonates with 91 IUGR neonates were eligible. Among AGA neonates, mortality (adjusted odds ratio [aOR], 0.13; 95% confidence interval [CI], 0.02 to 0.78), hypotension within 7 postnatal days (aOR, 0.20; 95% CI, 0.06 to 0.64), and severe bronchopulmonary dysplasia (BPD) or death (aOR, 0.24; 95% CI, 0.07 to 0.77) were lower in complete ACS group after adjusting for pregnancy induced hypertension and uncontrolled preterm labor. Mortality (aOR, 0.18; 95% CI, 0.04 to 0.78), hypotension (aOR, 0.26; 95% CI, 0.09 to 0.70), and severe BPD or death (aOR, 0.33; 95% CI, 0.12 to 0.92) were also lower in the incomplete ACS group. Among IUGR infants, after adjusting for birth weight and 5-minute Apgar score, inhaled nitric oxide use within 14 postnatal days was lower in both complete ACS (aOR, 0.07; 95% CI, 0.01 to 0.67) and incomplete ACS (aOR, 0.04; 95% CI, 0.01 to 0.37) groups. Conclusion: ACS was not effective in reducing morbidities in IUGR preterm infants.

• 보건행정학회지
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• 제30권4호
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• pp.493-504
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• 2020

Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15-1.17), overweight (OR, 1.36; 95% CI, 1.35-1.36), and obese (OR, 1.34; 95% CI, 1.33-1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14-1.16) and overweight (OR, 1.06; 95% CI, 1.06-1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61-0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡). Conclusion: The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.

• 보건행정학회지
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• 제30권4호
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• pp.479-492
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• 2020

Background: As the prevalence of hypertension is increasing in Korea, the government is seeking policy actions to manage patients with hypertension more efficiently. In this paper, we aimed to identify factors associated with the use of medical care at hospitals among outpatients with hypertension. Methods: We analyzed a total of 15,040 cases of 3,877 outpatients with hypertension obtained from the Korea Medical Panel database from 2010 to 2016. The dependent variable was whether a patient with hypertension visited a hospital or not; and independent variables were the patient's various socio-demographic, health-related, and heath-status characteristics. We conducted a generalized linear mixed model analysis with logit link for all the cases and then conducted it stratified by gender. Results: As a result of a multivariable analysis, women were less likely than to visit at a hospital (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.32-0.61) and people aged 65 years and older than those aged less than 65 years (OR, 0.71; 95% CI, 0.57-0.89). Residents in Busan, Ulsan, and Gyeongnam were more likely than those in than Seoul, Gyeonggi, Incheon, and Jeju to visit a hospital (OR, 1.40; 95% CI, 1.05-1.86). The likelihood of visiting a hospital was high in people belonging to a group of: the highest level of annual household income (OR, 1.73; 95% CI, 1.30-2.29); Medical care aid recipients (OR, 1.94; 95% CI, 1.34-2.83); people having three or more complex chronic diseases (OR, 1.59; 95% CI, 1.19-2.11); people having diabetes (OR, 1.81; 95% CI, 1.41-2.32); or people having ischemic heart disease or cerebrovascular disease (OR, 6.80; 95% CI, 5.28-8.76). Also, we found that factors associated with the use of medical care at hospitals among outpatients with hypertension differed between genders. Conclusion: A variety of factors seem to be associated with the use of medical care at hospitals among outpatients with hypertension. Future research needs to find a way to help patients with hypertension visit an appropriate medical institution between clinics and hospitals.

• Journal of Yeungnam Medical Science
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• 제38권2호
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• pp.136-141
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• 2021

Background: Postoperative acute kidney injury (AKI), which increases the risk of postoperative morbidity and mortality, poses a major concern to surgeons. We conducted this study to analyze the risk factors associated with the occurrence of AKI after orthopedic surgery. Methods: This was a retrospective study that included 351 patients who underwent total hip or knee replacement surgery at Inje University Haeundae Paik Hospital between January 2012 and December 2016. Results: AKI occurred in 13 (3.7%) of the 351 patients. The patients' preoperative estimated glomerular filtration rate (eGFR) was 66.66 ±34.02 mL/min/1.73 m² in the AKI group and 78.07±21.23 mL/min/1.73 m² in the non-AKI group. The hemoglobin levels were 11.21±1.65 g/dL in the AKI group and 12.39±1.52 g/dL in the non-AKI group. Hemoglobin level was related to increased risk of AKI (odds ratio [OR], 0.13; 95% confidence interval [CI], 0.02-0.68; p=0.016). Administration of crystalloid or colloid fluid alone and the perioperative amount of fluid did not show any significant relationship with AKI. Further analysis of the changes in eGFR was performed using a cutoff value of 7.54. The changes in eGFR were significantly related to decreased risk of AKI (OR, 0.74; 95% CI, 0.61-0.89; p=0.002). Conclusion: Renal function should be monitored closely after orthopedic surgery if patients have chronic kidney disease and low hemoglobin level. Predicting the likelihood of AKI occurrence, early treatment of high-risk patients, and monitoring perioperative laboratory test results, including eGFR, will help improve patient prognosis.

• Archives of Plastic Surgery
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• 제49권1호
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• pp.91-98
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• 2022

Background Predicting the need for post-traumatic reconstruction of lower extremity injuries remains a challenge. Due to the larger volume of cases in adults than in children, the majority of the medical literature has focused on adult lower extremity reconstruction. This study evaluates predictive risk factors associated with the need for free flap reconstruction in pediatric patients following lower extremity trauma. Methods An IRB-approved retrospective chart analysis over a 5-year period (January 1, 2012 to December 31, 2017) was performed, including all pediatric patients (<18 years old) diagnosed with one or more lower extremity wounds. Patient demographics, trauma information, and operative information were reviewed. The statistical analysis consisted of univariate and multivariate regression models to identify predictor variables associated with free flap reconstruction. Results In total, 1,821 patients were identified who fit our search criteria, of whom 41 patients (2.25%) required free flap reconstruction, 65 patients (3.57%) required local flap reconstruction, and 19 patients (1.04%) required skin graft reconstruction. We determined that older age (odds ratio [OR], 1.134; P =0.002), all-terrain vehicle accidents (OR, 6.698; P<0.001), and trauma team activation (OR, 2.443; P=0.034) were associated with the need for free flap reconstruction following lower extremity trauma in our pediatric population. Conclusions Our study demonstrates a higher likelihood of free flap reconstruction in older pediatric patients, those involved in all-terrain vehicle accidents, and cases involving activation of the trauma team. This information can be implemented to help develop an early risk calculator that defines the need for complex lower extremity reconstruction in the pediatric population.

• 방송공학회논문지
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• 제28권1호
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• pp.145-148
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• 2023

송신 안테나 수가 4개인 다중 송수신 안테나 시스템에서 랜덤 위상을 갖는 오픈 루프 옥토니언 시공간 블록 부호를 적용했을 때, 불법적인 수신자가 최대 유사도 추정으로 물리계층을 해킹하는 경우의 성능을 분석한다. 합법적 수신자만 알 수 있는 무작위 위상을 불법적 수신자인 해커가 전혀 모르거나 일부를 알아냈을 때 신호 대 잡음비에 따른 비트 에러율을 분석한다. 또한 기존 논문의 옥토니언 부호가 직교성이 충분하지 않음을 보이고 완전한 직교성을 갖는 옥토니언 부호를 적용한다. 컴퓨터 시뮬레이션에서 랜덤위상은 2-PSK 성운으로 하고 있다는 것을 해커가 알고 있고 4개 송신 안테나의 랜덤 위상을 모두 해커가 추정할 경우에는 신호 대 잡음비가 100dB까지 해킹이 불가능하다. 그러나 랜덤 위상의 일부를 알게 되면 신호 대 잡음비가 20dB 이상에서 비트에러율이 10^-3 정도로 유지되므로 해킹이 가능해진다.

• 한국시뮬레이션학회논문지
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• 제18권3호
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• pp.103-112
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• 2009

원자력발전소에서 센서의 주기적 교정은 안전운전을 위해 꼭 필요하다. 그러나 실제 드리프트가 발생하여 교정을 요하는 센서는 약 2% 미만이다. 또한, 센서의 작동 상태를 매 핵연료 주기마다 수행하는 것은 고장 혹은 드리프트가 발생한 센서를 최대 18개월까지 감지하지 못한 채 운전할 위험이 있다. 원전의 안전운전 및 불필요한 교정을 줄이기 위해 센서의 상시 교정 감시가 필요하다. 이를 위해 주성분 분석과 Support Vector Regression(SVR)을 이용한 PCSVR 알고리즘을 개발하였고, 고리원전 3호기의 출력증발 데이터를 이용하여 검증하였다. 주성분분석은 선형변환을 통한 입력공간의 축소 및 노이즈 제거 효과를 나타내며, AASVR은 해석학적 및 기계학적 모델로 모델링하기 힘든 복잡계를 쉽게 나타낼 수 있는 장점이 있다. SVR의 세가지 파라미터는 반응표면분석법에 의해 최적화하였다. 센서의 고장탐지를 위해 모델 출력의 잔차를 슈하르트 관리도, EWMA, CUSUM 및 일반화우도비검정(GLRT)을 통해 그 결과를 비교하였다. 미세한 드리프트에 대해 CUSUM과 GLRT가 우수한 결과를 보였다. 개발된 알고리즘은 수출형 원전 APR1000 설계시 적용가능 할 것으로 판단된다.