중등도 이상의 위험 수술을 받은 환자에서 수술 전후 항혈전제 약물 사용 평가

이현아,조윤희,조윤숙,한현주,이주연,정근화,이상건,Lee, Hyeon-Ah,Jo, Yun Hee,Cho, Yoonsook,Hahn, Hyeon Joo,Lee, Ju-Yeun,Jung, Keun-Hwa,Lee, Sang Kun 한국임상약학회 2017 한국임상약학회지 Vol.27 No.1

Objective: The perioperative management of antithrombotic therapy is often challenging and it requires a fine balance between the risk of hemorrhage and thrombosis. We aimed to evaluate the antithrombotic management for moderate to high risk patients in real world setting. Methods: Among the patients who were consulted to the neurologist for the evaluation of perioperative risk from 2010 to 2012, patients undergoing moderate to high risk surgery and taking antithrombotics within 30 days were identified. We analyzed the timing of discontinuation and reinitiation of antithrombotic drugs before or after surgery as well as the status of bridging therapy. In addition, the conformity with the guideline suggested by American College of Chest Physicians was assessed. The rate of thromboembolic event and major hemorrhage were also investigated. Results: A total of 329 patients were included. The concordance rate of warfarin stop and restart time with guideline was 23.4% and 10.3%, respectively. Continuing aspirin in patients undergoing coronary artery bypass surgery or non-cardiac surgery in patients with high risk for cardiovascular events were 59.2% and 2.6%, respectively. Bridging therapy was adopted in 92.9% and 81.2% in patients who had received anticoagulant before surgery and who were at high and low risk thromboembolism, respectively. In entire cohorts, 30-day incidence of major bleeding and thromboembolic event were 31.9% and 3.0%. Co-morbid renal disease were shown as independent predictor for major bleeding (adjusted OR 2.65. 95% CI 1.33-5.28). Conclusion: The concordance rate with guideline regarding perioperative antithrombotic use was low and bridging therapy was prevalent in patients undergoing moderate to high risk surgery.

임상간호사의 뇌사자 장기기증에 대한 지식과 태도에 영향을 미치는 요인

이현아,허유진,이영규,송가람,이은지,신수진,Lee, Hyun Ah,Hur, Yujin,Lee, Young Gew,Song, Garam,Lee, Eunji,Shin, Sujin 한국중환자간호학회 2017 중환자간호학회지 Vol.10 No.3

Purpose : This study investigated factors affecting the knowledge and attitude of organ procurement from brain dead patients in nurse clinicians. Methods : A survey was conducted with 160 clinical nurses from a university hospital in Seoul. Descriptive statistics, t-tests, an ANOVA, $Scheff{\acute{e}}^{\prime}s$ test, Pearson's correlation coefficient, and a multiple regression analysis were used. Results : The mean score for knowledge of organ procurement from brain dead patients was $12.41{\pm}2.16$ (mean correct answers = 62.1). Factors influencing the knowledge of organ procurement among nurse clinicians were working department (${\beta}=.454$, p < .001), a recent family death (${\beta}=.187$, p = .014), experience recognizing potential brain dead patients (${\beta}=.182$, p = .033), and experience referring to potential brain dead patients (${\beta}=-.192$, p = .048). Conclusion : To ensure effective organ procurement from brain dead patients, it is necessary to continually educate nurse clinicians to improve their attitude and knowledge concerning organ donation.

2차원 지리 객체를 위한 시공간 객체 모델 설계

이현아,남광우,류근호,Lee, Hyeon-Ah,Nam, Kwang-Woo,Ryu, Keun-Ho 한국정보처리학회 2002 정보처리학회논문지D Vol.9 No.1

지금까지 시공간 객체를 다양한 관점에서 접근하여 표현하려는 많은 연구가 이루어졌다. 이 대부분의 연구는 GIS적 관점과 시간 데이터베이스 관점, 그리고 객체 지향적 관점 및 데이터타입 접근 방법으로 시공간 객체를 표현하고 있다. 시공간 객체는 공간 속성이 불연속적으로 변하는 객체, 위치 정보가 연속적으로 변하는 객체, 그리고 면적과 위치가 연속적으로 변하는 객체로 분류된다. 그러나 기존의 시공간 모델들은 한 종류의 객체에만 초점을 맞추고 있다. 따라서 이 논문에서는 유클리드 평면상에서 세가지 형태의 객체를 모두 표현할 수 있는 시공간 객체 모델을 제안한다. 이를 위해 유효시간 개념을 확장한 시간 모델과 함께 객체의 연속된 두 버전간의 관계성을 정의하여 이동 객체와 이력 객체 모두를 표현하는 방식을 사용한다. 여기서 제안하는 2차원 시공간 객체 모델은 개방형 GIS 명세서에서 제시하고 있는 2차원 공간 객체 모델을 따름으로써 표준 공간 모델과의 호환성을 보장한다. Most of works have been performed on representation of spatiotemporal objects from various points of view. Most of them represent spatiotemporal objects using approaches from GIS, temporal databases, object-oriented databases or data type. Spatiotemporal objects can be classified as objects whose position and shape changes discretely over time, objects whose position changes continuously and objects whose shape changes continuously as well as position. Previous works on spatiotemporal model have focused on only one of them. In this paper, we propose a spatiotemporal model that can represent three types of objects in Euclidean plan. For this purpose, we represent both discrete and continuous moving objects by defining temporal model extended from valid time and by defining relationship between two consecutive versions of objects. The proposed spatiotemporal object model is based on open GIS specification so that it has compatibility with existing spatial data model.

영작문 자동 채점 시스템에서의 중복 보고 오류 제거를 통한 성능 향상

이현아,김지은,이공주,Lee, Hyun-Ah,Kim, Jee-Eun,Lee, Kong-Joo 한국정보처리학회 2009 정보처리학회논문지B Vol.16 No.2

The purpose of developing an automated scoring system for English composition is to score English writing tests and to give diagnostic feedback to the test-takers without human's efforts. The system developed through our research detects grammatical errors of a single sentence on morphological, syntactic and semantic stages, respectively, and those errors are calculated into the final score. The error detecting stages are independent from one another, which causes duplicating the identical errors with different labels at different stages. These duplicated errors become a hindering factor to calculating an accurate score. This paper presents a solution to detecting the duplicated errors and improving an accuracy in calculating the final score by eliminating one of the errors. 영어 작문 자동 채점 시스템은 수험자가 작성한 영작문을 사람의 개입 없이 시스템이 처리하여 점수나 피드백을 줄 수 있는 시스템이다. 본 논문에서 개발한 영작문 자동 채점 시스템은 단어 단계, 구문 단계, 의미 단계의 세 단계 처리 과정을 통해서 오류를 탐지하고 탐지된 오류 개수를 기반으로 채점 점수를 결정한다. 이와 같이 독립적인 세 단계의 처리 과정에서 오류를 탐지하므로 동일한 오류 현상에 대해 서로 다른 단계에서 서로 다른 이름으로 오류를 탐지하는 경우가 발생할 수 있다. 이는 결과적으로 전체 시스템의 채점 점수의 정확도를 저하시키는 원인이 된다. 본 논문에서는 동일한 오류 현상에 대해 서로 다른 단계에서 탐지된 오류 쌍을 '중복 보고 오류'라고 정의한다. 본 논문에서는 중복 보고 오류를 찾는 방법을 제안하고 중복 보고 오류 제거를 통해 영작문 자동 채점 시스템의 채점 점수를 향상시킬 수 있음을 보인다.

국내 지진 감시·예측을 위한 지하수관측망의 활용 방안

이현아,함세영,우남칠,Lee, Hyun A,Hamm, Se-Yeong,Woo, Nam C. 대한자원환경지질학회 2017 자원환경지질 Vol.50 No.5

To prevent the damages from earthquakes, various researches have been conducted around the world focusing on earthquake prediction and forecasting for several decades. Among various precursory phenomena, changes in groundwater level and quality are considered to be reliable for estimating the time of earthquake occurrence and its magnitude. In effects, some countries impacted by frequent earthquakes have established and operated the groundwater monitoring network for earthquake surveillance and prediction. In Korea, recently researches have begun for using groundwater monitoring techniques for earthquake prediction. In this paper, the groundwater monitoring networks of China, Japan, and the United States were reviewed focusing on the facilities and results of researches to deduce the tasks for earthquake prediction researches using groundwater monitoring techniques in Korea. In results, research needs are suggested in the implementation of groundwater monitoring networks for specifically earthquake surveillance with the real-time monitoring and the measures to quantify the degrees of abnormal changes in the relationship of distance from the earthquake epicenter. 지진에 의한 피해를 방지하기 위하여 지진 예측과 예보를 위한 다양한 연구가 전 세계적으로 시도되어 왔다. 지진예측지표 중, 지하수 수위 및 수질의 장기관측자료에서 지진 전에 나타나는 이상변동은 지질매체에 가해지는 압력의 변화와 매체 내 균열의 발달에 의한 것으로 지진의 발생 시기와 규모를 추측할 수 있는 것으로 평가되고 있다. 따라서 국외에서는 지하수 관측시스템을 지진감시 관측망의 보조관측망으로 활용하고 있으며, 실제 지진 예측에 활용되고 있다. 우리나라는 최근에서야 지하수를 활용한 지진예측연구가 시작되었으며, 그 가운데 발생한 2016년 9월의 경주지진 전후로 나타난 지하수의 변동은 많은 관심을 불러왔다. 이 연구는 지진감시 및 예측을 위해 적극적으로 지하수관측시설을 운용하고 있는 중국, 일본, 미국의 관측시설 현황 및 연구 사례를 분석, 검토하고 최근 우리나라에서 수행되기 시작한 지진예측 연구의 연구방향과 과제를 제시하고자 수행되었다. 그 결과, 앞으로 고품질의 자료를 생산할 수 있는 지진감시 전용의 단층대 지하수관측시설 구축과 주요 관측인자의 실시간 감시, 이상변동의 폭과 관측되는 거리에 대한 정밀한 평가 및 연구가 필요할 것으로 사료된다.

Bacillus cereus에 의한 대규모 집단식중독 원인 분석

이현아,고영은,이다연,윤경아,김현정,김옥,박준혁,Hyunah Lee,Youngeun Ko,Dayeon Lee,KyungA Yun,Hyeonjeung Kim,Ok Kim,Junhyuk Park 한국식품위생안전성학회 2024 한국식품위생안전성학회지 Vol.39 No.2

본 연구는 2020년 10월 중 충청남도내 단체 급식소에서 발생한 대규모 집단 식중독 원인에 대하여 분석하였다. 전체 급식원 135명 중 21명(15.6%)에서 음식을 섭취한 후 1시간 이내에 주로 매스꺼움과 구토 증상을 보였다. 유증상자 21명 중 11명과, 조리종사자 1명, 조리기구 2건과 보존식 8건에서 B. cereus가 검출됨에 따라 B. cereus에 의한 집단 식중독으로 판단하였다. 분리된 21개의 균주를 PFGE 분석한 결과, 19개의 균주가 동일한 것으로 판단되었고, 이들 균주가 가지고 있는 독소 유전자는 CER, nheA, entFM이었다. 실험결과, CER을 포함하고, 증상 발현 시간이 1시간 이내로 매우 짧아 B. cereus의 구토형 식중독으로 판단하였다. 집단식중독 원인으로 안전하지 않은 급식환경과 제대로 관리되지 않은 음식에 의한 것이라 조사되었다. 이러한 결과는 단체급식에서의 급식환경과 제공되는 음식이 철저하게 관리되어야 한다는 것을 보여준다. 이와 더불어 보존식에서 원인 병원체를 찾아내는 것은 식중독의 원인을 추정하는데 매우 중요하므로, 집단급식소에서 규정에 맞는 보존식 용기를 이용하여 이를 적정온도에 잘 보관해야한다. 또한 정밀한 식중독 역학조사를 기반으로 사례를 분석하고 결과를 전파함으로써 유사한 식중독이 재발하지 않도록 해야 한다. This study was performed to establish the epidemiological features of a food poisoning outbreak that occurred in the cafeteria of a company in Chungcheongnam-do Province, Korea, in October 2020, and to recommend measures to prevent similar outbreaks. Twenty-one patients with acute gastroenteritis, three food handlers, seven cooking utensils, and 12 preserved food samples were subjected to viral and bacterial analyses based on procedures described in the "Manual for Detection of Foodborne Pathogens at Outbreaks". Among 135 individuals who had been served the meals, 21 (15.6%) showed symptoms of nausea and vomiting within an hour of consuming the food. Bacillus cereus were isolated from 11 (52.4%) of the 21 patients, one food service employee, one item of cooking ware, and 12 preserved food samples. In addition, we confirmed the toxin genes CER, nheA, and entFM from the isolated B. cereus strains. Pulsed-field gel electrophoresis results indicated that all of the isolated B. cereus strains were closely related, with the exception of strains obtained from one patient and one sample of preserved food. These findings provide evidence to indicate that the isolated B. cereus originated from preserved foods and an unhygienic eating environment. This outbreak highlights that the provision of food in non-commercial food systems must be thoroughly managed. In addition, it emphasizes the necessity for the correct and timely identification of causal pathogens for tracing the cause of food poisoning outbreaks, and the need to preserve food under appropriate conditions. To prevent similar cases of food poisoning, it is necessary to investigate cases based on an epidemiological approach and share the findings.

인체의 일주기리듬

이현아,조철현,김린,Lee, Hyunah,Cho, Chul-Hyun,Kim, Leen 대한수면의학회 2014 수면·정신생리 Vol.21 No.2

A 'circadian rhythm' is a self-sustained biological rhythm (cycle) that repeats itself approximately every 24 hours. Circadian rhythms are generated by an internal clock, or pacemaker, and persist even in the absence of environmental time cues, collectively termed 'zeitgebers.' Although organisms generate circadian rhythms internally, they are entrained by environmental stimuli, particularly the light-dark cycle. Measurement of the endogenous melatonin rhythm provides relatively reliable surrogate way of assessing the timing of the internal circadian clock. Also, core body temperature and cortisol can be used as markers of circadian rhythms. The sleep-wake cycle, body temperature, and melatonin rhythm have a stable internal phase relationship in humans and other diurnal species. They play an important role in controlling daily behavioral rhythms including task performance, blood pressure, and synthesis and secretion of several hormones. In this review, we address not only the properties, methods of measurement, and markers of circadian rhythms, but also the physiological and psychological importance of human circadian rhythms.

지하수위 이상 변동에 나타난 2016 M_L5.8 경주 지진의 전조 가능성

이현아,함세영,우남칠,Lee, Hyun A,Hamm, Se-Yeong,Woo, Nam C. 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.4

2016년 9월 12일 발생한 $M_L5.8$ 경주 지진과 2017년 11월 15일 $M_L5.4$ 포항 지진은 국내에 지진 예측가능성에 대한 관심을 불러일으켰다. 지진 예측의 가능성에 대한 회의적인 의견이 있음에도 불구하고 세계적으로는 지진 발생 전 이상 변동을 보이는 인자들의 관측과 평가가 지속되고 있다. 본 연구에서는 양산단층대의 지하수위 정밀 관측을 위해 시범 운용 중인 양산 지하수 정밀관측공에서 2015년부터 관측된 지하수의 비정상적인 상승 사례를 보고하였다. 이 이상 변동은 다양한 수리지질학적 인자들을 고려하였을 때 지진 전조일 가능성이 높다고 판단된다. 그럼에도 불구하고 단일 관정의 단일 요소에서 나타난 자료만으로 지진 전조를 섣불리 판단할 수 없다. 장기적으로는 전조 현상 연구와 평가를 위한 전문기구의 설립이 필요하다. Despite some skeptical views on the possibility of earthquake prediction, observation and evaluation of precursory changes have been continued throughout the world. In Korea, the public concern on the earthquake prediction has been increased after 2016 $M_L5.8$ and 2017 $M_L5.4$ earthquakes occurred in Gyeongju and Pohang, the southeastern part in Korea, respectively. In this study, the abnormal increase of groundwater level was observed before the 2016 $M_L5.8$ Gyeongju earthquake in a borehole located in 52 km away from the epicenter. The well was installed in the Yangsan fault zone, and equipped for the earthquake surveillance. The abnormal change in the well would seem to be a precursor, considering the hydrogeological condition and the observations from previous studies. It is necessary to set up a specialized council to support and evaluate the earthquake prediction and related researches for the preparation of future earthquake hazards.

홍삼 성분의 혈당강하작용 연구 (I) :쥐의 배양 간세포의 당대사 관련 효소 활성에 미치는 홍삼 사포닌 성분의 영향 조사

이현아,권상옥,이희봉,Lee, Hyeon-A,Gwon, Sang-Ok,Lee, Hui-Bong 고려인삼학회 1997 Journal of Ginseng Research Vol.21 No.3

In this study, rat hepatocytes known to have active carbohydrate metabolism were obtained by using the liver perfusion technique to examine the hypoglycemic action of red ginseng saponin components [ginsenoside (mixture, $Rb_1$, and $Rg_1$)] and incubated in two different media-one containing insulin and glucagon (control group), and the other containing glucagon only, The specific activities of some regulatory enzymes such as glucokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and glucose 6-phosphatase, in main pathways which were directly related to the glucose metabolism were compared between these two kinds of hepatocytes cultured in two different media. The effects of red ginseng saponin components [ginsenoside (mixture, $Rb_1$, and $Rg_1$)] under the concentration of $10^3$~$10^6$% on these enzymes In hepatocytes were also investigated, when they were added to these two media. The results were as follows. The specific activity of enzymes such as glucokinase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase related to glucose-consuming pathways of insulin-deficient group was much less than control one, however, their decreased activity was recovered after the addition of ginseng components at all range of concentrations. The increased specific activity of these on - zymes was shown by the addition of ginseng components to the control group. On the other hand, the specific activity of glucose 6-phosphatase related to glucose-producing pathway of insulin-deficient group was much higher than control one, but their Increased activity was decreased after the addition of ginseng components at all range of concentrations. The same results were obtained after the addition of ginseng components to the control group. These results suggest that the red ginseng saponin components might better diabetic hyperglycemia by regulating the activity of enzymes related to glucose metabolism directly and/or Indirectly though more detailed studies were needed.

충격과 마모를 고려한 원자로 핵연료봉 지지격자의 설계

이현아,김종기,송기남,박경진,Lee, Hyun-Ah,Kim, Chong-Ki,Song, Kee-Nam,Park, Gyung-Jin 대한기계학회 2007 大韓機械學會論文集A Vol.31 No.10

The spacer grid set is a component in the nuclear fuel assembly. The set supports the fuel rods safely. Therefore, the spacer grid set should have sufficient strength for the external impact forces such as earthquake. The fretting wear occurs between the spring of the fuel rod and the spacer grid due to flow-induced vibration. Conceptual design of the spacer grid set is performed based on the Independence Axiom of axiomatic design. Two functional requirements are defined for the impact load and the fretting wear, and corresponding design parameters are selected. The overall flow of design is defined according to the application of axiomatic design. Design for the impact load is carried out by using nonlinear dynamic analysis to determine the length of the dimple. Topology optimization is carried out to determine a new configuration of the spring. The fretting wear is reduced by shape optimization using the homology theory. The deformation of a structure is called homologous if a given geometrical relationship holds before, during, and after the deformation. In the design to reduce the fretting wear, the deformed shape of the spring should be the same as that of the fuel rod. This condition is transformed to a function and considered as a constraint in the shape optimization process. The fretting wear is expected to be reduced due to the homology constraint. The objective function is minimizing the maximum stress to allow a slight plastic deformation. Shape optimization results are confirmed through nonlinear static analysis.