• Geomechanics and Engineering
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• 제24권6호
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• pp.519-529
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• 2021

In coal mining activities, the abutment stress of the coal has to undergo cyclic loading and unloading, affecting the strength and seepage characteristics of coal; additionally, it can cause dynamic disasters, posing a major challenge for the safety of coal mine production. To improve the understanding of the dynamic disaster mechanism of gas outburst and rock burst coupling, triaxial devices are applied to axial pressure cyclic loading-unloading tests under different axial stress peaks and different pore pressures. The existing empirical formula is use to perform a non-linear regression fitting on the relationship between stress and permeability, and the damage rate of permeability is introduced to analyze the change in permeability. The results show that the permeability curve obtained had "memory", and the peak stress was lower than the conventional loading path. The permeability curve and the volume strain curve show a clear symmetrical relationship, being the former in the form of a negative power function. Owing to the influence of irreversible deformation, the permeability difference and the damage of permeability mainly occur in the initial stage of loading-unloading, and both decrease as the number of cycles of loading-unloading increase. At the end of the first cycle and the second cycle, the permeability decreased in the range of 5.777 - 8.421 % and 4.311-8.713 %, respectively. The permeability decreases with an increase in the axial stress peak, and the damage rate shows the opposite trend. Under the same conditions, the permeability of methane is always lower than that of helium, and it shows a V-shape change trend with increasing methane pressures, and the permeability of the specimen was 3 MPa > 1 MPa > 2 MPa.

• 대한응급의학회지
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• 제29권6호
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• pp.687-698
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• 2018

Objective: This study examined the characteristics of suicidal attempters, including pre-hospital patients and those who visited the emergency department. Methods: Suicidal attempters who had been reported to the 119 call center were selected between July 2015 and June 2016. Sex, age, place, methods of suicidal attempt, season, time, and suicide success rate were reviewed in the fire center records. Results: A total 961 suicide attempters were enrolled. Among them, 53.6% were males who had an approximately 2.6 times higher mortality than that of females (9.2%). The most preferred place to commit suicide was the home in both sexes (68.0% in male, 82.8% in female) and the most preferred methods was drug intoxication, particularly pesticide. The method with the highest mortality was hanging and the lowest was self-harm. The season of the highest mortality was spring. The success of suicide and the time variation were similar. Most of the un-transferred patients also selected fatal suicide attempts compared to transfer patients. Conclusion: Unlike previous studies, this study includes information on un-transferred patients. Overall, the probability of death was highest as more than 50 years men chose hanging as a method, which had an influence on the un-transferred patients group.

• 한국수자원학회논문집
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• 제48권3호
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• pp.149-158
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• 2015

비상방류시설은 안전한 댐 운영 및 유지관리를 위해서 절대적으로 필요한 시설임에도 불구하고 국내 댐의 경우 이를 고려한 설계가 이루어지지 않아 각 댐의 비상방류 대응 적정성을 판단하기 곤란한 상황이다. 특히 국내 댐의 경우 비상방류시설규모를 산정하는 기준이 일정치 않을 뿐만 아니라 대부분의 용수댐은 별도의 방류시설 조차도 없는 실정이다. 따라서 본 연구에서는 기존댐 방류시설 현황 분석, 국내외 비상방류시설 설계기준 등의 검토와 함께 국내 댐설계기준을 적용한 가상 댐체와 수어댐을 대상으로 수위에 따른 방류능 분석을 수행하였다. 또한 SEEP 프로그램 등을 활용, 수위저하 속도에 따른 제체의 사면 안정성을 검토함으로써 비상방류 시설의 적정규모 산정기준을 제시하고자 하였다. 이를 위하여 수리학적 해석을 통해 저류수심에 따른 제체에 작용하는 힘을 분석하였으며 수위저하 속도 변화에 따른 제체의 안정성을 검토하여 허용수위저하 속도 범위를 제시하였다. 수위 25% 저감은 하중을 50%까지 감소시켜 초기수위 저감이 중요한 것을 알 수 있었다. 가상 댐체는 물론 수어댐에 수위저하 속도 1 m/일을 적용하더라도 제체의 안전성은 보장됨을 확인하였다. 다만, 방류능과 방류 소요일수는 수위별 저류용량 등 저류지 특성과 밀접한 관계가 있어 초기대응을 위해서는 7~10일 이내에 저류수심의 25%를 먼저 방류시키고 나머지 방류량은 1~2개월 이내에 방류할 것을 제안하였다.

• 보건의료산업학회지
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• 제1권1호
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• pp.110-124
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• 2007

Currently, we have seen sudden increase of demand for emergency medical services by reason for high-speed economic development increase of traffics, etc. in this society. Consequently the government enforced & operated emergency medical system in 1991 as a link of more positive countermeasure against it, but many problem; still remain in reality. In particular, the regional emergency medical center designated by the Ministry of Health and Welfare falls short of our expectations for its essential role by the reason of such as insufficiency in professional manpower and institutions concerned in small-scale hospital, matters with transportation system, preference of large hospital, etc. Therefore, this study was conducted grasp for the actual conditions of emergency medical system based upon literature research & the preceding studies and interview research the motive of coming hospital, satisfaction & understand to the subject of 150 persons of patients and their guardians who used regional emergency center of Pusan National University Hospital, thereby examining & analysing the cause of emergency room overcrowding by non-emergency cases, one of the problem; enumerated from preceding studies. The main result of this study is as follows. First the actual condition of non-emergency patients coming hospital for examining overcrowding of emergency medical center showed that, of the patients who used the emergency medical center, non-emergency patients accounted for 49.3%, which acted as the main cause of delaying medical care for emergency cases, cases of which medical person or first-aid man decided to come hospital accounted for 36.1 %, thereby suggesting essential need for re-education & wide public information to even the professional manpower besides patients & guardians for their using emergency medical system. Second, as the result of researching patient acknowledgement with reference to their using emergency medical center, the rate of their giving right answer is no more than 60%, which means that non-emergency cases' using as such is due to the shortage of their knowledge of the said emergency medical center, which suggests us that wider P.R for emergency medical system to common people who may be one of the patients of it at any time is still in need. Third, the result of researching for finding out a future remedy of emergency medical system showed that the users who know well of the way of using emergency medical center had relatively high satisfaction of it, ones who have lesser knowledge of it lower satisfaction and users who feel in need of emergency specialized manpower feel the necessity of public information of emergency medical information center(1339) at the same time. The finding of examining the subject of study, in conclusion, showed that the degree of the patients & their guardians' understanding of emergency medical system is lower and the medical persons concerned also had no distinct difference in their understanding of it from the common people's, which suggests us for extensive enforcement of systematic education and public information in aspect of the government via various media for the purpose of effective operation of emergency medical center.

• 방송공학회논문지
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• 제19권2호
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• pp.184-194
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• 2014

이동통신망을 이용한 재난경보의 신속한 방송을 위해 CBS 기능이 이용된다. 본 논문에서는 이 CBS 기능을 위한 동기식 협력통신 방식을 제안한다. 특히 고속 전송을 위한 동기 방식과 데이터 복구 기법을 제안한다. 고속 전송 환경에서의 동기를 위해 주기 전치부가 있는 프리엠블이 이용되며 데이터 복구를 위해 SC-FDE와 유사한 주파수 영역에서의 Alamouti 기법을 이용한다. 모의실험 결과는 제안된 방식이 CBS에 매우 적합함을 보여준다.

• 조명전기설비학회논문지
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• 제25권4호
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• pp.24-29
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• 2011

When an emergency light turns on due to a blackout, the intensity of illumination is drastically changed from hundreds [1x] to 1.0[1x]. This sharp change of illumination intensity not only lowers the darkness adaptation of the eye, it also degrades the obstacle cognitive ability of the evacuees, resulting in secondary critical accidents due to anxiety, and fear. Thus, this study proposed a convertible emergency lighting fixture that controls the rate of speed of light in two stages by time with darkness adaptation of the eye in consideration. In addition, the effect of such emergency light is verified by suggesting an illumination simulation without increasing the number of light or capacity of battery to make it economically feasible.

• 한국응급구조학회지
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• 제9권2호
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• pp.39-53
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• 2005

This study examines need and qualification of safety education teachers with elementary school students and aims to provide data for improving safety education of elementary school As a result of study, it was found that on need of safety education teacher at elementary school, 'very needed' showed the highest response and students who answered 'the first class emergency medical technician' on qualification of safety education teacher showed the highest safety consciousness and low rate of safety accidents. Therefore, for improving safety education at elementary school, adoption of optional course at college or university to learn qualification and functions necessary for being special teacher and institutional support by the ministry of education that employment after passing elementary school teacher appointment examination are needed.

• 성인간호학회지
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• 제20권1호
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• pp.126-134
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• 2008

Purpose: This study was to explore gender differences on presenting patients with acute myocardial infarction in the emergency department. Methods: The survey was done with 143 emergency medical charts presented to the emergency department and diagnosed with acute myocardial infarction between January 2005 and December 2006. The collected data were analyzed with frequency, chi-square, and t-test. Results: Significant gender differences were apparent in age, route to the emergency department, elapsed time from onset of symptoms to arrival, and initial heart rate. Women were significantly more likely to report hypertension, diabetes, and congestive heart failure than men, but men were significantly more likely to report smoking. Chest pain was the most common initial symptom in both men and women. Women were significantly more likely to report dyspnea and nausea/vomiting than men. Conclusion: Although similarities exist in the associated symptoms of acute myocardial infarction, women might experience different symptoms, compared to men. These findings have implication that patients and health care providers should consider gender difference in presenting symptoms.

• Nuclear Engineering and Technology
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• 제38권3호
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• pp.231-238
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• 2006

Whole-body exposure to high-dose radiation causes injury involving multiple organs that depends on their sensitivity to radiation. This acute radiation syndrome (ARS) is caused by a brief exposure of a major part of the body to radiation at a relatively high dose rate. ARS is characterized by an initial prodromal stage, a latent symptom-free period, a critical or manifestation phase that usually takes one of four forms (three forms): hematologic, gastrointestinal, or cardiovascular and neurological (neurovascular), depending upon the exposure dose, and a recovery phase or death. One of the most important factors in treating victims exposed to radiation is the estimation of the exposure dose. When high-dose exposure is considered, initial dose estimation must be performed in order to make strategy decisions for treatment as soon as possible. Dose estimation can be based on onset and severity of prodromal symptoms, decline in absolute lymphocyte count post exposure, and chromosomal analysis of peripheral blood lymphocytes. Moreover, dose assessment on the basis of calculation from reconstruction of the radiation event may be required. Experience of a criticality accident occurring in 1999 at Tokai-mura, Japan, showed that ARS led to multiple organ failure (MOF). This article will review ARS and discuss the possible mechanisms of MOF developing from ARS.

• 대한임상독성학회지
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• 제3권2호
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• pp.122-125
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• 2005

Paraquat, is a widely used for its great effect as a herbicide. But the mortality rate by paraquat intoxication is known to be very high. It is thought to act by changing form to superoxide and peroxide free radical. Almost paraquat intoxication is through ingestion. A few intoxication of paraquat is through skin absorption. But there was no known death case through skin absorption. We experienced a case of a expired patient by paraquat intoxication through skin abrasion and scratching wound. A 75-year-old man was visited emergency room after motorcycle accident during transporting paraquat. He has multiple abrasion and scratching wound on extremities, and pelvic bone fracture. There was no evidence of ingestion of paraquat. But serum/urine gramoxone level was all positive. In spite of wound irrigation and hemoperfusion, his condition was been gone form bed to worse. 2 days after, multiple organ failure and the respiratory arrest were developed and he was expired. Paraquat intoxication through skin wound is extremely dangerous and death by that could possibly happen