• Title/Summary/Keyword: operation research

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A Dynamic Behavior Evaluation of the Curved Rail according to Lateral Spring Stiffness of Track System (궤도시스템의 횡탄성에 따른 곡선부 레일의 동적거동평가)

  • Kim, Bag-Jin;Choi, Jung-Youl;Chun, Dae-Sung;Eom, Mac;Kang, Yun-Suk;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.517-528
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    • 2007
  • Domestic or international existing researches regarding rail damage factors are focused on laying, vehicle conditions, driving speed and driving habits and overlook characteristics of track structure (elasticity, maintenance etc). Also in ballast track, as there is no special lateral spring stiffness of track also called as ballast lateral resistance in concrete track, generally, existing study shows concrete track has 2 time shorter life cycle for rail replacement than ballast track due to abrasion. As a result of domestic concrete track design and operation performance review, concrete track elasticity is lower than track elasticity of ballast track resulting higher damage on rail and tracks. Generally, concrete track has advantage in track elasticity adjustment than ballast track and in case of Europe, in concrete track design, it is recommended to have same or higher performance range of vertical elastic stiffness of ballast track but domestically or internationally review on lateral spring stiffness of track is very minimal. Therefore, through analysis of service line track on site measurement and analysis on performance of maintenance, in this research, dynamic characteristic behaviors of commonly used ballast and concrete track are studied to infer elasticity of service line track and experimentally prove effects of track lateral spring stiffness that influence curved rail damage as well as correlation between track elasticity by track system and rail damage to propose importance of appropriate elastic stiffness level for concrete and ballast track.

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Studies on the Desertification Combating and Sand Industry Development(I) - Present Status and Countermeasures for the Combating Desertification in China - (사막화방지(沙漠化防止) 및 방사기술개발(防沙技術開發)에 관한 연구(硏究)(I) - 중국(中國)의 사막화현황(沙漠化現況) 및 방지대책(防止對策) -)

  • Woo, Bo-Myeong;Lee, Kyung-Joon;Jeon, Gi-Seong;Kim, Kyung-Hoon;Choi, Hyung-Tae;Lee, Seung-Hyun;Lee, Byung-Kwon;Kim, So-Yeon;Lee, Sang-Ho;Jeon, Jeong-Ill
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.3 no.3
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    • pp.45-76
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    • 2000
  • The purposes of this study were to investigate and understand the present status of various types of "deserts", such as sand desert, gravel desert, rock desert, earth desert, salt desert, desert, rocky desert, gobi desert, sandy desert, clay desert, etc., and the general countermeasures for the combating "desertification" "desertization", and to develop the technologies on the revegetation and restoration for the combating desertification in China. The methods of this study were mainly composed of field surveys on the several experimental sites and research institutes related to combating desertification in China, and examinations on the various technologies for the combating desertification at the Daxing Experimental Station of Beijing Forestry University. The conclusion from this study may be summarized as follows; 1. Status and tendency of desertification in China : China is one of the countries seriously threatened by desertification. Desertification affected areas in China are mainly distributed in arid, semi-arid and dry sub-humid areas in China, covering the most regions of the Northeast China (eastern region of Inner-Mongolia), the northern part of the North China (middle and western region of Inner-Mongolia, Shaanxi, Ningsha, Gansu) and the western part of the Northwest China (Xinzang, Qinghai, Xizang). The total area affected by desertification in China is approximately 2.622 million $km^2$. It covers 27.3% of the total territory of China. Until recently, it is estimated that the annual spreading ratio of desertification in China is 2,460 $km^2$. Therefore, desertification is mostly serious problems facing to the Chinese people. 2. The causes and environmental effect of desertification : The desertification in China is mainly caused by compound factors, including natural condition and human activities. In China, the desertification is started by the decrease of precipitation, continuous dry and drought, strong wind, wind and water erosion, land degradation and loss of natural vegetation caused by climate variation, and accelerated by the human activities, such as over-cultivating, over-grazing, over-cutting of woods, irrational use of water resources. Because desertification has affected the geographical features, soil nutrients contents, salinity, vegetation coverage and the functions of ecosystem, the environmental deteriorations in the desertification affected areas are very seriously. 3. The fundamental strategies of combating desertification in China are the increase of education and awareness of people through various mass media, the revision of laws to guarantee operation of Desertification Combating Law and to improve many relating laws and regulations, the application of advanced technologies and training of experts, the establishment of discriminative policies, and increasing arrangement of budget-investment, and so on. China, as a signed country in UNCCD, has made efforts for the combating desertification. Korea is also signed country in UNCCD, so we should play an important role in the desertification combating projects of China for the northest asia and global environmental conservation as well as environmental conservation of Korea.

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Laparoscopy Application to Determine Estrous Cycle in Korean Black Goats (복강경을 이용한 한국흑염소의 성주기 판정)

  • Yang, H.S.;Jang, S.K.;Yong, H.W.;Cho, J.K.;Shin, S.T.
    • Journal of Embryo Transfer
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    • v.22 no.1
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    • pp.69-74
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    • 2007
  • This study was performed to determine the estrous cycles by macroscopic observation of the ovarian changes using the laparoscopy and to make use of these results for embryo transfer in Korean black goat (Copra hircus aegagrus). Laparoscopic examinations of the ovaries were performed from 2 days after $CIDR^(R)$ removal to 22 days after ovulation. The serial morphological changes of follicles and corpus luteum (CL) were observed. CL was classified corpus hemorrhagicum(CH), corpus luteum (CL) and corpus albicans (CA) by its maturation and regression. On the day before ovulation (Day 0), Graafian follicles (GF) were found on one or both ovaries. On the day (Day 1) and $2^{nd}$day (Day 2) of ovulation, and ovulation depression (OD) and an early stage corpus hemorrhagicum $(CH_1)$ were observed at the site of GF, respectively. On Days 3 to 4, more developed and enlarged corpus hemorrhagicum $(CH_2\;and\;CH_3)$ arised from the ovulation of the GF with well vascularization. On Days 5 to 6, it was identified that mature corpus luteum $(CL_3)$ was grown on the ovary, and fully developed CL with adjacent follicles were occupied most part of the ovary on Days 17 and 18. Then the size of CL was diminished, and completely luteal regression $(CL_1\;or\;CA)$ with new large follicle was identified on Days 20 and 22. From these results, the 4 stages of the estrous cycle in Korean black goats were 1) estrus (Day 0) for 1 day, 2) metestrus $(Day\;1{\sim}4)$ for 4 days (stage of CH development), 3) diestrus $(Day\;5{\sim}16/17)$ for 12 or 13 days (luteal stage), and 4) proestrus $(Day\;17/18{\sim}20/22)$ for 4 or 5 days (stage of luteal regression and follicular growing). Laparoscopy for observation of ovarian changes was invasive than laparotomy. Additionally, it had advantages of reduced adhesion and quick operation time. It was considered that laparoscopic examination of ovarian changes will be useful for embryo transfer in the Korean black goats.

Real Option Analysis to Value Government Risk Share Liability in BTO-a Projects (손익공유형 민간투자사업의 투자위험분담 가치 산정)

  • KU, Sukmo;LEE, Sunghoon;LEE, Seungjae
    • Journal of Korean Society of Transportation
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    • v.35 no.4
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    • pp.360-373
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    • 2017
  • The BTO-a projects is the types, which has a demand risk among the type of PPP projects in Korea. When demand risk is realized, private investor encounters financial difficulties due to lower revenue than its expectation and the government may also have a problem in stable infrastructure operation. In this regards, the government has applied various risk sharing policies in response to demand risk. However, the amount of government's risk sharing is the government's contingent liabilities as a result of demand uncertainty, and it fails to be quantified by the conventional NPV method of expressing in the text of the concession agreement. The purpose of this study is to estimate the value of investment risk sharing by the government considering the demand risk in the profit sharing system (BTO-a) introduced in 2015 as one of the demand risk sharing policy. The investment risk sharing will take the form of options in finance. Private investors have the right to claim subsidies from the government when their revenue declines, while the government has the obligation to pay subsidies under certain conditions. In this study, we have established a methodology for estimating the value of investment risk sharing by using the Black - Scholes option pricing model and examined the appropriateness of the results through case studies. As a result of the analysis, the value of investment risk sharing is estimated to be 12 billion won, which is about 4% of the investment cost of the private investment. In other words, it can be seen that the government will invest 12 billion won in financial support by sharing the investment risk. The option value when assuming the traffic volume risk as a random variable from the case studies is derived as an average of 12.2 billion won and a standard deviation of 3.67 billion won. As a result of the cumulative distribution, the option value of the 90% probability interval will be determined within the range of 6.9 to 18.8 billion won. The method proposed in this study is expected to help government and private investors understand the better risk analysis and economic value of better for investment risk sharing under the uncertainty of future demand.

The Development of On-Line Statistics Program for Radiation Oncology (방사선종양학과 On-line 통계처리프로그램의 개발)

  • Kim Yoon-Jong;Lee Dong-Hoon;Ji Young-Hoon;Lee Dong-Han;Jo Chul-Ku;Kim Mi-Sook;Ru Sung-Rul;Hong Seung-Hong
    • Radiation Oncology Journal
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    • v.19 no.4
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    • pp.369-380
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    • 2001
  • Purpose : By developing on-line statistics program to record the information of radiation oncology to share the information with internet. It is possible to supply basic reference data for administrative plans to improve radiation oncology. Materials and methods : The information of radiation oncology statistics had been collected by paper forms about 52 hospitals in the past. Now, we can input the data by internet web browsers. The statistics program used windows NT 4.0 operation system, Internal Information Server 4.0 (IIS4.0) as a web server and the Microsoft Access MDB. We used Structured Query Language (SQL), Visual Basic, VBScript and JAVAScript to display the statistics according to years and hospitals. Results : This program shows present conditions about man power, research, therapy machines, technics, brachytherapy, clinic statistics, radiation safety management, institution, quality assurance and radioisotopes in radiation oncology department. The database consists of 38 inputs and 6 outputs windows. Statistical output windows can be increased continuously according to user's need. Conclusion : We have developed statistics program to process all of the data in department of radiation oncology for reference information. Users easily could input the data by internet web browsers and share the information.

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Factors Affecting the Survivals of Out-of-hospital Cardiac Arrests by 119 Fire Service (119구급대원의 심폐소생술 성적 분석 - 병원전 심정지를 중심으로 -)

  • Kang, Byung-Woo
    • The Korean Journal of Emergency Medical Services
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    • v.9 no.2
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    • pp.111-128
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    • 2005
  • Background: Cardiac arrest is one of the most critical diseases which can likely lead to severe cerebral disability or brain death when the cases can not recover their circulation within 10 minutes. Saving out-of-hospital cardiac arrest cases is a recent concern in Korea. Resuscitation has become an important multidisciplinary branch of medicine, demanding a spectrum of skills and attracting a plethora of specialities and organizations. The best survival can be achieved if all the following links have been optimized : rapid access, and early CPR, defibrillation and ACLS, Since the "Utstein Style" was advocated in 1991, many reports about out-of-hospital cardiac arrest have been published based on this guideline. These differences prevent valid inter-hospital and international comparisons. However, it is not known how effective resuscitation has become to the patients. In other words, there are no guidelines for reviewing, reporting, and conducting research on resuscitation in Korea. This dissertation aims to provide the basic data for a unified reporting guideline of resuscitation in Korea and evaluating the out-of-hospital factors associated with survival discharge of out-of-hospital cardiac arrest. Methods: As for this study, uses the collected data about Out-of-hospital cardiac arrests at 4 area, from January, 2005 to April. 2005. With a retrospective study, 174 cases were analyzed. The data was recorded based on the Out-of-Hospital Utstein Style. Results: Resuscitation was performed on 174 out-of-hospital cardiac arrest cases at the 4 area 14 patients(8.1%) recovered their spontaneous circulation. Overall, the ROSC of the out-of-hospital cardiac arrest patients was 8.1%, which was poorer than that of western countries. Gender distribution was 50 females(28.7%) and 124 males(71.3%), approximately twice as many males as females. ROSC of witnessed arrests was found out to be 97.7%. The ratio of the witnessed arrest groups showed higher results than that of unwitnessed arrest groups in the above-examined cases. Cardiac etiology consisted of cardiac(33.5%), non-cardiac(45.7%), trauma(20.1%), and unknown(6.0%). Cardiac was the best performance. Initial rhythm showed Ventricular Tachycardia/pulseless Ventricular Fibrillation in 8 patients(6.0%), asystole in 100(75.2%) and unknown in 25(18.8%). The results of the Ventricular Tachycardia/pulseless Ventricular Fibrillation showed higher results than the others cases, The proportion of the cardiogenic cause was 33.5%, which was only half of western countries. Ventricular Tachycardia/pulseless Ventricular Fibrillation is relatively rare. These differences were due to the prevalent pattern of Out-of-hospital cardiac arrest as well as prematurity of the EMSS. Bystander CPR was practiced on 13 patients(7.52%). ROSC was shown in 46.2% cases. CPR by EMT was carried out on 167 cases(96.5%). ACLS by EMf was rare. From collapse, 4 cases(2.6%) arrived to ED within 6 minutes. 13 (8.6%) within 10 minutes, and 49(32.5%) over 31 minutes. The sooner the patients arrived, the greater the ratio of ROSC and discharged alive became, and the same with collapse time to ROSC. As the results of the logistic regression analysis, ROSC was found out to be highly influenced by the time of ED arrival from collapse and Ventricular Tachycardia/pulseless Ventricular Fibrillation. Therefore, the ratio of ROSC depends on not any single factor but various intervention factors. Conclusion: This dissertation presents the following suggestions and directions of the study hereafter. First, the first step for a chain of survival should be taken to activate EMSS early with a phone as soon as cardiac arrests are witnessed. Second, it is keenly needed that emergency medical technicians should be increased through emergency education for living. Third, it is necessary to establish the emergency transportation system. Fourth, most of the Koreans have little understanding of EMT and the present operation systems have many problems, which should be fundamentally changed. Fifth, it is required to have an active medical control over Out-of-hospital CPR, And proper psychological supports should be given not only to patients themselves and their family but also individuals who are engaged in emergency situation. Finally, through studies hereafter on nationwide, comprehensive, and standard forms, it is needed to examine into the biological figures of human body, causes and trends of cardiac arrests, and then, to enhance the survival rate of Out-of-hospital cardiac arrests. Korean guidelines for Cardiopulmonary resuscitation need to be made.

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A Study on the Health Insurance Management System; With Emphasis on the Management Operating Cost (의료보험 관리체계에 대한 연구 - 관리비용을 중심으로 -)

  • 남광성
    • Korean Journal of Health Education and Promotion
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    • v.6 no.2
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    • pp.23-39
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    • 1989
  • There have been a lot of considerable. discussion and debate surrounding the management model in the health insurance management system and opinions regarding the management operating cost. It is a well known fact that there have always been dissenting opinions and debates surrounding the issue. The management operating cost varies according to the scale of the management organization and component members characteristics of the insurance carrier. Therefore, it is necessary to examine and compare the management operating cost to the simulated management models developed to cover those eligible for the health insurance scheme in this country. Since the management operating cost can vary according to the different models of management, four alternative management models have been established based on the critical evaluation of existing theories concerned, as well as on the basis of the survey results and simulation attempts. The first alternative model is the Unique Insurance Carrier Model(Ⅰ) ; desigened to cover all of the people with no classification of insurance qualifications and finances from the source of contribution of the insured, nationwide. The second is the Management Model of Large-scale District Insurance Carrier(Ⅱ) ; this means the Korean society would be divided into 21 large districts; each having its own insurance carrier that would cover the people in that particular district with no classification of insurance qualifications arid finances as in Model I. The third is the Management Model of Insurance Carrier Divided by Area and Classified with Occupation if Largescale (Ⅲ) ; to serve the self-employed in the 21 districts divided as in Model Ⅱ. It would serve the employees and their dependents by separate insurance carriers in large-scale similar to the area of the district-scale for the self-employed, so that the insurance qualifications and finances would be classified with each of the insurance carriers: The last is the Management Model of the Multi - insurance Carrier (Ⅳ) based on the Si. Gun. Gu area which will cover their own self- employed people in the area with more than 150 additional insurance carriers covering the employees and their dependents. The manpower necessary to provide services to all of the people according to the four models is calculated through simulation trials. It indicates that the Management Model of Large-scale District Insurance Carrier requires the most manpower among the four alternative models. The unit management operating costs per the insured individuals and covered persons are leveled with several intervals based on the insurance recipients. in their characteristics. The interval levels derived from the regression analysis reveal that the larger the scale of the insurance carriers is in the number of those insured and covered. the more the unit management operating cost decreases. significantly. Moreover. the result of the quadratic functional formula also shows the U-shape significantly. The management operating costs derived from the simulated calculation. on the basis of the average salary and related cost per staff- member of the Health Insurance Societies for Occupational Labours and Korean Medical Insurance Corporation for the Official Servants and Private School Teachers in 1987 fiscal year. show that the Model of Multi-insurance Carrier warrants the highest management operating cost. Meanwhile the least expensive management operating cost is the Management Model of Unique Insurance Carrier. Insurance Carrier Divided by Area and Classified with Occupation in Large-scale. and Large-scale District Insurance Carrier. in order. Therefore. it is feasible to select the Unique Insurance Carrier Model among the four alternatives from the viewpoint of the management operating cost and in the sense of the flexibility in promoting the productivity of manpower in the human services field. However. the choice of the management model for health insurance systems and its application should be examined further utilizing the operation research analysis for such areas as the administrative efficiency and factors related to computer cost etc.

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Surgical outcome of severe pulmonary arterial hypertension secondary to left-to-right shunt lesions (심한 폐동맥 고혈압을 동반한 좌우 단락 질환 환자의 수술 후 경과)

  • Lee, Cha Gon;Jeong, Su-In;Huh, June;Kang, I-Seok;Lee, Heung Jae;Yang, Ji-Hyuk;Jun, Tae Gook
    • Clinical and Experimental Pediatrics
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    • v.53 no.2
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    • pp.195-202
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    • 2010
  • Purpose : Despite recent advances in pulmonary hypertension management and surgery, appropriate guidelines remain to be developed for operability in congenital heart disease with pulmonary artery hypertension (PAH). Our aim was to evaluate clinical outcomes of patients with severe PAH who underwent surgical closure of left-to-right shunt lesions (LRSL) on the basis of pulmonary reactivity. Methods : We retrospectively reviewed 21 patients who underwent surgical closure of LRSL with severe PAH (${\geq}8$ Wood unit) from January 1995 to April 2009. The median age at operation was 26 years. Atrial septal defect, ventricular septal defect (VSD), VSD and patent ductus arteriosus (PDA), and PDA was present in 11, 4, 4, and 2 patients, respectively. Results : Operability was based on vasoreactivity of PAH. Of the 21 patients, 5 showed response to pulmonary vasodilator therapy and 8 showed vasoreactivity after balloon occlusion of defects. The remaining 8 patients were considered operable because of significant left-to-right shunt (Qp/Qs ${\geq}1.5$). Five patients underwent total closure of defects and 16 were left with small residual shunts. The median follow-up duration was 32 months. There was no significant postoperative mortality or morbidity. Systolic pulmonary artery pressure (PAP) decreased in all but 2 patients. All patients except 1 showed improvement of New York Heart Association functional class. Conclusion : Closure of LRSL in patients with severe PAH on the basis of pulmonary vasoreactivity seems reasonable. PAP and clinical symptoms improved in most patients. Further research is needed for the evaluation of long-term results.

A study on an evaluation model for industrial information systems by industry sectors (업종별 특성을 고려한 기업정보화 성숙모형)

  • 진경수;임춘성;박찬권
    • Proceedings of the CALSEC Conference
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    • 2002.01a
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    • pp.86-106
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    • 2002
  • Informatization is a process that corporation's external environmental factors and internal environmental factors influence as complex. is a phenomenon that appears via this process. To evaluate that informatization was propeled well or informatization level is high can be dangerous work extremely by only once-over-lightly some factors, organization information ability is superior or infrastructure is constructed well. Therefore, an evaluation for industrial information systems that consider corporation's external environment and internal environment configurationally and objective estimation through this is required in national dimension. This research sorted types of business using types of business classification of 2001 EIII(Evaluation Indices of Industrial Informatization) laying stress on corporation's product and product production process for reflecting various industrial classification. And we are dividing whole our country corporations by manufacture industry, the construction industry, distribution industry, service industry, banking industry 5 types of business. To see such classed types industry classification from consistent viewpoint, we saw them within new framework, purchase, operation, physical distribution, marketing and sale. service etc. laying stress on primary businesses except support businesses of planning, financial management etc. To draw special quality of business center from primary business of each types of business, we draw industry classification Key Capability that centers when plans corporation's corporate strategy and information strategy. And we deducted industrial classification key production business connected with industry classification Key Capability. After drawing an evaluation items for industrial information systems in informatization analysis viewpoint laying stress on drawn businesses. Finally we did Case Study by making out an evaluation for industrial information systems questionnaire that considers special quality of manufacturing industry. Through EIII that consider the industrial classification, we could know that it explains the corporation's purchase, production, distribution in general and detail.

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The Factors Influencing Survival of Out-of-hospital Cardiac Arrest with Cardiac Etiology (병원 밖에서 발생한 심인성 심장정지환자의 생존 관련 요인 7년간 국가심장정지조사사업 자료 활용)

  • Jeong, Su-Yeon;Kim, Chul-Woung;Hong, Sung-Ok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.560-569
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    • 2016
  • Purpose The purpose of this study was not only to explore the factors associated with the survival of OHCA(Out-of-hospital Cardiac Arrest), but to provide ideas for improving the operation of emergency medical system in Korea. Method 90,734 OHCAs(Out-of-hospital Cardiac Arrest) with a cardiac etiology, who had been transported by 119 EMS ambulances for seven years from 2006 to 2012 in Korea, were analyzed. The data had a multilevel structure in that patient's survival in the same region is interrelated, so two-level (patient-region) logistic regression analysis was applied to adjust this correlation. Results The adjusted OR in group who were given CPR(Cardiopulmonary Resuscitation) by a bystander were 1.40 for survival to discharge. In addition, the adjusted OR in the group with an implementation of AED (automated external defibrillator) before arriving in hospital was 2.98 for survival to discharge. we categorized some continuous variables (number of emergency physician, OHCAs volume fo hospital, area deprivation level) into five quintiles. The adjusted OR in the number of emergency physician compared with Q1(lowest) was 1.29(Q2), 2.89(Q3), 3.39(Q4), 4.07(Q5), respectively. the adjusted OR in OHCAs volume of each hospital compared with Q1(lowest) was 2.06(Q2), 3.06(Q3), 3.46(Q4), 4.36(Q5), respectively. Lastly, the adjusted OR in deprivation level compared with Q1(least deprived area) was 0.72(Q4), 0.64(Q5) so that the adjusted OR of survival to discharge tended to decrease in more deprived districts. Conclusion The survival to discharge was better significantly in group given CPR by a bystander and with the implementation of AED before arriving in hospital. The survival to discharge tended to be significantly better in hospitals with a larger number of emergency physicians and higher volume of OHCAs in less deprived districts.