레이저 스캐너 기반 자율주행용 교차로 내 주변 차량 인지 알고리즘 개발

학위논문 (석사)-- 서울대학교 대학원 공과대학 기계항공공학부, 2017. 8. 이경수.The aim of this study is designing surrounding vehicle movement perception algorithm in urban condition. In recent autonomous vehicle industry, many researchers are focusing on three major topics which is called environment perception, localization and designing controller for autonomous vehicle these days. Especially for the perception technology, the design of the algorithm follows the characteristics of the target environment or objects. In Urban condition, to design safe drivable path for autonomous vehicle, the objects position is much important than high way conditions. Also, various objects appear which cannot be detected with RADAR or yield fault case with camera. Because of these reasons, many research are trying to fuse different sensors including camera, RADAR and LiDAR to overcome the challenges that can occur in urban conditions, therefore, laser scanner based target detecting technology is needed to perceive in city road. The tracking filter consists of two parts, shape estimation and tracking filter. To fuse with other sensors or designing target filter, there should be a step for compressing point cloud group information into some representative point or state. Thus in shape estimation parts, we transform the laser scanners point cloud data into vehicle position state measurement value. Vehicle shape estimation also consists of two parts, clustering and shape extraction. Clustering classify the total point cloud into object level and shape extraction estimates the vehicle liked objects position information. The clustering part works based on Euclidean Minimum Spanning Tree (EMST), and for the shape extraction, Random Sample Consensus (RANSAC) method is used to estimate the target objects rear and side edge. The second part, tracking filter, has two different filters. Particle filter estimates the target vehicles position including heading angle. To improve the tracking performance of the particle filter, Kalman filter is also designed to estimate the velocity and yaw rate recursively to update the process model of the particle filter. The performance of the proposed algorithm has been verified with several stages. To check quantitative error level, off-line simulation is held for profile based motion tracking case and designed intersection simulator with simple path tracking algorithm for the target vehicle. In these conditions, the exact target vehicles position information was known, thus we verified the error level of the lateral/longitudinal direction of target vehicles local coordinate which is important information when designing driving path or controller. For the second step, simulation with point cloud data which is collected from the test vehicle was held to verify its performance for actual vehicle condition. As a final stage, for integrating into autonomous vehicle, the proposed algorithm evaluated into the test vehicle for guaranteeing on-line performance.Chapter 1 Introduction 1 1.1 Research Background 1 1.2 Research Overview 3 Chapter 2 Target Vehicle Tracking Filter 4 2.1 Laser scanner Data Post-processing 6 2.2 Vehicle Tracking with Particle Filter 9 2.3 Process model Input Update with Kalman Filter 11 Chapter 3 Simulation 14 3.1 Pre-defined Profile based Simulation 14 3.2 Intersection Environment based Simulation 22 Chapter 4 Vehicle Experiment Data Test 28 4.1 Test Vehicle Configuration 28 4.2 Vehicle Experiment data based Simulation 30 4.3 Actual Vehicle Test 40 Chapter 5 Conclusion 45 Bibliography 46 국문초록 49Maste

수술 후 사망률을 예측하기 위한 다면적 노쇠 평가 도구 개발

학위논문 (석사)-- 서울대학교 대학원 : 의학과, 2015. 2. 김광일.Background: The number of geriatric patients who undergo surgery has been increasing, and they show an increased mortality rate after surgery compared to younger patients. However there are insufficient tools to predict post-operative outcomes in older surgical patients. We aimed to design a predictive model for adverse outcomes in older surgical patients. Methods: From October 19, 2011, to July 31, 2012, we enrolled 275 consecutive elderly patients (aged ≥ 65 years) undergoing intermediate-risk or high-risk elective operations in the Department of Surgery of single tertiary hospital. Comprehensive geriatric assessment (CGA) was performed before surgery, and we developed a new scoring model to predict 1-year all-cause mortality using the results of CGA. The secondary outcomes were postoperative complications (eg, pneumonia, urinary tract infection, delirium, acute pulmonary thromboembolism, and unplanned intensive care unit admission), length of hospital stay, and discharge to nursing facility. Results: Twenty-five patients (9.1%) died during the follow-up period (median [interquartile range], 13.3 [11.5-16.1] months), including 4 in-hospital deaths after surgery. Twenty-nine patients (10.5%) experienced at least 1 complication after surgery and 24 (8.7%) were discharged to nursing facilities. Malignant disease and low serum albumin levels were more common in the patients who died. Among the geriatric assessment domains, Charlson Comorbidity Index, dependence in activities of daily living, dependence in instrumental activities of daily living, dementia, risk of delirium, short midarm circumference, and malnutrition were associated with increased mortality rates. A multidimensional frailty score model composed of the above items predicted all-cause mortality rates more accurately than the American Society of Anesthesiologists classification (area under the receiver operating characteristic curve, 0.821 vs 0.647P = .01). The sensitivity and specificity for predicting all-cause mortality rates were 84.0% and 69.2%, respectively, according to the models cutoff point (>5 vs ≤5). High-risk patients (multidimensional frailty score >5) showed increased postoperative mortality risk (hazard ratio, 9.0195% CI, 2.15-37.78P = .003) and longer hospital stays after surgery (median [interquartile range], 9 [5-15] vs 6 [3-9] daysP < .001). Conclusions: The multidimensional frailty score based on comprehensive geriatric assessment is more useful than conventional methods for predicting outcomes in geriatric patients undergoing surgery.Abstract i Contents iii List of tables and figures iv Introduction 1 Methods 3 Results 8 Discussion 22 References 26 Abstract in Korean 30Maste

스페인 펠리페 2세가 명나라 황제에게 보내는 편지

신의 은총으로 스페인과 나폴리, 시칠리아, 예루살렘 등의 왕이자, 또 한 (서)인도와 대양의 대륙과 섬들의 왕이며, 오스트리아의 대공이고, 밀 란과 브라반테의 부르고뉴 공작이고, 합스부르크와 플랑드르와 티롤 등의 백작인 돈 펠리페는 강력하고 경애하는 중국의 왕에게 진심으로 번영과 번창을 축원하며, 좋은 일들이 많이 일어나길 기원합니다. 필리핀 섬에 파견된 나의 총독들의 보고와 종교인들을 통해서 국왕께 서 위대한 왕국을 현명하고 정의롭게 다스리고 계시다는 사실과 우리가 도착해서 쉬고 있는 항구와 여러 곳에서 귀국의 신하들이 우리 신하들을 아주 잘 대해주고 있다는 것을 잘 알고 있습니다. 이에 대해 깊은 감사를 드리며 귀국의 우정에 대단히 기쁜 마음을 가지고 있습니다

하이데거 사유에서 생기(Ereignis)와 무(Nichts)의 관계에 대하여

학위논문 (석사) -- 서울대학교 대학원 : 인문대학 철학과(서양철학전공), 2020. 8. 박찬국.인간은 어떻게 고유한 자기로 거듭나게 되는가? 그가 존재의 유한함을 자각하는 것으로부터 고유한 자기가 되고자 하는 자각으로의 이끌림은 어떻게 가능한가? 인간(현존재)이 자신의 고유한 존재를 획득함에 따라서 세계와 존재가, 그리고 그가 경험하는 시간이 어떻게 변화하는가? 이 질문들에 대한 탐구로써 본고는 하이데거 사유에서 생기(Ereignis)와 무(Nichts)의 연관을 탐색하였다. 현존재가 자신의 실존을 고유하게 살아낸다는 의미를 지닌 본래성(Eigentlichkeit) 개념으로부터 발전된 생기 개념은 후기 하이데거의 주요 개념이다. 생기는 이뿐 아니라 세계의 고유한 생기를 의미하기도 하는데, 현존재와 세계의 고유한 현성을 아우르는 생기의 의미는 존재의 현성이다. 하이데거 사유에서 존재의 열려 있음, 그리고 현성은 존재의 은닉된 차원으로서의 무로부터 이해될 필요가 있다. 존재의 은닉, 곧 존재의 무성이 존재의 열려있음의 근거라는 것은 무엇을 의미하는가? 이 질문에 대한 탐구를 위해 본고는 전기 하이데거의 무 개념에서부터 후기 하이데거의 무 개념으로 넘어가는 과정을 살폈다. 무가 현존재의 고유한 자기에 대한 발견을 촉구할 뿐 아니라 현존재의 고유함의 근거가 되는 존재의 고유함이 무로부터 발원한다는 이해로 나아가는 과정을 추적했다. 이어 존재는 유한성에 의해 각인되어 있는데 따라서 존재의 무성은 시간의 유한성에 의해 근거지어지는 것으로 드러난다. 시간의 유한성은 존재 이해의 지평일 뿐 아니라 존재가 탈자적으로 현성하도록 하는 근거로서 드러난다. 존재의 자기 자신과의 관계가 동일자로의 회귀가 되지 못하도록 하는 것이 존재의 무성이며, 나아가 존재의 무성이 시간의 유한성 속에서 근거지어지기에 현존재의 고유한 생기는 시간의 유한성에 대한 수용 속에서 가능하다. 요약하건대 생기 개념의 탐색을 위해서 무에 대한 탐색이 필요했으며, 생기는 존재의 은닉으로서의 무가 존재의 열려있음에 대한 근거가 되는 사건을 가리킨다. 이는 존재가 시간의 무성(유한성) 속에서 고유하게 현성한다는 것을 의미한다. 존재의 현성으로서의 생기는 무가 갖고 있는 생성의 성격에 대한 긍정적인 표현이 된다.1.서론 5 2.생기로부터의 무 8 2.1.본래성(Eigentlichkeit)과 생기(Ereignis) 8 2.2.현존재의 무규정성과 시간 16 2.3.목적 개념에서의 능동성과 수동성 27 2.4.무로의 초월과 생기 34 3.무로서의 무 41 3.1.불안과 무: 전기 하이데거의 '불안의 무'의 한계 가늠 41 3.2.존재와 무의 공속 47 3.3.시간의 유한성과 무 56 3.4.유한함과 고유함: 무와 생기 62 4.생기와 무의 동일성 66 4.1.존재와 존재자에서 동일성과 차이의 층위 66 4.2.시간의 시간화에서의 생기와 무 72 4.3.세계의 세계화에서의 생기와 무 81 4.4.사물의 사물화에서의 생기와 무 87 5.결론 93Maste

Estudio sobre la Peregrinación de la Leyenda de Buda a España: Sobre la Primera Versión Cristianizada

중세에 스페인을 비롯한 전 유럽에서 널리 퍼졌던 성인 열전 은 부처 설화에서 그 원형을 찾을 수 있다. 인도에서 산스크리트어로 기록된 이 설화는 시간의 흐름에 따라 서진(西進)하여, 먼저 마니교 판본으로 고대 페르시아어와 고대 터키어의 판본으로 나타난다. 이후 아랍 지역에 유입되어 이슬람교적인 성격에 맞게 변형되어 유포되다가, 약 10-11세기경 그루지야와 그리스 지역으로 전해져 기독교화 된다. 인도에서 출발한 부처 설화가 긴 여정을 거치면서 여러 문화권으로 흡수, 변형되다가 종국에는 그루지야와 그리스를 거치면서 싯다르타가 기독교 성인 호사팥으로 탈바꿈하게 된다..

TSV 모델을 포함하는 상위 레벨 3D-IC 열 시뮬레이터

학위논문 (석사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2014. 8. 최기영.수십 년 동안 반도체 기술에서 주요 관심사는 집적도(degree of integration)를 높이는데 있었다. 그러나 기존의 2D 집적회로(Integrated Circuit)에서의 집적도 향상은 이제 한계에 다다르고 있다. 이에 2D의 die를 쌓아 올리는 방법을 고안하게 되었으며 이 3D stacking 방법은 유망한 기술로 전망되고 있다. 3D로 쌓아 올려진 die는 한 평면에 나란히 있을 때보다 같은 면적에 대해 수 배 이상 그 집적도가 커지고 나란히 연결되는 대신 수직으로 전선이 연결되기 때문에 그 길이도 현저히 짧아진다. 총 전선길이 감소는 실질적으로 임계 경로 지연시간(critical path delay)의 단축과 전선에서 소모하는 에너지 감소 등 여러 가지 장점들이 있다. 그러나 반대로 2D 상태에 비해 전력 소모의 집적도가 올라가고 공기 접촉 면적이 상대적으로 많이 감소하기 때문에 더 큰 열 문제를 맞이하게 된다. 열 문제를 분석하고 해결하기 위해서는 온도를 측정할 수 있는 열 시뮬레이터가 필요하다. 열 시뮬레이터는 포화 온도를 측정하는 steady state(정상 상태) 분석과 순간 온도를 측정하여 온도변화의 추이를 볼 수 있는 transient 분석 두 가지의 경우가 있다. 기존에 있던 많은 열 시뮬레이터들은 2D-IC를 다방면에서 분석하는 방법을 제시하였다. 그러나 3D-IC를 분석하는 열 시뮬레이터는 많지 않고 그 중에 TSV를 고려하는 동시에 steady state와 transient 분석을 모두 할 수 있는 시뮬레이터는 없었다. TSV와 온도를 고려하는 것은 충분히 의미가 있다. TSV(through silicon via)는 3D로 올려진 die들의 전선을 서로 연결하기 위한 장치로 구리(간혹 텅스텐이 사용되기도 함)로 이루어진 원기둥 형태이며 이는 die들을 관통하여 설치된다. 이 때 구리는 TSV 원기둥의 안 쪽에 위치한다. TSV는 전선을 연결하는 역할을 할 뿐만 아니라 전체 칩의 열 문제를 해소하는 역할도 한다. TSV는 보통 패키지에서 spreader와 heatsink를 제외한 die들을 관통하여 연결하고 있어서 spreader나 heatsink와 다른 die 사이의 열 교환을 쉽게 해 준다. TSV의 열 전도율은 칩의 열 전도율보다 크다. 또한 3D stack 중간에 필요에 의해 존재하는 여러 단열물질들을 관통함으로써 TSV는 큰 냉각역할을 할 수 있게 된다. 이에 TSV로 열 문제를 해결해 보려는 시도가 점차 많아지고 있다 [4]. 본 논문에서는 transient 열 분석과 steady state 열 분석이 모두 가능한 시뮬레이터를 제시하였으며 그 성능을 여러 실험들로 증명하였다.A High Level Thermal 3D-IC simulator including TSV model 성 명 Sunwook Kim 학과 및 전공 Electrical Engineering The Graduate School Seoul National University For decades, the main interest in semiconductor technology has been in increasing the degree of integration. However, the increase in integration on 2D ICs (integrated circuits) is approaching to its limit. So methods of stacking dies are considered to be a promising technology. 3D stacked die is far more scalable and allows higher degree of integration compared to 2D die. It shortens wire lengths and decreases not only critical path delays but also power consumed by wires. But as the result of stacking, the density of power dissipation rises whereas the area of the surface contacting air decreases. To analyze and solve the thermal problems, a thermal simulator that can estimate temperature is required. There are two aspects of thermal analysis. One is steady state analysis and the other is transient analysis. There are many existing simulators for thermal analysis of 2D-ICs. But there are a few simulators that can analyze 3D-ICs and none of them can perform both steady state and transient analysis while considering TSVs. TSVs made up of copper connect wires on different stacked dies using cylindrical holes through the dies. The copper of the TSVs fills up the cylindrical holes for the connection. As well as connecting wires, TSVs also help dissipating the heat. TSVs commonly connect multiple dies within a package to the spreader and heatsink then they makes it easy to exchange heat. In fact, the thermal conductance of a TSV of copper is higher than that of a chip of silicon. Moreover, since TSVs connect different dies through BEOL(back end of line) and TIM(thermal interface material) layers which blocks heat flow, they help a lot with heat dissipation. As a result there have been many attempts of solving the heat problems with TSVs. This paper presents an approach to the development of a simulator that can analyze both steady state and transient temperatures in 3D ICs with TSVs and shows the effectiveness with some experiments.제1장 서론 1 제2장 관련 연구 3 제1절 Hotspot simulator 3 제2절 3D-ICE 9 제3절 3D-acme 9 제3장 TSV 구현 10 제1절 TSV와 기존 시뮬레이터에 대한 고찰 10 제2절 TSV 구현 방식 10 제4장 실험 방식 및 결과 20 제1절 실험 목표 20 제2절 Steady state 열 분석 20 제3절 Transient 열 분석 25 제5장 결론과 향후 과제 30Maste

New Methods of Efficient Base Station Control for Green Wireless Communications

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2014. 2. 이병기.This dissertation reports a study on developing new methods of efficient base station (BS) control for green wireless communications. The BS control schemes may be classified into three different types depending on the time scale — hours based, minutes based, and milli-seconds based. Specifically, hours basis pertains to determining which BSs to switch on or offminutes basis pertains to user equipment (UE) associationand milli-seconds basis pertains to UE scheduling and radio resource allocation. For system model, the dissertation considers two different models — heterogeneous networks composed of cellular networks and wireless local area networks (WLANs), and cellular networks adopting orthogonal frequency division multiple access (OFDMA) with carrier aggregation (CA). By combining each system model with a pertinent BS control scheme, the dissertation presents three new methods for green wireless communications: 1) BS switching on/off and UE association in heterogeneous networks, 2) optimal radio resource allocation in heterogeneous networks, and 3) energy efficient UE scheduling for CA in OFDMA based cellular networks. The first part of the dissertation presents an algorithm that performs BS switchingon/off and UE association jointly in heterogeneous networks composed of cellular networks and WLANs. It first formulates a general problem which minimizes the total cost function which is designed to balance the energy consumption of overall network and the revenue of cellular networks. Given that the time scale for determining the set of active BSs is much larger than that for UE association, the problem may be decomposed into a UE association algorithm and a BS switching on/off algorithm, and then an optimal UE association policy may be devised for the UE association problem. Since BS switching-on/off problem is a challenging combinatorial problem, two heuristic algorithms are proposed based on the total cost function and the density of access points of WLANs within the coverage of each BS, respectively. According to simulations, the two heuristic algorithms turn out to considerably reduce energy consumption when compared with the case where all the BSs are always turned on. The second part of the dissertation presents an energy-per-bit minimized radioresource allocation scheme in heterogeneous networks equipped with multi-homing capability which connects to different wireless interfaces simultaneously. Specifically, an optimization problem is formulated for the objective of minimizing the energy-per-bit which takes a form of nonlinear fractional programming. Then, a parametric optimization problem is derived out of that fractional programming and the original problem is solved by using a double-loop iteration method. In each iteration, the optimal resource allocation policy is derived by applying Lagrangian duality and an efficient dual update method. In addition, suboptimal resource allocation algorithms are developed by using the properties of the optimal resource allocation policy. Simulation results reveal that the optimal allocation algorithm improves energy efficiency significantly over the existing resource allocation algorithms designed for homogeneous networks and its performance is superior to suboptimal algorithms in reducing energy consumption as well as in enhancing network energy efficiency. The third part of the dissertation presents an energy efficient scheduling algorithm for CA in OFDMA based wireless networks. In support of this, the energy efficiency is newly defined as the ratio of the time-averaged downlink data rate and the time-averaged power consumption of the UE, which is important especially for battery-constrained UEs. Then, a component carrier and resource block allocation problem is formulated such that the proportional fairness of the energy efficiency is guaranteed. Since it is very complicated to determine the optimal solution, a low complexity energy-efficient scheduling algorithm is developed, which approaches the optimal algorithm. Simulation results demonstrate that the proposed scheduling scheme performs close to the optimal scheme and outperforms the existing scheduling schemes for CA.Abstract i List of Figures viii List of Tables x 1 Introduction 1 2 A Joint Algorithm for Base Station Operation and User Association in Heterogeneous Networks 7 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.3 Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.4 UE Association Algorithm . . . . . . . . . . . . . . . . . . . . . . 14 2.5 BS Switching-on/off Algorithm . . . . . . . . . . . . . . . . . . . . 17 2.5.1 Cost Function Based (CFB) Algorithm . . . . . . . . . . . 19 2.5.2 AP Density Based (ADB) Algorithm . . . . . . . . . . . . 19 2.6 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . 20 2.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3 Energy-per-Bit Minimized Radio Resource Allocation in Heterogeneous Networks 27 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.2 System Model and Problem Formulation . . . . . . . . . . . . . . . 30 3.3 Parametric Approach to Fractional Programming . . . . . . . . . . 36 3.3.1 Parametric Approach . . . . . . . . . . . . . . . . . . . . . 37 3.3.2 Double-Loop Iteration to Determine Optimal θ . . . . . . . 38 3.4 Optimal Resource Allocation Algorithm . . . . . . . . . . . . . . . 39 3.4.1 Optimal Allocation of Subcarrier and Power . . . . . . . . . 41 3.4.2 Optimal Allocation of Time Fraction . . . . . . . . . . . . . 44 3.4.3 Lagrangian Multipliers Update Algorithm . . . . . . . . . . 48 3.5 Design of Suboptimal Algorithms . . . . . . . . . . . . . . . . . . 51 3.5.1 Time-Fraction Allocation First (TAF) Algorithm . . . . . . 51 3.5.2 Normalized Time-Fraction Allocation (NTA) Algorithm . . 53 3.6 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . 54 3.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 4 Energy Efficient Scheduling for Carrier Aggregation in OFDMA Based Wireless Networks 68 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 4.3 Energy Efficiency Proportional Fairness (EEPF) Scheduling . . . . 74 4.4 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . 78 4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 5 Conclusion 87 5.1 Research Contributions . . . . . . . . . . . . . . . . . . . . . . . . 87 5.2 Future Research Directions . . . . . . . . . . . . . . . . . . . . . . 91 References 93Docto

The Effect of Symptom Recognition on Pre-hospital Delay in Patients with Acute Coronary Syndrome

Purpose: This study was performed to determine the association of symptom recognition with pre-hospital delay in patients with acute coronary syndrome (ACS), and to determine the factors influencing symptom recognition. Methods: A prospective study from June 1, 2009 to July 31, 2009 was performed. The pre-hospital delay was calculated by subtraction of the hospital-arrival time from the symptom-onset time. The pre-hospital delay of the patients that recognized the symptoms as cardiovascular in origin was compared to the patients that did not recognize the symptoms as cardiac in origin. In addition, the socioeconomic indexes and risk factors were evaluated. Results: Eighty three subjects were enrolled from a total of 205 patients suspected of having an ACS during the study period. No statistical differences were identified in the comparison of the pre-hospital delay by socioeconomic and risk factors of ischemic heart disease. The median pre-hospital delay of the patients that recognized the symptoms as cardiac was 2.9 hours compared to 11.9 hours among the patients that did not recognize the symptoms as cardiac; this difference was statistically significant (p=0.003). There were statistically significant differences in symptom recognition between the patients that had a history of cardiovascular disease and those that did not (p=0.037), and between the patients that took aspirin and those that did not (p=0.014). In addition, the severity of symptoms differed between the patients that recognized their symptoms and those that did not; this difference was statistically significant (p=0.019). Only the severity of symptoms was statistically significant by the logistic regression analysis (p=0.018). Conclusion: The pre-hospital delay was shorter, if patients that recognized the symptoms as cardiac in origin. A history of cardiovascular disease, taking aspirin and severity of symptoms were factors influencing the recognition of symptomsope

Assessment of Severity Scoring Systems for Predicting the Prognosis of Early Goal Directed Therapy (EGDT) Enrolled Patients

Purpose: Mortality in emergency department sepsis (MEDS), sepsis-related organ failure assessment (SOFA), multiple organ dysfunction score (MODS), and serum lactate levels have shown their efficacy in the early detection of patients with a bad prognosis. However, those studies did not consider differences in treatment protocols and could not rule out the interference of these differences in treatment modalities. Hence, we aimed to assess the performance of MEDS, MODS, SOFA, and serum lactate levels for predicting a bad prognosis in patients scheduled for identical, standardized treatment protocols, EGDT. Methods: Medical records of patients who visited a tertiary level teaching hospital and were enrolled in an EGDT program between October 2009 and May 2010, were retrospectively reviewed. MEDS, SOFA, and MODS scores were calculated and recorded along with serum lactate levels. Receiver operating characteristics (ROC) curves of those predictors of mortality were plotted, Bivariate correlation analyses with overall lengths of admission and ICU lengths of stay were done for surviving patients. Results: None of the diagnostic methods (serum lactate level, MEDS, SOFA, MODS) showed a significant difference difference on ROC analysis (p=0.819, 0.506, 0.811, 0.873, respectively). Bivariate correlation analyses of MEDS, SOFA, MODS and overall lengths of admission showed significant results (p=0.048, 0.018, and 0.003, respectively. Pearson correlation coefficients were, 0.263, 0.312, and 0.381). Only MEDS showed a significant correlation with intensive care unit (ICU) length of stay (p=0.032, Pearson correlation coefficient = 0.332). Conclusion: Neither MEDS, SOFA, MODS, nor serum lactate level can predict mortality in EGDT-enrolled patients. MEDS may be correlated with ICU length of stayope

Predicting the Airway Patency using the Parameters of Soft-tissue Lateral Neck Radiography in Adult Patients with Acute Epiglottitis

Purpose: We wanted to predict the high risk group that requires urgent airway intervention by using the parameters of the soft-tissue lateral neck radiographs of adult acute epiglottitis patients. Methods: This retrospective study was conducted in two teaching hospitals. The patients who were diagnosed with acute epiglottitis from June, 2007 to May, 2009 were enrolled and their medical records and x-ray films were reviewed. The width of the epiglottis at the widest point (EW), the width of the arytenoid at the widest point (AW), the prevertebral soft tissue distance at the third cervical spine (PSTD), the shortest distance from the epiglottis to the hypopharyngeal wall (EHD) and the shortest distance from the epiglottic root to the arytenoids` tip (EAD) were investigated and we performed regression analyses of these parameters of the patients in the high risk group that required urgent airway intervention. Results: A total of 42 patients were enrolled. Dyspnea and hoarseness were more frequent in the high risk group that required urgent airway intervention (p=0.008, 0.040, respectively). The EW was significantly longer (p=0.001) in the high risk group. The EHD and EAD were significantly shorter (p=0.012, <0.001, respectively) in the high risk group. Only the EAD showed significant correlation with the percent of airway patency on linear regression analysis (p=0.003) and the EAD was the only significant predictor for the high risk group on multivariate logistic regression analysis (p=0.043). The receiver operating characteristics curve of the EW/EAD for the high risk group was obtained and it showed the best predictive power (AUC: 0.977, p<0.001). Conclusion: The EAD noted on soft-tissue lateral neck radiography is an important predictor of high risk patients who require urgent airway intervention. The cut-off value of the EW/EAD for the predicting the high risk group is 2.44 (sensitivity 100%, specificity 85.7%).ope