질병 환자와 비교한 외상 환자의 임상적 특성: 한국 단일 권역응급의료센터 연구

황요섭,조하영,유혜원,김영미,김혜영 대한소아응급의학회 2020 대한소아응급의학회지 Vol.7 No.2

Purpose: Trauma is the leading cause of death and disability in children. We aimed to compare the clinical characteristics of children with trauma and disease. Methods: We reviewed the medical records of children (< 19 years) who visited the emergency department of Pusan National University Hospital from 2016 through 2018. Data on the age, age group, sex, details of trauma or disease, severe trauma or disease (Korean Triage Acuity Scale 1-2), hospitalization rate (overall and intensive care unit [ICU]), hospital length of stay, in-hospital mortality, and the Injury Severity Score were compared between the children with trauma and those with disease. Results: In a total of 10,205 children, 3,028 (29.7%) had trauma. The children with trauma were older than those with disease (median age, 78.5 months [interquartile range, 35.0-165.0] vs. 49.0 [16.0-120.0]; P < 0.001). Boys were more common in the former group than the latter (63.7% vs. 56.3%; P < 0.001). The most common injury mechanism was traffic accident (16.0%), followed by fall and foreign body. The overall hospitalization rate was higher in the children with disease (17.1% vs. 35.9%; P < 0.001). However, the children with trauma underwent more frequent ICU hospitalization, and showed higher in-hospital mortality rate and longer hospital length of stay than those with disease (all P < 0.001). The children with severe trauma showed higher median age, percentage of boys, in-hospital mortality, and ICU hospitalization rate, and longer hospital length of stay than those with severe disease (all P < 0.001). Conclusion: Children with trauma tend to be older, and their condition may be more critical in severity than those with disease. This difference is more prominent in those with severe trauma or disease.

특징 점 기반의 ICP 알고리즘을 이용한 2차원 격자지도 보정

황요섭,이동주,유호윤,이장명,Hwang, Yu-Seop,Lee, Dong-Ju,Yu, Ho-Yun,Lee, Jang-Myung 제어로봇시스템학회 2015 제어·로봇·시스템학회 논문지 Vol.21 No.10

This paper suggests a feature point-based Iterative Closest Point (ICP) algorithm to compensate for the disparity error in building a two-dimensional map. The ICP algorithm is a typical algorithm for matching a common object in two different images. In the process of building a two-dimensional map using the laser scanner data, warping and distortions exist in the map because of the disparity between the two sensor values. The ICP algorithm has been utilized to reduce the disparity error in matching the scanned line data. For this matching process in the conventional ICP algorithm, pre-known reference data are required. Since the proposed algorithm extracts characteristic points from laser-scanned data, reference data are not required for the matching. The laser scanner starts from the right side of the mobile robot and ends at the left side, which causes disparity in the scanned line data. By finding the matching points between two consecutive frame images, the motion vector of the mobile robot can be obtained. Therefore, the disparity error can be minimized by compensating for the motion vector caused by the mobile robot motion. The validity of the proposed algorithm has been verified by comparing the proposed algorithm in terms of map-building accuracy to conventional ICP algorithm real experiments.

Risk factors associated with slit ventricle syndrome after ventriculoperitoneal shunt surgery

황요섭,이재민 대한정위기능신경외과학회 2023 대한정위기능신경외과학회지 Vol.19 No.1

ObjectiveSlit ventricle syndrome (SVS) is defined as a slit-like appearance of the lateral ventricles with associated symptoms such as headache, vomiting, or drowsiness. The study investigated the risk factors associated with the incidence of SVS following ventriculoperitoneal shunt surgery. MethodsWe retrospectively reviewed the medical records of patients who underwent ventriculoperitoneal shunt surgery from January 2011 to 2019 at a single institution. SVS was diagnosed by a slit-like appearance of the lateral ventricles and a low Evan’s ratio (<0.25) on follow-up radiologic images. ResultsSVS was diagnosed in 53 (18.2%) of 292 patients who underwent ventriculoperitoneal shunt surgery. The mean age of patients with SVS (48.3 years; range, 4-85 years) was significantly lower than the mean age of those without SVS (58.4 years; range, 0.5-85 years) (p=0.024). Male patients showed a slightly higher incidence of SVS, but the result was not statistically significant. Patients who had hydrocephalus with vascular causes (e.g., subarachnoid hemorrhage and intracranial hematoma) showed a significantly lower incidence of SVS than those with non-vascular causes (p=0.002). ConclusionThe incidence of SVS was higher in younger patients and in those with a non-vascular cause of hydrocephalus.

실시간 내장형 S / W의 성능분석을 위한 Control Flow Graph 추출

황요섭(Yoseop Hwang),안성용(Seongyong Ahn),이정아(Jeonga Lee),심재홍(Jaehong Shim) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.1A

최근 반도체 설계 및 생상 공정의 급속한 발달로 내장형 시스템이 대중화되는 추세이고 비용이나 제품출시 기간에 있어서 내장형 소프트웨어는 중요한 하나의 요소로 대두되고 있다. 내장형 시스템은 일반 PC와는 다르게 메모리 크기, 전력 소비, 신뢰성, 사이즈, 비용 등과 같은 제약사항들을 내포하기 때문에 제한된 자원의 효율적인 이용과 소프트웨어의 최적화를 위해 소프트웨어의 성능을 분석하기 위한 필요성이 대두된다. 본 논문에서는 소프트웨어 성능분석 도구인 'Cinderella'를 확장하기 위하여 현재 가장 널리 사용되고 있는 이진 실행 파일인 ELF파일에서 성능을 측정하기 위한 기본 요소로서 Control flow graph를 추출하기 위한 알고리즘을 제안한다. 본 논문에서 제안한 알고리즘은 향후 ARM기반의 머신에서 ELF파일의 내장형 소프트웨어의 시간분석에 필요한 요소이다.

ARM용 내장형 소프트웨어의 정적인 수행시간 분석 도구

황요섭(Yo-Seop Hwang),안성용(Seong-Yong Ahn),심재홍(Jea-Hong Shim),이정아(Jeong-A Lee) 한국정보과학회 2005 정보과학회 컴퓨팅의 실제 논문지 Vol.11 No.1

내장형 시스템에서 응용 프로그램을 구동시킬 때는 일련의 태스크들의 집합을 수행하여야 한다. 이러한 태스크들은 특정 하드웨어로 구현 될 수도 있고, 특정 프로세서에서 구동되는 소프트웨어로 구현될 수도 있다. 내장형 시스템에서 응용 프로그램을 구동시키기 위하여 하드웨어/소프트웨어의 자원 선택 및 작업 분할이 필요하게 되고 이때 하드웨어 및 소프트웨어의 성능 예측이 이용된다. 하드웨어 성능 예측과 달리 소프트웨어 성능 예측은 구동 환경과 밀접한 관계가 있으며, 하드웨어 소프트웨어 통합 설계를 위하여 최적 및 최악의 수행 시간 경계를 예측하는 것은 중요한 문제이다. 수행 시간 경계의 엄격한 예측은 저 비용의 프로세서를 사용할 수 있게 하며, 시스템 비용을 낮추는데 도움을 준다. 본 논문에서는 ARM용 내장형 시스템을 고려하여, loop문의 반복 횟수 경계 값과 프로그램의 추가적인 경로 호출 정보를 이용하여, 수행 시간의 경계를 최대한 실제 값에 접근하도록 예측하는 도구를 개발하였다. 개발된 도구는 현재 i960과 m68k 아키텍처를 지원하는 “Cinderella”라는 시간 분석 도구를 기본 도구로 활용하고 있다. ARM 프로세서를 지원하기 위하여 제어흐름과 디버깅 정보를 추출할 수 있는 ARM ELF 목적 파일 모듈을 추가하고, ARM 명령어 집합을 처리할 수 있는 모듈을 기존 도구에 추가하였다. 여러 가지 벤치마크 프로그램을 대상으로 실시한 실험 결과, 임의의 입력 데이타를 이용하고 수행 횟수를 고려한 ARMulator의 수행 시간이 구현된 도구에서의 정적인 수행 시간 예측 경계 값으로 들어오는 것을 확인할 수 있었다. Embedded systems have a set of tasks to execute. These tasks can be implemented either on application specific hardware or as software running on a specific processor. The design of an embedded system involves the selection of hardware software resources, partition of tasks into hardware and software, and performance evaluation. An accurate estimation of execution time for extreme cases (best and worst case) is important for hardware/software codesign. A tighter estimation of the execution time bound may allow the use of a slower processor to execute the code and may help lower the system cost. In this paper, we consider an ARM-based embedded system and developed a tool to estimate the tight boundary of execution time of a task with loop bounds and any additional program path information. The tool we developed is based on an exiting timing analysis tool named "Cinderella" which currently supports i960 and m68k architectures. We add a module to handle ARM ELF object file, which extracts control flow and debugging information, and a module to handle ARM instruction set so that the new tool can support ARM processor. We validate the tool by comparing the estimated bound of execution time with the run-time execution time measured by ARMulator for a selected bechmark programs.

이동로봇의 원격제어를 위한 햅틱 글러브 개발

황요섭(Yo-Seop Hwang),이장명(Jang-Myung Lee) 대한전기학회 2011 전기학회논문지 Vol.60 No.5

The remote control of mobile robot is widely used to perform dangerous and complex tasks such as underwater exploration and cleaning of nuclear reactor. For this purpose, the obstacle avoidance process will proceed to ensure a safe drive. In this paper, we tested that mobile robot drive in which replaced a pipe with a box. After we measured the distance around the obstacle through a sensor of robot, we got the information that changed haptic force from the distance of the obstacle.

모바일 로봇의 경사 주행 시 3차원 지도작성 알고리즘

황요섭(Yo-Seop Hwang),한종호(Jong-Ho Han),김현우(Hyun-Woo Kim),이장명(Jang-Myung Lee) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.3

This paper proposes a 3D map-building algorithm using one LRF (Laser Range Finder) while a mobile robot is navigating on the slanted surface. There are several researches on 3D map buildings using the LRF. However most of them are performing the map building only on the flat surface. While a mobile robot is moving on the slanted surface, the view angle of LRF is dynamically changing, which makes it very difficult to build the 3D map using encoder data. To cope with this dynamic change of the view angle in build 3D map, IMU and balance filters are fused to correct the unstable encoder data in this research. Through the real navigation experiments, it is verified that the fusion of multiple sensors are properly performed to correct the slope angle of the slanted surface. The effectiveness of the balance filter are also checked through the hill climbing navigations.

UAV의 정현파 궤적 알고리즘을 이용한 3차원 실내 맵빌딩

황요섭(Yo-Seop Hwang),최원석(Won-Suck Choi),우창준(Chang-Jun Woo),왕지도(Zhi-Tao Wang),이장명(Jang-Myung Lee) 제어로봇시스템학회 2015 제어·로봇·시스템학회 논문지 Vol.21 No.5

This paper proposes a robust 3D mapping system for a UAV (Unmanned Aerial Vehicle) that carries a LRF (Laser Range Finder) using the sinusoidal trajectory algorithm. In the case of previous 3D mapping research, the UAV usually takes off vertically and flights up and down while the LRF is measuring horizontally. In such cases, the measuring range is limited and it takes a long time to do mapping. By using the sinusoidal trajectory algorithm proposed in this research, the 3D mapping can be time-efficient and the measuring range can be widened. The 3D mapping experiments have been done to evaluate the performance of the sinusoidal trajectory algorithm by scanning indoor walls.

적응적 이진화를 이용하여 빛의 변화에 강인한 영상거리계를 통한 위치 추정

황요섭(Yo-Seop Hwang),유호윤(Ho-Yun Yu),이장명(Jangmyung Lee) 제어로봇시스템학회 2016 제어·로봇·시스템학회 논문지 Vol.22 No.9

In this paper, a robust visual odometry system has been proposed and implemented in an environment with dynamic illumination. Visual odometry is based on stereo images to estimate the distance to an object. It is very difficult to realize a highly accurate and stable estimation because image quality is highly dependent on the illumination, which is a major disadvantage of visual odometry. Therefore, in order to solve the problem of low performance during the feature detection phase that is caused by illumination variations, it is suggested to determine an optimal threshold value in the image binarization and to use an adaptive threshold value for feature detection. A feature point direction and a magnitude of the motion vector that is not uniform are utilized as the features. The performance of feature detection has been improved by the RANSAC algorithm. As a result, the position of a mobile robot has been estimated using the feature points. The experimental results demonstrated that the proposed approach has superior performance against illumination variations.

ARM 기반의 실시간 내장형 소프트웨어를 위한 성능분석 도구의 설계

황요섭(Yo-seop Hwang),안성용(Seong-yong Ahn),이정아(Jeong-a Lee),심재홍(Jae-hong Shim) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.2Ⅰ

내장형 컴퓨터 시스템은 특정 기능을 수행하기 위해 소프트웨어와 이를 구동시키기 위한 프로세서로 구성되어 있다. 이러한 시스템의 대부분은 실시간 제약들을 만족해야 한다. 실시간 제약들을 만족하는 애플리케이션을 빠른 시간안에 구현하기 위해서는 제작 전 성능을 예측하는 도구가 필수적이다. 본 논문에서는 현재 내장형 시스템 플랫폼으로 널리 활용되고 있는 ARM 기반의 내장형 애플리케이션의 극단적인(최적, 최악) 경우의 수행 시간 경계를 예측하는 문제를 연구하였다. ARM 기반의 내장형 시스템의 수행시간의 경계를 예측하기 위하여 기존의 실시간 내장형 소프트웨어의 성능 예측 도구인 "Cinderella"의 기본 프레임웍을 ARM 프로세서를 지원하도록 확장하여 성능분석도구를 설계하였다.