A study of Sn Content Effect on Electro-chemical Properties of Ir-Sn-O Coatings Deposited by Unbalanced Magnetron Sputtering

SungDae Kim,SangSik Kim,Ho Kim,EunSil Lee,MyungCheol Eo 한국표면공학회 2008 한국표면공학회 학술발표회 초록집 Vol.2008 No.-

Improving the Performance of AODV(-PGB) based on Position-based Routing Repair Algorithm in VANET

( Sungdae Jung ),( Sangsun Lee ),( Hyunseo Oh ) 한국인터넷정보학회 2010 KSII Transactions on Internet and Information Syst Vol.4 No.6

Vehicle ad hoc networks (VANET) are one of the most important technologies to provide various ITS services. While VANET requires rapid and reliable transmission, packet transmission in VANET is unstable because of high mobility. Many routing protocols have been proposed and assessed to improve the efficiency of VANET. However, topology-based routing protocols generate heavy overhead and long delay, and position-based routing protocols have frequent packet loss due to inaccurate node position. In this paper, we propose a position-based routing repair algorithm to improve the efficiency of VANET. This algorithm is proposed based on the premise that AODV (-PGB) can be used effectively in VANET, if the discovery, maintenance and repair mechanism of AODV is optimized for the features of VANET. The main focus of this algorithm is that the relay node can determine whether its alternative node exits and judge whether the routing path is disconnected. If the relay node is about to swerve from the routing path in a multi-hop network, the node recognizes the possibility of path loss based on a defined critical domain. The node then transmits a handover packet to the next hop node, alternative nodes and previous node. The next node repairs the alternative path before path loss occurs to maintain connectivity and provide seamless service. We simulated protocols using both the ideal traffic model and the realistic traffic model to assess the proposed algorithm. The result shows that the protocols that include the proposed algorithm have fewer path losses, lower overhead, shorter delay and higher data throughput compared with other protocols in VANET.

Closed Loop-based extrinsic calibration of multi-modal sensors

Sungdae Sim,Kiho Kwak,Jun Kim,Sang Hyun Joo 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

By increasing the requirement of reliable and accurate sensor information, the integration of multiple sensors has gained attention. Especially, the fusion of a LIDAR(Light Detection And Ranging) and a camera is one of the sensor combination broadly used because it provides the complementary and redundant information. Many existing calibration approaches consider the problem estimating the relative pose between each sensor pair such as a LIDAR and a camera. However, these approaches do not provide accurate solutions for multisensor configurations such as a LIDAR and cameras or LIDARs and cameras. In this paper, we propose a new extrinsic calibration algorithm using closed-loop constraints for multi-modal sensor configuration. The extrinsic calibration parameters are estimated by minimizing the distance between corresponding features projected onto the image plane. We conduct several experiments to evaluate the performance of our approach, such as comparison of the RMS distance of the ground truth and the projected points, and comparison between the independent sensor pair and our approach.

Real-time AR Edutainment System Using Sensor Based Motion Recognition

Sungdae Hong,Hyunyi Jung,Sanghyun Seo 보안공학연구지원센터(IJSEIA) 2016 International Journal of Software Engineering and Vol.10 No.1

Recently the Natural User Interface (NUI) technology which is capable of appreciating the whole human body has come to the fore with the development of digital technology. And this new interface has settled as the competitive contents in the growing experiential learning contents market, by arousing participants’ interests and maximizing their learning effect, through a gesture recognition-based noncontact type interactive education. This study suggests various interpretations on the basis of the education contents production which enables participant to experience the human body in real time. Also it has developed a gesture interface by utilizing the Kinect sensor that can recognize a participant’s skeleton and behavior, and its education contents design has produced the end product by using Unity 3D authoring tool which can combine the real-time 3D model and animation together. Consequently, participant will be able to learn various inner organs such as brain and heart by different gestures, and the developed real-time human body exploring augmented reality system is expected to be widely used in many educational institutions

Comparison of Conventional Surgical Tracheostomy and Percutaneous Dilatational Tracheostomy in the Neurosurgical Intensive Care Unit

Sungdae Lim,Hyun Park,Ja Myoung Lee,Kwangho Lee,Won Heo,Soo Hyun Hwang 대한신경손상학회 2022 Korean Journal of Neurotrauma Vol.18 No.2

Objective: Tracheostomy is a necessary procedure for patients admitted to the neurosurgery intensive care unit (ICU) with severe brain injury, because mechanical ventilation must be maintained for a long time following neurologic failure. The purpose of this study was to compare conventional surgical tracheostomy (CST) and percutaneous dilatational tracheostomy (PDT) performed at the bedside in critically ill neurosurgery patients requiring tracheostomy to determine which procedure has comparative advantages. Methods: This retprospective study was conducted between January 2019 and December 2020. PDT was performed on 52 patients and CST was performed on 44 patients. The baseline characteristics, procedural characteristics, and clinical outcomes were recorded. Results: The mean operative time in the CST group was 25.5±6.5 minutes and that in the PDT group was 15.1±2.5 minutes; the difference was statistically significant (p<0.01). Four patients in the CST group and none in the PDT group experienced bleeding requiring transfusion. However, there was no significant difference in total ICU mortality or length of hospital stay. There were no statistical differences in the individual complication categories between the 2 study groups. Conclusion: There were fewer procedure-induced complications among patients receiving PDT than among those receiving CST. In addition, the treatment time for PDT was shorter than that for CST treatment.

상륙 태풍에 의한 마산만 폭풍해일 변동성 분석 - 1. 극치 모의 태풍 시나리오의 결정

Sungdae Han 한국재난정보학회 2015 한국재난정보학회 논문집 Vol.11 No.4

남해안에 상륙한 태풍 자료를 기초로 하여 분석한 결과, 태풍 이동방향의 분포는 Beta 확률밀도함수를 따르며, 태풍 눈에서의 기압저하는 Rayleigh 확률밀도함수를 따르는 것으로 판단되었다. 이를 바탕으로 6개 상륙 지점에 따라 가장 확률적으로 높은 태풍의 진로와 기압저하에 따른 태풍 매미급의 극치 태풍 모의 시나리오를 결정하였다. 모의된 태풍의 상륙지점에 따른 마산만에서의 폭풍해일 변동성이 후속 연구에서 수치 모의될 것이다. Based on the typhoon paths landed on the southern coast of Korea, the distribution of typhoon moving directions follow the Beta probability density function and that of pressure drops in typhoon eyes follow the Rayleigh probability density function. Consequently, the extreme typhoon simulation scenarios for six landing positions are determined as most probable one in moving direction and extreme one of Typhoon Maemi level in pressure drop. The variation of storm surges in Masan bay associated with simulated typhoon landing position is analyzed through the numerical experiments in the next paper as the second part.

A Novel IEEE 802.11 Ad-Hoc MAC Scheme at Vehicle Emergency Situation

Sungdae Jung,Jaemyoung Kim,Sangsun Lee 한국자동차공학회 2006 한국자동차공학회 Symposium Vol.- No.-

This paper proposes a new scheme mode that can transmit emergency message efficiently by analyzing the DCF (Distributed Coordination Function) mode used in the vehicular Ad Hoc network of IEEE specification 802.11 and the PCF (Point Coordination Function) mode used the special case in emergency situations. The DCF and the PCF modes of IEEE 802.11 must coexist in a manner that permits both to operate concurrently within the same BSS (Basic Service Set). Although the BSS is basically used as the DCF mode in IEEE 802.11, the two access methods can be alternated in certain special cases in AP that support the PCF mode. Recent studies have proposed only a way to improve the fairness of message transmission using the contention-based DCF mode for vehicular Ad Hoc networks. However, it is more important to transmit data rapidly and reliably, rather than to improve the fairness in emergency situations. Through performance analysis, we propose the new scheme mode and confirmed that data can be transmitted quickly and correctly by utilizing the DCF mode and PCF mode in emergency situations.

제주 海民들의 이어도토피아

송성대(Sungdae Song) 한국문화역사지리학회 2009 문화 역사 지리 Vol.21 No.1

이어도는 두 개의 섬으로 존재해 왔다. 영원히 미궁의 섬으로서 남아 있어야 할 靈的 장소로서의 ‘신화 속의 이어도’, 그리고 현실에서 수면 위로 솟구친 사실적 장소로서의 ‘지리 속의 이어도’가 그것이다. 본고에서는 이 두 개의 이어도가 별개가 아닌 하나(不二)의 지리적 장소임을 논증해 보았다. 전과학시대에 이어도에 대한 제주해민들의 신비적 경험과 질곡의 日常이 피안의 이어도 스토리를 낳았다. 그 스토리는 제주해민들의 집단기억(collective memory)으로서 역사 이전의 역사, 즉 메타역사(meta-histories)로 전승되어 왔다. 이어도는 제주해민들의 ‘기억의 장소’(loci de mémoire)으로서 ‘지금, 여기(차안)’로서의 이승과 ‘나중, 저기(피안)’로서의 저승이 만나는 구체적인 지리적 장소다. 이승은 현실의 디스토피아이고 저승은 삶의 질곡에서 해방된 海中樂園으로서의 유토피아다. 이어도라는 이름은 제주인들의 삶의 사고방식을 표상하는 것이며 제주도민의 혼을 보존해가는 정신의 불씨다. Recently, the jurisdictional dispute of Ieodo became a hot issue between Korea and China. Ieodo was already involved culturally within the Korean jurisdiction, China has been arguing that Ieodo naming it Suenjao locates within its jurisdiction. In this paper, Ieodo has been proved as a fact of geographic entity beyond the fictitious Ieodo myth. Ieodo has been existed in two islets: one in 'Ieodo in a mythological story', a spiritual place to be loft over as an eternal mysterious islet and one in 'Ieodo in geography,' a real islet appearing above the sealevel. this paper tried to prove the two islets are one not separated two. Jeju seamen produced an Ieodo story from their myterious experiences and daily fetters in pre-scientific era. The story transmitted as a meta-histories, the history of pre-history in the collective memory of Jeju seamen. Ieodo is a specific geographic place where this world 'now, here' meets with the other world 'late, there'. This world is a dystopia and the other world is a utopia freed from the daily fetters. The name of Ieodo is a representation of Jeju locales' way of thinking about their lives and a spiritual kindling of preserving Jeju locales' spirit.

승용디젤엔진 촉매의 열화 모드 특성에 관한 연구

김성대(Sungdae Kim),최현필(Hyunpil Choi),김동희(Donghee Kim),여권구(Gwonku Yeo) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6

어텐션 네트워크를 이용한 보행자 경로 예측 방법

심성대(Sungdae Sim),민지홍(Jihong Min),김병준(Byungjun Kim),김준모(Junmo Kim) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.11

Trajectory prediction is one of the important technology for autonomous vehicles and robots. Recently, many learning-based trajectory prediction algorithms are released. Most approaches tend to use recurrent neural networks such as LSTM. Our approach is trajectory prediction using attention mechanisms. Our experiments show the attention mechanism outperforms RNN.