Accurate Path Tracking by Adjusting Look-Ahead Point in Pure Pursuit Method

안준우,신세호,김민성,박재흥 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.1

Path tracking is an essential aspect of the navigational process of self-driving cars. Especially, accurate pathtracking is important for not only normal urban roads but also narrow and complex roads such as parking lot and alleyway. The pure pursuit method is one of the geometric path-tracking methods. Using this method, the look-ahead point can be selected far away and the control input is computed in real-time, which is advantageous when the given path is not smooth or when the path is specified using waypoints. Moreover, this method is more robust to localization errors than the modelbased path-tracking method. However, the original pure pursuit method and its variants have limited tracking performance. Therefore, this paper proposes a new method that heuristically selects a look-ahead point by considering the relationship between a vehicle and a path. Using this new look-ahead point, the vehicle can stably converge to the desired path and track the path without encountering the cutting-corner problem. The proposed method was tested using simulation and our selfdriving car platform. Our results show that the vehicle tracks the desired path more accurately using our proposed algorithm than using the previous pure pursuit methods.

실내 이동 로봇을 위한 자연 표식과 인공 표식을 혼합한 위치 추정 기법 개발

안준우,신세호,박재흥 한국로봇학회 2016 로봇학회 논문지 Vol.11 No.4

The localization of the robot is one of the most important factors of navigating mobile robots. The use of featured information of landmarks is one approach to estimate the location of the robot. This approach can be classified into two categories: the natural-landmark-based and artificial-landmark-based approach. Natural landmarks are suitable for any environment, but they may not be sufficient for localization in the less featured or dynamic environment. On the other hand, artificial landmarks may generate shaded areas due to space constraints. In order to improve these disadvantages, this paper presents a novel development of the localization system by using artificial and natural-landmarks-based approach on a topological map. The proposed localization system can recognize far or near landmarks without any distortion by using landmark tracking system based on top-view image transform. The camera is rotated by distance of landmark. The experiment shows a result of performing position recognition without shading section by applying the proposed system with a small number of artificial landmarks in the mobile robot.

Effect of ionizing radiation on the DNA damage response in Chlamydomonas reinhardtii

안준우,최윤이,구광민,정세라,김진백,김상훈,권순재,정원중,정국현,강시용 한국유전학회 2017 Genes & Genomics Vol.39 No.1

The DNA damage response (DDR) is induced by various DNA damaging factors and maintains genome stability in all organisms. The Chlamydomonas reinhardtii genome contains putative homologous genes involved in DDR; however, little is known about the functions and responses of these genes to DNA damage. In this study, DDR by gamma radiation was determined in C. reinhardtii. Irradiation with 80, and 200 Gy gamma radiation caused death in approximately 47 and 97 % of C. reinhardtii cells, respectively. The absolute lethality of cells was at 300 Gy. The rate of DNA breaks was also determined using comet assays after exposure to different doses of gamma radiation. Irradiation with 80 and 400 Gy resulted in 17 and 34 % of nuclear degradation in C. reinhardtii cells, respectively. To identify the major DDR pathway of C. reinhardtii induced by gamma radiation, 24 putative DDR genes were selected from the Joint Genome Institute (JGI) database. Gamma radiation significantly affected expression of 15 genes among these. Therefore, these genes displaying expressional changes by gamma radiation are involved in DDR, which indicate that C. reinhardtii may possess a fundamental conserved DDR pathway with higher plants. Furthermore, radiation responsive proteins were identified by proteomic analysis, which are involved in metabolisms of carbohydrate, energy, and photosynthesis. This is the first report to describe the responses of DDR homologous genes to gamma radiation and to identify gamma radiation-responsive proteins in C. reinhardtii. Our data should provide molecular insights into gamma radiation responses including DNA damage in green algae.

CHRNA1 유전자변이와 연관된 선천근무력증후군

안준우,황수경,정훈,박진성 대한신경과학회 2021 대한신경과학회지 Vol.39 No.3

Congenital myasthenic syndromes are a genetically and clinically heterogeneous group of neuromuscular disorders linked by abnormal signal transmission at the motor endplate caused by various genetic defects. Major clinical symptoms include weakness and fatigue during the first years of life but patients may also present with hypotonia, facial weakness, swallowing difficulties, respiratory dysfunction, ptosis and ophthalmoparesis. Here we report a 10-year-old boy who presented with mild developmental delay and bilateral ptosis caused by a frameshift mutation in the CHRNA1 gene that co-segregated within the family, and finally diagnosed as autosomal dominant congenital myasthenic syndrome.

체외수정시술의 반복적인 실패 환자에서 옥시토신 길항제 주입이 착상 및 임신에 미치는 영향

안준우,김정훈,김소라,전균호,김성훈,채희동,강병문,Ahn, Jun-Woo,Kim, Chung-Hoon,Kim, So-Ra,Jeon, Gyun-Ho,Kim, Sung-Hoon,Chae, Hee-Dong,Kang, Byung-Moon 대한생식의학회 2009 Clinical and Experimental Reproductive Medicine Vol.36 No.4

목 적: 본 연구는 반복적으로 체외수정시술/난자세포질내 정자주입술을 실패했던 환자에서 배아 이식시 옥시토신 길항제의 투여가 임신율 및 착상율에 미치는 영향을 알아보고자 하였다. 연구방법: 2회 이상의 체외수정시술/난자세포질내 정자주입술을 실패했던 40명의 환자들을 대상으로 전향적 무작위 연구를 진행하였다. 과배란유도 방법으로 생식샘자극호르몬분비호르몬 길항제 다회투여법이 사용되었다. 실험군에서는 옥시토신 길항제로 atosiban (vasopressin $V_{1A}$/oxytocin antagonist)을 배아 이식 한 시간 전에 atosiban 6.25 mg을 일회 정주한 뒤, 18 mg/hour의 속도로 지속적 정맥 주입하였다. 배아 이식이 끝난 뒤 atosiban을 6 mg/hour로 감속하여 2시간 동안 추가로 정맥 주입하였다. 실험군과 대조군간의 체외수정시술 결과를 비교 분석하였다. 결 과: 실험군과 대조군간의 평균 나이, 불임 기간 및 체질량 지수와 기저 혈중 난포자극호르몬 및 에스트라디올 농도, 기저 난포강 난포의 수에 통계적으로 유의한 차이는 없었다. 또한 투여된 재조합 인간 난포자극호르몬 (rhFSH)의 총 용량과 투여 기간, 발달된 난포의 개수 및 자궁내막의 두께 역시 통계학적 유의한 차이를 보이지 않았다. 수집된 난자 및 성숙 난자의 수와 수정된 난자와 1등급 혹은 2등급의 배아 및 이식된 배아의 수에도 두 군간의 통계학적으로 유의한 차이를 보이지 않았다. 착상율을 비교하였을 때 실험군은 16.9% (11/65), 대조군은 6.0% (4/67)로 나타났고, p=0.047로 두군 간에 통계학적으로 유의한 차이를 보였다. 임상적 임신율의 경우 실험군은 40.0%로 대조군의 20.0%에 비해 높게 나타나으나 통계학적 유의성엔 도달하지 못하였다. 또한 자궁외 임신 및 유산율에 있어서는 두 군 간에 유의한 차이를 보이지 않았다. 결 론: 체외수정시술/난자세포질내 정자주입술을 시행 받는 환자들에서 배아 이식 동안 옥시토신 길항제를 투여하는 것은 자궁의 수축을 감소시켜 착상율을 증가시킬 수 있을 것으로 생각된다. Objective: This study was performed to evaluate the effect of oxytocin antagonist on the outcome of IVF/ICSI cycles in infertile patients with repeated failure of IVF/ICSI treatment. Method: Forty patients who had experienced two or more failures of IVF/ICSI treatment without low ovarian reserve, were recruited for this prospective randomized study. All patients received controlled ovarian stimulation (COS) using GnRH antagonist multidose protocol (MDP). For the intervention group, intravenous administration of atosiban (mixed vasopressin $V_{1A}$/oxytocin antagonist) started with a bolus dose 6.75 mg one hour before embryo transfer (ET) and continued at an infusion rate of 18 mg/hour. After ET, administered atosiban was reduced to 6 mg/hour and continued for 2 hours. The main efficacy endpoints were clinical pregnancy rate and implantation rate. Results: Patients' characteristics were comparable in the intervention and control groups. COS parameters and IVF results were also similar. The number of uterine contractions for 3 minutes measured just before ET was significantly lower in the intervention group than control group ($3.5{\pm}1.4$ vs $8.7{\pm}2.2$, p<0.001). While there was no statistically significant difference in the clinical pregnancy rate between control group and intervention group (20.0% and 40.0%, p=0.168), the implantation rate was significantly higher in the intervention group, with 16.9% (11/65) compared with 6.0% (4/67) in the control group (p=0.047). There were no differences in ectopic pregnancy rate and miscarriage rate between the two groups. Conclusion: This study demonstrates that administration of oxytocin antagonist during ET can improve the implantation rate probably by decreasing the frequency of uterine contractions in infertile patients undergoing IVF/ICSI treatment.

태아 일측성 다낭성 신장 이형성증과 연관된 태반 중간엽 이형성증

안준우 ( Jun Woo Ahn ),이필량 ( Pil Ryang Lee ),김민균 ( Min Gyun Kim ),김규래 ( Kyu Rae Kim ),심재윤 ( Jae Yoon Shim ),원혜성 ( Hye Sung Won ),김암 ( Ahm Kim ) 대한주산의학회 2010 Perinatology Vol.21 No.2

Placental mesenchymal dysplasia (PMD) is a rare placental disorder that may coexist with a normal fetus but is frequently associated with fetal growth restriction, fetal demise, prematurity, and Beckwith-Wiedemann syndrome, as well as with various fetal anatomical and vascular anomalies. In this case, ultrasonography performed at 14 weeks of gestation revealed multiple, variable sized cysts in the placenta along with a morphologically normal fetus. Serial sonographic examinations found that the fetus became small for gestational age and had a dysplastic right kidney. After delivery at 33 weeks of gestation, histopathologic examination of the placenta showed enlarged, hydropic stem villi with cavity formation and absence of trophoblastic proliferation and pseudoinclusions, all of which were consistent with PMD. Neonatal abdominal ultrasonography showed multiple cysts in the right kidney consistent with a multicystic dysplastic condition. This appears to be the first case of PMD associated with fetal multicystic dysplastic kidney.

자율 발렛 주차 시스템 개발 및 시뮬레이션 결과

안준우(Joonwoo Ahn),김민수(Minsoo Kim),임규범(GyuBeom Im),김민성(Minsung Kim),박재흥(Jaeheung Park) 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11

In this paper, we propose an efficient and safe method for autonomous valet parking system with a driving strategy considering uncertain environment in parking spaces. The proposed method consists of a vehicle controller with decision-making algorithms, a global and local path generation algorithm, and a three-dimensional LiDAR-based parking lot detection algorithm. The proposed method was validated via simulation results.

MSW에 대한 매립 및 소각처리방법에 따른 온실가스 발생량 비교

안준우(Jun-woo Ann),정진도(Jin-Do Chung) 한국열환경공학회 2018 한국열환경공학회 학술대회지 Vol.2018 No.-

복막 기원의 악성 혼합 뮬러리안 종양

안준우 ( Jun Woo Ahn ),권용순 ( Yong Soon Kwon ),공건영 ( Kun Yong Kong ),백수진 ( Su Jin Back ),한애라 ( Ae Ra Han ),김영탁 ( Young Tak Kim ),남주현 ( Joo Hyun Nam ) 대한산부인과학회 2007 Obstetrics & Gynecology Science Vol.50 No.9

클로소이드(Clothoid)를 사용한 주차 경로 후-처리를 통한 경로 추종 오차 및 승차감 개선

안준우(Joonwoo Ahn),김민수(Minsoo Kim),박재흥(Jaeheung Park) 한국자동차공학회 2020 한국자동차공학회 학술대회 및 전시회 Vol.2020 No.11