도심 항공 모빌리티(UAM)의 안정성 향상을 위한 공간정보 기반 영상 항법 및 비행 계획

이대규(Daegyu Lee),장인성(Insung Jang) 대한공간정보학회 2024 한국공간정보학회 학술대회 Vol.2024 No.5

프로펠러 직경 변화에 따른 드론용 모터의 추력 특성 비교연구

이대규(Dae Gyu Lee),이수용(Su yong Lee),조승태(Seung Tae Jo),김민재(Min Jae Kim),안태준(Tae Jun Ahn),박관수(Gwan Soo Park) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.7

Spiral CT에서 Interpolation이 선량증가에 미치는 영향에 관한 연구

이대규(Dae kyoo Lee),남윤철(Yoon Chul Nam),김문찬(Moon Chan Kim),한동균(Dong Kyoon Han) 대한CT영상기술학회 2008 대한CT영상기술학회지 Vol.10 No.1

The purpose of this study is to recognize how much dose and scan length increased by interpolation in spiral scan and to understand about correlation with factors such as beam collimation and pitch. We measured dose and scan length changing pitch and beam collimation using the GE company equipments.

가정연계 발달기록부에 나타난 학부모의 반응

이대규 ( Dae Kyun Lee ),이아름 ( A Reum Lee ) 한국어린이문학교육학회 2014 어린이문학교육연구 Vol.15 No.3

본 연구는 유치원과 가정 간의 연계지도를 위해 마련된 가정연계 발달기록부에 나타난 학부모의 이야기를 분석해 봄으로써, 유치원에서 가정과의 연계교육을 시행할 때 참고할 수 있는 기초 자료를 제공하기 위한 목적으로 수행되었다. 본 연구를 위해 A유치원에서 2012년과 2013년에 작성되었던 가정연계 발달기록부 300권을 분석하였다. 연구결과, 가정연계 발달기록부에 나타난 학부모의 반응은 담임교사에 대한 유치원 학부모의 바램과 담임교사에 대한 고마움의 두 가지로 구분되었다. 먼저 담임교사에 대한 학부모의 바램은 첫째, 거부감 없는 등원, 둘째, 원만한 친구관계의 형성 및 유지, 셋째, 문제행동의 수정, 넷째, 기본적인 학습태도 형성, 다섯째, 인성의 기초 형성으로 나타났으며, 담임교사에 대한 학부모의 고마움은 첫째, 유아들의 즐거운 유치원 생활, 둘째, 유아와 선생님과의 친밀한 관계 형성, 셋째, 교사의 세심한 배려, 넷째, 유아의 성장과 발전, 다섯째, 유아의 학업적 측면에서의 성취로 나타났다. This study aimed to analyze the effects of kindergarten development notebook which was monthly delivered to family. The results of this study would provide the basic information in developing the ways to support the mutual understanding between kindergarten and family. The subjects of this study were 300 kindergarten development notebooks for kindergarten children aged 3-5. As the parent’s demand, the first was adaptability to kindergarten. Second was the friend relationship. Third was the guidance for problem behavior. Fourth was the basic learning attitude. Fifth was the bringing up of human nature. As the parent’s gratitude, first was enjoying their kindergarten life. Second was to be loved by kindergarten teacher. Third was the kindness of kindergarten teacher. Fourth was the development and growth of their children. Fifth was academic accomplishment of their children.

인가전압에 따른 전기차용 초소형 히트펌프 냉난방 운전 특성

이대규(Daegyu Lee),이천규(Cheonkyu Lee),박동호(Dongho Park),정효재(Hyo Jae Jeong),강채동(Chaedong Kang) 대한기계학회 2020 大韓機械學會論文集B Vol.44 No.12

전기자동차의 배터리는 완충 후 사용시간에 따라 전압이 선형적으로 감소하므로 전기자동차용 히트펌프 개발을 위해 인가전압에 따른 히트펌프의 운전 특성 분석이 필요하다. 본 연구에서는 인가전압의 변화에 따른 초소형 히트펌프의 운전 특성 분석을 위한 연구를 수행하였다. 실험은 항온항습 챔버에서 냉방조건과 난방 조건으로 나뉘어 진행되었다. 외기온도는 냉방모드에서 27°C 및 35°C, 난방모드에서 24°C 및 -7°C로 각각 설정하여 실험을 수행하였다. 히트펌프에 인가되는 전압은 16V에서 32V까지 2V씩 변화를 주었다. 인가전압 증가에 따라 초소형 히트펌프의 냉·난방용량은 외기온도 27°C, 35°C, 24°C 그리고 -7°C 조건에서 각각 최대 51%, 54%, 43% 그리고 33% 증가하였다. 성능계수는 외기온도 27°C, 35°C, 24°C 그리고 -7°C 조건에서 인가전압 증가에 따라 각각 최대 35%, 39%, 22% 그리고 10% 증가하였다. It is necessary to analyze the operation characteristics of a heat pump under various applied voltages to develop a micro-heat pump for electric vehicles because the voltage of the battery in electric vehicles is linearly reduced with respect to the usage time after a full battery charge. In this study, the operation characteristics of a micro-heat pump were investigated with respect to applied voltages. Cooling and heating experiments were conducted by a using micro-heat pump in an isothermal-isohumidity control chamber. External temperatures of 27 °C and 35 °C were used for the cooling operations and 24 °C and -7 °C were used for the heating operations. The applied voltages were varied from 16 to 32 V at an interval of 2 V. As the applied voltage was increased, cooling and heating capacities increased by up to 51 %, 54 %, 43 %, and 33 % at external temperatures of 27 °C, 35 °C, 24 °C, and -7 °C, respectively. The coefficient of performance increased by up to 35 %, 39 %, 22 %, and 10 % as the applied voltage was increased at external temperatures of 27 °C, 35 °C, 24 °C, and -7 °C, respectively.

척수 혈관모세포종의 임상 분석

이대규,최우진,김동윤,이철희,정천기,김현집,Lee, Dae Kyu,Choe, Woo Jin,Kim, Dong Yoon,Lee, Chul Hee,Chung, Chun Kee,Kim, Hyun Jib 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.11

Objectives : The authors present a retrospective analysis of 14 patients treated for spinal cord hemangioblastoma (SCH) between Dec. 1986 and Mar. 2000. This study was conducted to evaluate and compare the difference of the functional outcomes associated with the extent of surgical removal of SCH. Methods : Eleven patients were male and three patients were female. Their mean age was 37.2 years that ranged from 19 to 62 years. Preoperative magnetic resonance(MR) imaging of the spine was performed in all cases, and preoperative angiography in eleven cases. They were followed from 15 months to 161 months(median follow-up period, 47 months), and we investigated the change of neurological symptoms and functional outcomes with radiological features, especially on MR imaging. Results : Six patients were accompanied by von Hippel-Lindau disease, and three of them had multiple CNS tumors. Thirteen patients had intramedullary tumor, and the remaining one had extradural. Syringomyelia around the tumor was observed in ten cases. All patients underwent surgical removal, and gross total removal(GTR) was achieved in ten cases. Preoperative embolization was performed in four cases. In four patients who were treated with preoperative embolization, intraoperative loss of blood was minimal and GTR was possible. One patient developed a transient swallowing difficulty postoperatively without permanent postoperative neurological deficits. In three of four patients in whom GTR was not possible, their functional outcomes were worsened postoperatively. The functional status at discharge was improved in seven patients, stationary in four patients, and worse in three. At the last follow-up(15-161 months), one of four patients who had been stationary at discharge showed improvement but, the rest did not show any change. All patients who showed neurological improvement were patients with GTR, and the patients with GTR had significant better outcome than those without GTR(p=0.015). Conclusion : Surgical treatment, and especially, GTR is considered as treatment of choice for spinal cord hemangioblastoma. Preoperative embolization may prevent intraoperative bleeding and improve surgical outcome.

광범위한 심부 정맥계의 경색:후두개와 수술 후 발생한 드문 합병증

이대규 ( Dae Kyu Lee ),황승균 ( Sung Kyun Hwang ),김동규 ( Dong Gyu Kim ),정희원 ( Hee Won Jung ),한문희 ( Moon Hee Han ) 대한뇌종양학회 2002 대한뇌종양학회지 Vol.1 No.1

Objective and Importance:Infarction of the deep cerebral venous system is a rare clinical entity and is different from the infarction of the superficial system in its presenting symptoms, severity of the disease and prognosis. The authors present a case of extensive infarction of the deep venous system associated with a postoperative epidural abscess in the posterior fossa following the surgery of a vestibular schwannoma. Pathogenesis is also discussed with diagnosis and treatment. Clinical Presentation:A 43-year-old woman underwent total removal of a vestibular schwannoma through retromastoid suboccipital craniectomy. The immediate postoperative course was uneventful. A high fever occurred on the eighth postoperative day and she subsequently became stuporous. Computed tomography(CT) revealed a crescent-shape lesion at the epidural space around the craniectomy site. Diffuse low-density lesions in the bilateral basal ganglia, thalamus and frontal paraventricular white matter were also seen. Intervention:Revision of the previous wound was performed and the epidural abscess was removed. Postoperative magnetic resonance(MR) imaging showed extensive infarction in the same areas that were seen in the previous CT scan. Occlusions in the straight and lateral sinus were demonstrated by MR venography. Anticoagulation therapy was started and the neurological status of the patient gradually improved. Conclusion:Although an infarction of the deep cerebral venous system is rare, it may occur in patients with postoperative intracranial infection in the vicinity of the dural sinus. A suspicion and rapid diagnosis are important, so that the morbidity of the disease may be reduced and the prognosis for the patient may be improved if an adequate treatment regimen would be taken early.

OTF 정밀측위를 위한 신속한 미지정수 결정방법

이대규(Dae-Kyu Lee),성태경(Tae-Kyung Sung) 제어로봇시스템학회 2004 제어·로봇·시스템학회 논문지 Vol.10 No.5

자기공진식 무선전력전송에서 수신코일의 직경이 최대전력전달 범위에 미치는 영향

이대규(Dae-Gyu Lee),채승안(Seung-Ahn Chae),엄대용(Dae-Yong Um),박관수(Gwan-Soo Park) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.11

Dual source CT에서 high pitch chestpain cardiac scan mode를 이용한 angiography 검사의 유용성 평가

이대규(Dae Kyu Lee),이민영(Min Yung Lee),장광현(Kwang Hyun Chang) 대한CT영상기술학회 2015 대한CT영상기술학회지 Vol.17 No.1

목적 : 128 channel dual source computed tomography(이하 DSCT)의 high pitch mode를 이용하여 뇌혈관, 경동맥, 심장혈관을 1초 이하의 scan time 으로 한번에 검사하는 CT protocol 을 연구, 검사하였고 기존의 helical scan mode로 심장혈관을 검사하고, 조영제 추가 주입 후 뇌혈관, 경동맥을 같은 방법으로 검사한 영상을 비교하여 그에 따른 선량감소와 그 유용성을 비교해 보고자 하였다. 대상 및 방법 : 팬텀실험에서는 2개의 128-channel detector의 사용이 가능한 Somatom Definition Flash(Siemens Healthcare, Forchheim, Germany)CT 장비, organ dose 측정을 위해서 Alderson Rando phantom(CNMC Company, USA)을 사용하였다. 선량측정을 위해 형광유리선량계인 Dose Ace(GD-351, 12 mm, FGD-1000 reader, Asahi Techno Glass Cooperation, Shizuoka, Japan)를 사용하였다. 또한 유리 선량계를 주 선속 부위에 속하는 두부, 목, 폐, 심장 부위에 각각 2개씩 위치 organ dose를 측정하였다. 임상조건에서는 2014년 3월 부터 2014년 8월 까지 CCTA를 시행한 환자 210 명을 대상으로 이 중 heart rate가 60 이하인 104 명을 high pitch scan mode 로 검사하였고 106명은 helical scan mode로 검사하였다. Phantom 연구와 동일한 장비를 사용하고 같은 조건으로 나누어 검사 하였으며, 조영 증강을 위해서 이중 조영제주입기(dual flow injector, Stellant, Medrad, Inc, USA)를 사용하였다. 각각의 방법에서 두부, 목, 심장 부위의 CNR,SNR 을 측정하여 비교하였고, 영상은 4단계로 구분하여 2명의 영상의학과 심장판독 전문의가 평가하였다. 선량 평가는 CTDIvol, DLP와 유효선량을 평가하였고, 임상영상평가와 선량평가를 위한 통계학적 분석은 Levene의 등분산 검정을 통하여 정규성 검정을 하였고 통계학적 유의수준은 0.05 미만으로 하였다. 결과 : 1. Phantom 선량평가 : High pitch scan mode가 standard pitch scan mode & helical scan mode 에 비하여 effective dose 는 약 35.7% 정도 감소하였다(p<0.05). 2. 임상 연구 선량평가 : Head ~ coronary 까지 1 scan 으로 high pitch mode 에서 검사한 유효선량 값이 standard pitch & helical scan 로 나뉘어 2 scan 한 선량보다 약 30% 낮았다(p<0.05). 3. 임상영상평가 : 두 검사모드의 정성적 정량적 평가 값에서 모두 유의한 차이를 나타냈다(p<0.05). 결론 : Heart rate가 60대 이하이면서 안정된 환자에게 있어 Chest pain cardiac scan mode 로 검사 시, image quality는 떨어지지 않으면서도 2.5 mSv 이하의 저 선량으로 뇌혈관, 경동맥, 심장혈관을 한번에 검사할 수 있으므로 이는 곧 건강검진 환자나 심장 뇌혈관 질환 환자의 진단에 유용할 것으로 사료된다. Purpose : Using chest pain flash mode of 128 channel dual source computed tomography (below DSCT), we studied and tested one scanning CT protocol with less than 1 second scan time for intra cranial, carotid, and coronary vessel, then examined coronary angiography with helical scan mode, comparing the images that intra and carotid after injecting additional contrast media, following that purposed the dose reduction and usefulness. Materials & Methods: In this phantom test, Somatom Definition Flash (Siemens Healthcare, Forchheim, Germany)CT equipment for two 128-channel detector and Alderson Rando phantom(CNMC Company, USA) was used for the organ dose evaluation. For dose evaluation, Dose Ace (GD-351, 12 mm, FGD-1000 reader, Asahi Techno Glass Cooperation, Shizuoka, Japan) which is fluorescent glass dosimeter was used. Also, organ dose were measured by glass dosimeters positioning each two on head, neck, lungs and heart, belonging to the main flux. The clinical condition tested by high pitch scan mode with 104 patients whose heart rate was under 60 and tested by helical scan mode with 106 patients targeting 210 patients having CCTA from March 2014 to August 2014. Phantom studies using the same equipment and inspection were divided in the same condition, and the double-contrast injector (dual flow injector, Stellant, Medrad, Inc, USA) for enhancement was used. In the way each evaluated, was compared by measuring the head, neck and heart CNR, SNR, and evaluated two reading heart specialist of Radiology, separated by step of 4 images. Statistical analysis for the subjective assessment was used to Mann-Whiteny test of Graphpad Instat ver 3.05 and statistically significant was less than 0.05. CTDIvol, DLP and effective dose were evaluated to dose evaluation, for statistical analysis, normality test was used through equal variance examination, T- test were for analysis, and statistical significance level was done less than 0.05. Results: 1. Phantom dose evaluation: the effective dose of High pitch scan mode decreased about 35.7% (p <0.05) comparing to standard pitch scan mode & helical scan mode. 2. Clinical study dose evaluation: the effective dose value tested high pitch mode with one scan from head to coronary decreased about 30% (p <0.05) which done two scan by standard pitch and helical scan. 3. Clinical image evaluation: Both were significant differences in the two test mode for qualitative and quantitative evaluation value (p <0.05). Conclusion : If Scanning chest pain Flash scan mode for patients whose heart rate is below 60, it is possible that direct one scanning intra cranial, carotid, and coronary angiography exams with less than 2.5 mSv and image quality is equal. So it could be considered to diagnosis for health care and heart- brain vessel disease patients usefully.