급성 자발성 경추 경막외 혈종 1례 : Case Report

백재민,정훈,최기환,여형태,이정길 대한신경외과학회 1991 Journal of Korean neurosurgical society Vol.20 No.6

Spontaneous spinal epidural hematoma is a rare cause of spinal cord compression. Recently, at our hospital, the author et al had the opportunity of observing case with spontaneous cervical epidural hematoma in a 28 years old woman who had suddenly felt a strong pain in interscapular area. Rapidly after she noticed weakness in her legs and one day later she was completely paraplegia. The MRI of spine was done. There show tubular like low signal intensity at posterior epidural space of C_(7) level due to cord compression effect. In this article, we are adding one more rare case of spontaneous cervical spinal epidural hematoma confirmed by MRI.

로봇 머니퓰레이터에서의 수렴속도 향상을 위한 적분 슬라이딩 모드 기반 적응 시간 제어 기법

백재민,강민석 대한임베디드공학회 2021 대한임베디드공학회논문지 Vol.16 No.6

This paper proposes an adaptive time-delayed control approach with the integral sliding-mode surface for the fast convergence rate of robot manipulators. Adaptive switching gain aims to guarantee the system stability in such a way as to suppress time-delayed estimation error in the proposed control approach. Moreover, it makes an effort to increase the convergence ability in reaching the phase. An integral sliding-mode surface is employed to achieve a fast convergence rate in the sliding phase. The stability of the proposed one is proved to be asymptotically stable in the Lyapunov stability. The efficiency of the proposed control approach is illustrated with a tutorial example in robot manipulator, which is compared to that of the existing control approach. This paper proposes an adaptive time-delayed control approach with the integral sliding-mode surface for the fast convergence rate of robot manipulators. Adaptive switching gain aims to guarantee the system stability in such a way as to suppress time-delayed estimation error in the proposed control approach. Moreover, it makes an effort to increase the convergence ability in reaching the phase. An integral sliding-mode surface is employed to achieve a fast convergence rate in the sliding phase. The stability of the proposed one is proved to be asymptotically stable in the Lyapunov stability. The efficiency of the proposed control approach is illustrated with a tutorial example in robot manipulator, which is compared to that of the existing control approach.

백령도 해조군집의 종조성과 생물량

백재민,황미숙,이재완,이욱재,김종인,Baek, Jae-Min,Hwang, Mi-Sook,Lee, Jae-Wan,Lee, Wook-Jae,Kim, Jong-In 한국조류학회(藻類) 2007 ALGAE Vol.22 No.2

The seasonal change of algal flora and intertidal community structures of Bagryoungdo Island was investigated at Dumujin from February to November 2006. The description of subtidal algal community was made in October by Scientific SCUBA-diving. The total of 43 species, including 6 Chlorophytes, 6 Phaeophytes, 29 Rhodophytes and 2 sea grasses were identified in this survey. The occurrence of species according to season, listed as follows, 26 species in winter, 34 in spring, 18 in summer and 18 in autumn. Three species, Laminaria japonica, Neorhodomela aculeata and Ulva pertusa were dominant. The algal zonation of intertidal zone was figured out by Porphyra spp., Gloiopeltis furcata, Caulacanthus okamurae, Gelidium divaricatum - Neorhodomela aculeata, Enteromorpha compressa - Ulva pertusa, Dumontia simplex, Laminaria japonica from upper to lower zone. The zonation of subtidal zone was figured out by Ulva pertusa - Laminaria japonica - Zostera marina (sea grass), crustacean red algal population in autumn. The average of biomass of macroalgae was measured as 119.4 g?dry wt/m2.

Antioxidant and Cholinesterase Inhibitory Activities of Aqueous Extract from Rainbow Trout Oncorhynchus mykiss

백재민,윤나영,김연계,이두석,윤호동,박정숙 한국수산과학회 2011 Fisheries and Aquatic Sciences Vol.14 No.2

We investigated the antioxidant and cholinesterase inhibitory activities of the aqueous extract of rainbow trout Oncorhynchus mykiss. The antioxidant activity of O. mykiss aqueous extract was determined by in vitro peroxynitrite scavenging activity and reducing power assays. The aqueous extract of O. mykiss showed potent peroxynitrite radical scavenging activity (IC_(50)=0.12±0.001 mg/mL) and reducing power (absorbance=0.47±0.001) at the concentration of 1 mg/mL. The in vitro cholinesterase inhibitory activity of O. mykiss aqueous extract was examined using spectrophotometric analyses of acetyl- and butyrylcholinesterase. The aqueous extract of O. mykiss showed acetylcholinesterase inhibitory activity (IC_(50)=1.61±0.13 mg/mL), but did not exhibit inhibitory activity against butyrylcholinesterase. These results suggest that O. mykiss possesses antioxidant and acetylcholinesterase inhibitory activities and provide scientific evidence for the health benefits of O. mykiss aqueous extract.

로봇 메니퓰레이터에 비특이 터미널 슬라이딩모드를 사용한 적응 시간지연 제어 기법

백재민,백형부 제어·로봇·시스템학회 2019 제어·로봇·시스템학회 논문지 Vol.25 No.10

This paper describes an adaptive time-delayed control approach with a non-singular terminal sliding-mode technique (ATDC-NTS) that is proposed for obtaining fast response and high tracking performance in robot manipulators. The proposed ATDC-NTS uses one-sampled delayed measurements to cancel the uncertainties and the unknown disturbances generated by the robot manipulators. The proposed method uses an adaptive sliding-mode control for not requiring the stability criteria inherent in the time-delayed control (TDC), and hence, the magnitude of the control gains used in ATDC-NTS is not restricted unlike that used in the existing TDC-based control approaches. In addition, as the proposed ATDC-NTS is based on the non-singular terminal sliding-mode technique, it provides strong attractivity while approaching the reference points within the finite time. The simulation results showed that the proposed ATDC-NTS had high tracking performance as compared to the existing control approach.

해조류 양식 산업의 현황과 전망

백재민 동아시아식생활학회 2007 동아시아식생활학회 학술발표대회논문집 Vol.- No.-

아동들의 인지를 바탕으로 한 수학 교수: 미국의 Cognitively Guided Instruction의 소개

백재민,Baek Jae Meen The Korea Society of Educational Studies in Mathem 2004 수학교육학연구 Vol.14 No.4

Cognitively Guided Instruction (CGI) is one of the most successful professional development programs for elementary mathematics teachers in US. This article introduces its theoretical background, research-based framework of addition and subtraction work, and how the program has been disseminated. Carpenter and Fennema started CGI aiming to develop a professional development program that focused on research knowledge of children"s thinking. Their goal was. to bring a significant change in teaching by helping teachers understand how children think mathematically. This 3-year NSF funded project grew to be 11-year long, and a number of publications have reported consistent successful learning and teaching by CGI students and teachers compared to counterparts throughout US. CGI′s success by focusing on improving teachers′ knowledge of children′s thinking offers possible opportunities for teacher educators to re-conceptualize teacher education in Korea.

로봇 매니퓰레이터를 위한 적분형 슬라이딩 매니폴드를 가진 광범위한 시간지연 제어 알고리즘

백재민,강민석,윤경수 대한기계학회 2023 大韓機械學會論文集A Vol.47 No.5

본 논문은 로봇 매니퓰레이터에 적용할 수 있는 적분형 슬라이딩 변수 기반 광범위한 시간지연 기법을 제안한다. 제안된 제어 알고리즘은 불가피하게 요구되는 시간지연 제어 기법의 안정성 기준에 위배되더라도 항상 로봇 매니퓰레이터의 안정성을 보장할 수 있고, 시간지연 추정 방법을 활용하기 때문에 로봇 매니퓰레이터에 대한 속성 정보를 필요로 하지 않는다. 게다가, 이 기법에서 사용된 적분형 슬라이딩 변수는 슬라이딩 단계에서 가장 많이 사용되는 1계 슬라이딩 변수보다 높은 수렴 속도를 보장할 수 있으며, 로봇 매니퓰레이터의 강인성을 향상시킨다. 제안된 기법에 대한 효과는 2축 평면 로봇 매니퓰레이터에 근간을 둔 시뮬레이터에서 분석되었고, 그것은 잘 알려진 광범위한 시간지연 기법의 성능과 비교하여 검증되었다.

두개강내 원발성 흑색종

백재민,최기환,박재복 대한신경외과학회 1991 Journal of Korean neurosurgical society Vol.20 No.10-11

본 교실에서는 중추 신경계에 매우 드물계 발생하는 종양인 원발성 악성 흑색종 1례를 진단 치험하였기에 문헌 고찰과 함께 보고 하는 바이다. The primary malignant melanoma arising in the leptomeninges of the central nervous system is extremely rare. We report a case of malignant melanoma, apparently thought to be originated from leptomeninges, with diffuse neoplastic process widely spreaded over the leptomeninges of 42 years old man, who had suffered severe headache, nausea and left hemiparesis. This patient is free of the symptoms for six months after operation. The literature on this subject is briefly reviewed.

붉은쏨뱅이 (Sebastiscus tertius) 피부계의 미세구조 및 조직화학적 특징

백재민,김철원,임상구,이제봉,이정식,Baek, Jae-Min,Kim, Chul-Won,Lim, Sang-Gu,Lee, Jae-Bong,Lee, Jung-Sick 한국현미경학회 2004 Applied microscopy Vol.34 No.2

Integumentary structures of the rockfish, Sebastiscus tertius were examined by means of the light and transmission electron microscopy. Stratified epidermal layer consists of supporting cells, unicellular glands, granular cells and mitochondria-rich cells. The epidermal layer could be classified into superficial, intermediate and basal layer by morphology and structure of the supporting cells. Mucous cells of unicellular gland were observed in the superficial and intermediate layer of the epidermis. The mucous materials were identified as acidic and carboxylated mucosubstance by histochemical methods. Club cell has well-developed central vacuole, rough endoplasmic reticula and Golgi complex in the cytoplasm. Granular cells were observed in the superficial layer and contained numerous granules of high electron density. Mitochondria-rich cells are characterized by well-developed microfilaments in cortex and numerous tubular mitochondria in medullar cytoplasm. Three types of pigment cells in the dermal layer could be distinguished with electron density of cytoplasmic inclusions. 붉은쏨뱅이의 피부 상피층은 다층상피층으로 지지세포, 선세포, 과립세포 그리고 mitochodria-rich cell들로 구성된다. 상피층은 지지세포의 형태와 구조에 따라 표면층, 중간층 및 기저층으로 구분할 수 있다. 점액세포들은 단세포선으로 상피의 표면층과 중간층에 분포하며, 산성의 비황화 뮤코다당류로 구성된 점액을 가진다. 곤봉상세포는 세포질에 잘 발달된 중심공포, 조면소포체 및 골지체를 가진다. 과립세포는 표면층에 존재하며, 전자밀도가 높은 과립을 가진다. mitochodria-rich cell의 주변부 세포질에는 미세섬유 다발이 발달되어 있으며, 수질부에는 다수의 관상 미토콘드리아를 가진다. 색소세포는 세포질에 존재하는 함유물의 전자밀도에 따라 세 종류로 구분할 수 있다.