Dynamic Comparator와 Merged CDAC을 이용한 10bit 10MHz 저잡음 SAR 아날로그-디지털 변환기

정동균(Dong Kyun Jung),기노천(No-Cheon Kee),장병기(Byeong Gi Jang),이강윤(Kang-Yoon Lee) 대한전자공학회 2016 대한전자공학회 학술대회 Vol.2016 No.11

초음파센서 기반 자율주행 로봇의 장애물회피

김민성(Min Sung Kim),심병균(Byoung Kyun Shim),정동연(Dong Yean Jung),한성현(Sung Hyun Han) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4

This paper achieves a research about avoidance of obstacles avoidance based on ultrasonic sensor. The performance of the proposed obstacle avoidance robot controller in order to determine the exact dynamic systems modeling system that uncertainty is difficult for nomadic controlled robot direction angle by ultrasonic sensors throughout controlled performance tests. In additionally, this study is an in different ways than the self-driving simulator in the development of ultrasonic sensors and unmanned remote control techniques used by the self-driving robot controlled driving through an unmanned remote controlled unmanned realize the performance of factory automation.

하중도의 발달에 따른 하천의 흐름 특성 및 수리학적 안전성

박찬익 ( Chan-ik Park ),정동균 ( Dong-kyun Jung ),유병로 ( Byong-ro Ryu ) 한국환경기술학회 2021 한국환경기술학회지 Vol.22 No.1

This study uses the RMA-2(Resource Management Associates) Model, a two-dimensional flow analysis model using a finite element method, to analyze the relationship between alluvial island development and flow characteristics of rivers. It is analyzed that the alluvial island located in the area under investigation is continuously developing and will accelerate in the future. The distribution of flow rates, water depths and water levels in the sub-load zone is degraded in the areas where alluvial island have developed. Because the section area of the water is reduced under the same flow conditions It was analyzed that the increases at the surrounding left and right sides of alluvial island. It was analyzed that the allowance decreased by at least 14 % and up to 84 % in comparison with the surplus height to review river safety due to rising water level. As a result of examining the flow characteristics of the river based on the development of alluvial islands, it was determined that the alluvial island not considered at the time of river master plan and implementation design had an effect on the possibility of river flooding. The water level of upstream increased significantly, so in order to create a safe river when formulating a river improvement plan, the dysfunctional aspects along with the functional aspects of the alluvial island need to be carefully considered.

연소재, 슬러지 및 식품폐기물 혼화물의 열적반응에 따른 멀칭용 조경재 개발

이민희 ( Min-hee Lee ),정영도 ( Young-do Jeoung ),유병로 ( Byong-ro Ryu ),정동균 ( Dong-kyun Jung ) 한국환경기술학회 2017 한국환경기술학회지 Vol.18 No.3

본 논문은 열적반응에 따른 산업폐기물(비산재, 바닥재, 슬러지 및 식품폐기물)의 자원화에 대한 연구이다. 산업부산물을 포함한 구형(10 mm)의 멀칭용 조경재는 700~1000℃에서 1시간 동안 반응시켜 제조되었다. 산업부산물의 혼합비율에 따라 다양하게 실험 제조되었으며, 멀칭용 조경재의 최적 혼합비는 800℃에서 반응시 무기물질 45%, 유기물질 25%, 물유리 30%이다. 멀칭용 조경재와 화산석 모두 SiO₂가 가장 많이 함유되어 있는 것으로 나타났으며, 제조된 조경재는 다공성이 형성되어 토양에 통기성을 높일 수 있는 구조로 형성되었음을 확인할 수 있었다. 멀칭용 조경재와 화산석의 물리화학적 특성은 각각 밀도 1.2 g/cm³, 1.4 g/cm³, 마모율 60.3%, 66.1%, 공극율 44.2%, 36.6%, 흡수율 39.8%, 16.8로 분석되었다. The studies on recycling of industrial wastes such as fly ash, bottom ash, sludge and food waste on thermal response are actively pursued. The landscape material of spherical shape of diameter(10 mm) containing industrial materials on thermal response were manufactured at 700~1000℃ for 1hour. By mixing industrial materials ratios of ash, sludge and food waste, various landscape material are manufactured and tested. An optimum mixture mulching landscape material is determined inorganic material 45%, organic material 25%, water glass 30% at 800℃. Both landscape material and volcanic rock showed that they had the greatest amount of SiO₂. The manufactured landscape material were constructed a structure formed by porous materials that were formed to enhance the permeability of the soil. The physical and chemical properties of landscape material and volcanic rock were analyzed to be density 1.2 g/cm³, 1.4 g/cm³, abrasion rate 60.3%, 66.1%, porosity 44.2%, 36.6%, absorption factor 39.8%, 16.8% respectively.

Actinobacillus actinomycetemcomitans Y-4에서 추출한 Lipopolysaccharide가 배양골조직의 골흡수에 미치는 영향에 관한 연구

김정근,이종흔,정동균 대한구강생물학회 1985 International Journal of Oral Biology Vol.9 No.1

The organ and cell culture in this study were carried out to observe the effect of Lipopolys-accharide (LPS) extracted from Actinobacillus actinomy cetem comitansY-4. For the organ culture experiment, ulnae and radii were removed from 19-day fetal rars, prelabelled by subcutaneous injection of 300 μCi ^45CaCl_2 into mother rats on the 17th day of gestation. One side of paired fetal ulnae and radii was employed as control, while the other side was employed as the corresponding experimental group. While control group was cultivated in BFJb media, experimental group was cultivated in BGJb media added with 3 different concentrations of LPS. Radioactivities of ^45Ca released into media after 3 different periods of culture and those fo ^45Ca remained in cultivated bone were measured. Bone resorption rate was calculated by the % ratio of radioactivity of ^45Ca released into media to total radioactivty that had been in the bone at the beginning of culture. The effect of LPS on bone resorption was observed by the ratio of bone resorption of experimental group to control. For the cell culture experiment, extracellular matrix of relvaria camoved from 19-day-old fetal rats were digested with collagenase. The harvested bone cells were divided into control and experimental groups. The cells were cultivated in Eagle's MEM in the control group, and the cells were cultivated in Eagle's MEM contained with 1μg/ml of LPS in the experimental group for 48 hours. Acid phosphatase and beta-glucuronidase released into media and remained in bone cells were determined by spectrophotometric method. The rate of enzyme lease was calculated by %ratio of enzyme released into media to the total enzymes (enzymes released from and remained in bone cells). The effect of LPS on enzyme release was observed by the ratio of released enzyme of experimental group to control. The results were as follows. 1. The increasing tendency of ^45Ca release was shown by the addition of 0.1μg/ml of LPS. However, addition of 1μg/ml and 10μg/ml of LPS produced marked and significant crease of ^45Ca release. 2 In the cell culture experiment, addition of 1μg/ml of LPS showed significant increase in the release of acid phosphatase and beta-glucuronidase since 24 hours of culture. 3. The time required for maximum release ratio was usually shorter in lyososomal enzyme than in ^45Ca.

Indomethacin과 Dexamethasone이 Lipopolysaccharide에 의한 골흡수에 미치는 영향

민병무,정동균,김정근 대한구강생물학회 1985 International Journal of Oral Biology Vol.9 No.1

Present study ws undertaken to determine the inhibitory effects of indomethacin and dexamethasone on LPS-induced bone resorption. Bone resorption was assessed in the period of 24, 48 and 72 hours by the release of previously incorporated ^45Ca from the shafts of radii and ulnae of 20 day fetal rats after 200μCi of ^45CaCl_2 was injected subcutaneously into the mothers on the 18th day gestation. The shafts were pre-cultured for 24 hours in BGJb media supplemented with bovine surum albumine (1㎎/ml)in a atmosphere of 5% CO_2 in air at 37℃. One pair of bones were used for drug effects while the other pair from the same fetus served as control. The experimental bones were then transfered to the LPS-containing (1μg/ml) media to which one of these drugs was added (10^-7 or 10^-5M)and control bones to the only LPS-containing media and cultured for 72 hours. Two concentrations of indomethacin inhibited LPS-induced ^45Ca release after 48 and 72 hours, and in dexamethasone, only 10^-5M concentration inhibited it after 48 and 72 hours. It is speculated that the inhibitory effect fo indomethacin or dexamethasone on LPS-induced bone resorption may be due to the inhibition of prostaglandin synthesis induced by LPS.

백서 두개관 세포군의 골형성능에 관한 연구

안중진,김관식,정동균 대한구강생물학회 1989 International Journal of Oral Biology Vol.13 No.2

To study the osteogenic capacity of rat calvarial cell populations, 5 bone cell populations were prepared from fetal rat calvaria by sequential enzyme digestion. After primary culture for 6-7 days each bone cell population was collected and resuspended at 0.5-1×10^6 cells/35mm culture dish and allowed to attach overnight. Cells were grown in α-MEM plus 15% FBS with or without 50㎍/ml ascorbic acid, 10mM β-glycerophosphate or 10^-7M dexamethasone for 23 days. After long-term culture, the cell layer was fixed with neutral buffered formalin and stained with von Kossa stain. The von Kossa positive nodules were counted. The observed results were as follows. 1. Nodule formation was begun after 7-10 days of culture and was increased with culture periods. 2. Mineralized bone nodules, positive for von Kossa stain, were formed only in population IV and V when cultured in media supplemented with 50㎍/ml ascorbic acid and 10mM β-glycerophosphate. 3. Mineralized nodule was not formed in all bone cell populations when cultured in media supplemented with ascorbic acid or β-glycerophosphate only. 4. Dexamethasone (10^-7M) increased significantly the formation of bone nodule in population IV and V. These results indicate that enzymatically released calvarial cells can form mineralized bone nodules in vitro, and along with biochemical data suggest that population IV and V express the osteoblastic phenotype.

Propranolol이 흰쥐 해마박편에서 GABA유리 및 CA1 추체세포의 활성에 미치는 영향

박정희,김형룡,김관식,정동균 대한구강생물학회 1992 International Journal of Oral Biology Vol.16 No.2

Present study was performed to clarify the effect of propranolol on the GABA release and CAl hippocampal synaptic activity employing rat hippocampal slices which appear to contain most of the intrinsic and afferent circuits and to maintain the physiological characteristics seen in the hippocampus in vivo. Hippocampal slices were prepared and pre-equilibrated in Krebs-bicarbonate medium(KBM, pH 7.4) for 1 hr at 37℃. Pre-equilibrated slices were incubated in fresh KBM and then veratrine-containing KBM for 10min period. Basal and veratrine-induced GABA release were determined from recovered medium by HPLC. After 30min resting period, slices were reincubated in propranolol-containing KBM and propranolol plus veratrine-containing medium consecutively for 10min period each to investigate the effect of propranolol on basal or veratrine-induced GABA release from hippocampal slices. Extracellular population spike from CAl stratum pyramidale was measured with tungsten electrode having a tip resistance of 3-5㏁. Propranolol inhibited veratrine-induced GABA release in a dose-dependent manner. Propranolol reduced orthodromically evoked population field potentials from CAl stratum pyramidale in a concentration-dependent manner. The inhibitory effect of propranolol on GABA release and evoked population field potentials seems to be a result of sodium channel blockade.

고압환경이 백서 장골의 Cyclic AMP와 교원섬유의 농도 변화에 미치는 영향

민병무,정동균,김정근 대한구강생물학회 1985 International Journal of Oral Biology Vol.9 No.1

The present investigation was performed to study the effects of hyperbaric environment on the changes of cAMP and collagen contents in rat long bones. Sprague-Dawley rats were exposed to hyperbaric environment, 2.5 ATA, with hyperbaric dry chamber for 72 hours. Rat long bones including humerus, femur and tibia were separated, and the specimens were analyzed for their contents of cAMP and hydroxyproline. The rats immediately sacrified after exposing to hyperbaric environment had a higher cAMP contents than those of control, but its contents in the rats sacrified at 7 days after exposing to hyperbaric environment were recovered in proximal femur, distal femur and proximal humerus. However,the rats immediately sacrified had a lower collagen contents than those of control, but its contents were recovered in the rats sacrified at 7 days. cAMP contents decreased, but collagen contents did not changed when compared with those of control in distal humerus and proximal tibia. The chemical bone changes induced by hyperbaric environment in proximal and distal femur were greater than those of proximal humerus, and its changes in distal humerus and proximal tibia were not shown. The results suggest that hyperbaric environment induces the chemical bone changes in rat long bones, but the dgree of its changes is different from each other.

위 천공과 거대점막주름을 동반한 Gastritis Cystica Profunda 1 예

김주현,윤명환,박동균,강동훈,김용일,이정선,이항진,정문기,김성권,정동해 대한소화기내시경학회 2001 Clinical Endoscopy Vol.23 No.3

Gastritis cystica profunda (GCP) is a rare disease in which cystically dilated gastric foveolae or glands extend into the muscularis mucosae or below. The pathogenesis of GCP has been described as an interruption of the muscularis mucosae and migration of epithelial elements to submucosa caused by presence of suture materials after surgery or erosion of the gastric mucosa in chronic gastritis and ischemia. Macroscopically, GCP may present not only as a giant gastric mucosal folds but also as a submucosal tumor or as solitary or diffuse polyps. An endoscopic ultrasonographic (EUS) findings clearly differ from findings in the other disordes. The combination of EUS and mucosectomy appears to be very useful for the diagnosis of GCP. Therefore, all unnecessary surgical procedures should be avoided in cases of GCP. We report a case of GCP associated with gastric perforation which presented as diffuse giant gastric folds and clinically advanced gastric cancer was suspected.