지능제어기를 이용한 자율 이동로봇의 운항

최정원,김연태,이석규,Choi, Jeong-Won,Kim, Yeon-Tae,Lee, Suk-Gyu 한국지능시스템학회 2003 한국지능시스템학회논문지 Vol.12 No.2

본 논문은 장애물에 대한 사전 정보를 가지고 있지 않은 공간에서 장애물의 회피와 지정된 목표점으로 이동할 수 있는 자율이동로봇을 위한 지능제어 알고리즘을 제안하고, 제안된 제어기의 효용성을 실험을 통하여 검증을 한다. 제시하는 지능 제어기는 계층구조의 알고리즘으로써, 그 하부에 로봇이 목표에 도달하기 위한 퍼지 알고리즘과 주행 중 만날 수 있는 장애물들에 대한 회피를 수행하는 퍼지-뉴럴 알고리즘이 존재하고, 상부의 가중치 퍼지 알고리즘은 로봇이 이동하면서 만날 수 있는 여러 가지 상황에 따라서 하부의 두 알고리즘에 적당한 가중치를 부여하여 장애물 회피동작과 목표점 도달동작을 수행할 수 있도록 구성되어 있다. 그리고 로봇의 현재 운동정보와 장애물까지의 거리정보를 바탕으로 가중치 퍼지 알고리즘의 출력부 소속도 함수를 조절함으로서 오목한 장애물에 대해서도 장애물 회피 동작을 수행하도록 하였다. 제작된 로봇으로 제시한 알고리즘의 실효성을 검증하였다. This paper proposes an intelligent navigation algorithm for multiple mobile robots under unknown dynamic environment. The proposed algorithm consists of three basic parts as follows. The first part based on the fuzzy rule generates the turning angle and moving distance of the robot for goal approach without obstacles. In the second part, using both fuzzy and neural network, the angle and distance of the robot to avoid collision with dynamic and static obstacles are obtained. The final adjustment of the weighting factor based on fuzzy rule for moving and avoiding distance of the robots is provided in the third stage. The experiments which demonstrate the performance of the proposed intelligent controller is described.

인가목(Rosa acicularis Lindl.) 잎 추출물의 대식세포에서 자가포식 유도활성

최정원,정진부,Jeong Won Choi,Jin Boo Jeong 한국자원식물학회 2023 한국자원식물학회지 Vol.36 No.4

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, water extracts from Rosa acicularis leaves (RAL) increased the production of immunostimulatory mediators and phagocytic activity in RAW264.7 cells. RAL increased p62/SQSTM1 expression. Inhibition of TLR4, JNK, and PI3K/AKT blocked RAL-mediated increase of p62/SQSTM1. RAL activated JNK and PI3K/AKT signaling. RAL-mediated activations of JNK and PI3K/AKT signaling were reversed by TLR4 inhibition. Taken together, it is believed that RAL-mediated autophagy may be dependent on activating via TLR4-dependent activation of JNK and PI3K/AKT signaling in macrophages.

Silymarin과 작약감초탕 병용투여의 C57BL/6 마우스 간조직 지질축적 및 염증 억제효과

최정원,조수정,신미래,박해진,Choi, Jeong Won,Cho, Su-Jung,Shin, Mi-rae,Park, Hae-Jin 대한본초학회 2022 大韓本草學會誌 Vol.37 No.5

Objective : The aim of the present study is to examine hepatic lipid-lowering and anti-inflammatory effects of silymarin combined with Jakyakgamcho-tang on non-alcoholic fatty liver disease in a high fat diet-induced obese mice model. Methods : C57BL/6 mice were divided into four dietary groups: (1) Normal, (2) Control (60% high-fat diet), (3) Control + silymarin 50 mg/kg/day (Silymarin), (4) Control + Silymarin 50 mg/kg/day + Jakyakgamcho-tang 100 mg/kg/day (SPG). After 12 weeks administration, mice were sacrificed and lipids and inflammation-related biomarkers were analyzed liver and plasma. Results : Silymarin and SPG treatments significantly lowered body and liver weights compared to the Control. Serumlipids (triglyceride (TG), total cholesterol) and pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin 1𝛽, and IL-6) concentrations were significantly lowered in the Silymarin and SPG groups than the Control group. Silymarin and SPG treatments suppressed hepatic TG level and hepatic lipid droplets compared to the Control. Theses two treatments significantly increased hepatic kinase B1 and AMP-activated protein kinase protein levels, and significantly decreased hepatic key lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthase and stearyl coenzyme A desaturase 1) protein levels than the Control. SPG also significantly increased hepatic fatty acid oxidation-related protein (peroxisome proliferator-activated receptor alpha and uncoupling protein 2) levels than the Control. Conclusions: Silymarin and SPG suppressed hepatic lipid accumulation by regulating hepatic protein expression, and lowered blood pro-inflammatory cytokines concentrations though the synergic effect of silymarin and Jakyakgamchotang was not clear.

임플랜트의 표면처리 방법이 골유착에 미치는 영향에 관한 연구

최정원,김광남,허성주,장익태,한종현,백홍구,최용창,Choi Jeong-Won,Kim Kwang-Nam,Heo Seong-Joo,Chang Ik-Tae,Han Chong-Hyun,Baek Hong-Gu,Choi Yong-Chang,Wennerberg Ann 대한치과보철학회 2001 대한치과보철학회지 Vol.39 No.1

The purpose of this study was to compare the effects of various surface treatments by measuring removal torque on bone healing around titanium implants. 40 Screw-shaped cp titanium implants with length of 4mm, outer diameter of 3.75mm, and pitch-height of 0.5mm were used Group 1 was left as machined(control), Group 2 was blasted with $50{\mu}m\;Al_2O_3$, group 3 was blasted and etched in etching solution($NH_4OH : H_2O_2:H_2O= 1 : 1 : 5$) at $90^{\circ}C$ for 1 minute group 4 was blasted and oxidated under pure oxygen at $800^{\circ}C$. The implant surface roughness was analyzed with SEM and CLSM(Confocal Laser Scanning Microscope) and implants were placed in proximal tibial metaphysis of 10 New Zealand White rabbits. After 3 months of healing period, removal torque of each implant was measured to compare bone healing around implant. The results obtained were as follows 1. In SEM view, blasting increased the roughness of the surface, but etching of that rough surface decreased the roughness due to the removal of the tip of the peak. Oxidation also decreased the roughness due to formation of needle-like oxide grains on the implant surface. 2. The Sa value from CLSM was least in the machined group($0.47{\mu}m$), greatest in blasted group($1.25{\mu}m$), and the value decreased after etching($0.91{\mu}m$) and oxidation($0.94{\mu}m$). 3. The removal torque of etched group(24.5Ncm) was greater than that of machined group(16.7Ncm) (P<0.05), and was greatest in the oxidated group(40.3Ncm) and the blasted group(34.7Ncm).

Cotoneaster mongolicus Pojark. 추출물의 HCl/ethanol로 유발된 위염 mice에 대한 보호효과

최정원,이진아,신미래,박해진,노성수,Choi, Jeong Won,Lee, Jin A,Shin, Mi-Rae,Park, Hae-jin,Roh, Seong-Soo 한국생약학회 2022 생약학회지 Vol.53 No.3

Cotoneaster mongolicus Pojark. (CM), in the family Rosaceae is an endemic plant to the Mongolian region (its name: Moнroл чapraй). In Mongolia, Cotoneaster species as a crude drug is mainly used for inflammatory diseases, diarrhea, and stomach indigestion. In this study, we evaluated the gastro-protective activity underlying mechanism of CM. For in vivo experiments, mice were divided into 5 groups; normal mice (Normal), gastritis mice (Control), gastritis mice treated with sucralfate 10 mg/kg (SC), gastritis mice treated with CM 100 mg/kg (CML), gastritis mice treated with CM 200 mg/kg (CMH). Gastritis was provoked by HCl/ethanol (60% ethanol in 150 mM HCl). After oral administration of each drug, HCl/ethanol was orally administered 90 mins later to induce gastritis. CM alleviated the damage to the gastric mucosa caused. As a result of confirming the expression of protein in gastric tissue through western blot, CM significantly reduced the expression of NF-κB activated due to gastritis. Also, it significantly modulated the Nrf2-Keap1 pathway. These results indicate that CM not only inhibits the nuclear metastasis of NF-𝛋B but also modulates the Nrf2-Keap1 pathway to relieve inflammation of the gastric mucosa.

Thioacetamide로 유도된 간섬유화 모델에서 생간건비탕(生肝健脾湯)의 보호 효과

최정원,정성미,신미래,정다운,노성수,Choi, Jeong Won,Chung, Sung Mi,Shin, Mi-Rae,Jeong, Da un,Roh, Seong-Soo 대한본초학회 2022 大韓本草學會誌 Vol.37 No.6

Objective : In modern society, liver diseases such as liver fibrosis are on the rise as inflammation and wound healing processes of the liver are repeated due to factors such as drinking, smoking, and stress. This study was conducted to evaluate the effect of Saenggangeonbi-tang (SGGBT) on thioacetamide (TAA)-induced liver fibrosis. Methods : The mice were divided into 4 groups for examination (n=6): Normal group (Nor), distilled water-treated liver fibrosis mice (Con), silymarin 50 mg/kg-treated liver fibrosis mice (Sily), SGGBT 200 mg/kg-treated liver fibrosis mice (S200). Liver fibrosis was established in the mice via TAA for 8 weeks (1 week 100 mg/kg, 2,3 weeks 200 mg/kg, 4-8 weeks 400 mg/kg, three times a week, intraperitoneal injection) and they were administered silymarin and SGGBT (every day, oral administration) with the TAA. Results : SGGBT significantly decreased the levels of aspartate aminotransferase, alanine aminotransferanse, ammonia, and myeloperoxidase in serum increased by liver fibrosis. As a result of confirming H&E and MT staining, it was confirmed that SGGBT reduced damage and inflammatory cell infiltration in liver tissue, and alleviated changes in collagen fiber deposition and histological fibrosis. Also, it was confirmed through PAS staining that it reduced glycogen deposition in liver tissue. In addition, SGGBT significantly decreased the NADPH oxidases as well as significantly modulated the expression of MMP-2 and TIMP-2. Conclusions : These results suggest that SGGBT regulates the expression of MMP/TIMP protein through inhibition of oxidative stress and alleviates liver fibrosis by reducing collagen and glycogen deposition in liver tissue.

MG63 Cell Attachments on the Titanium Disks after Micro-Arc Oxidation

최정원,허성주,장익태,곽재영,이재봉,임순호,Choi, Jeong-Won,Heo, Seong-Joo,Chang, Ik-Tae,Koak, Jai-Young,Lee, Jai-Bong,Yim, Soon-Ho Korean Academy of Stomatognathic Function and Occl 2004 구강회복응용과학지 Vol.20 No.1

이번 연구의 목적은 순수 타이타늄의 표면을 양극산화법으로 표면처리하여 표면의 특성변화를 연구하고, 이에 따른 세포부착 특성의 차이를 연구하는 것이다. 원반 모양의 타이타늄을 전해질용액에서 300V - 550V의 전압을 주어 양극산화 하고 표면특성을 관찰한 결과, 전압이 높아짐에 따라 표면의 분화구 크기가 커지는 양상을 보였으며 아울러 표면 거칠기도 증가되었다. 세포 부착 실험결과 전압이 증가함에 따라 세포부착 및 증식세포수는 감소하였다. 300V 이상의 양극산화 전압은 표면의 거칠기는 증가시키지만 세포증식은 오히려 억제되는 것이 관찰되었다.

도재파절 양상에 따른 수종의 도재 수복용 레진의 결합력에 관한 실험적 연구

최정원,한동후,정창모,Choi, Jeung Won,Han, Dong Hoo,Jeong, Chang Mo 대한치과보철학회 1990 대한치과보철학회지 Vol.28 No.2

Although dental porcelain demonstrates lasting esthetic results, it suffers from inherent brittle fractures. Various techniques and materials for intraoral porcelain repair has been suggested. This study investigated the in vitro shear strength of three porcelain repair systems according to aspects of the porcelain fractures. The purpose of this study was to evaluate the shear bond strength of three porcelain repair systems(All-bond, Clearfil, Scotchprime) according to fractured surface of porcelain - fused - to - metal restorations. For this study specimens were divided into five groups : group 1 represented fracture occurred at body porcelain layer, group 2 represented fracture occurred at opaque porcelain layer, group 3 represented fracture including 1/3 of metal exposure, group 4 represented fracture including 2/3 of metal exposure, and group 5 represented all metal surface was exposed. Specimens were stored in double deionized water(24Hr, $37^{\circ}C$) and thermocycling was performed(24Hr, 1080cycles), and subjected to a shear force parallel to the repair resin and porcelain interface by use of an University Testing Machine. The results of this study were obtained as follows : 1. In group 1 and 2, bond strength was relatively high, and bond strength showing reducing tendency as exposure of metal was increased. 2. In group 1, bond strength was relatively high, and no significant differences in porcelain repair system. 3. In group 2, 3 and 4, All-bond and Clearfil provided significantly higher bond strength than scotchprime. 4. In group 5, bond strength was the lowest among all groups and especially in case if Scotchprime. 5. Cohesive failure was observed in group 1 and 2, adhesive failure was observed in group 5, and cohesive / adhesive failures were observed in group 3 and 4.

종합건설사 실행예산 편성 시 리스크 비용 산정에 관한 인식 및 실태에 관한 연구 - 건축공사를 중심으로 -

최정원,김한수,Choi, Jeong Won,Kim, Han Soo 한국건설관리학회 2022 한국건설관리학회 논문집 Vol.23 No.3

Construction projects are exposed to various types of risks, which tend to increase. The increasing risks call for contractors' more attentions to forecasting and dealing with these risks. One of the measures to deal with contractors' risks is to forecast or estimate risk cost and include it in the construction budget. Although various researches in relation to risk cost have been observed, little attention has been paid to general contractors' perceptions and current practices in estimating risk cost of construction budget. The objective of the study is to identify and discuss key characteristics and implications based on the survey and analysis of general contractors' perceptions and current practices in estimating risk cost of construction budget. The study shows that there is a gap between the perception and the practice of estimating risk cost, that is, high perception of the importance of risk cost and a relatively low level of practice. It suggests that historical cost data, guidelines and corporate-level standard procedures are required to improve the current practice in addition to sufficient time allocations for risk cost estimating. It discusses that there is a need for using sophisticated estimating techniques including bid data analytics despite a low level of the current adoption, and also proposes that research and development in the field of the sophisticated estimating techniques should be further implemented in order to increase their practicality.

우슬 추출물의 3T3-L1 지방세포와 고지방식이로 유도된 C57BL/6 마우스에 대한 항비만 효과

최정원 ( Jeong Won Choi ),노성수 ( Seong-soo Roh ) 대구한의대학교 제한동의학술원 2021 東西醫學 Vol.46 No.1

Objectives : The objective of this study was to confirm the anti-obesity effect of the Achyranthis Radix 30% EtOH extract (AE). Methods : The AE treated with 100, 250, and 500 mg/mL on 3T3-L1 cells and then the cell viability was examined through MTT assay. In 3T3-L1 cells, Oil Red O staining was examined to detect triglyceride (TG) accumulation. Oil Red O staining for the examination of lipid accumulation was performed at concentrations 100, 250, and 500 mg/mL. Male C57BL/6 mice were fed on a high-fat diet (45% kcal fat; HFD) to induce obesity. Simultaneously, mice orally received 200 or 400 mg/kg AE for 6 weeks. Also, we measured the body weight gain and liver weight. Moreover, biochemical analyses including AST, ALT, TG, and TC levels were measured in serum. Results : As a result of Oil Red O staining, both cell differentiation and TG accumulation were inhibited compared with Blank group. In the animal experiment, body weight gain in the AEH treated group was significantly suppressed. Moreover, liver weight gain was markedly suppressed in all drug groups. The increased liver function markers such as AST and ALT significantly decreased by AE treatment. Thus, serum TG and TC levels in AE groups showed a significant reduction compared with Control group. Conclusion : Taken together, these results suggest that AE treatment showed anti-obesity effects by the inhibition of fat accumulation and the improvement of blood lipids. Therefore, AE could be utilized as a potential therapeutic agent for the prevention and treatment obesity.