The State Estimator for Underwater Vehicle Systems

Kim, Hwan-Seong,You, Sam0Sang,Lee, Jin-Woo 한국해양대학교 산업기술연구소 2003 연구논문집 Vol.20 No.-

In this paper, an estimation method for extimating teh states of underwater vehicle systems with external unknown disturbance is proposed. First, the dynamics of underwater vehicle are induced by Taylor series expansion in the vertical plane and horizontal plane, respectively. For constructing the vehicle model, the external efforts, i.e., the sea surface disturbances, the current, wave and etc., are regarded as external unknown disturbances. Thus the disturbances is added as external input into state-space form of underwater vehicle systems. To estimate the state of systems with unknown disturbance, a disturbance observer which does not effected the external unknown input is proposed, and the existence condition for the observer is given. Finally, the effectiveness of the proposed disturbance observer for underwater vehicle systems is verified by using numerical simulation.

Model-Based Feedforward Precompensation and VS-Type Robust Nonlinear Postcompensation for Uncertain Robotic Systems with/without Knowledge of Uncertainty Bounds ( II )

Sam Sang You,Seok Kwon Jeong 대한기계학회 1996 KSME International Journal Vol.10 No.3

Dynamical Analysis of the Mooring Vessel System Under Surge Excitations

Sang-Do Lee,Sam-Sang You 해양환경안전학회 2018 해양환경안전학회지 Vol.24 No.2

본 연구는 두점식 선박 계류시스템의 종방향 외력에 대한 비선형 동적거동 해석을 수행하였다. 특정 입력 매개변수에 대한 카 오스 운동과 한계주기궤도 등의 비선형 거동의 특성을 연구하였다. 주로 비선형복원력은 계류시스템의 강한 비선형성과 동적거동의 다양 성을 제공한다. 계의 운동방정식 시뮬레이션에 사용된 수치 적분기는 4차 룽게쿠타법이다. 외력진폭과 주파수를 변화시킬 때 분기 그림 과 동적불안정 현상들을 볼 수 있다. 외력의 주파수(진동수)가 0.4 rad/s인 경우 수많은 혼돈상태 점들 사이에 주기창이라 불리는 안정적인 주기해가 관측된다. 주파수가 0.7 rad/s인 경우는 외력진폭이 1.0을 초과할 때 혼돈 영역이 갑자기 증가한다. 주파수가 1.0 rad/s인 경우는 주 파수가 0.4 rad/s 및 0.7 rad/s인 경우와 비교해 볼 때, 혼돈 운동이 약화된다. 아울러, 두점식 계류시스템은 각 매개변수에서 준주기 운동, 한 계주기궤도, 대칭성의 깨짐과 같은 다양한 정상상태의 궤적이 관측된다. This paper deals with the dynamical analysis of a two-point mooring vessel under surge excitations. The characteristics of nonlinear behaviors are investigated completely including bifurcation and limit cycle according to particular input parameter changes. The strong nonlinearity of the mooring system is mainly caused by linear and cubic terms of restoring force. The numerical simulation is performed based on the fourth order Runge-Kutta algorithm. The bifurcation diagram and several instability phenomena are observed clearly by varying amplitudes as well as frequencies of surge excitations. Stable periodic solutions, called the periodic windows, can be obtained in succession between chaotic clouds of dots in case of frequency ω=0.4 rad/s. In addition, the chaotic region is unexpectedly increased when external forcing amplitude exceeds 1.0 with the angular frequency of ω=0.7 rad/s. Compared to the cases for ω=0.4, 0.7 rad/s, the region of chaotic behavior becomes more fragile than in the case of ω=1.0 rad/s. Finally, various types of steady states including sub-harmonic motion, limit cycle, and symmetry breaking phenomenon are observed in the two-point mooring system at each parameter value.

Optimum chemical composition of raw catalytic materials for a De-NOx SCR honeycomb

Sam-Sik Park,Dae-Hyun Yoon,Sang-Hee You,Won-Tea Bae,Dong-Woo Shin 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

The chemical composition of raw materials for a TiO2- based honeycomb extruded for De-NOx via selective catalytic reduction (SCR) was optimized in terms of catalytic activity and extrusion formability. The catalytic activity of powder mixtures containing TiO2, 10 w/o of WO3, 1-2 w/o of V2O5 and 1, 3 and 5 w/o of SO3 were examined. Various combinations of catalytic materials in the form of either oxide power or precursor dissolvable in an oxalic acid solution were attempted in order to differentiate the effect of homogeneity of catalytic materials while mixing with TiO2 powder. V2O5 powder or ammonium metavanadate (AMV), and WO3 powder or ammonium metatungstate hydrate (AMT) dissolved in an oxalic acid solution were used as sources of V2O5 and WO3, respectively. The powder mixture containing 1 w/o V2O5 and 10 w/o WO3 obtained from AMV and AMT dissolved in an oxalic acid solution, exhibited more than 90% of De-NOx activity at temperatures above 300 oC, attributed to the homogeneous dispersion of V2O5 in TiO2 particles due to the complete solubility of AMV in oxalic acid. Increasing the V2O5 content from 1 w/o to 2 w/o, and adding 1 w/o of SO3 in the form of H2SO4, while maintaining the WO3 content at 10 w/o, consequently with a chemical composition of TiO2/10 w/o WO3/2 w/o V2O5/1 w/o SO3, showed nearly 100% NOx reduction in the temperature range of 250 oC to 400 oC. Based on this composition of a catalytic powder mixture, the additives for extrusion forming such as inorganic binder, water, MC, and PEG were also optimized as 8, 40, 3.5 and 3.5 parts, respectively, with respect to the weight of the catalytic powder mixture. The processing developed in this study was applied in manufacturing a large scale commercial SCR honeycomb catalyst with 150 mm × 150 mm × 1,000 mm dimensions. The chemical composition of raw materials for a TiO2- based honeycomb extruded for De-NOx via selective catalytic reduction (SCR) was optimized in terms of catalytic activity and extrusion formability. The catalytic activity of powder mixtures containing TiO2, 10 w/o of WO3, 1-2 w/o of V2O5 and 1, 3 and 5 w/o of SO3 were examined. Various combinations of catalytic materials in the form of either oxide power or precursor dissolvable in an oxalic acid solution were attempted in order to differentiate the effect of homogeneity of catalytic materials while mixing with TiO2 powder. V2O5 powder or ammonium metavanadate (AMV), and WO3 powder or ammonium metatungstate hydrate (AMT) dissolved in an oxalic acid solution were used as sources of V2O5 and WO3, respectively. The powder mixture containing 1 w/o V2O5 and 10 w/o WO3 obtained from AMV and AMT dissolved in an oxalic acid solution, exhibited more than 90% of De-NOx activity at temperatures above 300 oC, attributed to the homogeneous dispersion of V2O5 in TiO2 particles due to the complete solubility of AMV in oxalic acid. Increasing the V2O5 content from 1 w/o to 2 w/o, and adding 1 w/o of SO3 in the form of H2SO4, while maintaining the WO3 content at 10 w/o, consequently with a chemical composition of TiO2/10 w/o WO3/2 w/o V2O5/1 w/o SO3, showed nearly 100% NOx reduction in the temperature range of 250 oC to 400 oC. Based on this composition of a catalytic powder mixture, the additives for extrusion forming such as inorganic binder, water, MC, and PEG were also optimized as 8, 40, 3.5 and 3.5 parts, respectively, with respect to the weight of the catalytic powder mixture. The processing developed in this study was applied in manufacturing a large scale commercial SCR honeycomb catalyst with 150 mm × 150 mm × 1,000 mm dimensions.

The effects of Cudrania tricuspidata extract on bone metabolism in ovariectomized rats

( You Young Jo ),( Sang Deog Seo ),( Ji Won Kim ),( Hyun Ji Cho ),( Jeong Woo Chon ),( Kwang Gill Lee ),( Heui Sam Lee ),( Yoo Kyoung Park ),( Haeyong Kweon ) 한국잠사학회 2016 International Journal of Industrial Entomology Vol.32 No.2

The effects of Cudrania tricuspidata (CT) extract on markers of osteoporosis were examined in ovariectomized rats. We classified 26 rats into five groups and provided a pellet chow diet and tap water throughout the 27-wk experimental period. During the last 15 wk, we added oral injections to each group as follows: sham-operated (SHAM, n=4) and ovariectomized-control (OVX, n=5) with distilled water, alendronate with 10 mg/kg/d of alendronate sodium (ALEN, n=5), CT (CT100, n=6) with 100 mg/kg/d of CT, and CT (CT300, n=6) with 300 mg/kg/d of CT. After the experimental period, blood, urine, and micro-CT images were assessed. The CT100 and OVX groups did not show any significant differences in urinary n-terminal telopeptide (NTx) (p<0.05 ), but with increases in CT concentration, the NTx level was slightly reduced. Serum osteocalcin was significantly higher in the CT groups than in all other groups (p<0.05 ). Notably, the serum calcium levels of all groups were within the normal range, but urinary calcium levels in the CT groups were significantly lower than the OVX group (p<0.05 ). In addition, the CT groups exhibited higher trabecular BMD than the OVX groups while showing similar BMD to the ALEN group (p<0.05 ). The Tb.Th of the ALEN group was lower than all other groups. Based on the overall analysis of results, CT prevented bone loss by inhibiting bone resorption and enhancing bone formation. Although alendronate showed a similar effect in preventing bone loss, it did so by solely inhibiting bone resorption, and its long-term use reportedly causes paradoxical effects such as hip fractures. Thus, for osteoporosis induced by ovariectomy, we conclude that CT extract is an effective natural treatment without severe side effects.

Kinematics and Dynamic Modeling for Holonomic Constrained Multiple Robot Systems Through Principle of Workspace Orthogonalization

Sam Sang You,Seok Kwon Jeong 대한기계학회 1998 KSME International Journal Vol.12 No.2

Robust Autopilot Design for Submarine Vehicles

Sam-Sang You(유삼상) 한국해양공학회 1997 韓國海洋工學會誌 Vol.11 No.3

잠수함이 저심도 조건에서 특수임무 수행시, 표면파도 및 조류등 외란의 영향하에서 요구심도 및 위치 유지를 위한 강인한 자동항법장치 설계는, 첨단 군용 잠수함 개발에 필수적이다. 본 연구는 잠수함 조종 운동역학계에 기초하여, 정확한 심도 및 피치 운동 제어를 위해 선형 행렬 부등식을 이용한 혼합 H₂/H∞ 설계법을 사용, 다중 목적 함수로 표현된 잠수함의 조종 성능들을 개선하였다. 또한, 제어기 설계법의 타당성을 수치 시뮬레이션을 통하여 검증하였다. 결과적으로, 본 제어법은 각종 외란 및 계의 불확실성하에서 잠수정의 만족스러운 과도 상태 응답과 일정 심도 유지 및 피치 각도 변동 최소화에 적합한 강인한 방법임이 검증되었다.

Diving Autopilot Design for Underwater Vehicle Using Multi-Objective Control Synthesis

Sam Sang You,Young Ho Chai 대한기계학회 1998 KSME International Journal Vol.12 No.6

Robust diving control of underwater robotic vehicle

Sam-Sang You,Hyeung-Sik Choi,Hwan-Seong Kim 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.6

In this paper, we examine controller design for pitch-axis motion of an underwater robotic vehicle in the vertical plane. First, an AUV mathematical model is established, Next, the control synthesis includes the ∞ H loop-shaping design. Then, the resulting controller has been evaluated extensively in both the frequency and the time-domains. Finally, it is found that the proposed vehicle system provides good maneuverability over a wide range of operating conditions, even under model uncertainties.

Ochnaflavone, a Natural Biflavonoid, Induces Cell Cycle Arrest and Apoptosis in HCT-15 Human Colon Cancer Cells

( You Jin Kang ),( Hye Young Min ),( Ji Young Hong ),( Yeong Shik Kim ),( Sam Sik Kang ),( Sang Kook Lee ) 한국응용약물학회 2009 Biomolecules & Therapeutics(구 응용약물학회지) Vol.17 No.3