Contribution of Gasoline Particulate Filter (GPF) and Lubricant to the TGDi System Solution

Simon Yang 한국트라이볼로지학회 2018 한국트라이볼로지학회 학술대회 Vol.2018 No.10

Anterolateral thigh free flaps and radial forearm free flaps in head and neck reconstruction: A 20-year analysis from a single institution

Yang, Simon,Hong, Jong Won,Yoon, In Sik,Lew, Dae Hyun,Roh, Tai Suk,Lee, Won Jai Korean Society of Plastic and Reconstructive Surge 2021 Archives of Plastic Surgery Vol.48 No.1

Background Reconstruction after removal of a malignant tumor in the head and neck region is crucial for restoring tissue integrity, function, and aesthetics. We retrospectively analyzed patients who underwent intraoral reconstruction surgery using radial forearm free flaps (RFFF) and anterolateral thigh free flaps (ALT) at a single institution to provide more information supporting the choice of a reconstruction method after removal of head and neck cancer. Methods The charts of 708 patients who underwent head and neck reconstruction between 1998 and 2018 at the Department of Plastic and Reconstructive Surgery at our institution were retrospectively reviewed. Patients' age, sex, and history of radiation therapy, diabetes mellitus, and smoking were retrieved. The primary cancer site, types of defects, and complications were investigated. Results Overall, 473 and 95 patients underwent reconstruction surgery with RFFF and ALT, respectively. RFFF was more often used in patients with cancers of the pharynx, larynx, esophagus, or tonsil, while ALT was more frequently used in patients with cancers of the mouth floor with tonsil or tongue involvement. The proportion of patients undergoing ALT increased gradually. Flap failure and donor site morbidities did not show significant differences between the two groups. Conclusions RFFF and ALT flaps resulted in similar outcomes in terms of flap survival and donor site morbidity. ALT can be an option for head and neck reconstruction surgery in patients with large and complex defects or for young patients who want to hide their donor site scars.

Stream-based Biomedical Classification Algorithms for Analyzing Biosignals

( Simon Fong ),( Yang Hang ),( Sabah Mohammed ),( Jinan Fiaidhi ) 한국정보처리학회 2011 Journal of information processing systems Vol.7 No.4

Classification in biomedical applications is an important task that predicts or classifies an outcome based on a given set of input variables such as diagnostic tests or the symptoms of a patient. Traditionally the classification algorithms would have to digest a stationary set of historical data in order to train up a decision-tree model and the learned model could then be used for testing new samples. However, a new breed of classification called stream-based classification can handle continuous data streams, which are ever evolving, unbound, and unstructured, for instance--biosignal live feeds. These emerging algorithms can potentially be used for real-time classification over biosignal data streams like EEG and ECG, etc. This paper presents a pioneer effort that studies the feasibility of classification algorithms for analyzing biosignals in the forms of infinite data streams. First, a performance comparison is made between traditional and stream-based classification. The results show that accuracy declines intermittently for traditional classification due to the requirement of model re-learning as new data arrives. Second, we show by a simulation that biosignal data streams can be processed with a satisfactory level of performance in terms of accuracy, memory requirement, and speed, by using a collection of stream-mining algorithms called Optimized Very Fast Decision Trees. The algorithms can effectively serve as a corner-stone technology for real-time classification in future biomedical applications.

Stream-based Biomedical Classification Algorithms for Analyzing Biosignals

Fong, Simon,Hang, Yang,Mohammed, Sabah,Fiaidhi, Jinan Korea Information Processing Society 2011 Journal of information processing systems Vol.7 No.4

Classification in biomedical applications is an important task that predicts or classifies an outcome based on a given set of input variables such as diagnostic tests or the symptoms of a patient. Traditionally the classification algorithms would have to digest a stationary set of historical data in order to train up a decision-tree model and the learned model could then be used for testing new samples. However, a new breed of classification called stream-based classification can handle continuous data streams, which are ever evolving, unbound, and unstructured, for instance--biosignal live feeds. These emerging algorithms can potentially be used for real-time classification over biosignal data streams like EEG and ECG, etc. This paper presents a pioneer effort that studies the feasibility of classification algorithms for analyzing biosignals in the forms of infinite data streams. First, a performance comparison is made between traditional and stream-based classification. The results show that accuracy declines intermittently for traditional classification due to the requirement of model re-learning as new data arrives. Second, we show by a simulation that biosignal data streams can be processed with a satisfactory level of performance in terms of accuracy, memory requirement, and speed, by using a collection of stream-mining algorithms called Optimized Very Fast Decision Trees. The algorithms can effectively serve as a corner-stone technology for real-time classification in future biomedical applications.

자기공명유속계 해상도 향상을 위한 4.7T MRI용 솔레노이드 RF코일 개발

송시몬(Simon Song),양병권(Byungkuen Yang),조지현(Jee-Hyun Cho) 한국가시화정보학회 2016 한국가시화정보학회 학술발표대회 논문집 Vol.2016 No.4

Magnetic resonance velocimetry (MRV) is a powerful tool to non-invasively measure the velocity of fluid flow in many fields ranging from medicine to engineering and biology. However, since the demands for accurate measurement in the solid/liquid interface for cardiovascular diseases and porous media increase, the improvement of spatial resolution is necessary. In this study, a solenoid RF coil is developed for high spatial resolution measurement. The signal-to-noise ratio in solenoid RF coil is increased seventeen times better than that in commercial coil. Moreover, the velocity distribution of hagen-poiseuille flow is measured with in-plane resolution of 36㎛ by 36㎛.

해상도 향상을 위한 4.7 T 자기공명유속계 용 솔레노이드 RF 코일 개발

양병권(Byungkuen Yang),조지현(Jee-Hyun Cho),송시몬(Simon Song) 한국가시화정보학회 2016 한국가시화정보학회지 Vol.14 No.2

Magnetic resonance velocimeter (MRV) is a powerful tool to non-invasively measure the velocity of a fluid flow in various fields ranging from medicine to engineering. However, since the demands for accurate measurement in the solid/liquid interface for cardiovascular diseases and porous media increase, the improvement of spatial resolution is required. In this study, a solenoid RF coil is developed for high spatial resolution measurement. The signal-to-noise ratio in solenoid RF coil is increased seventeen times better than that in commercial coil. Moreover, the velocity distribution of Hagen-Poiseuille flow is measured with in-plane resolution of 36 ㎛ by 36 μm and the accuracy of the measured velocity is compared with theoretical distribution of the laminar flow. Flow rate calculated by MRV is estimated with the flow rate injected by syringe pump.

Novel and facile criterion to assess the accuracy of WSS estimation by 4D flow MRI

Ko, Seungbin,Yang, Byungkuen,Cho, Jee-Hyun,Lee, Jeesoo,Song, Simon Elsevier 2019 Medical image analysis Vol.53 No.-

<P><B>Abstract</B></P> <P>Four-dimensional flow magnetic resonance imaging (4D flow MRI) is a versatile tool to obtain hemodynamic information and anatomic information simultaneously. The wall shear stress (WSS), a force exerted on a vessel wall in parallel, is one of the hemodynamic parameters available with 4D flow MRI and is thought to play an important role in clinical applications such as assessing the development of atherosclerosis. Nevertheless, the accuracy of WSS obtained with 4D flow MRI is rarely evaluated or reported in literature, especially in the in vivo studies. We propose a novel and facile criterion called Reynolds resolution to assess the accuracy of WSS estimation in 4D flow MRI studies. Reynolds resolution consists of a spatial resolution, encoding velocity, kinematic viscosity of a working fluid, and signal-to-noise ratio, which are readily accessible information in 4D flow MRI measurements. We explored the relationship between Reynolds resolution and the WSS error. To include diverse and extensive cases, we measured three circular tubing flows with a diameter of 40, 8, and 2 mm. The 40 mm tubing flow was measured by 3 Tesla (T) human MR scanner with a knee coil and spatial resolution of 0.5 mm. The 8 and 2 mm tubing flows were both measured by 4.7 T MR scanner, but the scans were performed with a conventional birdcage coil (8 mm tubing) and a custom-made solenoid coil (2 mm tubing), respectively. The spatial resolution was varied from 0.2, 0.4 or 0.8 mm for the 8 mm tubing flow, but was fixed at 0.090 mm for 2 mm tubing flow. In addition, the near-wall velocity gradient, required to be determined prior to the WSS, was calculated using two methods; these included assuming a linear velocity profile or quadratic velocity profile near wall. The accuracy of WSS obtained using each method and tubing flow was evaluated against the theoretical WSS value. As a result, we found that Reynolds resolution is in logarithmic relation to the WSS error.</P> <P><B>Highlight</B></P> <P> <UL> <LI> Reynolds resolution (RR) is portrayed as a novel criterion to assess WSS accuracy. </LI> <LI> A WSS error is approximated with RR though a true WSS is unknown. </LI> <LI> RR is calculated arithmetically with 4D flow MRI setting parameters. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

<i>In situ</i> analysis of post-annealing effect on Sn-doped indium oxide films

Lim, Hojoon,Yang, Hyeok-Jun,Kim, Ji Woong,Bae, Jong-Seung,Kim, Jin-Woo,Jeong, Beomgyun,Crumlin, Ethan,Park, Sungkyun,Mun, Bongjin Simon American Institute of Physics 2016 Journal of Applied Physics Vol.120 No.20

<P>Oxygen post-annealing effects on tin (Sn) doped indium oxide (ITO) film are investigated with various analytical tools as a function of temperature, including in situ XRD, ambient pressure XPS (AP-XPS), and Hall measurement. As the annealing temperature increases up to 200 degrees C under the oxygen pressure of 100 mTorr, the in situ XRD shows the evidence of crystallization of the film while the AP-XPS reveals the formation of oxygen vacancy and Sn4+ states on surface. In addition, the mobility of ITO thin film is increased as the post-annealing temperature increases, supporting the results of both in situ XRD and AP-XPS. The results of angle-resolved XPS reveal that the degree of Sn segregation changes little after post-annealing procedure. Published by AIP Publishing.</P>

관광통역안내사의 직업선택 동기와 직무만족도에 관한 연구

양필수(Pil Soo Yang),오상훈(Sang Hoon Oh),박시사(Simon Si Sa Park) 한국관광연구학회 2007 관광연구저널 Vol.21 No.1

Robust Adaptive Dynamic Surface Control Based on Structural Reliability for a Turret-moored Floating Production Storage and Offloading Vessel

Yulong Tuo,Yuanhui Wang,Simon X. Yang,Mohammad Biglarbegian,Mingyu Fu 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

For floating production storage and offloading (FPSO) vessels, a dynamic positioning controller is necessary because using only a mooring system is not possible to keep the ship within a predefined region. Position control of the FPSO vessel is extremely challenging due to model uncertainties and unknown control coefficients. This paper develops a new robust adaptive positioning controller consisting of several components: adaptive law, dynamic surface control (DSC) technology, sigmoid tracking differentiator (STD), Nussbaum gain function, and structural reliability index. Model uncertainties can be estimated by the adaptive law derived from the Lyapunov theory. The DSC technology is used to eliminate repeated differentiation by introducing first-order filtering of the virtual control. The chattering-free STD with the characteristics of global fast convergence can estimate the derivatives of model uncertainties that are difficult to calculate directly. Therefore, the DSC and STD techniques make the proposed controller simpler to compute and easier to implement in engineering practice. Most of the traditional controllers require the information about the control coefficients to guarantee the stability of the closed-loop system while the Nussbaum gain function can remove the requirement for a priori knowledge of the sign of control coefficients. The capacity of the mooring system can be fully utilized to position the FPSO vessel by adjusting the structural reliability index on the premise of ensuring the safety of mooring lines, and hence less control effort is needed for the positioning controller. Simulations using two sets of system parameters demonstrate the proposed controller’s effectiveness. In addition, a qualitative comparison with the adaptive backstepping controller shows that our proposed controller is computationally more efficient and does not require a priori knowledge of the sign of control coefficients. A quantitative comparison with robust adaptive controller without the structural reliability shows that less control effort is needed using our proposed controller.