Hybrid modeling for smart roller leveling in precision magnetic scale manufacturing

Brian Chen,Jen-Yuan Chang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.5

In smart manufacturing, machines are interconnected through cyber physical system (CPS) to achieve efficient manufacturing production. Manufacturing efficiency of precision magnetic scale has surfaced as an inevitable challenge. The manufacturing of precision magnetic scale requires precise flatness throughout production and handling processes. In the current technological shortcomings in magnetic scale manufacturing, any flatness defects in the scale would substantially influence its position sensing accuracy. Thus, the goal of this research is to develop and examine a hybrid mechanics model to ensure the scale’s flatness in manufacturing. This model is validated that accurate roller setting can be obtained prior to machine operation, which can significantly improve manufacturing efficiency. In this work, the proposed hybrid mechanics model is performed, validated, and compared to experimental and factory recommended results. The results have demonstrated its capability in predicting optimal leveling roller settings under given conditions, suggesting the possibility of smart manufacturing for magnetic scales.

Chinese-Speaking Undergraduates in Australia : A Lexical Approach to Teaching Academic Writing

Qin Chen,Anne Thwaite,Brian Moon 아시아영어교육학회 2023 The Journal of Asia TEFL Vol.20 No.2

Chinese-speaking students enroll in Australian tertiary institutions in large numbers. Success for these international students is heavily dependent upon their mastering the conventions of academic writing in English. How best to ensure such mastery among EAL learners has been a matter of debate among tertiary educators and language specialists, with competing theories and methods proposed. This paper reports on an attempt to improve English academic writing through intensive lexical instruction, a method proposed by Ackermann & Chen (2013), Boers et al. (2016), Lewis (1993), Selivan (2018), Wray (2005, 2018) and others. Nine Chinese-speaking tertiary students were offered training in recognising and employing those lexical constructions commonly found in relevant technical and academic genres. The project employed a mixed methods case study approach to describe students’ performance and their perceptions and responses to the teaching they underwent. While gains in performance were evident in some cases, the outcomes of the teaching were inconsistent and equivocal overall. We conclude that this raises questions about the efficacy of purely lexical methods and underscores the challenge involved in teaching complex genres at tertiary level. These findings have implications for those teaching Chinese-speaking students, particularly in EAL contexts.

A novel low-profile flow sensor for monitoring of hemodynamics in cerebral aneurysm

Chen, Yanfei,Jankowitz, Brian T.,Cho, Sung Kwon,Yeo, Woon-Hong,Chun, Youngjae Techno-Press 2015 Biomaterials and Biomechanics in Bioengineering Vol.2 No.2

A low-profile flow sensor has been designed, fabricated, and characterized to demonstrate the feasibility for monitoring hemodynamics in cerebral aneurysm. The prototype device is composed of three micro-membranes ($500-{\mu}m$-thick polyurethane film with $6-{\mu}m$-thick layers of nitinol above and below). A novel super-hydrophilic surface treatment offers excellent hemocompatibility for the thin nitinol electrode. A computational study of the deformable mechanics optimizes the design of the flow sensor and the analysis of computational fluid dynamics estimates the flow and pressure profiles within the simulated aneurysm sac. Experimental studies demonstrate the feasibility of the device to monitor intra-aneurysmal hemodynamics in a blood vessel. The mechanical compression test shows the linear relationship between the applied force and the measured capacitance change. Analytical calculation of the resonant frequency shift due to the compression force agrees well with the experimental results. The results have the potential to address important unmet needs in wireless monitoring of intra-aneurysm hemodynamic quiescence.

A phase I/II and pharmacogenomic study of pemetrexed and cisplatin in patients with unresectable, advanced gastric carcinoma

Chen, Jen-Shi,Chao, Yee,Bang, Yung-Jue,Roca, Enrique,Chung, Hyun C.,Palazzo, Felipe,Kim, Yeul H.,Myrand, Scott P.,Mullaney, Brian P.,Shen, Li J.,Linn, Carlos Lippincott Williams Wilkins, Inc. 2010 ANTICANCER DRUGS Vol.21 No.8

This phase I/II study was conducted to determine the maximum recommended dose of pemetrexed when given in combination with a fixed dose of cisplatin, and the efficacy, toxicity and association of 5,10-methylenetetrahydrofolate reductase (MTHFR) variants with this pemetrexed--cisplatin combination, in patients with unresectable, advanced gastric carcinoma. Patients 18–70 years of age, with stage IV disease or post-surgery recurrence, no earlier palliative chemotherapy, 0 or 1 Eastern Cooperative Oncology Group performance status, were included. The cisplatin dose was 75 mg/m. In phase I, the initial dose of pemetrexed was 600 mg/m, escalated in 100 mg/m increments. In phase II, efficacy, including overall response rate, overall survival, as well as toxicity and MTHFR pharmacogenetics were investigated. Phase I enrolled 16 patients; 700 mg/m was defined as pemetrexed recommended dose. Thirteen serious adverse events were reported; the most common grade 3/4 toxicities were haematologic (10 of 13, 76.9%). Phase II enrolled 73 patients, 69 qualified for safety and 68 for efficacy analysis; 65 for pharmacogenomic analysis. Overall response rate was 23.5% (14.1%, 35.4%), disease control rate 55.9%, median overall survival 11.8 months (95% confidence interval, 7.2–18.5 months), progression-free survival 4.9 months (95% confidence interval, 2.8–7.1 months), and median response duration 5.4 months. Patients with MTHFR A1298C variants had median overall survival of 6.6 months, significantly shorter than patients with the wild type (median 18.5 months, P=0.001). The pemetrexed--cisplatin combination in patients with advanced gastric cancer generates modest efficacy and a manageable toxicity profile. The reduced overall survival in patients with MTHFR A1298C polymorphism variants deserves further investigation.

A novel low-profile flow sensor for monitoring of hemodynamics in cerebral aneurysm

Chen, Yanfei,Jankowitz, Brian T.,Cho, Sung Kwon,Yeo, Woon-Hong,Chun, Youngjae Techno-Press 2015 Biomaterials and biomedical engineering Vol.2 No.2

A low-profile flow sensor has been designed, fabricated, and characterized to demonstrate the feasibility for monitoring hemodynamics in cerebral aneurysm. The prototype device is composed of three micro-membranes ($500-{\mu}m$-thick polyurethane film with $6-{\mu}m$-thick layers of nitinol above and below). A novel super-hydrophilic surface treatment offers excellent hemocompatibility for the thin nitinol electrode. A computational study of the deformable mechanics optimizes the design of the flow sensor and the analysis of computational fluid dynamics estimates the flow and pressure profiles within the simulated aneurysm sac. Experimental studies demonstrate the feasibility of the device to monitor intra-aneurysmal hemodynamics in a blood vessel. The mechanical compression test shows the linear relationship between the applied force and the measured capacitance change. Analytical calculation of the resonant frequency shift due to the compression force agrees well with the experimental results. The results have the potential to address important unmet needs in wireless monitoring of intra-aneurysm hemodynamic quiescence.

Preceding Vehicle Identification for Cooperative Adaptive Cruise Control Platoon Forming

Chen, Zheng,Park, Byungkyu Brian IEEE 2020 IEEE transactions on intelligent transportation sy Vol.21 No.1

<P>Cooperative adaptive cruise control (CACC) has shown great potential in enhancing traffic efficiency and sustainability. While past research efforts focused on the development of CACC systems and their demonstrations, very few of them considered in detail how to form a CACC platoon in real traffic, where the proper identification of preceding vehicle is required. To ensure safe and reliable CACC operations, the following vehicle needs to establish the correct connection with its preceding vehicle. Although this can be done by matching information shared by surrounding vehicles with the ego-vehicle’s radar measurements, the existence of sensor/global positioning system (GPS) errors makes it a challenging task. Considering possible sensor/GPS errors in real traffic, this paper proposes a procedure of identifying preceding vehicle under fully connected vehicle environment and evaluates three preceding vehicle identification systems (PVIS), namely, location-based PVIS, distance-based PVIS, and integrated PVIS combining both location and distance information. The mathematical models of PVISs are developed. The performance evaluation of the PVISs is conducted based on real vehicle trajectory data from the Next Generation Simulation (NGSIM) program, which reflects how vehicles’ relative positions change in a high-density segment of highway. The feasibility, performance, and potential of the three PVISs are compared. The results show that location-based PVIS requires a relative positioning accuracy below 1.1 m to ensure an acceptable identification time with zero failure rate. The integrated PVIS has the best performance, providing 99% confidence in identifying preceding vehicle within 1.3 s under typical sensor error settings.</P>

Frustration and Glasslike Character in RIn_1-<i>x</i>Mn_<i>x</i>O₃ (R = Tb, Dy, Gd)

Chen, Peng,Holinsworth, Brian S.,O’Neal, Kenneth R.,Luo, Xuan,Topping, Craig V.,Cheong, Sang W.,Singleton, John,Choi, Eun S.,Musfeldt, Janice L. American Chemical Society 2018 Inorganic Chemistry Vol.57 No.20

<P>We bring together <I>ac</I> susceptibility and <I>dc</I> magnetization to uncover the rich magnetic field-temperature behavior of a series of rare earth indium oxides, RInO<SUB>3</SUB> (R = Tb, Dy, and Gd). The degree of frustration is much larger than expected, particularly in TbInO<SUB>3</SUB>, and the ground states are glasslike with antiferromagnetic tendencies. The activation energy for spin reorientation is low. Chemical substitution with Mn<SUP>3+</SUP> ions to form TbIn<SUB>1-<I>x</I></SUB>Mn<SUB><I>x</I></SUB>O<SUB>3</SUB> (<I>x</I> ≤ 0.01) relieves much of the frustration that characterizes the parent compound and slightly enhances the short-range antiferromagnetic order. The phase diagrams developed from this work reveal the rich competition between spin orders and provide an opportunity to compare the dynamics in the RInO<SUB>3</SUB> and Mn-substituted systems. These structure-property relations may be useful for understanding magnetism in other geometrically frustrated multiferroics.</P><P>We combined <I>dc</I> magnetization and <I>ac</I> susceptibility to reveal the rich magnetic field-temperature phase diagrams of a series of rare earth indium oxides. These systems sport high degrees of frustration as described by the frustration index, <I>F</I>, as well as glasslike slow magnetic relaxation in combination with antiferromagnetic tendencies. Structure−composition−property investigations reveal that both the choice of rare earth center as well as introduction of a paramagnetic impurity like Mn<SUP>3+</SUP> can control frustration in this new class of geometrically frustrated multiferroics.</P> [FIG OMISSION]</BR>

Mixed Traffic of Connected-Automated and Human-Driven Vehicles

B. Brian Park,Zheng Chen 대한교통학회 2019 대한교통학회 학술대회지 Vol.80 No.-

본 발표는 일반차량들과 자율협력주행차량들이 함께 존재하는 상황에서 자율협력주행차량과 일반차량의 상호작용을 평가할 수 있는 통합된 시뮬레이션 모형을 설명하고, 혼재된 차량들의 성능을 향상할 수 있는 제어 방법론들에 대해서 논하고 시뮬레이션을 통해서 기존의 방법들과 비교한 결과를 보여줄 것이다. 통합 시뮬레이션 모형에서 중요한 요소들이 vehicle dynamics 모형, 센서 모델링, 통신 모형 그리고 휴먼운전자라는 것을 설명할 것이다. 또한, 기존의 자율협력주행 차들의 Cooperative Adaptive Cruise Control (CACC)은 일반차량을 만나면 Adaptive Cruise Control (ACC)로 제어를 해야하기 때문에 CACC의 효과를 얻지 못하는데, 본 연구에서 제안한 CACC with unconnected vehicle 제어방법은 기존의 ACC에 비해 훨씬 효율적으로 제어가 가능하며, Connected ACC 기능이 있는 일반차량도 CACC 차량이나 다른 connected 차량과 함께 움직일때 human CACC 제어 방법을 통해서 일반 운전자가 제어하는 챠량에 비해 훨씬 효율적인 제어가 가능하다는 것을 보여줄 것이다.

Block of T cell development in P53-deficient mice accelerates development of lymphomas with characteristic RAG-dependent cytogenetic alterations

Haines, Brian B.,Ryu, Chun Jeih,Chang, Sandy,Protopopov, Alexei,Luch, Andreas,Kang, Yun Hee,Draganov, Dobrin D.,Fragoso, Maria F.,Paik, Sang Gi,Hong, Hyo Jeong,DePinho, Ronald A.,Chen, Jianzhu Cell Press 2006 CANCER CELL Vol.9 No.2

<P><B>Summary</B></P><P>Mice deficient in the DNA damage sensor P53 display normal T cell development but eventually succumb to thymic lymphomas. Here, we show that inactivation of the TCR β gene enhancer (Eβ) results in a block of T cell development at stages where recombination-activating genes (RAG) are expressed. Introduction of the Eβ mutation into <I>p53<SUP>−/−</SUP></I> mice dramatically accelerates the onset of lethal thymic lymphomas that harbor RAG-dependent aberrant rearrangements, chromosome 14 and 12 translocations, and amplification of the chromosomal region 9A1–A5.3. Phenotypic and genetic analyses suggest that lymphomas emerge through a normal thymocyte development pathway. These findings provide genetic evidence that block of lymphocyte development at stages with RAG endonuclease activity can provoke lymphomagenesis on a background with deficient DNA damage responses.</P>

Solution Phase Exciton Diffusion Dynamics of a Charge-Transfer Copolymer <b>PTB7</b> and a Homopolymer <b>P3HT</b>

Cho, Sung,Rolczynski, Brian S.,Xu, Tao,Yu, Luping,Chen, Lin X. American Chemical Society 2015 The Journal of physical chemistry B Vol.119 No.24

<P>Using ultrafast polarization-controlled transient absorption (TA) measurements, dynamics of the initial exciton states were investigated on the time scale of tens of femtoseconds to about 80 ps in two different types of conjugated polymers extensively used in active layers of organic photovoltaic devices. These polymers are poly(3-fluorothienothiophenebenzodithiophene) (PTB7) and poly-3-hexylthiophene (P3HT), which are charge-transfer polymers and homopolymers, respectively. In PTB7, the initial excitons with excess vibrational energy display two observable ultrafast time constants, corresponding to coherent exciton diffusion before the vibrational relaxation, and followed by incoherent exciton diffusion processes to a neighboring local state after the vibrational relaxation. In contrast, P3HT shows only one exciton diffusion or conformational motion time constant of 34 ps, even though its exciton decay kinetics are multiexponential. Based on the experimental results, an exciton dynamics mechanism is conceived taking into account the excitation energy and structural dependence in coherent and incoherent exciton diffusion processes, as well as other possible deactivation processes including the formation of the pseudo-charge-transfer and charge separate states, as well as interchain exciton hopping or coherent diffusion.</P>