Browsing by Author "Lin, Yu-Hsuan"

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A 77-GHz 2T6R Transceiver With Injection-Lock Frequency Sextupler Using 65-nm CMOS for Automotive Radar System Application
(2016-10)
Hsiao, Yuan-Hung
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Chang, Yu-Chuan
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Tsai, Ching-Han
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Huang, Ting-Yi
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Aloui, Sofiane
In this paper, a CMOS multichannel transceiver (TRX) is proposed for angular identification in automotive car radar applications. Two transmitters (TXs) and six receivers (RXs) are placed on the same die using 65-nm CMOS technology with chip size 3.5x3 mm(2). To generate a millimeter-wave (MMW) frequency-modulated continuous-wave signal, an injection-lock frequency sextupler cascaded a 1-to-8 Wilkinson power dividing network with wideband isolation is designed as the LO-chain to convert external source from 12.5-13.7 to 75-82.2 GHz for both the TXs and RXs. Each TX achieves above 11-dBm output power and the RXs achieve 30-dB conversion gain from 75 to 82 GHz, and the total power dissipation of whole chip is 1.43 W. Compared with other published multichannel TRXs in silicon germanium (SiGe) process, this paper demonstrates compatible performances and the potential of multichannel TRX using CMOS for MMW automotive car radar application.
A Comprehensive Study of 3-stage High Resistance State Retention Behavior for TMO ReRAMs from Single Cells to a Large Array
(2017-01-01)
Lin, Yu-Hsuan
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Ho, Yung-Han
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Lee, Ming-Hsiu
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Wang, Chao-Hung
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Lin, Yu-Yu
For the first time the retention of high resistance state (HRS) in resistive random access memory (ReRAM) is found to compose of three stages - extending tail-bits, distribution shift, and then distribution broadening. This work provides a comprehensive study on the HRS's retention behavior in WOx-based ReRAMs from single device characteristics to group distribution. Different from conventional activation energy (Ea) analysis, the mean and variance of the array distribution are presented to overcome the non-uniform Ea issue. Since the extracted Ea fits well with Vo(2+) (oxygen vacancy) migration characteristics, the three retention stages are suggested to be the competing results from the migration, recombination, and generation of the Vo(2+) and O2- in the gap region. A three-dimensional retention model with kinetic Monte Carlo simulator and trap-assisted tunneling conduction is proposed to discuss the dominating mechanism in different time and temperature scales. The mechanism for random telegraph noise is also included to illustrate the fluctuating nature of the HRS cells.
A Novel Varying-Bias Read Scheme for MLC and Wide Temperature Range TMO ReRAM
(2016-11)
Lin, Yu-Hsuan
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Lee, Ming-Hsiu
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Wu, Jau-Yi
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Lin, Yu-Yu
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Lee, Feng-Ming
Resistance of transition metal oxide (TMO) resistive random access memory (ReRAM) depends sharply on temperature, resulting in drastic memory window loss at high temperature. Thus, it is difficult to design the ReRAM that can serve a wide range of operating conditions. It is especially challenging to achieve multi-level-cell (MLC) ReRAM because of the large temperature dependency. This letter investigates both the temperature and read bias dependencies of WOx ReRAM, and found both can be well understood by a modified space-charge limited conduction model. Using this model, we have designed a novel read scheme that varies the read bias according to the device temperature and compensates for the temperature effect on cell resistance. Since TMO ReRAM devices depend on defect states, cell-to-cell and cycle-to-cycle variations are naturally large. An algorithm is designed to address the variability. A 1-Mb WOx ReRAM array is fabricated to both characterize the bias and temperature dependencies and verify the new read scheme. A large and constant memory window is preserved for MLC across a wide temperature range (-40 degrees C-125 degrees C), suitable for high-reliability applications.
A WSN-Based Intelligent Light Control System Considering User Activities and Profiles
(2008-09-01)
Pan, Meng-Shiuan
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Yeh, Lun-Wu
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Chen, Yen-Ann
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Lin, Yu-Hsuan
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Tseng, Yu-Chee
Recently, wireless sensor networks (WSNs) have been widely discussed in many applications. In this paper, we propose a WSN-based intelligent light control system for indoor environments. Wireless sensors are responsible for measuring current illuminations. Two kinds of lighting devices, namely, whole lighting and local lighting devices, are used to provide background and concentrated illuminations, respectively. Users may have various illumination requirements according to their activities and profiles. An illumination requirement is as the combination of background and concentrated illumination demands and users' locations. We consider two requirement models, namely, binary satisfaction and continuous satisfaction models, and propose two decision algorithms to determine the proper illuminations of devices and to achieve the desired optimization goals. Then, a closed-loop device control algorithm is applied to adjust the illumination levels of lighting devices. The prototyping results verify that our ideas are practical and feasible.
Applications of plasmonic hotspots on laser-treated AgOx thin film
(2012)
Tseng, Ming Lun
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Huang, Yao-Wei
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Hsiao, Min-Kai
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Huang, Hsin Wei
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Lin, Yu-Hsuan
The femto-second-laser-treated AgOx thin film is used as the plasmon-active substrate for the applications of surface-enhanced Raman scattering (SERS), molecule sensing, and photocatalyst. The proposed technique is helpful for the solar energy harvest, green energy source, and biosensing with high efficiency and throughput.
Cardiac Autonomic Modulation during on-Call Duty under Working Hours Restriction
(2020-02-01)
Chien, Jien-Wen
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Chen, Chung-Yen
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Lin, Sheng-Hsuan
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Lin, Shih-Wen
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Lin, Yu-Hsuan
Background: Medical residency is a time of high stress and long working hours, which increase the risk of cardiovascular disease. This study aimed to investigate the autonomic modulation of resident physicians throughout the on-call duty cycle. Methods: Spectral analysis of heart rate variability (HRV) was used to compute cardiac parasympathetic modulation (high-frequency power, HF) and cardiac sympathetic modulation (normalized low-frequency power, LF%, and the ratio of LF and HF, LF/HF) of 18 residents for a consecutive 4-day cycle. Results: Male residents show reduced cardiac sympathetic modulation (i.e., higher LF/HF and LF%) than the female interns. Medical residents' cardiac parasympathetic modulation (i.e., HF) significantly increased on the first and the second post-call day compared with the pre-call day. In contrast, LF% was significantly decreased on the first and the second post-call day compared with the pre-call day. Similarly, LF/HF was significantly decreased on the second post-call day compared with the pre-call day. LF/HF significantly decreased on the first post-call day and on the second post-call day from on-call duty. Conclusion: The guideline that limits workweeks to 80 h and shifts to 28 h resulted in reduced sympathetic modulation and increased parasympathetic modulation during the two days following on-call duty.
Development of a mobile application (App) to delineate "digital chronotype" and the effects of delayed chronotype by bedtime smartphone use
(2019-03-01)
Lin, Yu-Hsuan
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Wong, Bo-Yu
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Lin, Sheng-Hsuan
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Chiu, Yu-Chuan
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Pan, Yuan-Chien
The widespread use and deep reach of smartphones motivate the use of mobile applications to continuously monitor the relationship between circadian system, individual sleep patterns, and environmental effects. We selected 61 adults with 14-day data from the "Know Addiction" database. We developed an algorithm to identify the "sleep time" based on the smartphone behaviors. The total daily smartphone use duration and smartphone use duration prior to sleep onset were identified respectively. We applied mediation analysis to investigate the effects of total daily smartphone use on sleep through pre-sleep use (PS). The results showed participants' averaged pre-sleep episodes within 1 h prior to sleep are 2.58. The duration of three pre-sleep uses (PS1-3) maybe a more representative index for smartphone use before sleep. Both total daily duration and the duration of the last three uses prior to sleep of smartphone use significantly delayed sleep onset, midpoint of sleep and reduced total sleep time. One hour of increased smartphone use daily, delays the circadian rhythm by 3.5 min, and reduced 5.5 min of total sleep time (TST). One hour of increased pre-sleep smartphone use delayed circadian rhythm by 1.7 min, and reduced 39 s of TST. The mediation effects of PSI 3 significantly impacted on these three sleep indicators. PS1-3 accounted for 14.3% of total daily duration, but the proportion mediated of delayed circadian rhythm was 44.0%. We presented "digital chronotype" with an automatic system that can collect high temporal resolution data from naturalistic settings with high ecological validity. Smartphone screen time, mainly mediated by pre-sleep use, delayed the circadian rhythm and reduced the total sleep time.
Endurance improvement and resistance stabilization of transparent multilayer resistance switching devices with oxygen deficient WOx layer and heat dissipating AlN buffer layer
(2017-12-31)
Lin, Yu-Hsuan
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Huang, Ding-Chiuan
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Lou, Jen-Chung
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Tseng, Tseung-Yuen
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電子工程學系及電子研究所
In this study, indium tin oxide (ITO), zinc oxide (ZnO), tungsten oxide (WOx), and aluminum nitride (AlN) were employed to fabricate and investigate four transparent resistive random access memory (ReRAMs) structures: ITO/ZnO/ITO (structure 1), ITO/WO3/ZnO/ITO (structure 2), ITO/WOx(x < 3)/WO3/ZnO/ITO (structure 3), and ITO/WOx(x < 3)/WO3/ZnO/AlN/ITO (structure 4). Structure 4 exhibited less variation in low-resistance states, lower operating voltages, and higher endurance compared with other structures. This phenomenon was attributed to the oxygen-deficient WOx layer in structure 4, which acted as an oxygen ion reservoir for efficient resistive changes, and the WO3 layer limited the filament rupture and formation region. Moreover, the high thermal conductivity of the AlN layer alleviated the thermally activated ion movement of the ReRAM and strengthened the high-resistance state. Structure 4 was found to be the optimal structure, with median operating voltages 1.6 V for SET operations and -1.0 V for RESET operations, retention of > 10(4) s at 200 degrees C, and endurance of 10(4) cycles with a resistance ratio of over 20. Structure 4 exhibited extremely high stability in both low- and high-resistance states during cycling. The transmittance of structure 4 was 85.49%, which is suitable for optoelectronic applications.
Excellent High Temperature Retention of TiOXNV ReRAM by Interfacial Layer Engineering
(2018-01-01)
Lin, Yu-Hsuan
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Lee, Dai-Ying
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Wang, Chao-Hung
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Lee, Ming-Hsiu
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Ho, Yung-Han
Since the resistance switching of the transition metal oxide (TMO) resistive random access memory (ReRAM) is based on thc interaction between the oxygen ions and vacancies, the unintentional oxygen/vacancy reaction should be avoided during data retention. This work demonstrates significant improvements on the retention performance by inserting a Si layer in the TiO Ny ReRAM to block the diffusion of oxygen ions through the Ti/TiO,N interface. The mechanism and factors that influenced thc IIRS and LRS retention arc also studied. The retention performance of HRS is correlated with its RESET level while the LRS retention depends on the programming current. The proposed Ti/Si/TiO,N, ReRAMs can switch for more than 103 cycles from array testing results.
Excellent Resistance Variability Control of WOx ReRAM by a Smart Writing Algorithm
(2016)
Lin, Yu-Hsuan
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Wu, Jau-Yi
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Lee, Ming-Hsiu
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Wang, Tien-Yen
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Lin, Yu-Yu
TMO ReRAMs, being built on defect states, are intrinsically subject to variability. In this work, cell to cell variability is studied by applying write shots with different current and voltage for Forming, SET and RESET operation, respectively. We found the keys to eliminate tail bits consist of (1) longer write pulse, (2) higher write current and (3) higher write voltage. In order to optimize the performance of write speed, write power and device reliability, we developed a novel resistance control method using a smart writing algorithm. Compared to the conventional ISPP writing scheme, this smart writing algorithm covers much wider switching condition variability and cell-to-cell variation by controlling both current and voltage for ReRAM operation.
iLamp: A Sensor-Enhanced Lamp with Surface-Tracking Capability Based on Light Intensity
(2009)
Yeh, Lun-Wu
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Lu, Che-Yen
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Lin, Yu-Hsuan
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Liao, Jia-Liang
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Tseng, Yu-Chee
The iLamp(1) system is a sensor-enhanced desk lamp with surface-tracking capability based on received light intensity. It consists of two components: lamp and bookmark. The bookmark is a ZigBee-enabled sensor node that can report its sensed light intensity to the lamp with a user-friendly interface and two-way communication capability. The lamp can use its LEDs to locate user's reading surface to which the bookmark is attached, move toward the surface, and further tune its luminous intensity to meet user's preference. We develop the geometrical model for surface tracking. iLamp demonstrates a new centimeter-level location-tracking system using light intensity alone without other extra media or devices.
Modeling of switching speed and retention time in volatile resistive switching memory by ionic drift and diffusion
(2019-01-01)
Wang, Wei
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Covi, Erika
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Lin, Yu-Hsuan
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Ambrosi, Elia
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Ielmini, Daniele
The understanding of the dynamic mechanism of volatile resistive switching memory devices is of paramount importance to further increase the switching speed. It is also of great value for future neuromorphic applications which use such devices in temporal domain In this work, we investigate the switching speed and retention time of metallic filamentary volatile resistive switching devices. We find that the switching speed can be quantitatively described by the ionic mobility, while the retention time can be quantitatively described by the surface ionic diffusion following the gradient descent of surface atomic concentration. Further analysis reveals that the ionic mobility and surface diffusivity can be connected with Einstein relation. Finally, evidences supporting this relation and experimental data showing the competition of the ionic drift and diffusion are collected and shown.
Nanoimprinted Anisotropic Topography Preferentially Guides Axons and Enhances Nerve Regeneration
(2018-12-01)
Huang, Yun-An
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Ho, Chris T.
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Lin, Yu-Hsuan
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Lee, Chen-Ju
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Ho, Szu-Mo
Surface topography has a profound effect on the development of the nervous system, such as neuronal differentiation and morphogenesis. While the interaction of neurons and the surface topography of their local environment is well characterized, the neuron-topography interaction during the regeneration process remains largely unknown. To address this question, an anisotropic surface topography resembling linear grooves made from poly(ethylene-vinyl acetate) (EVA), a soft and biocompatible polymer, using nanoimprinting, is established. It is found that neurons from both the central and peripheral nervous system can survive and grow on this grooved surface. Additionally, it is observed that axons but not dendrites specifically align with these grooves. Furthermore, it is demonstrated that neurons on the grooved surface are capable of regeneration after an on-site injury. More importantly, these injured neurons have an accelerated and enhanced regeneration. Together, the data demonstrate that this anisotropic topography guides axon growth and improves axon regeneration. This opens up the possibility to study the effect of surface topography on regenerating axons and has the potential to be developed into a medical device for treating peripheral nerve injuries.
Near-Field Optical Imaging of a Porous Au Film: Influences of Topographic Artifacts and Surface Plasmons
(2013-06-01)
Lin, Yu-Hsuan
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Haendel, Benjamin
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Huang, Hung Ji
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Chen, Hsiang-An
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Chen, Yung-Fu
In this work, near-field scanning optical microscopy is employed to study a porous Au film and the direct observation of topographic artifacts and surface plasmon influences is revealed. Under tip illumination, topographic artifacts are found to be present in a reflection mode optical image but not in a transmission mode image. A simple algorithm is used for filtering the topographic artifacts and extracting a correct near-field optical image approximately. On the other hand, surface plasmon influences are present in both modes. By using three exciting wavelengths of 488, 647.1, and 520.8 nm, it is confirmed that a suitable wavelength should be chosen for avoiding the surface plasmon interference in a near-field optical investigation of morphological or material dielectric contrast. Finally, plasmonic or nonplasmonic regions on the porous Au film can be identified from the observed optical intensity variation in the optical images obtained at incident polarizations of 0 degrees, 90 degrees, and 45 degrees.
Near-field scanning optical microscopy using a super-resolution cover glass slip
(2012-07-16)
Lin, Yu-Hsuan
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Tsai, Din Ping
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電子物理學系
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Department of Electrophysics
This study presents a novel near-field optics technology. A near-field cover glass slip (NF-CGS) was developed to improve the resolution of optical microscopy beyond the diffraction limit. A multi-layered structure of cover glass/ZnS-SiO2 (130 nm)/AgOx (15 nm)/ ZnS-SiO2 (40 nm) was employed to generate the optical coupling effect for increasing the contrast and enhancing resolution of imaging. This novel innovation is expected to be employed in near-field imaging techniques for samples in different environments because of its simplicity, rapid laser scanning, and minimal costs. Experimental results of 500 nm, 200 nm, and 100 nm standard polystyrene nanospheres on NF-CGS and normal cover glass are demonstrated and imaged by using a laser scanning confocal microscope. (C) 2012 Optical Society of America
New designed electrode patterns on rear side of bifacial PERC solar cells
(2019-01-01)
Lin, Yu-Hsuan
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Li, Li-Yu
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Chen, Sung-Yu
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Hsu, Shih-Peng
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Chen, Yu-Shen
In this paper, we demonstrate new electrode pattern on rear side of p-type bifacial passivated emitter and rear cells (bifacial-PERC) solar cells for reducing series resistance loss caused by the aluminum grid lines. Cell efficiency of bifacial PERC is enhanced by rear Al grids add multi bus-bar (MBB) or grid segments interconnection. The high J(sc) and FF value of the PERC+ using local grid with MBB as rear electrodes which increases the J(sc) by 0.5 mA/cm(2) and FF by 2.58 % compare to the PERC+ without rear MBB. The high Jsc and FF value of the PERC+ using local grid with vertical line segments as rear electrodes which increases the J(sc) by 0.34 mA/cm(2) and FF by 3.6 % compare to the PERC+ without vertical line segments. In contrast to the PERC cell, the bifacial PERC cell using localized Al grid on rear side and with thicker back surface field (BSF).
Optical imaging with spectrum aberration correction using a filtering macrolens
(2013-07-20)
Lin, Yu-Hsuan
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Lai, Jyun-Yi
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Tsai, Hsin-Yi
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Chang, Han-Chao
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Huang, Hung Ji
A filtering macrolens was developed to simultaneously achieve macro-optical imaging and correct spectrum aberration. The macrolens was a doublet lens comprising a filtering lens and a close-up lens. The shape of the filtering lens was designed to eliminate the optical path differences between the light rays in the absorbing medium. The close-up lens was designed to decrease the effective focal length of an ordinary camera lens to provide high magnification capability and collimate the diverging beams through the filtering lens. Experimental results demonstrated that the spectrum uniformity of the macro-optical images was markedly improved by the filtering macrolens. This innovation may be used in finite conjugate optical systems. (C) 2013 Optical Society of America
Performance Impacts of Analog ReRAM Non-ideality on Neuromorphic Computing
(2019-03-01)
Lin, Yu-Hsuan
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Wang, Chao-Hung
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Lee, Ming-Hsiu
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Lee, Dai-Ying
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Lin, Yu-Yu
Resistive random access memory (ReRAM) is often considered as a strong candidate for storing the weights in non-von Neumann neuromorphic computing systems. This paper studies how nonideal memory characteristics, which include programing error, read fluctuation, and retention, affect the inference accuracy of the analog ReRAM neural networks by incorporating memory characteristics extracted from 1-Mb ReRAM into a simulated inference-only neural network. This paper also shows that the different layer in the network can tolerate different amount of such imperfects. We learned four key points: 1) the conductance range of memory with less relative fluctuation is preferred for designing the weight-conductance mapping; 2) the control of programing error is essential for high inference accuracy; 3) retention-induced conductance drift can be fatal to the neuromorphic system. A compensation scheme is proposed in this paper which can effectively recover the inference accuracy; and 4) for multilayer networks, avoiding weight errors in the front layers can help to maintain the inference accuracy by reducing calculation error which may otherwise accumulate and pass down the networks. The concepts and approaches of this paper can also be applied to evaluate other types of nonvolatile memories for artificial neural networks.
Resistive Switching Characteristics of WO3/ZrO2 Structure With Forming-Free, Self-Compliance, and Submicroampere Current Operation
(2015-07-01)
Tsai, Tsung-Ling
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Lin, Yu-Hsuan
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Tseng, Tseung-Yuen
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The homogeneous switching of Ti/WO3/ZrO2/W resistive switching memory devices with stable resistive switching, forming-free, self-compliance, and multilevel operation characteristics are demonstrated. The area dependence of current at the low resistance and high resistance states confirms that the switching mechanisms of the devices are homogeneous conduction. The devices exhibit the stable bipolar resistive switching behavior with a low operating current (<10(-6) A) by inserting the WO3 layer with high electron affinity between the Ti top electrode and the ZrO2 layer and modulating the potential profiles at the WO3/ZrO2 interface. In addition, multilevel operation can be achieved by adjusting the magnitudes of set/reset voltages.
Temporal Stability of Smartphone Use Data: Determining Fundamental Time Unit and Independent Cycle
(2019-03-26)
Pan, Yuan-Chien
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Lin, Hsiao-Han
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Chiu, Yu-Chuan
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Lin, Sheng-Hsuan
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Lin, Yu-Hsuan
Background: Assessing human behaviors via smartphone for monitoring the pattern of daily behaviors has become a crucial issue in this century. Thus, a more accurate and structured methodology is needed for smartphone use research. Objective: The study aimed to investigate the duration of data collection needed to establish a reliable pattern of use, how long a smartphone use cycle could perpetuate by assessing maximum time intervals between 2 smartphone periods, and to validate smartphone use and use/nonuse reciprocity parameters. Methods: Using the Know Addiction database, we selected 33 participants and passively recorded their smartphone usage patterns for at least 8 weeks. We generated 4 parameters on the basis of smartphone use episodes, including total use frequency, total use duration, proactive use frequency, and proactive use duration. A total of 3 additional parameters (root mean square of successive differences, Control Index, and Similarity Index) were calculated to reflect impaired control and compulsive use. Results: Our findings included (1) proactive use duration correlated with subjective smartphone addiction scores, (2) a 2-week period of data collection is required to infer a 2-month period of smartphone use, and (3) smartphone use cycles with a time gap of 4 weeks between them are highly likely independent cycles. Conclusions: This study validated temporal stability for smartphone use patterns recorded by a mobile app. The results may provide researchers an opportunity to investigate human behaviors with more structured methods.