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121.
Jun‐Kyul Song Donghee Son Jaemin Kim Young Jin Yoo Gil Ju Lee Liu Wang Moon Kee Choi Jiwoong Yang Mincheol Lee Kyungsik Do Ja Hoon Koo Nanshu Lu Ji Hoon Kim Taeghwan Hyeon Young Min Song Dae‐Hyeong Kim 《Advanced functional materials》2017,27(6)
Transparent electrodes have been widely used for various electronics and optoelectronics, including flexible ones. Many nanomaterial‐based electrodes, in particular 1D and 2D nanomaterials, have been proposed as next‐generation transparent and flexible electrodes. However, their transparency, conductivity, large‐area uniformity, and sometimes cost are not yet sufficient to replace indium tin oxide (ITO). Furthermore, the conventional ITO is quite rigid and susceptible to mechanical fractures under deformations (e.g., bending, folding). In this study, the authors report new advances in the design, fabrication, and integration of wearable and transparent force touch (touch and pressure) sensors by exploiting the previous efforts in stretchable electronics as well as novel ideas in the transparent and flexible electrode. The optical and mechanical experiment, along with simulation results, exhibit the excellent transparency, conductivity, uniformity, and flexibility of the proposed epoxy‐copper‐ITO (ECI) multilayer electrode. By using this multi‐layered ECI electrode, the authors present a wearable and transparent force touch sensor array, which is multiplexed by Si nanomembrane p‐i‐n junction‐type (PIN) diodes and integrated on the skin‐mounted quantum dot light‐emitting diodes. This novel integrated system is successfully applied as a wearable human–machine interface (HMI) to control a drone wirelessly. These advances in novel material structures and system‐level integration strategies create new opportunities in wearable smart displays. 相似文献
122.
Moon Ho Lee Jong Oh Park Yasuhiko Yasuda 《Multidimensional Systems and Signal Processing》1990,1(4):389-398
in this paper, simple 1-D and 2-D systolic array for realizing the discrete cosine transform (DCT) based on the discrete Fourier transform (DFT) fo an input sequence are presented. The proposed arrays are obtained by a simple modified DFT (MDFT) and an inverse DFT (IDFT) version of the Goertzel algorithm combined with Kung's approach. The 1-D array requiresN cells, one multiplier and takesN clock cycles to produce a completeN-point DCT. The 2-D array takes N clock cycles, faster than the 1-D array, but the area complexity is larger. A continuous flow of input data is allowed and no idle time is required between the input sequences. 相似文献
123.
Jeong-hoon Nam Young-Shig Choi Moon G. Joo 《Analog Integrated Circuits and Signal Processing》2013,74(1):193-201
A novel phase-locked loop that has a loop filter consisting of only one capacitor is designed with a frequency voltage converter (FVC). Simulation and measurement results show that the proposed phase-locked loop (PLL) works stably demonstrating that the FVC works effectively as a resistor. Measurement results of the proposed PLL fabricated in a one-poly six-metal 0.18 μm CMOS process show that the phase noise is ?109 dBc/Hz at 10 MHz offset from 752.7 MHz output frequency. 相似文献
124.
Byung S Kim Sun K Yoo Moon H Lee 《IEEE transactions on information technology in biomedicine》2006,10(1):77-83
The delay performance of compression algorithms is particularly important when time-critical data transmission is required. In this paper, we propose a wavelet-based electrocardiogram (ECG) compression algorithm with a low delay property for instantaneous, continuous ECG transmission suitable for telecardiology applications over a wireless network. The proposed algorithm reduces the frame size as much as possible to achieve a low delay, while maintaining reconstructed signal quality. To attain both low delay and high quality, it employs waveform partitioning, adaptive frame size adjustment, wavelet compression, flexible bit allocation, and header compression. The performances of the proposed algorithm in terms of reconstructed signal quality, processing delay, and error resilience were evaluated using the Massachusetts Institute of Technology University and Beth Israel Hospital (MIT-BIH) and Creighton University Ventricular Tachyarrhythmia (CU) databases and a code division multiple access-based simulation model with mobile channel noise. 相似文献
125.
Min Jeong Im Sung Yun Son Byung Joon Moon Gang-Young Lee Joo Hyun Kim Taiho Park 《Organic Electronics》2013,14(11):3046-3051
The packing effects induced by the hydrophilic ethylene glycol oligomer side chains occurred in a P3HT:PC61BM mixture upon the addition of small amounts of BP93 (containing 7 mol% PEGT blocks), leading to an enhanced crystallinity among the P3HT molecules, even in a P3HT:PC61BM blend. The enhanced crystallinity improved the charge transport and current density (8.3–11.1 mA/cm2) and increased the power conversion efficiency (3.1–3.9%) in an organic solar cell. 相似文献
126.
Jaecheon Han Gucheol Kang Daesung Kang Yongtae Moon Hwanhee Jeong June-O Song Tae-Yeon Seong 《Journal of Electronic Materials》2013,42(10):2876-2880
We investigated the effect of two different quantum well (QW) structures having different indium contents on the optical performance of fully packaged GaN-based light-emitting diodes (LEDs). Dual-spectrum QW LEDs exhibit ~4% higher external quantum efficiency (at 350 mA) than single-spectrum QW LEDs. However, the two types of LEDs exhibit similar efficiency droop behavior. For both types of LEDs, the output power decreases with increasing junction temperature. When the junction temperature exceeds 70°C, the dual-spectrum QW LEDs exhibit lower output power than the single-spectrum QW LEDs. The wavelength dependence of the output power (at 350 mA) of single-spectrum QW LEDs shows that the LEDs with shorter wavelengths experience more rapid optical degradation than the LEDs with longer wavelengths. Based on the wavelength- and junction-temperature-dependent output power, the droop behavior of the dual-spectrum QW LEDs is described and discussed. 相似文献
127.
Boeun Cho Seong Hun Yu Moo Hyung Lee Juhee Lee Jun Young Lee Jeong Ho Cho Moon Sung Kang 《Organic Electronics》2014,15(12):3439-3444
We demonstrate the versatility of the threshold voltage control for organic thin-film transistors (OTFTs) based on formation of discontinuous pn-heterojunction on the active channel layer. By depositing n-type dioctyl perylene tetracarboxylic diimide molecules discontinuously onto base p-type pentacene thin films (the formation of the discontinuous pn-heterojunction), a positive shift of the threshold voltage was attained which enabled realizing a depletion-mode transistor from an original enhancement-mode pristine pentacene transistor. Careful control of the threshold voltage based on this method led assembling a depletion-load inverter comprising a depletion-mode transistor and an enhancement-mode transistor connected in series that yielded tunable signal inversion voltage approaching 0 V. In addition, the tunability could be applied to improve the program/erase signal ratio for non-volatile transistor memories by more than 4 orders of magnitude compared to reference memory devices made of pristine pentacene transistors. 相似文献
128.
Jangwon Moon Junwoo Kim Hoon Lee Youngjin Moon Yongsu Lee Youngjo Bang Kyungyeol Sohn Jungsook Bae Kwangseon Kim Seungjae Bahng Heesoo Lee 《ETRI Journal》2023,45(5):781-794
Uncrewed aerial vehicles (UAVs) have become a vital element in nonterrestrial networks, especially with respect to 5G communication systems and beyond. The use of UAVs in support of 4G/5G base station (uncrewed aerial vehicle base station [UAV-BS]) has proven to be a practical solution for extending cellular network services to areas where conventional infrastructures are unavailable. In this study, we introduce a UAV-BS system that utilizes a high-capacity wireless backhaul operating in millimeter-wave frequency bands. This system can achieve a maximum throughput of 1.3 Gbps while delivering data at a rate of 300 Mbps, even at distances of 10 km. We also present the details of our testbed implementation alongside the performance results obtained from field tests. 相似文献
129.
Kwang‐Seong Choi Ki‐Jun Sung Byeong‐Ok Lim Hyun‐Cheol Bae Sunghae Jung Jong‐Tae Moon Yong‐Sung Eom 《ETRI Journal》2010,32(2):342-344
A novel, maskless, low‐volume bumping material, called solder bump maker, which is composed of a resin and low‐melting‐point solder powder, has been developed. The resin features no distinct chemical reactions preventing the rheological coalescence of the solder, a deoxidation of the oxide layer on the solder powder for wetting on the pad at the solder melting point, and no major weight loss caused by out‐gassing. With these characteristics, the solder was successfully wetted onto a metal pad and formed a uniform solder bump array with pitches of 120 µm and 150 µm. 相似文献
130.
Constraints are commonly used in both simulation and formal verification in order to specify expected input conditions and
state transitions. Constraint solving is a process to determine input vectors which satisfy the set of constraints during constrained random simulation. Even though
constraints are used in formal property checking to restrict the search space, constraint solving has never had direct application
to formal property checking. There are often many simple, yet powerful, invariants that can be learned from constraint solving
during constrained random simulation. These invariants are shown in this paper to significantly simplify the formal verification
problem. We use approximate constraint solving to compute an approximate set of valid input vectors. The approximate set of
valid input vectors are a strict superset of the set of all legal input vectors. We use BDD techniques to compute these input
vectors during constrained random simulation, then process the resulting BDDs for learning invariants which can be used during
formal property checking. This paper presents efficient BDD algorithms to learn invariants from the BDDs generated from approximate
constraint solving. We also present how these learned invariants can be applied to the formal property checking. Experimental
results show that invariants learned during constraint solving can significantly improve the performance of formal property
checking with many industrial designs. 相似文献