Patents by Inventor Donhee Ham

Donhee Ham has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20220147805
    Abstract: Disclosed is an apparatus and method mapping a natural neural network into an electronic neural network device of an electronic device. The method includes constructing a neural network map of a natural neural network based on membrane potentials of a plurality of biological neurons of the natural neural network, where the membrane potentials correspond to at least two different respective forms of membrane potentials, and mapping the neural network map to the electronic neural network device. The constructing of the neural network map and the mapping of the neural network map implement learning of the electronic neural network device. The method may further includes obtaining an input or stimuli, activating the learned electronic neural network device, provided the obtained input or stimuli, to perform neural network operations, and generating a neural network result for the obtained input or stimuli based on a result of the activated learned electronic neural device.
    Type: Application
    Filed: November 11, 2021
    Publication date: May 12, 2022
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Donhee HAM, Sang Joon KIM
  • Publication number: 20220147799
    Abstract: Disclosed is a neural computer including an image sensor capable of controlling a photocurrent. The neural computer according to an embodiment includes a preprocessor configured to receive an image and generate a feature map for the received image; a flattening unit configured to transform the feature map generated by the preprocessor into tabular data to provide data output; and an image classifier configured to classify images received through the preprocessor by using the data output by the flattening unit as an input value. The preprocessor includes an optical signal processor configured to receive the image and generate the feature map.
    Type: Application
    Filed: October 13, 2021
    Publication date: May 12, 2022
    Applicants: Samsung Electronics Co., Ltd., President and Fellows Of Harvard College
    Inventors: Changhyun KIM, Houk JANG, Henry Julian HINTON, Hyeonjin SHIN, Minhyun LEE, Donhee HAM
  • Publication number: 20210371846
    Abstract: Methods and systems for stimulating and monitoring electrogenic cells are described. Some systems for stimulating electrogenic cells are based on the injection of electric currents into the cells via electrodes connected to the cells. Such stimulators may comprise an impedance element having an input terminal and an output terminal coupled to an electrode, and a voltage follower coupled between the input terminal and the output terminal of the impedance element, the voltage follower being configured to maintain a substantially constant voltage between the input terminal and the output terminal of the impedance element. The impedance element may comprise one or more switched capacitors at least in some embodiments. In some embodiments, the voltage follower may be implemented using a source follower.
    Type: Application
    Filed: July 6, 2018
    Publication date: December 2, 2021
    Applicant: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Donhee Ham, Jeffrey T ABBOTT, Hongkun PARK, Wenxuan WU
  • Publication number: 20210187280
    Abstract: The present invention generally relates to nanowires. In one aspect, the present invention is generally directed to systems and methods of individually addressing nanowires on a surface, e.g., that are substantially upstanding or vertically-oriented with respect to the surface. In some cases, one or more nanowires may be individually addressed using various integrated circuit (“IC”) technologies, such as CMOS. For example, the nanowires may form an array on top of an active CMOs integrated circuit.
    Type: Application
    Filed: January 8, 2021
    Publication date: June 24, 2021
    Applicant: President and Fellows of Harvard College
    Inventors: Hongkun Park, Donhee Ham, Jeffrey T. Abbott, Ling Qin, Marsela Jorgolli, Tianyang Ye
  • Publication number: 20210151678
    Abstract: A nonvolatile memory device includes a resistance switching layer, a gate on the resistance switching layer, a gate oxide layer between the resistance switching layer and the gate, and a source and a drain, spaced apart from each other, on the resistance switching layer. A resistance value of the resistance switching layer is changed based on an illumination of light irradiated onto the resistance switching layer and is maintained as a changed resistance value.
    Type: Application
    Filed: November 10, 2020
    Publication date: May 20, 2021
    Applicants: Samsung Electronics Co., Ltd., President and Fellows Of Harvard College
    Inventors: Minhyun LEE, Houk JANG, Donhee HAM, Chengye LIU, Henry HINTON, Haeryong KIM, Hyeonjin SHIN
  • Patent number: 10910794
    Abstract: A light-emitting device includes a substrate including a photonic cavity and configured to function as a gate, an active layer including a two-dimensional material, a first conductive contact, and a second conductive contact. The wavelength range of light generated by the light-emitting device may be narrowed based on the photonic cavity being included in the substrate, and the intensity and wavelength range of the generated light may be controlled based on the substrate functioning as a gate.
    Type: Grant
    Filed: April 25, 2018
    Date of Patent: February 2, 2021
    Assignees: Samsung Electronics Co., Ltd., President and Fellows of Harvard College
    Inventors: Jinseong Heo, Minhyun Lee, Seongjun Park, Philip Kim, Hongkun Park, Donhee Ham
  • Publication number: 20200395540
    Abstract: Provided are memristors and neuromorphic devices including the memristors. A memristor includes a lower electrode and an upper electrode that are apart from each other and first and second two-dimensional material layers that are arranged between the lower electrode and the upper electrode and stacked without a chemical bond therebetween.
    Type: Application
    Filed: March 19, 2020
    Publication date: December 17, 2020
    Applicants: Samsung Electronics Co., Ltd., President and Fellows Of Harvard College
    Inventors: Minhyun LEE, Dovran AMANOV, Renjing XU, Houk JANG, Haeryong KIM, Hyeonjin SHIN, Yeonchoo CHO, Donhee HAM
  • Publication number: 20200292482
    Abstract: Methods and systems for monitoring the activity of electrogenic networks are described. One representative system includes an array of electrode coupled to an analyzer having a stimulator and a receiver. The electrode is placed in contact with an electrogenic cell. The electrodes can be shaped as nanowires, tubes, cavities and/or cones. The analyzer may be configured to operate in a voltage stimulation mode, in which the cells are stimulated via voltages and monitored via current, or in a current stimulation mode, in which the cells are stimulated via currents and monitored via voltages. The analyzers may be arranged as single-stage amplifiers, and may include a feedback loop shared between the stimulation signal path and the sensing signal path. The feedback loop may be arranged to provide overlapping stimulation and sensing of the electrogenic network's cells.
    Type: Application
    Filed: October 30, 2018
    Publication date: September 17, 2020
    Applicant: President and Fellows of Harvard College
    Inventors: Donhee Ham, Hongkun Park, Keith Krenek, Tianyang Ye, Jeffrey T. Abbott, Wenxuan Wu
  • Patent number: 10295636
    Abstract: An integrated circuit is provided for use in conjunction with an external antenna. The integrated circuit includes a memory circuit, a pulse sequencer, an NMR transmitter circuit and an NMR receiver circuit. The memory circuit is configured to store user-defined parameter data pertaining to an excitation period and an acquisition period that are part of an NMR pulse sequence. The pulse sequencer and the NMR transmitter circuit are configured to cooperate to generate RF signals in accordance the user-defined parameter data stored in the memory circuit, wherein such RF signals are supplied to the external antenna for emitting excitation signals from the external antenna during the excitation period of the NMR pulse sequence. The NMR receiver circuit is configured to receive electrical signals generated by the external antenna during the acquisition period of the NMR pulse sequence.
    Type: Grant
    Filed: October 28, 2014
    Date of Patent: May 21, 2019
    Assignees: SCHLUMBERGER TECHNOLOGY CORPORATION, PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Yi-qiao Song, Jeffrey Paulsen, Donhee Ham, Dongwan Ha
  • Publication number: 20190013648
    Abstract: A light-emitting device includes a substrate including a photonic cavity and configured to function as a gate, an active layer including a two-dimensional material, a first conductive contact, and a second conductive contact. The wavelength range of light generated by the light-emitting device may be narrowed based on the photonic cavity being included in the substrate, and the intensity and wavelength range of the generated light may be controlled based on the substrate functioning as a gate.
    Type: Application
    Filed: April 25, 2018
    Publication date: January 10, 2019
    Applicants: Samsung Electronics Co., Ltd., President and Fellows Of Harvard College
    Inventors: Jinseong HEO, Minhyun LEE, Seongjun PARK, Philip KIM, Hongkun PARK, Donhee HAM
  • Publication number: 20160274204
    Abstract: An integrated circuit is provided for use in conjunction with an external antenna. The integrated circuit includes a memory circuit, a pulse sequencer, an NMR transmitter circuit and an NMR receiver circuit. The memory circuit is configured to store user-defined parameter data pertaining to an excitation period and an acquisition period that are part of an NMR pulse sequence. The pulse sequencer and the NMR transmitter circuit are configured to cooperate to generate RF signals in accordance the user-defined parameter data stored in the memory circuit, wherein such RF signals are supplied to the external antenna for emitting excitation signals from the external antenna during the excitation period of the NMR pulse sequence. The NMR receiver circuit is configured to receive electrical signals generated by the external antenna during the acquisition period of the NMR pulse sequence.
    Type: Application
    Filed: October 28, 2014
    Publication date: September 22, 2016
    Applicants: SCHLUMBERGER TECHNOLOGY CORPORATION, PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Yi-qiao Song, Jeffrey Paulsen, Donhee Ham, Dongwan Ha
  • Patent number: 8643368
    Abstract: The Rabi frequency of oscillation of the nuclear magnetization vector of a sample in an NMR system may be controlled by modifying only the duty cycle of RF pulses delivered to the sample, without modifying the amplitude of the RF pulses, until the energy delivered at the Larmor frequency is adjusted to a desired amount. An impedance matching network between an NMR transceiver and an NMR coil may perform both power matching and noise matching simultaneously. During a transmission mode, the impedance matching network is connected to a transmitter portion of the transceiver, and the impedance of the coil is matched to the driver resistance. During a receiver mode, the impedance matching network is disconnected from the transmitter portion so that the impedance matching network remains connected only to the receiver portion, and signal-to-noise ratio in received NMR signals is maximized.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: February 4, 2014
    Assignee: President and Fellows of Harvard College
    Inventors: Nan Sun, Donhee Ham
  • Patent number: 8390489
    Abstract: Digital background calibration in a pipelined ADC is performed by extracting a capacitor mismatch value ? that represents a mismatch between a sampling capacitor C1 and a feedback capacitor C2 in the pipelined ADC, and using ? to correct the capacitor mismatch error. ? is extracted by performing commutated feedback capacitor switching (CFCS) in a background correlation loop. The error caused by the capacitor mismatch is calibrated out by subtracting the error from a digital output Dout of the pipelined ADC. Convergence speed may be accelerated and convergence accuracy may be increased during digital background calibration of pipelined ADCs, by using a higher order LPF. A bandwidth switching scheme may be implemented by the LPF, i.e. a larger bandwidth may be utilized during calibration start-up to increase convergence speed during start-up and a smaller bandwidth may be utilized during steady state to increase convergence accuracy during steady state.
    Type: Grant
    Filed: January 21, 2009
    Date of Patent: March 5, 2013
    Assignee: President and Fellows of Harvard College
    Inventors: Nan Sun, Donhee Ham
  • Patent number: 8154354
    Abstract: Methods and apparatus for implementing stable self-starting and self-sustaining high-speed electrical nonlinear pulse (e.g., soliton, cnoidal wave, or quasi-soliton) oscillators. Chip-scale nonlinear pulse oscillator devices may be fabricated using III-V semiconductor materials (e.g., GaAs) to attain soliton pulse widths on the order of a few picoseconds or less (e.g., 1 to 2 picoseconds, corresponding to frequencies of approximately 300 GHz or greater). In one example, a nonlinear pulse oscillator is implemented as a closed loop structure that comprises a nonlinear transmission line and a distributed nonlinear amplifier arrangement configured to provide a self-adjusting gain as a function of an average voltage of the oscillator signal.
    Type: Grant
    Filed: September 6, 2006
    Date of Patent: April 10, 2012
    Assignee: President and Fellows of Harvard College
    Inventors: David Ricketts, Donhee Ham, Xiaofeng Li
  • Publication number: 20110091987
    Abstract: The present application describes devices, systems, and techniques related to a chip-based, miniaturized NMR diagnostic platform for rapid, quantitative and multi-channeled detection of biological targets.
    Type: Application
    Filed: October 6, 2008
    Publication date: April 21, 2011
    Inventors: Ralph Weissleder, Hakho Lee, Donhee Ham, Nan Sun, Yong Liu
  • Publication number: 20110057654
    Abstract: The Rabi frequency of oscillation of the nuclear magnetization vector of a sample in an NMR system may be controlled by modifying only the duty cycle of RF pulses delivered to the sample, without modifying the amplitude of the RF pulses, until the energy delivered at the Larmor frequency is adjusted to a desired amount. An impedance matching network between an NMR transceiver and an NMR coil may perform both power matching and noise matching simultaneously. During a transmission mode, the impedance matching network is connected to a transmitter portion of the transceiver, and the impedance of the coil is matched to the driver resistance. During a receiver mode, the impedance matching network is disconnected from the transmitter portion so that the impedance matching network remains connected only to the receiver portion, and signal-to-noise ratio in received NMR signals is maximized.
    Type: Application
    Filed: February 25, 2009
    Publication date: March 10, 2011
    Applicant: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Nan Sun, Donhee Ham
  • Publication number: 20110043395
    Abstract: Digital background calibration in a pipelined ADC is performed by extracting a capacitor mismatch value ? that represents a mismatch between a sampling capacitor C1 and a feedback capacitor C2 in the pipelined ADC, and using ? to correct the capacitor mismatch error. ? is extracted by performing commutated feedback capacitor switching (CFCS) in a background correlation loop. The error caused by the capacitor mismatch is calibrated out by subtracting the error from a digital output Dout of the pipelined ADC. Convergence speed may be accelerated and convergence accuracy may be increased during digital background calibration of pipelined ADCs, by using a higher order LPF. A bandwidth switching scheme may be implemented by the LPF, i.e. a larger bandwidth may be utilized during calibration start-up to increase convergence speed during start-up and a smaller bandwidth may be utilized during steady state to increase convergence accuracy during steady state.
    Type: Application
    Filed: January 21, 2009
    Publication date: February 24, 2011
    Applicant: PRESIDENT AND FELLOWS OF HARVARD COLLEGE
    Inventors: Nan Sun, Donhee Ham
  • Publication number: 20100007426
    Abstract: Methods and apparatus for implementing stable self-starting and self-sustaining high-speed electrical nonlinear pulse (e.g., soliton, cnoidal wave, or quasi-soliton) oscillators. Chip-scale nonlinear pulse oscillator devices may be fabricated using III-V semiconductor materials (e.g., GaAs) to attain soliton pulse widths on the order of a few picoseconds or less (e.g., 1 to 2 picoseconds, corresponding to frequencies of approximately 300 GHz or greater). In one example, a nonlinear pulse oscillator is implemented as a closed loop structure that comprises a nonlinear transmission line and a distributed nonlinear amplifier arrangement configured to provide a self-adjusting gain as a function of an average voltage of the oscillator signal.
    Type: Application
    Filed: September 6, 2006
    Publication date: January 14, 2010
    Applicant: President and Fellows of Harvard College
    Inventors: David Ricketts, Donhee Ham, Xiaofeng Li
  • Publication number: 20100006439
    Abstract: Methods and apparatus for manipulation, detection, imaging, characterization, sorting and/or assembly of biological or other materials, involving an integration of CMOS or other semiconductor-based technology and microfluidics. In one implementation, various components relating to the generation of electric and/or magnetic fields are implemented on an IC chip that is fabricated using standard protocols. The generated electric and/or magnetic fields are used to manipulate and/or detect one or more dielectric and/or magnetic particles and distinguish different types of particles. A microfluidic system is fabricated either directly on top of the IC chip, or as a separate entity that is then appropriately bonded to the IC chip, to facilitate the introduction and removal of cells in a biocompatible environment, or other particles/objects of interest suspended in a fluid.
    Type: Application
    Filed: September 15, 2009
    Publication date: January 14, 2010
    Applicant: President and Fellows of Harvard College
    Inventors: Donhee Ham, Robert Westervelt, Thomas Hunt, Yong Liu, Hakho Lee
  • Publication number: 20090315631
    Abstract: Methods and apparatus utilizing the quantum inductance of one-dimensional (ID) nanoscale structures (e.g., nanowires, carbon nanotubes). In one exemplary circuit implementation, all elements of a high-frequency circuit path are constituted by nanoscale structures without significant intervening structures (e.g., metal contacts) that would introduce undesirable resistance in the high-frequency circuit path. In this manner, the deleterious effects of contact resistance (e.g., metal-to-nanostructure interfaces) on the quality factor associated with the quantum inductance, and ultimately operation of the circuit, may be significantly reduced or avoided.
    Type: Application
    Filed: October 30, 2006
    Publication date: December 24, 2009
    Applicant: President and Fellows of Harvard College
    Inventors: Donhee Ham, Xiaofeng Li