Jihun Lee

A vastly enhanced capability to bi-directionally interface with cortical microcircuits in a clinically viable way is the ultimate aspiration in neuroengineering. This necessitates a paradigm shift in neural interface system design beyond current bulky, monolithic constructs which are challenging to scale past 100-200 channels due to anatomic and engineering design constraints. A neural interface system relying on a spatially-distributed network of wireless microscale implantable sensors offers a

We describe a custom wireless power and data transmission (WPDT) link and analyze its performance in a prototype implantable sensor system of ensembles of CMOS sensor ASICs (“Neurograins”) embedding 0.5 mm × 0.5 mm planar microcoil antennas. We use near-field RF at ~1 GHz for wireless powering in a resonant 3-coil architecture including an implanted relay coil in a quadrant layout architecture to maximize coverage area and RF transfer efficiency. We demonstrate successful WPDT across antenna cro

Networks of spatially distributed radiofrequency identification sensors could be used to collect data in wearable or implantable biomedical applications. However, the development of scalable networks remains challenging. Here we report a wireless radiofrequency network approach that can capture sparse event-driven data from large populations of spatially distributed autonomous microsensors. We use a spectrally efficient, low-error-rate asynchronous networking concept based on a code-division mul

Semiconductor products used in high-performance computing (HPC) and artificial intelligence (AI) applications require higher memory bandwidth, greater input/output (I/O) count, better power delivery network (PDN) performance and improved heat dissipation characteristics. To meet these requirements, a 2.5D package architecture with a Through Silicon Via (TSV)-bearing silicon (Si) interposer is mainly used in volume production. However, a redistribution layer (RDL) interposer is emerging as a cost

ABSTRACT Multichannel electrophysiological sensors and stimulators, especially those used for studying the nervous system, are most commonly based on monolithic microelectrode arrays. Such architecture limits the spatial flexibility of individual electrode placement, posing constraints for scaling to a large number of nodes, particularly across non-contiguous locations. We describe the design and fabrication of sub-millimeter size electronic microchips (“Neurograins”) which autonomously perform

In this study, the characteristic analysis of a permanent magnet synchronous generator was performed using the analytical method, and the validity of the analytical method was compared with that of the finite element method (FEM). For the initial design, the rotor size was selected using the torque per rotor volume method, and the stator size was selected according to the saturation of the stator iron core. In addition, fast Fourier transform analysis was performed to determine the appropriate m

UAV기반 멀티센서 시스템을 통해 취득된 영상의 지오레퍼런싱 정확도는 사용된 GPS/INS 시스템의 성능뿐만 아니라 카메라와 GPS/INS 시스템간의 상호관계를 나타내는 탑재변수의 정확도에 의해 영향을 받는다. 따라서 멀티센서 시스템 개발에 있어서 탑재변수의 정확한 추정은 필수적이다. 현재 우리는 재난/재해와 같은 긴급 상황에 대한 빠른 대응을 위해 실시간으로 대상지역을 감시할 수 있는 저고도 UAV기반의 실시간 공중자료획득 시스템을 개발하고 있다. 본 연구는 현재 개발 중인 시스템의 탑재변수 추정을 위한 시스템 캘리브레이션 방법론을 제안한다. 또한 실제 시스템의 제원을 이용한 시뮬레이션 데이터를 이용하여 정확하고 효율적인 캘리브레이션을 위한 효과적인 비행경로 및 지상기준점의 필요 개수를 도출하였다. 실험 결과, 총 6개의 스트립으로 구성된 비행경로를 따라 획득된 데이터와 5점 이상의 지상기준점 정보를 이용하면 제안된 방법론을 통해 정확한 탑재변수의 추정이 가능함을 확인할 수 있었다

Biomedical inductively-coupled transcutaneous implants with internal batteries typically rely on a two-coil charging system which places fundamental and practical limits such as requiring short coil-to-coil distance for useful Wireless Power Transfer (WPT) efficiency. In case of hermetic metal enclosures equipped with finite size dielectric window for magnetic flux penetration, two-coil configurations can induce substantial additional loss due to eddy currents generated on e.g. Ti metal surface

본 연구는 캐릭터 스토리의 독창성, 캐릭터의 매력성, 캐릭터의 친근성, 신뢰성, 유사성이 캐릭터 제품 선호도에 미치는 영향관계를 파악하고, 이를 통해 캐릭터 업계에 캐릭터 스토리 및 컨텐츠 개발과 마케팅 제안점을 제시하고자 하였다. 따라서 연구 결과 다음과 같은 시사점을 찾아내었다.BR 첫째, 캐릭터 업체들은 신규 캐릭터 발굴 및 개발 시 기존과 차별화된 독특한 스토리를 먼저 창작한 후 이를 통해 캐릭터의 외적 및 내적 이미지 등을 표현할 수 있는 형태로 개발을 해야 한다. 또한 스토리와 캐릭터 간의 관계성을 최대한 연결할 수 있는 이미지를 다양한 방법을 통해 소비자들에게 제대로 전달 할 필요가 있다.BR 둘째, 캐릭터 업체들은 캐릭터의 모습을 형상화 할 시 캐릭터가 가질 수 있는 기본 설정 구성, 인성적 특성 경향, 타인과 구별되는 개인적인 습관 및 취향 등을 최대한 외적인 모습에 담아낼 수 있도록 개발해야 할 것이다.BR 마지막으로 캐릭터 업체들은 캐릭터 제품 호감도를 높이기 위

Objective: To investigate whether suppression of right inferior frontal gyrus (Broca's homologue) by 1 Hz repetitive transcranial magnetic stimulation (rTMS) can improve speech recovery. Method: We applied low frequency rTMS on right Broca's homologue twice a week for 6 weeks in eight subcortical aphasia patients who were 3 months to 3 years poststroke onset. They were tested with Korean Version-Western Aphasia Battery before and after procedure. Also, they were tested with Parallel Short Forms

This article was originally published under standard Springer Nature license (© The Author(s), under exclusive licence to Springer Nature Limited). It is now available as an open-access paper under a Creative Commons Attribution 4.0 International license, © The Author(s). The error has been corrected in the HTML and PDF versions of the article.

A method to extract main palm lines from high resolution palm images(5312×2988) is presented in this paper in order to extract palm lines more easily just by using only an image of a hand by using Sobel mask and a mosaic-like method. At first, RGB information is converted to YCbCr color model which is less sensitive to brightness change. The palm region is extracted by simple thresholding using widely known skin color information of Y: 0~255, Cb: 77~255, Cr: 133~255. After that, histogram stretc