Seungjoo Kim

The expeditious development of information technology has led to the rise of artificial intelligence (AI). However, conventional computing systems are prone to volatility, high power consumption, and even delay between the processor and memory, which is referred to as the von Neumann bottleneck, in implementing AI. To address these issues, memristor-based neuromorphic computing systems inspired by the human brain have been proposed. A memristor can store numerous values by changing its resistanc

In complementary metal–oxide–semiconductor (CMOS)‐based von Neumann architectures, the intrinsic power and speed inefficiencies are worsened by the drastic increase in information with big data. With the potential to store numerous values in I – V pinched hysteresis, memristors (memory resistors) have emerged as alternatives to existing CMOS‐based computing systems. Herein, four types of memristive devices, namely, resistive switching, phase‐change, spintronics, and ferroelectric tunnel junction

Halide perovskites have been noted for their exotic properties such as fast ion migration, tunable composition, facile synthetic routes, and flexibility in addition to large light absorption coefficients, long carrier diffusion lengths, and high defect tolerance. These properties have made halide perovskites promising materials for memristors. Applications in the field of resistive switching memory devices and artificial synapses for neuromorphic computing are especially noteworthy. This Perspec

Abstract Organometallic and all‐inorganic halide perovskites (HPs) have recently emerged as promising candidate materials for resistive switching (RS) nonvolatile memory due to their current–voltage hysteresis caused by fast ion migration. Lead‐free and all‐inorganic HPs have been researched for non‐toxic and environmentally friendly RS memory devices. However, only HP‐based devices with electrochemically active top electrode (TE) exhibit ultra‐low operating voltages and high on/off ratio RS pro

The extrinsic Pb 0 interfacial trap states induce strong Fermi-level pinning at metal/CH 3 NH 3 PbI 3 interfaces. This is due to the interfacial reaction between the deposited metals and iodine from CH 3 NH 3 PbI 3 .

Abstract Monitoring taste‐inducing ions and molecules continuously in liquids or solutions is of great considerable matter for the realization of the electronic tongue (E‐tongue). Particularly from the five major tastes, the highly selective, sensitive detection of Na + in real‐time is prioritized. Prioritization is due to the saltiness of food is the key ingredient in most meals. Nevertheless, existing Na + detecting devices have relatively low performances of selectivity, sensitivity, and lack

New rosin-based photoactive polyamideimides (PAI-a and PAI-b) with a large second-order nonlinear optical coefficient and photoinduced birefringence were synthesized by the polycondensation of rosin–maleic anhydride adduct (RMA) with azo-dye diamines, 2-(2-{ethyl-[4-(4-nitrophenylazo)phenyl]aminoethoxy)benzene-1,4-diamine (4a) or 2-(2-{ethyl-[4-(4-methylsulfonylphenylazo)phenyl]amino}ethoxy)benzene-1,4-diamine (4b). Due to the bulky alicyclic structure of the rosin, these polymers were highly so

The advancement of the Internet of Things and artificial intelligence has increased the demand for air quality monitoring to protect human health. Nitrogen dioxide (NO 2 ), a hazardous pollutant, causes inflammatory responses, even at low concentrations, necessitating sensitive gas sensors. Although metal oxide semiconductor sensors are commonly used, their high-operating temperature and reliance on additional heaters limit miniaturization and increase power consumption. Here, a lead-free, trans

Halide perovskites are gaining prominence as promising materials for future electronic applications, primarily due to their unique properties including long carrier diffusion lengths, tunable bandgap, facile synthesis, and cost efficiency. However, polycrystalline halide perovskite thin films, which have been widely studied to date, have significant drawbacks including uncontrollable grain boundaries and instability issues. Recently, low-dimensional halide perovskites (LD HPs) offer enhanced sta

본 논문에서는 QIM(Quantization Index Modulation) 워터마킹 방식에서 워터마크 삽입 후의 이미지 품질과 워터마크의 강인성을 결정하는 양자화 구간 간격을 크게 하기 위한 방법을 제안한다. 일반적으로 양자화 구간 간격을 크게 할 경우, 삽입 강도는 높아지나 워터마크 삽입 후의 이미지 품질이 저하되며, 작게 하는 경우는 그 반대가 된다. 그러나 원본 이미지와 워터마크 삽입 후의 예상 결과를 이용하여 양자화 구간 간격을 결정하면 삽입 강도와 워터마크 삽입 후의 이미지 품질을 모두 높일 수 있다.

최근 그룹 지향적 응용 서비스가 증가함에 따라 유무선 네트워크상에서 사용 가능한 멀티캐스트 통신에 대한 연구가 활발히 진행되고 있다. 그러나 멀티캐스트 통신에 대한 안전성과 효율성에 대한 해결책은 아직 미비한 상태이다. 본 논문에서는 유무선 통합 멀티캐스트 서비스 지원을 위해, 인증을 제공하는 안전한 멀티캐스팅 프로토콜을 제안한다. 제안하는 프로토콜은 개인 휴대단말기 등과 같은 낮은 연산 처리 능력을 가지는 시스템에서 사용 가능한 효율적인 프로토콜이다.

New rosin-based photoactive polyamideimides (PAI-a and PAI-b) with a large second-order nonlinear optical coefficient and photoinduced birefringence were synthesized by the polycondensation of rosin–maleic anhydride adduct (RMA) with azo-dye diamines, 2-(2-{ethyl-[4-(4-nitrophenylazo)phenyl]aminoethoxy)benzene-1,4-diamine (4a) or 2-(2-{ethyl-[4-(4-methylsulfonylphenylazo)phenyl]amino}ethoxy)benzene-1,4-diamine (4b). Due to the bulky alicyclic structure of the rosin, these polymers were highly so

The development of semiconductor-based electronic devices has significantly advanced sensor-based data acquisition and processor-driven data analysis. However, conventional complementary metal-oxide-semiconductor technologies are now facing fundamental limitations in scaling, speed, and power efficiency. In response, neuromorphic sensing and computing devices inspired by biological nervous systems have emerged as promising alternatives to address these challenges. Among various material platform