Kyung Min Kim

Korea Advanced Institute of Science and Technology | KAIST · Department of Materials Science and Engineering

A one-selector-one-memristor crossbar array was developed, capable of driving Monte Carlo DropConnect network. This could be achieved through a hardware and algorithm co-design approach, involving mutual improvement of them.

Heat dissipation is a natural consequence of operating any electronic system. In nearly all computing systems, such heat is usually minimized by design and cooling. Here, we show that the temporal dynamics of internally produced heat in electronic devices can be engineered to both encode information within a single device and process information ac...

Edge computing devices, which generate, collect, process, and analyze data near the source, enhance the data processing efficiency and improve the responsiveness in real-time applications or unstable network environments. To be utilized in wearable and skin-attached electronics, these edge devices must be compact, energy efficient for use in low-po...

Introduction: We aimed to investigate the risk factors associated with post-stroke epilepsy (PSE) among patients with different subtypes of stroke, focusing on age-related risk and time-varying effects of stroke subtype on PSE development. Methods: A retrospective, nationwide, population-based cohort study was conducted using Korean National Hea...

Transient global amnesia (TGA) often involves precipitating events associated with changes in autonomic nervous system (ANS), and heart rate variability (HRV) reflects the ANS state. This study aimed to investigate HRV changes after TGA. A retrospective analysis of HRV included patients diagnosed with TGA between January 2015 and May 2020. The time...

Insects can efficiently perform object motion detection via a specialized neural circuit, called an elementary motion detector (EMD). In contrast, conventional machine vision systems require significant computational resources for dynamic motion processing. Here, a fully memristive EMD (M‐EMD) is presented that implements the Hassenstein–Reichardt...

Background : External beam radiation therapy (EBRT) is one of the treatment modalities for meningioma, and there are a few clinical reports about its short-term efficacy. However, studies reporting the long-term clinical outcomes with serial volumetric analysis are rare. This study reports the long-term clinical outcome of primary EBRT for meningio...

Hardware-based cryptography that exploits physical unclonable functions is required for the secure identification and authentication of devices in the Internet of Things. However, physical unclonable functions are typically based on anticounterfeit identifiers created from randomized microscale patterns or non-predictable fluctuations of electrical...

Memristive stateful logic for Boolean computers and memristive neural networks for neuromorphic computers are two distinct emerging applications enabled by memristors in future computing. Interestingly, they both utilize an identical crossbar array platform, suggesting their simultaneous implementation is possible. Herein, a new methodology combini...

Information technology advances may help in conducting epidemiological studies using web-based surveys. Questionnaire-based headache diagnosis should be validated against the doctor’s diagnosis. This study aimed to develop and validate a web-based diagnostic questionnaire for migraine, probable migraine (PM), and tension-type headache (TTH). We con...

Neuromorphic engineering aims to mimic brain functions to achieve energy‐efficient artificial intelligence. Since researchers have indicated that memristors can mimic synapses and neurons, various studies have demonstrated the operation of neural networks using memristive dot product engine (MDPE) hardware. However, although several feasible implem...

Objective: Intraoperative language mapping under general anesthesia is imperative for brain tumor surgery because awake surgery is not always feasible. Monitoring corticocortical evoked potential (CCEP) is known to be a useful method for tracking neuronal connectivity and localizing functional areas. The authors evaluated the clinical benefit of i...

Augmented reality (AR) offers a new medical treatment approach. We aimed to evaluate frameless (mask) fixation navigation using a 3D-printed patient model with fixed-AR technology for gamma knife radiosurgery (GKRS). Fixed-AR navigation was developed using the inside-out method with visual inertial odometry algorithms, and the flexible Quick Respon...

Background: The immunologic features of children with coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are not clearly delineated. This study was conducted to evaluate SARS-CoV-2-specific antibody responses in children with COVID-19. Methods: The levels of anti-spike (S) IgG, anti-SARS-Co...

Mitochondria are energy-generating organelles and mitochondrial biogenesis is stimulated to meet energy requirements in response to extracellular stimuli, including exercise. However, the mechanisms underlying mitochondrial biogenesis remain unknown. Here, we demonstrate that transcriptional coactivator with PDZ-binding motif (TAZ) stimulates mitoc...

Visual aura (VA) presents in 98% of cases of migraine with aura. However, data on its prevalence and impact in individuals with migraine and probable migraine (PM) are limited. Data from the nation-wide, population-based Circannual Change in Headache and Sleep Study were collected. Participants with VA rating scale scores ≥ 3 were classified as hav...

Obstructive sleep apnea (OSA) is known to be associated with various health concerns, including sleepiness, fatigue, cognitive dysfunction, diminished quality of life, hypertension, cardiovascular diseases, and stroke. OSA-induced sleepiness at the wheel reduces vigilance and driving performance, which significantly increase the risk of motor vehic...

Narcolepsy is a chronic sleep disorder characterized by irresistible sleep attacks, hypersomnolence, cataplexy (sudden loss of muscle tone provoked by emotion), and sleep paralysis. Individuals with narcolepsy are at a high risk of experiencing sleepiness while driving leading to road traffic accidents. To prevent such accidents, some countries hav...

A memristive stateful neural network allowing complete Boolean in-memory computing attracts high interest in future electronics. Various Boolean logic gates and functions demonstrated so far confirm their practical potential as an emerging computing device. However, spatio-temporal efficiency of the stateful logic is still too limited to replace co...

Augmented reality (AR) offers a new medical treatment approach. We aimed to evaluate frameless fixation navigation using a 3D-printed patient model with fixed-AR technology for gammaknife radiosurgery. Fixed-AR navigation was developed using the inside-out method with visual inertial odometry algorithms, and the flexible Quick Response (QR) marker...

Background There is limited information on the association between weekend catch-up sleep (CUS), which has beneficial effects on health, and depression. This study aimed to investigate the association between CUS and depression in adults. Methods We used the data of the Seventh Korea National Health and Nutrition Examination Survey, 2016. Depressi...

Background Nasopharyngeal (NP) colonization with Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi) is common in children and may evolve as the source of invasive infections. In Korea, the pneumococcal conjugate vaccines (PCVs) had been introduced >10 years, allowing us to study the effect of the vaccine in preventing carriage....

Driving is a complicated process that demands coordination between a range of neurocognitive functions, including attention, visuo-perception, and appropriate judgment, as well as sensory and motor responses. Therefore, several factors may reduce the driving performance of an individual, such as sleepiness, distraction, overspeeding, alcohol consum...

Objective: With the advancement of 3D modeling techniques and visualization devices, augmented reality (AR)-based navigation (AR navigation) is being developed actively. The authors developed a pilot model of their newly developed inside-out tracking AR navigation system. Methods: The inside-out AR navigation technique was developed based on the...

The intrinsic stochasticity of the memristor can be used to generate true random numbers, essential for non-decryptable hardware-based security devices. Here, we propose a novel and advanced method to generate true random numbers utilizing the stochastic oscillation behavior of a NbOx mott memristor, exhibiting self-clocking, fast and variation tol...

Memristive stateful logic enables complete in‐memory computing, allowing low‐power and low‐cost Boolean computing. Its characteristics are consistent with the requirements of edge computing devices, which will occupy a considerable segment in the coming Internet of things (IoT) era. In this review, recent developments in stateful logic technology a...

The usefulness of 3-dimensional (3D)-printed disease models has been recognized in various medical fields. This study aims to introduce a production platform for patient-specific 3D-printed brain tumor model in clinical practice and evaluate its effectiveness. A full-cycle platform was created for the clinical application of a 3D-printed brain tumo...

Background The impact of adjuvant radiotherapy (RT) on atypical meningioma (AM) underwent a gross total resection (GTR) remains unclear, showing conflicting results from various studies. The objective of this study was to perform an updated meta-analysis for observational studies to determine the effect of adjuvant RT after GTR on local recurrence...

Square-shaped or rectangular nanoparticles (NPs) of lanthanum oxide (LaOx) were synthesized and layered by convective self-assembly to demonstrate an analog memristive device in this study. Along with non-volatile analog memory effect, selection diode property could be co-existent without any implementation of heterogeneous multiple stacks with ~1...

Considering the mild degree of coronavirus disease 2019 (COVID-19) in children and the enormous stress caused by isolation in unfamiliar places, policies requiring mandatory isolation at medical facilities should be reevaluated especially given the impact of the pandemic on the availability of hospital beds. In this study, we assessed the usefulnes...

Cutaneous allodynia (CA) is a pain in response to non-nociceptive stimulation and a marker of central sensitisation. Probable migraine (PM) is a migraine subtype that fulfils all but one criterion of migraine. Headache intensity and the disability of individuals with PM are similar or lower than individuals with migraine. This study compared CA pre...

Background and purpose: Identifying changes in the prevalence, disability, and management patterns of migraine is important for reducing the burden of this disease. However, data on the changes in these variables are scarce. Methods: We compared data obtained in the 2009 Korean Headache Survey and the 2018 Korean Sleep-Headache Survey. Results:...

Neuromorphic devices that mimic a human brain have attracted significant attention in the field of next-generation semiconductors. The human brain can efficiently process information with low power consumption. Several energy...

Purpose Nasal pain, as an epileptic aura, has been poorly recognized. This study aims to demonstrate clinical features of patients with epilepsy who have nasal pain as an aura. Methods We retrospectively investigated consecutive patients who visited the epilepsy clinic of tertiary hospital from April 2000 to September 2019. All included patients u...

Information on sex differences in the association between chronotype and depression is scarce. We aimed to investigate these differences using data from the Korea National Health and Nutrition Examination Survey in 2016. Chronotypes were categorised based on mid-sleep time on free days corrected by sleep debt accumulated on workdays (MSFsc): early...

The intrinsic stochasticity of the memristor can be used to generate true random numbers, essential for non-decryptable hardware-based security devices. Here we propose a novel and advanced method to generate true random numbers utilizing the stochastic oscillation behavior of a NbOx mott memristor, exhibiting self-clocking, fast and variation tole...

Background Tongue pressure is an effective index of swallowing function, and it decreases with aging and disease progression. Previous research has shown beneficial effects of swallowing exercises combined with myofunctional tongue-strengthening therapy on tongue function. Tongue exercises delivered through mobile health (mHealth) technologies have...

Background: Cutaneous allodynia (CA) is a common feature of migraine and a clinical marker of central sensitization. Probable migraine (PM) is a subtype of migraine that fulfils all but one criterion of migraine. The present study aimed to evaluate the prevalence and characteristics of CA and those of migraine in PM. Methods: We used the data of th...

BACKGROUND Tongue pressure is one of the effective indices of swallowing function, which decreases with aging and disease progression. Previous research has shown beneficial effects of swallowing exercises combined with myofunctional tongue strengthening therapy on tongue function. Tongue exercises utilizing mobile Health (mHealth) technologies may...

Memristive stateful logic allows complete in‐memory computing and is considered to be a next‐generation computing technology for low power edge applications. Since the first stateful IMP gate was proposed in 2010, few studies have yet addressed the operating reliability issues that should be resolved before the technology is practically realized. H...

Background Cumulative evidence regarding the use of brain magnetic resonance imaging (MRI) for predicting prognosis of unconscious out-of-hospital cardiac arrest (OHCA) survivors treated with targeted temperature management (TTM) is available. Theoretically, these patients are at a high risk of developing cerebral infarction. However, there is a pa...

A Gram stain negative, motile, non-spore-forming, rod-shaped, strictly aerobic, beige-pigmented bacterium, designated strain BO-7T, was isolated from soil of cattle farm, in Seosan, Republic of Korea. On the basis of 16S rRNA gene sequencing, strain BO-7T clustered with species of the genus Ochrobactrum and appeared closely related to O. haematophi...

Memristive neural networks can perform vector matrix multiplication efficiently, which can be used for the accelerator of neuromorphic computing. To train the memristor cells in a memristive neural network, the analog conductance state of the memristor should be programmed in parallel; otherwise, the resulting long training time can limit the size...

Background A close association has been reported between depression and migraine. However, information concerning the impacts of migraine on the clinical presentation and prevalence of depression in a population-based study is currently limited. Methods Data from the Korean Headache-Sleep Study, a nationwide survey about headache and sleep for adu...

Although tin monosulfide (SnS) is one of the promising earth-abundant semiconducting materials for photoelectrochemical water splitting, the performance of SnS photocathodes remains poor. Herein, we report a stepwise approach for the fabrication of highly efficient photocathodes based on SnS nanoplates via elaborate modulation of molecular solution...

Flexible perovskite solar cells (PSCs) have attracted significant interest as promising candidates for portable and wearable devices. Copper nanowires (CuNWs) are promising candidates for transparent conductive electrodes for flexible PSCs because of their excellent conductivity, flexibility, and cost-effectiveness. However, because of the thermal/...

Memristive stateful logic enables energy‐ and cost‐efficient in‐memory computing, which is desirable for edge computing in the coming IoT era. Researchers have recently developed various stateful logic gates, and have shown viable computing applications based on ideal memristive characteristics. However, few studies have demonstrated a system‐level...

Ultraviolet (UV) irradiation induces the proliferation and differentiation of keratinocytes in the basal layer of the epidermis, which increases epidermal thickness in skin regeneration. However, the mechanism underlying this phenomenon is not yet known in detail. In this study, we aimed to demonstrate that the transcriptional coactivator with PDZ-...

Background: Comparable to circumferential resection margin in rectal cancer, radial margin is a potential prognostic factor in colon cancer that has just begun to be studied. No previous studies have investigated the influence of radial margin in the context of complete mesocolic excision. Objective: This study aimed to examine the impact of rad...

Anxiety, depression, and insomnia are highly prevalent among migraineurs and are associated with negative health consequences. Anxiety and depression, however, unlike insomnia, are usually underdiagnosed, due to less self-reporting of these two conditions. The aim of the present study was to evaluate the risk of anxiety and depression in migraineur...

Objective Considering the clinical heterogeneity of temporal lobe epilepsy with amygdala enlargement (TLE‐AE), identifying distinct prognostic subgroups of TLE‐AE has clinical implications. Until now, baseline volume of the enlarged amygdala (EAV) has consistently failed to predict prognosis in TLE‐AE. Based on studies suggesting that patients resp...

Stateful logic enables highly energy‐efficient computation because the time and energy consumption for data transfer between the memory and the computing units, such as central processing unit and graphics processors, in the traditional computation system can significantly be saved. This is due to the combined functionalities of logic operation and...

Excessive daytime sleepiness (EDS) is a prevalent sleep-related complaint across the general population and has been reported to be associated with headache. Tension-type headache (TTH) is the most commonly encountered headache and accounts for a significant amount of disease burden. However, the association between EDS and TTH is currently scarce....

Background We evaluated the accuracy of nasal endoscopy in diagnosing chronic rhinosinusitis (CRS) compared with paranasal sinus computed tomography (CT). Methods Two authors independently searched the 5 databases (PubMed, SCOPUS, Embase, the Web of Science, and the Cochrane database) up to March 2019. For all included studies, we calculated corre...

Tricuspid atresia with absent pulmonary valve and intact ventricular septum is an extremely rare cardiac malformation, historically associated with a poor prognosis. Only a few cases with successful surgical palliation have been reported in the literature. We present the case of an 8-month-old infant with this malformation who underwent successful...

The thin film growth conditions in a plasma-enhanced atomic layer deposition for the (3.0 – 4.5) nm thick HfO2 film were optimized to use the film as the resistive switching element in a neuromorphic circuit. The film was intended to be used as a feasible synapse with analog-type conductance tuning capability. The 4.5 nm thick HfO2 films on both co...

Background: The aim of this study was to compare epidermal growth factor receptor (EGFR) mutations between non-small cell lung cancer (NSCLC) and corresponding brain metastases (BMs) in Korea society. Methods: From 2011 to 2016, a total of 74 patients underwent surgical resection of a metastatic brain tumor from NSCLC. Among them, we performed r...

Williams syndrome is a genetic disorder associated with various cardiovascular abnormalities, most commonly supravalvar aortic stenosis and peripheral pulmonary stenosis. However, isolated severe mitral regurgitation necessitating surgical intervention is extremely rare. Here, we present the case of a 14‐year‐old child with Williams syndrome and is...

Study Objectives: Coronary artery disease is considered to be the major cause of death amongst patients with ischemic stroke. The coronary artery calcium (CAC) score is related not only to sleep-disordered breathing, but also with future risk of cardiovascular mortality. We investigated the association between the severity of sleep-disordered breat...

The conditional switching of memristors to execute stateful implication logic is an example of in-memory computation to potentially provide high energy efficiency and improved computation speed by avoiding the movement of data back and forth between a processing chip and memory and/or storage. Since the first demonstration of memristor implication...

In article number 1800740, H. Song et al. propose an analog data‐programming method for memristors via in‐memory operation in a crossbar array. Analog data can be transferred from a selected reference resistor cell to the target memristor cell by appropriate voltage clocking. Such data transfer can be triggered at any location in the array accurate...

Analog memristors enable compact neuromorphic computing with low power consumption. One of the issues with the technology is slow precise analog data programming. In this study, a novel analog data programming method utilizing a self‐limited set switching is proposed. The method can transfer any resistance values from reference resistors to the tar...

Stateful logic provides an attractive device‐level solution in achieving in‐memory computation, which can solve the critical problem of the von Neumann bottleneck − “memory wall” − in the current computer architecture. Recently, fully functional stateful logic operations and cascading are reported using a TiOx‐based dual‐bit memristor. In that work...

In response to liver injury, the liver undergoes a regeneration process to retain its mass and function. However, the regeneration mechanism has not been fully clarified. This study investigated the role of transcriptional coactivator with PDZ‐binding motif (TAZ), a Hippo‐signaling effector, in liver regeneration. We observed that TAZ stimulates li...

Insulin regulates blood glucose levels by binding its receptor and stimulating downstream proteins through the insulin receptor substrate (IRS). Impaired insulin signalling leads to metabolic syndrome, but the regulation of this process is not well understood. Here, we describe a novel insulin signalling regulatory pathway involving TAZ. TAZ upregu...

By combining the functions of Boolean gates and non‐volatile memory, stateful logic may enable significant savings in time and energy for computational processes that can be performed directly in main memory and for data analyses in edge environments. A simple reduction to practice this concept is demonstrated by Borghetti et al. in 2010 via a mate...

A nociceptor is a critical and special receptor of a sensory neuron that is able to detect noxious stimulus and provide a rapid warning to the central nervous system to start the motor response in the human body and humanoid robotics. It differs from other common sensory receptors with its key features and functions, including the "no adaptation" a...