Jun‐Seok Park

In this paper, a novel three-pole coupled-line bandpass filter with a microstrip configuration is presented. Presented bandpass filters use defected ground structure (DGS) sections to simultaneously realize a resonator and an inverter. The proposed coupled-line bandpass filter provides compact size with low insertion-loss characteristic. Furthermore, a DGS shape for a microstrip line is newly proposed. The proposed DGS unit structure has a resonance characteristic in some frequency band. The pro

In this paper, a novel equivalent circuit and modeling method for a defected ground structure is proposed to design an optimized DGS lowpass filter circuit. The equivalent circuit presented in this paper has parallel capacitance to explain the fringing fields due to the defects on the metallic ground plane. Several comparisons between the EM-simulations on the DGS circuits and circuit simulations on its equivalent circuits are demonstrated to show the validity of the proposed model. Optimization

On-device machine learning is critical for mobile products as it enables real-time applications (e.g. AI-powered camera applications), which need to be responsive, always available (i.e. do not require network connectivity) and privacy preserving. The platforms used in such situations have limited computing resources, power, and memory bandwidth. Enabling such on-device machine learning has triggered wide development of efficient neural-network accelerators that promise high energy and area effi

Recent work on neural-network accelerators has focused on obtaining high performance in order to meet the needs of real-time applications with vastly different performance requirements, including high precision computation, efficiency for various Deep Learning (DL) layer types, and extremely low power to run always-on applications. Applying a single mode or datatype uniformly across these different scenarios would be less efficient than using different operating modes according to different oper

This letter is to present a new defected ground structure (DGS), which is useful for mounting an active device, and its application to a microwave oscillator. The newly proposed DGS circuit is useful for mounting a transistor such as a BJT or field effect transistor (FET) on ground plane. In order to bias dc to a transistor, it is necessary to implement the dc isolated circuit in a practically applied active device with a DGS. For dc isolation, each branch of DGS should be isolated from ground.

This paper introduces an interrogation enhancer (IE) as an external system that boosts a reader continuous wave (CW) with its auxiliary CW. The boosted reader CW powers the backscatters from a passive ultrahigh frequency radio frequency identification (UHF RFID) tag to reach the reader in extended range. The system performance is verified according to the measured ranges in practical tests. The IE permits the reader to successfully interrogate the tag in tripled or doubled range (e.g., 80-290 an

A pattern-matching based image recognition accelerator (PRA) is presented for embedded vision applications. It is a hardware accelerator that performs interest point detection and matching for image-based recognition applications in real time in both mobile devices and vehicles. The proposed system is implemented as a small IP, and it has eight times higher throughput than state-of-the-art object recognition processors, which are implemented based on a heterogeneous many-core system. PRA has thr

The thermal physiological and psychological responses in vehicles, influenced by gender and age, play a crucial role in ensuring passengers' comfort. However, these differences have often been overlooked. This study aims to comprehensively examine passengers' thermal comfort and investigate gender and age disparities based on their physiological and psychological responses. Experiments were conducted inside a vehicle placed in a climate chamber under cooling and heating conditions, with the coll

In this paper, a unified interest-point detection and matching hardware with an optimized memory architecture is proposed for a real-time stereo-matching system. In order to support a stereo-matching algorithm, the unified datapath in the hardware performs not only interest-point detection and matching algorithms such as features from the accelerated segment test (FAST) and binary robust independent elementary feature (BRIEF) in real time but also a census transform, which is widely used in ster

For the purpose of examining about seasonal change in concentration of indoor organic compounds in Seoul, 96 houses in the winter and 49 houses in the summer were investigated. Indoor organic compounds concentration were measured and survey was performed by questionnaire. Indoor organic compounds were monitored with two diffusive samplers. One was a cartridge treated with 2,4-dinitrophenylhydrazine for aldehydes sampling. The other was a passive charcoal tube for VOCs sampling. Two samplers were

A low-noise offset-cancellation method is proposed to increase the sensitivity of CMOS Hall sensors. Conventional CMOS Hall sensors have low sensitivity because of high offset, flicker (1/f) noise, and chopper switching noise. To improve the sensitivity of Hall sensors, we need to reduce the noise generation and separate the Hall signal from the noise. Therefore, in this study, switching noise and harmonics are reduced by applying a low-noise offset-cancellation method using a reduced number of

In this paper, novel RF phase shifter structure using DGS (Defected Ground Structure) is proposed for the low insertion loss and linear phase variation characteristic. Equivalent circuit of the proposed phase shifter is derived by employing the equivalent circuit of DGS section. Varactor diode is chosen as an electrical control device, which is placed on metallic backside ground plane. Theoretical consideration and experiments verify the presented phase shifter. The experimental results for a si

Abstract This article presents a TX leakage cancellation scheme for UHF RFID readers. A prototype is implemented on a UHF RFID reader board, which includes a circulator, directional coupler, microcontrol unit (MCU)‐controlled variable attenuator, and phase shifter. The difference between a conventional TX leakage canceller and this new one is that, reflected signals caused by mismatches between the front‐end and the antenna are included; in addition, high isolation is supplemented at variable fr

The purpose of this study was to evaluate the potential work performance benefits of increased ventilation rates. Perceived air quality, Sick Building Syndrome(SBS) symptoms and work performance were experimented in a normally furnished Mock-up space ventilated with an outdoor. Six groups of three man and female subjects were exposed to the three ventilation rates, 5, 12 and 21 L/sec per person and the temperature, the relative humidity and all other environmental parameters remained unchanged.