최민호 교수

Demand for DC-DC voltage conversion from a 48V input has been on the rise due to proliferation of server and automotive applications with a 48V intermediate bus and 48V batteries, respectively. Compared to a 12V, the 48V architecture reduces the power loss thanks to the low distribution losses in the power delivery network. However, improving efficiency is a major challenge in the design of a 48V point-of-load (PoL) DC-DC converter due to the high step-down ratio and high output current. To impr

A high step-down ratio three-level half-bridge (TLHB) dc–dc converter with a current-doubler rectifier is presented for power conversion from a 48-to-60-V input to a 0.5-to-1-V output. The proposed TLHB topology and operation employed on the primary side improve the power-conversion efficiency by reducing the switching loss while minimizing the turn ratio of the transformer by converting the input voltage down to one quarter on the primary side. Moreover, it reduces the voltage stress on switche

The SASGT (Self-Aligning Silicon Groove Technology) platform has been developed for use as a real passive alignment. Key technologies of this platform are precise size control technology for optical active chips, three-step anisotropic etching technology for the silicon optical bench, and flux-and pressure-free die bonding technology. Precisely size controlled laser diode chip was fabricated by etching of V-grooves for cleaving along the [110] and [110] directions. We obtained the size controlle

Achieving a fast-transient response is a major challenge when designing a switching regulator for a processor. Furthermore, high-frequency operation with small passive devices and robust control with a small area footprint in a CMOS-logic process are essential for integrated digital-system voltage regulators. A 4-phase hysteretic converter [1] has a superior transient response using a 3.3V input voltage. However, the analog control circuit under a low input voltage suffers from limited dynamic r

A synthesizable digital adaptive on-time (AOT) 4-phase buck voltage regulator (VR) for digital systems is presented. A current-mode digital AOT controller with the proposed ripple-injection schemes allow a fast and stable output voltage regulation, a fixed switching frequency operation, and phase synchronization for a multiphase VR. The digital AOT controller is implemented in the area of 0.0054 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</

본 연구에서는 27개 시군구의 커뮤니티웰빙 여섯 자본에 대한 평가와 지역주민의 삶의 질에 대한 설문조사 결과 분석을 통해, 지방자치단체에 정책적 시사점을 제공하는 분석틀을 제안하고자 한다. 먼저, 통상적으로 인식하는 도시 대 농촌의 구분이 유의미한지에 대해서 삶의 질과 커뮤니티웰빙 모형의 측면에서 분석을 수행하였다. 다음으로 자료포락분석 방법을 적용하여 27개 기초지자체의 효율성 지수를 파악하고, 끝으로 잔여분 기반 모형을 통해 상대적으로 효율적인 지역을 벤치마킹 할 수 있도록 각 자본별 잔여분 및 최적화 값을 도출하는 탐색적 연구를 수행하였다. 분석결과, 생활환경 수준의 차이를 나타내는 커뮤니티웰빙 자본 중, 인적자본과 자연자본을 제외한 나머지 영역에서는 도시와 농촌에서 유의미한 차이가 나타나지 않았으며, 삶의 질 또한 유의한 차이를 발견할 수 없었다. 자료포락분석의 결과에서도 도시 대 농촌의 구분이 삶의 질-커뮤니티웰빙 관점의 효율성을 구분하는 것에 대한 기준으로 고려하기 어렵다

A 12b 50 MS/s 0.18 µm CMOS ADC with a highly linear variable gain amplifier (VGA) for medical ultrasound and CCD image sensor applications is presented. The proposed four-step pipeline ADC optimises power and chip area at target specifications while the front-end VGA, based on a conventional approximated log function, employs a merged capacitor switching scheme to improve the VGA gain linearity. The proposed input VGA shows a linearity error less than 0.013 dB in a gain range from −3 to 0 dB by

Although stool examination is the standard diagnostic method of clonorchiasis, serodiagnosis byELISA using crude antigen is now widely used because of its convenience. However, ELISA diagnosis stillsuffers from cross-reactions, and therefore there is a need to improve the present conventional ELISA. Thepresent study was undertaken to evaluate the diagnostic value of ELISA using excretory-secretory antigen(ESA) instead of crude antigen (CA) of Clonorchis sinensis. The diagnostic sensitivity of EL

Congestion is generated by buffer overflow and generally is considered in transport layer. However, there is almost no considered one about existing routing protocols of sensor network because it is difficult to apply congestion control in transport layer of WSNs (wireless sensor networks) that have limited resources such as energy, buffer, and bandwidth of sensor nodes. Therefore, routing protocol of sensor networks must deliberate how to control congestion. In order to overcome this problem, w

A soft-switching hybrid DC-DC converter with a 2-phase switched capacitor is proposed for the implementation of a fully-integrated voltage regulator in a 65 nm standard CMOS process. The soft-switching operation is implemented to minimize power loss due to the parasitic capacitance of the flying capacitor. The 2-phase switched capacitor topology keeps the same resonance value for every soft-switching operation, resulting in minimizing the voltage imbalance of the flying capacitor. The proposed a

Optical and hybrid convolutional neural networks (CNNs) recently have become of increasing interest to achieve low-latency, low-power image classification, and computer-vision tasks. However, implementing optical nonlinearity is challenging, and omitting the nonlinear layers in a standard CNN comes with a significant reduction in accuracy. We use knowledge distillation to compress modified AlexNet to a single linear convolutional layer and an electronic backend (two fully connected layers). We o

The rise of the Internet of Things, autonomous navigation systems, and wearable devices created a growing need for ultra-compact, low-power, low-latency vision sensors that bridge the physical and digital worlds. Vision sensors capture vast amount of data that require swift processing for semantic scene understanding. However, most computer vision algorithms suffer from large power consumption and latency, necessitating the sacrifice of spatial resolution. Optical systems can potentially address

Artificial neural networks (ANNs) have fundamentally transformed the field of computer vision, providing unprecedented performance. However, these ANNs for image processing demand substantial computational resources, often hindering real-time operation. In this paper, we demonstrate an optical encoder that can perform convolution simultaneously in three color channels during the image capture, effectively implementing several initial convolutional layers of a ANN. Such an optical encoding result

The Kato-Katz (KK) method is a well-known method of fecal examination for helminthiases. Its diagnosticsensitivity was found very high for clonorchiasis. The present study evaluated the correlation of Clonorchis sinensisegg counts by the KK method with those by direct smear and formalin-ether (FE) technique. The egg counts obtainedby the KK method (Y) were correlated with the counts by direct smear (X) with the equation of Y = 659.4 + 0.266X (r2= 0.738), but not with those by the FE method. The

Itraconazole has a statistically significant pharmacokinetic interaction with zopiclone but this is only of limited clinical importance, at least in young adults.