Ji-Young Lee

We have developed thermally activated delayed fluorescence emitters with wide ranges of emission colors and singlet–triplet energy gaps.

This paper presents a method to calculate motor parameters considering magnetic nonlinearity in interior permanent magnet synchronous motors (IPMSM). To analyze motor characteristics by using equivalent circuits, inductance and iron loss resistance, which are affected critically magnetic saturation, are obtained by using static finite-element analysis. For a fabricated IPMSM, input current and motor characteristics such as torque and efficiency are calculated, and the proposed method is verified

The aim of this paper is to present optimal design process and optimized model of transverse flux rotary motor. The stator and rotor tooth shapes are optimized to reduce cogging torque. Design of experiment and response surface methodology are used as an optimization method and all the experimental samples are obtained from three-dimensional finite-element analysis. The validity of this method is verified by comparing the optimized model to the initial model

Abstract The lithium metal battery (LMB) is a promising energy storage platform with a distinctively high energy density in theory, outperforming even those of conventional Li‐ion batteries. In practice, however, the actual achievable energy density of LMBs is significantly limited due to the Li metal anode (LMA) being too thick (50–250 μm), and there are difficulties with expanding the highly reactive Li metal into large‐format cells due to safety concerns. Therefore, the recent focus of LMB re

ArF lithography is essential to develop a sub-100 <i>nm</i> device, however, line edge roughness (LER) and line width roughness (LWR) is playing a critical role due to the immaturity of photoresist and the lack of etch resistance. Researchers are trying to improve LER/LWR properties by optimizing photoresist materials and process conditions. In this paper, experiment results are presented to study the impact of LER/LWR to device performance so that the reasonable control range of LER/LWR can be

This paper presents a characteristic analysis of a wye-connected toroidal winding switched reluctance motor (TSRM) driven by 6-switch converter. The voltage equations considering both TSRM and the drive topology are introduced for steady state dynamic simulation. Inductances, which mainly affect motor characteristics, are calculated by finite element analysis and stored in a look-up table. During the dynamic analysis with the proposed voltage equations, the inductances are fitted using a spline

This paper deals with a design of an axial flux permanent magnet (AFPM) generator which is a key element of a compact size portable and manual generator system composed of a gear system, a generator, a rectifier, and a battery charger. The design objects of the AFPM generator are its compact size, light weight, and high efficiency, and the three design objects are the main criteria to select the value of design variables. A soft magnetic composite core is used instead of a silicon steel core in

This paper proposes an effective method to calculate inductance and static thrust of a permanent magnet (PM)-type transverse flux linear motor (TFLM). The proposed method is a simple and fast way considering three-dimensional (3-D) flux path of the TFLM, and it can be used not only in characteristic assessment, but also in the design process. Two-dimensional (2-D) finite element analysis (FEA) and 3-D equivalent magnetic circuit network (EMCN) analysis are conducted to analyze the magnetic field

This paper presents methods to calculate motor parameters considering magnetic nonlinearity in solid core transverse flux linear motors (TFLM) for dynamic simulation. The magnetic field characteristics of the machine are analyzed by using 3-D equivalent magnetic circuit network (3-D EMCN) method, and parameters for dynamic simulation such as linkage flux, thrust, attraction force, and core loss are calculated by using the magnetic field analysis results. The calculated parameters are used as a f

Abstract Thermally activated delayed fluorescence (TADF) emitters consisting of a xanthone acceptor unit and a para-, meta-linked tercarbazole donor unit were developed. The influence of the regioisomeric donor–acceptor structures on their photophysical and TADF properties was studied. Blue organic light-emitting diodes employing these TADF emitters showed high external electroluminescence quantum efficiencies of up to 14.4% with suppressed roll-off characteristics.

The aim of this paper is to provide performance comparisons between conventional longitudinal flux and transverse flux permanent-magnet machines using three-dimensional finite element analysis considering both electro-magnetic and mechanical fields. For a turret application with 2 meters in diameter size, not only electro-magnetic performance but also mechanical structural strength is important. Therefore, the comparison is focused on the torque density, machine efficiency, time constant, magnet

The goal of this work is zero-shot text-to-speech synthesis, with speaking styles and voices learnt from facial characteristics. Inspired by the natural fact that people can imagine the voice of someone when they look at his or her face, we introduce a face-styled diffusion text-to-speech (TTS) model within a unified framework learnt from visible attributes, called Face-TTS. This is the first time that face images are used as a condition to train a TTS model.We jointly train cross-model biometri

This paper deals with a comparative study of switched reluctance motors (SRMs) with conventional and toroidal windings, which is called CSRM and TSRM, respectively. In the CSRM there is a complete magnetic decoupling between phases, so that torque is produced entirely due to the rate of change of winding self inductance. If the same machine is wound with toroidal windings then it can be shown that a new configuration produces torque as a result of changing phase inductance, which becomes much sm

This paper presents the design of an axial-flux permanent-magnet (AFPM) generator used for hybrid electric propulsion drone applications. The design objectives of the AFPM generator are high power density, which is defined as output power per generator weight, and high efficiency. In order to satisfy the requirements for the target application and consider the practical problems in the manufacturing process, the structure of the AFPM generator comprising a double-rotor single-stator (DR-SS) was

본 연구는 신문사설에서 저출산 현상 해결담론의 표상, 생산 및 소비, 사회․문화적 맥락에서의 공고화를 비판적 담론분석을 통해 살펴보았다. 연구결과, 담론의 내용은 저출산 인식과 원인, 그 영향 및 결과, 해결방안으로 구성되어 있었다. 저출산 현상의 부정적 수식어와 비유 사용은 부정적 인식을 심어주고 있었다. 담론 생산 및 소비 분석결과, 사설로서의 담론질서를 갖고 있었고, 유아교육 공교육화와 무상보육지원 관련 담론에서 신문사의 전통적인 담론 성향이 나타났다. 담론의 사회․문화적 맥락분석 결과, 담론은 시장경제중심의 자본주의, 관련 정책 수립과 실행, 선거공약과 실행의 영향을 받고 있었다. 이는 저출산 해결 목적이 삶의 질 향상, 인간행복의 가치보다 경제 활성화를 위한 노동력 확보라는 경제학적 가치가 우위에 있음을 나타낸다. 선행 국가들의 저출산 극복정책 경향이 ‘유아교육의 질적 강화’임을 볼 때, 근본적으로 경제적 가치보다는 교육․복지적 가치에서 접근해야 할 필요가 있으며 대중의 인