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루이스 알베르토 데 쿠엔카의 시에 나타나는 70세대와 80세대적 요소들
남영우 ( Nam¸ Youngwoo ) 한국스페인어문학회 2021 스페인어문학 Vol.- No.100
1. 시작하는 말 2. 루이스 알베르토 데 쿠엔카와 70세대의 문화주의 3. 루이스 알베르토 데 쿠엔카와 80세대의 시 4. 정리하는 말 참고문헌
Proximate In-Phase Current Estimator to Reduce Torque Ripple in Permanent-Magnet Stepping Motor
Youngwoo Lee,Donghoon Shin,Wonhee Kim,Chung Choo Chung IEEE 2016 IEEE transactions on industrial electronics Vol.63 No.3
<P>This paper proposes microstepping via a proximate in-phase current estimator (PIpCE) to improve position control performance with reduced torque ripples in permanent-magnet (PM) stepping motors. In conventional microstepping control, low-pass filters (LPFs) are used to filter out measurement noise resulting from the implemented current feedback loops. However, the phase lag caused by LPFs can degrade position control performance. In this paper, we propose a current tracking controller with PIpCE. The globally uniformly ultimately bounded current tracking error is proved via the Lyapunov theory. The proposed PIpCE also enhances current tracking performance over that of the conventional method. The proposed controller not only reduces the torque ripple caused by the phase lag but also increases the operational range of microstepping by pushing the electromechanical resonance frequency to a high-frequency region. We experimentally validated the effectiveness of the proposed method and observed that this method provides uniform position tracking performance without step-out or speed reversal, even in high-speed operation.</P>
Youngwoo Nam,Sang-Hyun Koh,Sung-Jae Jeon,Ho-Joong Youn,Young-Seuk Park,Won Il Choi 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.04
This study examined the effects of environmental factors on the abundance of black pine bast scale (BPBS), Matsucoccus thunbergianae Miller and Park, in coastal disaster prevention forest stands composed mostly of Japanese black pine. Geographical factors, soil conditions and forest stand conditions were measured to evaluate the hazard rating for the occurrence of BPBS from 35 plots in the coastal forest stands. To assess the hazard rating, a combination of a self-organizing map (SOM), which classified the samples according to their characteristics, and a random forest model, which predicted the probability of the occurrence of BPBS from SOM results, was used in this study. Our results showed that major factors determining the abundance of BPBS were climate, tree size, and tree health. BPBS was more common in low latitude coastal forests, suggesting that warmer conditions were favorable to BPBS population buildup. Tree size also influenced the abundance of BPBS, which was higher in forests composed of larger trees (greater DBH). Finally, BPBS was also more abundant in areas with high soil salinity and clay-loam soil, and north-facing slopes where tree vigor was lower.
( Youngwoo Jang ),( Heekyung Ahn ),( Eunyoung Kim ),( Jungkeun Moon ),( Yangbin Jeon ),( Kyuchan Lee ),( Yeonho Park ),( Eunyoung Cho ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1
Primary cardiac cancer is a very rare disease, as the prevalence is 0.001 to 0.03%. Primary cardiac angiosarcoma is one of the most frequent types of primary cardiac cancers, however, is characterized by extremely poor prognosis, as the mean survival is reported to be only three to four months, and optimal treatment is unknown. Here we report a patient of primary cardiac angiosarcoma with hemorrhagic pericardial effusion who achieved a durable response with tumor excision followed by concurrent chemoradiotherapy with docetaxel. A sixty year old male with underlying history of diabetes mellitus presented with rapidly progressing shortness of breath. Cardiac tamponade was diagnosed, and 420 cc of bloody fiuid was drained with pericardiocentesis. The patient`s blood pressure was restored to within normal limit after pericardial effusion drainage. Subsequent chest computed tomography scan, echocardiography and cardiac Magnetic Resonance Image revealed a 4.5x3.5cm sized infiltrative mass in the right atrium. Tumor excision was performed, of which pathologic findings revealed cardiac angiosarcoma with tumor involvement of resection margin. The patient underwent adjuvant radiotherapy (5000cGys/30fractions) with concurrent chemotherapy with docetaxel. There was no evidence of recurrence until ten months later, when multiple liver metastases were found on CT scan. Hepatic metastasectomy with periop chemotherapy with weekly paclitaxel was followed. As of Jul 2014, the patient is receiving chemotherapy with overall survival of 16 months and counting. Currently there are only three published case reports of cardiac angiosarcoma which showed response to radiation and taxane, and this is the fourth case report of successful treatment. Further investigation on this regimen is warranted.
Youngwoo Bryan Yoon,Minah Kim,Junhee Lee,Kang Ik K,Cho,Seoyeon Kwak,Tae Young Lee,Jun Soo Kwon 대한신경정신의학회 2019 PSYCHIATRY INVESTIGATION Vol.16 No.3
We aim to investigate the effect of fronto-temporal transcranial direct current stimulation (tDCS) on the interactions among functional networks and its association with psychotic symptoms. In this pilot study, we will determine possible candidate functional networks and an adequate sample size for future research. Seven schizophrenia patients with treatment-refractory auditory hallucinations underwent tDCS twice daily for 5 days. Resting-state fMRI data and measures of the severity of psychotic symptoms were acquired at baseline and after completion of the tDCS sessions. At baseline, decreased functional network interaction was negatively correlated with increased hallucinatory behavior. After tDCS, the previously reduced functional network connectivity significantly increased. Our results showed that fronto-temporal tDCS could possibly remediate aberrant hallucination-related functional network interactions in patients with schizophrenia.
Performance Analysis of Software Architectures with Real-time Kernel Patches for the Rescue Robot
Youngwoo Lee,Myeong Eon Jang,Jun Kim,Yong Woon Park 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10
This paper introduces software architectures of the Rescue Robot that lifts and moves wounded soldiers in battle fields or hospitals. Since the Rescue Robot interacts with humans, the robot needs a real-time operation for human safety. Moreover, it is necessary that a large number of calculations and various sensing data to move the soldiers without any damages. One of challenging problems of designing the robot software architecture is that a large number of calculations and data would disturb to decrease a response time taken until robot reacting from user’s commands or emergency sensing data. The Rescue Robot uses Linux with real-time kernel patches as a real-time operating system and EtherCAT as a real-time network. We test three kinds of software architectures, Linux, Xenomai, and RTAI, for the Rescue Robots about the time taken until output commands are sent to joint motors just after the sensing data or input commands are delivered. Furthermore, we suggest a method to handle urgent commands or data quickly with a slightly modified kernel and a kernel module that reduces the time dramatically. This paper also analysis the difference of the real-time kernel patches.
Simple Field Weakening Control for Permanent Magnet Stepper Motors without DQ Transformation
Youngwoo Lee,Wonhee Kim,Donghoon Shin,Chung Choo Chung 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10
In this paper, a simple field weakening control (FWC) without direct quadrature (DQ) transformation is proposed for position tracking of permanent magnet stepper motors (PMSMs). The proposed method consists of the PID controller for a torque modulation and a commutation scheme to achieve FWC without DQ transformation. In proposed commutation scheme, the desired negative direct current is designed to cancel the back-emf so that the required inputs can decreased. The commutation scheme is equivalent to microstepping where currents have time-varying amplitude over 0.5π electrical phase advance. For simple implementation, proportional integral (PI) current feedback was used to guarantee the desired current. Simulation results validate the performance of the proposed method.