Mr.Sammler's Planet에 나타난 Saul Bellow의 도덕의식

이광운 한국영미어문학회 1985 영미어문학 Vol.- No.36

변압기 보조권선을 이용한 자기 구동 능동 클램프 포워드 컨버터

이광운,林範善,김희준 대한전자공학회 2003 電子工學會論文誌-SC (System and control) Vol.40 No.9

This study proposes a new self-driven active clamp forward converter eliminating the extra drive circuit for the active clamp switch. The converter used the auxiliary winding of the power transformer to drive the active clamp switch and a simple R-C circuit to get the dead time between the two switches. The operation principle was presented and experimental results were used to verify theoretical predictions. A 100-W (5V/20A) prototype converter built that only exhibited 1.5-turn winding number in the auxiliary winding was sufficient to drive the active clamp switch on the input of 50V. Finally, the measured efficiency of the converter was presented and the maximum efficiency of 91% was obtained. 본 논문에서는 능동 클램프 스위치를 위한 별도의 구동 회로가 생략된 새로운 자기 구동 능동 클램프 포워드 컨버터를 제안하였다. 능동 클램프 스위치의 구동에는 컨버터 자체의 변압기의 보조 권선을 이용하였고, 두 스위치 구동 신호 사이의 데드 타임을 설정하기 위하여 간단한 R-C지연 회로를 추가하였다. 제안된 컨버터의 동작 원리를 제시하였고 실험 결과를 가지고 이론적인 결과를 입증하였다. 출력 100W(5V/20A)의 컨버터를 제작하였으며, 입력이 50V일 때 능동 클램프 스위치의 구동에 단지 1.5T의 보조 권선의 권선수로 충분하다는 점을 보였다. 끝으로 제안된 컨버터의 측정 효율을 제시하였고 91%의 최대 효율을 달성하였다.

로버트 블라이의 종교적 상상력

이광운 한국문학과종교학회 2004 문학과종교 Vol.9 No.1

It seems that the poetry of Robert Bly is the embodiment of his religious imagination and a record of his spiritual pilgrimage. Although Bly has a Lutheran heritage and uses the Biblical allusions quite often throughout his poetry, his religious impulses are far removed from the orthodox Christianity. The purpose of this paper is to suggest that religious imagination is the foundation of Bly's poetry and to analyze the nature of it. From specific discussion of the poetry, this study will reveal that the unconscious is the source of Bly's religious imagination. In "Sleepers Joining Hands," Bly depicts his spiritual vision in which he transcends the masculine/feminine and man/nature dichotomy through the individuation process. Bly, who assumes that human beings are a part of nature, also believes in the existence of the circular cosmic energy as a life giving power as well as god. Ile suggests that the energy, Gott-natur(the holy nature), "senses the interdependence of all things alive." Bly's sense of interrelatedness of all things is similar to the Zen Buddhistic idea of the Law of Interdependent Origination and the natural religion of the American Indians. In many of the poems in This Body is Made of Camphor and Gopherwood, Bly does not draw a clear distinction between the body and the soul. On the contrary, he suggests that the body is the vehicle of salvation ascribing the religious impulse to the body. Like Lawrence before him, Bly, who considers sexuality as divine, praises natural eros as an act of continuation of life. In conclusion, Bly's poetry as the products of his religious impulses helps heal the modern man's fragmented and divided emotions.

Voltage Angle Control of Surface Permanent Magnet Synchronous Motor for Low-Cost Applications

이광운,김규철 한국전기전자학회 2018 전기전자학회논문지 Vol.22 No.3

This paper presents a voltage angle control strategy for surface permanent magnet synchronous motor (SPMSM) drives used in low-cost applications, wherein a current vector control is not employed. In the proposed method, the current vector control scheme, which requires high precision phase-current sensing units and a fast calculation capability of a motor drive controller, is replaced with the voltage angle controller. The proposed voltage angle controller calculates a d-axis voltage command to make the d-axis current zero by using a simple equation obtained from the voltage equation of SPMSM. The proposed method shows performance similar to the current vector controlled SPMSM drive during steady-states and its structure is very simple and thus it can be easily implemented with a low-cost microcontroller. The effectiveness of the proposed method is verified through simulations and experiments.

가상 d-q 변환을 이용한 승압형 단상 PFC 컨버터의 디지털 전류 제어 방법

이광운,김학준 전력전자학회 2020 전력전자학회 논문지 Vol.25 No.1

A digital current control scheme using virtual d-q transformation for a boost single-phase power factor correction (PFC) converter is proposed. The use of virtual d-q transformation in single-phase power converters is known to improve current control performance. However, the conventional virtual d-q transformation-based digital current control scheme cannot be directly applied to the boost single-phase PFC converter because the current and average voltage waveforms of the inductor used in the converter are not sinusoidal. To cope with this problem, this study proposes a virtual sinusoidal signal generation method that converts the current and average voltage waveform of the inductor into a sinusoidal waveform synchronized with the grid. Simulation and experimental results are provided to show that the virtual d-q transformation-based digital current control is successfully applied to the boost single-phase PFC converter with the aid of the proposed virtual sinusoidal signal generation method.

이중 PLL 구조를 이용한 표면부착형 영구자석 동기전동기 센서리스 구동장치의 성능 개선

이광운 전력전자학회 2017 전력전자학회 논문지 Vol.22 No.6

This paper presents a simple approach for improving the performance of back-electromotive force (back-EMF)-estimation-based sensorless drives for surface-mounted permanent magnet synchronous motors (SPMSM). Similar to conventional approaches, a hypothetical d-q synchronous reference frame model of SPMSM is employed in the proposed approach to estimate the back-EMFs. This approach also employs a dual phase locked loop structure to compensate for the effect of the dead time and parameter uncertainty of the inverter on the estimated back-EMFs. The proposed algorithm is validated by conducting experiments.

월트 휘트먼 시의 풀 이미지

이광운 대구효성가톨릭대학교 외국어문학연구소 1997 語文學硏究 Vol.9 No.-

The image of grass is the most dominant throughtout Whitman's 'Leaves of Grass'. The grass, first of all, is identified with the poems and the poet as viewed in "Song of myself" and "Whoever You are Holding me New in Hand". Whitman uses the grass, microcosm, as a symbol of cosmic principle and a symbol of immortality. He also uses it as a symbol of egalitarian spirit and democracy. Whitman's attempt to identify himself with the grass represents his poetic technique to embody reality with the words. The grass image found in "Calamus" poems is used to establish the poet-reader relationship. Whitman who perceives his poetry as "the frailest leaves" believe that the hearts of the readers are the soil in which his leaf-poems sprout. The spiritul merge between the poet and the reader is the essence of "Calamus" poems.

휘트먼의 시에 나타난 노인의 목소리

이광운 새한영어영문학회 2006 새한영어영문학 Vol.48 No.4

Throughout Whitman's poetry, two voices of the aged are sharply contrasted. One voice is dispersed in his early poetry written mostly during his highest stage of poetic achievement in which Whitman reveals his ideal characteristics of the aged person. The other voice is found in his later poetry written after he experienced his first stroke at the age of fifty four. The former voice reveals Whitman's concept of the aged and shows his idealistic qualities of an ideal old person. Whitman suggests that the ideal old person should be equipped with many realistic qualities, such as off-spring, good health, and sociability along with inner traits such as serenity, ripeness, and majesty. The purpose of this paper is to show that Whitman had a deep interest in old age and the quality of its life and to suggest the voice of the aged found in his later poetry is the most personal and heart-felt and it must be thought of as a vital element of Whitman canon. Since Whitman's later poetry is the record of his personal life, it easily earns the sympathy of the readers. Moreover, the readers may find that the literary achievement of Whitman is directly related with his humane goal of achieving serenity and peace of mind. In short, Whitman's sense of the aged revealed both in his early poetry and later poetry is significant in that it integrates the real and ideal dealing with his fundamental theme of life and death.

월트 휘트먼 시에 나타난 물과 상상력

李珖雲 대구효성가톨릭대학교 외국어문학연구소 1994 語文學硏究 Vol.7 No.-

Water is one of the most pervasive sorces of Whitman's poetic imagination. It seems that many of Whitman's poems are like ingredients contained in various kinds of water vessels. The spermatic imagery found in "Song of Myself", "Song of the Open Road", and in many poems belonging to "Children of Adam" embodies his poetics of effusion. In other words, it is the poet's device to create within his poems life force. The pond imagery, which can mostly be found in "Calamus" poems, is to suggest the "adhesive" human relationship through the characteristics of water which cannot be seperable. The pond is also a symbol of the space of the poet's and the readers' inner consciousness in which the poet's poems grow. Therefore, it can be a place where the poet and the readers meet spiritually. Whereas the water in the poems of the "Calamus" group represents the static human relationship, the river in "Crossing the Brooklyn Ferry" suggests the dynamic human contact. Since the river is identified with the time itself in the poem, the watr becomes a symbol of spiritual union among mankind transcending through time and space. The sea functions as the most powerful sources of Whitman's imagination. The oceanic poems of Whitman represent life, death, eroticism, destruction, and union etc. Through the use of the poetic metaphor of the ebb and flow representing the liquid relationship, Whitman achieves a symbolic union between the two opposite elements of body and soul, land and sea, good and evil etc.

Evaluation of Back-EMF Estimators for Sensorless Control of Permanent Magnet Synchronous Motors

이광운,하정익 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.4

This paper presents a comparative study of position sensorless control schemes based on back-electromotive force (back-EMF) estimation in permanent magnet synchronous motors (PMSM). The characteristics of the estimated back-EMF signals are analyzed using various mathematical models of a PMSM. The transfer functions of the estimators, based on the extended EMF model in the rotor reference frame, are derived to show their similarity. They are then used for the analysis of the effects of both the motor parameter variations and the voltage errors due to inverter nonlinearity on the accuracy of the back-EMF estimation. The differences between a phase-locked-loop (PLL) type estimator and a Luenberger observer type estimator, generally used for extracting rotor speed and position information from estimated back-EMF signals, are also examined. An experimental study with a 250-W interior-permanent-magnet machine has been performed to validate the analyses.