Smooth singular value thresholding algorithm for low-rank matrix completion problem

이근섭 대한수학회 2024 대한수학회지 Vol.61 No.3

The matrix completion problem is to predict missing entries of a data matrix using the low-rank approximation of the observed entries. Typical approaches to matrix completion problem often rely on thresholding the singular values of the data matrix. However, these approaches have some limitations. In particular, a discontinuity is present near the thresholding value, and the thresholding value must be manually selected. To overcome these difficulties, we propose a shrinkage and thresholding function that smoothly thresholds the singular values to obtain more accurate and robust estimation of the data matrix. Furthermore, the proposed function is differentiable so that the thresholding values can be adaptively calculated during the iterations using Stein unbiased risk estimate. The experimental results demonstrate that the proposed algorithm yields a more accurate estimation with a faster execution than other matrix completion algorithms in image inpainting problems.

Poe as a poet-critic

李懃燮 이화여자대학교 한국문화연구원 1966 韓國文化硏究院 論叢 Vol.6 No.-

Edgar Allan Poe는 主로 短篇作家로서 이름이 났지만 詩人으로서도 또는 批評家로서도 無視할 수 없는 存在다. 作品의 量으로 보아 詩는 五十篇 도 넘지 않고 批評도 또한 僅少하나 이 중에는 注目할만한 力作이 많이 包含되어 있다. 그의 批評은 특히 文學原理論으로서 유명하다. 散文에 있어서나 韻文에 있어서나 그는 原理를 提示하고 그 原理를 實際 創作에 最大限度로 利用한 흔적이 여기 저기 보인다. 그의 作詩法 理論은 Rationale of Verse에 또 Marginalia에 斷片的으로 나타나 있지만 美國의 作詩法理論으로서는 最初로 注目할만한 力作이라고 하겠다. 그는 詩의 音樂的 要素를 지나치리만큼 强調하고 있는데 그의 詩는 정말 音樂的이다. 例를 들면 "Annabel Lee"는 詩에서 使用할 수 있는 모든 音樂的 要素를 最大限度로 利用한 느낌을 준다. 非單 이 詩 뿐만 아니라 어느 詩를 골라도 音響의 效果가 매혹적이 아닌 것은 없다. 特히 注目할만한 事實은 그의 脚韻 使用法이다. 그의 脚韻은 大部分 音樂的인 音響을 갖고 있다. 英語는 본래 子音이 적기 때문에 音樂的인 母音으로 끝나는 單語가 많지 않아 脚韻이 非音樂的인 경우가 많지만 Poe에게 있어서는 이 弱點이 最大限度로 回避되어 있다. 意識的이었건 無意識的이었건 간에 그의 脚韻은 마치 中國詩와 마찬가지로 母音 혹은 半母音으로 끝나는 것이 딴 詩人에 比해 越等히 많다. 그의 詩論은 좀 편협하여 敍事詩 獻詩를 時의 영역에서 除外하고 있지만 敍情詩에 對한 理論은 그의 實踐과 더불어 길이 기억될 것이다.

George Herbert의 詩的 技攷

李懃燮 이화여자대학교 한국문화연구원 1968 韓國文化硏究院 論叢 Vol.12 No.-

Reading through George Herbert's The Temple, one can easily be impressed with the fact that he uses carious forms of poetry. He uses 140 different poetic forms out of 171 pieces in The Temple, but never uses any traditional forms except sonnets. Even in the case of sonnets he writes only six pieces after the fashion of the English sonnet form out of 15 pieces. The others are of the form of his own device in which he sometimes mixes the English form with Italian sestets. He never uses even such a popular form as the ballad metre probably because he prefers rhymed verse to the unrhymed. There are no unrhymed verses in The Temple with the possible exception in the case of his deliberate technical device. Even though he prefers iambic pentameters (more than half of his whole verses are in pentametres) he never uses any blank verse. His chief technique lies in his subtle device of various rhyme schemes as shown, for example, in "Man" in which he uses different rhyme schemes in every stanza but one. He tries to conform his matter or sense with the poetic form in accordance with his various poetic moods and experiences. Not all of his poetic techniques is successful, but his artistic endeavour is not to be disregarded or underestimated. Any practitioners of verse can be greatly profited by the study of Herbert's verse. He is one of the greatest originators of various verse forms of English poetry.

Petrarchan Sonnet과 Milton

李懃燮 한국영어영문학회 1967 영어 영문학 Vol.24 No.-

Henry Vaughan의 詩

李懃燮 한국영어영문학회 1962 영어 영문학 Vol.11 No.-

George Herbert 평가의 변천과정

이근섭 이화여자대학교 한국문화연구원 1984 韓國文化硏究院 論叢 Vol.45 No.-

After death, George Herbert, a professional sacred poet of seventeenth century England, was received favorably when The Temple, the only volume of his religious poems(and quite congenial with the pious minds of the Anglican Church) was published posthumously. His poems were studied seldomly from an artistic point of view. Coleridge was the first to recognize Herbert as a true poet. In his lifetime, Herbert did not thrive in the eyes of the eminent critics, Consequently, he was not considered an important poet. It is only in the early poet of this century, that George Herbert gained recognition. The revival of Metaphysical poetry by Sir Grierson drew attention to Herbert and his religious lyrics from a number of critics and scholars. Important critics of Herbert in the 1930's include Williamson, Eliot, Bennett, White and Leishman; in the 1940's Freeman and Knight's; in the 1950's Tuve, Bottrall, and Summers; in the 1960's Rickey and Stein; in the 1970's and onward. Vendler, Freer, Fish, Charles and Asals. In addition to the above-mentioned, there are numerous other scholar-critics as Nuttall, Lewanlski, Low, Slights, Halewood, Colie, Mahood, Marts, Patrides, Di Cesare and Elsky who also have studied Herberts poems. One camp of modern Herbert critics, represented by Summers, can be called the "traditional camp". These critics concentrate on Herbert's constant search of a proper language for his poetry. They maintain that Herbert tried to achieve eloquence by means of plainness. Another camp, represented by Fish, hearing jarring notes in Herbert's poetry, maintains a "deconstructionist" view of literary indeterminacy. This is central to the modern leading critics' regard of Herbert as a major poet.

17세기 영국 종교 시인론

이근섭 이화여자대학교 한국문화연구원 1994 韓國文化硏究院 論叢 Vol.64 No.1

The Authorized Version of the English Bible was firtst published in 1611, which was one of the basic sources of religious verses of the Seventeenth Century English poetry. Although the former century produced several religious poets such as William Alabaster and Robert Southwell among others, the Seventeenth Century was abundant in religious poets which included such noteworthy poets as John Donne, George Herbert, Richard Crashaw, Henry Vaughan, Thomas Traherne, let alone John Milton. The above mentioned poets with the exception of Milton(who cannot be confined in a small group) are usually classified as Metaphysical poets, and curiously enough all of them wrote the first class religious poems. Donnes later works, the whole body of Herberts poems, most of Crashaws and Vaughans works and all of Trahernes works are religious poems. Especially in Vaughans case he used to be regarded as an unimportant imitator of Donnes love poems whereas his later religious lyrics were highly praised as excellent works. Their common characteristics can be summed up as simplicity, plainness, directness, concreteness and sincerity. These are drawn from the English Bible. Herbert learned his simplicity and plainness from the Bible and followed Biblical example when he used homely images. His poetic statements may seem simple and plain but they contain profound truth. Vaughans religious awakening leads to his poetic awareness which makes him aware of profound meaning behind everyday matter of experiences surrounded by natural beauty. T.S. Eliot once praised Herbert as a major poet who was sincere and true to his own religious experience. "The great danger, for the poet who would write religious verse, is that of setting down what he would like to feel rather than be faithful to the experience of what he really feels. Of such pious insincerity Herbert is never guilty." Seventeenth Century Metaphysical poets religious poems are exempt from such insincerity and true to their own religious experiences. That is why their religious poems do not lose their attractions, still now.

The English Bible and the seventeenth century English prose

李懃燮 이화여자대학교 한국문화연구원 1964 韓國文化硏究院 論叢 Vol.5 No.-

초록없음

이상 탐지를 위한 시스템콜 시퀀스 임베딩 접근 방식 비교

이근섭,박경선,김강석 중소기업융합학회 2022 융합정보논문지 Vol.12 No.2

최근 지능화된 보안 패러다임의 변화에 따라, 다양한 정보보안 시스템에서 발생하는 각종 정보를 인공지능 기반 이상탐지에 적용하기 위한 연구가 증가하고 있다. 따라서 본 연구는 로그와 같은 시계열 데이터를 수치형 특성인 벡터로 변환하기 위하여 딥러닝 기반 Word2Vec 모델의 CBOW와 Skip-gram 추론 방식과 동시발생 빈도 기반 통계 방식을 사용하여 공개된 ADFA 시스템콜 데이터에 대하여, 벡터의 차원, 시퀀스 길이 및 윈도우 사이즈를 고려한 다양한 임베딩 벡터로의 변환에 대한 실험을 진행하였다. 또한 임베딩 모델로 생성된 벡터를 입력으로 하는 GRU 기반 이상 탐지 모델 을 통해 탐지 성능뿐만 아니라 사용된 임베딩 방법들의 성능을 비교 평가하였다. 통계 모델에 비해 추론 기반 모델인 Skip-gram이 특정 윈도우 사이즈나 시퀀스 길이에 치우침 없이 좀 더 안정되게(stable) 성능을 유지하여, 시퀀스 데이 터의 각 이벤트들을 임베딩 벡터로 만드는데 더 효과적임을 확인하였다. Recently, with the change of the intelligent security paradigm, study to apply various information generated from various information security systems to AI-based anomaly detection is increasing. Therefore, in this study, in order to convert log-like time series data into a vector, which is a numerical feature, the CBOW and Skip-gram inference methods of deep learning-based Word2Vec model and statistical method based on the coincidence frequency were used to transform the published ADFA system call data. In relation to this, an experiment was carried out through conversion into various embedding vectors considering the dimension of vector, the length of sequence, and the window size. In addition, the performance of the embedding methods used as well as the detection performance were compared and evaluated through GRU-based anomaly detection model using vectors generated by the embedding model as an input. Compared to the statistical model, it was confirmed that the Skip-gram maintains more stable performance without biasing a specific window size or sequence length, and is more effective in making each event of sequence data into an embedding vector.

[문화] 꽃 노래

이근섭 새가정사 1971 새가정 Vol.- No.-