DNA methyltransferase 3B와 상호 결합하는 새로운 단백질들의 동정 및 기능에 관한 연구

Thesis(doctor`s)--서울대학교 대학원 :협동과정 종양생물학전공,2007.Docto

효율적인 어텐션 연산을 위한 근사기법의 적용

학위논문(석사)--서울대학교 대학원 :공과대학 컴퓨터공학부,2020. 2. 이재욱.With the increasing computational demand of the neural networks, many accelerators for neural networks have been proposed. Such existing neural network accelerators often focus on popular neural network types such as convolutional neural networks (CNNs) and recurrent neural networks (RNNs); however, not much attention has been paid to attention mechanisms, an emerging neural network primitive that enables neural networks to retrieve most relevant information from a knowledge-base, external memory, or past states. The attention mechanism is widely adopted by many state-of-the-art neural networks for computer vision, natural language processing, and machine translation, and accounts for a large portion of total execution time. We observe today's practice of implementing this mechanism using matrix-vector multiplication is suboptimal as the attention mechanism is semantically a content-based search where a large portion of computations ends up not being used. Based on this observation, we design and architect A2, which accelerates attention mechanisms in neural networks with algorithmic approximation.인공신경망 연산의 수요가 증가함에 따라 많은 인공신경망 가속기들이 제안되어 왔다. 대체로, 이러한 인공신경망 가속기들은 컨볼루션 신경망(CNN), 순환 신경망(RNN)과 같은 대중적인 종류의 신경망에 주목하고 있다. 반면 새로이 등장한 어텐션 신경망은, 외부 메모리에 저장된 과거의 정보로부터 가장 연관성 있는 정보를 도출하는 것을 가능케 했으나, 아직 충분히 주목받지 못하고 있다. 현재 어텐션 연산은 컴퓨터 비젼, 자연 언어 처리, 자동 번역 등 다양한 분야의 첨단 인공신경망에 적용되어 총 실행 시간의 높은 비중을 차지 하고 있다. 이 논문은 현재 실용되고 있는 행렬-벡터 연산을 통한 어텐션 연산의 구현이 최적이 아님을 밝힌다. 어텐션 연산은 내용 기반 검색에 해당하며 검색되지 않는 많은 부분의 연산이 실제로 쓰이지 못하기 때문이다. 이 사실에 기반하여, 이 논문에서 우리는 A2를 설계하여, 알고리즘 적인 근사를 통해 어텐션 연산을 가속한다.Introduction - 1 Background and Motivation - 3 Approximate Attention - 8 Evaluation - 15 Related Work - 19 Conclusion - 21 Bibilography - 22 국문초록 - 31Maste

Study on landscape planning system in rural village area : forcused on resoruce investigation and evaluation

학위논문 (박사)-- 서울대학교 대학원 : 협동과정 조경학, 2011.8. 양병이.Docto

Dandy-walker malformation associated with neurocutaneous melanosis

Neurocutaneous melanosis associated with Dandy-Walker malformation is a rare dysmorphogenesis that is associated with single or multiple giant pigmented cutaneous nevi and diffuse involvement of the central nervous system. In this article, we present a 2-month-old patient with neurocutaneous melanosis associated with Dandy-Walker malformation. In addition, we reviewed the literature and discussed the pathogenesis based on the preferred hypotheses. © 2011 The Korean Neurosurgical Society

Usefulness of silicone elastomer sheet as another option of adhesion preventive material during craniectomies

Objective: We describe the use of a silicone elastomer sheet (SILASTIC®) to prevent peridural fibrosis in patients who underwent a craniectomy and a subsequent cranioplasty. Materials and methods: We performed a decompressive craniectomy and a subsequent cranioplasty with an autologous bone flap in 50 patients (mean age, 40 years) between 1996 and 2005 at our institution. Most of the craniectomies were performed as an emergency procedure for relief of brain swelling. The standard decompressive craniectomy technique that we performed included bone removal and a duroplasty in 26 of the 50 patients, however, a SILASTIC® sheet was added to the standard decompressive craniectomy in the remaining patients in an attempt to prevent dural adhesions. The development of adhesion formation between the tissue layers was evaluated during the cranioplasty in terms of operative time and the amount of blood loss. Results: During the cranioplasty, we observed that the SILASTIC® sheet succeeded in creating a controlled dissection plane, which facilitated access to the epidural space, shortened the operative time by approximately 24.8% and diminished the intraoperative blood loss by 37.9% as compared with the group of patients who underwent the standard cranioplasty. These differences were statistically significant (p < 0.05). Conclusions: The use of a SILASTIC® sheet to prevent peridural scarring and to facilitate cranioplasty in patients who have previously undergone a craniectomy is a good technique, regardless of the procedural indication. © 2007 Elsevier B.V. All rights reserved