저궤도 위성 통신을 위한 합성곱 신경망 기반의 4D-8PSK-TCM 설계

학위논문(석사)--아주대학교 일반대학원 :AI융합네트워크학과,2021. 21. Introduction 1 1.1 Background 1 1.2 Motivation 2 1.3 Contributions 3 1.4 Overview 4 2, Related Works 6 2.1 TCM 6 2.2 Low latency decoder 8 3. Design of 4D-8PSK-TCM 10 3.1 Transmitter 10 3.1.1 Differential encoder 10 3.1.2 Convolutional coder 13 3.1.3 Constellation mapper 14 3.2 Receiver 19 3.2.1 Transition metric unit 19 3.2.2 Viterbi decoder and symbol decision unit 20 3.2.3 De-mapper unit and differential decoder 23 3.3 Performance evaluation 23 4.Proposed Adaptive Decoder 28 4.1 T-algorithm 28 4.2 Convolutional neural network 32 4.3 Eb/N0 classification model 33 4.4 Performance evaluation 39 5,Conclusion 43 Reference 44MasterThe consultative committee for space data systems (CCSDS) recommends four dimensional eight-ary phase shift keying trellis coded modulation (4D-8PSK-TCM) for a high-speed transmission technology in the X-band. The 4D-8PSK-TCM can reduce computational complexity with T-algorithm that gains benefits by removing elements below the threshold.This thesis designs the digital communication system using 4D-8PSK-TCM and proposes adaptive decoder to maintain the bit error rate (BER) performance and minimize computational complexity for all intervals of energy per bit to noise spectral density ratio (Eb/N0). The designed system is applied with zero termination to prevent degradation of BER performance. The proposed adaptive decoder is applied with Eb/N0 classification model that optimize T-algorithm value by estimation of Eb/N0 of received signal using image generator and convolutional neural network (CNN). Moreover, this thesis compares the conventional 4D-8PSK-TCM and the 4D-8PSK-TCM using proposed adaptive decoder in terms of computational complexity and BER performance. The performance evaluation results show that proposed adaptive decoder can minimize to computational complexity while maintaining BER performance for all intervals of Eb/N0. It is expected that the proposed adaptive decoder can be used in low Earth orbit (LEO) satellite for low latency decoding

International Transfer of Tacit Knowledge: The Transmission of Shipbuilding Skills from Scotland to South Korea in the Early 1970s

This article analyzes the transfer of tacit knowledge between countries and continents, based on a case from the shipbuilding industry. The South Korean shipbuilder Hyundai Heavy Industries (HHI) was established in the early 1970s and had by the late 1980s become the world's leading shipbuilder. Aided by foreign loan capital, HHI acquired technology through foreign licenses and imported equipment. However, shipbuilding is about more than hardware. This article presents and analyzes another important means of knowledge transfer: the acquisition of tacit knowledge in the form of shipbuilding skills, including shipyard processes and operations. This transfer was mainly accomplished through the "import" of foreign managers and the dispatch abroad of South Korean employees. One important element, which we investigate in detail, was the Korean personnel that HHI sent in 1972 to the Scott Lithgow shipyards in Scotland to observe and learn. Based on archival sources and interviews, we detail the manner in which tacit knowledge could be transferred across language and cultural barriers

2014년 4개시도 금강정책공동연구회 제1회 워크숍'4대강 사업 이후의 물관리 과제와 전망'(배덕효,김송,이현정,이영근,조용모,허재영,최지용)

I 4대강 사업 조사·평가 추진경과 및 과제 □ 추진 경과 ㅇ 4대강 사업 시행 : `08.12∼`12.4 - 16개 보(한강 3, 낙동강 8, 금강 3, 영산강 2), 22.5조원 투입 ㅇ 4대강 사업에 대한 감사원 감사결과 발표 : `13.1.17 - 보 내구성 저하․수질개선 차질․유지관리 비용 과다 우려 등 ㅇ 감사원 발표이후, 시설물 안전 및 사업효과 등에 대한 논란이 확대됨에 따라학회 중심의 민간 점검․평가 계획 발표 : `13.2.15 - 총리실, 국토해양부, 환경부, 농식품부, 문화부 등 부처합동 * 일부 학회 공정성 문제로 학회 중심의 민간 점검․평가 계획에 대한 문제점 제기 ㅇ 대통령께서 민간위원회 구성을 통한 4대강 사업에 대한 철저 점검 지시 :`13.3(국무회의) ㅇ 중립적인(찬․반․중립인사 포함) 민간위원회를 구성하여 4대강 사업 조사․평가를 추진키로 결정 : `13.5.24(국가정책조정회의) - 이후 생략Ⅰ. 주제발표 발표 1. 4대강사업 조사평가위원회 활동 결과 발표 2. 4대강사업 이후의 물관리 전망과 비전 발표 3. 4대강의 미래와 재자연화 발표 4. 일본의 물순환기본법 제정 동향과 시사점 Ⅱ. 토