• 인문언어
• /
• 제1권2호
• /
• pp.197-217
• /
• 2001

The literary products of Authors Under the Service of the Army during the Korean War have been neglected on the whole because of the perception that they were little more than war propaganda. The majority of the works (poetry, serial novels, and short stories) Published by these authors in various Army publications such as Junsunmunhak (Literature of the War Front) and Comet, as well as in regular literary periodicals, supports this perception. Most of these works convey simplistic emotions and stereotypes that project untroubled patriotism and strongly antipathetic sentiments against to the Communist North. The appointed leader of this group, Dock-Kyun Choi regarded the pen as another form of weapon to be used against the Communists in the North, and did not shy away from describing in graphic details the atrocities committed by his enemies. But what truly deserves our attention is the fact that many of the same authors who wrote highly propagandistic works also wrote works that can only be described as antiwar. In these works are depicted as faithfully as possible the human sufferings of the war. These works resist and even question the very ideologies that have brought about the conflict, focusing instead on the dark side of the war -the horrifying deaths, the separation of families, and the displacement of people from their homes, How we are to interpret this ambivalence in many of these authors is a task that remains to be carried out. We must approach these works with more seriousness and begin by comparing them with similar products from authors under the service of the Navy and the Air Force during the Korean War.

• Bulletin of the Korean Chemical Society
• /
• 제28권6호
• /
• pp.947-952
• /
• 2007

Mycobacterium tuberculosis is a pathogen responsible for 2-3 million deaths every year worldwide. The emergence of drug-resistant and multidrug-resistant tuberculosis has increased the need to identify new antituberculosis targets. Acetohydroxy acid synthase, (AHAS, EC 2.2.1.6), an enzyme involved in branched-chain amino acid synthesis, has recently been identified as a potential anti-tuberculosis target. To assist in the search for new inhibitors and “receptor-based” design of effective inhibitors of tubercular AHAS (TbAHAS), we constructed four different structural models of TbAHAS and used one of the models as a target for virtual screening of potential inhibitors. The quality of each model was assessed stereochemically by PROCHECK and found to be reliable. Up to 89% of the amino acid residues in the structural models were located in the most favored regions of the Ramachandran plot, which indicates that the conformation of each residue in the models is good. In the models, residues at the herbicide-binding site were highly conserved across 39 AHAS sequences. The binding mode of TbAHAS with a sulfonylurea herbicide was characterized by 32 hydrophobic interactions, the majority of which were contributed by residue Trp516. The model based on the highest resolution X-ray structure of yeast AHAS was used as the target for virtual screening of a chemical database containing 8300 molecules with a heterocyclic ring. We developed a short list of molecules that were predicted to bind with high scores to TbAHAS in a conformation similar to that of sulfonylurea derivatives. Five sulfonylurea herbicides that were calculated to efficiently bind TbAHAS were experimentally verified and found to inhibit enzyme activity at micromolar concentrations. The data suggest that this time-saving and costeffective computational approach can be used to discover new TbAHAS inhibitors. The list of chemicals studied in this work is supplied to facilitate independent experimental verification of the computational approach.

• 대한조선학회논문집
• /
• 제56권6호
• /
• pp.488-496
• /
• 2019

The estimation of block erection work time at a dock is one of the important factors when establishing or managing the total shipbuilding schedule. In order to predict the work time, it is a natural approach that the existing block erection data would be used to solve the problem. Generally the work time per unit is the product of coefficient value, quantity, and product value. Previously, the work time per unit is determined statistically by unit load data. However, we estimate the work time per unit through work time coefficient value from series ships using machine learning. In machine learning, the outcome depends mainly on how the training data is organized. Therefore, in this study, we use 'Feature Engineering' to determine which one should be used as features, and to check their influence on the result. In order to get the coefficient value of each block, we try to solve this problem through the Ensemble learning methods which is actively used nowadays. Among the many techniques of Ensemble learning, the final model is constructed by Stacking Ensemble techniques, consisting of the existing Ensemble models (Decision Tree, Random Forest, Gradient Boost, Square Loss Gradient Boost, XG Boost), and the accuracy is maximized by selecting three candidates among all models. Finally, the results of this study are verified by the predicted total work time for one ship among the same series.

• 한국지능시스템학회논문지
• /
• 제21권6호
• /
• pp.692-697
• /
• 2011

로봇의 이동성 향상을 위해 다양한 환경에 적응할 수 있는 로봇의 연구 개발이 활발하게 진행되고 있다. 본 논문에서는 휠(wheel)과 다리(Leg)기반 변형이 가능하고, 로봇간 상호 결합이 가능한 복합 이동형 로봇을 제안하였다. 복합 이동형 로봇은 로봇간 결합을 위해 페그 모듈과 컵 모듈을 로봇의 전면과 후면에 각각 장착하고, 주행과 보행이 가능하도록 구현하였다. 다양한 지형에서 이동성을 향상을 위해 임베디드 영상기반 결합 및 분리 알고리즘을 제안하였으며, 로봇간 결합을 통해 끊어진 도로와 비평탄 지형에서의 결합 이동 방법을 제안하였다. 제안한 방법은 로봇의 전면과 밑면에 장착된 PSD 센서를 이용하여 지형을 인식하고, 지형에 맞은 극복 알고리즘을 통해 로봇간 협력을 통해 이동성을 향상시킨다. 제안한 방법들은 임베디드시스템 기반의 복합 주행 이동형 로봇을 실제 제작하여 실험 통해 성능을 검증하였다.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2002년도 추계학술대회 논문집
• /
• pp.142-148
• /
• 2002

Autonomous underwater vehicles (AUVs) are unmanned underwater vessels to investigate sea environments, oceanography and deep-sea resources autonomously. Docking systems are required to increase the capability of the AUVs to recharge the batteries and to transmit data in real time for specific underwater works, such as repeated jobs at sea bed. This paper presents a visual servo control system for an AUV to dock into an underwater station with a camera mounted at the nose center of the AUV. To make the visual servo control system, this paper derives an optical flow model of a camera, where the projected motions of the image plane are described with the rotational and translational velocities of the AUV. This paper combines the optical flow equation of the camera with the AUVs equation of motion, and derives a state equation for the visual servoing AUV. This paper proposes a discrete-time MIMO controller minimizing a cost function. The control inputs of the AUV are automatically generated with the projected target position on the CCD plane of the camera and with the AUVs motion. To demonstrate the effectiveness of the modeling and the control law of the visual servoing AUV, simulations on docking the AUV to a target station are performed with the 6-dof nonlinear equations of REMUS AUV and a CCD camera.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2003년도 춘계학술대회 논문집
• /
• pp.89-93
• /
• 2003

The Korea Research Institute of Ships and Ocean Engineering (KRISO), the ocean engineering branch of KORDI, has designed and manufactured a model of an autonomous underwater vehicle (AUV) to test underwater docking. This paper introduces the AUV model, ASUM, equipped with a visual servo control system to dock into an underwater station with a camera and motion sensors. To make a visual servoing AUV, this paper implemented the visual servo control system designed with an augmented state equation, which was composed of the optical flow model of a camera and the equation of the AUV's motion. The system design and the hardware configuration of ASUM are presented in this paper. A small long baseline acoustic positioning system was developed to monitor and record the AUV's position for the experiment in the Ocean Engineering Basin of KRISO, KORDI. ASUM recognizes the target position by processing the captured image for the lights, which are installed around the end of the cone-type entrance of the duct. Unfortunately, experiments are not yet conducted when we write this article. The authors will present the results for the docking test of the AUV in near future.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
• /
• pp.275-279
• /
• 2006

부산항 북항은 일제 강점기에 축조된 일반부두(1,2,중앙,3,4)에서 시작하여 자성대, 신선대, 감만 부두 등으로 확장되었다. 그러나 도심과 접합 항만의 입지적 특성으로 인하여 물류 활동 및 도시 활동 양 측면에서 문제가 대두되어 왔다. 장치장 부족으로 인한 부두밖 장치장(ODCY) 확대가 대표적이다. 이것은 물류비용 증가뿐만 아니라 우암로, 충장로 등 주요 간선 도로상의 화물 차량 비중을 높이는 결과를 가져와서 심각한 사회 문제가 되고 있다. 본 연구는 일반부두와 자성대부두 재개발로 인한 충장로, 우암로 등 인접 주요 간선도로의 통행량 감소 효과를 분석하고 그동안 차량 통행으로 발생된 교통혼잡으로 인한 사회적 비용의 절감효과를 분석하여 두 부두의 재개발로 인한 효과를 제시하는데 목적이 있다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2018년도 춘계학술대회
• /
• pp.228-229
• /
• 2018

선박의 대형화와 더불어 증가하는 컨테이너 물동량을 처리하기 위해 부산항은 글로벌 인프라를 조성, 신설 부두 추진, 항만의 개발 등 다양한 시각으로 노력하고 있다. 부산항이 향후 대형 선박 접안에 대비하여 인프라를 갖출 수 있다면 20,000TEU 이상 선박의 작업도 가능할 것이며, Megamax 시대의 중심 항만으로 성장할 수 있을 것이다. 하지만, 대형 선박 접안시 많은 선석과 장비, 작업시간이 필요하기 때문에 선박의 체선문제가 발생할 수 밖에 없다. 이에 따라, 본 연구에서는 시뮬레이션을 통해 대형선박 접안이 컨테이너 터미널 체선에 미치는 영향을 분석하고자 한다.

• 방송공학회논문지
• /
• 제9권4호
• /
• pp.371-383
• /
• 2004

본 논문에서는 단일 주파수 망(Single Frequency Network: SFN)을 통해 ATSC(Advanced Television Systems Committee) 지상과 디지털 TV 방송을 서비스하기 위해 필요한 기술적인 요구 사항에 대하여 고찰하고, 기존 디지털 동일 채널 중계기(Digital On-Channel Repeater: DOCK)가 가지는 단점을 극복한 등화형 동일 채널 중계기(Equalization Digital On-Channel Repeater: EDOCR)를 제안한다. EDOCR은 오류정정(Forward Error Correction: FEC) 복호 및 부호화부를 사용하지 않기 때문에 모호성(ambiguity) 문제가 발생하지 않아서 EDOCR의 입력 신호와 출력 신호가 동일하며, 고성능 등화기를 사용하여 주송신기와 EDOCR 사이의 전송로에 의해 야기된 잡음 및 다중경로 신호를 제거하므로 EDOCR 출력 신호의 품질이 입력 신호 보다 우수하다. 또한 낮은 안테나 격리도(isolation)로 인해 야기된 궤환(feedback) 신호를 EDOCR 등화기에서 제거할 수 있기 때문에 송신 출력을 높일 수 있다.

• 한국주조공학회지
• /
• 제27권1호
• /
• pp.31-35
• /
• 2007

본 연구에서는 Mg합금의 반응고성형 공정기술을 개발하기 위하여 여러 가지 전단속도와 냉각속도에 따른 Mg합금의 점도와 딕소트러픽 거동을 분석하였으며, 이를 전산모사연구와 비교 검토하였다. 전산모사연구에서는 미세조직과 공정변수를 고려한 반응고 슬러리의 유변학적 거동을 분석하였다. 반응고 온도영역에서의 Mg합금(AZ91D) 슬러리의 점도는 고상율에 따라 지수함수적으로 증가하였으며, 전단속도가 증가하면 감소하는 경향을 나타났다. Mg합금 슬러리의 유변학적 거동을 정확하게 분석하기 위하여 Carreau 모델을 사용하여 ANYCAST 프로그램에서 고압다이캐스팅용 금형으로의 Mg합금 반응고 슬러리의 충진거동을 모사하였다. 전산모사된 결과는 동일한 조건에서의 실제 실험결과와 잘 일치하였다.