• 한국전자파학회논문지
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• 제24권10호
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• pp.958-963
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• 2013

본 논문에서는 세라믹을 이용한 유전체 도파관 듀플렉서를 제안한다. 송신단과 수신단 대역 통과 필터를 설계한 후, 상호 간섭이 최소화되도록 결합하여 듀플렉서를 완성한다. 본 논문에서 제안한 안테나단 설계 방법으로는 분배기를 이용하여 투과 손실을 결정하고, 간섭을 피하기 위해 송수신 필터의 공진기 길이를 보정한다. 제작시 상대 유전율이 9.46인 세라믹을 이용하였으며, SMD 형태로 PCB에 표면 실장이 가능하도록 한다.

• 로봇학회논문지
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• 제19권1호
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• pp.58-64
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• 2024

The ability of the robot gripper to handle a wide range of objects significantly impacts its operational effectiveness. Among the robot grippers commonly used, the economically feasible choice is the relatively simple structure of a parallel gripper. To perform more densely packed tasks with a parallel gripper, it should be capable of handling small objects. Therefore, this study designs a parallel gripper mechanism equipped with assisting grippers to ensure smooth grasping of small objects. The parallel gripper is designed using a rack and pinion gear system, with two additional grippers on both side, and these assisting grippers are designed to be detachable. The two assisting grippers have different type of tip to grasp thin fabric shapes and thin stick shapes. The gripper prototype is used to verify the grasping capabilities for shapes achievable with a conventional parallel gripper and those intended for grasping with the assisting grippers through grasping experiments. Consequently, by equipping a conventional parallel gripper with assisting grippers as in this study, it becomes capable of handling a broader range of objects, in addition to its existing functionality.

• 대한인간공학회지
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• 제29권4호
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• pp.521-525
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• 2010

UX (User Experience) Design was an interdisciplinary approach in humanities, engineering, science and design. We classified the roles of user experience; requirement analysis which are user research, constraints analysis and direction analysis, concept design, information architecture, physical UI, graphical UI, sound UI, Olfactory UI, prototype, evaluation, launch, localization, and knowledge management/UI DB. User research methods were classified by the relation of designer, user, and product/service. We reviewed three issues of UX design; complexity management, efficiency management, and mapping management.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 춘계학술발표대회
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• pp.485-487
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• 2023

컴퓨터 비전의 하위 태스크(Task)인 의미론적 분할(Semantic Segmentation)은 자율주행, 해상에서 선박찾기 등 다양한 분야에서 연구되고 있다. 기존 FCN(Fully Conovlutional Networks) 기반 의미론적 분할 모델은 다운샘플링(Dowsnsampling)과정에서 공간정보의 손실이 발생하여 정확도가 하락했다. 본 논문에서는 공간정보 손실을 완화하고자 PSA(Polarized Self-attention)의 공간정보 강조 모듈을 HRNet(High-resolution Networks)의 합성곱 블록 사이에 추가한다. 실험결과 파라미터는 3.1M, GFLOPs는 3.2G 증가했으나 mIoU는 0.26% 증가했다. 공간정보가 의미론적 분할 정확도에 영향이 미치는 것을 확인했다.

• Computers and Concrete
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• 제30권1호
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• pp.75-83
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• 2022

This study introduced a post-tensioned precast concrete system that was developed and designed to improve the performance of joints by post-tensioning. Full-scaled specimens were tested to investigate flexural performances at the negative moment region, where the test variables were the presence of slabs, tendon types, and post-tensioned lengths. A specimen with slabs exhibited significantly higher stiffness and strength values than a specimen without slabs. Thus, it would be reasonable to consider the effects of a slab on the flexural strength for an economical design. A specimen with unbonded mono-tendons had slightly lower initial stiffness and flexural strength values than a specimen with bonded multi-tendons but showed greater flexural strength than the value specified in the design codes. The post-tensioned length was found to have no significant impact on the flexural behavior of the proposed post-tensioned precast concrete system. In addition, a finite element analysis was conducted on the proposed post-tensioned precast concrete system, and the tests and analysis results were compared in detail.

• Ocean Systems Engineering
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• 제9권1호
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• pp.79-95
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• 2019

The material analysis of an offshore structure is generally conducted in the contract design phase for the price quotation of a new offshore project. This analysis is conducted manually by an engineer, which is time-consuming and can lead to inaccurate results, because the data size from previous projects is too large, and there are so many materials to consider. In this study, the piping materials in an offshore structure are analyzed for contract design using a big data framework. The big data technologies used include HDFS (Hadoop Distributed File System) for data saving, Hive and HBase for the database to handle the saved data, Spark and Kylin for data processing, and Zeppelin for user interface and visualization. The analyzed results show that the proposed big data framework can reduce the efforts put toward contract design in the estimation of the piping material cost.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권4호
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• pp.335-352
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• 2012

An underwater hull cleaning robot can be a desirable choice for the cleaning of large ships. It can make the cleaning process safe and economical. This paper presents a hydrodynamic design of an underwater cleaning robot and its evaluation for an underwater ship hull cleaning robot. The hydrodynamic design process of the robot body is described in detail. Optimal body design process with compromises among conflicting design requirements is given. Experimental results on the hydrodynamic performance of the robot are given.

• 한국산업융합학회 논문집
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• 제22권6호
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• pp.649-655
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• 2019

Fracture behaviors of SCM435 high strength bolt have been studied including macroscopic and microscopic fracture observation, Energy Dispersive X-ray Spectroscopy, Vickers hardness test and applied stress evaluation. cracks (ratchet marks) were generated by the repetitive loads acting on the bolts, initial stress of bolt and the stress concentration. The applied stress was found to be slightly higher than the fatigue limit of the material. The initial stress of bolt must be removed, and the mold temperature during the process must be maintained by room temperature. Bolts are recommended to be peened to improve fatigue limit.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.1-11
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• 2013

The investigation on wind farm design using CFD technique was carried out to reduce turbulence intensity in a wind farm. A potential wind farm in Gasiri of Jeju Island was selected for the design and the commercial S/W of Meteodyn WT was used for applying CFD technique. The initial layout of wind turbines was derived using WindPRO which is mainly used for wind farm design in Korea. Then, the distribution of turbulence intensity on complex terrain was calculated and visible by Meteodyn WT. Based on the distribution, wind turbines were positioned properly. As a result, wind turbines could be deployed at positions with minimum turbulence intensity as well as maximum Annual Energy Production, AEP, using Meteodyn WT. It is necessary to take into account turbulence intensity in wind farm design to avoid wind turbine failure.

• 한국정보통신학회논문지
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• 제18권5호
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• pp.1201-1206
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• 2014

소규모 상점은 상품 관리를 대부분 수기에 의존하고 있다. 이러한 수기 관리는 다양한 제품의 입출고 현황을 관리하는데 제한적이며 실시간 상품현황 관리는 별도의 통계 시스템을 이용해야 한다. 이러한 문제점을 해결하기 위해 개발된 기존의 POS 시스템은 고가의 비용 및 공간의 제약으로 중대형 및 특수매장 위주로 운용되고 있다. 이 때문에 소규모 상점의 수기에 의한 상품관리 대신 비용부담이 적지만 자동화된 새로운 상품관리 시스템이 필요하다. 본 논문에서는 NFC 기능을 탑재한 스마트폰을 활용하여 소규모 상점에서 판매되는 상품을 실시간으로 관리할 수 있는 시스템을 개발하였다.