• 대한조선학회논문집
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• 제51권3호
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• pp.203-211
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• 2014

To raise the industrial competitiveness in the field of ship-building, it is crucially important that the yard should use production facilities and working space effectively. Among the related works, the management of tremendous blocks' number, the limited area of assembly shops and inefficient personnel and facility management still need to be improved in terms of being exposed to a lot of problems. To settle down these conundrums, the various strategies of block arrangement on the assembly floors have been recently presented and in the results, have increasingly began to be utilized in practice. However, it is a wonder that the sampled or approximated block shapes which usually are standardized projections or the geometrically convex contour only have been prevailed until now. In this study, all parts including the panel, stiffeners, outer shells, and all kinds of outfitting equipment are first extracted using the Volume Primitive plug-in module from the ship customized CAD system and then, the presented system constructs a simpler and more compact ship data structure and finally generates the novel projected contours for the block arrangement system using the adaptive concave hull algorithm.

• 대한조선학회논문집
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• 제43권1호
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• pp.87-95
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• 2006

There are hundreds of ship blocks which are under the block assembly, painting, and outfitting assembly works in the pre-erection shops of shipyard. Generally, each block is planned to be processed in a pre-erection shop according to the block type by the long-term production-scheduling before six months. However, many blocks can't be processed in the planned time and the planned shop since the before and after block-processing changes or delays the planned sequential works in pre-erection shops. Therefore, it is essential to monitor the current location of each block and work in process to cope with the changed situation of pre-erection shops. Present study integrates PDA, GPS, and CDMA not only to chase the location of each block but also to exchange the pre-erection work order and the work report between the production-scheduling server and the production managers in the pre-erection shops. This study shows a prototype for the block tracing and process monitoring in the pre-erection shops.

• 대한산업공학회지
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• 제39권6호
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• pp.577-586
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• 2013

In a shipyard, it is hard to predict block movement due to the uncertainty caused during the long period of shipbuilding operations. For this reason, block movement is rarely scheduled, while main operations such as assembly, outfitting and painting are scheduled properly. Nonetheless, the high operating costs of block movement compel task managers to attempt its management. To resolve this dilemma, this paper proposes a new block movement analysis framework consisting of the following operations: understanding the entire process, log clustering to obtain manageable processes, discovering the process model and detecting exceptional processes. The proposed framework applies fuzzy mining and trace clustering among the process mining technologies to find main process and define process models easily. We also propose additional methodologies including adjustment of the semantic expression level for process instances to obtain an interpretable process model, definition of each cluster's process model, detection of exceptional processes, and others. The effectiveness of the proposed framework was verified in a case study using real-world event logs generated from the Block Process Monitoring System (BPMS).

• 한국정보통신학회논문지
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• 제18권9호
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• pp.2079-2086
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• 2014

조선소에서 생산관리는 생산성 향상과 가장 밀접한 업무 중의 하나이다. 현업 생산관리자와 공정계획 엔지니어들은 상호 간의 정보 공유 미흡으로 인해 공정계획 및 공정관리에 대한 충분한 생산정보를 얻지 못한다. 본 연구에서는 생산계획과 공정관리의 요구사항 분석을 통하여 생산공정모니터링 시스템에 대한 주요 이슈를 도출하고, 콤포넌트 기반 설계 기법을 활용하여 시스템 아키텍처를 수립하였다. 제안한 시스템의 주요 기능은 블록 조립에서 안벽의장 단계까지 수립하여 생산공정현황을 시각적으로 보여 줄 뿐 아니라 공정정보 공유를 극대화하는 것이다. 본 시스템은 생산관리자에게 신뢰성 있고 정확한 생산 정보를 제시간에 제공할 수 있을 것으로 기대된다.

• 한국해양공학회지
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• 제34권3호
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• pp.217-226
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• 2020

An offshore plant is an offshore platform that can process oil and gas resources in rough seas with a poor working environment. Moreover, it is a complex structure with different types of offshore facilities and a large amount of outfitting that connects different offshore installations. In particular, an enormous amount of various piping materials is installed in a relatively narrow space, and thus, the difficulty of working is relatively high compared to working in ships or ground plants. Generally, when the 3D detailed design is completed, an offshore plant piping process is carried out at the shipyard with ISO 2D fabrication drawings and ISO 2D installation drawings. If a worker wants to understand the three-dimensional piping composition in the working area, he can only use three-dimensional viewers that provide limited functionality. As offshore plant construction progresses, correlating work with predecessors becomes more complicated and rework occurs because of frequent design changes. This viewer function makes it difficult to identify the 3D piping structure of the urgently needed part. This study deals with the process support method based on a system using a 3D simulator to improve the efficiency of the piping process. The 3D simulator is based on the Unity3D engine and can be simulated by considering the classification and priority of 3D models by the piping process in the system. Further, it makes it possible to visualize progress information of the process. In addition, the punch content can be displayed on the 3D model after the pipe inspection. Finally, in supporting the data in relation to the piping process, it is considered that 3D-simulator-supported piping installing could improve the work efficiency by more than 99% compared to the existing method.

• 센서학회지
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• 제20권2호
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• pp.137-144
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• 2011

Wireless sensor network(WSN) has the potential to greatly effect many aspects of u-healthcare. By outfitting the potential with WSN, wearable sensor node can collects real-time data on physiological status and transmits through base station to server PC. However, there is a significant gap between WSN and healthcare. WSN has the limited resource about computing capability and data transmission according to bio-sensor sampling rates and channels to apply healthcare system. If a wearable node transmits ECG and accelerometer data of 4 channel sampled at 100 Hz, these data may occur high loss packets for transmitting human activity and ECG to server PC. Therefore current wearable sensor nodes have to solve above mentioned problems to be suited for u-healthcare system. Most WSN based activity and ECG monitoring system have been implemented some algorithms which are applied for signal vector magnitude(SVM) algorithm and ECG noise algorithm in server PC. In this paper, A wearable sensor node using integrated ECG and 3-axial accelerometer based on wireless sensor network is designed and developed. It can form multi-hop network with relay nodes to extend network range in WSN. Our wearable nodes can transmit 1-channel activity data processed activity classification data vector using SVM algorithm to 3-channel accelerometer data. ECG signals are contaminated with high frequency noise such as power line interference and muscle artifact. Our wearable sensor nodes can remove high frequency noise to clear original ECG signal for healthcare monitoring.

• 한국추진공학회지
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• 제21권1호
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• pp.44-50
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• 2017

지상고정장치는 발사체 엔진의 추력이 정상상태에 도달할 때까지 발사체를 발사대에 고정시켜주는 역할을 한다. 본 연구에서는 지상고정장치에 적용되는 구동 유압실린더의 형상 및 운동 특성에 대한 해석적 연구를 수행하였다. 유압 실린더의 수축 운동은 분리 동작에 가장 중요한 요소로서, 해석 결과 실린더의 slit 면적이 축소되고 초기 충전 압력이 증가될수록 수축 하중이 증가함을 확인하였다. 이를 통해 최적화된 slit 면적과 초기 충전압력을 결정하였다. Transient 해석을 통해 실린더가 수축 시 발생하는 하중, 변위, 내부 압력분포를 확인하였다. 해석 결과 실린더가 발생시키는 하중은 실린더에 작용하는 외력과 동일한 값을 발생시키는 것을 확인하였다. 또한 실린더가 운동하는 중에 실린더 내부의 압력분포는 일정한 것을 확인할 수 있었다.

• 정보기술응용연구
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• 제1권
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• pp.99-127
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• 1999

최근 기업의 생산성 향상을 위한 설계 및 생산 환경의 분산화에 따른 원격지 공동설계의 필요성이 증대되고 있다. 마찬가지로 선박설계 과정도 그 과정이 매우 복잡하고 많은 양의 데이터를 다루고 있는 작업으로서 그 환경이 분산화, 이질화됨에 따라 최근 들어 CSCW (Computer Supported Collaborative Work)의 요구가 증대되고 있다. 본 논문에서는 분산된 선박설계 환경에서의 원격지 공동설계를 지원하기 위한 에이전트기반 선박설계 시스템을 개발하였다. 특히 여기서는 에이전트간의 정보교환 및 지식공유 과정에서 발생하는 의사충돌 문제를 해결하기 위하여 사례기반 추론 기법을 이용하여 이의 해결을 시도하였다. 설계 에이전트, 이들을 중재하는 퍼실리테이터, 충돌 처리기, 그리고 사례기반 시스템의 유기적인 도움을 받아 설계자는 설계과정에서 발생하는 설계 시스템간의 의사충돌 문제에 대한 의사결정을 과거의 유사한 문제해결 사례로부터 효과적으로 처리할 수 있다.

• 한국소음진동공학회논문집
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• 제25권5호
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• pp.321-328
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• 2015

최근 극지 선박의 수요가 늘어나고 있고 IACS(국제선급연합)에서는 대빙 선박에 대한 새로운 기준이 적용되고 있다. 이 선박에서는 추진시스템에 대한 대빙 설계 기준으로 빙 충격 토크는 프로펠러 날개 수를 중심으로 한 조화 함수로 규정되어 있다. 그러나 실 상황에서는 이러한 주기적인 기진 토크보다는 불규칙한 빙의 충격 토크가 발생할 수 있는 확률이 오히려 크다. 이 논문에서는 비틀림진동이 비교적 큰 6개의 실린더를 갖는 디젤엔진을 주 기관으로 한 추진시스템의 안정성을 검토하고자 한다. 특히 불규칙한 빙 충격 토크와 디젤엔진에서 발생하는 진동토크를 동시에 고려하여 비틀림진동의 공진점을 통과할 과도 비틀림 진동 응답을 이론적으로 해석하였다. 여기서 빙 충격토크는 빙이 프로펠러에 부딪칠 때를 여러 유형별로 가상하여 선급에서 규정된 방법에 의해서 구하였다. 전체적인 시스템의 과도응답 해석은 직접적분방법의 하나인 뉴마크(Newmark) 법을 이용하였다.

• 대한조선학회논문집
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• 제55권1호
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• pp.66-74
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• 2018

In order to evaluate the precision degree of the blocks on the dock, the shipyards recently started to use the point cloud approaches using the 3D scanners. However, they hesitate to use it due to the limited time, cost, and elaborative effects for the post-works. Although it is somewhat traditional instead, they have still used the electro-optical wave devices which have a characteristic of having less dense point set (usually 1 point per meter) around the contact section of two blocks. This paper tried to expand the usage of point sets. Our approach can estimate the rework time to weld between the Pre-Erected(PE) Block and Erected(ER) block as well as the precision of block construction. In detail, two algorithms were applied to increase the efficiency of estimation process. The first one is K-mean clustering algorithm which is used to separate only the related contact point set from others not related with welding sections. The second one is the Concave hull algorithm which also separates the inner point of the contact section used for the delayed outfitting and stiffeners section, and constructs the concave outline of contact section as the primary objects to estimate the rework time of welding. The main purpose of this paper is that the rework cost for welding is able to be obtained easily and precisely with the defective point set. The point set on the blocks' outline are challenging to get the approximated mathematical curves, owing to the lots of orthogonal parts and lack of number of point. To solve this problems we compared the Radial based function-Multi-Layer(RBF-ML) and Akima interpolation method. Collecting the proposed methods, the paper suggested the noble point matching method for minimizing the rework time of block-welding on the dock, differently the previous approach which had paid the attention of only the degree of accuracy.