Earticle

플로팅 구조물은 열악한 해양환경상태에 있기 때문에 구조물응답에 대한 실시간 모니터링 기술을 적용하여 구조안전성을 확보하여야 한다. 이 논문에서는 플로팅 구조물의 거동을 알아보기 위해 플로팅 구조물의 하부 구조물 축소모델을 제작하여 광섬유센서를 부착하고 하중을 적용시켜 축소모델의 거동을 측정한다. 유한요소 법에 의한 해석결과와 실험결과를 비교분석하여 광섬유센서를 이용한 플로팅구조물의 모니터링에 대한 적용 성을 알아보고자 한다. FBG센서를 이용한 플로팅 구조물 축소 모델의 변형률을 광학 스펙트럼 분석기를 이용하여 측정하였을 때 하 중 작용에 따른 중심파장 스펙트럼이 실시간으로 출력되어 축소모델 상부 판의 거동을 하중 적용과 동시에 확 인 할 수 있었으며, 광섬유센서를 이용하여 플로팅 구조물의 변형특성을 잘 나타낼 수 있음을 확인하였다.

Floating structures have to meet structural safety applying real-time monitoring technology because they are in a state of very poor ocean conditions. In this study, Fiber Bragg Grating (FBG) sensors were attached to the scaled model of floating structure and the scaled model's wavelength was measured by optical spectrum analyzer for monitoring a behavior of floating structure. The results of experiment was compared with those of finite element analysis using ABAQUS program. It could confirm behaviors of upper plate of the scaled model because wavelength spectrum according to load application can be demonstrated instantly and the strain characteristics of floating structure are well presented using fiber optic sensor.

In general, the semi-rigid connections are preferred for low rise structure. If semi-rigid connections are used for floating structure, the additional moments due to wave loads can be reduced and more economical construction will be possible. In this study, the moment-rotation relationship of semi-rigid connections are assumed by the power model that have three parameters such as initial stiffness, ultimate moment capacity, and shape coefficient of the connection. In order to conduct the probability analysis of semi-rigid frames, the monte-carlo method is used. In this study, the lateral drifts can be predicted though the stochastic method.

지구 온난화로 인한 해수면 상승과 도시팽창에 의한 토지 부족 문제를 해결하기 위해 부유식 해양도시 건설에 대한 관심이 증가하고 있다. 해수면 상승으로 위협받 는 몇몇 도서국가에서는 해양도시 건설을 추진하고 있다. 부유식 해양도시는 기존의 매립 방식보다 한층 어려운 기술력이 필요하고 해상여 건의 제약 요인이 있지만, 지난 수십 년 동안 연구와 기술이 축적되면서 충분히 실 현이 가능한 것으로 평가되고 있다. 그러나 이와 관련된 법적 쟁점에 대한 연구가 미흡한 실정이다. 해양도시는 연안 국의 관할 해수면에서 건설되기 때문에 완전한 주권이 미치는 육지와 달리 국제해양 법에 따른 고려가 필요하다. 유엔해양법협약이나 다른 국제조약은 해양도시라는 새 로운 형태에 대한 해양지형의 출현을 예상하지 못했기 때문에 입법적인 미비가 있다. 국내법에서도 해양구조물을 이용한 건축물이나 시설에 대해 입법적 공백이 남아있다. 우리나라 건축법에서 부유식 건축물에 대한 조항이 신설되었으나 부유식 건축물이 나 시설에 대한 권리행사를 명확히 하기에는 미흡한 실정이다. 새로운 형태의 해양지 형을 수용하고 국제법적 틀에서 규율할 수 있도록 유엔해양법협약에 반영하거나 새로 운 조약의 채택이 필요하다고 본다. 국내법적으로는 부유식 건축물에 대한 건설을 지 원하고 권리행사 관계를 명확히 하는 특별법 성격의 법제 마련을 서둘러야 한다.

The needs for building floating cities have been growing under the circumstances that global warming has led to the sea level rise and many coastal cities are facing the scarcity of land due to the urban crawl. Some island countries threatened by the sea level rise are engaged in the building of floating cities. The building of floating cities is more difficult than a way of reclamation and is also subject to the sea conditions. However, it is viewed that technology advances over years enable the building of floating cities highly feasible in technical terms. Nonetheless it appears that research efforts on legal issues concerning floating cities have not been paid much attention. The issues concerning the law of the sea need to be reviewed, since floating cities are built in the sea under the jurisdiction of the coastal state, unlike the land under a full sovereignty control of the coastal state. Since the UN Convention on the Law of the Sea and other treaties did not expect the emergence of floating cities when adopted, there exists a legal vacuum in international law. This is the same case in domestic legislations regulating buildings and installations employing floating structures. Although the 2016 amendment to the Building Act newly added the provision of ‘floating buildings,’ it is not sufficient to legally entitle and define rights and duties with regard to floating buildings and installations. UN Convention on the Law of the Sea needs to incorporate or a new international treaty needs to be adopted to accommodate the new form of maritime features. Domestically a special law that states the legal status of floating buildings need to be enacted.

This paper aims to review the development process and trends of floating structure through the chronological cases studies and to provide some reference ideas for new floating structure projects on water. Conclusions can be summarized as followings; early houseboats have developed into almost all types of floating structures such as house, exhibition hall, hotel, ferry terminal, cafe, restaurant, prison, stadium, boat/yacht/kayak clubhouse, stage, event hall, office, garden, bridge, swimming pool, school, green house, dormitory, workshop, cultural center, visitor center around the world with extreme ups and downs; pontoon for floating structure is mainly made of concrete and mooring facility is dolphin in major with concrete or steel(development process); prefabrication and modular construction with factory production, minimum waste and little noise in site as physical aspect; environmental consideration with material usage, renewable energy application, water treatment system as environmental aspect; enhancement of social sustainability with unique and comfortable place, natural view, social and psychological sense, role of revitalization catalyst in declined area as social aspect(development trend)

Owing to climate change and global warming, the level of sea continuously rises with frequent and severe flooding. People prefer to live and enjoy leisure activities on the water according to the increased income level. So proper countermeasures such as floating technology are required. This paper aims to investigate the trends of floating technology application through the survey of floating structures in Europe and to suggest some reference ideas for the new structure planning on the water. The conclusions can be summarized as follows; gradual expansion of floating structures from low-income house to every kinds of structures, reinforcements of environment-friendly approaches through renewable energy usage and application of echo-friendly construction/material, catalyst usage of urban regeneration by providing the public space of recreation/social activities and recognition of landmark by sculpture-like shape. By applying the floating technology, large scale of floating city needs to be studied for preventing the disaster due to sea level rise and the expansion of human residential area.

Concrete pontoon of floating structure is transformed in accordance with wave loads. This transformation has an effect on the superstructure. As a result of depending on the stiffness variation of concrete pontoon and period of wave, moment of superstructure decreases according to the increasing stiffness of concrete pontoon, but the effect on the axial force is insignificant. If stiffness of concrete pontoon is same, moment of superstructure increases according to the increasing period of wave.

This paper presents vibration evaluation of floating structure which is located in Yeosu using acceleration responses data. In order to evaluate vibration usability, AIJ(1991) vibration performance criteria and ISO(2631-2) vibration criteria are considered. Natural frequency and acceleration responses are needed to apply those vibration criteria. Modal impact test was accomplished to obtain the floating structure's natural frequency. The acceleration responses from ambient vibration at 35 different points on a floating structure were measured. Then the first natural frequency and 35 points acceleration responses were applyed foreign vibration criteria for vibration evaluation of floating structure.

플로팅구조물은 육상에서와 다르게 파랑하중의 영향으로 상부구조물에 부가모멘트를 발생시키는데, 본 연구에서는 부가모멘트를 줄이기 위해 상부구조물에 반강접 접합을 적용한다. 반강접 접합은 실제구조물의 모멘트-회전거동을 파악하기 위해 주로 특정 실험을 통해 이뤄지고 있다. 본 논문에서는 모멘트-회전거동의 예측 모델식의 변수가 가지고 있는 불확실성을 확률이론에 입각한 신뢰성이론에 적용하여 구조물의 안전성 지표인 신뢰성지수와 파괴확률로 평가하여 플로팅구조물의 신뢰성해석을 위한 기초자료로 제공하고자 한다.

In general, the semi-rigid connections are preferred for low rise structure. If semi-rigid connections are used for floating structure, the additional moments due to wave loads can be reduced and more economical construction will be possible. In case of semi-rigid connection, it takes place mostly through specific experiment in order to identify actual structure’s moment-rotation. Thus, it is necessary to identify the structure’s movement by applying the uncertainty of the variables related to the moment-rotation relationship to the reliability theory based on the probability theory. Accordingly, the objective of this study is to propose the reliability analysis which can evaluate probability of failure and reliability index of floating structure.

The baseplate of a floating structure which is a connection part of upper- structure and ponton is influenced by lateral load caused by wind, tidal current, and waves as well as vertical load subjected by upper-structures. This research is intended to study the behavior characteristics of transfer-beam connection by conducting experiments and finite element analysis when they are subjected to moment under lateral load. A lateral load test and finite element analysis were conducted on test and mock-up models with a different angle thickness. A load-displacement curve and a moment-rotation curve are analysed from the results of analysis and experiment.

본 연구의 목적은 주기적 모니터링을 통해 부유식 콘크리트 구조물의 구조 건전성을 평가하는 것이다. 실제 부유식 콘크리트 구조물을 대상으로 주기적 모니터링을 실시하여 동적 특성을 추출하였다. 추출된 동적 특성과 수치해석 모델을 이용하여 다음 두 가지 활동을 통해 구조 건전성을 평가하였다. 먼저, 비파괴 손상 평가기법을 이용하여 손상의 발생 및 진전을 평가하였으며, 균열도와의 비교를 통하여 그 결과의 신뢰성을 검증하였다. 다음으로, 구조계 추정기법을 이용하여 강성 저하 추이를 분석하였다. 그 결과로, 구조물의 요구 성능 확보여부를 판단할 수 있었다.

The objective of this study is to evaluate the structural integrity of the floating concrete structure through periodic monitoring. Dynamic characteristics of the actual floating concrete structure were extracted from the periodic monitoring. The structural integrity using the extracted dynamic characteristics and numerical model was evaluated by the following two activities. First, the structure damage was evaluated for occurrence and progress using the damage detection method. The reliability of the results was verified by comparison with the crack drawing. Second, the stiffness degradation trend was analyzed using the system identification method. As a result, the structural satisfy performance criteria and safety.

Application areas of floating marine structure systems have been increased with the development of power generation systems using renewable energy. Hence it is necessary to analyze the behavior of these floating systems for efficient design and operation. In this study, a computational analysis was performed to predict the characteristics of mooring lines load variation connected to a floating marine structure with waves. Pressure on the floating body and mooring lines load were analyzed with wave direction and height. The floating body stability severely decreased for 90° of the wave incident direction, and maximum load of the mooring lines increased with the height. These results are expected to be applicable for optimal design of the marine floating system.

중국이 호적제도의 개혁과 도시화를 통해 지속적으로 개혁과 발전을 거듭하는 과정에서 인구이동은 경제발전의 핵심적인 현상으로 부각되었고, 또한 지역별로 인구이동이 잦아졌다. 구이양(贵阳)은 중국서부의 경제발전지역으로서 어느 정도 영향을 받았다. 빠른 경제발전과정 에서 구이양의 이주인구는 계속해서 증가하고 있다. 본 논문은 이러한 흐름을 배경으로 구이양 이주 인구의 공간적 패턴의 특성을 소개하고 도시화 과정에서 핵심적인 전략이슈 인구이양 이주 인구의 공간 패턴의 시공간적 변화를 설명한다. 구이양은 중국서부에서 급속하게 발전하고 있는 지역으로, 새로운 서부개발 정책을 바탕으로 구이양시의 독특한 장점을 통해 이 도시를 방문하고, 살고, 일하고, 공부할 수 있는 이주인구를 대거 유치하고 있다. 많은 인구의 유입은 한편으로는 구이양의 경제발전을 위한 우수한 인재를 공급함으로써 지역경제 발전과정에서 중요한 역할을 하지만, 다른 한편으로는 사회범죄와 불충분한 사회보장을 야기한다. 구이양은 경제성장전환과 안정적인 경제발전과정에서 이주 인구문제를 효과적으로 해결해야 하며 구이 양을 중국서부의 영향력 있는 지역 성장의 거점이자 중심도시로 만들기 위해서는 반듯이 해결해야 할 핵심적인 문제이다. 시장경제의 급속한 발전으로 중국의 산업구조가 고도화 되고 조정될 수 있는 중요한 기회가 있다. 산업구조와 고용구조의 조정은 여전히 거시경제발전에 중요한 영향을 미칠 것 이다. 특히 과학과 교육을 통해 국가를 발전시키고 인재육성을 통해 국가 역량을 강화하는 전략이 시작된 이후 고등교육 분야의 인재 고용은 지역의 산업구조발전과도 밀접한 관련이 있다. 우리는 지역의 경제발전을 가속화하기 위해 중국 서부 구이양 지역의 산업구조와 고등교육 고용구조의 시너지를 촉진하기 위한 구체적인 최적화 전략을 제안한다. 산업구조는 고용 구조에 결정적인 영향을 미치며, 고용구조는 다시 산업구조 및 기타경제구조에 영향을 미칠 수 있다. 본 논문에서는 SPSS 소프트웨어를 사용하여 구이양（贵阳）지역 고등 교육 인구의 고용 구조와 구이양 지역 산업 구조 변화 간의 상관관계를 분석하여 구이양 지역 산업 구조와 고등 교육 고용 구조의 영향을 받는 변수가 유의미한 양의 상관관계를 보인다는 결과를 얻었다. 현재 중국은 산업 구조 조정의 중요한 시기에 있으며, 산업 구조 고도화를 위해서는 고급 인재 공급망이 필요하지만 이동 인구의 취업이 어려운 구조적 문제도 존재한다. 양립할 수 없는 상황에 대한 합리적인 검토, 중국 서부 저개발 지역의 관점에서 이동 인구의 고용과 산업 구조 최적화 및 업그레이드 촉진 간의 관계에 대한 연구, 기존 비대칭 상태의 개선, 산업 구조와 고용 구조의 조정을 촉진하면서 전환 및 업그레이드를 가속화하고, 불균형 발전 을 해결 등 중국 서부 도시화의 지속 가능한 발전에 참고할 수 있는 연구라 할 수 있다.

In the process of China’s continuous development of reform and development, with the reform of the household registration system and urbanization, population movement has become a key phenomenon of economic development, and population movement between different regions has become more frequent. Guiyang, as a region of economic development in western China, has also been affected to some extent. In the process of rapid economic development, the size of Guiyang’s migrant population continues to grow. Based on this background, this paper introduces the basic characteristics of the spatial pattern of the migrant population in Guiyang and explains the spatial and temporal changes in the spatial pattern of the migrant population in Guiyang, which is a key strategic issue in the process of modernization of the city. Guiyang is a rapidly developing region in western China, and based on the background of the new western development, Guiyang City attracts a large number of migrant populations to visit, live, work, and study in Guiyang through its unique advantages. The large influx of people provides talents for Guiyang’s economic development and plays an important role in the process of economic development. In addition, it also causes social crimes and insufficient social security. Guiyang needs to effectively solve the problem of the migrant population in the process of economic growth transformation and stable economic development, and it is a key issue that needs to be solved to make Guiyang an influential regional growth pole and a central city in western China. With the rapid development of the market economy, there are significant opportunities for the upgrading and adjustment of China’s industrial structure. The coordination between industrial structure and employment structure will still have an important impact on macroeconomic development. Especially since the launch of the strategy of developing the country through science and education and strengthening the country through talents, employment in higher education is also closely related to the development of the industrial structure of the region. We propose specific optimization strategies to promote the synergy of industrial structure and higher education employment structure in the Guiyang region of western China in order to accelerate the region’s economic development. The industrial structure has a decisive influence on the employment structure, and the employment structure can in turn influence the industrial structure and other economic structures. The coordination between industrial structure and employment structure has a significant impact on the adjustment and optimization of industrial structure and the adequate and rational allocation of labor resources. In this paper, the coordination of industrial structure and employment structure in Guiyang is analyzed quantitatively and qualitatively through several indicators. It measures whether the development between the two is relevant and how it needs to be adjusted in the future to achieve sustainable development.

中国通过户籍制度的改革，在城市化发展过程中不断调整生产关系并促进生产要素的 流动，人口迁移成为经济发展的重要问题，不同地区人口迁移也日益频繁. 贵阳作为中 国西部经济发展较为核心区域，在经济快速发展的过程中，流动人口不断增加. 本文以 这种趋势为背景，介绍了贵阳流动人口空间模式的特点，并阐述了城市化进程中关键要 素流动人口的空间结构变化. 贵阳是中国西部发展较快的地区，中国在实施新西部大开 发政策的基础上，凭借贵阳市独特的优势，吸引大批来此旅游、生活、工作和学习的流 动人口. 大量人口的涌入一方面为贵阳经济发展提供优秀人才，在区域经济发展过程中 发挥着重要作用，另一方面也造成社会犯罪和社会保障不足. 贵阳在转变经济增长模式 和稳定经济发展过程中，要有效解决流动人口问题，把贵阳建设成为中国西部有影响的 区域增长点和中心城市，是目前亟待统筹解决的重点问题. 随着市场经济的快速发展，中国目前面临产业结构升级和调整的重要机遇. 产业结构 和就业结构的调整将对宏观经济的发展产生重要影响，特别是中国“科教兴国”战略开 始后,高素质教育的人才流动与地区产业结构的发展也密切相关. 提出具体优化战略，促 进中国西部地区产业结构和高等教育就业结构协同发展，是区域经济健康发展之路. 产 业结构对就业结构有决定性影响，就业结构可能再次影响产业结构和其他经济结构， 产业结构和就业结构的关系调整对产业结构的优化升级以及劳动力资源的合理配置有 很大影响. 本文通过运用SPSS软件对贵阳地区高等教育人群就业结构与贵阳地区产业结构变 化情况进行相关性分析，得到贵阳地区产业结构与高等教育就业结构影响的变量呈 现显著的正相关关系的结果. 当前中国处于产业结构调整的关键时期，产业结构升级 需要更高级的人才供给链的同时，流动人口也存在着就业难的结构性问题. 理性审视 其中不相适应的情况，从西部欠发达地区视角研究流动人口就业与推动产业结构优 化升级的关系，改善存在的非对称状态，加快转型升级的同时推动产业结构和就业结构的协调，解决发展中不协调与不平衡现象对中国西部地区城镇化可持续发展具 有参考意义.

This paper purposes on stimulating the dynamic behavior of a floating structure model with the image processing and the close-range photogrammetry, instead of the contact sensors. Previously, the movement of structures was presented by the exterior orientation estimation from a single camera following the space resection. The inverse resection yields to 6 orientation parameters of the floating structure, with respect to the camera coordinates system. The single camera solution of interest in applications is characterized by the restriction in terms of costs, unfavorable observation conditions, or synchronization demands when using multiple cameras. This paper discusses the theoretical determinations of camera exterior orientation by using the least squares adjustment, applied of the values from the DLT (Direct Linear Transformation) and the photogrammetric resection. This proposed method is applied to monitor motions of a floating model. The results of 6DOF (Six Degrees of Freedom) from the inverse resection were signified that applying appropriate initial values from DLT in the least square adjustment is effective in obtaining precise exterior orientation parameters. Therefore, the proposed method can be concluded as an efficient solution to simulate movements of the floating structure.

The objective of this paper is to simulate the dynamic behavior of a floating structure model, using image processing and close-range photogrammetry, instead of the contact sensors. Previously, the movement of structure was presented through the exterior orientation estimation of a single camera by space resection. The inverse resection yields the 6 orientation parameters of the floating structure, with respect to the camera coordinate system. The single camera solution is of interest in applications characterized by restriction in term of costs, unfavorable observation conditions, or synchronization demands when using multiple cameras. This article discusses the theoretical determinations of camera exterior orientation based on Direct Linear Transformation and photogrammetric resection using least squares adjustment. The proposed method was used to monitor the motion of a floating model. The results of six degrees of freedom (6-DOF) by inverse resection show that the appropriate initial values by DLT can be effectually applied in least squares adjustment, to obtain the precision of exterior orientation parameters. Additionally, a comparison between the close-range photogrammetry and total station results was feasibly verified. Therefore, the proposed method can be considered as an efficient solution to simulating the movement of floating structure.

Offshore floating structures have so-called moonpool in the centre area for the purpose of drilling, installation of subsea structures, recovery of Remotely-Operated Vehicle (ROV) and divers. However, this vertical opening has an effect on the operating performance of floating offshore structure in the vicinity of moonpool resonance frequency; piston mode and sloshing mode. Experimental study based on model test was carried out. Moonpool resonance of floating offshore structure on fixed condition and motion free condition were investigated. And, the effect of cofferdam which is representative inner structure inside moonpool was examined. Model test results showed that Molin's theoretical formula can predict moonpool resonance on fixed condition quite accurately. However, motion free condition has higher resonance frequency when it is compared with that of motion fixed. The installation of cofferdam moves resonance frequency to higher region and also generates secondary resonance at lower frequency. Furthermore, it was found that cofferdam was the cause of generating waves in the longitudinal direction when the vessel was in beam sea.

Identification of the modal properties of a structural system has received much attention over the years because of its importance in structural model updating, structural health monitoring and structural control. This paper presents experimental modal test results such as natural frequencies and mode shapes of a scale model of floating structure. A modal testing is performed on the structure and modal parameters for the structure are extracted from the measured data. The results are compared to a finite element model and the correlation between the measured and analytical modal parameters is investigated.

Researches on a superstructure built on a floating structure in the shape of pontoon type have begun in recent years. A superstructure responds by wave load and it is important to evaluate its habitability. The purpose of this study is evaluation and investigation of habitability of a superstructure due to wave for 10 year return period. In this study, response analyses of the superstructure built on middle-sized floating structure due to the waves of three cases were carried out by 3-D integration analysis, which means analyzing the calculation model integrated a superstructure with a floating structure, and its habitability was evaluated by the evaluation diagrams. As the result, the habitability differed by each wave condition The use of a superstructure is restricted according to the disposition of a floating structure for incident wave angle.

Previous valves have initial gap problem, high voltage or high pressure problem. In this paper, various micro valves with free floating structure have been fabricated and tested to solve the initial gap and high pressure problems. The paper presents how to etch Parylene-C which is a valve cap material without A1 mask layer. The maximum flow-rate of fabricated micro valve is$118{\mu\ell}$/min with $370{\mu}m$ orifice size and the leakage at the initial and reverse pressure is not observed.

In this study, we focus on the submerged plate built into the Very Large Floating Structure with the partial openings of Sm long, which enables the reverse flow of incident wave to generate the wave breaking. The purpose of this study is to investigate the characteristics of wave exciting forces acting on the submerged plate and the fore part of VLFS. Firstly, we have carried out the extensive experiments to understand the characteristics of the wave exciting forces. Then we have performed the numerical simulations by applying the Marker and Cell method (MAC method) and compared with the experimental results. We discuss the validity of MAC method and the effects of the submerged plate on the motion of VLFS. As a result, we get the conclusion that the submerged plate is useful for reducing the wave exciting forces acting on the structure behind the submerged plate.