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대형선망어업의 생산력 재편과 경영 개선 과제 (The Study on the Reorganization of the Large Purse Seine Fisheries in Korea)

  • 김대영
    • 수산해양교육연구
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    • 제21권3호
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    • pp.373-389
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    • 2009
  • The aims of this study are to examine urgent problems for reorganization into future-proof large purse seine fisheries in order to positively cope with rapidly changing domestic and foreign fisheries circumstances. First, this paper provides current situations of the large purse seine fisheries. The current situations of it are composed of fisheries influence such as vessel number, vessel power, and fisher number, use of resource and fishing places, and changes in products and sales of species caught by the large purse seine. Secondly, this paper reviews current problems of the large purse seine fisheries including cost reduction and increase of value added. Thirdly, this paper suggests basic development direction and countermeasures for strengthening competitiveness of the large purse seine fisheries. In conclusion, urgent problems of the larger purse seine fisheries can be summarized as inefficiency of distribution structures and retarded landing system and facilities as well as the worse of profitability according to shrink of fishing places, reduction of products, lack of workers, and increase in oil price. To solve the urgent problems, the large purse seine fisheries should be changed into an industry with low cost and high efficiency, and also need to introduce of new production system, strengthen autonomous management of natural resource, and increase in value added to products.

Effective 3-D FEM for large-scale high temperature superconducting racetrack coil

  • Huang, Xiangyu;Huang, Zhen;Xu, Xiaoyong;Li, Wan;Jin, Zhijian
    • 한국초전도ㆍ저온공학회논문지
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    • 제21권3호
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    • pp.32-37
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    • 2019
  • In various types of large-scale electrical applications, the number of coil turns in such machines is usually large. Electromagnetic simulation of large-scale superconducting coils (tens to hundreds of turns) is indispensable in the design process of superconducting electrical equipment. However, due to the large scale of the coil and the large aspect ratio of super-conducting material layer in HTS coated conductor, it is usually difficult or even unable to perform 3-D transient electromagnetic simulation. This paper introduces an effective 3-D electromagnetic simulation method for large-scale HTS coated conductor coil based on T-A formulation. The simulation and experimental results show that the 3-D model based on the T-A formulation using homogeneous strategy is more accurate than the traditional 2-D models. The memory usage is not sensitive to the number of turns and this model will be even more superior as the number of turns becomes larger.

키르기스스탄 코코메렌강 유역의 대규모 산사태 유형과 지형 발달 (Types and Geomorphic Development of Large Landslides in the Kokomeren River Basin, Kyrgyzstan)

  • 오정식
    • 한국지형학회지
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    • 제26권1호
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    • pp.1-14
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    • 2019
  • Large landslide is a type of mass movement that causes drastic landform changesin a short period, and it causes huge human and property damage over a large area. The purpose of this study is to categorize the types and characteristics of large landslides around the Kokomeren River basin, Kyrgyzstan and to discuss the geomorphic development after the large landslides. The topographic analysis about a total of 20 landslides documented collapsed volumes of 0.01 to 1.10 km3, height drops of 180 to 1,770 m, and runout distances of 1,200 to 5,400 m. Rock avalanche and rockslide are identified as major types of large-scale landslides in the study area. Rock avalanches can be divided into P-type, J-type, and S-type based on the features of slope failure and kinematic characteristics of rock debris. Landslide synchronistic landforms such as trimlines, transverse ridges, longitudinal ridges, levees, and hummocks are well developed in the rock avalanche. The pieces of evidence of landslide dam, landslide-dammed lake, and remnant outburst flood deposits are observed in the upstream and downstream where the rockslides occurred. The Ak-Kiol landslide dam is the best example of a geomorphic development due to lake spillover and the large landslides were likely to be triggered by huge paleo-seismic events.

수부 및 상지의 피부에 발생한 원발성 피부 무형성 대세포 림프종 증례보고 1례 (Primary Cutaneous Anaplastic Large Cell Lymphoma: A Case Report)

  • 유중석;이동락;임준규;윤인모;이병두;이동은
    • Archives of Plastic Surgery
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    • 제33권6호
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    • pp.757-760
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    • 2006
  • Purpose: Anaplastic large cell lymphoma, has the following three characteristics of a malignant lymphoma; 1) An irregular large nucleus, called pathologic atypical cells, 2) Eosinophilic cytoplasm, 3) Immunologically positive for Ki-1. Anaplastic large cell lymphoma occurs mostly in the lymph nodes, but about 40% has been observed to occur in other tissues. Skin is the one of the main sources of origin and it is called 'primary cutaneous anaplastic large cell lymphoma'. Methods: A 69-year-old male patient with an erythematous nodule, sized $1.5{\times}1.7cm$ on his right hand dorsum was excised under local anesthesia and on biopsy was diagnosed as 'Dermatofibrosarcoma Protuberans'. Three months after the local excision and biopsy, same natured mass reoccurred in the same region, and then spontaneous regressed after three weeks. However, metastatic large mass of $4.0{\times}5.0cm$, of same nature was observed on the elbow. The large mass was operated with wide excision and biopsy. Results: On final diagnosis, with an immunofluorescent stain with CD30(Ki-1), 'Primary cutaneous large cell lymphoma' was made. After follow up for three years, we did not observed recurrence and metastasis. Conclusion: We have reported that we have diagnosed primary cutaneous large cell lymphoma and treated without recurrence and metastasis.

한 번의 데이터베이스 탐색에 의한 빈발항목집합 탐색 (Frequent Patterns Mining using only one-time Database Scan)

  • 채덕진;김룡;이용미;황부현;류근호
    • 정보처리학회논문지D
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    • 제15D권1호
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    • pp.15-22
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    • 2008
  • 본 논문에서는 한 번의 데이터베이스 스캔으로 빈발항목집합들을 생성할 수 있는 효율적인 알고리즘을 제안한다. 제안하는 알고리즘은 빈발 항목과 그 빈발항목을 포함하고 있는 트랜잭션과의 관계를 나타내는 이분할 그래프(bipartite graph)를 생성한다. 그리고 생성된 이분할 그래프를 이용하여 후보 항목집합들을 생성하지 않고 빈발 항목집합들을 추출할 수 있다. 이분할 그래프는 빈발항목들을 추출하기위해 대용량의 트랜잭션 데이터베이스를 스캔할 때 생성된다. 이분할 그래프는 빈발항목들과 그들이 속한 트랜잭션들 간의 관계를 엣지(edge)로 연결한 그래프이다. 즉, 본 논문에서의 이분할 그래프는 대용량의 데이터베이스에서 쉽게 발견할 수 없는 빈발항목과 트랜잭션의 관계를 검색하기 쉽게 색인(index)화한 그래프이다. 본 논문에서 제안하는 방법은 한 번의 데이터베이스 스캔만을 수행하고 후보 항목집합들을 생성하지 않기 때문에 기존의 방법들보다 빠른 시간에 빈발 항목집합들을 찾을 수 있다.

Robust Hierarchical Data Fusion Scheme for Large-Scale Sensor Network

  • Song, Il Young
    • 센서학회지
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    • 제26권1호
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    • pp.1-6
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    • 2017
  • The advanced driver assistant system (ADAS) requires the collection of a large amount of information including road conditions, environment, vehicle status, condition of the driver, and other useful data. In this regard, large-scale sensor networks can be an appropriate solution since they have been designed for this purpose. Recent advances in sensor network technology have enabled the management and monitoring of large-scale tasks such as the monitoring of road surface temperature on a highway. In this paper, we consider the estimation and fusion problems of the large-scale sensor networks used in the ADAS. Hierarchical fusion architecture is proposed for an arbitrary topology of the large-scale sensor network. A robust cluster estimator is proposed to achieve robustness of the network against outliers or failure of sensors. Lastly, a robust hierarchical data fusion scheme is proposed for the communication channel between the clusters and fusion center, considering the non-Gaussian channel noise, which is typical in communication systems.

LARGE SCALE MAGNETOGENESIS THROUGH RADIATION PRESSURE

  • LANGER MATHIEU;PUGET JEAN-LOUP;AGHANIM NABILA
    • 천문학회지
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    • 제37권5호
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    • pp.553-556
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    • 2004
  • We present a new model for the generation of magnetic fields on large scales occurring at the end of cosmological reionisation. The inhomogeneous radiation provided by luminous sources and the fluctuations in the matter density field are the major ingredients of the model. More specifically, differential radiation pressure acting on ions and electrons gives rise to electric currents which induce magnetic fields on large scales. We show that on protogalactic scales, this process is highly efficient, leading to magnetic field amplitudes of the order of $10^{-1l}$ Gauss. While remaining of negligible dynamical impact, those amplitudes are million times higher than those obtained in usual astrophysical magnetogenesis models. Finally, we derive the relation between the power spectrum of the generated field and the one of the matter density fluctuations. We show in particular that magnetic fields are preferably created on large (galactic or cluster) scales. Small scale magnetic fields are strongly disfavoured, which further makes the process we propose an ideal candidate to explain the origin of magnetic fields in large scale structures.

3차원파동장에 있어서 대형연직케이슨에 작용하는 선형 및 비선형의 파압분포특성에 관한 연구 (Linear and Nonlinear Wave Pressure Distributions Acting on Vertical Caisson of Large Size in 3-Dimensional Wave Fields)

  • 김도삼;신동훈;이봉재
    • 한국해양공학회지
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    • 제15권3호
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    • pp.114-119
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    • 2001
  • Goda formula (Goda, 1973) has been used in the determination of wave pressures acting on a large size caisson such as the pier of the cable stayed bridge at sea. Goda formula, however, is to evaluate the wave pressures acting the infinite vertical caisson of composite breakwater so that it can`t be applied to a large caisson with finite width and length because of diffraction effects. In the present study, three dimensional nonlinear frequence domain method based on perturbation method and boundary integral method is applied to the computation of the linear and nonlinear wave pressures acting on the front of a large size caisson under the variation of its width and length, and angle of incident wave. The numerical results are compared to Goda\`s ones, and then the characteristics of wave pressure distributions acting on a large size caisson are discussed.

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변화하는 감쇠를 갖는 계가 조화력을 받을 때의 운동 - 이론적 해석 (Motion of a System with Varying Damping Subject to Harmonic Force - Analytical Analysis)

  • 박오철;이건명
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 추계학술대회논문집
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    • pp.898-902
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    • 2006
  • The motion of a system composed of a plate, constant springs and varying dampers is considered when the system is subject to harmonic force. Letting the frequencies of harmonic force and damper variation ${\Large f}_1\;and\;{\Large f}_2$ respectively, the displacement at the center of the plate has the strongest component at frequency ${\Large f}_1$. The angular displacement of the plate has strong components at ${\Large f}_1-{\Large f}_2$ and the natural frequency of the rotational mode of the system. If these two frequencies coincide, the plate oscillates with almost single frequency and a large amplitude. Part of these simulation results are proved analytically.

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멤스 기술을 이용한 대변형 바이모프 구동기 (Large Displacement Bimorph Actuator Using MEMS Technology)

  • 정원규;최석문;김용준
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.1286-1289
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    • 2004
  • A new thermal bimorph actuator for large out-of-plane displacement is designed, fabricated and tested. The deflecting beam is composed of polyimide, heater, and polyvinyl difluorides with tetrafluoroethylene(PVDF-TrFE). The large difference of coefficient of thermal expansion(CTE) of two polymer layers (polyimide and PVDF-TrFE) can generate a large deflection with relatively small temperature rising. Compared to the most conventional micro actuators based on MEMS(micro-electro mechanical system) technology, a large displacement, over 1 mm at 20 mW, could be achieved. The proposed actuator can find applications where a large vertical displacement is needed while keeping compact overall device size, such as a micro zooming lens.

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