• 제목/요약/키워드: Flows Control

검색결과 680건 처리시간 0.027초

Thematic Map Construction of Erosion and Deposition in Rivers Using GIS-based DEM Comparison Technique

  • Han, Seung Hee
    • 한국측량학회지
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    • 제34권2호
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    • pp.153-159
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    • 2016
  • Rivers refer to either natural or artificial structures whose primary functions are flood control and water conservation. Due to recent localized torrential downpours led by climate change, large amounts of eroded soil have been carried away, forming deposits downstream, which in turn degrades the capacity to fulfill these functions. To manage rivers more effectively, we need data on riverbed erosion and deposition. However, environmental factors make it challenging to take measurements in rivers, and data errors tend to prevent researchers from grasping the current state of erosions and deposits. In this context, the aim of the present study is to provide basic data required for river management. To this end, the author made annual measurements with a Real-time Kinematic-Global Positioning System (RTK-GPS) and a total station in Pats Cabin Canyon, Oregon, United States, and also prepared thematic maps of erosion and deposition thickness as well as water depth profiles based on a GIS spatial analysis. Furthermore, the author statistically analyzed the accuracy of three dimensional (3D) measurement points and only used the data that falls within two standard deviations (i.e. ±2σ). In addition, the author determined a threshold for a DEM of Difference (DoD) by installing measurement points in the rivers and taking measurements, and then estimated erosion and deposition thickness within a confidence interval of ±0.1m. Based on the results, the author established reliable data on river depth profiles and thematic maps of erosion and deposition thickness using pre-determined work flows. It is anticipated that the riverbed data can be utilized for effective river management.

Spherical and cylindrical microencapsulation of living cells using microfluidic devices

  • Hong, Joung-Sook;Shin, Su-Jung;Lee, Sang-Hoon;Wong, Edeline;Cooper-White, Justin
    • Korea-Australia Rheology Journal
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    • 제19권3호
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    • pp.157-164
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    • 2007
  • Microencapsulation of cells within microfluidic devices enables explicit control of the membrane thickness or cell density, resulting in improved viability of the transplanted cells within an aggressive immune system. In this study, living cells (3T3 and L929 fibroblast cells) are encapsulated within a semi-permeable membrane (calcium crosslinked alginate gel) in two different device designs, a flow focusing and a core-annular flow focusing geometry. These two device designs produce a bead and a long microfibre, respectively. For the alginate bead, an alginate aqueous solution incorporating cells flows through a flow focusing channel and an alginate droplet is formed from the balance of interfacial forces and viscous drag forces resulting from the continuous (oil) phase flowing past the alginate solution. It immediately reacts with an adjacent $CaCl_2$ drop that is extruded into the main flow channel by another flow focusing channel downstream of the site of alginate drop creation. Depending on the flow conditions, monodisperse microbeads of sizes ranging from $50-200\;{\mu}m$ can be produced. In the case of the microfibre, the alginate solution with cells is extruded into a continuous phase of $CaCl_2$ solution. The diameter of alginate fibres produced via this technique can be tightly controlled by changing both flow rates. Cell viability in both forms of alginate encapsulant was confirmed by a LIVE/DEAD cell assay for periods of up to 24 hours post encapsulation.

Hop-by-Hop Dynamic Addressing Based Routing Protocol for Monitoring of long range Underwater Pipeline

  • Abbas, Muhammad Zahid;Bakar, Kamalrulnizam Abu;Ayaz, Muhammad;Mohamed, Mohammad Hafiz;Tariq, Moeenuddin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권2호
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    • pp.731-763
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    • 2017
  • In Underwater Linear Sensor Networks (UW-LSN) routing process, nodes without proper address make it difficult to determine relative sensor details specially the position of the node. In addition, it effects to determine the exact leakage position with minimized delay for long range underwater pipeline monitoring. Several studies have been made to overcome the mentioned issues. However, little attention has been given to minimize communication delay using dynamic addressing schemes. This paper presents the novel solution called Hop-by-Hop Dynamic Addressing based Routing Protocol for Pipeline Monitoring (H2-DARP-PM) to deal with nodes addressing and communication delay. H2-DARP-PM assigns a dynamic hop address to every participating node in an efficient manner. Dynamic addressing mechanism employed by H2-DARP-PM differentiates the heterogeneous types of sensor nodes thereby helping to control the traffic flows between the nodes. The proposed dynamic addressing mechanism provides support in the selection of an appropriate next hop neighbour. Simulation results and analytical model illustrate that H2-DARP-PM addressing support distribution of topology into different ranges of heterogeneous sensors and sinks to mitigate the higher delay issue. One of the distinguishing characteristics of H2-DARP-PM has the capability to operate with a fewer number of sensor nodes deployed for long-range underwater pipeline monitoring.

불면(不眠)에 대한 침구치료(鍼灸治療)의 접근 방법론 연구 - 경락생리(經絡生理) 및 혈성(穴性)을 중심으로 - (A study of methods for Acupuncture and moxibustional treatment to Insomnia)

  • 김근우
    • Korean Journal of Acupuncture
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    • 제21권3호
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    • pp.147-158
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    • 2004
  • Objectives : This study was aimed to investigate the methods for acupuncture and moxibustional treatment to insomnia Methods : The insomnia is classified by seven cause at main subject. According to this, arrange the acupuncture and moxibustional treatment for classical books, and explain eight meridian related to insomnia. Results : 1. Insomnia means deficiency of sleeping and it is the word generally used when a short period of sleeping, difficulty for deep sleeping and difficulty for recovery of original vital energy comes out. In oriental medicine, they understand that uneasiness condition occurred by abnormal operation of the internal organs as heart, liver, gallbladder, spleen, stomach, kidney, etc. caused by external affection or internal injury becomes Insomnia. 2. Cause of insomnia can be classified majorly as fire-transformation of liver and gallbladder , inner shaking of phlegm-heat , insufficiency of both the heart and the spleen, disharmony between heat and kidney, the dysfunction of the stomach, timidity of heart and gallbladder, the deficiency of Qi of the lung. They make insomnia with bad influence upon body and spirit. 3. The meridian system such as Heart Meridian of Hand Soeum, Pericardium Meridian of Hand Gworeum, Stomach Meridian of Foot Yangmyeong, Spleen Meridian of Foot Taeeum, Bladder Meridian of Foot Taeyang, Kidney Meridian of Foot Soeum, Gallbladder Meridian of Foot Soyang, Liver Meridian of Foot Gworeum and Lung Meridian of Hand Taeeum are used to treat insomnia. Sinmun acupoint and Naegwan acupoint are often used in particular because the they are good for calmming the spirit, the heart and purging the heart of (pathogenic) fire. 4. Especialy, Back-Su points of Bladder Meridian of Foot Taeyang was used by each causes. The Back-su Points was mainly used for heal the insomnia because the Back-Su points has good competent to control the ability of internal organs by direct effect to it. It is because the vitality flows through around back-Su. Conclusions : It comes to a conclusion as follows with research for relevancy of the main cause of insomnia and meridian system includes meridian point.

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Experimental Study on the Hydrophilic Porous Film Coating for Evaporative Cooling Enhancement

  • Lee, Dae-Young;Lee, Jae-Wan;Kang, Byung-Ha
    • International Journal of Air-Conditioning and Refrigeration
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    • 제13권2호
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    • pp.99-106
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    • 2005
  • Falling film heat transfer has been widely used in many applications in which heat and mass transfer occur simultaneously, such as evaporative coolers, cooling towers, absorption chillers, etc. In such cases, it is desirable that the falling film spreads widely on the surface to form a thin liquid film to enlarge contact surface and to reduce the thermal resistance across the film and/or the flow resistance to the vapor stream over the film. In this respect, hydrophilic treatment of the surface has been tried to improve the surface wettability by decreasing the contact angle between the liquid and the surface. However, the hydrophilic treatment was found not very effective to increase the surface wettedness of inclined surfaces, since the liquid flow forms rivulet patterns instead of a thin film as it flows down the inclined surface and accelerates gradually by the gravity. In this work, a novel method is suggested to improve the surface wettedness enormously. In this work, the surface is treated to have a thin hydrophilic porous layer on the surface. With this treatment, the liquid can spread widely on the surface by the capillary force resulting from the porous structure. In addition to this, the liquid can be held within the porous structure to improve surface wettedness regardless of the surface inclination. The experiment on the evaporative cooling of inclined surfaces has been conducted to verify the effectiveness of the surface treatment. It is measured that the latent heat transfer increases almost by $80\%$ at the hydrophilic porous layer coated surface as compared with the untreated surface.

자동배차 지원시스템의 휴리스틱 알고리듬 설계 (Design of Heuristic Algorithm of Automatic Vehicle Delivery Support System)

  • 이명호
    • 디지털융복합연구
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    • 제11권3호
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    • pp.181-187
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    • 2013
  • 공급자와 소비자간의 정보공유는 기능 중심에서 프로세스 중심이 되면서, 유연성과 고객 서비스를 극대화하기 위한 새로운 물류 개념을 요구하게 되었다. 다시 말하면 원부자재의 조달에서부터 생산을 거쳐 고객에게 판매되기까지의 전 과정에 걸친 개체간의 수요와 공급의 사슬관계를 의미하는 공급망 내에서 정보, 자금 그리고 물의 흐름을 관리 통제하는 공급사슬경영(SCM)이 사업의 핵심역량으로 인식되고 있다. 또한 국내 기업들의 수 배송 업무의 합리화는 국내 기업 물류관리의 가장 중요한 과제중의 하나로 부각되고 있다. 물류센터로부터 각 거래처로 물품을 배달하는 배송업무의 경우에는 기업의 물류정보시스템이 상류 중심의 데이터 체계로 구축되어왔기 때문에 물류관리 업무의 합리화에 활용할 수 있는 기초 데이터 부재와 현실적인 제약조건들을 고려한 효율적인 자동배차 알고리듬을 적용하지 못했기 때문에 배차담당자들의 수작업 조정시간이 장시간 소요되었다. 따라서 본 논문에서는 현실적인 다양한 제약조건을 만족하고, 수작업 조정시간이 대폭 줄이면서, 우편중심 좌표를 이용한 차량별 근거리 그룹핑으로 자동배차 지원시스템의 휴리스틱 알고리듬을 설계하도록 한다.

다지점 오픈플로우 사이트들을 위한 자동화된 연동 도구의 설계 및 구현 (Design and Implementation of an Automated Inter-connection Tool for Multi-Point OpenFlow Sites)

  • 나태흠;김종원
    • 정보과학회 컴퓨팅의 실제 논문지
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    • 제21권1호
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    • pp.1-12
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    • 2015
  • 미래형 서비스 실증을 위해서 실험자들에게 소프트웨어-정의 네트워킹(Software-Defined Networking: SDN)과 클라우드 컴퓨팅(Cloud Computing: CC) 기반으로 융합된 컴퓨팅/네트워킹 자원들을 유연하게 제공하는 통합된 시험/실증 환경의 중요성이 확산되고 있다. 이러한 추세에 맞춰서 OF@TEIN(OpenFlow @ Trans Eurasian Information Network) 시험/실증 환경에서는 국내외 다수 지역들에 가상화를 지원하는 융합형 자원인 SmartX Rack들을 설치하고 이들을 오픈플로우(OpenFlow) 기반의 SDN에 의해 연동하여 활용한다. 본 논문에서는 다지점에 설치된 오픈플로우 사이트들을 2계층 이더넷(Ethernet) 차원에서 연동할 때 원하는 토폴로지에 부합하도록 NVGRE(network virtualized generic route encapsulation) 터널링을 자동으로 설정하고 관제하는 관리도구를 소개한다. 제안한 관리 도구를 활용하면 운용자는 다수의 오픈플로우 사이트들간의 네트워크 연동을 신속하고 효율적으로 관리할 수 있고, 이와 동시에 실험자들은 원하는 가상화된 사용자 네트워크(virtual tenant network)를 최대한 자율적으로 구성하고 활용할 수 있다.

시퀀스 다이어그램으로부터 테스트 케이스 자동 생성을 위한 M2M(Model-to-Model) 변환 규칙 (M2M Transformation Rules for Automatic Test Case Generation from Sequence Diagram)

  • 김진아;김수지;서용진;천은영;김현수
    • 정보과학회 컴퓨팅의 실제 논문지
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    • 제22권1호
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    • pp.32-37
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    • 2016
  • 시퀀스 다이어그램에 대한 모델 기반 테스트를 수행하기 위하여 시퀀스 다이어그램으로부터 테스트 케이스를 자동으로 생성해야 한다. 이를 위해서는 시퀀스 다이어그램이 나타내는 시나리오를 파악하고 테스트 커버리지를 만족하는 경로를 추출하여 테스트 정보를 생성해야 한다. 하지만 시퀀스 다이어그램은 결합 조각을 사용하여 반복 및 조건, 대안 정보를 나타내므로 시퀀스 다이어그램으로부터 테스트 케이스를 자동으로 생성하는 것은 복잡하다. 이러한 문제를 해결하기 위하여 본 논문에서는 시퀀스 다이어그램으로부터 액티비티 다이어그램으로 변환을 수행하는 모델 변환 프로세스를 정의하고, 이를 통해 시퀀스 다이어그램의 시나리오를 제어 흐름 형태로 표현하고 여기에 테스트 커버리지를 적용하여 테스트 케이스를 생성하는 과정을 정의한다. 마지막으로, 사례 연구를 통하여 시퀀스 다이어그램으로부터 테스트 케이스를 생성하는 과정을 보인다.

도시 유역 아파트 단지내 소하천의 홍수특성 분석 (Analysis of Flood Characteristics for A Small Stream in Apartment Complex of Urban Watershed)

  • 곽재원;안경수;박두호;김형수
    • 한국습지학회지
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    • 제9권3호
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    • pp.25-34
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    • 2007
  • 본 연구는 도심지 유역인 경기도 부천 여월동 단지 내의 도시하천에 대해서 유출 및 홍수 특성을 분석하였다. 해당 유역의 하천은 차집 관로에 의한 생활하수와 흐름의 차단으로 인하여 평상시에는 매우 적은 유량만이 흐르고 있으나, 홍수 시에는 상대적으로 높은 홍수위로 인해 홍수 피해의 위험성을 보이고 있다. 홍수에 대한 안전성을 확인하기 위하여 유출 해석 모형을 적용하고, 또한 해당 유역에 대해 구축된 GIS 자료 및 하천 단면과 HEC-RAS를 이용, 홍수위를 예측하여 이를 바탕으로 해당 하천의 치수 안정성을 검토하였다. 검토 결과 다목적 소하천을 목적으로 설치된 하천 구조물로 인하여 홍수 피해 발생 위험이 있었으며, 하천 안정성에 대한 불안요소를 포함하고 있었다. 이러한 단지내 소규모의 도시유역에 대한 홍수 유출 해석에서는 홍수 유출 외에도 구조물에 의한 배수위 변동과 유속 등과 같은 여러 위험 요인에 대하여 함께 고려해야 할 것으로 판단된다.

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조선 PDM구축을 위한 기능 연구 및 시험 구현 사례 (A Functional Review and Prototype for Ship PDM implementation)

  • 이장현;김용균;오대균;신종계
    • 대한조선학회논문집
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    • 제42권6호
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    • pp.686-697
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    • 2005
  • The current challenge with which most shipyards are faced is to reduce the design time and the time-to-delivery benefits of new information technologies such as ERP, APS, and SCM system. These technologies should integrate the information that flows in the enterprise wide activities. First of all we should maintain control of ship design and product data such as bill of material, product structure, drawing, 30 modeling and manufacturing information for the integration. The product data management (POM) system copes with these requirements. All the product data is stored in POM database and vaults in a structured manner and all the changes of product data are monitored, controlled and recorded. This study discusses how POM system can be implemented in shipyard. The procedure is surveyed to apply a POM system for the ship design data management. This study also presents several examples in order to make a practical guidance for ship POM implementation. Proposed studies can be useful for shipyards planning to adopt POM systems in enterprise wide manner.