• Journal of Chest Surgery
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• 제28권6호
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• pp.579-582
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• 1995

The extended transseptal approach to the mitral valve replacement has been used for 30 patients. There were 19 women and 11 men. Twenty five patients had rheumatic heart disease, 4 had degenerative valve ,and 1 had valve prolapse. Fifteen of 30 patients had other associated procedure; 10 had aortic valve replacement; 5 had tricuspid annuloplasty. There were no postoperative complications associated with the approaches, ie, no bleeding, no sinus node dysfuction, and no atrioventricular conduction disturbance. Despite division of the sinus node artery, preoperative atrial rhythms[3 sinus rhythms and 27 atrial fibrillations were not changed during postoperative period. The extended transseptal approach provides good mitral valve exposure without inherent complications, and is superior to that of standard approach, so we use it routinely for mitral valve procedure.

• 대한전자공학회논문지TC
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• 제44권10호
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• pp.76-82
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• 2007

노드들의 이동성을 보장하고, 별도의 인프라가 필요하지 않다는 점에서 최근에 MANET에 대한 관심이 커지고 연구가 활발히 진행되고 있다. 최근 들어 노드들이 이동한다는 개념이 단순이 걸어 다니는 것이 아니라 GPS를 기반으로 빠른 속도로 움직이는 자동차에 대한 Ad hoc 망의 이용에 많은 관심을 가지게 됨에 따라 MANET에서의 이동성이 과거에 비해 중요시되고 있다. 노드들이 빠르게 이동하는 경우 각 노드들이 목적지를 탐색하고 라우팅 하는 것은 많은 비용을 비롯하여 여러 문제가 발생한다. 이러한 문제를 해결하기 위하여 No path-Location Aided Routing (N-LAR) 란 새로운 라우팅 프로토콜을 제안한다. 제안하는 방법은 이동성이 큰 MANET에서 좀 더 짧은 응답속도와 높은 전송성공률을 갖는다.

• 한국공간정보시스템학회 논문지
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• 제11권2호
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• pp.1-6
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• 2009

Localization of nodes is a key technology for application of wireless sensor network. Having a GPS receiver on every sensor node is costly. In the past, several approaches, including range-based and range-free, have been proposed to calculate positions for randomly deployed sensor nodes. Most of them use some special nodes, called anchor nodes, which are assumed to know their own locations. Other sensors compute their locations based on the information provided by these anchor nodes. This paper uses a single mobile anchor node to move in the sensing field and broadcast its current position periodically. We provide a weighted centroid localization algorithm that uses coefficients, which are decided by the influence of mobile anchor node to unknown nodes, to prompt localization accuracy. We also suggest a criterion which is used to select mobile anchor node which involve in computing the position of nodes for improving localization accuracy. Weighted centroid localization algorithm is simple, and no communication is needed while locating. The localization accuracy of weighted centroid localization algorithm is better than maximum likelihood estimation which is used very often. It can be applied to many applications.

• 한국컴퓨터정보학회논문지
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• 제8권4호
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• pp.126-131
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• 2003

다중 유니캐스트 전송기법보다 멀티캐스트 전송기법이 장점이 많은 것이 사실이지만 IP 멀티캐스트 프로토콜은 간편한 관리제어 목적으로 몇몇 네트워크 영역으로 국한된다. 영역간 멀티캐스트 배치는 기술적인 면과 관리적인 면으로 인하여 진척이 느려지고 있다. 이에 대안으로 최근에 오버레이 멀티캐스팅 기술이 제시되었고, 본 논문에서 우리는 종단 호스트 멀티캐스트 트리 프로토콜 (EMTP)를 제안한다. EMTP는 리프 노드에 도달할 때까지 한번에 트리의 두 레벨을 검색하면서 또 한편으로는 가입하고자 하는 노드와 트리상의 가장 가까운 노드를 찾아낸다. 비록 해당 위치의 노드가 허용 가능한 차수가 없을지라도 그 노드를 잠재적인 부모노드로 선택 가능하게 함으로써 차후에 스위칭 횟수를 줄여 트리의 안정성을 높이고 데이터 전송 시간의 감소를 가져온다.

• 대한두경부종양학회지
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• 제25권1호
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• pp.43-46
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• 2009

Nasopharyngeal carcinomas are epithelial neoplasm derived from nasopharyngeal mucosa. Nasopharyngeal carcinoma involved cervical lymph nodes frequently. However, nasopharyngeal carcinoma with metastatic axillary node after concurrent chemoradiotherapy was reported rarely. We report the patients who was a 34-year-old man diagnosed as nasopharyngeal carcinoma. He was treated by concurrent chemo-radiotherapy. But axillary node metastasis was found after treatment in 2 years. After surgical resection of axillary lymph node, there is no evidence of disease.

• Journal of Chest Surgery
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• 제54권5호
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• pp.342-347
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• 2021

Thoracic surgeons need to be aware of several important points regarding intraoperative lymph node dissection during surgery for non-small cell lung cancer with ground-glass opacities. The first point relates to the need for lymph node dissection during sublobar resection. Since even patients undergoing sublobar resection may benefit from lymph node dissection, it should be selectively performed according to adequate indications, which require further study. Second, there seems to be no difference in postoperative morbidity between systematic sampling and systematic dissection, but the survival benefit from systematic dissection remains unclear. The results of randomized controlled trials on this topic are conflicting, and their evidence is jeopardized by a high risk of bias in terms of the study design. Therefore, further randomized controlled trials with a sound design should investigate this issue. Third, more favorable survival outcomes tend to be positively associated with the number of examined lymph nodes. Minimum requirements for the number of examined lymph nodes in non-small cell lung cancer should be defined in the future. Finally, lobe-specific lymph node dissection does not have a negative prognostic impact. It should not be routinely performed, but it can be recommended in selected patients with smaller, less invasive tumors. Results from an ongoing randomized controlled trial on this topic should be awaited.

• 한국정보전자통신기술학회논문지
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• 제16권5호
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• pp.354-361
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• 2023

빅데이터 분석 시스템들은 다양한 형태의 방대한 데이터를 저장 및 처리, 분석을 위해 MongoDB와 같은 NoSQL 데이터베이스를 적용한다. MongoDB는 환경 구성에 따라 분산 처리 및 데이터 복제를 통해 확장성과 빠른 데이터 처리 속도를 제공한다. 본 논문에서는 구현하는 빅데이터 분석 시스템에 적합한 MongoDB 환경 구성에 대해 연구한다. 성능 평가를 위한 환경은 크게 싱글 노드와 다중 노드 환경으로 구성하였으며, 다중 노드 환경은 데이터 노드의 수를 2대에서 3대까지 확장하여 각 환경별 성능을 측정하였다. 분석 결과, 3차원 이상의 복잡한 데이터 구조의 데이터 처리 속도는 싱글 노드 환경이 2개의 데이터 노드 환경에 비해 약 5.75% 빠르게 처리하지만,3개의 데이터 노드 환경은 싱글 노드 환경에 비해 약 25.15% 이상 빠르게 처리한다. 그러나 데이터 구조가 단순한 1차원 데이터 구조는 다중 노드 환경이 싱글 노드 환경에 비해 약 28.63% 빠르게 처리한다. 향후 본 연구를 기반으로 다양한 데이터 구조 및 방대한 양의 데이터를 통한 실질적인 검증이 필요하다.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.53-62
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• 2011

With the steady growth of mobile technology and applications, demand for more storage in mobile devices has also increased. A lightweight block-level protocol, Internet Advanced Technology Attachment (iATA), has been developed to deliver a cost-effective storage network solution for mobile devices to obtain more storage. This paper seeks to contribute to designing and implementing Load Balancing (LB), Network Monitoring (NM) and Write Replication (WR) modules to improve the protocol's scalability and data availability. LB and NM modules are invoked to collect system resources states and current network status at each associate node (server machine). A dynamic weight factor is calculated based on the collected information and sent to a referral server. The referral server is responsible to analyze and allocate the most ideal node with the least weight to serve the client. With this approach, the client can avoid connecting to a heavily loaded node that may cause delays in subsequent in-band I/O operations. Write replication is applied to the remaining nodes through a WR module by utilizing the Unison file synchronization program. A client initially connected to node IP A for write operations will have no hindrances in executing the relevant read operations at node IP B in new connections. In the worst case scenario of a node crashing, data remain recoverable from other functioning nodes. We have conducted several benchmark tests and our results are evaluated and verified in a later section.

• 대한수의학회지
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• 제31권4호
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• pp.381-387
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• 1991

Deer hemal nodes were studied by gross anatomy and light microscopy. Hemal nodes were scattered in the periphery of thoracic and abdominal aortae, and spherical or avoid in shape. A hemal node consisted of a thin capsule and a hilum, and had numerous small subcapsular and deep sinuses distended by a great number of erythrocytes. Although a few lymphatic nodules and tissues were seen in the parenchyma, no typical cortex and medulla was defined. Blood vessels occurred, but lymph vessel was not observed in nodes. The parenchyma of the hemal node consisted of many erythrocytes and lymphocytes, and a few granulocytes, plasma cells megakaryocytes and macrophages. The stroma was composed of reticular cells and fibers. The capsule and trabecula was a collagenous connective tissue with smooth myofibers. The above findings suggest that the hemal nodes are involved in blood storage, blood filtration and immune reaction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.877-895
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• 2010

The state-of-the-art techniques of storing XML data, modeled as an XML tree, are node-based in the sense that they are centered around XML node labeling and the storage unit is an XML node. In this paper, we propose a generalization of such techniques so that the storage unit is an XML subtree that consists of one or more nodes. Despite several advantages with such generalization, a major problem would be inefficiency in XPath processing where the stored subtrees are to be parsed on the fly in order for the nodes inside them to be accessed. We solve this problem, proposing a technique whereby no parsing of the subtrees involved in XPath processing is needed at all unless they contain the nodes of the final query result. We prove that the correctness of XPath processing is guaranteed with our technique. Through implementation and experiments, we also show that the overhead of our technique is acceptable.