• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4717-4737
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• 2017

Today, smart grids, smart homes, smart water networks, and intelligent transportation, are infrastructure systems that connect our world more than we ever thought possible and are associated with a single concept, the Internet of Things (IoT). The number of devices connected to the IoT and hence the number of traffic flow increases continuously, as well as the emergence of new applications. Although cutting-edge hardware technology can be employed to achieve a fast implementation to handle this huge data streams, there will always be a limit on size of traffic supported by a given architecture. However, recent cloud-based big data technologies fortunately offer an ideal environment to handle this issue. Moreover, the ever-increasing high volume of traffic created on demand presents great challenges for flow management. As a solution, flow aggregation decreases the number of flows needed to be processed by the network. The previous works in the literature prove that most of aggregation strategies designed for smart grids aim at optimizing system operation performance. They consider a common identifier to aggregate traffic on each device, having its independent static aggregation policy. In this paper, we propose a dynamic approach to aggregate flows based on traffic characteristics and device preferences. Our algorithm runs on a big data platform to provide an end-to-end network visibility of flows, which performs high-speed and high-volume computations to identify the clusters of similar flows and aggregate massive number of mice flows into a few meta-flows. Compared with existing solutions, our approach dynamically aggregates large number of such small flows into fewer flows, based on traffic characteristics and access node preferences. Using this approach, we alleviate the problem of processing a large amount of micro flows, and also significantly improve the accuracy of meeting the access node QoS demands. We conducted experiments, using a dataset of up to 100,000 flows, and studied the performance of our algorithm analytically. The experimental results are presented to show the promising effectiveness and scalability of our proposed approach.

• Journal of Chest Surgery
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• v.9 no.2
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• pp.117-124
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• 1976

Hemorrhage into the biliary system as a consequence of injury to the liver has been called "traumatic hemobilia," a term introduced by Sandblom in 1948. The source of gastrointestinal hemorrhage has been frequently misinterpreted, resulting in inadequate or inappropriate treatment, often with catastrophic results and needless fatalities. It is now being diagnosed with increasing frequency, due to more widespread knowledge of the syndrome and improved diagnostic means. we experienced 2 cases of hemobilia following blunt chest trauma, One patient had! multiple rib fractures on right chest by car traffic accident and 13 days later, suddenly massive melena was developed with nausea, vomiting, jaundice and severe pain on right upper quadrant. And so, he had operated on the ligation of Rt. hepatic artery and partial right hepatectomy for a traumatic hemobilia. The other one also revealed similar symptoms 20 days later following blunt chest injury by falling down accident. However, uneventful recovery was seen without any of surgical intervention in this case.

• ETRI Journal
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• v.34 no.4
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• pp.591-601
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• 2012

Unstructured peer-to-peer (p2p) networks usually employ flooding search algorithms to locate resources. However, these algorithms often require a large storage overhead or generate massive network traffic. To address this issue, previous researchers explored the possibility of building efficient p2p networks by clustering peers into communities based on their social relationships, creating social-like p2p networks. This study proposes a social relationship p2p network that uses a measure based on Hebbian theory to create a social relation weight. The contribution of the study is twofold. First, using the social relation weight, the query peer stores and searches for the appropriate response peers in social-like p2p networks. Second, this study designs a novel knowledge index mechanism that dynamically adapts social relationship p2p networks. The results show that the proposed social relationship p2p network improves search performance significantly, compared with existing approaches.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.787-790
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• 2012

In downtown, construction noise related claims are the most important issues. Sometimes noise related claims halt the construction process. Therefore, Introduction of noise reduction measures is common to construction process with a loud noise. This case is about concrete pouring for mat foundation of super tall building. Concrete pouring process using High Pressure Pumping machine causes high noise level in the vicinity of area. And large number of transit-mixer truck cause traffic congestion. This paper introduces effort and process to prevention of construction noise claims on massive scale concrete pouring.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3357-3376
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• 2015

Wireless sensor network is an important research topic that has attracted a lot of attention in recent years. However, most of the interest has focused on wireless sensor network to gather scalar data such as temperature, humidity and vibration. Scalar data are insufficient for diverse applications such as video surveillance, target recognition and traffic monitoring. However, if we use camera sensors in wireless sensor network to collect video data which are vast in information, they can provide important visual information. Video sensor networks continue to gain interest due to their ability to collect video information for a wide range of applications in the past few years. However, how to efficiently store the massive data that reflect environmental state of different times in video sensor network and how to quickly search interested information from them are challenging issues in current research, especially when the sensor network environment is complicated. Therefore, in this paper, we propose a fast algorithm for extracting key frames from video and describe the design and implementation of key frame extraction and sharing in Android for wireless video sensor network.

• Archives of Reconstructive Microsurgery
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• v.8 no.2
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• pp.120-129
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• 1999

There were many difficulties in the treatment of extensive, massive, and composite defect in the lower extremity until early 1980's. Recently, microscopic reconstruction of wide soft tissue defect is popularized. But, the combined flap, which requires wide coverage of lower extremity after soft tissue sarcoma excision or traffic accident, is still challenging to the orthopaedic surgeons. We experienced 12 cases of combined scapular and latissimus dorsi flap from 1983 to 1997 in the lower extremity reconstruction of soft tissue defect with satisfactory result. There were no serious donor site complications such as functional disturbance of shoulder joint.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1105-1113
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• 2008

Subway is used as a useful transportation method to solve the metropolitan traffic problem for its advantages of being not only accurate, safe and massive, but also of not producing any exhaustion gas in compare with the other ground transportation systems. However, noise inside the car due to concrete based rail track and tunnel structure has become a social problem. So, an analysis on the noise characteristics according to their routes and locations was made on the basis of the actually measured results from the trial run.

• Annual Conference of KIPS
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• 2014.04a
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• pp.696-699
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• 2014

최근 소셜 네트워크 서비스가 확산되면서 대량 트랜잭션 환경에서의 RDBMS 성능에 대한 관심이 높아지고 있다. 본 논문에서는 대량 트랜잭션 환경에서 DBMS가 SQL문을 처리하면서 발생시키는 I/O의 특징을 고려하여 데이터의 쓰기 블록 수와 트랜잭션 간에 발생하는 배타적 Lock의 빈도를 최소화시키기 위한 모델링을 제안하고 일반적인 모델링과 성능 비교 실험을 하였다. 실험 분석 결과 DBMS의 트랜잭션 처리량이 많고 트랜잭션 간의 교착 빈도가 높게 발생할수록 일반적인 모델링보다 제안하는 모델링에서의 SQL문 처리 성능이 우수하였다.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.4
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• pp.149-158
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• 2023

As data utilization is becoming more important recently, the importance of data centers is also increasing. However, the data center is a problem in terms of environment and economy because it is a massive power-consuming facility that runs 24 hours a day. Recently, studies using deep learning techniques to reduce power used in data centers or servers or predict traffic have been conducted from various perspectives. However, the amount of traffic data processed by the server is anomalous, which makes it difficult to manage the server. In addition, many studies on dynamic server management techniques are still required. Therefore, in this paper, we propose a dynamic server management technique based on Long-Term Short Memory (LSTM), which is robust to time series data prediction. The proposed model allows servers to be managed more reliably and efficiently in the field environment than before, and reduces power used by servers more effectively. For verification of the proposed model, we collect transmission and reception traffic data from six of Wikipedia's data centers, and then analyze and experiment with statistical-based analysis on the relationship of each traffic data. Experimental results show that the proposed model is helpful for reliably and efficiently running servers.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.418-423
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• 1979

Chest injuries due to blunt trauma often result in severe derangements that lead to death. And we have to diagnose and treat the patients who have blunt chest trauma immediately and appropriately. A clinical analysis was made on 324 cases of chest injury due to blunt trauma experienced at department of Thoracic and Cardiovascular Surgery, College of Medicine, Kyung Hee University during 8-year period from 1972 to 1979. Of 324 patients of blunt chest injuries, there were 189 cases of rib fracture, 121 of hemothorax or/and pneumothorax, 108 of soft tissue injury of the chest wall only, 41 of lung contusion, 24 of flail chest, 13 of scapular fracture, 7 of diaphragmatic rupture and others. The majority of blunt chest injury patients were traffic accident victims and falls accounted for the next largest group of accidents. Chest injuries were frequently encountered in the age group between 3rd decade and 4th decade [60%] and 238 patients were male comparing to 86 of female [Male: Female = 3:1 ]. In the patients who have the more number of fractured ribs, the more incidence of intrathoracic injury and intraabdominal organ damage were found. The principal associated injuries were head injury on 58 cases, long bone fractures on 37, skull fractures on 12, pelvic fractures on 10, renal injuries on 6 and intraabdominal organ injuries on 5 patients. The principle of early treatment of chest injury due to blunt trauma were rapid reexpansion of the lung by closed thoracotomy which was indicated on 96 cases, but open thoractomy was necessary on 14 cases because massive bleeding, intrapleural hematoma and/or fibrothorax, or diaphragmatic laceration-On 15 cases who were young and have multiple rib fracture with severe dislocation delayed elective open reduction of the fractured ribs with wire was done on the purpose of preserving normal active life. The over all mortality was 2.8% [9 of 324 cases] due to head injury on 3 cases, massive bleeding on 2,wet lung syndrome, acute renal failure on 1 and septicemia on 1 patient.