• KIPS Transactions on Computer and Communication Systems
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• v.4 no.1
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• pp.15-22
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• 2015

Estimating the number of distinct values is really well-known problems in network data measurement and many effective algorithms are suggested. Recent works have built upon technique called Linear Counting to solve the estimation problem for massive sets or spreaders in small memory. Sampling is used to reduce the measurement data, and it is assumed that sampling gives bad effect on the accuracy. In this paper, however, we show that the sampling on multi-set estimation sometimes gives better results for CSE with sampling than for MCSE that examines all the packets without sampling in terms of accuracy and estimation range. To prove this, we presented mathematical analysis, conducted experiment with real data, and compared the results of CSE, MCSE, and CSES.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.307-315
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• 1988

A clinical analysis was performed on 97 cases of chest injuries experienced at Department of Thoracic and cardiovascular Surgery, Armed Forces Capital Hospital during 2 years period from 1986 to 1988. Of 97 patients of chest trauma, 39 cases were result from penetrating injuries whereas 58 cases were from non-penetrating injuries, and there were 77 cases of hemothorax and / or pneumothorax, 47 of rib fracture, 8 of foreign body, 6 scapular and clavicle fracture, 5 of diaphragmatic injuries, 4 of paraplegia. The majority of chest injuries were encounted in the age group between 21 and 30 years-old, mean age was 25.9 years-old and all cases were male except one. Gun-shot wound was the most common cause in the penetrating injuries and the majority of non-penetrating chest injury patients were traffic accident and fist or kick accounted for next. The principles of therapy for chest trauma were rapid expansion of the lung by closed thoracostomy[45 cases] and thoracentesis only[3 cases] but thoracotomy done at 27 cases because of massive bleeding or intrapleural hematoma, foreign body, cardiac injury, diaphragmatic injury and bronchial rupture. The over-all mortality was 2.07 percent[2 cases among all], a case was from penetrating injuries and another was from non-penetrating injuries.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2C
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• pp.283-290
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• 2004

With the development of Web technologies, the demand for multimedia contents and network bandwidth is increasing explosively. In this situation, Caching, P2P and CDN are using for fast transmission with low traffic. In this research, we designed and implemented a redirection system for best replica selection where contents are distributed to multiple replicated web servers. This redirection system selects a close and least loaded replica and redirect a client's request to the replica. As a result, this system improved user-perceived performance. It is expected that this redirection system will contribute to the faster and more stable transmission of massive multimedia contents.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.329-334
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• 2009

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. To reduce the interior noise of subway train, the side part of rolling stock should have a noise blocking system fur low band frequency noise, the floor of it should have that for medium range frequency noise and the side part as well as lower part of it should have good noise reduction and absorption function.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1142-1144
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• 1997

A case of fatal hematemesis due to an aberrant right subclavian arterioesophageal fistula which is a rare complication of the vascular ring is presented. A 42-year-old man with multiple injury by traffic accident presented severe upper gastrointestinal bleeding and was taken emergent operation. He was keeping tracheostomy tube and nasogastric tube for 7 weeks. We could find an aberrant right subclavian arterioesophageal fistula through left thoracotomy which was made by irritation of the prolonged nasogastric ube. We carried division of the aberrant right subclavian artery and fistulectomy. He was doing well postoperatively. But massive bleeding occurred at the fifth postoperative day. We performed emergent reoperation at CCU and found the tear point on the suture site of the aorta, which might be developed due to irritation of the chest tube andfor infection of the surrounding tissues. He was expired at the 8th postoperative day due to ischemic brain damage.

• Current Optics and Photonics
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• v.1 no.4
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• pp.315-324
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• 2017

In recent years, multicast services such as high-definition television (HDTV), video conferencing, interactive distance learning, and distributed games have increased exponentially, and wavelength-division multiplexing (WDM) networks are considered to be a promising technology due to their support for multicast applications. Multicast survivability in WDM networks has been the focus of extensive attention since a single-link failure in an optical network may result in a massive loss of data. But the improvement of network survivability increases energy consumption due to more resource allocation for protection. In this paper, an energy-efficient multicast algorithm (EEMA) is proposed to reduce energy consumption in WDM networks. Two cost functions are defined based on the link state to determine both working and protection paths for a multicast request in WDM networks. To increase the number of sleeping links, the link cost function of the working path aims to integrate new working path into the links with more working paths. Sleeping links indicate the links in sleep mode, which do not have any working path. To increase bandwidth utilization by sharing spare capacity, the cost function of the protection path is defined to use sleeping fibers for establishing new protection paths. Finally, the performance of the proposed algorithm is evaluated in terms of energy consumption, and also the blocking probability is evaluated under various traffic environments through OPNET. Simulation results show that our algorithm reduces energy consumption while maintaining the quality of service.

• ETRI Journal
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• v.39 no.6
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• pp.820-831
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• 2017

File systems and applications try to implement their own update protocols to guarantee data consistency, which is one of the most crucial aspects of computing systems. However, we found that the storage devices are substantially under-utilized when preserving data consistency because they generate massive storage write traffic with many disk cache flush operations and force-unit-access (FUA) commands. In this paper, we present DJFS (Delta-Journaling File System) that provides both a high level of performance and data consistency for different applications. We made three technical contributions to achieve our goal. First, to remove all storage accesses with disk cache flush operations and FUA commands, DJFS uses small-sized NVRAM for a file system journal. Second, to reduce the access latency and space requirements of NVRAM, DJFS attempts to journal compress the differences in the modified blocks. Finally, to relieve explicit checkpointing overhead, DJFS aggressively reflects the checkpoint transactions to file system area in the unit of the specified region. Our evaluation on TPC-C SQLite benchmark shows that, using our novel optimization schemes, DJFS outperforms Ext4 by up to 64.2 times with only 128 MB of NVRAM.

• Structural Engineering and Mechanics
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• v.39 no.5
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• pp.621-642
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• 2011

Passive tuned mass dampers (TMDs) efficiently suppress vibrations induced by quasi-stationary dynamic inputs, such as winds, sea waves or traffic loads, but may prove of little use against pulse-like excitations, such as near-field (NF) ground motions. The extent of such impairment is however controversial, partly due to the different evaluation criteria adopted within the literature, partly to the limited number of seismic records used in most investigations. In this study, three classical techniques and two new variants for designing a TMD on an SDOF structure are tested under 338 NF records from the PEER NGA database, including 156 records with forward-directivity features. Percentile response reduction spectra are introduced to statistically assess TMD performance, and TMD robustness is verified through Monte Carlo simulations. The methodology is extended to a variety of MDOF bending-type and shear-type frames, and simulated on a case study building structure recently constructed in Central Italy.Results offer an interesting insight into the performance of TMDs against NF earthquakes, ultimately showing that, if properly designed and sufficiently massive, TMDs are effective and robust even in the face of pulse-like ground motions. The two newly proposed design techniques are shown to generally outperform the classical ones.

• Anxiety and mood
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• v.8 no.2
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• pp.71-78
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• 2012

The mass social trauma, such as organized violence, wars, oppression by dictatorships and massive terrorist attacks, exposes thousands of people to trauma in a short period of time. Therefore, the mass social trauma is distinguished from individualized trauma, such as a violent attack, rape or a traffic accident in that it results in multiple and extended consequences beyond the individual. During the Khmer Rouge regime, one quarter of the Cambodian population was killed as a result of malnutrition, forced labor and mass killings. Until now, its evil continues to affect Cambodian's physical and mental health problems. Although there is ongoing debate, to date, no consensus has been reached supporting a clear set of recommendations for the intervention and longitudinal study regarding the influence of killing field massacre being too little. And comparative cultural studies, such as comparing the East to West or other Asian cultures are also lacking. This article gives an overview of previous study results about the mental health of Cambodians, and suggests a possible research issue and therapeutic interventions to determine the impact of mass trauma to the members of society and post-traumatic recovery factors.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.9
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• pp.495-502
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• 2004

A rapid growth of the Internet user and rich media content cause an excessive server load and high network traffic, and thus it decreases the quality of service. A solution to this problem is to distribute the content on multiple replicated servers. However, in this circumstance, clients face additional task of selecting the best server to provide proper so${\gamma}$vice which clients request. This paper is intended to propose an adaptive server selection mechanism for a client request based on distance and server load. This will offer a fast and scalable service in response to the increase of massive and realtime multimedia content and contribute to floating a new business model of digital content service.