• The Journal of the Korea Contents Association
• /
• v.5 no.6
• /
• pp.49-56
• /
• 2005

To reduce server bottlenecks in client-server computing, each client may have its own cache for later reuse. The pessimistic approach for cache management protocol leads to unnecessary waits, because, it can not be commit a transaction until the transaction obtains all requested locks. In addition, optimistic approach tends to make needless aborts. This paper suggests an efficient optimistic protocol that overcomes such shortcomings. In this paper, we present a simulation-based analysis on the performance of our scheme with other well-known protocols. The analysis was executed under the Zipf workload which represents the popularity distribution on the Web. The simulation experiments show that our scheme performs as well as or better than other schemes with low overhead.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.40 no.11
• /
• pp.42-50
• /
• 2003

In this paper we propose a method of evaluating the performance of a Softswitch that provides call control to voice services in NGN (next generation network). First, we describe the architecture for voice services in NGN and anatomize the call control processes such as call initiation, call re-initiation and call release of a voice connection. kiter that we propose a method of estimating appropriate server capacity of the Softswitch using approximate queuing model. Via numerical experiments we illustrate the implication of the work

• Journal of Korean Society of Steel Construction
• /
• v.25 no.4
• /
• pp.379-388
• /
• 2013

This paper aims to experimentally investigate the fire resistance of U-shaped hybrid composite beams protected by spay and paint insulations. Subjected to two and three hours of the Standard ISO fire, the flexural performance of 4.4m beams with/without imposed loadings was examined with respect to failure criteria such as deflection and deflection rate of the mid-span and temperatures measured in the steel section. The results demonstrated that the proposed configuration of the composite beam is able to achieve a very competitive 3-hour fire resistance rating in economical aspects.

• Korean Journal of Construction Engineering and Management
• /
• v.5 no.1 s.17
• /
• pp.157-167
• /
• 2004

In developing an automated construction system, it is essential to propose a performance evaluation model and methodology, which can measure productivity, quality, safety and economic feasibility in order to verify its superiority. Recently, a tele-operated hume concrete pipe laying machine has been developed to solve several problems related to safety, quality, productivity in conventional method. The primary objective of this study is to propose a model and methodology for the performance evaluation of the developed tele-operated hume concrete pipe laying machine. Furthermore, this study evaluates the automation machine's performance compared with the existing hume pipe laying work by using data which obtained in many field trials. It is anticipated that the proposed model and methodology might be effectively used in analyzing the performance of other automation robots.

• Proceedings of the KAIS Fall Conference
• /
• 2009.05a
• /
• pp.759-761
• /
• 2009

본 논문에서는 스피커폰의 통화 음량 평가 방법을 제안하였다. 이 방법은 ITUT P.340과 3GPP TS26.132의 규격을 참고하여 평가 기준을 만들었다. 제안한 평가 기준은 정량적이므로 스피커폰의 품질 수준을 일괄적으로 관리 할 수 있게 되었다. 실험에서 본 논문의 평가 방법이 기존의 감성적 방법보다 향상된 통화 성능을 보였다.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.5
• /
• pp.83-90
• /
• 2010

The purpose of this study is to establish the standard of fire lane design to improve the performance of disaster prevention in local area. To accomplish it, we have focused on three research methods as below: first, we have expected disaster occurrence based on emergency tendency in local area; second, we have verified fire lane routes design through fire lane modeling and network analysis; third, we have quantitatively examined a possibility of danger of fire lanes through current road network modeling and analysis. The result of this study could be helpful to effective fire lane designs and quantitative analyses.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.1
• /
• pp.46-49
• /
• 2017

In this letter, we investigate the impact of image downsampling on the performance of background subtraction in Full-HD soccer videos. To this end, we evaluated the performance of background subtraction in terms of both accuracy and computational time. Furthermore, for the sake of completeness, we used two different background subtraction methods under the same experimental setup. For the quantitative comparison, we employed the F-measure and FPS(frames per second). We believe that this study serves as a practically useful benchmark for researchers and practitioners in developing a fast background subtraction algorithm adopted for building real-time intelligent soccer video analysis systems.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2009.04a
• /
• pp.100-109
• /
• 2009

화재시 발생하는 연기 및 유독가스를 효과적으로 제어하기 위한 제연설비는 일정한 성능이 요구되며 각 장치에 대한 성능시험방법과 평가기준이 마련되어 있어야 하지만 아직 국내기준은 서류에 의한 예비검사나 부위검사 등으로 되어 있어 성능위주의 평가기준이 미비한 실정이다. 본 연구에서는 제연설비 주요 구성품 중 제연댐퍼에 대해 국내외 기준을 비교분석하고 정량적인 성능기준을 제시하여 이에 따른 평가와 적합성을 분석하고자 하였다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.634-637
• /
• 2003

A tele-operated hume concrete pipe laying machine has been developed to solve several problems on safety, quality, productivity, etc. It is required to propose a performance evaluation model and methodology in order to measure productivity, economic feasibility, quality and safety. The primary objective of this study is to propose a model and methodology for the performance evaluation of the developed tele-operated hume concrete pipe laying machine. Furthermore, this study evaluates its performance compared with the existing hume pipe laying work by using data which obtained in field trials. It is anticipated that the proposed model and methodology might be effectively used in analyzing the performance of other automation robots.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.132-137
• /
• 2000

차량 개발에 있어서 승차감(Ride)과 조향성능(Handling)의 평가는 차량의 동적 성능을 판단하는 주 인자인데, 차량업계에서는 이들 평가의 대부분을 주관적인 방법에 의존하고 있다. 최근에는 주관평가의 문제점을 해소하기 위해 차량의 동적 거동을 직접 측정함으로써 평가를 객관화하려는 시도가 많이 행해지고 있다. 본 연구에서는 숭차감 평가를 위한 정량화 지수를 개발하는데 있어서 저해 요인들을 분석하고 이에 대한 해결방안을 제안함으로써 측정된 물리량을 이용하여 주관평가 결과를 대체할 수 있는 방안을 정립하고자 한다. 우선 정적, 동적 승차감에 대한 모형을 통해서 승차감 정량화의 한계와 기존의 승차감 평가지수에 대해 고찰하고, 실제 차량 시험에서 얻어진 주관 평가치와 측정 가속도간의 상관관계 정립을 통해 관계식을 수립하는 방안에 대해 서술하고자 한다. 이 과정에서 주행시 간헐적으로 들어오는 충격성 입력을 처리하는 방법도 함께 논하였다.