• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.95-97
• /
• 2007

Large area flicker is one of the most annoying image defects, and it is an inherent characteristic of impulsively driven displays such as CRTs. Recently, LCDs have also adopted impulsive driving methods for improved motion picture quality, therefore LCDs can also show large area flicker. Existing metrics do not account for the non-linearity of human brightness perception. This paper presents an improved large area flicker metric to more accurately quantify large area display flicker performance.

• Journal of Ecology and Environment
• /
• v.40 no.1
• /
• pp.34-44
• /
• 2016

Background: Little is known about how chemical water quality is associated with ecological stream health in relation to landuse patterns in a watershed. We evaluated spatial characteristics of water quality characteristics and the ecological health of Dongjin-River basin, Korea in relation to regional landuse pattern. The ecological health was assessed by the multi-metric model of Index of Biological Integrity (IBI), and the water chemistry data were compared with values obtained from the health model. Results: Nutrient and organic matter pollution in Dongjin-River basin, Korea was influenced by land use pattern and the major point sources, so nutrients of TN and TP increased abruptly in Site 4 (Jeongeup Stream), which is directly influenced by wastewater treatment plants along with values of electric conductivity (EC), bacterial number, and sestonic chlorophyll-a. Similar results are shown in the downstream (S7) of Dongjin River. The degradation of chemical water quality in the downstream resulted in greater impairment of the ecological health, and these were also closely associated with the landuse pattern. Forest region had low nutrients (N, P), organic matter, and ionic content (as the EC), whereas urban and agricultural regions had opposite in the parameters. Linear regression analysis of the landuse (arable land; $A_L$) on chemicals indicated that values of $A_L$ had positive linear relations with TP ($R^2=0.643$, p < 0.01), TN ($R^2=0.502$, p < 0.05), BOD ($R^2=0.739$, p < 0.01), and suspended solids (SS; ($R^2=0.866$, p < 0.01), and a negative relation with TDN:TDP ratios ($R^2=0.719$, p < 0.01). Conclusions: Chemical factors were closely associated with land use pattern in the watershed, and these factors influenced the ecological health, based on the multimetric fish IBI model. Overall, the impairments of water chemistry and the ecological health in Dongjin-River basin were mainly attributes to point-sources and land-use patterns.

• Journal of KIISE:Software and Applications
• /
• v.30 no.10
• /
• pp.912-924
• /
• 2003

Design restructuring improves software quality by reorganizing design elements and reduces maintenance cost. Object-oriented metrics can help to detect design flaws and find transformations to reorganize design elements. Basically, the transformations must preserve the behavior of an initial system. This paper describes a metric based restructuring technique preserving the behavior of object-oriented designs, founded on set theory, and gives its validity by applying the technique to applications written in Java. This paper also compares the technique with a technique using simulated annealing algorithm to show its effectiveness.

• Convergence Security Journal
• /
• v.14 no.4
• /
• pp.55-60
• /
• 2014

In this study, we propose a cryptographic module quality evaluation system referenced by ISO/IEC 9000 quality system with Quality, Quality Factor, Quality Subfactor, Metric. Practical application process encryption algorithm based on the encryption algorithm to encrypt the pros and cons valuation of diagnosis, point selection algorithm, analysis, and quality items(quality factor), eliciting constraints derived, such as the cryptographic module design quality evaluation system is set to step 5. The five steps are examples of field-based diagnostic tool for cryptographic operations, the most essential work to be done in order to derive one will work. 2-Factor encryption module for connection between indicator items(quality factor) to identify and ensure the quality of the item the constraints of the environment are two kinds of cryptographic operations. This study is an encryption module and a practical field application system, it presents the standardized model. We have to meet the rapid changes in information technology. The environment, development and the encryption algorithm applied to model a wide variety of on-site development encryption will be able to expect the efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.2
• /
• pp.620-636
• /
• 2015

Survivability is a necessary property of network system in disturbed environment. Recovery ability is a key actor of survivability. This paper concludes network survivability into a novel composite metric, i.e. Network Recovery Degree (NRD). In order to measure this metric in quantity, a concept of Source-Destination Pair (SD Pair), is created to abstract end-to-end activity based on end nodes in network, and the quality of SD Pair is also used to describe network performance, such as connectivity, quality of service, link degree, and so on. After that, a Survivability Test method in large scale Network based on SD pairs, called STNSD, is provided. How to select SD Pairs effectively in large scale network is also provided. We set up simulation environment to validate the test method in a severe destroy scenario and evaluate the method scalability in different large scale network scenarios. Experiment and analysis shows that the metric NRD correctly reflects the effort of different survivability strategy, and the proposed test method STNSD has good scalability and can be used to test and evaluate quantitative survivability in large scale network.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.3B
• /
• pp.204-211
• /
• 2012

Wireless Mesh Network (WMN) has drawn much attention due to wide service coverage with low system cost. However, WMN suffers from high bit error rate, which provides different link capacity among wireless mesh routers. The conventional routing metrics select the path based on link quality. The link with the best quality is preferred as the data transmission path, and they becomes the bottleneck links, which leads to network performance degradation. In this paper, we propose a routing metric that considers the available bandwidth and the number of nodes suffering congestion in the path. Through computer simulations, we verified that the proposed routing metric outperforms the existing routing metrics in terms of average transmission delay, packet loss, system throughput.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.11B
• /
• pp.1676-1684
• /
• 2010

Tactical network environments are characterized by unreliable connectivity, communication links which has limited bandwidth compared to commercial networks and distributed architecture where users have high mobility. The best route should be selected based on the required traffic characteristics which can be a wireless channel environments and a status of nodes which are moving. Those characteristics are self aware and should be a routing decision factor in order to guarantee a reliable data transfer. In this paper we define the requirements of services and traffic characteristics on tactical network environments and suggest the new routing method "AODV-IMTC" based on selective routing metric to enable efficient data transfer in wireless ad hoc networks.

• Journal of Advanced Navigation Technology
• /
• v.13 no.6
• /
• pp.861-875
• /
• 2009

In order to make high quality software and high reliability software, systematic development management and organizational support are essential needed. Since 1990's Software process models such as ISO/IEC 15504 and CMMI have been used to improve organization capability. But these models have problems that are used to apply on large scaled organization or large project and so many practices are actually required. We present characteristics of ISO/IEC 15504, CMMI and K-model can easily apply to small and medium sized business or project, and propose the standard quality metric and accreditate procedure based on K-model for measuring quantitative quality level.

• Journal of Korean Society for Quality Management
• /
• v.33 no.4
• /
• pp.75-87
• /
• 2005

Generally speaking, weapon system is defined as a combination of primary system and support system which are evaluated by capability and operational availability respectively. Recently comparison of total life cycle cost shows that logistic support system is proved to be more important than primary system. However, until now systematic approach to support system development has not been applied in the area of developing support system. We need to construct a universal metric for effectiveness of logistic support system and to cut out whatever activities or support elements which do not contribute to the metric. This paper describes a new approach based on system engineering approach to logistic support system and also classifies five factors of failure, stock-out frequency, administrative delay time, active repair time and logistic delay time that have influence on operational availability of logistic support system.

• Journal of Korean Society for Quality Management
• /
• v.37 no.3
• /
• pp.33-38
• /
• 2009

When we estimate the parameters of software reliability models, we usually use maximum liklihood estimator(MLE). But this method is required a large data set. In particular, when we want to estimate it with small observed data such as early stages of testing, we give rise to the non-existence of MLE. Therefore, it is interesting to look into the influence of parameter estimators obtained using MLE. In this paper, we use two non-homogenous poisson process software reliability growth model: delayed S-shaped model and log power model. In this paper, we calculate the sensitivity of estimators about failure intensity function for two SRGMs respectively.