• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.3
• /
• pp.18-26
• /
• 2017

Defense industries which require high reliability need an optimized quality management system with well-planned implementation. And the government should examine the overall status of defense industries, then establish practical policies with a proper support plan in required areas to upgrade the quality management level of manufacturers. Thus, DTaQ developed the model for 2 years from 2014, which specialized in quality management level analysis for defense industries. And a survey has been undertaken with that model by DTaQ and Korea Research Center in 2016. The surveyed companies randomly sampled among those which have more than 30 employees and delivery history over past 3 years, and finally 106 defense industries were selected. This paper present survey method and indexes for survey of defense industry quality management level. The survey was conducted in the order of planning, data collection and data processing, and the validity and reliability of the data were verified to increase objectivity of survey results. The survey contents mainly consist of system quality and management quality. System quality includes Product Development Management, Production Operation Management, supply chain quality management, Safety & Environment Management and Reliability Management, on the other hand, management quality includes Strategic Leadership, Human Resource Management, Customer Market Management and Information & Knowledge Management. Thus this proposes the current overall quality management status of the 106 defense industries and shows level differences by company sizes and manufacturing sectors based on the result of survey. Specifically, this paper enables to track the areas which need prompt government support with the policy directions to make quality management level higher. Therefore, it is expected that this can be used as reference data in establishing quality policies for military supplies in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.7
• /
• pp.2257-2285
• /
• 2022

Cyber-physical systems (CPS) have been growing exponentially due to improved cloud-datacenter infrastructure-as-a-service (CDIaaS). Incremental expandability (scalability), Quality of Service (QoS) performance, and reliability are currently the automation focus on healthy Tier 4 CDIaaS. However, stable QoS is yet to be fully addressed in Cyber-physical data centers (CP-DCS). Also, balanced agility and flexibility for the application workloads need urgent attention. There is a need for a resilient and fault-tolerance scheme in terms of CPS routing service including Pod cluster reliability analytics that meets QoS requirements. Motivated by these concerns, our contributions are fourfold. First, a Distributed Non-Recursive Cloud Model (DNRCM) is proposed to support cyber-physical workloads for remote lab activities. Second, an efficient QoS stability model with Routh-Hurwitz criteria is established. Third, an evaluation of the CDIaaS DCN topology is validated for handling large-scale, traffic workloads. Network Function Virtualization (NFV) with Floodlight SDN controllers was adopted for the implementation of DNRCM with embedded rule-base in Open vSwitch engines. Fourth, QoS evaluation is carried out experimentally. Considering the non-recursive queuing delays with SDN isolation (logical), a lower queuing delay (19.65%) is observed. Without logical isolation, the average queuing delay is 80.34%. Without logical resource isolation, the fault tolerance yields 33.55%, while with logical isolation, it yields 66.44%. In terms of throughput, DNRCM, recursive BCube, and DCell offered 38.30%, 36.37%, and 25.53% respectively. Similarly, the DNRCM had an improved incremental scalability profile of 40.00%, while BCube and Recursive DCell had 33.33%, and 26.67% respectively. In terms of service availability, the DNRCM offered 52.10% compared with recursive BCube and DCell which yielded 34.72% and 13.18% respectively. The average delays obtained for DNRCM, recursive BCube, and DCell are 32.81%, 33.44%, and 33.75% respectively. Finally, workload utilization for DNRCM, recursive BCube, and DCell yielded 50.28%, 27.93%, and 21.79% respectively.

• Journal of Broadcast Engineering
• /
• v.13 no.6
• /
• pp.892-904
• /
• 2008

As a video encoding in resource constrained environments such as sensor networks has become an important issue, DVC(Distributed Video Coding) has been intensively investigated as a solution for light weighted video encoding problem. Known as one of the representative schemes of DVC, the Wyner-Ziv coding generates side information of current frame only at decoder, using correlation among frames, and reconstructs video through noise elimination on the side information using channel code. Accordingly, the better quality of side information brings less channel noise, thus attains better coding performance of the Wyner-Ziv coder. However, since it is hard for decoder to generate an accurate side information without any information of original frame, a method to successively improve side information using successively decoded original frame, based on decoding reliability, was previously developed. However, to improve side information from decoding results, not only an error rate of the decoding result as a reliability, but also the amount of reliable information from the decoding result is important. Therefore, we propose TDWZ(Transform-domain Wyner-Ziv coding) with successively improving side information based on decoding reliability considering not only an error rate but also the amount of reliable information of the decoding results. Our experiment shows the proposed method gains average PSNR up to 1.7 dB over the previous TDWZ, that is without successive side information improvement.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.273-277
• /
• 2010

This research was performed to examine changes in the timing of the growth of crops along with changes in temperatures due tochanges and to analyze the change of water-supply-reliability by adding an analysis of the change of agricultural water supply patterns in the basin area of Miryang dam in Korea. Had-CM3 model from U.K. was the tool adopted for the GCM model, a stochastic, daily-meteorology-generation-model called LARS-WG was alsoused for downscaling and for the climate change scenario (A1B) which represents Korea's circumstances best. First of all, to calculate changes in the timing of the growth of crops during this period, the theory of GDD was applied. Except for the period of transplanting and irrigation, there was no choice but to find the proper accumulated temperature by comparing actual temperature data and the supply pattern of agricultural use due to limited temperature data. As a result, proper temperatures were found for each period. $400^{\circ}C$ for the preparation period of a nursery bed, $704^{\circ}C$ for a nursery bed's period, $1,295^{\circ}C$ for the rice-transplanting period, $1,744^{\circ}C$ for starting irrigation, and $3,972^{\circ}C$ for finishing irrigation. To analyze future agricultural supply patter changes, the A1B scenario of Had-CM3 model was adopted, and then Downscaling was conducted adopting LARS-WG. To conduct a stochastical analysis of LARS-WG, climate scenarios were generated for the periods 2011~2030, 2046~2065, 2080~2099 using the data of precipitation andMax/Min temperatures collected from the Miryang gauging station. Upon reviewing the result of the analysis of accumulated temperatures from 2011~2030, the supply of agricultural water was 10 days earlier, and in the next periods-2046~2065, 2080~2099 it also was 10 days earlier. With these results, it is assumed that the supply of agricultural water should be about 1 month ahead of the existing schedule to meet the proper growth conditions of crops. From the results of the agricultural water supply patterns should be altered, but the reliability of water supply becomes more favorable, which is caused from the high precipitation change. Furthermore, since the unique characteristics of precipitation in Korea, which has high precipitation in the summer, water-supply-reliability has a pattern that the precipitation in September could significantly affect the chances of drought the following winter and spring. It could be more risky to make changes to the constant supply pattern under these conditions due to the high uncertainty of future precipitation. Although, several researches have been conducted concerning climate changes, in the field of water-industry, those researches have been solely dependent on precipitation. Even so, with the high uncertainty of precipitation, it is difficult for it to be reflected in government policy. Therefore, research in the field of water-supply-patterns or evapotranspiration according to the temperature or other diverse effects, which has higher reliability on anticipation, could obtain more reliable results in the future and that could result in water-resource maintenance to be safer and a more advantageous environment.

• Journal of Korea Water Resources Association
• /
• v.55 no.9
• /
• pp.687-700
• /
• 2022

For comprehensively assessment the water resources performance of multi-purpose dams and water supply dams in South Korea, a methodology was proposed to utilize the durational reliability along with the integrated auxiliary indicators including resiliency, dimensionless vulnerability, water resource efficiency, specific inflow, and specific water supply. In addition, for the purpose of sustainable dam operation in the future, a plan to grade the water resources performance was presented to periodically evaluate the performance and determine the priority of each dam's structural or non-structural planning according to the evaluation results. As major results, in the case of Sumjingang Dam, the durational reliability was 99.0%, but the integrated auxiliary index was the lowest of 44 points, which was 5th grade. This means that despite the current high reliability, hydrological changes due to future climate change or regional change of water demand-supply balance can have significant impacts on the water resources performances. In contrast, the Chungju Dam with a durational reliability of 93.0%, which is below the average among all multi-purpose dams, shows the 76 points of the integrated auxiliary index, which is 3^rd highest following the Soyanggang Dam and the Namgang Dam. Nevertheless, due to the size of the basin, the specific inflow is sufficiently high as 185%, so the actual performance could be evaluated relatively high. The water supply dams designed for a single purpose tend to be evaluated relatively high because they have a high proportion of industrial and municipal water supply and have enough room for the supply capacity.

• Journal of Korea Water Resources Association
• /
• v.57 no.6
• /
• pp.409-419
• /
• 2024

Climate change is already impacting sustainable water resource management. The influence of climate change on water supply from reservoirs has been generally assessed using climate change scenarios generated based on global climate models. However, inherent uncertainties exist due to the limitations of estimating climate change by assuming IPCC carbon emission scenarios. The decision scaling approach was applied to mitigate these issues in this study focusing on four reservoir watersheds: Chungju, Yongdam, Hapcheon, and Seomjingang reservoirs. The reservoir water supply reliablity was analyzed by combining the rainfall-runoff model (IHACRES) and the reservoir operation model based on HEC-ResSim. Water supply reliability analysis was aimed at ensuring the stable operation of dams, and its results ccould be utilized to develop either structural or non-structural water supply plans. Therefore, in this study, we aimed to assess potential risks that might arise during the operation of reserviors under various climate conditions. Using observed precipitation and temperature from 1995 to 2014, 49 climate stress scenarios were developed (7 precipitation scenarios based on quantiles and 7 temperature scenarios ranging from 0℃ to 6℃ at 1℃ intervals). Our study demonstrated that despite an increase in flood season precipitation leading to an increase in reservoir discharge, it had a greater impact on sustainable water management compared to the increase in non-flood season precipitation. Furthermore, in scenarios combining rainfall and temperature, the reliability of reservoir water supply showed greater variations than the sum of individual reliability changes in rainfall and temperature scenarios. This difference was attributed to the opposing effects of decreased and increased precipitation, each causing limitations in water and energy-limited evapotranspiration. These results were expected to enhance the efficiency of reservoir operation.

• Journal of Fisheries and Marine Sciences Education
• /
• v.21 no.1
• /
• pp.16-27
• /
• 2009

The purpose of this study was to develop of learning strategy scale for college students. This study further classified several sub-areas and defined each concepts of learning strategy. Based upon the classification of each sub-areas, tentative test items were developed through the verification of validity by three professionals. A pilot study of the developed scale was administered to 239 college students. And the research collected major data from 1,012 college students. Data were analyzed to obtain item quality, reliability, and validity analysis. The results of this study were as follows. The scale for learning strategy was defined by eight factors and they were 'self-management strategy', 'examination-readiness strategy', 'cognitive strategy', 'memorizing strategy', 'reporting strategy', 'resource-utilization strategy', 'self-regulated strategy', 'cooperative learning strategy'. The results of the confirmatory factor analysis proved the eight factors in the learning strategy. And criterion validity evidence was also obtained from a correlation analysis of the level of academic achievement.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2002.11a
• /
• pp.195-199
• /
• 2002

Requirements of a well-designed VPNs(Virtual Private Networks) are scalability, performance, reliability, ease of management, interoperability and security. Tunneling is a important technology to support these. This paper researches VPNs tunneling technologies used currently and proposes VPN service models for the scalability that is a problem in VPNs and for the resource limit of Mobile Station in Mobile VPNs environment.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2573-2580
• /
• 2011

SMRT(Seoul Metropolitan Rapid Transit Corporation) changed PC-oriented office system to Smart-Phone oriented mobile office system(STnF: SMRT Talk & Flash), and provided smart phone to all staffs. STnF make it possible not only voice communication between staff, but also to input and inquiry all kind of information related to work(ex: Facility maintenance, Rolling Stock management, office management, Finance, human resource etc.) based on smart phone. STnF conquers the limitation of time and space. All staffs can commute to the site directly to reduce moving time and to share information between staffs, so SMRT improve speed and reliability of work by making a quick decision and action on the spot. After introduction of STnF, within 1 year, the equipment failure ratio fell to 47%. Mobile office system reduced and level-off the step of approval. so enhanced civil customer service. Quantification and scientific movement of work make it fast evolution and development. These business improvement make it possible to put more outstanding manpower on new business and R&D project, and this contributes to company's management effectiveness.

• ETRI Journal
• /
• v.21 no.3
• /
• pp.6-15
• /
• 1999

Many studies in the software reliability have attempted to develop a model for predicting the faults of a software module because the application of good prediction models provides the optimal resource allocation during the development period. In this paper, we consider the change request data collected from the field test of the software module that incorporate a functional relation between the faults and some software metrics. To this end, we discuss the general aspect if regression method, the problem of multicollinearity and the measures of model evaluation. We consider four possible regression models including two stepwise regression models and two nonlinear models. Four developed models are evaluated with respect to the predictive quality.