• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.409-429
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• 1997

Problems encountered during software development or pteration nay result from defects in the software,ghrdware,or their oterations.Because of their diversity,the determination of the sources of a problem and its corrective adtion requires a centrally controlled system for monitoring provlems and detemining systematiccauses. In the paper,the SPR/SCR management system was developed and applied for the collection and analysis of the error data,process data and product data delected by each phasd in SDLC.There are four objectibes in the SPR/SCR management system.The first is to assure that software errors are documented,corrected,and vot forgottem. The second is to assure that SPR.are assessed for their validity.The third is to provide feedback on SPR status to the developer and the user.The fourth is ot prvide data for measuring and prediciting sofware quality and reliability.These goals could be satisfied by the application of the SPR/SCR mangement system.Also,the accomplishment rate of software reliability,criterion of test completion,estimation of release time, efficient development and management can be reflected by applying the SPR/SCR management system.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.980-987
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• 2012

Nonpoint source pollution causes leaks and overtopping, depending on the state of the sewer network as well as aggravates the pollution load of the aqueous water system as it is introduced into the sewer by wash-off. According, the need for efficient sewer monitoring system which can manage the sewage flowrate, water quality, inflow/infiltration and overflow has increased for sewer maintenance and the prevention of environmental pollution. However, the sewer monitoring is not easy since the sewer network is built in underground with the complex nature of its structure and connections. Sewer decontamination mechanism as well as pipe network monitoring and fault diagnosis of water network system on system analysis proposed in this study. First, the pollution removal pattern and behavior of contaminants in the sewer pipe network is analyzed by using sewer process simulation program, stormwater & wastewater management model for expert (XP-SWMM). Second, the sewer network fault diagnosis was performed using the multivariate statistical monitoring to monitor water quality in the sewer and detect the sewer leakage and burst. Sewer decontamination mechanism analysis with static and dynamic state system results showed that loads of total nitrogen (TN) and total phosphorous (TP) during rainfall are greatly increased than non-rainfall, which will aggravate the pollution load of the water system. Accordingly, the sewer outflow in pipe network is analyzed due to the increased flow and inflow of pollutant concentration caused by rainfall. The proposed sewer network monitoring and fault diagnosis technique can be used effectively for the nonpoint source pollution management of the urban watershed as well as continuous monitoring system.

• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.29-37
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• 2014

Telemetry, satellite event and error information are used to check the satellite status in ground station. Different from telemetry which only informs the parameter value, event and error gives explicit information of a certain operation or status. Event also contains ground action information because every command execution is logged as event. Currently, those information is gathered and applied only for monitoring of the satellite. However, the load of the operation is getting grown because of the excessively increased information of the satellite with the number of satellite increasement. Also, the process of reporting problem to developer (or an expert) induce time delay for satellites fault management. In this paper, we propose a satellite operation assistant system which collects event sequence and stores in different group by its feature, and then recommends or executes an appropriate action for the identified abnormal state. This system is applicable to on board system for resolving LEO-satellite autonomous fault situation since is has limited contact time.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.750-754
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• 2014

Quantitative risk analysis has been performed for a pervaporation process for production of high test peroxide. Potential main accidents are explosion and fire caused by a decomposition reaction. As the target process has a laboratory scale, the consequence is considered to belong to Category 3. An event tree has been developed as a model for occurrence of a decomposition reaction in the target process. The probability functions of the accident causes have been established based on the frequency data of similar events. Using the constructed model, the failure rate has been calculated. The result indicates that additional safety devices are required in order to achieve an acceptable risk level, i.e. an accident frequency less than $10^{-4}/yr$. Therefore, a layer of protection analysis has been applied. As a result, it is suggested to introduce inherently safer design to avoid catalytic reaction, a safety instrumented function to prevent overheating, and a relief system that prevents explosion even if a decomposition reaction occurs. The proposed method is expected to contribute to developing safety management systems for various chemical processes including concentration of hydrogen peroxide.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.11
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• pp.1036-1042
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• 2007

It is rather difficult to improve flight control computer(FLCC) hardware(H/W) development schedule due to lack of commercial off-the-self(COTS) tools or target specific tools. Thus, it is suggested to develop an enhanced process utilizing modeling, simulation and virtual reality tools. This paper presents H/W design process enhancement tool(PET) for FLCC design requirements such as FLCC input/output(I/O) signal flow, I/O fault detection, failure management algorithm, circuit logic, PCB assembly configuration and installation utilizing simulation and visualization in virtual space. New tool will provide simulation capability of various FLCC design configuration including shop replaceable unit(SRU) level assembly/dis-assembly utilizing open flight format 3-D modeling data.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.321-326
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• 2008

The software defects that are not found in the course of a project frequently appear during the conduct of the maintenance procedure after the complete development of the software. As the frequency of surfacing of defects during the maintenance procedure increases, the cost likewise increases, and the quality and customer reliability decreases. The defect rate will go down only if cause analysis and process improvement are constantly performed. This study embodies the defect tracking system (DTS) by considering the Pareto principle: that most defects are repetitions of defects that have previously occurred. Based on the records of previously occurring defects found during the conduct of a maintenance procedure, DTS tracks the causes of the software defects and provides the developer, operator, and maintenance engineer with the basic data for the improvement of the software concerned so that the defect will no longer be manifested or repeated. The basic function of DTS is to analyze the defect type, provide the measurement index for it, and aggregate the program defect type. Doing these will pave the way for the full correction of all the defects of a software as it will enable the defect correction team to check the measured defect type. When DTS was applied in the software configuration management system of the W company, around 65% of all its software defects were corrected.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.660-670
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• 2009

Neighboring construction becomes mainstream of Ground excavation in downtown area. This causes the displacement, deformation, stress condition, etc of the ground surroundings. Therefore Neighboring construction have an effect on Neighboring structure. All these years a lot of Neighboring construction carried out, and the accumulation of technology also get accomplished. But earth retaining structure collapse happens yet. Types of earth retaining structure collapse are 12. 1. Failure of anchor or strut system, 2. Insufficiency of penetration, 3. H-pile Failure on excessive bending moment, 4. Slope sliding failure, 5. Excessive settlement of the back, 6. Deflection of H-pile, 7. Joint failure of coupled H-pile, 8. Rock failure when H-pile penetration is rock mass, 9. Plane arrangement of support systems are mechanically weak, 10. Boiling, 11. Heaving, 12. Over excavation. But field collapses are difficult for classification according to the type, because collapse process are complex with various types. When we consider the 12 collapse field, insufficient recognition of ground condition is 4 case. Thorough construction management prevents from fault construction. For limitations of soil survey, It is difficult to estimate ground condition exactly. Therefore, it should estimate the safety of earth retaining system, plan for necessary reinforcement, according to measurement and observation continuously.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5269-5286
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• 2018

Task scheduling is one of the key issues in improving system performance and optimizing resource management in cloud computing environment. In order to provide appropriate services for heterogeneous users, we propose a novel task scheduling strategy with service differentiation, in which the delay sensitive tasks are assigned to the rapid cloud with high-speed processing, whereas the fault sensitive tasks are assigned to the reliable cloud with service restoration. Considering that a user can receive service from either local SaaS (Software as a Service) servers or public IaaS (Infrastructure as a Service) cloud, we establish a hybrid queueing network based system model. With the assumption of Poisson arriving process, we analyze the system model in steady state. Moreover, we derive the performance measures in terms of average response time of the delay sensitive tasks and utilization of VMs (Virtual Machines) in reliable cloud. We provide experimental results to validate the proposed strategy and the system model. Furthermore, we investigate the Nash equilibrium behavior and the social optimization behavior of the delay sensitive tasks. Finally, we carry out an improved intelligent searching algorithm to obtain the optimal arrival rate of total tasks and present a pricing policy for the delay sensitive tasks.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.5
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• pp.496-502
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• 2016

In this study, we investigated the comparative NHPP software model based on learning techniques that operators in the process of software testing and development of software products that can be applied to software test tool. The life distribution was applied Makeham distribution based on finite fault NHPP. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. As a result, the learning factor is larger than automatic error that is usually well-organized model could be established. This paper, a trust characterization of applying using time among failures and parameter approximation using maximum likelihood estimation, after the effectiveness of the data through trend examination model selection were well-organized using the mean square error and $R^2$. From this paper, the software operators must be considered life distribution by the basic knowledge of the software to confirm failure modes which may be helped.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.415-422
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• 2004

Automation systems improve the productivity of works which relate to product design, facilities management, fault processing and quality evaluation. In these systems, the description language for monitoring and control process is called new control language. These are five flow control languages : IL, ST, FBD, SFC and LD. IL and ST are based on left form. FBD, SFC and LD are based on graphic form. Generally, a software which monitors and controls a system is allowed to use just one flow control language. It is impossible to use more than two languages for simulation in the same system environment. In this paper, we analyzed the characteristics of flow control languages and the process of programming in the legacy system. In addition, for the Integrated processing of languages, we propose Extended ST based on the high-level ST language. Based on this research, we implement a graphical language editor and EST-IL convertor. The graphical language editor makes sequence rules, and converts graphical language into EST. EST-IL convertor has a function to convert EST into IL which is similar to assembly language. As the result of this paper, we present a scheme which integrates all the flow control language processing based on IL.