• Journal of Korea Water Resources Association
• /
• v.53 no.4
• /
• pp.273-283
• /
• 2020

Quantitative forecasting of groundwater levels for the assessment of groundwater variation and vulnerability is very important. To achieve this purpose, various time series analysis and machine learning techniques have been used. In this study, we developed a prediction model based on LSTM (Long short term memory), one of the artificial neural network (ANN) algorithms, for predicting the daily groundwater level of 11 groundwater wells in Hankyung-myeon, Jeju Island. In general, the groundwater level in Jeju Island is highly autocorrelated with tides and reflected the effects of precipitation. In order to construct an input and output variables based on the characteristics of addressing data, the precipitation data of the corresponding period was added to the groundwater level data. The LSTM neural network was trained using the initial 365-day data showing the four seasons and the remaining data were used for verification to evaluate the fitness of the predictive model. The model was developed using Keras, a Python-based deep learning framework, and the NVIDIA CUDA architecture was implemented to enhance the learning speed. As a result of learning and verifying the groundwater level variation using the LSTM neural network, the coefficient of determination (R²) was 0.98 on average, indicating that the predictive model developed was very accurate.

• The KIPS Transactions:PartD
• /
• v.14D no.5
• /
• pp.555-564
• /
• 2007

Internet streaming systems consist of a media server, a streaming sewer, and terminals. The media server delivers multimedia contents such as video and/or audio to the streaming server, which distributes the contents to terminals as well. Existing Internet streaming systems have a bottleneck problem in the streaming server because of the limit of the processing capacity of the streaming server and therefore a streaming server can not accomodate more terminals than the limit. As a solution to this problem, P2P streaming systems have been lately proposed and investigated, using P2P distributed architectures. Actually, however, there exist many difficulties in the design and implementation of P2P streaming systems, because it needs many real computers and various network constructions. In this paper, we have proposed and defined a P2P streaming system model such as the architectural model, the timing model, the behavior model, and the performance metrics. And also we have implemented an NS2 based P2P streaming system simulator called P2PStreamSim. Finally, we have verified it through test simulations and analyzed the results.

• Information Systems Review
• /
• v.7 no.2
• /
• pp.1-21
• /
• 2005

Integrated Railroad Information System(IRIS) Construction Project is one of the super projects in Korea required to invest over 100 billion won and 10,000 engaged manpower until Dec 30, 2004. Composition of this paper is as follows; firstly, examined individual contents and aspects of IRIS, and studied formality and contents that have been based to project methodology for successful propulsion of project in overall situation of SI project progress until present. Secondly, presented for construction background of IRIS as well as Project Management and Project Development Methodologies. Thirdly, described each characteristic and development substance for individual systems after present whole contents and system image of the system. Finally, presented successful propulsion result of this project and development directions. We presented development example laying stress on IRIS's Project contents and propulsion circumstances. Evaluation about operation results should be analyzed and studied in detail operating system from now on.

• Journal of Korea Multimedia Society
• /
• v.12 no.11
• /
• pp.1680-1691
• /
• 2009

To improve the quality of healthcare and build up the health delivery system, electronic health record system is important for healthcare institutions providing health services. However, the systems currently operated in domestic healthcare institutions use independent software interface with distributed environment for data search and process. Therefore, it raises an additional expense to buy or develop each interface module when there is a link to new system and the problem of complexity. To solve these problems, this study implemented the service oriented architecture basis for home nursing service and carried out an assessment. The study defined the process modeling and business requirements based on the scenario of service and drew 17 suitable services based on five verification items for service design. To draw the final service, seven services were selected by service litmus test (SLT). The study found that, by the improvement of business process for healthcare service support department, SOA based information system has an effect of time reduction of patient processing time. In conclusion, to enable the hospital information system to cope with various demands of healthcare consumers, it is necessary to consider the application of SOA technology which has excellent interoperability, reusability and maintenance.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.2
• /
• pp.425-433
• /
• 2016

In smart grid, enhancement of efficiency and interoperability of electric power system is achieved through the connection with outer network, and this induces that power grid system is threatened increasingly, becomes the main target of cyber terrorism, and is sincerely required to design the secure power system. Although SSDLC(Secure System Development Life Cycle) is used for risk management from the design phase, traditional development life cycle is somewhat limited for satisfaction of information security indicator of power control system. Despite that power control system should reflect control entities of information security considering its own characteristics, validation elements are insufficient to apply into real tasks based on existing compliance. To make design of diagnostic model and assessment process for power control system possible and to give a direction for information security and present related indicator, we propose the new risk management framework of power control system which is applied operational security controls and standard architecture presented by IEC 62351 TC 57 with enterprise risk management framework.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.12
• /
• pp.3715-3724
• /
• 2009

Recently, component-based software development is getting accepted in industry as a new effective software development paradigm. Since the introduction of component-based software engineering (CBSE) in later 90's, the CBSD research has focused largely on component modeling, methodology, architecture and component platform. However, as the number of components available on the market increases, it becomes more important to devise metrics to quantify the various characteristics of components. In this Paper, we propose metrics for measuring the complexity, customizability, and reusability of software components. Complexity metric can be used to evaluate the complexity of components. Customizability is used to measure how efficiently and widely the components can be customized for organization specific requirement. Reusability can be used to measure the degree of features that are reused in building applications. We expect that these metrics can be effectively used to quantify the characteristics of components.

• The Journal of the Korea Contents Association
• /
• v.17 no.10
• /
• pp.587-597
• /
• 2017

Recently, the demand for real-time performance in mobile environment is increasing due to the improvement of hardware performance, however a GPOS(General-Purpose Operating System) such as Android and Linux do not provide real-time performance. We developed RTiK(Real-Time implant Kernel) for this problem, but it has the disadvantage of supporting only x86 Architecture. In this paper, we designed and implemented a RTiKA(Real-Time implanted Kernel for ARM) to support real-time in ARM Linux. We used MCT(Multi-Core Timer) timer which replaces Local APIC Timer for real-time support, and we measured the period of generated real-time task for performance verification and evaluation. As the recent the RTiKA can guarantee the operating of several real-time tasks based on the cycle of 1ms.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.1
• /
• pp.1-9
• /
• 2007

At present various methods relating resource access control in grid environment are being studied. Most of the access authorization to grid resource is designed fit to the attributes and the role of user. But resource access control is to be made in the respect of business model to activate grid. Therefore this study suggests a model that can operate resource access control driven by grid accounting information. On the base of collection of accounting information about grid job, processing cost is yielded. If the user's available fund is less than processing cost, it gets to control grid job by the resource access control policy. Finally when grid job is completed, user is assigned to pay the charges for using resource of supplier. Then resource provider gets to supply stable resource in grid by participating it voluntarily to use idle resource. This study is esteemed to realize utility computing environment correspondent to economic principle by ensuring resource access policy of organizations which participate in grid.

• Journal of Korea Multimedia Society
• /
• v.10 no.8
• /
• pp.1078-1091
• /
• 2007

This paper proposes the system to manage profiles effectively that are necessary for content adaptation services. The proposed profiles for providing content adaptation services are used in the various services. However, currently, there are lack of the interoperability in profiles due to the different configuration, which is affected by different services. The service providers also spend a lot of operating costs by operating profiles respectively. To solve theses problems, the system which can integrate and manage the various kinds of the profiles is necessary. Based on profile services architecture and the previous profile research to the necessary functions for the proposed integrated management system of profile are derived. The proposed integrated management system of profile supports also the functions such as receiving, processing, saying, managing, providing and supports profiles that are made of RDF form and comply with the CC/PP specification. The metadata constitution technique and dynamic technique for effective content adaptation also are applied. As a result of performance evaluation the proposed techniques improve the performance 4% compared with the previous techniques.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.11B
• /
• pp.1329-1338
• /
• 2011

This paper proposes an algorithm and hardware architecture for a broadcast communication which has the worst bottleneck among multiprocessor using distributed memory architectures. In conventional systems, collective communication is converted into point-to-point communications by MPI library cell without considering the state of communication port of each processing node which represents the processing node is in busy state or free state. If conflicting point-to-point communication occurs during broadcast communication, the transmitting speed for broadcast communication is decreased. Thus, this paper proposed an algorithm which determines the order of point-to-point communications for broadcast communication according to the state of each processing node. According to the state of each processing node, the proposed algorithm decreases total broadcast communication time by transmitting message preferentially to the processing node with communication port in free state. The proposed MPI unit for broadcast communication is evaluated by modeling it with systemC. In addition, it achieved a highly improved performance for broadcast communication up to 78% with 16 nodes. This result shows the proposed algorithm is useful to improving total performance of MPSoC.