• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.1-13
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, it is necessary to install the facilities that can cope with the initial stormwater. Most researches have been conducted on the design of facilities applying the Low Impact Development (LID) and the reduction effect on rainfall runoff to examine with 1D or 2D numerical models. However, the studies on the examination about flow characteristics and stability of pipe network systems were relatively insufficient in the literature. In this study, the stability of the pipe network system in rainwater storage tank was examined by using 3D numerical model, FLOW-3D. The changes of velocity and dynamic pressure were examined according to the number of rainwater storage tank and compared with the design criteria to derive the optimal design plan for a rainwater storage tank. As a results of numerical simulation with the design values in the previous study, it was confirmed that the velocity became increased as the number of rainwater storage tank increased. And magnitude of the velocity in pipes was formed within the design criteria. However, the velocity in the additional rainwater storage pipe was about 3.44 m/s exceeding the allowable range of the design criteria, when three or more additional rainwater storage tanks were installed. In the case of turbulence intensity and bottom shear stress, the bottom shear stress was larger than the critical shear stress as the additional rainwater storage was increased. So, the deposition of sediment was unlikely to occur, but it should be considered that the floc was formed by the reduction of the turbulence intensity. In addition, the dynamic pressure was also satisfied with the design criteria when the results were compared with the allowable internal pressure of the pipes generally used in the design of rainwater storage tank. Based on these results, it was suitable to install up to two additional rainwater storage tanks because the drainage becomes well when increasing of the number of storage tank and the velocity in the pipe becomes faster to be vulnerable to damage the pipe. However, this study has a assumption about the specifications of the rainwater storage tanks and the inflow of stormwater and has a limitation such that deriving the suitable rainwater storage tank design by simply adding the storage tank. Therefore, the various storage tank types and stormwater inflow scenarios will be asked to derive more efficient design plans in the future.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.11
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• pp.66-73
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• 1993

This paper presents an analog circuit implementation and experimental resuls of the Hopfield type neural network. The proposed architecture enables the reconfiguration betwewn feedback and feedforward networks and employs new circuit designs for the weight supply and storage, analog multilier, nd current-voltage converter, in order to achieve area efficiency as well as function al versatility. The layout design of the eight-neuron neural network is tested as an associative memory to verify its applicability to real world.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.66-71
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• 2019

In digital pathology, an electronic system in the biomedical domain storage of the files is a big constrain and because all the analysis and annotation takes place at every user-end manually, it becomes even harder to manage the data that is being shared inside an enterprise. Therefore, we need such a storage system which is not only big enough to store all the data but also manage it and making communication of that data much easier without losing its true from. A virtual server setup is one of those techniques which can solve this issue. We set a main server which is the main storage for all the virtual machines(that are being used at user-end) and that main server is controlled through a hypervisor so that if we want to make changes in storage overall or the main server in itself, it could be reached remotely from anywhere by just using the server's IP address. The server in our case includes XML-RPC based API which are transmitted between computers using HTTP protocol. JAVA API connects to HTTP/HTTPS protocol through JAVA Runtime Environment and exists on top of other SDK web services for the productivity boost of the running application. To manage the server easily, we use Tkinter library to develop the GUI and pmw magawidgets library which is also utilized through Tkinter. For managing, monitoring and performing operations on virtual machines, we use Python binding to XML-RPC based API. After all these settings, we approach to make the system user friendly by making GUI of the main server. Using that GUI, user can perform administrative functions like restart, suspend or resume a virtual machine. They can also logon to the slave host of the pool in case of emergency and if needed, they can also filter virtual machine by the host. Network monitoring can be performed on multiple virtual machines at same time in order to detect any loss of network connectivity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1211-1219
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• 1999

High quality real-time interactive multimedia services like VOD gained huge momentum by information technology industries during the middle of 1990, but failed successful commercial service deployment despite of the expectations. Among the number of reasons, lack of high bandwidth and QoS support from the network infrastructure have become main cause of the failure. On the other hand, the advance of computer industry-driven storage technologies has been reducing the price of in-home storage dramatically. This fact and the delivery of audio-visual material in a digital form to the home storage make very interesting multimedia service applications possible. It enables anytime content delivery (e.g., during off-peak time) without user interaction and anytime content play and, also, enhances utilization by reducing the loads applied to servers and networks using multicast network infrastructure. In this paper, we propose design and implementation of our anytime multimedia service system based on in-home storage, called IMPRESS-AMS.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.520-532
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• 2002

A new architecture called the Storage Area Network(SAN) was developed in response to the requirements of high availability of data scalable growth and system performance. In order to use SAN more efficiently, most SAN operating systems support storage virtualization concepts that allow users to view physical storage devices attached to SAN as a large volume virtually. A logical volume manager plays a key role in storage virtualization. In order for mapping managers to process snap-shots and reorganizations, an efficient freespace manager is required, and it affects the overall performance of logical volume. In this thesis, we design and implement a freespace manager for logical volume manager. The freespace manager efficiently allocates physical blocks for logical blocks. Also, it processes space allocation requests for suports snapshots and reorganizations.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.42-47
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• 2016

Due to advances such as photovoltaic power generation and energy storage system, energy self-consumption smart home system in which energy management system is built and energy is generated in house has been actively researched. In particular, due to the instability of the grid after the Fukushima nuclear accident, home system in which generating electricity from photovoltaic, storing and using it in energy storage system was commercialized in Japan. While subsidizing renewable energy projects through a combination of solar and energy storage systems in North America and Europe has expanded home installation. In this paper, we describe development of self-consumption smart home system which is connecting photovoltaic system and energy storage system in home area network and operating it based on real-time price. We implemented automated self-consumption home in which optimizing the use of energy from the power grid with minimal user's intervention.

• Food Quality and Culture
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• v.3 no.2
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• pp.53-58
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• 2009

This study was conducted to investigate the quality characteristics of frozen stored mungbean starch gels added with sucrose fatty acid ester (SE). The study showed a delay of gelatinization of mungbean starch by SE addition through the measurements conducted by using Rapid Visco Analyzer (RVA) and Differential Scanning Calorimeter (DSC). In the color of SE added frozen stored gels, lightness (L) and yellowness (b) values were increased compared to those of values measured from freshly prepared gel, whereas redness (a) value was decreased. The addition of 1% SE on mungbean starch gel prevented the color change during frozen storage. Rupture stress and rupture energy of frozen stored gel was higher than those of freshly prepared gel, whereas rupture strain of frozen stored gel was lower than that of freshly prepared gel. The addition of 1% SE on mungbean starch gel prevented the change of rupture characteristics during frozen storage. Texture profile analysis(TPA) characteristics revealed a significant change of the gel texture during frozen storage by showing an increase of hardness of the frozen stored gels compared to the freshly prepared gels with newly discovered fracturability, which resulted to show a large difference of gel texture by showing the disappearance of adhesiveness and large reduction of cohesivenes. The addition of 1% SE on mungbean starch gel prevented the change of TPA characteristics during frozen storage. Scanning electron micrographs showed that network structure of frozen stored gel was more rough than that of freshly prepared gel, and the addition of 1% SE on mungbean starch gel could suppress the breakdown of network structure. Thus the addition of 1.0% SE on mungbean starch gel was appropriate method for remaining gel characteristics during frozen storage.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.520-532
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• 2002

A new architecture called the Storage Area Network(SAN) was developed in response to the requirements of high availability of data, scalable growth, and system performance. In order to use SAN more efficiently, most SAN operating systems support storage virtualization concepts that allow users to view physical storage devices attached to SAN as a large volume virtually. A logical volume manager plays a key role in storage virtualization. In order for mapping managers to process snap-shots and reorganizations, an efficient freespace manager is required, and it affects the overall performance of logical volume. In this thesis, we design and implement a freespace manager for logical volume manager. The freespace manager efficiently allocates physical blocks for logical blocks. Also, it processes space allocation requests for supports snapshots and reorganizations.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.32-40
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• 2007

A mobile device accesses large-sized data in object-based IP storage as an object unit over IP network. It relies heavily on a WLAN device, which has been known as one of the major power consumers. This paper designs and implements low-power object-based IP storage for mobile devices using an efficient WLAN power control. The proposed WLAN power control exploits prefetch buffer to maximize the idleness for incoming network traffic and controls available WLAN power modes to minimize the power consumption. Our experimental results reveal that the proposed WLAN control can save the total power consumption in a PXA270-based mobile device about 9% while playing the multimedia contents through an object-based IP storage device

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5B
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• pp.465-475
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• 2004

Transport Control Protocol (TCP) has been implemented in software running on CPU in end systems, and the protocol processing has appeared as a new bottleneck due to advanced link technology. TCP processing is a critical issue in Storage Area Network (SAN) such as iSCSL, and the overall performance of the Storage Area Network heavily depends on speed of TCP processing. TCP Engine implemented in hardware reduces the load of CPU in end systems as well as accelerates the protocol processing, and hence high speed data processing is achieved. In this paper, we have proposed a hardware engine for TCP processing. TCP engine consists of three major block, TCP Connection block Rx TCP block and Tx TCP block TCP Connection block is responsible for managing TCP connection states. Rx TCP block is responsible for receive flow which receives packets from network and sends to CPU. Rx TCP performs header and data processing and sends header information to TCP connection block and Tx TCP block It also assembles out-of-ordered data to in-ordered before it transfers data to CPU. Tx TCP block is responsible for transmit flow which transfers data from CPU to network. Tx TCP performs retransmission for reliable data transfer and management of transmit window and sequence number. Various test-cases are used to verify the TCP functions. The TCP Engine is synthesized using 0.18 micron technology and results in 51K gates not including buffers for temporal data storage.