• Kyungpook Mathematical Journal
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• v.57 no.3
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• pp.433-439
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• 2017

It is well known that an integral domain D is a Dedekind domain if and only if D is a Noetherian almost Dedekind domain. In this paper, we show that an integral domain D is a Dedekind domain if and only if D is an almost Dedekind domain such that Max(D) is a Noetherian topological space as a subspace of Spec(D) with respect to the Zariski topology. We also give a new characterization of ZPI-rings.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.479-488
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• 2001

As the SoC designs complexity constantly increases, the simulation that uses their software models simply takes too much time. To solve this problem, FPGA-based logic emulators have been developed and commonly used in the industry. However, FPGA-based logic emulators are facing with the problems of which not only very low FPGA resource usage rate due to the very limited number of pins in FPGAs, but also the emulation speed getting slow drastically as the complexity of designs increases. In this paper, we proposed a new innovative emulation architecture and its software that has high FPGA resource usage rate and makes the emulation extremely fast. The proposed emulation system has merits to overcome the FPGA pin limitation by pipelined ring which transfers multiple logic signal through a single physical pin, and it also makes possible to use a high speed system clock through the intelligent ring topology. In this topology, not only all signal transfer channels among EPGAs are totally separated from user logic so that a high speed system clock can be used, but also the depth of combinational paths is kept swallow as much as possible. Both of these are contributed to achieve high speed emulation. For pipelined singnals transfer among FPGAs we adopt a few heuristic scheduling having low computation complexity. Experimental result with a 12 bit microcontroller has shown that high speed emulation possible even with these simple heuristic scheduling algorithms.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.197-203
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• 2012

This paper studies network recovery method using logical multiple ring architecture embedded in WDM optical Internet environment. The multiple ring-based recovery method provides fast and simple network restoration operation, and performs local recovery that is detouring the failed link. The multiple ring architecture can provide higher resource efficiency by sharing the backup routes and reducing the number of spare wavelengths. This paper calculates the required spare capacity ratio using Cut-Sets in the given network topology and performs simulation for comparative analysis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.1
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• pp.5-25
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• 2009

In recent years the popularity of multi-hop wireless networks has been growing. Its flexible topology and abundant routing path enables many types of applications. However, the lack of a centralized controller often makes it difficult to design a reliable service in multi-hop wireless networks. While packet routing has been the center of attention for decades, recent research focuses on data discovery such as file sharing in multi-hop wireless networks. Although there are many peer-to-peer lookup (P2P-lookup) schemes for wired networks, they have inherent limitations for multi-hop wireless networks. First, a wired P2P-lookup builds a search structure on the overlay network and disregards the underlying topology. Second, the performance guarantee often relies on specific topology models such as random graphs, which do not apply to multi-hop wireless networks. Past studies on wireless P2P-lookup either combined existing solutions with known routing algorithms or proposed tree-based routing, which is prone to traffic congestion. In this paper, we present two wireless P2P-lookup schemes that strictly build a topology-dependent structure. We first propose the Ring Interval Graph Search (RIGS) that constructs a DHT only through direct connections between the nodes. We then propose the ValleyWalk, a loosely-structured scheme that requires simple local hints for query routing. Packet-level simulations showed that RIGS can find the target with near-shortest search length and ValleyWalk can find the target with near-shortest search length when there is at least 5% object replication. We also provide an analytic bound on the search length of ValleyWalk.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.667-694
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• 2015

The suspended dome system is a new structural form that has become popular in the construction of long-span roof structures. Suspended dome is a kind of new pre-stressed space grid structure that has complex mechanical characteristics. In this paper, an optimum topology design algorithm is performed using the enhanced colliding bodies optimization (ECBO) method. The length of the strut, the cable initial strain, the cross-sectional area of the cables and the cross-sectional size of steel elements are adopted as design variables and the minimum volume of each dome is taken as the objective function. The topology optimization on lamella dome is performed by considering the type of the joint connections to determine the optimum number of rings, the optimum number of joints in each ring, the optimum height of crown and tubular sections of these domes. A simple procedure is provided to determine the configuration of the dome. This procedure includes calculating the joint coordinates and steel elements and cables constructions. The design constraints are implemented according to the provision of LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Constitution). This paper explores the efficiency of lamella dome with pin-joint and rigid-joint connections and compares them to investigate the performance of these domes under wind (according to the ASCE 7-05), dead and snow loading conditions. Then, a suspended dome with pin-joint single-layer reticulated shell and a suspended dome with rigid-joint single-layer reticulated shell are discussed. Optimization is performed via ECBO algorithm to demonstrate the effectiveness and robustness of the ECBO in creating optimal design for suspended domes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1049-1057
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• 2017

In-vehicle multimedia systems are one of the most important factors in the automotive industry. Especially, multimedia systems are more important in advanced commercial vehicles such as premium express buses. In this paper, we proposed a multimedia streaming system architecture using MEP(MOST Ethernet Packets) for premium express buses based on MOST150. We have designed and implemented the prototype of proposed multimedia streaming system. We have designed a board based on i.MX6 to operate a proposed multimedia streaming system. The software has designed a multimedia system for premium express buses based on Android which is an open source platform. MOST(Media Oriented Systems Transport) is a high-speed multimedia network technology for in-vehicle multimedia system. The MOST network is able to manage up to 64 devices and ring topology is used basically. In addition, the MOST Network meets EMI(Electro-Magnetic Interference)/ EMC(Electro-Magnetic Compatibility) requirements because it uses plastic optical fibers(POF).

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.891-900
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• 2005

This paper studies network recovery methods for WDM optical mesh networks, concentrating on improving spare resource utilization. The resource efficiency can be obtained by sharing spare resources needed for network recovery. To improve the sharability of spare resources in WDM networks, methods to share backup paths us well as spare capacity should be studied. The proposed method in this paper uses multiple ring-covers and this method provides fast and simple recovery operation by exploiting the characteristics of logical ring topology, and also provides efficient resource utilization by using multiple distributed backup paths to improve the sharability of overall spare resources in the networks. This method can provide layered reliability to network service by enabling hierarchical robustness against multiple failures. The performance results show that the proposed method provide improved resource efficiency for single failure and enhanced robustness for multiple failures.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.2
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• pp.177-187
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• 2000

In the past several years, many systems which adopted ring topology with high-speed unidirectional point-to-point links have emerged to overcome the limit of bus for interconnection network of clustered multiprocessor system. However, rapid increase of processor speed and performance improvement of local bus and memory system limit scalability of system with point-to-point link of standard bandwidth. Therefore, necessity to extend bandwidth is emphasized. In this paper, we adopt PANDA system as base model, which is clustering-based multiprocessor system. By simulating a model adopting commercial processor and local bus specification, we show that point-to-point link is bottleneck of system performance, and bandwidth expansion by more than 200% is needed. To expand bandwidth of interconnection network, it needs excessive design cost and time to develop new point-to-point link with doubled bandwidth. As an alternative to double bandwidth, we propose several ways to implement dual ring -simple dual ring, transaction-separated dual ring, direction-separated dual ring- by using off-the-shelf point-to-point links with IEEE standard bandwidth. We analyze pros. and cons. of each model compared with doubled-bandwidth single ring by simulation.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.1
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• pp.86-91
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• 2014

In the field of shipbuilding and marine, electrical power system is that each of the distributed bus bars is connected electrically. In this way, it would be appropriate to recognize as grid-connecting rather than the redundant bus. Short-circuit capacity of the electric power system will be increased proportionally which is due to the addition of the bus. The increase of short-circuit capacity needs high initial cost associated with equipment and can generate the blackout when the equipment with a physically connected to the bus occurs the electric failure. In order to solve these problems, marine electrical power system in which current limiting reactor has been applied is classified according to the network topology, bus network, star network and ring network. And short circuit analysis for each network is performed by the fault types. The results are presented pros and cons compared to each other.

• Spatial Information Research
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• v.20 no.2
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• pp.117-127
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• 2012

The purpose of this study is to develop the auto-building algorithm of the Geometric Network Model(GNM), a topology model including geometric information because of the need to reflect the features' geometric characteristic into the topology model, which is for development of indoor 3D virtual model enabling queries. As the critical algorithm, the Straight Medial Axis Transformation(SMAT) algorithm is proposed in order to automatically extract the medial axis of features. The SMAT algorithm is generalized from the existing S-MAT algorithm and a range of target features where applicable is extended from simple polygons to weakly simple polygons which mean the polygons containing the inner ring inside. The GNM built automatically is finally printed out as the .csv file for easy access and w ide application in other systems. This auto-building algorithm of the GNM is available for plenty of cases such as finding a shortest path, guiding a route in emergency situation, and semantic analysis.