• The Journal of the Acoustical Society of Korea
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• v.18 no.3E
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• pp.37-43
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• 1999

In this paper, we present a new technique for the optimal local decomposition of convex structuring elements on a hexagonal grid, which are used as templates for morphological image processing. Each basis structuring element in a local decomposition is a local convex structuring element, which can be contained in hexagonal window centered at the origin. Generally, local decomposition of a structuring element results in great savings in the processing time for computing morphological operations. First, we define a convex structuring element on a hexagonal grid and formulate the necessary and sufficient conditions to decompose a convex structuring element into the set of basis convex structuring elements. Further, a cost function was defined to represent the amount of computation or execution time required for performing dilations on different computing environments and by different implementation methods. Then the decomposition condition and the cost function are applied to find the optimal local decomposition of convex structuring elements, which guarantees the minimal amount of computation for morphological operation. Simulation shows that optimal local decomposition results in great reduction in the amount of computation for morphological operations. Our technique is general and flexible since different cost functions could be used to achieve optimal local decomposition for different computing environments and implementation methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.1935-1944
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• 1994

FMS is a distributed system composed of various programmable manufacturing hardware such as robots and NC machines. For the autonomous operation of such a system, an integrated software layer for the control and monitoring in needed on top of the manufacturing hardware. However, constructing and maintaining such a software layer is difficult due to the complexity of a underlying FMS and its frequently changing nature. To cope with this problem, this paper proposes an object-oriented FMS integration model, in which objects acting as virtual manufacturing cells are instantiated for each physical cell in the underlying object-oriented database. Various other entities involved in manufacturing processes and their relationship to the cell objects are also captured in the database. This paper describes the structure of this object-oriented FMS database on our prototype implementation called FREE.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.107-112
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• 2012

In this contribution, we designed a general purpose input/output (GPIO) suitable for embedded systems, especially for Bluetooth baseband. Proposed architecture is compatible for the APB bus in AMBA bus architecture. General purpose I/O should be used as multi-functional and versatile interrupt sources. We considered the edge-sensitive mode as well as the level-sensitive mode for acquiring the interrupt sources. Also, we provided an option to select the operation polarity for flexible application to the embedded systems. The designed GPIO module was automatically synthesized, placed, and routed. The proposed GPIO was implemented through the Altera FPGA and well operated at 25MHz clock frequency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2B
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• pp.120-129
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• 2012

Wireless mesh network (WMN) has recently emerged as a promising technology for tactical operation. If a platoon is organized with MPs, this system is suitable for tactical coverage is given for battle field where there is a shortage of wired infrastructure. However, MPs of typical WMN are generally fixed. This condition does not apply to diverse tactical scenarios. In this paper, it is considered that MPs have group mobility for flexible tactical networks. We propose cluster based multi-channel MAC scheme for mobilie WMN with single antenna condition. We have reduced the collision problems and message storming problems occur by mobility, so the reliability of WMN has been improved. Consequently, reliable communication is guaranteed by our framework in mobile WMN.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.1
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• pp.125-134
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• 1991

Since comprehensive examination of flexible pavement is complex, evaluation of its condition has been based on subjective judgements. Especially, qualitative measure of pavement has been based on linguistic expressions which often cause misinterpretation. There has been no such a criterion that can appropiately assess pavement status. Therefore, this study was devised to develop an approach, using fuzzy set concept, for evaluation of current and expected service conditions of flexibel pavement surface course. An example study was conducted to verify its usefulness. Since arithematic operation of fuzzy set can quantify the linguistic values and translate them into illustrative models, the results shown in the example was easy for anyone to understand.

• ETRI Journal
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• v.29 no.3
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• pp.259-269
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• 2007

The ubiquitous flexible operating system (UbiFOS) is a real-time operating system designed for cost-conscious, low-power, small to medium-sized embedded systems such as cellular phones, MP3 players, and wearable computers. It offers efficient real-time operating system services like multi-task scheduling, memory management, inter-task communication and synchronization, and timers while keeping the kernel size to just a few to tens of kilobytes. For flexibility, UbiFOS uses various task scheduling policies such as cyclic time-slice (round-robin), priority-based preemption with round-robin, priority-based preemptive, and bitmap. When there are less than 64 tasks, bitmap scheduling is the best policy. The scheduling overhead is under 9 ${\mu}s$ on the ARM926EJ processor. UbiFOS also provides the flexibility for user to select from several inter-task communication techniques according to their applications. We ported UbiFOS on the ARM9-based DVD player (20 kB), the Calm16-based MP3 player (under 7 kB), and the ATmega128-based ubiquitous sensor node (under 6 kB). Also, we adopted the dynamic power management (DPM) scheme. Comparative experimental results show that UbiFOS could save energy up to 30% using DPM.

• Journal of Korean Academy of Nursing
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• v.34 no.6
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• pp.1117-1128
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• 2004

Purpose: This study was carried out to substantiate the application process of activity-based costing on the current cost of hospital home care (HHC) service. The study materials were documents, 120 client charts, health insurance demand bills, salary of 215 HHC nurses, operating expense, 6 HHC agencies, and 31 HHC nurses. Method: The research was carried out by analyzing the HHC activities and then collecting labor and operating expenses. For resource drivers, HHC activity performance time and workload were studied. For activity drivers, the number of HHC activity performances and the activity number of visits were studied. Result: The HHC activities were classified into 70 activities. In resource, the labor cost was 245￦per minute, operating cost was 9,570￦ per visit and traffic expense was an average of 12,750￦. In resource drivers, education and training had the longest time of 67 minutes. Average length of performance for activities was 13.7 minutes. The workload was applied as a relative value. The average cost of HHC was 62,741￦ and the cost ranged from 55,560￦ to 74,016￦. Conclusion: The fixed base rate for a visit in the current HHC medical fee should be increased. Exclusion from the current fee structure or flexible operation of traveling expenses should be reviewed.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.658-662
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• 2004

This paper proposes an orthogonal reception structure for OS/SS communication with time-shifted m-sequences, and compares the performances of the proposed and conventional receiver. This structure provides two important characteristics to reference user signal with not only increment of auto-correlation value but also cancel of the cross-correlation value out to zero between the reference user and other user signals. In addition, the structure can be easily implemented with the conventional receiver adding an additional integrator path in parallel and an adder that sums the conventional path output and the new path output signal. Hence, the proposed structure can be applied for channel impulse response measurement, and efficiently used for multi-user interference signal cancellation and channel capacity increment by flexible structural inter-working operation, connection or disconnection, of the new path to conventional receiver structure.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1185-1188
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• 2005

Recently, ubiquitous computing and sensor networks are making a rapid development. These technology can enable a new way of biomedical signal processing and healthcare. that is, they can improve care giving by a more flexible acquisition of relevant vital sign data, and by providing more convenience for patients. In this paper, we realize the biomedical sensor networks by applying IEEE 802.15.4/Zigbee networks to some various biomedical sensing unit. For address this, we developed minimized zigbee module and set-up procedure using PDA. The main advantages that we achieve are interference-free operation of different body sensor networks in the vicinity, as well as intuitive usage by the nontechnical personnel.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.9-17
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• 2020

In this paper, as part of the research for the infrastructure of very high flexible and reconfigurable data center using very high speed crossbar switches, we developed a simulator that can model two and three dimensional connection structure of switches with an efficient control algorithm using software defined network and verified the functions and analyzed the performance accordingly. The simulator consists of a control module and a switch module that was coded using Python language based on the Mininet and Ryu Openflow frameworks. The control module dynamically controls the operation of switching cells using a shortest multipath algorithm to calculate efficient paths adaptively between configurable computing resources. Performance analysis by using the simulator shows that the three-dimensional switch architecture can accommodate more hosts per port and has about 1.5 times more successful 1:n connections per port with the same number of switches than the two-dimensional architecture. Also simulation results show that connection length in a 3-dimensional way is shorter than that of 2-dimensional way and the unused switch ratio in a 3-dimensional case is lower than that of 2-dimensional cases.