• Journal of KIISE:Computing Practices and Letters
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• v.13 no.3
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• pp.141-152
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• 2007

In this paper, we present a network-oriented lightweight real-time system, which is composed of an event-driven operating system called the Embedded Lightweight Operating System (ELOS) and a generic multi hop ad hoc routing protocol suite. In the ELOS, a conditional preemptive FCFS scheduling method with a guaranteed time slot is designed for efficient real-time processing. For more elaborate configurations, we reinforce fault tolerance by supplementing semi-auto configuration using wireless agent nodes. The developed hardware platform is also introduced, which is a scalable prototype constructed using off-the-shelf components. In addition, in order to evaluate the performance of the proposed system, we developed a ubiquitous network test-bed on which several experiments with respect to various environments are conducted. The results show that the ELOS is considerably favorable for tiny ubiquitous networked systems with real-time constraints.

• Journal of Korean Academy of Nursing Administration
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• v.19 no.1
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• pp.95-107
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• 2013

Purpose: The purpose of this study was to examine the effectiveness of Action Research (AR) approach in nursing. Methods: Participants were 64 perioperative nurses recruited from C hospital in Gwangju, Korea. The nurses were engaged in the project through 2 cycles of planning, acting, observing, and reflecting. A mixed-methods design was used to examine changes in participants and their knowledge management practice. Quantitative data were analyzed using SPSS 20.0 program and qualitative reflection data underwent content analysis. Results: During the project, participants developed standardized pre-operative checklists and opened an Internet Cafe to better manage their perioperative nursing information. At the end of the project, there was a significant increase in nurses' knowledge management (p=.015) and the rate of surgical material prescription errors decreased from 8.0% to 2.9%. Core AR project team members' teamwork skills and organizational commitment increased significantly (p=.040, p=.301, respectively). The main themes that emerged from the qualitative data were learning how to solve problems in practice, facilitating team activities through motivation, barriers of large participation, and rewarded efforts and inflated expectations. Conclusion: The AR project contributed to empowering participants to solve local problems. AR is a useful methodology to promote changes in practices and research participants.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.6
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• pp.371-377
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• 2007

In this paper, we propose the effective operating device in the container freight station by applying the RTLS (Real Time Location System) that provides information on the container's location in real time so that the performance of the port operating system can be improved. For this, we proposed the improved dual cycling method made with the new application of two types of container's location & yard tractor's location information. we applied the RTLS to the container freight station to send the container location data to the operating system in real time; we designed the data on the Yard Tractor's location to be received via the GPS receiver and then be sent to the operating system in real time via the CDMA module. According to the analysis and evaluation of the performance of the proposed method, up to 24% of performance improvement was shown compared with the existing methods, in aspect of evaluation of work time, work time deviation and performance. Therefore, we proved that the RTLS and the GPS receiver are essential elements for efficient port operation.

• International Journal of Contents
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• v.12 no.4
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• pp.76-82
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• 2016

This study aims to evaluate the effectiveness of the dual-punishment system by analysis of the financial performance of pharmaceutical companies before and after introduction of the dual-punishment system. This study analyzed the business performance of 136 pharmaceutical companies from 2009 to 2011. The results from paired t-tests found that sales, operating cost, and EBITDA showed significant differences in performance, and, according to the variance analysis, the five groups obtained through a hierarchical cluster analysis differed from each other in sales, operating cost, EBITDA, and research and development cost. Differences in financial performance among the groups seem to be related to the strategy for response to the regulation. The introduction of the dual-punishment system is generally acknowledged to have had positive effects on the pharmaceutical industry. However, some companies appear to be continuing kickback practices.

• Ocean and Polar Research
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• v.26 no.2
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• pp.187-197
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• 2004

The purpose of this paper is to investigate economic feasibility of manganese nodules in Korea area (Clarion-Clipperton Fracture Zone). We assumed that the production scale of manganese nodules were 3.0MT or 1.5MT and analyzed that the capital cost and operating cost were estimated in the four sectors, exploration, mining, transportation and metallurgical process. The capital cost and operating cost evaluation reflects the latest technical practices. First, for analyzing economic feasibility, the scenario suggests that the production of 4 metals can be made for 25 years. Assuming the discount rate at 8.0%, equity capital at 50% and tax at 27%. When manganese nodule were mininged 3.0 MT, economic feasibility analyses showed that IRR was 12.8 and pay-back period was 9.2 years, and when manganese nodules were mininged 1.5 MT, economic feasibility analyses showed that IRR was 4.0 and pay-back period was 11.8 years. This study indicated there is economic validity of at the product of manganese nodules 3.0 MT. In addition, we carried out a sensitivity analysis at the change of cobalt price on mining 1.5 MT. The result of sensitivity analysis clearly showed that economic validity is high at increasing of cobalt price 50% up.

• KIISE Transactions on Computing Practices
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• v.23 no.1
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• pp.80-84
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• 2017

Existing operating systems experience scalability issues as the number of cores increases. The network I/O performance on manycore systems is faced with the major limiting factors of cache consistency costs and locking overheads. Legacy methods resolve this issue include the new microkernel-like operating system or modification of existing kernels; however, these solutions are not fully application transparent. In this study, we proposed a library that improves the network performance by separating system call context from user context and by applying the core affinity without any kernel and application modifications. Experiment results showed that our implementation can improve the network throughput of Apache by up to 30%.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1056-1060
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• 2010

The software running on avionic systems is required to be highly reliable and productive. Due to these demands, the standard such as ARINC 653 has been suggested, which includes the abstraction of resource partitioning and defines interfaces between avionic operating system and applications. Though there are many manned aerial vehicles employing ARINC 653 based operating systems, Linux-based ARINC 653 for unmanned aerial vehicles has not been studied yet. In this paper, we propose the design of Linux-based ARINC 653 process model and present preliminary implementation. The experiment results present that the implementation is enough to support control software of unmanned helicopter.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.36-45
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• 2002

This paper introduces the design and implementation of a flash memory simulator to emulate a real flash memory. Since this simulator provides exact execution time information and parameter testing functions as well as the type, total capacity, block size, and page size of flash memory, it can be used as a real flash memory as viewed by the operating system. Furthermore, the simulator provides time logging functions of the internal routines of the flash memory management software allowing the monitoring of bottlenecks within the software. Finally, we show the performance measurements of applications under the Linux operating systems on both the simulator and a test board verifying the simulator's use as a replacement for real flash memory.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.4
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• pp.373-382
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• 2000

This paper is concerned with development of a communication module of POFS(Parallel Operating File System), which is the parallel file system to be operated on SPAX computer. SPAX is multiprocessor computer with clustering SMP architecture and being developed by ETRI. The operating system for SPAX is MISIX based on the Chorus microkernel. POFS has client/server architecture basically so that it is important to design a communication module. The communication module is so easily affected by network environment that bad design is the major reason that decreases the portability and performance of the parallel file system. This paper describes the structure and performance of the communication of the POFS. the theme is issued in the course of designing and developing POFS. The communication module of POFS was designed to support the portability and the architecture of parallel file system.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.1
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• pp.52-62
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• 2008

As various types of embedded devices are widely used, a technology that supports reuse of applications on multiple platforms is needed in order for time-to-market development of the applications. The interface middleware is one of such technology and it hides platform dependency from application programmers. Existing interface middleware such as the MT project, Xenomai and Legacy2linux have limitation in that the APIs provided by each of these middleware are fixed to a specific operating system, and the middleware does not provide dynamic expansion of its API set. In this paper, we propose a middleware which hides operating system dependencies and enables porting of applications on various operating systems. In addition, the middleware has scalable structure so that it is suitable for resource-limited embedded systems. The overhead of the middleware, i.e., the time delay occurred by the middleware is between $0.3{\mu}sec\;and\;5{\mu}sec$ in most cases. We believe that the amount of overhead is reasonable and does not hurt the performance of applications.