• Journal of East-West Nursing Research
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• v.15 no.1
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• pp.18-25
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• 2009

Purpose: The study was investigated to identify the relationship between nursing workload and aseptic technique performance by clinical nurses, and to decrease the incidence rate of nosocomial infection. Methods: Participants (N=283) were recruited in B city from April to June 2007. The data were collected by a structured questionnaire and analyzed with descriptive statistics, t-test, ANOVA and Pearson's correlation coefficient. Results: Nursing workload was rated 9.85 out of a total score of 15. The level of aseptic technique performance as the basis for insertion of a Foley catheter was 42.72 out of a total score of 50, and as basis for insertion of intravenous catheter for fluid therapy was 40.11 out of a total score of 55. There was not a significant relationship between aseptic technique performance and nursing workload. There was a significant positive relationship between the aseptic technique performance in insertion of Foley catheter and that of intravenous catheter for fluid therapy (r=.279, p<.001). Conclusions: Attention to asepsis by nurses is crucial in nosocomial infection-related clinical nursing skills.

• Journal of KIISE
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• v.44 no.11
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• pp.1130-1137
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• 2017

The multi-leveling technique that stores multiple bits in a single memory cell has significantly improved the density of NAND flash memory along with shrinking processes. However, because of the side effects of the multi-leveling technique, the average write performance of MLC NAND flash memory is degraded more than twice that of SLC NAND flash memory. In this paper, we introduce existing cross-layer optimization techniques proposed to improve the performance of MLC NAND flash-based storages, and propose a new integration technique that overcomes the limitations of existing techniques by exploiting their complementarity. By fully exploiting the performance asymmetry in MLC NAND flash devices at the flash translation layer, the proposed technique can handle many write requests with the performance of SLC NAND flash devices, thus significantly improving the performance of NAND flash-based storages. Experimental results show that the proposed technique improves performance 39% on average over individual techniques.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.847-856
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• 2013

This paper presents an AP placement technique considering indoor location-awareness and examines its performance. The proposed AP placement technique is addressed from three performance metrics: location-awareness and AP-based wireless network performance as well as its cost. The proposed AP placement technique consists of meta-heuristic algorithms that yield a near optimal AP configuration for given performance metrics, and deterministic algorithms that improve the fast convergence of the near optimal AP configuration. The performance of the AP placement technique presented in this paper is measured under the environments simulating indoor space, and numerical results obtained by experimental evaluation yield the fast convergence of a near-optimal solution to a given performance metric.

• Journal of Communications and Networks
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• v.9 no.3
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• pp.274-281
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• 2007

In this paper, we present a hybrid multi-antenna technique that can minimize the outage probability by combining the diversity and beamforming techniques. The hybrid technique clusters the transmission antennas into multiple groups and exploit diversity among different groups and beamforming within each group. We analyze the performance of the resulting hybrid technique for an arbitrary correlation among the transmission antennas. Through the performance analysis, we derive a closed-form expression of the outage probability for the hybrid technique. This enables to optimize the antenna grouping for the given spatial correlation. We show through numerical results that the hybrid technique can balance the trade-offs between diversity and beamforming according to the spatial correlation and that the optimally designed hybrid technique yields a much lower outage probability than the diversity or beamforming technique does in partially correlated fading channels.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.983-991
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• 1996

This paper proposes an improved write-piggybacking technique called hybrid write-piggybacking, and evaluates its performance. The performance of the proposed hybrid write-piggybacking technique is done through a trace-driven simulation using a model of a real disk system. The results of simulation show that the proposed hybrid write-piggybacking has better performance compared to the original write-piggybacking technique.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.274-279
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• 1991

The development of a guided weapon system, such as a tactical missile, requires a performance analysis of a nonlinear system. Generally, the Monte Carlo analysis method is used for this purpose. The limitation of this method, a large number of simulations, for a nonlinear system performance analysis strongly motivated the development of a more efficient analytic technique. In this paper, the statisfical linearization methods is used for the performance analysis to the guided weapon system with the help of covariance analysis technique. Because the statistical linearization methods cannot be used to the look-up table nonlinear form such as aerodynamic coefficients, the second order polynomial representations is obtained from the table using the Lagrange interpolating polynomial and linearized statistically. Simple simulations about initial state conditions and random component in guidance command shows the results of this technique.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.4
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• pp.449-455
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• 2013

When a missile is launched, a fracture-type canister cover should be properly broken by a collision with a missile or inner pressure of a canister. The fracture performance of a canister cover should be evaluated by a test using a real missile; however, it is unrealistic due to high cost and time restriction in a design stage. In this study, a test technique is newly developed to predict fracture performance of a canister cover. The test was design to have same kinetic energy with a real missile test when the cover is collide with a missile. The effectiveness of the suggested test technique was proved by comparing the test result with that of a real missile test.

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1289-1296
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• 2019

Non-functional requirements plays a critical role in designing variety of applications domain ranges from safety-critical systems to simple gaming applications. Performance is one of the crucial non-functional requirement, especially in control and safety systems, that validates the design. System risk can be quantified as a product of probability of system failure and severity of its impact. In this paper, we devise a technique to do the performance analysis of safety critical and control systems and to estimate performance based risk factor. The technique elaborates Petri nets to estimate performability to ensure system dependability requirements. We illustrate the technique on a case study of Nuclear Power Plant system. The technique has been validated on 17 safety critical and control systems of Nuclear Power Plant.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.382-389
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• 2013

In anti-jamming GPS receiver, adaptive signal processing techniques in which the radiation pattern of adaptive array antenna of elements may be adaptively changed used to reject interference, clutter, and jamming signals. In this paper, I describes adaptive signal processing technique using the sample matrix inversion(SMI) algorithm. This adaptive signal processing technique can be applied effectively to wideband/narrowband anti-jamming GPS receiver because it does not consider the satellite signal directions and GPS signal power level exists below the thermal noise. I also analyzed the effects of covariance matrix sample size and diagonal loading technique on the system performance of five-element circular array antenna. To attain near optimum performance, more samples required for calculation covariance matrix. Diagonal loading technique reduces the system nulling capability against low-power jamming signals, but this technique improves robustness of adaptive array antenna.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.780-787
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• 2017

The propellant grain configuration is a design variable that determines the shape and performance of a solid rocket motor. Grain configuration variables have complicated effects on the motor performance; so the global optimization problem has to be solved in order to design the configuration variables. The grain performance has been analyzed by means of the grain burn-back and internal ballistic analysis, and the optimization technique searches for the configuration variables that satisfy the requirements. The deterministic and stochastic optimization techniques have been applied for the grain optimization, but the results are imperfect. In this study, the optimization design of the configuration variables has been performed using the hybrid optimization technique, which combines those two techniques. As a result, the hybrid optimization technique has proved to be efficient for the grain optimization design.