• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.3
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• pp.253-259
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• 2007

Standard design and suitable environmental test method should be applied to increase the reliability of UAV flight control systems. UAV flight control systems under development domestically have enough capabilities for complicated missions. However, most low cost systems are not designed with concepts of compatibility, adaptability, and environmental compliance. This paper explains ATR(Air Transport Rack) standard that is widely used on aircraft. The paper presents a design uses commercial off-the-shelf parts. The paper also presents various environmental standards for airborne equipments, including U.S. military specifications. The developed FCS was tested under these specifications. The paper shows the test procedures and results.

• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.704-716
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• 2005

Assembling new software systems from Prepared components is an attractive alternative to traditional software development method to reduce development cost and schedule dramatically. However, if separately developed components are tested, integrated and verified with unreasonable effort and high cost, it would not be an effective way to software development. Components are not distributed in the shape of white-box source code so that should be hard to validate and test in new application environment. For solving this problem, built-in tester components are suggested to check the contract-compliance of their server components. If components have various and complex function, built-in tester should be heavy and unflexible to test in composition of components. This paper suggests enhancing automated wrapper technique which substitutes with built-in tester components and shows the usability of the wrapper by design and implementation. Component testing in this way reduces the cost and effort associated with preparation of component testing and makes the various test experiments in components assembly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12A
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• pp.1191-1199
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• 2008

We propose the Staggered-zone Resource Allocation (SRA) in order to relax throughput decrease problems by the co-channel interference of the cell boundary users at the cellular OFDMA system using frequency reuse factor K=1 and analyze the throughput improvement. The proposed algorithm allocates the resources to the users in compliance with resource allocation rule which is planned in order to minimize co-channel interference between cells without any additional information. The resource allocation method in the SRA lines up the users in pathloss order as descending series, and then allocates from pre-determined resource allocation region where decides differently in each cell. This algorithm prevents the co-channel interferences of the cell boundary user to be caused by using same resource simultaneously and equalizes interference to the users in the cell.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.4
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• pp.307-314
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• 2017

In this study, we propose a method to improve the guideline for accessibility of mobile applications based on the results of manual evaluation of 8 mobile online shopping applications which are widely used in Korea. 13 items of mobile online shopping application were found to have low compliance rate, and 5 items such as response time control were observed and there was no corresponding items. In the current mobile application accessibility guidelines, it is necessary to delete the check items that are not relevant or meaningless, and to provide additional logical items such as logical ordering and form creation, and to improve the accessibility of mobile applications, The government should make efforts to develop and disseminate the development guide, and to resolve the digital devides.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.359-360
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• 2013

The effect of electrode and deposition methods on non-linear interfacial resistive switching in HfO2 based $250{\times}250$ nm2 cross-point device was studied. HfO2 based device has the interfacial resistive switching properties of non-linearity and self-compliance current switching. The operating current in HfO2 based device was increased with negatively increasing the heat of formation energy in top electrode. Also, it was investigated that the operating current in HfO2 based device was changed with deposition methods of O3 reactant ALD, H2O reactant ALD and dc reactive sputtering, resulting the magnitude of the operating current and on/off ratio in order of HfO2 films deposited by dc reactive sputtering, H2O reactant ALD, and O3 reactant ALD. To investigate the effect of electrode and deposition methods on operating current of non-linear interfacial resistive switching in the cross-point device, X-ray photoelectron spectroscopy was measured. Through the analysis of O 1s spectra, non-lattice oxygen concentration, which is closely related to oxygen vacancies, was increased in order of Pt, TiN, and Ti top electrodes and in order of O3 reactant ALD, H2O reactant ALD, and O3 reactant ALD, and dc reactive sputtering deposition method. From all results, non-lattice oxygen concentration in ultra-thin HfO2 films play a crucial role in the operating current and memory states (LRS & HRS) in the non-linear interfacial resistive switching.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.357-358
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• 2013

The non-linear characteristics of ON states are important for the application to the high density cross-point memory industry because the sneak current in neighbor cells occurred during reading, erasing, and writing process. Kw of above 20 in ON states, which is the writing current @ Vwrite/the current @ 1/2Vwrite, was required in cross-point ReRAM memory industry. The high current density non-linear IV curve of ZnSe selector was shown and the ALD HfO2 switching device has the linear properties of ON states and the compliance current of 100 uA. To evaluate the performance of the selection device, we connected itto HfO2 switching device in series. The bottom electrode of the selection device was connected to the top electrode of the RRAM. All of the bias was applied with respect to the top electrode of the selection device, whereas the bottom electrode of the RRAM was grounded. In the cross-point application, 1/2Vwrite and -1/2Vwrite were applied to the word-line and bit-line, respectively, which were connected to the selected cell, and a zero bias was applied to the unselected word-lines and bit-lines. The current @ 1/2Vwrite of the unselected cells was blocked by the selection device, thus eliminating the sneak path and obtaining a writing voltage margin. Using this method, the writing voltage margin was analyzed on the basis of the memory size.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.131-143
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• 2013

There is the difference of criteria to apply guidelines among the project participants and to depend on the purpose of utilizing BIM models, although modeling criteria are basically provided through BIM guidelines. Therefore, it is quite important to check compliance with guidelines to raise quality of the BIM model. But Quality Checking (QC) items and method for BIM model modeled in accordance with guidelines is not provided. This study suggested QC items and Rule Specifications(RS) for automatic QC. First of all, QC items were derived by analyzing domestic BIM guidelines and a process for structuring natural language is conducted by utilizing flowchart and pseudocode. So, by combining them, RS was suggested. Finally, RS-based case study was conducted by implementing automatic QC process with solibri model checker$^{TM}$. This study will contribute to the improvement of design quality and completeness of BIM model including huge data of 3 dimension. Furthermore, it is necessary to develop BIM guidelines according to the use case and to provide detailed process and standard for QC of BIM model.

• Journal of Biomedical Engineering Research
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• v.17 no.3
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• pp.337-346
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• 1996

The patency of small size vascular grafts is poor, and the blood flow characteristics in the artery graft anastomosis are suspected as one of the important factors influencing intimal hyperplasia. Disturbed flow patterns caused by sixte and compliance mismatch generate unfavorable flow environment which promotes intimal thickening. Tapered vascular yuts are suggested in order to reduce sudden expansion near the anastomosis. The photochromic flow visualization method is used to measure the flout fields in the end-to-end anastomosis model under the carotid and femoral artery flow wave form. The results show that flow disturbance near the anastomosis is diminished in the tapered grafts comparing to the tubular graft. As the divergent ang1e decreases, we can reduce the low and oscillatory wall shear stress zone which is prone to intimal hyperplasia. The flow wave form effects the wall shear rate dis- tribution significantly. The steep deceleration and back flow in the femoral flow wAve form cause low mean wall shear rate and high oscillatory shear index.

• Nuclear Engineering and Technology
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• v.27 no.6
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• pp.825-832
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• 1995

The effect of loading variables and temperature on fatigue crack growth rate in SA508 Cl.3 nuclear pressure vessel steel was investigated in air environment Crack growth rate tests on compact tension specimen of thickness 12mm were conducted by using sinusoidal waveform. The crack length was monitored by compliance method. Test conditions were at 0.1 and 0.5 of load ratio, at 1 and 10 Hz of loading frequency, and at room temperature to 40$0^{\circ}C$. At the lower temperatures, the fatigue crack propagation was not affected by the frequency and temperature, while at the higher temperatures above 12$0^{\circ}C$, fatigue crack growth rate increased with decreasing loading frequency and increasing temperature. This accelerated fatigue crack propagation was associated with the increase of oxidation rate at the ahead of crack tip. Fatigue crack growth rate increased with in-creasing the load ratio. The effect of load ratio was more significant at the lower temperature, while the dependence on load ratio decreased with increasing temperature. The sensitivity of load ratio to temperature can be explained by crack closure with the oxidation process.

• Journal of Korean Academy of Nursing
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• v.37 no.5
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• pp.665-675
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• 2007

Purpose: The purpose of this study was to explore the experiences of people with chronic hepatitis B (CHB) in Korea. The specific aim was to identify major problems that people with CHB face and strategies that they are dealing with. Methods: A grounded theory method was utilized. The data were collected by individual in-depth interviews from 12 CHB patients from one of the major hospitals in Korea. Results: After constant comparative analysis, a core category emerged as "illness management with self-reliance and will." Seven major strategies that were identified in dealing with the illness were maintaining receptive and positive attitudes; restraining excessive work and greed; searching for information; controlling illness information; adhering to practices for not spreading the viral disease; abstaining from alcohol and smoking and maintaining healthy eating habits; nd using alternative therapies. The outcomes that result from employing these strategies were identified as burden, depression and helplessness, stress for maintaining compliance, and dispirited interpersonal relationships. Conclusion: The results of this study suggest that most people with CHB in Korea have problems in psychosocial area. Thus health professionals need to provide not only informational support but also emotional one to improve quality of life of the people with CHB.