• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.4
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• pp.321-331
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• 2011

The present work is aimed to analyze the creep characteristics of a turbojet engine turbine blade using the theta projection method. The theta projection method has been widely used due to its advantages and flexibility. For the creep characteristic analysis of the turbine blade, tests are performed considering the operating conditions and the non-linear material properties. Results from the creep test are fitted using the four theta model. The predicted proprieties using the four theta model are compared with the prediction model and creep test results. To obtain an optimum value of the four theta parameters in non-linear square method, a number of computing processes in the non-linear least square method were carried out to obtain full creep curves. Results using the theta model has more than 0.95 value of $R^2$. The results between the experimental values and predicted four theta model has about 90.0% accuracy. The theta projection method can be utilized for a design purpose to predict the creep behavior.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.2
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• pp.1-7
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• 2002

Since multimedia data such as video and audio data are displayed within a certain time constraint, their computation and manipulation should be handled under limited condition. Traditional real-time scheduling algorithms could not be directly applicable, because they are not suitable for multimedia scheduling applications which support many clients at the same time. Rate Regulating Proportional Share Scheduling Algorithm is a scheduling algorithm considered the time constraint of the multimedia data. This scheduling algorithm uses a rate regulator which prevents tasks from receiving more resource than its share in a given period. But this algorithm loses fairness, and does not show graceful degradation of performance under overloaded situation. This paper proposes a new modified algorithm, namely Modified Proportional Share Scheduling Algorithm considering the characteristics of multimedia data such as its continuity and time dependency. Proposed scheduling algorithm shows graceful degradation of performance in overloaded situation and the reduction in the number of context switching. Furthermore, a new evaluation method is proposed which can evaluate the flexibility of scheduling algorithm.

• Convergence Security Journal
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• v.20 no.3
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• pp.47-52
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• 2020

The introduction of virtualization technology in the broadcasting field is actively progressing broadcasting service automation and intelligence based on the effective operation of IT resources throughout the broadcasting industry ecosystem. In recent years, there is increasing interest in increasing the flexibility of various broadcasting resources and increasing the efficiency of interworking with other networks through network virtualization of the broadcasting network infrastructure. The fundamental transformation from the broadcasting network to the IP paradigm is facing a situation where it is necessary to solve various problems for the effective interworking of Internet-based service platforms and 5G networks and the development of new convergence services. In other words, for organic and effective interworking with the next-generation broadcasting network represented by ATSC 3.0, a mobile communication network represented by 5G, and the Internet, a number of difficulties must be solved. In this paper, the basic technology and status for the convergence of ATSC 3.0 broadcasting network and mobile communication network represented by 5G was examined, and a plan for the ATSC 3.0 broadcasting network and 5G network to interwork with each other as a network was described.

• Journal of muscle and joint health
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• v.7 no.2
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• pp.227-240
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• 2000

The purpose of this article was to identify trend in Arthritis research and to provide ba an approach of Arthritis research. The results of analysis of 69 Arthritis articles public year of between 1970-1999 found that most articles(27.6%, n=19) were published since few(10.1%, n=7) were before 1994. Vast majority of articles(79.8%, n=55) were printed in The Journal of Rheumatology Health, and 79.8%(n=55) of those were quantitative research, 8.7%(n=6) were qualitative research, and 14%(n=1) was methodological research. 29.0%(n=20) of quantitative research were carried in experimental design and over half(50.8%, n=35) in nonexperimental design. Having concerned the types of treatment(or intervention) used in experimental study, the most common treatment was 'exercise' (45.0%, n=9), and other less common were 'self-help education(15.0%, n=3), home care(10.0%, n=2) supportive care(10.0%, n=2), flexibility exercise combined with local heat therapy(5.0%, n=1), relaxation training(5.0%, n=1). Of the types of exercise, aquatic exercise was 30.0%(n=6). The effect of exercise on outcome variable was found to be most strong among the other types of treatment. 18 articles of nonexperimental research were correlational research. From the analysis of correlational research, 29 concepts were identified, and the relationship between depression and other variable were strongly reported. In descriptive studies, most commonly physiological variables were examined in 5 articles(29.5%). Only one study(5.9%) explored patient's perception of the causal factors and those causality. In qualitative researches, two study were carried out by the means of grounded theory. Majority of those subjects were RA patients, and the largest number of sample were 23 and the smallest was 1 In two studies, patient's perceived causality of RA was identified as a research problems, and an experience of ADL, fatigue Phenomenon, an experience of having a total knee replacement with osteoarthritis were each found in one study. Methodological research was carried out to test validity and reliability of the RA Fatigue Scale.

• Journal of Family Resource Management and Policy Review
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• v.23 no.3
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• pp.75-88
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• 2019

This study focuses on changes in a father's role from one that is work-centered to a work-family balance, analyzing the type of father's work-family reconciliation and to compare the differences among the types. An online survey was conducted with 1,037 fathers of school-aged children. The survey subjects were assigned to a ratio of 1:2:1:1 for fathers who have a child in kindergarten, elementary school, middle school and high school. The fathers' work-family reconciliation type was a variable composed of three categories: work-centered, family-centered, and work-family centered. In the research model of this study, the fathers' work-family reconciliation type was influenced by family characteristics(the age of first child, the number of children, dual earner, and spouse support) and work characteristics(weekly working hours, work flexibility, and leaving work on time). We analyzed characteristics of work-family reconciliation through housework time, child care time, leisure time, family meals, and time spend talking with their children. The results showed that father's work-family reconciliation type was significantly different according to the characteristics such as first child age and spouse support, work characteristics such as weekly working hours and leaving work on time. The time distribution differed significantly depending on the father's work-family reconciliation type. Therefore, a fathers' work-family reconciliation can be considered typified by the interaction of family and work characteristics. This study suggests policy implications for supporting fathers' work-family reconciliation.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.3 s.18
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• pp.23-28
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• 2005

This study defined engineering mechanism and compensation method to establish reference pressure of smoke control zone with atmospheric pressure that is compensated for temperature. The reliable pressure differential sensor was developed by establishing the specifications, algorithms and constructing engineering data. The development of pressure differential sensor can cut down number of processes, manufacturing and installation cost by removing pressure measurement pipe established separately for non smoke control zone, and improve the accuracy of pressure differential by embedding pressure measurement ports for non smoke control zone. More correct and reliable pressure differentials can be obtained by the central control rather than the existent individual control. This will provide the basics and the flexibility to the integral smoke control system and accordingly improve the performance of disaster prevention.

• Journal of National Security and Military Science
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• s.5
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• pp.203-239
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• 2007

The current problems with the changing nature of the battlefield of the future point up the serious need for more and better research on the nature of effective military leadership. The purpose of this study was to examine effective leadership traits and behaviors of junior officers in combat situation. During times of peace, leader study battles and imagine themselves in all sorts of combat situations while at the same time, they must cope with numerous challenges and fill a variety of roles that they perceive are not battle related. This illustrates one of the fundamental paradoxes of the peacetime environment. Early studies, showing that combat leadership and noncombat leadership needed different talents, produced some clusters of traits which good combat leader were said to possess. Good combat leaders, for example, were described as possessing courage(e.g., bravery, fearlessness, daring, prowess, gallantry, guts, intrepidity, undaunted courage, fighting spirit, aggressive action), personal integrity(e.g., sincerity, flair, calmness, modesty), adaptability(e.g., flexibility, rapidity in action, speedy decision-making, clarity of thought) and so on. Behaviors found to be important in both combat and noncombat situations bore some relation to role requirements common to both situations. Behaviors important in one situation but not the other could be explained in terms of situational differences in role requirements for effective leadership. In order to achieve this purpose, a number of literature reviews were analysed. These results, though obtained in a somewhat rough and ready fashion, were useful not because they pointed to different leaders in war and in peace, but because they showed leaders the different things that were expected of them in different situations. It was also worth knowing how develop combat leadership. While these findings clearly suggest combat and noncombat differences, they do not necessarily confirm the complete study on effective leadership in combat situation. In conclusion, this study would be useful basis for further improvement on effective combat leadership and some further researches were recommended.

• Journal of Arbitration Studies
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• v.13 no.1
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• pp.125-167
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• 2003

ADR program is designed to solve the problem such as the increase of suits and decision delayed. ADR program has the several significances, decreasing inappropriate cost as time and burden of courts, providing an approachable measure of relief and more efficient tool for settlement of dispute. Particularly ADR program satisfies the needs Intellectual property disputes need specialists that are versed in the subjected problem and, need to be souled quickly in confidence. And parties concerned are not good at the strict judicial procedure in courts, At this point, ADR program holds some advantages over court proceeding for intellectual property disputes. Specialists can be selected as arbitrators or mediator; Cofidentiality may be preserved; Flexibility allows settlement based on mutual commercial interests; Single solution is possible for multiple disputes involving parties from different countries. However, ADR program has not been properly used in. Korea, which is due to not only the lack of understanding the ADR program, but the poor number of filings and settlements. Intermediaries are not professional and also they do not take active hands in disputes. Sometimes, their fairness is asked as peacemakers. Eventually, it is said that this program is not enough to settle international disputes. To activate the ADR program, we can propose the ADR program annexed to court for example. And we can introduce the conciliation and arbitration to disputes in intellectual property. Traditionally arbitration has been a crucial issue in intellectual property disputes. In that intellectual property rights are granted by the local sovereign power, many legal systems in the past maintained the position that the existence, extent, meaning and application of such rights could only be definitively decided by the granting authority or the courts of that country. There is wide recognition that the arbitration of intellectual property is desirable. The law in most of the major countries has been changed in recent years in favor of arbitrability of intellectual property rights. We can also propose ADR on-line.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.315-324
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• 2017

The smart grid with distributed power supply introduces a number of problems including not only the problems of the existing power grid but also the problem of protection co-operation due to new electric phenomenon because it has a mixed operation structure combining the existing radial operation structure and the new loop operation structure. The EMTP based power system analysis method has flexibility and convenience from the view of system configuration but it requires another experimental verification because of uncertainty of design and analysis results. On the other hand, the real demonstration system has difficulties in observing accurate fault on large scale system due to considerable economical and spatial construction cost, system configuration constraint, and it is difficult to demonstrate the distributed, autonomous and adaptive control strategy of smart grid. In this paper, a basic theory for a micro smart grid simulator design using MEMS(Micro Electro-Mechanical Systems) miniaturization technology is studied which can safely and freely experiment and observe electrical phenomena, and distribution, autonomous adaptive control strategy for disturbances on 22.9kV smart grid under minimum economic and spatial cost.

• The Journal of the Korean dental association
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• v.57 no.11
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• pp.672-678
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• 2019

AIM: The purpose of this study was to evaluate and compare the torsional fracture resistances, cyclic fatigue resistance, and bending stiffness of two nickel-titanium (NiTi) rotary instruments made of different heat-treated alloy: Aurum Blue (heat-treated) and Aurum Pro (conventional). Methods: Forty-five Aurum Blue and Aurum Pro NiTi files were selected for the three mechanical tests (n=15). For the torsional resistance test, 3 mm file tip was fixed and the shaft was driven clockwise at 2 rpm until fracture occurred by using a customized device. Cyclic fatigue resistance was evaluated by rotating instruments in artificial canal with dynamic mode. Bending stiffness was tested by observation of the bending moment on attaining a 45° bend. The results were analyzed by student-t tests at a significance level of 95%. The fractured surface of each groups were examined under a scanning electron microscope (SEM). Results: Aurum Blue showed significantly higher toughness, ultimate strength, distortion angle, and number of cycles to failure than those of Aurum Pro (p < 0.05). However, Aurum Blue and Aurum Pro did not differ significantly in terms of bending stiffness. SEM showed typical topographic appearances of the cyclic fatigue and torsional fracture. Conclusions: Under the limitations of this study, heat-treated instruments showed higher flexibility and fracture resistances than conventional NiTi instruments.