• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2178-2182
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• 2011

Recently, the synthesis of ordered macroporous materials has received much attention due to its potential use as photonic band gap materials.$^1$ In this study, we have used the three-dimensional (3D) latex array template impregnated with benzenesulfonic acid (BSA), which is capable of catalyzing the reaction using tetraethyl orthosilicate (TEOS) as a precursor and distilled water. The polystyrene (PS) templates were reacted with TEOS in $scCO_2$ at 40 $^{\circ}C$ and at 80 bar. In the reactor, TEOS was filtrated into the PS particle lattice. After the reaction, porous silica materials were obtained by calcinations of the template. The stability test of the PS template in pure $CO_2$ was conducted before the main experiment. Scanning electron microscopy (SEM) images showed that the reaction in $scCO_2$ takes place only on the particle surface. This new method using $scCO_2$ has advantages over conventional sol-gel processes in its capability to control the fluid properties such as viscosity and interfacial tension. It has been found that the reaction in $scCO_2$ occurs only on the particle surface, making the proposed technique as more rapid and sustainable method of synthesizing inverse opal materials than conventional coating processes in the liquid phase and in the vapor phase.

• Nuclear Engineering and Technology
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• v.28 no.1
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• pp.17-26
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• 1996

The in-reactor fuel rod support conditions against the fretting wear-induced damage can be evaluated by residual spacer grid spring deflection or rod-to-grid gap. In order to evaluate the impact of fuel design parameters on the fretting wear-induced damage, a simulation methodology of the in-reactor fuel rod supporting conditions as a function of burnup has been developed and implemented in the GRIDFORCE program. The simulation methodology takes into account cladding creep rate, initial spring deflection, initial spring force, and spring force relaxation rate as the key fuel design parameters affecting the in-reactor fuel rod supporting conditions. Based on the parametric studies on these key parameters, it is found that the initial spring deflection, the spring force relaxation rate and cladding creepdown rate are in the order of the impact on the in-reactor fuel rod supporting conditions. Application of this simulation methodology to the fretting wear-induced failure experienced in a commercial plant indicates that this methodology can be utilized as an effective tool in evaluating the capability of newly developed cladding materials and/or new spacer grid designs against the fretting wear-induced damage.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.120-130
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• 2013

A study was conducted for the performance characteristics of methane taking recently the limelight in the world as a next-generation propellant, with the survey for state of the art in the development of methane/oxygen rocket engine being accompanied. Liquid methane as a rocket fuel has the favorable characteristics such as non-toxic, low cost, regenerative cooling capability, and potential for in-situ resource utilization (ISRU). The combination of liquid methane and liquid oxygen also provides the excellent performance including high specific impulse and low system mass. For these reasons, many researches have been actively carried out on the methane/oxygen engine, nevertheless, its technology readiness level is not that high enough just yet. Therefore, it is judged that it is the time to mitigate the technical gap with the space technology of advanced countries through a swift onset of the development of methane rocket engine.

• Journal of Preventive Medicine and Public Health
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• v.34 no.1
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• pp.55-60
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• 2001

Objectives : The SERVQUAL scale is based on gap theory, which suggests the difference between consumers' expectations and the quality of the medical service actually received. However, problems in the implementation of the SERVQUAL scale have been identified by several researchers. Some researchers have proposed a simple performance-based measure (SERVPERF) or au exportation-controlled performance-based measure(Non-Diff) as alternatives to the SERVQUAL scale. On the basis of the theoretical concerns discussed, we examined the capability of each of the three scales(SERVQUAL, Non-Diff, SERVPERF) to explain variations in consumer satisfaction. Methods : Data was gathered from a self-administered questionnaire in a 430 bed hospital. Questionnaires evaluating medical services were distributed to 180 ambulatory patients. A total of 167 usable questionnaires were gathered. The questionnaire was composed of 10 expectation, performance and expectation-controlled performance items. In addition, overall satisfaction and purchase intention were measured. Results : Compared with the SERVQUAL scale, the Non-Diff and SERVPERF scales better explained the observed variations in consumer satisfaction(SERVOQUAL, $R^2=0.29;\;Non-Diff,\;R^2=0.51;\;SERVPERF,\;R^2=0.48$) and purchase intention(SERVQUAL, $R^2=0.22;\;Non-Diff,\;R^2=0.33;\;SERVPERF,\;R^2=0.34$). Conclusion : The maier conclusion from our study is that the Non-Diff and SERVPERF scales are more efficient in assessing consumer satisfaction than the SERVQUAL scale. Therefore we suggest that consumer satisfaction he measured by the Non-Diff or SEVPERF scales.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.66-73
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• 2014

The Korean construction industry has been severely impacted by the 2008 global financial crisis, which resulted in a significant reduction in the overall contract amount. For survival, many construction management (CM) companies had to adapt a strategy of lowering bid prices to maintain their competitiveness. As a result of the strategy, companies faced a number of issues including their decreased capability in risk management. However, most risk management-related studies focused on construction risk management, yet these studies lacked consideration of enterprise-level risk management practices. To fill the gap, the objectives of the present study are (1) to investigate, the risk management practices of Korean CM companies, (2) to identify factors that determine efficient enterprise-level risk management practices, and (3) to propose a module for the development of enterprise-level risk management. Lastly, the efficiency of the proposed development module was validated by using a survey.

• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.137-144
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• 2011

Wireless sensor network(WSN) has the potential to greatly effect many aspects of u-healthcare. By outfitting the potential with WSN, wearable sensor node can collects real-time data on physiological status and transmits through base station to server PC. However, there is a significant gap between WSN and healthcare. WSN has the limited resource about computing capability and data transmission according to bio-sensor sampling rates and channels to apply healthcare system. If a wearable node transmits ECG and accelerometer data of 4 channel sampled at 100 Hz, these data may occur high loss packets for transmitting human activity and ECG to server PC. Therefore current wearable sensor nodes have to solve above mentioned problems to be suited for u-healthcare system. Most WSN based activity and ECG monitoring system have been implemented some algorithms which are applied for signal vector magnitude(SVM) algorithm and ECG noise algorithm in server PC. In this paper, A wearable sensor node using integrated ECG and 3-axial accelerometer based on wireless sensor network is designed and developed. It can form multi-hop network with relay nodes to extend network range in WSN. Our wearable nodes can transmit 1-channel activity data processed activity classification data vector using SVM algorithm to 3-channel accelerometer data. ECG signals are contaminated with high frequency noise such as power line interference and muscle artifact. Our wearable sensor nodes can remove high frequency noise to clear original ECG signal for healthcare monitoring.

• Korean Journal of Comparative Education
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• v.26 no.4
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• pp.125-152
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• 2016

This study aims to analyze the impacts of the QS Asia University Rankings (QSAUR) indicators and to compare the scores obtained by major countries. Hierarchical multiple regression was performed on the results of the QSAUR 2013-2015 and the average indicator and overall scores of each country were calculated. In the QSAUR, the most influential indicator was academic reputation. Each indicator's influence corresponded to its assigned weights and standard deviations. The results of the comparison revealed that Japan, South Korea, and China had the largest number of institutions among the top 150, while Singapore maintained the highest average scores on the indicators as well as the overall score. Each country had different areas that required improvement. South Korean colleges scored lower than some countries on academic reputation, papers per faculty, and international faculty. To attain higher ranks in the QSAUR, academic reputation, institutions' research capability improvement, and internationalization are needed. The implementation of these strategies is necessary to diminish the gap between South Korean institutions and other Asian institutions.

• Health Policy and Management
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• v.31 no.3
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• pp.280-291
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• 2021

Background: Based on the fact that the Korea Medical Dispute Mediation and Arbitration Agency is a public institution established by social demands for medical disputes, this study reviews the publicness of public organization and discusses its policy implications. Methods: Through Moore's strategic triangle, which consists of legitimacy and support, public value and operational capacity, the process of creating public value is examined. For the analysis, case studies were conducted using related literature data from 2012, when the agency was established, to the present. Results: As a result of the analysis, first, the related law examined in the operational capability has been revised dozens of times, but the revised law has its own contradictions and limitations. The human resource system is also being improved, but there is a problem with the fairness and reliability of the arbitration process, especially due to the limitations of the appraiser system. Second, in terms of legitimacy and support, a regional gap occurred despite efforts to improve accessibility through the expansion of the organization. And the arbitration agency failed to reconcile conflicts caused by stakeholders' perception of each other as a trade-off relationship. Third, the public value result shows that, despite many explicit (statistical) achievements, citizens' use of the past dispute resolution means (litigation) has not decreased. Likewise, the perception of value makers (citizens) is important for creating public value as an invisible result, but it has not yet been formally investigated, so the performance can not be recognized. Conclusion: While the organization's efforts for continuous change and improvement are encouraging, it is not perceived as a better means of resolving disputes and improving quality of services. Therefore, it is necessary to reconsider the institutional design centered on value creators.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.25-31
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• 2022

By an aid of needle coating, we have fabricated a spherical microlens array using poly(methyl methacrylate) for potential applications in light extraction of organic light-emitting diodes. With an attempt to achieve high-density and high-aspect-ratio microlens arrays, we have investigated the coating behaviors by varying the material parameters such as the solute concentration and wettability of the poly(methyl methacrylate) solution and process parameters such as the dwell time of needle near the substrate, retract distance of needle from the substrate, and coating gap between the needle and substrate. Under the optimized coating conditions, it is demonstrated that high-aspect-ratio microlens arrays can be obtained using a coating solution with high solute concentration and a small amount of a hydrophobic solvent. It is found that the diameter and height of microlens array are decreased with increasing poly(methyl methacrylate) concentration, yet the overall aspect ratio is rather enhanced. By the addition of 5 wt% hexylamine in 35 wt% poly(methyl methacrylate) solution, we have achieved a spherical microlens with the height of 7.7 ㎛ and the width of 94.24 ㎛ (the aspect ratio of 0.082). To estimate the capability of light extraction by the microlens array, we have performed ray tracing simulations and demonstrated that the light extraction efficiency of organic light-emitting diode is expected to be enhanced up to 24%.

• Journal of English Language & Literature
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• v.57 no.6
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• pp.1111-1130
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• 2011

Reading postmodern texts certainly situates readers in roles different from the ones we have been used to. Recently, postmodern metafiction forms a significant body of children's literature that is intended to challenge and transform the conventions of books in the digital age. While many studies have been done as to how child readers have capabilities to appreciate and interpret postmodern metafiction picture books, few studies on teachers and preservice teachers' reactions are not readily available. The role of teachers and preservice teachers are crucial for child readers to have access to affluent reading resources. This study discusses how preservice teachers read and respond to postmodern metafiction picture books using a deconstructive approach by means of binary opposites. Data was collected with 14 preservice teachers as to their likes/dislikes, reading levels, and reading paths about postmodern metafiction picture books. Expected pedagogical implications for literacy and language education were requested to address in their reading diaries and response papers. With their likes/ dislikes, since binary opposites always imply the hierarchy of power and value, the likes is apparently more valued and appreciated over their dislikes. This differentiated values are discussed in more detail with three recurring themes-Education, Morals and Behavior, and Tradition. With reading levels, there seems to be a gap existing between the authors' implied reader and literary critics' and the preservice teachers' ideal readers for the postmodern metafiction picture books. Although many studies have already revealed young readers' capability of appreciating postmodern metafiction, it depends a lot more on the teachers and preservice teachers whether children's right to have access to affluent literacy resources is respected or not. Preservice teachers' awareness of the potential of postmodern metafiction will work as an initial step to bring and realize the new reading path and new literacies in classrooms. By challenging metanarratives of children's literature, preservice teachers' readings of postmodern picture books reveals potentials to raise different reading paths and develop new literacies and other educational implications.