• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1284-1291
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• 2015

This study was conducted as a descriptive study with the aim of identifying the effects of clinical nurses' resilience and social problem solving abilities on burnout. Data collection for the study was carried out between May $30^{th}$ and June $19^{th}$, 2013 by surveying 192 clinical nurses working in university medical centers and general hospitals located in D city. Measures were subjects' resiliency, social problem solving abilities, and burnout. For the analysis of the data, the statistical methods of frequency, mean and standard deviation, t-test, ANOVA, Pearson's correlation coefficients, and multiple regression analysis were employed. When the category of burnout was analyzed by general features, placement in a desired department and size of hospital, there were significant differences. Burnout correlated negatively with resilience and social problem solving abilities. Factors affecting clinical nurses' burnout were identified in the order of resilience, size of hospital, social problem solving abilities, and placement in a desired department and the explanatory power was 43.1%. The findings of the study indicate that in order to decrease clinical nurses' burnout, their resilience and social problem solving abilities have to be enhanced.

• Korean Journal of Child Education & Care
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• v.18 no.4
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• pp.187-197
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• 2018

Objective: The purpose of this study was to investigate relationship between teacher's emotional intelligence, consciousness of professionalism, and strategies of problem behavior guidance of early childhood. Methods: The subjects in this study were 237 childcare center teachers in Seoul and Gyoungi Province in South Korea. Three different inventories were utilized. As for data analysis, the frequency analysis, reliability analysis, correlation analysis, and Multiple Regressions were conducted through SPSS 21.0 program. Results: The findings of the study were discussed as follows. First, emotional intelligence of teacher had the relationship with strategies of problem behavior guidance of early childhood. Second, consciousness of professionalism of teacher had the relationship with strategies of problem behavior guidance of early childhood. Conclusion/Implications: First, The findings showed that as teachers had the high level of ability in recognizing and expressing their emotion preciously, so the elements triggering the situation of problem were identified and captured, and the ability of use of preventive strategies in advance increased. Second, The findings showed that as teachers had the high level of ability in recognizing and expressing their emotion preciously, so the elements triggering the situation of problem were identified and captured, and the ability of use of preventive strategies in advance increased.

• Geophysics and Geophysical Exploration
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• v.5 no.4
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• pp.280-290
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• 2002

Three-dimensional (3-D) electromagnetic (EM) modeling algorithm has been developed using finite element method (FEM) to acquire more efficient interpretation techniques of EM data. When FEM based on nodal elements is applied to EM problem, spurious solutions, so called 'vector parasite', are occurred due to the discontinuity of normal electric fields and may lead the completely erroneous results. Among the methods curing the spurious problem, this study adopts vector element of which basis function has the amplitude and direction. To reduce computational cost and required core memory, complex bi-conjugate gradient (CBCG) method is applied to solving complex symmetric matrix of FEM and point Jacobi method is used to accelerate convergence rate. To verify the developed 3-D EM modeling algorithm, its electric and magnetic field for a layered-earth model are compared with those of layered-earth solution. As we expected, the vector based FEM developed in this study does not cause ny vector parasite problem, while conventional nodal based FEM causes lots of errors due to the discontinuity of field variables. For testing the applicability to high frequencies 100 MHz is used as an operating frequency for the layer structure. Modeled fields calculated from developed code are also well matched with the layered-earth ones for a model with dielectric anomaly as well as conductive anomaly. In a vertical electric dipole source case, however, the discontinuity of field variables causes the conventional nodal based FEM to include a lot of errors due to the vector parasite. Even for the case, the vector based FEM gave almost the same results as the layered-earth solution. The magnetic fields induced by a dielectric anomaly at high frequencies show unique behaviors different from those by a conductive anomaly. Since our 3-D EM modeling code can reflect the effect from a dielectric anomaly as well as a conductive anomaly, it may be a groundwork not only to apply high frequency EM method to the field survey but also to analyze the fold data obtained by high frequency EM method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.455-464
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• 2019

The sensorless control based on the flux linkage of PM synchronous motors has excellent position estimation characteristics at low speeds. However, a limitation arises because the integrator of flux estimator is saturated by the DC offset generated during the analog to digital conversion(ADC) process of the measured current. In order to overcome this limitation, HPF with a low cutoff frequency is used. However, the estimation performance is deteriorated (Ed- the verb deteriorate already includes the meaning of 'problem') at high speed due to the low cutoff frequency, and increasing the cutoff frequency of the HPF induces further problems of phase leading and initial starting failure at low speeds. In this paper, the cutoff frequency of HPF was synchronized to the operation frequency of the motor: at low speeds the cutoff frequency was set to low in order to reduce the phase leading of the estimated flux, and at high speeds it was set to high to raise the DC offset removal performance. As a result, the operating range was increased by 200%. Furthermore, a phase compensation algorithm is proposed to reduce the phase leading of the HPF to less than 1.5 degrees over the full operating range. The proposed sensorless control algorithm was verified by experiment with a PM synchronous motor for a washing machine.

• The Journal of the Acoustical Society of Korea
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• v.42 no.4
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• pp.320-328
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• 2023

Underwater active target detection is vital for defense systems, requiring accurate detection and estimation of distance and velocity. Sequential transmission is necessary at each beam angle, but divided pulse length leads to range ambiguity. Multi-frequency transmission results in time-bandwidth product losses when bandwidth is divided. To overcome these problem, we propose a novel method using Generalized Sinusoidal Frequency Modulation (GSFM) for rapid target detection, enabling low-correlation pulses between subpulses without bandwidth division. The proposed method allows for rapid updates of the distance and velocity of target by employing GSFM with minimized pulse length. To evaluate our method, we simulated an underwater environment with reverberation. In the simulation, a linear frequency modulation of 0.05 s caused an average distance estimation error of 50 % and a velocity estimation error of 103 % due to limited frequency band. In contrast, GSFM accurately and quickly tracked targets with distance and velocity estimation errors of 10 % and 14 %, respectively, even with pulses of the same length. Furthermore, GSFM provided approximate azimuth information by transmitting highly orthogonal subpulses for each azimuth.

• Journal of Korean Home Economics Education Association
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• v.23 no.1
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• pp.159-176
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• 2011

The purpose of this study was to investigate 1) how the middle school Home Economics teachers perceive the importance of the practical problem-focused instruction, 2) how often they perform the instruction, and 3) what they require for the implementation the instruction. Data were collected from 150 Home Economics teachers via e-mail survey and from 6 Home Economics teachers' face-to-face interviews. Descriptive statistics including frequency, percentage, average, and standard deviation, and the results of such analyses as ANOVA, T-test, and correlation were reported using SPSS/win 10.1. The results of this research were as follows: First, even though the majority of the respondents recognized the high need for practical problem-focused instruction, only a small portion of the respondents reported that they performed that instruction in the classroom. There was no correlation between the perception of the need for practical problem-focused instruction and the degree of performance of practical problem-focused instruction. Secondly, the of performance of practical problem-focused instruction was significantly different depending on the years of teaching experience and the subject that the teachers majored in. Job satisfaction had positive correlations with the perception of the need for practical problem-focused instruction and the degree of performance of practical problem-focused instruction. Thirdly, the more teachers shared information and materials with colleagues, the better they tended to be at practical problem-focused instruction. On the other hand, insufficient time for their instruction and a deficiency in understanding the rationale of the instruction were pointed out as barriers to classroom practice. The respondents answered that long-term training programs on the philosophical foundation of practical problem-focused instruction, materials related to the instruction as well as additional credits for Home Economics are most critical to reduce the discrepancy between the teacher perception and the classroom practice of practical problem-focused instruction.

• Journal of Engineering Education Research
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• v.19 no.1
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• pp.3-10
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• 2016

This study was conducted to identify Korea's TRIZ research trends and to propose implications for setting a direction for future TRIZ research by analyzing TRIZ-related research over the past 15 years, or from 1998 to 2013. The subjects in this study were 256 published studies, including 149 studies in academic journals, 97 master theses, and 10 doctorate theses. This study reached the following conclusion. First, academic journals were the most frequent form of publication of TRIZ-related studies, followed by master's degree theses, and doctorate theses. Second, two or more TRIZ tools were used to solve problems and the most frequently used topic was technical contradiction as the result of frequency analysis for TRIZ research topics. This signified that it was easier to solve problems when various TRIZ tools were used, rather than applying a single TRIZ tool while technical contradiction was considered to be actively used as it allowed the relatively easy understanding of TRIZ. Third, the use of TRIZ research topics had increased and diversified each year. This could be interpreted to be based on the increased understanding of TRIZ. Fourth, case studies and experimental research were the most frequently used methods in TRIZ-related research. This was because various TRIZ tools were applied on problem solving situations, which were directly proposed as the research result. Fifth, the use of TRIZ was increasing in the educational field. Specifically, it was noted that TRIZ was used in creativity education with the use of 40 invention principles in elementary, middle, and high schools.

• Quality Improvement in Health Care
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• v.7 no.1
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• pp.46-58
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• 2000

Background : Despite favorable effects of guidelines on patient care, guidelines often fail to achieve their objectives. Poorly implemented medical practice guidelines can produce only weak effects on the process of health care delivery. Therefore, we performed this study to investigate barriers related development of clinical practice guidelines. Methods : Cardiopulmonary resuscitation was selected as a target problem. Self questionnaires about management of cardiopulmonary resuscitation were developed by a researcher with advisory 8 experts. The questionnaires were designed as a unstructured methods. The data were collected from March 1 to May 31, 1999. A total 50 death case admitted inpatient to Inha University Hospital were subjected to evaluate the development and application of clinical practice guidelines for cardiopulmonary resuscitation. The data were examined by frequency, t-test with SPSS. Result : The article reviewed several common barriers that might limit successful implementation of guidelines in clinical practice, as illustrated by evaluating recommendations for cardiopulmonary resuscitation clinical practice guidelines. Some major problems with guidelines were characterized as follows (1) ethical problem : euthanasia, (2) occurrence on various emergency event and setting, (3) non-medical problems (4) unreliable of medical record etc. Conclusion : Careful analysis of guideline attributes, anticipated effect on medical care, and organizational factors revealed several barriers to successful guideline implementation that should be addressed in the design of future guideline-based interventions.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.397-400
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• 1996

In this paper, robust motion control of a flexible micro-actuator is presented. The actuator is made of a bimorph piezoelectric high-polymer material (PVDF). No mathematical model system can exactly model a physical system such a flexible micro-actuator. For this reason we must be aware of how modeling errors might adversely affect the performance of a control system for such a model. The H method addresses a wide range of the control problems, combining the frequency and time domain approaches. The design is an optimal one in the sense of minimization of the maximum of the closed-loop transfer function. It includes colored measurement and process noise. It also addresses the issues of robustness due to model uncertainties, and is applicable to the, flexible micro-actuator control problem. Therefore, we adopt the H control problem to the robust motion control of the flexible micro-actuator. Theoretical and experimental results demonstrate the satisfactory performance and the effectiveness of the designed controller. the effectiveness of the designed controller.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.428-432
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• 2003

Quantitative Feedback Theory (QFT) is one of most effective methods of robust controller design and can be considered as a suitable method for systems with parametric uncertainties. Particularly it allows us to obtain controllers less conservative than other methods like $H_{\infty}$ and ${\mu}$-synthesis. In QFT method, we transform all the uncertainties and desired specifications to some boundaries in Nichols chart and then we have to find the nominal loop transfer function such that satisfies the boundaries and has the minimum high frequency gain. The major drawback of the QFT method is that there is no effective and useful method for finding this nominal loop transfer function. The usual approach to this problem involves loop-shaping in the Nichols chart by manipulating the poles and zeros of the nominal loop transfer function. This process now aided by recently developed computer aided design tools proceeds by trial and error and its success often depends heavily on the experience of the loop-shaper. Thus for the novice and First time QFT user, there is a genuine need for an automatic loop-shaping tool to generate a first-cut solution. In this paper, we approach the automatic QFT loop-shaping problem by using an algorithm involving Linear Programming (LP) techniques and Genetic Algorithm (GA).