• Journal of the Korean Home Economics Association
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• v.48 no.8
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• pp.13-26
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• 2010

This study tested the path model with regard to how certain variables (control attribution, demand-control-support of activity, and control strategy) affected the elderly workers' subjective well-being(swb). In the path model, the exogenous variables were internal and external control attribution. We used demand-control-support of activity, and primary and secondary control strategies as mediating variables. The endogenous variable was each elderly worker's swb. Study participants were 205 elders participating in an "education activity". We used descriptive statistical analysis, Pearson's correlation and hierarchical multiple regression to examine data collected from structured interviews with the participants. Path analysis revealed the followings: First, secondary control strategy was the strongest predictor of participants' swb but internal control attribution, demand of activity, and support of activity also positively affected participants' swb. Second, internal control attribution indirectly affected the participants' swb. Finally primary control strategy negatively affected on the participants' swb.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.2
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• pp.63-70
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• 2013

Objectives: The purpose of this study was to investigate the wound healing effect of primary cultured oral mucosal keratinocytes (OMKs) and to assess their roles in skin wounds. Materials and Methods: OMK labeled with BromodeoxyUridine were scattered onto $1.5{\times}1.5$ cm skin defects of adult female nude mice (OMK group, n=15). For the control, culture media were placed on the wound (control group, n=15). Mice in both groups were sacrificed at three days (n=5), one week (n=5), and two weeks (n=5), and histomorphometric and immunoblot analyses with keratinocyte growth factor (KGF), interleukin (IL)-6, and IL-$1{\alpha}$ antibody were performed for the biopsied wound specimen. To verify the effect of the cytokine, rhIL-$1{\alpha}$ was applied instead of OMK transplantation, and the OMK and control groups were compared with regard to re-epithelialization. Results: Histomorphometric analyses demonstrated faster re-epithelialization in the graft group than in the control group at the third day, first week, and second week. Newly forming epithelium showed maintenance of the histological character of the skin epithelium. The graft group showed superior expression of KGF, IL-6, and IL-$1{\alpha}$ protein, compared with the control group. Similar faster re-epithelialization was observed after treatment with rhIL-$1{\alpha}$ instead of OMK transplantation. Conclusion: We successfully confirmed that the graft of primary cultured OMKs promoted regeneration of skin defects. The mechanism of accelerated wound healing by primary cultured OMKs was attributed to inducement of cytokine expression as required for re-epithelialization.

• Smart Structures and Systems
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• v.25 no.1
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• pp.65-80
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• 2020

In order to protect a structure over its full life cycle, a novel tuned mass damper (TMD), the so-called semi-active eddy current pendulum tuned mass damper (SAEC-PTMD), which can retune its frequency and damping ratio in real-time, is proposed in this study. The structural instantaneous frequency is identified through a Hilbert-Huang transformation (HHT), and the SAEC-PTMD pendulum is adjusted through an HHT-based control algorithm. The eddy current damping parameters are discussed, and the relationship between effective damping coefficients and air gaps is fitted through a polynomial function. The semi-active eddy current damping can be adjusted in real-time by adjusting the air gap based on the linear-quadratic-Gaussian (LQG)-based control algorithm. To verify the vibration control effect of the SAEC-PTMD, an idealized linear primary structure equipped with an SAEC-PTMD excited by harmonic excitations and near-fault pulse-like earthquake excitations is proposed as one of the two case studies. Under strong earthquakes, structures may go into the nonlinear state, while the Bouc-Wen model has a wild application in simulating the hysteretic characteristic. Therefore, in the other case study, a nonlinear primary structure based on the Bouc-Wen model is proposed. An optimal passive TMD is used for comparison and the detuning effect, which results from the cumulative damage to primary structures, is considered. The maximum and root-mean-square (RMS) values of structural acceleration and displacement time history response, structural acceleration, and displacement response spectra are used as evaluation indices. Power analyses for one earthquake excitation are presented as an example to further study the energy dissipation effect of an SAECPTMD. The results indicate that an SAEC-PTMD performs better than an optimized passive TMD, both before and after damage occurs to the primary structure.

• Research in Community and Public Health Nursing
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• v.5 no.2
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• pp.162-180
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• 1994

The control of the chronic degenerative diseases becomes a challenge in Korea as the aging of the population progresses. Accordingly, the importance of the control of the hypertension, one of the major chronic degenerative diseases, in the primary health care settings increases. However, such control activities are still minimal. This study gives brief description of how the rural residents who are currently registered for the control of the hypertension feel about the activities of the health centers, subcenters and the CHP posts, in relation to the control of the hypertension. We also describe the knowledge and practice of the registered hypertensive. In general, the knowledge, the acceptance and the satisfaction of the respondents about the hypertension control activities were not very high. Respondents being managed by the health center showed the highest knowledge, acceptance and satisfaction, and those being managed by the subcenters ranked lowest. The knowledge about the hypertension was not satisfactory. There were great variations among the items in terms of the proportion answered correctly. As many as 60% of the respondents take medication regularly but only 4.5% were practicing weight control regularly. Despite some limitations of the study, the results can be very useful for those planning hypertension control programs. The educational materials and the dietary protocols need to be developed in accordance with the regional social and food pattern, so that they can be utilized with minimal modification for each beneficiary. We also suggest to minimize the area a health personnel covers. In other word, running several small health posts at village level would be more effective than running a subcenter at the township level, in terms of the hypertension control.

• Journal of Nutrition and Health
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• v.25 no.2
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• pp.150-161
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• 1992

The purpose of this study was to evaluate the riboflavin status of primary school children. Fiftyone subjects were selected as obese group and fiftyfive subjects were selected as control group according to Body Mass Index(BMI) of fifth-graders at a primary school in Taegu. For each subject information on nutrient intake and daily activity pattern were obtained by questionnaire. The riboflavin status was evaluated by urinary riboflavin exvretion The daily energy expenditure per kilogram of body weight was significantly lower in obese group(=47kcal/day) than in control group(=58kcal/day) (p<0.001) However the entire energy consumption was siginificantly greater in the obese children(=2005kcal/day) than their nono-baser peers(=1837kcal/day)(p<0.001). Riboflavin intake was 0.67mg/100kcal in the control group and 0.61mg/1000kcal in the obese group. Thus intakes for both groups met the current group and control group were 86.9$\mu\textrm{g}$/day and 98.7$\mu\textrm{g}$/day. repectively. There was no significnat Assesment of clinical signs of riboflavin deficiency indicated that angular lesion was 4.7% and glossitis was 6.6% of all subjects. Thirty one percent of subjects excrete riboflavin below 78$\mu\textrm{g}$/g creatinine which is defined as deficient. Therefore this group would be considered at high risk for developing riboflavin deficiency. From this study current recommendation of 0.6mg/1000kcal of riboflavin intake may not be adequate during growth and associated stress.

• Parasites, Hosts and Diseases
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• v.57 no.3
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• pp.291-294
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• 2019

Primary amebic encephalitis (PAM) is a devastating central nervous system infection caused by Naegleria fowleri, a free-living amoeba, which can survive in soil and warm fresh water. Here, a 43-year-old healthy male was exposed to warm freshwater 5 days before the symptom onset. He rapidly developed severe cerebral edema before the diagnosis of PAM and was treated with intravenous conventional amphotericin B while died of terminal cerebral hernia finally. Comparing the patients with PAM who has similar clinical symptoms to those with other common types of meningoencephalitis, this infection is probably curable if treated early and aggressively. PAM should be considered in the differential diagnosis of purulent meningoencephalitis, especially in patients with recent freshwater-related activities during the hot season.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.110-113
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• 2000

In general, speed control method of the elevator system has used motor pole change type or motor primary voltage control type. But it will change to vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control that primary current of the induction motor be controlled independently with magnetizing current(field current of DC motor) and torque current(armature current of DC motor). In this paper, by analyzing the effect of the time constant variation of rotor of the induction motor on the slip frequency type indirect vector control, a drive system for the motor will be constructed using a fuzzy slip frequency type indirect vector controller with fuzzy control method for estimating the vector time constant in the slip frequency type indirect vector control. The goal of this study is to enabling even more efficient speed control by constructing on elevator driver based on the newly developed drive system.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1130-1137
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• 2006

Relaxed Static Stability(RSS) concept has been applied to improve aerodynamic performance of modern version supersonic jet fighter aircraft. Therefore, the flight control systems are necessary to stabilizes the unstable aircraft and provides adequate handling qualities. The initial production flight control system are verified by flight test and it's always an elements of danger because of flight-critical nature of control law function and design error due to model base design method. These critical issues impact to flight safety, and it could be lead to a loss of aircraft and pilot's life. Therefore, development of an easily modifiable RFCS(Research Flight Control System) capable of reverting to a PFCS(Primary Flight Control System) of reliable control law must be developed to guarantee the flight safety. This paper addresses the concept of SSWM(Software Switching Mechanism) using the fader logic such as TFS(Transient Free Switch) based on T-50 flight control law. The result of the analysis based on non-real time simulation in-house software using SSWM reveals that the flight control system are switching between two computers without any problem.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.972-981
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• 2008

A New ZVS(Zero Voltage Switching) and ZVZCS(Zero Voltage and Zero Current Switching) Three-Level Converter is proposed. The proposed converter presented in this paper used a phase shift control with a flying capacitor in the primary side to achieve ZVS for the all switch. A primary auxiliary circuit, which consists of one coupled inductor, is added in the primary to provide ZVZCS conditions to primary switches. Many advantages including simple circuit topology high efficiency, and low cost make this converter attractive for high power applications. The principle of operation, feature and design considerations are illustrated and verified through the experiment with a 2kW(27V, 74A) 40 kHz IGBT based experimental circuit.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.3
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• pp.637-643
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• 2001

Two-phase flow in a combustion chamber is experimentally analyzed according to the five different conditions in the Reynolds numbers of $1.02{\times}10^4$. As the height difference between the primary and secondary jets increases, the secondary has a little less effect on the primary one in the case on the same height difference, the primary jet is affects as the velocity of th secondary on increase. The primary-jet flow field cause the particle concentration since is controlled by the velocity of secondary jet, the height difference, and the angle of primary jet in the test section.