• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.135-142
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• 2015

Human-powered self-generating devices have been attractive with its operation characteristic independent from outer environment such as weather condition and wind speed. However, conventional self-generators have low electric power output due to their weakly-coupled electromagnetic structure. More importantly, rotary crank motion which is usually adopted by conventional self-generator to generate electricity requires specific skeletal muscles to maintain large torque circular motion and consequently, causes fatigue on those muscles before it can generate enough amount of electricity for any practical application. Without improvement in electric power output and usability, the human-powered self-generator could not be used in everyday life. This study aims to develop a human-powered self-generator which realized a strong electromagnetic coupling in a closed-loop tubular structure (hula-hoop shape) for easy and steady long-term driving as well as larger electric output. The performance and usability of the developed human-powered generator is verified through experimental comparison with a commercial one. Additionally, human workload which is a key element of a human-powered generator but not often considered elsewhere, is estimated based on metabolic energy expenditure measured respiratory gas analyzer. Further study will focus on output and portability enhancement, which can contribute to the continuous power supply of mobile equipments.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.1
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• pp.40-49
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• 1986

Crack, craze and void are common defects which may be found in the bulk of polymeric materials such as either themoplastics or thermosets. The healing phenomena, autohesion, of these defects are known to be a intrinsic material property of various polymeric materials. However, only a few experimental and theoretical investigations on crack, void and craze healing phenomena for various polymeric materials have been reported up to date [1, 2, 3]. This may be partly due to the complications of healing processes and lacking of appropriate theoretical developments. Recently, some investigators have been urged to study the healing phenomena of various polymenic materials since the significance of the use of polymer based alloys or composites has been raised in terms of specific strength and energy saving. In the earlier published reports [1, 2, 3, 4], the crack and void healing velocity, healing toughness and some other healing mechanical and physical properties were measured experimentally and compared with predicted values by utilizing a simple model such as the reptation model under some resonable assumptions. It seems, however, that the general acceptance of the proposed modeling analyses is yet open question. The crack healing processes seem to be complicate and highly dependent on the state of virgin material in terms of mechanical and physical properties. Furthermore, it is also strongly dependent on the histories of crack, craze and void development including fracture suface morphology, the shape of void and the degree of disentanglement of fibril in the craze. The rate of crack healing may be a function of environmental factors such as healing temperature, time and pressure which gives different contact configurations between two separated surfaces. It seems to be reasonable to assume that the crack healing processes may be divided in several distinguished steps like stress relaxation with molecular chain arrangement, surface contact (wetting), inter- diffusion process and com;oete healing (to obtain the original strength). In this context, it is likely that we no longer have to accept the limitation of cumulative damage theories and fatigue life if it is probable to remove the defects such as crack, craze and void and to restore the original strength of polymers or polymer based compowites by suitable choice of healing histories and methods. In this paper, we wish to present a very simple and intuitive theoretical model for the prediction of healed fracture toughness of cracked or defective polymeric components. The central idea of this investigation, thus, may be the modeling of behavior of chain molecules under healing conditions including the effects of chain scission on the healing processes. The validity of this proposed model will be studied by making comparisons between theoretically predicted values and experimentally determined results in near future and will be reported elsewhere.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.3
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• pp.464-476
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• 1999

This study was conducted between October 1, 1998, and December 31, 1998, in order to provide basic data to develop better self-management educational programs for systemic lupus erythematosus (lupus) patients. In the study, the extent of each patients knowledge on the disease and their learning needs about it were examined for 100 lupus inpatients and outpatients at the Kangnam St. Marys Hospital. Data were collected by using questionnaires to those patients. Frequencies, percentage, average, standard deviation, t-test, ANOVA, and Duncans multiple range test were examined through the SAS program. The result of study follows : 1) The average score of patients knowledge on the disease was 15.7 (range, 7-20; standard deviation, 2.74). Subjects scored higher as far as the extent of their knowledge in the following categories : management of daily life, diet, characteristics of the disease, risk factors, and medication. Two categories shared the highest percentage of correct answers : 99% of subjects correctly identified that fatigue and stress aggravate symptoms of lupus and symptoms of lupus vary among individuals in range and type. However, when subjects were asked if patients should get a regular examination by an ophthalmologist every 4-6 months while they are on medication to treat rashes, lupus can be completely cured, and contraceptives that include a female hormone (estrogen) are good as contraceptive methods, the percentages of correct answers were low (32%, 31%, and 20%, respectively). In terms of subjects knowledge about the disease by their general characteristics, single subjects had more knowledge about the disease than married subjects did (t=2.14, p=0.0353). The extent of knowledge also varied by monthly income (F=4.96. p=0.0097). Those with more formal education had more knowledge about lupus than those who had less formation education did (t=2.95, 0.0039). Additionally, those who were satisfied with their education about the disease had better knowledge about it than those who were dissatisfied with their education did (t=2.71, p=0.0090). 2) The extent to which lupus patients wanted to be educated about the disease was, on average, 64.5 (range, 46-75; standard deviation, 7.91). Areas for which patients requested education are listed here in order : risk factors, sexual lives and patients associations. Patients who had been hospitalized demonstrated wanting more education than those who had not been did(t=3.73, p=0.0003). The extent to which they wanted the information was different by the number of educational sessions they had (F=3.98, p=0.0249). In conclusion, the results above would be considered when the education programme is planned for SLE patients.

• Korean Journal of Adult Nursing
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• v.12 no.2
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• pp.175-183
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• 2000

The study was done by applying a phenomenological study, which is qualitative research methods, in order to understand the meaning of the lived experiences, to confirm and describe the meaning structure, and to prepare nursing interventive strategies centering around the meanings of the inpatients' families in the intensive care units. In the study, the family members were the main important nursing providers for in the inpatients' who were admitted in the neurosurgical intensive care unit in K-university hospital and who agreed to participate in the study after being given on explanation about the purpose of the study. The data were collected from the seven participants who had feelings of trust and intimacy favorable toward the researcher as they were families of patients who had been cared for by the researcher in the ICU where the researcher has been assigned. The data were collected from April to October, 1999. The participants described their experiences as candidly as possible. The researcher described closely the lived experiences with their own words and the observations of the researcher. A tape recorder was used with the consent of the participants to prevent nursing information and communication. The analysis of the data was made through the phenomenological analytic method suggested by Giorgi; as an unit of description, which include the participants' expressions and the researcher's observations, the analysis was used based on the data described from the expressions of the participants and the details of observations of the researcher. The conclusions of the study were as follows : The meanings of the lived experience of the inpatients' families in the ICU was confirmed by indepth interviews and observations including these of the participatants : (1) Psychological impact: confusion, impatience, surprise, insensibility; (2) Physical suffering: fatigue, discomfort, indigestion; (3) Psychological suffering: heartbreaking emotion, anxiety, annoyance, fear, compassion, grief; (4) Economical suffering: economical difficulties; (5) Psychological disagreement: escape from reality, personnel avoidance, grudge, powerlessness, carefulness, transposition of life-tract, abandonment, role-crisis, hope, lack of understanding, regret, feeling of ambivalence(progressive process, medical personnel interest); (6) Psychological dependency; self-reliance group support, family support, religious support; (7) Psychological acceptance; acquaintance, gratitude, reassurance; The study will offer better understanding of experiences therefore, based on the experiences confirmed by the study, it may facilitate more appropriate nursing interventive strategies for health maintenance and to prevent occurrence of possible problems with the inpatients' families in the ICUs.

• Journal of Yeungnam Medical Science
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• v.24 no.1
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• pp.55-67
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• 2007

Background : The goal of this study was to examine the health behaviors of nurses and provide basic information on health promotion for nurses. Materials and Methods : A self-administered questionnaire survey was completed by 340 nurses working at a university hospital in Daegu, Korea from March 6 to March 30, 2006. The questionnaire included demographic characteristics, working environment, health behaviors, self-assessed health status, and the practice of health promotion activities according to the work group(shift group vs. non-shift group). Results : There were significant differences in 'regular diet', 'drinking', 'ordinary health management', 'regular exercise', 'leisure activities', 'rest', and 'feeling of fatigue' between the two groups. The score for the practice of health promotion activities of the non-shift group was 121.9, which was higher than the 115.4 for the shift group. By field of practice of health promotion activities, there were significant differences in 'self-realization' and 'nutrition' between the two groups. Conclusion : The shift group did not appear to have enough time to take care of their health. It is therefore important to provide a working environment in which nurses are encouraged to increase their interest and efforts to maintain healthy behaviors. In addition, programs for education and training should be developed to help nurses adopt healthy life styles and enhance their self-esteem.

• Journal of Korean Academy of Nursing
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• v.30 no.3
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• pp.659-669
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• 2000

Many patients of acute myocardial infarction showed delay time before seeking treatment although they needed immediate thrombolytic therapy once they perceived their symptoms. The objectives of this study were to identify the relationship between clinical symptoms and the delay, and to find the time spent before seeking the treatment. This study was a retrospective research. The delay time for the treatment consisted of the length of delay from symptom onset to patients' decision (T1), from patients' decision making to finding transportation (T2), and from taking transportation to the first hospital arrival(T3). The subjects were 89 patients who were admitted in the ICU and Cardiac Ward at Chonnam University Hospital with the first attack of acute myocardial infarction. Center, USA The data was collected for three months from March 1st to May 31st of 1998 through questionnaires and reviewing patients' charts: The chart information was suppled by two nurses working at the ICU and Cardiac Ward. The data was analyzed by using frequency, mean and ANOVA through the SAS program. The results of study summarized as follows: 1. Sixty two patients (69.7%) were male and twenty seven patients (30.3%) were female, the ratio of male to female was 2.3 : 1. 2. In daily life, the 70.8% of the patients felt chest pain and discomfort fatigue in 67.4%, dyspnea in 57.3%, and pain in arm, neck, and jaw in 52.8%. During the attack, 97.8% of the patients felt chest pain and discomfort dyspnea in 82.1%, pain in arm, neck, jaw in 67.4% and perspiration in 51.7%. 3. The length of time a patient spent seeking time for treatment (T1+T2+T3) was 94.6 minutes, in which the time for patients' decision making for treatment (T1) was 70.3 minutes, time for finding transportation (T2) was 8.2 minutes, and time for the transportation of the patient to the first hospital (T3) was 16.1 minutes. Time for patients' decision making to go to a hospital(T1) was 74.2% of the total time sought for treatment. 4. The differences of time sought for treatment between perceptions about the seriousness of the symptoms were significant (F= 6.5, p< .01). The more serious the heart symptoms they felt, the shorter the seeking time for treatment. 5. The differences of the time delay before treatment between the degree of the symptoms were significant (F= 2.9, p< .05). The patients with the typical chest pain and discomfort spent shorter the seeking time for treatment than those with the atypical symptoms of acute myocardial infarction. 6. The differences of transportation time to the first hospital between the types of cars that the patients used, were significant (F= 4.3, p< .01). When the patients used 119 or 129 they spent the least time (5.3 minutes) for transportation, and followed by way of an ambulance (15.6 minutes), private car (20.6 minutes), and taxi (24.8 minutes).

• The Korean Journal of Pain
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• v.12 no.1
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• pp.27-35
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• 1999

Background: Fibromyalgia is a common syndrome of musculoskeletal pain and fatigue. Lacking distinctive histological or laboratory abnormality in diagnosis, it has often been considered a form of "psychogenic rheumatism". Fibromyalgia causes much distress to the affected patients and often frustrates physicians, who are unable to start rational therapy on any logical disease pathology. Methods: Growth hormone is essential for muscular homeostasis. In the present study, the notion that the stage-4 sleep anomaly typically seen in the fibromyalgia syndrome may disrupt growth hormone secretion was tested. Because growth hormone has a very short half-life, serum levels of somatomedin C were measured; somatomedin C is the major mediator of growth hormone's anabolic actions and is a prerequisite for normal muscle homeostasis. Serum levels of somatomedin C using acid-extraction procedure and two-site immunoradiome-tric assay (IRMA) and number of tender points were measured in 27 female patients with fibromyalgia from 40 to 60 years old and 27 healthy controls. Results: There were no differences in the concentration of somatomedin C between fibromyalgia patients and controls ($mean{\pm}SD$: $178.3{\pm}75.5$ ng/ml versus $166.3{\pm}76.6$ ng/ml; p=0.55). And there were no correlations between number of tender point and serum somatomedin C level by linear regression analysis. Conclusions: These findings did not support that there is a distinctive disruption of the growth hormone-somatomedin C neuroendocrine axis in a fibromyalgia syndrome. But we can not discard the hypothesis that disturbed sleep predispose to muscle pain.

• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.427-434
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• 2003

In this paper, we present a speech-based Environmental Control System(ECS) and its application. In the concrete, an ECS using the speech recognition and an portable wheelchair lift control system with the speech synthesis are developed through the simulation and the embodiment. The developed system apply to quadriplegic man and we evaluate the result of physical effect and of mental effect. Speech recognition system is constructed by real time modules using HMM model. For the clinical application of the device, we investigate the result applied to 54-years old quadriplegic man during a week through the questionnaires of Beck Depression Inventory and of Activity Pattern Indicator. Also the motor drive control system of potable wheelchair lift is implemented and the mechanical durability is tested by structural analysis. Speech recognition rate results in over 95% through the experiment. The result of the questionnaires shows higher satisfaction and lower nursing loads. In addition, the depression tendency of the subject were decreased. The potable wheelchair lift shows good fatigue life-cycle as the material supporting the upper wheelchair and shows the centroid mobility of safety. In this paper we present an example of ECS which consists of real-time speech recognition system and potable wheelchair lift. Also the experiments shows needs of the ECS for korean environments. This study will be the base of a commercial use.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.4
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• pp.37-47
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• 2013

PURPOSE : Club dance is one of the most popular cultures worldwide and is getting popular in Korea over time. However, club still has negative awareness in the country due to the media spreading only harmful aspects of club culture. At any rate, nowadays many young aged people can easily have chances to experience clubs so we tried to find out the bad effects caused by clubs. METHOD : We conducted a survey and the number of participants who agreed to participate in this survey was 500, including both men and women. There are a total of 50 questions in the questionnaire form used by this study and the questions were divided into three categories: general(18), psychologic-related(7), social-cultural(9), and physical-related(16) questions. Data collected for this study was analyzed via frequency analysis using SPSS. RESULT : In our survey, most students who had already experienced the club culture tend to go to club once or twice a month, and they answered that they would feel bored if they were nor able to do so. In terms of social life, most respondents said that they had lower efficiency in working and studying the next day after going to clubs because of fatigue. In physical aspect, club users use then pelvis and lower back a lot while dancing. The respondents answered that they experienced muscle soreness, a loss in weight, and changes in their body as a consequence of intense dancing. They complaint pain mostly in lower limbs, so we could find out the fact that legs were primarily used for the club dance. CONCLUSION : To sum up, the club culture in undergraduate students affects on their daily living and body, and also has good effects as well as bad ones. Therefore, we need to look at the club culture positively and to improve bad effects of club culture.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.520-526
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• 2015

Reinforcing bar splices are inevitable in reinforced concrete structure. In these days, there are three main types of splices used in reinforced concrete construction site - lapped splice, mechanical splice and welded splice. Low cost, practicality in construction site, less time consuming and high performance make gas pressure welding become a favorable splice method. However, reinforcing bar splice experiences thermal loading history during the welding procedure. This may lead to the presence of residual stress in the vicinity of the splice which affects the fatigue life of the reinforcing bar. Therefore, residual stress analysis and tensile test of the gas pressure welded splice are carried out in order to verify the load bearing capacity of the gas pressure welded splice. The reinforcing bar used in this work is SD400, which is manufactured in accordance with KS D 3504. The results show that the residual stresses in welded splice is relatively small, thus not affecting the performance of the reinforcing bar. Moreover, the strength of the gas pressure welded splice is high enough for the development of yielding in the bar. As such, the reinforcing bar with gas pressure welded splice has enough capacity to behave as continuous bar.