• 한국안전학회지
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• 제7권1호
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• pp.20-29
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• 1992

Effects of strain hardening exponents on the retardation behavior of fatigue crack propagation are experimentally investigated. The retardation of fatigue crack propagation seems to be induced by the crack closure at crack tip. The phenomenon of crack closure becomes remarkable with the increment of strain hardening exponent and magnitude of percent peak load. The ratio of crack growth increment(a$\_$d//w$\_$d/) is influenced by a single overloading (a$\_$d/) and estimated plastic zone size (W$\_$d/=2r$\_$y/) is increased according with the increasing of strain ha.dening exponents. The number of retarded crack growth cycles were (N$\_$d/) decreased as the baseline stress intensity factor .ange( K$\_$b/) was increased. Within the limitation of these experimental results obtained under the single overload, an empirical relation between crack retardation ratio (Nd/N＊), strain hardening exponent (n) and percent peak load (％PL) has been proposed as; Nd/N＊＝ exp [PL $.$ PL$.$A(n)＋B(n) ] where, A(n)＝${\alpha}$n＋${\beta}$, B(n)＝${\gamma}$n＋$\delta$, PL＝％PL/100 and ${\alpha}$＝0.78, ${\beta}$＝0.54, ${\gamma}$＝0.58 and $\delta$＝-0.01, It is interesting to note that all these constants are identical for materials such as aluminum(A3203), steel(S4SC), steel(SS41) and stainless steel(SUS316) used in this experimental study.

• 한국구조물진단유지관리공학회 논문집
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• 제3권3호
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• pp.129-137
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• 1999

Reinforced concrete structures using early age concrete were result in the degradation of structural performance due to crack, overload, unexpected vibration and impact load. It demands urgently that reinforced concrete structure using early age concrete should be improved the serviceability and structural performance with the application of new fiber materials. Therefore specimens, designed by the test varibles, such as with or without stirrup and percent of steel fiber incorporated, were constructed and tested to evaluate and develop the structural performance of reinforced steel fiber concrete beam. Based on the test results reported in this study, the following conclusions are made. Specimens, designed by the over 0.75% of steel fiber incorporated, were showed the ductile behavior and failed slowly with flexure and flexure-shear. Comparing with the load-displacement relationship of specimen BSS, designed by the recommendations of the Ministry of Construction and Transportation, reinforced steel fiber concrete beam using early age concrete, over 0.75% of steel fiber incorporated, gets enough load carrying capacity and ductility. Increasing the percent of steel fiber incorporated(0.25~2.0%), the ultimate shear stress of each specimen were increased 12~40% than that of control specimen SSS.

• 지역사회간호학회지
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• 제13권4호
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• pp.608-617
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• 2002

The purpose of this study was to analyze phenomena and characteristics of family nursing in Korea based on the study by Yun et al. (1999) by ICNP. The subjects of this study were 115 reports on family nursing care in Korea National Open University. The results of this study were as follows; 1. In the phenomenon of family nursing, 'Inappropriate family coping' comprised of 17.0% and 'Inadequate care for a sick member' comprised of 16.8%. 2. It was found that 'A few close neighbors was 62.5%, 'Lack of communication between married couple' was 60.0%, 'Neglet of general child rearing' was 40.9%, 'Closed communication pattern of the head of a family' was 36.0%, and 'Inadequate distribution of each family member's role' was 27.2%. 3. 'Lack of family interaction in community' and 'Social isolation' were combined with 'Lack of family interaction in community', and 'Disturbance in family communication' and 'Lack of family intimacy' were combined with 'Disturbance in family communication'. 4. 'Dual-loading with office work and housework', 'Overload of caring one's elders because of the status as a dual-income family' and 'Lack of family support system' were added into 'Inappropriate family coping'.

• ETRI Journal
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• 제39권4호
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• pp.546-557
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• 2017

In a long term evolution-advanced (LTE-A) system, the traffic overload of machine type communication devices is a challenge because too many devices attempt to access a base station (BS) simultaneously in a short period of time. We discuss the challenge of the gap between the theoretical maximum throughput and the actual throughput. A gap occurs when the BS cannot change the number of preambles for a random access channel (RACH) until multiple numbers of RACHs are completed. In addition, a preamble partition approach is proposed in this paper that uses two groups of preambles to reduce this gap. A performance evaluation shows that the proposed approach increases the average throughput. For 100,000 devices in a cell, the throughput is increased by 29.7% to 114.4% and 23.0% to 91.3% with uniform and Beta-distributed arrivals of devices, respectively.

• 대한간호
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• 제28권1호
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• pp.77-88
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• 1989

The purpose of this study is to propose the baseline data for -developing the occupational stress measurement tool for Psychiatric nurses Working in the hospital. 135 staff nurses in psychiatric unit of 11. hospital were participated during the period from August 1 to August 20, 1988. Though the pretest and literature review a questionnaire was coristructed with 88 stressors which were experienced by the psychiatric nurses in the hospital. Subjects were given instruction to rate 1~6 likert type scale according to the level of stress experienced by each stressor described. Reliability of the tool was tested by Cronbach's Alpha and the reasult was ${\alpha}=0.94871$. Factor analysis was applied to organize 88 items together: As the result, 14 factors were obtained. The factors were; 1) Administration problem 2) Work overload 3) Role conflict as a profession 4) Lack of professional knowledge and skill 5) Conflict with nurses 6) Conflict with other health teams 7) Conflict in nurse-clint relationship 8) Conflict with supervisor 9) Conflict with suborinate 10) Low reward 11) Scheduling probrem 12) Inappropriate physical environment 13) Staff inadequate 14) Inadequate of equipment.

• Journal of Information Technology Applications and Management
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• 제16권4호
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• pp.167-184
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• 2009

New internet trend, such as Web 2.0, has brought about new roles of users and changes in the web ecosystem. In the age of information overload like nowadays, activities in the brand community sites help to make more reasonable decisions in choosing certain brands and products. In order to examine organizational strategic aspects of brand community, this study examine (1) what difference exists in user satisfaction according to the brand community types (the user-initiated type and the corporate-established type), and (2) which dimensions of service quality affect brand community users' satisfaction. Research findings show that types of brand community influence perceived user satisfaction, and tangibility, reliability, interactivity, and stability dimensions of service quality make a positive influence on user satisfaction as well. Practical implications for managing brand community sites in marketing perspectives are further discussed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.609-610
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• 2008

In this paper, a 110 dB, 1.024 MHz fourth-order single-loop Delta-Sigma sigma modulator has been presented with an over-sampling ratio of 128 and an overload factor of -6 dB for a bandwidth of 4 kHz. In particular, this ${\Sigma}-{\Delta}$ modulator is well suited for high accuracy measure systems. The whole modulator consumes only 3-mW from a single 3.3V supply in a $0.35-{\mu}m$ CMOS technology.

• Journal of Veterinary Science
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• 제22권5호
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• pp.60.1-60.9
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• 2021

Background: Echocardiography is a primary tool used by veterinarians to evaluate heart diseases. In recent years, various studies have targeted standard echocardiographic values for different breeds. Reference data are currently lacking in Maltese dogs and it is important to fill this gap as this breed is predisposed to myxomatous mitral valve disease, which is a volume overload disease. Objectives: To establish the normal echocardiographic parameters for Maltese dogs. Methods: In total, 23 healthy Maltese dogs were involved in this study. Blood pressure measurements, thoracic radiography, and complete transthoracic echocardiography were performed. The effects of body weight, age and sex were evaluated, and the correlations between weight and linear and volumetric dimensions were calculated by regression analysis. Results: The mean vertebral heart size was 9.1 ± 0.4. Aside from the ejection fraction, fractional shortening, and the left atrial to aorta root ratio, all the other echocardiographic parameters were significantly correlated with weight. Conclusion: This study describes normal echocardiographic parameters that may be useful in the echocardiographic evaluation of Maltese dogs.

• 간호행정학회지
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• 제9권2호
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• pp.217-232
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• 2003

Purpose : This paper was attempted to identify the job stress related factors among the staff nurses and to provide the basic data concerning development of stress management program focused on hospitals. Method : The subjects were 309 staff nurses at two general hospitals in Seoul. Data were collected with self-reported questionnaires and analyzed by SPSS-PC+10.0 for descriptive analysis, ANOVA, stepwise multiple regression, factor analysis. Results : The subjects exhibit significantly highest level of 'the participation in decision making factor'. The mean score of 'control coping strategies' was higher than 'avoid coping strategies'. The mean scores of social support and stress responses were high. The main factor that affected the stress responses was 'the job characteristic factor' and it was explained 23.0% out of the total variance of the stress responses. Also, it would be explained 42.6% out of the total variance of the stress responses with 'the control coping strategies, work overload factors, social support, and participation in decision making factors'. Conclusion: For developing the hospital- focused stress management program for staff nurses, 'the participation in decision making factors' and 'the job characteristics' should be considered. Also, the organizational efforts and supports should be required to support and use of 'control coping strategies' of nurses

• 한국식품위생안전성학회지
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• 제11권2호
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• pp.83-87
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• 1996

The objective of this study is to investigate the direct effects of green tea catechins(GTC) on vascular smooth muscle tension and 45Ca2+ Uptake in rat aorta. The methods used in this study are isometric tension measurements using physiograph, Lanthanum method for 45Ca2+(2 uCi/ml) uptake measurement in rat aorta. GTC modified tension induced by 40 mM KCl or 1 uM norepinephrine in rat aorta. Low concentrations of GTC(<0.5mg/ml) increased tension by 40 mM KCl or 1 uM norepinephrine, individually. However, high conecentration of GTC(>0.5 mg/ml) inhibiited tension by 40 mM KCl or 1 uM norepinephrine, individually. GTC increased 45Ca uptake induced by 40 mM KCl in a dose-dependent manner. From these results, GTC has the dual actions in vascular smooth muscle in vitro. Low concentrations of GTC augments tension by K or norepinephrine. However, high concentrations of GTC inhibits tension by K or norepinephrine GTC may have Ca2+ channel activation, action, which may result in unphysiological vasodilation by Ca2+ overload in vascular smooth muscle.