• Title/Summary/Keyword: Fatigue design

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The Effect of Self-Help Program for Promotion of Health for Arthritis Patients at various Health Centers in Seoul (서울시 보건소에서 실시한 관절염환자 자조관리과정 평가)

  • Lee, Eun-Ok;Suh, Moon-Ja;Kang, Hyun-Sook;Lim, Nan-Young;Han, Sang-Sook;Song, Kyeong-Yae;Eum, Ok-Boon;Lee, In-Ok;Kim, Mi-Ra;Choi, Hee-Jung
    • Journal of muscle and joint health
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    • v.5 no.2
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    • pp.155-173
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    • 1998
  • The purpose of this study was to evaluate the effects of self-help programs which had been conducted at each health center of Seoul using the protocol developed by Korean Rheumatology Health Professionals Society(KRHPS). This program was developed to initially increase self-efficacy, and then to decrease the symptoms and finally to increase the functions of the patients. This study was designed as one group pretest-posttest design. Data were collected by self-administered questionnaires for 140 out of 303 program participants, and only 102 subjects were analyzed because of missing values. The subjects were composed of 25.5% of rheumatoid arthritis patients and 60.8% of degenerative arthritis patients. The results showed that arthritis self-help program was effective in increasing self-efficacy and then improving pain, fatigue, depression, and activities of daily living. But the number of pain sites was not decreased. This result explains that degenerative arthritis patients composed of more than half of the participants has less number of pain sites than rheumatoid arthritis, and their pain was not completely relieved. As a result, it was confirmed that arthritis patients' physical and psychological states can be improved by self-help program in the community. These findings emphasize the implication of this program for each institute to promote health of arthritis patients.

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A case study on the bolt failure of the moving parts of a marine diesel engine (선박용 디젤기관의 운동부 볼트 손상사례에 대한 연구)

  • Kim, Jong-Ho;Lee, Jae-Hyun
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.1
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    • pp.118-124
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    • 2017
  • To investigate and analyze the cause of the failure of the connecting rod bolt and the crank pin bearing bolt of the diesel engine of this study, the following results were obtained through site surveying, the investigation of literature referring to similar failures, testing and inspection of the fracture surface, and the experience of the researchers. The fractured crank pin bearing bolt of the diesel engine is estimated to be damaged later than the connecting rod bolt. From the shape of fracture surface, it is evident that the failed connecting rod bolt is fractured by fatigue failure due to abnormally repeated loads (e.g. loosening of the connecting bolt, etc.), and is not failed by brittle fractures due to the impact load. The surface of the U-nut on the fractured connecting rod bolt has been worsening due to the improper use of lubricant (agent for prevention of thread fixing) and no usage of separating the each connecting rod on each cylinder. Moreover, there is the possibility that those poor surface conditions of the fractured connecting rod bolt have affected the failure of the connecting rod bolt of the main engine. And it could be assumed that the mechanical characteristic and manufacturing process of the failed connecting rod bolt and crank pin bearing bolt, which were made by a domestic company, conform to the design requirements for those bolts.

Structural Capacity of High Strength Steel Pipe Pile After Pile Driving (고강도 강관말뚝의 항타후 구조성능 분석)

  • La, SeungMin;Yoo, Hankyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.6C
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    • pp.251-258
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    • 2011
  • Steel pipe piles have been used as various deep foundation materials for a long time. Recent increase in steel material cost has made engineers reluctant in using it even with its good quality and ease of construction. Therefore when constructing with steel pipe pile, the decision to reuse the excessive pile length that is cut off from the designed pile head elevation after pile driving can be cost saving. This has caused many constructors to reuse the pile leftovers with new piles, but the absence of quantitative structural capacity behaviors of steel pipe pile after pile driving or appropriate countermeasures and standards in reusing steel pipe pile has resulted in wrong applications, pile structural integrity problems, inappropriate limitation of reusable pile length, etc. The structural performance analysis between a new pile and a pile that has undergone working state and ultimate state stress level during pile driving was performed in this research by means of comparing the results between the dynamic pile load test, tensile load test, charpy energy test and fatigue test for high strength steel of $440N/mm^2$ yield strength. Test results show that under working load conditions the yield strength variation is less than 2% and for ultimate load conditions the variation is less than 5% for maximum total blow count of 3000. The results have been statistically analyzed to check the sensitivity of each factors involved. From the test results, reusability of steel pipe pile lies not in the main pipe yield strength deviation but in the reduction of absorb energy, strength changes and quality control at the welded section, shape deformation and local buckling during pile driving.

The Effect of Self-help Health Promotion Program for Arthritis Patients from Year 1997 to 2000 (1997-2000 관절염 자조관리 과정의 효과 분석 연구)

  • Lee, Eun-Ok;Suh, Moon-Ja;Kim, Keum-Soon;Kang, Hyun-Sook;Han, Sang-Sook;Lim, Nan-Young;Sohng, Kyeong-Yae;Kim, Jong-Im;Lee, Kyung-Sook;Lee, In-Ok
    • Journal of muscle and joint health
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    • v.9 no.1
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    • pp.5-17
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    • 2002
  • The purpose of this one group pre and post test study was to evaluate the effect of self-help programs(SHP) which has been conducted from 1997 to 2000. The SHP was held by Korean Rheumatology Health Professionals Society(KRHP) once a week for 6 weeks for chronic arthritis patients in Korea. Eight hundred fifty five subjects completed the program at 43 sites. The effect of SHP were evaluated by flexibility, pain, activities of daily living(ADL), fatigue, depression and self-efficacy. After SHP, followings were found: 1. Participants' characteristics of SHP were most common in living in Seoul, women, sixties, high school graduates, house wifes, osteoarthritis, completed in 1999. 2. The flexibility of arm, knee, ankle joint were significantly increased, but the flexibility of the shoulder was not changed. 3. Level of pain was decreased significantly from 5.21 to 3.99, and the number of painful joints were decreased from 4.96 to 4.18 significantly. 4. The score of ADL was increased from 53.74 to 54.97 significantly. 5. The score of depression and self-efficacy was not changed. In conclusion, SHP was clearly proved to be an effective nursing intervention to Increase the flexibility of arm, knee, ankle joint and enhanced ADL. Also SHP decreased pain and fatigue. More research is needed to determine the role of self-efficacy and depression in the SHP, use of a randomized design and longer follow up period to understand more about the effects of the program.

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Multidimensional Factors Influencing Burnout in Intensive Care Unit Nurses (다차원적 요인이 중환자실 간호사의 소진에 미치는 영향)

  • Kim, Se Ra;Jeon, Mi-Kyeong;Hwang, Jin Hee;Choi, Ae Ran;Kim, In Sook;Pyon, Mi Kyoung;Moon, Kyoung Eun;Kim, Mun Hee;Shin, Na Ra;Lee, Soon Haeng
    • Journal of Korean Clinical Nursing Research
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    • v.23 no.1
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    • pp.9-19
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    • 2017
  • Purpose: This study aimed to identify multidimensional factors influencing burnout in intensive care unit(ICU) nurses. Methods: A descriptive cross-sectional design was used. Data were collected during February 2016 from a convenience sample of 222 tertiary hospital ICU nurses and analyzed using t-test, ANOVA, correlation analysis, and multiple regression analysis. Results: Burnout correlated positively with compassion fatigue (CF)(r=.37, p<.001), and negatively with compassion satisfaction (CS)(r=-.66, p<.001). The regression model explained 57% of the variance in burnout. For individual characteristics in the model, perceived health status (${\beta}=-.27$, p<.001) and gender (${\beta}=.14$, p=.028) were the most influential factors for ICU nurses' burnout. In the model with added work-related characteristics, nursing environment (${\beta}=-.22$, p=.001), perceived health status (${\beta}= -.20$, p=.001), and satisfaction with department (${\beta}=-.19$, p=.007) were the most influential factors. Finally, for the model with psychological characteristics added, CS (${\beta}=-.56$, p<.001) and CF (${\beta}=.35$, p<.001) were the most influential factors. Conclusion: Results reveal that most ICU nurses have a moderate level of CF and a moderate to high level of CS and burnout, and that individual, work-related and psychological factors are relevant in ICU nurses' burnout. Programs or interventions to reduce burnout should be developed taking into account these multidimensional factors.

An Effect of Steel Corrosion on Bond Stress-slip Relationship under Repeated Loading (반복하중하의 부착응력-슬립 관계에 미치는 철근 부식의 영향)

  • Kim, Chul-Min;Park, Jong-Bum;Chang, Sung-Pil;Kim, Jee-Sang
    • Journal of the Korea Concrete Institute
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    • v.22 no.2
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    • pp.179-186
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    • 2010
  • The bond between steel and concrete in reinforced concrete members is essential to resist external load, but the bond mechanism in reinforced concrete beams deteriorated by steel corrosion has not been clearly known yet. Most existing researches have dealt with the bond behavior of corroded steel under monotonic loading, but scarce are researches dealing with bond behavior of corroded steel under repeated loading. This study includes the experimental investigation on the bond behavior with respect to the various degrees of steel corrosion under repeated loading. According to the test results, the bond strength of corroded steel under monotonic loading increases as the rate of steel corrosion increases unless the splitting crack occurs. The slip versus number of load cycles relation was found to be approximately linear in double logarithmic scale, not only in specimens without steel corrosion but also in specimens with steel corrosion. The test results also show that the steel corrosion does not negatively affect the bond strength of corroded steel after repeated loading unless the splitting crack occurs. But the fatigue life decreases sharply after splitting crack occurs. This research will be helpful for the realistic durability design and condition assessment of reinforced concrete structures.

Research a Person's Eyesight Changes on According to the Optimum Color Temperature for the Stand Lamp Using White Light LED Sources (백색광 LED를 사용한 독서등의 최적 색온도에 따른 사람의 시력 변화 연구)

  • Kim, Juhyun;Chang, Wonbeom;Lee, Seokhwan;Jung, Kwangkyo;Kim, Donghyun;Kim, Jeongmi;Ryu, Jaejun;Moon, Seongdeuk;Lee, Seunghyun;Ko, Youngsu;Huh, San;Jang, Mina;Jung, Changho;Chang, Jiho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.1
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    • pp.80-82
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    • 2013
  • White light emitting diode (LED) determined the most appropriate color temperature in reading lighting evaluated fatigue degree of eye according to color temperature. The eye fatigue degrees are determined by brightness and color temperature. Therefore, we measured the results of eyes test according to the change of color temperature and brightness. Experiments except for astigmatic corrected visual acuity of 0.8 more and age 20 to 25 years old, male and female college students was conducted in 100 patients. And constant illumination conditions, visual acuity was measured by varying the color temperature. The optometry at 10 minutes in the darkroom adapted eye. And then the temperature of $25{\pm}3$ degrees, the humidity was carried out at $50{\pm}5%$. As a result of typical color temperature of white light (5,600 K) has identification of the readability.

Strength Analyses of New 2- and 3-Axis-Type Small Multiplying Gears in Dental Hand-Pieces (치과드릴 구동용 신 소형 2축 및 3축형 증속기어 강도특성 비교)

  • Kim, Cheol;Kim, Ju-Yeong;Lee, Jung-Ho;Kwak, Se-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.9
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    • pp.1027-1032
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    • 2012
  • Two types of very small multiplying gears and arrays have been developed for new dental hand-pieces, and the increased speed ratios, modules, number of teeth, gear diameters, and gear types were calculated based on the dynamics of the machinery. The contacting and bending strengths were evaluated for gear teeth with two design concepts using AGMA equations and finite element analyses, and the contacting stresses on teeth with and without DLC (diamond-like-carbon) coating layers were calculated. Fatigue and tension tests were performed to obtain an S-N curve, the Young's modulus, and the strength of the gear material, and these were utilized in the analyses. Slightly larger stresses were found for 2-axis-type gears than for other types of gears, and the S-N curves showed that a gear lifetime of 109 cycles was satisfied. The contacting stresses in gears coated with DLC were reduced by 30%. A new prototype model of a hand-piece with small gears was successfully fabricated and tested.

Characterization of Asphalt Pavement Distress Using Korean Pavement Research Program (한국형포장설계법을 이용한 아스팔트포장의 파손특성)

  • Lee, Kwan-Ho;Lee, Kyung-Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.487-493
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    • 2017
  • The main purpose of this study is to evaluate the main parameters involved in the asphalt pavement distresses, including IRI (International Rough Index), fatigue, and permanent deformation. The main parameters are the region (Seoul and Busan), traffic level, asphalt binder, maximum aggregate of surface course, thickness of the surface course and base. A total of 64 case studies were carried out under the auspices of the KPRP (Korea Pavement Research Program). From the analysis of the KPRP test results, the key factors for the asphalt pavement distress were determined. Considering the effect of one variable in the basic condition, asphalt binder was the major factor having an effect on the distresses for an AADT (Annual Average Daily Traffic) of 5000 in the Seoul area. Among the remaining factors, the results were found to be in the order of the base layer thickness (A), surface layer thickness (B), and aggregate particle size thickness (D). The same results were obtained for an AADT of 10000. In the case of Busan with an AADT of 5000, the same result was obtained as for Seoul. Among the remaining factors, the results were in the order of the base layer thickness (A), aggregate particle thickness (D), and surface layer thickness (B). Even though there was a slight difference in the effect of the traffic level and region, asphalt binder was the parameter having the greatest effect on the asphalt pavement distress. In the case where the effect of multiple parameters was analyzed, the combination of the asphalt binder and base thickness showed a relatively strong effect.

Vehicle HUD's cognitive emotional evaluation - Focused on color visibility of driving information (차량용 HUD의 인지적 감성 평가 -주행정보의 색채 시인성을 중심으로-)

  • Choi, Won-Jung;Lee, Won-Jung;Lee, Seol-Hee;Park, YungKyung
    • Science of Emotion and Sensibility
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    • v.16 no.2
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    • pp.195-206
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    • 2013
  • The main causes of traffic accidents while driving a car is of the driver's visual distraction. In this study, the color sensitivity of the information projected on the windshield were evaluated for HUD (Head Up Display) system which helps the driver's eyes on the road while driving. The driving Information were projected $9^{\circ}$ downward from front sight $0^{\circ}$ under lab's fluorescent lights, LED floorlights and the TV had having 25 [lux] illumination when driving at night environment and 100,000 [lux] of daylight environment. Munsell color hue of the basic five colors (R, Y, G, B, P) and the color of traffic lights YR, W were the color of the seven characters, each character were outlined by White, Gray except for W. Total of 19 experimental stimuli was shown in the environment of day and night driving for asking visibility information of color, fatigue, preferences, and evaluate the degree of interference. The results came out that the bright Y and G color is visibility significantly for daylight. Second, with the outline of the text, the color of the outline works as a background for luminance contrast effects and affects visibility. Third, without the outline, the glass in front of the vehicle acts as the background and the luminance contrast of characters achieve greater brightness and visibility. The luminance contrast between the stimuli and background should be considered for increasing color visibility for driving information which is an important factor for HUD commercialization.

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