• Title/Summary/Keyword: stress factors

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Optimization of Soil-Nailing Designs Considering Three Failure Modes (쏘일네일링의 세 가지 파괴모드를 고려한 설계 최적화에 대한 연구)

  • Seo, Hyung-Joon;Lee, Gang-Hyun;Park, Jeong-Jun;Lee, In-Mo
    • Journal of the Korean Geotechnical Society
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    • v.28 no.7
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    • pp.5-16
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    • 2012
  • Soil-nailing is the most popular method of reinforcing for slope stability. In general, two factors are considered as failure modes during the soil-nailing design stages: pullout failure mode and shear failure mode that will occur on the most probable failure plane. In many cases, however, shallow failure can also occur when the ground near the slope face is swept away by the horizontal stress release during the staged top-down excavation. In this paper, an optimized soil-nailing design methodology is proposed by considering the three failure modes mentioned above: pullout failure; shear failure; and shallow failure. The variables to be optimized include the bonded length and number of soil-nailings, and the confining pressure that should be applied at the slope face. The procedure to obtain the optimized design variables is as follows: at first, optimization of soil-nailings, i.e. bonded length and number, against pullout and shear failure modes; and then, optimization of confining pressure at each excavation stage that is needed to prevent shallow failure. Since the two processes are linked with each other, they are repeated until the optimized design variables can be obtained satisfying all the constrained design requirements in both of the two processes.

Characteristics of Hericium erinaceus fruit body genesis in winter (동절기 노루궁뎅이버섯 자실체 발생 특성)

  • Moon, Ji-Won;Lee, Chan-Jung;Cheong, Jong-Chun;Kong, Won-Sik
    • Journal of Mushroom
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    • v.14 no.2
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    • pp.39-43
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    • 2016
  • In this study, we observed differences in the fruit body genesis in with seasonal changes. The mushrooms generated different spines even when under same environmental conditions in equivalent growth chambers during different seasons. The growth chamber conditions were set at $18^{\circ}$, 1000 ppm CO and 95% humidity for uniform primordium formation. Following this, the humidity was reduced to 85% during growth and development. The characteristics of the fruit body were measured: yield (weight), length (size), hardness, and chromaticity. Each measure was relatively compared owing standard data for. We investigated the environmental factors to assess the cause of variation in fruit body. Change in temperature and humidity were especially focused on, apart from climate that can affect mushroom growth. It was observed that temperature and humidity both influence fruit body growth. Not the absolute value of the elevation, there was a change of climate which the temperature is lowered and lowered the humidity can be assumed that the changes in the environmental conditions inside the growth chamber the mushroom growth.

A study for Shear Strength Characteristics of Frozen Soils under Various Temperature Conditions and Vertical Confining Pressures (동결온도조건 및 수직구속응력에 따른 동결토의 전단강도 변화에 관한 연구)

  • Lee, Joonyong;Choi, Changho
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.11
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    • pp.51-60
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    • 2012
  • In order to characterize the shear strength of the frozen sand for foundation design in cold region and prediction of adfreeze bond strength, many researchers developed test techniques and carried out many tests to analyze shear strength properties of the frozen sand for half a century. However, many studies for shear strength properties of the frozen sand have been carried out with limited circumstances, even though shear strength of the froze sand can be affected by various influence factors such as soil type, temperature conditions, and magnitude of normal stress. In this study, direct shear test equipment was used to analyze the shear strength characteristics of the frozen sand. Direct shear test equipment was designed for cold weather, and the direct shear tests were carried out inside of large-scaled low temperature chamber. Three soil types-two uniform sands and one well graded soil were used to analyze the shear strength of the frozen sand with three different temperature conditions and three different vertical confining pressures. In this research, a series of direct shear tests for shear strength of the frozen sand have been conducted to demonstrate the efficiency of effectiveness of the test equipment and low temperature chamber. This research also showed that shear strength of the froze sand increased with decreasing temperature condition, but the influence of vertical confining pressure was insignificant to the shear strength of the frozen sand.

Flexural Tensile Strength of Concrete Block Masonry (비보강 콘크리트 조적조의 휨인장강도)

  • Kim, Young-Sang
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.4
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    • pp.119-126
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    • 2005
  • The objective of this paper is to evaluate the flexural tensile strength of unreinforced concrete masonry wall to ensure the structural safety in out-of-plane behaviors under the wind or earthquake loads. Flexural tensile strength of unreinforced concrete masonry wall has been obtained from the full scale tests of total 327 specimens and the statistical analysis are performed for each of the cases. The flexural tensile strength derived from experiments is classified as 13 groups according to masorny units, mortar ingredients, and the direction of tensile stresses and the mean tensile strength and the variable coefficient are obtained for each case. The uniform and concentrated transverse loads have been applied over the face of the wall specimens. The ultimate mean flexural tensile strengths are distributed from 1,564 kPa to 363 kPa according to masonry units, mortar ingredients, and other factors. The allowable flexural tension stress criteria will be established based on the mean flexural tensile strengths in the future.

Influencing Factors of Radiological Technologist Image of Allied Health College Students (보건계열 대학생들의 방사선사 이미지에 영향을 미치는 요인)

  • Eom, Jong-Kwon;Shin, Seong-Gyu
    • Journal of radiological science and technology
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    • v.35 no.1
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    • pp.25-33
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    • 2012
  • Perception level and social position of radiological technologist influence satisfaction level of their job. This study aims to use foundational data to improve perception level and social position of radiological technologists. We conducted interviews and a fill-out survey with 233 students who have been majoring in health-related fields at five universities and colleges located in Busan and who finished internship programs. The study analyzed 233 answer sheets excluding 17 inadequate answer sheets using T-test, ANOVA and multiple regression analysis with SAS9.1. The mean score of perception level was $3.33{\pm}0.56$. The personal image of radiological technologist showed the best score($3.43{\pm}0.56$) whereas the social image showed the worst($3.12{\pm}0.58$). According to the classification of the subject, the answer, "radiological technologist is specialized job", showed the best score($3.99{\pm}0.79$). The answer "radiological technologist suffered from less stress and workload than others when they work usually" showed the worst score($2.88{\pm}0.98$). According to the classification of each health-related major, the mean score of students who are a major in the department of the radiological technologist was the best($3.46{\pm}0.46$) and the students who are major in department of the physical therapy was the worst($3.24{\pm}0.40$). The radiological technologist have to effort to make positive image in the hospital. It is possible to be developed their knowledge and professionalism by cooperating between school and hospital as well as advertising with mass madia.

Mechanism of aging and prevention (노화의 기전과 예방)

  • Kim, Jay Sik
    • IMMUNE NETWORK
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    • v.1 no.2
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    • pp.104-108
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    • 2001
  • Aging is a senescence and defined as a normal physiologic and structural alterations in almost all organ systems with age. As Leonard Hayflick, one of the first gerontologists to propose a theory of biologic aging, indicated that a theory of aging or longevity satisfies the changes of above conditions to be universal, progressive, intrinsic and deleterious. Although a number of theories have been proposed, it is now clear that cell aging (cell senescence) is multifactorial. No single mechanism can account for the many varied manifestations of biological aging. Many theories have been proposed in attempt to understand and explain the process of aging. Aging is effected in individual by genetic factors, diet, social conditions, and the occurrence of age-related diseases as diabetes, hypertension, and arthritis. It involves an endogenous molecular program of cellular senescence as well as continuous exposure throughout life to adverse exogenous influences, leading to progressive infringement on the cell's survivability so called wear and tear. So we could say the basic mechanism of aging depends on the irreversible and universal processes at cellular and molecular level. The immediate cause of these changes is probably an interference in the function of cell's macromolecules-DNA, RNA, and cell proteins-and in the flow of information between these macromolecules. The crucial questions, unanswered at present, concerns what causes these changes in truth. Common theories of aging are able to classify as followings for the easy comprehension. 1. Biological, 1) molecular theories - a. error theory, b. programmed aging theory, c. somatic mutation theory, d. transcription theory, e. run-out-of program theory, 2) cellular theories - a. wear and tear theory, b. cross-link theory, c. clinker theory, d. free radical theory, e. waste product theory, 3) system level theory-a. immunologic/autoimmune theory, 4) others - a. telomere theory, b. rate of living theory, c. stress theory, etc. Prevention of aging is theoretically depending on the cause or theory of aging. However no single theory is available and no definite method of delaying the aging process is possible by this moment. The most popular action is anti-oxidant therapy using vitamin E and C, melatonin and DHEA, etc. Another proposal for the reverse of life-span is TCP-17 and IL-16 administration from the mouse bone marrow B cell line study for the immunoglobulin VDJ rearrangement with RAG-1 and RAG-2. Recently conclusional suggestion for the extending of maximum life-span thought to be the calory restriction.

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Predicting Health-Promoting Behaviors in Patients with Stomach Cancer (건강증진행위의 영향요인 분석 -위암환자중심 -)

  • 오복자
    • Journal of Korean Academy of Nursing
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    • v.25 no.4
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    • pp.681-695
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    • 1995
  • It has been noted that a genetic alteration of cells influenced by unhealthy lifestyle In addition to a series of other carcinogens increases various neoplasmic diseases. Therefore the importance of lifestyle that minimizes such impact on health should be emphasized. Since stomach cancer, the most common neoplasmic disease in Korea, is re-lated to the Korean lifestyle and as there's a possibility of its recurrence, people with stomach cancer need to lead a healthy lifestyle. The purpose of this study is to provide a basis for nursing intervention strategies to promote health promoting behaviors that are constructive to a healthy lifestyle. A multivariate model was constructed based on the fender's health promotion model and Booker's health belief model by including influential factors such as hope. The sample was composed of 164 patients with stomach cancer who visited outpatient clinics of a university hospital in Seoul. The following instruments were used in the study after some adaptation : Wallston and others' multidimensional health locus of control scale Laffrey's health conception scale, Lawston and others' health self- rating scale, Walker and others' health promotion lifestyle profile and Rogenberg's self esteem scale. In addition Moon's health belief scale was used with some modification. For self efficacy, the present author constructed a self-efficacy scale based on previous research. The above mentioned instruments were tested in a pilot study with 24 patients with stomach cancer. The reliabilities of instruments were tested with Cronbach's alpha(0.574∼0.949). Data were analyzed using a SAS program (or Pearson correlation coefficients, descriptive correlational statistics and stepwise multiple regression. The results are as follows : 1. The scores on the health promoting behavior scale ranged from 55 to 145 with a mean of 107.91 (S. D : 16.50). The mean scores(range 1-4) on the different dimensions were nutrition 3.14, exercise 2.48, stress management 2.69, health responsibility 2.65, interpersonal relationship 2.878E self actualization 2.85. 2. There were significant correlations among all the predictive variables & the health promoting behavior (r=.20-.55, p〈.01) 3. Stepwise multiple regression analysis showed that : 1) Hope was the main predictor and accounted for 29.8% of the total variance. 2) Self efficacy, perceived barriers & self esteem accounted for an additional 14.6% of the total variance. 3) Hope, self efficacy, perceived barriers & self esteem altogether accounted for 44.3% of the total variance. In conclusion, hope, self efficacy, perceived barriers & self esteem were identified as important variables that contributed to promote health promoting behavior.

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A Study on the Factors Affecting on Worker's Quality of Life (근로자의 삶의 질 영향요인 연구)

  • Park, Eun-Hee;Kim, Hye-Suk
    • Journal of Digital Convergence
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    • v.15 no.11
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    • pp.581-589
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    • 2017
  • The purpose of this study was to confirm the effect of the marital satisfaction, depression, and self-esteem on the quality of life. 131 workers in K area were used for the final analysis. The data collection was conducted from March 15nd, 2017 to April 10th, 2017. The quality of life was measured by means of Korean version of life scale abbreviated version, WHOQOL-BREF. Descriptive statics, t-test, two-way ANOVA, Pearson correlation coefficient and step wise multiple regression with SPSS/WIN 18.0 were used to analyze the data. As a result of study, it was confirmed that regular workers were higher than irregular workers in the quality of life, marital satisfaction, depression, and self-esteem all. The quality of life was explained by the martial satisfaction, depression, averagely monthly pay, and spouse relationship as 34.3%. It is necessary to essentially implement the government's support and the corporate cooperation for the improvement of working condition in order to enhance the life quality of workers. Also, workers need to give value to themselves leading their life and form a positive relationship with people around them not to let their family life be negatively affected due to the employment stress.

Survey of Adults' Perceptions of the Association between Chronic Diseases and Oral Health (일부 성인의 만성질환과 구강건강 연관성에 대한 인식조사)

  • Kim, Cheoul-Sin;Choi, Yong-Keum
    • Journal of dental hygiene science
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    • v.17 no.1
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    • pp.12-19
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    • 2017
  • The aim of this study was to investigate adult individuals' perceptions on the association between chronic diseases and oral health provide basic data required for motivating individuals to follow ideal oral health behaviors and boost their interests in oral disease prevention and treatment. Subjects in their 20s to 50s were selected through the convenience sampling method and eleven questions were set as factors and answered via self-administered questionnaires. To determine statistical significance, analysis of variance was used with the level of significance set at 0.05. The subjects' perception of the association between chronic diseases and oral health were analyzed with respect to their health behaviors. Individuals with relatively higher stress levels demonstrated higher levels of perception levels (p<0.05). Public education regarding the association between chronic diseases and oral health has not been ideally effective in South Korea. Thus, the general public's perceptions of the association between chronic diseases and oral health should be revised. In addition aspects regarding this matter should be enhanced within oral health education programs which often only focus on demonstrating the importance of oral health management so that individuals can get sufficient information on the association between chronic diseases and oral health.

A Study on Importance-Performance of Wellbeing Fusion Menu using IPA (IPA를 활용한 웰빙 퓨전 메뉴의 중요도-성취도 연구)

  • Kang, Hye-Jung;Lee, Yeon-Jung
    • Culinary science and hospitality research
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    • v.16 no.2
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    • pp.77-95
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    • 2010
  • This study aims to analyze importance and performance factors on the quality of wellbeing fusion menu of fusion restaurants to provide helpful information for building up a detailed marketing strategy and present considerations for sales increase and more efficient business results. Importance on menu quality scored a higher level than performance on the whole in fusion restaurants. Notably, in regard to attributes of menu quality, it was found that respondents put higher stress on 'taste of food', 'sanitary of food', 'cleanliness of vessels', 'quality of menu' and 'freshness of food' than anything else. Wellbeing fusion menu which has an high intake frequency rate includes 'green vegetable noodles with black bean sauce', 'sweet pumpkin salad', 'salmon salad', and 'shrimp vegetable gratin' in that order. On the other hand, the intake frequencies of 'ovened green perilla gratin', 'pomegranate dressing tofu', 'bacon roll with glutinous rice powder', and 'pomegranate dressing bacon' were rated very low. In terms of the IPA analysis on wellbeing fusion menu quality, it was important to continuously maintain 'taste of food', 'sanitary of food', 'cleanliness of vessels', 'freshness of food', 'quality of menu', 'diet menu(low fat, low calories)', 'vegetable menu', 'nutrition of food', 'variety of menu' etc. Such items as 'price', 'distinction with existing food', and 'environment-friendly organic agriculture food material' are in need of intensive care and operation.

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