An Exploratory Study of the Derivation of the Constructed Factors of the Parents' Strength Through the Phenomenological Study and the Revised Delphi Survey

이성아,정효정,김민정 융합연구학회 2022 융합연구학회지 Vol.6 No.3

The purpose of this study is to define the concept of the parents’ strengths and derive the constructed factors. To this end, a draft concept and the constructed factors were prepared by reviewing the literatures on the parents’ strengths, and the components of strengths necessary for the parents were explored and confirmed through a phenomenological study and a modified Delphi survey. After collecting the daily experience data that reconstructed activities and situations in which their parents’ strengths were expressed from 13 parents selected through an intentional sampling method, over 3 weeks, the components of the parents’ strengths were corrected through the in-depth interviews. Ten experts on parent education or positive psychology were selected as an expert panel, and a Delphi survey was conducted twice on the components of the parents’ strengths, and the content validity was secured by analyzing the mean, standard deviation, and the CVR values. According to the results, the parents’ strengths were consisted of the four factors of strengths related to growing, strengths related to building relationships, strengths related to problem-solving, and strengths related to contributing. Examining each sub-factor yielded what follows: 1) Strengths related to growing: Self-confidence, Introspection, Curiosity, Courage, Learning, Sincerity, Future-orientated, and Aesthetic, 2) Strengths related to building relationships: Love, Gratitude, Bonding, Accepting, Empathy, Expression, Individualization, and Caring, 3) Strengths related to problem-solving: Self-regulation, Flexibility, Deliberation, Insight, Resource utilization, Execution, Creativity, and Concentration, 4) Strengths related to contributing: Positive, Compassionate, Humorous, Vitality, Responsibility, Facilitating, Fairness, and Structuring. By identifying the definition of the parents’ strengths and their constituent factors, this study could contribute to the development of tools to measure the parents’ strengths and a strengths-based approach in the parenting education.

A Study on the Push and Pull Strength for the Design of Cart Handle

Dong-Pil Woo,Dong-Choon Lee 대한인간공학회 2013 大韓人間工學會誌 Vol.32 No.4

Objective: Product design process without considering the strength of the user can cause the excessive burden on musculoskeletal system of human body. Since the muscle strength will vary depending on the body posture, the design of product should consider the characteristics of body posture. This study was performed to investigate the effects of forearm postures on the push and pull strength. Background: Overexerted force has been identified to cause musculoskeletal disorders. It is important to know the push and pull strength exerted by human when designing so that exerted force does not exceed the safety limits. Method: Maximum isometric push and pull strength of left, right and both hands were measured according to forearm postures with pronation, neutral and supination. For the study, 66 male and 30 female undergraduate students were participated as subjects. All subjects were normal and healthy with no clinical history. Results: The results showed that the push strength of male and female were 93.3% and 85.4% of pull strength. It showed that the strength of one-hand was 72.1~81.0% of the strength of two-hands, and the strength of left hand was 93.1~95.8% of the strength of right hand. The strength of female was 62% of the one of male. It was found that the strength with pronation 90° was reduced up to 20% compared to the strength with neutral posture. Conclusion: Push and pull strength of male and female were reduced when forearm was rotated extremely. Application: The results of this study will be used for the prevention of work related musculoskeletal disorders and design of industrial equipment.

Strength Characteristics of the Cement-Stabilized Surface Layer in Dredged and Reclaimed Marine Clay, Korea

Yun, Jung-Mann,Song, Young-Suk,Lee, Jae-Ho,Kim, Tae-Hyung Taylor Francis 2006 Marine georesources & geotechnology Vol.24 No.1

<P>A series of tests in both laboratory and field were performed to investigate the engineering and mechanical properties, especially flexural strength, of cement-stabilized soils. The strength of cement-stabilized soils mainly depends on water-to-cement ratio and curing temperature. The higher curing temperature and the longer curing time, the higher strength in cement-stabilized soils generates. The high ratio of water-to-cement results in lower strength. The compressive strength observed in the field is similar to the strength in the laboratory. Field tests on a cement-stabilized soil layer indicate that the strength is significantly affected by the thickness of the improved layer, which is directly related to the moment of inertia. In addition, the failure shape observed in a cement-stabilized layer in the field looks likes a bending failure type, because the flexural tensile strength, rather than the compressive strength, mainly dominates the failure of cement-stabilized layer. The flexural tensile strength is closely related to the moment of inertia. Therefore, the flexural tensile strength should be considered for determining the thickness and strength in improvement of soft clay.</P>

유아의 강점에 기반한 교수 · 학습 적용 실행 연구

최혜진,권유선 한국생태유아교육학회 2015 생태유아교육연구 Vol.14 No.4

This study aimed at exploring and applying strengths-based teaching and learning at educational institutions, converting current education practice to a practice that puts priority on young children's happiness. To this end, the study was carried out in three stages: strength recognition, strength utilization, and cyclic strength application. The results showed, first, that young children showed their strengths more frequently and grew in their peer relationships as they recognized their own and their peers' strengths. In addition, they showed an improvement in learning attitudes as they actively cooperated with their peers, producing successful results, through the experience of utilizing their strengths. Furthermore, through the cyclic application of strength utilization, the habit of cooperation took root among young children, and they thought more about how to cooperate, resulting in the appearance of elaborate and sophisticated expressions. Next, in the process of applying strengths-based teaching and learning, young children became more autonomous, were able to form positive relationships with their peers, and showed fewer weaknesses. Teachers felt greater satisfaction about their roles when they changed their perspective to discovering and utilizing young children's strengths, rather than remedying their shortcomings. As parents came to know what their children were interested in and good at, and learned about their children's positive achievements at school, they consistently supported their children to continue activities they liked. All this showed the value strengths-based teaching and learning for young children, and the further possibilities of applying such methods. This study, therefore, suggests that more research be conducted applying strengths-based teaching methods. 본 연구의 목적은 유아의 강점에 기반한 교수·학습 적용을 통한 유아의 행복을 지향하는 교육으로의 인식 전환 및 실천을 강화하는 것에 있다. 이를 위해 강점 인식하기, 강점 활용하기의 단계로 구분하여 연구를 실행하였다. 그 결과 첫째, 유아들의 강점 행동의 빈도가 증가하고 적극적인 학습태도 형성뿐만 아니라 협력의 방법이 정착되었으며, 아이디어가 증가하여 정교하고 세련된 표현이 나타났다. 둘째, 유아는 자신감을 얻어 자율적인 존재로의 변화, 또래와 긍정적인 관계맺음으로의 변화, 약점이 점점 작아지는 존재로의 변화가 나타났으며, 교사는 유아의 부족한 부분을 보완하기 보다는 강점을 발견하고 그 강점을 활용하는 관점의 변화로 교사로서의 삶 대한 의미와 만족감을 느꼈다. 부모는 자녀가 잘하는 것에 대해 알게 되고 교육기관에서의 긍정적 성취에 대한 정보를 얻게 됨으로써 유아가 좋아하는 것을 지속적으로 지지해 주는 역할을 수행하게 되었다.

Strength and toughness prediction of slurry infiltrated fibrous concrete using multilinear regression

Shelorkar, Ajay P.,Jadhao, Pradip D. Techno-Press 2022 Advances in concrete construction Vol.13 No.2

This paper aims to adapt Multilinear regression (MLR) to predict the strength and toughness of SIFCON containing various pozzolanic materials. Slurry Infiltrated Fibrous Concrete (SIFCON) is one of the most common terms used in concrete manufacturing, known for its benefits such as high ductility, toughness and high ultimate strength. Assessment of compressive strength (CS.), flexural strength (F.S.), splitting tensile strength (STS), dynamic elasticity modulus (DME) and impact energy (I.E.) using the experimental approach is too costly. It is time-consuming, and a slight error can lead to a repeat of the test and, to solve this, alternative methods are used to predict the strength and toughness properties of SIFCON. In the present study, the experimentally investigated SIFCON data about various mix proportions are used to predict the strength and toughness properties using regression analysis-multilinear regression (MLR) models. The input parameters used in regression models are cement, fibre, fly ash, Metakaolin, fine aggregate, blast furnace slag, bottom ash, water-cement ratio, and the strength and toughness properties of SIFCON at 28 days is the output parameter. The models are developed and validated using data obtained from the experimental investigation. The investigations were done on 36 SIFCON mixes, and specimens were cast and tested after 28 days of curing. The MLR model yields correlation between predicted and actual values of the compressive strength (C.S.), flexural strength, splitting tensile strength, dynamic modulus of elasticity and impact energy. R-squared values for the relationship between observed and predicted compressive strength are 0.9548, flexural strength 0.9058, split tensile strength 0.9047, dynamic modulus of elasticity 0.8611 for impact energy 0.8366. This examination shows that the MLR model can predict the strength and toughness properties of SIFCON.

고분자 접착제와 금속 피착재의 접착강도에 미치는 피착재 두께의 영향

하윤근,심준형,백주환,김민균,조영래,Ha, Yungeun,Sim, Jun-Hyung,Baeg, Ju-Hwan,Kim, Min-Kyun,Cho, Young-Rae 한국마이크로전자및패키징학회 2020 마이크로전자 및 패키징학회지 Vol.27 No.4

고분자 재료인 접착제와 금속 피착재 사이의 정량적인 접착강도 측정은 중요하다. 고분자 재료인 접착제와 금속 피착재 사이의 접착강도 측정 시, 피착재의 종류와 두께 변화가 접착강도에 미치는 영향에 대해 연구하였다. 금속 피착재의 종류로는 알루미늄과 스텐리스강 2종류가 선택되었으며, 접착강도의 측정에는 돌리테스트와 전단시험이 사용되었다. 인장응력 방식의 돌리테스트로 고분자 접착제와 금속 피착재 사이의 접착강도 측정 시, 금속 피착재의 두께 변화는 접착강도의 크기에 거의 영향을 미치지 않았으나, 피착재의 종류에 따라 접착강도는 다르게 나타났다. 반면, 전단시험으로 고분자 접착제와 금속 피착재 사이의 접착강도 측정 시, 금속 피착재의 상대적 두께 변화는 접착강도의 크기에 영향을 주었다. 이유는 전단시험 시 접착부의 모서리 부분에서 발생하는 피착재의 휘어짐 현상은 접착부에 추가적인 인장응력을 발생시켜 접착강도를 낮추는데 기여하기 때문이다. 이 연구의 결과, 돌리테스트는 피착재의 두께가 변해도 접착강도의 변화가 거의 없기 때문에 고분자 접착제와 금속 피착재의 정량적인 접착강도 측정 시 널리 사용될 것으로 예상된다. It is important to measure the quantitative adhesive strength between an organic adhesive and a metal adherend. In measuring the adhesive strength between an organic adhesive and a metal adherend, the effect of the kind and thickness of the adherend on the adhesive strength was studied. Two kinds of metal adherends were selected, aluminum (Al1050) and stainless steel (STS304), and a dolly test and a lap shear test were used to measure the adhesive strength. When measuring the adhesive strength between the organic adhesive and the metal adherend by the tensile stress mode of dolly test, the change in the thickness of the metal adherend had little effect on the adhesive strength, however, the adhesive strength was different depending on the kind of the adherend. On the other hand, when measuring the adhesive strength between the organic adhesive and the metal adherend by the lap shear test, the change in the relative thickness of the metal adherend had an effect on the adhesive strength. The reason is that the bending phenomenon of the adherend occurring in the edge of bonding region during the lap shear test contributes to lowering the adhesive strength by generating additional tensile stress in the bonding region. From this work, it is concluded that the dolly test could be widely used when measuring the quantitative adhesive strength of organic adhesives and metal adherend because there is little change in adhesive strength even though the thickness of the adherend is changed.

C-Sphere Strength-Size Scaling in a Bearing-Grade Silicon Nitride

Andrew A. Wereszczak,Timothy P. Kirkland,Osama M. Jadaan,Kevin T. Strong,Gregory J. Champoux 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.9

A “C-sphere” specimen geometry was used to determine the failure strength distributions of a commercially-available bearinggrade silicon nitride (Si3N4) with ball diameters of 12.7 and 25.4 mm. Strengths for both diameters were determined using the combination of failure load, C-sphere geometry, and finite element analysis and fitted using two-parameter Weibull distributions. Effective areas of both diameters were estimated as a function of Weibull modulus and used to explore whether the strength distributions predictably scaled between each size. They did not. That statistical observation suggested that the same flaw type did not limit the strength of both ball diameters indicating a lack of material homogeneity between the two sizes. Optical fractography confirmed that. It showed there were two distinct strength-limiting flaw types common to both ball diameters, that one flaw type was always associated with lower strength specimens, and that a significantly higher fraction of the 25.4-mm-diameter Csphere specimens failed from it. Predictable strength-size-scaling would therefore not result as a consequence of this because these flaw types were not homogenously distributed and sampled in both C-sphere geometries. A “C-sphere” specimen geometry was used to determine the failure strength distributions of a commercially-available bearinggrade silicon nitride (Si3N4) with ball diameters of 12.7 and 25.4 mm. Strengths for both diameters were determined using the combination of failure load, C-sphere geometry, and finite element analysis and fitted using two-parameter Weibull distributions. Effective areas of both diameters were estimated as a function of Weibull modulus and used to explore whether the strength distributions predictably scaled between each size. They did not. That statistical observation suggested that the same flaw type did not limit the strength of both ball diameters indicating a lack of material homogeneity between the two sizes. Optical fractography confirmed that. It showed there were two distinct strength-limiting flaw types common to both ball diameters, that one flaw type was always associated with lower strength specimens, and that a significantly higher fraction of the 25.4-mm-diameter Csphere specimens failed from it. Predictable strength-size-scaling would therefore not result as a consequence of this because these flaw types were not homogenously distributed and sampled in both C-sphere geometries.

Prediction of the Tensile Strength of Normal and Steel Fiber Reinforced Concrete Exposed to High Temperatures

Mehrdad Abdi Moghadam,Ramezan Ali Izadifard 한국콘크리트학회 2021 International Journal of Concrete Structures and M Vol.15 No.6

The tensile strength of concrete has a great impact on the performance of concrete structures, especially for members exposed to high temperatures. The inclusion of steel fibers in concrete is one of the measures to retrieve the loss of tensile strength. The previous equations for the prediction of the tensile strength, are valid for conventional concrete and can predict the tensile strength after high-temperature exposure. Therefore, they are unsatisfactory for forecasting the tensile strength of plain and steel fiber reinforced concrete under high-temperature exposure. To establish a model that can effectively simulate the tensile strength of plain concrete, specimens with compressive strengths of 20-80 MPa are tested. Then by performing tensile strength tests on the specimens containing various content of steel fiber, an equation for prediction of the tensile strength at the ambient temperature is proposed. Meanwhile, the tensile strength tests are conducted at temperatures of 100-800 °C to develop a model for high-temperature exposure. The results indicate that an increase of compressive strength from 20 to 84 improves the tensile strength by 169.4%, and the incorporation of 0.25 and 0.5% of steel fibers can improve the tensile strength of normal concrete by 58.48 and 80.29% on average at the tested temperatures, respectively. Moreover, the proposed model is able to predict the tensile strength of normal and steel fiber reinforced concrete exposed to high temperatures accurately. This equation would help a wider application of the steel fibers in the construction industry with the risk of a fire accident.

휠체어 테니스 운동이 의전차 추진 척수손상 장애인의 손 근력에 미치는 영향

박석(Park Sok),정석현(Jung Suk-Hyun),김태영(Kim Tae-Young) 한국체육과학회 2006 한국체육과학회지 Vol.15 No.4

This study measures grip strength, pinch strength, static and three point pinch strength among undamaged person, wheelchair propelling spinal cord injured patient and wheelchair tennis player who exercise ann muscle regularly. The measurement was done by BTE Work Simulator. The results are as followed. 1. After measuring undamaged person, wheelchair propelling spinal cord injured patient and wheelchair tennis player, wheelchair tennis player was significant difference between wheelchair propelling spinal cord injured patient on dominant hand for grip strength, pinch strength and three point pinch strength. 2. Comparing non-dominant hand among undamaged person, wheelchair propelling spinal cord injured patient and wheelchair tennis player, between wheelchair propelling spinal cord injured patien and wheelchair tennis player there were significant difference on grip strength, pinch strength and three point pinch strength. 3. There were no noticeable muscular strength difference between dominant and non-dominant hands among undamaged person and spinal cord damaged person. But there was significant difference between dominant hand and non-dominant hand on grip strength, pinch strength and three point pinch strength for wheelchair tennis player. Above results show that wheelchair tennis player have overall higher hand muscular strength than wheelchair propelling spinal cord injured patient. Muscular strength difference between dominant hand and non-dominant hands for wheelchair tennis player is due to training of dominant hand to improve skills for the tennis match. Dominant hand has developed to accommodate new environment. Measured results of grip strength, lateral pinch, static muscular strength and dynamic muscular strength of three point pinch and stamina in this study can be used for objective data to evaluate movement ability of hand.

전단파 속도를 이용한 콘크리트의 압축강도 추정연구

안지환,남정희,권수안,조성호 한국도로학회 2008 한국도로학회논문집 Vol.10 No.3

Compressive strength of concrete has been regarded as a very important parameter of the quality control both in new and existing concrete pavement. It has been used a lot as the concrete strength evaluation both in the various-mixture-using laboratory and construction field using the same mixture. An error usually occurs in the test experiments of the strength, even in the test experiments with evenly mixed and compacted specimens of the compressive strength. It is caused by the 'manually operated' compressing testing, or by the specimens preparation with eccentricity. When compressive strength of evenly mixed concrete is investigated by the curing ages at the construction field, there have to be lots of specimens. And it needs much labor and cost. To substitute the endlessly repeated test experiments of compressive strength, presumption of compressive strength, by nondestructive tests, is needed. In this study, elastic waves were used among various nondestructive tests. Compressive strength of concrete was presumed according to the curing ages, by using the shear wave velocity which is not affected by restricted conditions. In the result, shear wave velocity is very closely related to the compressive strength at the evenly mixed concrete. Compressive strength of concrete has been regarded as a very important parameter of the quality control both in new and existing concrete pavement. It has been used a lot as the concrete strength evaluation both in the various-mixture-using laboratory and construction field using the same mixture. An error usually occurs in the test experiments of the strength, even in the test experiments with evenly mixed and compacted specimens of the compressive strength. It is caused by the 'manually operated' compressing testing, or by the specimens preparation with eccentricity. When compressive strength of evenly mixed concrete is investigated by the curing ages at the construction field, there have to be lots of specimens. And it needs much labor and cost. To substitute the endlessly repeated test experiments of compressive strength, presumption of compressive strength, by nondestructive tests, is needed. In this study, elastic waves were used among various nondestructive tests. Compressive strength of concrete was presumed according to the curing ages, by using the shear wave velocity which is not affected by restricted conditions. In the result, shear wave velocity is very closely related to the compressive strength at the evenly mixed concrete.