• Title/Summary/Keyword: essential norm

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A POSTERIORI ERROR ESTIMATOR FOR HIERARCHICAL MODELS FOR ELASTIC BODIES WITH THIN DOMAIN

  • Cho, Jin-Rae;J. Tinsley Oden
    • Journal of Theoretical and Applied Mechanics
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    • v.3 no.1
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    • pp.16-33
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    • 2002
  • A concept of hierarchical modeling, the newest modeling technology. has been introduced early In 1990. This nu technology has a goat potential to advance the capabilities of current computational mechanics. A first step to Implement this concept is to construct hierarchical models, a family of mathematical models which are sequentially connected by a key parameter of the problem under consideration and have different levels in modeling accuracy, and to investigate characteristics In their numerical simulation aspects. Among representative model problems to explore this concept are elastic structures such as beam-, arch-. plate- and shell-like structures because the mechanical behavior through the thickness can be approximated with sequential accuracy by varying the order of thickness polynomials in the displacement or stress fields. But, in the numerical analysis of hierarchical models, two kinds of errors prevail: the modeling error and the numerical approximation errors. To ensure numerical simulation quality, an accurate estimation of these two errors Is definitely essential. Here, a local a posteriori error estimator for elastic structures with thin domain such as plate- and shell-like structures Is derived using element residuals and flux balancing technique. This method guarantees upper bounds for the global error, and also provides accurate local error Indicators for two types of errors, in the energy norm. Comparing to the classical error estimators using flux averaging technique, this shows considerably reliable and accurate effectivity indices. To illustrate the theoretical results and to verify the validity of the proposed error estimator, representative numerical examples are provided.

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A posteriori error estimator for hierarchical models for elastic bodies with thin domain

  • Cho, Jin-Rae
    • Structural Engineering and Mechanics
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    • v.8 no.5
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    • pp.513-529
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    • 1999
  • A concept of hierarchical modeling, the newest modeling technology, has been introduced in early 1990's. This new technology has a great potential to advance the capabilities of current computational mechanics. A first step to implement this concept is to construct hierarchical models, a family of mathematical models sequentially connected by a key parameter of the problem under consideration and have different levels in modeling accuracy, and to investigate characteristics in their numerical simulation aspects. Among representative model problems to explore this concept are elastic structures such as beam-, arch-, plate- and shell-like structures because the mechanical behavior through the thickness can be approximated with sequential accuracy by varying the order of thickness polynomials in the displacement or stress fields. But, in the numerical, analysis of hierarchical models, two kinds of errors prevail, the modeling error and the numerical approximation error. To ensure numerical simulation quality, an accurate estimation of these two errors is definitely essential. Here, a local a posteriori error estimator for elastic structures with thin domain such as plate- and shell-like structures is derived using the element residuals and the flux balancing technique. This method guarantees upper bounds for the global error, and also provides accurate local error indicators for two types of errors, in the energy norm. Compared to the classical error estimators using the flux averaging technique, this shows considerably reliable and accurate effectivity indices. To illustrate the theoretical results and to verify the validity of the proposed error estimator, representative numerical examples are provided.

Speech and language disorders in children (소아에서 말 언어장애)

  • Chung, Hee Jung
    • Clinical and Experimental Pediatrics
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    • v.51 no.9
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    • pp.922-934
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    • 2008
  • Developmental language disorder is the most common developmental disability in childhood, occurring in 5-8% of preschool children. Children learn language in early childhood, and later they use language to learn. Children with language disorders are at increased risk for difficulties with reading and written language when they enter school. These problems often persist through adolescence or adulthood. Early intervention may prevent the more serious consequences of later academic problems, including learning disabilities. A child's performance in specific speech and language areas, such as phonological ability, vocabulary comprehension, and grammatical usage, is measured objectively using the most recently standardized, norm-referenced tests for a particular age group. Observation and qualitative analysis of a child's performance supplement objective test results are essential for making a diagnosis and devising a treatment plan. Emphasis on the team approach system in the evaluation of children with speech and language impairments has been increasing. Evidence-based therapeutic interventions with short-term, long-term, and functional outcome goals should be applied, because there are many examples of controversial practices that have not been validated in large, controlled trials. Following treatment intervention, periodic follow-up monitoring by a doctor is also important. In addition, a systematized national health policy for children with speech and language disorders should be provided.

A Classification of Luxury Fashion Brands' E-commerce Sites

  • Kim, Sunghee
    • Journal of Fashion Business
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    • v.17 no.6
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    • pp.125-140
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    • 2013
  • The aim of this study was to analyze e-commerce sites of luxury fashion brands in order to provide insights on how to enhance online site quality. For the research, forty-eight components of thirty-one luxury fashion brands' e-commerce sites were investigated during October 2013. For the analysis of clustering e-commerce site components and segmenting e-commerce sites of luxury brands, a hierarchical cluster analysis was applied through using the Ward's method and squared Euclidian distance for binary data. Further, Fisher's exact test was applied in order to distinguish three groups of characteristics in the luxury e-commerce sites. These analyses were carried out by SPSS 21. The result indicated that the components of e-commerce sites were grouped into three categories: basic elements, additional elements and elements of building brand identity. These components were categorized by whether their functions were basic and essential or additional and advanced. The other norm of categorization was related to brand identity. Furthermore, the luxury brands' e-commerce sites were segmented into three groups: a group of endeavoring to promote goods, a group of undistinguished performance, and a group of endeavoring to intensify brand identity. In this segmentation, brand identity or promotional aspects were decisive. Overall, luxury brands were trying to convey their traditional strength through their e-commerce sites. In order to achieve this purpose, brand identity or promotional aspects played an important role.

CEPHALOMETRIC ANALYSIS FOR CHILDREN WITH NORMAL OCCLUSION IN THE PRIMARY DENTITION (정상교합을 가진 유치열기 아동의 두부방사선 계측학적 연구)

  • Suh, Moon-Sun;Son, Heung-Kyu;Baik, Hyung-Sun;Choi, Hyung-Jun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.32 no.1
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    • pp.109-118
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    • 2005
  • In the field of pediatric dentistry, comparison and analysis of cephalogram values of children are important fir evaluation of growth and development, and are essential to evaluate the craniofacial form and growth pattern for early diagnosis of malocclusion. For this, cephalographic norm values are important, but not many studies on the primary dentition exist. To compare the past norm values of normal occlusion in the primary dentition with current norms, preschool children, 4 to 5 years of age, with normal occlusion in the primary dentition who visited our hospital were examined. Among these children, 46 children with normal facial form and developmental status were chosen for evaluation of cephalogram values. The following results were as follows: 1. For skeletal values, the angular values showed no significant differences between males and females, and the linear values were generally greater in males than females. 2. SNA was $81.3^{\circ}$, SNB was $76.6^{\circ}$ and ANB difference was $4.7^{\circ}$. 3. The ratio for Mandibular body length to Anterior cranial base length was 0.9 : 1 for both male and female and the ratio for posterior facial height to anterior facial height was 61.4 % for male, 62.0 % for female. 4. For dental values, IMPA was $84.2^{\circ}$ and UA to SN was $90.8^{\circ}$. 5. The upper lip to Ricketts esthetic line was positioned 2.6 mm anteriorly, and the lower lip to Ricketts esthetic line was positioned 2.5 mm anteriorly.

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Application of the Theory of Planned Behavior and the Theory of Reasoned Action to Predicting Cervix Cancer Screening Behavior (자궁암 조기검진행태 예측을 위한 계획된 행동이론과 이성적 행동이론의 적용)

  • Kim, Yong-Ik;Kim, Chang-Yup;Shin, Young-Soo;Lee, Kun-Sei
    • Journal of Preventive Medicine and Public Health
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    • v.34 no.4
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    • pp.379-388
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    • 2001
  • Background : Cervix cancer is the most common form of cancer among Korea women. in spite of proof that cervical cancer screening could reduce death rates substantially, the screening rates reported by previous Korean studies remain stubbornly very low. Behavioral studies to increase the cervix cancer screening rate are essential in order to develop the cancer screening program. Objective : To evaluate the factors which are related to the intention and behavior for cervix cancer screening using the Theory of Planned Behavior (TPB) and the Theory of Reasoned Action (TRA). Methods : The survey was conducted from July 21 st to 26th in 1998. Of 3,218 women, 303(12.2%) between 30 and 55 years old, voluntarily participated in the survey in the 3 Myeons in Choongju city. Charge-free cervix cancer screening was provided for the subjects 3 months later. Results : The R-square of both TPB and TRA to the intention (30% and 42%, respectively) was greater than the actual behavior (21% and 13%, respectively. TPB and TRA were found to provide an appropriate framework for the study of cervix cancer screening behavior. However, TRA was more powerful in explaining the intention, not only because the perceived behavioral control component exhibited lower reliability and validity than other components(altitude and subjective norm), but also because there may have been a few limitations in this study design. Consequently, the use of TRA is preferred in attempting to explain intention and actual behavior in this study. Conclusions : This study suggests that a successful intervention program should focus on changing attitudes and reducing psychologic barriers, rather than on just providing information. Physician recommendations, and the support of family members and friends are also very important factors in cervix cancer program participation. Physicians, friends, family members, and opinion leaders in rural areas, all of whom could affect the individual subjective norm, may all have the potential to play great roles as facilitators.

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Limit states design for tunnels: related researches and present state of application (터널 한계상태설계법 관련 연구 및 적용 동향)

  • Kim, Hong-Moon;Kim, Dong-Kook;Lee, Sang-Duk
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.16 no.3
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    • pp.341-346
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    • 2014
  • The representative Limit State Design(LSD) codes, AASHTO LRFD and Eurocodes, are widely being applied when designing civil structures. However, these codes are only applying tunnel lining design and segments design for shield tunnels. Recently in Europe, the Eurocode 7 committee was trying to create a research group called EG12, but they reluctantly decided not to create EG12 since it could have an impact on some of the other Eurocodes(including Eerocodes 2 and 3). Still there is an effort to continue researching LSD for tunnelling. LSD method will become the norm for the field of civil structural design in the near future. Therefore, it is important to fully understand Eurocode7:Geotechnical design in connection with Eurocode 2 and Eurocode 3. In addition, it is essential to follow international research trends and also to research for application to tunnelling.

A Study on Improvement of the Standards for the Manoeuvring space at Doors (출입문 측면 활동공간 설치기준 개선에 관한 연구)

  • Shin, Dong-Hong;Park, Kwang-Jae
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.25 no.4
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    • pp.71-79
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    • 2019
  • Purpose: The manoeuvring space at doors must be secured for users of walking aids, wheelchair users, stroller users, luggage carriers, etc., so clear criteria must be established. The korean standards for the manoeuvring space at doors need to be improved to present clear criteria depending on the type of entrance and the direction of opening and closing. Method: Korean standard, International Standard(ISO 21542, 2011), German Standard(DIN 18040-1, 2010), Austrian Standard(OENORM B 1600, 2017) and Swiss Standard(Norm SIA 500, 2009) were investigated and analyzed. A comprehensive improvement of the criteria for the manoeuvring space at doors is proposed. Results: The manoeuvring space at doors, which is essential for the disabled to use the door, shall be installed with a comprehensive consideration of the width of doors, the Circulation space, the direction of access, and the method of opening and closing of the door. Korean standards, such as the width of doors, the Circulation space, and the manoeuvring space at doors, are different from international and international standards, which require improvement of standards. The criteria for the manoeuvring space at doors shall be clearly improved so as not to be misinterpreted during the installation of doors and the BF-certification. Implication: The criteria for the installation of doors shall be presented as a comprehensive alternative through continued study of details. In addition, improvements in standards that reflect changes in international standards should be made.

The Problem of Individuality and Intrinsic Norms in Canguilhem's Philosophy of Life (캉길렘의 생명철학에서 개체성과 내재적 규범의 문제)

  • Hwang, Su-young
    • Philosophy of Medicine
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    • v.15
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    • pp.3-37
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    • 2013
  • George Canguilhem(1904-1995) is one of the rare French philosophers of the 20th century to develop an approach that was shaped by a medical education. For him, medicine is considered as "a technique or an art at the junction of many different sciences, rather than a proper science." The thesis that medicine is a technique is presented not at a practical level, but on an axiological horizon which reflects the totality of humanity. This character of medicine became a motive that concretized Canguilhem's philosophical thinking. Medical knowledge is not an application of physiology, but is derived from clinical observations which are based on the personal experiences of each patient. If medicine were based on scientific knowledge and its practice the very application of this pure knowledge, the patient might be a passive object. However, the patient doesn't remain passive, but reacts to the menace of disease according to attitude that the patient developed over the course of his or her life. Canguilhem characterizes this point as 'normativity', the core of individual life, which eludes positivist medicine. Here appear the essential contents of his vitalism. Although they emphasized the activity of individual living being, other modern French vitalists didn't consider this dimension of norms. Since the normativity in Canguilhem concerns the subjectivity of the first person, it avoids a mechanical form of explanation. Thus Canguilhem's originality is found in his derivation of the essence of medicine from individuality, values and norms.

Kiosk Use Among Seniors: An Empirical Investigation of the Effects of Technostress and Subjective Norms on Awareness of Shadow Work (고령층의 키오스크 사용에서의 기술스트레스와 주관적 규범이 그림자노동 지각에 미치는 영향: 실증 분석)

  • Ji, Do-Sung;Koh, Joon
    • Informatization Policy
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    • v.30 no.4
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    • pp.62-88
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    • 2023
  • While the introduction of kiosk has become an essential element, enjoying the effect of labor cost reduction, it has not been able to embrace the senior population due to the digital divide. This study investigated which factors have relationships with conflict over use for kiosk from the viewpoint of shadow work that appears during self-service kiosk use. An analysis of 159 seniors through survey revealed that both technostress and subjective norms had significant relationships with conflict over use for kiosk, and that the perception of shadow work had a partial mediating effect on these relationships. Further, user experience showed a moderating effect on the relationship between technostress and perception of shadow work. These results suggest theoretical and practical implications related to digital shadow work, providing the relevant policy regarding digital inclusion for seniors.