• Title/Summary/Keyword: Experience curve

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Seismic response of current RC buildings in Kathmandu Valley

  • Chaulagain, Hemchandra;Rodrigues, Hugo;Spacone, Enrico;Varum, Humberto
    • Structural Engineering and Mechanics
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    • v.53 no.4
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    • pp.791-818
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    • 2015
  • RC buildings constitute the prevailing type of construction in earthquake-prone region like Kathmandu Valley. Most of these building constructions were based on conventional methods. In this context, the present paper studied the seismic behaviour of existing RC buildings in Kathmandu Valley. For this, four representative building structures with different design and construction, namely a building: (a) representing the non-engineered construction (RC1 and RC2) and (b) engineered construction (RC3 and RC4) has been selected for analysis. The dynamic properties of the case study building models are analyzed and the corresponding interaction with seismic action is studied by means of non-linear analyses. The structural response measures such as capacity curve, inter-storey drift and the effect of geometric non-linearities are evaluated for the two orthogonal directions. The effect of plan and vertical irregularity on the performance of the structures was studied by comparing the results of two engineered buildings. This was achieved through non-linear dynamic analysis with a synthetic earthquake subjected to X, Y and $45^{\circ}$ loading directions. The nature of the capacity curve represents the strong impact of the P-delta effect, leading to a reduction of the global lateral stiffness and reducing the strength of the structure. The non-engineered structures experience inter-storey drift demands higher than the engineered building models. Moreover, these buildings have very low lateral resistant, lesser the stiffness and limited ductility. Finally, a seismic safety assessment is performed based on the proposed drift limits. Result indicates that most of the existing buildings in Nepal exhibit inadequate seismic performance.

Teaching and Learning Concepts of Tangent in School Mathematics (학교 수학에서 접선 개념 교수 방안 연구)

  • 임재훈;박교식
    • Journal of Educational Research in Mathematics
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    • v.14 no.2
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    • pp.171-185
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    • 2004
  • Students are exposed to a concept of tangent from a specific context of the relation between a circle and straight lines at the 7th grade. This initial experience might cause epistemological obstacles regarding learning concepts of tangent to additional curves. The paper provides a method of how to introduce a series of concepts of tangent in order to lead students to revise and improve the concept of tangent which they have. As students have chance to reflect and revise a series of concepts of tangent step by step, they realize the facts that the properties such as 'meeting the curve at one point' and 'touching but not cutting the curve' may be regarded as the proper definition of tangent in some limited contexts but are not essential in more general contexts. And finally students can grasp and appreciate that concept of tangent as the limit of secants and the relation between tangent and derivative.

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Development on the Questionnaire of Cold-Heat Pattern Identification Based on Usual Symptoms for Health Promotion - Focused on Agreement Study (건강 증진을 위한 평소 증상 기반의 한열변증 설문지 개발 - 일치도를 중심으로)

  • Bae, Kwang-Ho;Yoon, Youngheum;Yeo, Minkyung;Kim, Ho-Seok;Lee, Youngseop;Lee, Siwoo
    • Journal of Society of Preventive Korean Medicine
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    • v.20 no.2
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    • pp.17-26
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    • 2016
  • Objectives : We presented the results of reliability study in advance, and analyzed agreement between Korean medicine doctors(KMDs)' diagnosis and cold-heat pattern identification questionnaire(CHPI)'s diagnosis. Methods : This survey was conducted from May 16 to 17, 2015. The subjects were 93 adults living in rural society. Diagnosis of CHPI was performed by 2 KMDs who have clinical experience more than 5 years. The KMDs' diagnosis was set as a reference index, and then we compare 23 items(cold pattern 11 items and heat pattern 12 items) of CHPI questionnaire and 15 items(cold pattern 8 items and heat pattern 7 items) that were brief form of it. We had cut-off value by standard of KMDs' diagnosis using receiver operating characteristic-curve(ROC-curve), with which we calculated agreement including kappa value. Correlation analysis between CHPI evaluation score by KMDs and by the questionnaire was fulfilled as well. Results : Agreement about 11 and 8 cold pattern items showed 87.1% together, and the value of kappa each recorded 0.742 and 0.741. Agreement about 12 and 7 heat pattern items suggested 81.7% and 78.5%, and the value of kappa showed 0.634 and 0.570. Correlation coefficients were 0.803 of 11 items and 0.761 of 8 items about cold pattern. In addition, correlation coefficients were 0.789 of 12 items and 0.767 of 7 items about heat pattern. The significant probability (p-value) was under 0.001. Conclusions : We have developed CHPI questionnaire involving reliability and agreement based on usual symptoms, and hope additional complements so that Korean medicine diagnostics and Korean preventive medicine would be improved.

Diagnostic Potential of Strain Ratio Measurement and a 5 Point Scoring Method for Detection of Breast Cancer: Chinese Experience

  • Parajuly, Shyam Sundar;Lan, Peng Yu;Yun, Ma Bu;Gang, Yang Zhi;Hua, Zhuang
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1447-1452
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    • 2012
  • Aim: To evaluate the differential diagnostic potential of lesion stiffness assessed by the sonoelastographic strain index ratio (SR) and elastographic color scoring system (UE) for breast lesions. Materials and Methods: Three hundred and forty two breast masses (158 benign and 184 malignant) from 325 consecutive patients (mean age 44.2 years; range 16-81)who had been scheduled for a sonographically guided core biopsy were examined proposed by Itoh et al, with scoring 1-3=benign and 4-5=malignant. Strain and area ratios of each lesion were calculated within the same machine. Histological diagnosis was used as the reference standard. The area under the curve (AUC) and cut-off point were obtained by receiver operating curve and the cross table Fischer Test was carried out for assessing diagnostic value. Sensitivity, specificity, PPV, NPV, accuracy and false-discovery rates were compared. Results: The mean strain ratios for benign and malignant lesions were 1.87 and 7.9 respectively. (P<0.0001). When a cutoff point of 3.54 was used, SR had a sensitivity of 94.6%, a specificity 94.3%, a PPV of 95.1%, an NPV of 93.7% and an accuracy of 94.4%. The AUC values were 0.90 for the 5 point scoring system (UE) and 0.96 for the strain index ratio. The overall diagnostic performance was SR method was better (P<0.05). Conclusions: Strain ratio measurement could be another effective predictor in elastography imaging besides 5 the point scoring system for differential diagnosis of breast lesions.

Contact lens Prescription and Satisfaction with Astigmatism Eye (난시안의 콘택트렌즈 처방과 만족도에 관한 연구)

  • Kim, Mi-Yeon;Kim, Yeong-Mi;Kim, Tae-Hun;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.4
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    • pp.317-322
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    • 2006
  • For this study we made up a question investigation to analyze a grade of satisfaction and a side effect about the prescription actual condition of contact lens of person with astigmatism among the person who has a error of refraction. The whole patient of refractive error was 46 person, there were 11 person who only wear spectacles by correction of visual acuity among person to a question investigation and 35 person who only wear contact lens. Under investigation 35 person who only wear contact lens, there were 25 person who experience the problem which occurs because of contact lens wearing for a long time. The most patient who made up a question investigation very choose remainder item except for item of very satisfaction. The their reason that could not satisfaction was non corrected astigmatism, wrong prescription, wrong Base curve, out of life span etc.

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Theoretical Review of Highway Grades Considering Vehicle Performances (차량성능을 고려한 최대종단경사 합리화 연구)

  • Kim, Sang-Yeop;Lee, Seung-Yong;Han, Hyeong-Gwan;Choe, Jae-Seong
    • Journal of Korean Society of Transportation
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    • v.25 no.5
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    • pp.79-90
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    • 2007
  • In determining vertical grades in highway alignment design, engineers usually consider heavy vehicle performances on the upgrade. Heavy vehicles usually experience speed reduction on the upgrade and with recent years weight/horsepower improvements for heavy vehicles the speed reduction shows some change. However, in spite of the weight to horsepower improvements for the design vehicles from 300lb/HP to 200lb/HP in the AASHTO, there was no change in the maximum vertical grades. Therefore, a review of the maximum vertical grade reflecting existing heavy vehicle performances is required. In particular, in South Korea where highways pass through lots of mountaineous terrain, the maximum vertical grades must be reviewed throughly. In this study the amount of heavy vehicle performances during past decades were investigated and their expected impacts on highway vertical alignment designs were subsequently analyzed. A worldwide terrain analysis and international design standards were compared to set South Korean vertical grade standards. Traffic flow simulation Vissim was utilized to simulate vehicular flows on the upgrade and new truck performance curves on the grades were developed. Based on the new curve, it was decided that $1{\sim}2%$ increase of the maximum vertical grades could be allowed.

A Study on the Deperm of Ferromagnetic Material using Preisach Model (Preisach 모델을 이용한 강자성체의 탈자기법 연구)

  • Ju, Hye Sun;Park, Gwan Soo;Won, Hyuk
    • Journal of the Korean Magnetics Society
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    • v.23 no.2
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    • pp.54-61
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    • 2013
  • Ferromagnetic material's residual magnetization is remained because of the interaction between domains from external apply field, so the electrical and electronic industry and area of defense development request deperm protocol which makes the residual magnetization to 0. But the deperm protocols which are used theses days are developed by using only experience and experiment, so we have to develop deperm protocol considering hysteresis curve. In this paper, Anhysteretic Deperm, Deperm-ME, Flash-Deperm were analyzed using two dimensional finite element method and Preisach model that was formulated by property of magnetic materials. From that analysis, the relations between hysteresis curve and deperm variable are compared by analyzing the trace of Preisach plane. Also, an efficient current ratio of deperm protocol, is proposed.

A Methodology Study for Estimating the Benefits of Tilting Train Deployment (틸팅열차 투입에 따른 추정가능한 편익계상 연구)

  • Lee, Jin-Sun;Kim, Kyoung-Tae;Eom, Jin-Ki
    • Journal of the Korean Society for Railway
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    • v.12 no.5
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    • pp.700-706
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    • 2009
  • Unlike high-speed KTX trains and dual track railways, most single-track railways are not popular among passengers because of long travel hours. As a solution to the problem, tilting trains will be deployed along the conventional line. Tilting train has a mechanism that enables increased speed on regular and curved railway tracks. As a train rounds a curve at speed, objects inside the train experience centrifugal force. This can cause packages to slide about or seated passengers to feel squashed by the outboard armrest due to its centripetal force, and standing passengers to lose their balance. Tilting trains possess a top speed of up to 180 km per hour as opposed to the previous 140 km per hour, so allow the train to pass curve at higher speed without affecting passenger comfort. This paper describes the methodology study to estimate the benefits, especially on the extra benefits in case of tilting actuation.

Narrative Strategies for Learning Enhanced Interface Design "Symbol Mall"

  • Uttaranakorn, Jirayu;McGregor, Donna-Lynne;Petty, Sheila
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.417-420
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    • 2002
  • Recent works in the area of multimedia studies focus on a wide range of issues from the impact of multimedia on culture to its impact on economics and anything in between. The interconnectedness of the issues raised by this new practice is complicated by the fact that media are rapidly converging: in a very real way, multimedia is becoming a media prism that reflects the way in which media continually influence each other across disciplines and cultural borders. Thus, the impact of multimedia reflects a complicated crossroads where media, human experience, culture and technology converge. An effective design is generally based on shaping aesthetics for function and utility, with an emphasis on ease of use. However, in designing for cyberspace, it is possible to create narratives that challenge the interactor by encoding in the design an instructional aspect that teaches new approaches and forms. Such a design offers an equally aesthetic experience for the interactor as they explore the meaning of the work. This design approach has been used constructively in many applications. The crucial concern is to determine how little or how much information must be presented for the interactor to achieve a suitable level of cognition. This is always a balancing act: too much difficulty will result in interactor frustration and the abandonment of the activity and too little will result in boredom leading to the same negative result In addition, it can be anticipated that the interactor will bring her or his own level of experiential cognition and/or accretion, to the experience providing reflective cognition and/or restructure the learning curve. If the design of the application is outside their present experience, interactors will begin with established knowledge in order to explore the new work. Thus, it may be argued that the interactor explores, learns and cognates simultaneously based on primary experiential cognition. Learning is one of the most important keys to establishing a comfort level in a new media work. Once interactors have learned a new convention, they apply this cognitive knowledge to other new media experiences they may have. Pierre Levy would describe this process as a "new nomadism" that creates "an invisible space of understanding, knowledge, and intellectual power, within which new qualities of being and new ways of fashioning a society will flourish and mutate" (Levy xxv 1997). Thus, navigation itself of offers the interactors the opportunity to both apply and loam new cognitive skills. This suggests that new media narrative strategies are still in the process of developing unique conventions and, as a result, have not reached a level of coherent grammar. This paper intends to explore the cognitive aspects of new media design and in particular, will explore issues related to the design of new media interfaces. The paper will focus on the creation of narrative strategies that engage interactors through loaming curves thus enhancing interactivity.vity.

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The Usability of Sit to Stand Test Performance in Chronic Stroke (만성 뇌졸중 환자들의 Sit to Stand Test의 임상적 유용성)

  • Cho, Hwi-Young;An, Seung-Heon;Lee, Yun-Bok;Hong, Hyun-Hwa;Lee, Gyu-Chang
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.4
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    • pp.549-558
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    • 2013
  • PURPOSE: This study is designed as a retrospective study, and identified the clinical usability of Sit to Stand (STS) test for predicting of fall incidence in stroke patients who experienced a fall within 1 year. METHODS: Between July 2011 and November 2012, 69 inpatients with stroke in K rehabilitation hospital were participated under voluntarily signing the informed consent form. STS test and 10m walk test (10MWT) were used to assess the muscle strength of lower-extremity and walking velocity, respectively. Also, we tested dynamic balance and motor function of lower-extremity in affected-side using with the Berg balance scale (BBS) and the Fugl-Meyer assessment of lower extremity (FM-L/E). METHODS: There were significant differences between subjects with fall-experienced group and without subjects without fall-experienced group in STS test, 10MWT, BBS scores and FM-L/E. STS test significantly showed a negative correlation between 10MWT (r=-.657), BBS (r=-.512), and FM-L/E (r=-.563). And, 10MWT have a influence on the performance of STS test (the capacity of explanation = 20%). The cut-off value of STS performance predicting falls experience is ${\geq}14.36$ seconds (sensitivity=76%; specificity=79%, area under curve=.785). According to logistic regression analysis of falls experience, subjects ${\geq}14.36$ s showed that 4.164 times (odd ratio) increased in falls than subjects < 14.36 s in STS test. CONCLUSION: This study demonstrated that STS test may be a useful tool predicting and measuring falls in patients with stroke. Further study will be needed to elucidate the kinematic analysis of STS test and the relationship between physical activity level and falls in stroke patients.