• Title/Summary/Keyword: Hyperbolic

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Ten Year Literature on Psychological and Behavioral Interventions Against Cancer: a Terms Analysis

  • Feng, Rui;Chai, Jing;Wang, De-Bin;Xia, Yi;Cheng, Peng-Lai;Dai, Zhao-Yang
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.5171-5176
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    • 2012
  • We here performed a systematic review of PBIC literature using terms analysis in a hope of both identifying potential trends and patterns and exploring methods leveraging traditional literature reviews in this specific area. Articles meeting inclusion criteria were retrieved from PUBMED and translated into dichotomized article records representing presence or non-presence of MeSH terms and a metric consisting of numbers of times of co-occurrence between all pairs of terms identified using a self-designed program. The occurrence of and relations among the terms were calculated and visualized using Excel2007 and UCINET respectively. A total of 1,742 terms were identified from 997 articles retrieved. Put in a descending order, the lines representing the times of term occurrence formed a typical hyperbolic curve; when plotted along the x-axis of whole MESH terms, the lines clustered within four specific regions. Comparison of term occurrence between 2002 and 2011 revealed priority changes in population and subjects (from general groups to priority groups), intervention approaches (from medicine to exercise and psychotherapy), methodology and techniques (from cohort studies to randomized controlled trials) and outcomes (from health and mental health to quality of life, depression etc.). Networks of the terms featured a number of closely linked groups of topics including method and questionnaires, therapy and outcomes, survival management, psychological assessment and intervention, behavioral intervention (individual and community oriented). Terms analysis revealed interesting trends and patterns about PBIC publications and both the analysis methods and findings have implications for future research and literature reviews.

Analysis on an Inducing Current Change between Railway Power Feeding Plants (전기철도 전자기 유도 전류의 급전구간 상대적 위치 관계에 따른 변화 분석)

  • Lee, Sangmu;Choi, Mun Hwan;Cho, Pyung-dong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.567-569
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    • 2012
  • An inducing current of power feeding line of high-speed railway system is varied by a relative position of telecommunication cable to the feeding line between plants. An analytical calculation formula of this inducing current is described in ITU-T Directives using multiconductor line method or two line method. In this paper, using the two line method, a variation characteristic of inducing current is simulated. The inducing current has a characteristic of hyperbolic function which is a symmetric shape of curve in the range between power feeding plants. This basic variation property can be considered when a power induction protection measure is planned.

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Numerical Modelling on the Strength of Reinforced Concrete Simple-Continuous Deep Beams with Openings by an Upper-Bound Theorem (상계치 이론을 이용한 개구부를 갖는 철근콘크리트 단순·연속 깊은 보 내력의 수치해석 모델)

  • Yang, Keun-Hyeok;Eun, Hee-Chang;Chung, Heon-Soo
    • Journal of the Korea Concrete Institute
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    • v.18 no.4 s.94
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    • pp.469-477
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    • 2006
  • Models to predict the ultimate strength of simply supported or continuous deep beams with web openings are proposed. The derived equations are based on upper-bound theorem. The concrete is assumed as a perfectly plastic material obeying the modified Coulomb failure criteria with zero tension cutoff. Reinforcing bar is considered as elastic-perfectly plastic material and its stress is calculated from the limiting principal compressive strain of concrete. The governing failure mechanisms based on test results are idealized as rigid moving blocks separated by a hyperbolic yield line. The effective compressive strength of concrete is calculated from the formula proposed by Vecchio and Collins. Comparisons with existing test results are performed, and they show good agreement.

Phosphorus Budget of a River Reservoir, Paldang (하천형 호수인 팔당호의 인 수지)

  • Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.34 no.3
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    • pp.270-284
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    • 2018
  • Paldang is a river reservoir located in the Midwest of Korea, with a water volume of $244{\cdot}10^6m^3$ and a water surface area of $36.5km^2$. It has eutrophied since the construction of a dam at the end of 1973, and the phosphorus concentration has decreased since 2001. Average hydraulic residence time of the Paldang reservoir is about 10 days during the spring season and 5.6 days as an annual level. The hydraulics and water quality of the reservoir can differ greatly, both temporally and spatially. For the spring period (March to May) in 2001 ~ 2017, the reservoir mean total phosphorus concentration calculated from the budget model based on a plug-flow system (PF) and a continuous stirred-tank reaction system (CSTR) was 13 % higher and 10 % lower than the observed concentration, respectively. A composite flow system (CF) was devised by assuming that the transition zone was plug flow, and that the lacustrine zone was completely mixed. The mean concentration calculated from the model based on CF was not skewed from the observed concentration, and showed just 6 % error. The retention coefficient of the phosphorus derived from the CF was 0.30, which was less than those of the natural lakes abroad or river reservoirs in Korea. The apparent settling velocity of total phosphorus was estimated to be $93m\;yr^{-1}$, which was 6 ~ 9 times higher than those of foreign natural lakes. Assuming CF, the critical load line for the total phosphorus concentration showed a hyperbolic relation to the hydraulic load in the Paldang reservoir. This is different from the previously known straight critical load line. The trophic state of the Paldang reservoir has recently been estimated to be mesotrophic based on the critical-load curve of the phosphorus budget model developed in this study. Although there is no theoretical error in the newly developed budget model, it is necessary to verify the validity of the portion below the inflection point of the critical-load curve afterwards.

Precision and Safety Comparison for SM, CRM and ATD in Phase I Clinical Trials (제 1상 임상시험의 SM, CRM, ATD에서 결정된 MTD의 정확성과 안전성 비교)

  • Kim, Dong-Uk;Kil, Sun-Kyoung
    • Communications for Statistical Applications and Methods
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    • v.16 no.1
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    • pp.51-65
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    • 2009
  • The purpose of a phase I clinical trial is to determine the maximum tolerated dose(MTD) of a new drug. This paper investigates the performance of standard method, continual reassessment method and accelerated titration designs in phase I clinical trials. Especially we study the precision and safety at the MTD of these methods. We utilize hyperbolic tangent function and power function to define dose-toxicity model. For each method, expected toxicity rate at MTD is computed and compared with target toxicity probability. We also suggest some modifications of these methods and show some improvements in performance.

Changes in Physico-chemical Properties of Moss Peat Based Root Media and Growth of Potted Chrysanthemums as Influenced by Blending Ratios of Root Media in a C-channel Mat Irrigation System

  • Kang, Seung-Won;Hong, Jong-Won;Lee, Gung-Pyo;Seo, Sang-Gyu;Pak, Chun-Ho
    • Horticultural Science & Technology
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    • v.29 no.3
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    • pp.201-210
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    • 2011
  • This experiment was conducted to investigate physical and chemical characteristics by volume fractions of root media using peatmoss, perlite, and vermiculite, along with effects on the growth of pot chrysanthemums (Dendranthema ${\times}$ grandiflorum 'Vemini') in a C-channel mat irrigation system. To evaluate the physico-chemical properties of 20 root media, the bulk density, particle density, total pore space, pore space, ash content, organic matter, pH, and electrical conductivity were measured and data were analyzed using principal component analysis (PCA). PCA scores revealed that physico-chemical properties changed by the blending of peatmoss, perlite, and vermiculite. The 20 root media were divided into three main groups by hierarchical cluster analysis. At the end of the experiment, the pH and EC of the root media were measured from media divided into four layers. The pH of root media without plants showed a strong linear relationship and the pH of root media with plants increased exponentially. The change of EC in the root medium was indicated as a hyperbolic curve. Plant growth characteristics according to growth in the 20 root media were analyzed by PCA. It was found that the mixing ratios of the root media affected plant growth characteristics. Therefore, mixing ratio is an important factor for pot-plant production in a subirrigation system.

A Usability Evaluation on the Visualization of Information Extraction Output (정보추출결과의 시각화 표현방법에 관한 이용성 평가 연구)

  • Lee Jee-Yeon
    • Journal of the Korean Society for Library and Information Science
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    • v.39 no.2
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    • pp.287-304
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    • 2005
  • The goal of this research is to evaluate the usability of visually browsing the automatically extracted information. A domain-independent information extraction system was used to extract information from news type texts to populate the visually browasable knowledge base. The information extraction system automatically generated Concept-Relation-Concept triples by applying various Natural Language Processing techniques to the text portion of the news articles. To visualize the information stored in the knowledge base, we used PersoanlBrain to develop a visualization portion of the user interface. PersonalBrain is a hyperbolic information visualization system, which enables the users to link information into a network of logical associations. To understand the usability of the visually browsable knowledge base, IS test subjects were observed while they use the visual interface and also interviewed afterward. By applying a qualitative test data analysis method. a number of usability Problems and further research directions were identified.

Extractive Ethanol Fermentation Characteristics of K.fragilis in an Aqueous Two Phase System (수성이상계에서 K.fragilis의 에탄올 추출발효 특성에 관한 연구)

  • 김진한;허병기목영일
    • KSBB Journal
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    • v.9 no.5
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    • pp.443-449
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    • 1994
  • Fermentation characteristics of Kluyveromyces fragilis CBS 1555 with Jerusalem artichoke juice, in extractive ethanol fermentation in aqueous two phase systems composed of polyethylene glycol 20000 (PEG) and crude dextran(Dx), were investigated as a function of initial sugar concentrations, concentrations of ethanol formed, or fermentation time. Both specific ethanol production rate increased with decrease in concentrations of PEG and Dx in two-phase systems. Without being related to the compositions of aqueous two-phase system, maximum specific cell growth rate and maximum specific ethanol production rate were showed in the initial sugar concentration fo $80g/\ell$ and $120g/\ell$, respectively. The inhibition effects of ethanol on specific cell growth rate and specific ethanol production rate decreased with decrease in PEG concentration and in the range of 2.5 to 5% Dx. Specific cell growth rate and specific ethanol production rate was fitted as an exponential function and a hyperbolic function, respectively, of the concentrations of ethanol formed. Overall ethanol productivity increased with increase in initial sugar concentrations, and also the required time for the maximum productivity was so. Ethanol production rate by the elapsed fermentation time showed the maximum value in the initial sugar concentration of $160g/\ell$.

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An Evaluation of Shear Strength Parameters$(c,\varphi)$ for Weathering Decomposed Granite Soil (화강풍화토의 전단정수$(c,\varphi)$ 평가)

  • 이문수;이광찬
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.181-194
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    • 1999
  • Both the chemical components and the physical and mechanical properties of the compacted and undisturbed weathered granite soils were estimated to investigate the influences of the degree of weathering and saturation on the shear strength. The weathered granite soils used in this study were taken from six different sites in Korea. The results showed that the shear strength of weathered granite soil decreased with increasing the degree of weathering and saturation. Under the normal stresses less that 40kPa, the shape of Mohr-Coulomb failure envelope followed curved or hyperbolic relationship and a half of cohesion value obtained by the common shear test was observed. Using the Sueoka's method, the values of CWI were ranged from 21.5 to 31.26 which can be characterized as a completely weathered granite soil. Large decrease in shear strength and remarkable variation in dilatancy were observed in saturated granite soil compared to unsaturated soil. It was also found that the shear strength of undisturbed weathered granite soil of Pungam site can be expressed approximately by the equation of ${(\tau)_{sat}= 1.0(\tau)_{unsat}-12.48}$ and this equation can be extended to the other sites considered in this study.

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An Assessment of a Resilient Modulus Model by Comparing Predicted and Measured Elastic Deformation of Railway Trackbeds (철도노반의 탄성변위 예측 및 측정을 통한 회복탄성계수 모델 평가)

  • Park, Chul-Soo;Kim, Eun-Jung;Oh, Sang-Hoon;Kim, Hak-Sung;Mok, Young-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1404-1414
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    • 2008
  • In the mechanistic-empirical trackbed design of railways, the resilient modulus is the key input parameter. This study focused on the resilient modulus prediction model, which is the functions of mean effective principal stress and axial strain, for three types of railroad trackbed materials such as crushed stone, weathered soil, and crushed-rock soil mixture. The model is composed with the maximum Young's modulus and nonlinear values for higher strain in parallel with dynamic shear modulus. The maximum values is modeled by model parameters, $A_E$ and the power of mean effective principal stress, $n_E$. The nonlinear portion is represented by modified hyperbolic model, with the model parameters of reference strain, ${\varepsilon}_r$ and curvature coefficient, a. To assess the performance of the prediction models proposed herein, the elastic response of a test trackbed near PyeongTaek, Korea was evaluated using a 3-D nonlinear elastic computer program (GEOTRACK) and compared with measured elastic vertical displacement during the passages of freight and passenger trains. The material types of sub-ballasts are crushed stone and weathered granite soil, respectively. The calculated vertical displacements within the sub-ballasts are within the order of 0.6mm, and agree well with measured values with the reasonable margin. The prediction models are thus concluded to work properly in the preliminary investigation.

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