• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.197-203
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• 2002

The estimation of pile bearing capacity is important since the design details are determined from the result. There are numerous ways of determining the pile design load, but only few of them are chosen in the actual design. According to the recent investigation in Korea, the formulas proposed by Meyerhof based on the SPT N values are most frequently chosen in the design stage. In the study, various static and dynamic formulas have been used in predicting the allowable bearing capacity of a pile. Further, the reliability of these formulas has been verified by comparing the perdicted values with the static and dynamic load test measurements. Also in cases, these methods of pile bearing capacity determination do not take the time effect consideration, the actual allowable load as determined from pile load test indicates severe deviation from the design value. The principle results of this study are summarized as follows : A a result of estimate the reliability in criterion of the Davisson method, in was showed that Terzaghi & Peck > Chin > Meyerhof > Modified Meyerhof method was the most reliable method for the prediction of bearing capacity. Comparisons of the various pile-driving formulas showed that Modified Engineering News was the most reliable method. However, a significant error happened between dynamic bearing capacity equation was judged that uncertainty of hammer efficiency, characteristics of variable , time effect etc... was not considered. As a result of considering time effect increased skin friction capacity higher than end bearing capacity. It was found out that it would be possible to increase the skin friction capacity 1.99 times higher than a driving. As a result of considering 7 day's time effect, it was obtained that Engineering News. Modified Engineering News. Hiley, Danish, Gates, CAPWAP(CAse Pile Wave Analysis Program ) analysis for relation, respectively, $Q_{u(Restrike)}$ $Q_{u(EOID)}$ = 0.971 $t_{0.1}$, 0.968 $t_{0.1}$, 1.192 $t_{0.1}$, 0.88 $t_{0.1}$, 0.889 $t_{0.1}$, 0.966 $t_{0.1}$, 0.889 $t_{0.1}$, 0.966 $t_{0.1}$

• Wind and Structures
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• v.17 no.1
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• pp.87-105
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• 2013

Modeling an equilibrium atmospheric boundary layer (ABL) in an empty computational domain has routinely been performed with the k-${\varepsilon}$ turbulence model. However, the research objects of structural wind engineering are bluff bodies, and the SST k-${\omega}$ turbulence model is more widely used in the numerical simulation of flow around bluff bodies than the k-${\varepsilon}$ turbulence model. Therefore, to simulate an equilibrium ABL based on the SST k-${\omega}$ turbulence model, the inlet profiles of the mean wind speed U, turbulence kinetic energy k, and specific dissipation rate ${\omega}$ are proposed, and the source terms for the U, k and ${\omega}$ are derived by satisfying their corresponding transport equations. Based on the proposed inlet profiles, numerical comparative studies with and without considering the source terms are carried out in an empty computational domain, and an actual numerical simulation with a trapezoidal hill is further conducted. It shows that when the source terms are considered, the profiles of U, k and ${\omega}$ are all maintained well along the empty computational domain and the accuracy of the actual numerical simulation is greatly improved. The present study could provide a new methodology for modeling the equilibrium ABL problem and for further CFD simulations with practical value.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.106-111
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• 2002

The estimation of pile bearing capacity is important since the design details are determined from the result. There are numerous ways of determining the pile design load, but only few of them are chosen in the actual design. According to the recent investigation in Korea, the formulas proposed by Meyerhof based on the SPT N values are most frequently chosen in the design stage. In the study, various static and dynamic formulas have been used in predicting the allowable bearing capacity of a pile. Further, the reliability of these formulas has been verified by comparing the perdicted values with the static and dynamic load test measurements. Also, in most cases, these methods of pile bearing capacity determination do not take the time effect consideration, the actual allowable load as determined from pile load test indicates severe deviation from the design value. The principle results of this study are summarized as follows : As a result of estimate the reliability in criterion of the Davisson method, t was showed that Terzaghi & Peck >Chin>Meyerhof > Modified Meyerhof method was the most reliable method for the prediction of bearing capacity. Comparisons of the various pile-driving formulas showed that Modified Engineering News was the most reliable method. However, a significant error happened between dynamic bearing capacity equation was judged that uncertainty of hammer efficiency, characteristics of variable, time effect etc... was not considered. As a result of considering time effect increased skin friction capacity higher than end bearing capacity. It was found out that it would be possible to increase the skin friction capacity 1.99 times higher than a driving. As a result of considering 7 day's time effect, it was obtained that Engineering news, Modified Engineering News, Hiley, Danish, Gates, CAPWAP(CAse Pile Wave Analysis Program) analysis for relation, repectively, $Q_{u(Restrike)} / Q_{u(EOID)} = 0.98t_{0.1}$ , $0.98t_{0.1}$, $1.17t_{0.1}$, $0.88t_{0.1}$, $0.89t_{0.1}$, $0.97t_{0.1}$.

• Journal of Korean Physical Therapy Science
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• v.15 no.2
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• pp.87-95
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• 2008

Background: Hemiplegic patients usually have difficulty maintaining balance. Balance training is a major component of there habilitation program for patients with neurological impairment. The purpose of this study was to investigate the effects of PLS(Posterior Leaf Spring), FES(Functional Electrical stimulation), treadmill training, and neurodevelopmental treatment on the improvement of balance in patients with hemiplegia. Methods: We looked into published studies from Dankook University’s electronic library databases of RISS4U, KMbase, NCBI, and MEDLIS concerning the effectiveness of any form of intervention leading to improvement of balance. All types of studies relevant to the topic that were published in English during the time period of 1986 to 2005 were included. Results: 1. There were significant differences in standing balance, dynamic activity balance, and gait speed between barefoot subjects and subjects who wore SPAFO and HPAFO(p<.05). 2. The changes in ROM and FRT related to sex, age, height, and weight part of the diagnosis, as well as experience relapse, was of meaningless value. Changes in ROM related to the duration of pain and experiences of falling down were also meaningless. However, FRT showed significant static differences(p<.05). 3. The body-weight-support treadmill training scoring of standing balance, step length, and a timed 10m walking test showed definite improvement. 4. The proprioceptive control approach improved dynamic balance in patients with hemiplegia. Conclusion: Consequently, further study is needed to verify methods when physical therapists are researching balance ability in hemiplegic patient.

• PNF and Movement
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• v.10 no.3
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• pp.7-18
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• 2012

Purpose : This study was to compare the difference Trunk Control Test(TCT), Postural Assessment Scale for Stroke(PASS-TC), and Trunk Impairment Scale(TIS) and its subscales in relation to the difference MBI(Modified Barthel Index), BBS(Berg Balance Scale), and to establish the association between MBI, BBS, Fugl Meyer-motor function(FM-M), and to predict MBI-subscales from the variables. Methods : 58 stroke patients, attending a rehabilitation programme, participated in the study. Trunk control was measured with the use of the TCT, PASS-TC, TIS, and the performance of Activities daily living was obtained by MBI, and dynamic balance ability(by BBS). Trunk control scores from the difference MBI, BBS were compared using the 1-way ANOVA(Mann Whitney U test) and the data were analyzed using Pearson product correlation. Multiple stepwise regression analyses were performed to identify prognostic factors for ADL subscale. Results : Trunk control scores showed significant differences between MBI(F=2.139~13.737, p<.05~.001), BBS(t=3.491~7.705, p<.01~.001). It was significantly related with value of the MBI(r=.25~.50), BBS(r=.38~.68), FMM( r=.31~.48). Stepwise linear regression analysis showed an additional, significant contribution of the TCT, in addition to the PASS-TC, dynamic sitting balance subscale of the TIS for measures of MBI subscales. Conclusion : Measures of trunk control were significantly related with values of MBI, BBS score, so the management of trunk rehabilitation after stroke should be emphasized. The use of both quantitative and qualitative scales was shown to be a good measuring instrument for the classification of the general performance of the stroke patients. Further study about trunk control is needed using a longitudinal study design.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.97-100
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• 2006

Accelerating ability is one of the most important performance of the vehicle. Unlike conventional internal combustion vehicles and power-assist hybrid vehicles, the maximized acceleration of dual mode hybrid vehicles is not simply. achieved by maximizing engine or motor torque Because of the dynamic stability of planetary gear, speeds and torques control of engine, motor 1 and motor 2 is essential and according to control value, acceleration performance is changed There are two control values which are velocity and torque for each component totalling six. These six values can be variables for an objective function. However, because three velocity variables can be regarded as only one variable speed ratio and the remaining three torque variables can be solved analytically, without complicated numerical algorithm the solution for the objective function can be obtained. This optimized solution shows the best performance possible to the specified dual mode system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.97-107
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• 1990

The epidemiology of plant disease deals with the dynamic processes of host-pathogen interactions, which determine the prevalence and severity of the disease. Epidemic processes for most foliar diseases of plants follow a series of steps: arrival of pathogens on plant surfaces, initial infection, incubation period, latent period, sporulation, dissemination of secondary inoculum, and infectious period. These complex biological processes are influenced by the environment-Man also often interfers with these processes by altering the host and pathogen populations and the environment. Slowing or halting any of the epidemic processes can delay the development of the epidemic, so that serious losses in yield due to disease do not occur. It is generally recognized that the most effective and efficient method of minimizing disease damage is through the use of resistant cultivars, particularly when other methods such as fungicide applications are not economically feasible-Populations of plant pathogens are not genetically uniform nor are they necessarily stable. Cultivars bred for resistance to current populations of a pathogen may not be resistant in the future due to selection pressures placed on the pathogen populations. Understanding population development and genetic variability in the pathogen, and knowledge of the genetics of resistance in the plant should help in developing breeding strategies that wi1l provide effective and stable disease control through genetic resistance. In the United States, soybeans have ranked first in value of crops sold off the farm in recent years. Soybeans have been the leading U. S.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.38-45
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• 2007

A one-dimensional kinematic wave model was used to calculate temporal and spatial changes of the highway runoff. Infiltration into pavement was considered using Darcy's law, as a function of flow depth and pavement hydraulic conductivity ($K_p$). The model equation was calculated using the method of characteristics (MOC), which provided stable solutions for the model equation. 22 storm events monitored in a highway runoff monitoring site in west Los Angeles in the U.S. were used for the model calculation and evaluation. Using three different values of $K_p$ ($5{\times}10^{-6}$, $10^{-5}$, and $2{\times}10^{-5}cm/sec$), total runoff volume and peak flow rate were calculated and then compared with the measured data for each storm event. According to the calculation results, $10^{-5}cm/sec$ was considered a site representative value of $K_p$. The study suggested a one-dimensional method to predict hydrodynamic behavior of highway runoff, which is required for the water quality prediction.

• Journal of English Language & Literature
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• v.56 no.1
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• pp.47-64
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• 2010

It is unfair that environmental pragmatism has been regarded as a mouthpiece for industrial expediency and business boosterism. John Dewey's radical pragmatism known as 'Instrumentalism' has provoked ecological fundamentalists' criticism more vehemently than any other pragmatic philosophies. However, most of the presumptive misunderstandings of such critics as Holmes Rolston, J. Baird Calliott, Erich Katz, C. A. Bowers and many others come from their limited or reduced reading of Deweyan pragmatism. The following three aspects of Deweyan pragmatism can work out in opening up a dialogical space with those eco-centrist thinkers mentioned above. First, the concept of Dewey's 'primary experience' can articulate the foundationalist view of nature, which is often found in aboriginal cultures. Second, as Andrew Light points out, ecological essentialism can share its metaphilosophical position with the pragmatist epistemology. While Anthony Weston pursues pluralism, admitting that the foundationalism might be one of the efficient approaches to nature, Eric Katz is also clearly attracted to the metaphilosophical element in Weston's argument that anyone who attempts to claim the 'inherent value' of non-human nature never possibly avoids a pitfall of anthropomorphism. Lastly, in a more comprehensive perspective, Dewey's pragmatism shows a philosophical complexity, what Larry A. Hickman calls 'post-postmodernism.' a dynamic interaction between modernism and postmodernism. Significantly enough, the environmental version of this complexity can procure a meeting ground between foundationalist ecology and the pragmatic view of nature.

• Asia Marketing Journal
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• v.16 no.1
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• pp.35-69
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• 2014

The impact of competition on pricing has been studied in the context of counterfactual merger analyses where expected optimal prices in a hypothetical monopoly are compared with observed prices in an oligopolistic market. Such analyses would typically assume static decision making by consumers and firms and thus have been applied mostly to data obtained from consumer packed goods such as cereal and soft drinks. However such static modeling approach is not suitable when decision makers are forward looking. When it comes to the markets for durable products with indirect network effects, consumer purchase decisions and firm pricing decisions are inherently dynamic as they take into account future states when making purchase and pricing decisions. Researchers need to take into account the dynamic aspects of decision making both in the consumer side and in the supplier side for such markets. Firms in a two-sided market typically subsidize one side of the market to exploit the indirect network effect. Such pricing behaviors would be more prevalent in competitive markets where firms would try to win over the battle for standard. While such qualitative expectation on the relationship between pricing behaviors and competitive structures could be easily formed, little empirical studies have measured the extent to which the distinct pricing structure in two-sided markets depends on the competitive structure of the market. This paper develops an empirical model to measure the impact of competition on optimal pricing of durable products under indirect network effects. In order to measure the impact of exogenously determined competition among firms on pricing, we compare the equilibrium prices in the observed oligopoly market to those in a hypothetical monopoly market. In computing the equilibrium prices, we account for the forward looking behaviors of consumers and supplier. We first estimate a demand function that accounts for consumers' forward-looking behaviors and indirect network effects. And then, for the supply side, the pricing equation is obtained as an outcome of the Markov Perfect Nash Equilibrium in pricing. In doing so, we utilize numerical dynamic programming techniques. We apply our model to a data set obtained from the U.S. video game console market. The video game console market is considered a prototypical case of two-sided markets in which the platform typically subsidizes one side of market to expand the installed base anticipating larger revenues in the other side of market resulting from the expanded installed base. The data consist of monthly observations of price, hardware unit sales and the number of compatible software titles for Sony PlayStation and Nintendo 64 from September 1996 to August 2002. Sony PlayStation was released to the market a year before Nintendo 64 was launched. We compute the expected equilibrium price path for Nintendo 64 and Playstation for both oligopoly and for monopoly. Our analysis reveals that the price level differs significantly between two competition structures. The merged monopoly is expected to set prices higher by 14.8% for Sony PlayStation and 21.8% for Nintendo 64 on average than the independent firms in an oligopoly would do. And such removal of competition would result in a reduction in consumer value by 43.1%. Higher prices are expected for the hypothetical monopoly because the merged firm does not need to engage in the battle for industry standard. This result is attributed to the distinct property of a two-sided market that competing firms tend to set low prices particularly at the initial period to attract consumers at the introductory stage and to reinforce their own networks and eventually finally to dominate the market.