• Structural Engineering and Mechanics
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• v.46 no.3
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• pp.353-370
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• 2013

This paper presents a new method to study the impact factor of an old bridge based on the model updating technique. Using the genetic algorithm (GA) by minimizing an objective function of the residuals between the measured and predicted responses, the bridge and vehicle coupled vibration models were updated. Based on the displacement relationship and the interaction force relationship at the contact patches, the vehicle-bridge coupled system can be established by combining the equations of motion of both the bridge and vehicles. The simulated results show that the present method can simulate precisely the response of the tested bridge; compared with the other bridge codes, the impact factor specified by the bridge code of AASHTO (LRFD) is the most conservative one, and the value of Chinese highway bridge design code (CHBDC) is the lowest; for the large majority of old bridges whose road surface conditions have deteriorated, calculating the impact factor with the bridge codes cannot ensure the reliable results.

• Journal of Agricultural Extension & Community Development
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• v.15 no.4
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• pp.577-597
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• 2008

The purpose of this study is to examine the effects of residents' perceptions of tourism impact and conflicts on residents' participation in rural tourism village. Method of analysis involves factor analysis and regression analysis in this study. In order to measure the level of perception, three factors(economic benefits, social benefits, social and environmental cost) are derived from the factor analysis. And also in order to measure the level of conflict, two factor(openness of information, leading of operation) are derive from the factor analysis. The result of regression analysis indicate that perceived economic benefits and social benefits are rather greater impacts on residents' participation than social and environmental cost, and also openness of information is rather greater impacts on residents' participation than leading of operation.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.2
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• pp.357-379
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• 2010

The citation analysis is not applied to group measurements but to individual papers finding their impact factors among citation chains which are created by tracing citing-cited relationship between any two papers in data set. The individual impact factor is measured by adding each value derived from citation chain. Each paper's impact factor index is calculated by adding the values of each index by direct citing-cited relationship, and the values of each impact factor made by indirectly influencing to the papers in the citation chain. The research introduces a grace period, in which the system holds the papers not cited by other papers yet, but are expected to be cited within this period. Eventually not cited papers after the grace period would be eliminated by the system. The experiment suggests a reasonable database in which the highly influenced papers are gathered, and could be serviced in stead of buying databases filled with worthless not-cited-papers.

• Journal of the Korean Society for information Management
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• v.27 no.1
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• pp.269-287
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• 2010

The journal impact factor(JIF) of the Thomson Reuters(ISI) has been widely used to assess the impact of journal as well as its quality. However, the JIF contains its critical limitation, in which it does not measure the impact of journal but the average impact of articles in journal. Besides significant number of problems of the JIF has been noticed. Furthermore, given the limited coverage of domestic citation index database in comparison to those of international citation index, it is necessary to apply a more appropriate index with a high level of discriminating power. This study, therefore, aims to introduce some practical methods to measure the impact of domestic journals by using the Hirsch-type indices. As the Hirsch-type indices has been often used for overcoming the limitations of the JIF in worldwide, we hope that our research outcome offers an effective alternative to gauge the impact of journals more accurately. Consequently, using the variations of the h-index($h_s$-index, $f_s$-index) or the sum of issue level(issue based h-index, issue based f-index), we argue that it would improve the discrimination capacity of the Hirsch-type indices significantly and that we can measure the impact of domestic journals more clearly.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.2
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• pp.298-309
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• 1990

In this paper, a new method is suggested to analyze impulsive stresses at loading poing of concentrated impact load under certain impact conditions determined by impact velocity, stiffness of plate and mass of impact body, etc. The impulsive stresses are analyzed by using the three dimensional dynamic theory of elasticity so as to analytically clarify the generation phenomenon of cone crack at the impact fracture of fragile materials (to be discussed if the second paper). The Lagrange's plate theory and Hertz's law of contact theory are used for the analysis of impact load, and the approximate equation of impact load is suggested to analyze the impulsive stresses at the impact point to decide the ranage of impact load factor. When impact load factors are over and under 0.263, approximate equations are suggested to be F(t)=Aexp(-Bt)sinCt and F(t)=Aexp(-bt) {1-exp(Ct)} respectively. Also, the inverse Laplace transformation is done by using the F.F.T.(fast fourier transform) algorithm. And in order to clarity the validity of stress analysis method, experiments on strain fluctuation at impact point are performed on a supported square glass plate. Finally, these analytical results are shown to be in close agreement with experimental results.

• Journal of Korean Society of Rural Planning
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• v.17 no.4
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• pp.1-11
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• 2011

This study analyzed push, pull motivation factors and satisfaction of visitors who visited Yangdong village in order to maintain, conserve and seek for effective utilization of this village. The result of this study was summarized as follows. Firstly, the result was that 'personal relations' has a positive impact on 'regional environment' and 'amenities', 'the pursuit of knowledge' has a positive impact on 'regional environment' and 'amenities' on the correlation between the visit motivation and the visit satisfaction. Secondly, 'the pursuit of knowledge' and 'the desire to new experience' have positive impact on the visit satisfaction on a part of the push factor generally. Physical environment was a only factor that has a positive impact on the visit satisfaction on a part of the pull factors. Thirdly, the intention of recommendation was a only factor to has a positive impact on the visit satisfaction on the correlation between the intention of return visit, recommendation and the visit satisfaction. It was proved that the intention of return visit was strongly associated with the intention of recommendation. This result of this study confirmed the important pull and push factor to enhance the tourist attraction of Yangdong village. It will be helpful to make the preliminary data for planning and conservation guidance of traditional village.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.543-553
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• 2015

This study analyzed that the impact of the bus use environment on users' stress in each step of bus use, from accessing to leaving to transfer, in the city of Daejeon. For this, we collected the stress data from 300 users using personal interviews at the bus stops and on-board bus. Also, we used factor analysis and structural equation model method for analysis of the impact of external and internal bus environments on stress of users. The results of this study showed that the highest stress impact factor was an onboard factor(${\beta}=.416$) including 'density and crowding', 'no seat to seat' and 'low ride comfort and safe'. The next stress impact factor was transfer factor including 'insufficient transfer information', 'lack of connectivity of bus and subway' and 'uncomfort transfer route'. From the above, we recommend that bus policies need to focus on not the supplier but users and also, this user based policy need to be more specified considering the characteristics of various users such as females, the elderly, irregular users, and so on.

• Structural Engineering and Mechanics
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• v.59 no.2
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• pp.277-290
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• 2016

This paper investigates the ground vibration induced by high-speed trains moving on multi-span continuous bridges. The dynamic impact factor of multi-span continuous bridges under trainloads was first determined in the parametric study, which shows that the dynamic impact factor will be large when the first bridge vertical natural frequency is equal to the trainload dominant frequencies, nV/D, where n is a positive integer, V is the train speed, and D is the train carriage interval. In addition, more continuous spans will produce smaller dynamic impact factors at this resonance condition. Based on the results of three-dimensional finite element analyses using the soil-structure interaction for realistic high-speed railway bridges, we suggest that the bridge span be set at 1.4 to 1.5 times the carriage interval for simply supported bridges. If not, the use of four or more-than-four-span continuous bridges is suggested to reduce the train-induced vibration. This study also indicates that the vibration in the train is major generated from the rail irregularities and that from the bridge deformation is not dominant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.730-736
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• 2016

In a previous study, the impact factor response spectrum and corresponding method for evaluating the load carrying capacity of bridges was suggested to improve the existing evaluation method. To verify the applicability of the suggested method, which is based on the frequency of bridges, the dynamic characteristic test for an actual single span simply-supported bridge was conducted. Through a field test under ambient traffic conditions, the dynamic response of the bridge was obtained using wireless accelometers and its fundamental frequency was identified. The peak impact factor was determined from the identified frequency and the impact factor response spectrum. The load carrying performance variation of the bridge was estimated considering the performance reduction factor, which was calculated using the current and previous natural frequency and impact factor. From the result, the load carrying capacity of the bridge was decreased, but the capacity was still enough because its value is greater than the design live load. Through the overall procedures and technical details presented in this paper, the suggested evaluation method can be applied to actual bridges with the acceleration data measured under ambient traffic conditions and the impact factor response spectrum.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.259-264
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• 2001

This paper presents impact factors of domestic journals in mechanical engineering area to present an objective data for journal evaluation. For this purpose, reference data of 47 Korean journals are databased and analyzed. From the developed database, impact factor, immediacy index and self citation index are calculated.