• The Korean Journal of Malacology
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• v.27 no.4
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• pp.345-351
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• 2011

Comparison of different morphological characteristics of bivalves is very useful for distinguishing species. Therefore, this study used a morphometric approach to document patterns of phenotypic change through the specimens of family Pinnidae inhabiting the bottom sediments at the coasts of An Thoi Archipelago (south-eastern Gulf of Thailand), in that way excluding intraspecific variations among different populations along a wide geographical range. It was revealed that individuals determined as Pinna trigonium separated from specimens of Pinna nigra and Atrina vexillum at high level, but P. nigra and A. vexillum were the single species A. vexillum, as it is assumed now. Also, it was found that both groups of P. trigonium individuals and A. vexillum specimens divided into tree subgroups unified the specimens with the similar morphometric parameters: small, medium and large within the populations, though there were no evident divisions into subgroups in the size distributions of the populations. In addition to the interspecific morphological variations, the species also showed significant intraspecific morphological variations even in the same population. Most probable reason for the appearance of the intraspecific morphological variations and division of all specimens into size-specific subgroups in the population is the fact that the growth of Pinnidae bivalves is not isometric.

• Structural Monitoring and Maintenance
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• v.5 no.3
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• pp.363-377
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• 2018

The proper functioning of critical points on transport infrastructure is decisive for the entire network. Tunnels and bridges certainly belong to the critical points of the surface transport network, both road and rail. Risk management should be a holistic and dynamic process throughout the entire life cycle. However, the level of risk is usually determined only during the design stage mainly due to the fact that it is a time-consuming and costly process. This paper presents a simplified quantitative risk analysis method that can be used any time during the decades of a tunnel's lifetime and can estimate the changing risks on a continuous basis and thus uncover hidden safety threats. The presented method is a decision support system for tunnel managers designed to preserve or even increase tunnel safety. The CAPITA method is a deterministic scenario-oriented risk analysis approach for assessment of mortality risks in road tunnels in case of the most dangerous situation - a fire. It is implemented through an advanced risk analysis CAPITA SW. Both, the method as well as the resulting software were developed by the authors' team. Unlike existing analyzes requiring specialized microsimulation tools for traffic flow, smoke propagation and evacuation modeling, the CAPITA contains comprehensive database with the results of thousands of simulations performed in advance for various combinations of variables. This approach significantly simplifies the overall complexity and thus enhances the usability of the resulting risk analysis. Additionally, it provides the decision makers with holistic view by providing not only on the expected risk but also on the risk's sensitivity to different variables. This allows the tunnel manager or another decision maker to estimate the primary change of risk whenever traffic conditions in the tunnel change and to see the dependencies to particular input variables.

• Smart Structures and Systems
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• v.15 no.4
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• pp.931-947
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• 2015

This paper focuses on the design of an intelligent control system. The used techniques are based on Neuro Fuzzy approaches applied to a magnetorheological damper in order to reduce the vibrations over footbridges; it has been applied to the Science Museum Footbridge of Valladolid, particularly. A model of the footbridge and of the damper has been built using different simulation tools, and a successful comparison with the real footbridge and the real damper has been carried out. This simulated model has allowed the reproduction of the behaviour of the footbridge and damper when a pedestrian walks across the footbridge. Once it is determined that the simulation results are similar to real data, the control system is introduced into the model. In this sense, different strategies based on Neuro Fuzzy systems have been studied. In fact, an ANFIS (Artificial Neuro Fuzzy Inference System) method has also been used, in addition to an alternative Neuro Fuzzy approach. Several trials have been carried out, using both techniques, obtaining satisfactory results after using these techniques.

• Spatial Information Research
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• v.11 no.4
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• pp.453-464
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• 2003

The Competitive power of the country in knowledge information can be determined that how efficiently useful knowledge and information can be circulated. Korean government established the second National GIS Master Plan, and constructed National Geographic Information Clearinghouse to the goal 'whole nation's internet circulation of the geographic information and practical use'. But every departments of government are trying to circulate their geographic information individually, And this case, consumer group should approach to several dissemination network in various routing line to get the geographic information. In fact, it is difficult to present the solution for uilified single dissemination network. It is difficult to present suitable linkage plan coinciding in special environment and characteristics of all systems. Consequently, in this study, we suggested linkage element that should consider far link with National Geographic Information Clearinghouse, and presented linkage plan by linkage target type.

• Structural Engineering and Mechanics
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• v.43 no.2
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• pp.239-251
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• 2012

The analysis of laterally loaded piles is generally carried out by idealizing the soil mass as Winkler springs, which is a crude approximation; however this approach gives reasonable results for many practical applications. For more precise analysis, the three- dimensional finite element analysis (FEA) is one of the best alternatives. The FEA uses the modulus of elasticity $E_s$ of soil, which can be determined in the laboratory by conducting suitable laboratory tests on undisturbed soil samples. Because of the different concepts and idealizations in these two approaches, the results are expected to vary significantly. In order to investigate this fact in detail, three-dimensional finite element analyses were carried out using different combinations of soil and pile characteristics. The FE results related to the pile deflections are compared with the closed-form solutions in which the modulus of subgrade reaction $k_s$ is evaluated using the well-known $k_s-E_s$ relationship. In view of the observed discrepancy between the FE results and the closed-form solutions, an improved relationship between the modulus of subgrade reaction and the elastic constants is proposed, so that the solutions from the closed-form equations and the FEA can be closer to each other.

• Korean Journal of Materials Research
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• v.20 no.1
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• pp.42-46
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• 2010

Phosphorus exhibits considerable segregation in steelmaking slag. In order to recover phosphorus from slag to $K_3PO_4$ via molten iron, a carbothermic reaction using microwave heating was suggested recently. The carbothermic reduction of phosphorus from slag to molten iron using microwave heating was carried out at 2073K. However, at this temperature the thermodynamic properties of both slag and molten iron cannot be determined experimentally. Therefore, the computational approach of the so-called CALPHAD method is very useful to understand the transfer of phosphorus from slag to metal and to enhance this reaction. In the present investigation, a theoretical study of the reduction behavior of phosphorus in slag was carried out at much lower temperatures using the recently developed thermodynamic database in the FactSage program. The calculated results showed reasonable accordance with the experimental data; namely, the thermodynamic database could be applied successfully to higher temperature reactions. The current study found that higher temperature and high $SiO_2$ concentration are favorable for the recovery of phosphorus from slag.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.231-246
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• 2023

Purpose - This study attempts to provide a new theoretical perspective on the quality signaling and its impact on a market under information asymmetry, focusing on how the accuracy and the cost of quality signaling affect sellers' and buyers' profit, suggesting appropriate designs of quality signaling methods which mitigates information asymmetry. Design/methodology/approach - In order to examine the effect of quality signaling on strategic interactions within the market, we establish an analytic model where market outcomes are determined by seller's quality claim and price, and buyers are risk-neutral. By investigating this analytic model through relevant game trees, we find the subgame perfect Nash equilibria of the market and predict related market outcomes based on sellers' quality signaling strategy. Findings - Our analytic model shows counterintuitive results that seller profit will be the lowest with inaccurate quality signaling and the highest with no quality signaling, mostly due to the certification cost. Consequently, sellers should proceed with caution if the quality signaling is less than accurate, as it may backfire. We believe that this is due to the fact that the inaccuracy of quality signaling causes some confusion and uncertainty in both sellers and buyers' decision to maximize profit, making it hard for sellers to predict buyers' behavior. Research implications or Originality - Although the sources and types of quality signaling errors have been investigated in the literature, there has not been satisfactory understanding regarding how inaccuracy of quality certification affects specific market outcomes. We expect that our theoretical model would provide important implications on how to utilize quality signaling to solve adverse selection issues in markets under information asymmetry.

• Journal of Families and Better Life
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• v.5 no.2
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• pp.65-82
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• 1987

Product characteristic approach and hedonic method were explained and applied to demand behavior of housing for 360 households sampled from four districts of Seoul. Th major findings are: 1) Housing prices are determined by housing characteristics, i.e., basic structure, interior space, interior quality, and neighborhood quality. 2) as income increase , the demand for basic structure, interior space, interior of quality, and neighbor hood quality increases. As compared to the counties that have advanced housing financial systems, income elasticity form housing characteristics was low. 3) householder's educational level has insignificant effects on the demand for neighborhood quality. 4) the housing need of family is different to a family life cycle. In the first stage, the increase of income enhances the demand for basic structure. interior space, and interior quality, but inversed with neighborhood quality. In the second and third stages, the demand for basic structure, interior space, and interior quality increases as the income increases. 5) It is predicted that the larger the family size, the more housing space is required. But in the low-income group, an increase in family size results in a decrease in the demand for interior space because expenses for food and education are indispensable ones. In the middle -income group the demand for interior space, interior quality increases as the family size increases, In the high-income group, the larger the family size the more interior quality is demanded. As mentioned above, the demand for housing is derived form characteristics and the demand behavior far housing characteristics is varied with individual household's characteristics. Therefore, the fact that different housing needs according to various income groups should be considered in housing policy.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.7-16
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• 2015

PURPOSES : This study was performed to determine a systematic approach for measuring the coefficient of thermal expansion (COTE) of concrete specimens. This approach includes the initial calibration of measurement equipment. Test variables include coarse aggregate types such as natural aggregate, job-site produced recycled concrete aggregate, and recycled aggregate processed from an intermediate waste treatment company. METHODS : First, two cylindrical SUS-304 specimens with a known COTE value of $17.3{\times}10^{-6}m/m/^{\circ}C$. were used as reference specimens for the calibration of each measurement system. The well-known AASHTO TP-60 COTE apparatus for concrete measurement was utilized in this study. Four different measurement apparatuses were used with each LVDT installed and a calibration value was determined using each measurement apparatus. RESULTS : In the initial experimental stage, calibration values for each measurement apparatus were assumed to be almost identical. However, using the SUS-304 samples as a reference, the calibration values for the four different measurement apparatuses were found to range from 3.49 to $8.86{\times}10^{-6}m/m/^{\circ}C$. Using different adjusted values for each measurement apparatuses, COTE values for the three different concrete specimens were obtained. The COTE value of concrete made with natural coarse aggregate was $9.91{\times}10^{-6}m/m/^{\circ}C$, that of job-site produced recycled coarse aggregate was $10.45{\times}10^{-6}m/m/^{\circ}C$, and that of recycled aggregate processed from the intermediate waste treatment company was $10.82{\times}10^{-6}m/m/^{\circ}C$. CONCLUSIONS : We observed that the COTE value of concrete made from recycled concrete aggregates (RCA) was higher than that of concrete made from natural coarse aggregate. This difference is due to the fact that the total volumetric mortar proportion in the RCA mix is higher than that in the concrete mix made with natural coarse aggregate.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.18-29
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• 2016

For most organizations, a security infrastructure to protect company's core information and their technology is becoming increasingly important. So various approaches to information security have been made but many security accidents are still taking place. In fact, for many Korean companies, information security is perceived as an expense, not an asset. In order to change this perception, it is very important to recognize the need for information security and to find a rational approach for information security. The purpose of this study is to present a framework for information security strategies of companies. The framework classifies companies into eight types so company can receive help in making decisions for the development of information security strategy depending on the type of company it belongs to. To develope measures to classify the types of companies, 12 information security professionals have done brainstorming, and based on previous studies, among the factors that have been demonstrated to be able to influence the information security of the enterprise, three factors have been selected. Delphi method was applied to 29 security experts in order to determine sub items for each factor, and then final items for evaluation was determined by verifying the content validity and reliability of the components through the SPSS analysis. Then, this study identified characteristics of each type of eight companies from a security perspective by utilizing the developed sub items, and summarized what kind of actual security accidents happened in the past.