• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.870-873
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• 2014

Green roof systems has widely been used on rooftop of buildings by considering environmental benefits in aspects of bio-diversity, storm-water runoff as well as noise reduction. To predict noise reduction effect by green roof systems, it is necessary to measure in-situ acoustical properties of the components by devices enabling in-situ measurements. In this study, Micro-flown, which is the state of the arts device to measure in-situ normalized impedance and absorption coefficient has been used to measure acoustical properties of green roof materials according to different water saturation condition in the materials.

• Korean journal of communication and information
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• v.61
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• pp.98-117
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• 2013

In 2009, Korea Communications Commission(KCC) added a new clause which regulates the protection of the media diversity to the Broadcasting Act. Specifically, the provision, Article 35-4, contains the creation of the Media Diversity Committee which is responsible for (1) the measure of TV audience share by media company; and (2) the development of summing up index of the different media influence by the end of 2012. Although the Korean version of diversity index as German KEK was made after a careful consideration based on the necessity to devise a criterion to determine the appropriate level of ownership regulation for the media companies, several issues including the measurement method have been raising the consistent controversy among experts. This study focuses on the evaluation of the media diversity policy by indicating the problems of the devised index and showing the concrete issues of the contention. As the result of the policy delphi-analysis targeted 10 media experts, this study suggest that the Article 35-4 of Broadcasting Act needs to be amend into the realistic and rational directions in well with the tenets of the law.

• Asia pacific journal of information systems
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• v.33 no.2
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• pp.261-281
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• 2023

The proliferation of online customer reviews has completely changed how consumers purchase. Consumers now heavily depend on authentic experiences shared by previous customers. However, deceptive reviews that aim to manipulate customer decision-making to promote or defame a product or service pose a risk to businesses and buyers. The studies investigating consumer perception of deceptive reviews found that one of the important cues is based on review content. This study aims to investigate the impact of the information amount of review on the review truthfulness. This study adopted the Information Manipulation Theory (IMT) as an overarching theory, which asserts that the violations of one or more of the Gricean maxim are deceptive behaviors. It is regarded as a quantity violation if the required information amount is not delivered or more information is delivered; that is an attempt at deception. A topic modeling algorithm is implemented to reveal the distribution of each topic embedded in a text. This study measures information amount as topic diversity based on the results of topic modeling, and topic diversity shows how heterogeneous a text review is. Two datasets of restaurant reviews on Yelp.com, which have Filtered (deceptive) and Unfiltered (genuine) reviews, were used to test the hypotheses. Reviews that contain more diverse topics tend to be truthful. However, excessive topic diversity produces an inverted U-shaped relationship with truthfulness. Moreover, we find an interaction effect between topic diversity and reviews' ratings. This result suggests that the impact of topic diversity is strengthened when deceptive reviews have lower ratings. This study contributes to the existing literature on IMT by building the connection between topic diversity in a review and its truthfulness. In addition, the empirical results show that topic diversity is a reliable measure for gauging information amount of reviews.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.181-193
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• 2020

This study examines the relationship between gender diversity (women on the board and women on the audit committee) and a firm's financial stability. The ordinary least square analysis was used to determine the relationship. To measure the financial stability of Malaysian suspect firms, i.e., firms with the lowest positive earnings, the Altman (1993) Z-Score measurement was utilized. The results indicate that women on the board are significantly and negatively associated with the firm's financial stability. That is, they are related to low financial stability, which contradicts the agency and resource dependence theories. Regarding women directors on the audit committee, there is no significant relationship with financial stability, meaning that they cannot protect the company against financial distress. These results are robust and do not change when using different measurements of gender diversity, one-year lag of independent variables, and other methods of analysis, namely random effect panel data. This study is the first to alert policymakers, stakeholders, researchers, and society in general to the need to re-evaluate and strengthen the role of women directors in improving firms' financial stability, particularly in emerging economies like Malaysia.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.2
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• pp.146-151
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• 2010

This paper proposes a rank-based control method of mutation probability for improving the performances of genetic algorithms (GAs). In order to improve the performances of GAs, GAs should not fall into premature convergence phenomena and should also be able to easily get out of the phenomena when GAs fall into the phenomena without destroying good individuals. For this, it is important to keep diversity of individuals and to keep good individuals. If a method for keeping diversity, however, is not elaborately devised, then good individuals are also destroyed. We should devise a method that keeps diversity of individuals and also keeps good individuals at the same time. To achieve these two objectives, we introduce a rank-based control method of mutation probability in this paper. We set high mutation probabilities to lowly ranked individuals not to fall into premature convergence phenomena by keeping diversity and low mutation probabilities to highly ranked individuals not to destroy good individuals. We experimented our method with typical four function optimization problems in order to measure the performances of our method. It was found from extensive experiments that the proposed rank-based control method could accelerate the GAs considerably.

• Journal of Intelligence and Information Systems
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• v.16 no.1
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• pp.93-116
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• 2010

Ensemble approach is applied to the detection modeling of illegal cash accommodation (ICA) that is the well-known type of fraudulent usages of credit cards in far east nations and has not been addressed in the academic literatures. The performance of fraud detection model (FDM) suffers from the imbalanced data problem, which can be remedied to some extent using an ensemble of many classifiers. It is generally accepted that ensembles of classifiers produce better accuracy than a single classifier provided there is diversity in the ensemble. Furthermore, recent researches reveal that it may be better to ensemble some selected classifiers instead of all of the classifiers at hand. For the effective detection of ICA, we adopt ensemble size reduction technique that prunes the ensemble of all classifiers using accuracy and diversity measures. The diversity in ensemble manifests itself as disagreement or ambiguity among members. Data imbalance intrinsic to FDM affects our approach for ICA detection in two ways. First, we suggest the training procedure with over-sampling methods to obtain diverse training data sets. Second, we use some variants of accuracy and diversity measures that focus on fraud class. We also dynamically calculate the diversity measure-Forward Addition and Backward Elimination. In our experiments, Neural Networks, Decision Trees and Logit Regressions are the base models as the ensemble members and the performance of homogeneous ensembles are compared with that of heterogeneous ensembles. The experimental results show that the reduced size ensemble is as accurate on average over the data-sets tested as the non-pruned version, which provides benefits in terms of its application efficiency and reduced complexity of the ensemble.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.39-50
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• 2015

This research selected Daegu Metropolitan City representing a combination of natural space and urban space for this case study. To achieve this, a prerequisite was to set up an optimal block size to evaluate landscape diversity of the research site by using a RPR-Area Curve. Further, landscape diversity evaluation was conducted based on land cover map by using FRAGSTATS to analyze spatio-temporal changes. Notably, this research regarded it as the most significant to set forth criteria in order to apply landscape diversity to the development plans of the newtown and outskirt of a city under high pressure development. Results derived from this research are summarized as follows. According to the results derived from establishing the optimal block size, a size about $2km^2$ was analyzed to measure landscape diversity of the research site. Also, according to the results derived from land diversity evaluation based on land cover map, land diversity was highly measured around urban stream such as Nakdong River and Geumho River, and in particular, the value of landscape diversity was measured considerably high around the urban parks. Results derived from analysis on spatio-temporal changes of land diversity demonstrated that a certain level of urban development exerted a positive effect on an increase in land diversity, but consistent urban development lowered a value of landscape diversity. Results derived from regression analysis to set forth the optimal urban space showed that an urban area of a space about $2km^2$ exerted a positive effect at a rate of about 0~43.3% and a negative effect at a rate about 43.3~100%. In conclusion, the results of this research are considered to provide important basic data for future urban and landscape planning. Nonetheless, as only the layout on the 2D plane was analyzed in this research, further research in future is required to complexly consider diverse factors such as height of structure and change in visible real area arising from geographical features.

• Journal of Environmental Impact Assessment
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• v.19 no.3
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• pp.347-356
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• 2010

Forests are being seriously fragmented as a result of land development. Land development with disregard to its subsequent environmental impacts is a primary threat to biodiversity by incurring massive habitat losses and changes in structure and composition of forests. The purpose of this study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest species to determine degree of impact from land development. The edge effect of forest fragmentation on the number of bird species, population size, and bird diversity was obvious. In particular, the bird diversity sharply declines around the forest edge where intensive land development projects take place. To assess the disturbance of forest species, the factors selected were the bird diversity and the rate of edge species. The impact assessment model about bird diversity was explained by type of forest fragmentation and type of vegetation ($R^2$=0.23, p<0.005). The other model about edge species explained by a distance, type of forest fragmentation, type of vegetation, and width of road ($R^2$=0.34, p<0.001). In order to test the applicability of the model developed in this study, the models was applied to the Samsong housing development in Goyang-si, Gyunggi-do. The impacts of land development on the bird species were reasonably quantified to suggest effective mitigation measure. The impact assessment model developed in this study is useful to assess the magnitude of disturbance of bird species. Particularly, the model could be applied to the current Environmental Impact Assessment practices to predict and quantify the impacts of land developments projects on forest bird species.

• Korean Journal of Plant Taxonomy
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• v.45 no.1
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• pp.29-35
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• 2015

Sasa borealis (Hack.) Makino & Shibata is widely distributed in South Korea. With amplified fragment length polymorphism (AFLP) markers, we analyzed the genetic diversity of S. borealis to predict and measure the phytogeographical factors of these populations. Relatively high levels of genetic diversity (PPL = 37.2%, h = 0.143, I = 0.205) and genetic differentiation ($G_{ST}$ = 0.324, ${\theta}^B$ = 0.395) were confirmed in populations of S. borealis. Moreover, an analysis of molecular variance (AMOVA) showed that the rate of differentiation among the populations was 47.7%. The results showed that genetic diversity is inversely proportional to the latitude of the S. borealis populations, indicating that the distribution of S. borealis may have extended from lower to higher latitudes. This method of investigating the correlation between genetic diversity and latitude presents critical information for estimating changes in distributions and plant conservation due to climate change.

• Animal cells and systems
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• v.16 no.4
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• pp.321-328
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• 2012

The oily bittering Acheilognathus koreensis is a freshwater species that is endemic to Korea and is experiencing severe declines in natural populations as a result of habitat fragmentation and water pollution. For the conservation and restoration of this species, it is necessary to assess its genetic diversity at the population level. We developed 13 polymorphic microsatellite loci that were used to analyze the genetic diversity of two populations collected from the Kum River and the Tamjin River in Korea. All loci exhibited Mendelian inheritance patterns when examined in controlled crosses. Both populations revealed high levels of variability, with the number of alleles ranging from 3 to 20 and observed and expected heterozygosities ranging from 0.500 to 0.969 and from 0.529 to 0.938, respectively. None of the loci showed significant deviation from Hardy-Weinberg equilibrium, and one pair of loci showed significant linkage disequilibrium after Bonferroni correction. Pairwise $F_{ST}$ and genetic distance estimation showed significant differences between two populations. These results suggest that the microsatellites developed herein can be used to study the genetic diversity, population structure and conservation measure of A. koreensis.