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In cities with high density, heat is often trapped between buildings which increases the frequency and intensity of heat events. Researchers have focused on developing strategies to mitigate the negative impacts of heat in cities. Adopting green infrastructure and cooling pavements are some of the many ways to promote thermal comfort against heat. The purpose of this study is to improve microclimate conditions and thermal comfort levels in high-density living conditions in Seoul, South Korea.

This study compares six design alternatives of an apartment complex with different paving and planting systems. It also examines the thermal outcome of the alternatives under normal and extreme heat conditions to suggest strategies to secure acceptable thermal comfort levels for the inhabitants. Each alternative is analyzed using ENVI-met, a software program that simulates microclimate conditions and thermal comfort features based on relationships among buildings, vegetation and pavements.

The results indicate that grass paving was more effective than stone paving in lowering air temperature and improving thermal comfort at the near-surface level. Coniferous trees were found to be more effective than broadleaf trees in reducing temperature. Thermal comfort levels were most improved when coniferous trees were planted in paired settings.

Landscape elements show promise for the improvement of thermal conditions because it is much easier to redesign landscape elements, such as paving or planting, than to change fixed urban elements like buildings and roads. The results identified the potential of landscape design for improving microclimate and thermal comfort in urban residential complexes.

The results contribute to the literature by examining the effect of tree species and layout on thermal comfort levels, which has been rarely investigated in previous studies.

This article uses a Kalman filter to fit yields of investment-grade corporate bonds to the model of instantaneous default risk, based on Duffee (1999. Review of Financial Studies. 12. PP. 197-226). The first part of this article fits the term structure of default-free interest rates to a translated two-factor square-root diffusion model. The parameters in the two-factor model are estimated by using a quasi-maxirnum-likelihood estimator in a state-space model in the Korean treasury bond market. A Kalman filter is used to estimate the unobservable factors.

The two-factor model successfully incorporates random variations in the slope of the term structure and the level of interest rates‘ After estimating the default-free term structure of interest rates, the second part of this article extends the model to noncallable corporate bonds‘ This is done by assuming that the probability of default follows a translated square-root diffusion process with the possibility of being correlated with default-free interest rates. The parameters of the process are estimated for investment-grade corporate bonds including AM. AA, A. and BBB. Empirical results show that the default risk is negatively correlated with default-free interest rates and confirm that the default risk is greater for lower grades. In addition, the estimated model successfully produces the term structures of credit spreads for corporate bonds and show that the credit spreads for lower grade bonds are more steeply sloped than those for higher grade bonds. These results show that Duffee's model can reasonably account for the observed corporate bond prices in the Korean bond market.

This paper proposes a method that estimates credit ratings by mapping empirical probability of default (PD) and standardized historical financial ratios. Unlike standard approaches such as the parametric logit model. discriminant analysis. neural network. and survival function model. the proposed approach has an advantage of offering a multiple credit rating categories. as opposed to either default or not default. of obligors. It would provide an useful information to practitioners because the probability of default for each credit rating category is a critical input under New Basel Capital Accord. Emoirical results based upon the historical PD and financial ratios of Korean savings bank industry from 2000 and 2003 suggest that the industry’s average credit rating belong to a speculative grade. that is BB and below.

In addition, the computed transition matrix indicates that volatility of transition matrix fluctuates substantially each year and the orobability of staying in the same rating category at the end of the year tended to be much smaller than the average reported by the rating agencies for the overall Korean companies. The proposed method can easily be applied to industries other than savings bank industry.

The purpose of this paper is to provide a model for quantitatively analyzing the security profile of an organization’s IT environment. The model considers the security risks associated with stored data, as well as services and devices that can act as channels for data leakages. The authors propose a sensitive information (SI) leakage vulnerability model.

Factors identified as having an impact on the security profile are identified, and scores are assigned based on detailed criteria. These scores are utilized by mathematical models that produce a vulnerability index, which indicates the overall security vulnerability of the organization. In this chapter, the authors verify the model result extracted from SI leakage vulnerability weak index by applying the proposed model to an actual incident that occurred in South Korea in January 2014.

The paper provides vulnerability result and vulnerability index. They are depends on SI state in information systems.

The authors identify and define four core variables related to SI leakage: SI, security policy, and leakage channel and value of SI. The authors simplify the SI leakage problem. The authors propose a SI leakage vulnerability model.

The purpose of this paper is to analyze maritime logistics connectivity of ports and shipping networks in the East Sea Economic Rim (ESER) to promote international trade in the context of China’s Belt and Road Initiative (BRI), considering centrality, primary flow and clustering interaction.

The paper applies a complex network model, using a big data system consisting of an automated identification system, electronic data interchange and distributive and complex data. Three perspectives, including connectivity in trading ports and regions, centralities in the realm of complex network and potential marketing and regional impacts, and sixteen criteria are considered for this analysis. A visual approach has been also applied to highlight port connectivity and ship flows for the reader’s convenience.

The paper shows that port connectivity and maritime logistics are enablers to promote Korean international trade in Northeast China through the ESER, and 25 major ports are well connected to promote international trade in the region with visual data of ship flows by ship type and by flag.

Owing to the lack of port management information systems among the countries in the ESER except Korea and Japan, this paper could not capture cargo types and amounts on board. Port connectivity analysis shows links of the ports in the ESER to major ports in southeast Asia along the Twenty-first Century Maritime Silk Road (MSR). These results contribute to drawing policy implications to promote the ESER and provide suggestions for promoting Korean international trade by enhancing maritime logistics connectivity.

Unlike the existing literature showing descriptive and policy-oriented research related to ESER, this paper applied a vigorous method with a big amount of data to analyze port connectivity and ship flows in the ESER, considering China’s BRI affecting the global supply chain system, maritime transportation, and logistics. In addition, the paper shows how the seaports in the ESER are connected along the MSR.

The rotor system supported by the cylindrical roller bearings is widely used in various fields such as aviation, space and machinery due to its importance. In the study of the dynamic characteristics of the cylindrical roller bearings, it is important to accurately calculate the stiffness of the cylindrical roller bearings. The stiffness of the cylindrical roller bearings is very important in the analysis of the vibration characteristics of the rotor system. Therefore, in this paper, the method of creating a comprehensive stiffness model of the cylindrical roller bearing is mentioned. The purpose of this study is to improve the dynamic stability of the rotor system supported by the cylindrical roller bearing by accurately establishing the comprehensive stiffness calculation model of the cylindrical roller bearings.

In consideration of the radial clearance of the cylindrical roller bearing, the radial load acting on the cylindrical roller bearing was derived, and based on this, a model for calculating the Hertz contact stiffness of the cylindrical roller bearing was created. Based on the load considering the radial clearance, an oil film stiffness model of the cylindrical roller bearing was created under the elastohydrodynamic lubrication (EHL) theory. Then, the comprehensive stiffness was calculated by combining Hertz contact stiffness and the oil film stiffness of the cylindrical roller bearing, and the dynamic parameters are calculated by using the MATLAB program.

When the radial clearance of the cylindrical roller bearing is considered, the comprehensive stiffness is larger than when the radial clearance is not taken into account, and the radial clearance of the cylindrical roller bearing is an important factor that directly affects the comprehensive stiffness of the cylindrical roller bearing.

In this paper, based on Hertz contact theory and the EHL theory, the authors investigated the method of creating a comprehensive stiffness model of the cylindrical roller bearing considering the radial clearance. These results will contribute to the theoretical basis for studying the mechanics of cylindrical roller bearings and optimizing their structures, and they will provide an important theoretical basis for analyzing the dynamic characteristics of the rotor system supported by the cylindrical roller bearing.

While the origin of Korean Industrial Relations goes back 150 years when the country opened its seaports to foreign countries, it didn’t emerge as a field of study until 1950s when academics began to write books and papers on the Korean labor movement, labor laws, and labor economics. In this paper, we sketch this history and describe important events and people that contributed to the development of industrial relations in Korea. Korean industrial relations in the early 20th century were significantly distorted by the 35-year-Japanese colonial rule (1910–1945). After regaining its independence, the U.S. backed, growth-oriented, military-based, authoritarian Korean government followed suit and consistently suppressed organized labor until 1987. Finally, the 1987 Great Labor Offensive allowed the labor movement to flourish in a democratized society. Three groups were especially influential in the field of industrial relations in the early 1960s: labor activists, religious leaders, and university faculty. Since then, numerous scholars have published books and papers on Korean industrial relations, whose perspectives, goals, and processes are still being debated and argued. The Korean Industrial Relations Association (KIRA) was formed on March 25, 1990 and many other academic and practitioner associations have also come into being since then. The future of industrial relations as a field of study in Korea does not seem bright, however. Issues regarding organized labor are losing attention because of a steadily shrinking unionization rate, changing societal attitude toward labor unions, and the enactment of new and improved laws and regulations regarding employment relationships more broadly. Thus, we suggest that emerging issues such as contingent workers, works councils and tripartite partnership, conflict management, and human rights will be addressed by the field of industrial relations in Korea only if this field breaks with its traditional focus on union and union–management relations.