• International Journal of Highway Engineering
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• v.14 no.2
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• pp.131-143
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• 2012

The past researches on roadway segment safety estimation focused on intersections, which are the primary traffic accident regions. The past researches on roadway segments, However, analyzed the effects of certain factors on the traffic accident occurrence rate by organizing the individual geometric structures of the roads, and there is still a dearth of researches on the development of a traffic accident estimation model for rural roadway segments. Therefore, this research focused on rural two-lane and multilane roadway segments and developed traffic accident estimation models through the application of statistical techniques. This is required to explain such high frequency of zero counts in the traffic accident data. In this research, it was found that the Hurdle model is more suitable than the Poisson or negative binomial-regression model for explaining the excess zeros case. In addition, main variables were chosen to estimate their effects on traffic accident occurrence at rural roadway segments, and the safety at such rural roadway segments was estimated. In this research, it was assumed that there are different factors that affect the safety at two-way lane and multilane roadway segments, and a traffic accident estimation model was developed by dividing the two-way lane and multilane roadway segments.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.211-219
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• 2015

Objectives: We aimed to examine the association between experience of workplace violence and musculoskeletal pain among wage workers in South Korea. Methods: We analyzed a cross-sectional survey of 29,601 wage workers from the third wave Korean Working Conditions Survey in 2011. Experience of workplace violence was assessed through three questions, "Over the past 12 months, have you ever experienced: (1) physical violence, (2) bullying, or (3) sexual harassment at workplace?" Musculoskeletal pain was measured using the three questions, "Over the past 12 months, have you ever experienced: (1) low back pain, or (2) upper limb pain(i.e. shoulder, neck, and arm), or (3) lower limb pain(i.e. hip, leg, knee, and foot)?" Wage workers could answer 'Yes' or 'No' to each of the three questions. Multivariate negative binomial regression was applied to examine the association between workplace violence and musculoskeletal pain after adjusting for confounders including self-reported physical work factors. All analyses were performed using STATA/SE version 13.0. Results: Physical violence was associated with low back pain(PR: 2.16, 95% CI: 1.77, 2.65), upper(PR: 1.65, 95% CI: 1.45, 1.88) and lower limb pain(PR: 1.81, 95% CI: 1.52, 2.15) among male wage workers whereas it was related to upper(PR: 1.86, 95% CI: 1.53, 2.26) and lower limb pain(PR: 2.95, 95% CI: 2.47, 3.53) among female wage workers. Significant association was observed between sexual harassment and upper(PR: 1.25, 95% CI: 1.01, 1.56) and lower limb pain(PR: 2.41, 95% CI: 1.97, 2.93) among female wage workers whereas the association was only significant in the analysis with lower limb pain(PR: 1.87, 95% CI: 1.17, 2.97) among male wage workers. Bullying was associated only with lower limb pains among both male(PR: 1.77, 95% CI: 1.32, 2.37) and female(PR: 2.10, 95% CI: 1.69, 2.61) wage workers. Conclusions: This study found that experience of workplace violence, particularly physical violence and sexual harassment, was associated with musculoskeletal pain among Korean wage workers.

• Journal of Digital Convergence
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• v.9 no.6
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• pp.173-186
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• 2011

In this study, the influence of the CEOs' characteristics on the technology innovation performances of IT venture companies was analyzed. The relation between business performance and the characteristics of CEOs has been dealt with in earlier studies, but most paid attention to financial perspective, and few of these focused on the influence of managers on technology innovation. On the other hand, most of the studies related to the role of managers in technology innovation mainly focused on R&D investment and research infrastructure but did not delve on the characteristics of them in an in-depth way. In this study, the characteristics of CEOs and their technology innovation performances were empirically analyzed based on the results of a recently conducted survey on the IT venture companies. In the analytical aspect, a negative binominal model was applied to solve the over-dispersion problem that often appears in the count variable analysis. As a result, it was found that major, work type, and work experience, among managers' characteristics, have significant influences on managers' technology innovation performances, along with the company's innovation capacity, technological competitiveness, market competition, and support from the government.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.84-92
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• 2019

The deterioration of the urban heat environment due to climate change and the occurrence of heat-related diseases have emerged as one of the major social problems. This has led to more research on climate change, including heat waves, but it is mainly focused on climate factors. However, the urban heat island phenomenon accelerates the summer heat wave, and the increasing trend of heat-related patients in urban areas suggests the impact of the city's environment. Thus, this study analyzed the effects of physical and social characteristics of urban areas on heat-related patients in Seoul and Gyeonggi-do. The analysis showed that the ratio of the total area of residential, commercial and industrial facilities, the main source of heat energy locality, among the land use statuses, was not statistically significant, but the road area and the green area were found to have a positive and negative The population density and the percentage of people aged 65 or older, the percentage of people living alone and the proportion of people receiving basic living were all shown to be significant, with only the ratio of elderly living alone and the ratio of population density having negative effects. The results of the study can be used to develop urban policy alternatives related to local warming patients.

• Strategy21
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• s.46
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• pp.123-157
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• 2020

This research focuses on one important type of non-traditional threat, maritime piracy, and tries to supplement previous research from the perspective of military power, especially naval power. When considering the elements of military power, naval power is a core independent variable to explain piracy incidents. Indeed, naval power can play a key role in solving piracy problems, since naval power is the only legitimate force to respond to piracy in the sea. It is natural that well equipped and trained naval power in the sea increases the probability of capturing pirates, which leads to increasing the costs of piracy and decreasing its occurrences. In addition, since naval combatant ships have more impressive weapons than those of pirate boats, just the presence of naval combatant ships could serve to deter piracy incidents in the sea. The main purpose of this research is finding the effectiveness of large multinational naval efforts to deter piracy incidents in Africa. With this research purpose, I analyze 771 piracy incidents that occurred in African states from 2009 to 2014. Furthermore, I include all 33 coastal states in Africa regardless of the experiences of piracy incidents in order to avoid selection bias, which is very common in quantitative-based piracy incidents research. The dependent variable of this research is frequency of maritime piracy incidents for a country-year and the independent variable is the number of multi-national naval warships that operate near Somalia. With this analysis, I find the large number of multi-state naval combatant ships are negatively related to piracy incidents. In other words, as a main means to counteract piracy incidents, multi-state naval combatant ships are conducive to reduce piracy incidents near Somalia, since it increases costs (being captured) of conducting piracy.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.74-83
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• 2017

The recently introduced public rental housing REITs was just different the business structure from the existing public rental housing system and the basic supply system is the same. So the ownership conversion for public house over 10 years rental duration is possible after half of the obligated rental duration according to the agreement between lessor and lessee. However rental business operators are likely to have a negative attitude to the early ownership conversion because of less expected profit. Thus, there is a need for an analysis of proper early ownership conversion moment that can achieve public purposes while ensuring the profitability of public rental housing REITs. In this study, the characteristics of the ownership conversion rights that can lessee to exercise considered to be options. Also the nature of 'REITs', 'public rental housing REITs' is considered to be affected by the macroeconomic variables. Thus, this study analyzed the value for ownership conversion in the public rental housing REITs according to real option scenarios reflecting macroeconomic variables. As a result, according to the change of the variation rate of the macroeconomic variables, it was found that with adjustable early ownership conversion time using the DCF(Discounted Cash Flow) model. Therefore, it is possible to ensure profitability of early ownership conversion by predicting the variation of variables.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.343-353
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• 2011

The unsignalized intersections in a community road in the city of Seoul have 3,753 traffic accidents(9%) of total 41,702 cases in 2008, not high in the occurrence rate of traffic accidents, but seem to have a quite high potential of accidents due to the unreasonable and insufficient operation of systems and facilities in the part of traffic foundations. In particular, the un-signalized intersections in a community road have an insufficient measure for safety as compared to the crossroads with signals, and there are few analysis of traffic accidents and domestic researches on the model of affecting factors. Our country also has no concept of passing priority in operating a crossroad without signals, differently from foreign countries, so the researches and safety measures for improving the safety of a crossroad without signals in a community road are urgent. Therefore, This study set out to analyze the road conditions, traffic conditions, and traffic environment conditions on unsignalized intersection, to identify the elements that would impose obstructions in safety, and develop a traffic accident prediction model to evaluate the safety of an unsignalized intersection using the correlation between the elements and an accident. In addition, the focus was made on suggesting appropriate traffic safety policies by dealing with the danger elements in advance and on enhancing the safety on intersection in developing a traffic accident prediction model for an unsignalized intersection.

• Journal of Korea Port Economic Association
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• v.28 no.3
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• pp.235-257
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• 2012

Recently the role of ports has been changed to satisfy flexibly needs of demands in global economy. A new concept for ports is not just a place for international trade but an important nodal point in logistics chain. The changing environment like this trend creates a high degree of uncertainty and leaves port managers confused with the question how to respond effectively to dynamic market. The latest studies provide that the port must have a good hinterland to achieve competitive advantages in a logistics chain. Korean Government announced "The Master Development Plan for Port Logistics Parks in Korea" in 2006. This contains the plan of hinterland construction of Busan New Port to achieve the status of logistics hub in Asian market. Previous studies rely solely on traditional DCF(discounted cash flow) analysis for investment of hinterland. However DCF method does not include irreversibility, uncertainty and the choice of timing for investment project. This thesis introduces a ROPM(real options pricing model) which overcomes the limitations of traditional valuation methods. The option valuations in this study utilize the Black-Scholes model, the binomial model and the MonteCarlo simulation to value investment opportunity of a port hinterland. In this thesis, an attempt is made to modify the NPV criterion by incorporating the real options approach, and its application is demonstrated in a hinterland construction investment plan. This research has conducted an empirical analysis by calculating economic value of the investment for a hinterland of Busan New Port.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.1
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• pp.269-281
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• 2018

Many organizations are threatened by numerous information security attacks which are resulting in information security incidents. To prevent information security incidents, organizations invest on various information security measures like information security products, monitoring services and security training and educations. However they do not have enough knowledge about measurable utilities of information security investments. Since there is little studies empirically examining the effect of information security investments, this research aims to find out utilities of information security investment. We especially focuse on information security service investments. This study examined the data from the survey on information security for business sector which was conducted by Korean information & security agency. We utilized negative binomial regression model, which is a suitable model for over-dispersed count data. We found out that an investment on information security education and vulnerability testing have direct impact on reducing information security incidents. This research academically contributed to shed light on the utility of information security investments on reducing information security incidents. This research practically contributed to providing information security investment guideline for organizations which want to reduce information security incidents efficiently.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.107-116
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• 2002

Crash Cushion is a kind of safety facilities on roadside which acts the role of absorbing impact energy when vehicles are driven out of normal route such as Gore area of freeway off ramp. Criteria for severity index considering accident occurrence possibility are needed to have strong effect on installing the facilities. However, present criteria for establishing crash cushion design do not include such processes. Therefore, the paper presents two kinds of study to develop criteria for severity index. First of all, development of accident forecasting model on freeway off ramp is presented. The module is a relationship between accidents and road environment by negative binomial distribution (NB) which is called to reflect very well quality of accidents at Gore of crash cushion installed freeway Secondly, freeway exiting behavior model is developed because the human factor is the most important one. However, many literatures have shown between road environment and accidents which are more quantitative than human factor. The study supposed advanced process steps on actual freeway and analysed correlation between variables and accidents. The criteria for severity index is presented to determine whether to install or not by benefit cost analysis for each module. The standard for severity index will help to determine whether to install the crash cushion or not and to estimate severity for freeway and off ramp.