• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.41 no.1
• /
• pp.75-83
• /
• 2021

Over-urbanization has contributed to the increase in traffic problems. This makes the need for effective road planning and design more important than ever. I have been able to learn how to build a new road, and how to use it. However, in spite of the importance of good road planning, there are no systematic standards or methods for calculating traffic volume on railroad routes. Therefore, in this study, to strengthen the competitiveness of railroads, the concept of line capacity is introduced to railroads, and a clear standard and method for calculating railroad line capacity are presented. Based on the results, the line capacity of main railway lines for domestic railways was calculated. By applying the method of calculating the line capacity presented in this study, the capacity of existing railway lines and newly expanded routes can be calculated. It is expected that our findings will be able to provide systematic standards that can be applied to yield a more effective investment and design planning stage; the findings will also help improve the efficiency of railroad operation.

• Maritime Security
• /
• v.2 no.1
• /
• pp.151-184
• /
• 2021

Global warming due to climate change is one of the biggest challenges in the 21st century. Global warming is not only a disaster that threatens the global ecosystem but also an opportunity to reduce logistics costs and develop mineral resources by commercializing Arctic routes. The Arctic paradox, in which ecological and environmental threats and new economic opportunities coexist, is expected to have a profound impact on the global environment. As the glaciers disappear, routes through the Arctic Ocean without passing through the Suez and Panama Canals emerged as the 'third route.' This can reduce the distance of existing routes by 30%. Global warming has also brought about changes in the geopolitical paradigm. As Arctic ice begins to melt, the Arctic is no longer a 'constant' but is emerging as the largest geopolitical 'variable' in the 21st century. Accordingly, the Arctic, which was recognized as a 'space of peace and cooperation' in the post-Cold War era, is now facing a new strategic environment in which military and security aspects are emphasized. After the Cold War, the Arctic used to be a place for cooperation centered on environmental protection, but it is once again changing into a stage of competition and confrontation between superpowers, heralding 'Cold War 2.0.' The purpose of this study is to evaluate the strategic value of the Arctic Ocean from geopolitical and geoeconomic perspectives and derive strategic implications by analyzing the dynamics of the New Cold War taking place in the Arctic region.

• Journal of Korea Port Economic Association
• /
• v.36 no.4
• /
• pp.53-74
• /
• 2020

It is important to understand the current status and problems of the North Korean shipping industry to prepare for inter-Korean trade in the future era of peace in the Korean Peninsula. In this study, the status of vessels calling in North and South ports was analyzed by year, cargo type (vessel type), and North Korean port type using Port-MIS data. In particular, considering the three years (2006-2008) in which inter-Korean trade was the most active, the flow of maritime transport was analyzed by visualizing data on vessels' arrival and departure in the North and South ports. Findings revealed that sea transportation between Haeju-Incheon was the most frequent, while the Haeju-Mokpo and Nampo-Incheon routes in the west coast area, and the Najin-Busan route in the east coast area were active. With reference to general cargo vessels, ports located on the west coast of Korea tended to operate between those located on the North coast of North Korea and on the east coast of South Korea. These results are expected to serve as a basis for establishing research and policies related to coastal shipping between the two Koreas in the future.

• Journal of Life Science
• /
• v.33 no.2
• /
• pp.216-226
• /
• 2023

Since nylon 66, a polyamide resin, has been developed and applied to toothbrush bristles, plastic consumption has increased rapidly every year, along with the increase in the amount of plastic discarded. Among the various forms of plastic debris produced by the decomposition of plastics, microplastics with a size of less than 5 mm are widely distributed in the environment, which poses a threat not only to the environment but also to animals and humans. The pathway through which microplastics enter the human body is known as ingestion by water and food, inhalation from air, and skin contact. Microplastics introduced into the human body affect human health. Recently, food-related studies have begun to be reported among microplastics-related studies, and analyses of the presence of microplastics in processed foods, such as canned foods, dried seaweed, beverages, beer, milk, sugar, and honey, are underway. Here, we present trends in the production and consumption of plastics, the generation of microplastics, the route of human inflow and human risk, and the microplastics present in processed foods, which are limited but have recently been reported. Thus far, studies on microplastics and risk assessment in processed foods have been insufficient, but microplastics are gradually being recognized as a factor that affects the environment and food. Future studies are expected to have implications for regulations regarding microplastics present in processed foods.

• Maritime Security
• /
• v.6 no.1
• /
• pp.1-35
• /
• 2023

The purpose of this study is to present the direction of development of our navy's response strategy through analysis at the ends, ways, and means level of the Chinese navy's offensive strategy for the West Sea. As a result of the analysis, at the ends level, the Chinese Navy's offensive strategy for the West Sea strategy is being linked to a grand strategy to protect maritime rights and achieve maritime power between the U.S. and China competition, at the ways level, the Chinese Navy is expected to create a foundation for the international community to recognize the West Sea as China's inland sea through "routine entry" and "exercise authority", and in case of emergency, it will try to secure sea control in the West Sea in a short period of time by blocking Korea's maritime transportation route based on the overwhelming preemptive attack capability of aircraft carriers. At the means level, it is accelerating the construction of aircraft carrier warfare units and improving its ability to engage long-range missiles. As a direction of development of the Korean Navy's response strategy in response to this, first, Establishment and Development of National Maritime Security Strategy in conjunction with the Korean Indo-Pacific Strategy. Second, it proposes the development of the concept of effective security operations for the east sea area of the West Sea intermediate line, and third, the development of the concept of combat performance and capacity building to strengthen survival and lethality.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3D
• /
• pp.317-323
• /
• 2008

Mass transit information can contribute many benefits to users. Especially, transportation information technology is developing highly with information technology in Korea recently. Hereafter, it is expected to give customized transportation information to users individually with the advent of ubiquitous age in earnest. This public transportation information service can be realized by path finding algorithm in public transportation networks including travel and transfer attributes. In this research, constraints are constructed with the primary facts influencing users. Moreover, the method reducing user's path finding condition arbitrarily is proposed by making the maximum value as variables. In this study, transfer frequency, total travel time, seat confirmation, transfer time and travel time become constraint condition based on k path finding algorithm considering service time constraint condition. Moreover, case study about user customized transfer information is performed in Seoul and metropolitan subway networks.

• Korean Journal of Environment and Ecology
• /
• v.37 no.5
• /
• pp.337-346
• /
• 2023

Although wildlife bridge are built as a way to reduce habitat fragmentation caused by road construction, there is still a lot of debate about their effectiveness. Monitoring methods such as footprint traps and camera traps are used evaluate the effectiveness of wildlife bridge, but there is a limit to evaluate of effectiveness. In this study, the degree of use the wildlfe bridge was surveyed by striped field mouse that is likely use the wildlife bridge and surrounding as a habitat with capture-mark-recapture method.(Apodemus agraius). The distance and route of movement were identified by connecting the capture points, and the environmental factors on the use of the wildlife bridge implemented a generalized linear model(GLM) with the capture number of captured as a dependent variable. Consequently of capture, no individuals crossing the wildlife bridge, striped field mouse use the wildlife bridge as a habitat.The environmental factors affecting the use of mice were vegetation cover(1~2m, 2~8m, over 8m), vegetation construction, maximum diameter at breast height were positively correlated and slope was nagatively correlated. In conclusion, it is expected that the effectiveness of the wildlife bridge will be further improved by planting shrubs and trees and preventing high slope and cut slope increasing the utilization of the rat, such as being used as a food source in the ecosystem.

• Journal of Navigation and Port Research
• /
• v.47 no.6
• /
• pp.430-436
• /
• 2023

Study on Changes in Vessel Traffic Services Due to Introduction of Maritime Autonomous Surface ShipsThe development of technologies related to Maritime Autonomous Surface Ships (MASS) has been actively progressing since the mid-2010s, focusing on themes such as collision avoidance, route planning, digital twin, and communication technologies. On the other hand, research on land-based infrastructure connected with MASS, such as logistics systems, port facilities, and vessel traffic services, has relatively received less attention. This study analyzed impact of emergence of MASS on existing vessel traffic service operations and proposed changes in control operations to prepare for its impact. To do this, current vessel traffic service operations were analyzed and elements of MASS technology that could affect vessel traffic control were identified. A survey was conducted among vessel traffic controllers to identify items related to the control of MASS. Results analyzed using the AHP method showed that preparation for emergency response and communication methods with MASS were the most important. Based on this, we were able to derive detailed plans for basic MASS control procedures and emergency response procedures based on data communication within maritime traffic control areas. MASS control procedures proposed in this study are expected to be used as a solution to resolve issues related to traffic safety of MASS in coastal areas.

• Journal of Navigation and Port Research
• /
• v.47 no.6
• /
• pp.401-409
• /
• 2023

This study compared and analyzed the performance of a distributed area search algorithm and a distributed probability search algorithm based on information exchange between ships. The distributed algorithm is a method that can search for an optimal avoidance route based on information exchange between ships. In the distributed area search algorithm, only a ship with the maximum cost reduction among neighboring ships has priority, so the next expected location can be changed. The distributed stochastic search algorithm allows a non-optimal value to be searched with a certain probability so that a new value can be searched. A circular-based ship collision avoidance model was used for the ship-to-ship collision avoidance experiment. The experimental method simulated the distributed area search algorithm and the distributed stochastic search algorithm while increasing the number of ships from 2 to 50 that were the same distance from the center of the circle. The calculation time required for each algorithm, sailing distance, and number of message exchanges were compared and analyzed. As a result of the experiment, the DSSA(Distributed Stochastic Search Algorithm) recorded a 25%calculation time, 88% navigation distance, and 84% of number of message exchange rate compared to DLSA.

• Journal of Korean Public Health Nursing
• /
• v.12 no.1
• /
• pp.132-146
• /
• 1998

This Study was attempted to provide the basic data necessary in the development and introduction of Home Health Nursing System by investigating the recognition and attitude level of Home Health Nursing System. The data were collected by means of questionaires presented to 74 patients who had been admitted in C general hospital in Chon Ju, from June 30, 1997. As the tool for this study, the questionares developed by Kim Yong. Soon, et al (1990) and Han Bok Hee(1993) were modified and supplemented for the aim of this study. The computer was used for data analysis. The items about the charateristics of the subjects and the attitude to the management plan of Home Health Nursing System were represented as the frequency and percentage. The standard deviation and calculation average were produced on the items related to definition, recognition, necessity, expected effect of the attitude of Home Health Nursing System and the items related to admission. The ANOVA test was .used according to the characteristics of variables to analyze the necessity and difference of Home Health Nursing System. The results of this study were as follows 1) The general characteristics of the subjects were as follows ; for sex, man, $58.1\%$ ; for age, 50-59 years, $29.7\%$ ; for the level of education, high school, $51.4\%$ ; $79.7\%$ of them were married; for the family forms, small family, $73.0\%$ ; and $68.9\%$ of them take the monthly income over 100 million won. 2) The characteristics related to admissions of the subjects were as follows ; for clinic, surgical department, $78.4\%$ ; addmission not more then 7days, $47.3\%$ ; for the operation-performance $71.6\%$ of them were experienced; for the admission route, via outpatients clinic, $54.1\%$ ; for waiting period to the admission day, 1-2 days, $71.6\%$. 3) The difficulties comming from the hospitalization were related mostly to the factor that they felt hospital life more inconvenient than home.(3.66) The reasons for the difficulties in the admission which was due to insufficient beds in the hospital was related to the concentration to the general hospital because of 'The Whole National Medical Insurance System'(4.05). 4) On the previous informations about the Home Health Nursing System, those who have heard of only the name were 42 $(56.8\%)$, and on the recognition of it, they thought that it is periodic treatment by the licenced nurses for the recovering pateints after early discharge(3.73). On the attitude about the necessity of Home Health Nursing System, they thought that it is necessary because of the increasing trend of a psychological disease by the change of environment and complexity of the social structure(4.24). On the expected effect of Home Health Nursing System, they answered that it is convinient for the family of the patient to take care of them(4.l8). 5) On the attitude to the management plan of the Home Health Nursing System, those who had intention to participate in the system in the case of systemic support were 42(56.8). In the visiting time, 'visit periodically' and 'visit when the patient needs' were $28(37.8\%)$ respectively. For the application of medical insurance, if possoble, they will use $(91.9\%)$; for the method of payment for the treatment, 'pay by the time required' was $23(31.1\%)$, for the subject of management, 'National public institute must operate' was $33(44.6\%)$. 6) The relationship between the general characteristics of the subjects and the necessity of Home Health Nursing System showed the notable difference in the age (F=3.508, P<0.05) and marrage state (F=5.402, P<.023).