• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.5
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• pp.433-441
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• 2006

With a development of electrical technology in recent, it is possible to measure distance without direct contact to object using laser which launched at instrument and reflect from object. Furthermore, the advent of non prism total station brought the increment of application in many fields including not only road, airport, and harbors but also measurement and monitoring of structural displacement in construction fields. In this study, therefore, to evaluate accuracy of non prism total station, accuracy was analyzed by measuring certain distance which classified by both certain materials and angle of reflection. By this method, the derived values were applied to topographical survey for the efficient applicability. According to a study, result value of non prism total station was satisfBctory regardless of material when the angle of reflection was 90 degrees. RMSE increased when the angle of reflection are gradually increased to acute angle. In result of regression analysis using certain distance which classified by both materials and angles of reflection, there is relationship between distance and angle of reflection, but material has no relevance to the result value. When carrying out general topographical survey, proper application of non prism total station will go far conducting safe and prompt survey at the dangerous site such a road which have lots of traffic flow and rock joint which have high angles of inclination.

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.4
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• pp.50-60
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• 1983

305 samples of alluvial deposit in inland and harbour districts were selected and consolidation charateristics of the alluvium were put in order statiscally. The correlations between them were as follows. 1. The relationships between LL(liguid limit) and Cc (compression index) were explained as Cc=0. 03(LL-21. 7) in case of inland district soil and as Cc=0. 019(LL-19) in case of harbour district soil. As compared with formular proposed by Skernpton, the gradient of this linear line was slight steep. 2. The relationships between PI(plastic index) and Cc were explained as Cc=0. 063 PI-0. 52 in case of inland district soil and Cc=0. 043 PI-0. 31 in case of harbour district soil. 3. As void ratio and natural moisture content were increased, Cc was increased, and as wet density was increased, Cc was decreased with a gentle curve. 4. As LL and P1 increased, mv(coefficient of volume compressibility) was increased but if LL and P1 was increased beyond a certain extend, mv has a tendency of constant value, that is, mv show a tendency to take constant value in the very soft clay. and mv in P=2. 5kg/cm$^2$ was about l${\times}$ l0-$^1$cm$^2$/kg in case of land district soil and 6x 10-$^1$crn$^2$/kg in case of harbour district soil lower than that in P=0. 25kg/crn2. 5. Cv(coefficient of consolidation) was a tendency to decrease with a gentle curve as LL was increased, and Cv in P=0. 25kg/crn2 was about 3x l0-$^1$crn$^2$/min larger than that in P=2. 5kg/crn$^2$. 6. Relationships between Py(pre-consolidation pressure) which is included over consolidation soil and ∑r1h(effective over-burden pressure) were explained as Py=l. 12 ∑r'h in case of land district soil and as Py=l. l5∑r'h in case of harbour district soil. 7. Some of the properties show good correlations between them, practical and effective applications of these correlations are expected in the planning and excution of soil investigation and also in the evaluation of the results.

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.151-162
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• 2013

This paper presents a comparison of Korean and Manchurian railway system during the Japanese colonial era of Korea. While both railways share the common characteristics of an imperial railway, they revealed several differences. Firstly, the Manchurian railway was likely a private company, although it was operated half privately and half by the government. The Manchurian railway operated like the East Indian Company in India during the English colonial era. On the other hand, the Korean railway was fully operated by the government at a ministry level. While the Korean railway solely concentrated on the railway, the Manchurian railway was involved in regional development and the coal-mining industry as well. Secondly, in contrast to the Korean railway, the Manchurian railway was more lucrative, and was relatively more predominant regarding carriage of freights. Thirdly, railway officers in Korea were elected government bureaucrats, while Manchurian railway officers came from diverse political parties and social strata. After the annexation by the Kwantung Army, the Manchurian railway was mainly influenced by the military. The common characteristic here was that both railways were utilized for military purposes as imperial railways. In partilcular, the Manchurian railway executed military orders directly. Hereafter, through a comparative study between the Japanese and Taiwanese railways, a clear and accurate understanding of the characteristics of the Korean railway during the Japanese era will be revealed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.379-385
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• 2017

In general, distribution board, panel board and motor control center can be installed over a wide area such as residence of group, building, schools, factories, ports, airports, water service and sewerage, substation and heavy industries that are used to supply converts the voltages extra high voltage into optimal voltage. There are electrical accidents due to rise of contact temperature, loose contact between busbar, deterioration of the contact resistance, over temperature of the busbars. In this paper, we designed and implemented the busbar joint and temperature measurement system, which can measure the joint resistance of busbar and loose connection between busbar using potentiometer and non-contact infrared sensor. The experimental results show that tightening the bolt and nut is fully engaged, resistance was decreased and maximum error range was 0.1mm. Also, the experimental result showed that the temperature at the contact area is increased from $27.3^{\circ}C$ to $69.3^{\circ}C$by the contact resistance.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.69-81
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• 2021

Coastal shipping performs a pivotal role as a national transportation network and is highly valuable in terms of enabling more economical transportation at affordable prices than road transportation. In this regard, this study aimed to examine changes in the characteristics and centrality of South Korea's costal shipping sea-route networks by analyzing the centrality of domestic coastal shipping. To this end, social network analysis was used as an analysis technique that enables an analysis on the characteristics of coastal shipping networks. As a result, Jeollanam-do showed the highest degree centrality, ranking first in both the in-degree and the out-degree. Jeollanam-do also exhibited the highest betweenness centrality, and Gangwon-do registered the highest closeness centrality. In terms of hub and authority centrality, Jeollanam-do topped the list, followed by Gyeongsangnam-do and Gangwon-do in order. Lastly, Jeollanam-do ranked highest in the hub index, followed by Incheon, other regions, and Gangwon-do in order. This study is significant for suggesting the cities and provinces that play a key role in coastal shipping each year and their corresponding items. Future studies are recommended to identify the trend of coastal shipping through more detailed research on each port by city and province.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.107-116
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• 2022

Local management trade ports are small-sized trade ports, which require active operation to strengthen the local cities' economic power and enhance the local industries' added value. In addition, local management trade ports should berth ships larger than the existing ships to increase efficiency and keep up with the international trend where ships are becoming larger. Furthermore, they should also prepare operating standards. This study selected Okgye Port among local management trade ports. We performed a mooring safety simulation evaluation according to the scenario where a 50,000 DWT vessel is moored at the current 20,000 DWT class pier. The emergency departure criteria were 27kts at 3.2s of wave period and 22kts at 5.0s of wave period at the existing pier. Results showed that mooring limit condition increased by about 50% to 41kts at 3.2s of wave period and 36kts at 5.0s of wave period. This study can be used for strengthening mooring facilities and setting operational standards for safe port operation when large ships are berthing.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.10-20
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• 2022

About 21% of domestic chemical accidents are caused by transport vehicles for the past 10 years in Korea. Also, ammonia is a chemical substance with the largest number of accidents, 82 out of 672. In this study, supposed seasonal alternative scenario and worst scenario in case of releasing ammonia during bunkering it from tank lorry to fishing vessel and interpreted seasonal impact and range through Python, ALOHA, Probit analysis. Radiation impact range of possibility for 2nd burn and for maximum radiation in winter scenario, which is one of the alternative scenarios, was the highest(range: 41m, radiation: 5.01kW/m²) while overpressure impact was less than minimum standard of impact. And toxicity impact range(EPRG-2) of the summer scenario was the widest(5.0km) and took a very high death rate near accident area(port area, tourist area) according to Probit analysis. the wort scenario had a similar impact and range of summer scenario.

• Journal of the Korean Geotechnical Society
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• v.25 no.10
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• pp.99-110
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• 2009

In order to provide the design criteria, the characteristics of consolidation for soft ground improvement have been investigated using the field banking test performed by the vertical drain method at the northern container section in Busan New Port. Field test results indicated that the estimated degree of consolidation in design stage decreased by about 7% compared with the measured one. This difference is attributed to the fact that the conservative geological properties were applied with relatively high amount of maximum clay mixture ratio during the design stage. Based on this findings, another laboratory oedometer test was implemented to consider various combination of mixture ratio. It was found that the consolidation degree increased in accordance with the increase of sand/silt mixture ratio. Also, the proportion of 10%, 50%, and 40% for sand, silt, and clay, respectively, was observed as the best combination of mixture ratio to the actual measurement, which is very similar to the average grain size distribution in the banking test area. Therefore, it is suggested that the overall geological characteristics as well as the grain size distribution should be considered in design stage to improve the soft ground that contains mixture of sand, silt, and clay.

• Journal of Environmental Health Sciences
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• v.50 no.3
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• pp.181-190
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• 2024

Background: Air pollutants have been reported to have harmful effects on human health. Busan is a vulnerable area in terms of air quality due to the installation of various industrial complexes, particularly the port industry. However there is limited research data on the ambient air quality of residential areas near ports and industrial complexes. Objectives: This study aimed to determine the quarterly levels of air pollutants near industrial complexes and ports and to identify trends and characteristics of air pollutant exceedances. Methods: Air measurements were conducted quarterly. The measured air pollutants included O₃, SO₂, CO, NO₂, PM₁₀, and PM_2.5. PM₁₀ and PM_2.5 were measured using BAM-1020 equipment, while O₃, SO₂, CO, and NO₂ were measured using AP-370 Series equipment. The quarterly concentration levels of air pollutants were determined, and the influence of precipitation and commuting hours on fine particulate matter was examined. Analysis of variance (ANOVA) was conducted to determine if there was significance between the concentrations of fine particulate matter during commuting hours and non-commuting hours. Results: The concentrations of air pollutants were generally higher in the first and second quarters. Furthermore, the concentrations of PM₁₀ and PM_2.5 tended to decrease continuously following consecutive rainfall, with concentrations at the end of rainfall periods lower than those observed at the beginning. The frequency of exceeding average concentrations of PM₁₀ and PM_2.5 was higher on weekdays. Moreover, the average concentrations of PM₁₀ and PM_2.5 during weekday commuting hours were higher compared to non-commuting hours. Conclusions: The concentrations of air pollutants in the survey area were found to be higher than the overall average in Busan. Based on this study, continuous air quality monitoring is necessary for residential areas near industrial complexes and ports. For further research, health biomonitoring of residents in these areas should be conducted to assess their exposure levels.

• Journal of Environmental Impact Assessment
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• v.33 no.3
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• pp.116-130
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• 2024

Historically, humans settled in waterside areas that provided abundant resources and water resources. Afterwards, as industrialization progressed, the city's waterfront contributed to the development of the city through water resources, transportation, and maritime trade. In response to changes in industrial structure, over the past few decades, the city's waterfront has transitioned from an industrial and port-oriented function to a public space function. And from the perspective of urban regeneration, research and design on sustainable waterfront space development are being promoted around the world. However, areas near waterfronts are geographically vulnerable to the direct impact of natural disasters caused by climate change, such as sea levelrise and floods. Therefore, it is essential to establish a systematic management plan to ensure the safety of citizens and publicness. Since the 1990s, New York City in the United States has been establishing a city-level waterfront space management plan to ensure the public nature, safety, and equity of waterfront spaces. On the other hand, in South Korea, there is a lack of research on city-level waterfront management plans. Accordingly, this study sought to find implications and policy improvement measures for domestic waterfront space planning by examining the development process and major policies of New York City's waterfront comprehensive plan.