• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.3
• /
• pp.640-655
• /
• 2018

Recently, the construction of the urban area has been rapidly increasing, and the excavation work of the ground has been frequently performed at the upper part of the existing underground structures. Especially, when the structure is constructed after the excavation of the ground, the loading and unloading process in the ground under the excavation basement can affect the existing underground structures. Therefore, in order to maintain the stability of the existing underground structure due to the excavation of the ground, it is necessary to accurately grasp the influence of the excavation and the structure load in the adjoining part. In this study, the effect of the excavation of the ground and the new structure load on the existing tunnel was experimentally implemented and the influence of the adjacent construction on the existing tunnel was investigated. For this purpose a large testing model with 1/5 scale of the actual size was manufactured. The influence of ground excavation, width of the load due to new structure, and distance between centers of tunnel and of excavation on the existing tunnel was investigated. In this study, it was confirmed that the influence on the existing tunnel gets larger, as the excavation depth get deeper. At the same distance, it was confirmed that the tunnel displacement increased up to three times according to the increase of the building load width. That is, the load width influences the existing tunnel larger than the excavation depth. As the impact of the distance between centers of tunnel and of excavation, it was confirmed that tunnel crown displacement decreased by 48%. The result showed that a tunnel is located in the range of 1D (D: tunnel diameter) from the center of excavation, the effect of excavation is the largest.

• Journal of Navigation and Port Research
• /
• v.44 no.3
• /
• pp.195-202
• /
• 2020

The production of larger of ships is a survival strategy for global shipping companies to pursue the economics of scale. According to this strategy, to respond to this situation, many containers are loading/unloading simultaneously in the hub port. Additionally, the container terminals are promoting the introduction of automation to expand the terminal facilities and increase efficiency/productivity of the container yards. European ports have introduced automation to address rising labor costs and shortages of labor. Recently, the construction of fully automated container terminals is increasing in the United States and China to resolve problems such as the slow growth of the global economy, the emergence of large ships, air pollution, and safety accidents. Domestic ports are at an early stage compared to the world's advanced container terminals, and countermeasures are being prepared to respond to the changing ports. However, research on the recognition difference analysis that examines the opinions of stakeholders is insufficient. As a result of analyzing the recognition among the groups, it was found that container terminal operators reduced labor costs, improved shipping services for shipping companies, prevented safety accidents for port union labor, and increased service for port authority and government agencies. Thus, to closely examine the perception among the groups, one-way ANOVA was performed, and then the implications were deduced as the basic data for the smooth introduction of automation.

• Journal of Environmental Health Sciences
• /
• v.42 no.6
• /
• pp.430-437
• /
• 2016

Objectives: The new Chemical Control Act from the Korean Ministry of Environment (2014-259) simply states only in basic phrases that every worker handling the listed chemicals should wear personal protective equipment (PPE) and does not consider the different hazard characteristics of particular chemicals or work types. The purpose of this study was to produce an exposure risk matrix and assign PPE to the categories of this matrix, which would be useful for revising the act to suggest PPE to suit work types or situations. Methods: An exposure risk matrix was made using hazard ranks of chemicals and workplace exposure risks in the previous study. For the 20 categories of exposure risk matrix PPE, levels A, B, C, D as classified by OSHA/EPA were assigned. After 69 hazardous chemicals were divided into 11 groups according to their physiochemical characteristics, respirators, chemical protective clothing (CPC), gloves and footwear were suggested on the basis of the assigned PPE levels. Results: PPE table sheets for the 11 groups were made on the basis of work types or situations. Full facepiece or half-mask for level C was recommended in accordance with the exposure risk matrix. Level A was, in particular, recommended for loading or unloading work. Level A PPE should be worn in an emergency involving hydrogen fluoride because of the number of recent related accidents in Korea. Conclusion: PPE assignment according to the exposure risk matrix made by chemical hazards and work type or situation was suggested for the first time. Each type of PPE was recommended for the grouped chemicals. The research will be usefully used for the revision of the Chemical Control Act in Korea.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.15 no.4
• /
• pp.381-390
• /
• 2017

In Korea, commercial nuclear power plants and research reactors have on-site storage systems for the spent nuclear fuel, but it is difficult to expand the facilities used for the storage systems. If decommissioning of nuclear power plants starts, an amount of high level radioactive waste will be generated. In this study, a radiological impact assessment of the railroad transport of high level radioactive waste was carried out considering radiation workers and the public, using the developed transport container as the transport package. The dose rates for workers and the public during the transport period were estimated, considering anticipated transport scenarios, and the results compared with the regulatory limit. A sensitivity analysis was also carried out by considering the different release ratios of the radioactive materials in the high level radioactive waste, and different distances between the transport container and workers during loading and unloading phases and while attaching another freight car. For all the anticipated transport scenarios, the radiological impacts for workers and the public met the regulatory limits.

• Journal of Digital Convergence
• /
• v.16 no.10
• /
• pp.169-178
• /
• 2018

Gyeongin Port has low awareness, insufficient hinterland infrastructures, and lower competitiveness. So, in this study, we conducted Fuzzy-IPA analysis reflecting the recognition of the consignor companies that are using Gyeongin port to suggest present practical improvement measures for the activation of the operation of Gyeongin port hereafter. As a result of the analysis, three factors, that is, cargo loading/unloading/storage costs, port facility fees, and incentive and support were derived as priority investment areas. Three factors, that is, cargo safety, infrastructure equipment, and inland transportation costs were derived as the areas for maintenance strengthening and factors related to cargo handling and service factors were derived as areas for maintenance of the status quo and areas for gradual improvement, respectively. This study is significant in that it analyzed the recognition of the consignor companies that are using Gyeongin port using a quantifying method and suggested realizable measures for activation based on the results of the analysis. In future studies, the frequency of ships' calling at the port and measures to diversify the sea routes should be additionally reflected on the analysis.

• Fire Science and Engineering
• /
• v.28 no.4
• /
• pp.81-88
• /
• 2014

This study identified the complaint ratio of musculoskeletal symptom by 119 EMTs and investigated the work risk extent through ergonomics evaluation about the patient transport works, which cause work-related musculoskeletal disorders (WMSDs) to 119 EMTs. For this, the complaint ratio of musculoskeletal symptom utilized questionnaire tool based on KOSHA Code H-30-2008 and the risk extent about the patient transport work evaluated by using ergonomics evaluation tools such as OWAS, RULA and REBA. According to the study result, 60.9% of 119 EMTs experienced musculoskeletal symptom. Among them, the symptom on back was the most common (36.1%). The work, which mostly causes WMSDs, has been found as patient transport work (48.4%). Among the patient transport motion, loading/unloading of ambulance cot to/from ambulance and the lifting of patient by stretcher were OWAS risk-level 3 and RULA/REBA risk-level 3 to 4. Among the patient transport environment, carrying patient on stairway using emergency mini-stretcher, moving patient in vehicle using spine board and piggy-back carrying or cradle carrying patient on stairway or slope way were OWAS, RULA, REBA risk level 3 to 4. It is suggested that immediate improvement in work postures for these works should contribute to prevention against WMSDs to 119 EMTs.

• Journal of Navigation and Port Research
• /
• v.44 no.6
• /
• pp.550-556
• /
• 2020

Over the past years, the role of ports in the global network of supply chains has becoming increasingly important, not merely as a physical location for loading and unloading goods, but also as an essential center of economic activity where additional value is added to cargo. Due to the overall growing importance of ports, each country has chosen to adopt hub growth as a primary economic strategy. Northeast Asia in particular, due to its high population density, experiences intense competition between its ports. Busan's port, as a result, has used the establishment of Distripark in order to attract high and stable trade volume, and compete more effectively with other ports in the region. This study estimates the unit cost of the logistic process for the all principal cargos handled at Busan New Port, with the findings revealing that unit cost increases gradually starting with chemical products, LME bulk goods, automobile parts, LME containers, general cargoes, and LME inland transportation goods coming in last. Future research will look more closely at all all categories of cargo handled in the Distrpark of Busan New Port, thereby enabling us to better understand the value created by the port, and how to best implement effective trade volume-attraction strategy.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.4D
• /
• pp.323-330
• /
• 2010

The time in port for vessels is one of the important factors for analyzing the operation status and the capacity of ports. In addition, the time in port for vessels can be directly used for estimating the greenhouse gas emissions resulted from vessels in port. However, it is unclear which variables can affect the time in port for vessels and what the marginal effect of each variable is. With these challenges in mind, the study analyzes the time in port for vessels arriving and departing port of Busan by using a parametric survival model. The results show that the log-logistic accelerated failure time model is appropriate to explain the time in port for 19,167 vessels arriving and departing port of Busan in 2008, in which the time in port is significantly affected by gross tonnage of vessels, service capacity of terminal, and vessel type. This study also shows that the greenhouse gas emission resulted from full-container vessels, which accounted for about 61% of all vessels with loading/unloading purpose arriving and departing port of Busan in 2008, is about "17 ton/vessel" in the boundary of port of Busan. However, the hotelling greenhouse gas emissions resulted from non-container vessels (3,774 vessels; 20%) are greater than those from the full-container vessels. Hence, it is necessary to take into account more efficient port management polices and technologies to reduce the service time of non-container vessels in port of Busan.

• Journal of Digital Convergence
• /
• v.13 no.8
• /
• pp.281-288
• /
• 2015

The container terminals use convergence technology that exchange information for cargo work, using wireless communication between the TOS(Terminal Operations System) and the handling equipments(CC, TC, YT). But if the container cargoes pile up high in the container yard, delayed cargo work and cargo working list information error happen because of communication dead spots(the worker can not receive the information) which wireless communication is disconnected. At this time the driver of the yard tractor(YT) must be able to recognize the communication state. If then, delayed cargo work and cargo working list information errors that occur in the shaded communication area can be avoided, and can process the delayed work due to wireless communication break. In this project, we have built wireless communication environment to increase the efficiency of the loading and unloading operations which the operator can respond actively, when the work is delayed and work orders result in errors. That is, the flow of the wireless communication module has been changed.

• Journal of Sensor Science and Technology
• /
• v.9 no.2
• /
• pp.96-105
• /
• 2000

Fiber optic TR-EFPI(total reflected extrtinsic Fabry-Perot interferometric) sensor was developed to measure the strain of structures, such as building, bridge, aircraft, etc. It has been difficult to distinguish the increase and decrease of the strain from the conventional fiber optic EFPI sensor because their signals only have a sinusoidal wave pattern related to the change of strain. Also, the absolute strain could not be measured by the simple fiber optic EFPI sensor. In this study, in order to measure the magnitude of strain with the direction of strain, the fiber optic sensor was simply constructed with the total reflected EFPI sensor probe. This probe was manufactured with a single mode fiber and a mirror coated fiber in a silica glass capillary tube. The output signal of this fiber optic TR-EFPT sensor can give the information about the magnitude and the direction of strain. The loading-unloading test was performed by the universal testing machine with alluminum beam specimen to compare the strain from fiber optic TR-EFPI sensor with the value from electrical strain gauge. In the result of this experiment. the strain from fiber optic TR-EFPI sensor had a good agreement with the values from the electrical strain gauge.