• Journal of Korean society of Dental Hygiene
• /
• v.20 no.1
• /
• pp.73-83
• /
• 2020

Objectives: This study aimed to measure the knowledge of dental hygienists regarding dental waste, and identify the relationship between general characteristics and infection control characteristics. Methods: This study was conducted using a self-reported questionnaire in 250 dental hygienists. The questionnaire consisted of 21 items: storage container (5 items), storage locations (5 items), storage period (9 items), and storage method (3 items). The collected data were analyzed using the t-test and analysis of variance. Results: The education experience of infection management within the last year was reviewed for significant differences among dental hygienists regarding storage container and storage periods (p<0.05). Statistically significant differences were observed regarding the knowledge of storage container, storage locations, storage period, and storage method among the enrolled dental hygienists (p<0.05). Conclusions: This study examined the necessity of developing conservative education and job education programs to improve the knowledge level of dental hygienists regarding dental waste management.

• Journal of Navigation and Port Research
• /
• v.31 no.8
• /
• pp.705-710
• /
• 2007

The productivity of automated container terminals is significantly affected by not only the speed related performances of automated transfer cranes(ATCs) but also the sizes of container blocks. In this paper, it is discussed how to determine the size of import container blocks considering both the container handling times of an ATC and their storage space. Firstly, evaluation models are suggested for the container handling times of an ATC in a typical import container blocks. Secondly, three mathematical formulations are suggested to determine the size of import container blocks. Numerical experiments for the suggested models to determine the size of import container block are provided.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.20 no.1
• /
• pp.127-131
• /
• 2022

The structural safety of prototype transport and storage containers for very low-level radioactive liquid waste was experimentally estimated for its localization development. Transport containers for radioactive liquid waste have been researched and developed, however, there are no standardized commercial containers for very low-level radioactive waste in Korea. In this study, the structural safety of the designated IP-2 type container capable of transporting and temporarily storing large amounts of very low-level liquid waste, which is generated during the operation and decommissioning of nuclear power plants, was demonstrated. The stacking and drop tests, which were conducted to determine the structural integrity of the container, verified that there was no external leakage of the contents in spite of its structural deformation due to the drop impact. This study shows the effort required for the localization of the technology used in manufacturing transport and storage containers for very low-level radioactive liquid waste, and the additional structural reinforcement of the container in which the commercial intermediate bulk container (IBC) external frame was coupled.

• Journal of the Korean Institute of Navigation
• /
• v.21 no.1
• /
• pp.1-11
• /
• 1997

Because of the sharp increase of its export and import container cargo volumes contrast to the lack of related Container Terminal facility, equipment and inefficient procedure, there is now heavy container cargo congestions in Pusan Container Terminal. As a result of such a situation, many container ships avoid their calls into Pusan port. This is a major cause that in tum kads to weakening intemational competitiveness of the Korean industry. This study, therefore, aims are to make a quantitative analysis of Container Terminal System through the computer simulation, especially focusing on its 4 sub-system of a handling system, 'it is checked whether the current operation is being performed effectively through the computer simulation. The overall findings are as folIows; Firstly, average tonnage of the ships visiting the BCTOC was 32,360 G/T in from January '96, to may '96. The average arrival interval and service time of container ships at BCTOC are 5.63 hours and 18.67 hours respectively. Ship's arrival and service pattern at BCTOC was exponential distribution with 95% confidence and Erlang-4 distribution with 99% confidence. Secondly, average waiting time and number of ships was 9.9 hours, 235 ships(38%) among 620 ships. Number of stevedoring container per ship was average 747.7 TED, standard deviation 379.1 TEU and normal distribution with 99% confidence. Thirdly, from the fact that the average storage days of containers at BCTOC are 2.75 days (3.0 days when import, 2.5 days when export). it is founds that most containers were transfered to the off-dock storage areas with the free periods(5 days when import, 4 days when export), the reason for which is considered to be the insufficient storage area at BCTOC. Fourthly, in the case of gate in-out at BCTOC, occupied containers and emptied containers are 89% and 11% respectively in the gate-in, 75% and 25% seperately in the gate-out. Finally, from the quantitative analysis results for container terminal at BCTOC, ship's average wating time of ships was found to be 20.77 hours and berth occupancy rate(${\rho}$) was 0.83. 5~6 berths were required in order that the berth occupancy rate(${\rho}$) may be maintained up to 60% degree.

• Journal of Korean Port Research
• /
• v.5 no.1
• /
• pp.55-69
• /
• 1991

A Container terminal is a physical link between the ocean and land modes of transport and a major component of the container physical distribution system. A number of projects to increase terminal productivity in the world were found to be tied directly to increasing the efficiency of the intermodal activities, that is, to improving the physical distribution process. This is an indication that the productivity of container terminal is being considered withing a system prospective. The purpose of this study is to establish a model of the container physical distribution system for Pusan port linked with 4 sub-systems including Navigational aids system, Cargo handling/transfer/storage system on dock, Off-dock CY system and In-land transport connection system. and to analyze the system. From this analysis, we found that the system had three bottlenecks on the container physical distribution process in Pusan port : a) cargo handling b) storage and c) inland transport, and showed a way to improve the system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.261-267
• /
• 2006

The required storage inventory is a very important decision variable which determines the storage capacity of a container terminal. Generally, the required storage inventory is dependent upon such factors as ship headway, allowable dwell time of containers, loading/unloading time per ship, and so on. Until now, the required storage inventory is estimated under the assumption that the factors are deterministic in several studies. However, this study proposes how to estimate a required storage inventory satisfying the required service level under the assumption that a containership's load size is probabilistic. Numerical experiments, which use a simulation show that the proposed method can estimate more adequately the maximum storage inventory than other methods under a probabilistic environment.

• Journal of Environmental Science International
• /
• v.24 no.2
• /
• pp.253-260
• /
• 2015

Enlargement of street tree planting area is the proper and effective solution to reduce carbon dioxide. This solution bases on the ability of carbon storage and uptake by tree metabolism. However, the circumstance of road side has fatal disadvantages in tree metabolism such as growth and maturity because cutting and filling of roadsides cause unnatural soil composition. In this point, early rootage of street tree is the main factor of reducing carbon dioxide. This study aimed to find a appropriate transplantation planting method for sound and rapid rootage of street tree. For the study, Korean Mountain Ash(Sorbus alnifolia) were used for experimental groups. The groups were categorized by three groups such as trees produced on container with mulching treatment, trees produced in outdoor with mulching treatment, trees produced on container with weeding treatment. Each group consisted 10 trees with same size and transplanted in experimental site. Five months after transplanting, each group was estimated the biomass and carbon storage through a direct harvesting method. According to results of the study, the carbon storage of trees produced on container with mulching treatment is 42% more than trees produced in outdoor with mulching treatment. And the carbon storage of trees produced on container with mulching treatment is 19.5% more than trees produced on container with weeding treatment. These results may imply that transplantation of container produced tree with mulching treatment is the most rapid rootage among other groups. The weeding treatment is more effective than mulching treatment for rapid rootage of street trees.

• Journal of Korean Institute of Industrial Engineers
• /
• v.22 no.4
• /
• pp.753-770
• /
• 1996

In order to reduce the number of rehandles during the loading operation of export containers in port container terminals, the storage location of each arriving container should be determined considering of its weight. We formulate the problem by a dynamic programming model to get the optimal storage location. And a heuristic rule is suggested in order to overcome computational difficulties of the optimization model. The performance of the rule is evaluated by comparing it with the result of DP model.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1996.04a
• /
• pp.473-476
• /
• 1996

In order to reduce the number of rehandles during the loading operation of export containers in port container terminals, the storage location of each arriving container should be determined considering of its weight. We formulate the problem by a dynamic programming model to get the optimal storage location.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.31 no.3
• /
• pp.11-25
• /
• 2006

Space may be a scarce resource in manufacturing shops, warehouses, freight terminals, and container terminals. This Paper discusses how to locate temporary storage Inventories In limited storage areas. A typical inventory is delivered from the location of the preceding process to the storage area and stored In the storage area during the certain period of time. And it may be relocated from the storage position to another. Finally. it is delivered from the final storage area to the location of the next process. Because this logistic process for an inventory requires handling activities, transportation activities, and storage spaces, the limitation in capacities of handling equipment, transportation equipment, and storage space must be considered when allocating spaces to the inventory. This problem Is modeled as a multicommodity minimal cost flow problem. And a heuristic algorithm for the Problem is proposed. Numerical experiments are presented to validate the mathematical model and the heuristic algorithm.