• The Journal of Society for e-Business Studies
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• v.17 no.2
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• pp.149-163
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• 2012

Logistics systems provide their service to customers by coordinating the resources with limited capacity throughout the underlying processes involved to each other. To maintain the high level of service under such complicated condition, it is essential to carry out the real-time monitoring and continuous management of logistics processes. In this study, we propose a method of estimating the service completion time of key processes based on process-state information collected in real time. We first identify the factors that influence the process completion time by modeling and analyzing an influence diagram, and then suggest algorithms for quantifying the factors. We suppose the container terminal logistics and the process of discharging and loading containers to a vessel. The remaining service time of a vessel is estimated using a decision tree which is the result of machine-learning using historical data. We validated the estimation model using container terminal simulation. The proposed model is expected to improve competitiveness of logistics systems by forecasting service completion in real time, as well as to prevent the waste of resources.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.798-809
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• 2023

In this study, we evaluated the impacts of land-based pollution sources on seawater and shellfish in the Jindongman area after 20.5 mm and 90.6 mm rainfall events. We analyzed sanitary indicator microorganisms used in survey management, such as total coliform, fecal coliform, Escherichia coli, and male-specific coliphage in Waste water treatment plant (WWTP), major inland pollution source,s seawater, and shellfish for 4 days after rainfall events. Our results showed that the range of coliform group and fecal coliform was 1.8-49 and <1.8-4.5 MPN (most probable number)/100 mL, respectively, after rainfall events in WWTP discharge water. Furthermore, the radius of the calculated impacted area of major inland pollution sources ranged from 5 to 798 m after 20.5 mm of rainfall and 30 to 1,031 m after 90.6 mm of rainfall. The fecal coliform of seawater at 30 stations in the shellfish growing area and areas adjacent to four stations was <1.8-130 and from <1.8-79 MPN/100 mL, respectively. The E. coli level of shellfish at 7 stations in the shellfish growing area was <18-220 MPN/100 g.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.152-168
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• 2019

The element arsenic, which is abundant in the Earth's crust, is used for various industrial purposes including materials for disease treatment and household goods. Various human activities, such as the disposal of soil waste, metal mining and smelting, and combustion of fossil fuels, have caused the pollution of the environment with arsenic. Recently, guidelines for arsenic in rice have been adopted by the Korean ministry of food and drug safety to prevent health risks based on rice consumption. Because of the exposure to arsenic and its accumulation in the human body through various channels, such as air inhalation, skin contact, ingestion of drinking water, and food consumption, integrated multimedia risk assessment is required to adopt appropriate risk management policies. Therefore, integrated human health risk assessment was carried out in this study using integrated exposure assessment based on multimedia (e.g., air, water, and soil) and multi-route (e.g., oral, inhalation, and dermal) scenarios. The results show that oral uptake via drinking water is the most common pathway of arsenic into the human body, accounting for 57%-96% of the total arsenic exposure. Among various age groups, the highest exposures to arsenic were observed in infants because the body weight of infants is low and the surface areas of infant bodies are large. Based on the results of the exposure assessment, the cancer and non-cancer risks were calculated. The cancer risk for CTE and RME is in the range of 2.3E-05 to 6.7E-05 and thus is negligible because it does not exceed the cancer probability of 1.0E-04 for all age groups. On the other hand, the cancer risk for RME varies from 6.4E-05 to 1.8E-04 and from 1.3E-04 to 1.8E-04 for infants and preschool children, exceeding the excess cancer risk of 1.0E-04. The non-cancer risks range from 5.4E-02 to 1.9E-01 and from 1.5E-01 to 6.8E-01, respectively. They do not exceed the hazard index 1 for all scenarios and all ages.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.75-84
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• 2020

Modular construction is a construction method whereby prefabricated volumetric units are produced in a factory and are installed on site to form a building block. The construction productivity can be substantially improved by the manufacturing and assembly of standardized modular units. 3D printing is a computer-controlled fabrication method first adopted in the manufacturing industry and was utilized for the automated construction of small-scale houses in recent years. Implementing 3D printing in the fabrication of modular units brings huge benefits to modular construction, including increased customization, lower material waste, and reduced labor work. Such implementation also benefits the large-scale and wider adoption of 3D printing in engineering practice. However, a critical issue for 3D printed modules is the loading capacity, particularly in response to horizontal forces like wind load, which requires a deeper understanding of the building structure behavior and the design of load-bearing modules. Therefore, this paper presents the state-of-the-art literature concerning recent achievement in 3D printing for buildings, followed by discussion on the opportunities and challenges for examining 3D printing in modular construction. Promising 3D printing techniques are critically reviewed and discussed with regard to their advantages and limitations in construction. The appropriate structural form needs to be determined at the design stage, taking into consideration the overall building structural behavior, site environmental conditions (e.g., wind), and load-carrying capacity of the 3D printed modules. Detailed finite element modelling of the entire modular buildings needs to be conducted to verify the structural performance, considering the code-stipulated lateral drift, strength criteria, and other design requirements. Moreover, integration of building information modelling (BIM) method is beneficial for generating the material and geometric details of the 3D printed modules, which can then be utilized for the fabrication.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.153-161
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• 1996

Several main nuclides($^{241}Am$, $^{152}Eu$ and $^{237}Np$) in radioactive waste solution were selected and examined to mutual separation with di-(2-ethylhexyl) phosphoric acid by solvent extraction technique. $^{237}Np$ was extracted more than 99.9% adding the $H_2O_2$ that was a good reductant for the oxidation state control of $^{237}Np$. $^{241}Am$, $^{152}Eu$ and $^{237}Np$ could be fairly well separated one another during the different sequence stripping stages, but about 7~9.6% of the other nuclides were still remained for the $^{241}Am$ stripping solution. This result shows that the product of $^{152}Eu$ and $^{237}Np$ was good, but $^{241}Am$ may be needed to further purification process. It was also discussed on the cause of the third phase formation phenomenon that was found in the solvent regeneration.

• The Journal of Society for e-Business Studies
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• v.18 no.2
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• pp.223-240
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• 2013

RFID(Radio Frequency Identification) is use of an RFID tag applied to object for the purpose of identification and tracking using radio waves. Recently, it is being actively researched and introduced in logistics and manufacturing. RFID portals in supply chains are meant to identify all the tags within a given interrogation zone. Hence the hardware and software mechanisms for RFID tag identification mostly focus on successful read of multiple tags simultaneously. Such mechanisms, however, are inefficient for determining moving direction of tags, sequence of consecutive tags, and validity of the tag reads from the viewpoint of workflow. These types of problems usually cause many difficulties in RFID portal implementation in manufacturing environment, there by having RFID-system developers waste a considerable amount of time. In this research, we designated an RFID portal system with SDO(Sequence, Direction, and Object-flow)-perception capability by using fundamental data supplied by ordinary RFID readers. Using our work, RFID system developers can save a great amount of time building RFID data-capturing applications in manufacturing environment.

• Journal of Environmental Health Sciences
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• v.40 no.5
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• pp.331-345
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• 2014

Objectives: The exponential growth of chemicals, an area of high concern in developed countries like the US (i.e., the Gore Initiative) and in the EU (i.e., REACH), as well as recent chemical accidents in Korea, have provoked nationwide concerns and resultant legal enforcement. This study aims to compare the laws of the Ministry of Environment (the Chemical Substances Control Act (CSCA), Act on the Registration and Evaluation, etc. of Chemical Substances (ARECS)) with those of the Ministry of the Employment and Labor (Occupational Safety and Health Act (OSHA)). Methods: Each law pertaining to the Ministry of Environment and the Ministry of the Employment and Labor was downloaded from the official legal information system (www.law.go.kr). The objectives of each law and the major contents related to chemical management were compared and summarized. Results: The CSCA and the ARECS are focused on the protection of people and the environment, while the OSHA relates to the protection of workers. The right to know of people and workers has been reinforced. The former two laws emphasize prevention, but the OSHA contains both preventive and post-accident measures. The role of the Ministry of Employment was reinforced with the promulgation of the CSCA and ARECS, which contain regulations such as adjacent area impact evaluation, risk control planning, chemical statistical survey and construction and operation of information, provision of risk control plans, response to chemical accidents and registration of chemical substances. Conclusion: We found that the three laws discussed here have several similar clauses designed to protect people and the environment from risks that may be caused by the use of chemicals, even though there are some differences among them in terms of objectives and contents. This review concluded that several clauses that can be regarded as double regulation should be unified in order to minimize the waste of government administrative resources and socio-economic losses.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.662-669
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• 2017

This study evaluated the ecotoxicological properties of livestock waste water treated by a LID (Low Impact Development) system, using a mixture of bio-reeds and bio-ceramics as suitable bed media for a subsequent treatment process of a livestock wastewater treatment plant. The relationship between the pollutant reduction rate and the ecotoxicity was analyzed with the effluents from the inlet pilot plant, with vegetated swale and wetlands and the batch type of an infiltration trench. Each pilot plant consisted of a bio process using bio-reeds and bio-ceramics as bed media, as well as a general process using general reeds and a bed as a control group. The results indicated that, after applying the HRT 24 hour LID method, the ecotoxicity was considerably lowered and the batch type pilot plant was shown to be effective for toxicity reduction. The LID method is expected to be effective for water quality management, considering ecotoxicity by not only as a nonpoint source pollution abatement facility but also, as a subsequent treatment process linked with a livestock manure purification facility. It is necessary to take the LID technic optimization study further to apply it as a subsequent process for livestock wastewater treatment.

• International Commerce and Information Review
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• v.19 no.1
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• pp.305-324
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• 2017

Industry-University cooperation for pioneering overseas market contributes to improve the quality of manpower and the export performance. However, performance is showing that without exporting experience, exploring overseas market is not promising. Without systematic training and preparation, pioneering overseas market can be a waste of time and budget. I have conducted interviews with 30 participants in Industry-University cooperation for pioneering overseas market. As a result, I have derived a model for each phase of Industry-University cooperation. 8 stages of this model are student selection, cooperation company networking, student education, overseas market research, selection of trade fair, preparation of trade fair, dispatch of trade fair and follow-up management. Opinions of experts have been reflected and compiled to each suggested stage. Specific details can be applied directly to those affiliated who want to start the first or foremost pioneering overseas markets.

• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.1-5
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• 2010

In this paper, we propose for improving QoS in wireless micro cellular network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP and propose for performance of realtime and non-real time handoff service using Handoff state machine Paging Route Cache. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it bas its vulnerability in frequent handoff environment. On the other hand, Cellular IP combines the capability of cellular networks to provide high performance handoff and efficient location management of active and idle mobile users with the inherent flexibility, robustness and scalability found in IP networks. Also Cellular-IP/PRC use semi-soft handoff. During semi-soft hand off a mobile host may be in contact with either of the old and new base stations and receive packets from them. Packets intended to the mobile node are sent to both base stations and buffered, so when the mobile host eventually moves to the new location it can continue to receive packets without interruption. It should be suitable for realtime service such as multimedia traffic. But, much waste of resource will occur in this method, especially for non-real time services such as FTP and E-mail. Therefore, a new algorithm that performs different handoff according to characteristic of each traffic by use of reserved field in IP packet is proposed in this thesis. This hand off state machine using differentiated handoff improves quality of services in Cellular-IP/PRC. Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. Matlab simulation results are improving QoS, show call drop and call blocking provided to Paging Router Cache during handoff state machine in Cellular-IP/PRC.