• Journal of Environmental Science International
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• v.29 no.12
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• pp.1171-1184
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• 2020

The green synthesis of inorganic nanoparticles (NPs) using biomaterials has garnered considerable attention in recent years because of its eco-friendly, non-toxic, simple, and low-cost nature. In this study, we synthesized NPs of noble metals, such as Ag and Au using an aqueous extract of a marine seaweed, Ecklonia cava. The formation of AgNPs and AuNPs was confirmed by the presence of surface plasmon resonance peaks in UV-Vis absorption spectra at approximately 430 and 530 nm, respectively. Various properties of the NPs were evaluated using characterization techniques, such as dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Phytochemicals in the seaweed extract, such as phlorotannins, acted as both reducing and stabilizing agents for the growth of the NPs. The green-synthesized AgNPs and AuNPs were found to exhibit high catalytic activity for the decomposition of organic dyes, including azo dyes, methylene blue, rhodamine B, and methyl orange.

• ALGAE
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• v.37 no.3
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• pp.239-247
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• 2022

Enzyme-assisted hydrolysis is frequently used as a cost-effective and efficient method to obtain functional ingredients from bioresources. This study involved the enzyme-assisted hydrolyzation and purification of fucoidan from Ecklonia maxima stipe and the investigation of its anti-inflammatory activity in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Fucoidans of Viscozyme-assisted hydrolysate from E. maxima (EMSFs) harvested in Jeju, Korea. Structural and chemical characterizations were performed using fourier transform infrared spectroscopy, scanning electron microscope, and monosaccharide analysis. Among fucoidans, EMSF6 was rich in fucose and sulfate and had a similar structural character to commercial fucoidan. EMSF6 showed a strong inhibitory effect on nitric oxide generation in LPS-induced RAW 264.7 cells and significantly decreased the production of LPS-induced pro-inflammatory cytokines, including interleukin-6, interleukin-1β, and tumor necrosis factor α. The anti-inflammatory potential of EMSF6 was mediated through the downregulation of inducible nitric oxide synthase and cyclooxygenase-2 expression. Thus, fucoidans from E. maxima stipe are promising candidates for functional food products.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.975-983
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• 2022

This paper presents an innovative way of integrating scheduling and project controls with the environmental impact of a construction project to track, monitor, and manage environmental emissions at the activity level. As a starting point, scheduling and project controls help monitor the status of a project to provide an assessment of the duration and sequence of activities. Additionally, project schedules can also reflect resource allocation and costs associated with various phases of a construction project. Owners, contractors and construction managers closely monitor tasks or activities on the critical path(s) and/or longest path(s) calculated through network based scheduling techniques. However, existing industry practices do not take into account environmental impact associated with each activity during the life cycle of a project. Although the environmental impact of a project may be tracked in various ways, that tracking is not tied to the project schedule and, as such, generally is not updated when schedules are revised. In this research, a Cradle to Gate approach is used to estimate environmental emissions associated with each activity of a sample project schedule. The research group has also investigated the potential determination of scenarios of lowest environmental emissions, just as project managers currently determine scenarios with lowest cost or time. This methodology can be scaled up for future work to develop a library of unit emissions associated with commonly used construction materials and equipment. This will be helpful for project owners, contractors, and construction managers to monitor, manage, and reduce the carbon footprint associated with various projects.

• Nuclear Engineering and Technology
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• v.56 no.9
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• pp.3566-3570
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• 2024

The production of the radioisotope molybdenum-99 in the WWR-K research reactor is achieved through the activation method ⁹⁸Mo(n,γ)⁹⁹Mo, utilizing a target of natural molybdenum trioxide irradiated under standard conditions (thermal neutron spectra and water environment). Under such conditions, the maximum specific activity of molybdenum-99 reaches (2.3 ± 0.3) Ci/g Mo after 7 d of irradiation. However, the escalating demand for molybdenum-99 and the need to reduce its production cost, necessitates urgent and increased productivity. This study aims to optimize the irradiation conditions for molybdenum powder in the WWR-K reactor to increase the specific activity of molybdenum-99. For this purpose, we evaluated various irradiation capsule designs comprised various neutron moderator materials and thicknesses. Through extensive modeling calculations, we obtained an optimal capsule design that increases the specific activity of molybdenum-99 to 3.31 Ci per 1 g of Mo.

• Journal of Preventive Medicine and Public Health
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• v.11 no.1
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• pp.123-127
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• 1978

The major objective of this research is to identify those hospital characteristics that best explain cost variation among hospitals and to formulate linear models that can predict hospital costs. Specific emphasis is placed on hospital output, that is, the identification of diagnosis related patient groups (DRGs) which are medically meaningful and demonstrate similar patterns of hospital resource consumption. A casemix index is developed based on the DRGs identified. Considering the common problems encountered in previous hospital cost research, the following study requirements are estab-lished for fulfilling the objectives of this research: 1. Selection of hospitals that exercise similar medical and fiscal practices. 2. Identification of an appropriate data collection mechanism in which demographic and medical characteristics of individual patients as well as accurate and comparable cost information can be derived. 3. Development of a patient classification system in which all the patients treated in hospitals are able to be split into mutually exclusive categories with consistent and stable patterns of resource consumption. 4. Development of a cost finding mechanism through which patient groups' costs can be made comparable across hospitals. A data set of Medicare patients prepared by the Social Security Administration was selected for the study analysis. The data set contained 27,229 record abstracts of Medicare patients discharged from all but one short-term general hospital in Connecticut during the period from January 1, 1971, to December 31, 1972. Each record abstract contained demographic and diagnostic information, as well as charges for specific medical services received. The 'AUT-OGRP System' was used to generate 198 DRGs in which the entire range of Medicare patients were split into mutually exclusive categories, each of which shows a consistent and stable pattern of resource consumption. The 'Departmental Method' was used to generate cost information for the groups of Medicare patients that would be comparable across hospitals. To fulfill the study objectives, an extensive analysis was conducted in the following areas: 1. Analysis of DRGs: in which the level of resource use of each DRG was determined, the length of stay or death rate of each DRG in relation to resource use was characterized, and underlying patterns of the relationships among DRG costs were explained. 2. Exploration of resource use profiles of hospitals; in which the magnitude of differences in the resource uses or death rates incurred in the treatment of Medicare patients among the study hospitals was explored. 3. Casemix analysis; in which four types of casemix-related indices were generated, and the significance of these indices in the explanation of hospital costs was examined. 4. Formulation of linear models to predict hospital costs of Medicare patients; in which nine independent variables (i. e., casemix index, hospital size, complexity of service, teaching activity, location, casemix-adjusted death. rate index, occupancy rate, and casemix-adjusted length of stay index) were used for determining factors in hospital costs. Results from the study analysis indicated that: 1. The system of 198 DRGs for Medicare patient classification was demonstrated not only as a strong tool for determining the pattern of hospital resource utilization of Medicare patients, but also for categorizing patients by their severity of illness. 2. The wei틴fed mean total case cost (TOTC) of the study hospitals for Medicare patients during the study years was $11,27.02 with a standard deviation of $117.20. The hospital with the highest average TOTC ($1538.15) was 2.08 times more expensive than the hospital with the lowest average TOTC ($743.45). The weighted mean per diem total cost (DTOC) of the study hospitals for Medicare patients during the sutdy years was $107.98 with a standard deviation of $15.18. The hospital with the highest average DTOC ($147.23) was 1.87 times more expensive than the hospital with the lowest average DTOC ($78.49). 3. The linear models for each of the six types of hospital costs were formulated using the casemix index and the eight other hospital variables as the determinants. These models explained variance to the extent of 68.7 percent of total case cost (TOTC), 63.5 percent of room and board cost (RMC), 66.2 percent of total ancillary service cost (TANC), 66.3 percent of per diem total cost (DTOC), 56.9 percent of per diem room and board cost (DRMC), and 65.5 percent of per diem ancillary service cost (DTANC). The casemix index alone explained approximately one half of interhospital cost variation: 59.1 percent for TOTC and 44.3 percent for DTOC. Thsee results demonstrate that the casemix index is the most importand determinant of interhospital cost variation Future research and policy implications in regard to the results of this study is envisioned in the following three areas: 1. Utilization of casemix related indices in the Medicare data systems. 2. Refinement of data for hospital cost evaluation. 3. Development of a system for reimbursement and cost control in hospitals.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1639-1650
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• 2013

Road pavement management is an important activity that affects to national economy, movement and safety of people, and also demands huge amount of budget. Therefore, its management strategy must be established under objective information. In addition, decision support system that produces the management strategy needs to consider practical benefits from various aspects. Considering these aspects, this paper aimed to develop a customized Korean life cycle cost analysis model estimating various effects on road users and socio-environmental costs based on pavement condition. The suggested LCCA model focused on Korean national highway, and tried to adopt a national guideline recommended by Korean government for securing credibility of estimation results. In the development processes, some of the suggestions that do not fit well in the situations of pavement management field were added, altered, or partially modified. These attempts to develop customized asset management system would be an important step to break away from passive attitudes relying on ready-made software, but also to improve awareness about the social benefits from the better maintenance strategy.

• Journal of Information Technology Applications and Management
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• v.24 no.2
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• pp.25-37
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• 2017

The aim of this study is to analyze the effect of the growing activities of large purchasing enterprises on the trust of small and medium size contractors, which is mediated by 'purchase accompany activity'. This subject study includes the first and second contractor companies in Korea. The results of this study are as follow. First, the knowledge and cost price sharing activities of major purchase vendor with cooperative company had a positive effect on the trust of cooperative company, however this was not so with the information sharing activities in that case. Second, the trust of contractors on large purchasing enterprises was positively influenced by sharing activities with purchasing activities of major company. Third, the knowledge and cost price sharing activities of purchasing enterprise with contractors on the sharing activities were mediated by the trust of contracting company on the large purchase enterprise. According to this study, the mediated effect of trust relationship can influence a contracting company. Whereas preceding studies of sharing activities were conducted about unidirectional instruct of large purchase enterprises to small and medium size contracting companies, this study was conducted on bidirectional effects, which included knowledge, cost price, information sharing activities between contracting companies and large purchasing enterprises. Conclusively, this study showed the possibility of spreading cognitive and change about mutual benefits strategy between small and medium size contracting company and large purchasing enterprise.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.111-126
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• 2015

Currently, many enterprises are trying to allocate the investment costs and risks through collaboration, and strengthen their competitiveness by sharing their resources and gains. Intercorporate sharing economy, a type of intercorporate collaboration, refers to the economic activity to share the idle resources of enterprises and enhance their efficiency. For a successful intercorporate economy with the participation of various stakeholders, there is a need to establish the clear allocation method of gains. Accordingly, this study suggested three methods-the MST method that can apply transaction cost incurred when forming a coalition for sharing economy; the average of transaction cost incurred by each participant, and the Shapley Value application method for the transaction cost incurred between the participants. In addition, this study also suggested gain allocation methods such as the "Equal distribution of gain" method, a gain allocation method based on the Cooperative Game Theory, the the "Proportional distribution of gain" method, and the Shapley Value method that takes in consideration the transaction costs.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.1
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• pp.9-16
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• 2023

The importance of team activities increases as the problem to be solved in the industrial field become more diverse and complex. Team performance is not simply the sum of team members' performances, but synergies are gained or reduced depending on the team's interactions. Analytical research on team activities using ICT has been conducted, but developing and utilizing these technologies is time-consuming and costly, making it difficult for field practitioners and researchers to utilize them. In this study, we design a system that collects interaction information during conversations at a low cost using Arduino and Raspberry Pi and verify that conversation interaction information is collected from multiple devices and correctly stored in the database. Through the low-cost information collection system proposed in this study, we intend to create an environment where follow-up research can be conducted in various fields of industrial information.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.467-474
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• 2013

Construction contactors must continuously seek to improve their cash flows, which reside at the heart of their financial success. They require careful planning, analysis, and optimization to avoid the risk of bankruptcy, remain profitable, and secure long-term growth. Sources of cash include bank loans and retained earnings, which are conceptually similar in that they both incur a cost of capital. Financial management therefore requires accurate yet customizable modeling capabilities that can quantify all expenses, including said cost of capital. However, currently existing cash flow models in construction engineering and management have strongly simplified the manner in which interest is assessed, which may even lead to overstating it at a disadvantage to contractors. The variable nature of cash balances, especially in the early phases of construction projects, contribute to this challenging issue. This research therefore extends a new cash flow model with an accurate interest calculation. It utilizes singularity functions, so called because of their ability to flexibly model changes across any number of different ranges. The interest function is continuous for activity costs of any duration and allows the realistic case that activities may begin between integer time periods, which are often calendar months. Such fractional interest calculation has hitherto been lacking from the literature. It also provides insights into the self-referential behavior of compound interest for variable cash balances. The contribution of this study is twofold; augmenting the corpus of financial analysis theory with a new interest formula, whose strengths include its generic nature and that it can be evaluated at any fractional value of time, and providing construction managers with a tool to help improve and fine-tune the financial performance of their projects.