• Journal of the Korea Concrete Institute
• /
• v.21 no.3
• /
• pp.367-375
• /
• 2009

Recently, more focus is shift to imbalances in aggregate market supply and demand and an exhaustion of natural resources. In this situation, Electric arc furnace oxidizing slag (EAF slag) has high application possibility as aggregate for concrete due to similar property with general aggregate. However, it is inherent the problem which causes pop-out by free-CaO contained in slag In this study, we've got the plan to assure the chemical stability of EAF slag, and then experimentally tested the mechanical performance and durability for the fine aggregate used EAF slag. On this test result, we suggest the application plan. At the result of this study, it shows that EAF slag would reduce the surface defect such as pop-out due to natural aging for the fixed hour and adjustment the grain size of EAF slag. And mechanical performance and durability according to the replacement rate of concrete service, were revealed more than equal or equal compare to general aggregate. Hereafter, quality control must precede not to impede the beauty of concrete surface as assure the safety for aging and processing. And, to establish the environmental resource recycling system for by-products of steel, it should be made development of various application and guideline of quality control for the EAF slag aggregate. Moreover, it must be constantly studied all kind of engineering performance and durability for related to this study.

• YAKHAK HOEJI
• /
• v.58 no.4
• /
• pp.229-244
• /
• 2014

Background: Antibiotic skin test(AST) is very useful for the diagnosis of drug allergies to prevent immediate allergic reactions. Although it is a safe and widespread method, it is performed very diversely by doctors and nurses without consistency and it also differs from countries and hospitals. This study aims to evaluate the current practice of AST by nurses in Korea and to compare it to the general guidelines. Methods: During January 1, 2013 to May 20, 2013, the study was conducted as questionnaires and case-based survey. The questionnaires were given to the nurses who were randomly selected in various University Hospitals (University Hospitals N=276, and Medical center N=19). The case-based surveys were given to the nurses who were conducting AST at various wards of a University Hospital (N=130). The analysis and evaluations of the responses were carried out. Results: The response rate for the questionnaires was 97.6% and 130 cases of the actual case-based surveys were collected. There were clear differences between the survey results and the general guidelines, such as the method of skin test (skin prick test was not conducted), the method of patient selection for AST, test drugs, concentration, volume and interpretation of AST. AST conducted by nurses was highly variable and inconsistent, even among nurses who worked in the same wards and hospitals. Manufactured standard concentration antibiotic solution of AST showed consistency of concentration to a certain degree. Conclusion: Although the general guidelines have been published by several countries including Korea, these are not a great help to nurses as they lack details for conducting AST, practical consideration for nurses in the clinical setting, propagation and education. Standardized guideline for nurses should be published and it should be a safe, clear, comfortable and easily accessible protocol. Futhermore, additional antibiotic solutions to standardize skin test should be developed and manufactured. Lastly, it would be the pharmacists role to compare their hospitals antibiotic skin test methods with the standard guidelines and develop a protocol within the hospital for patients' safety, and to strive to consistently implement it.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.1
• /
• pp.39-48
• /
• 2015

Reinforced concrete (RC) structures strengthened with FRP materials would cause the loss of the reinforcing effect and the sudden failure of the structure due to the debonding of FRP. The debonding fracture strength of the FRP-strengthened concrete structures has been evaluated using the same strength method as applied in RC structures based on the debonding strain of FRP. However, the values of the FRP debonding strain are different according to design guidelines. Thus, this study carried out an experimental study on RC beams reinforced with GFRP and evaluated the debonding fracture strength of the strengthened beams from each design guideline. Since the debonding failure occurs prior to reaching the ultimate value of concrete compressive strain, this study accounts for the nonlinear stress distribution of concrete. This study also proposed equations that can evaluate the debonding strength of GFRP-strengthened RC beams with similar safety to the ultimate flexural strength of non-strengthened RC beams.

• Information Systems Review
• /
• v.14 no.1
• /
• pp.67-84
• /
• 2012

Recent increases in uncertainty and speed of market change are driving the adoption of new intelligent mobile office systems. Organizational information systems paradigm suggests that a right match between organizational characteristics and the use of technology is critical in producing desired results. Following such perspective this study developed the mobile office system case of Seoul Metropolitan Railway Transit(SMRT) in Korea. SMRT developed the mobile task-supporting environment that help the management of subway lines real-time without the restriction of time and space. They named the system as ST&F(SMRT Talk and Flash). They decided to develop the application systems in-houses they did not want to be overly dependent on external services in future changes and developments of the system. The new practice reduced the time for moving back and forth to 10% of their working time from previous 20%. The time used for paper works and administration chore also reduce to 10% of their working time from previous 30% on the average. The employees could use 80% of their time to concentrate on the completion of assigned task. The effects of this improvement resulted in the heightened efficiency of the use of human resources and the heightened level of railway safety. The case of SMRT shows that the mobile office system can be applied and extended to various business areas such as facility management and maintenance beyond such typical uses as sales and marketing support. Also, The result of case study will be a useful guideline on the construction and using of mobile office system.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.6
• /
• pp.25-31
• /
• 2016

With the development of IOT technology and the expansion of ICT services recently, a variety of home network services have been advanced based on wired and wireless high speed telecommunication. Domestic and global companies have been studying on the innovative technology for the users using IOT based technology and the environment for the smart home services has been gradually developed. The users live their lives with more convenience due to the expansions and developments of smart phones. However, the threatening on the security of the smart home network had occurred by various attacks with the connection to the smart environment telecommunication, lack of applications on low powered and light weight telecommunication, and the problems of security guideline. In addition, the solutions are required for the new and variant attacking cases such as data forgery and alteration of the device for disguising approach with ill will. In this article, the safe communication protocol was designed using certification management technique based on AKI which supplemented the weakness of PKI, the existing certification system in the smart environment. Utilizing the signature technique based on ECDSA, the efficiency on the communication performance was improved, and the security and the safety were analyzed on the security threat under the smart home environment.

• Journal of Environmental Health Sciences
• /
• v.44 no.3
• /
• pp.238-243
• /
• 2018

Objectives: The purpose of this study was to determine skin adhesion rate of children's modeling clay for exposure assessment. Methods: Children's modeling clays were classified into 10 categories as PVA clay, PVA soft clay, starch-based clay, foam clay, rubber clay, oil clay, muddy clay, terra clay, paper clay and slime. A total of 26 children's clay goods was selected. Moisture content (%) and hardness of clays were measured. Five adults aged 20 to 25were recruited for experiment. Gravimetric difference of modeling clay was determined after 3 minutes playing time. Skin adhesion rate ($g/min/cm^2$) was estimated bythe amount of skin adhesion per minute (g/min) and each individual's palm surface area ($cm^2$). Results: Twenty four of the 26 children's modeling clay products were adhesive to skins. Two products of foam and rubber clay were not adhered to skin. For the 24 products, the average skin adhesion rate was $5.5{\times}10^{-4}{\pm}4.0{\times}10^{-4}g/min/cm^2$. The highest skin adhesion rate was $1.3{\times}10^{-3}{\pm}4.4{\times}10^{-4}g/min/cm^2$ for paper clay. The lowest skin adhesion rate was $4.6{\times}10^{-5}{\pm}1.1{\times}10^{-4}g/min/cm^2$ for oil clay. The skin adhesion rate was increased with increase of moisture content. Adhesion rates of some clays were varied by person and testing trials. Conclusion: The study determined skin adhesion rate of children's modeling clay. The adhesion rate is useful for exposure and risk assessments and setting safety guideline to protect children's health.

• Korean Journal of Clinical Pharmacy
• /
• v.11 no.1
• /
• pp.19-29
• /
• 2001

Teicoplanin, a glycopeptide antibiotic, has potential for use as an alternative to vancomycin in the treatment of gram-positive bacterial infections. However, unlike vancomycin, there is a lack of study on teicoplanin's efficacy and safety and the guideline for its use is not available, yet. The objective of this study was to investigate and evaluate the pattern of teicoplanin usage in a university hospital. A retrospective study was performed on 72 adult patients, who took teicoplanin for 3 continuous days at D. University hospital from 1 January 1999 to 30 June 2000. The microorganisms treated with teicoplanin were methicillin-resistant Staphylocorcus aureus $(69\%)$, coagulase-negative Staphylococci $(12\%)$, Enterococcus $(4\%)$, vancomycin-resistant Enterococci $(2\%)$, Streptococci $(2\%)$, and Bacillus $(1\%)$. The types of infection treated with teicoplanin were surgical wound infection $(58\%)$, lower respiratory infection $(11\%)$, bactremia $(7\%)$, urinary tract infection $(5\%)$, pleural fluid infection $(4\%)$, and peritoneal fluid infection $(2\%)$. The mean duration of teicoplanin usage was 16.5 days and teicoplanin was used with 1.4 other antibiotics, which were aminoglycosides (isepamicin, amikacin, netilmicin, astromicin) or quinolones (ciprofloxacin, tosufloxacin) or the third generation cephalosporin (ceftazidime). Only 24 cases $(28.6\%)$ met with the criteria for the justification of use, and the rest of 60 cases $(71.4\%)$ did not meet the criteria. In 84 cases $(100\%)$, blood culture tests were performed prior to the initial dose of teicoplanin. In 83 cases $(99\%)$, serum creatinine were conducted before the initial doses. In 45 cases $(53.6\%)$, serum creatinine was monitored at least twice weekly. In 55 cases $(65.5\%)$, WBC was tested at least twice weekly. In 84 cases $(100\%)$, body temperature was monitored at least once per nursing shift. In 15 cases out of 56 cases, maximum temperature decreased at least 1 degree within 3 days of teicoplanin use. In 15 case out of 35 cases, WBC values were within the normal range after treatment. In 23 cases $(27.4\%)$, dosage regimen was appropriate. Drug-related adverse effects were reported in 13 cases. Nephrotoxicity (progressively increasing SCr. or sustained SCr increase of $\geq$0.5 mg/dl from baseline) was noted in five cases. Neutropenia (absolute neutrophil count <1,500 $cells/mm^3$) was noted in one case and eosinophilia (total eosinophil count >350 $cells/mm^3$) was noted in seven cases. A more strict control on use of teicoplanin is required, considering that teicoplanin is categorized as one of restricted antibiotics.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.1
• /
• pp.51-59
• /
• 2011

With the increased demand for membrane structures in recent years, there have been many studies of their mechanical properties, to the extent that such structures have become recognized as independent structures with a level of safety and durability comparable to those of other general structures. But in reality, the study for the maintenance of membrane structures has not been as active. In particularly, the study of watertightness from the perspective of maintenance has been very limited. Accordingly, a study on securing watertightness performance and the guidelines for maintenance is necessary. In this study, through a case study of water leakage accidents in membrane structures overseas, causes of leakage were selected from the membrane material itself, joint parts and open door of roof part in membrane structure. The water leakage and deterioration elements were analyzed from those leakage causes. The degree of importance of the water leakage and deterioration index was also designated using the AHP (Analytic Hierarchy Process) method. As a result, the basic technical index was suggested for the maintenance of the roofs of large-span membrane structures to prevent water leakage. This index will be used to make a guideline for the long-term maintenance of the roofs of large-span membrane structures.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.1
• /
• pp.317-327
• /
• 2014

This study focuses on developing railway facility charging scheme and more understanding of its corresponding regulations, which is to be utilized as a principal guideline toward a railway competitive market in future. European countries where railway competition is already in place have referred as case studies. The study first defined what the railway facility charges are based upon a spatial concept, railway networks with links and nodes. There are two types of charging: first is on railway tracks which are identical to links, and another at stations which are identical to nodes, such that the railway facility charges become a summation of track charges and station charges covering all the railway networks. Next, we have identified what the objectives of imposing track and station charges are, including factors being able to reflect each objective. 6 objectives are proposed as for the track charges, and 3 objectives as for the station charges. The factors found are accordingly belonged to the objectives. In the end, relevant regulations are compared with the European regime to diagnose what further requirements or/and principals have to be guided into them. In summary, both charging scheme and the direction of regulation updates can be utilized in setting an appropriate charging scheme and corresponding regulations to ensure fair competitions.

• Analytical Science and Technology
• /
• v.24 no.6
• /
• pp.503-509
• /
• 2011

Specific surface area is becoming a very important factor when newly developed advanced nano-materials are evaluated. But there have been many differences in results when measuring specific surface areas, depending on the measuring equipments and analysis method. To verify the reliability of the specific surface area measurement device supplied within the country, Round Robin Test (RRT) has been done at 21 affiliated research institutes. As a result, it was found that several institute had problems in measuring of gas adsorption amount in measuring equipment, and this proved the need for certified reference material (CRM). Furthermore, it was also found that the results from BET analysis is easily swayed by the analyst's subjectivism, and the calculated results may differ up to 16% in case of CRM I depending on the selection range of BET analysis. So this showed that a standard guideline for BET constant C value and fitting correlation coefficient R is needed, to properly select range in BET analysis. The experience in RRT, distribution of CRM, and standardized procedure would result in improved reliability in industrial processes, and thus, would contribute to the quality management, the productivity improvement, the safety evaluation, and the new material development.