• Journal of the Korean Society for Railway
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• v.8 no.1
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• pp.15-20
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• 2005

The ministry of Environment, Korea, are designing the TMDL(Total Maximum daily Load) program far 4 major large rivers to improve water quality from possible pollutants. It can be successfully performed as controling of nonpoint pollutants from watershed area. Railway stations are stormwater intensive land use because of high imperviousness and high pollutant mass emissions from various activities. Especially the metal pollutants from the railway station were recognized as an important pollutants because of its toxicities. In order to characterize the washed-off pollutants. the monitoring were performed on a railway station during storms. Pollutant concentrations are exponentially decreasing during the storm duration. The 95％ confidence interval of pollutant concentrations in an hour storm duration ranges from 61.6 to 115.4mg/L for TSS(mean=88.50mg/L),103.8-244.1mg/L for COD(mean=174 mg/L) and 7.68-17.32mg/L for Oil & Grease(mean=12.5mg/L). The ranges of metals were 39.2-84.0 $\mu\textrm{g}$/L for total Cu(mean=61.6$\mu\textrm{g}$/L), 14.0-25.8$\mu\textrm{g}$/L for total Pb(mean=19.9$\mu\textrm{g}$/L) and 182.2-376.l $\mu\textrm{g}$/L for total Zn(mean=279.2$\mu\textrm{g}$/L). The first flush criteria for best management practices can be suggested to 50％ pollutant mass emissions during 30％ of the total flow.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.318-328
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• 1991

The present paper describes the experimental study on the fixed-type wave-energy conversion system, consisting of the OWC-type wave-energy absorbing chamber and the duct for the air turbine. For simplicity, a screen of wire mesh was employed in place of an air turbine in order to simulate its effects on OWC chamber. Experiments were performed at the towing tank in regular waves with the frequency range of 0.22-0.75Hz. Comparison wish the numerical prediction using a potential flow-based method [4] was made to validate the capability of numerical code. It was shown that the agreements between measured and calculated results are quite good, giving a confidence in prediction method. Simulation of air turbine using a wire-mesh screen was successful, at least in a qualitative sense, to investigate the inter action between the OWC chamber and an air turbine. Results also showed that the effects of a wire-mesh screen on chamber efficiency are negligible, and the present model can be effectively utilized for the practical use in ocean waves with the frequency range under 0.3Hz.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.12-25
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• 2009

The purpose of this study is to identify and analyze drivers' attitude related to usage of traffic information and traffic management service. A sample survey on Seohaeanseon Expressway(15), Gyeongbu Experssway(1), Youngdong Expressway(50) was conducted to analyze drivers' attitude ; sample size is 304 with 95% of confidence level and ${\pm}3.6%$ of sampling error. The analysis lists of drivers' attitude are usage of traffic information, awareness about information dissemination devices, and awareness about traffic control information related to LCS or RWIS. The results of this study is that drivers want pre-trip information, voice-based Hi-pass OBU, and fast incident management. According to the IPA, KEC's main consideration is a traffic flow improvement.

• The Journal of Information Technology
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• v.1 no.1
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• pp.173-188
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• 1998

In this paper we discussed various types of electronic payment schemes that are emerging. Threats vary from malicious hackers attempting to crash a system, to threats to data or transaction integrity. An understanding of the various types of threats can assist a security manager in selecting appropriate cost-effective controls to protect valuable information resources. An overview of many of today's common threats presented in this paper will be useful to mangers studying their own threat environments with a view toward developing solutions specific to their organization. To ensure security on the Internet, several methods have been developed and deployed. They include authentication of users and servers, encryption, and data integrity. Transaction security is critical : without it, information transmitted over the Internet is susceptible to fraud and other misuse. So computer systems represents an Intermediary with the potential to access the flow of information between a user. Security is needed to ensure that intermediaries cannot eavesdrop on transactions, or copy/modify data. Online firms must take additional precautions to prevent security breaches. To protect consumer information, they must maintain physical security of their servers and control access to software passwords and private keys. Techniques such as secret and public-key encryption and digital signatures play a crucial role in developing consumer confidence in electronic commerce.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.126-135
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• 2008

The purpose of this study is to develop the efficient information system for managing owner's requirement(O/R) throughout the design phases. In order to derive an improvement, current status of O/R management both in domestic and foreign design company has been analyzed. Through the literature reviews and interviews with experts, the Information on design process and detailed activities were investigated. Based on the basic research, inputs, outputs and participants were defined and information flow diagram was drawn. O/R's were categorized according to comprehensive interviews with specialists, and a prototype system was suggested. Conducting systematized O/R management will improve the confidence of owners' role on design, reduce re-work in design tasks, and finally elevate design quality.

• Advances in aircraft and spacecraft science
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• v.5 no.3
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• pp.363-383
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• 2018

One-dimensional (1D) models of incompressible flows, can be of interest for many applications in which fast resolution times are demanded, such as fluid-structure interaction of flows in compliant pipes and hemodynamics. This work proposes a higher-order 1D theory for the flow-field analysis of incompressible, laminar, and viscous fluids in rigid pipes. This methodology is developed in the domain of the Carrera Unified Formulation (CUF), which was first employed in structural mechanics. In the framework of 1D modelling, CUF allows to express the primary variables (i.e., velocity and pressure fields in the case of incompressible flows) as arbitrary expansions of the generalized unknowns, which are functions of the 1D computational domain coordinate. As a consequence, the governing equations can be expressed in terms of fundamental nuclei, which are invariant of the theory approximation order. Several numerical examples are considered for validating this novel methodology, including simple Poiseuille flows in circular pipes and more complex velocity/pressure profiles of Stokes fluids into non-conventional computational domains. The attention is mainly focused on the use of hierarchical McLaurin polynomials as well as piece-wise nonlocal Lagrange expansions of the generalized unknowns across the pipe section. The preliminary results show the great advantages in terms of computational costs of the proposed method. Furthermore, they provide enough confidence for future extensions to more complex fluid-dynamics problems and fluid-structure interaction analysis.

• Tuberculosis and Respiratory Diseases
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• v.84 no.4
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• pp.274-281
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• 2021

Background: The Korea National Health and Nutrition Examination Survey (KNHANES) is a well-designed survey to collect national data, which many researchers have used for their studies. In KNHANES, although portable spirometry was used, its reliability has not been verified. Methods: We prospectively enrolled 58 participants from four Korean institutions. The participants were classified into normal pattern, obstructive pattern, and restrictive pattern groups according to their previous spirometry results. Lung function was estimated by conventional spirometry and portable spirometry, and the results were compared. Results: The intraclass correlation coefficients of forced vital capacity (FVC) (coefficient, 9.993; 95% confidence interval [CI], 0.988-0.996), forced expiratory volume in 1 second (FEV₁) (coefficient, 0.997; 95% CI, 0.995-0.998), FEV₁/FVC ratio (coefficient, 0.995; 95% CI, 0.992-0.997), and forced expiratory flow at 25-75% (FEF25-75%; coefficient, 0.991; 95% CI, 0.984-0.994) were excellent (all p<0.001). In the subgroup analysis, the results of the three parameters were similar in all groups. In the overall and subgroup analyses, Pearson's correlation of all the parameters was also excellent in the total (coefficient, 0.986-0.994; p<0.001) and subgroup analyses (coefficient, 0.915-0.995; p<0.001). In the paired t-test, FVC, FEV₁/FVC, and FEF25-75% estimated by the two instruments were statistically different. However, FEV₁ was not significantly different. Conclusion: Lung function estimated by portable spirometry was well-correlated with that estimated by conventional spirometry. Although the values had minimal differences between them, we suggest that the spirometry results from the KNHANES are reliable.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.1
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• pp.149-163
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• 2021

Objectives This study is to review the effectiveness of exercise after lung cancer surgery. Methods Relevant randomized controlled trials (RCTs) were searched in PubMed database. The systematic review was conducted through flow diagram. The risk of biases were assessed through the Cochrane guideline. Characteristics and outcomes were extracted from each study. Meta-analyses of forced expiratory volume in one second (FEV1), 6-minute walk test (6MWT), quality of life (QoL), pulmonary complications were conducted. Results 14 RCTs were selected. In meta-analysis, exercise improved FEV1 (mean difference [MD] 0.14; 95% confidence interval [CI] 0.04 to 0.25; p=0.009; I2=55%) and mean change of FEV1 (MD 0.11; 95% CI 0.02 to 0.20; p=0.02; I2=0%). Exercise increased the distance of 6MWT, but there was considerable heterogeneity (MD 45; 95% CI 21.16 to 68.83; p=0.0002, I2=89%). There was no differences in QoL scores by 2 questionnaires (European Organisation for Research and Treatment of Cancer quality of life questionnaire, short form-36). Exercise reduced the duration of hospital stay (MD -3.32; 95% CI -5.27 to -1.36; I2=0%; 2 studies) but not duration of chest tube intubation (MD -1.37; 95% CI -2.81 to 0.06; I2=0%) and incidence of pulmonary complications (pooled risk ratio 0.54; 95% CI 0.23 to 1.30; I2=0%). Conclusions Exercise might reduce the duration of hospital stay after lung surgery. There was not enough evidence to prove improvement of lung function, aerobic capacity, muscle strength, QoL, and decline of pulmonary complications. Low-quality risk of bias, different units or estimation of outcome, different exercise type and duration, heterogeneity among studies make the evidence of effectiveness weak. Future researches are required to redeem these defects.

• Journal of Korean Medicine Rehabilitation
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• v.32 no.3
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• pp.29-35
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• 2022

Objectives The purpose of this systematic review is to analyse randomized controlled trials about acupuncture for patellofemoral pain syndrome (PFPS) and evaluate it's pain improvement effect. Methods Studies will be searched from ten databases (Medline/PubMed, Cochrane Library, EMBASE, China National Knowledge Infrastructure [CNKI], WanFang Data, Citation Information by NII [CiNII], ScienceON, Koreanstudies Information Service System [KISS], KMBASE, and KoreaMed). Participants will be patients diagnosed with PFPS, regardless of cause, gender, age or race, and interventions will be acupuncture, electroacupuncture, dry needling, fire needle, and acupotomy. Other treatments than interventions will be the control group and the main outcome will be reviewed by visual analogue scale (VAS). Results Data will be extracted and assessed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis flow chart and Cochrane risk of bias tools. Meta-analysis will be conducted using random effect model within 95% confidence interval. Conclusions We expect this systematic review to provide useful data about the pain improvements of patellofemoral pain using acupuncture and expect to stimulate and systematize acupuncture treatment on PFPS in the future.

• Journal of The Korean Association of Information Education
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• v.26 no.5
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• pp.327-340
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• 2022

This study applied effective playful learning to increase the learning motivation of non-CS major students to help them achieve learning and to successfully operate online SW liberal arts classes for 560 students. As a result of analyzing the students' reflection journals, most of the students accepted the 'white radish' of dialect names as fun playful learning in the process of learning local variables and global variables. And they were surprised and amazed at discovering unexpected contents in our SW class. It was found that they experienced delight in learning, learning-flow, confidence, and intrinsic motivation. In the final term exam at the end of the semester, it was confirmed that the correct rate of 92% for questions related to local and global variables was higher than the average rate of other questions' correctness of 67.1%.