• Journal of Aerospace System Engineering
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• v.17 no.1
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• pp.79-87
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• 2023

To design a control law of an aircraft, an accurate aircraft dynamic model is required. To obtain an aerodynamic database (DB) to build a dynamic model, a large number of wind tunnel tests are typically required. However, when flight test data of target aircraft exist such as in the process of unmanned conversion of a manned aircraft, an aircraft dynamic model can be obtained through a parameter estimation method and a DB tuning procedure. This paper describes a nonlinear model construction process and a verification method for KC-100 OPV aircraft. Flight data compatibility analysis was performed to determine suitability of the estimation method application. Linear model estimation was performed using the maximum likelihood estimation method. Results of aerodynamic DB tuning process and verification applying the FFS standard to the nonlinear model constructed are presented.

• Korea Journal of Hospital Management
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• v.28 no.1
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• pp.24-36
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• 2023

Purposes: The purpose of this study was to analyze the factors associated with current smoking status in Wonju-si and Chuncheon-si, and to study the cause of difference in smoking rates between these two regions. Methodology: Data was from the National Health Insurance Service database from 2019 to 2020. Current smoking status was based on the response to the health examination questionnaire. Logistic regression analysis was conducted to identify factors associated with current smoking status. The study included 207,307 individuals from Wonju-si and 173,698 individuals from Chuncheon-si. Findings: The smoking rate of Wonju-si was 19.83%, and Chuncheon-si was 18.20%, showing a difference in the smoking rates between the two regions. Logistic regression analysis found that men, those aged 40-49, being a self-employed insured, a medical-aid beneficiary, having a lower income, working in construction, transport, storage, communication, or manufacturing industries, having a high-risk drinking level and being underweight were significantly associated with a higher likelihood of smoking(p<0.05). Additionally, having a chronic disease was associated with a lower likelihood of smoking in the case of Chuncheon-si(p<0.05). Practical Implication: This study found the differences of factors associated with smoking rates between the two regions and could provide implications for establishing intervention programs or policies that could contribute to lowering the smoking rate in areas with high smoking rates.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.55 no.8
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• pp.498-507
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• 2012

Background and Objectives We aimed to develop a Korean version of the velopharyngeal insufficiency (VPI) speech corpus system. Subjects and Method After developing a 3-channel simultaneous speech recording device capable of recording nasal/oral and normal compound speech separately, voice data were collected from VPI patients aged more than 10 years with/without the history of operation or prior speech therapy. This was compared to a control group for which VPI was simulated by using a french-3 nelaton tube inserted via both nostril through nasopharynx and pulling the soft palate anteriorly in varying degrees. The study consisted of three transcriptors: a speech therapist transcribed the voice file into text, a second transcriptor graded speech intelligibility and severity and the third tagged the types and onset times of misarticulation. The database were composed of three main tables regarding (1) speaker's demographics, (2) condition of the recording system and (3) transcripts. All of these were interfaced with the Praat voice analysis program, which enables the user to extract exact transcribed phrases for analysis. Results In the simulated VPI group, the higher the severity of VPI, the higher the nasalance score was obtained. In addition, we could verify the vocal energy that characterizes hypernasality and compensation in nasal/oral and compound sounds spoken by VPI patients as opposed to that characgerizes the normal control group. Conclusion With the Korean version of VPI speech corpus system, patients' common difficulties and speech tendencies in articulation can be objectively evaluated. Comparing these data with those of the normal voice, mispronunciation and dysarticulation of patients with VPI can be corrected.

• Structural Engineering and Mechanics
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• v.86 no.5
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• pp.589-605
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• 2023

This paper investigates the ductility demands of steel frames equipped with self-centring fuses under near-fault earthquake motions considering multiple yielding stages. The study is commenced by verifying a trilinear self-centring hysteretic model accounting for multiple yielding stages of steel frames equipped with self-centring fuses. Then, the seismic response of single-degree-of-freedom (SDOF) systems following the validated trilinear self-centring hysteretic law is examined by a parametric study using a near-fault earthquake ground motion database composed of 200 earthquake records as input excitations. Based on a statistical investigation of more than fifty-two (52) million inelastic spectral analyses, the effect of the post-yield stiffness ratios, energy dissipation coefficient and yielding displacement ratio on the mean ductility demand of the system is examined in detail. The analysis results indicate that the increase of post-yield stiffness ratios, energy dissipation coefficient and yielding displacement ratio reduces the ductility demands of the self-centring oscillators responding in multiple yielding stages. A set of empirical expressions for quantifying the ductility demands of trilinear self-centring hysteretic oscillators are developed using nonlinear regression analysis of the analysis result database. The proposed regression model may offer a practical tool for designers to estimate the ductility demand of a low-to-medium rise self-centring steel frame equipped with self-centring fuses progressing in the ultimate stage under near-fault earthquake motions in design and evaluation.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.1
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• pp.59-72
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• 2024

To investigate the mechanism of Wenshen Xuanbi Decoction (WSXB) in treating osteoarthritis (OA) via network pharmacology, bioinformatics analysis, and experimental verification. The active components and prediction targets of WSXB were obtained from the TCMSP database and Swiss Target Prediction website, respectively. OA-related genes were retrieved from GeneCards and OMIM databases. Protein-protein interaction and functional enrichment analyses were performed, resulting in the construction of the Herb-Component-Target network. In addition, differential genes of OA were obtained from the GEO database to verify the potential mechanism of WSXB in OA treatment. Subsequently, potential active components were subjected to molecular verification with the hub targets. Finally, we selected the most crucial hub targets and pathways for experimental verification in vitro. The active components in the study included quercetin, linolenic acid, methyl linoleate, isobergapten, and beta-sitosterol. AKT1, tumor necrosis factor (TNF), interleukin (IL)-6, GAPDH, and CTNNB1 were identified as the most crucial hub targets. Molecular docking revealed that the active components and hub targets exhibited strong binding energy. Experimental verification demonstrated that the mRNA and protein expression levels of IL-6, IL-17, and TNF in the WSXB group were lower than those in the KOA group (p < 0.05). WSXB exhibits a chondroprotective effect on OA and delays disease progression. The mechanism is potentially related to the suppression of IL-17 and TNF signaling pathways and the down-regulation of IL-6.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1215-1224
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• 2013

Great efforts have been made worldwide to reduce the Green House Gas (GHG) emission following the "Kyoto Protocol" declared during the United Nations Framework Convention on Climate Change in 1997. Many industries have restructured to meet the standard set by the Protocol. However, no clear guidance has been established for the purpose of reducing the GHG emission in construction industry. In addition, no significant effort has been made to conserve the energy during construction activities. For more effective energy saving in construction industry, it is essential to collect data about energy consumption, quantity of environmental emissions and costs. However, most studies on sustainable construction have been concentrated on the use of equipment, maintenance and repair works during construction due to the difficulties of collecting such data. This study suggests a method to select the most environmentally friendly equipment combination for earthwork with comparing environmental loads and costs using the database of Life Cycle Inventory in the Ministry of Knowledge Economy and Ministry of Environment of Korea.

• Land and Housing Review
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• v.3 no.4
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• pp.415-421
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• 2012

In case of Korean housing complex, there became more mixed arrangement of buildings with different number of layers for a variety of urban skyline, recently. For example, around 33% of the construction sites of 'A' public corporation have gaps of more than 4 layers between high-rise buildings and low-rise ones in the same site, according to the survey. Generally, construction duration of the housing complex is estimated based on the layers of the highest building. Due to this baseline, whole construction duration could be extended so that the project cost could be increased. Therefore, framework duration of higher-rise buildings should be reduced to secure the feasibility of the project. On the other hands, these shortenings could adversely harm the feasibility in some cases because there are a wide range of combinations of the buildings with different number of layers in designing housing complex. Therefore, this study shows the results of analysis on effects of framework time shortening on the cost in housing complex project. Moreover, this could set the baseline of checking possibilities in condensing the construction duration of projects with buildings of different layers by supplying comprehensive database.

• Korean Journal of Construction Engineering and Management
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• v.16 no.3
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• pp.113-122
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• 2015

VE workshop is performed based on VE expert' experiences without retrieving VE data of similar previous projects. Moreover, it usually omitted or applied for the sake of formality due to insufficiently understanding VE function, limited time, space and budget. Even though many studies have established VE databases for retrieving and reusing VE data, VE workshop is still inefficient and ineffective to improve projects' values. With this regard, this study proposes a preliminary prototype for improving VE workshop, which utilizes the state-of-the-art information communication technologies(ICTs) including Building Information Modeling(BIM), Mobile Computing(MC), Network Service System(NSS), and Database Management System(DBMS) for better managing, storing and reusing VE data. The prototype was developed to evaluate advantages and limitations. The results show that the proposed prototype can support visual VE data retrieval from similar previous projects, enhance communication among VE team and save much time and cost comparing to traditional VE. Through this, the productivity of VE workshop can improve efficiently and effectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.113-119
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• 2014

Recently, R.O.K. Navy is increasing re-usability of design data and application of M&S(Modeling and Simulation) through the establishment of collaborative product development environment focused on Naval Ship Product Model(NSPM). As a result, the reliability of the result of design is getting better, and furthermore, a study to improve quality of construction through simulation of production/operation is in progress. Accordingly, the database construction of design data and the DB(Database) quality become important, but there was not research related to those or it was just initial state. This paper conducted research about system of the quality verification process of shape elements which compose NSPM based on the quality verification guideline of NSPM as the result of the precedent study. The hull surface was limited as verification object. The study to verify two things that application of basic drawing by the cad model of hull surface, and whether there is error in the geometric quality of cad model was progressed. To achieve this goal, the verification criteria and algorithm were defined and the prototype system which is based on was developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.43-49
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• 2017

In recent years, the use of BIM in domestic construction has been increasing, but it is used mainly for internal and external visualization rather than for BIM design including drawings. For this reason, several studies have highlighted the lack of libraries and economic problems for BIM design. In other words, for the most economically small domestic design offices, activating the BIM design is a negative factor because it is difficult to invest the necessary manpower and cost to produce and use the required BIM library. The BIM design can be more applicable if the library can be supplied economically, easily, and quickly. In this study, BIM library business model and consideration factors that can provide BIM library service economically, easily, and quickly by considering the existing building material selection task and BIM library are presented. The proposed business model will increase the number of suppliers of BIM libraries, which are lacking in Korea, and will enable an effective BIM design at low cost and effort. If a service that reflects the business model proposed in this study is made, an integrated database that can consistently share information in the design, construction, and maintenance stages will be constructed. This can monitor the changes in material and equipment information during the life cycle of the building. The database can be used to monitor any changes in material and equipment information throughout the life cycle of a building, so that it can be used as historical data for effective design and maintenance as well as for material and equipment upgrades.