• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.10
• /
• pp.1005-1009
• /
• 2017

In this study, the shock resistance of a gas turbine package subjected to a shock load caused by non-contact underwater explosion was investigated using numerical analysis. To perform shock analysis, the time-history shock load was calculated according to BV-043 (German Navy Regulation). The direct transient response analysis in the time domain for the simplified Whole Engine Model (WEM) was performed using the calculated shock load. In addition, the structural integrity of a detailed model was evaluated by considering the shock load transferred to each component. As a result, it was confirmed that the safety factor was at least 1.0 as compared with the reference stress. Finally, the structural and functional integrity of the Engine Management System (EMS) of the gas turbine package was verified through an actual shock test.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.2
• /
• pp.503-508
• /
• 2020

The three-dimensional precision numerical analysis was performed using the finite element model applied with the railway track model consisting of rails, As a result of analyzing the track deformation level of the existing tunnel due to the excavation work adjacent to the urban transit, it was found that the evaluation criteria (allowed values) of conventional railways lines were satisfied. Based on the numerical analysis, it was analyzed that the results of the prediction of the tunnel structural stability of due to the excavation work and the level of the tunnel deformation occurring at the actual site could be approximated as closely as possible.

• Korean Medical Education Review
• /
• v.25 no.3
• /
• pp.273-284
• /
• 2023

According to the World Health Organization, for medical schools to fulfill their obligation of social accountability, it is necessary for medical education, research, and service areas to ref lect the healthcare system's relevance, quality, cost-effectiveness, and equity. This study utilized Boelen and Heck's (1995) social accountability grid model to analyze the degree to which the Accreditation Standards of Korean Institute of Medical Education and Evaluation 2019 (ASK2019) standards apply the World Federation for Medical Education's (WFME) standards. The social accountability characteristics of the former were compared to those of the WFME, the Liaison Committee on Medical Education, and the Australian Medical Council. Experts with experience and certification in medical education and evaluation classified the ASK2019 standards according to the grid model, evaluated social accountability perspectives, and categorized them according to the process, content, and outcome. Of the 92 standards, 61 (66.30%) were selected as social accountability standards; these encompassed all areas. There was a particular focus on outcome-related areas, such as "mission and outcomes," "student assessment," "educational evaluation," and "continuous improvement." Education and quality were the most common (33, 54.11%), followed by 18 standards related to education and relevance. However, the standards on cost effectiveness and equity corresponding to education, research, and service were significantly insufficient. As a result of classification using a logic model, many criteria were incorporated into the process, producing results similar to those of international accreditation institutions. Therefore, to fulfill medical schools' social accountability, it is necessary to develop cost effectiveness and equity standards with reference to grid models and expand them beyond education to include research and service areas. Developing content and outcome standards is also required.

• Korean Journal of Biological Psychiatry
• /
• v.16 no.2
• /
• pp.69-75
• /
• 2009

Objectives : The detrended fluctuation analysis is one of the nonlinear methods for the investigation of biological time series. It quantifies the fractal scaling properties and is known to be useful in the evaluation of long-range correlations in time series. The heart rate variability(HRV) of obstructive sleep apnea syndrome (OSAS) patients during nighttime was analyzed by detrended fluctuation analysis to assess its relationship with the severity of the symptoms. Methods : Fifty nine untreated male OSAS patients with moderate to severe symptoms(mean age=45.4${\pm}$11.7 years, apnea-hypopnea index, AHI${\geq}$15) underwent nocturnal polysomnography. Moderate(AHI=15-30, N=22) and severe(AHI>30, N=37) OSAS patients were compared for the indices derived from detrended fluctuation analysis and frequency domain analysis of HRV. Results : In the detrended fluctuation analysis, the alpha values were 0.75${\pm}$0.11 and 0.82${\pm}$0.07 for the severe and the moderate OSAS groups respectively. The difference was significant(p<.01). The alpha value had negative correlation with AHI(r=-.425, p=.001). Negative correlation coefficients were also found in the relationships between the alpha values and very low frequency(VLF)(r=-.425, p=.001), low frequency(LF)(r=-.633, p= <.001) and the LF/HF ratio(r=-.305, p=.019) respectively. LF/HF ratio(p=.005) was higher in the severe OSAS group compared to that of the moderate OSAS group. Conclusion : In this study, the detrended fluctuation analysis showed the significant difference between the two OSAS groups classified according to their severity of symptoms. The scaling exponent showed the negative correlation with AHI and indicies of frequency domain analysis. This result suggests that detrended fluctuation analysis can be helpful to estimate the severity of OSAS.

• The Journal of Korean Physical Therapy
• /
• v.24 no.5
• /
• pp.377-382
• /
• 2012

Purpose: The purpose of this qualitative study was to understand the application of clinical reasoning throughout clinical and therapeutic knowledge of clinical pediatric physical therapists under physician prescriptions. Methods: Purposive sampling techniques were used in selection of nine clinical pediatric physical therapists in South Korea. Open and semi structured interviews were conducted, and were thoroughly examined and reviewed, followed by analysis of the clinical reasoning portion. Results: Pediatric physical therapists have been influenced by information gathering, physical function and evaluation of their patients, hypothesis-orientation, and re-evaluation and self-monitoring. Novice physical therapists were more dependent on physician prescriptions and parent's hope than the result of their own evaluation and critical pathway. Middle experienced pediatric physical therapists were more dependent on rapport with children and their parents. Highly experienced pediatric physical therapists were more reliant on hypothesis-orientation and self-monitoring. As reports on clinical experience of pediatric physical therapists have accumulated, clinical reasoning of pediatric physical therapists has been influenced by their experience, such as education, clinical pathology conference, their own clinical experience and rapport with patients and their parents than physicians' prescriptions. Conclusion: The findings of the current study are generally consistent with existing research on clinical reasoning. The results of the current study may be used by educators for enhancement of clinical reasoning abilities and knowledge of students or novices as well as development of a guide for use by suitable novices or students, and could provide important information for use in physical therapy practice and research.

• Journal of Digital Convergence
• /
• v.14 no.8
• /
• pp.47-56
• /
• 2016

This study is on the actual analysis of R&D investment effect through DEA in terms of efficiency resulted from forestry sector climate change response R&D project. Namely, it is clarifying the mechanism of the scientific, technological, social performance result and output, depending on research development cost, employment size as same input. Also, it is in-depth analysis on which performance operates more efficiently in any detailed business. With the study result, we seek political implications to enhance investment effect and core element to consider R&D business project in the future.

• The Journal of Bigdata
• /
• v.6 no.1
• /
• pp.1-12
• /
• 2021

The rapid growth of mobile-based online shopping and the appearance of untact business initiated by COVID-19 has led to an explosive increase in demand for logistics services such as delivery services. In order to respond to the rapidly growing demand, most logistics and distribution companies are working to improve customer service levels through the establishment of a full-filament center in the city center. However, due to social factors such as high land prices and traffic congestion, it becomes more difficult to establish the logistics facilities in the city center. In this study, it has been proposed the way to choose the candidate locations for the shared distribution centers among the space nearby the tall-gate which can be idle after the smart tolling service is widely extended. In order to evaluate the candidate locations, it has been evaluated the centralities of all candidates using social network analysis (SNA). To understand the result considering the characteristics of centrality, the network structure was regenerated based on the distance and the traveling time, respectively. It is possible to refer the result of evaluation based on the cumulative relative importance to choose the best set of candidates.

• Journal of the Korean Geotechnical Society
• /
• v.24 no.12
• /
• pp.85-92
• /
• 2008

It is necessary to develop a rational design method for surface reinforcement of very soft ground because most current design works rely on merely crude empirical correlations. In this paper, the mechanical behavior of very soft ground that is surficially reinforced was investigated with the aid of a series of numerical analyses. Several material properties of each dredged soft ground, reinforcement and backfill sand mat have been exercised in the numerical analysis. The result of numerical analysis was compared with those of the laboratory model test. Through the matching process between the numerical and experimental result, it is possible to determine representative material properties of the dredged soft ground, reinforcements and backfill sand mat. These verified material properties permit to evaluate the effect of the stiffness of reinforcement and the thickness of sand mat on the overall deformation of the reinforced soft ground.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.03b
• /
• pp.239-246
• /
• 2000

It has been generally much fine contents in West Coast of Korea. When cyclic shear stress causing liquefaction was estimated as using cyclic triaxial tests in these grounds, it didn't appear linear relations between deviator stress and confining stress where σ'₃ was more than 150 kpa. Namely, due to no normalization of cyclic shear stress ratio, the errors of this is increased. Therefore, more confining stress is increased, more increment of deviator stress is decreased. So, using linear relations between tanø'/sub d/ of dynamic internal friction angle and CSR where σ'₃ was less than 150 kpa, liquefaction of these grounds was evaluated. Also, as doing detail evaluation which had carried response analysis of earthquake, this appeared good results which was well compatible with empirical methods using N-value of SPT. It was thought that these result evaluated vulnerable liquefaction area more correct than existing methods. Also, characteristics of liquefaction in West Coast grounds was compared with clean sands, with analysis of behavior of pore pressure ratio and axial strain affected by fine contents, as cyclic loading was applied.

• Journal of Sensor Science and Technology
• /
• v.20 no.5
• /
• pp.311-316
• /
• 2011

Monitoring the carbon dioxide concentration in arterial blood is vital for the evaluation and prevention of pulmonary disease. Yet, domestic pure arterial blood carbon dioxide sensor technologies are not being developed, instead all sensors are imported. In this paper, we develop a real time monitoring system for arterial blood partial pressure of carbon dioxide($pCO_2$) gas from the wrist by using a carbon micro-heater. The micro-heater was fabricated with a thickness of 0.3 ${\mu}m$ in order to collect the carbon dioxide under the skin. The micro-heater has been designed to perform temperature compensation in order to prevent damage to the skin. Two clinical trials of the system were undertaken. As a result, we demonstrated that a portable, transcutaneous carbon dioxide analysis($TcpCO_2$) device produced domestically is possible. In addition, this system reduced the analysis time significantly. Carbon films could reduce the unit price of these sensors by replacing the gold film used in foreign models. Also, we developed a real time monitoring system which can be used with optical biosensors for medical diagnostics as well as gas sensors for environmental monitoring.