• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.247-250
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• 2007

Flexible media such as the paper, the film, etc. are thin, light and very flexible. They behave in geometrically nonlinear. Any of small force makes large deformation. So we must including aerodynamic effect when its behavior is predicted. Thus, it becomes fully coupled fluid-structure interaction(FSI) problem. In FSI problems, where the fluid mesh near the structure undergoes large deformations and becomes unacceptably distorted, which drive the time step to a very small value for explicit calculations, the arbitrary Lagrangian-Eulerian(ALE) methods or rezoning are used to create a new undistorted mesh for the fluid domain, which allows the calculations to continue. In this paper, FE sheet model considering geometric nonlinearity is formulated to simulate the behavior of the flexible media. Aerodynamic force to the media by surrounding air is calculated by solving the incompressible Navier-Stokes equations. Q2Q1(Taylor-Hood) element which means biquadratic for velocity and bilinear for pressure is used for fluid domain. Q2Q1 element satisfies LBB condition and any stabilization technique is not needed. In this paper, cantilevered sheet in the viscous incompressible Navier-Stokes flow is simulated to check the mesh motion and numerical integration scheme, and then falling paper in the air is simulated and the effects of some representative parameters are investigated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.841-846
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• 2000

The compression wave produced when a high-speed train enters a tunnel propagates along the tunnel ahead of the train. The micro pressure wave related to He compression wave is a special physics Phenomena created by high-speed train-tunnel interfaces. On this work, the method for reducing the micro pressure wave is to delay the gradient of the compression wave by using aerodynamic structures. The objective of this paper is to determine the optimum angle of the slanted portal using the moving model rig. According to the results of the present study, the maximum value of micro pressure wave is reduced by 19.2% fer the $45^{\circ}$ slanted portal installed at the entrance of the tunnel and reduced by 41.9% far the $45^{\circ}$ slanted portals at the entrance and exit of the tunnel. Also it is reduced by 34.6% for the $30^{\circ}$ slanted portals installed at the entrance and exit of the tunnel.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.110-113
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• 2006

This paper describes the development process of body and full vehicle for reduced idle vibration through the data level of frequency and sensitivity. The vibration mode map is used to separate body structure modes from resonance of engine idle nm and steering system. This paper describes the analysis approach process to reduce the variation of uncertainties for idle vibration performance at initial design stage. The robust design method is performed to increase the stabilization performance under vehicle vibration. It is used to predict the effects of the stiffness deviation according to the spot welding condition of the body structure. The tolerance associated with hood over slam bumper is analyzed for the quality deviation of the moving system in full vehicle. And the glass sealant stiffness and weight difference is considered for the deviation characteristic. The design guideline is suggested considering sensitivity about body and full vehicle by using mother car at initial design stage. It makes possible to design the good NVH performance and save vehicles to be used in tests. These improvements can lead to shortening the time needed to develop better vehicles.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2008년도 춘계학술발표대회 논문집
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• pp.427-430
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• 2008

The present study is a preliminary research improving the dwelling quality of apartment house as a kind of multi-family housing. The purpose of the study is to find out the present condition on noise level and types including residents' living noise in apartment units. The method was field survey consisted of field measurements on equivalent noise level, observation on noise type, and interview on residents' responses. The results are as follows. 1) Averages of indoor noise levels of subject houses were measured as $43.9{\sim}62.2\;dB(A)_{Leq5min}$, the average of each house except one was higher than the permissible level, 45 dB(A). 2) The noise types observed were mostly residents' living noise and classified as 'water hammer', 'living equipment noise', 'noise by family', 'hood noise', and 'kitchen noise' in own unit, 'walking and talking noise in stairs and corridors', 'noise by neighborhood house', 'noise by the upper story' in building, and outdoor noise. 3) The residents show slightly non-positive responses at 'noise by the upper story', 'noise by neighborhood house', 'water hammer', and 'noise by family'. Therefore, it is required to plan for preventing deterioration of the sound environment quality by residents' living noise in own unit as well as by neighborhood houses.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.883-888
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• 2008

Various effluents generated in cooking processes contribute a great deal to indoor air pollution among many other indoor pollutants such as dusts from outdoor and carbon dioxide from human body. Kitchen exhaust hoods are not believed to exhaust indoor contaminants properly in many cases, while generating too much noise. Instead of focusing on individual products of kitchen hoods, we should address the problem by attacking the ventilation system as a whole including vertical shafts and building air-tightness. In this study, it is intended to investigate the pressure distribution along the vertical shaft depending on various system parameters, such as shaft size, concurrent hood usage rate, roof fan, inlet pressure loss, and outdoor temperature. The maximum static pressure in the vertical shaft has been obtained using the method of design of experiments and analyzed by the analysis of variance. The results can be used for the design of kitchen exhaust systems by analyzing the pressure distributions in vertical shafts.

• 대한기관식도과학회지
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• 제1권1호
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• pp.122-128
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• 1995

The experience with treatment of acquired subglottic stenosis in 20 adults is reviewed. Nine of the 20 patients (45%) had opeated by other institues before treatment. Causes of the disease were 10(50%) of blunt neck trauama and 10(50%) of prolonged intubation. The most common associated airway diseases were nine patients (45%) of bilateral vocal cord fixations. Twelve patients (60%) underwent anterior cartilage grafts, five patients (25%) had anterior and posterior cartilage grafts and three patients (15%) had end to end anastomosis according to the severity of cricoid deformities and mucosal defects. Associated procedures were 9 patients (45%) of arytenoidectomy. Thirteen of 20 patients (65%) have been decannulated. Fe-male group was significantly higher decannulation rate than male group (p=0.0074). Decannulation rates were decreased from anterior cartilage graft group to anterior and posterior cartilage grafts group and to end to end anastomosis group (p= 0.00247), this finding suggested the patients with severe cricoid deformitiy were higher likely hood of failure because we selected the method used in this study according to the severity of cricoid deformities and mucosal defects. Our results support the more aggressive treatment is indicated for subglottic stenosis in adults.

• 한국주거학회논문집
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• 제20권6호
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• pp.127-134
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• 2009

This study initially analyzes the meaning of Community-Based Residential Environment Improvement. A residential environment improvement factor was determined through an analysis of the function, components, Planning techniques of the community, the evaluation criteria of the residential environment, and through relative literature documenting plans for the adjustment of urban and housing environments. In terms of the methodological approach, decisions were made based on the results of an expert focus-group-interview, a goodness-of-fit test, and by using the analytic network decision-making method from which the correlation among items can be considered. Results of this analysis show that the, order of importance of factors for a community-based residential environment is as follows: interactional character, cognitive character, and locational character. Furthermore, the most important aspect for each of these factors are the neighbor-hood relationship in terms of the interactional character, common consciousness for the cognitive character and place for locational character. The results of this study can be used by linking them with questionnaire items for basic resident research when a residential environment improvement project or a plan for the adjustment of urban and housing environments is planned.

• 대한간호학회지
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• 제34권4호
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• pp.617-624
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• 2004

Purpose. Korean American women have twice the rate of cervical cancer than white women and demonstrate low rates in participation in cervical cancer screening. This study was to describe the perceptions about cervical cancer and factors related to cervical cancer screening among Korean American women. Method. Focus group methods. Results. Five themes emerged. First, knowledge about cervical cancer; misconceptions about cervical cancer, its causes, reproductive anatomy and the treatment Second, perceived meanings of having cervical cancer; most of the women felt that cervical cancer represented a loss of femininity and existential value of woman-hood. Third, knowledge about cervical cancer screening; regular medical check-ups were necessary for early detection and prevention of cervical cancer. Forth, experiences and perceived meanings of cervical cancer screening; the participants expressed their feelings; embarrassment, fear, shame and shyness. Fifth, practices of cervical cancer screening; various intervals in participating in cervical cancer screening. But they mentioned several deterrents, language, insurance, time constraint, embarrassment, fear of the screening results, misbelief about susceptibility, lack of health prevention behavior, and lack of information written in Korean. Conclusion: Results emphasize the critical need for culturally appropriate health education to encourage participation of Korean American women in cervical cancer screening.

• International journal of advanced smart convergence
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• 제9권4호
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• pp.132-138
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• 2020

Worldwide, the number of corona virus disease 2019 (COVID-19) confirmed cases is rapidly increasing. Although vaccines and treatments for COVID-19 are being developed, the disease is unlikely to disappear completely. By attaching a smart sensor to the respirator worn by medical staff, Internet of Things (IoT) technology and artificial intelligence (AI) technology can be used to automatically detect the medical staff's infection symptoms. In the case of medical staff showing symptoms of the disease, appropriate medical treatment can be provided to protect the staff from the greater risk. In this study, we design and develop a system that detects cough, a typical symptom of respiratory infectious diseases, by applying IoT technology and artificial technology to respiratory protection. Because the cough sound is distorted within the respirator, it is difficult to guarantee accuracy in the AI model learned from the general cough sound. Therefore, coughing and non-coughing sounds were recorded using a sensor attached to a respirator, and AI models were trained and performance evaluated with this data. Mel-spectrogram conversion method was used to efficiently classify sound data, and the developed cough recognition system had a sensitivity of 95.12% and a specificity of 100%, and an overall accuracy of 97.94%.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4678-4684
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• 2023

Using the Monte Carlo method, the impact of the angular distribution of the electron source on the dose distribution for the 2.5 MeV ELV electron accelerator was explored. The experiment measured the 3-D dose distribution in the irradiation chamber for electron energies of 1.0 MeV and 2.5 MeV. The simulation used the MCNP6.2 code to evaluate three angular distribution models of the source: a mono-directional beam, a cone shape, and a triangular shape. Of the three models, the triangular shape with angles θ = 30°, φ = 0° best represents the angle of the scan hood through which the electron beam exits. The MCNP6.2 simulation results demonstrated that the triangular model is the most accurate representation of the angular distribution of the electron source for the 2.5 MeV ELV electron accelerator.