• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 춘계학술대회 논문집
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• pp.126-129
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• 2007

In this paper, an iterative MAP approach using a Bayesian model based on the lognormal distribution for image intensity and a GRF for image texture is proposed for despeckling the SAR images that are corrupted by multiplicative speckle noise. When the image intensity is logarithmically transformed, the speckle noise is approximately Gaussian additive noise, and it tends to a normal probability much faster than the intensity distribution. The MRF is incorporated into digital image analysis by viewing pixel type s as states of molecules in a lattice-like physical system defined on a GRF. Because of the MRFGRF equivalence, the assignment of an energy function to the physical system determines its Gibbs measure, which is used to model molecular mteractions. The proposed adaptive iterative method was evaluated using simulation data generated by the Monte Carlo method. In the extensive experiments of this study, the proposed method demonstrated the capability to relax speckle noise and estimate noise-free intensity.

• 한국연소학회:학술대회논문집
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• 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
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• pp.241-246
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• 2003

Numerical simulations are performed at atmospheric pressure in order to understand the effect of additives on flame speed and the NOx formation in freely propagating $H_{2}/O_{2}/N_{2}$ flames with oxygen enrichments. A chemical kinetic mechanism is developed, which involves 26 gas-phase species and 99 reactions. Under several equivalence ratios and oxygen enrichments, flame speeds are calculated and compared with those obtained from the experiments, the results of which is in good agreement. As hydrogen chloride as additive is added into $H_{2}/O_{2}/N_{2}$ flames with low oxygen enrichments, its chemical effect causes the decrease of flame speed, radical concentration, and the NO production rate. It is found that the chemical effect of additive has much more influence on the reduction of EINO than its physical effect. However, in flames with very high flame temperature the physical effect rather than the chemical effect becomes more important on the reduction of EINO.

• 대한기계학회논문집A
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• 제21권9호
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• pp.1414-1421
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• 1997

This paper examines the physics and mechanics governing the dynamic interaction between physical systems and suggests the four structures of bond graph prototypes, considered as a general model that can promise their dynamic behavior physically resonable. The bond graph prototypes originating from the paper are more realistic junction structures than those used to model dynamic systems conventionally by bond graph standards in whether physical constraints are involved or not when the energy exchange between two dynamic components arises. It is shown that the bond graph prototypes are dynamic or energetic in their describing equations compared to the bond graph standards, and connectivity and causality are properties of dynamic systems upon which the steps developed in this paper for the bond graph prototypes are wholly based and their definitions an concepts are highly emphasized all through the paper.

• 대한원격탐사학회지
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• 제23권1호
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• pp.33-42
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• 2007

In this paper, an iterative MAP approach using a Bayesian model based on the lognormal distribution for image intensity and a GRF for image texture is proposed for despeckling the SAR images that are corrupted by multiplicative speckle noise. When the image intensity is logarithmically transformed, the speckle noise is approximately Gaussian additive noise, and it tends to a normal probability much faster than the intensity distribution. MRFs have been used to model spatially correlated and signal-dependent phenomena for SAR speckled images. The MRF is incorporated into digital image analysis by viewing pixel types as slates of molecules in a lattice-like physical system defined on a GRF Because of the MRF-SRF equivalence, the assignment of an energy function to the physical system determines its Gibbs measure, which is used to model molecular interactions. The proposed Point-Jacobian Iterative MAP estimation method was first evaluated using simulation data generated by the Monte Carlo method. The methodology was then applied to data acquired by the ESA's ERS satellite on Nonsan area of Korean Peninsula. In the extensive experiments of this study, The proposed method demonstrated the capability to relax speckle noise and estimate noise-free intensity.

• Physical Therapy Rehabilitation Science
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• 제10권3호
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• pp.320-327
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• 2021

Objective: The community has implemented a variety of exercise programs for the elderly population. However, studies comparing changes in the cardiovascular system through body composition and blood analysis after applying aqua aerobic exercise are insufficient. The purpose of this study was to investigate the effect of a 12 weeks aqua exercise on body composition and cardiovascular index in elderly women. Design: Non-equivalence pre-post design. Methods: Thirty elderly women were assigned to aquarobic group(n=15) and control group(n=15). The aquarobic exercise was 60 minutes per every session, 2times per week, for 12weeks. Weight, skeletal muscle mass, body fat percentage, total cholesterol, triglyceride, HDL cholesterol, and LDL cholesterol were measured before and after the exercise program. Paired and independent t-tests were performed using SPSS program. Results: The result showed was weight(p<0.05), body fat percentage(p<0.05), total cholesterol(p<0.05), triglyceride(p<0.05), HDL cholesterol(p<0.05), and LDL cholesterol(p<0.05) were significantly decreased and skeletal muscle mass(p>0.05) was not significantly increased after aquatic exercise program. Conclusions: According to the study result, aqua exercise program made a positive effect in the improvement of obesity and cardiovascular function in elderly women. Therefore, we suggest that you actively consider implementing the Aquarobic exercise program when operating the community health promotion program in the future. In addition, in future studies, comparative studies according to various ages and genders and studies on the effects of aqua aerobic exercise as a community exercise program for chronically illness patients are needed.

• 대한물리의학회지
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• 제6권4호
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• pp.475-488
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• 2011

Purpose: The aims of the study were to develop and to establish reliability in Korean versions of World Health Organization Disability Assessment Schedule 2.0(KWHODAS 2.0): 12 item-self(12-self) and 12 item-interviewer(12-interviewer) versions. Methods: KWHODAS 2.0: 12-item versions were developed in idiomatic modern Korean with a process involving independent translation, synthesis of the translations, independent back translation, and review by an expert committee to achieve equivalence with the original English. 88 participants were included in the study. 33 of participants filled the 12-self version twice to examine test-retest reliability and 55 of participants were assessed simultaneously by four interviewers using the 12-interviewer version. Intra-rater reliability was evaluated using the intra-class correlation coefficient(ICC) and inter-rater reliability was evaluated using both the ICC and k statistic. Results: Test-retest reliability for the 12-self version was excellent with $ICC_{(2,1)}$ value ranged from 0.94(CI 0.88-0.98) to 0.96(CI 0.90-0.98). Inter-rater reliability for the 12-interviewer version showed excellent agreement with $ICC_{(2,1)}$ from 0.94(CI 0.91-0.96) to 1(CI 1.0-1.0). K value was observed from 0.95 to 1. Conclusion: KWHODAS 2.0: 12-self and 12-interviewer versions were successfully translated and both scales showed excellent reliability. It is now suitable for use in clinical and research applications.

• 한국컴퓨터정보학회논문지
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• 제24권10호
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• pp.167-174
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• 2019

본 연구는 기관 내 삽관 수행 시 성공률에 영향을 미치는 신체적 요인에 대해 알아보기 위한 비동등성 단일군 사후 유사 실험연구이다. 연구결과 기관 내 삽관을 성공적으로 수행한 시간과 신체적 요인은 상관관계가 있는 것으로 나타났다. 특히 기관 내 삽관 수행 시 수행자의 팔의 각도는 수행시간에 영향을 미쳤으며, 팔의 각도가 좁아질수록 수행시간이 짧아지는 결과를 보였다. 기관 내 삽관 수행 시 수행자의 팔의 각도를 줄일 수 있도록 노력한다면 성공적인 기관 내 삽관을 시행할 수 있을 것이다. 하지만 다양한 환경 및 직군에 대한 추가적인 후속 연구를 통해 임상적 활용의 가능성을 확인해야 할 것이다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.191-194
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• 2003

A series of computational simulations have been carried out for non-reacting and reacting flows in a supersonic combustor configuration with and without a cavity. Transverse injection of hydrogen, a simplest form of fuel supply, is considered in the present study with the injection pressure of 0.5 and 1.0 ㎫. The corresponding equivalence ratios are 0.17 and 0.33. The work features detailed resolution of the flow and flame dynamics in the combustor, which was not typically available in most of the previous studies. In particular, oscillatory flow characteristics are captured at a scale sufficient to identify the underlying physical mechanisms. Much of the flow unsteadiness is related not only to the cavity, but also to the intrinsic unsteadiness in the flowfield. The interactions between the unsteady flow and flame evolution may cause a large excursion of flow oscillation. The role of the cavity, injection pressure, and amount of heat addition are examined systematically.

• Journal of Mechanical Science and Technology
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• 제17권1호
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• pp.157-167
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• 2003

The exciplex fluorescence technique with the TMPD (tetamethyl-Ρ-phenylene-diamine) / naphthalene dopant system was applied in a combustion-type constant-volume spray chamber. A detailed set of calibration experiments has been performed in order to quantify the TMPD fluorescence signal. It has been demonstrated that the TMPD fluorescence intensity was directly proportional to concentration, was independent of the chamber pressure, and was not sensitive to quenching by either water vapor or carbon dioxide. Using a dual heated-jet experiment, the temperature dependence of TMPD fluorescence up to 1000 K was measured. The temperature field in the spray images was determined using a simple mixing model, and an iterative solution method was used to determine the concentration and temperature field including the additional effects of the laser sheet extinction. The integrated fuel vapor concentration compared favorably with the measured amount of injected fuel when all of the liquid fuel had evaporated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.2180-2185
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• 2003

Numerical simulations of freely propagating flames burning $H_2/HCl/Air$ mixtures are performed at atmospheric pressure in order to understand the effect of HCl on the NOx reduction. A chemical kinetic mechanism is developed, which involves 26 gas-phase species and 99 reactions. Under several equivalence ratios the flame speeds are calculated and compared with those obtained from the experiments, the results of which is in good agreement. As HCl is added into $H_2/Air$ flame as additive, its chemical effect causes the reduction of radicals (H, OH, and O), and then the decrease of the net rate of NO production. It is found that the chemical effect of additive has much more influence on the reduction of EINO than its physical effect.