• The Journal of Korean Physical Therapy
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• 제18권2호
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• pp.47-58
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• 2006

Purpose: The study to pulsed ultrasound effects of diabetes mellitus fracture model in rat. Methods: We used 36 Sprague-Dawely rats which were divided into 3 groups; the animals were divided into group of 4 rats each 4th, 14th and 28th days. All animal was induced diabetes mellitus model to used streptozotocin with 45 mg/kg. Pulsed wave were divided into $50\;mW/cm^2$ and $100\;mW/cm^2$. Results: T-ALP value was significantly change from group II, III on 14th, 28th days (p<0.05). Especially T-ALP value to between groups was significantly change from group II on 14th days (p<0.05). Osteocalcin value was significantly change from group II on 28th days(p<0.05). At fracture site, osteoblast, osteoclast expression was observed from 4th days after treatment and it reached its maximum intensity at 28th days. At fracture site, $TGF-{\beta}_1$ expression was observed from 4th days after treatment and it reached maximum intensity at 14th days. Conclusion: According to this study, diabetes mellitus fracture model to the more effective is divided into $50m\;W/cm^2$ pulsed ultrasound.

• International Journal of Aerospace System Engineering
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• 제3권1호
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• pp.30-38
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• 2016

The The turbulent mixing characteristics of Kerosene-LOx in a coaxial swirl injector 100 bar have been numerically investigated. Turbulent model is based on large eddy simulation with real-fluid transport and thermodynamics. The effects of equation of state (EOS), chamber pressure are evaluated in a point of the mixing efficiency and pressure fluctuations. The dominant frequency is same as the hairpin vortex shedding frequency generated by film wave at the LOx post.

• Korean Chemical Engineering Research
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• 제52권6호
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• pp.706-712
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• 2014

폭약은 높은 에너지를 포함하는 반응성 물질이며 폭발이 발생할 경우 강한 빛, 높은 열, 소음 및 고압을 발생시킨다. 폭발 지점 주변의 손상은 대부분 높은 과압과 폭풍파에 영향을 받는다. 따라서 폭발에 의한 압력 및 폭풍파의 분석이 매우 중요하다. 본 연구에서는 HMX와 같은 고폭화약의 최대 과압 및 폭풍파 속도를 분석하였다. 먼저 HMX 폭발에 관하여 4가지 경우를 선정하고 폭발현상을 모델링하였으며 HMX의 양에 따른 폭발시뮬레이션을 통하여 최대 과압 및 폭풍파 속도를 도출하였다. 또한, 폭발이 Geometry 중심에서 일어난다고 가정하고 계산된 과압과 폭풍파 속도로부터 폭심에서 인접해 있는 위치의 영향을 분석하였다. 대조군으로 이용된 TNT도 함께 시뮬레이션 및 분석하였으며 HMX 시뮬레이션 결과와 비교함으로써 HMX의 상대적인 과압 및 폭풍파속도를 확인하였다. 본 연구는 HMX가 포함된 복합화약이 폭발하였을 경우 최대 과압 및 폭풍파속도 산정 시 기초데이터로 활용할 수 있다.

• Progress in Superconductivity
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• 제11권2호
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• pp.112-117
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• 2010

We examine phase transition of the spin density wave and $\pi$ phase shifted superconductivity in the Fe pnictide superconductors. The phase diagram is described in the plane of the temperature T and the doping x with the combination of Ginzburg-Landau expansion of the free energy near the multi-critical temperature $T_c$ and the self-consistent numerical iterations of the gap equations. The phase separation or coexistence is determined by computing the 4-th order terms of the free energy which is confirmed by the numerical calculations. We can show the phase coexistence when the spin density wave is incommensurate. And the first order phase transition is observed near the boundary between commensurate and incommensurate spin density wave.

• 한국전산구조공학회논문집
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• 제33권4호
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• pp.255-261
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• 2020

본 논문은 충격을 줄이기 위해 효과적인 충격완충장치를 구성하는 방법을 제안했다. 기존의 충격완충장치는 폴리에틸렌으로만 만들어졌지만, 새로운 충격완충장치는 외측에는 폴리에틸렌, 내측에는 고밀도 재료로 구성하였다. 충격은 내측과 외측 물질 사이의 밀도 차이가 더 클 때 줄어들었다. 2층 구조의 외측으로 설계하기 위해 알루미늄, 티타늄, 구리를 선택하였다. 가장 밀도가 높은 구리에서는 충격 감소가 가장 좋았으며, 기존 충격완충장치보다 최대 감가속도는 43%, 충격량은 51% 감소하였다. 4층, 6층 충격완충장치의 경우, 충격량은 줄였지만, 최대 감가속도는 증가하였다. 신관은 가장 큰 충격으로부터 살아남아야 하며 나머지 충격파는 임계값을 초과하지 않으므로, 본 논문은 폴리에틸렌-구리를 사용한 2층 구조용 충격완충장치를 제안하였다.

• 한국주거학회논문집
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• 제23권5호
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• pp.75-86
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• 2012

The primary purpose of this study is to prove the relationship between housing environment and mental health with depression and self-esteem in the republic of Korea. The raw data of 10,608 respondents, was gathered from the 4th wave of Korea Welfare Panel Study (KoWePS) in 2009. Some variables related to housing environment and mental health were selected in KoWePS' data. Data was analyzed by SPSS 19.0 and AMOS 17.0. The major results are as follow: 1) Householder economic variables significantly relate to housing environment and resident mental health. 2) Housing environment variables are significantly related to resident mental health, and these variables explain 4.3% of depression and 6.7% of self-esteem. 3) Throughout path analysis of economic, housing environment, and mental health variables, housing environment variable is a parameter. In conclusion, these results show that better quality of housing environment would contribute to the residents' better mental health.

• 벤처혁신연구
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• 제4권2호
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• pp.77-95
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• 2021

4차산업혁명과 코로나19 팬데믹이라는 2중의 파도속에서 이 파도를 타는 기업은 승승장구 할 수 있지만, 그렇지 못한 기업은 파도 속에 빠져 허우적거릴 것이다. 4차산업혁명과 관련하여 다양한 기술들이 나오고 상용화되고 있다. 이러한 시점에서 소비자 특히 태어나면서부터 디지털과 함께 온 디지털 네이티브 들은 이러한 기술을 사용 함에 있어서 어떠한 요인들이 사용 의도에 영향을 미치며 그 요인 중에서 가장 중요하게 영향을 미치는 것이 무엇인지를 규명하고자 했다. 이를 위해 디지털 네이티브인 20대 150명을 대상으로 FinTech 기술과 AR기술의 사용의도에 영향을 미치는 요인에 대해 데이터를 설문조사를 통해 수집하였다.이를 토대로 통계분석을 실시한 결과 다음과 같은 결과를 얻었다. 기술의 종류에 상관없이 전체적으로 분석을 한 결과는 성과기대, 노력기대, 사회적영향, 습관이 디지털 네이티브의 4차산업기술 사용의도에 정(+)의 영향을 미치는 것으로 나타났다. 반면, 촉진조건과 쾌락적 동기는 유의한 영향관계가 검정되지 않았다. 영향력은 사회적영향과 습관이 매우 큰 영향을 미치는 것으로 나타났다. 이를 보다 세분화하여 본 연구에서 대상으로 삼은 FinTech와 AR의 경우 나누어 분석한 결과 다른 양상이 나타났다. 실용적인 가치를 중시하는 FinTech 기술의 경우 성과기대, 노력기대, 사회적영향, 습관이 사용의도에 정(+)의 영향을 미쳤다. 영향력은 습관과 사회적 영향이 큰 영향을 미치는 것으로 나타났다. 쾌락적 가치를 중시하는 AR의 경우 본 연구에서 채택한 모든 변인들이 기술 사용의도에 정(+)의 영향을 미쳤다. 쾌락적 동기와 사회적 영향이 큰 영향을 미치는 것으로 나타났다. 분석결과를 종합해보면 사회적 영향은 4차산업기술의 종류와 관계없이 중요한 영향 변수로 나타났다. 서비스가 보편화되고 있는 모바일 뱅킹과 같은 FinTech 기술은 습관이, 아직은 보편화 되어 있지 않고 엔터테인먼트 위주로 서비스 되고 있는 AR의 경우 쾌락적 동기가 중요한 영향 요인으로 나타났다. 본 연구는 디지털 네이티브들의 4차산업 기술 수용에 영향을 미치는 요인을 위와 같이 확인함으로써 이를 토대로 학술적 및 실무적 시사점을 제시할 수 있었다.

• 패션비즈니스
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• 제22권4호
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• pp.59-75
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• 2018

The purpose of this study was to investigate the relations and differences in Korean national image, Korean wave (Hanryu) interest, and Korean beauty service satisfaction of Korean, Chinese, and Vietnamese living in Korea and to lay the foundations for the export of various contents, especially beauty services, through the enhancement of Korea's national image. The present study was conducted from $10^{th}$ June to $10^{th}$ August 2017, by presenting 523 questionnaires to Koreans living in Seoul and another metropolitan area, and to Chinese and Vietnamese students studying in different Korean language Institutes in Seoul and other areas' universities. The basic questionnaire items were analyzed based on frequency analysis. The data on the national image, Korean wave interest, and Korean beauty service satisfaction were reduced by the factor analysis. The effects of each items were analyzed by regression. The differences in three factors were analyzed by ANOVA, and the differences were calculated by mean values. Consequently, it was observed that three factors are mutually affected each other. Therefore, it is necessary to establish a synergetic relationship between the individual factors. In addition, the individual items exhibited higher mean value in Vietnam, China, and Korea in a descending order. This indicates that Koreans are more likely to de-evaluate their cultures than others. Therefore, Koreans should be aware of the excellence of their culture and try to spread Korean culture and technology to the rest of the world with pride.

• Ocean and Polar Research
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• 제43권3호
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• pp.179-192
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• 2021

In this study, an integrated wave model from global to coastal scales was developed to improve the operational wave prediction performance of the Korean Meteorological Administration (KMA). In this system, the wave model was upgraded to the WaveWatch III version 6.07 with the improved parameterization of the source term. Considering the increased resolution of the wind input field and the introduction of the high-performance KMA 5^th Supercomputer, the spatial resolution of global and regional wave models has been doubled compared to the operational model. The physical processes and coefficients of the wave model were optimized for the current KMA global atmospheric forecasting system, the Korean Integrated Model (KIM), which is being operated since April 2020. Based on the sensitivity experiment results, the wind-wave growth parameter (β_max) for the global wave model was determined to be 1.33 with the lowest root mean square errors (RMSE). The value of β_max showed the lowest error when applied to regional/coastal wave models for the period of the typhoon season when strong winds occur. Applying the new system to the case of August 2020, the RMSE for the 48-hour significant wave height prediction was reduced by 13.4 to 17.7% compared to the existing KMA operating model. The new integrated wave prediction system plans to replace the KMA operating model after long-term verification.

• Human Ecology Research
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• 제59권3호
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• pp.341-351
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• 2021

The purpose of this study was to examine the longitudinal relationships between Korean adolescents'mobile phone dependency, trajectories of depression, and self-regulated learning abilities. To achieve these goals, structural equation modeling analysis was conducted, using the 3rd, 5th and 7th wave of the data on 4th graders taken from the Korean Children and Youth Panel Survey. The results can be summarized as follows. First, growth-curve longitudinal analysis indicates that depression in 6th through 10th grade has increased. Second, mobile phone dependency among adolescents at 6th grade has a significant effect on both the initial value and the rate of change in depression. Also, the initial value and the rate of change in depression have significant relationships with mobile phone dependency at 10th grade. Moreover, both increased levels of mobile phone dependency and the rate of change in depression significantly influence adolescents'self-regulated learning abilities at 10th grade. Based on a longitudinal data set, these findings demonstrate the causal relationships between Korean adolescents'trajectories of depression and their mobile phone dependency. The findings also provide a comprehensive framework with implications for adolescents'development through an understanding of the relationships between adolescents'depression and mobile phone dependency, which impact their self-regulated learning abilities.