• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.4-4
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• 2000

일반적인 액체추진제 로켓엔진의 연소는 분사제트의 미립화, 액적의 증발, 기상 추진제의 혼합, 화학반응 등, 일련의 물리적 과정들로 이루어지고, 여기서 특성속도 효율은 크게 분사특성 및 연소의 두 단계에서 결정되게 된다. 액체추진제 로켓엔진에 사용되는 여러 분무형태 중, 동축형 분사기에서는 액상과 기상 제트의 운동량 차에 의해 미립화가 이루어지며, 분무 액적들의 전개와 더불어 분사기 출구를 포함한 전 영역에서 연소가 발생되므로 매우 복잡한 물리적 특성들을 포함하게 된다. 본 연구에서는 기상 연료-액상 산화제의 동축형 분무연소를 JANNAF의 방법을 사용하여 수식화 하였으며, 이를 바탕으로 분무특성과 연소성능 예측을 위한 프로그램을 작성, 분사조건에 의한 분무특성과 그에 따른 연소성능을 계산하였다. 연속, 운동량, 에너지 및 혼합비 방정식의 지배방정식들을 바탕으로 기상 유동을 수식화 하였으며, 별도로 액적의 소산 및 연소과정을 모사하기 위한 별도의 수식들이 추가되었고, 이 식들을 결합하여 액적의 크기, 분포를 포함하는 액체 제트의 미립화 정도를 공간적으로 계산하였다. 미립화 모델의 검증을 위하여 계산 결과를 Reitz의 실험과 Giridharan의 모델 등과 비교하였으며 잘 일치하는 경향을 나타내었다. 또한 동축형 분사기에서의 분무 특성을 예측하기 위해 액체 산소, 기체 수소를 추진제 조합으로 하는 동축형 분무 연소장에서의 제트 길이, 액적의 크기, 액체 제트의 속도를 계산하였다. 계산 결과 액체 제트의 접촉길이는 분사공의 지름이 증가할수록 웨버수가 증가되므로 짧아지는 것으로 관찰되었으며 액적의 크기도 분사공의 지름이 증가할수록 작아지는 경향을 나타내었다. 액체 제트의 속도는 처음에는 일정하게 유지되다가 운동량을 보존하기 위해 가스로부터 운동량을 받아 점차 가속되어지는 것으로 나타났다.본 규격은 키, 총장, 어깨길이, 등길이, 머리길이, 머리둘레, 진동둘레, 목둘레, 가슴둘레, 허리둘레, 배둘레, 엉덩이둘레, 앞품, 뒤품, drop치를 포함하고 있고, 각 규격에서 호칭간 치수 간격도 함께 제시하고 있다. 본 연구 결과에서 보듯, 현행 8규격의 무진복의 각 호칭간 적정 허용범위를 고려해 합리적인 치수체계를 정립한다면 치수에 대한 적합도가 상당히 증가할 뿐 아니라 생산비용도 상당히 감축할 것으로 생각된다.나타났다. 4) 호감적 서비스능력 차원에서 세 독립변수간에 유의한 3원 상호작용이 존재하는 것으로 나타나( $F_{2,228}$=15.62, P<.001) 20대에 적합한 의복 착용시( $F_{2,228}$=3.98, P<.05)와 60대에 적합한 의복 착용시( $F_{2,228}$=16.55, P<.001) 점포유형과 격식차림간에는 유의한 상호작용이 존재하는 것으로 나타났다. 5) 호감을 구성하는 세 요인들이 구매의도에 미치는 영향을 조사한 결과 호감적 인상차원은 29%(P<.001), 호감적 서비스능력차원은 6%(P<.001)의 구매의도를 설명해 주는 것으로 나타났다. 본 연구결과 노년 소비자에게 호감을 주는 판매원의 외모는 구매의도에 영향을 주어 실버의류산업의 이익증대와 밀접한 연관을 갖는 서비스품질의 중요한 요인으로 밝혀졌다.중요한 요인으로 밝혀졌다.로운 단백질 EPSPS가 다른 여러 식물에 이미 존재하고 있는 단백질로서 우리가 이미 이러한 식품을 섭취할 때 이 단백질도 같이 섭취해오고 있었다는 점, 둘째. 이 단백질이 소화액 분해 실험에서 짧은 시간내에 분해가 되었다는 점, 셋째. 재조합 된 콩과 자연 콩이 성분 분석에서 차이를 나타내지 않았다는 점, 네 번째. 쥐를 통한 다양섭취 실험에서 아무런 이상 반응이 없었

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.851-860
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• 2020

With an increase in the aging population and a rising social interest in health and welfare, studies to improve healthcare in the elderly are being actively conducted. This study attempted to improve the current design and manufacture of elevating electric wheelchairs to enhance user safety and convenience. Seat design based on the user's body shape, convenience while boarding or alighting, caster turning radius and, safety and stability features that prevent shaking when the user gets up or sits down were improved. A driving experiment was conducted to evaluate the operation of the indoor electric wheelchair designed and manufactured with these additional functionalities. During the test, the performance parameters evaluated were continuous driving time, turning radius, maximum lifting and lowering load, maximum lifting height, noise level, minimum distance sensing by the driving auxiliary sensor, ability to interact with server and app programs, and the duty cycle maximum error rate. The test confirmed that this improved electric wheelchair successfully met target parameters. In a future study, we will evaluate this improved electric wheelchair from a user's perspective for its usability parameters, such as satisfaction, convenience and stability.

• International Area Studies Review
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• v.22 no.4
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• pp.3-18
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• 2018

In this study, I examined capital market shock reaction effects of 29 OECD countries with the past 24 years sample period consisting of daily stock market return using T-GARCH model focused on volatility feedback hypothesis. US daily stock market return is used as a unique independent variable in this model in consideration of its characteristics of biggest market share and as an origin country of Global Financial Crisis. As a result, France, Finland, and Mexico in order are shown to be the strongest countries in the aspect of return spillovers from US. Canada, Mexico, and France are shown to be the highest countries in the aspect of explanatory power of model. The degrees of shock reaction are proved to be higher in order in Germany, Chile, Switzerland, and Denmark and those of downside shock reaction are seen higher in order in Greece, Great Britain, Australia, and Japan. Canada and Mexico belonging to NAFTA are shown to be higher in the return spillover from US and in the model explanatory power, but they are shown to be lower in the impact of shock reaction, suggesting that regional distance effect or gravity theory cannot be applied to financial spillovers any longer. In the analysis of subsample period of Global Financial Crisis, north American three countries do not show any consistent results as in the full sample period but shock reaction in the European countries are shown to record stronger, suggesting that shocks from US in the Crisis Times are transferred mainly to European region.

• 한국노년학
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• v.38 no.2
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• pp.291-308
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• 2018

The purpose of this study is to analyze the factors influencing financial preparedness for retirement of the middle-aged North Korean defectors (resettling in South Korea) using concepts of 'financial literacy' and 'financial inclusion'. Those questioned were 100 North Korean defectors of 40-60 years-old residing in Seoul and Gyeonggi-do Province selected by convenience sampling, one of the non-probability sampling. Path analysis is used as a main analysis method. The results of the study show a direct effect in which increased financial literacy resulted in better financial preparedness for retirement among middle-aged North Korean defectors at a statistically significant level. In addition, by boost-trapping method, financial inclusion has its mediating effect on the relationship between financial literacy and financial preparedness for retirement. However, this study shows that influence of financial literacy on financial preparedness for retirement is different across economic statues. The mediating effect of financial inclusion on the relationship between financial literacy and financial preparedness is statistically significant only for the low-income group. Meanwhile, for the above average income group, financial literacy has a direct effect on the financial preparedness after retirement at a statistically significant level. Based on these results, this study suggests practical and policy implementation such as necessity of customized financial education suited to their economic status, development of financial instruments for retirement, introduction of financial social workers to prepare stable old age of North Korean defectors.

• International Area Studies Review
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• v.22 no.4
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• pp.99-121
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• 2018

This study investigated the factors influencing the knowledge acquisition of Thai local partners from advanced foreign partners through international joint ventures(IJVs). For this purpose, this study initially identified three dimensions of characteristics in the context of IJVs that would influence local partners' knowledge acquisition - a local partners' own characteristic (absorptive capacity), a relationship characteristic with IJVs (proximity to the equal equity ownership), and a relationship characteristic with foreign partners (trust), and examined their effects on local partners' knowledge acquisition. The study further investigated the moderating effects of the tacitness of knowledge on the relationships between those characteristics and knowledge acquisition. Based on the data collected from Thai IJV local partners, results revealed that a local partners' own characteristic, absorptive capacity, and a relationship characteristic with IJVs, proximity to the equal equity ownership, had a strong positive effect on local partners' knowledge acquisition. Results further showed that the tacitness of knowledge strengthened the relationships between absorptive capacity and knowledge acquisition and between trust and knowledge acquisition, but not the relationship between proximity to the equal equity ownership and knowledge acquisition.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.308-320
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• 2019

This study aims at investigating the major symptoms that help family carers detect mental illness in elderly patients. Another purpose of this study is to empirically verify the major factors determining the utilization of mental health services with a focus on family carers. The results of this study are as follows. First, the most commonly detected symptoms that caused the family carers to suspect mental illness in the elderly patients were memory decline and other forms of cognitive function decline. Second, the determinants of the elderly's utilization of mental health services included the patient's long-term care insurance level, the age of the family carer, the period of care, the level stress associated with the provision of care felt by the carer, his understanding of geriatric mental illness, and the level of perception about community mental health services. Based on these findings, this study suggests policies and practical implications for the early detection of and response to elderly mental health problems and the utilization of related services from the viewpoint of the family carers of the elderly.

• International Area Studies Review
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• v.21 no.1
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• pp.221-243
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• 2017

In this study, I examine overall conditions and problems of personal asset management processes by the old age people in Korea from the global perspectives. Major recommended policy implications for those are as follows.. First, the IRR (income replacement ratio) of public pensions in Korea is found to rank nearly the lowest among the OECD member countries. The relatively low fund performance compared to that of developed countries as well as this low IRR can be pointed out as major problems of public pension in Korea. It is recommended to reinforce specialty in fund management as a top priority to solve out these problems related with public pensions in Korea. Second, it is needed to set retirement pensions to be mandatory for almost all the firms in Korea to substitute for the above lower IRR of public pensions and to recover from the highest elderly poverty ratio among the OECD countries. Third, it is required to discuss about the expansion of tax refund policy application in the individual pension sector and many financial investment products under the correction of current budget control to motivate voluntary subscription for individual pension planning and to stabilize elderly lives of ordinary people in Korea. Fourth, it is required to induce market mechanism in controling price and longevity risk of reverse mortgages for the long-run sustainability.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.215-228
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• 2021

The purpose of this qualitative study was to identify cultural factors among older Americans that could influence them to accept new welfare technologies. This study also explored how social and cultural-based plans could increase the acceptability of welfare technologies for improving the quality of life of older adults in the future. In-depth interviews were conducted with ten professionals who work with older adults. The collected interview data were subsequently analyzed using a two-cycle open coding process. The data analysis generated 29 codes that were organized into 7 primary codes, or categories, and 22 secondary codes nested within the primary codes. Several themes were identified: individualism, family-oriented culture, pragmatism, low-context culture, privacy, fun-seeking culture, and a less hierarchical culture. These findings will inform the development of a future survey to examine the relationship between older adults' intentions when using technology and socio-cultural factors in community settings. In order to explore the different impact levels of the cultural factors found in this study, the future study will need to include measures for identifying socio-cultural variations among individuals in one country or across countries.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.429-433
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• 2022

We analyzed both current local policies and in-depth survey data to find out a way to provide job opportunity and income source to local young people in so-called job guarantee system. The young generation in current Korean society has been experiencing both growth without employment and severe economic inequality at the same time, though they should have taken part actively in social development. Their rights for work and survival have also been threatened and losing hope for the future is an widespread symptom in this generation. Kwangju metropolitan city(KMC) has been supporting certain amount of case income and job experience to young people in Kwangju through a local government policy called Kwangju Young Generation Job Experience Dream Service. In spite of high level of satisfaction from the participants, limitations such as below average job performance level of participants and a barrier in the transition to regular position still remain. This study hopes that a case of Kwangju gives pragmatic insights for a realizable path to expanding universal welfare through assuring job opportunity to the young generation in local area.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.129-134
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• 2023

This study purports to investigate potential factors in various levels that affect respondents' use of youth facilities. Those levels include individual, family, and school. The data from 「2021 Youth Survey on Human Right Conditions」 will be analyzed. Hierarchical multiple regression analysis shows several results. First of all, respondents' age and level of human rights related information strongly influence respondents' use of youth facilities. Secondly, the analysis also shows that subjective well -being, abusive language and physical punishment from school faculty, and experience of human rights violation in schools affect the level of respondents' use of youth facilities. The order of effect sizes among significant variables are as follows; respondents' age, level of human rights related information, subjective well -being, abusive language and physical punishment from school faculty, and experience of human rights violation in schools. The independent variables in the model explain roughly 20 percent of whole variation of dependents variable.