후륜 구동 A/T 차량의 구동축 강성이 발진 가속에 미치는 영향

안동환(Donghwan Ahn),위효성(Hyoseong Wi),박진일(Jinil Park),이종화(Jonghwa Lee) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

Drivers are requiring higher drivability as the quality of life rises and the performance of the vehicle improves. Especially, drive shaft stiffness is closely related to drivability influential factors of a vehicle such as responsiveness, acceleration, and quietness. In order to make good drivability, powertrain of vehicle must generate driving force that corresponds to acceleration performance requested by the driver. In this paper, vehicle acceleration characteristics - one of the most important factor of drivability - are analyzed according to the drive shaft stiffness. In order to predict vehicle acceleration characteristics, a model to analyze the torque flow of an actual vehicle and a model coefficient measurement methodology are required, contribution of each component in the power distribution process must be understood, and a corresponding simulation model must be established. And based on the simulation result of this research, initial vehicle acceleration characteristics depending on driveshaft stiffness was predicted.

차량 실내 소음 주파수 특성 변경이 운전성 평가에 미치는 영향

안동환(Donghwan Ahn),이동현(Donghyun Lee),김영관(Younggwan Kim),위효성(Hyoseong Wi),이진우(Jinwoo Lee),박진일(Jinil Park),이종화(Jonghwa Lee),김범수(Beomsoo Kim),이석재(Seogjae Lee) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

Vehicle performance is improving day by day. So drivers want to higher quality of drivability, which include acceleration performance, interior noise, vibrations and etc. In particular, the vehicle interior noise which is a major factor in the evaluation drivability is important factor. In this study, According to the frequency of vehicle interior noise, vehicle interior noise were analyzed which based on sound pressure level. On the basis of this analysis, the interior noise was changed through sound equipment, such as a microphone and equalizer. This interior noise was evaluated by drivers and identified a correlation between subject’s responses and changing of the frequency. As a result of this research, frequency bands and sound pressure levels which affect evaluation drivability were presented to meet the needs of consumers about acceleration, noise and vibration.

Co / NiMn의 교환 자기결합에 관한 연구

안동환(DongHwan Ahn),조권구(Kwon-Koo Cho),주승기(Seung-Ki Joo) 한국자기학회 2000 韓國磁氣學會誌 Vol.10 No.4

Exchange coupling of Co/NiMn bilayers fabricated by RF magnetron sputtering method was studied. We investigated the variation of exchange coupling field (Hex) for different annealing temperature and time. The maximum exchange coupling field was obtained after 13hr annealing at 300℃. With respect to deposition sequence, it was demonstrated that NiMn-top bilayers had higher exchange coupling field than NiMn-bottom bilayers. Ta capping layer was shown to be essential in achieving exchange coupling and Auger Electron Spectroscopy (AES) proved that uncapped NiMn/Co bilayers did not have exchange coupling because of oxygen incorporation into film. We also observed the effect of Ta underlayer on exchange coupling. It was found that Ta underlayer had better not be used for attaining higher exchange coupling. XRD analysis showed that Ta underlayer helped bilayers develop texture, but it was not essential to exchange coupling of Co/NiMn bilayers, which is in contrast to NiFe/NiMn system. Furthermore, the NiMn and Co thickness dependence of exchange coupling has been investigated. The exchange coupling strength reached the maximum above 200 Å NiMn thickness and had inversely proportional relation with Co thickness.

농촌 과소화마을의 변화 분석

박진우,이태호,안동환,Park, Jen-Woo,Lee, Taeho,An, Donghwan 한국농촌계획학회 2018 농촌계획 Vol.24 No.2

The main purpose of this study is to explore the factors that affect the transformation of over-depopulated rural villages. Specifically, we investigated the reasons of the rapid decrease in the number of over-populated rural villages shown by recent census data in spite of the continuing decrease of population in rural area. We used a binary-logit model and the Census of Agriculture, Forestry and Fisheries data(2010, 2015). The main results are summarized as followed: First, the over-depopulated rural villages with strong agronomic base are more likely to exit from over-depopulation. Second, returners from urban to rural have a positive impacts on the revival of over-depopulated rural areas. Thirds, improving the basic services accessibility of rural residents is also critical for keeping rural community more sustainable. These findings can be used to make effective strategies to revive the depopulated rural villages.

수입 밀 가격의 밀가루 및 라면에 대한 비대칭적 가격전이 효과 분석

우성휘(Woo, Sunghwi),안동환(An, Donghwan),김관수(Kim, Kwansoo) 한국농업경제학회 2017 農業經濟硏究 Vol.58 No.4

This study examines the effects of imported wheat on price of flour and ramen with a focus on asymmetric price transmission. The rise in price of imported wheat affects the change in domestic wholesale price of flour after a considerable period of time. And the effects of flour’s wholesale prices on retail prices differ slightly depending on distribution channels. In particular, asymmetric price transmission is relatively clear in distribution channels which have large sales, compared to small distribution channels. The above results show that the cause of asymmetric price transmission may be the difference of the distribution process of products. On the other hand, fluctuations in prices of raw materials, including flour, did not affect the wholesale price of ramen. This seems to be because the share of raw materials in the production cost of ramen is lower than that of flour, and ramen is the subject of government s price control.

자연재해 위험이 농지가격에 미치는 영향 : 풍수해를 중심으로

김지은(Jieun Kim),안동환(Donghwan An) 한국농업경제학회 2020 農業經濟硏究 Vol.61 No.3

While the frequency and intensity of extreme weather events due to climate change is expected to gradually increase, various industrial groups are exposed to the effects of climate change. In particular, the agricultural sector is very vulnerable to natural disasters, as it causes damage to crops and farmland directly when an extreme event occurs. This study especially focused on the effect of the occurrence of storm and flood on farmland prices in Korea. The materials mainly used in this study are official land value, inundation trace map, and the properties of individual parcels and regions. In addition, Hausman-Taylor estimation method was used considering the endogeneity of the rice yield variable. It is shown that the number of disaster risk zones, inundation in the previous year, cumulative frequency, and the average inundation depth in the last three years have a negative effect on farmland prices. The results imply that the occurrence of natural disasters which can affect both net income from farmland and the value when converted to other uses in the future actually lead to price reduction. The flooding affects not only the production of crops, but also requires the repair cost for damaged farmland. This risk cost can be seen as a result of price internalization.

순자산가치를 고려한 농가의 빈곤탈출 요인 분석

강민정(Minjeong Kang),안동환(Donghwan An) 한국농업경제학회 2017 農業經濟硏究 Vol.58 No.3

This study examined the factors affecting exit from poverty of farm household based on an income net worth approach by using a stratified Cox proportional hazard model called PWP-CP model. We found that exit from poverty is more difficult for the households who are young, female headed, and small scale. Our results also show that farm households with less land and transfer income including subsidies are more likely to suffer from long-term poverty. These results imply that with an expansion to subscribe Reverse Mortgage Products such as farmland pensions, income diversification policies such as the 6th-industrialization policies, and the expansion of a fundamental welfare policy should be also considered important in order to solve long-term poverty problems of the farm household.

농가의 리스크 밸런싱 행위 분석

추성민(Sungmin Cheu),안동환(Donghwan An) 한국농업경제학회 2018 農業經濟硏究 Vol.59 No.3

This study examines farm households’ risk balancing behavior in Korea. We use a SUR (seemingly unrelated regression) model to reflect the interdependence in farm households’ risk balancing behavior where they adjust their financial structure, off-farm work decisions, and consumption level, etc. We find that Korean farm households make strategic farm financial risk decisions, off-farm business decisions, and consumption adjustment in response to exogenous changes in expected farm risk or business risk. This study also shows that large farms make more use of off-farm risk balancing, while small farms appear to make more use of financial risk balancing and adjusting consumption level.

북한 대중예술 및 미디어 보도의 표현분석을 통한 협동 농장 정책 연구: 분조의 주인과 로동신문을 중심으로

임채환 ( Lim Chehwan ),안동환 ( An Donghwan ) 북한연구학회 2020 北韓硏究學會報 Vol.24 No.2

2000년대 이후 북한은 경제난을 타개하기 위하여 여러 경제 개혁 조치를 시행하고 있으며, 농업 분야에서도 각종 농업정책이 도입되고 있다. 그러나 북한은 여전히 세계 최빈국 수준이며, 식량 증산에 실패하여 만성적 결핍 상태가 지속되고 있다. 본 연구는 북한의 대중예술(영화 분조의 주인)과 미디어 보도(로동신문)를 활용하여 북한 당국이 선전하는 농업 정책과 실질적인 성과를 미시적 단위(협동농장)에서 살펴본다. 통계와 수치자료에 기반하지 않은 정성적 분석 방법은 연구의 한계이지만, 동시에 북한의 정량적 자료가 제약된 상황 하에서 북한의 농정(협동농장) 실태를 조망하고, 변화를 추적하기 위하여 시도된 노력이라고 평가할 수 있다. 분석 결과, 영화에 반영된 과거(2012년)와 로동신문에 나타난 최근(2015~2020년) 동안 협동농장 운영에 관한 표현은 유사성이 매우 높았다. 북한 당국은 여전히 식량 증산의 절박성과 시급성을 다양한 수사로 강조하고 있었으며, 농업정책 또한 농장 구성원을 사상적으로 교양시켜 신실한 근로자로 만들며 주요 농업 투입재로 후민산 비료의 도입과 적절한 사용을 강조하고 있었다. 협동농장 운영 정책이 유의미하게 변화하지 않았다는 것은 북한 농업 개혁의 실패의 주요 원인 가운데 하나로 작용되었을 것으로 판단된다. Since the 2000s, North Korea has implemented various economic reform measures to overcome its economic difficulties, and various agricultural policies have been introduced in the agricultural sector. However, North Korea is still the poorest country in the world, and its failure to increase food production has led to chronic shortages. This study uses North Korea’s popular arts (the owner of the movie division) and media coverage (Rodong Sinmun) to examine the agricultural policies and practical achievements promoted by the North Korean authorities in micro-unit (cooperative farm) and suggest the cause of the failure of the agricultural administration. While qualitative analysis methods, which are not based on statistics and numerical data, are the limitations of research, at the same time, it can be evaluated as a new effort that has been attempted to view changes and actual conditions in North Korea’s agricultural administration under circumstances where quantitative data in the North is restricted. According to the analysis, the terms used in the Rodong Sinmun to describe how cooperative farms operate in 2012 and in the period between 2015 and 2020 were very similar. The North Korean authorities were still emphasizing the urgency of increasing food production through various investigations, and the agricultural policy was also emphasizing the introduction and proper use of the Fumic fertilizer as a major agricultural input, by enhancing the knowledge of farm workers and making them more devoted to their work . The fact that the policy of operating cooperative farms has not changed significantly is believed to have served as one of the main reasons for the failure of North Korea’s agricultural reform.

어가의 어촌 6차산업화 사업유형 결정요인 분석

이세진 ( Lee Sejin ),안동환 ( An Donghwan ) 한국농촌계획학회 2021 농촌계획 Vol.27 No.1

The purpose of this study is to investigate the factors affecting the types of the 6th industrialization of fishery households. In this study we tried to explain the significance of the demographic and managerial characteristics of fishery households when they choose the types of the 6th industrialization business. Multinomial logistic model was used for this analysis. This study shows that the household and fishery management characteristics, main method of fishing, and regional factors matters for fishery households to choose their business types. Our results implies that it is necessary to reflect the detailed support measures differentiated by business types when implementing the 6th industrialization policy for fishery sector. In addition, the sixth industrialization of fishery should not be limited to marine products, but agricultural products produced in fishing villages should be included.