퍼지논리를 이용한 수평 머시닝 센터의 열변형 오차 모델링

이재하,이진현,양승한,Lee, Jae-Ha,Lee, Jin-Hyeon,Yang, Seung-Han 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.10

As current manufacturing processes require high spindle speed and precise machining, increasing accuracy by reducing volumetric errors of the machine itself, particularly thermal errors, is very important. Thermal errors can be estimated by many empirical models, for example, an FEM model, a neural network model, a linear regression model, an engineering judgment model, etc. This paper discusses to make a modeling of thermal errors efficiently through backward elimination and fuzzy logic strategy. The model of a thermal error using fuzzy logic strategy overcomes limitation of accuracy in the linear regression model or the engineering judgment model. It shows that the fuzzy model has more better performance than linear regression model, though it has less number of thermal variables than the other. The fuzzy model does not need to have complex procedure such like multi-regression and to know the characteristics of the plant, and the parameters of the model can be mathematically calculated. Also, the fuzzy model can be applied to any machine, but it delivers greater accuracy and robustness.

원/달러 역내현물환시장과 역외NDF시장간의 인과관계

이재하,임상규,Lee, Jae-Ha,Lim, Sang-Gyu 한국재무관리학회 2000 재무관리연구 Vol.17 No.2

본 연구는 외환위기 이후 1998년 10월부터 2000년 3월까지의 일별 데이터를 사용하여 원/달러 역내시장과 역외시장간의 가격정보 이전에 관한 동조화여부를 실증분석 하였다. 원/달러 역내시장의 가격대용으로 원/달러 현물환율을 사용하였으며, 원/달러 역외시장의 가격대용으로 원/달러 역외선물환율인 NDF 1개월물을 사용하였다. 수익률이 중심이 된 기존의 많은 인과관계 연구들과는 달리 본 연구에서는 환율의 변화율에 대한 그랜져 인과관계 분석과 함께 이변량 GARCH모형을 이용하여 두 시장간에 있어서의 환율의 변화율과 변동성의 인과관계를 분석하였다. 그랜져 인과관계분석 결과 현물환율은 역외선물환율에 대해 강한 선도관계를 가지며 상대적으로 약하지만 역외선물환율 또한 현물환율에 대해 선도관계를 가지는 것으로 나타났다. 본 연구에 사용된 이변량 GARCH모형은 AR(1)-GARCH(1,1)모형으로서 분식 결과를 보면 조건부 변동성이 두 시장간에 상호의존적이며 한 시장의 변화율충격이 다른 시장의 변동성에 영향을 미치는 것이 양 시장간에 유의적으로 나타났다. 이는 현물환시장의 거래정보가 역외선물환시장의 가격형성에 영향을 미치며 역외선물환시장 거래정보 또한 현물환시장으로 이전되어 원/달러 역내시장과 역외시장이 잘 동조화 되어 있다고 말할 수 있다. 즉 정보가 먼저 한 시장에 반영 된 후 다른 시장에 전달되는 정보의 일방 통행적 흐름이 아니라 정보의 반영이 두 시장에서 동시에 이루어지고 정보의 흐름이 양방향으로 이루어짐을 알 수 있다.

2008년 계육산업 전망

이재하,Lee, Jae-Ha 한국단미사료협회 2008 피드저널 Vol.6 No.1

KOSPI 200 선물을 이용한 포트폴리오 보험전략

이재하,장광열,Lee, Jae-Ha,Jang, Gwang-Youl 한국재무관리학회 1999 재무관리연구 Vol.16 No.2

본 연구는 KOSPI 200 선물을 이용하여 옵션복제방식에 의한 포트폴리오 보험전략을 구축하고 KOSPI 200 지수와 KOSPI 200 구성주식의 일부로 이루어지는 개별 포트폴리오들을 대상으로 실증분석을 하였다. 본 연구의 결과에 의하면, 포트폴리오 보험전략의 성과는 헤지의 대상이 되는 현물포트폴리오별, 보험수준별, 재조정 기준별로 차이가 있는 것으로 나타났다. KOSPI 200 지수포트폴리오에 대한 헤지는 대체로 약세시장에서 포트폴리오 가치하락을 감소시키면서 시세상승에 편승할 수 있는 것으로 나타났다. KOSPI 200 구성주식의 일부로 이루어진 포트폴리오에 대한 헤지는 수익성이 높고 베타값이 높으면서 시가총액이 큰 제조업이나 전기통신업에 속하는 기업의 주식으로 포트폴리오가 구성되었을 때 대체로 헤지성과가 높았다. 또한 KOSPI 200 지수포트폴리오는 보험수준을 낮게 할수록 헤지성과가 높은 것으로 나타난 반면, KOSPI 200 구성주식의 일부로 이루어진 포트폴리오의 경우에는 보험수준과 헤지성과간의 관계가 일정치가 않았다. 재조정 기준별로는 3% 재조정 기준을 적용하였을 때 헤지성과가 가장 높았으며, 가장 빈번하게 재조정을 해야하는 일별 재조정 기준에 의할 경우는 거래비용이 상대적으로 높았다.

연변조선족자치주의 지역성 변화에 관한 세계체제론적 분석

이재하(Jae Ha Lee),김석주(Shi Zhu Jin) 한국지역지리학회 2007 한국지역지리학회지 Vol.13 No.4

To understand the changing regionality of the Yanbian Korean Autonomous Prefecture(YKAP) in China within the world-economy, this paper examined the spatial division of labor in agriculture and industry with three divisions of period through the regional geography of world-system. In the Japanese colonial period(1909~1949), the YKAP was made into a typical peripheral agricultural and industrial region which was exploited by the Japanese empire. In the socialist period(1949~1978) which China separated from the world-system, the YKAP was transformed into a socialistic agricultural and industrial region. In the reform and open-door period(1978~present), the YKAP still plays a role as a peripheral region due to the late open-door policy in 1992 of Chinese government on the border land and else, while most littoral areas of China are developed into a semi-peripheral region. Therefore if the YKAP continues to exist in the furture, it is a critical matter to raise the position of the YKAP within the world-economy into a semi-periphery as soon as possible to increase the ratio of Korean ethnic in the YKAP.

살기좋은 지역 만들기의 방향과 과제

이재하(Jae Ha Lee) 한국지역지리학회 2007 한국지역지리학회지 Vol.13 No.1

중국 연길시에 (延吉市) 대한 상업 서비스업의 투자입지전략모색

이재하(Jae Ha Lee),김석주(Shizhu Jin) 한국지역지리학회 1998 한국지역지리학회지 Vol.4 No.1

Yanji(延吉) city is the district seat of the Yanbian(延邊) Korean Autonomous District where is located in the Jilin(吉林) Province in China, and also the largest city with a population of three hundred sixty thousand. Since the mid-1980s, the inter-exchange and cooperation between Yanbian District and South Korea has been increased rapidly. That draw many scholars attention to studying Yanbian District and Korean Chinese as a research theme for area studies. Unfortunately they neglect the study of the commerce and service industry in Yanbian city, which has indicated its rapid growth by the market economic policy of China, and an inter-exchange between Korean Chinese and Korean. The purpose of this study is to provide an information to many Korean potential investors for an investment strategy of the commerce and service industry in Yanji city. In order to do so, this study consists of three major steps. First of all, we analyzed the regional structure and locational characteristics of the commerce and service industry in Yanji City. Secondly, we investigated the characteristics of consumers behavior toward purchasing goods and service facilities. Finally, we supplied the proper businesses and location information for investment to Korean firms according to the results that identified above. In conclusion, we suggest that the proper businesses to invest are department store, retail clothing store, shoes store, cosmetics store, electronics and home appliances store, oversea branch offices of trading companies, Korean-style restaurant, hotel, nightclubs, Korean-style music room(Noraebang), travel agencies, beauty parlors, video rooms, electronic games, and so on. We also suggest that the proper locational areas to invest those businesses are the core area of the commerce and service industry in Yanji, where are Xinxing(新興) 3-zone and Jinxue(進學) 2-zone expressed in the Yanji city figure.

세계화시대에 적실한 지역연구방법론 모색

이재하(Jae Ha Lee) 한국지역지리학회 1997 한국지역지리학회지 Vol.3 No.1

We now live in the new era of globalization which implies the functional integration or increase of inter-dependency between internationally dispersed economic activities. As globalization impacts our various activities and daily lives, social sciences, including, geography, attempt to approach social phenomena from a global perspective. From this point of view, new regional geography, which has been articulated in recent social theory since the 1980s, also must adjust to these new world realities. This paper aims to search for a suitable methodology or approach to area study or regional geography in the era of globalization and to suggest the field of area study that Korean geographers should be concerned with in the future. This paper has reviewed the existing various methodologies of regional geography such as the ecological approach, the landscape approach, the areal differentiation approach, the system approach, the structuration theory, the spatial division of labour, and the world-system, which have deviced in the traditional and new regional geography. Peter Taylor`s regional geography of world systems among them has an appropriate rationale of area study in the globalization era, because world-systems theory explains well globalization. However the regional geography of world-systems must be revised to become more suitable to the area-study approach in the globalization era. Firstly, the regional geography of world-systems explains that regions(historical regions) are made by general mechanisms of the capitalist world-economy that operate through social, economic, and political agents within regions such as individuals, households, social classes, economic enterprises, states, political movements, and many other organizations. But these mechanisms can also act through other regional agents of geographical location, natural conditions, and cultural characteristics. Therefore, the generating process of regions needs to be explained by locational, natural, and cultural elements in addition to social, economic, and political elements within regions. Secondly, Taylor`s world-systems approach does not express composite characteristics of regions, because it focuses on the economic characteristics or position of regions within the world-economy. Regions incorporated into world-economy systems are not only changed economically, but also changed spatially, socially, culturally, and politically. Hence the world-systems approach must try to analyze these composite characteristics and their change of regions. Thirdly, The world-system approach proposed that the geography of regions within world-systems could be divided and analyzed as three regional types at the geographical scale such as international regions, state regions, and intra-state regions. However such a regionalization is usually not identified distinctly, because the geographical range of regions in world-systems shaped by economic boundaries of the general mechanisms of the world-economy is fluid and also occasionally overlaps with other political regions. Hence I propose that the world-systems approach should choose political boundaries of states and local autonomies in addition to economic boundaries for objective regionalization and systematic areal study. The revised regional geography of world-systems that I have suggested in this paper can be more effectively and properly applied to regional geography or area study in the globalization era. Globalization intensifies competition between states and also between local autonomies in the world. Therefore we must make efforts to study such areas or regions through the revised regional geography of world-system.

청도 소싸움 축제의 지역관광 활성화에 대한 파급효과

이재하(Jae Ha Lee),배기학(Ki Hak Bae) 한국지역지리학회 2004 한국지역지리학회지 Vol.10 No.3

정부의 독도개발정책 문제점과 미래대안 모색

이재하(Jae Ha Lee) 한국지역지리학회 2013 한국지역지리학회지 Vol.19 No.2

This study regards that a cause of intensifying sovereignty disputes between Korea and Japan over the Dokdo island has resulted from the fallacy of Dokdo`s development policy directly related to exertion and consolidation of Korean government`s sovereignty on Dokdo, which has been under Korea`s effective control since 1953. From this internal view, this study critically reviews the Korean government`s development policy for Dokdo from the 1950s to the end of July 2012 and suggests an ideal alternative for future development of Dokdo on the basis of the discussion of the problems of Dokdo`s development policy and its different future development directions proposed in Korean society. The Korean government implemented quite passively the development policy for the inhabited island which is required for the consolidation of sovereignty over Dokdo not to hinder the friendly diplomatic relationship between Korea and Japan. Dokdo is currently not acknowledged as the Korea`s Dokdo island in international society, but mostly called Liancourt Rocks. It may be due to the fact that Korea did not positively develop Dokdo as a valuable island which a number of Koreans can inhabit. Consequently this paper proposes ``Dokdo eco-village`` as an alternative development plan from the perspective of sustainable development which the UN has adopted. It is a small scale village that contains economic function of eco-friendly fishing, eco-tourism and East Sea research. The hope is that Dokdo eco-village draft plan will be a clue to the discussion and establishment of new Dokdo`s development policy to strengthen the Korea`s sovereignty and effective control over Dokdo in the future.