• 기술혁신연구
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• 제21권1호
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• pp.109-139
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• 2013

본 연구는 미국과 한국의 오픈 소스 소프트웨어(OSS) 기업의 사례를 중심으로 기존 기술추격이론이 지식 집약적인 OSS 산업에서도 적용되는 지를 분석하고 후발기업들이 기술추격의 발판을 마련할 시사점을 연구하는 것을 그 목적으로 한다. 이를 위하여, 국내 SW 기업들의 인터뷰와 미국 SW 기업들의 기록문서 분석 및 2차 출처들의 검토를 통한 실증적 연구를 수행하였으며, 패러다임의 변곡점 판별과 기술체제의 비교라는 분석의 틀을 이용하여 소프트웨어(SW) 기업의 기술추격 과정을 연구하였다. 본 연구결과, OSS 기업의 기술추격을 설명하는데 있어 기존 기술추격이론의 이론적 논거가 유효하지 않다고 판별하였고 기술체제의 비교 결과, 후발기업의 기술추격을 효과적으로 촉진하는 유효한 요소들을 파악하였다. 또한 저자들은 OSS 기업의 사례연구 결과를 통하여 탈 추격이론이 주장하는 기존 이론의 제약을 진단하고 OSS 의 낮은 전유성이 역설적으로 기술추격을 촉진하는 새로운 기술 체제에 대한 해석을 논의한다.

• Nuclear Engineering and Technology
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• 제44권5호
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• pp.543-550
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• 2012

The decrease in the fracture toughness of ferritic steels in a reactor pressure vessel is an important factor in determining the lifetime of a nuclear power plant. A surveillance program has been in place in Korea since 1979 to assess the structural integrity of RPV steels. In this work, the surveillance data were collected and analyzed statistically in order to derive the empirical relationship between the embrittlement and strengthening of irradiated reactor pressure vessel steels. There was a linear relationship between the yield strength change and the transition temperature shift change at 41 J due to irradiation. The proportional coefficient was about $0.5^{\circ}C$/MPa in the base metals (plate/forgings). The upper shelf energy decrease ratio was non-linearly proportional to the yield strength change, and most of the data lay along the trend curve of the US results. The transition regime temperature interval, ${\Delta}T_T$, was less than the US data. The overall change from irradiation was very similar to the US results. It is expected that the results of this study will be applied to basic research on the multiscale modeling of the irradiation embrittlement of RPV materials in Korea.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 추계 학술대회지
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• pp.3-11
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• 2000

The Asian summer monsoon has a profound social and economic impact in East Asia and its surrounding countries. The monsoon is basically a response of the atmosphere to the differential heating between the land mass of the Asian continent and the adjacent oceans. The atmospheric response, however, is quite complicated due to the interactions between the atmospheric heat sources, land-sea contrast, and topography, The occurrence of extreme summertime floods in Korea, Japan, and China in 1998 and 1999 has highlighted the range of variability of the East Asian summertime monsoon circulation and spurred interest in investigating the cause of such extreme variability. While ENSO is often considered a prime mechanism responsible for the unusual hydrological disasters in East Asia, understanding of the connection between ENSO and the East Asian monsoon is hampered by their dynamic complexities. Along with a recent phenomenon of weather abnormalities observed in many parts of the globe, Korea has seen its share of increased weather abnormalities such as the record-breaking heavy rainfalls due to a series of flash floods in the summers of 1998 and 1999, following devastating Yangtze river floods in China. A clear regime shift is found in the tropospheric mean temperature in the northern hemisphere middle latitudes and the surface temperature over the Asian continent during the summer with a sudden warming since 1977. Either decadal climate variation or climate regime shift in the Asian continent is evident and may have altered the characteristics of the East Asian summer monsoon. Considering the summertime rainfall amount in Korea is overall increased lately, the 1998/99 heavy rainfalls may not be isolated episodes related only to ENSO, but could be a part of long-term climate variation. The record-breaking heavy summer rainfalls in Korea may not be direct impact of ENSO. Instead, the effects of decadal climate variation and ENSO may be coupled to each other and also to the East Asian summer monsoon system, while their individual impacts are difficult to separate.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2004년도 제24회 동계학술대회 논문집
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• pp.288-315
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• 2004

This paper has examined the leapfrogging thesis with the case of catch-up in digital TV by the Korean firms. Despite the disadvantages implied by the technological regime of digital TV and the risks facing early entrants in trajectory choice and initial market formation, the Korean firms had achieved a 'path-creating catch-up' in the sense they chose a different path from the Japanese forerunning firms. As they have been closely watching the technological trends and the standard setting process, there was less risk of choosing the right or wrong technological trajectory. Also, despite the lack of sufficient capability and core knowledge base, the Korean firms had some complementary asset, such as the experience of producing analogue TV, and were able to develop the prototype digital TV and the ASIC chips, given the accesses to the foreign knowledge via overseas R&D posts and acquisition of a foreign company. To secure the initial market size, the Korean targeted the US market from the beginning, and their sources for competitive advantages were the speedy setting up the production system for mass production of products at the initial stage. The initial failure of the Japanese firms and the success of the Korean firms do suggest that the period of paradigm shift, like this toward digital technology, can serve as a window of opportunity for late-comers while penalizing the forerunner.

• 한국기후변화학회지
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• 제7권1호
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• pp.31-39
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• 2016

In this study, the time series of the number of days with $25^{\circ}C$ or higher temperatures in the Jeju region were analyzed and they showed a strong trend of increase until recently. To determine the existence of a climate regime shift in this time series, the statistical change-point analysis was applied and it was found that the number of days with $25^{\circ}C$ or higher temperatures in the Jeju region increased sharply since 1993. Therefore, in order to examine the cause of the sharp increase of the days with $25^{\circ}C$ or higher temperatures in the Jeju region, the differences between the averages of 1994~2013 and the averages of 1974~1993 were analyzed for the large-scale environment. In the Korean Peninsula including the Jeju region, precipitable water and total cloud cover decreased recently due to the intensification of strong anomalous anticyclones near the Korean Peninsula in the top, middle and bottom layers of the troposphere. As a result of this, the number of days with $25^{\circ}C$ or higher temperatures in the Jeju region could increase sharply in recent years. Furthermore, in the analysis of sensible heat net flux and daily maximum temperatures at 2 m, which is the height that can be felt by people, the Korean Peninsula was included in the positive anomaly region. In addition, the frequency of typhoons affecting the Korean Peninsula decreased recently, which reduced the opportunities for air temperature drops in the Jeju region.

• 환경정책연구
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• 제1권1호
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• pp.1-24
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• 2002

Due to the recent increase in greenhouse gases in atmosphere, world climate is rapidly changing and in turn, the earth ecosystem responds upon the climate changes. Comparing the ecosystem in the past, the present shapes of ecosystem is the result of the serious modification. Fishery resources in marine ecosystem, which usually occupy the upper trophic level, are also inevitable from such changes, because they always react to the natural environmental conditions. The northwestern Pacific is the most productive ocean in the world producing about 30% of world catch. From time to time, however, it has been notified that abundance, distribution and species composition of major fish species were altered by climate events. Furthermore, primary productivity of the ocean is not stable under the changing environments, so that carrying capacity of the ocean varies from one climate regime to another. Major climate events such as global warming, atmospheric circulation pattern, climate regime shift in the North Pacific, and El Nino event in the Pacific tropical waters were introduced in relation to fisheries aspects. The current status and future projection of fishery production was investigated, especially in the North Pacific including Korean waters. This new paradigm, ecosystem response to environmental variability, has become the main theme in marine ecology and fishery science, and the GLOBEC-type researches might provide a solution far cause-effect mechanism as well as prediction capability. Ecosystem management principles for multi-species should be adopted for better understanding and management of ecosystem.

• Applied Science and Convergence Technology
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• 제23권4호
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• pp.192-199
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• 2014

The electronic property of graphene was investigated by hydrazine treatment. Hydrazine ($N_2H_4$) highly increases electron concentrations and up-shifts Fermi level of graphene based on significant shift of Dirac point to the negative gate voltage. We have observed contact resistance and channel length dependent mobility of graphene in the back-gated device after hydrazine monohydrate treatment and continuously monitored electrical characteristics under Nitrogen or air exposure. The contact resistance increases with hydrazine-treated and subsequent Nitrogen-exposed devices and reduces down in successive Air-exposed device to the similar level of pristine one. The channel conductance curve as a function of gate voltage in hole conduction regime keeps analogous value and shape even after Nitrogen/Air exposure specially whereas, in electron conduction regime change rate of conductance along with the level of conductance with gate voltage are decreased. Hydrazine could be utilized as the highly effective donor without degradation of mobility but the stability issue to be solved for future application.

• 사회경제평론
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• 제38호
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• pp.163-198
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• 2012

본 연구의 거시동학모형은 전통적인 포스트 케인지언 성장 분배모형에 기업부채라는 금융변수를 고려함으로써 기업부채와 자본축적 간의 동학적 관계를 구축하고 있다. 이 거시동학모형에 기초하여 본 연구는 우리나라의 자료를 이용하여 정부의 금융지출이 자본축적에 미치는 효과를 실증 분석하고, 1997/98년 외환위기를 전후하여 축적 레짐의 전환이 발생하였는지를 실증 분석하였다. 실증 분석 결과, 금융시장 안정화를 위한 정부의 금융지출은 자본축적 경로에 긍정적으로 영향을 미쳤음을 알 수 있었다. 본 연구의 실증 분석 결과는 금융(경제)위기가 발발할경우 정부의 적극적인 금융시장 개입을 지지한다. 한편, 본 연구는 1997/98년 외환위기 전후 축적 레짐에 변화가 발생하였을 것으로 추측할 수 있는 상당한 근거를 발견하였다.

• Journal of information and communication convergence engineering
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• 제14권1호
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• pp.40-44
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• 2016

The device coupling between the stacked top/bottom field-effect transistors (FETs) in two types of monolithic 3D inverter (M3INV) with/without a metal layer in the bottom tier is investigated, and then the regime of the thickness T_ILD and dielectric constant ε_r of the inter-layer distance (ILD), the doping concentration N_d (N_a), and length L_g of the channel, and the side-wall length L_SW where the stacked FETs are coupled are studied. When N_d (N_a) < 10¹⁶ cm^-3 and L_SW < 20 nm, the threshold voltage shift of the top FET varies almost constantly by the gate voltage of the bottom FET, but when N_d (N_a) > 10¹⁶ cm^-3 or L_SW > 20 nm, the shift decreases and increases, respectively. M3INVs with T_ILD ≥ 50 nm and ε_r ≤ 3.9 can neglect the interaction between the stacked FETs, but when T_ILD or ε_r do not meet the above conditions, the interaction must be taken into consideration.

• 한국지구과학회지
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• 제32권5호
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• pp.453-460
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• 2011

By performing a statistical change-point analysis of activities of the tropical cyclones (TCs) that have affected Korea (K-TCs), it was found that there was a significant change between 1983 and 1984. During the period of 1984-2004 (P2), more TCs migrated toward the west, recurved in the southwest, and affected Korea, compared to the period of 1965-1983 (P1). These changes for P2 were related to the southwestward expansion of the subtropical western North Pacific high (SWNPH) and simultaneously elongation of its elliptical shape toward Korea. Because of these changes, the central pressure and lifetime of K-TC during P2 were deeper and longer, respectively, than figures for P1. This stronger K-TC intensity for P2 was related to the more southwestward genesis due to the southwestward expansion of the SWNPH. The weaker vertical wind shear environment during P2 was more favorable for K-TC to maintain a strong intensity in the mid-latitudes of East Asia.