TIME/FREQUENCY ANALYSIS OF TERRESTRIAL IMPACT CRATER RECORDS

Chang Heon-Young The Korean Space Science Society 2006 Journal of Astronomy and Space Sciences Vol.23 No.3

The terrestrial impact cratering record recently has been examined in the time domain by Chang & Moon (2005). It was found that the ${\sim}26$ Myr periodicity in the impact cratering rate exists over the last ${\sim}250$ Myrs. Such a periodicity can be found regardless of the lower limit of the diameter up to D ${\sim}35km$. It immediately called pros and cons. The aim of this paper is two-fold: (1) to test if reported periodicities can be obtained with an independent method, (2) to see, as attempted earlier, if the phase is modulated. To achieve these goals we employ the time/frequency analysis and for the first time apply this method to the terrestrial impact cratering records. We have confirmed that without exceptions noticeable peaks appear around ${\sim}25$ Myr, corresponding to a frequency of ${\sim}0.04(Myr)^{-1}$. We also find periodicities in the data base including small impact craters, which are longer. Though the time/frequency analysis allows us to observe directly phase variations, we cannot find any indications of such changes. Instead, modes display slow variations of power in time. The time/frequency analysis shows a nonstationary behavior of the modes. The power can grow from just above the noise level and then decrease back to its initial level in a time of order of 10 Myrs.

Open Innovation Platform-based Business Startup Incubation Model in Incheon International Airport Corporation

Young J. Rho(노영주),Sei-Chang Sohn(손세창),Dong-Heon Yang(양동헌),Choongseok Lee(이충석) 한국산업경영시스템학회 2017 한국산업경영시스템학회지 Vol.40 No.4

More people travel oversea as the economic size of Korea is getting larger and more new jobs are requested to be created by the society. To respond to these trend and request, Incheon International Airport Corporation (IIAC) is about to expand its processing capability with a new terminal; 54 million passengers to 72 million. IIAC is also introducing new strategies such as open innovation (OI) and creating shared value (CSV). With these changes, IIAC faces new challenges of restructuring its business and organization with new ideas. Most organizations including IIAC are becoming more dependent on external resources to keep their competitive advantages under the turbulence of global business environmental changes. Therefore, they focus on the OI paradigm which is reported as a convincing strategy to improve competitiveness in terms of budget and time-to-market. OI is to quickly react to the rapidly changing business environment and is adopted to support startup incubation. In the previous research with IIAC, three major tasks were defined; utilizing the IIAC brand power for external vendors, building a technology road-map, and introducing a collaboration support system. This paper deals with the collaboration system as proposed in the previous research. We focused on the collaboration process for startup incubation. Cases were studied; the K-startup model by the government, a university model to explore youth startups, and a R&D institute model to study professional startups. Based on the case studies, we defined an IIAC model and proposed issues to take care of. The model is distinguished from the other studied models since IIAC is a prospective customer of new technology.

인천공항공사 개방형 혁신 도입방안에 관한 연구

노영주(Young J Rho),손세창(Sei Chang Sohn),양동헌(Dong Heon Yang),이충석(Choong seok Lee) 한국산업경영시스템학회 2015 한국산업경영시스템학회지 Vol.38 No.4

Recently, companies and organizations are becoming increasingly dependent on external resources to keep their competitive advantages under the turbulence of global business environmental changes. Therefore, they focus on the paradigm 'Open Innovation (OI)' which is reported as a convincing strategy to improve competitive advantage in terms of budget and time-to-market. The management of Incheon International Airport Corporation (IIAC) also considers the introduction of Open Innovation not only to adapt the business environmental changes but also to be devoted its social role as a public corporation. In this paper, we describe how we derived the promotion tasks for the introduction of OI and prioritized the tasks, performing our research on the IIAC Open Innovation. For these purposes, this research conducted the following three steps; the first stage for the analysis of current situation on the IIAC Open Innovation, the second stage for the elicitation of promotion tasks, and the last stage for the prioritization of the promotion tasks. In the first stage, critical success factors (CSFs) for open innovation introduction were derived from different research papers and case studies. In the following stage, promotion tasks were elicited from the IIAC based on the CSFs. In the last stage, the promotion tasks were evaluated on the base of criteria by using Analytic Hierarchy Process (AHP). And then the promotion tasks were grouped by the result of the evaluation. In this case, thirteen promotion tasks were derived for open innovation, ten promotion tasks except three inevitable promotion tasks were evaluated, and then they were grouped into four categories based on the importance-possibility analysis.

Structural Alterations in the Gill of the Red Sea Bream, Pagrus major, Exposed to the Harmful Dinoflagellate Cochlodinium polykrikoides

Kim, Chang Sook,Jee, Bo-Young,Bae, Heon Meen 한국수산학회 2002 Fisheries and Aquatic Sciences Vol.5 No.1

The effects of Cochlodinium polykrikoides on the gill of red sea bream, Pagrus major, were examined to clarify the ichthyotoxic mechanisms of this plankton species. The gill of fish exposed to dense blooms over 3,000 cells/mL for 24 h showed severe epithelial separation: a severe edema was found in the secondary lamellar epithelium and interlamellar regions of primary filament. In addition, lipid peroxidation of gill tissue in Chchlodinium-exposed fish was about 2.5 times higher than that of control. The composition of glycoproteins in the gill mucus of Cochlodinium-exposed fish was also changed. These results suggest that the loss of structural integrity of cell membrances in fish gill may be deeply involved in fish death by C. polykrikoides.

췌장염에 의한 가성낭종내에 생긴 가성동맥류 : 1례 보고

오연희,이채경,김승현,이성우,양창현,이정호,이영현 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

만성 췌장염의 합병증으로 생긴 가성동맥류는 드문질환으로, 반복적으로 다량의 출혈을 일으킬 수 있으며, 치료를 하지 않을 경우 사망율이 높기 때문에, 조기 진단과 치료가 필수적이다. 저자들은 38세 남자 환자에서 췌장염의 합병증으로 생긴 가성낭종내에서 발생한 가성동맥류 1예를 경험하였기에 보고하는 바이다. 가성 동맥류의 색혈류도플러상 낭종내에 양방향 흐름의 와류를 볼 수 있었다. Pancreatic Pseudoaneurysm within Pseudocyst from Pancreatitis: 1 Case Department of Diagnostic Radiology and Internal Medicine, College of Medicine,DongGuk University Yeon Hee OH M.D., Chae Kyeong Lee M.D., Seoung Hyeon Kim M.D., Sung Woo Lee M.D., Chang Heon Yang M.D., Jung Ho Lee M.D., Young Hyun Lee M.D. Pseudoaneurysm from pancreatitis is uncommon, but it can cause recurrent and massive hemorrhage. Because of high morbidity and mortality, early detection and treatment of the pseudoaneurysm is needed. We report a case of pseudoaneurysm within pseudocyst from pancreatitis. Color-flow Doppler sonography shows bidirectional flow and turbulent arterial flow, within anechoic mass.

선천성 후비공 폐쇄증 : 7예의 분석

김창훈,이정권,최윤석,유신영,윤주헌 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.3

셀(Cell) 단위 도시성장 모델링

문태헌,최창영 대한건축학회 2003 대한건축학회논문집 Vol.19 No.7

Excessive concentration of population into city has resulted in urban sprawl and environmental deterioration of suburbs in some cities. To prevent our cities from unfavorable situation of urban development, we are greatly in need of understanding of the city's growing appearance in the future. This paper examines an urban growth model of Jinju City. Existing urban growth models elaborated have difficulties in dynamic simulation. Easy geographic visualization and spatial exploration is another hard barriers to overcome. For these reasons we integrate Cellular Automate (CA) as an urban dynamic model and Geographic Information System (GIS) for visualization. Cell-based CA model was programmed with Visual C++ under the transition rules proposed with 1918 to 1986 growing trend of Jinju City. CA model constructed then was simulated as changing parameters into three cases. As a result, a CA model made was proved to regenerate urban growth as high as 93% of accuracy.

성문상 부분 후두절제술 후 인후두의 봉합방법에 따른 술후기능과 합병증에 관한 관찰

최은창,최홍식,김영호,김세헌,고윤우,박헌이 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.3

지연유합과 불유합에서 저신호 강도 초음파의 유용성

윤여헌,김종오,고영도,유재두,정준모,오종건,방한천,최창호,신명철 대한골절학회 2003 대한골절학회지 Vol.16 No.1

목 적 : 저 신호 강도 초음파를 이용한 지연유합과 불유합의 치료에 대한 유용성을 알아보고자 하였다. 대상 및 방법 : 2001년 7월부터 2002년 5월까지 본원에 내원한 지연유합 7례와 불유합 8례를 대상으로 5개월간 저 신호 강도 초음파로 치료하여 5개월후 골유합 여부를 알아 보았다. 결 과 : 총 15례 중 대퇴골 간부 2례, 경골 간부 1례, 상완골 간부 1례, 요골 1례의 지연유합에서 골유합을 얻었고 대퇴골 간부 불유합 3례에서 유합을 얻었다. 지연주합은 71%의 유합율을, 불유합은 37.5%의 유합율을 보였다. 결 론 : 저 신호 강도 초음파는 골유합을 촉진 시킬 수 있으며 지연유합에서 시도해 볼 만 하나 불유합 치료를 위해서는 보다 많은 연구가 필요 하다. Purpose : To evaluation of usefulness of low-intensity ultrasound for nonunion and delayed union. Materials and Methods : For 5 months, we treated 7 delayed union and 8 nonunion using low-intensity ultrasound. After 5 months, in checked X-ray AP and Lateral view, when cortical bridge formation was done, we through union. Results : In 7 delayed union, 5 cases-2 femur, tibia, humerus, radius were healed. In 8 nonunion, 3 femur nonunion were healed. Union rate was 71% in delayed union 37.5% in nonunion. Conclusion : we thought that the low-intensity ultrasound has capacity of induction of union and was considered as the method of treatment for delayed union.

Nondimensional modelling of 2D beam for slope discontinuity problem in ANCF

Ji-Heon Kang,이재욱,Jinseok Jang,Chang Young Choi,김건우 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.9

Various mechanical and structural systems possess slope discontinuity. Some bodies with slope discontinuity can be modeled using absolute nodal coordinate formulation, which can accurately express the rigid body mode when using the element and global shape functions. However, at the intersection of slope discontinuities, it is not easy to construct the equation of motion because the orientation changes. The problem of modeling at the intersection can be solved by defining the global slope vector in the body coordinate system instead of the element coordinate system. The analysis time in absolute nodal coordinate formulation is mostly greater than that in floating frame of reference formulation owing to the highly non-linear stiffness matrix. In this study, based on the work of Shabana and Mikkola, the analysis efficiency was demonstrated using the nondimensional model for the slope discontinuity problem in the absolute node coordinate system.