• Journal of Climate Change Research
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• v.7 no.4
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• pp.407-419
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• 2016

The low flow is the necessary and important index to establish national water planning, however there are lots of uncertainty in the low flow estimation. Therefore, the objectives of this study are to assess the climate change uncertainty and the effects of hydrological models on low flow estimation. The 5 RCMs (HadGEM3-RA, RegCM4, MM5, WRF, and RSM), 5 statistical post-processing methods and 2 hydrological models were applied for evaluation. The study area were selected as Chungju dam and Soyang river dam basin, and the 30 days minimum flow is used for the low flow evaluation. The results of the uncertainty analysis showed that the hydrological model was the largest source of uncertainty about 41.5% in the low flow projection. The uncertainty of hydrological model is higher than the other steps (RCM, statistical post-processing). Also, VIC model is more sensitive for climate change compared to SWAT model. Therefore, the hydrological model should be thoroughly reviewed for the climate change impact assessment on low flow.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.187-199
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• 2017

We attempted to assess the impact of climate change on rice yields in Cambodia and to investigate adaptation strategies to climate change including more drastically shifting the planting dates and considering more fertilizer application levels. The potential yields of two wet season rice cultivars (Sen Pidao and Phka Rumduol) under two climate change scenarios in Cambodia were simulated using the CERES-Rice model. Field experiments conducted at the Cambodian Agricultural Research and Development Institute (CARDI), in 2010, 2011, and 2013 and climate variables from the HadGEM3-RA model were collected for this study. Compared with the baseline (1991-2000), yields of Sen Pidao rice will decrease under climate change and yields of Phka Rumduol rice could increase or decrease depending on fertilizer rates and the periods (2040s, 2050s, and 2080s). In general, the variations in the simulated effects of climate change on yields were more sensitive at fertilizer N100-N200 and less sensitive at fertilizer N0-N50. It is likely that forward shifts of planting date from the baseline plating date for the two cultivars in the future can be more benefitted than backward shifts. It is concluded that the CERES-Rice model can be useful to provide efficacious adaptation strategies in Cambodia.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.168-168
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• 2018

최근 기후변화로 인하여 전 세계적으로 과거 강우사상에서 확인되지 않는 극치사상이 빈번하게 관측되고 있으며 이에 따른 피해도 증가하고 있다. 미래의 기상학적 변동성 및 기후변화 영향은 지구순환모형 (General Circulation Models, GCM)을 통해 구체화되며 가장 일반적인 기후변화 전망자료로서 활용된다. 그러나 산정된 기후변화 시나리오마다 서로 그 특성에 차이가 있으며 이러한 이유로 다양한 원인으로 인해 큰 변동성을 가지는 미래 극치강우를 하나의 시나리오로 분석하기에는 무리가 있다. 또한 다양한 시나리오를 통해 분석한 결과값이 상이하며 이러한 시나리오별 산정 결과의 차이는 사용자에게 혼란을 야기할 수 있어 이를 하나의 결과로 나타낼 필요성이 있으나 정량적인 대푯값을 얻기 위해 특정 시나리오를 선택하는 것은 신뢰성에 문제가 있다. 본 연구에서는 시나리오들을 정량적 지표에 의거하여 혼합된 하나의 시나리오로 표출하고자 하였다. CORDEX-RCMs 시나리오 중 HadGEM3-RA, RegCM, SNU_WRF 및 GRIMs를 입력 자료로 하여 다중모형앙상블(Multi-Model Ensemble, MME)을 통해 낙동강 유역의 극치강우에 대한 하나의 최적 기후변화 시나리오를 도출하고자 하였으며 계층적 베이지안 (Hierarchical Bayesian Model, HBM) 기법을 통하여 기후변화 시나리오에 내제된 불확실성에 대한 정량적인 해석을 수행하였다.

• Journal of applied mathematics & informatics
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• v.39 no.1_2
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• pp.197-214
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• 2021

In this paper, we have studied dynamics of fractional order mathematical model of malaria transmission for two groups of human population say semi-immune and non-immune along with growing stages of mosquito vector. The present fractional order mathematical model is the extension of integer order mathematical model proposed by Ousmane Koutou et al. For this study, Atangana-Baleanu fractional order derivative in Caputo sense has been implemented. In the view of memory effect of fractional derivative, this model has been found more realistic than integer order model of malaria and helps to understand dynamical behaviour of malaria epidemic in depth. We have analysed the proposed model for two precisely defined set of parameters and initial value conditions. The uniqueness and existence of present model has been proved by Lipschitz conditions and fixed point theorem. Generalised Euler method is used to analyse numerical results. It is observed that this model is more dynamic as we have considered all classes of human population and mosquito vector to analyse the dynamics of malaria.

• Journal of Korean Society for Quality Management
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• v.50 no.3
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• pp.305-332
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• 2022

Purpose: As the public interest in entrepreneurship has been highlighted and entrepreneurship policies have been generated, this study is to construct Entrepreneurship Ecosystem (EE) models which have a significant relationship to national entrepreneurship with quantitative analysis. It aims to provide implications to EE policymakers that which national components are effective in cultivating innovative entrepreneurship and validate its EE quality based on quantitative performance goals. Methods: This study utilizes secondary data, categorized under the PESTLE factor from credible international organizations (WB, UNDP, GEM, GEDI, and OECD) to determine significant factors in the quality of the entrepreneurial ecosystem. This paper uses the Multiple Linear Regression (MLR) analysis to select the significant variables contributing to entrepreneurship performance. Using the AUC-ROC performance evaluation method for machine learning MLR results, this paper evaluates the performance of EE models so that it can allow approving EE quality by predicting potential performance. Results: Among nine hypothesis models, MLR analysis examines that the number of the Unicorn company, Unicorn companies' economic value, and entrepreneurship measured as GEI can be reasonable dependent variables to indicate the performance derived from EE quality. Rather than government policies and regulations, the social, finance, technology, and economic variables are significant factors of EE quality determining its performance. By having high Area Under Curve values under AUC-ROC analysis, accepted MLR models are regarded as having high prediction accuracy. Conclusion: Superior EE contributes to the outstanding Unicorn companies, and improvement in macro-environmental components can enhance EE quality.

• BMB Reports
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• v.56 no.8
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• pp.417-425
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• 2023

In various organisms, the Hippo signaling pathway has been identified as a master regulator of organ size determination and tissue homeostasis. The Hippo signaling coordinates embryonic development, tissue regeneration and differentiation, through regulating cell proliferation and survival. The YAP and TAZ (YAP/TAZ) act as core transducers of the Hippo pathway, and they are tightly and exquisitely regulated in response to various intrinsic and extrinsic stimuli. Abnormal regulation or genetic variation of the Hippo pathway causes a wide range of human diseases, including cancer. Recent studies have revealed that Hippo signaling plays a pivotal role in the immune system and cancer immunity. Due to pathophysiological importance, the emerging role of Hippo signaling in blood cell differentiation, known as hematopoiesis, is receiving much attention. A number of elegant studies using a genetically engineered mouse (GEM) model have shed light on the mechanistic and physiological insights into the Hippo pathway in the regulation of hematopoiesis. Here, we briefly review the function of Hippo signaling in the regulation of hematopoiesis and immune cell differentiation.

• 한국벤처창업학회:학술대회논문집
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• 2022.11a
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• pp.83-88
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• 2022

디지털 전환은 기존 산업의 진입장벽 파괴에 따른 새로운 비즈니스 기회 확대, 자산의 디지털화에 따른 초기창업비용의 축소 등 창업 및 기업가적 활동 측면에서 중대한 환경적 변화를 초래하고 있다. 이러한 변화로 인해 기존의 기업가정신 이론으로 기업가들이 새로운 비즈니스 기회를 인식하고 기업가적 가치를 추구하는 일련의 과정을 이해하기에는 충분치 않으며, 기업가정신의 특성 및 효과에 대한 새로운 접근이 필요하다는 문제의식을 바탕으로 최근 디지털 경제 환경에서의 기업가정신을 조망하는 새로운 이론적 틀로서 '디지털 기업가정신'이라는 개념 및 관련 연구분야가 부상하고 있다. 본 연구에서는 국가 단위에서 디지털 기업가정신의 고용효과를 탐색적으로 파악하기 위하여 국제 기업가정신 관련 조사인 「글로벌 기업가정신 모니터(GEM)」 데이터를 활용한 상관 관계 분석을 실시하였다. 연구 결과, 기업가적 활동에 있어서의 디지털 기술 활용 의지, 창업 의지, 6인 이상의 고용창출 의지 등이 상호 간 긍정적인 관련성을 가지는 것으로 나타났다. 이는 디지털 기술에 기반한 창업 또는 기업가적 활동에 대한 의지가 일자리 창출과 긍정적인 관계를 가진다는 의미다. 해외 학자들을 중심으로 이루어지고 있는 디지털 기업가정신 연구는 기업가정신 및 창업 프로세스에 대한 디지털화의 영향이나 디지털 기술의 혁신 및 새로운 벤처의 탄생에 의해 창출된 기업가적 기회에 대한 논의가 주를 이루고 있는 데 반하여, 본 연구에서는 디지털 기업가정신에 의해 창출되는 성과에 대해 살펴본다는 점에서 차별성이 있다. 또한 국내에서 많이 다루지 않은 디지털 기업가정신 관련 연구를 수행하고 그 결과를 발표함으로써 동 분야에 대한 국내 학계의 관심을 촉진할 것으로 기대된다는 점에서도 학술적 의의가 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.433-435
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• 2023

본 연구는 기업가정신 글로벌비즈니스 세미나 과목의 과제로써 기업가정신이 무엇인지 확립하고 기업가정신과 연관 지을 수 있는 주제를 선정하여 스스로 연구함으로써 그 의미를 구체화 하고 새로운 패러다임을 제시하고자 하는데 의미가 있다고 볼 수 있다. 저자들은 '문화'가 갖는 상대성에 주목하여 기업가 정신을 해석하였으며 재학 중 배웠던 '홉스테드의 문화 특성' 이론과 접목시켜 문화가 기업가 정신에 어떤 영향을 끼치는지 연구하였다. 글로벌 기업가정신 모니터(GEM)의 글로벌 기업가 지수 순위 조사 결과와, 홉스테드 인사이트(Hofstede-insight)의 6가지 차원에 따른 국가별 문화지수 파일을 접목시켜 수치화하고, 시각적 그래프 및 엑셀 데이터 다중 회귀분석을 통하여 결과를 도출하였다. 홉스테드의 문화 특성이 기업가 정신 순위에 영향을 미칠 것이라고 가정하고 분석한 결과, 홉스테드의 6가지 차원 중 하나인 불확실성 회피성향이 기업가 정신에 가장 높은 영향을 미친다는 사실을 발견하였다. 이번 연구를 통해기업가 정신을 계승하는 기업문화를 제고하고 경제학과 인류학 통합 연구의 필요성을 제시한다.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.763-770
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• 1998

Salmonella typhimurium is a causitive agent of diarrhea, fever, gastroenteritis, septicemia and sudden death in piglet. The currently used methods such as IFA, ELISA, DNA hybridization assay is needed a long-time and difficult to detect the organism in carrier animal or contaminated sample with other agents. However, it is important to detect rapidly and sensitively S typhimurium in piglet with other infectious pathogens to minimize an economic loss. Two sets of PCR primer, rfbJ forward primer(5'-AGAATATGTAATTGTCAG-3') and reverse primer(5'-TAACCGTTTCAGTAGTTC-3') were designed to amplify a 882 by fragment of Salmonella serovar type B gene. The target genomic DNA for PCR was extracted from the cultivated materials with various enrichment periods in a nonselective enrichment agar and broth with clinical specimens. The PCR is carried out here made it possible to detect the gene from two hours. Also, the amplified fragment with PCR was cloned into pGEM-T vector and digested with restrict enzyme, and sequenced for the identification of Salmonella serotype B rfbJ gene. Duplicated cultivation agar-broth followed by PCR were performed to develop a rapid and sensitive detection of S typhlmurium based on serovar type. This duplicated cultivation-PCR method provides a sensitive and rapid diagnostic tool to detect Salmonella from infected piglet with improved sensitivity.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.1
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• pp.22-31
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• 1997

The grain boundary etching method as a method for assessing degradation of structural materials has received much attention because it is simple, inexpensive and easy to apply to real components. In this study, the effectiveness of the method is verified by successfully applying the technique to in-service components of aged fossil power plants such as main steam pipes, boiler headers an turbine rotors. A new degradation parameter, intersecting number ratio (N$_{1}$/N$_{0}$), is employed. The intersecting number ratio (N$_{1}$/N$_{0}$) is defined as the ratio of intersection number (N$_{1}$) obtained from 5-minute picric acid etched surface to the number (N$_{0}$) obtained from nital etched surface. Two kinds of test materials, 2.25Cr-1Mo steel and 1Cr-1Mo-0.25V steel, were artificially thermal-aged at 630.deg. C in different levels of degradation., (N$_{1}$/N$_{0}$) were measured. And, correlations between the measured values and LMP values calculated from aging temperature and aging time were sought. To check the validity of the correlations obtained in laboratory, similar data were measured from service components in four old Korean fossil power plants. These on-site measurement data were in good correlation with those obtained in the laboratory.oratory.