• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.73-73
• /
• 2021

가뭄의 계절적 예측성을 개선하기 위해서는 대기-지면-해양의 상호 작용이 현실적으로 모의할 수 있는 지구 기후 예보 모델의 개선이 필수적이다. 제한적인 기후 예보 모델의 예측성으로 인하여 다중 기후 모델들의 다중 앙상블 계절 예보 시스템이 제안되었다. 2008년에 제안된 북미 다중 모델 다중 앙상블 시스템(North American Multimodel Multiensemble System; NMME)은 다양한 모델 개발팀의 참여로 현재까지 운영되면서 계절적 예측성 연구에 큰 이바지를 하였다. 본 연구에서는 NMME 프로젝트에 참여하는 기후 예보 모델들의 북방 여름철 근지표면 온도과 강우량의 예측성을 진단하고 이들의 상관 관계의 강도를 관측데이터와 비교 분석하였다. 대부분의 NMME 모델들에서는 관측데이터에서 보다 강한 음의 상관 관계를 보였다. 이런 근지표면 온도와 강우량의 강한 상관 관계로 우수한 근지 표면 온도 예보는 각각의 해마다 그 역할이 다른 것을 발견되었다. 예를 들어 가문 여름에는 우수한 근지표면 온도 예보가 강우량 예보에 도움이 되고 강우량이 많은 여름에는 우수한 근지표면 온도 예보는 오히려 강우량 예측성을 제한하게 된다. 따라서 기존의 기후 예보 모델들에서 근지표면 온도와 강우량의 상관관계를 사실적으로 나타낼 수 있도록 모델 개선이 요구된다. 마지막으로 관측데이터와 기후 모델데이터에서 태평양과 대서양의 해수면 온도와 미국의 북방 여름철 날씨의 관계를 비교하였다. 근지표면 온도과 강우량에 대한 제한적 예측성에 비해, 대부분의 NMME 기후 예보 모델들에서 해수면 온도의 예측기술은 우수함을 발견하였고 몇몇 모델들에서는 미국의 북방 여름철 기후에 영향력을 주는 대서양과 태평양의 지역까지 잘 모사하는 것을 발견하였다. 따라서 본 연구는 보다 우수한 기후 예보 기술을 위해 앙상블 평균 예보값만이 아닌 NMME의 계절적 예보를 선택적인 사용이 필요함을 제안하였고 앞으로 북미 대륙 뿐만이 아니라 유럽-아시아의 계절적 이상 기후 예측성에 대한 연구 필요성을 강조하였다.

• Proceedings of the Korean Association for Survey Research Conference
• /
• 2000.11a
• /
• pp.141-155
• /
• 2000

현재 국내의 여론조사에서는 전화조사가 주로 이용되고 있으며, 최근 들어 인터넷조사를 활용하는 방법들이 연구되고 있다. 그러나 인테넷조사의 경우 모집단 구조가 편향된 특성을 가지고 있으므로 이에 대한 보완 수정없이 결과의 직접적인 이용은 많은 비표본오차를 발생시킬 수 있다. 그러므로 본 연구에서는 사회여론조사를 수행함에 있어서 편향모집단에서의 인터넷조사로부터의 추정값과 전화조사를 통한 추정값의 적절한 결합추정방법을 제안하고, 지난 4.13 총선의 조사자료를 이용하여 이들 결합추정의 효율성을 검토하였다.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.600-612
• /
• 2009

Special banks primarily using Internet have different properties in transactions with customers, risk management, capital strength, and branch networks with general banks. The success and failure factors of Internet banks have been explained only by the economies of scale, and learning and experience effects of Internet banks based on the perspective of organizational ecologies. In this study, the success factors of Internet banks are investigated based on strategic choice by organizations and resource-based view of the firms instead of organizational ecology perspective. To this end, 31 major Internet banks operating in overseas market have been classified by the size and profitability of banks, and three strategic groups have been derived. three representative company cases were analyzed. critical success factors of Internet banks were derived, and considerable points when operating Internet banks were discussed.

• Journal of the Society of Disaster Information
• /
• v.20 no.2
• /
• pp.379-389
• /
• 2024

Purpose and Method: Crowed Events can lead to sudden accidents caused by unpredictable variables. Therefore, focusing on the '10.29 Itaewon accident' among the representative cases, we examined the accident as the process of occurrence. In addition, improvement measures were suggested through analysis of related legal systems. Result: In the Itaewon accident, a "colony wave phenomenon" occurred due to "ultra-high-density cluster stay". In addition, cluster destruction occurred from a weak location in the cluster due to clusters and pressures in different directions to avoid this. Looking at the laws related to the safety management of Crowed Events, the laws and regulations differ depending on the location and type. Due to the complementary nature of the approach to the legal blind spot, the legal system that uses similar terms of the same concept and is not systematic is causing uncertainty in the application and interpretation of the law. Conclusion: Crowd control and on-site management should be carried out for events when the cluster density is expected to reach 8 people/m² or reached. Consistency should be maintained through the unified application of legislation to related legislation.

• Journal of KIISE
• /
• v.43 no.2
• /
• pp.237-245
• /
• 2016

In this paper we introduce a novel database research area called science of databases (SoDB) and carry out a comprehensive analysis of its case studies. SoDB aims to better understand interesting phenomena observed across multiple database management systems (DBMSes). While mathematical and engineering work in the database field has been dominant, less attention has been given to scientific approaches through which DBMSes can be better understood. Scientific investigations can lead to better engineered designs through deeper understanding of query optimizers and transaction processing. The SoDB research has investigated several interesting phenomena observed across different DBMSes and provided several engineering implications based on our uncovered results. In this paper we introduce a novel scientific, empirical methodology and describe the research infrastructure to enable the methodology. We then review each of a selected group of phenomena studied and present an identified structural causal model associated with each phenomenon. We also conduct a comprehensive analysis on the case studies. Finally, we suggest future directions to expand the SoDB research.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.836-839
• /
• 2007

At the present, all resources on ubiquitous are smart and networking. it deduces the environment that any service could be provided without any restriction of time and space and maximizes life quality and creation of people and industry productivity. especially, it converses and integrates all fields in the city based on Ubiquitous computing, IT. Furthermore, the study on the technology concerned with Ubiquitous is actively conducted. In this paper, we would like to look onto the types of necessary system and technology when the Ubiquitous system is applied to buildings. Besides, as analyzing necessity and expecting effect of ubiquitous system, we suggest the method to establish ubiquitous system in multi-complex buildings.

• The Journal of the Korea Contents Association
• /
• v.1 no.1
• /
• pp.51-58
• /
• 2001

Electronic commerce system must provide convenient interface, easy and fast searching function, and production information satisfying customers. To do this, many kinds of studies are being advanced actively about electronic commerce system using intelligent agent electronic This paper suggests 2-tier electronic commerce system using intelligent multi agent. We propose a combined reasoning agent system which provides production information satisfying customer's needs using both case-based reasoning and rule-based reasoning. And this system distribute network and sewer system load based on load balancing and 2-tier agent structure. This system can find production information through teaming of rule-based reasoning method and case-based reasoning method. This system can provide the best suitable production information to customers by using combined reasoning agent system. And we can prevent customer's unexpected long waiting causes by network traffic and server load.

• Journal of Korea Technology Innovation Society
• /
• v.13 no.2
• /
• pp.231-251
• /
• 2010

The numbers of SCI paper or patent in science and technology are expected to be related with the number of researcher and knowledge stock (R&D stock, paper stock, patent stock). The results of the regression model showed that severe multicollinearity existed and errors were made in the estimation and testing of regression coefficients. To solve the problem of multicollinearity and estimate the effect of the independent variable properly, principal component regression model were applied for three cases with S&T knowledge production. The estimated principal component regression function was transformed into original independent variables to interpret properly its effect. The analysis indicated that the principal component regression model was useful to estimate the effect of the highly correlate production factors and showed that the number of researcher, R&D stock, paper or patent stock had all positive effect on the production of paper or patent.

• Journal of Technology Innovation
• /
• v.22 no.4
• /
• pp.199-233
• /
• 2014

This paper attempts to investigate how and why the additionality effects occur in the case when a firm receives government subsidy as opposed to counterfactual situation. To demonstrate this, we selected 12 SMEs(small and medium enterprises) firms in Daejeon area and have conducted multiple case studies. In order to analyse the multiple cases of firms, we classified firms innovative activities into three stages which are composed of input, behaviour and output stages and related various factors. Furthermore, we investigated the differences according to types of firms and stages of firm growth. Empirical results show that various input, behaviour and output additionality effects exist when firms receive public subsidies. Compared to companies in the growth and mature stages, startup phase companies depend on government subsidy extensively and they use public subsidies strategically to develop new product and to change their strategic direction. The attitude of firms to use government subsidies is different according to their types and stage of growth as well.

• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.1
• /
• pp.121-128
• /
• 2016

Many studies are focused on image data and classifier for comparison or improvement of classification accuracy. Therefore studies are needed aspect of the training samples on supervised classification which depend on reference data or skill of analyst. This study tries to assess usability of field spectra as training samples on supervised classification. Classification accuracies of hyperspectral and multispectral images were assessed using training samples from image itself and field spectra, respectively. The results shown about 90% accuracy with training sample collected from image. Using field spectra as training sample, accuracy was decreased 10%p for hyperspectral image, and 20%p for multispectral image. Especially, some classes shown very low accuracies due to similar spectral characteristics on multispectral image. Therefore, field spectra might be used as training samples on classification of hyperspectral image, although it has limitation for multispectral image.