• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.3
• /
• pp.26-38
• /
• 2020

Mixture design of self-compacting concrete is a typical multi-criteria decision making problem and conventional mixture designs are based on the low level engineering method like trials and errors through iteration method to satisfy the various requirements. This study concerns with performing the straightforward multiobjective design optimization of economic SCC mixture considering relative importances of the various requirements and cost-effectives of SCC. Total five requirements of 28day compressive strength, filling ability, segregation stability, material cost and mass were taken into consideration to prepare the objective function to be formulated in form of the weighted-multiobjective mixture design optimization problem. Economic SCC mixture computational design can be given in a rational way which considering material costs and the relative importances of the requiremets and from the result of this study it is expected that the development of SCC mixtue computational design and the consequent univeral concrete material design optimization methodology can be advanced.

• Journal of Korea Water Resources Association
• /
• v.54 no.9
• /
• pp.705-718
• /
• 2021

Climate change has a significant impact on vegetation growth and terrestrial ecosystems. In this study, the possibility of ecological drought was investigated using satellite remote sensing data. First, the Vegetation Health Index was estimated from the Normalized Difference Vegetation Index and Land Surface Temperature provided by MODIS. Then, a joint probability model was constructed to estimate the possibility of vegetation-related drought in various precipitation/evaporation scenarios in forest areas around 60 major ASOS sites of the Meteorological Administration located throughout Korea. The results of this study show the risk pattern of drought related to forest vegetation under conditions of low atmospheric moisture supply or high atmospheric moisture demand. It also identifies the sensitivity of drought risks associated with forest vegetation under various meterological drought conditions. These findings provide insights for decision makers to assess drought risk and develop drought mitigation strategies related to forest vegetation in a warming era.

• Journal of the Korea Convergence Society
• /
• v.12 no.7
• /
• pp.45-51
• /
• 2021

In accordance with the rapid non-face-to-face environment and mobile first strategy, the explosive increase and creation of many structured/unstructured data every year demands new decision making and services using big data in all fields. However, there have been few reference cases of using the Hadoop Ecosystem, which uses the rapidly increasing big data every year to collect and load big data into a standard platform that can be applied in a practical environment, and then store and process well-established big data in a relational database. Therefore, in this study, after collecting unstructured data searched by keywords from social network services based on Hadoop 2.0 through three virtual machine servers in the Spring Framework environment, the collected unstructured data is loaded into Hadoop Distributed File System and HBase based on the loaded unstructured data, it was designed and implemented to store standardized big data in a relational database using a morpheme analyzer. In the future, research on clustering and classification and analysis using machine learning using Hive or Mahout for deep data analysis should be continued.

• The Journal of the Korea Contents Association
• /
• v.19 no.2
• /
• pp.684-694
• /
• 2019

This study deals with the university students who experienced closing department in the restructuring process of university. The purpose of this study is to examine what kind of experience university students have experienced and to understand the essence of the experience in depth. For this purpose, the subjects of the study conducted in - depth interviews with 6 students who expressed their intention to participate in the study. Results of the study were analyzed through the phenomenological study procedure of Giorgi, a qualitative research method. As a result, eight essential themes and sixteen sub themes were derived. The eight essential themes are 'an event of a psychological difficulty', 'deepening a negative emotions', 'anxiety about the future', 'desperation', 'discrimination', 'efforts to overcome difficulties', 'regret and sorriness' and 'acceptance'. Participants in this study suggested ways to reduce psychological difficulties for students who were in closing department condition. Participants said that they needed to provide accurate information about closing department, provide students with the right to know, prepare alternative plans, and emotional cares. The implications of these results are discussed.

• The Korean Journal of Applied Statistics
• /
• v.32 no.3
• /
• pp.391-404
• /
• 2019

Customers' fixed characteristics have often been used to predict customer behavior. It has recently become possible to track customer web logs as customer activities move from offline to online. It has become possible to collect large amounts of web log data; however, the researchers only focused on organizing the log data or describing the technical characteristics. In this study, we predict the decision-making time until each customer makes the first reservation, using Airbnb customer data provided by the Kaggle website. This data set includes basic customer information such as gender, age, and web logs. We use various methodologies to find the optimal model and compare prediction errors for cases with web log data and without it. We consider six models such as Lasso, SVM, Random Forest, and XGBoost to explore the effectiveness of the web log data. As a result, we choose Random Forest as our optimal model with a misclassification rate of about 20%. In addition, we confirm that using web log data in our study doubles the prediction accuracy in predicting customer behavior compared to not using it.

• 한국벤처창업학회:학술대회논문집
• /
• 2018.11a
• /
• pp.187-192
• /
• 2018

현재 급변하는 정보기술, 다양성을 추구하는 시장의 니즈, 미리 예측하지 못한 다양한 형태의 경쟁자 등의 출현으로 인해 경영환경이 급변하고 있는 것은 더 이상 새로운 현상이라고 보기는 어렵다. 이와 같이 급변하는 경영 환경은 기업 간 경쟁 심화를 불러일으키고 있으며, 경쟁 심화는 생존 및 발전을 위해 기업 특성에 맞지 않는 무분별한 전략을 활용하면서 오히려 역효과를 내고 있다는 문제를 야기하고 있다. 특히 변화하고 있는 환경 내 벤처기업 및 창업기업들의 경우 창업 후 생존율이 점차 낮아지면서 일반 기업들에 비해 경쟁력을 갖춘 기업을 찾아보기 어려운 것이 현실이다. 이에 벤처기업들은 도태되지 않고 생존하기 위해경쟁력을 강화시킬 수 있는 다양한 전략을 구사하고 있다. 벤처기업은 하나의 비즈니스 생태계 내 유기적 생명체로서 진화하기 위해 제품이나 산업의 수명주기와 마찬가지로 창업기, 초기 성장기, 고도 성장기, 성숙기, 쇠퇴기 등의 정형화된 단계를 거친다. 따라서 벤처기업은 무차별적인 전략을 통해 기업의 생존 및 성장을 도모 하는 것이 아니라 해당 기업이 놓인 수명주기 단계별로 전략, 조직 구조, 의사결정방식, 통제유형 등을 상이하게 판단하고 이에 적절한 전략을 수행해야 한다. 예를 들어, 동일 생산요소를 투입하더라도 이를 적용할 수 있는 지식이 있는 경우 더 높은 가치 창출이 가능(Aghion & Howitt, 1992) 하지만 창업 초창기의 기업은 고도 성장기의 기업보다 보유한 지식 수준 및 경험이 상대적으로 낮기 때문에 다양한 협력을 필요로 한다. 그러나 현재의 여러 선행연구들은 기업이 처한 상황을 고려하지 않은 단편적인 대처 방안이거나 혹은 부분적인 방법론을 제공하는 수준에 그치고 있다는 한계가 있다(이병헌 외, 2014). 따라서 본 연구에서는 '2016년 벤처기업정밀실태조사' 데이터를 기반으로 기업의 외부 협력 정도 및 벤처기업 지원제도 활용 정도가 경쟁력과 성과에 미치는 영향이 기업의 수명주기별로 상이하다고 보고 관련 전략 프레임워크를 제시하고자 한다.

• Journal of Digital Convergence
• /
• v.17 no.1
• /
• pp.403-412
• /
• 2019

The purpose of this study is to analyze temporal and spatial variations of atopic dermatitis and to identify major factors. Data utilized in the study were collected by the Community Health Survey, KOSIS and so and on from 2009 to 2013. This study was analyzed using descriptive statistics and Geographically weighted regression model. As a result, regional diagnosis rate of atopic dermatitis was increased by 5 years, and difference related to geographic location was so large. The regional characteristics that contribute to the diagnosis of atopic dermatitis were as follows: older adults population ratio, ratio of basic living security received people, depression experience rate, high risk drinking rate, number of wastewater discharge business, number of tobacco retail business, number of fast food restaurant business. This study is meaningful in that it provided basic data on health policy direction and provided information on prioritization of health business in each region.

• The Journal of the Korea Contents Association
• /
• v.19 no.5
• /
• pp.363-370
• /
• 2019

The purpose of this paper is to investigate motivational factors and consequence of the herd behavior of adolescent consumers under the buying decision process in the connected era of internet. For such purpose, this study built a research model and examined how sensitivity to fads, interaction and inaccuracy affect the disequilibrium consumption of adolescents. We also examined the relationship between disequilibrium consumption and consumption happiness. The survey method was used for this paper, and data from a total of 142 students were used for the analysis. And structural equation model was used to analyze the data. The results of this empirical study is summarized as followings. First, sensitivity to fads and interaction have direct effect on the disequilibrium consumption of adolescents. Second, disequilibrium consumption has a positive effect on adolescents' consumption happiness. This implies that the importance of herd behavior in designing rational choice in adolescents' consumption behaviors.

• Journal of Digital Convergence
• /
• v.17 no.10
• /
• pp.141-147
• /
• 2019

This paper analyzes the price movements and the possibility of delisting by research and development intensity of firm which made technological innovation disclosure in the Korean stock market. The sample consists of firms listed on the KRX which made technological information disclosure between January 2002 and December 2014. The results are summarized as follows. The higher R&D intensity is observed for the delisted firms group. The logit regression result shows that the research and development intensity is a significant predictor of the possibility of delisting. This shows that exposure to the risk of delisting may increase as the proportion and uncertainty of intangible assets in the assets of individual firms increases. This empirical result is expected to serve as a good guide line for the stakeholders.

• Journal of Platform Technology
• /
• v.8 no.1
• /
• pp.10-15
• /
• 2020

Recently, various industrial sectors have introduced cloud service actively in their business because cloud computing technology enables storage·management and analysis·utilization of data easily in anytime, anywhere. Especially in financial sector, the business provocatively adopted the service and creates various innovative cases; furthermore, already in abroad, the sector has been accelerating digitization of analysis in cases of credit risk, financial fraud data, stock trading etc. On the contrary, in the domestic financial industry, not only the cloud service introduction and innovation cases are underperformed, but most of them are focused on the back-office service. Most Korean financial corporations are burdened with the adoption of cloud service due to various conservative regulatory requirements, such as regulations on data storage and management, regulations on privacy, and other tasks such as developing decision models and establishing responsibility standard for security incidents and service failures. In this study, it would be aimed to contribute to promote the introduction of the cloud in the domestic financial sector by drawing up preemptive challenges and inspecting priorities.