• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.217-217
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• 2023

상수도관망은 사용자에게 고품질의 물을 안정적으로 공급하는 것을 목적으로 하며, 이를 평가하기 위한 지표 중 하나로 압력을 활용한다. 최근 스마트 센서의 설치가 확장됨에 따라 기계학습기법을 이용한 실시간 데이터 기반의 분석이 활발하다. 따라서 어디에서 데이터를 수집하느냐에 대한 센서 위치 결정이 중요하다. 본 연구는 eXtreme Gradient Boosting(XGBoost) 모델을 활용하여 대규모 상수도관망 내 센서 위치를 최적화하는 방법론을 제안한다. XGBoost 모델은 여러 의사결정 나무(decision tree)를 활용하는 앙상블(ensemble) 모델이며, 오차에 따른 가중치를 부여하여 성능을 향상시키는 부스팅(boosting) 방식을 이용한다. 이는 분산 및 병렬 처리가 가능해 메모리리소스를 최적으로 사용하고, 학습 속도가 빠르며 결측치에 대한 전처리 과정을 모델 내에 포함하고 있다는 장점이 있다. 모델 구현을 위한 독립 변수 결정을 위해 압력 데이터의 변동성 및 평균압력 값을 고려하여 상수도관망을 대표하는 중요 절점(critical node)를 선정한다. 중요 절점의 압력 값을 예측하는 XGBoost 모델을 구축하고 모델의 성능과 요인 중요도(feature importance) 값을 고려하여 센서의 최적 위치를 선정한다. 이러한 방법론을 기반으로 상수도관망의 특성에 따른 경향성을 파악하기 위해 다양한 형태(예를 들어, 망형, 가지형)와 구성 절점의 수를 변화시키며 결과를 분석한다. 본 연구에서 구축한 XGBoost 모델은 추가적인 전처리 과정을 최소화하며 대규모 관망에 간편하게 사용할 수 있어 추후 다양한 입출력 데이터의 조합을 통해 센서 위치 외에도 상수도관망에서의 성능 최적화에 활용할 수 있을 것으로 기대한다.

• Cartoon and Animation Studies
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• s.41
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• pp.487-510
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• 2015

In recently, thanks to the development of computer and internet, and reinforcement of digital media literacy of ordinary people, many users of comics and animations recombine contents into various ways, including UCCs. In a glance, it seems these outputs violates the copyrights of contents. But in reality, they helps the growth of the ecosystem of contents market, with increase of contents users. The reason of these reproductions inclines the characteristics of animation media. Animation, which are constituted by plastic symbols, auditory symbols, and narrative symbols, and Comic, which supports stories of Animations, affects as 'Imaginary signifier'. These signifiers helps users of contents to dismantle and reassemble stories. These aspects are seen in doujin culture, animation soundtrack fandom, and voice actor fandom. But In this article, we will concentrate into cosplay culture. Cosplay culture shows more active appearances than another fandoms. In especially, cosplay stage and daily cafe show more active reproductions of characters and communications. However, they are done by youth fans, which has not enough financial abilities: therefore, events are not sustainable and discontinued. And they have another limits, like lack of opportunity of performance. In the reality of Korean society, which needs of community making by community member, and hybrid culture, comics and animation productions in Korea are in need of access positively and encourage reproductions of active receivers of animations.

• 한국사회정책
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• v.25 no.1
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• pp.345-375
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• 2018

This study examines labour market and unemployment protection policies as a configuration in 12 OECD countries in order to investigate how countries from different regime conform to or diverse from previous welfare state regime discussion, and to examine its relationship with poverty and inequality. In analyzing the combination of the unemployment insurance, the unemployment assistance, and active labour market policy, firstly, fuzzy scores of unemployment insurance was calculated by analyzing the strictness of eligibility, duration of benefit and the generosity of income replacement rate. For unemployment assistance, the ratio of public assistance expenditure to the GDP in each country and the ratio of unemployment benefit level to the average wage in each country have been considered. As for the active labour market policy, the total expenditure per GDP of this policy was converted into fuzzy points and analyzed. As a result, 5 types in 2005 and 6 types in 2010 were generated. Specifically, 'assistance type(iAp)', 'insurance type (Iap)', 'comprehensive safety net type (IAP)', 'weak safety net type(iap)' were analyzed. This paper suggested policy implication for South Korean case, which consistently had high score for weak safety net type(iap).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.647-657
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• 2006

Probabilistic Risk Assessment considering statistically random variables is performed for the preliminary design of a Cable Stayed Bridge, which is Prestressed Concrete Bridge consisted of cable and plate girders, based on the method of Working Stress Design and Strength Design. Component reliabilities of cables and girders have been evaluated using the response surface of the design variables at the selected critical sections based on the maximum shear, positive and negative moment locations. Response Surface Method (RSM) is successfully applied for reliability analyses for this relatively small probability of failure of the complex structure, which is hard to obtain through Monte-Carlo Simulations. or through First Order Second Moment Method that can not easily calculate the derivative terms of implicit limit state functions. For the analysis of system reliability, parallel resistance system consisting of cables and plate girder is changed into series connection system and the result of system reliability of total structure is presented. As a system reliability, the upper and lower probabilities of failure for the structural system have been evaluated and compared with the suggested prediction method for the combination of failure modes. The suggested prediction method for the combination of failure modes reveals the unexpected combinations of element failures in significantly reduced time and efforts compared with the previous permutation method or system reliability analysis method, which calculates upper and lower bound failure probabilities.

• The KIPS Transactions:PartD
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• v.16D no.1
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• pp.55-64
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• 2009

Various business model and computing environments are currently merged into web services and many web related application products are also develop. Most of IT enterprises in Korea use the Service-oriented architecture (SOA) whenever they develop the web applications. SOA is an approach to loosely coupled, protocol independent, standards-based distributed computing where software resources available on the network are considered as Services. SOA is believed to become the future enterprise technology solution that promises the agility and flexibility the business users have been looking for by leveraging the integration process through composition of the services spanning multiple enterprises. But, There are no specific development methodology to apply into SOA standard model until now. The developer uses the currently existing methodology to develop the application with SOA. The users have some limitations to use it. In this paper, we suggest a Frameworks for applying agile methodology into SOA to address the productivity and quality of small web related project. We design and implement a frameworks architecture for applying the agile method into SOA and describe the process model to implement it. We finally evaluate the frameworks with productivity, flexibility and maintainability.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2001.11a
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• pp.169-186
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• 2001

The researches about the general flow of new product development process was achieved in various field. But there was little discussion about the methodologies and tools used in that process. So we suggest new DEA model as the methodology that determines sustainable price and quality attributes and this can substitute econometric hedonic methodology. To make smooth surface composed of quality attributes and price, we use QC-DEA model. Additionally we make AR-QC DEA model by introducing AR to reflect consumer perceptions on quality attributes. AR-QC DEA overcomes the limits of parametric methodology and represents product-specific shadow prices, so it is possible to supply the information about quality attributes and price combination in new product development process and to simulate easily whether new product can exist in the market. Finally by empirical research on notebook computer we can show that AR-QC DEA has the ability to explain market change.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.163-167
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• 1999

The relational data model can't be applied to CAD/CAM, CE, and CIM since it can't support the semantic model concept such as complex object, random data definition, manipulation, version control, generalization, aggregation and so on. In this paper, the IPCS(Integrated Production Control System) for hand-rail of ship is parted into several module according to process function. further more, the object oriented data model is designed with UML(Unified Modeling Language). UML is the object oriented design methodology of industrial standard that combines the Booch's methodology, the Rumbaugh's On(Object Modeling Technique), and the Jacobson's OOSE(Object-Oriented Software Engineering) methodology. The efficient management is expected with object-oriented data model construction, since this developed system can achieve efficient process control, system maintenance, repair and extension.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.3
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• pp.153-164
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• 2007

Nowaday, in Korea, many u-City projects have been developed as a core business in the new town development project by national or local level of government. However, the new business projects have some problems, such as excessive number of u-services, increased project funds and period, and lower u-services due to lack of u-service evaluation methodologies. Therefore, this paper proposes a new u-service evaluation methodology to solve current problems. The methodology gives an ability to guard general u-service groups for reaching the main goal of the u-City project, and then select alternative u-service groups against being limited by the law and technology in the project year. Besides, as a key variable on performing u-City plans, the complexity between stakeholders is considered in the methodology. Finally, through the Optimal Sequential Method in the methodology, the maximum value of u-service group is obtained as a optimal service group of u-City.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.203-208
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• 2013

Although the first case of supernumerary teeth had been documented almost 20 centuries ago, the etiology of supernumerary teeth still remains unclear. The prevalence of supernumerary teeth in the general Asian population is between 2.7% and 3.4%. The pathogenesis of supernumerary teeth has been attributed to phylogenetic reversion(atavism), splitting of the tooth bud(dichotomy theory), locally induced hyperactivity of the dental lamina and a combination of genetic and environmental factors(unified etiologic explanation). This report describes 3 cases of monozygotic twins with mesiodens who visited the pediatric dental clinic of Kyungpook national university hospital, and this is significant to support genetic factors involoved in the development of supernumerary teeth.

• Journal of the Korea Society for Simulation
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• v.15 no.4
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• pp.11-19
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• 2006

With the emergence of pervasive computing, personalization becomes an important issue to provide with users customized services, anywhere and anytime in their specific environment. Many researches have shown the possibilities of personalization by acquiring and processing sensor information around users. However, personalization remains still at its infancy, since most researches have failed to consider various contexts comprehensively besides sensor data, and just developed tailored services for a specific application domain. In this work, we propose a simulation-based CAS (context Aware Web Services) development methodology. Our methodology considers various contexts on users (eg. current location), web services (eg. response time), devices (eg. availability) and environment (eg. sensor data) all together by simulating them on the fly for personalized and adaptable services.