• International Journal of Aeronautical and Space Sciences
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• 제17권2호
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• pp.268-283
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• 2016

Aircraft manufacturing companies have to consider multiple derivatives to satisfy various market requirements. They modify or extend an existing aircraft to meet new market demands while keeping the development time and cost to a minimum. Many researchers have studied the derivative design process, but these research efforts consider baseline and derivative designs together, while using the whole set of design variables. Therefore, an efficient process that can reduce cost and time for aircraft derivative design is needed. In this research, a more efficient design process is proposed which obtains global changes from local changes in aircraft design in order to develop aircraft derivatives efficiently. Sensitivity analysis was introduced to remove unnecessary design variables that have a low impact on the objective function. This prevented wasting computational effort and time on low priority variables for design requirements and objectives. Additionally, uncertainty from the fidelity of analysis tools was considered in design optimization to increase the probability of optimization results. The Reliability Based Design Optimization (RBDO) and Possibility Based Design Optimization (PBDO) methods were proposed to handle the uncertainty in aircraft conceptual design optimization. In this paper, Collaborative Optimization (CO) based framework with RBDO and PBDO was implemented to consider uncertainty. The proposed method was applied for civil jet aircraft derivative design that increases cruise range and the number of passengers. The proposed process provided deterministic design optimization, RBDO, and PBDO results for given requirements.

• 복식문화연구
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• 제8권1호
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• pp.15-29
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• 2000

Nowadays every part no company continues to gain the upper hand of a competitive superiority. Strategic Alliances between companies have been rapidly increased to preoccupy a market. The purpose of this study is to find devices of strategic alliances for the competitive distribution environment of Korean fashion industries. This reseach has been done by the literature review of the related articles, books, and the case studies in domestic markets as well as foreign ones. Strategic alliances are business relationships established by tow or more companies which cooperate out of mutual need and share risk in achieving a common objective. Today the purpose of international strategic alliances is to be competitive in global markets by meeting of exceeding new standards for products and technology use. Various types of alliances are occurred and this situation will be more common and generalized since one parter's weakness is offset by the other's strength. Strategic alliances are characterized by being horizontal, collaborative, and mutually beneficial to all parties. When used in good faith, the strengths gained in a strategic alliance are great. Therefore retailer should find that to gain faithful partners is important and should effort positively to enrich alliances based on a mutual belief. Finally, to become a company for leading the global market, it is necessary that we operate strategic alliances mixed foreign investments and domestic technology with local distributions.

• 경영정보학연구
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• 제5권2호
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• pp.151-168
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• 2003

A knowledge portal is an integrated gateway for accessing relevant knowledge, collaborating and communicating with other users, and also linking internal applications which is becoming crucial in the age of information abundance. Research and development is a typical knowledge-intensive activity. However, knowledge management support in R&D has been minimal in most research organizations. In this paper, a knowledge portal is designed to support team-based researches in science and technology for searching and browsing knowledge, and also communicating with other team members, coordinating research project and collaborating with other researchers. Automating knowledge acquisition from various knowledge sources, knowledge categorization by applying text categorization method, and knowledge recommendation can help to relieve management effort and increase the efficiency of knowledge management processes. A prototype system based on the suggested model is also presented.

• Educational Technology International
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• 제6권1호
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• pp.103-119
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• 2005

This study investigated to designand implement web-based collaborative learning system Co-Net and map out students' learning procedure using the system, based upon Student Team Achievement Division (STAD Slavin, 1990, 1996). There are technical process and instructional considerations to be made during the design process. The former are those that concern equipment requirements and specifications and include Ease of Use, Speed of Access, and Flexibility. On the other hand, instructional considerationsare concerned with the delivery and access of instructional materials and their outcomes on learners. They are cooperative interactions within groups and group heterogeneity, learner control, group incentives, individual accountability, equal opportunity for earning high scores and contributing to group effort, task specialization, and competition among groups. A web site for a virtual learning environment designed and built by the authors and known as Co-Net is then explained along with the whole process learners inside the environment. The main page of Co-Net consists of 15 menus to implement cooperative learning process. The cooperative learning activities using 15 menus are composed of six phases (1) preparation of the new knowledge (2) presentation of the new knowledge (3) knowledge assimilation and application (4) team and individual evaluation (5) team and individual recognition Throughout the five phases, the appropriate use of cooperative learning techniques has been shown to have both academic and social benefits to learners.

• Journal of Information Technology Applications and Management
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• 제15권4호
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• pp.159-188
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• 2008

This study suggests strategies which can enable to creation of new opportunities of competitive advantages while operating a long lasting and consistent business with major trading partners, based on interorganizational information systems (IOISs) specially established and installed for interorganizational transactions. Nowadays, IOISs based mechanism having been widely expanded as a conventional business infrastructure for the interorganizational transactions and/or exchanges, it is customary difficult to obtain any strongly sound advantage over the competitors who have adopted even the simplest deployment of the IOIS mechanisms. In this connection, this study intends to investigate the interorganizational collaborative activities conducted by under the auspicious of IOISs, focused on the prospect of the exploitation of IOISs rather than the implementation of the IOISs. In this study, we, firstly, suggest the concept of Electronic Collaboration which can be defined by the collaborative activities conducted by IOISs, compared to the ones conducted on off-line. In addition, we suggest the Electronic Collaboration as a multi-dimensional concept, constituted by three sub-constructs, the Electronic Information Sharing (EIS), the Electronic Joint Activity (EJA), and the construction of the Electronic Relational Knowledge Store (ERKS). Secondly, we empirically verify the effects of relational and environmental determinants on the Electronic Collaboration. In this study, the relational determinants relate to the variables created in interorganizational relationship like Trust, Influence, Relational Specific Asset-asset invested for the transaction-, and Continuity of the relationship. On the other hand, the environmental determinants relate to the variables surrounding the relationship which are difficult to control. We consider Product Complexity, Technological Uncertainty, and Market Variability as the domain of the environmental determinants. To test our hypotheses, we conducted both paper-based survey and online-based survey. After refining the data with missing responses, a total of 150 data was used for analysis. The results were as follows : Firstly, it is statistically significant that the Electronic Collaboration is composed of EIS, EJA, and ERKS. In particular, the results imply that the firms are able to accumulate relational knowledge base as well as to exchange information or knowledge, and to conduct joint activities through effort to further expand the Electronic Collaboration. Secondly, we have verified the individual effects of the relational and the environmental determinants on the Electronic Collaboration. Product Complexity has been revealed as the most influential variable affecting the Electronic Collaboration. Next, Interorganizational Trust and Technological Uncertainty, in that order, have been seen to have significant effects on the Electronic Collaboration. In other words, when products or services seem to be difficult to standardize, and the core technologies seem to rapidly change, the need for the Electronic Collaboration increase. In addition, the observation dictates that the interorganizational trust turns out to be a critical variable in building a relationship and in seeking further collaboration. The results, further, illustrate that the environmental determinants are relatively more effective than the relational determinants, which is not consistent with a few prior researches relational determinants emphasized. It is because this study doesn't consider the size of the firm. A few researchers have given an emphasis on the relational determinants like trust and influence, especially from the perspective of small firms in interorganizational relationship. However, in our study, where all the sizes of the firms are contained, electronic collaboration is considerably affected by the environmental determinants.

• 한국시뮬레이션학회논문지
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• 제15권3호
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• pp.23-30
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• 2006

추천자 시스템은 전자상거래 사이트에서 고객의 상품 구매 정보를 수집하여 고객에 대한 예상 구매 상품을 추천하는 목적으로 개발되었다. 본 연구는 대형 전자상거래 사이트에서 고객의 상품 구매 이력이 활용 가능한 경우에 전통적인 통계기법인 군집분석 및 고객 간의 상품 구매 상관성을 이용하는 기존 추천자 시스템(협력적 필터링 기법)과 문서 검색에서 사용되는 LSI분석에 기반한 협업 필터링 기법을 상품 추천에 적용하여 각 기법의 상품 추천 효율성을 비교 분석하였다. 문서-용어 행렬과 유사한 구조를 가지는 고객-상품 구매 행렬에 문서 검색에 사용되는 LSI 분석법은 고객의 상품구매 경향을 원 상품 수보다 축소된 차원의 변환 상품을 통하여 파악함으로써 목표고객에 대한 인접고객군의 생성 노력을 현저히 감소시킬 수 있어 결과적으로 실시간으로 적용되는 추천자 알고리즘의 효율성을 개선할 수 있을 것으로 기대할 수 있다. 가상적인 고객-상품 구매 리스트를 대상으로 실행한 시뮬레이션 실험 결과에서도 알고리즘의 효율성 평가측도인 recall과 정확도 및 F1에서 LSI 기반 협력적 필터링 기법이 기존의 방법보다 우수한 결과를 나타내었다. 시뮬레이션 결과, 인접고객 군의 크기가 일정한 수준에 이르면 그 크기를 증가시키더라도 알고리즘의 효율성은 별로 개선되지 않으며 또한 추천 상품 수가 일정 수준에 도달하면 추천 정확도가 낮아지는 정도에 비해 recall의 개선도는 별 변화가 없는 것으로 나타나고 있다. 추천자 시스템을 구현하는 용도에 따라 이러한 정보는 유용하게 사용될 수 있다고 판단된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권7호
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• pp.1951-1975
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• 2023

Recent advances in Cognitive Radio Networks (CRN) have elevated them to the status of a critical instrument for overcoming spectrum limits and achieving severe future wireless communication requirements. Collaborative spectrum sensing is presented for efficient channel selection because spectrum sensing is an essential part of CRNs. This study presents an innovative cooperative spectrum sensing (CSS) model that is built on the Firefly Algorithm (FA), as well as machine learning artificial neural networks (ANN). This system makes use of user grouping strategies to improve detection performance dramatically while lowering collaboration costs. Cooperative sensing wasn't used until after cognitive radio users had been correctly identified using energy data samples and an ANN model. Cooperative sensing strategies produce a user base that is either secure, requires less effort, or is faultless. The suggested method's purpose is to choose the best transmission channel. Clustering is utilized by the suggested ANN-FA model to reduce spectrum sensing inaccuracy. The transmission channel that has the highest weight is chosen by employing the method that has been provided for computing channel weight. The proposed ANN-FA model computes channel weight based on three sets of input parameters: PU utilization, CR count, and channel capacity. Using an improved evolutionary algorithm, the key principles of the ANN-FA scheme are optimized to boost the overall efficiency of the CRN channel selection technique. This study proposes the Artificial Neural Network with Firefly Algorithm (ANN-FA) for cognitive radio networks to overcome the obstacles. This proposed work focuses primarily on sensing the optimal secondary user channel and reducing the spectrum handoff delay in wireless networks. Several benchmark functions are utilized We analyze the efficacy of this innovative strategy by evaluating its performance. The performance of ANN-FA is 22.72 percent more robust and effective than that of the other metaheuristic algorithm, according to experimental findings. The proposed ANN-FA model is simulated using the NS2 simulator, The results are evaluated in terms of average interference ratio, spectrum opportunity utilization, three metrics are measured: packet delivery ratio (PDR), end-to-end delay, and end-to-average throughput for a variety of different CRs found in the network.

• 산업경영시스템학회지
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• 제39권3호
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• pp.170-179
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• 2016

In this paper we have tackled the outstanding inventory planning problems over new product launching period in a more holistic manner by addressing first the definition of efficient business rules to effectively control and reduce the inventory risks followed by the rigorous explanations on the implementation guide on suggested inventory planning rules. It is not unusual for many companies in the consumer electronics market to make a great effort to reduce the time to launch a new product because the ability to bring out higher performing products in such a short time period greatly increases the probability for them to remain competitive in the high tech market. Among so many newly developed products, those products with new features and technologies appeal to many potential customers while products which fail to win customers by design and prices rapidly disappear in the market. To adapt to this business environment, those companies have been trying to find the answer to minimize the inventory of old products so they can move to next generation products quickly with less obsolete material. In the experimental implementation of our rule-based inventory planning, Company 'S' reduced the inventory cost for the outgoing products as low as 49% of its peak level of its preceding product version in just 5 month after the adoption of rule-based inventory planning process and system. This paper concluded the subject with a suggestion that the best performance of rule-based inventory planning is guaranteed not from one-time campaign of process improvement along with system development but the decision maker's continuing support and attention even without seeing any upcoming business crisis.

• 정보관리학회지
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• 제26권2호
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• pp.127-147
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• 2009

자연언어에서 유사어의 처리는 사람과 컴퓨터간의 의사소통에 적지 않은 장애가 되어왔고, 이는 사용자의 임의적 단어사용에 기반을 두고 있는 웹 2.0 애플리케이션, 특히 소셜태깅 분야에 있어서 그 장애의 정도가 더 심각해질 수 있다. 본 연구는 한 대표적인 웹 2.0 애플리케이션에서 자동 유사어 추출에 관한 문제를 다루고 있다. 더 구체적으로, 가장 널리 사용되는 소셜북마킹 애플리케이션인 딜리셔스를 기반으로, 유사태그를 추출하는 방법(FolkSim)을 제시하고자 한다. 제시한 방법의 평가를 위하여, 문서유사도의 측정을 위해서 쓰여진 고전적 벡터모델에 의거한 유사태그를 추출하는 방법(CosSim)과 그 결과들을 서로 비교분석하여 보았다. 몇 가지 면에서 FolkSim가 더 나은 결과 산출해내는 증거들이 관찰되어졌다. 또한, FolkSim 방법에 의한 유사태그가 만들어지지 않는 경우에 대비하여, 그 대안 또한 제시하고 있다.

• 정보관리학회지
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• 제37권2호
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• pp.171-195
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• 2020

본 연구는 대표적인 온라인 협업커뮤니티인 한국 위키피디아의 초기 2002년부터 2019년까지의 편집로그 빅데이터를 해체하여 공동협업과정을 시계열적으로 분석하였다. 공개된 오픈데이터의 표준화된 XML 문서편집 기록을 활용해 Phython과 R을 이용하여 분석 요소를 추출하여 이를 활용하였다. 연구 분석 결과 한국 위키피디아 편집자의 참여 방법, 데이터 내용의 특징, 문서 생성의 추이 등을 설명할 수 있었다. 소수 편집자들의 적극적 활동과 대다수 편집자들의 느슨한 참여도 밝혀졌으며, 온라인에서도 나타나는 사회 문화적 특징이 한국 위키피디아에서도 나타났다. 집단지성을 지속화시키기 위해서는 새롭고 다양한 외부자원이 필수인데 신규 진입자들이 공동편집 커뮤니티에 안착하기 위한 다각적인 고려가 필요하며, 관리자 그룹의 고착화를 탈피하여 순환구조를 통한 개방성이 필요함을 제언하였다.