• 정보보호학회논문지
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• 제16권3호
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• pp.29-38
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• 2006

최근 무선통신기술의 발달은 센서 네트워크 관련연구를 촉진하였으며 다양한 형태의 센서 네트워크 통신방식에 적합한 방법들이 제안되고 있다. 센서 네트워크 연구방향은 제한된 자원에서 에너지효율을 극대화시키기 위한 방법과 그동안 주목받지 못했던 보안관련 연구들로 구분된다. 에너지효율을 높이기 위한 방법으로 노드간 데이터 통합과 통합을 수행하는 클러스터 헤드의 적절한 선택 알고리즘이 제안되었으며, 보안성 강화를 위해 센서에 적용 가능한 암호화 기법과 비밀 키를 관리하기 위한 방법들이 제안되고 있다. 그러나 다양한 형태의 통신방식이 존재하는 센서 네트워크에서 안전하면서도 동시에 에너지 효율성을 고려한 통합적 연구는 아직 초기단계에 있다. 본 논문에서는 자원효율적인 클러스터링 프로토콜과 다양한 통신방식에 적당한 키 관리 알고리즘을 결합하여 향후 민감한 데이터를 처리하는 센서네트워크 시스템에 적용할 수 있는 통합적 프로토콜을 제안한다.

• STI Policy Review
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• 제1권1호
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• pp.43-62
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• 2010

Whatever the country, nanotechnology features as a key priority of most national research and innovation policies. This focus on nanotechnology is due to the promises of this general purpose technology, this new technological wave. As 'one size does not fit all', policies supporting its development cannot just adopt the 'best practices' of the preceding wave. We argue that specific on-going dynamics of nanoscience and technology production justifies the existence of dedicated nanotechnology policies. It also questions the portfolio of instruments mobilized and their balance. In this article, we discuss policies developed for the preceding technological waves and, based on the characteristics of nanosciences and technologies, propose five dimensions of policies to be taken into consideration for their governance at the country and cluster levels.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.150-153
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• 2015

The construction industry is an integral part of any nation's economy, whether measured by dollar volume or workforce size. In spite of its strong influence, there has been very little specifically aimed at evaluating the current industry performance. This research investigates the macroeconomic performance of the construction industry by accounting for crucial performance affecting factors such as labor productivity and gross margin. A clustering analysis, followed by a series of statistical analyses, yielded a notable finding that labor productivity is the most important factor that affects industry's profitability. The results of the analysis also revealed that the states with the strongest labor productivity show the highest level of profitability in terms of gross margin. This study should be of value to decision-makers when plotting a roadmap for future growth and rendering a strategic business decision.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.5-23
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• 2012

Nowadays, most researchers and manufacturers always pay attention on wireless sensor networks (WSNs) due to its potential applications in many regions such as military, industrial and civilian areas. WSNs are the basic components of Internet of Things (IoT) and the key to machine-to-machine communications and the future Internet. Also, the security is an essential element for deploying WSNs. Recently the concept of trust-based mechanism was proposed in WSNs such as traditional cryptographic and authentication mechanisms. However, there is lack a survey on trust management for WSNs, IoT even future Internet. In this paper, we discuss the concept and potential application areas of trust management for WSNs and IoT worlds. Furthermore, we survey different trust management issues (i.e., cluster, aggregation, reputation). Finally, future research directions with respect to trust management in WSNs and future IoT world are provided. We give not only simple WSNs for IoT environments but also a simulated bootstrap platform to provide the discussion of open challenges and solutions for deploying IoT in Future Internet.

• 한국의류학회지
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• 제32권5호
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• pp.692-703
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• 2008

In the fashion enterprises of today, there are many kinds of inter-enterprises' collaborations which are related to the strategic management for reinforcing their competitiveness in various fields. These inter-enterprises' collaborations, which began to increase in the year 2000, will increase even more in the near future. The study investigated the differences of collaboration motive types in collaboration areas, trust/devotion, performance and satisfactions of collaborations, and characteristics of collaborated companies and their partners. A questionnaire was administered to 194 key employees of the fashion enterprises in Korea and the analysis was performed by factor analysis, cluster analysis, ANOVA, and $X^2$ test. The results showed that the collaboration motive had four factors: economic efficiency, business expansion, product planning improvement, and brand competitiveness increase. The cluster analysis showed that there were four collaboration motive types: brand competitiveness type, economic efficiency type, product planning type, and passive collaboration type. There were significant differences among the collaboration motive types in regard to collaboration areas, trust/devotion, and the performance/satisfactions of collaboration, and characteristics of companies. The brand competitiveness motive type tended to choose the marketing and brand collaboration areas, had a higher trust, and had higher scores on the performance and satisfactions of collaboration than did the other types.

• 대한산업공학회지
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• 제42권3호
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• pp.222-230
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• 2016

As the global game market has been more competitive, it has been important to analyze success factors of game products. In this paper, we applied a Bass Diffusion Model and Clustering Analysis to identify the success factors of games based on data from Steam, an international game platform. By using a diffusion model, we first categorize game products into two groups : successful and unsuccessful games. Then, each group has been analyzed by using clustering analysis based on product features such as genres, price, and minimum system requirements. As a result, success factors of a game have been identified. The result shows that customers in game industry appreciate sophisticated contents. Unlike many other industries, price is not considered as a key success factor in the game industry. Expecially, advanced independent video games (commonly referred to as indie games) with killer contents show competitiveness in the market.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4145-4164
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• 2016

Energy harvesting is an increasingly attractive source of power for cellular networks, and can be a promising solution for green networks. In this paper, we consider a cellular network with power beacons powering multiple mobile terminals with microwave power transfer in energy beamforming. In this network, the power beacons are powered by grid and renewable energy jointly. We adopt a dual-level control architecture, in which controllers collect information for a core controller, and the core controller has a real-time global view of the network. By implementing the water filling optimized power allocation strategy, the core controller optimizes the energy allocation among mobile terminals within the same cluster. In the proposed green energy cooperation paradigm, power beacons dynamically share their renewable energy by locally injecting/drawing renewable energy into/from other power beacons via the core controller. Then, we propose a new water filling optimized green energy cooperation management strategy, which jointly exploits water filling optimized power allocation strategy and green energy cooperation in cellular networks. Finally, we validate our works by simulations and show that the proposed water filling optimized green energy cooperation management strategy can achieve about 10% gains of MT's average rate and about 20% reduction of on-grid energy consumption.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권7호
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• pp.1873-1893
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• 2023

The development of lightweight, low energy and small-sized sensors incorporated with the wireless networks has brought about a phenomenal growth of Wireless Sensor Networks (WSNs) in its different fields of applications. Moreover, the routing of data is crucial in a wide number of critical applications that includes ecosystem monitoring, military and disaster management. However, the time-delay, energy imbalance and minimized network lifetime are considered as the key problems faced during the process of data transmission. Furthermore, only when the functionality of cluster head selection is available in WSNs, it is possible to improve energy and network lifetime. Besides that, the task of cluster head selection is regarded as an NP-hard optimization problem that can be effectively modelled using hybrid metaheuristic approaches. Due to this reason, an Improved Coyote Optimization Algorithm-based Clustering Technique (ICOACT) is proposed for extending the lifetime for making efficient choices for cluster heads while maintaining a consistent balance between exploitation and exploration. The issue of premature convergence and its tendency of being trapped into the local optima in the Improved Coyote Optimization Algorithm (ICOA) through the selection of center solution is used for replacing the best solution in the search space during the clustering functionality. The simulation results of the proposed ICOACT confirmed its efficiency by increasing the number of alive nodes, the total number of clusters formed with the least amount of end-to-end delay and mean packet loss rate.

• 산업공학
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• 제20권3호
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• pp.277-287
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• 2007

Semiconductor manufacturing is one of the most complex and capital-intensive processes composed of several hundreds of operations. In today’s competitive business environments, it is more important than ever before to manage manufacturing process effectively to achieve better performances in terms of customer satisfaction and productivity than those of competitors. So, many semiconductor manufacturing companies implement advanced planning and scheduling (APS) system as a management tool for the complex semiconductor manufacturing process. In this study, we explain roles of production planning and scheduling in semiconductor manufacturing and principal factors that make the production planning and scheduling more difficult. We describe the APS system implementation project at Korean semiconductor manufacturing company in terms of key issues with realistic samples.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (1)
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• pp.598-600
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• 2003

이동 Ad Hoc 네트워크는 무선 채널 특성으로 인해 많은 보안상 위협에 노출될 수 있으므로 인증, 무결성, 기밀성 등의 보안 서비스를 제공하기 위한 키 관리 메커니즘이 요구된다. 그런데 Ad Hoc 네트워크는 중앙 집중적인 관리 노드의 부재, 동적인 위상 변화, 통신 자원의 제약 등의 특성을 고려하여 키 관리 메커니즘을 설계하도록 요구하고 있다. 따라서 본 논문에서는 클러스터 기반의 Ad Hoc 네트워크에서 ID 기반의 임계치 암호화 기법을 사용하여 공개키의 사전 분배 가정을 제거함으로써 토폴로지의 확장성과 유연성을 반영하고, 분산적이며 확장성있는 키분배 서비스가 가능하게 하였다. 또한 클러스터간에 교환되는 메시지의 무결성을 보장하기 위한 클러스터 MAC키 협상 방안, 헤드와 클러스터 내 특정 멤버간의 보안 채널 구축 통신하고자 하는 클러스터 멤버 호스트간에 안전하게 세션키를 생성, 분배하는 메커니즘 등을 제안하였다.