• Korean Journal of Optics and Photonics
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• v.34 no.1
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• pp.1-12
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• 2023

In this study, we propose a hybrid phase-control algorithm for multi-channel coherent beam combining (CBC) system by combining the covariant matrix adaption evolution strategy (CMA-ES) and stochastic parallel gradient descent (SPGD) algorithms and analyze its operational performance. The proposed hybrid CMA-ES/SPGD algorithm is a sequential process which initially runs the CMA-ES algorithm until the combined final output intensity reaches a preset interim value, and then switches to running the SPGD algorithm to the end of the whole process. For ideal 7-channel and 19-channel all-fiber-based CBC systems, we have found that the mean convergence time can be reduced by about 10% in comparison with the case when the SPGD algorithm is implemented alone. Furthermore, we analyzed a more realistic situation in which some additional phase noise was introduced in the same CBC system. As a result, it is shown that the proposed algorithm reduces the mean convergence time by about 17% for a 7-channel CBC system and 16-27% for a 19-channel system compared to the existing SPGD alone algorithm. We expect that for implementing a CBC system in a real outdoor environment where phase noise cannot be ignored, the hybrid CMA-ES/SPGD algorithm proposed in this study will be exploited very usefully.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.57.4-58
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• 2021

Asteroids have undergone various processes such as impacts, space weathering, and thermal evolution. Because they expose their surfaces to space without atmosphere, these evolutional processes have been recorded directly on their surfaces. The remote-sensing observations have been conducted to reveal these evolutional histories of the target asteroids. For example, crater and boulder distributions are unambiguous evidence for past nondestructive impacts with other celestial bodies. Multiband and spectroscopic observations have revealed space-weathering history (as well as compositions). Whereas most physical quantities have been examined intensively using spacecraft and telescopes, only a little has been studied on "the grain size". It is one of the fundamental physical quantities for diagnosing the collisional and thermal history of asteroids. Our group has conducted polarimetric research of asteroids (as well as Moon [1]) to determine the particle size and further investigate the evolutional histories of target asteroids [2],[3]. For example, the existence of regolith on an S-type asteroid, Toutatis, was suggested almost twenty years before space exploration [4]. Moreover, we reported that near-Sun asteroids indicate a signature of submillimeter grains, which could be created by a thermal sintering process by solar radiation [5]. However, it is important to note that in-situ polarimetry has not been reported on the asteroid surface, although the Korean Lunar Exploration Program aims to do polarimetry on the lunar surface [6]. Therefore, it is expected that the polarizer mounted on the Korean Apophis spacecraft can make the first estimate of the grain size and its regional variation over the Apophis surface. In this presentation, we outline research of S-type asteroid surfaces through remote-sensing observations and consider the role of polarimetry. Based on this review, we consider the purpose, potentiality, and strategy of the polarimetry using the onboard device for the Apophis spacecraft. We will report a possible polarization phase curve of Apophis estimated from ordinary chondrites and past observational data of S-type asteroids, taking account of the space weathering effect. Based on this estimation, we will consider the strategy of how to determine the particle size (and space weathering degree) of the Apophis surface. We will also mention the detectability of dust hovering on the surface.

• Korean Journal of Optics and Photonics
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• v.35 no.3
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• pp.107-114
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• 2024

In this study, the feasibility of using the covariance-matrix-adaptation-evolution-strategy (CMA-ES) algorithm in a multichannel coherent-beam-combining (CBC) system was experimentally verified. We constructed a multichannel CBC system utilizing a spatial light modulator (SLM) as a multichannel phase-modulator array, along with a coherent light source at 635 nm, implemented the stochastic-parallel-gradient-descent (SPGD) and CMA-ES algorithms on it, and compared their performances. In particular, we evaluated the characteristics of the CMA-ES and SPGD algorithms in the CBC system in both 16-channel rectangular and 19-channel honeycomb formats. The results of the evaluation showed that the performances of the two algorithms were similar on average, under the given conditions; However, it was verified that under the given conditions the CMA-ES algorithm was able to operate with more stable performance than the SPGD algorithm, as the former had less operational variation with the initial phase setting than the latter. It is emphasized that this study is the first proof-of-principle demonstration of the CMA-ES phase-control algorithm in a multichannel CBC system, to the best of our knowledge, and is expected to be useful for future experimental studies of the effects of additional channel-number increments, or external-phase-noise effects, in multichannel CBC systems based on the CMA-ES phase-control algorithm.

• Information Systems Review
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• v.12 no.2
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• pp.1-23
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• 2010

Most enterprise information systems today are silo systems in that they are not properly aligned nor integrated with one another. Such silo systems result because enterprises lack an architectural perspective in the planning and development of the systems. This paper proposes an Enterprise Architecture Orientation Model as a framework for the analysis, planning and design of the architectural quality of enterprise information systems. The model decomposes enterprise architecture into two dimensions-alignment and integration, and specifies for each dimension the general development and evolution stages enterprises may traverse. The alignment dimension represents the vertical strategic alignment of the systems with the vision, mission, strategy and goals of the enterprise, and is analyzed in terms of the performance, capability, and strategy of the enterprise. The integration dimension, on the other hand, represents the horizontal and functional integration among the systems that span organizational functions and boundaries, and is analyzed in terms of such technological components as IT infrastructure, data, application, and business processes. The model combines the alignment and integration dimensions to form a two-dimensional conceptual space for mapping the architectural quality of the enterprise. It is proposed that an enterprise use the model to identify and understand its position now and in the future in the architectural quality of the enterprise information systems. It is also proposed that the model provides a tool for the planning and design of the transition from one stage to the next in the alignment and integration of the systems to reach an architectural maturity. At the end, the paper discusses how the model can be applied differently according to the strategic orientation of the enterprise. An example of the usage of the model is presented.

• Journal of Distribution Science
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• v.12 no.12
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• pp.83-92
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• 2014

Purpose - A business ecosystem refers to mutually dependent systems interconnected by a loose foundation of various ecosystem members such as customers, suppliers, partners, and other stakeholders. The ecosystem-based strategy attempts to achieve competitive advantage for firms by enriching a business ecosystem or building a sustainable business ecosystem through the collaboration and co-evolution of its members. A sustainable business ecosystem is a source of competitiveness for firms anda manageable resource for gaining a competitive advantage. Customers represent the core membership of the business ecosystem and play a pivotal role in building a sustainable business ecosystem. This study examines the effects of customer participation on economic and social value in the business ecosystem and suggests a course of action for building a sustainable business ecosystem. Research design, data, and methodology - Two business cases of South Korea are selected from two different business types: business-to-business (B2B) and business-to-customer (B2C) firms. Business ecosystems for B2B and B2C firms reflect contrasting characteristics. Data was collected from in-depth interviews with four representatives of four firms. Results - The study suggested seven propositions for the relationships between customer participation and a sustainable business ecosystem through multiple case studies based on in-depth interviews. The results reveal the following four strategic actions for building sustainable business ecosystems based on the suggested propositions: alignment, systemization, socialization, and co-evolution. Alignment refers to achieving a harmonic balance or virtuous circle among the firm's mission, investment, and value creation. Systemization refers to building and implementing management and infrastructure systems rooted in the corporate culture. Socialization of customers in the business ecosystem reinforces the harmony or virtuous cycle. Finally, co-evolution is associated with the relationship between firms and customers as buyer firms in a restricted business ecosystem. Conclusions - This study considers multiple cases for the execution of a sustainable business ecosystem in collaboration with customers and suggests seven propositions and four strategic actions. The results are based on qualitative data from interviews with business associates from two firms in an open business ecosystem and two firms in a restricted business ecosystem, both in South Korea. Our research results regarding two contrasting business ecosystems shed light on business issues and policy making in Asian business environments, which are in the transition stages from a traditional conglomerate-driven to an inclusive growth-driven economy. The business ecosystem itself should be considered a manageable resource for firms' competitive positions in the market. A customer is a member of the business ecosystem and should thus be viewed not only as a purchasing entity and an object of relationship management but also as a co-creator of value. Therefore, firms should collaborate with customers to build sustainable business ecosystems. For this, firms must create social value, which cannot be created by customers alone, within the business ecosystem. Then, customers participate in a business ecosystem and build it to be favorable to them. Implications for academics and practitioners were suggested.

• Maritime Security
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• v.4 no.1
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• pp.1-56
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• 2022

Why has India become a key actor in the maritime-configured Indo-Pacific region? There are some external factors, but for India, its geo-strategic frontier encompassing its geopolitical and maritime interests is expanding rapidly beyond its territorial space across both the Indian and Pacific oceans amidst an increasingly arduous geopolitical and security environment. India must, therefore, acquire the ability to influence events within this strategic arena using all facets of national power, including maritime-military power. Lately, therefore, New Delhi has invested much intellectual capital to review its maritime-security strategy. India's new strategy is premised on the concept of holistic security involving the 'softer' aspects of maritime-security, and a rekindling of maritime consciousness in India, a nation that has traditionally been beset by 'sea-blindness'. The strategy adopts a region-wide, inclusive, and a more proactive approach than hitherto, as is evident in its title 'Ensuring Secure Seas: Indian Maritime Security Strategy'. While it deals with the growing concern of new non-traditional threats in the Indian littoral and the need for military deterrence and preparedness, it also addresses the imperatives for India to seek a favorable and rules-based benign environment in its immediate and extended maritime periphery, including through multi-vectored strategic partnerships dictated by its enduring principle of strategic autonomy. For a more profound and comprehensive understanding of India's maritime-security strategy, this paper examines the key unstated and implicit factors that underpin the strategy. These include India's historical and cultural evolution as a nation; its strategic geography; its geopolitical and security perceptions; and the political directions to its security forces. The paper deals specifically with India's response to maritime threats ranging from natural disasters, crime and state-sponsored terrorism to those posed by Pakistan and China, as well as the Indian Navy's envisaged security role East of the Malacca Straits. It also analyzes the aspects of organizational restructuring and force planning of India's maritime-security forces.

• Journal of the Korean Academic Society of Industrial Cluster
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• v.1 no.1
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• pp.47-66
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• 2007

The progress of digital revolution leads to technology and industry infusion which make new products and new commodity markets in the existing industries. Under the circumstance of new innovation patterns in industries and globalization of the world, innovation firms adapt different evolution processes for different business situations. Technological innovation enhances the competitiveness of fins in the business world. This paper shows the researches on technological innovation which make constant economy growth in the knowledge based economy. And this paper also suggests the policy on technological innovation for the future growth of society. Main focus of this paper are as follows. First, the theoretical survey on technological innovation is reviewed. Second, the program and the supporting system for technological innovation in the USA and Europe are investigated. Third, the situation and problems of Korea is analysed. Fourth, strategy and suggestions on the development of technological innovation in the 21st century knowledge based economy is suggested through the window of cluster and regional economy development.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.42.4-43
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• 2018

Most galaxies are believed to evolve through mergers and accretions. In particular, minor mergers and gas accretion appear to play an important role in galaxy evolution in the present-day Universe. Tidally-disrupted debris from such processes remain as diffuse, low-surface brightness structures because the dynamical timescale in the outskirts is significantly longer than that in the central regions. Although these structures will give us useful insight into the mass assembly history of galaxies, it is difficult to detect them due to their faint surface brightness. In order to investigate the structural properties of outskirts in nearby galaxies, we conduct deep and wide-field imaging survey with KMTNet. We present our observing strategy and an optimal data reduction process to recover faint extended features in the images of KMTNet. Using the imaging data of NGC 1291 obtained from KMTNet, we find that a peak-to-peak sky gradient can be reduced less than 0.4-0.6% of the original sky level in the entire image. We also find that we can reach the surface brightness of ${\mu}_{(B,1{\sigma})}$ ~ 29.5, ${\mu}_{(R,1{\sigma})}$ ~ 28.5 mag $arcsec^{-2}$ in one-dimensional profile, that is mainly limited by the uncertainty in the sky determination. It indicates that deep imaging data of KMTNet is suitable to study the extended faint features of nearby galaxies, such as stellar halos, outer disks, and dwarf companions.

• International Commerce and Information Review
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• v.7 no.3
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• pp.195-212
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• 2005

International trade has been changed from traditional trade to e-trade due to the fast expanding of information technology like e-marketplace, EDI (Electronic data interchange) using Internet since mid of 1990's. e-Trade, as a new trade method, could handle every trade procedure such as market research, contract, customs clearance, logistics and payment using IT like internet without restriction of time and space. The evolution of transaction-based business model is upon us. The business models of many e-Marketplace in their early stages have typically been based on transaction fees. Many e-Marketplaces have even called out transaction revenues as a core element of their business plans. The transaction business represents the most simple of business models, but it does not provide a long-term sustain able advantage. For buyer's convenience, wide selection and test price hold appeal. For suppliers, the extended global market reach and direct access to customers and consortiums of customers is powerful. To maximize leverage of these new e-marketplace, you must from both a buyer perspective as well as a supplier perspective. Also required is a strategy that takes in account all of the various e-Marketplace transaction standards and one that allows the easy accomodation to new e-marketplace as the market change. These new e-marketplace will need to be factored into the sales channel strategies. To be successful, integration with these e-marketplaces should occur at a complete business process level. This study would suggest on the role of buyers and sellers for e-trade which could maximize effect of e-trade in order to cope with rapid changing IT environment and global trade environment. Therefore, this study suggests top priority tasks for implementing on the specialization strategy of e-trade process.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.153-165
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• 2010

Brassica rapa is considered an ideal candidate to act as a reference species for Brassica genomic studies. Among the three basic Brassica species, B. rapa (AA genome) has the smallest genome (529 Mbp), compared to B. nigra (BB genome, 632 Mbp) and B. oleracea (CC genome, 696 Mbp). There is also a large collection of available cultivars of B. rapa, as well as a broad array of B. rapa genomic resources available. Under international consensus, various genomic studies on B. rapa have been conducted, including the construction of a physical map based on 22.5X genome coverage, end sequencing of 146,000 BACs, sequencing of >150,000 expressed sequence tags, and successful phase 2 shotgun sequencing of 589 euchromatic region-tiling BACs based on comparative positioning with the Arabidopsis genome. These sequenced BACs mapped onto the B. rapa genome provide beginning points for genome sequencing of each chromosome. Applying this strategy, all of the 10 chromosomes of B. rapa have been assigned to the sequencing centers in seven countries, Korea, UK, China, India, Canada, Australia, and Japan. The two longest chromosomes, A3 and A9, have been sequenced except for several gaps, by NAAS in Korea. Meanwhile a China group, including IVF and BGI, performed whole genome sequencing with Illumina system. These Sanger and NGS sequence data will be integrated to assemble a draft sequence of B. rapa. The imminent B. rapa genome sequence offers novel insights into the organization and evolution of the Brassica genome. In parallel, the transfer of knowledge from B. rapa to other Brassica crops would be expected.