• Bulletin of the Korean Chemical Society
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• v.7 no.3
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• pp.238-240
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• 1986

Complex formations between syndiotactic poly(methacrylic acid) (st-PMAA) and poly(N-vinyl pyrrolidone) (PVP), and that between st-PMAA and polyethyleneoxide (PEO) through hydrogen bonding were studied by viscometry and potentiometry. Reduced viscosity (${\eta}_{red}$) was measured at various mole fraction of PVP or PEO with respect to a constant amount of st-PMAA. Observation shows a sharp minimum at the 1:1 mole ratio of st-PMAA:PVP or st-PMAA:PEO, which shows that the complexation becomes optimal and the complex has a compact structure in this ratio. Variation of pH also supports this conclusion. This is the case of the system of st-PMAA and PVP in water as well as in DMF. Also the complexation is much enhanced when the molecular weight of PVP is high. Meanwhile, the system of st-PMAA and PEO shows a little different behavior, i.e., this system does not form the complex in DMF and does only in water. It is because the interaction st-PMAA with PEO is weaker than that with PVP.

• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.88-98
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• 2021

Korean industry has achieved dramatic growth in a short time through continuous technical innovations. However, safety consciousness and management have not kept pace with industry growth. The characteristics of industrial accidents in socio-technical systems have become so complicated that it has been challenging for safety professionals to implement effective preventive measures because it is difficult to determine what is happening in the complex workplace. Thus far, they have focused on technical improvements and the requirements of OSH regulations to avoid legal responsibility. Accordingly, this study has used the systemic analysis method to explain the emergence of something unexpected in complex and multi-layered business structures, which is usually related to the variabilities of humans and organizations. This study chose a shipyard where a few fatal accidents had occurred because the shipbuilding industry includes numerous variabilities, including obtaining orders, manpower supply, procurement, etc. Systemic analysis progressed using FRAM based on two accident cases related to the truss platform used in LNG vessels. The outcome shows that each function within the system has its variabilities and has become coupled or dependent on other functions, increasing the possibility of accidents. This analysis method can provide OSH professionals with practical techniques for explaining what is happening in a complex socio-technical system and how to take proper measures.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.2
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• pp.101-118
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• 2016

For the effective classification of complex subjects, a library classification scheme should adopt multiple division principles (or facets). Each of the multiple principles adopted for the division of complex subjects is sequentially applied at each stage of division. The order of application of these multiple principles during the process of division of complex subjects is called citation order. In order for a classification scheme to be consistent and logical, the citation order of division principles applied to classify complex subjects should be concrete and consistent. Especially, in case of enumerative classification system, decisions on citation order to represent complex subjects significantly affect the structure and organization of the classification system. There are basic principles and theoretical canons of the classification theory on the citation order and its application, but they cannot be applied solidly in the process of classification system development for practical reasons. Therefore, this paper first reviews previous works on classification theories regarding citation order, then explores the conditions and circumstances for the application of citation order.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.1
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• pp.37-42
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• 2001

In order to answer the challenge that development gave to environment, Chinese cities are making up and putting into effect the green space system planning. The planning main keys are: set down standards and scope of green space; bring the characteristics of every types of green space in to full play and made into basic units of the system; formed powerful links of the system; make full use of the natural system of city, constituted the urban and countryside as a organic whole green space system, therefore give full play their function and ecological effect. In fact, this green space system is a complex system. It is the main body of city ecological system, a main container of the citizen activities of leisure and recreation and a leading factor for making characteristic city landscape. Therefore it is a system carrying city's environment sustainable development.

• Korean Journal of Construction Engineering and Management
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• v.13 no.6
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• pp.84-93
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• 2012

The information generated from large and complex construction projects transfer and evolve in long-term business cycle. Therefore, while there is any problem, such as delay, the cause of the problem might relate to the previous business process rather than where it arises. However, for complex project players and business relationships, it is unsuitable to search an information flow using traditional retrieval methods. This research addresses a relationship-based information search system to analyze the information flow in large-scale and complex construction projects. First, we identified the components of the information retrieval system customizing for a large-scale complex construction projects, and then developed the inference algorithm which define the relationship between business processes. For the validation, we applied the system on a business information system of urban regeneration projects and suggested some application using information flow retrieval system for project players and project managers. Using the system, players are easy to prepare for their work process and managers can define the causal flow of the problem.

• Journal of Industrial Convergence
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• v.17 no.4
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• pp.1-8
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• 2019

The purpose of this study is to analyze the actual condition of tourism complex and to apply IoT-based integrated management system to tourism complex to improve the utilization and management of tourism complex. Tourists need various information to take the lead in tourism activities, and all of these necessary information is collected through various routes such as information of the Internet, travel agencies, newspapers, and surrounding experiences. Recently, information provision through the Internet has taken a large part due to the development of information technology, and systems that combine IoT technology are being constructed. This is because the popularization of IoT technology improves the diversity, accessibility and convenience of information and makes it convenient to use. The purpose of this study is to suggest the importance of tourism information service using IoT-based system and future research directions. The previous studies on IoT-based system construction were also reviewed considering the efficiency of IoT technology. In order to solve the problems of tourism complex, this study improved the IoT-based tourism complex operation system and conducted operation management. IoT-based management system is expected to be improved as a tourism complex platform and is expected to be improved by overall management cases and experiences.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.242-246
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• 1996

High viscous hyaluronic acid complex from Klebsiella sp. L-10 NTG 50 mutant was purified by two-phase extraction system using PEG-K2HP04 and its physicochemical properties were Investigated. Viscosity of the purified hyaluronic acid complex was decreased as temperature and salts concentration were Increased and also showed low viscosity at below pH 5.0 and above pH 11.0. Hardness, cohesiveness and adhesiveness of the purified hyaluronic acid complex were 1, 20kg, 1.91 and 0.62, respectively. Water holding capacity was 6.9ml per gram of the purified hyaluronic acid complex powder.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.53-60
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• 2005

The concentrations of volatile organic compounds(VOCs) in the ambient air were measured at various point(Source, source boundary) in Seongseo industrial complex during May to November 2003. Air samples were collected in Silcocan canister $(1{\ell},\;6{\ell})$ and analyzed using a cryogenic preconcentration system and GC/MSD. We identified 37 species by the US EPA(TO-14 method). The result showed a variety distribution of the con­centration, Higher concentrations of BTX, Styrene, 1,3,5-Trimethylbenzene, 1,2,4-Trimethylbenzene were observed at the sampling sites. They seemed to be emitted from the facility of wastewater treatment, reaction tank of chemistry factory and facility of Tenter. The concentrations of VOCs contents in Seongseo industrial complex were generally higher than those in Yeosu complex and Ulsan complex, although those were similar in Sihwa­Banwol complex.

• Journal of the Korean Mathematical Society
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• v.47 no.5
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• pp.1001-1015
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• 2010

Let M be a $C^{\infty}$ real hypersurface in $\mathbb{C}^{n+1}$, $n\;{\geq}\;1$, locally given as the zero locus of a $C^{\infty}$ real valued function r that is defined on a neighborhood of the reference point $P\;{\in}\;M$. For each k = 1,..., n we present a necessary and sufficient condition for there to exist a complex manifold of dimension k through P that is contained in M, assuming the Levi form has rank n - k at P. The problem is to find an integral manifold of the real 1-form $i{\partial}r$ on M whose tangent bundle is invariant under the complex structure tensor J. We present generalized versions of the Frobenius theorem and make use of them to prove the existence of complex submanifolds.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.171-171
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• 1997

Sound intensity distributions and energy flow in the near field of dipole source system and flat plate were investigated. First, the effectiveness of complex acoustic intensity was proved by using mathmatical and experimental methods in order to indentify noise sources and transmission paths of dipole field which is effected by the presence of neighbouring coherent sources. Next, analytical complex acoustic intensity method was discussed and the characteristics and energy flow of sound induced from the plate are clarified. The velocity of plate obtained from Finite Element Method was used for calculation of complex acoustic intensity in the near field. Finally experimental complex acoustic intensity method was applied to a passenger car. It can be seen that complex acoustic intensity method using both of active and reactive intensity is vital in devising a strategy for the identification and the reduction of vibration and noise.