• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1C
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• pp.65-73
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• 2006

The purpose of this study is to design and analyze the pre-modulation filter with the variable -3dB cutoff frequency and linear phase response for bandlimiting the allocation of radio frequency bandwidth in PCM/FM transmission system. For the implementation of this required filter, the digital FIR filter, DAC and variable 2nd order LPF have been constructed with the filter block which designed and analyzed by each stage in order to satisfy the attenuation characteristic requirement of the analog 7th order bessel filter. The paper also concerned the linear phase properties for the filter block. Especially we have carried out the linear phase simulation with real parts for variable 2nd order LPF and compared this simulation results with the one of the fixed bandwidth 2nd order bessel filter for validating the linear phase requirement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.244-245
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• 2021

Design VE (Value Engineering) has been basic design and implementation design separately, but due to the recent change in guidelines, it is changing to implement only once in the implementation design stage. However, in the implementation design stage, construction costs, plans, and specifications based on the volume details are almost completed. Therefore, it is effective to perform the function analysis step after identifying information analysis and key issues through CostModeling based on functional center for the selected target in the process of implementing the VE performance procedure.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.3
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• pp.241-248
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• 2016

Plant life cycle consists of design, construction, certification, operation, and maintenance phases, and various and enormous plant life cycle data is involved in each phase. Plant life cycle data should be linked with each other based on its proper relationships, so that plant operators can access necessary plant data during their regular operations and maintenance works. Currently, the relationships of plant life cycle data may not be defined explicitly, or they are scattered over several plant information systems. This paper proposes high level design of a plant life cycle data management system based on pre-defined plant life cycle database design. ISO-15926 standard is adapted for the database design. User-interface designs of the plant life cycle data management system are explained based on analysis of plant owners' requirements. A conceptual design of the database is also described with the entity-relationship diagram.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.958-960
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• 2003

Although the researches and developments are performed for superconducting technologies, many problems such as AC loss and quench phenomenon still remain to design the superconducting transformer. In addition, pre-study on the three phase high temperature superconducting (HTS) transformer is a sort of time and expense consuming work, thus it is very worthy of being analyzing the characteristics of HTS transformer in advance through proper simulation programs and skills. This paper presents an effective simulation method for the three phase HTS transformer using components developed in the PSCAD/EMTDC.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.1
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• pp.47-52
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• 2018

In this study, a collimator composed of multi-dielectric structures is designed using the phase field design method, a kind of topology optimization methods. It is also purposed to improve the mechanical-structural performance of a collimator by replacing previously used air regions with another dielectric material. Polypropylene and paraffin are selected as the dielectric materials for the design process taking manufacturability into account. The design objective is formulated by integrating the intensity of the electromagnetic field in the pre-determined target area to realize the collimating performance. The model for accurate numerical analysis was derived from the final result obtained from the design process through the simple cut-off method and it shows the improved performance of 105% compared with the free space wave propagation. For the designed model, the possibility of reverse transformation, the mechanical durability evaluation under the compression load, and the electromagnetic performance in the X-band range were also evaluated.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.223-232
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• 2002

The government, in order to settle and activate the use of Construction Management (CM) method, clarified the legal Issues pertaining to infrastructure development and is taking an active role to promote CM through government sponsored pilot projects. However, when a CM method is applied to a turn-key protect, many applicational difficulites are expected. With design and construction are performed under the simple responsibility in a turn-key method, roles of CM's is overlapped. Also, the characteristics of turn-key method are not reflected to the present $\lceil$CM Work Guideline$\rfloor$. Over the years, various problems have been identified from turn-key projects. Korea's $\lceil$CM Work Guideline$\rfloor$ is more inclusive compared to the CM services of CMAA and overlooks the importance of CM's roles in pre-design phase. In this study, CM's roles of pre-construction phase (pre-bidding, bidding, detail design, contracting) in construction turn-key projects were identified and complementary policy for institution was suggested. We further look into dividing the roles of the CM at turn-key project Into professional role and emotional role. Also, we speculate problems of the existing experience in turn-key projects and suggest a rough methodology on how these concepts can be adjusted for improve the turn-key method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1433-1441
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• 2011

Design rules of optical transmission links with dispersion management (DM) and optical phase conjugation (OPC) for compensating optical signal distortion due to chromatic dispersion and self phase modulation (SPM) of single mode fiber (SMF) are investigated in this paper. Design rules consist of optimal net residual dispersion (NRD) and optimal range of launching power of wavelength division multiplexed (WDM) channels as a function of total transmission length and span length. In all considered total transmission length and span length, optimal NRD are obtained to +10 ps/nm and -10 ps/mn for transmission links, which is controlled by precompensation and postcompensation, respectively. It is confirmed that system performances are more improved and effective NRD for wide launching power have wider range as total transmission length and span length are more decreased.

• Journal of Fashion Business
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• v.24 no.3
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• pp.69-84
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• 2020

The purpose of this study is to analyze examples of online fashion product planning of domestic fashion brands, to grasp the characteristics and step-by-step problems in product planning, and to suggest product planning methods. This study consists of a literature study and a case study. The results of th study are as follows. First, in the information analysis and product planning, product planning according to analysis and targeting of online consumers should be conducted separately from offline, and the proportion of online-only products should be expanded. Second, in the design planning and product development stages, it should be possible to secure the quantity through the pre-planning of fabrics, a to acquire the novelty of the material through the preemption of good fabrics and the pre-planning of colors to secure competitive design. Third, in the convention, a systematic review process involving company members and customer review teams should be conducted to ensure product quality and sales-ability Fourth, in the production stage, the production period must be to reduce cost. Fifth, differentiated services according to the characteristics of their products for each brand in the promotion and sales stages. Based on this analysis, a desirable approach online product planning should first run promotion phase, increasing pre-planning for the product, and organizing specialize work and manpower issues.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.42-52
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• 2011

As environmental issues are rising recently efforts to reduce environmental stress are emerging in all industry segments. Especially environmental impact of buildings occupy a critical portion, so each country is operating green building rating system for life cycle of buildings. Accordingly green building rating system for every facility is operating in Korea. And acquisition of grade I for building energy efficiency is mandatory for every new public buildings since 2010. To design green building efficiently and systematically eco-friendly elements should be considered and checked from the schematic design phase. But in many cases eco-friendly elements are checked at the end of constructed design phase. So applying eco-friendly elements at the value engineering process, which is performing through schematic and constructed design phase, could make a efficient and systematic green building design. Value engineering process is divided into pre workshop, workshop and post workshop stages. And subject selection in pre workshop stage is the step that finds out the subjects which has the great possibility to be improved to perform efficient value engineering workshop. So this study present the Green VE subject selection model to select the most considerable eco-friendly subjects in projects.

• Journal of Advanced Navigation Technology
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• v.12 no.3
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• pp.201-207
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• 2008

Design rule of optical transmission link consisted of dispersion management (DM) controlling accumulated dispersion in total fiber length by precompensation and postcompensation, and optical phase conjugator (OPC) positioned at mid-way are proposed. DM schemes investigated in this paper are 2 types depending on the position of precompensation and postcompensation; bi-end type and concentration type. It is confirmed that effective residual dispersion ranges, as a design parameter of optical link, of transmission section from transmitter to OPC and transmission section from OPC to receiver are independence on the positions of dispersion compensating fiber (DCF) accomplishing precompensation and postcompensation, if both DCF position is symmetry with respect to OPC.