• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.8-15
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• 2010

Besides its basic function of illuminating a space, lighting can greatly affect the efficiency of a space when an advanced technology and planning, together with the effects of various presentations, are applied to lighting. A lighting plan suitable for maximizing the efficiency of a space will only be made feasible by considering the location of a space and the characteristics of the lamps to be used. In particular, the lighting plan for a space with a special function requires prior investigation and analysis of that space. In this study, the feasibility of a lighting environment for the tunnel of a radioactive waste disposal facility is investigated via a prior lighting design and simulation, which take into account the spatial characteristics of the tunnel. For this study, the use of fluorescent induction lamp is suggested, and the standards of lighting plan and structure are followed depending on the location of each segment of the tunnel. Then, a simulation analysis is conducted to investigate the feasibility of the plan.

• International Journal of Fluid Machinery and Systems
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• v.2 no.1
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• pp.1-12
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• 2009

Surrogate modeling is applied to a compressor blade shape optimization to modify its stacking line and thickness to enhance adiabatic efficiency and total pressure ratio. Six design variables are defined by parametric curves and three objectives; efficiency, total pressure and a combined objective of efficiency and total pressure are considered to enhance the performance of compressor blade. Latin hypercube sampling of design of experiments is used to generate 55 designs within design space constituted by the lower and upper limits of variables. Optimum designs are found by formulating a PRESS (predicted error sum of squares) based averaging (PBA) surrogate model with the help of a gradient based optimization algorithm. The optimum designs using the current variables show that, to optimize the performance of turbomachinery blade, the adiabatic efficiency objective is improved substantially while total pressure ratio objective is increased a very small amount. The multi-objective optimization shows that the efficiency can be increased with the less compensation of total pressure reduction or both objectives can be increased simultaneously.

• International Journal of Fluid Machinery and Systems
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• v.4 no.1
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• pp.172-178
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• 2011

This paper presents an optimization procedure for high-efficiency design of a mixed-flow pump. Optimization techniques based on a weighted-average surrogate model are used to optimize a vane diffuser of a mixed-flow pump. Validation of the numerical results is performed through experimental data for head, power and efficiency. Three-level full factorial design is used to generate nine design points within the design space. Three-dimensional Reynoldsaveraged Navier-Stokes equations with the shear stress transport turbulence model are discretized by using finite volume approximation and solved on hexahedral grids to evaluate the efficiency as the objective function. In order to reduce pressure loss in the vane diffuser, two variables defining the straight vane length ratio and the diffusion area ratio are selected as design variables in the present optimization. As the results of the design optimization, the efficiency at the design flow coefficient is improved by 7.05% and the off-design efficiencies are also improved in comparison with the reference design.

• Korean Institute of Interior Design Journal
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• no.25
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• pp.11-17
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• 2000

The purpose of this study is to suggest a new system and standards of system furniture for promoting the efficiency of a l living space in order to cope with any possible change of a resident’s lifestyle. For this purpose, the study premises that the i idea of "flexibility" can provide a solution to problems with the resident’s current living space, and furthermore, it can fulfill the r resident’ s needs of a flexible living space. T To decide the needs of the flexibility of a living space, this paper examined and analyzed sever머 studies on the necessity of t the flexibility of a living space according to changes of one's lifestyle, characteristics and problems of each type of existing f furniture, and applications of each type of system furniture and it's flexibility. The results of this study is as follows: First, a new furniture system is necessary so that a resident can adjust one’s living space. Second, a plan for flexible interior s space can meet a current resident's demand of a flexible living space, not to mention an initial resident's .. Third, a systematic plan is needed to install system furniture in a living space to cope with changes of a resident’s lifestyle.s lifestyle.

• Journal of the Korean Institute of Educational Facilities
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• v.16 no.4
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• pp.79-88
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• 2009

To enhance the administrational efficiency and for university facility and space management to be public, this research suggests a competent and an objective evaluation system and index. The study will assist national and university finances to contribute towards advanced education. Furthermore, figure out the space management condition of national university by utilizing the evaluation system, and through that suggesting efficient special management method. According to the result of this study, evaluation system for university facility can be widely divided into seven categories; system preparation, members conference, propriety of space allocation, propriety of management system, space use ratio, time control of space use, imposition index of surplus use. Based on these subdivisions, the space management category contains 19 evaluation items and the marking system allows perfect score of 100 points. In result of examining space management condition using the evaluation system, space management was well enforced in research focused university group where as in education centered university group, it shows relatively low enforcement. It also illustrated that efforts of evaluation items were required in categories of imposition index of surplus use and special use ratio in order for efficient space management.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.80.2-80.2
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• 2019

We present newly discovered dwarf galaxy candidates in deep wide-field images of NGC 1291 obtained with KMTNet. We initially identify 20 dwarf galaxy candidates through visual inspection. 13 out of 20 appears to be high priority candidates, according to their central surface brightness (${\mu}_{0,R}{\sim}22.5$ to $26.5mag\;arcsec^{-2}$) and effective radii (350 pc to 1 kpc). Structural and photometric properties of dwarf candidates appear to be consistent with those of ordinary dwarf galaxies in nearby groups and clusters. Using imaging simulations, we demonstrate that our imaging data is complete up to $26mag\;arcsec^{-2}$ with > 70% of the completeness rate. In order to find an optimal way to automate detecting dwarf galaxies in our dataset, we test detection methods by varying parameters in SExtractor. We find that the detection efficiency from the automated method is relatively low and the contamination due to the artifacts is non-negligible. Therefore, it can be only applicable for pre-selection. We plan to conduct the same analysis for deep images of other nearby galaxies obtained through KMTNet Nearby Galaxy Survey (KNGS).

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.119-128
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• 2011

This paper introduces design space exploration of many-core processors that meet high performance and low power required by the beamforming algorithm of image signals of mobile ultrasound. For the design space exploration of the many-core processor, we mapped different number of ultrasound image data to each processing element of many-core, and then determined an optimal many-core processor architecture in terms of execution time, energy efficiency and area efficiency. Experimental results indicate that PE=4096 and 1024 provide the highest energy efficiency and area efficiency, respectively. In addition, PE=4096 achieves 46x and 10x better than TI DSP C6416, which is widely used for ultrasound image devices, in terms of energy efficiency and area efficiency, respectively.

• Journal of Astronomy and Space Sciences
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• v.37 no.4
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• pp.219-228
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• 2020

A CubeSat platform has become a popular choice due to inexpensive commercial off-the-shelf (COTS) components and low launch cost. However, it requires more power-efficient and higher-data rate downlink capability for space applications related to remote sensing. In addition, the platform is limited by the size, weight and power (SWaP) constraints as well as the regulatory issue of licensing the radio frequency (RF) spectrum. The requirements and limitations have put optical communications on promising alternatives to RF communications for a CubeSat platform, owing to the power efficiency and high data rate as well as the license free spectrum. In this study, we analyzed the performance of optical downlink communications compatible with CubeSat platforms in terms of data rate, bit error rate (BER) and outage probability. Mathematical models of BER and outage probability were derived based on not only the log-normal model of atmospheric turbulence but also a transmitter with a finite extinction ratio. Given the fixed slot width, the optimal guard time and modulation orders were chosen to achieve the target data rate. And the two performance metrics, BER and outage data rate, were analyzed and discussed with respect to beam divergence angle, scintillation index and zenith angle.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.248-261
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• 2021

Scientific and technological performances (e.g., patents and publications) made through R&D play a pivotal role for national economic growth. National governments encourage academia-industry cooperation and thereby pursue continuous development of science technology and innovation. Increasing R&D-related investments and manpower are crucial for national industrial development, but evidence of poor performance in business performance, efficiency, and effectiveness has recently been found in Korea. This study evaluates performance efficiency of the 6T sector (Information Technology, Bio Technology, Nano Technology, Space Technology, Environment Technology, Culture Technology), which is considered a high-potential promising industry for the next generation growth and currently occupies two thirds of the national R&D projects. The study measures the relative efficiency of R&D in a comparative perspective by employing the Data Envelopment Analysis (DEA) method. The result reveals overall low efficiency in basic R&D (0.2112), applied R&D (0.2083), development R&D (0.2638), and others (0.0641), confirming that economic performance and efficiency were relatively poor compared to production efficiency. Efficient R&D needs policy makers to create strategies that can increase overall efficiency by improving productivity performance and quality while increasing economic performance.

• Journal of the Korea Furniture Society
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• v.24 no.1
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• pp.15-23
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• 2013

The form of the furniture developed variously according to the flow of the time. The Soban used in the modern living space is used as a decoration. but the furniture has to be used according to the form of the modern life and residential space. The furniture is the medium interacting with the surrounding environment in the residential space. I reconstruct the splendid fanciness of the pattern of the Haejuban and nature of structure and apply to the table design. The table gave the change of the form in order to be suitable for the residential space. and it raised the efficiency of the convenient of the custody and space utilization.