• Journal of Communications and Networks
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• v.8 no.2
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• pp.169-174
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• 2006

In this paper, the algorithm of a methodology for the calculation of spectrum requirements was implemented. As well, the influence of traffic distribution ratio among radio access technology groups, spectral efficiency, and flexible spectrum usage (FSU) margin was analyzed in terms of the spectrum requirements, with a view toward for future development of international mobile telecommunication (IMT)-2000 and systems beyond IMT-2000. The calculated spectrum requirement in the maximum spectral efficiency case is reduced by approximately 40% compared to a minimum spectral efficiency case. The effect of the distribution ratio on the required spectrum is smaller than the effect of the spectral efficiency. As the flexible spectrum usage margin increases by 1.0 dB, the total spectrum requirement decreases by 0.9 dB. The required spectrum for the market input parameter, ${\rho}$ = 0.5 is 801.63 MHz, while the required spectrum for ${\rho}$ = 1.0 is 6295.4 MHz. This is equivalent to an increase of 785.32 %.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.8
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• pp.610-618
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• 2003

Recently, many deterministic built-in self-test schemes to reduce test time have been researched. These schemes can achieve a good quality test by shortening the whole test process, but require complex algorithms or much hardware. In this paper, a new deterministic BIST scheme is provided that reduces the additional hardware requirements, as well as keeping test time to a minimum. The proposed BIST (Built-In Self-Test) methodology brings about the reduction of the hardware requirements for pseudo-random tests as well. Theoretical study demonstrates the possibility of reducing the hardware requirements for both pseudo-random and deterministic tests, with some explanations and examples. Experimental results show that in the proposed test scheme the hardware requirements for the pseudo-random test and deterministic test are less than in previous research.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1580-1586
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• 2021

The application of induction bending processes to industrial pipe production is increasing. The induction bending process has the effect of reducing the number of inspections and preventing leaks by reducing the weld of the pipe. For these reasons, efforts have been made to apply an induction bending process to the pipe of the PGSFR under development in Korea and this is the first attempt in the SFR design. Since the PGSFR pipe has a relatively large diameter-to-thickness ratio, it is difficult to fabricate an induction bending pipe that meets the requirements. In addition, the material properties may change because the pipe heats to a very high temperature during the induction bending process. In this study, P91 pipes were fabricated by induction bending, and the results from analyzing the induction bending process' applicability to the P91 pipe of the PGSFR are examined. The various dimensional measurements of the pipes fabricated by the induction bending process were surveyed to determine whether the requirements of the ASME Code were met. The minimum thickness, ovality, and wall buckling measured in the fabricated pipe met all the requirements. Tensile, impact, and hardness tests at various locations of the fabricated pipe also satisfied the requirements.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.691-711
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• 2011

This study examines the preliminary license and approval facilitation standards for improvements in quality for childcare centers focusing on the number of children, building space standards, facilities and equipment, and childcare program. Data from 48 caese was collected from childcare centers nationwide in Korea through a questionnaire and building plan. The first step for starting care licensing is to work out the ages and numbers of children within four or five age ranges. The second step is to work out the number of children as small, medium, or large considering staff to child ratios and building size. The Nnext step is to make a choice about childcare service quality classification as minimum, fair, or good, considering space requirements per child for the building, the classroom and the outdoor playground. The next step is to make a choice of space organization relating to service programs, considering the sleeping and eating area, indoor play area, toilet & washing facilities, classroom layouts such as cluster type, double zone type, single zone type, and others. Also, each room and entrance, office, kitchen, storage, laundry, teacher's area, and chilldren's area, need to be checked for space requirements and performances. The last step is to arrange the childcare program with the building and site plan. In conclusion childcare service quality will get better by upgrading of license regulation especially in minimum space requirements per child, corresponding with an increase in GNP and housing area per person. This is needed for childcare licensing in order to determine the quality level of childcare service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.457-460
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• 2018

The mobile communication based train control is the train control system by utilizing wireless communication rather than conventional wired communication. Traditional train control operates train occupation, safety integrity and moving authority using fixed block wired railway signal system. Since introduction of mobile communication in railway area, railway operators can provide improved passager services. Futhermore, it can replace inefficient train onboard equipments and railway ground facilities for economic benefits. In this paper we introduce mobile communication based railway system currently in operation around the world. Moreover, we provide the minimum requirements of the radio communication performance. Proposed minimum requirements of the radio communication improve more secure and efficient mobile communication based train control system.

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.765-776
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• 2013

Civilian aircraft industry, even if the superior performance of the product in order to ensure the safety of aircraft navigation safety requirements necessary for compliance does not receive a legally recognized can not be used in aircraft characteristics. These are applied in a variety of safety in avionics for navigation of civil aircraft certification standards for the technology is implemented. KTSO-C113 aircraft for the purpose of electronic display technology to authenticate standard contains minimum performance standards. Standard design and manufacturing technology for type approval means approval by mounting the aircraft in order to use a separate approval is required. Through this paper, multi-display technology standards for aircraft type certification approval system and demonstrate compliance with the requirements for the certification practices introduced are presented.

• Journal of the Korean housing association
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• v.19 no.6
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• pp.21-32
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• 2008

The purpose of this research is firstly to derive regular sizes of average dwellings in Korea and to examine minimum living standards in light of those regular dwellings in order to meet future housing requirements of low income households. Two plan types of unit floor area 60 $m^2$ and 85 $m^2$ have become prevalent and ubiquitous so as to reflect the basic requirements of ordinary living standards. Thus, dimensional characteristics of each space in those two plan types is thoroughly investigated in this research. The background of regular plans and their popularized process is first reviewed and the 120 cases of apartment units which were constructed between 2000 and 2007, are selected from those three regional groups and surveyed in detail. The area, depth, width and proportion of each space of unit plans are compared and analyzed in various aspects. As a result, proper space sizes and standards for low income households are reviewed and compared. The regional difference of space dimensions is not significant as expected but area and size characteristics of each space is very much regularized and obvious. And it is argued that those dimensional characteristics should convey the social and cultural values of Korean housing. The average dimensions of each spaces of surveyed apartment unit turns out to be much closer to guidable living standards rather than minimum living standards. Thus, it is very probable that the present guidable living standards could be upgraded to become the future minimum living standards soon.

• Earthquakes and Structures
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• v.11 no.4
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• pp.539-561
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• 2016

The rate of occurrence of intraplate earthquake events has been surveyed around the globe to ascertain the average level of intraplate seismic activities on land. Elastic response spectra corresponding to various levels of averaged (uniform) seismicity for a return period of 2475 years have then been derived along with modifying factors that can be used to infer ground motion and spectral response parameters for other return period values. Estimates derived from the assumption of uniform seismicity are intended to identify the minimum level of design seismic hazard in intraplate regions. The probabilistic seismic hazard assessment presented in the paper involved the use of ground motion models that have been developed for regions of different tectonic and crustal classifications. The proposed minimum earthquake loading model is illustrated by the case study of Peninsular Malaysia which has been identified with a minimum effective peak ground acceleration (EPGA) of 0.1 g for a return period of 2475 years, or 0.07 g for a notional return period of 475 years.

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.323-333
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• 2016

In this study, the uncertainty requirements for orbit, attitude, and burn performance were estimated and analyzed for the execution of the $1^{st}$ lunar orbit insertion (LOI) maneuver of the Korea Pathfinder Lunar Orbiter (KPLO) mission. During the early design phase of the system, associate analysis is an essential design factor as the $1^{st}$ LOI maneuver is the largest burn that utilizes the onboard propulsion system; the success of the lunar capture is directly affected by the performance achieved. For the analysis, the spacecraft is assumed to have already approached the periselene with a hyperbolic arrival trajectory around the moon. In addition, diverse arrival conditions and mission constraints were considered, such as varying periselene approach velocity, altitude, and orbital period of the capture orbit after execution of the $1^{st}$ LOI maneuver. The current analysis assumed an impulsive LOI maneuver, and two-body equations of motion were adapted to simplify the problem for a preliminary analysis. Monte Carlo simulations were performed for the statistical analysis to analyze diverse uncertainties that might arise at the moment when the maneuver is executed. As a result, three major requirements were analyzed and estimated for the early design phase. First, the minimum requirements were estimated for the burn performance to be captured around the moon. Second, the requirements for orbit, attitude, and maneuver burn performances were simultaneously estimated and analyzed to maintain the $1^{st}$ elliptical orbit achieved around the moon within the specified orbital period. Finally, the dispersion requirements on the B-plane aiming at target points to meet the target insertion goal were analyzed and can be utilized as reference target guidelines for a mid-course correction (MCC) maneuver during the transfer. More detailed system requirements for the KPLO mission, particularly for the spacecraft bus itself and for the flight dynamics subsystem at the ground control center, are expected to be prepared and established based on the current results, including a contingency trajectory design plan.

• Advances in Computational Design
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• v.3 no.1
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• pp.49-69
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• 2018

This paper shows an optimal design for reinforced concrete rectangular combined footings based on a criterion of minimum cost. The classical design method for reinforced concrete rectangular combined footings is: First, a dimension is proposed that should comply with the allowable stresses (Minimum stress should be equal or greater than zero, and maximum stress must be equal or less than the allowable capacity withstand by the soil); subsequently, the effective depth is obtained due to the maximum moment and this effective depth is checked against the bending shear and the punching shear until, it complies with these conditions, and then the steel reinforcement is obtained, but this is not guaranteed that obtained cost is a minimum cost. A numerical experimentation shows the model capability to estimate the minimum cost design of the materials used for a rectangular combined footing that supports two columns under an axial load and moments in two directions at each column in accordance to the building code requirements for structural concrete and commentary (ACI 318S-14). Numerical experimentation is developed by modifying the values of the rectangular combined footing to from "d" (Effective depth), "b" (Short dimension), "a" (Greater dimension), "${\rho}_{P1}$" (Ratio of reinforcement steel under column 1), "${\rho}_{P2}$" (Ratio of reinforcement steel under column 2), "${\rho}_{yLB}$" (Ratio of longitudinal reinforcement steel in the bottom), "${\rho}_{yLT}$" (Ratio of longitudinal reinforcement steel at the top). Results show that the optimal design is more economical and more precise with respect to the classical design. Therefore, the optimal design presented in this paper should be used to obtain the minimum cost design for reinforced concrete rectangular combined footings.