• Journal of Internet Computing and Services
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• v.25 no.4
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• pp.65-72
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• 2024

To faithfully represent the intention of the work in the exhibition space, lighting that provides high color reproduction like natural light is required. Thus, many lighting technologies have been introduced to improve CRI, but most of them only evaluated the general color rendering index (CRI Ra), which considers eight pastel colors. Natural light provides excellent color rendering performance for all colors, including red and blue, expressed by color rendering index of R9 and R12, but most artificial lighting has the problem that color rendering performance such as R9 and R12 is significantly lower than that of natural light. Recently, lighting technology that provides CRI at the level of natural light is required to realistically express the colors of works including primary colors but related research is very insufficient. Therefore this paper proposes exhibition hall lighting that fulfills CRI with a focus on CRI Ra, R9, and R12 based on the characteristics of natural light. First reinforcement wavelength bands for improving R9 and R12 are selected through analysis of the actual measurement SPD of natural and artificial lighting. Afterward virtual SPDs with a peak wavelength within the reinforcement wavelength band are created and then SPD combination conditions that satisfy CRI Ra≥95, R9, and R12≥90 are derived through combination simulation with a commercial LED light source. Through this, after specifying two types of light sources with 405,630nm peak wavelength that had the greatest impact on the improvement of R9 and R12, the exhibition hall lighting applied with two W/C White LEDs is designed and a control Index DB of the lighting is constructed. Afterward experiments with the proposed method showed that it was possible to achieve high CRI at the level of natural light with average CRI Ra 96.5, R9 96.2, and R12 94.0 under the conditions of illuminance (300-1,000 Lux) and color temperature (3,000-5,000K).

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.3
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• pp.145-155
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• 2002

The results of the present feasibility study are summarized as follows, 1. The three unit bridge of knitted material and UD fibre reinforcement has both the rigidity and the strength against a vertical occlusal load of 75N. 2. Stress concentration at the junctional area between the bridge and the abutments, i.e. between the pontic and the knitted caps was observed. In the case of the bridge with reinforcement straps, it was partly shown that the concentration problem could be improved by simply increasing the fillet size at the area. Further refining in the surface of the junctional area will be needed to ensure a further improvement in the stress distribution. This will require some trade off in the level of the stress and the available space. A parametric study will help to decide the appropriate size of the fillet. 3. Design refinement is a must to improve the stress distribution and realize the most favourable shape in terms of fabrication. The current straight bar with a constant cross section area can be redesigned to a tapered shape. The curve from the dental arch should also be placed on the pontic design. In accordance with design refinement, the resistance of the bridge frame to other load cases should be evaluated. 4. Although not included in the present feasibility study, it is estimated that bridges of the anterior teeth can be made strong enough with the knitted material without further reinforcement using unidirectional materials. In this regard, a feasibility study on design concepts and stress analysis for 3, 4, 5 unit bridge is suggested. 5. Two types of bridge were analysed in terms of fatigue. The safe life design concept, i.e. fatigue design concept, looks reasonable for the bridge where if cracks should form and propagate there is virtually nothing a dentist to do. The bridge must be designed so that no crack will be initiated during the life span. In the case of crowns, however, if constructed with composite resin with knitted materials, it might be possible to repair them, which in general is impossible for crowns of PFM or of metal. Therefore for composite resin crowns, a damage tolerance design concept can be applied and reasonably higher operational stresses can be allowed. In this case, of course, a periodic inspection program should be established in parallel. 6. Parts of future works in terms of structural viewpoint which need to be addressed are summarized as the following: 1) To develop processing technology to accommodate design concepts; 2) More realistic modelling of the bridge and analysis-geometry and loading condition. Thickness variation in the knitted material, taper in the pontic, design for anterior tooth bridge, the effect of combined loads, etc, will need to be included; 3) To develop appropriate design concepts and design goals for the fibre composite FPD aiming at taking the best advantage of knitted materials, including the damage tolerance design concept; 4) To develop testing method and perform test such as static ultimate load test, fatigue test, repair test, etc, as necessary.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.81-89
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• 2009

The seepage should be analyzed to design or reinforce the levees. The steady seepage analysis is an usual application in USA and European countries where the large scaled dams and levees are existed. However, Korea and Japan, where the reaching time is short, the excessive forces are applied on the levees at the short reaching time if the seepages are analyzed in steady condition. Accordingly, the unsteady analysis based on the variation of time is necessitated. In the unsteady analysis, the flood wave type is necessary. No criteria and standards, however, are derived for the unsteady seepage in Korea. In the study, the flood wave type is derived for the unsteady seepage. The major reliable flood surface data are collected in 5 stations including Jindong of the Nakdong river basin. The data are sorted in duration, and they are non-dimensionalized. The statistical method is also applied to derive the waves. To verify the study, the seepage is analyzed by the derived wave and applied to the prototype. The results are also compared with the Japanese Method. The errors between the hydraulic gradient and critical velocity method are $0{\sim}0.7%$, $0{\sim}0.7%$ at the Jindong, $1.6{\sim}4.0%$, $1.7{\sim}4.1%$ at the Hyunpoong, $0.6{\sim}3.6%$, $0.6{\sim}3.7%$ at the Waegwan, $2.0{\sim}8.1%$, $2.0{\sim}8.1%$ at the Nakdong, and $1.2{\sim}9.8%$, $1.3{\sim}9.9%$ at the Jeongam, respectively. The relationship($R^2$) between each method is relatively high as $0.983{\sim}0.999$. This means the results are more logical than the Japanese method, and the study is applicable to the design of hydraulic structures.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.175-181
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• 2017

The purpose of this study is evaluating the characteristics of tensile strength of UHPC and examining tensile performance of notched specimens by direct tensile test. For test variables, 120, 150, and 180MPa of target design standard strength were aimed at. With general water curing and $90^{\circ}C$ high temperature steam as curing conditions, the properties were reviewed. Overall, it was represented that the specimens of notch-type direct tensile strength concrete was effective in inducing central cracks compared with existing direct tension specimens. Through this, it was judged that data construction with high reliability was possible. Above all, in a graph of direct tensile strength and strain, in the case of steam curing at high temperature, there was great difference of initial tensile strength compared with water curing. As passing of ages, an aspect that the difference gradually decreased was shown. Maximum tensile strength was found to increase steadily with increasing age for all target design strengths in water curing, in the case of steam curing, the tendency to increase significantly due to the initial strength development effect at 7 days of age. The initial crack strength increases with age in case of underwater curing, in the case of steam curing, it was higher than that of water curing in 7 days, while the strength of 28 days was lowered. In this part, it is considered necessary to examine the arrangement condition of the steel fiber.

• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.751-760
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• 2007

The purpose of this study is to evaluate the seismic performance of the frame which is assumed to be used with Welded Unreinforced Flange-Bolted web (WUF-B) connections and detailed in compliance with FEMA 350 recommended seismic design criteria. In FEMA 350, these types of connections are only valid for Ordinary Moment-Resisting Steel Frames (OMRSFs). For this purpose, based on test results, we proposed an analytical model for the Post-Northridge WUF-B connections with different panel zone strength ratios. Using the connection model, SAC Phase II three and nine-story frames were modeled and analyzed. From a nonlinear static pushover analysis, ductility, maximum strength, and the maximum interstory drift ratio were investigated for buildings with Post-Northridge details. Moreover, the maximum interstory drift ratio of each performance level (IO and CP) was also investigated through Incremental Dynamic Analysis (IDA). Analytical results were compared with those of buildings with either Pre-Northridge connection or ductile connections with no fracture. The analytical results showed that buildings with Post-Northridge WUF-B connections provide superior strength and interstory drift ratio capacity than buildings with Pre-Northridge WUF-B connections.

• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.50-57
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• 2011

This study investigates the structural safety of typical greenhouse to be utilized for developing plant factory. New long-span greenhouse systems were presented according to the results of structural analyses performed by finite-element program, ABAQUS. Reasonable values of design loads such as wind and snow loads in the Greenhouse Design Specifications (1995) were applied to check the new greenhouse systems. It was concluded that the new greenhouse systems were consistently safe enough to resist to both wind load and snow load. The new greenhouse system can be used to make simple and economic plant factory.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.243-255
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• 2010

The slope design of an open-pit mine must consider economical efficiency and stability. Thus, the overall slope angle is the principal factor because of limited support or reinforcement options available in such a setting. In this study, slope displacement, as monitored by a GPS system, was analyzed for a coal mine at Pasir, Indonesia. Predictions of failure time by inverse velocity analysis showed good agreement with field observations. Therefore, the failure time of an unstable slope can be roughly estimated prior to failure. A GIS model that combines fuzzy theory and the analytical hierarchy process (AHP) was developed to assess slope instability in open-pit coal mines. This model simultaneously considers seven factors that influence the instability of open-pit slopes (i.e., overall slope gradient, slope height, surface flows, excavation plan, tension cracks, faults, and water body). Application of the proposed method to an open-pit coal mine revealed an enhanced prediction accuracy of failure time and failure site compared with existing methods.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.121-129
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• 2012

Any development plan of a Korean space-based navigational system has been neither designed nor introduced yet. However, the demand for the development of a domestic regional satellite navigation system can be originated from the outside of market. The growing dependency on satellite navigational systems in Korea eventually requires the retainment and the operation of a domestic navigational satellite system. There is not many choices on the orbit designs and the system design concepts of a regional augmented navigation satellite system or a regional navigation satellite system for the service on the vicinity of the Korean peninsular. Space situational awareness (SSA) has been a rising issue for both national security and more realistic space business in Korea. Also SSA related technologies in Korea is a newly inaugurated area and is necessary to generate a navigation messages and maintain a future Korean navigation satellite system. In this study, the availability of Japanese Quasi Zenith Satellite System (QZSS) expected to be deployed definitely sooner than Korean counter-part is analyzed. The availability of the similar configured system over Korea is investigated with assumed QZSS type orbit. Also, feasible configuration of orbits for domestic navigation satellite system is suggested. And the observability of a ground-based optical tracking system as a secondary tracking capability is analyzed.

• The Korean Nurse
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• v.22 no.1 s.119
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• pp.47-64
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• 1983

간호원은 비록 그가 양호교사가 아니라고 하더라도 그가 처한 위치에서 거의 매일 건강교육을 실시하고 있다고 할 수 있다. 그러한 비정규직 교육은 상황에 따라 간호활동의 대상자들에게 수시로 별 준비 없이 실시한 경우도 있겠으나 효율적인 결과를 얻을 수 있는 체계적인 보건교육은 구체적인 학습목적과 교육과정이 교육적으로 미리 계획되어 있어야만 가능하다고 할 것이다. 양호교사의 기본적인 역할이 학교 구성원들의 건강증진과 질병예방에 있으며 효율적인 건강교육을 통하여 이러한 목적을 달성한다고 할 때, 양호교사는 자신을 그 학교공동체의 주된 건강교육자로 이해하고 학교에서 이루어지는 모든 보건교육 과정에 적극적인 참여를 하여야만 한다. 그러한 역할중의 하나는 보건에 관한 수업을 실시하는 학과목 교사나 담임교사들이 건강교육에 관련한 협의를 양호교사에게 요청하도록 적극적인 건강교육환경을 학교 내에 조성하여야 하는 일과 중요한 건강주제에 대하여서는 양호교사가 직접 수업을 교실에서 이끌어야 하는 것일 것이다. 이 논문에서 다룬 보건교육 교안 연구는 양호교사에게 또 건강에 관한 주제를 가지고 수업을 하는 일반교사에게 중학생의 건강교육 과정의 한 모델로써 사용하는데 도움이 될 것으로 본다. 건강교육 프로그램을 질병예방, 건강증진에 초점을 두어 설계한다고 할 때 건강교육의 주된 방향은 대상자 하나 하나의 생활에서 건강을 위한 바람직한 행위를 생활화하도록 하는 것이다. 이 목적을 학교에서 달성하기 위해서는 건강교육 프로그램을 통하여 학생들에게 건강에 대한 지식을 전달하고 그 지식 위에 건강을 위한 바람직한 행위를 하도록 동기를 부여하며 그러한 행위를 지속하도록 보강하는 것이 필요하다고 할 것이다. 사람들은 건강에 대한 지식이나 정보를 가지게 되면, 행위는, 그것에 상응하여 바람직하게 행할 것이라고 가정하기가 쉽다. 그리하여 건강에 대한 정보를 주는 것 건강교육을 했다고 간주하기도 한다. 그러나 실제적으로 건강을 위한 정보를 받고 지식을 가졌다 하더라도 바람직한 행위를 실천하지 않거나, 습관된 반건강 행위를 바꾸지 않는 경우가 많다. 그러므로 건강한 행위를 실천하기 위해서는 그에 대한 가치관이나 태도가 먼저 분명하게 세워져야 한다. 학생들의 경우에도 그 가치관이 확립되어야 하겠으므로 이를 위한 효과적인 교육방법이 제시된 교육안 모델이 있어야 할 것이다. 즉 건강문제에 대한 태도의 확립과 그에 따른 올바른 행위를 실천하도록 하기 위하여 구체적으로 치밀하게 계획된 건강교육 안이 연구되어 지는 것이 건강교육의 가장 중요한 과제중의 하나이다. 이 연구에서 제시하는 건강교육 프로그램에서는 많은 부분의 정보가 학생들 스스로에 의해서 수집되도록 하였다. 그렇게 함으로써 그들이 흡연에 관한 사실들을 스스로 명백하게 파악할 수 있었기 때문이다. 또한 소그룹 토의와 논쟁의 방법을 통해서 학생들이 흡연에 대해서 자신들의 생각하고 있는 것을 검토하여 올바른 판단을 하도록 하는 기회를 가질 수 있도록 하였다.

• Journal of Navigation and Port Research
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• v.35 no.10
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• pp.823-827
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• 2011

The present Common Structural Rules for double hull oil tanker is not included the residual strength, which is one of the functional requirements in design part of Goal-based new ship construction standards (GBS). The GBS will be enforced after July 1, 2016. The requirement related residual strength has the goal to build safe ship even if she has the specified damages due to marine accidents including collision and grounding. In order to assess the residual strength based on risk for structural damages according to GBS, tons of nonlinear FE analysis work taking into account various types of damage will be needed. The Smith's method, a kind of simplified method for the strength analysis is very useful for this purpose. In this paper, the residual strength assessments based on ultimate strength using Smith's method were carried out. The objected ship is VLCC with stranding damage in bottom structures. Also, the results were compared with that of nonlinear FE analysis using three cargo hold model.